Verifier.cpp

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//===-- Verifier.cpp - Implement the Module Verifier -----------------------==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the function verifier interface, that can be used for some
// basic correctness checking of input to the system.
//
// Note that this does not provide full `Java style' security and verifications,
// instead it just tries to ensure that code is well-formed.
//
//  * Both of a binary operator's parameters are of the same type
//  * Verify that the indices of mem access instructions match other operands
//  * Verify that arithmetic and other things are only performed on first-class
//    types.  Verify that shifts & logicals only happen on integrals f.e.
//  * All of the constants in a switch statement are of the correct type
//  * The code is in valid SSA form
//  * It should be illegal to put a label into any other type (like a structure)
//    or to return one. [except constant arrays!]
//  * Only phi nodes can be self referential: 'add i32 %0, %0 ; <int>:0' is bad
//  * PHI nodes must have an entry for each predecessor, with no extras.
//  * PHI nodes must be the first thing in a basic block, all grouped together
//  * All basic blocks should only end with terminator insts, not contain them
//  * The entry node to a function must not have predecessors
//  * All Instructions must be embedded into a basic block
//  * Functions cannot take a void-typed parameter
//  * Verify that a function's argument list agrees with it's declared type.
//  * It is illegal to specify a name for a void value.
//  * It is illegal to have a internal global value with no initializer
//  * It is illegal to have a ret instruction that returns a value that does not
//    agree with the function return value type.
//  * Function call argument types match the function prototype
//  * A landing pad is defined by a landingpad instruction, and can be jumped to
//    only by the unwind edge of an invoke instruction.
//  * A landingpad instruction must be the first non-PHI instruction in the
//    block.
//  * Landingpad instructions must be in a function with a personality function.
//  * Convergence control intrinsics are introduced in ConvergentOperations.rst.
//    The applied restrictions are too numerous to list here.
//  * The convergence entry intrinsic and the loop heart must be the first
//    non-PHI instruction in their respective block. This does not conflict with
//    the landing pads, since these two kinds cannot occur in the same block.
//  * All other things that are tested by asserts spread about the code...
//
//===----------------------------------------------------------------------===//
 
#include "llvm/IR/Verifier.h"
#include "VerifierInternal.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/AttributeMask.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/BundleAttributes.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Comdat.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/ConstantRangeList.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/ConvergenceVerifier.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/EHPersonalities.h"
#include "llvm/IR/FPEnv.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GCStrategy.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsAArch64.h"
#include "llvm/IR/IntrinsicsARM.h"
#include "llvm/IR/IntrinsicsNVPTX.h"
#include "llvm/IR/IntrinsicsRISCV.h"
#include "llvm/IR/IntrinsicsWebAssembly.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MemoryModelRelaxationAnnotations.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSlotTracker.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/ProfDataUtils.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/User.h"
#include "llvm/IR/VFABIDemangler.h"
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/ModRef.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/RISCVTargetParser.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Coroutines/CoroInstr.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <limits>
#include <memory>
#include <optional>
#include <queue>
#include <string>
#include <utility>
 
using namespace llvm;
 
static cl::opt<bool> VerifyNoAliasScopeDomination(
    "verify-noalias-scope-decl-dom", cl::Hidden, cl::init(false),
    cl::desc("Ensure that llvm.experimental.noalias.scope.decl for identical "
             "scopes are not dominating"));
 
namespace {
 
class Verifier : public InstVisitor<Verifier>, VerifierSupport {
  friend class InstVisitor<Verifier>;
  DominatorTree DT;
 
  /// When verifying a basic block, keep track of all of the
  /// instructions we have seen so far.
  ///
  /// This allows us to do efficient dominance checks for the case when an
  /// instruction has an operand that is an instruction in the same block.
  SmallPtrSet<Instruction *, 16> InstsInThisBlock;
 
  /// Keep track of the metadata nodes that have been checked already.
  SmallPtrSet<const Metadata *, 32> MDNodes;
 
  /// Keep track which DISubprogram is attached to which function.
  DenseMap<const DISubprogram *, const Function *> DISubprogramAttachments;
 
  /// For each visited DIScope, whether walking its scope chain reaches a
  /// repeated node.
  DenseMap<const Metadata *, bool> DIScopeChainReachesCycle;
 
  /// Track all DICompileUnits visited.
  SmallPtrSet<const Metadata *, 2> CUVisited;
 
  /// The result type for a landingpad.
  Type *LandingPadResultTy;
 
  /// Whether we've seen a call to @llvm.localescape in this function
  /// already.
  bool SawFrameEscape;
 
  /// Whether the current function has a DISubprogram attached to it.
  bool HasDebugInfo = false;
 
  /// Stores the count of how many objects were passed to llvm.localescape for a
  /// given function and the largest index passed to llvm.localrecover.
  DenseMap<Function *, std::pair<unsigned, unsigned>> FrameEscapeInfo;
 
  // Maps catchswitches and cleanuppads that unwind to siblings to the
  // terminators that indicate the unwind, used to detect cycles therein.
  MapVector<Instruction *, Instruction *> SiblingFuncletInfo;
 
  /// Cache which blocks are in which funclet, if an EH funclet personality is
  /// in use. Otherwise empty.
  DenseMap<BasicBlock *, ColorVector> BlockEHFuncletColors;
 
  /// Cache of constants visited in search of ConstantExprs.
  SmallPtrSet<const Constant *, 32> ConstantExprVisited;
 
  /// Cache of declarations of the llvm.experimental.deoptimize.<ty> intrinsic.
  SmallVector<const Function *, 4> DeoptimizeDeclarations;
 
  /// Cache of attribute lists verified.
  SmallPtrSet<const void *, 32> AttributeListsVisited;
 
  // Verify that this GlobalValue is only used in this module.
  // This map is used to avoid visiting uses twice. We can arrive at a user
  // twice, if they have multiple operands. In particular for very large
  // constant expressions, we can arrive at a particular user many times.
  SmallPtrSet<const Value *, 32> GlobalValueVisited;
 
  // Keeps track of duplicate function argument debug info.
  SmallVector<const DILocalVariable *, 16> DebugFnArgs;
 
  TBAAVerifier TBAAVerifyHelper;
  ConvergenceVerifier ConvergenceVerifyHelper;
 
  SmallVector<IntrinsicInst *, 4> NoAliasScopeDecls;
 
  void checkAtomicMemAccessSize(Type *Ty, const Instruction *I);
 
public:
  explicit Verifier(raw_ostream *OS, bool ShouldTreatBrokenDebugInfoAsError,
                    const Module &M)
      : VerifierSupport(OS, M), LandingPadResultTy(nullptr),
        SawFrameEscape(false), TBAAVerifyHelper(this) {
    TreatBrokenDebugInfoAsError = ShouldTreatBrokenDebugInfoAsError;
  }
 
  bool hasBrokenDebugInfo() const { return BrokenDebugInfo; }
 
  bool verify(const Function &F) {
    llvm::TimeTraceScope timeScope("Verifier");
    assert(F.getParent() == &M &&
           "An instance of this class only works with a specific module!");
 
    // First ensure the function is well-enough formed to compute dominance
    // information, and directly compute a dominance tree. We don't rely on the
    // pass manager to provide this as it isolates us from a potentially
    // out-of-date dominator tree and makes it significantly more complex to run
    // this code outside of a pass manager.
 
    // First check that every basic block has a terminator, otherwise we can't
    // even inspect the CFG.
    for (const BasicBlock &BB : F) {
      if (!BB.empty() && BB.back().isTerminator())
        continue;
 
      if (OS) {
        *OS << "Basic Block in function '" << F.getName()
            << "' does not have terminator!\n";
        BB.printAsOperand(*OS, true, MST);
        *OS << "\n";
      }
      return false;
    }
 
    // FIXME: It's really gross that we have to cast away constness here.
    if (!F.empty())
      DT.recalculate(const_cast<Function &>(F));
 
    auto FailureCB = [this](const Twine &Message) {
      this->CheckFailed(Message);
    };
    ConvergenceVerifyHelper.initialize(OS, FailureCB, F);
 
    Broken = false;
    // FIXME: We strip const here because the inst visitor strips const.
    visit(const_cast<Function &>(F));
    verifySiblingFuncletUnwinds();
 
    if (ConvergenceVerifyHelper.sawTokens())
      ConvergenceVerifyHelper.verify(DT);
 
    InstsInThisBlock.clear();
    DebugFnArgs.clear();
    DIScopeChainReachesCycle.clear();
    LandingPadResultTy = nullptr;
    SawFrameEscape = false;
    SiblingFuncletInfo.clear();
    verifyNoAliasScopeDecl();
    NoAliasScopeDecls.clear();
 
    return !Broken;
  }
 
  /// Verify the module that this instance of \c Verifier was initialized with.
  bool verify() {
    Broken = false;
 
    // Collect all declarations of the llvm.experimental.deoptimize intrinsic.
    for (const Function &F : M)
      if (F.getIntrinsicID() == Intrinsic::experimental_deoptimize)
        DeoptimizeDeclarations.push_back(&F);
 
    // Now that we've visited every function, verify that we never asked to
    // recover a frame index that wasn't escaped.
    verifyFrameRecoverIndices();
    for (const GlobalVariable &GV : M.globals())
      visitGlobalVariable(GV);
 
    for (const GlobalAlias &GA : M.aliases())
      visitGlobalAlias(GA);
 
    for (const GlobalIFunc &GI : M.ifuncs())
      visitGlobalIFunc(GI);
 
    for (const NamedMDNode &NMD : M.named_metadata())
      visitNamedMDNode(NMD);
 
    for (const StringMapEntry<Comdat> &SMEC : M.getComdatSymbolTable())
      visitComdat(SMEC.getValue());
 
    visitModuleFlags();
    visitModuleIdents();
    visitModuleCommandLines();
    visitModuleErrnoTBAA();
 
    verifyCompileUnits();
 
    verifyDeoptimizeCallingConvs();
    DISubprogramAttachments.clear();
    DIScopeChainReachesCycle.clear();
    return !Broken;
  }
 
private:
  /// Whether a metadata node is allowed to be, or contain, a DILocation.
  enum class AreDebugLocsAllowed { No, Yes };
 
  /// Metadata that should be treated as a range, with slightly different
  /// requirements.
  enum class RangeLikeMetadataKind {
    Range,           // MD_range
    AbsoluteSymbol,  // MD_absolute_symbol
    NoaliasAddrspace // MD_noalias_addrspace
  };
 
  // Verification methods...
  void visitGlobalValue(const GlobalValue &GV);
  void visitGlobalVariable(const GlobalVariable &GV);
  void visitGlobalAlias(const GlobalAlias &GA);
  void visitGlobalIFunc(const GlobalIFunc &GI);
  void visitAliaseeSubExpr(const GlobalAlias &A, const Constant &C);
  void visitAliaseeSubExpr(SmallPtrSetImpl<const GlobalAlias *> &Visited,
                           const GlobalAlias &A, const Constant &C);
  void visitNamedMDNode(const NamedMDNode &NMD);
  void visitMDNode(const MDNode &MD, AreDebugLocsAllowed AllowLocs);
  void visitMetadataAsValue(const MetadataAsValue &MD, Function *F);
  void visitValueAsMetadata(const ValueAsMetadata &MD, Function *F);
  void visitDIArgList(const DIArgList &AL, Function *F);
  void visitComdat(const Comdat &C);
  void visitModuleIdents();
  void visitModuleCommandLines();
  void visitModuleErrnoTBAA();
  void visitModuleFlags();
  void visitModuleFlag(const MDNode *Op,
                       DenseMap<const MDString *, const MDNode *> &SeenIDs,
                       SmallVectorImpl<const MDNode *> &Requirements);
  void visitModuleFlagCGProfileEntry(const MDOperand &MDO);
  void visitFunction(const Function &F);
  void visitBasicBlock(BasicBlock &BB);
  void verifyRangeLikeMetadata(const Value &V, const MDNode *Range, Type *Ty,
                               RangeLikeMetadataKind Kind);
  void visitRangeMetadata(Instruction &I, MDNode *Range, Type *Ty);
  void visitNoFPClassMetadata(Instruction &I, MDNode *Range, Type *Ty);
  void visitNoaliasAddrspaceMetadata(Instruction &I, MDNode *Range, Type *Ty);
  void visitDereferenceableMetadata(Instruction &I, MDNode *MD);
  void visitNoFreeObjMetadata(Instruction &I, MDNode *MD);
  void visitProfMetadata(Instruction &I, MDNode *MD);
  void visitCallStackMetadata(MDNode *MD);
  void visitMemProfMetadata(Instruction &I, MDNode *MD);
  void visitCallsiteMetadata(Instruction &I, MDNode *MD);
  void visitCalleeTypeMetadata(Instruction &I, MDNode *MD);
  void visitDIAssignIDMetadata(Instruction &I, MDNode *MD);
  void visitMMRAMetadata(Instruction &I, MDNode *MD);
  void visitAnnotationMetadata(MDNode *Annotation);
  void visitAliasScopeMetadata(const MDNode *MD);
  void visitAliasScopeListMetadata(const MDNode *MD);
  void visitAccessGroupMetadata(const MDNode *MD);
  void visitCapturesMetadata(Instruction &I, const MDNode *Captures);
  void visitAllocTokenMetadata(Instruction &I, MDNode *MD);
  void visitInlineHistoryMetadata(Instruction &I, MDNode *MD);
  void visitMemCacheHintMetadata(Instruction &I, MDNode *MD);
 
#define HANDLE_SPECIALIZED_MDNODE_LEAF(CLASS) void visit##CLASS(const CLASS &N);
#include "llvm/IR/Metadata.def"
  void visitDIType(const DIType &N);
  void visitDIScope(const DIScope &N);
  void visitDIScopeChain(const DIScope &N);
  bool hasDIScopeCycle(const Metadata *S);
  DISubprogram *getSubprogram(Metadata *LocalScope);
  void visitDIVariable(const DIVariable &N);
  void visitDILexicalBlockBase(const DILexicalBlockBase &N);
  void visitDITemplateParameter(const DITemplateParameter &N);
 
  void visitTemplateParams(const MDNode &N, const Metadata &RawParams);
 
  void visit(DbgLabelRecord &DLR);
  void visit(DbgVariableRecord &DVR);
  // InstVisitor overrides...
  using InstVisitor<Verifier>::visit;
  void visitDbgRecords(Instruction &I);
  void visit(Instruction &I);
 
  void visitTruncInst(TruncInst &I);
  void visitZExtInst(ZExtInst &I);
  void visitSExtInst(SExtInst &I);
  void visitFPTruncInst(FPTruncInst &I);
  void visitFPExtInst(FPExtInst &I);
  void visitFPToUIInst(FPToUIInst &I);
  void visitFPToSIInst(FPToSIInst &I);
  void visitUIToFPInst(UIToFPInst &I);
  void visitSIToFPInst(SIToFPInst &I);
  void visitIntToPtrInst(IntToPtrInst &I);
  void checkPtrToAddr(Type *SrcTy, Type *DestTy, const Value &V);
  void visitPtrToAddrInst(PtrToAddrInst &I);
  void visitPtrToIntInst(PtrToIntInst &I);
  void visitBitCastInst(BitCastInst &I);
  void visitAddrSpaceCastInst(AddrSpaceCastInst &I);
  void visitPHINode(PHINode &PN);
  void visitCallBase(CallBase &Call);
  void visitUnaryOperator(UnaryOperator &U);
  void visitBinaryOperator(BinaryOperator &B);
  void visitICmpInst(ICmpInst &IC);
  void visitFCmpInst(FCmpInst &FC);
  void visitExtractElementInst(ExtractElementInst &EI);
  void visitInsertElementInst(InsertElementInst &EI);
  void visitShuffleVectorInst(ShuffleVectorInst &EI);
  void visitVAArgInst(VAArgInst &VAA) { visitInstruction(VAA); }
  void visitCallInst(CallInst &CI);
  void visitInvokeInst(InvokeInst &II);
  void visitGetElementPtrInst(GetElementPtrInst &GEP);
  void visitLoadInst(LoadInst &LI);
  void visitStoreInst(StoreInst &SI);
  void verifyDominatesUse(Instruction &I, unsigned i);
  void visitInstruction(Instruction &I);
  void visitTerminator(Instruction &I);
  void visitCondBrInst(CondBrInst &BI);
  void visitReturnInst(ReturnInst &RI);
  void visitSwitchInst(SwitchInst &SI);
  void visitIndirectBrInst(IndirectBrInst &BI);
  void visitCallBrInst(CallBrInst &CBI);
  void visitSelectInst(SelectInst &SI);
  void visitUserOp1(Instruction &I);
  void visitUserOp2(Instruction &I) { visitUserOp1(I); }
  void visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call);
  void visitConstrainedFPIntrinsic(ConstrainedFPIntrinsic &FPI);
  void visitVPIntrinsic(VPIntrinsic &VPI);
  void visitDbgLabelIntrinsic(StringRef Kind, DbgLabelInst &DLI);
  void visitAtomicCmpXchgInst(AtomicCmpXchgInst &CXI);
  void visitAtomicRMWInst(AtomicRMWInst &RMWI);
  void visitFenceInst(FenceInst &FI);
  void visitAllocaInst(AllocaInst &AI);
  void visitExtractValueInst(ExtractValueInst &EVI);
  void visitInsertValueInst(InsertValueInst &IVI);
  void visitEHPadPredecessors(Instruction &I);
  void visitLandingPadInst(LandingPadInst &LPI);
  void visitResumeInst(ResumeInst &RI);
  void visitCatchPadInst(CatchPadInst &CPI);
  void visitCatchReturnInst(CatchReturnInst &CatchReturn);
  void visitCleanupPadInst(CleanupPadInst &CPI);
  void visitFuncletPadInst(FuncletPadInst &FPI);
  void visitCatchSwitchInst(CatchSwitchInst &CatchSwitch);
  void visitCleanupReturnInst(CleanupReturnInst &CRI);
 
  void verifySwiftErrorCall(CallBase &Call, const Value *SwiftErrorVal);
  void verifySwiftErrorValue(const Value *SwiftErrorVal);
  void verifyTailCCMustTailAttrs(const AttrBuilder &Attrs, StringRef Context);
  void verifyMustTailCall(CallInst &CI);
  bool verifyAttributeCount(AttributeList Attrs, unsigned Params);
  void verifyAttributeTypes(AttributeSet Attrs, const Value *V);
  void verifyParameterAttrs(AttributeSet Attrs, Type *Ty, const Value *V);
  void checkUnsignedBaseTenFuncAttr(AttributeList Attrs, StringRef Attr,
                                    const Value *V);
  void verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
                           const Value *V, bool IsIntrinsic, bool IsInlineAsm);
  void verifyFunctionMetadata(ArrayRef<std::pair<unsigned, MDNode *>> MDs);
  void verifyUnknownProfileMetadata(MDNode *MD);
  void visitConstantExprsRecursively(const Constant *EntryC);
  void visitConstantExpr(const ConstantExpr *CE);
  void visitConstantPtrAuth(const ConstantPtrAuth *CPA);
  void verifyInlineAsmCall(const CallBase &Call);
  void verifyStatepoint(const CallBase &Call);
  void verifyFrameRecoverIndices();
  void verifySiblingFuncletUnwinds();
 
  void verifyFragmentExpression(const DbgVariableRecord &I);
  template <typename ValueOrMetadata>
  void verifyFragmentExpression(const DIVariable &V,
                                DIExpression::FragmentInfo Fragment,
                                ValueOrMetadata *Desc);
  void verifyFnArgs(const DbgVariableRecord &DVR);
  void verifyNotEntryValue(const DbgVariableRecord &I);
 
  /// Module-level debug info verification...
  void verifyCompileUnits();
 
  /// Module-level verification that all @llvm.experimental.deoptimize
  /// declarations share the same calling convention.
  void verifyDeoptimizeCallingConvs();
 
  void verifyAttachedCallBundle(const CallBase &Call,
                                const OperandBundleUse &BU);
 
  /// Verify the llvm.experimental.noalias.scope.decl declarations
  void verifyNoAliasScopeDecl();
};
 
} // end anonymous namespace
 
/// We know that cond should be true, if not print an error message.
#define Check(C, ...)                                                          \
  do {                                                                         \
    if (!(C)) {                                                                \
      CheckFailed(__VA_ARGS__);                                                \
      return;                                                                  \
    }                                                                          \
  } while (false)
 
/// We know that a debug info condition should be true, if not print
/// an error message.
#define CheckDI(C, ...)                                                        \
  do {                                                                         \
    if (!(C)) {                                                                \
      DebugInfoCheckFailed(__VA_ARGS__);                                       \
      return;                                                                  \
    }                                                                          \
  } while (false)
 
void Verifier::visitDbgRecords(Instruction &I) {
  if (!I.DebugMarker)
    return;
  CheckDI(I.DebugMarker->MarkedInstr == &I,
          "Instruction has invalid DebugMarker", &I);
  CheckDI(!isa<PHINode>(&I) || !I.hasDbgRecords(),
          "PHI Node must not have any attached DbgRecords", &I);
  for (DbgRecord &DR : I.getDbgRecordRange()) {
    CheckDI(DR.getMarker() == I.DebugMarker,
            "DbgRecord had invalid DebugMarker", &I, &DR);
    if (auto *Loc =
            dyn_cast_or_null<DILocation>(DR.getDebugLoc().getAsMDNode()))
      visitMDNode(*Loc, AreDebugLocsAllowed::Yes);
    if (auto *DVR = dyn_cast<DbgVariableRecord>(&DR)) {
      visit(*DVR);
      // These have to appear after `visit` for consistency with existing
      // intrinsic behaviour.
      verifyFragmentExpression(*DVR);
      verifyNotEntryValue(*DVR);
    } else if (auto *DLR = dyn_cast<DbgLabelRecord>(&DR)) {
      visit(*DLR);
    }
  }
}
 
void Verifier::visit(Instruction &I) {
  visitDbgRecords(I);
  for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
    Check(I.getOperand(i) != nullptr, "Operand is null", &I);
  InstVisitor<Verifier>::visit(I);
}
 
// Helper to iterate over indirect users. By returning false, the callback can ask to stop traversing further.
static void forEachUser(const Value *User,
                        SmallPtrSet<const Value *, 32> &Visited,
                        llvm::function_ref<bool(const Value *)> Callback) {
  if (!Visited.insert(User).second)
    return;
 
  SmallVector<const Value *> WorkList(User->materialized_users());
  while (!WorkList.empty()) {
   const Value *Cur = WorkList.pop_back_val();
    if (!Visited.insert(Cur).second)
      continue;
    if (Callback(Cur))
      append_range(WorkList, Cur->materialized_users());
  }
}
 
void Verifier::visitGlobalValue(const GlobalValue &GV) {
  Check(!GV.isDeclaration() || GV.hasValidDeclarationLinkage(),
        "Global is external, but doesn't have external or weak linkage!", &GV);
 
  if (const auto *GO = dyn_cast<GlobalObject>(&GV)) {
    if (const MDNode *Associated =
            GO->getMetadata(LLVMContext::MD_associated)) {
      Check(Associated->getNumOperands() == 1,
            "associated metadata must have one operand", &GV, Associated);
      const Metadata *Op = Associated->getOperand(0).get();
      Check(Op, "associated metadata must have a global value", GO, Associated);
 
      const auto *VM = dyn_cast_or_null<ValueAsMetadata>(Op);
      Check(VM, "associated metadata must be ValueAsMetadata", GO, Associated);
      if (VM) {
        Check(isa<PointerType>(VM->getValue()->getType()),
              "associated value must be pointer typed", GV, Associated);
 
        const Value *Stripped = VM->getValue()->stripPointerCastsAndAliases();
        Check(isa<GlobalObject>(Stripped) || isa<Constant>(Stripped),
              "associated metadata must point to a GlobalObject", GO, Stripped);
        Check(Stripped != GO,
              "global values should not associate to themselves", GO,
              Associated);
      }
    }
 
    // FIXME: Why is getMetadata on GlobalValue protected?
    if (const MDNode *AbsoluteSymbol =
            GO->getMetadata(LLVMContext::MD_absolute_symbol)) {
      verifyRangeLikeMetadata(*GO, AbsoluteSymbol,
                              DL.getIntPtrType(GO->getType()),
                              RangeLikeMetadataKind::AbsoluteSymbol);
    }
 
    if (GO->hasMetadata(LLVMContext::MD_implicit_ref)) {
      Check(!GO->isDeclaration(),
            "ref metadata must not be placed on a declaration", GO);
 
      SmallVector<MDNode *> MDs;
      GO->getMetadata(LLVMContext::MD_implicit_ref, MDs);
      for (const MDNode *MD : MDs) {
        Check(MD->getNumOperands() == 1, "ref metadata must have one operand",
              &GV, MD);
        const Metadata *Op = MD->getOperand(0).get();
        const auto *VM = dyn_cast_or_null<ValueAsMetadata>(Op);
        Check(VM, "ref metadata must be ValueAsMetadata", GO, MD);
        if (VM) {
          Check(isa<PointerType>(VM->getValue()->getType()),
                "ref value must be pointer typed", GV, MD);
 
          const Value *Stripped = VM->getValue()->stripPointerCastsAndAliases();
          Check(isa<GlobalObject>(Stripped) || isa<Constant>(Stripped),
                "ref metadata must point to a GlobalObject", GO, Stripped);
          Check(Stripped != GO, "values should not reference themselves", GO,
                MD);
        }
      }
    }
 
    if (auto *Props = GO->getMetadata(LLVMContext::MD_elf_section_properties)) {
      Check(Props->getNumOperands() == 2,
            "elf_section_properties metadata must have two operands", GO,
            Props);
      if (Props->getNumOperands() == 2) {
        auto *Type = dyn_cast<ConstantAsMetadata>(Props->getOperand(0));
        Check(Type, "type field must be ConstantAsMetadata", GO, Props);
        auto *TypeInt = dyn_cast<ConstantInt>(Type->getValue());
        Check(TypeInt, "type field must be ConstantInt", GO, Props);
 
        auto *Entsize = dyn_cast<ConstantAsMetadata>(Props->getOperand(1));
        Check(Entsize, "entsize field must be ConstantAsMetadata", GO, Props);
        auto *EntsizeInt = dyn_cast<ConstantInt>(Entsize->getValue());
        Check(EntsizeInt, "entsize field must be ConstantInt", GO, Props);
      }
    }
  }
 
  Check(!GV.hasAppendingLinkage() || isa<GlobalVariable>(GV),
        "Only global variables can have appending linkage!", &GV);
 
  if (GV.hasAppendingLinkage()) {
    const auto *GVar = dyn_cast<GlobalVariable>(&GV);
    Check(GVar && GVar->getValueType()->isArrayTy(),
          "Only global arrays can have appending linkage!", GVar);
  }
 
  if (GV.isDeclarationForLinker())
    Check(!GV.hasComdat(), "Declaration may not be in a Comdat!", &GV);
 
  if (GV.hasDLLExportStorageClass()) {
    Check(!GV.hasHiddenVisibility(),
          "dllexport GlobalValue must have default or protected visibility",
          &GV);
  }
  if (GV.hasDLLImportStorageClass()) {
    Check(GV.hasDefaultVisibility(),
          "dllimport GlobalValue must have default visibility", &GV);
    Check(!GV.isDSOLocal(), "GlobalValue with DLLImport Storage is dso_local!",
          &GV);
 
    Check((GV.isDeclaration() &&
           (GV.hasExternalLinkage() || GV.hasExternalWeakLinkage())) ||
              GV.hasAvailableExternallyLinkage(),
          "Global is marked as dllimport, but not external", &GV);
  }
 
  if (GV.isImplicitDSOLocal())
    Check(GV.isDSOLocal(),
          "GlobalValue with local linkage or non-default "
          "visibility must be dso_local!",
          &GV);
 
  forEachUser(&GV, GlobalValueVisited, [&](const Value *V) -> bool {
    if (const auto *I = dyn_cast<Instruction>(V)) {
      if (!I->getParent() || !I->getParent()->getParent())
        CheckFailed("Global is referenced by parentless instruction!", &GV, &M,
                    I);
      else if (I->getParent()->getParent()->getParent() != &M)
        CheckFailed("Global is referenced in a different module!", &GV, &M, I,
                    I->getParent()->getParent(),
                    I->getParent()->getParent()->getParent());
      return false;
    } else if (const auto *F = dyn_cast<Function>(V)) {
      if (F->getParent() != &M)
        CheckFailed("Global is used by function in a different module", &GV, &M,
                    F, F->getParent());
      return false;
    }
    return true;
  });
}
 
void Verifier::visitGlobalVariable(const GlobalVariable &GV) {
  Type *GVType = GV.getValueType();
 
  if (MaybeAlign A = GV.getAlign()) {
    Check(A->value() <= Value::MaximumAlignment,
          "huge alignment values are unsupported", &GV);
  }
 
  if (GV.hasInitializer()) {
    Check(GV.getInitializer()->getType() == GVType,
          "Global variable initializer type does not match global "
          "variable type!",
          &GV);
    Check(GV.getInitializer()->getType()->isSized(),
          "Global variable initializer must be sized", &GV);
    visitConstantExprsRecursively(GV.getInitializer());
    // If the global has common linkage, it must have a zero initializer and
    // cannot be constant.
    if (GV.hasCommonLinkage()) {
      Check(GV.getInitializer()->isNullValue(),
            "'common' global must have a zero initializer!", &GV);
      Check(!GV.isConstant(), "'common' global may not be marked constant!",
            &GV);
      Check(!GV.hasComdat(), "'common' global may not be in a Comdat!", &GV);
    }
  }
 
  if (GV.hasName() && (GV.getName() == "llvm.global_ctors" ||
                       GV.getName() == "llvm.global_dtors")) {
    Check(!GV.hasInitializer() || GV.hasAppendingLinkage(),
          "invalid linkage for intrinsic global variable", &GV);
    Check(GV.materialized_use_empty(),
          "invalid uses of intrinsic global variable", &GV);
 
    // Don't worry about emitting an error for it not being an array,
    // visitGlobalValue will complain on appending non-array.
    if (const auto *ATy = dyn_cast<ArrayType>(GVType)) {
      const auto *STy = dyn_cast<StructType>(ATy->getElementType());
      PointerType *FuncPtrTy =
          PointerType::get(Context, DL.getProgramAddressSpace());
      Check(STy && (STy->getNumElements() == 2 || STy->getNumElements() == 3) &&
                STy->getTypeAtIndex(0u)->isIntegerTy(32) &&
                STy->getTypeAtIndex(1) == FuncPtrTy,
            "wrong type for intrinsic global variable", &GV);
      Check(STy->getNumElements() == 3,
            "the third field of the element type is mandatory, "
            "specify ptr null to migrate from the obsoleted 2-field form");
      Type *ETy = STy->getTypeAtIndex(2);
      Check(ETy->isPointerTy(), "wrong type for intrinsic global variable",
            &GV);
    }
 
    auto *Init = GV.hasInitializer()
                     ? dyn_cast<ConstantArray>(GV.getInitializer())
                     : nullptr;
    if (Init) {
      for (const Use &U : Init->operands()) {
        auto *Structor = dyn_cast<ConstantStruct>(U);
        if (!Structor || Structor->getNumOperands() != 3)
          continue;
        Check(!isa<ConstantPtrAuth>(Structor->getOperand(1)),
              "signing of ctors/dtors should be requested via module flags");
      }
    }
  }
 
  if (GV.hasName() && (GV.getName() == "llvm.used" ||
                       GV.getName() == "llvm.compiler.used")) {
    Check(!GV.hasInitializer() || GV.hasAppendingLinkage(),
          "invalid linkage for intrinsic global variable", &GV);
    Check(GV.materialized_use_empty(),
          "invalid uses of intrinsic global variable", &GV);
 
    if (const auto *ATy = dyn_cast<ArrayType>(GVType)) {
      const auto *PTy = dyn_cast<PointerType>(ATy->getElementType());
      Check(PTy, "wrong type for intrinsic global variable", &GV);
      if (GV.hasInitializer()) {
        const Constant *Init = GV.getInitializer();
        const auto *InitArray = dyn_cast<ConstantArray>(Init);
        Check(InitArray, "wrong initializer for intrinsic global variable",
              Init);
        for (Value *Op : InitArray->operands()) {
          Value *V = Op->stripPointerCasts();
          Check(isa<GlobalVariable>(V) || isa<Function>(V) ||
                    isa<GlobalAlias>(V),
                Twine("invalid ") + GV.getName() + " member", V);
          Check(V->hasName(),
                Twine("members of ") + GV.getName() + " must be named", V);
        }
      }
    }
  }
 
  // Visit any debug info attachments.
  SmallVector<MDNode *, 1> MDs;
  GV.getMetadata(LLVMContext::MD_dbg, MDs);
  for (MDNode *MD : MDs) {
    if (auto *GVE = dyn_cast<DIGlobalVariableExpression>(MD))
      visitDIGlobalVariableExpression(*GVE);
    else
      CheckDI(false, "!dbg attachment of global variable must be a "
                     "DIGlobalVariableExpression");
  }
 
  // Scalable vectors cannot be global variables, since we don't know
  // the runtime size.
  Check(!GVType->isScalableTy(), "Globals cannot contain scalable types", &GV);
 
  // Check if it is or contains a target extension type that disallows being
  // used as a global.
  Check(!GVType->containsNonGlobalTargetExtType(),
        "Global @" + GV.getName() + " has illegal target extension type",
        GVType);
 
  // Check that the the address space can hold all bits of the type, recognized
  // by an access in the address space being able to reach all bytes of the
  // type.
  Check(!GVType->isSized() ||
            isUIntN(DL.getAddressSizeInBits(GV.getAddressSpace()),
                    GV.getGlobalSize(DL)),
        "Global variable is too large to fit into the address space", &GV,
        GVType);
 
  if (!GV.hasInitializer()) {
    visitGlobalValue(GV);
    return;
  }
 
  // Walk any aggregate initializers looking for bitcasts between address spaces
  visitConstantExprsRecursively(GV.getInitializer());
 
  visitGlobalValue(GV);
}
 
void Verifier::visitAliaseeSubExpr(const GlobalAlias &GA, const Constant &C) {
  SmallPtrSet<const GlobalAlias*, 4> Visited;
  Visited.insert(&GA);
  visitAliaseeSubExpr(Visited, GA, C);
}
 
void Verifier::visitAliaseeSubExpr(SmallPtrSetImpl<const GlobalAlias*> &Visited,
                                   const GlobalAlias &GA, const Constant &C) {
  if (GA.hasAvailableExternallyLinkage()) {
    Check(isa<GlobalValue>(C) &&
              cast<GlobalValue>(C).hasAvailableExternallyLinkage(),
          "available_externally alias must point to available_externally "
          "global value",
          &GA);
  }
  if (const auto *GV = dyn_cast<GlobalValue>(&C)) {
    if (!GA.hasAvailableExternallyLinkage()) {
      Check(!GV->isDeclarationForLinker(), "Alias must point to a definition",
            &GA);
    }
 
    if (const auto *GA2 = dyn_cast<GlobalAlias>(GV)) {
      Check(Visited.insert(GA2).second, "Aliases cannot form a cycle", &GA);
 
      Check(!GA2->isInterposable(),
            "Alias cannot point to an interposable alias", &GA);
    } else {
      // Only continue verifying subexpressions of GlobalAliases.
      // Do not recurse into global initializers.
      return;
    }
  }
 
  if (const auto *CE = dyn_cast<ConstantExpr>(&C))
    visitConstantExprsRecursively(CE);
 
  for (const Use &U : C.operands()) {
    Value *V = &*U;
    if (const auto *GA2 = dyn_cast<GlobalAlias>(V))
      visitAliaseeSubExpr(Visited, GA, *GA2->getAliasee());
    else if (const auto *C2 = dyn_cast<Constant>(V))
      visitAliaseeSubExpr(Visited, GA, *C2);
  }
}
 
void Verifier::visitGlobalAlias(const GlobalAlias &GA) {
  Check(GlobalAlias::isValidLinkage(GA.getLinkage()),
        "Alias should have private, internal, linkonce, weak, linkonce_odr, "
        "weak_odr, external, or available_externally linkage!",
        &GA);
  const Constant *Aliasee = GA.getAliasee();
  Check(Aliasee, "Aliasee cannot be NULL!", &GA);
  Check(GA.getType() == Aliasee->getType(),
        "Alias and aliasee types should match!", &GA);
 
  Check(isa<GlobalValue>(Aliasee) || isa<ConstantExpr>(Aliasee),
        "Aliasee should be either GlobalValue or ConstantExpr", &GA);
 
  visitAliaseeSubExpr(GA, *Aliasee);
 
  visitGlobalValue(GA);
}
 
void Verifier::visitGlobalIFunc(const GlobalIFunc &GI) {
  visitGlobalValue(GI);
 
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  GI.getAllMetadata(MDs);
  for (const auto &I : MDs) {
    CheckDI(I.first != LLVMContext::MD_dbg,
            "an ifunc may not have a !dbg attachment", &GI);
    Check(I.first != LLVMContext::MD_prof,
          "an ifunc may not have a !prof attachment", &GI);
    visitMDNode(*I.second, AreDebugLocsAllowed::No);
  }
 
  Check(GlobalIFunc::isValidLinkage(GI.getLinkage()),
        "IFunc should have private, internal, linkonce, weak, linkonce_odr, "
        "weak_odr, or external linkage!",
        &GI);
  // Pierce through ConstantExprs and GlobalAliases and check that the resolver
  // is a Function definition.
  const Function *Resolver = GI.getResolverFunction();
  Check(Resolver, "IFunc must have a Function resolver", &GI);
  Check(!Resolver->isDeclarationForLinker(),
        "IFunc resolver must be a definition", &GI);
 
  // Check that the immediate resolver operand (prior to any bitcasts) has the
  // correct type.
  const Type *ResolverTy = GI.getResolver()->getType();
 
  Check(isa<PointerType>(Resolver->getFunctionType()->getReturnType()),
        "IFunc resolver must return a pointer", &GI);
 
  Check(ResolverTy == PointerType::get(Context, GI.getAddressSpace()),
        "IFunc resolver has incorrect type", &GI);
}
 
void Verifier::visitNamedMDNode(const NamedMDNode &NMD) {
  // There used to be various other llvm.dbg.* nodes, but we don't support
  // upgrading them and we want to reserve the namespace for future uses.
  if (NMD.getName().starts_with("llvm.dbg."))
    CheckDI(NMD.getName() == "llvm.dbg.cu",
            "unrecognized named metadata node in the llvm.dbg namespace", &NMD);
  for (const MDNode *MD : NMD.operands()) {
    if (NMD.getName() == "llvm.dbg.cu")
      CheckDI(MD && isa<DICompileUnit>(MD), "invalid compile unit", &NMD, MD);
 
    if (!MD)
      continue;
 
    visitMDNode(*MD, AreDebugLocsAllowed::Yes);
  }
}
 
/// Parent scope operand of \p S, or null if \p S has no parent (a \c DIFile,
/// \c DICompileUnit, or non-scope). Mirrors \c DIScope::getScope() without
/// asserting on unexpected metadata kinds.
static const Metadata *getRawDIScopeParent(const Metadata *S) {
  if (!S)
    return nullptr;
  if (auto *T = dyn_cast<DIType>(S))
    return T->getRawScope();
  if (auto *SP = dyn_cast<DISubprogram>(S))
    return SP->getRawScope();
  if (auto *LB = dyn_cast<DILexicalBlockBase>(S))
    return LB->getRawScope();
  if (auto *NS = dyn_cast<DINamespace>(S))
    return NS->getRawScope();
  if (auto *CB = dyn_cast<DICommonBlock>(S))
    return CB->getRawScope();
  if (auto *M = dyn_cast<DIModule>(S))
    return M->getRawScope();
  return nullptr;
}
 
/// True if following the scope operand from \p S repeats a node.
bool Verifier::hasDIScopeCycle(const Metadata *S) {
  SmallPtrSet<const Metadata *, 8> Seen;
  auto CacheSeen = [&](bool HasCycle) {
    for (const Metadata *M : Seen)
      DIScopeChainReachesCycle[M] = HasCycle;
    return HasCycle;
  };
 
  while (auto *Scope = dyn_cast_or_null<DIScope>(S)) {
    auto It = DIScopeChainReachesCycle.find(Scope);
    bool IsInCache = It != DIScopeChainReachesCycle.end();
    if (IsInCache)
      return CacheSeen(It->second);
    bool AlreadySeen = !Seen.insert(Scope).second;
    if (AlreadySeen) // New cycle detected
      return CacheSeen(true);
    // No new cycle detected
    S = getRawDIScopeParent(Scope);
  }
 
  // Finished walking node chain without detecting any cycles
  return CacheSeen(false);
}
 
void Verifier::visitDIScopeChain(const DIScope &N) {
  CheckDI(!hasDIScopeCycle(&N), "DIScope scope chain must not contain a cycle",
          &N);
}
 
void Verifier::visitMDNode(const MDNode &BaseMD,
                           AreDebugLocsAllowed AllowLocs) {
  // Only visit each node once.  Metadata can be mutually recursive, so this
  // avoids infinite recursion here, as well as being an optimization.
  if (!MDNodes.insert(&BaseMD).second)
    return;
 
  std::queue<const MDNode *> Worklist;
  Worklist.push(&BaseMD);
 
  while (!Worklist.empty()) {
    const MDNode *CurrentMD = Worklist.front();
    Worklist.pop();
    Check(&CurrentMD->getContext() == &Context,
          "MDNode context does not match Module context!", CurrentMD);
 
    switch (CurrentMD->getMetadataID()) {
    default:
      llvm_unreachable("Invalid MDNode subclass");
    case Metadata::MDTupleKind:
      break;
#define HANDLE_SPECIALIZED_MDNODE_LEAF(CLASS)                                  \
  case Metadata::CLASS##Kind:                                                  \
    visit##CLASS(cast<CLASS>(*CurrentMD));                                     \
    break;
#include "llvm/IR/Metadata.def"
    }
 
    // A scope chain must terminate.
    if (const auto *S = dyn_cast<DIScope>(CurrentMD))
      visitDIScopeChain(*S);
 
    for (const Metadata *Op : CurrentMD->operands()) {
      if (!Op)
        continue;
      Check(!isa<LocalAsMetadata>(Op), "Invalid operand for global metadata!",
            CurrentMD, Op);
      CheckDI(!isa<DILocation>(Op) || AllowLocs == AreDebugLocsAllowed::Yes,
              "DILocation not allowed within this metadata node", CurrentMD,
              Op);
      if (auto *N = dyn_cast<MDNode>(Op)) {
        if (MDNodes.insert(N).second)
          Worklist.push(N);
        continue;
      }
      if (auto *V = dyn_cast<ValueAsMetadata>(Op)) {
        visitValueAsMetadata(*V, nullptr);
        continue;
      }
    }
 
    // Check llvm.loop.estimated_trip_count.
    if (CurrentMD->getNumOperands() > 0 &&
        CurrentMD->getOperand(0).equalsStr(LLVMLoopEstimatedTripCount)) {
      Check(CurrentMD->getNumOperands() == 2, "Expected two operands",
            CurrentMD);
      auto *Count =
          dyn_cast_or_null<ConstantAsMetadata>(CurrentMD->getOperand(1));
      Check(Count && Count->getType()->isIntegerTy() &&
                cast<IntegerType>(Count->getType())->getBitWidth() <= 32,
            "Expected second operand to be an integer constant of type i32 or "
            "smaller",
            CurrentMD);
    }
 
    // Enforce the single-operand form of the loop enable/disable pairs.
    if (CurrentMD->getNumOperands() > 0 &&
        any_of(OldBooleanLoopTags, [CurrentMD](const BooleanLoopTags &Tags) {
          return CurrentMD->getOperand(0).equalsStr(Tags.Enable) ||
                 CurrentMD->getOperand(0).equalsStr(Tags.Disable);
        }))
      Check(CurrentMD->getNumOperands() == 1,
            "Expecting only the metadata name", CurrentMD);
 
    // Check these last, so we diagnose problems in operands first.
    Check(!CurrentMD->isTemporary(), "Expected no forward declarations!",
          CurrentMD);
    Check(CurrentMD->isResolved(), "All nodes should be resolved!", CurrentMD);
  }
}
 
void Verifier::visitValueAsMetadata(const ValueAsMetadata &MD, Function *F) {
  Check(MD.getValue(), "Expected valid value", &MD);
  Check(!MD.getValue()->getType()->isMetadataTy(),
        "Unexpected metadata round-trip through values", &MD, MD.getValue());
 
  auto *L = dyn_cast<LocalAsMetadata>(&MD);
  if (!L)
    return;
 
  Check(F, "function-local metadata used outside a function", L);
 
  // If this was an instruction, bb, or argument, verify that it is in the
  // function that we expect.
  Function *ActualF = nullptr;
  if (auto *I = dyn_cast<Instruction>(L->getValue())) {
    Check(I->getParent(), "function-local metadata not in basic block", L, I);
    ActualF = I->getParent()->getParent();
  } else if (auto *BB = dyn_cast<BasicBlock>(L->getValue())) {
    ActualF = BB->getParent();
  } else if (auto *A = dyn_cast<Argument>(L->getValue())) {
    ActualF = A->getParent();
  }
  assert(ActualF && "Unimplemented function local metadata case!");
 
  Check(ActualF == F, "function-local metadata used in wrong function", L);
}
 
void Verifier::visitDIArgList(const DIArgList &AL, Function *F) {
  for (const ValueAsMetadata *VAM : AL.getArgs())
    visitValueAsMetadata(*VAM, F);
}
 
void Verifier::visitMetadataAsValue(const MetadataAsValue &MDV, Function *F) {
  Metadata *MD = MDV.getMetadata();
  if (auto *N = dyn_cast<MDNode>(MD)) {
    visitMDNode(*N, AreDebugLocsAllowed::No);
    return;
  }
 
  // Only visit each node once.  Metadata can be mutually recursive, so this
  // avoids infinite recursion here, as well as being an optimization.
  if (!MDNodes.insert(MD).second)
    return;
 
  if (auto *V = dyn_cast<ValueAsMetadata>(MD))
    visitValueAsMetadata(*V, F);
 
  if (auto *AL = dyn_cast<DIArgList>(MD))
    visitDIArgList(*AL, F);
}
 
static bool isType(const Metadata *MD) { return !MD || isa<DIType>(MD); }
static bool isScope(const Metadata *MD) { return !MD || isa<DIScope>(MD); }
static bool isDINode(const Metadata *MD) { return !MD || isa<DINode>(MD); }
static bool isMDTuple(const Metadata *MD) { return !MD || isa<MDTuple>(MD); }
 
void Verifier::visitDILocation(const DILocation &N) {
  CheckDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
          "location requires a valid scope", &N, N.getRawScope());
  if (auto *IA = N.getRawInlinedAt())
    CheckDI(isa<DILocation>(IA), "inlined-at should be a location", &N, IA);
  if (auto *SP = dyn_cast<DISubprogram>(N.getRawScope()))
    CheckDI(SP->isDefinition(), "scope points into the type hierarchy", &N);
}
 
void Verifier::visitGenericDINode(const GenericDINode &N) {
  CheckDI(N.getTag(), "invalid tag", &N);
}
 
void Verifier::visitDIScope(const DIScope &N) {
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
}
 
void Verifier::visitDIType(const DIType &N) {
  CheckDI(isScope(N.getRawScope()), "invalid scope", &N, N.getRawScope());
  visitDIScope(N);
  CheckDI(N.getRawFile() || N.getLine() == 0, "line specified with no file", &N,
          N.getLine());
}
 
void Verifier::visitDISubrangeType(const DISubrangeType &N) {
  visitDIType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_subrange_type, "invalid tag", &N);
  auto *BaseType = N.getRawBaseType();
  CheckDI(!BaseType || isType(BaseType), "BaseType must be a type");
  auto *LBound = N.getRawLowerBound();
  CheckDI(!LBound || isa<ConstantAsMetadata>(LBound) ||
              isa<DIVariable>(LBound) || isa<DIExpression>(LBound) ||
              isa<DIDerivedType>(LBound),
          "LowerBound must be signed constant or DIVariable or DIExpression or "
          "DIDerivedType",
          &N);
  auto *UBound = N.getRawUpperBound();
  CheckDI(!UBound || isa<ConstantAsMetadata>(UBound) ||
              isa<DIVariable>(UBound) || isa<DIExpression>(UBound) ||
              isa<DIDerivedType>(UBound),
          "UpperBound must be signed constant or DIVariable or DIExpression or "
          "DIDerivedType",
          &N);
  auto *Stride = N.getRawStride();
  CheckDI(!Stride || isa<ConstantAsMetadata>(Stride) ||
              isa<DIVariable>(Stride) || isa<DIExpression>(Stride),
          "Stride must be signed constant or DIVariable or DIExpression", &N);
  auto *Bias = N.getRawBias();
  CheckDI(!Bias || isa<ConstantAsMetadata>(Bias) || isa<DIVariable>(Bias) ||
              isa<DIExpression>(Bias),
          "Bias must be signed constant or DIVariable or DIExpression", &N);
  // Subrange types currently only support constant size.
  auto *Size = N.getRawSizeInBits();
  CheckDI(!Size || isa<ConstantAsMetadata>(Size),
          "SizeInBits must be a constant");
}
 
void Verifier::visitDISubrange(const DISubrange &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_subrange_type, "invalid tag", &N);
  CheckDI(!N.getRawCountNode() || !N.getRawUpperBound(),
          "Subrange can have any one of count or upperBound", &N);
  auto *CBound = N.getRawCountNode();
  CheckDI(!CBound || isa<ConstantAsMetadata>(CBound) ||
              isa<DIVariable>(CBound) || isa<DIExpression>(CBound),
          "Count must be signed constant or DIVariable or DIExpression", &N);
  auto Count = N.getCount();
  CheckDI(!Count || !isa<ConstantInt *>(Count) ||
              cast<ConstantInt *>(Count)->getSExtValue() >= -1,
          "invalid subrange count", &N);
  auto *LBound = N.getRawLowerBound();
  CheckDI(!LBound || isa<ConstantAsMetadata>(LBound) ||
              isa<DIVariable>(LBound) || isa<DIExpression>(LBound),
          "LowerBound must be signed constant or DIVariable or DIExpression",
          &N);
  auto *UBound = N.getRawUpperBound();
  CheckDI(!UBound || isa<ConstantAsMetadata>(UBound) ||
              isa<DIVariable>(UBound) || isa<DIExpression>(UBound),
          "UpperBound must be signed constant or DIVariable or DIExpression",
          &N);
  auto *Stride = N.getRawStride();
  CheckDI(!Stride || isa<ConstantAsMetadata>(Stride) ||
              isa<DIVariable>(Stride) || isa<DIExpression>(Stride),
          "Stride must be signed constant or DIVariable or DIExpression", &N);
}
 
void Verifier::visitDIGenericSubrange(const DIGenericSubrange &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_generic_subrange, "invalid tag", &N);
  CheckDI(!N.getRawCountNode() || !N.getRawUpperBound(),
          "GenericSubrange can have any one of count or upperBound", &N);
  auto *CBound = N.getRawCountNode();
  CheckDI(!CBound || isa<DIVariable>(CBound) || isa<DIExpression>(CBound),
          "Count must be signed constant or DIVariable or DIExpression", &N);
  auto *LBound = N.getRawLowerBound();
  CheckDI(LBound, "GenericSubrange must contain lowerBound", &N);
  CheckDI(isa<DIVariable>(LBound) || isa<DIExpression>(LBound),
          "LowerBound must be signed constant or DIVariable or DIExpression",
          &N);
  auto *UBound = N.getRawUpperBound();
  CheckDI(!UBound || isa<DIVariable>(UBound) || isa<DIExpression>(UBound),
          "UpperBound must be signed constant or DIVariable or DIExpression",
          &N);
  auto *Stride = N.getRawStride();
  CheckDI(Stride, "GenericSubrange must contain stride", &N);
  CheckDI(isa<DIVariable>(Stride) || isa<DIExpression>(Stride),
          "Stride must be signed constant or DIVariable or DIExpression", &N);
}
 
void Verifier::visitDIEnumerator(const DIEnumerator &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_enumerator, "invalid tag", &N);
}
 
void Verifier::visitDIBasicType(const DIBasicType &N) {
  visitDIType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_base_type ||
              N.getTag() == dwarf::DW_TAG_unspecified_type ||
              N.getTag() == dwarf::DW_TAG_string_type,
          "invalid tag", &N);
  // Basic types currently only support constant size.
  auto *Size = N.getRawSizeInBits();
  CheckDI(!Size || isa<ConstantAsMetadata>(Size),
          "SizeInBits must be a constant");
}
 
void Verifier::visitDIFixedPointType(const DIFixedPointType &N) {
  visitDIBasicType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_base_type, "invalid tag", &N);
  CheckDI(N.getEncoding() == dwarf::DW_ATE_signed_fixed ||
              N.getEncoding() == dwarf::DW_ATE_unsigned_fixed,
          "invalid encoding", &N);
  CheckDI(N.getKind() == DIFixedPointType::FixedPointBinary ||
              N.getKind() == DIFixedPointType::FixedPointDecimal ||
              N.getKind() == DIFixedPointType::FixedPointRational,
          "invalid kind", &N);
  CheckDI(N.getKind() != DIFixedPointType::FixedPointRational ||
              N.getFactorRaw() == 0,
          "factor should be 0 for rationals", &N);
  CheckDI(N.getKind() == DIFixedPointType::FixedPointRational ||
              (N.getNumeratorRaw() == 0 && N.getDenominatorRaw() == 0),
          "numerator and denominator should be 0 for non-rationals", &N);
}
 
void Verifier::visitDIStringType(const DIStringType &N) {
  visitDIType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_string_type, "invalid tag", &N);
  CheckDI(!(N.isBigEndian() && N.isLittleEndian()), "has conflicting flags",
          &N);
}
 
void Verifier::visitDIDerivedType(const DIDerivedType &N) {
  // Common type checks.
  visitDIType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_typedef ||
              N.getTag() == dwarf::DW_TAG_pointer_type ||
              N.getTag() == dwarf::DW_TAG_ptr_to_member_type ||
              N.getTag() == dwarf::DW_TAG_reference_type ||
              N.getTag() == dwarf::DW_TAG_rvalue_reference_type ||
              N.getTag() == dwarf::DW_TAG_const_type ||
              N.getTag() == dwarf::DW_TAG_immutable_type ||
              N.getTag() == dwarf::DW_TAG_volatile_type ||
              N.getTag() == dwarf::DW_TAG_restrict_type ||
              N.getTag() == dwarf::DW_TAG_atomic_type ||
              N.getTag() == dwarf::DW_TAG_LLVM_ptrauth_type ||
              N.getTag() == dwarf::DW_TAG_member ||
              (N.getTag() == dwarf::DW_TAG_variable && N.isStaticMember()) ||
              N.getTag() == dwarf::DW_TAG_inheritance ||
              N.getTag() == dwarf::DW_TAG_friend ||
              N.getTag() == dwarf::DW_TAG_set_type ||
              N.getTag() == dwarf::DW_TAG_template_alias,
          "invalid tag", &N);
  if (N.getTag() == dwarf::DW_TAG_ptr_to_member_type) {
    CheckDI(isType(N.getRawExtraData()), "invalid pointer to member type", &N,
            N.getRawExtraData());
  } else if (N.getTag() == dwarf::DW_TAG_template_alias) {
    CheckDI(isMDTuple(N.getRawExtraData()), "invalid template parameters", &N,
            N.getRawExtraData());
  } else if (N.getTag() == dwarf::DW_TAG_inheritance ||
             N.getTag() == dwarf::DW_TAG_member ||
             N.getTag() == dwarf::DW_TAG_variable) {
    auto *ExtraData = N.getRawExtraData();
    auto IsValidExtraData = [&]() {
      if (ExtraData == nullptr)
        return true;
      if (isa<ConstantAsMetadata>(ExtraData) || isa<MDString>(ExtraData) ||
          isa<DIObjCProperty>(ExtraData))
        return true;
      if (auto *Tuple = dyn_cast<MDTuple>(ExtraData)) {
        if (Tuple->getNumOperands() != 1)
          return false;
        return isa_and_nonnull<ConstantAsMetadata>(Tuple->getOperand(0).get());
      }
      return false;
    };
    CheckDI(IsValidExtraData(),
            "extraData must be ConstantAsMetadata, MDString, DIObjCProperty, "
            "or MDTuple with single ConstantAsMetadata operand",
            &N, ExtraData);
  }
 
  if (N.getTag() == dwarf::DW_TAG_set_type) {
    if (auto *T = N.getRawBaseType()) {
      auto *Enum = dyn_cast_or_null<DICompositeType>(T);
      auto *Subrange = dyn_cast_or_null<DISubrangeType>(T);
      auto *Basic = dyn_cast_or_null<DIBasicType>(T);
      CheckDI(
          (Enum && Enum->getTag() == dwarf::DW_TAG_enumeration_type) ||
              (Subrange && Subrange->getTag() == dwarf::DW_TAG_subrange_type) ||
              (Basic && (Basic->getEncoding() == dwarf::DW_ATE_unsigned ||
                         Basic->getEncoding() == dwarf::DW_ATE_signed ||
                         Basic->getEncoding() == dwarf::DW_ATE_unsigned_char ||
                         Basic->getEncoding() == dwarf::DW_ATE_signed_char ||
                         Basic->getEncoding() == dwarf::DW_ATE_boolean)),
          "invalid set base type", &N, T);
    }
  }
 
  CheckDI(isType(N.getRawBaseType()), "invalid base type", &N,
          N.getRawBaseType());
 
  if (N.getDWARFAddressSpace()) {
    CheckDI(N.getTag() == dwarf::DW_TAG_pointer_type ||
                N.getTag() == dwarf::DW_TAG_reference_type ||
                N.getTag() == dwarf::DW_TAG_rvalue_reference_type,
            "DWARF address space only applies to pointer or reference types",
            &N);
  }
 
  auto *Size = N.getRawSizeInBits();
  CheckDI(!Size || isa<ConstantAsMetadata>(Size) || isa<DIVariable>(Size) ||
              isa<DIExpression>(Size),
          "SizeInBits must be a constant or DIVariable or DIExpression");
}
 
/// Detect mutually exclusive flags.
static bool hasConflictingReferenceFlags(unsigned Flags) {
  return ((Flags & DINode::FlagLValueReference) &&
          (Flags & DINode::FlagRValueReference)) ||
         ((Flags & DINode::FlagTypePassByValue) &&
          (Flags & DINode::FlagTypePassByReference));
}
 
void Verifier::visitTemplateParams(const MDNode &N, const Metadata &RawParams) {
  auto *Params = dyn_cast<MDTuple>(&RawParams);
  CheckDI(Params, "invalid template params", &N, &RawParams);
  for (Metadata *Op : Params->operands()) {
    CheckDI(Op && isa<DITemplateParameter>(Op), "invalid template parameter",
            &N, Params, Op);
  }
}
 
void Verifier::visitDICompositeType(const DICompositeType &N) {
  // Common type checks.
  visitDIType(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_array_type ||
              N.getTag() == dwarf::DW_TAG_structure_type ||
              N.getTag() == dwarf::DW_TAG_union_type ||
              N.getTag() == dwarf::DW_TAG_enumeration_type ||
              N.getTag() == dwarf::DW_TAG_class_type ||
              N.getTag() == dwarf::DW_TAG_variant_part ||
              N.getTag() == dwarf::DW_TAG_variant ||
              N.getTag() == dwarf::DW_TAG_namelist,
          "invalid tag", &N);
 
  CheckDI(isType(N.getRawBaseType()), "invalid base type", &N,
          N.getRawBaseType());
 
  CheckDI(!N.getRawElements() || isa<MDTuple>(N.getRawElements()),
          "invalid composite elements", &N, N.getRawElements());
  CheckDI(isType(N.getRawVTableHolder()), "invalid vtable holder", &N,
          N.getRawVTableHolder());
  CheckDI(!hasConflictingReferenceFlags(N.getFlags()),
          "invalid reference flags", &N);
  unsigned DIBlockByRefStruct = 1 << 4;
  CheckDI((N.getFlags() & DIBlockByRefStruct) == 0,
          "DIBlockByRefStruct on DICompositeType is no longer supported", &N);
  CheckDI(llvm::all_of(N.getElements(), [](const DINode *N) { return N; }),
          "DISubprogram contains null entry in `elements` field", &N);
 
  if (N.isVector()) {
    const DINodeArray Elements = N.getElements();
    CheckDI(Elements.size() == 1 &&
                Elements[0]->getTag() == dwarf::DW_TAG_subrange_type,
            "invalid vector, expected one element of type subrange", &N);
  }
 
  if (auto *Params = N.getRawTemplateParams())
    visitTemplateParams(N, *Params);
 
  if (auto *D = N.getRawDiscriminator()) {
    CheckDI(isa<DIDerivedType>(D) && N.getTag() == dwarf::DW_TAG_variant_part,
            "discriminator can only appear on variant part");
  }
 
  if (N.getRawDataLocation()) {
    CheckDI(N.getTag() == dwarf::DW_TAG_array_type,
            "dataLocation can only appear in array type");
  }
 
  if (N.getRawAssociated()) {
    CheckDI(N.getTag() == dwarf::DW_TAG_array_type,
            "associated can only appear in array type");
  }
 
  if (N.getRawAllocated()) {
    CheckDI(N.getTag() == dwarf::DW_TAG_array_type,
            "allocated can only appear in array type");
  }
 
  if (N.getRawRank()) {
    CheckDI(N.getTag() == dwarf::DW_TAG_array_type,
            "rank can only appear in array type");
  }
 
  if (N.getTag() == dwarf::DW_TAG_array_type) {
    CheckDI(N.getRawBaseType(), "array types must have a base type", &N);
  }
 
  auto *Size = N.getRawSizeInBits();
  CheckDI(!Size || isa<ConstantAsMetadata>(Size) || isa<DIVariable>(Size) ||
              isa<DIExpression>(Size),
          "SizeInBits must be a constant or DIVariable or DIExpression");
}
 
void Verifier::visitDISubroutineType(const DISubroutineType &N) {
  visitDIType(N);
  CheckDI(N.getTag() == dwarf::DW_TAG_subroutine_type, "invalid tag", &N);
  if (auto *Types = N.getRawTypeArray()) {
    CheckDI(isa<MDTuple>(Types), "invalid composite elements", &N, Types);
    for (Metadata *Ty : N.getTypeArray()->operands()) {
      CheckDI(isType(Ty), "invalid subroutine type ref", &N, Types, Ty);
    }
  }
  CheckDI(!hasConflictingReferenceFlags(N.getFlags()),
          "invalid reference flags", &N);
}
 
void Verifier::visitDIFile(const DIFile &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_file_type, "invalid tag", &N);
  std::optional<DIFile::ChecksumInfo<StringRef>> Checksum = N.getChecksum();
  if (Checksum) {
    CheckDI(Checksum->Kind <= DIFile::ChecksumKind::CSK_Last,
            "invalid checksum kind", &N);
    size_t Size;
    switch (Checksum->Kind) {
    case DIFile::CSK_MD5:
      Size = 32;
      break;
    case DIFile::CSK_SHA1:
      Size = 40;
      break;
    case DIFile::CSK_SHA256:
      Size = 64;
      break;
    }
    CheckDI(Checksum->Value.size() == Size, "invalid checksum length", &N);
    CheckDI(Checksum->Value.find_if_not(llvm::isHexDigit) == StringRef::npos,
            "invalid checksum", &N);
  }
}
 
void Verifier::visitDICompileUnit(const DICompileUnit &N) {
  CheckDI(N.isDistinct(), "compile units must be distinct", &N);
  CheckDI(N.getTag() == dwarf::DW_TAG_compile_unit, "invalid tag", &N);
 
  // Don't bother verifying the compilation directory or producer string
  // as those could be empty.
  CheckDI(N.getRawFile() && isa<DIFile>(N.getRawFile()), "invalid file", &N,
          N.getRawFile());
  CheckDI(!N.getFile()->getFilename().empty(), "invalid filename", &N,
          N.getFile());
 
  CheckDI((N.getEmissionKind() <= DICompileUnit::LastEmissionKind),
          "invalid emission kind", &N);
 
  CheckDI(N.getSourceLanguage().getDialect() <= dwarf::DW_LLVM_LANG_DIALECT_max,
          "invalid language dialect", &N);
 
  if (auto *Array = N.getRawEnumTypes()) {
    CheckDI(isa<MDTuple>(Array), "invalid enum list", &N, Array);
    for (Metadata *Op : N.getEnumTypes()->operands()) {
      auto *Enum = dyn_cast_or_null<DICompositeType>(Op);
      CheckDI(Enum && Enum->getTag() == dwarf::DW_TAG_enumeration_type,
              "invalid enum type", &N, N.getEnumTypes(), Op);
      CheckDI(!Enum->getScope() || !isa<DILocalScope>(Enum->getScope()),
              "function-local enum in a DICompileUnit's enum list", &N,
              N.getEnumTypes(), Op);
    }
  }
  if (auto *Array = N.getRawRetainedTypes()) {
    CheckDI(isa<MDTuple>(Array), "invalid retained type list", &N, Array);
    for (Metadata *Op : N.getRetainedTypes()->operands()) {
      CheckDI(
          Op && (isa<DIType>(Op) || (isa<DISubprogram>(Op) &&
                                     !cast<DISubprogram>(Op)->isDefinition())),
          "invalid retained type", &N, Op);
    }
  }
  if (auto *Array = N.getRawGlobalVariables()) {
    CheckDI(isa<MDTuple>(Array), "invalid global variable list", &N, Array);
    for (Metadata *Op : N.getGlobalVariables()->operands()) {
      auto *GVE = dyn_cast_or_null<DIGlobalVariableExpression>(Op);
      CheckDI(GVE, "invalid global variable ref", &N, Op);
      CheckDI(!isa_and_nonnull<DILocalScope>(GVE->getVariable()->getScope()),
              "function-local variables are not allowed in a DICompileUnit's "
              "global variables list",
              &N, Op);
    }
  }
  if (auto *Array = N.getRawImportedEntities()) {
    CheckDI(isa<MDTuple>(Array), "invalid imported entity list", &N, Array);
    for (Metadata *Op : N.getImportedEntities()->operands()) {
      auto *IE = dyn_cast_or_null<DIImportedEntity>(Op);
      CheckDI(IE, "invalid imported entity ref", &N, Op);
      CheckDI(!isa_and_nonnull<DILocalScope>(IE->getScope()),
              "function-local imports are not allowed in a DICompileUnit's "
              "imported entities list",
              &N, Op);
    }
  }
  if (auto *Array = N.getRawMacros()) {
    CheckDI(isa<MDTuple>(Array), "invalid macro list", &N, Array);
    for (Metadata *Op : N.getMacros()->operands()) {
      CheckDI(Op && isa<DIMacroNode>(Op), "invalid macro ref", &N, Op);
    }
  }
  CUVisited.insert(&N);
}
 
void Verifier::visitDISubprogram(const DISubprogram &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_subprogram, "invalid tag", &N);
  CheckDI(isScope(N.getRawScope()), "invalid scope", &N, N.getRawScope());
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
  else
    CheckDI(N.getLine() == 0, "line specified with no file", &N, N.getLine());
  auto *T = N.getRawType();
  CheckDI(T, "DISubprogram requires a non-null type", &N);
  CheckDI(isa<DISubroutineType>(T), "invalid subroutine type", &N, T);
  CheckDI(isType(N.getRawContainingType()), "invalid containing type", &N,
          N.getRawContainingType());
  if (auto *Params = N.getRawTemplateParams())
    visitTemplateParams(N, *Params);
  if (auto *S = N.getRawDeclaration())
    CheckDI(isa<DISubprogram>(S) && !cast<DISubprogram>(S)->isDefinition(),
            "invalid subprogram declaration", &N, S);
  if (auto *RawNode = N.getRawRetainedNodes()) {
    auto *Node = dyn_cast<MDTuple>(RawNode);
    CheckDI(Node, "invalid retained nodes list", &N, RawNode);
 
    DenseMap<unsigned, DILocalVariable *> Args;
    for (Metadata *Op : Node->operands()) {
      CheckDI(Op, "nullptr in retained nodes", &N, Node);
 
      auto True = [](const Metadata *) { return true; };
      auto False = [](const Metadata *) { return false; };
      bool IsTypeCorrect = DISubprogram::visitRetainedNode<bool>(
          Op, True, True, True, True, True, False);
      CheckDI(IsTypeCorrect,
              "invalid retained nodes, expected DILocalVariable, DILabel, "
              "DIImportedEntity, DIType or DIGlobalVariableExpression",
              &N, Node, Op);
 
      auto *RetainedNode = cast<MDNode>(Op);
      auto *RetainedNodeScope = dyn_cast_or_null<DILocalScope>(
          DISubprogram::getRawRetainedNodeScope(RetainedNode));
      CheckDI(RetainedNodeScope,
              "invalid retained nodes, retained node is not local", &N, Node,
              RetainedNode);
 
      DISubprogram *RetainedNodeSP = getSubprogram(RetainedNodeScope);
      DICompileUnit *RetainedNodeUnit =
          RetainedNodeSP ? RetainedNodeSP->getUnit() : nullptr;
      CheckDI(
          RetainedNodeSP == &N,
          "invalid retained nodes, retained node does not belong to subprogram",
          &N, Node, RetainedNode, RetainedNodeScope, RetainedNodeSP,
          RetainedNodeUnit);
 
      auto *DV = dyn_cast<DILocalVariable>(RetainedNode);
      if (!DV)
        continue;
      if (unsigned ArgNum = DV->getArg()) {
        auto [ArgI, Inserted] = Args.insert({ArgNum, DV});
        CheckDI(Inserted || DV == ArgI->second,
                "invalid retained nodes, more than one local variable with the "
                "same argument index",
                &N, N.getUnit(), Node, RetainedNode, Args[ArgNum]);
      }
    }
  }
  CheckDI(!hasConflictingReferenceFlags(N.getFlags()),
          "invalid reference flags", &N);
 
  auto *Unit = N.getRawUnit();
  if (N.isDefinition()) {
    // Subprogram definitions (not part of the type hierarchy).
    CheckDI(N.isDistinct(), "subprogram definitions must be distinct", &N);
    CheckDI(Unit, "subprogram definitions must have a compile unit", &N);
    CheckDI(isa<DICompileUnit>(Unit), "invalid unit type", &N, Unit);
    // There's no good way to cross the CU boundary to insert a nested
    // DISubprogram definition in one CU into a type defined in another CU.
    auto *CT = dyn_cast_or_null<DICompositeType>(N.getRawScope());
    if (CT && CT->getRawIdentifier() &&
        M.getContext().isODRUniquingDebugTypes())
      CheckDI(N.getDeclaration(),
              "definition subprograms cannot be nested within DICompositeType "
              "when enabling ODR",
              &N);
  } else {
    // Subprogram declarations (part of the type hierarchy).
    CheckDI(!Unit, "subprogram declarations must not have a compile unit", &N);
    CheckDI(!N.getRawDeclaration(),
            "subprogram declaration must not have a declaration field");
  }
 
  if (auto *RawThrownTypes = N.getRawThrownTypes()) {
    auto *ThrownTypes = dyn_cast<MDTuple>(RawThrownTypes);
    CheckDI(ThrownTypes, "invalid thrown types list", &N, RawThrownTypes);
    for (Metadata *Op : ThrownTypes->operands())
      CheckDI(Op && isa<DIType>(Op), "invalid thrown type", &N, ThrownTypes,
              Op);
  }
 
  if (N.areAllCallsDescribed())
    CheckDI(N.isDefinition(),
            "DIFlagAllCallsDescribed must be attached to a definition");
}
 
void Verifier::visitDILexicalBlockBase(const DILexicalBlockBase &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_lexical_block, "invalid tag", &N);
  CheckDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
          "invalid local scope", &N, N.getRawScope());
  if (auto *SP = dyn_cast<DISubprogram>(N.getRawScope()))
    CheckDI(SP->isDefinition(), "scope points into the type hierarchy", &N);
}
 
void Verifier::visitDILexicalBlock(const DILexicalBlock &N) {
  visitDILexicalBlockBase(N);
 
  CheckDI(N.getLine() || !N.getColumn(),
          "cannot have column info without line info", &N);
}
 
void Verifier::visitDILexicalBlockFile(const DILexicalBlockFile &N) {
  visitDILexicalBlockBase(N);
}
 
void Verifier::visitDICommonBlock(const DICommonBlock &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_common_block, "invalid tag", &N);
  if (auto *S = N.getRawScope())
    CheckDI(isa<DIScope>(S), "invalid scope ref", &N, S);
  if (auto *S = N.getRawDecl())
    CheckDI(isa<DIGlobalVariable>(S), "invalid declaration", &N, S);
}
 
void Verifier::visitDINamespace(const DINamespace &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_namespace, "invalid tag", &N);
  if (auto *S = N.getRawScope())
    CheckDI(isa<DIScope>(S), "invalid scope ref", &N, S);
}
 
void Verifier::visitDIMacro(const DIMacro &N) {
  CheckDI(N.getMacinfoType() == dwarf::DW_MACINFO_define ||
              N.getMacinfoType() == dwarf::DW_MACINFO_undef,
          "invalid macinfo type", &N);
  CheckDI(!N.getName().empty(), "anonymous macro", &N);
  if (!N.getValue().empty()) {
    assert(N.getValue().data()[0] != ' ' && "Macro value has a space prefix");
  }
}
 
void Verifier::visitDIMacroFile(const DIMacroFile &N) {
  CheckDI(N.getMacinfoType() == dwarf::DW_MACINFO_start_file,
          "invalid macinfo type", &N);
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
 
  if (auto *Array = N.getRawElements()) {
    CheckDI(isa<MDTuple>(Array), "invalid macro list", &N, Array);
    for (Metadata *Op : N.getElements()->operands()) {
      CheckDI(Op && isa<DIMacroNode>(Op), "invalid macro ref", &N, Op);
    }
  }
}
 
void Verifier::visitDIModule(const DIModule &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_module, "invalid tag", &N);
  CheckDI(!N.getName().empty(), "anonymous module", &N);
}
 
void Verifier::visitDITemplateParameter(const DITemplateParameter &N) {
  CheckDI(isType(N.getRawType()), "invalid type ref", &N, N.getRawType());
}
 
void Verifier::visitDITemplateTypeParameter(const DITemplateTypeParameter &N) {
  visitDITemplateParameter(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_template_type_parameter, "invalid tag",
          &N);
}
 
void Verifier::visitDITemplateValueParameter(
    const DITemplateValueParameter &N) {
  visitDITemplateParameter(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_template_value_parameter ||
              N.getTag() == dwarf::DW_TAG_GNU_template_template_param ||
              N.getTag() == dwarf::DW_TAG_GNU_template_parameter_pack,
          "invalid tag", &N);
}
 
void Verifier::visitDIVariable(const DIVariable &N) {
  if (auto *S = N.getRawScope())
    CheckDI(isa<DIScope>(S), "invalid scope", &N, S);
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
}
 
void Verifier::visitDIGlobalVariable(const DIGlobalVariable &N) {
  // Checks common to all variables.
  visitDIVariable(N);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_variable, "invalid tag", &N);
  CheckDI(isType(N.getRawType()), "invalid type ref", &N, N.getRawType());
  // Check only if the global variable is not an extern
  if (N.isDefinition())
    CheckDI(N.getType(), "missing global variable type", &N);
  if (auto *Member = N.getRawStaticDataMemberDeclaration()) {
    CheckDI(isa<DIDerivedType>(Member),
            "invalid static data member declaration", &N, Member);
  }
}
 
void Verifier::visitDILocalVariable(const DILocalVariable &N) {
  // Checks common to all variables.
  visitDIVariable(N);
 
  CheckDI(isType(N.getRawType()), "invalid type ref", &N, N.getRawType());
  CheckDI(N.getTag() == dwarf::DW_TAG_variable, "invalid tag", &N);
  CheckDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
          "local variable requires a valid scope", &N, N.getRawScope());
  if (auto Ty = N.getType())
    CheckDI(!isa<DISubroutineType>(Ty), "invalid type", &N, N.getType());
}
 
void Verifier::visitDIAssignID(const DIAssignID &N) {
  CheckDI(!N.getNumOperands(), "DIAssignID has no arguments", &N);
  CheckDI(N.isDistinct(), "DIAssignID must be distinct", &N);
}
 
void Verifier::visitDILabel(const DILabel &N) {
  if (auto *S = N.getRawScope())
    CheckDI(isa<DIScope>(S), "invalid scope", &N, S);
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
 
  CheckDI(N.getTag() == dwarf::DW_TAG_label, "invalid tag", &N);
  CheckDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
          "label requires a valid scope", &N, N.getRawScope());
}
 
void Verifier::visitDIExpression(const DIExpression &N) {
  CheckDI(N.isValid(), "invalid expression", &N);
}
 
void Verifier::visitDIGlobalVariableExpression(
    const DIGlobalVariableExpression &GVE) {
  CheckDI(GVE.getVariable(), "missing variable");
  if (auto *Var = GVE.getVariable())
    visitDIGlobalVariable(*Var);
  if (auto *Expr = GVE.getExpression()) {
    visitDIExpression(*Expr);
    if (auto Fragment = Expr->getFragmentInfo())
      verifyFragmentExpression(*GVE.getVariable(), *Fragment, &GVE);
  }
}
 
void Verifier::visitDIObjCProperty(const DIObjCProperty &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_APPLE_property, "invalid tag", &N);
  if (auto *T = N.getRawType())
    CheckDI(isType(T), "invalid type ref", &N, T);
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
}
 
void Verifier::visitDIProperty(const DIProperty &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_property, "invalid tag", &N);
  if (auto *T = N.getRawType())
    CheckDI(isType(T), "invalid type ref", &N, T);
  if (auto *F = N.getRawFile())
    CheckDI(isa<DIFile>(F), "invalid file", &N, F);
  // DWARF allows a property getter to forward to a subprogram, variable, or
  // constant too, but the backend only knows how to forward to a member.
  if (DINode *BackingStorage = N.getBackingStorage()) {
    auto *DT = dyn_cast<DIDerivedType>(BackingStorage);
    CheckDI(DT && DT->getTag() == dwarf::DW_TAG_member,
            "property backing storage must be a member", &N, BackingStorage);
  }
}
 
void Verifier::visitDIImportedEntity(const DIImportedEntity &N) {
  CheckDI(N.getTag() == dwarf::DW_TAG_imported_module ||
              N.getTag() == dwarf::DW_TAG_imported_declaration,
          "invalid tag", &N);
  if (auto *S = N.getRawScope())
    CheckDI(isa<DIScope>(S), "invalid scope for imported entity", &N, S);
  CheckDI(isDINode(N.getRawEntity()), "invalid imported entity", &N,
          N.getRawEntity());
}
 
void Verifier::visitComdat(const Comdat &C) {
  // In COFF the Module is invalid if the GlobalValue has private linkage.
  // Entities with private linkage don't have entries in the symbol table.
  if (TT.isOSBinFormatCOFF())
    if (const GlobalValue *GV = M.getNamedValue(C.getName()))
      Check(!GV->hasPrivateLinkage(), "comdat global value has private linkage",
            GV);
}
 
void Verifier::visitModuleIdents() {
  const NamedMDNode *Idents = M.getNamedMetadata("llvm.ident");
  if (!Idents)
    return;
 
  // llvm.ident takes a list of metadata entry. Each entry has only one string.
  // Scan each llvm.ident entry and make sure that this requirement is met.
  for (const MDNode *N : Idents->operands()) {
    Check(N->getNumOperands() == 1,
          "incorrect number of operands in llvm.ident metadata", N);
    Check(dyn_cast_or_null<MDString>(N->getOperand(0)),
          ("invalid value for llvm.ident metadata entry operand"
           "(the operand should be a string)"),
          N->getOperand(0));
  }
}
 
void Verifier::visitModuleCommandLines() {
  const NamedMDNode *CommandLines = M.getNamedMetadata("llvm.commandline");
  if (!CommandLines)
    return;
 
  // llvm.commandline takes a list of metadata entry. Each entry has only one
  // string. Scan each llvm.commandline entry and make sure that this
  // requirement is met.
  for (const MDNode *N : CommandLines->operands()) {
    Check(N->getNumOperands() == 1,
          "incorrect number of operands in llvm.commandline metadata", N);
    Check(dyn_cast_or_null<MDString>(N->getOperand(0)),
          ("invalid value for llvm.commandline metadata entry operand"
           "(the operand should be a string)"),
          N->getOperand(0));
  }
}
 
void Verifier::visitModuleErrnoTBAA() {
  const NamedMDNode *ErrnoTBAA = M.getNamedMetadata("llvm.errno.tbaa");
  if (!ErrnoTBAA)
    return;
 
  Check(ErrnoTBAA->getNumOperands() >= 1,
        "llvm.errno.tbaa must have at least one operand", ErrnoTBAA);
 
  for (const MDNode *N : ErrnoTBAA->operands())
    TBAAVerifyHelper.visitTBAAMetadata(nullptr, N);
}
 
void Verifier::visitModuleFlags() {
  const NamedMDNode *Flags = M.getModuleFlagsMetadata();
  if (!Flags) return;
 
  // Scan each flag, and track the flags and requirements.
  DenseMap<const MDString*, const MDNode*> SeenIDs;
  SmallVector<const MDNode*, 16> Requirements;
 
  // Either both aarch64-elf-pauthabi-* flags should be set or none at all.
  std::optional<uint64_t> PAuthABIPlatform;
  std::optional<uint64_t> PAuthABIVersion;
  // Signing of init/fini pointers: address diversity implies basic signing.
  uint64_t HasPtrauthInitFini = 0;
  uint64_t HasPtrauthInitFiniAddr = 0;
 
  for (const MDNode *MDN : Flags->operands()) {
    visitModuleFlag(MDN, SeenIDs, Requirements);
    if (MDN->getNumOperands() != 3)
      continue;
 
    if (const auto *FlagName = dyn_cast_or_null<MDString>(MDN->getOperand(1))) {
      auto GetFlagNamed = [&](StringRef Name) -> std::optional<uint64_t> {
        if (FlagName->getString() != Name)
          return std::nullopt;
        if (const auto *FlagValue =
                mdconst::dyn_extract_or_null<ConstantInt>(MDN->getOperand(2)))
          return FlagValue->getZExtValue();
 
        CheckFailed(Name + ": module flag expects integer value");
        return std::nullopt;
      };
 
      if (auto Value = GetFlagNamed("aarch64-elf-pauthabi-platform"))
        PAuthABIPlatform = *Value;
      else if (auto Value = GetFlagNamed("aarch64-elf-pauthabi-version"))
        PAuthABIVersion = *Value;
      else if (auto Value = GetFlagNamed("ptrauth-init-fini"))
        HasPtrauthInitFini = *Value;
      else if (auto Value =
                   GetFlagNamed("ptrauth-init-fini-address-discrimination"))
        HasPtrauthInitFiniAddr = *Value;
    }
  }
 
  Check(llvm::is_contained({0u, 1u}, HasPtrauthInitFini),
        "ptrauth-init-fini must be 0 or 1");
  Check(llvm::is_contained({0u, 1u}, HasPtrauthInitFiniAddr),
        "ptrauth-init-fini-address-discrimination must be 0 or 1, if set");
  if (HasPtrauthInitFiniAddr)
    Check(HasPtrauthInitFini, "ptrauth-init-fini-address-discrimination module "
                              "flag requires ptrauth-init-fini");
 
  if (PAuthABIPlatform.has_value() != PAuthABIVersion.has_value())
    CheckFailed("either both or no 'aarch64-elf-pauthabi-platform' and "
                "'aarch64-elf-pauthabi-version' module flags must be present");
 
  // Validate that the requirements in the module are valid.
  for (const MDNode *Requirement : Requirements) {
    const MDString *Flag = cast<MDString>(Requirement->getOperand(0));
    const Metadata *ReqValue = Requirement->getOperand(1);
 
    const MDNode *Op = SeenIDs.lookup(Flag);
    if (!Op) {
      CheckFailed("invalid requirement on flag, flag is not present in module",
                  Flag);
      continue;
    }
 
    if (Op->getOperand(2) != ReqValue) {
      CheckFailed(("invalid requirement on flag, "
                   "flag does not have the required value"),
                  Flag);
      continue;
    }
  }
}
 
void
Verifier::visitModuleFlag(const MDNode *Op,
                          DenseMap<const MDString *, const MDNode *> &SeenIDs,
                          SmallVectorImpl<const MDNode *> &Requirements) {
  // Each module flag should have three arguments, the merge behavior (a
  // constant int), the flag ID (an MDString), and the value.
  Check(Op->getNumOperands() == 3,
        "incorrect number of operands in module flag", Op);
  Module::ModFlagBehavior MFB;
  if (!Module::isValidModFlagBehavior(Op->getOperand(0), MFB)) {
    Check(mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(0)),
          "invalid behavior operand in module flag (expected constant integer)",
          Op->getOperand(0));
    Check(false,
          "invalid behavior operand in module flag (unexpected constant)",
          Op->getOperand(0));
  }
  MDString *ID = dyn_cast_or_null<MDString>(Op->getOperand(1));
  Check(ID, "invalid ID operand in module flag (expected metadata string)",
        Op->getOperand(1));
 
  // Check the values for behaviors with additional requirements.
  switch (MFB) {
  case Module::Error:
  case Module::Warning:
  case Module::Override:
    // These behavior types accept any value.
    break;
 
  case Module::Min: {
    auto *V = mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2));
    Check(V && V->getValue().isNonNegative(),
          "invalid value for 'min' module flag (expected constant non-negative "
          "integer)",
          Op->getOperand(2));
    break;
  }
 
  case Module::Max: {
    Check(mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2)),
          "invalid value for 'max' module flag (expected constant integer)",
          Op->getOperand(2));
    break;
  }
 
  case Module::Require: {
    // The value should itself be an MDNode with two operands, a flag ID (an
    // MDString), and a value.
    auto *Value = dyn_cast<MDNode>(Op->getOperand(2));
    Check(Value && Value->getNumOperands() == 2,
          "invalid value for 'require' module flag (expected metadata pair)",
          Op->getOperand(2));
    Check(isa<MDString>(Value->getOperand(0)),
          ("invalid value for 'require' module flag "
           "(first value operand should be a string)"),
          Value->getOperand(0));
 
    // Append it to the list of requirements, to check once all module flags are
    // scanned.
    Requirements.push_back(Value);
    break;
  }
 
  case Module::Append:
  case Module::AppendUnique: {
    // These behavior types require the operand be an MDNode.
    Check(isa<MDNode>(Op->getOperand(2)),
          "invalid value for 'append'-type module flag "
          "(expected a metadata node)",
          Op->getOperand(2));
    break;
  }
  }
 
  // Unless this is a "requires" flag, check the ID is unique.
  if (MFB != Module::Require) {
    bool Inserted = SeenIDs.insert(std::make_pair(ID, Op)).second;
    Check(Inserted,
          "module flag identifiers must be unique (or of 'require' type)", ID);
  }
 
  StringRef Name = ID->getString();
  if (Name == "wchar_size") {
    ConstantInt *Value
      = mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2));
    Check(Value, "wchar_size metadata requires constant integer argument");
    return;
  }
 
  if (Name == "long-double-type") {
    Check(MFB == Module::Error,
          "long-double-type module flag must use 'error' merge behavior", Op);
    const MDString *Value = dyn_cast_or_null<MDString>(Op->getOperand(2));
    Check(Value, "long-double-type metadata requires a string argument");
    if (Value)
      Check(parseLongDoubleFormat(Value->getString()).has_value(),
            "invalid long-double-type metadata value", Op);
    return;
  }
 
  if (Name == "float-abi") {
    Check(MFB == Module::Error,
          "float-abi module flag must use 'error' merge behavior", Op);
    const MDString *Value = dyn_cast_or_null<MDString>(Op->getOperand(2));
    Check(Value, "float-abi metadata requires a string argument");
    if (Value)
      Check(FloatABI::parseABIType(Value->getString()).has_value(),
            "invalid float-abi metadata value", Op);
    return;
  }
 
  if (Name == "target-abi") {
    const MDString *Value = dyn_cast_or_null<MDString>(Op->getOperand(2));
    Check(Value && !Value->getString().empty(),
          "target-abi metadata requires a non-empty string argument", Op);
    return;
  }
 
  if (Name == "Linker Options") {
    // If the llvm.linker.options named metadata exists, we assume that the
    // bitcode reader has upgraded the module flag. Otherwise the flag might
    // have been created by a client directly.
    Check(M.getNamedMetadata("llvm.linker.options"),
          "'Linker Options' named metadata no longer supported");
    return;
  }
 
  if (Name == "SemanticInterposition") {
    ConstantInt *Value =
        mdconst::dyn_extract_or_null<ConstantInt>(Op->getOperand(2));
    Check(Value,
          "SemanticInterposition metadata requires constant integer argument");
    return;
  }
 
  if (Name == "CG Profile") {
    for (const MDOperand &MDO : cast<MDNode>(Op->getOperand(2))->operands())
      visitModuleFlagCGProfileEntry(MDO);
    return;
  }
 
  // Target-specific module flag checks.
  verifyAMDGPUModuleFlag(*this, ID, MFB, Op);
}
 
void Verifier::visitModuleFlagCGProfileEntry(const MDOperand &MDO) {
  auto CheckFunction = [&](const MDOperand &FuncMDO) {
    if (!FuncMDO)
      return;
    auto F = dyn_cast<ValueAsMetadata>(FuncMDO);
    Check(F && isa<Function>(F->getValue()->stripPointerCasts()),
          "expected a Function or null", FuncMDO);
  };
  auto Node = dyn_cast_or_null<MDNode>(MDO);
  Check(Node && Node->getNumOperands() == 3, "expected a MDNode triple", MDO);
  CheckFunction(Node->getOperand(0));
  CheckFunction(Node->getOperand(1));
  auto Count = dyn_cast_or_null<ConstantAsMetadata>(Node->getOperand(2));
  Check(Count && Count->getType()->isIntegerTy(),
        "expected an integer constant", Node->getOperand(2));
}
 
void Verifier::verifyAttributeTypes(AttributeSet Attrs, const Value *V) {
  for (Attribute A : Attrs) {
 
    if (A.isStringAttribute()) {
#define GET_ATTR_NAMES
#define ATTRIBUTE_ENUM(ENUM_NAME, DISPLAY_NAME)
#define ATTRIBUTE_STRBOOL(ENUM_NAME, DISPLAY_NAME)                             \
  if (A.getKindAsString() == #DISPLAY_NAME) {                                  \
    auto V = A.getValueAsString();                                             \
    if (!(V.empty() || V == "true" || V == "false"))                           \
      CheckFailed("invalid value for '" #DISPLAY_NAME "' attribute: " + V +    \
                  "");                                                         \
  }
 
#include "llvm/IR/Attributes.inc"
      continue;
    }
 
    if (A.isIntAttribute() != Attribute::isIntAttrKind(A.getKindAsEnum())) {
      CheckFailed("Attribute '" + A.getAsString() + "' should have an Argument",
                  V);
      return;
    }
  }
}
 
// VerifyParameterAttrs - Check the given attributes for an argument or return
// value of the specified type.  The value V is printed in error messages.
void Verifier::verifyParameterAttrs(AttributeSet Attrs, Type *Ty,
                                    const Value *V) {
  if (!Attrs.hasAttributes())
    return;
 
  verifyAttributeTypes(Attrs, V);
 
  for (Attribute Attr : Attrs)
    Check(Attr.isStringAttribute() ||
              Attribute::canUseAsParamAttr(Attr.getKindAsEnum()),
          "Attribute '" + Attr.getAsString() + "' does not apply to parameters",
          V);
 
  if (Attrs.hasAttribute(Attribute::ImmArg)) {
    unsigned AttrCount =
        Attrs.getNumAttributes() - Attrs.hasAttribute(Attribute::Range);
    Check(AttrCount == 1,
          "Attribute 'immarg' is incompatible with other attributes except the "
          "'range' attribute",
          V);
  }
 
  // Check for mutually incompatible attributes.  Only inreg is compatible with
  // sret.
  unsigned AttrCount = 0;
  AttrCount += Attrs.hasAttribute(Attribute::ByVal);
  AttrCount += Attrs.hasAttribute(Attribute::InAlloca);
  AttrCount += Attrs.hasAttribute(Attribute::Preallocated);
  AttrCount += Attrs.hasAttribute(Attribute::StructRet) ||
               Attrs.hasAttribute(Attribute::InReg);
  AttrCount += Attrs.hasAttribute(Attribute::Nest);
  AttrCount += Attrs.hasAttribute(Attribute::ByRef);
  Check(AttrCount <= 1,
        "Attributes 'byval', 'inalloca', 'preallocated', 'inreg', 'nest', "
        "'byref', and 'sret' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::InAlloca) &&
          Attrs.hasAttribute(Attribute::ReadOnly)),
        "Attributes "
        "'inalloca and readonly' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::StructRet) &&
          Attrs.hasAttribute(Attribute::Returned)),
        "Attributes "
        "'sret and returned' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::ZExt) &&
          Attrs.hasAttribute(Attribute::SExt)),
        "Attributes "
        "'zeroext and signext' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::ReadNone) &&
          Attrs.hasAttribute(Attribute::ReadOnly)),
        "Attributes "
        "'readnone and readonly' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::ReadNone) &&
          Attrs.hasAttribute(Attribute::WriteOnly)),
        "Attributes "
        "'readnone and writeonly' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::ReadOnly) &&
          Attrs.hasAttribute(Attribute::WriteOnly)),
        "Attributes "
        "'readonly and writeonly' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::NoInline) &&
          Attrs.hasAttribute(Attribute::AlwaysInline)),
        "Attributes "
        "'noinline and alwaysinline' are incompatible!",
        V);
 
  Check(!(Attrs.hasAttribute(Attribute::Writable) &&
          Attrs.hasAttribute(Attribute::ReadNone)),
        "Attributes writable and readnone are incompatible!", V);
 
  Check(!(Attrs.hasAttribute(Attribute::Writable) &&
          Attrs.hasAttribute(Attribute::ReadOnly)),
        "Attributes writable and readonly are incompatible!", V);
 
  AttributeMask IncompatibleAttrs = AttributeFuncs::typeIncompatible(Ty, Attrs);
  for (Attribute Attr : Attrs) {
    if (!Attr.isStringAttribute() &&
        IncompatibleAttrs.contains(Attr.getKindAsEnum())) {
      CheckFailed("Attribute '" + Attr.getAsString() +
                  "' applied to incompatible type!", V);
      return;
    }
  }
 
  if (isa<PointerType>(Ty)) {
    if (Attrs.hasAttribute(Attribute::Alignment)) {
      Align AttrAlign = Attrs.getAlignment().valueOrOne();
      Check(AttrAlign.value() <= Value::MaximumAlignment,
            "huge alignment values are unsupported", V);
    }
    if (Attrs.hasAttribute(Attribute::ByVal)) {
      Type *ByValTy = Attrs.getByValType();
      SmallPtrSet<Type *, 4> Visited;
      Check(ByValTy->isSized(&Visited),
            "Attribute 'byval' does not support unsized types!", V);
      // Check if it is or contains a target extension type that disallows being
      // used on the stack.
      Check(!ByValTy->containsNonLocalTargetExtType(),
            "'byval' argument has illegal target extension type", V);
      Check(DL.getTypeAllocSize(ByValTy).getKnownMinValue() < (1ULL << 32),
            "huge 'byval' arguments are unsupported", V);
    }
    if (Attrs.hasAttribute(Attribute::ByRef)) {
      SmallPtrSet<Type *, 4> Visited;
      Check(Attrs.getByRefType()->isSized(&Visited),
            "Attribute 'byref' does not support unsized types!", V);
      Check(DL.getTypeAllocSize(Attrs.getByRefType()).getKnownMinValue() <
                (1ULL << 32),
            "huge 'byref' arguments are unsupported", V);
    }
    if (Attrs.hasAttribute(Attribute::InAlloca)) {
      SmallPtrSet<Type *, 4> Visited;
      Check(Attrs.getInAllocaType()->isSized(&Visited),
            "Attribute 'inalloca' does not support unsized types!", V);
      Check(DL.getTypeAllocSize(Attrs.getInAllocaType()).getKnownMinValue() <
                (1ULL << 32),
            "huge 'inalloca' arguments are unsupported", V);
    }
    if (Attrs.hasAttribute(Attribute::Preallocated)) {
      SmallPtrSet<Type *, 4> Visited;
      Check(Attrs.getPreallocatedType()->isSized(&Visited),
            "Attribute 'preallocated' does not support unsized types!", V);
      Check(
          DL.getTypeAllocSize(Attrs.getPreallocatedType()).getKnownMinValue() <
              (1ULL << 32),
          "huge 'preallocated' arguments are unsupported", V);
    }
  }
 
  if (Attrs.hasAttribute(Attribute::Initializes)) {
    auto Inits = Attrs.getAttribute(Attribute::Initializes).getInitializes();
    Check(!Inits.empty(), "Attribute 'initializes' does not support empty list",
          V);
    Check(ConstantRangeList::isOrderedRanges(Inits),
          "Attribute 'initializes' does not support unordered ranges", V);
  }
 
  if (Attrs.hasAttribute(Attribute::NoFPClass)) {
    uint64_t Val = Attrs.getAttribute(Attribute::NoFPClass).getValueAsInt();
    Check(Val != 0, "Attribute 'nofpclass' must have at least one test bit set",
          V);
    Check((Val & ~static_cast<unsigned>(fcAllFlags)) == 0,
          "Invalid value for 'nofpclass' test mask", V);
  }
  if (Attrs.hasAttribute(Attribute::Range)) {
    const ConstantRange &CR =
        Attrs.getAttribute(Attribute::Range).getValueAsConstantRange();
    Check(Ty->isIntOrIntVectorTy(CR.getBitWidth()),
          "Range bit width must match type bit width!", V);
  }
}
 
void Verifier::checkUnsignedBaseTenFuncAttr(AttributeList Attrs, StringRef Attr,
                                            const Value *V) {
  if (Attrs.hasFnAttr(Attr)) {
    StringRef S = Attrs.getFnAttr(Attr).getValueAsString();
    unsigned N;
    if (S.getAsInteger(10, N))
      CheckFailed("\"" + Attr + "\" takes an unsigned integer: " + S, V);
  }
}
 
// Check parameter attributes against a function type.
// The value V is printed in error messages.
void Verifier::verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
                                   const Value *V, bool IsIntrinsic,
                                   bool IsInlineAsm) {
  if (Attrs.isEmpty())
    return;
 
  if (AttributeListsVisited.insert(Attrs.getRawPointer()).second) {
    Check(Attrs.hasParentContext(Context),
          "Attribute list does not match Module context!", &Attrs, V);
    for (const auto &AttrSet : Attrs) {
      Check(!AttrSet.hasAttributes() || AttrSet.hasParentContext(Context),
            "Attribute set does not match Module context!", &AttrSet, V);
      for (const auto &A : AttrSet) {
        Check(A.hasParentContext(Context),
              "Attribute does not match Module context!", &A, V);
      }
    }
  }
 
  bool SawNest = false;
  bool SawReturned = false;
  bool SawSRet = false;
  bool SawSwiftSelf = false;
  bool SawSwiftAsync = false;
  bool SawSwiftError = false;
 
  // Verify return value attributes.
  AttributeSet RetAttrs = Attrs.getRetAttrs();
  for (Attribute RetAttr : RetAttrs)
    Check(RetAttr.isStringAttribute() ||
              Attribute::canUseAsRetAttr(RetAttr.getKindAsEnum()),
          "Attribute '" + RetAttr.getAsString() +
              "' does not apply to function return values",
          V);
 
  unsigned MaxParameterWidth = 0;
  auto GetMaxParameterWidth = [&MaxParameterWidth](Type *Ty) {
    if (Ty->isVectorTy()) {
      if (auto *VT = dyn_cast<FixedVectorType>(Ty)) {
        unsigned Size = VT->getPrimitiveSizeInBits().getFixedValue();
        if (Size > MaxParameterWidth)
          MaxParameterWidth = Size;
      }
    }
  };
  GetMaxParameterWidth(FT->getReturnType());
  verifyParameterAttrs(RetAttrs, FT->getReturnType(), V);
 
  // Verify parameter attributes.
  for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
    Type *Ty = FT->getParamType(i);
    AttributeSet ArgAttrs = Attrs.getParamAttrs(i);
 
    if (!IsIntrinsic) {
      Check(!ArgAttrs.hasAttribute(Attribute::ImmArg),
            "immarg attribute only applies to intrinsics", V);
      if (!IsInlineAsm)
        Check(!ArgAttrs.hasAttribute(Attribute::ElementType),
              "Attribute 'elementtype' can only be applied to intrinsics"
              " and inline asm.",
              V);
    }
 
    verifyParameterAttrs(ArgAttrs, Ty, V);
    GetMaxParameterWidth(Ty);
 
    if (ArgAttrs.hasAttribute(Attribute::Nest)) {
      Check(!SawNest, "More than one parameter has attribute nest!", V);
      SawNest = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::Returned)) {
      Check(!SawReturned, "More than one parameter has attribute returned!", V);
      Check(Ty->canLosslesslyBitCastTo(FT->getReturnType()),
            "Incompatible argument and return types for 'returned' attribute",
            V);
      SawReturned = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::StructRet)) {
      Check(!SawSRet, "Cannot have multiple 'sret' parameters!", V);
      Check(i == 0 || i == 1,
            "Attribute 'sret' is not on first or second parameter!", V);
      SawSRet = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::SwiftSelf)) {
      Check(!SawSwiftSelf, "Cannot have multiple 'swiftself' parameters!", V);
      SawSwiftSelf = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::SwiftAsync)) {
      Check(!SawSwiftAsync, "Cannot have multiple 'swiftasync' parameters!", V);
      SawSwiftAsync = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::SwiftError)) {
      Check(!SawSwiftError, "Cannot have multiple 'swifterror' parameters!", V);
      SawSwiftError = true;
    }
 
    if (ArgAttrs.hasAttribute(Attribute::InAlloca)) {
      Check(i == FT->getNumParams() - 1,
            "inalloca isn't on the last parameter!", V);
    }
  }
 
  if (!Attrs.hasFnAttrs())
    return;
 
  verifyAttributeTypes(Attrs.getFnAttrs(), V);
  for (Attribute FnAttr : Attrs.getFnAttrs())
    Check(FnAttr.isStringAttribute() ||
              Attribute::canUseAsFnAttr(FnAttr.getKindAsEnum()),
          "Attribute '" + FnAttr.getAsString() +
              "' does not apply to functions!",
          V);
 
  Check(!(Attrs.hasFnAttr(Attribute::NoInline) &&
          Attrs.hasFnAttr(Attribute::AlwaysInline)),
        "Attributes 'noinline and alwaysinline' are incompatible!", V);
 
  if (Attrs.hasFnAttr(Attribute::OptimizeNone)) {
    Check(Attrs.hasFnAttr(Attribute::NoInline),
          "Attribute 'optnone' requires 'noinline'!", V);
 
    Check(!Attrs.hasFnAttr(Attribute::OptimizeForSize),
          "Attributes 'optsize and optnone' are incompatible!", V);
 
    Check(!Attrs.hasFnAttr(Attribute::MinSize),
          "Attributes 'minsize and optnone' are incompatible!", V);
 
    Check(!Attrs.hasFnAttr(Attribute::OptimizeForDebugging),
          "Attributes 'optdebug and optnone' are incompatible!", V);
  }
 
  Check(!(Attrs.hasFnAttr(Attribute::SanitizeRealtime) &&
          Attrs.hasFnAttr(Attribute::SanitizeRealtimeBlocking)),
        "Attributes "
        "'sanitize_realtime and sanitize_realtime_blocking' are incompatible!",
        V);
 
  if (Attrs.hasFnAttr(Attribute::OptimizeForDebugging)) {
    Check(!Attrs.hasFnAttr(Attribute::OptimizeForSize),
          "Attributes 'optsize and optdebug' are incompatible!", V);
 
    Check(!Attrs.hasFnAttr(Attribute::MinSize),
          "Attributes 'minsize and optdebug' are incompatible!", V);
  }
 
  Check(!Attrs.hasAttrSomewhere(Attribute::Writable) ||
        isModSet(Attrs.getMemoryEffects().getModRef(IRMemLocation::ArgMem)),
        "Attribute writable and memory without argmem: write are incompatible!",
        V);
 
  if (Attrs.hasFnAttr("aarch64_pstate_sm_enabled")) {
    Check(!Attrs.hasFnAttr("aarch64_pstate_sm_compatible"),
           "Attributes 'aarch64_pstate_sm_enabled and "
           "aarch64_pstate_sm_compatible' are incompatible!",
           V);
  }
 
  Check((Attrs.hasFnAttr("aarch64_new_za") + Attrs.hasFnAttr("aarch64_in_za") +
         Attrs.hasFnAttr("aarch64_inout_za") +
         Attrs.hasFnAttr("aarch64_out_za") +
         Attrs.hasFnAttr("aarch64_preserves_za") +
         Attrs.hasFnAttr("aarch64_za_state_agnostic")) <= 1,
        "Attributes 'aarch64_new_za', 'aarch64_in_za', 'aarch64_out_za', "
        "'aarch64_inout_za', 'aarch64_preserves_za' and "
        "'aarch64_za_state_agnostic' are mutually exclusive",
        V);
 
  Check((Attrs.hasFnAttr("aarch64_new_zt0") +
         Attrs.hasFnAttr("aarch64_in_zt0") +
         Attrs.hasFnAttr("aarch64_inout_zt0") +
         Attrs.hasFnAttr("aarch64_out_zt0") +
         Attrs.hasFnAttr("aarch64_preserves_zt0") +
         Attrs.hasFnAttr("aarch64_za_state_agnostic")) <= 1,
        "Attributes 'aarch64_new_zt0', 'aarch64_in_zt0', 'aarch64_out_zt0', "
        "'aarch64_inout_zt0', 'aarch64_preserves_zt0' and "
        "'aarch64_za_state_agnostic' are mutually exclusive",
        V);
 
  if (Attrs.hasFnAttr(Attribute::JumpTable)) {
    const GlobalValue *GV = cast<GlobalValue>(V);
    Check(GV->hasGlobalUnnamedAddr(),
          "Attribute 'jumptable' requires 'unnamed_addr'", V);
  }
 
  if (auto Args = Attrs.getFnAttrs().getAllocSizeArgs()) {
    auto CheckParam = [&](StringRef Name, unsigned ParamNo) {
      if (ParamNo >= FT->getNumParams()) {
        CheckFailed("'allocsize' " + Name + " argument is out of bounds", V);
        return false;
      }
 
      if (!FT->getParamType(ParamNo)->isIntegerTy()) {
        CheckFailed("'allocsize' " + Name +
                        " argument must refer to an integer parameter",
                    V);
        return false;
      }
 
      return true;
    };
 
    if (!CheckParam("element size", Args->first))
      return;
 
    if (Args->second && !CheckParam("number of elements", *Args->second))
      return;
  }
 
  if (Attrs.hasFnAttr(Attribute::AllocKind)) {
    AllocFnKind K = Attrs.getAllocKind();
    AllocFnKind Type =
        K & (AllocFnKind::Alloc | AllocFnKind::Realloc | AllocFnKind::Free);
    if (!is_contained(
            {AllocFnKind::Alloc, AllocFnKind::Realloc, AllocFnKind::Free},
            Type))
      CheckFailed(
          "'allockind()' requires exactly one of alloc, realloc, and free");
    if ((Type == AllocFnKind::Free) &&
        ((K & (AllocFnKind::Uninitialized | AllocFnKind::Zeroed |
               AllocFnKind::Aligned)) != AllocFnKind::Unknown))
      CheckFailed("'allockind(\"free\")' doesn't allow uninitialized, zeroed, "
                  "or aligned modifiers.");
    AllocFnKind ZeroedUninit = AllocFnKind::Uninitialized | AllocFnKind::Zeroed;
    if ((K & ZeroedUninit) == ZeroedUninit)
      CheckFailed("'allockind()' can't be both zeroed and uninitialized");
  }
 
  if (Attribute A = Attrs.getFnAttr("alloc-variant-zeroed"); A.isValid()) {
    StringRef S = A.getValueAsString();
    Check(!S.empty(), "'alloc-variant-zeroed' must not be empty");
    Function *Variant = M.getFunction(S);
    if (Variant) {
      Attribute Family = Attrs.getFnAttr("alloc-family");
      Attribute VariantFamily = Variant->getFnAttribute("alloc-family");
      if (Family.isValid())
        Check(VariantFamily.isValid() &&
                  VariantFamily.getValueAsString() == Family.getValueAsString(),
              "'alloc-variant-zeroed' must name a function belonging to the "
              "same 'alloc-family'");
 
      Check(Variant->hasFnAttribute(Attribute::AllocKind) &&
                (Variant->getFnAttribute(Attribute::AllocKind).getAllocKind() &
                 AllocFnKind::Zeroed) != AllocFnKind::Unknown,
            "'alloc-variant-zeroed' must name a function with "
            "'allockind(\"zeroed\")'");
 
      Check(FT == Variant->getFunctionType(),
            "'alloc-variant-zeroed' must name a function with the same "
            "signature");
 
      if (const auto *F = dyn_cast<Function>(V))
        Check(F->getCallingConv() == Variant->getCallingConv(),
              "'alloc-variant-zeroed' must name a function with the same "
              "calling convention");
    }
  }
 
  if (Attrs.hasFnAttr(Attribute::VScaleRange)) {
    unsigned VScaleMin = Attrs.getFnAttrs().getVScaleRangeMin();
    if (VScaleMin == 0)
      CheckFailed("'vscale_range' minimum must be greater than 0", V);
    else if (!isPowerOf2_32(VScaleMin))
      CheckFailed("'vscale_range' minimum must be power-of-two value", V);
    std::optional<unsigned> VScaleMax = Attrs.getFnAttrs().getVScaleRangeMax();
    if (VScaleMax && VScaleMin > VScaleMax)
      CheckFailed("'vscale_range' minimum cannot be greater than maximum", V);
    else if (VScaleMax && !isPowerOf2_32(*VScaleMax))
      CheckFailed("'vscale_range' maximum must be power-of-two value", V);
  }
 
  if (Attribute FPAttr = Attrs.getFnAttr("frame-pointer"); FPAttr.isValid()) {
    StringRef FP = FPAttr.getValueAsString();
    if (FP != "all" && FP != "non-leaf" && FP != "none" && FP != "reserved" &&
        FP != "non-leaf-no-reserve")
      CheckFailed("invalid value for 'frame-pointer' attribute: " + FP, V);
  }
 
  checkUnsignedBaseTenFuncAttr(Attrs, "tail-pad-to-size", V);
  checkUnsignedBaseTenFuncAttr(Attrs, "tail-pad-value", V);
  checkUnsignedBaseTenFuncAttr(Attrs, "patchable-function-prefix", V);
  checkUnsignedBaseTenFuncAttr(Attrs, "patchable-function-entry", V);
  if (Attrs.hasFnAttr("patchable-function-entry-section"))
    Check(!Attrs.getFnAttr("patchable-function-entry-section")
               .getValueAsString()
               .empty(),
          "\"patchable-function-entry-section\" must not be empty");
  checkUnsignedBaseTenFuncAttr(Attrs, "warn-stack-size", V);
 
  if (auto A = Attrs.getFnAttr("sign-return-address"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (S != "none" && S != "all" && S != "non-leaf")
      CheckFailed("invalid value for 'sign-return-address' attribute: " + S, V);
  }
 
  if (auto A = Attrs.getFnAttr("sign-return-address-key"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (S != "a_key" && S != "b_key")
      CheckFailed("invalid value for 'sign-return-address-key' attribute: " + S,
                  V);
    if (auto AA = Attrs.getFnAttr("sign-return-address"); !AA.isValid()) {
      CheckFailed(
          "'sign-return-address-key' present without `sign-return-address`");
    }
  }
 
  if (auto A = Attrs.getFnAttr("branch-target-enforcement"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (S != "" && S != "true" && S != "false")
      CheckFailed(
          "invalid value for 'branch-target-enforcement' attribute: " + S, V);
  }
 
  if (auto A = Attrs.getFnAttr("branch-protection-pauth-lr"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (S != "" && S != "true" && S != "false")
      CheckFailed(
          "invalid value for 'branch-protection-pauth-lr' attribute: " + S, V);
  }
 
  if (auto A = Attrs.getFnAttr("guarded-control-stack"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (S != "" && S != "true" && S != "false")
      CheckFailed("invalid value for 'guarded-control-stack' attribute: " + S,
                  V);
  }
 
  if (auto A = Attrs.getFnAttr("vector-function-abi-variant"); A.isValid()) {
    StringRef S = A.getValueAsString();
    const std::optional<VFInfo> Info = VFABI::tryDemangleForVFABI(S, FT);
    if (!Info)
      CheckFailed("invalid name for a VFABI variant: " + S, V);
  }
 
  if (auto A = Attrs.getFnAttr("modular-format"); A.isValid()) {
    StringRef S = A.getValueAsString();
    SmallVector<StringRef> Args;
    S.split(Args, ',');
    Check(Args.size() >= 5,
          "modular-format attribute requires at least 5 arguments", V);
    unsigned UpperBound = FT->getNumParams() + (FT->isVarArg() ? 1 : 0);
    unsigned FormatIdx;
    Check(!Args[1].getAsInteger(10, FormatIdx),
          "modular-format attribute format string index is not an integer", V);
    Check(FormatIdx > 0,
          "modular-format attribute format string index must be greater than 0",
          V);
    Check(FormatIdx <= UpperBound,
          "modular-format attribute format string index is out of bounds", V);
    unsigned FirstArgIdx;
    Check(!Args[2].getAsInteger(10, FirstArgIdx),
          "modular-format attribute first arg index is not an integer", V);
    Check(FirstArgIdx <= UpperBound,
          "modular-format attribute first arg index is out of bounds", V);
    Check(!Args[3].empty(),
          "modular-format attribute modular implementation function name "
          "cannot be empty",
          V);
    Check(!Args[4].empty(),
          "modular-format attribute implementation name cannot be empty", V);
  }
 
  if (auto A = Attrs.getFnAttr("target-features"); A.isValid()) {
    StringRef S = A.getValueAsString();
    if (!S.empty()) {
      for (auto FeatureFlag : split(S, ',')) {
        if (FeatureFlag.empty())
          CheckFailed(
              "target-features attribute should not contain an empty string");
        else
          Check(FeatureFlag[0] == '+' || FeatureFlag[0] == '-',
                "target feature '" + FeatureFlag +
                    "' must start with a '+' or '-'",
                V);
      }
    }
  }
}
void Verifier::verifyUnknownProfileMetadata(MDNode *MD) {
  Check(MD->getNumOperands() == 2,
        "'unknown' !prof should have a single additional operand", MD);
  auto *PassName = dyn_cast<MDString>(MD->getOperand(1));
  Check(PassName != nullptr,
        "'unknown' !prof should have an additional operand of type "
        "string");
  Check(!PassName->getString().empty(),
        "the 'unknown' !prof operand should not be an empty string");
}
 
void Verifier::verifyFunctionMetadata(
    ArrayRef<std::pair<unsigned, MDNode *>> MDs) {
  for (const auto &Pair : MDs) {
    if (Pair.first == LLVMContext::MD_prof) {
      MDNode *MD = Pair.second;
      Check(MD->getNumOperands() >= 2,
            "!prof annotations should have no less than 2 operands", MD);
      // We may have functions that are synthesized by the compiler, e.g. in
      // WPD, that we can't currently determine the entry count.
      if (MD->getOperand(0).equalsStr(
              MDProfLabels::UnknownBranchWeightsMarker)) {
        verifyUnknownProfileMetadata(MD);
        continue;
      }
 
      // Check first operand.
      Check(MD->getOperand(0) != nullptr, "first operand should not be null",
            MD);
      Check(isa<MDString>(MD->getOperand(0)),
            "expected string with name of the !prof annotation", MD);
      MDString *MDS = cast<MDString>(MD->getOperand(0));
      StringRef ProfName = MDS->getString();
      Check(ProfName == MDProfLabels::FunctionEntryCount ||
                ProfName == MDProfLabels::SyntheticFunctionEntryCount,
            "first operand should be 'function_entry_count'"
            " or 'synthetic_function_entry_count'",
            MD);
 
      // Check second operand.
      Check(MD->getOperand(1) != nullptr, "second operand should not be null",
            MD);
      Check(isa<ConstantAsMetadata>(MD->getOperand(1)),
            "expected integer argument to function_entry_count", MD);
    } else if (Pair.first == LLVMContext::MD_kcfi_type) {
      MDNode *MD = Pair.second;
      Check(MD->getNumOperands() == 1,
            "!kcfi_type must have exactly one operand", MD);
      Check(MD->getOperand(0) != nullptr, "!kcfi_type operand must not be null",
            MD);
      Check(isa<ConstantAsMetadata>(MD->getOperand(0)),
            "expected a constant operand for !kcfi_type", MD);
      Constant *C = cast<ConstantAsMetadata>(MD->getOperand(0))->getValue();
      Check(isa<ConstantInt>(C) && isa<IntegerType>(C->getType()),
            "expected a constant integer operand for !kcfi_type", MD);
      Check(cast<ConstantInt>(C)->getBitWidth() == 32,
            "expected a 32-bit integer constant operand for !kcfi_type", MD);
    } else if (Pair.first == Context.getMDKindID("reqd_work_group_size")) {
      MDNode *MD = Pair.second;
      Check(MD->getNumOperands() == 3,
            "reqd_work_group_size must have exactly three operands", MD);
      if (MD->getNumOperands() != 3)
        continue;
 
      uint64_t Product = 1;
      for (unsigned I = 0; I != 3; ++I) {
        ConstantInt *C = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
        Check(C, "reqd_work_group_size operands must be integer constants", MD);
        if (!C)
          break;
 
        const APInt &Value = C->getValue();
        Check(Value.getActiveBits() <= 64,
              "reqd_work_group_size operands must fit in 64 bits", MD);
        if (Value.getActiveBits() > 64)
          break;
 
        uint64_t Dim = Value.getZExtValue();
        Check(Dim == 0 || Product <= std::numeric_limits<uint64_t>::max() / Dim,
              "reqd_work_group_size product must fit in 64 bits", MD);
        if (Dim != 0 && Product > std::numeric_limits<uint64_t>::max() / Dim)
          break;
        Product *= Dim;
      }
    }
  }
}
 
void Verifier::visitConstantExprsRecursively(const Constant *EntryC) {
  if (EntryC->getNumOperands() == 0)
    return;
 
  if (!ConstantExprVisited.insert(EntryC).second)
    return;
 
  SmallVector<const Constant *, 16> Stack;
  Stack.push_back(EntryC);
 
  while (!Stack.empty()) {
    const Constant *C = Stack.pop_back_val();
 
    // Check this constant expression.
    if (const auto *CE = dyn_cast<ConstantExpr>(C))
      visitConstantExpr(CE);
 
    if (const auto *CPA = dyn_cast<ConstantPtrAuth>(C))
      visitConstantPtrAuth(CPA);
 
    if (const auto *GV = dyn_cast<GlobalValue>(C)) {
      // Global Values get visited separately, but we do need to make sure
      // that the global value is in the correct module
      Check(GV->getParent() == &M, "Referencing global in another module!",
            EntryC, &M, GV, GV->getParent());
      continue;
    }
 
    // Visit all sub-expressions.
    for (const Use &U : C->operands()) {
      const auto *OpC = dyn_cast<Constant>(U);
      if (!OpC)
        continue;
      if (!ConstantExprVisited.insert(OpC).second)
        continue;
      Stack.push_back(OpC);
    }
  }
}
 
void Verifier::visitConstantExpr(const ConstantExpr *CE) {
  if (CE->getOpcode() == Instruction::BitCast)
    Check(CastInst::castIsValid(Instruction::BitCast, CE->getOperand(0),
                                CE->getType()),
          "Invalid bitcast", CE);
  else if (CE->getOpcode() == Instruction::PtrToAddr)
    checkPtrToAddr(CE->getOperand(0)->getType(), CE->getType(), *CE);
}
 
void Verifier::visitConstantPtrAuth(const ConstantPtrAuth *CPA) {
  Check(CPA->getPointer()->getType()->isPointerTy(),
        "signed ptrauth constant base pointer must have pointer type");
 
  Check(CPA->getType() == CPA->getPointer()->getType(),
        "signed ptrauth constant must have same type as its base pointer");
 
  Check(CPA->getKey()->getBitWidth() == 32,
        "signed ptrauth constant key must be i32 constant integer");
 
  Check(CPA->getAddrDiscriminator()->getType()->isPointerTy(),
        "signed ptrauth constant address discriminator must be a pointer");
 
  Check(CPA->getDiscriminator()->getBitWidth() == 64,
        "signed ptrauth constant discriminator must be i64 constant integer");
 
  Check(CPA->getDeactivationSymbol()->getType()->isPointerTy(),
        "signed ptrauth constant deactivation symbol must be a pointer");
 
  Check(isa<GlobalValue>(CPA->getDeactivationSymbol()) ||
            isa<ConstantPointerNull>(CPA->getDeactivationSymbol()),
        "signed ptrauth constant deactivation symbol must be a global value "
        "or null");
}
 
bool Verifier::verifyAttributeCount(AttributeList Attrs, unsigned Params) {
  // There shouldn't be more attribute sets than there are parameters plus the
  // function and return value.
  return Attrs.getNumAttrSets() <= Params + 2;
}
 
void Verifier::verifyInlineAsmCall(const CallBase &Call) {
  const InlineAsm *IA = cast<InlineAsm>(Call.getCalledOperand());
  unsigned ArgNo = 0;
  unsigned LabelNo = 0;
  for (const InlineAsm::ConstraintInfo &CI : IA->ParseConstraints()) {
    if (CI.Type == InlineAsm::isLabel) {
      ++LabelNo;
      continue;
    }
 
    // Only deal with constraints that correspond to call arguments.
    if (!CI.hasArg())
      continue;
 
    if (CI.isIndirect) {
      const Value *Arg = Call.getArgOperand(ArgNo);
      Check(Arg->getType()->isPointerTy(),
            "Operand for indirect constraint must have pointer type", &Call);
 
      Check(Call.getParamElementType(ArgNo),
            "Operand for indirect constraint must have elementtype attribute",
            &Call);
    } else {
      Check(!Call.paramHasAttr(ArgNo, Attribute::ElementType),
            "Elementtype attribute can only be applied for indirect "
            "constraints",
            &Call);
    }
 
    ArgNo++;
  }
 
  if (auto *CallBr = dyn_cast<CallBrInst>(&Call)) {
    Check(LabelNo == CallBr->getNumIndirectDests(),
          "Number of label constraints does not match number of callbr dests",
          &Call);
  } else {
    Check(LabelNo == 0, "Label constraints can only be used with callbr",
          &Call);
  }
}
 
/// Verify that statepoint intrinsic is well formed.
void Verifier::verifyStatepoint(const CallBase &Call) {
  assert(Call.getIntrinsicID() == Intrinsic::experimental_gc_statepoint);
 
  Check(!Call.doesNotAccessMemory() && !Call.onlyReadsMemory() &&
            !Call.onlyAccessesArgMemory(),
        "gc.statepoint must read and write all memory to preserve "
        "reordering restrictions required by safepoint semantics",
        Call);
 
  const int64_t NumPatchBytes =
      cast<ConstantInt>(Call.getArgOperand(1))->getSExtValue();
  assert(isInt<32>(NumPatchBytes) && "NumPatchBytesV is an i32!");
  Check(NumPatchBytes >= 0,
        "gc.statepoint number of patchable bytes must be "
        "positive",
        Call);
 
  Type *TargetElemType = Call.getParamElementType(2);
  Check(TargetElemType,
        "gc.statepoint callee argument must have elementtype attribute", Call);
  auto *TargetFuncType = dyn_cast<FunctionType>(TargetElemType);
  Check(TargetFuncType,
        "gc.statepoint callee elementtype must be function type", Call);
 
  const int NumCallArgs = cast<ConstantInt>(Call.getArgOperand(3))->getZExtValue();
  Check(NumCallArgs >= 0,
        "gc.statepoint number of arguments to underlying call "
        "must be positive",
        Call);
  const int NumParams = (int)TargetFuncType->getNumParams();
  if (TargetFuncType->isVarArg()) {
    Check(NumCallArgs >= NumParams,
          "gc.statepoint mismatch in number of vararg call args", Call);
 
    // TODO: Remove this limitation
    Check(TargetFuncType->getReturnType()->isVoidTy(),
          "gc.statepoint doesn't support wrapping non-void "
          "vararg functions yet",
          Call);
  } else
    Check(NumCallArgs == NumParams,
          "gc.statepoint mismatch in number of call args", Call);
 
  const uint64_t Flags
    = cast<ConstantInt>(Call.getArgOperand(4))->getZExtValue();
  Check((Flags & ~(uint64_t)StatepointFlags::MaskAll) == 0,
        "unknown flag used in gc.statepoint flags argument", Call);
 
  // Verify that the types of the call parameter arguments match
  // the type of the wrapped callee.
  AttributeList Attrs = Call.getAttributes();
  for (int i = 0; i < NumParams; i++) {
    Type *ParamType = TargetFuncType->getParamType(i);
    Type *ArgType = Call.getArgOperand(5 + i)->getType();
    Check(ArgType == ParamType,
          "gc.statepoint call argument does not match wrapped "
          "function type",
          Call);
 
    if (TargetFuncType->isVarArg()) {
      AttributeSet ArgAttrs = Attrs.getParamAttrs(5 + i);
      Check(!ArgAttrs.hasAttribute(Attribute::StructRet),
            "Attribute 'sret' cannot be used for vararg call arguments!", Call);
    }
  }
 
  const int EndCallArgsInx = 4 + NumCallArgs;
 
  const Value *NumTransitionArgsV = Call.getArgOperand(EndCallArgsInx + 1);
  Check(isa<ConstantInt>(NumTransitionArgsV),
        "gc.statepoint number of transition arguments "
        "must be constant integer",
        Call);
  const int NumTransitionArgs =
      cast<ConstantInt>(NumTransitionArgsV)->getZExtValue();
  Check(NumTransitionArgs == 0,
        "gc.statepoint w/inline transition bundle is deprecated", Call);
  const int EndTransitionArgsInx = EndCallArgsInx + 1 + NumTransitionArgs;
 
  const Value *NumDeoptArgsV = Call.getArgOperand(EndTransitionArgsInx + 1);
  Check(isa<ConstantInt>(NumDeoptArgsV),
        "gc.statepoint number of deoptimization arguments "
        "must be constant integer",
        Call);
  const int NumDeoptArgs = cast<ConstantInt>(NumDeoptArgsV)->getZExtValue();
  Check(NumDeoptArgs == 0,
        "gc.statepoint w/inline deopt operands is deprecated", Call);
 
  const int ExpectedNumArgs = 7 + NumCallArgs;
  Check(ExpectedNumArgs == (int)Call.arg_size(),
        "gc.statepoint too many arguments", Call);
 
  // Check that the only uses of this gc.statepoint are gc.result or
  // gc.relocate calls which are tied to this statepoint and thus part
  // of the same statepoint sequence
  for (const User *U : Call.users()) {
    const auto *UserCall = dyn_cast<const CallInst>(U);
    Check(UserCall, "illegal use of statepoint token", Call, U);
    if (!UserCall)
      continue;
    Check(isa<GCRelocateInst>(UserCall) || isa<GCResultInst>(UserCall),
          "gc.result or gc.relocate are the only value uses "
          "of a gc.statepoint",
          Call, U);
    if (isa<GCResultInst>(UserCall)) {
      Check(UserCall->getArgOperand(0) == &Call,
            "gc.result connected to wrong gc.statepoint", Call, UserCall);
    } else if (isa<GCRelocateInst>(Call)) {
      Check(UserCall->getArgOperand(0) == &Call,
            "gc.relocate connected to wrong gc.statepoint", Call, UserCall);
    }
  }
 
  // Note: It is legal for a single derived pointer to be listed multiple
  // times.  It's non-optimal, but it is legal.  It can also happen after
  // insertion if we strip a bitcast away.
  // Note: It is really tempting to check that each base is relocated and
  // that a derived pointer is never reused as a base pointer.  This turns
  // out to be problematic since optimizations run after safepoint insertion
  // can recognize equality properties that the insertion logic doesn't know
  // about.  See example statepoint.ll in the verifier subdirectory
}
 
void Verifier::verifyFrameRecoverIndices() {
  for (auto &Counts : FrameEscapeInfo) {
    Function *F = Counts.first;
    unsigned EscapedObjectCount = Counts.second.first;
    unsigned MaxRecoveredIndex = Counts.second.second;
    Check(MaxRecoveredIndex <= EscapedObjectCount,
          "all indices passed to llvm.localrecover must be less than the "
          "number of arguments passed to llvm.localescape in the parent "
          "function",
          F);
  }
}
 
static Instruction *getSuccPad(Instruction *Terminator) {
  BasicBlock *UnwindDest;
  if (auto *II = dyn_cast<InvokeInst>(Terminator))
    UnwindDest = II->getUnwindDest();
  else if (auto *CSI = dyn_cast<CatchSwitchInst>(Terminator))
    UnwindDest = CSI->getUnwindDest();
  else
    UnwindDest = cast<CleanupReturnInst>(Terminator)->getUnwindDest();
  return &*UnwindDest->getFirstNonPHIIt();
}
 
void Verifier::verifySiblingFuncletUnwinds() {
  llvm::TimeTraceScope timeScope("Verifier verify sibling funclet unwinds");
  SmallPtrSet<Instruction *, 8> Visited;
  SmallPtrSet<Instruction *, 8> Active;
  for (const auto &Pair : SiblingFuncletInfo) {
    Instruction *PredPad = Pair.first;
    if (Visited.count(PredPad))
      continue;
    Active.insert(PredPad);
    Instruction *Terminator = Pair.second;
    do {
      Instruction *SuccPad = getSuccPad(Terminator);
      if (Active.count(SuccPad)) {
        // Found a cycle; report error
        Instruction *CyclePad = SuccPad;
        SmallVector<Instruction *, 8> CycleNodes;
        do {
          CycleNodes.push_back(CyclePad);
          Instruction *CycleTerminator = SiblingFuncletInfo[CyclePad];
          if (CycleTerminator != CyclePad)
            CycleNodes.push_back(CycleTerminator);
          CyclePad = getSuccPad(CycleTerminator);
        } while (CyclePad != SuccPad);
        Check(false, "EH pads can't handle each other's exceptions",
              ArrayRef<Instruction *>(CycleNodes));
      }
      // Don't re-walk a node we've already checked
      if (!Visited.insert(SuccPad).second)
        break;
      // Walk to this successor if it has a map entry.
      PredPad = SuccPad;
      auto TermI = SiblingFuncletInfo.find(PredPad);
      if (TermI == SiblingFuncletInfo.end())
        break;
      Terminator = TermI->second;
      Active.insert(PredPad);
    } while (true);
    // Each node only has one successor, so we've walked all the active
    // nodes' successors.
    Active.clear();
  }
}
 
// visitFunction - Verify that a function is ok.
//
void Verifier::visitFunction(const Function &F) {
  visitGlobalValue(F);
 
  // Check function arguments.
  FunctionType *FT = F.getFunctionType();
  unsigned NumArgs = F.arg_size();
 
  Check(&Context == &F.getContext(),
        "Function context does not match Module context!", &F);
 
  Check(!F.hasCommonLinkage(), "Functions may not have common linkage", &F);
  Check(FT->getNumParams() == NumArgs,
        "# formal arguments must match # of arguments for function type!", &F,
        FT);
  Check(F.getReturnType()->isFirstClassType() ||
            F.getReturnType()->isVoidTy() || F.getReturnType()->isStructTy(),
        "Functions cannot return aggregate values!", &F);
 
  Check(!F.hasStructRetAttr() || F.getReturnType()->isVoidTy(),
        "Invalid struct return type!", &F);
 
  if (MaybeAlign A = F.getAlign()) {
    Check(A->value() <= Value::MaximumAlignment,
          "huge alignment values are unsupported", &F);
  }
 
  AttributeList Attrs = F.getAttributes();
 
  Check(verifyAttributeCount(Attrs, FT->getNumParams()),
        "Attribute after last parameter!", &F);
 
  bool IsIntrinsic = F.isIntrinsic();
 
  // Check function attributes.
  verifyFunctionAttrs(FT, Attrs, &F, IsIntrinsic, /* IsInlineAsm */ false);
 
  // On function declarations/definitions, we do not support the builtin
  // attribute. We do not check this in VerifyFunctionAttrs since that is
  // checking for Attributes that can/can not ever be on functions.
  Check(!Attrs.hasFnAttr(Attribute::Builtin),
        "Attribute 'builtin' can only be applied to a callsite.", &F);
 
  Check(!Attrs.hasAttrSomewhere(Attribute::ElementType),
        "Attribute 'elementtype' can only be applied to a callsite.", &F);
 
  if (Attrs.hasFnAttr(Attribute::Naked))
    for (const Argument &Arg : F.args())
      Check(Arg.use_empty(), "cannot use argument of naked function", &Arg);
 
  // Check that this function meets the restrictions on this calling convention.
  // Sometimes varargs is used for perfectly forwarding thunks, so some of these
  // restrictions can be lifted.
  switch (F.getCallingConv()) {
  default:
  case CallingConv::C:
    break;
  case CallingConv::X86_INTR: {
    Check(F.arg_empty() || Attrs.hasParamAttr(0, Attribute::ByVal),
          "Calling convention parameter requires byval", &F);
    break;
  }
  case CallingConv::AMDGPU_KERNEL:
  case CallingConv::SPIR_KERNEL:
  case CallingConv::AMDGPU_CS_Chain:
  case CallingConv::AMDGPU_CS_ChainPreserve:
    Check(F.getReturnType()->isVoidTy(),
          "Calling convention requires void return type", &F);
    [[fallthrough]];
  case CallingConv::AMDGPU_VS:
  case CallingConv::AMDGPU_HS:
  case CallingConv::AMDGPU_GS:
  case CallingConv::AMDGPU_PS:
  case CallingConv::AMDGPU_CS:
    Check(!F.hasStructRetAttr(), "Calling convention does not allow sret", &F);
    if (F.getCallingConv() != CallingConv::SPIR_KERNEL) {
      const unsigned StackAS = DL.getAllocaAddrSpace();
      unsigned i = 0;
      for (const Argument &Arg : F.args()) {
        Check(!Attrs.hasParamAttr(i, Attribute::ByVal),
              "Calling convention disallows byval", &F);
        Check(!Attrs.hasParamAttr(i, Attribute::Preallocated),
              "Calling convention disallows preallocated", &F);
        Check(!Attrs.hasParamAttr(i, Attribute::InAlloca),
              "Calling convention disallows inalloca", &F);
 
        if (Attrs.hasParamAttr(i, Attribute::ByRef)) {
          // FIXME: Should also disallow LDS and GDS, but we don't have the enum
          // value here.
          Check(Arg.getType()->getPointerAddressSpace() != StackAS,
                "Calling convention disallows stack byref", &F);
        }
 
        ++i;
      }
    }
 
    [[fallthrough]];
  case CallingConv::Fast:
  case CallingConv::Cold:
  case CallingConv::Intel_OCL_BI:
  case CallingConv::PTX_Kernel:
  case CallingConv::PTX_Device:
    Check(!F.isVarArg(),
          "Calling convention does not support varargs or "
          "perfect forwarding!",
          &F);
    break;
  case CallingConv::AMDGPU_Gfx_WholeWave:
    Check(!F.arg_empty() && F.arg_begin()->getType()->isIntegerTy(1),
          "Calling convention requires first argument to be i1", &F);
    Check(!F.arg_begin()->hasInRegAttr(),
          "Calling convention requires first argument to not be inreg", &F);
    Check(!F.isVarArg(),
          "Calling convention does not support varargs or "
          "perfect forwarding!",
          &F);
    break;
  }
 
  // Check that the argument values match the function type for this function...
  unsigned i = 0;
  for (const Argument &Arg : F.args()) {
    Check(Arg.getType() == FT->getParamType(i),
          "Argument value does not match function argument type!", &Arg,
          FT->getParamType(i));
    Check(Arg.getType()->isFirstClassType(),
          "Function arguments must have first-class types!", &Arg);
    if (!IsIntrinsic) {
      Check(!Arg.getType()->isMetadataTy(),
            "Function takes metadata but isn't an intrinsic", &Arg, &F);
      Check(!Arg.getType()->isTokenLikeTy(),
            "Function takes token but isn't an intrinsic", &Arg, &F);
      Check(!Arg.getType()->isX86_AMXTy(),
            "Function takes x86_amx but isn't an intrinsic", &Arg, &F);
    }
 
    // Check that swifterror argument is only used by loads and stores.
    if (Attrs.hasParamAttr(i, Attribute::SwiftError)) {
      verifySwiftErrorValue(&Arg);
    }
    ++i;
  }
 
  if (!IsIntrinsic) {
    Check(!F.getReturnType()->isTokenLikeTy(),
          "Function returns a token but isn't an intrinsic", &F);
    Check(!F.getReturnType()->isX86_AMXTy(),
          "Function returns a x86_amx but isn't an intrinsic", &F);
  }
 
  // Get the function metadata attachments.
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  F.getAllMetadata(MDs);
  assert(F.hasMetadata() != MDs.empty() && "Bit out-of-sync");
  verifyFunctionMetadata(MDs);
 
  // Target-specific function metadata checks.
  verifyAMDGPUFunctionMetadata(*this, F);
 
  // Check validity of the personality function
  if (F.hasPersonalityFn()) {
    auto *Per = dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts());
    if (Per)
      Check(Per->getParent() == F.getParent(),
            "Referencing personality function in another module!", &F,
            F.getParent(), Per, Per->getParent());
  }
 
  // EH funclet coloring can be expensive, recompute on-demand
  BlockEHFuncletColors.clear();
 
  if (F.isMaterializable()) {
    // Function has a body somewhere we can't see.
    Check(MDs.empty(), "unmaterialized function cannot have metadata", &F,
          MDs.empty() ? nullptr : MDs.front().second);
  } else if (F.isDeclaration()) {
    for (const auto &I : MDs) {
      // This is used for call site debug information.
      CheckDI(I.first != LLVMContext::MD_dbg ||
                  !cast<DISubprogram>(I.second)->isDistinct(),
              "function declaration may only have a unique !dbg attachment",
              &F);
      Check(I.first != LLVMContext::MD_prof,
            "function declaration may not have a !prof attachment", &F);
 
      // Verify the metadata itself.
      visitMDNode(*I.second, AreDebugLocsAllowed::Yes);
    }
    Check(!F.hasPersonalityFn(),
          "Function declaration shouldn't have a personality routine", &F);
  } else {
    // Verify that this function (which has a body) is not named "llvm.*".  It
    // is not legal to define intrinsics.
    Check(!IsIntrinsic, "llvm intrinsics cannot be defined!", &F);
 
    // Check the entry node
    const BasicBlock *Entry = &F.getEntryBlock();
    Check(pred_empty(Entry),
          "Entry block to function must not have predecessors!", Entry);
 
    // The address of the entry block cannot be taken, unless it is dead.
    if (Entry->hasAddressTaken()) {
      Check(!BlockAddress::lookup(Entry)->isConstantUsed(),
            "blockaddress may not be used with the entry block!", Entry);
    }
 
    unsigned NumDebugAttachments = 0, NumProfAttachments = 0,
             NumKCFIAttachments = 0;
    // Visit metadata attachments.
    for (const auto &I : MDs) {
      // Verify that the attachment is legal.
      auto AllowLocs = AreDebugLocsAllowed::No;
      switch (I.first) {
      default:
        break;
      case LLVMContext::MD_dbg: {
        ++NumDebugAttachments;
        CheckDI(NumDebugAttachments == 1,
                "function must have a single !dbg attachment", &F, I.second);
        CheckDI(isa<DISubprogram>(I.second),
                "function !dbg attachment must be a subprogram", &F, I.second);
        CheckDI(cast<DISubprogram>(I.second)->isDistinct(),
                "function definition may only have a distinct !dbg attachment",
                &F);
 
        auto *SP = cast<DISubprogram>(I.second);
        const Function *&AttachedTo = DISubprogramAttachments[SP];
        CheckDI(!AttachedTo || AttachedTo == &F,
                "DISubprogram attached to more than one function", SP, &F);
        AttachedTo = &F;
        AllowLocs = AreDebugLocsAllowed::Yes;
        break;
      }
      case LLVMContext::MD_prof:
        ++NumProfAttachments;
        Check(NumProfAttachments == 1,
              "function must have a single !prof attachment", &F, I.second);
        break;
      case LLVMContext::MD_kcfi_type:
        ++NumKCFIAttachments;
        Check(NumKCFIAttachments == 1,
              "function must have a single !kcfi_type attachment", &F,
              I.second);
        break;
      }
 
      // Verify the metadata itself.
      visitMDNode(*I.second, AllowLocs);
    }
  }
 
  // If this function is actually an intrinsic, verify that it is only used in
  // direct call/invokes, never having its "address taken".
  // Only do this if the module is materialized, otherwise we don't have all the
  // uses.
  bool isMaterialized = F.getParent()->isMaterialized();
  if (F.isIntrinsic() && isMaterialized) {
    const User *U;
    if (F.hasAddressTaken(&U, false, true, false,
                          /*IgnoreARCAttachedCall=*/true))
      Check(false, "Invalid user of intrinsic instruction!", U);
  }
 
  // Verify if the intrinsic's signature and name are valid. We do this if
  // the intrinsic has at least one materialized use, or if the module is fully
  // materialized.
  Intrinsic::ID IID = F.getIntrinsicID();
  if (IID && (isMaterialized || !F.materialized_use_empty())) {
    // Verify that the intrinsic prototype lines up with what the .td files
    // describe.
    std::string ErrMsg;
    raw_string_ostream ErrOS(ErrMsg);
    SmallVector<Type *, 4> OverloadTys;
    bool IsValid = Intrinsic::isSignatureValid(IID, FT, OverloadTys, ErrOS);
    Printable PrintDecl([&F](raw_ostream &OS) { F.print(OS); });
    Check(IsValid, ErrMsg, PrintDecl);
 
    // Now that we have the intrinsic ID and the actual argument types (and we
    // know they are legal for the intrinsic!) get the intrinsic name through
    // the usual means. This allows us to verify the mangling of argument types
    // into the name.
    const std::string ExpectedName = Intrinsic::getName(
        IID, OverloadTys, const_cast<Module *>(F.getParent()), FT);
    Check(ExpectedName == F.getName(),
          "Intrinsic name not mangled correctly for type arguments! "
          "Should be: " +
              ExpectedName,
          PrintDecl);
  }
 
  auto *N = F.getSubprogram();
  HasDebugInfo = (N != nullptr);
  if (!HasDebugInfo)
    return;
 
  // Check that all !dbg attachments lead to back to N.
  //
  // FIXME: Check this incrementally while visiting !dbg attachments.
  // FIXME: Only check when N is the canonical subprogram for F.
  SmallPtrSet<const MDNode *, 32> Seen;
  auto VisitDebugLoc = [&](const Instruction &I, const MDNode *Node) {
    // Be careful about using DILocation here since we might be dealing with
    // broken code (this is the Verifier after all).
    const DILocation *DL = dyn_cast_or_null<DILocation>(Node);
    if (!DL)
      return;
    if (!Seen.insert(DL).second)
      return;
 
    Metadata *Parent = DL->getRawScope();
    CheckDI(Parent && isa<DILocalScope>(Parent),
            "DILocation's scope must be a DILocalScope", N, &F, &I, DL, Parent);
 
    DILocalScope *Scope = DL->getInlinedAtScope();
    Check(Scope, "Failed to find DILocalScope", DL);
 
    if (!Seen.insert(Scope).second)
      return;
 
    // Cycles are diagnosed when the DIScope nodes themselves are visited.
    if (hasDIScopeCycle(Scope))
      return;
 
    DISubprogram *SP = Scope->getSubprogram();
 
    // Scope and SP could be the same MDNode and we don't want to skip
    // validation in that case
    if ((Scope != SP) && !Seen.insert(SP).second)
      return;
 
    CheckDI(SP->describes(&F),
            "!dbg attachment points at wrong subprogram for function", N, &F,
            &I, DL, Scope, SP);
  };
  for (auto &BB : F)
    for (auto &I : BB) {
      VisitDebugLoc(I, I.getDebugLoc().getAsMDNode());
      // The llvm.loop annotations also contain two DILocations.
      if (auto MD = I.getMetadata(LLVMContext::MD_loop))
        for (unsigned i = 1; i < MD->getNumOperands(); ++i)
          VisitDebugLoc(I, dyn_cast_or_null<MDNode>(MD->getOperand(i)));
      if (BrokenDebugInfo)
        return;
    }
}
 
// verifyBasicBlock - Verify that a basic block is well formed...
//
void Verifier::visitBasicBlock(BasicBlock &BB) {
  InstsInThisBlock.clear();
  ConvergenceVerifyHelper.visit(BB);
 
  // Ensure that basic blocks have terminators!
  Check(BB.getTerminator(), "Basic Block does not have terminator!", &BB);
 
  // Check constraints that this basic block imposes on all of the PHI nodes in
  // it.
  if (isa<PHINode>(BB.front())) {
    SmallVector<BasicBlock *, 8> Preds(predecessors(&BB));
    SmallVector<std::pair<BasicBlock*, Value*>, 8> Values;
    llvm::sort(Preds);
    for (const PHINode &PN : BB.phis()) {
      Check(PN.getNumIncomingValues() == Preds.size(),
            "PHINode should have one entry for each predecessor of its "
            "parent basic block!",
            &PN);
 
      // Get and sort all incoming values in the PHI node...
      Values.clear();
      Values.reserve(PN.getNumIncomingValues());
      for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
        Values.push_back(
            std::make_pair(PN.getIncomingBlock(i), PN.getIncomingValue(i)));
      llvm::sort(Values);
 
      for (unsigned i = 0, e = Values.size(); i != e; ++i) {
        // Check to make sure that if there is more than one entry for a
        // particular basic block in this PHI node, that the incoming values are
        // all identical.
        //
        Check(i == 0 || Values[i].first != Values[i - 1].first ||
                  Values[i].second == Values[i - 1].second,
              "PHI node has multiple entries for the same basic block with "
              "different incoming values!",
              &PN, Values[i].first, Values[i].second, Values[i - 1].second);
 
        // Check to make sure that the predecessors and PHI node entries are
        // matched up.
        Check(Values[i].first == Preds[i],
              "PHI node entries do not match predecessors!", &PN,
              Values[i].first, Preds[i]);
      }
    }
  }
 
  // Check that all instructions have their parent pointers set up correctly.
  for (auto &I : BB)
  {
    Check(I.getParent() == &BB, "Instruction has bogus parent pointer!");
  }
 
  // Confirm that no issues arise from the debug program.
  CheckDI(!BB.getTrailingDbgRecords(), "Basic Block has trailing DbgRecords!",
          &BB);
}
 
void Verifier::visitTerminator(Instruction &I) {
  // Ensure that terminators only exist at the end of the basic block.
  Check(&I == I.getParent()->getTerminator(),
        "Terminator found in the middle of a basic block!", I.getParent());
  visitInstruction(I);
}
 
void Verifier::visitCondBrInst(CondBrInst &BI) {
  Check(BI.getCondition()->getType()->isIntegerTy(1),
        "Branch condition is not 'i1' type!", &BI, BI.getCondition());
  visitTerminator(BI);
}
 
void Verifier::visitReturnInst(ReturnInst &RI) {
  Function *F = RI.getParent()->getParent();
  unsigned N = RI.getNumOperands();
  if (F->getReturnType()->isVoidTy())
    Check(N == 0,
          "Found return instr that returns non-void in Function of void "
          "return type!",
          &RI, F->getReturnType());
  else
    Check(N == 1 && F->getReturnType() == RI.getOperand(0)->getType(),
          "Function return type does not match operand "
          "type of return inst!",
          &RI, F->getReturnType());
 
  // Check to make sure that the return value has necessary properties for
  // terminators...
  visitTerminator(RI);
}
 
void Verifier::visitSwitchInst(SwitchInst &SI) {
  Check(SI.getType()->isVoidTy(), "Switch must have void result type!", &SI);
  // Check to make sure that all of the constants in the switch instruction
  // have the same type as the switched-on value.
  Type *SwitchTy = SI.getCondition()->getType();
  SmallPtrSet<ConstantInt*, 32> Constants;
  for (auto &Case : SI.cases()) {
    Check(isa<ConstantInt>(Case.getCaseValue()),
          "Case value is not a constant integer.", &SI);
    Check(Case.getCaseValue()->getType() == SwitchTy,
          "Switch constants must all be same type as switch value!", &SI);
    Check(Constants.insert(Case.getCaseValue()).second,
          "Duplicate integer as switch case", &SI, Case.getCaseValue());
  }
 
  visitTerminator(SI);
}
 
void Verifier::visitIndirectBrInst(IndirectBrInst &BI) {
  Check(BI.getAddress()->getType()->isPointerTy(),
        "Indirectbr operand must have pointer type!", &BI);
  for (unsigned i = 0, e = BI.getNumDestinations(); i != e; ++i)
    Check(BI.getDestination(i)->getType()->isLabelTy(),
          "Indirectbr destinations must all have pointer type!", &BI);
 
  visitTerminator(BI);
}
 
static bool isSupportedCallBrIntrinsic(Intrinsic::ID ID) {
  // Currently we only support callbr for amdgcn.kill. Add more checks here as
  // needed.
  return isAMDGPUCallBrIntrinsic(ID);
}
 
void Verifier::visitCallBrInst(CallBrInst &CBI) {
  if (!CBI.isInlineAsm()) {
    Check(CBI.getCalledFunction(),
          "callbr: indirect function / invalid signature");
    Check(!CBI.hasOperandBundles(),
          "callbr for intrinsics currently doesn't support operand bundles");
 
    if (!isSupportedCallBrIntrinsic(CBI.getIntrinsicID())) {
      CheckFailed(
          "callbr currently only supports asm-goto and selected intrinsics");
    }
    visitIntrinsicCall(CBI.getIntrinsicID(), CBI);
  } else {
    const InlineAsm *IA = cast<InlineAsm>(CBI.getCalledOperand());
    Check(!IA->canThrow(), "Unwinding from Callbr is not allowed");
 
    verifyInlineAsmCall(CBI);
  }
  visitTerminator(CBI);
}
 
void Verifier::visitSelectInst(SelectInst &SI) {
  Check(!SelectInst::areInvalidOperands(SI.getOperand(0), SI.getOperand(1),
                                        SI.getOperand(2)),
        "Invalid operands for select instruction!", &SI);
 
  Check(SI.getTrueValue()->getType() == SI.getType(),
        "Select values must have same type as select instruction!", &SI);
  visitInstruction(SI);
}
 
/// visitUserOp1 - User defined operators shouldn't live beyond the lifetime of
/// a pass, if any exist, it's an error.
///
void Verifier::visitUserOp1(Instruction &I) {
  Check(false, "User-defined operators should not live outside of a pass!", &I);
}
 
void Verifier::visitTruncInst(TruncInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  // Get the size of the types in bits, we'll need this later
  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
  unsigned DestBitSize = DestTy->getScalarSizeInBits();
 
  Check(SrcTy->isIntOrIntVectorTy(), "Trunc only operates on integer", &I);
  Check(DestTy->isIntOrIntVectorTy(), "Trunc only produces integer", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(),
        "trunc source and destination must both be a vector or neither", &I);
  Check(SrcBitSize > DestBitSize, "DestTy too big for Trunc", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitZExtInst(ZExtInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  // Get the size of the types in bits, we'll need this later
  Check(SrcTy->isIntOrIntVectorTy(), "ZExt only operates on integer", &I);
  Check(DestTy->isIntOrIntVectorTy(), "ZExt only produces an integer", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(),
        "zext source and destination must both be a vector or neither", &I);
  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
  unsigned DestBitSize = DestTy->getScalarSizeInBits();
 
  Check(SrcBitSize < DestBitSize, "Type too small for ZExt", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitSExtInst(SExtInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  // Get the size of the types in bits, we'll need this later
  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
  unsigned DestBitSize = DestTy->getScalarSizeInBits();
 
  Check(SrcTy->isIntOrIntVectorTy(), "SExt only operates on integer", &I);
  Check(DestTy->isIntOrIntVectorTy(), "SExt only produces an integer", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(),
        "sext source and destination must both be a vector or neither", &I);
  Check(SrcBitSize < DestBitSize, "Type too small for SExt", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitFPTruncInst(FPTruncInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
  // Get the size of the types in bits, we'll need this later
  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
  unsigned DestBitSize = DestTy->getScalarSizeInBits();
 
  Check(SrcTy->isFPOrFPVectorTy(), "FPTrunc only operates on FP", &I);
  Check(DestTy->isFPOrFPVectorTy(), "FPTrunc only produces an FP", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(),
        "fptrunc source and destination must both be a vector or neither", &I);
  Check(SrcBitSize > DestBitSize, "DestTy too big for FPTrunc", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitFPExtInst(FPExtInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  // Get the size of the types in bits, we'll need this later
  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
  unsigned DestBitSize = DestTy->getScalarSizeInBits();
 
  Check(SrcTy->isFPOrFPVectorTy(), "FPExt only operates on FP", &I);
  Check(DestTy->isFPOrFPVectorTy(), "FPExt only produces an FP", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(),
        "fpext source and destination must both be a vector or neither", &I);
  Check(SrcBitSize < DestBitSize, "DestTy too small for FPExt", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitUIToFPInst(UIToFPInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  bool SrcVec = SrcTy->isVectorTy();
  bool DstVec = DestTy->isVectorTy();
 
  Check(SrcVec == DstVec,
        "UIToFP source and dest must both be vector or scalar", &I);
  Check(SrcTy->isIntOrIntVectorTy(),
        "UIToFP source must be integer or integer vector", &I);
  Check(DestTy->isFPOrFPVectorTy(), "UIToFP result must be FP or FP vector",
        &I);
 
  if (SrcVec && DstVec)
    Check(cast<VectorType>(SrcTy)->getElementCount() ==
              cast<VectorType>(DestTy)->getElementCount(),
          "UIToFP source and dest vector length mismatch", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitSIToFPInst(SIToFPInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  bool SrcVec = SrcTy->isVectorTy();
  bool DstVec = DestTy->isVectorTy();
 
  Check(SrcVec == DstVec,
        "SIToFP source and dest must both be vector or scalar", &I);
  Check(SrcTy->isIntOrIntVectorTy(),
        "SIToFP source must be integer or integer vector", &I);
  Check(DestTy->isFPOrFPVectorTy(), "SIToFP result must be FP or FP vector",
        &I);
 
  if (SrcVec && DstVec)
    Check(cast<VectorType>(SrcTy)->getElementCount() ==
              cast<VectorType>(DestTy)->getElementCount(),
          "SIToFP source and dest vector length mismatch", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitFPToUIInst(FPToUIInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  bool SrcVec = SrcTy->isVectorTy();
  bool DstVec = DestTy->isVectorTy();
 
  Check(SrcVec == DstVec,
        "FPToUI source and dest must both be vector or scalar", &I);
  Check(SrcTy->isFPOrFPVectorTy(), "FPToUI source must be FP or FP vector", &I);
  Check(DestTy->isIntOrIntVectorTy(),
        "FPToUI result must be integer or integer vector", &I);
 
  if (SrcVec && DstVec)
    Check(cast<VectorType>(SrcTy)->getElementCount() ==
              cast<VectorType>(DestTy)->getElementCount(),
          "FPToUI source and dest vector length mismatch", &I);
 
  visitInstruction(I);
}
 
void Verifier::visitFPToSIInst(FPToSIInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  bool SrcVec = SrcTy->isVectorTy();
  bool DstVec = DestTy->isVectorTy();
 
  Check(SrcVec == DstVec,
        "FPToSI source and dest must both be vector or scalar", &I);
  Check(SrcTy->isFPOrFPVectorTy(), "FPToSI source must be FP or FP vector", &I);
  Check(DestTy->isIntOrIntVectorTy(),
        "FPToSI result must be integer or integer vector", &I);
 
  if (SrcVec && DstVec)
    Check(cast<VectorType>(SrcTy)->getElementCount() ==
              cast<VectorType>(DestTy)->getElementCount(),
          "FPToSI source and dest vector length mismatch", &I);
 
  visitInstruction(I);
}
 
void Verifier::checkPtrToAddr(Type *SrcTy, Type *DestTy, const Value &V) {
  Check(SrcTy->isPtrOrPtrVectorTy(), "PtrToAddr source must be pointer", V);
  Check(DestTy->isIntOrIntVectorTy(), "PtrToAddr result must be integral", V);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(), "PtrToAddr type mismatch",
        V);
 
  if (SrcTy->isVectorTy()) {
    auto *VSrc = cast<VectorType>(SrcTy);
    auto *VDest = cast<VectorType>(DestTy);
    Check(VSrc->getElementCount() == VDest->getElementCount(),
          "PtrToAddr vector length mismatch", V);
  }
 
  Type *AddrTy = DL.getAddressType(SrcTy);
  Check(AddrTy == DestTy, "PtrToAddr result must be address width", V);
}
 
void Verifier::visitPtrToAddrInst(PtrToAddrInst &I) {
  checkPtrToAddr(I.getOperand(0)->getType(), I.getType(), I);
  visitInstruction(I);
}
 
void Verifier::visitPtrToIntInst(PtrToIntInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  Check(SrcTy->isPtrOrPtrVectorTy(), "PtrToInt source must be pointer", &I);
 
  Check(DestTy->isIntOrIntVectorTy(), "PtrToInt result must be integral", &I);
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(), "PtrToInt type mismatch",
        &I);
 
  if (SrcTy->isVectorTy()) {
    auto *VSrc = cast<VectorType>(SrcTy);
    auto *VDest = cast<VectorType>(DestTy);
    Check(VSrc->getElementCount() == VDest->getElementCount(),
          "PtrToInt Vector length mismatch", &I);
  }
 
  visitInstruction(I);
}
 
void Verifier::visitIntToPtrInst(IntToPtrInst &I) {
  // Get the source and destination types
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  Check(SrcTy->isIntOrIntVectorTy(), "IntToPtr source must be an integral", &I);
  Check(DestTy->isPtrOrPtrVectorTy(), "IntToPtr result must be a pointer", &I);
 
  Check(SrcTy->isVectorTy() == DestTy->isVectorTy(), "IntToPtr type mismatch",
        &I);
  if (SrcTy->isVectorTy()) {
    auto *VSrc = cast<VectorType>(SrcTy);
    auto *VDest = cast<VectorType>(DestTy);
    Check(VSrc->getElementCount() == VDest->getElementCount(),
          "IntToPtr Vector length mismatch", &I);
  }
  visitInstruction(I);
}
 
void Verifier::visitBitCastInst(BitCastInst &I) {
  Check(
      CastInst::castIsValid(Instruction::BitCast, I.getOperand(0), I.getType()),
      "Invalid bitcast", &I);
  visitInstruction(I);
}
 
void Verifier::visitAddrSpaceCastInst(AddrSpaceCastInst &I) {
  Type *SrcTy = I.getOperand(0)->getType();
  Type *DestTy = I.getType();
 
  Check(SrcTy->isPtrOrPtrVectorTy(), "AddrSpaceCast source must be a pointer",
        &I);
  Check(DestTy->isPtrOrPtrVectorTy(), "AddrSpaceCast result must be a pointer",
        &I);
  Check(SrcTy->getPointerAddressSpace() != DestTy->getPointerAddressSpace(),
        "AddrSpaceCast must be between different address spaces", &I);
  if (auto *SrcVTy = dyn_cast<VectorType>(SrcTy))
    Check(SrcVTy->getElementCount() ==
              cast<VectorType>(DestTy)->getElementCount(),
          "AddrSpaceCast vector pointer number of elements mismatch", &I);
  visitInstruction(I);
}
 
/// visitPHINode - Ensure that a PHI node is well formed.
///
void Verifier::visitPHINode(PHINode &PN) {
  // Ensure that the PHI nodes are all grouped together at the top of the block.
  // This can be tested by checking whether the instruction before this is
  // either nonexistent (because this is begin()) or is a PHI node.  If not,
  // then there is some other instruction before a PHI.
  Check(&PN == &PN.getParent()->front() ||
            isa<PHINode>(--BasicBlock::iterator(&PN)),
        "PHI nodes not grouped at top of basic block!", &PN, PN.getParent());
 
  // Check that a PHI doesn't yield a Token.
  Check(!PN.getType()->isTokenLikeTy(), "PHI nodes cannot have token type!");
 
  // Check that all of the values of the PHI node have the same type as the
  // result.
  for (Value *IncValue : PN.incoming_values()) {
    Check(PN.getType() == IncValue->getType(),
          "PHI node operands are not the same type as the result!", &PN);
  }
 
  // All other PHI node constraints are checked in the visitBasicBlock method.
 
  visitInstruction(PN);
}
 
void Verifier::visitCallBase(CallBase &Call) {
  Check(Call.getCalledOperand()->getType()->isPointerTy(),
        "Called function must be a pointer!", Call);
  FunctionType *FTy = Call.getFunctionType();
 
  // Verify that the correct number of arguments are being passed
  if (FTy->isVarArg())
    Check(Call.arg_size() >= FTy->getNumParams(),
          "Called function requires more parameters than were provided!", Call);
  else
    Check(Call.arg_size() == FTy->getNumParams(),
          "Incorrect number of arguments passed to called function!", Call);
 
  // Verify that all arguments to the call match the function type.
  for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
    Check(Call.getArgOperand(i)->getType() == FTy->getParamType(i),
          "Call parameter type does not match function signature!",
          Call.getArgOperand(i), FTy->getParamType(i), Call);
 
  AttributeList Attrs = Call.getAttributes();
 
  Check(verifyAttributeCount(Attrs, Call.arg_size()),
        "Attribute after last parameter!", Call);
 
  auto *Callee =
      dyn_cast<Function>(Call.getCalledOperand()->stripPointerCasts());
  bool IsIntrinsic = Callee && Callee->isIntrinsic();
  if (IsIntrinsic)
    Check(Callee->getFunctionType() == FTy,
          "Intrinsic called with incompatible signature", Call);
 
  // Verify if the calling convention of the callee is callable.
  Check(isCallableCC(Call.getCallingConv()),
        "calling convention does not permit calls", Call);
 
  // Disallow passing/returning values with alignment higher than we can
  // represent.
  // FIXME: Consider making DataLayout cap the alignment, so this isn't
  // necessary.
  auto VerifyTypeAlign = [&](Type *Ty, const Twine &Message) {
    if (!Ty->isSized())
      return;
    Align ABIAlign = DL.getABITypeAlign(Ty);
    Check(ABIAlign.value() <= Value::MaximumAlignment,
          "Incorrect alignment of " + Message + " to called function!", Call);
  };
 
  if (!IsIntrinsic) {
    VerifyTypeAlign(FTy->getReturnType(), "return type");
    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
      Type *Ty = FTy->getParamType(i);
      VerifyTypeAlign(Ty, "argument passed");
    }
  }
 
  if (Attrs.hasFnAttr(Attribute::Speculatable)) {
    // Don't allow speculatable on call sites, unless the underlying function
    // declaration is also speculatable.
    Check(Callee && Callee->isSpeculatable(),
          "speculatable attribute may not apply to call sites", Call);
  }
 
  if (Attrs.hasFnAttr(Attribute::Preallocated)) {
    Check(Call.getIntrinsicID() == Intrinsic::call_preallocated_arg,
          "preallocated as a call site attribute can only be on "
          "llvm.call.preallocated.arg");
  }
 
  Check(!Attrs.hasFnAttr(Attribute::DenormalFPEnv),
        "denormal_fpenv attribute may not apply to call sites", Call);
 
  // Verify call attributes.
  verifyFunctionAttrs(FTy, Attrs, &Call, IsIntrinsic, Call.isInlineAsm());
 
  // Conservatively check the inalloca argument.
  // We have a bug if we can find that there is an underlying alloca without
  // inalloca.
  if (Call.hasInAllocaArgument()) {
    Value *InAllocaArg = Call.getArgOperand(FTy->getNumParams() - 1);
    if (auto AI = dyn_cast<AllocaInst>(InAllocaArg->stripInBoundsOffsets()))
      Check(AI->isUsedWithInAlloca(),
            "inalloca argument for call has mismatched alloca", AI, Call);
  }
 
  // For each argument of the callsite, if it has the swifterror argument,
  // make sure the underlying alloca/parameter it comes from has a swifterror as
  // well.
  for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
    if (Call.paramHasAttr(i, Attribute::SwiftError)) {
      Value *SwiftErrorArg = Call.getArgOperand(i);
      if (auto AI = dyn_cast<AllocaInst>(SwiftErrorArg->stripInBoundsOffsets())) {
        Check(AI->isSwiftError(),
              "swifterror argument for call has mismatched alloca", AI, Call);
        continue;
      }
      auto ArgI = dyn_cast<Argument>(SwiftErrorArg);
      Check(ArgI, "swifterror argument should come from an alloca or parameter",
            SwiftErrorArg, Call);
      Check(ArgI->hasSwiftErrorAttr(),
            "swifterror argument for call has mismatched parameter", ArgI,
            Call);
    }
 
    if (Attrs.hasParamAttr(i, Attribute::ImmArg)) {
      // Don't allow immarg on call sites, unless the underlying declaration
      // also has the matching immarg.
      Check(Callee && Callee->hasParamAttribute(i, Attribute::ImmArg),
            "immarg may not apply only to call sites", Call.getArgOperand(i),
            Call);
    }
 
    if (Call.paramHasAttr(i, Attribute::ImmArg)) {
      Value *ArgVal = Call.getArgOperand(i);
      Check((isa<ConstantInt>(ArgVal) || isa<ConstantFP>(ArgVal)) &&
                !isa<VectorType>(ArgVal->getType()),
            "immarg operand has non-immediate parameter", ArgVal, Call);
 
      // If the imm-arg is an integer and also has a range attached,
      // check if the given value is within the range.
      if (Call.paramHasAttr(i, Attribute::Range)) {
        if (auto *CI = dyn_cast<ConstantInt>(ArgVal)) {
          const ConstantRange &CR =
              Call.getParamAttr(i, Attribute::Range).getValueAsConstantRange();
          Check(CR.contains(CI->getValue()),
                formatv("immarg value {} for arg {} out of range {}",
                        CI->getValue(), i, CR),
                Call);
        }
      }
      if (auto *CI = dyn_cast<ConstantInt>(ArgVal))
        Check(Intrinsic::isImmArgValueInRangeSet(Call.getIntrinsicID(), i,
                                                 CI->getValue()),
              formatv("immarg value {} for arg {} out of range set",
                      CI->getValue(), i),
              Call);
    }
 
    if (Call.paramHasAttr(i, Attribute::Preallocated)) {
      Value *ArgVal = Call.getArgOperand(i);
      bool hasOB =
          Call.countOperandBundlesOfType(LLVMContext::OB_preallocated) != 0;
      bool isMustTail = Call.isMustTailCall();
      Check(hasOB != isMustTail,
            "preallocated operand either requires a preallocated bundle or "
            "the call to be musttail (but not both)",
            ArgVal, Call);
    }
  }
 
  if (FTy->isVarArg()) {
    // FIXME? is 'nest' even legal here?
    bool SawNest = false;
    bool SawReturned = false;
 
    for (unsigned Idx = 0; Idx < FTy->getNumParams(); ++Idx) {
      if (Attrs.hasParamAttr(Idx, Attribute::Nest))
        SawNest = true;
      if (Attrs.hasParamAttr(Idx, Attribute::Returned))
        SawReturned = true;
    }
 
    // Check attributes on the varargs part.
    for (unsigned Idx = FTy->getNumParams(); Idx < Call.arg_size(); ++Idx) {
      Type *Ty = Call.getArgOperand(Idx)->getType();
      AttributeSet ArgAttrs = Attrs.getParamAttrs(Idx);
      verifyParameterAttrs(ArgAttrs, Ty, &Call);
 
      if (ArgAttrs.hasAttribute(Attribute::Nest)) {
        Check(!SawNest, "More than one parameter has attribute nest!", Call);
        SawNest = true;
      }
 
      if (ArgAttrs.hasAttribute(Attribute::Returned)) {
        Check(!SawReturned, "More than one parameter has attribute returned!",
              Call);
        Check(Ty->canLosslesslyBitCastTo(FTy->getReturnType()),
              "Incompatible argument and return types for 'returned' "
              "attribute",
              Call);
        SawReturned = true;
      }
 
      // Statepoint intrinsic is vararg but the wrapped function may be not.
      // Allow sret here and check the wrapped function in verifyStatepoint.
      if (Call.getIntrinsicID() != Intrinsic::experimental_gc_statepoint)
        Check(!ArgAttrs.hasAttribute(Attribute::StructRet),
              "Attribute 'sret' cannot be used for vararg call arguments!",
              Call);
 
      if (ArgAttrs.hasAttribute(Attribute::InAlloca))
        Check(Idx == Call.arg_size() - 1,
              "inalloca isn't on the last argument!", Call);
    }
  }
 
  // Verify that there's no metadata unless it's a direct call to an intrinsic.
  if (!IsIntrinsic) {
    for (Type *ParamTy : FTy->params()) {
      Check(!ParamTy->isMetadataTy(),
            "Function has metadata parameter but isn't an intrinsic", Call);
      Check(!ParamTy->isTokenLikeTy(),
            "Function has token parameter but isn't an intrinsic", Call);
    }
  }
 
  // Verify that indirect calls don't return tokens.
  if (!Call.getCalledFunction()) {
    Check(!FTy->getReturnType()->isTokenLikeTy(),
          "Return type cannot be token for indirect call!");
    Check(!FTy->getReturnType()->isX86_AMXTy(),
          "Return type cannot be x86_amx for indirect call!");
  }
 
  if (Intrinsic::ID ID = Call.getIntrinsicID())
    visitIntrinsicCall(ID, Call);
 
  // Verify that a callsite has at most one "deopt", at most one "funclet", at
  // most one "gc-transition", at most one "cfguardtarget", at most one
  // "preallocated" operand bundle, and at most one "ptrauth" operand bundle.
  bool FoundDeoptBundle = false, FoundFuncletBundle = false,
       FoundGCTransitionBundle = false, FoundCFGuardTargetBundle = false,
       FoundPreallocatedBundle = false, FoundGCLiveBundle = false,
       FoundPtrauthBundle = false, FoundKCFIBundle = false,
       FoundAttachedCallBundle = false;
  for (unsigned i = 0, e = Call.getNumOperandBundles(); i < e; ++i) {
    OperandBundleUse BU = Call.getOperandBundleAt(i);
    for (const Value *Input : BU.Inputs)
      Check(!Input->getType()->isLabelTy(),
            "Operand bundle operands cannot be labels", Call);
    uint32_t Tag = BU.getTagID();
    if (Tag == LLVMContext::OB_deopt) {
      Check(!FoundDeoptBundle, "Multiple deopt operand bundles", Call);
      FoundDeoptBundle = true;
    } else if (Tag == LLVMContext::OB_gc_transition) {
      Check(!FoundGCTransitionBundle, "Multiple gc-transition operand bundles",
            Call);
      FoundGCTransitionBundle = true;
    } else if (Tag == LLVMContext::OB_funclet) {
      Check(!FoundFuncletBundle, "Multiple funclet operand bundles", Call);
      FoundFuncletBundle = true;
      Check(BU.Inputs.size() == 1,
            "Expected exactly one funclet bundle operand", Call);
      Check(isa<FuncletPadInst>(BU.Inputs.front()),
            "Funclet bundle operands should correspond to a FuncletPadInst",
            Call);
    } else if (Tag == LLVMContext::OB_cfguardtarget) {
      Check(!FoundCFGuardTargetBundle, "Multiple CFGuardTarget operand bundles",
            Call);
      FoundCFGuardTargetBundle = true;
      Check(BU.Inputs.size() == 1,
            "Expected exactly one cfguardtarget bundle operand", Call);
    } else if (Tag == LLVMContext::OB_ptrauth) {
      Check(!FoundPtrauthBundle, "Multiple ptrauth operand bundles", Call);
      FoundPtrauthBundle = true;
      Check(BU.Inputs.size() == 2,
            "Expected exactly two ptrauth bundle operands", Call);
      Check(isa<ConstantInt>(BU.Inputs[0]) &&
                BU.Inputs[0]->getType()->isIntegerTy(32),
            "Ptrauth bundle key operand must be an i32 constant", Call);
      Check(BU.Inputs[1]->getType()->isIntegerTy(64),
            "Ptrauth bundle discriminator operand must be an i64", Call);
    } else if (Tag == LLVMContext::OB_kcfi) {
      Check(!FoundKCFIBundle, "Multiple kcfi operand bundles", Call);
      FoundKCFIBundle = true;
      Check(BU.Inputs.size() == 1, "Expected exactly one kcfi bundle operand",
            Call);
      Check(isa<ConstantInt>(BU.Inputs[0]) &&
                BU.Inputs[0]->getType()->isIntegerTy(32),
            "Kcfi bundle operand must be an i32 constant", Call);
    } else if (Tag == LLVMContext::OB_preallocated) {
      Check(!FoundPreallocatedBundle, "Multiple preallocated operand bundles",
            Call);
      FoundPreallocatedBundle = true;
      Check(BU.Inputs.size() == 1,
            "Expected exactly one preallocated bundle operand", Call);
      auto Input = dyn_cast<IntrinsicInst>(BU.Inputs.front());
      Check(Input &&
                Input->getIntrinsicID() == Intrinsic::call_preallocated_setup,
            "\"preallocated\" argument must be a token from "
            "llvm.call.preallocated.setup",
            Call);
    } else if (Tag == LLVMContext::OB_gc_live) {
      Check(!FoundGCLiveBundle, "Multiple gc-live operand bundles", Call);
      FoundGCLiveBundle = true;
    } else if (Tag == LLVMContext::OB_clang_arc_attachedcall) {
      Check(!FoundAttachedCallBundle,
            "Multiple \"clang.arc.attachedcall\" operand bundles", Call);
      FoundAttachedCallBundle = true;
      verifyAttachedCallBundle(Call, BU);
    }
  }
 
  // Verify that callee and callsite agree on whether to use pointer auth.
  Check(!(Call.getCalledFunction() && FoundPtrauthBundle),
        "Direct call cannot have a ptrauth bundle", Call);
 
  // Verify that each inlinable callsite of a debug-info-bearing function in a
  // debug-info-bearing function has a debug location attached to it. Failure to
  // do so causes assertion failures when the inliner sets up inline scope info
  // (Interposable functions are not inlinable, neither are functions without
  //  definitions.)
  if (Call.getFunction()->getSubprogram() && Call.getCalledFunction() &&
      !Call.getCalledFunction()->isInterposable() &&
      !Call.getCalledFunction()->isDeclaration() &&
      Call.getCalledFunction()->getSubprogram())
    CheckDI(Call.getDebugLoc(),
            "inlinable function call in a function with "
            "debug info must have a !dbg location",
            Call);
 
  if (Call.isInlineAsm())
    verifyInlineAsmCall(Call);
 
  ConvergenceVerifyHelper.visit(Call);
 
  visitInstruction(Call);
}
 
void Verifier::verifyTailCCMustTailAttrs(const AttrBuilder &Attrs,
                                         StringRef Context) {
  Check(!Attrs.contains(Attribute::InAlloca),
        Twine("inalloca attribute not allowed in ") + Context);
  Check(!Attrs.contains(Attribute::InReg),
        Twine("inreg attribute not allowed in ") + Context);
  Check(!Attrs.contains(Attribute::SwiftError),
        Twine("swifterror attribute not allowed in ") + Context);
  Check(!Attrs.contains(Attribute::Preallocated),
        Twine("preallocated attribute not allowed in ") + Context);
  Check(!Attrs.contains(Attribute::ByRef),
        Twine("byref attribute not allowed in ") + Context);
}
 
static AttrBuilder getParameterABIAttributes(LLVMContext& C, unsigned I, AttributeList Attrs) {
  static const Attribute::AttrKind ABIAttrs[] = {
      Attribute::StructRet,  Attribute::ByVal,          Attribute::InAlloca,
      Attribute::InReg,      Attribute::StackAlignment, Attribute::SwiftSelf,
      Attribute::SwiftAsync, Attribute::SwiftError,     Attribute::Preallocated,
      Attribute::ByRef};
  AttrBuilder Copy(C);
  for (auto AK : ABIAttrs) {
    Attribute Attr = Attrs.getParamAttrs(I).getAttribute(AK);
    if (Attr.isValid())
      Copy.addAttribute(Attr);
  }
 
  // `align` is ABI-affecting only in combination with `byval` or `byref`.
  if (Attrs.hasParamAttr(I, Attribute::Alignment) &&
      (Attrs.hasParamAttr(I, Attribute::ByVal) ||
       Attrs.hasParamAttr(I, Attribute::ByRef)))
    Copy.addAlignmentAttr(Attrs.getParamAlignment(I));
  return Copy;
}
 
void Verifier::verifyMustTailCall(CallInst &CI) {
  Check(!CI.isInlineAsm(), "cannot use musttail call with inline asm", &CI);
 
  Function *F = CI.getParent()->getParent();
  FunctionType *CallerTy = F->getFunctionType();
  FunctionType *CalleeTy = CI.getFunctionType();
  Check(CallerTy->isVarArg() == CalleeTy->isVarArg(),
        "cannot guarantee tail call due to mismatched varargs", &CI);
  Check(CallerTy->getReturnType() == CalleeTy->getReturnType(),
        "cannot guarantee tail call due to mismatched return types", &CI);
 
  // - The calling conventions of the caller and callee must match.
  Check(F->getCallingConv() == CI.getCallingConv(),
        "cannot guarantee tail call due to mismatched calling conv", &CI);
 
  // - The call must immediately precede a :ref:`ret <i_ret>` instruction.
  // - The ret instruction must return the value produced by the call or void.
  Instruction *Next = CI.getNextNode();
 
  // Check the return.
  ReturnInst *Ret = dyn_cast_or_null<ReturnInst>(Next);
  Check(Ret, "musttail call must precede a ret", &CI);
  Check(!Ret->getReturnValue() || Ret->getReturnValue() == &CI ||
            isa<UndefValue>(Ret->getReturnValue()),
        "musttail call result must be returned", Ret);
 
  AttributeList CallerAttrs = F->getAttributes();
  AttributeList CalleeAttrs = CI.getAttributes();
  if (CI.getCallingConv() == CallingConv::SwiftTail ||
      CI.getCallingConv() == CallingConv::Tail) {
    StringRef CCName =
        CI.getCallingConv() == CallingConv::Tail ? "tailcc" : "swifttailcc";
 
    // - Only sret, byval, swiftself, and swiftasync ABI-impacting attributes
    //   are allowed in swifttailcc call
    for (unsigned I = 0, E = CallerTy->getNumParams(); I != E; ++I) {
      AttrBuilder ABIAttrs = getParameterABIAttributes(F->getContext(), I, CallerAttrs);
      SmallString<32> Context{CCName, StringRef(" musttail caller")};
      verifyTailCCMustTailAttrs(ABIAttrs, Context);
    }
    for (unsigned I = 0, E = CalleeTy->getNumParams(); I != E; ++I) {
      AttrBuilder ABIAttrs = getParameterABIAttributes(F->getContext(), I, CalleeAttrs);
      SmallString<32> Context{CCName, StringRef(" musttail callee")};
      verifyTailCCMustTailAttrs(ABIAttrs, Context);
    }
    // - Varargs functions are not allowed
    Check(!CallerTy->isVarArg(), Twine("cannot guarantee ") + CCName +
                                     " tail call for varargs function");
    return;
  }
 
  // - The caller and callee prototypes must match.
  if (!CI.getIntrinsicID()) {
    Check(CallerTy->getNumParams() == CalleeTy->getNumParams(),
          "cannot guarantee tail call due to mismatched parameter counts", &CI);
    for (unsigned I = 0, E = CallerTy->getNumParams(); I != E; ++I) {
      Check(CallerTy->getParamType(I) == CalleeTy->getParamType(I),
            "cannot guarantee tail call due to mismatched parameter types",
            &CI);
    }
  }
 
  // - All ABI-impacting function attributes, such as sret, byval, inreg,
  //   returned, preallocated, and inalloca, must match.
  for (unsigned I = 0, E = CallerTy->getNumParams(); I != E; ++I) {
    AttrBuilder CallerABIAttrs = getParameterABIAttributes(F->getContext(), I, CallerAttrs);
    AttrBuilder CalleeABIAttrs = getParameterABIAttributes(F->getContext(), I, CalleeAttrs);
    Check(CallerABIAttrs == CalleeABIAttrs,
          "cannot guarantee tail call due to mismatched ABI impacting "
          "function attributes",
          &CI, CI.getOperand(I));
  }
}
 
void Verifier::visitCallInst(CallInst &CI) {
  visitCallBase(CI);
 
  if (CI.isMustTailCall())
    verifyMustTailCall(CI);
}
 
void Verifier::visitInvokeInst(InvokeInst &II) {
  visitCallBase(II);
 
  // Verify that the first non-PHI instruction of the unwind destination is an
  // exception handling instruction.
  Check(
      II.getUnwindDest()->isEHPad(),
      "The unwind destination does not have an exception handling instruction!",
      &II);
 
  visitTerminator(II);
}
 
/// visitUnaryOperator - Check the argument to the unary operator.
///
void Verifier::visitUnaryOperator(UnaryOperator &U) {
  Check(U.getType() == U.getOperand(0)->getType(),
        "Unary operators must have same type for"
        "operands and result!",
        &U);
 
  switch (U.getOpcode()) {
  // Check that floating-point arithmetic operators are only used with
  // floating-point operands.
  case Instruction::FNeg:
    Check(U.getType()->isFPOrFPVectorTy(),
          "FNeg operator only works with float types!", &U);
    break;
  default:
    llvm_unreachable("Unknown UnaryOperator opcode!");
  }
 
  visitInstruction(U);
}
 
/// visitBinaryOperator - Check that both arguments to the binary operator are
/// of the same type!
///
void Verifier::visitBinaryOperator(BinaryOperator &B) {
  Check(B.getOperand(0)->getType() == B.getOperand(1)->getType(),
        "Both operands to a binary operator are not of the same type!", &B);
 
  switch (B.getOpcode()) {
  // Check that integer arithmetic operators are only used with
  // integral operands.
  case Instruction::Add:
  case Instruction::Sub:
  case Instruction::Mul:
  case Instruction::SDiv:
  case Instruction::UDiv:
  case Instruction::SRem:
  case Instruction::URem:
    Check(B.getType()->isIntOrIntVectorTy(),
          "Integer arithmetic operators only work with integral types!", &B);
    Check(B.getType() == B.getOperand(0)->getType(),
          "Integer arithmetic operators must have same type "
          "for operands and result!",
          &B);
    break;
  // Check that floating-point arithmetic operators are only used with
  // floating-point operands.
  case Instruction::FAdd:
  case Instruction::FSub:
  case Instruction::FMul:
  case Instruction::FDiv:
  case Instruction::FRem:
    Check(B.getType()->isFPOrFPVectorTy(),
          "Floating-point arithmetic operators only work with "
          "floating-point types!",
          &B);
    Check(B.getType() == B.getOperand(0)->getType(),
          "Floating-point arithmetic operators must have same type "
          "for operands and result!",
          &B);
    break;
  // Check that logical operators are only used with integral operands.
  case Instruction::And:
  case Instruction::Or:
  case Instruction::Xor:
    Check(B.getType()->isIntOrIntVectorTy(),
          "Logical operators only work with integral types!", &B);
    Check(B.getType() == B.getOperand(0)->getType(),
          "Logical operators must have same type for operands and result!", &B);
    break;
  case Instruction::Shl:
  case Instruction::LShr:
  case Instruction::AShr:
    Check(B.getType()->isIntOrIntVectorTy(),
          "Shifts only work with integral types!", &B);
    Check(B.getType() == B.getOperand(0)->getType(),
          "Shift return type must be same as operands!", &B);
    break;
  default:
    llvm_unreachable("Unknown BinaryOperator opcode!");
  }
 
  visitInstruction(B);
}
 
void Verifier::visitICmpInst(ICmpInst &IC) {
  // Check that the operands are the same type
  Type *Op0Ty = IC.getOperand(0)->getType();
  Type *Op1Ty = IC.getOperand(1)->getType();
  Check(Op0Ty == Op1Ty,
        "Both operands to ICmp instruction are not of the same type!", &IC);
  // Check that the operands are the right type
  Check(Op0Ty->isIntOrIntVectorTy() || Op0Ty->isPtrOrPtrVectorTy(),
        "Invalid operand types for ICmp instruction", &IC);
  // Check that the predicate is valid.
  Check(IC.isIntPredicate(), "Invalid predicate in ICmp instruction!", &IC);
 
  visitInstruction(IC);
}
 
void Verifier::visitFCmpInst(FCmpInst &FC) {
  // Check that the operands are the same type
  Type *Op0Ty = FC.getOperand(0)->getType();
  Type *Op1Ty = FC.getOperand(1)->getType();
  Check(Op0Ty == Op1Ty,
        "Both operands to FCmp instruction are not of the same type!", &FC);
  // Check that the operands are the right type
  Check(Op0Ty->isFPOrFPVectorTy(), "Invalid operand types for FCmp instruction",
        &FC);
  // Check that the predicate is valid.
  Check(FC.isFPPredicate(), "Invalid predicate in FCmp instruction!", &FC);
 
  visitInstruction(FC);
}
 
void Verifier::visitExtractElementInst(ExtractElementInst &EI) {
  Check(ExtractElementInst::isValidOperands(EI.getOperand(0), EI.getOperand(1)),
        "Invalid extractelement operands!", &EI);
  visitInstruction(EI);
}
 
void Verifier::visitInsertElementInst(InsertElementInst &IE) {
  Check(InsertElementInst::isValidOperands(IE.getOperand(0), IE.getOperand(1),
                                           IE.getOperand(2)),
        "Invalid insertelement operands!", &IE);
  visitInstruction(IE);
}
 
void Verifier::visitShuffleVectorInst(ShuffleVectorInst &SV) {
  Check(ShuffleVectorInst::isValidOperands(SV.getOperand(0), SV.getOperand(1),
                                           SV.getShuffleMask()),
        "Invalid shufflevector operands!", &SV);
  visitInstruction(SV);
}
 
void Verifier::visitGetElementPtrInst(GetElementPtrInst &GEP) {
  if (auto *MD = mdconst::extract_or_null<ConstantInt>(
          GEP.getModule()->getModuleFlag("require-logical-pointer")))
    Check(!MD->getZExtValue(),
          "Non-logical getelementptr disallowed for this module.");
 
  Type *TargetTy = GEP.getPointerOperandType()->getScalarType();
 
  Check(isa<PointerType>(TargetTy),
        "GEP base pointer is not a vector or a vector of pointers", &GEP);
  Check(GEP.getSourceElementType()->isSized(), "GEP into unsized type!", &GEP);
 
  if (auto *STy = dyn_cast<StructType>(GEP.getSourceElementType())) {
    Check(!STy->isScalableTy(),
          "getelementptr cannot target structure that contains scalable vector"
          "type",
          &GEP);
  }
 
  SmallVector<Value *, 16> Idxs(GEP.indices());
  Check(
      all_of(Idxs, [](Value *V) { return V->getType()->isIntOrIntVectorTy(); }),
      "GEP indexes must be integers", &GEP);
  Type *ElTy =
      GetElementPtrInst::getIndexedType(GEP.getSourceElementType(), Idxs);
  Check(ElTy, "Invalid indices for GEP pointer type!", &GEP);
 
  auto *PtrTy = dyn_cast<PointerType>(GEP.getType()->getScalarType());
 
  Check(PtrTy && GEP.getResultElementType() == ElTy,
        "GEP is not of right type for indices!", &GEP, ElTy);
 
  if (auto *GEPVTy = dyn_cast<VectorType>(GEP.getType())) {
    // Additional checks for vector GEPs.
    ElementCount GEPWidth = GEPVTy->getElementCount();
    if (GEP.getPointerOperandType()->isVectorTy())
      Check(
          GEPWidth ==
              cast<VectorType>(GEP.getPointerOperandType())->getElementCount(),
          "Vector GEP result width doesn't match operand's", &GEP);
    for (Value *Idx : Idxs) {
      Type *IndexTy = Idx->getType();
      if (auto *IndexVTy = dyn_cast<VectorType>(IndexTy)) {
        ElementCount IndexWidth = IndexVTy->getElementCount();
        Check(IndexWidth == GEPWidth, "Invalid GEP index vector width", &GEP);
      }
      Check(IndexTy->isIntOrIntVectorTy(),
            "All GEP indices should be of integer type");
    }
  }
 
  // Check that GEP does not index into a vector with non-byte-addressable
  // elements.
  for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
       GTI != GTE; ++GTI) {
    if (GTI.isVector()) {
      Type *ElemTy = GTI.getIndexedType();
      Check(DL.typeSizeEqualsStoreSize(ElemTy),
            "GEP into vector with non-byte-addressable element type", &GEP);
    }
  }
 
  Check(GEP.getAddressSpace() == PtrTy->getAddressSpace(),
        "GEP address space doesn't match type", &GEP);
 
  visitInstruction(GEP);
}
 
static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
  return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
}
 
/// Verify !range and !absolute_symbol metadata. These have the same
/// restrictions, except !absolute_symbol allows the full set.
void Verifier::verifyRangeLikeMetadata(const Value &I, const MDNode *Range,
                                       Type *Ty, RangeLikeMetadataKind Kind) {
  unsigned NumOperands = Range->getNumOperands();
  Check(NumOperands % 2 == 0, "Unfinished range!", Range);
  unsigned NumRanges = NumOperands / 2;
  Check(NumRanges >= 1, "It should have at least one range!", Range);
 
  ConstantRange LastRange(1, true); // Dummy initial value
  for (unsigned i = 0; i < NumRanges; ++i) {
    ConstantInt *Low =
        mdconst::dyn_extract<ConstantInt>(Range->getOperand(2 * i));
    Check(Low, "The lower limit must be an integer!", Low);
    ConstantInt *High =
        mdconst::dyn_extract<ConstantInt>(Range->getOperand(2 * i + 1));
    Check(High, "The upper limit must be an integer!", High);
 
    Check(High->getType() == Low->getType(), "Range pair types must match!",
          &I);
 
    if (Kind == RangeLikeMetadataKind::NoaliasAddrspace) {
      Check(High->getType()->isIntegerTy(32),
            "noalias.addrspace type must be i32!", &I);
    } else {
      Check(High->getType() == Ty->getScalarType(),
            "Range types must match instruction type!", &I);
    }
 
    APInt HighV = High->getValue();
    APInt LowV = Low->getValue();
 
    // ConstantRange asserts if the ranges are the same except for the min/max
    // value. Leave the cases it tolerates for the empty range error below.
    Check(LowV != HighV || LowV.isMaxValue() || LowV.isMinValue(),
          "The upper and lower limits cannot be the same value", &I);
 
    ConstantRange CurRange(LowV, HighV);
    Check(!CurRange.isEmptySet() &&
              (Kind == RangeLikeMetadataKind::AbsoluteSymbol ||
               !CurRange.isFullSet()),
          "Range must not be empty!", Range);
    if (i != 0) {
      Check(CurRange.intersectWith(LastRange).isEmptySet(),
            "Intervals are overlapping", Range);
      Check(LowV.sgt(LastRange.getLower()), "Intervals are not in order",
            Range);
      Check(!isContiguous(CurRange, LastRange), "Intervals are contiguous",
            Range);
    }
    LastRange = ConstantRange(LowV, HighV);
  }
  if (NumRanges > 2) {
    APInt FirstLow =
        mdconst::dyn_extract<ConstantInt>(Range->getOperand(0))->getValue();
    APInt FirstHigh =
        mdconst::dyn_extract<ConstantInt>(Range->getOperand(1))->getValue();
    ConstantRange FirstRange(FirstLow, FirstHigh);
    Check(FirstRange.intersectWith(LastRange).isEmptySet(),
          "Intervals are overlapping", Range);
    Check(!isContiguous(FirstRange, LastRange), "Intervals are contiguous",
          Range);
  }
}
 
void Verifier::visitRangeMetadata(Instruction &I, MDNode *Range, Type *Ty) {
  assert(Range && Range == I.getMetadata(LLVMContext::MD_range) &&
         "precondition violation");
  verifyRangeLikeMetadata(I, Range, Ty, RangeLikeMetadataKind::Range);
}
 
void Verifier::visitNoFPClassMetadata(Instruction &I, MDNode *NoFPClass,
                                      Type *Ty) {
  Check(AttributeFuncs::isNoFPClassCompatibleType(Ty),
        "nofpclass only applies to floating-point typed loads", I);
 
  Check(NoFPClass->getNumOperands() == 1,
        "nofpclass must have exactly one entry", NoFPClass);
  ConstantInt *MaskVal =
      mdconst::dyn_extract<ConstantInt>(NoFPClass->getOperand(0));
  Check(MaskVal && MaskVal->getType()->isIntegerTy(32),
        "nofpclass entry must be a constant i32", NoFPClass);
  uint32_t Val = MaskVal->getZExtValue();
  Check(Val != 0, "'nofpclass' must have at least one test bit set", NoFPClass,
        I);
 
  Check((Val & ~static_cast<unsigned>(fcAllFlags)) == 0,
        "Invalid value for 'nofpclass' test mask", NoFPClass, I);
}
 
void Verifier::visitNoaliasAddrspaceMetadata(Instruction &I, MDNode *Range,
                                             Type *Ty) {
  assert(Range && Range == I.getMetadata(LLVMContext::MD_noalias_addrspace) &&
         "precondition violation");
  verifyRangeLikeMetadata(I, Range, Ty,
                          RangeLikeMetadataKind::NoaliasAddrspace);
}
 
void Verifier::checkAtomicMemAccessSize(Type *Ty, const Instruction *I) {
  unsigned Size = DL.getTypeSizeInBits(Ty).getFixedValue();
  Check(Size >= 8, "atomic memory access' size must be byte-sized", Ty, I);
  Check(!(Size & (Size - 1)),
        "atomic memory access' operand must have a power-of-two size", Ty, I);
}
 
void Verifier::visitLoadInst(LoadInst &LI) {
  auto *PTy = dyn_cast<PointerType>(LI.getOperand(0)->getType());
  Check(PTy, "Load operand must be a pointer.", &LI);
  Type *ElTy = LI.getType();
  if (MaybeAlign A = LI.getAlign()) {
    Check(A->value() <= Value::MaximumAlignment,
          "huge alignment values are unsupported", &LI);
  }
  Check(ElTy->isSized(), "loading unsized types is not allowed", &LI);
  if (LI.isAtomic()) {
    Check(LI.getOrdering() != AtomicOrdering::Release &&
              LI.getOrdering() != AtomicOrdering::AcquireRelease,
          "Load cannot have Release ordering", &LI);
 
    if (LI.isElementwise()) {
      Check(LI.getOrdering() != AtomicOrdering::SequentiallyConsistent,
            "atomic elementwise load cannot be sequentially consistent.", &LI);
      auto *VecTy = dyn_cast<FixedVectorType>(ElTy);
      Check(VecTy,
            "atomic elementwise load operand must have fixed vector type!", &LI,
            ElTy);
      if (VecTy)
        checkAtomicMemAccessSize(VecTy->getElementType(), &LI);
    }
 
    Check(ElTy->getScalarType()->isIntOrPtrTy() ||
              ElTy->getScalarType()->isByteTy() ||
              ElTy->getScalarType()->isFloatingPointTy(),
          "atomic load operand must have integer, byte, pointer, floating "
          "point, or vector type!",
          ElTy, &LI);
 
    checkAtomicMemAccessSize(ElTy, &LI);
  } else {
    Check(!LI.isElementwise(), "non-atomic load cannot be elementwise", &LI);
    Check(LI.getSyncScopeID() == SyncScope::System,
          "Non-atomic load cannot have SynchronizationScope specified", &LI);
  }
 
  visitInstruction(LI);
}
 
void Verifier::visitStoreInst(StoreInst &SI) {
  auto *PTy = dyn_cast<PointerType>(SI.getOperand(1)->getType());
  Check(PTy, "Store operand must be a pointer.", &SI);
  Type *ElTy = SI.getOperand(0)->getType();
  if (MaybeAlign A = SI.getAlign()) {
    Check(A->value() <= Value::MaximumAlignment,
          "huge alignment values are unsupported", &SI);
  }
  Check(ElTy->isSized(), "storing unsized types is not allowed", &SI);
  if (SI.isAtomic()) {
    Check(SI.getOrdering() != AtomicOrdering::Acquire &&
              SI.getOrdering() != AtomicOrdering::AcquireRelease,
          "Store cannot have Acquire ordering", &SI);
 
    if (SI.isElementwise()) {
      Check(SI.getOrdering() != AtomicOrdering::SequentiallyConsistent,
            "atomic elementwise store cannot be sequentially consistent.", &SI);
 
      auto *VecTy = dyn_cast<FixedVectorType>(ElTy);
      Check(VecTy,
            "atomic elementwise store operand must have fixed vector type!",
            &SI, ElTy);
      if (VecTy)
        checkAtomicMemAccessSize(VecTy->getElementType(), &SI);
    }
 
    Check(ElTy->getScalarType()->isIntOrPtrTy() ||
              ElTy->getScalarType()->isByteTy() ||
              ElTy->getScalarType()->isFloatingPointTy(),
          "atomic store operand must have integer, byte, pointer, floating "
          "point, or vector type!",
          ElTy, &SI);
    checkAtomicMemAccessSize(ElTy, &SI);
  } else {
    Check(!SI.isElementwise(), "non-atomic store cannot be elementwise", &SI);
    Check(SI.getSyncScopeID() == SyncScope::System,
          "Non-atomic store cannot have SynchronizationScope specified", &SI);
  }
  visitInstruction(SI);
}
 
/// Check that SwiftErrorVal is used as a swifterror argument in CS.
void Verifier::verifySwiftErrorCall(CallBase &Call,
                                    const Value *SwiftErrorVal) {
  for (const auto &I : llvm::enumerate(Call.args())) {
    if (I.value() == SwiftErrorVal) {
      Check(Call.paramHasAttr(I.index(), Attribute::SwiftError),
            "swifterror value when used in a callsite should be marked "
            "with swifterror attribute",
            SwiftErrorVal, Call);
    }
  }
}
 
void Verifier::verifySwiftErrorValue(const Value *SwiftErrorVal) {
  // Check that swifterror value is only used by loads, stores, or as
  // a swifterror argument.
  for (const User *U : SwiftErrorVal->users()) {
    Check(isa<LoadInst>(U) || isa<StoreInst>(U) || isa<CallInst>(U) ||
              isa<InvokeInst>(U),
          "swifterror value can only be loaded and stored from, or "
          "as a swifterror argument!",
          SwiftErrorVal, U);
    // If it is used by a store, check it is the second operand.
    if (auto StoreI = dyn_cast<StoreInst>(U))
      Check(StoreI->getOperand(1) == SwiftErrorVal,
            "swifterror value should be the second operand when used "
            "by stores",
            SwiftErrorVal, U);
    if (auto *Call = dyn_cast<CallBase>(U))
      verifySwiftErrorCall(*const_cast<CallBase *>(Call), SwiftErrorVal);
  }
}
 
void Verifier::visitAllocaInst(AllocaInst &AI) {
  if (auto *MD = mdconst::extract_or_null<ConstantInt>(
          AI.getModule()->getModuleFlag("require-logical-pointer")))
    Check(!MD->getZExtValue(),
          "Non-logical alloca disallowed for this module.");
 
  Type *Ty = AI.getAllocatedType();
  SmallPtrSet<Type*, 4> Visited;
  Check(Ty->isSized(&Visited), "Cannot allocate unsized type", &AI);
  // Check if it's a target extension type that disallows being used on the
  // stack.
  Check(!Ty->containsNonLocalTargetExtType(),
        "Alloca has illegal target extension type", &AI);
  Check(AI.getArraySize()->getType()->isIntegerTy(),
        "Alloca array size must have integer type", &AI);
  if (MaybeAlign A = AI.getAlign()) {
    Check(A->value() <= Value::MaximumAlignment,
          "huge alignment values are unsupported", &AI);
  }
 
  if (AI.isSwiftError()) {
    Check(Ty->isPointerTy(), "swifterror alloca must have pointer type", &AI);
    Check(!AI.isArrayAllocation(),
          "swifterror alloca must not be array allocation", &AI);
    verifySwiftErrorValue(&AI);
  }
 
  visitInstruction(AI);
 
  // Target-specific alloca checks.
  verifyAMDGPUAlloca(*this, AI);
}
 
void Verifier::visitAtomicCmpXchgInst(AtomicCmpXchgInst &CXI) {
  Type *ElTy = CXI.getOperand(1)->getType();
  Check(ElTy->isIntOrPtrTy(),
        "cmpxchg operand must have integer or pointer type", ElTy, &CXI);
  checkAtomicMemAccessSize(ElTy, &CXI);
  visitInstruction(CXI);
}
 
void Verifier::visitAtomicRMWInst(AtomicRMWInst &RMWI) {
  Check(RMWI.getOrdering() != AtomicOrdering::Unordered,
        "atomicrmw instructions cannot be unordered.", &RMWI);
  auto Op = RMWI.getOperation();
  Type *ElTy = RMWI.getOperand(1)->getType();
  Check(!ElTy->isScalableTy(), "atomicrmw operand may not be scalable", &RMWI);
  if (RMWI.isElementwise()) {
    Check(RMWI.getOrdering() != AtomicOrdering::SequentiallyConsistent,
          "atomicrmw elementwise cannot be sequentially consistent.", &RMWI);
    auto *VecTy = dyn_cast<FixedVectorType>(ElTy);
    Check(VecTy, "atomicrmw elementwise operand must have fixed vector type!",
          &RMWI, ElTy);
    if (VecTy)
      checkAtomicMemAccessSize(VecTy->getElementType(), &RMWI);
  }
 
  if (Op == AtomicRMWInst::Xchg) {
    Check((ElTy->isIntOrIntVectorTy() || ElTy->isFPOrFPVectorTy() ||
           ElTy->isPtrOrPtrVectorTy()),
          "atomicrmw " + AtomicRMWInst::getOperationName(Op) +
              " operand must be an integer type, a floating-point type, a "
              "pointer type, or a fixed vector of any of these types!",
          &RMWI, ElTy);
  } else if (AtomicRMWInst::isFPOperation(Op)) {
    Check(ElTy->isFPOrFPVectorTy(),
          "atomicrmw " + AtomicRMWInst::getOperationName(Op) +
              " operand must have floating-point or fixed vector of "
              "floating-point "
              "type!",
          &RMWI, ElTy);
  } else {
    Check(ElTy->isIntOrIntVectorTy(),
          "atomicrmw " + AtomicRMWInst::getOperationName(Op) +
              " operand must have integer or fixed vector of integer type!",
          &RMWI, ElTy);
  }
  checkAtomicMemAccessSize(ElTy, &RMWI);
  Check(AtomicRMWInst::FIRST_BINOP <= Op && Op <= AtomicRMWInst::LAST_BINOP,
        "Invalid binary operation!", &RMWI);
  visitInstruction(RMWI);
}
 
void Verifier::visitFenceInst(FenceInst &FI) {
  const AtomicOrdering Ordering = FI.getOrdering();
  Check(Ordering == AtomicOrdering::Acquire ||
            Ordering == AtomicOrdering::Release ||
            Ordering == AtomicOrdering::AcquireRelease ||
            Ordering == AtomicOrdering::SequentiallyConsistent,
        "fence instructions may only have acquire, release, acq_rel, or "
        "seq_cst ordering.",
        &FI);
  visitInstruction(FI);
}
 
void Verifier::visitExtractValueInst(ExtractValueInst &EVI) {
  Check(ExtractValueInst::getIndexedType(EVI.getAggregateOperand()->getType(),
                                         EVI.getIndices()) == EVI.getType(),
        "Invalid ExtractValueInst operands!", &EVI);
 
  visitInstruction(EVI);
}
 
void Verifier::visitInsertValueInst(InsertValueInst &IVI) {
  Check(ExtractValueInst::getIndexedType(IVI.getAggregateOperand()->getType(),
                                         IVI.getIndices()) ==
            IVI.getOperand(1)->getType(),
        "Invalid InsertValueInst operands!", &IVI);
 
  visitInstruction(IVI);
}
 
static Value *getParentPad(Value *EHPad) {
  if (auto *FPI = dyn_cast<FuncletPadInst>(EHPad))
    return FPI->getParentPad();
 
  return cast<CatchSwitchInst>(EHPad)->getParentPad();
}
 
void Verifier::visitEHPadPredecessors(Instruction &I) {
  assert(I.isEHPad());
 
  BasicBlock *BB = I.getParent();
  Function *F = BB->getParent();
 
  Check(BB != &F->getEntryBlock(), "EH pad cannot be in entry block.", &I);
 
  if (auto *LPI = dyn_cast<LandingPadInst>(&I)) {
    // The landingpad instruction defines its parent as a landing pad block. The
    // landing pad block may be branched to only by the unwind edge of an
    // invoke.
    for (BasicBlock *PredBB : predecessors(BB)) {
      const auto *II = dyn_cast<InvokeInst>(PredBB->getTerminator());
      Check(II && II->getUnwindDest() == BB && II->getNormalDest() != BB,
            "Block containing LandingPadInst must be jumped to "
            "only by the unwind edge of an invoke.",
            LPI);
    }
    return;
  }
  if (auto *CPI = dyn_cast<CatchPadInst>(&I)) {
    if (!pred_empty(BB))
      Check(BB->getUniquePredecessor() == CPI->getCatchSwitch()->getParent(),
            "Block containg CatchPadInst must be jumped to "
            "only by its catchswitch.",
            CPI);
    Check(BB != CPI->getCatchSwitch()->getUnwindDest(),
          "Catchswitch cannot unwind to one of its catchpads",
          CPI->getCatchSwitch(), CPI);
    return;
  }
 
  // Verify that each pred has a legal terminator with a legal to/from EH
  // pad relationship.
  Instruction *ToPad = &I;
  Value *ToPadParent = getParentPad(ToPad);
  for (BasicBlock *PredBB : predecessors(BB)) {
    Instruction *TI = PredBB->getTerminator();
    Value *FromPad;
    if (auto *II = dyn_cast<InvokeInst>(TI)) {
      Check(II->getUnwindDest() == BB && II->getNormalDest() != BB,
            "EH pad must be jumped to via an unwind edge", ToPad, II);
      auto *CalledFn =
          dyn_cast<Function>(II->getCalledOperand()->stripPointerCasts());
      if (CalledFn && CalledFn->isIntrinsic() && II->doesNotThrow() &&
          !IntrinsicInst::mayLowerToFunctionCall(CalledFn->getIntrinsicID()))
        continue;
      if (auto Bundle = II->getOperandBundle(LLVMContext::OB_funclet))
        FromPad = Bundle->Inputs[0];
      else
        FromPad = ConstantTokenNone::get(II->getContext());
    } else if (auto *CRI = dyn_cast<CleanupReturnInst>(TI)) {
      FromPad = CRI->getOperand(0);
      Check(FromPad != ToPadParent, "A cleanupret must exit its cleanup", CRI);
    } else if (auto *CSI = dyn_cast<CatchSwitchInst>(TI)) {
      FromPad = CSI;
    } else {
      Check(false, "EH pad must be jumped to via an unwind edge", ToPad, TI);
    }
 
    // The edge may exit from zero or more nested pads.
    SmallPtrSet<Value *, 8> Seen;
    for (;; FromPad = getParentPad(FromPad)) {
      Check(FromPad != ToPad,
            "EH pad cannot handle exceptions raised within it", FromPad, TI);
      if (FromPad == ToPadParent) {
        // This is a legal unwind edge.
        break;
      }
      Check(!isa<ConstantTokenNone>(FromPad),
            "A single unwind edge may only enter one EH pad", TI);
      Check(Seen.insert(FromPad).second, "EH pad jumps through a cycle of pads",
            FromPad);
 
      // This will be diagnosed on the corresponding instruction already. We
      // need the extra check here to make sure getParentPad() works.
      Check(isa<FuncletPadInst>(FromPad) || isa<CatchSwitchInst>(FromPad),
            "Parent pad must be catchpad/cleanuppad/catchswitch", TI);
    }
  }
}
 
void Verifier::visitLandingPadInst(LandingPadInst &LPI) {
  // The landingpad instruction is ill-formed if it doesn't have any clauses and
  // isn't a cleanup.
  Check(LPI.getNumClauses() > 0 || LPI.isCleanup(),
        "LandingPadInst needs at least one clause or to be a cleanup.", &LPI);
 
  visitEHPadPredecessors(LPI);
 
  if (!LandingPadResultTy)
    LandingPadResultTy = LPI.getType();
  else
    Check(LandingPadResultTy == LPI.getType(),
          "The landingpad instruction should have a consistent result type "
          "inside a function.",
          &LPI);
 
  Function *F = LPI.getParent()->getParent();
  Check(F->hasPersonalityFn(),
        "LandingPadInst needs to be in a function with a personality.", &LPI);
 
  // The landingpad instruction must be the first non-PHI instruction in the
  // block.
  Check(LPI.getParent()->getLandingPadInst() == &LPI,
        "LandingPadInst not the first non-PHI instruction in the block.", &LPI);
 
  for (unsigned i = 0, e = LPI.getNumClauses(); i < e; ++i) {
    Constant *Clause = LPI.getClause(i);
    if (LPI.isCatch(i)) {
      Check(isa<PointerType>(Clause->getType()),
            "Catch operand does not have pointer type!", &LPI);
    } else {
      Check(LPI.isFilter(i), "Clause is neither catch nor filter!", &LPI);
      Check(isa<ConstantArray>(Clause) || isa<ConstantAggregateZero>(Clause),
            "Filter operand is not an array of constants!", &LPI);
    }
  }
 
  visitInstruction(LPI);
}
 
void Verifier::visitResumeInst(ResumeInst &RI) {
  Check(RI.getFunction()->hasPersonalityFn(),
        "ResumeInst needs to be in a function with a personality.", &RI);
 
  if (!LandingPadResultTy)
    LandingPadResultTy = RI.getValue()->getType();
  else
    Check(LandingPadResultTy == RI.getValue()->getType(),
          "The resume instruction should have a consistent result type "
          "inside a function.",
          &RI);
 
  visitTerminator(RI);
}
 
void Verifier::visitCatchPadInst(CatchPadInst &CPI) {
  BasicBlock *BB = CPI.getParent();
 
  Function *F = BB->getParent();
  Check(F->hasPersonalityFn(),
        "CatchPadInst needs to be in a function with a personality.", &CPI);
 
  Check(isa<CatchSwitchInst>(CPI.getParentPad()),
        "CatchPadInst needs to be directly nested in a CatchSwitchInst.",
        CPI.getParentPad());
 
  // The catchpad instruction must be the first non-PHI instruction in the
  // block.
  Check(&*BB->getFirstNonPHIIt() == &CPI,
        "CatchPadInst not the first non-PHI instruction in the block.", &CPI);
 
  Check(llvm::all_of(CPI.arg_operands(),
                     [](Use &U) {
                       auto *V = U.get();
                       return isa<Constant>(V) || isa<AllocaInst>(V);
                     }),
        "Argument operand must be alloca or constant.", &CPI);
 
  visitEHPadPredecessors(CPI);
  visitFuncletPadInst(CPI);
}
 
void Verifier::visitCatchReturnInst(CatchReturnInst &CatchReturn) {
  Check(isa<CatchPadInst>(CatchReturn.getOperand(0)),
        "CatchReturnInst needs to be provided a CatchPad", &CatchReturn,
        CatchReturn.getOperand(0));
 
  visitTerminator(CatchReturn);
}
 
void Verifier::visitCleanupPadInst(CleanupPadInst &CPI) {
  BasicBlock *BB = CPI.getParent();
 
  Function *F = BB->getParent();
  Check(F->hasPersonalityFn(),
        "CleanupPadInst needs to be in a function with a personality.", &CPI);
 
  // The cleanuppad instruction must be the first non-PHI instruction in the
  // block.
  Check(&*BB->getFirstNonPHIIt() == &CPI,
        "CleanupPadInst not the first non-PHI instruction in the block.", &CPI);
 
  auto *ParentPad = CPI.getParentPad();
  Check(isa<ConstantTokenNone>(ParentPad) || isa<FuncletPadInst>(ParentPad),
        "CleanupPadInst has an invalid parent.", &CPI);
 
  visitEHPadPredecessors(CPI);
  visitFuncletPadInst(CPI);
}
 
void Verifier::visitFuncletPadInst(FuncletPadInst &FPI) {
  User *FirstUser = nullptr;
  Value *FirstUnwindPad = nullptr;
  SmallVector<FuncletPadInst *, 8> Worklist({&FPI});
  SmallPtrSet<FuncletPadInst *, 8> Seen;
 
  while (!Worklist.empty()) {
    FuncletPadInst *CurrentPad = Worklist.pop_back_val();
    Check(Seen.insert(CurrentPad).second,
          "FuncletPadInst must not be nested within itself", CurrentPad);
    Value *UnresolvedAncestorPad = nullptr;
    for (User *U : CurrentPad->users()) {
      BasicBlock *UnwindDest;
      if (auto *CRI = dyn_cast<CleanupReturnInst>(U)) {
        UnwindDest = CRI->getUnwindDest();
      } else if (auto *CSI = dyn_cast<CatchSwitchInst>(U)) {
        // We allow catchswitch unwind to caller to nest
        // within an outer pad that unwinds somewhere else,
        // because catchswitch doesn't have a nounwind variant.
        // See e.g. SimplifyCFGOpt::SimplifyUnreachable.
        if (CSI->unwindsToCaller())
          continue;
        UnwindDest = CSI->getUnwindDest();
      } else if (auto *II = dyn_cast<InvokeInst>(U)) {
        UnwindDest = II->getUnwindDest();
      } else if (isa<CallInst>(U)) {
        // Calls which don't unwind may be found inside funclet
        // pads that unwind somewhere else.  We don't *require*
        // such calls to be annotated nounwind.
        continue;
      } else if (auto *CPI = dyn_cast<CleanupPadInst>(U)) {
        // The unwind dest for a cleanup can only be found by
        // recursive search.  Add it to the worklist, and we'll
        // search for its first use that determines where it unwinds.
        Worklist.push_back(CPI);
        continue;
      } else {
        Check(isa<CatchReturnInst>(U), "Bogus funclet pad use", U);
        continue;
      }
 
      Value *UnwindPad;
      bool ExitsFPI;
      if (UnwindDest) {
        UnwindPad = &*UnwindDest->getFirstNonPHIIt();
        if (!cast<Instruction>(UnwindPad)->isEHPad())
          continue;
        Value *UnwindParent = getParentPad(UnwindPad);
        // Ignore unwind edges that don't exit CurrentPad.
        if (UnwindParent == CurrentPad)
          continue;
        // Determine whether the original funclet pad is exited,
        // and if we are scanning nested pads determine how many
        // of them are exited so we can stop searching their
        // children.
        Value *ExitedPad = CurrentPad;
        ExitsFPI = false;
        do {
          if (ExitedPad == &FPI) {
            ExitsFPI = true;
            // Now we can resolve any ancestors of CurrentPad up to
            // FPI, but not including FPI since we need to make sure
            // to check all direct users of FPI for consistency.
            UnresolvedAncestorPad = &FPI;
            break;
          }
          Value *ExitedParent = getParentPad(ExitedPad);
          if (ExitedParent == UnwindParent) {
            // ExitedPad is the ancestor-most pad which this unwind
            // edge exits, so we can resolve up to it, meaning that
            // ExitedParent is the first ancestor still unresolved.
            UnresolvedAncestorPad = ExitedParent;
            break;
          }
          ExitedPad = ExitedParent;
        } while (!isa<ConstantTokenNone>(ExitedPad));
      } else {
        // Unwinding to caller exits all pads.
        UnwindPad = ConstantTokenNone::get(FPI.getContext());
        ExitsFPI = true;
        UnresolvedAncestorPad = &FPI;
      }
 
      if (ExitsFPI) {
        // This unwind edge exits FPI.  Make sure it agrees with other
        // such edges.
        if (FirstUser) {
          Check(UnwindPad == FirstUnwindPad,
                "Unwind edges out of a funclet "
                "pad must have the same unwind "
                "dest",
                &FPI, U, FirstUser);
        } else {
          FirstUser = U;
          FirstUnwindPad = UnwindPad;
          // Record cleanup sibling unwinds for verifySiblingFuncletUnwinds
          if (isa<CleanupPadInst>(&FPI) && !isa<ConstantTokenNone>(UnwindPad) &&
              getParentPad(UnwindPad) == getParentPad(&FPI))
            SiblingFuncletInfo[&FPI] = cast<Instruction>(U);
        }
      }
      // Make sure we visit all uses of FPI, but for nested pads stop as
      // soon as we know where they unwind to.
      if (CurrentPad != &FPI)
        break;
    }
    if (UnresolvedAncestorPad) {
      if (CurrentPad == UnresolvedAncestorPad) {
        // When CurrentPad is FPI itself, we don't mark it as resolved even if
        // we've found an unwind edge that exits it, because we need to verify
        // all direct uses of FPI.
        assert(CurrentPad == &FPI);
        continue;
      }
      // Pop off the worklist any nested pads that we've found an unwind
      // destination for.  The pads on the worklist are the uncles,
      // great-uncles, etc. of CurrentPad.  We've found an unwind destination
      // for all ancestors of CurrentPad up to but not including
      // UnresolvedAncestorPad.
      Value *ResolvedPad = CurrentPad;
      while (!Worklist.empty()) {
        Value *UnclePad = Worklist.back();
        Value *AncestorPad = getParentPad(UnclePad);
        // Walk ResolvedPad up the ancestor list until we either find the
        // uncle's parent or the last resolved ancestor.
        while (ResolvedPad != AncestorPad) {
          Value *ResolvedParent = getParentPad(ResolvedPad);
          if (ResolvedParent == UnresolvedAncestorPad) {
            break;
          }
          ResolvedPad = ResolvedParent;
        }
        // If the resolved ancestor search didn't find the uncle's parent,
        // then the uncle is not yet resolved.
        if (ResolvedPad != AncestorPad)
          break;
        // This uncle is resolved, so pop it from the worklist.
        Worklist.pop_back();
      }
    }
  }
 
  if (FirstUnwindPad) {
    if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(FPI.getParentPad())) {
      BasicBlock *SwitchUnwindDest = CatchSwitch->getUnwindDest();
      Value *SwitchUnwindPad;
      if (SwitchUnwindDest)
        SwitchUnwindPad = &*SwitchUnwindDest->getFirstNonPHIIt();
      else
        SwitchUnwindPad = ConstantTokenNone::get(FPI.getContext());
      Check(SwitchUnwindPad == FirstUnwindPad,
            "Unwind edges out of a catch must have the same unwind dest as "
            "the parent catchswitch",
            &FPI, FirstUser, CatchSwitch);
    }
  }
 
  visitInstruction(FPI);
}
 
void Verifier::visitCatchSwitchInst(CatchSwitchInst &CatchSwitch) {
  BasicBlock *BB = CatchSwitch.getParent();
 
  Function *F = BB->getParent();
  Check(F->hasPersonalityFn(),
        "CatchSwitchInst needs to be in a function with a personality.",
        &CatchSwitch);
 
  // The catchswitch instruction must be the first non-PHI instruction in the
  // block.
  Check(&*BB->getFirstNonPHIIt() == &CatchSwitch,
        "CatchSwitchInst not the first non-PHI instruction in the block.",
        &CatchSwitch);
 
  auto *ParentPad = CatchSwitch.getParentPad();
  Check(isa<ConstantTokenNone>(ParentPad) || isa<FuncletPadInst>(ParentPad),
        "CatchSwitchInst has an invalid parent.", ParentPad);
 
  if (BasicBlock *UnwindDest = CatchSwitch.getUnwindDest()) {
    BasicBlock::iterator I = UnwindDest->getFirstNonPHIIt();
    Check(I->isEHPad() && !isa<LandingPadInst>(I),
          "CatchSwitchInst must unwind to an EH block which is not a "
          "landingpad.",
          &CatchSwitch);
 
    // Record catchswitch sibling unwinds for verifySiblingFuncletUnwinds
    if (getParentPad(&*I) == ParentPad)
      SiblingFuncletInfo[&CatchSwitch] = &CatchSwitch;
  }
 
  Check(CatchSwitch.getNumHandlers() != 0,
        "CatchSwitchInst cannot have empty handler list", &CatchSwitch);
 
  for (BasicBlock *Handler : CatchSwitch.handlers()) {
    Check(isa<CatchPadInst>(Handler->getFirstNonPHIIt()),
          "CatchSwitchInst handlers must be catchpads", &CatchSwitch, Handler);
  }
 
  visitEHPadPredecessors(CatchSwitch);
  visitTerminator(CatchSwitch);
}
 
void Verifier::visitCleanupReturnInst(CleanupReturnInst &CRI) {
  Check(isa<CleanupPadInst>(CRI.getOperand(0)),
        "CleanupReturnInst needs to be provided a CleanupPad", &CRI,
        CRI.getOperand(0));
 
  if (BasicBlock *UnwindDest = CRI.getUnwindDest()) {
    BasicBlock::iterator I = UnwindDest->getFirstNonPHIIt();
    Check(I->isEHPad() && !isa<LandingPadInst>(I),
          "CleanupReturnInst must unwind to an EH block which is not a "
          "landingpad.",
          &CRI);
  }
 
  visitTerminator(CRI);
}
 
void Verifier::verifyDominatesUse(Instruction &I, unsigned i) {
  Instruction *Op = cast<Instruction>(I.getOperand(i));
  // If the we have an invalid invoke, don't try to compute the dominance.
  // We already reject it in the invoke specific checks and the dominance
  // computation doesn't handle multiple edges.
  if (auto *II = dyn_cast<InvokeInst>(Op)) {
    if (II->getNormalDest() == II->getUnwindDest())
      return;
  }
 
  // Quick check whether the def has already been encountered in the same block.
  // PHI nodes are not checked to prevent accepting preceding PHIs, because PHI
  // uses are defined to happen on the incoming edge, not at the instruction.
  //
  // FIXME: If this operand is a MetadataAsValue (wrapping a LocalAsMetadata)
  // wrapping an SSA value, assert that we've already encountered it.  See
  // related FIXME in Mapper::mapLocalAsMetadata in ValueMapper.cpp.
  if (!isa<PHINode>(I) && InstsInThisBlock.count(Op))
    return;
 
  const Use &U = I.getOperandUse(i);
  Check(DT.dominates(Op, U), "Instruction does not dominate all uses!", Op, &I);
}
 
void Verifier::visitDereferenceableMetadata(Instruction& I, MDNode* MD) {
  Check(I.getType()->isPointerTy(),
        "dereferenceable, dereferenceable_or_null "
        "apply only to pointer types",
        &I);
  Check((isa<LoadInst>(I) || isa<IntToPtrInst>(I)),
        "dereferenceable, dereferenceable_or_null apply only to load"
        " and inttoptr instructions, use attributes for calls or invokes",
        &I);
  Check(MD->getNumOperands() == 1,
        "dereferenceable, dereferenceable_or_null "
        "take one operand!",
        &I);
  ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(MD->getOperand(0));
  Check(CI && CI->getType()->isIntegerTy(64),
        "dereferenceable, "
        "dereferenceable_or_null metadata value must be an i64!",
        &I);
}
 
void Verifier::visitNoFreeObjMetadata(Instruction &I, MDNode *MD) {
  Check(I.getType()->isPointerTy(), "nofreeobj applies only to pointer types",
        &I);
  Check((isa<IntToPtrInst>(I)),
        "nofreeobj applies only to inttoptr instruction", &I);
  Check(MD->getNumOperands() == 0, "nofreeobj metadata must be empty", &I);
}
 
void Verifier::visitProfMetadata(Instruction &I, MDNode *MD) {
  auto GetBranchingTerminatorNumOperands = [&]() {
    unsigned ExpectedNumOperands = 0;
    if (auto *BI = dyn_cast<CondBrInst>(&I))
      ExpectedNumOperands = BI->getNumSuccessors();
    else if (auto *SI = dyn_cast<SwitchInst>(&I))
      ExpectedNumOperands = SI->getNumSuccessors();
    else if (isa<CallInst>(&I))
      ExpectedNumOperands = 1;
    else if (auto *IBI = dyn_cast<IndirectBrInst>(&I))
      ExpectedNumOperands = IBI->getNumDestinations();
    else if (isa<SelectInst>(&I))
      ExpectedNumOperands = 2;
    else if (auto *CI = dyn_cast<CallBrInst>(&I))
      ExpectedNumOperands = CI->getNumSuccessors();
    return ExpectedNumOperands;
  };
  Check(MD->getNumOperands() >= 1,
        "!prof annotations should have at least 1 operand", MD);
  // Check first operand.
  Check(MD->getOperand(0) != nullptr, "first operand should not be null", MD);
  Check(isa<MDString>(MD->getOperand(0)),
        "expected string with name of the !prof annotation", MD);
  MDString *MDS = cast<MDString>(MD->getOperand(0));
  StringRef ProfName = MDS->getString();
 
  if (ProfName == MDProfLabels::UnknownBranchWeightsMarker) {
    Check(GetBranchingTerminatorNumOperands() != 0 || isa<InvokeInst>(I),
          "'unknown' !prof should only appear on instructions on which "
          "'branch_weights' would",
          MD);
    verifyUnknownProfileMetadata(MD);
    return;
  }
 
  Check(MD->getNumOperands() >= 2,
        "!prof annotations should have no less than 2 operands", MD);
 
  // Check consistency of !prof branch_weights metadata.
  if (ProfName == MDProfLabels::BranchWeights) {
    unsigned NumBranchWeights = getNumBranchWeights(*MD);
    if (isa<InvokeInst>(&I)) {
      Check(NumBranchWeights == 1 || NumBranchWeights == 2,
            "Wrong number of InvokeInst branch_weights operands", MD);
    } else {
      const unsigned ExpectedNumOperands = GetBranchingTerminatorNumOperands();
      if (ExpectedNumOperands == 0)
        CheckFailed("!prof branch_weights are not allowed for this instruction",
                    MD);
 
      Check(NumBranchWeights == ExpectedNumOperands, "Wrong number of operands",
            MD);
    }
    for (unsigned i = getBranchWeightOffset(MD); i < MD->getNumOperands();
         ++i) {
      auto &MDO = MD->getOperand(i);
      Check(MDO, "second operand should not be null", MD);
      Check(mdconst::dyn_extract<ConstantInt>(MDO),
            "!prof brunch_weights operand is not a const int");
    }
  } else if (ProfName == MDProfLabels::ValueProfile) {
    Check(isValueProfileMD(MD), "invalid value profiling metadata", MD);
    ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
    Check(KindInt, "VP !prof missing kind argument", MD);
 
    auto Kind = KindInt->getZExtValue();
    Check(Kind >= InstrProfValueKind::IPVK_First &&
              Kind <= InstrProfValueKind::IPVK_Last,
          "Invalid VP !prof kind", MD);
    Check(MD->getNumOperands() % 2 == 1,
          "VP !prof should have an even number "
          "of arguments after 'VP'",
          MD);
    if (Kind == InstrProfValueKind::IPVK_IndirectCallTarget ||
        Kind == InstrProfValueKind::IPVK_MemOPSize)
      Check(isa<CallBase>(I),
            "VP !prof indirect call or memop size expected to be applied to "
            "CallBase instructions only",
            MD);
 
    DenseSet<uint64_t> ProfileValues;
    for (unsigned I = 3; I < MD->getNumOperands(); I += 2) {
      ConstantInt *ProfileValue =
          mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
      Check(ProfileValue, "VP !prof value operand is not a const int", MD);
      uint64_t ProfileValueInt = ProfileValue->getZExtValue();
      auto [ValueIt, Inserted] = ProfileValues.insert(ProfileValueInt);
      Check(Inserted, "VP !prof should not have duplicate profile values", MD);
    }
  } else {
    CheckFailed("expected either branch_weights or VP profile name", MD);
  }
}
 
void Verifier::visitDIAssignIDMetadata(Instruction &I, MDNode *MD) {
  assert(I.hasMetadata(LLVMContext::MD_DIAssignID));
  // DIAssignID metadata must be attached to either an alloca or some form of
  // store/memory-writing instruction.
  // FIXME: We allow all intrinsic insts here to avoid trying to enumerate all
  // possible store intrinsics.
  bool ExpectedInstTy =
      isa<AllocaInst>(I) || isa<StoreInst>(I) || isa<IntrinsicInst>(I);
  CheckDI(ExpectedInstTy, "!DIAssignID attached to unexpected instruction kind",
          I, MD);
  // Iterate over the MetadataAsValue uses of the DIAssignID - these should
  // only be found as DbgAssignIntrinsic operands.
  if (auto *AsValue = MetadataAsValue::getIfExists(Context, MD)) {
    for (auto *User : AsValue->users()) {
      CheckDI(isa<DbgAssignIntrinsic>(User),
              "!DIAssignID should only be used by llvm.dbg.assign intrinsics",
              MD, User);
      // All of the dbg.assign intrinsics should be in the same function as I.
      if (auto *DAI = dyn_cast<DbgAssignIntrinsic>(User))
        CheckDI(DAI->getFunction() == I.getFunction(),
                "dbg.assign not in same function as inst", DAI, &I);
    }
  }
  for (DbgVariableRecord *DVR :
       cast<DIAssignID>(MD)->getAllDbgVariableRecordUsers()) {
    CheckDI(DVR->isDbgAssign(),
            "!DIAssignID should only be used by Assign DVRs.", MD, DVR);
    CheckDI(DVR->getFunction() == I.getFunction(),
            "DVRAssign not in same function as inst", DVR, &I);
  }
}
 
void Verifier::visitMMRAMetadata(Instruction &I, MDNode *MD) {
  Check(canInstructionHaveMMRAs(I),
        "!mmra metadata attached to unexpected instruction kind", I, MD);
 
  // MMRA Metadata should either be a tag, e.g. !{!"foo", !"bar"}, or a
  // list of tags such as !2 in the following example:
  //    !0 = !{!"a", !"b"}
  //    !1 = !{!"c", !"d"}
  //    !2 = !{!0, !1}
  if (MMRAMetadata::isTagMD(MD))
    return;
 
  Check(isa<MDTuple>(MD), "!mmra expected to be a metadata tuple", I, MD);
  for (const MDOperand &MDOp : MD->operands())
    Check(MMRAMetadata::isTagMD(MDOp.get()),
          "!mmra metadata tuple operand is not an MMRA tag", I, MDOp.get());
}
 
void Verifier::visitCallStackMetadata(MDNode *MD) {
  // Call stack metadata should consist of a list of at least 1 constant int
  // (representing a hash of the location).
  Check(MD->getNumOperands() >= 1,
        "call stack metadata should have at least 1 operand", MD);
 
  for (const auto &Op : MD->operands())
    Check(mdconst::dyn_extract_or_null<ConstantInt>(Op),
          "call stack metadata operand should be constant integer", Op);
}
 
void Verifier::visitMemProfMetadata(Instruction &I, MDNode *MD) {
  Check(isa<CallBase>(I), "!memprof metadata should only exist on calls", &I);
  if (isa<CallBase>(I))
    Check(I.hasMetadata(LLVMContext::MD_callsite),
          "!memprof metadata requires !callsite metadata", &I, MD);
  Check(MD->getNumOperands() >= 1,
        "!memprof annotations should have at least 1 metadata operand "
        "(MemInfoBlock)",
        MD);
 
  // Check each MIB
  for (auto &MIBOp : MD->operands()) {
    auto *MIB = dyn_cast<MDNode>(MIBOp);
    // The first operand of an MIB should be the call stack metadata.
    // There rest of the operands should be MDString tags, and there should be
    // at least one.
    Check(MIB->getNumOperands() >= 2,
          "Each !memprof MemInfoBlock should have at least 2 operands", MIB);
 
    // Check call stack metadata (first operand).
    Check(MIB->getOperand(0) != nullptr,
          "!memprof MemInfoBlock first operand should not be null", MIB);
    Check(isa<MDNode>(MIB->getOperand(0)),
          "!memprof MemInfoBlock first operand should be an MDNode", MIB);
    auto *StackMD = dyn_cast<MDNode>(MIB->getOperand(0));
    visitCallStackMetadata(StackMD);
 
    // The second MIB operand should be MDString.
    Check(isa<MDString>(MIB->getOperand(1)),
          "!memprof MemInfoBlock second operand should be an MDString", MIB);
 
    // Any remaining should be MDNode that are pairs of integers
    for (unsigned I = 2; I < MIB->getNumOperands(); ++I) {
      auto *OpNode = dyn_cast<MDNode>(MIB->getOperand(I));
      Check(OpNode, "Not all !memprof MemInfoBlock operands 2 to N are MDNode",
            MIB);
      Check(OpNode->getNumOperands() == 2,
            "Not all !memprof MemInfoBlock operands 2 to N are MDNode with 2 "
            "operands",
            MIB);
      // Check that all of Op's operands are ConstantInt.
      Check(llvm::all_of(OpNode->operands(),
                         [](const MDOperand &Op) {
                           return mdconst::hasa<ConstantInt>(Op);
                         }),
            "Not all !memprof MemInfoBlock operands 2 to N are MDNode with "
            "ConstantInt operands",
            MIB);
    }
  }
}
 
void Verifier::visitCallsiteMetadata(Instruction &I, MDNode *MD) {
  Check(isa<CallBase>(I), "!callsite metadata should only exist on calls", &I);
  // Verify the partial callstack annotated from memprof profiles. This callsite
  // is a part of a profiled allocation callstack.
  visitCallStackMetadata(MD);
}
 
void Verifier::visitCalleeTypeMetadata(Instruction &I, MDNode *MD) {
  Check(isa<CallBase>(I), "!callee_type metadata should only exist on calls",
        &I);
  for (Metadata *Op : MD->operands()) {
    Check(isa<MDNode>(Op),
          "The callee_type metadata must be a list of callgraph metadata nodes",
          Op);
    auto *CallgraphMD = cast<MDNode>(Op);
    Check(CallgraphMD->getNumOperands() == 1,
          "Well-formed callgraph metadata must contain exactly one "
          "operand",
          Op);
    Check(isa<MDString>(CallgraphMD->getOperand(0)),
          "The operand of callgraph metadata for functions must be an MDString",
          Op);
  }
}
 
void Verifier::visitAnnotationMetadata(MDNode *Annotation) {
  Check(isa<MDTuple>(Annotation), "annotation must be a tuple");
  Check(Annotation->getNumOperands() >= 1,
        "annotation must have at least one operand");
  for (const MDOperand &Op : Annotation->operands()) {
    bool TupleOfStrings =
        isa<MDTuple>(Op.get()) &&
        all_of(cast<MDTuple>(Op)->operands(), [](auto &Annotation) {
          return isa<MDString>(Annotation.get());
        });
    Check(isa<MDString>(Op.get()) || TupleOfStrings,
          "operands must be a string or a tuple of strings");
  }
}
 
void Verifier::visitAliasScopeMetadata(const MDNode *MD) {
  unsigned NumOps = MD->getNumOperands();
  Check(NumOps >= 2 && NumOps <= 3, "scope must have two or three operands",
        MD);
  Check(MD->getOperand(0).get() == MD || isa<MDString>(MD->getOperand(0)),
        "first scope operand must be self-referential or string", MD);
  if (NumOps == 3)
    Check(isa<MDString>(MD->getOperand(2)),
          "third scope operand must be string (if used)", MD);
 
  auto *Domain = dyn_cast<MDNode>(MD->getOperand(1));
  Check(Domain != nullptr, "second scope operand must be MDNode", MD);
 
  unsigned NumDomainOps = Domain->getNumOperands();
  Check(NumDomainOps >= 1 && NumDomainOps <= 2,
        "domain must have one or two operands", Domain);
  Check(Domain->getOperand(0).get() == Domain ||
            isa<MDString>(Domain->getOperand(0)),
        "first domain operand must be self-referential or string", Domain);
  if (NumDomainOps == 2)
    Check(isa<MDString>(Domain->getOperand(1)),
          "second domain operand must be string (if used)", Domain);
}
 
void Verifier::visitAliasScopeListMetadata(const MDNode *MD) {
  for (const MDOperand &Op : MD->operands()) {
    const auto *OpMD = dyn_cast<MDNode>(Op);
    Check(OpMD != nullptr, "scope list must consist of MDNodes", MD);
    visitAliasScopeMetadata(OpMD);
  }
}
 
void Verifier::visitAccessGroupMetadata(const MDNode *MD) {
  auto IsValidAccessScope = [](const MDNode *MD) {
    return MD->getNumOperands() == 0 && MD->isDistinct();
  };
 
  // An empty node is an access scope, and it must be 'distinct'. It is never a
  // list, because an empty list is not allowed: it would look the same as an
  // access scope.
  if (MD->getNumOperands() == 0) {
    Check(MD->isDistinct(), "Access scope must be 'distinct'", MD);
    return;
  }
 
  // A non-empty node is a list of access scopes.
  for (const MDOperand &Op : MD->operands()) {
    const auto *OpMD = dyn_cast<MDNode>(Op);
    Check(OpMD != nullptr, "Access scope list must consist of MDNodes", MD);
    Check(IsValidAccessScope(OpMD),
          "Access scope list contains invalid access scope", MD);
  }
}
 
void Verifier::visitCapturesMetadata(Instruction &I, const MDNode *Captures) {
  static const char *ValidArgs[] = {"address_is_null", "address",
                                    "read_provenance", "provenance"};
 
  auto *SI = dyn_cast<StoreInst>(&I);
  Check(SI, "!captures metadata can only be applied to store instructions", &I);
  Check(SI->getValueOperand()->getType()->isPointerTy(),
        "!captures metadata can only be applied to store with value operand of "
        "pointer type",
        &I);
  Check(Captures->getNumOperands() != 0, "!captures metadata cannot be empty",
        &I);
 
  for (Metadata *Op : Captures->operands()) {
    auto *Str = dyn_cast<MDString>(Op);
    Check(Str, "!captures metadata must be a list of strings", &I);
    Check(is_contained(ValidArgs, Str->getString()),
          "invalid entry in !captures metadata", &I, Str);
  }
}
 
void Verifier::visitAllocTokenMetadata(Instruction &I, MDNode *MD) {
  Check(isa<CallBase>(I), "!alloc_token should only exist on calls", &I);
  Check(MD->getNumOperands() == 2, "!alloc_token must have 2 operands", MD);
  Check(isa<MDString>(MD->getOperand(0)), "expected string", MD);
  Check(mdconst::dyn_extract_or_null<ConstantInt>(MD->getOperand(1)),
        "expected integer constant", MD);
}
 
void Verifier::visitInlineHistoryMetadata(Instruction &I, MDNode *MD) {
  Check(isa<CallBase>(I), "!inline_history should only exist on calls", &I);
  for (Metadata *Op : MD->operands()) {
    // Can be null when a function is erased.
    if (!Op)
      continue;
    Check(isa<ValueAsMetadata>(Op) &&
              isa<Function>(cast<ValueAsMetadata>(Op)
                                ->getValue()
                                ->stripPointerCastsAndAliases()),
          "!inline_history operands must be functions or null", MD);
  }
}
 
void Verifier::visitMemCacheHintMetadata(Instruction &I, MDNode *MD) {
  Check(I.mayReadOrWriteMemory(),
        "!mem.cache_hint is only valid on memory operations", &I);
 
  Check(MD->getNumOperands() % 2 == 0,
        "!mem.cache_hint must have even number of operands "
        "(operand_no, hint_node pairs)",
        MD);
 
  const auto *CB = dyn_cast<CallBase>(&I);
  if (CB)
    Check(CB->getIntrinsicID() != Intrinsic::not_intrinsic,
          "!mem.cache_hint is not supported on non-intrinsic calls", &I);
 
  unsigned NumOperands = CB ? CB->arg_size() : I.getNumOperands();
 
  SmallDenseSet<unsigned, 4> SeenOperandNos;
  std::optional<uint64_t> LastOperandNo;
 
  // Top-level metadata alternates: i32 operand_no, MDNode hint_node.
  for (unsigned J = 0; J + 1 < MD->getNumOperands(); J += 2) {
    auto *OpNoCI = mdconst::dyn_extract<ConstantInt>(MD->getOperand(J));
    Check(OpNoCI,
          "!mem.cache_hint must alternate between i32 operand numbers and "
          "metadata hint nodes",
          MD);
 
    Check(OpNoCI->getValue().isNonNegative(),
          "!mem.cache_hint operand number must be non-negative", MD);
 
    uint64_t OperandNo = OpNoCI->getZExtValue();
    Check(OperandNo < NumOperands,
          "!mem.cache_hint operand number is out of range", &I);
 
    Value *Operand =
        CB ? CB->getArgOperand(OperandNo) : I.getOperand(OperandNo);
    Check(Operand->getType()->isPtrOrPtrVectorTy(),
          "!mem.cache_hint operand number must refer to a pointer operand", &I);
 
    bool Inserted = SeenOperandNos.insert(OperandNo).second;
    Check(Inserted, "!mem.cache_hint contains duplicate operand number", MD);
 
    Check(!Inserted || !LastOperandNo || OperandNo > *LastOperandNo,
          "!mem.cache_hint operand numbers must be in increasing order", MD);
    LastOperandNo = OperandNo;
 
    const auto *Node = dyn_cast<MDNode>(MD->getOperand(J + 1));
    Check(Node,
          "!mem.cache_hint must alternate between i32 operand numbers and "
          "metadata hint nodes",
          MD);
 
    Check(Node->getNumOperands() % 2 == 0,
          "!mem.cache_hint hint node must have even number of operands "
          "(key-value pairs)",
          Node);
 
    StringSet<> SeenKeys;
    for (unsigned K = 0; K + 1 < Node->getNumOperands(); K += 2) {
      const auto *Key = dyn_cast<MDString>(Node->getOperand(K));
      Check(Key, "!mem.cache_hint key must be a string", Node);
 
      StringRef KeyStr = Key->getString();
      Check(SeenKeys.insert(KeyStr).second,
            "!mem.cache_hint hint node contains duplicate key", Node);
 
      const Metadata *Value = Node->getOperand(K + 1).get();
      Check(isa_and_nonnull<MDString>(Value) ||
                mdconst::dyn_extract<ConstantInt>(Value),
            "!mem.cache_hint value must be a string or integer", Node);
    }
  }
}
 
/// verifyInstruction - Verify that an instruction is well formed.
///
void Verifier::visitInstruction(Instruction &I) {
  BasicBlock *BB = I.getParent();
  Check(BB, "Instruction not embedded in basic block!", &I);
 
  if (!isa<PHINode>(I)) {   // Check that non-phi nodes are not self referential
    for (User *U : I.users()) {
      Check(U != (User *)&I || !DT.isReachableFromEntry(BB),
            "Only PHI nodes may reference their own value!", &I);
    }
  }
 
  // Check that void typed values don't have names
  Check(!I.getType()->isVoidTy() || !I.hasName(),
        "Instruction has a name, but provides a void value!", &I);
 
  // Check that the return value of the instruction is either void or a legal
  // value type.
  Check(I.getType()->isVoidTy() || I.getType()->isFirstClassType(),
        "Instruction returns a non-scalar type!", &I);
 
  // Check that the instruction doesn't produce metadata. Calls are already
  // checked against the callee type.
  Check(!I.getType()->isMetadataTy() || isa<CallInst>(I) || isa<InvokeInst>(I),
        "Invalid use of metadata!", &I);
 
  // Check that all uses of the instruction, if they are instructions
  // themselves, actually have parent basic blocks.  If the use is not an
  // instruction, it is an error!
  for (Use &U : I.uses()) {
    if (auto *Used = dyn_cast<Instruction>(U.getUser()))
      Check(Used->getParent() != nullptr,
            "Instruction referencing"
            " instruction not embedded in a basic block!",
            &I, Used);
    else {
      CheckFailed("Use of instruction is not an instruction!", U);
      return;
    }
  }
 
  // Get a pointer to the call base of the instruction if it is some form of
  // call.
  const auto *CBI = dyn_cast<CallBase>(&I);
 
  for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) {
    Check(I.getOperand(i) != nullptr, "Instruction has null operand!", &I);
 
    // Check to make sure that only first-class-values are operands to
    // instructions.
    if (!I.getOperand(i)->getType()->isFirstClassType()) {
      Check(false, "Instruction operands must be first-class values!", &I);
    }
 
    if (auto *F = dyn_cast<Function>(I.getOperand(i))) {
      // This code checks whether the function is used as the operand of a
      // clang_arc_attachedcall operand bundle.
      auto IsAttachedCallOperand = [](Function *F, const CallBase *CBI,
                                      int Idx) {
        return CBI && CBI->isOperandBundleOfType(
                          LLVMContext::OB_clang_arc_attachedcall, Idx);
      };
 
      // Check to make sure that the "address of" an intrinsic function is never
      // taken. Ignore cases where the address of the intrinsic function is used
      // as the argument of operand bundle "clang.arc.attachedcall" as those
      // cases are handled in verifyAttachedCallBundle.
      Check((!F->isIntrinsic() ||
             (CBI && &CBI->getCalledOperandUse() == &I.getOperandUse(i)) ||
             IsAttachedCallOperand(F, CBI, i)),
            "Cannot take the address of an intrinsic!", &I);
      Check(!F->isIntrinsic() || isa<CallInst>(I) || isa<CallBrInst>(I) ||
                F->getIntrinsicID() == Intrinsic::donothing ||
                F->getIntrinsicID() == Intrinsic::seh_try_begin ||
                F->getIntrinsicID() == Intrinsic::seh_try_end ||
                F->getIntrinsicID() == Intrinsic::seh_scope_begin ||
                F->getIntrinsicID() == Intrinsic::seh_scope_end ||
                F->getIntrinsicID() == Intrinsic::coro_resume ||
                F->getIntrinsicID() == Intrinsic::coro_destroy ||
                F->getIntrinsicID() == Intrinsic::coro_await_suspend_void ||
                F->getIntrinsicID() == Intrinsic::coro_await_suspend_bool ||
                F->getIntrinsicID() == Intrinsic::coro_await_suspend_handle ||
                F->getIntrinsicID() ==
                    Intrinsic::experimental_patchpoint_void ||
                F->getIntrinsicID() == Intrinsic::experimental_patchpoint ||
                F->getIntrinsicID() == Intrinsic::fake_use ||
                F->getIntrinsicID() == Intrinsic::experimental_gc_statepoint ||
                F->getIntrinsicID() == Intrinsic::wasm_throw ||
                F->getIntrinsicID() == Intrinsic::wasm_rethrow ||
                IsAttachedCallOperand(F, CBI, i),
            "Cannot invoke an intrinsic other than donothing, patchpoint, "
            "statepoint, coro_resume, coro_destroy, clang.arc.attachedcall or "
            "wasm.(re)throw",
            &I);
      Check(F->getParent() == &M, "Referencing function in another module!", &I,
            &M, F, F->getParent());
    } else if (auto *OpBB = dyn_cast<BasicBlock>(I.getOperand(i))) {
      Check(OpBB->getParent() == BB->getParent(),
            "Referring to a basic block in another function!", &I);
    } else if (auto *OpArg = dyn_cast<Argument>(I.getOperand(i))) {
      Check(OpArg->getParent() == BB->getParent(),
            "Referring to an argument in another function!", &I);
    } else if (auto *GV = dyn_cast<GlobalValue>(I.getOperand(i))) {
      Check(GV->getParent() == &M, "Referencing global in another module!", &I,
            &M, GV, GV->getParent());
    } else if (auto *OpInst = dyn_cast<Instruction>(I.getOperand(i))) {
      Check(OpInst->getFunction() == BB->getParent(),
            "Referring to an instruction in another function!", &I);
      verifyDominatesUse(I, i);
    } else if (isa<InlineAsm>(I.getOperand(i))) {
      Check(CBI && &CBI->getCalledOperandUse() == &I.getOperandUse(i),
            "Cannot take the address of an inline asm!", &I);
    } else if (auto *C = dyn_cast<Constant>(I.getOperand(i))) {
      visitConstantExprsRecursively(C);
    }
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_fpmath)) {
    Check(FPMathOperator::isSupportedFloatingPointType(I.getType()),
          "fpmath requires a floating point result!", &I);
    Check(MD->getNumOperands() == 1, "fpmath takes one operand!", &I);
    if (ConstantFP *CFP0 =
            mdconst::dyn_extract_or_null<ConstantFP>(MD->getOperand(0))) {
      const APFloat &Accuracy = CFP0->getValueAPF();
      Check(&Accuracy.getSemantics() == &APFloat::IEEEsingle(),
            "fpmath accuracy must have float type", &I);
      Check(Accuracy.isFiniteNonZero() && !Accuracy.isNegative(),
            "fpmath accuracy not a positive number!", &I);
    } else {
      Check(false, "invalid fpmath accuracy!", &I);
    }
  }
 
  if (MDNode *Range = I.getMetadata(LLVMContext::MD_range)) {
    Check(isa<LoadInst>(I) || isa<CallInst>(I) || isa<InvokeInst>(I),
          "Ranges are only for loads, calls and invokes!", &I);
    visitRangeMetadata(I, Range, I.getType());
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_nofpclass)) {
    Check(isa<LoadInst>(I), "nofpclass is only for loads", &I);
    visitNoFPClassMetadata(I, MD, I.getType());
  }
 
  if (MDNode *Range = I.getMetadata(LLVMContext::MD_noalias_addrspace)) {
    Check(isa<LoadInst>(I) || isa<StoreInst>(I) || isa<AtomicRMWInst>(I) ||
              isa<AtomicCmpXchgInst>(I) || isa<CallInst>(I),
          "noalias.addrspace are only for memory operations!", &I);
    visitNoaliasAddrspaceMetadata(I, Range, I.getType());
  }
 
  if (I.hasMetadata(LLVMContext::MD_invariant_group)) {
    Check(isa<LoadInst>(I) || isa<StoreInst>(I),
          "invariant.group metadata is only for loads and stores", &I);
  }
 
  if (I.hasMetadata(LLVMContext::MD_invariant_load)) {
    auto *II = dyn_cast<IntrinsicInst>(&I);
    Check(isa<LoadInst>(I) || (II && II->onlyReadsMemory()),
          "invariant.load metadata is only for loads and readonly "
          "intrinsic calls",
          &I);
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_nonnull)) {
    Check(I.getType()->isPointerTy(), "nonnull applies only to pointer types",
          &I);
    Check(isa<LoadInst>(I),
          "nonnull applies only to load instructions, use attributes"
          " for calls or invokes",
          &I);
    Check(MD->getNumOperands() == 0, "nonnull metadata must be empty", &I);
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_noundef)) {
    Check(isa<LoadInst>(I), "noundef applies only to load instructions", &I);
    Check(MD->getNumOperands() == 0, "noundef metadata must be empty", &I);
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_dereferenceable))
    visitDereferenceableMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_dereferenceable_or_null))
    visitDereferenceableMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_nofreeobj))
    visitNoFreeObjMetadata(I, MD);
 
  if (MDNode *TBAA = I.getMetadata(LLVMContext::MD_tbaa))
    TBAAVerifyHelper.visitTBAAMetadata(&I, TBAA);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_noalias))
    visitAliasScopeListMetadata(MD);
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_alias_scope))
    visitAliasScopeListMetadata(MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_access_group))
    visitAccessGroupMetadata(MD);
 
  if (MDNode *AlignMD = I.getMetadata(LLVMContext::MD_align)) {
    Check(I.getType()->isPointerTy(), "align applies only to pointer types",
          &I);
    Check(isa<LoadInst>(I),
          "align applies only to load instructions, "
          "use attributes for calls or invokes",
          &I);
    Check(AlignMD->getNumOperands() == 1, "align takes one operand!", &I);
    ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(AlignMD->getOperand(0));
    Check(CI && CI->getType()->isIntegerTy(64),
          "align metadata value must be an i64!", &I);
    uint64_t Align = CI->getZExtValue();
    Check(isPowerOf2_64(Align), "align metadata value must be a power of 2!",
          &I);
    Check(Align <= Value::MaximumAlignment,
          "alignment is larger that implementation defined limit", &I);
  }
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_prof))
    visitProfMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_memprof))
    visitMemProfMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_callsite))
    visitCallsiteMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_callee_type))
    visitCalleeTypeMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_DIAssignID))
    visitDIAssignIDMetadata(I, MD);
 
  if (MDNode *MMRA = I.getMetadata(LLVMContext::MD_mmra))
    visitMMRAMetadata(I, MMRA);
 
  if (MDNode *Annotation = I.getMetadata(LLVMContext::MD_annotation))
    visitAnnotationMetadata(Annotation);
 
  if (MDNode *Captures = I.getMetadata(LLVMContext::MD_captures))
    visitCapturesMetadata(I, Captures);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_alloc_token))
    visitAllocTokenMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_inline_history))
    visitInlineHistoryMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata(LLVMContext::MD_mem_cache_hint))
    visitMemCacheHintMetadata(I, MD);
 
  if (MDNode *MD = I.getMetadata("amdgpu.expected.active.lanes")) {
    Check(MD->getNumOperands() == 1,
          "!amdgpu.expected.active.lanes must have exactly one operand", &I,
          MD);
    ConstantInt *CI =
        mdconst::dyn_extract_or_null<ConstantInt>(MD->getOperand(0));
    Check(CI && CI->getType()->isIntegerTy(32),
          "!amdgpu.expected.active.lanes operand must be an i32 constant", &I,
          MD);
  }
 
  if (MDNode *N = I.getDebugLoc().getAsMDNode()) {
    CheckDI(isa<DILocation>(N), "invalid !dbg metadata attachment", &I, N);
    visitMDNode(*N, AreDebugLocsAllowed::Yes);
 
    if (auto *DL = dyn_cast<DILocation>(N)) {
      if (DL->getAtomGroup()) {
        DISubprogram *SP = getSubprogram(DL->getRawScope());
        CheckDI(SP && SP->getKeyInstructionsEnabled(),
                "DbgLoc uses atomGroup but DISubprogram doesn't have Key "
                "Instructions enabled",
                DL, SP);
      }
    }
  }
 
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  I.getAllMetadata(MDs);
  for (auto Attachment : MDs) {
    unsigned Kind = Attachment.first;
    auto AllowLocs =
        (Kind == LLVMContext::MD_dbg || Kind == LLVMContext::MD_loop)
            ? AreDebugLocsAllowed::Yes
            : AreDebugLocsAllowed::No;
    visitMDNode(*Attachment.second, AllowLocs);
  }
 
  InstsInThisBlock.insert(&I);
}
 
/// Allow intrinsics to be verified in different ways.
void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
  Function *IF = Call.getCalledFunction();
 
  // If the intrinsic takes MDNode arguments, verify that they are either global
  // or are local to *this* function.
  for (Value *V : Call.args()) {
    if (auto *MD = dyn_cast<MetadataAsValue>(V))
      visitMetadataAsValue(*MD, Call.getCaller());
    if (auto *Const = dyn_cast<Constant>(V))
      Check(!Const->getType()->isX86_AMXTy(),
            "const x86_amx is not allowed in argument!");
  }
 
  switch (ID) {
  default:
    break;
  case Intrinsic::assume: {
    if (Call.hasOperandBundles()) {
      auto *Cond = dyn_cast<ConstantInt>(Call.getArgOperand(0));
      Check(Cond && Cond->isOne(),
            "assume with operand bundles must have i1 true condition", Call);
    }
    for (auto OBU : Call.operand_bundles()) {
      // Separate storage assumptions are special insofar as they're the only
      // operand bundles allowed on assumes that aren't parameter attributes.
 
      auto GetTypeAt = [&](unsigned Index) {
        return OBU.Inputs[Index]->getType();
      };
 
      switch (getBundleAttrFromOBU(OBU)) {
      case BundleAttr::None:
        CheckFailed("tags must be valid attribute names", Call);
        break;
      case BundleAttr::Align:
        Check(OBU.Inputs.size() >= 2 && OBU.Inputs.size() <= 3,
              "alignment assumptions should have 2 or 3 arguments", Call);
        Check(GetTypeAt(0)->isPointerTy(), "first argument should be a pointer",
              Call);
        Check(GetTypeAt(1)->isIntegerTy() &&
                  GetTypeAt(1)->getIntegerBitWidth() <= 64,
              "second argument should be an integer with a maximum width of 64 "
              "bits",
              Call);
        Check(OBU.Inputs.size() < 3 ||
                  (GetTypeAt(2)->isIntegerTy() &&
                   GetTypeAt(2)->getIntegerBitWidth() <= 64),
              "third argument should be an integer with a maximum width of 64 "
              "bits if present",
              Call);
        break;
      case BundleAttr::Cold:
        Check(OBU.Inputs.size() == 0,
              "cold assumptions should have no arguments", Call);
        break;
      case BundleAttr::Dereferenceable:
      case BundleAttr::DereferenceableOrNull:
        Check(OBU.Inputs.size() == 2,
              "dereferenceable assumptions should have 2 arguments", Call);
        Check(GetTypeAt(0)->isPointerTy(), "first argument should be a pointer",
              Call);
        Check(GetTypeAt(1)->isIntegerTy() &&
                  GetTypeAt(1)->getIntegerBitWidth() <= 64,
              "second argument should be an integer with a maximum width of 64 "
              "bits",
              Call);
        break;
      case BundleAttr::Ignore:
        break;
      case BundleAttr::NonNull:
        Check(OBU.Inputs.size() == 1,
              "nonnull assumptions should have 1 argument", Call);
        Check(GetTypeAt(0)->isPointerTy(), "first argument should be a pointer",
              Call);
        break;
      case BundleAttr::NoUndef:
        Check(OBU.Inputs.size() == 1,
              "noundef assumptions should have 1 argument", Call);
        break;
      case BundleAttr::SeparateStorage:
        Check(OBU.Inputs.size() == 2,
              "separate_storage assumptions should have 2 arguments", Call);
        Check(GetTypeAt(0)->isPointerTy() && GetTypeAt(1)->isPointerTy(),
              "arguments to separate_storage assumptions should be pointers",
              Call);
        break;
      }
    }
    break;
  }
  case Intrinsic::ucmp:
  case Intrinsic::scmp: {
    Type *SrcTy = Call.getOperand(0)->getType();
    Type *DestTy = Call.getType();
 
    Check(DestTy->getScalarSizeInBits() >= 2,
          "result type must be at least 2 bits wide", Call);
 
    bool IsDestTypeVector = DestTy->isVectorTy();
    Check(SrcTy->isVectorTy() == IsDestTypeVector,
          "ucmp/scmp argument and result types must both be either vector or "
          "scalar types",
          Call);
    if (IsDestTypeVector) {
      auto SrcVecLen = cast<VectorType>(SrcTy)->getElementCount();
      auto DestVecLen = cast<VectorType>(DestTy)->getElementCount();
      Check(SrcVecLen == DestVecLen,
            "return type and arguments must have the same number of "
            "elements",
            Call);
    }
    break;
  }
  case Intrinsic::coro_begin:
  case Intrinsic::coro_begin_custom_abi:
    Check(isa<AnyCoroIdInst>(Call.getArgOperand(0)),
          "id argument of llvm.coro.begin must refer to coro.id");
    break;
  case Intrinsic::coro_id: {
    Check(isa<ConstantInt>(Call.getArgOperand(0)),
          "align argument only accepts constants");
    auto *Promise = Call.getArgOperand(1);
    Check(isa<ConstantPointerNull>(Promise) || isa<AllocaInst>(Promise),
          "promise argument must refer to an alloca");
 
    auto *CoroAddr = Call.getArgOperand(2)->stripPointerCastsAndAliases();
    bool BeforeCoroEarly = isa<ConstantPointerNull>(CoroAddr);
    Check(BeforeCoroEarly || isa<Function>(CoroAddr),
          "coro argument must refer to a function");
 
    auto *InfoArg = Call.getArgOperand(3);
    bool BeforeCoroSplit = isa<ConstantPointerNull>(InfoArg);
    if (BeforeCoroSplit)
      break;
 
    Check(!BeforeCoroEarly, "cannot run CoroSplit before CoroEarly");
    auto *GV = dyn_cast<GlobalVariable>(InfoArg);
    Check(GV && GV->isConstant() && GV->hasDefinitiveInitializer(),
          "info argument of llvm.coro.id must refer to an initialized "
          "constant");
    Constant *Init = GV->getInitializer();
    Check(isa<ConstantStruct>(Init) || isa<ConstantArray>(Init),
          "info argument of llvm.coro.id must refer to either a struct or "
          "an array");
    break;
  }
  case Intrinsic::is_fpclass: {
    const ConstantInt *TestMask = cast<ConstantInt>(Call.getOperand(1));
    Check((TestMask->getZExtValue() & ~static_cast<unsigned>(fcAllFlags)) == 0,
          "unsupported bits for llvm.is.fpclass test mask");
    break;
  }
  case Intrinsic::fptrunc_round: {
    // Check the rounding mode
    Metadata *MD = nullptr;
    auto *MAV = dyn_cast<MetadataAsValue>(Call.getOperand(1));
    if (MAV)
      MD = MAV->getMetadata();
 
    Check(MD != nullptr, "missing rounding mode argument", Call);
 
    Check(isa<MDString>(MD),
          ("invalid value for llvm.fptrunc.round metadata operand"
           " (the operand should be a string)"),
          MD);
 
    std::optional<RoundingMode> RoundMode =
        convertStrToRoundingMode(cast<MDString>(MD)->getString());
    Check(RoundMode && *RoundMode != RoundingMode::Dynamic,
          "unsupported rounding mode argument", Call);
    break;
  }
  case Intrinsic::convert_to_arbitrary_fp: {
    // Check that vector element counts are consistent.
    Type *ValueTy = Call.getArgOperand(0)->getType();
    Type *IntTy = Call.getType();
 
    if (auto *ValueVecTy = dyn_cast<VectorType>(ValueTy)) {
      auto *IntVecTy = dyn_cast<VectorType>(IntTy);
      Check(IntVecTy,
            "if floating-point operand is a vector, integer operand must also "
            "be a vector",
            Call);
      Check(ValueVecTy->getElementCount() == IntVecTy->getElementCount(),
            "floating-point and integer vector operands must have the same "
            "element count",
            Call);
    }
 
    // Check interpretation metadata (argoperand 1).
    auto *InterpMAV = dyn_cast<MetadataAsValue>(Call.getArgOperand(1));
    Check(InterpMAV, "missing interpretation metadata operand", Call);
    auto *InterpStr = dyn_cast<MDString>(InterpMAV->getMetadata());
    Check(InterpStr, "interpretation metadata operand must be a string", Call);
    StringRef Interp = InterpStr->getString();
 
    Check(!Interp.empty(), "interpretation metadata string must not be empty",
          Call);
 
    // Valid interpretation strings: mini-float format names.
    Check(APFloatBase::isValidArbitraryFPFormat(Interp),
          "unsupported interpretation metadata string", Call);
 
    // The integer type width must equal the arbitrary FP format width.
    if (unsigned FormatBits =
            APFloatBase::getArbitraryFPFormatSizeInBits(Interp))
      Check(IntTy->getScalarSizeInBits() == FormatBits,
            "integer type bit width must equal the arbitrary FP format width",
            Call);
 
    // Check rounding mode metadata (argoperand 2).
    auto *RoundingMAV = dyn_cast<MetadataAsValue>(Call.getArgOperand(2));
    Check(RoundingMAV, "missing rounding mode metadata operand", Call);
    auto *RoundingStr = dyn_cast<MDString>(RoundingMAV->getMetadata());
    Check(RoundingStr, "rounding mode metadata operand must be a string", Call);
 
    std::optional<RoundingMode> RM =
        convertStrToRoundingMode(RoundingStr->getString());
    Check(RM && *RM != RoundingMode::Dynamic,
          "unsupported rounding mode argument", Call);
    break;
  }
  case Intrinsic::convert_from_arbitrary_fp: {
    // Check that vector element counts are consistent.
    Type *IntTy = Call.getArgOperand(0)->getType();
    Type *ValueTy = Call.getType();
 
    if (auto *ValueVecTy = dyn_cast<VectorType>(ValueTy)) {
      auto *IntVecTy = dyn_cast<VectorType>(IntTy);
      Check(IntVecTy,
            "if floating-point operand is a vector, integer operand must also "
            "be a vector",
            Call);
      Check(ValueVecTy->getElementCount() == IntVecTy->getElementCount(),
            "floating-point and integer vector operands must have the same "
            "element count",
            Call);
    }
 
    // Check interpretation metadata (argoperand 1).
    auto *InterpMAV = dyn_cast<MetadataAsValue>(Call.getArgOperand(1));
    Check(InterpMAV, "missing interpretation metadata operand", Call);
    auto *InterpStr = dyn_cast<MDString>(InterpMAV->getMetadata());
    Check(InterpStr, "interpretation metadata operand must be a string", Call);
    StringRef Interp = InterpStr->getString();
 
    Check(!Interp.empty(), "interpretation metadata string must not be empty",
          Call);
 
    // Valid interpretation strings: mini-float format names.
    Check(APFloatBase::isValidArbitraryFPFormat(Interp),
          "unsupported interpretation metadata string", Call);
 
    // The integer type width must equal the arbitrary FP format width.
    if (unsigned FormatBits =
            APFloatBase::getArbitraryFPFormatSizeInBits(Interp))
      Check(IntTy->getScalarSizeInBits() == FormatBits,
            "integer type bit width must equal the arbitrary FP format width",
            Call);
    break;
  }
#define BEGIN_REGISTER_VP_INTRINSIC(VPID, ...) case Intrinsic::VPID:
#include "llvm/IR/VPIntrinsics.def"
#undef BEGIN_REGISTER_VP_INTRINSIC
    visitVPIntrinsic(cast<VPIntrinsic>(Call));
    break;
#define INSTRUCTION(NAME, NARGS, ROUND_MODE, INTRINSIC)                        \
  case Intrinsic::INTRINSIC:
#include "llvm/IR/ConstrainedOps.def"
#undef INSTRUCTION
    visitConstrainedFPIntrinsic(cast<ConstrainedFPIntrinsic>(Call));
    break;
  case Intrinsic::dbg_declare: // llvm.dbg.declare
  case Intrinsic::dbg_value:   // llvm.dbg.value
  case Intrinsic::dbg_assign:  // llvm.dbg.assign
  case Intrinsic::dbg_label:   // llvm.dbg.label
    // We no longer interpret debug intrinsics (the old variable-location
    // design). They're meaningless as far as LLVM is concerned we could make
    // it an error for them to appear, but it's possible we'll have users
    // converting back to intrinsics for the forseeable future (such as DXIL),
    // so tolerate their existance.
    break;
  case Intrinsic::memcpy:
  case Intrinsic::memcpy_inline:
  case Intrinsic::memmove:
  case Intrinsic::memset:
  case Intrinsic::memset_inline:
    break;
  case Intrinsic::experimental_memset_pattern: {
    const auto Memset = cast<MemSetPatternInst>(&Call);
    Check(Memset->getValue()->getType()->isSized(),
          "unsized types cannot be used as memset patterns", Call);
    break;
  }
  case Intrinsic::memcpy_element_unordered_atomic:
  case Intrinsic::memmove_element_unordered_atomic:
  case Intrinsic::memset_element_unordered_atomic: {
    const auto *AMI = cast<AnyMemIntrinsic>(&Call);
 
    ConstantInt *ElementSizeCI =
        cast<ConstantInt>(AMI->getRawElementSizeInBytes());
    const APInt &ElementSizeVal = ElementSizeCI->getValue();
    Check(ElementSizeVal.isPowerOf2(),
          "element size of the element-wise atomic memory intrinsic "
          "must be a power of 2",
          Call);
 
    auto IsValidAlignment = [&](MaybeAlign Alignment) {
      return Alignment && ElementSizeVal.ule(Alignment->value());
    };
    Check(IsValidAlignment(AMI->getDestAlign()),
          "incorrect alignment of the destination argument", Call);
    if (const auto *AMT = dyn_cast<AnyMemTransferInst>(AMI)) {
      Check(IsValidAlignment(AMT->getSourceAlign()),
            "incorrect alignment of the source argument", Call);
    }
    break;
  }
  case Intrinsic::call_preallocated_setup: {
    auto *NumArgs = cast<ConstantInt>(Call.getArgOperand(0));
    bool FoundCall = false;
    for (User *U : Call.users()) {
      auto *UseCall = dyn_cast<CallBase>(U);
      Check(UseCall != nullptr,
            "Uses of llvm.call.preallocated.setup must be calls");
      Intrinsic::ID IID = UseCall->getIntrinsicID();
      if (IID == Intrinsic::call_preallocated_arg) {
        auto *AllocArgIndex = dyn_cast<ConstantInt>(UseCall->getArgOperand(1));
        Check(AllocArgIndex != nullptr,
              "llvm.call.preallocated.alloc arg index must be a constant");
        auto AllocArgIndexInt = AllocArgIndex->getValue();
        Check(AllocArgIndexInt.sge(0) &&
                  AllocArgIndexInt.slt(NumArgs->getValue()),
              "llvm.call.preallocated.alloc arg index must be between 0 and "
              "corresponding "
              "llvm.call.preallocated.setup's argument count");
      } else if (IID == Intrinsic::call_preallocated_teardown) {
        // nothing to do
      } else {
        Check(!FoundCall, "Can have at most one call corresponding to a "
                          "llvm.call.preallocated.setup");
        FoundCall = true;
        size_t NumPreallocatedArgs = 0;
        for (unsigned i = 0; i < UseCall->arg_size(); i++) {
          if (UseCall->paramHasAttr(i, Attribute::Preallocated)) {
            ++NumPreallocatedArgs;
          }
        }
        Check(NumPreallocatedArgs != 0,
              "cannot use preallocated intrinsics on a call without "
              "preallocated arguments");
        Check(NumArgs->equalsInt(NumPreallocatedArgs),
              "llvm.call.preallocated.setup arg size must be equal to number "
              "of preallocated arguments "
              "at call site",
              Call, *UseCall);
        // getOperandBundle() cannot be called if more than one of the operand
        // bundle exists. There is already a check elsewhere for this, so skip
        // here if we see more than one.
        if (UseCall->countOperandBundlesOfType(LLVMContext::OB_preallocated) >
            1) {
          return;
        }
        auto PreallocatedBundle =
            UseCall->getOperandBundle(LLVMContext::OB_preallocated);
        Check(PreallocatedBundle,
              "Use of llvm.call.preallocated.setup outside intrinsics "
              "must be in \"preallocated\" operand bundle");
        Check(PreallocatedBundle->Inputs.front().get() == &Call,
              "preallocated bundle must have token from corresponding "
              "llvm.call.preallocated.setup");
      }
    }
    break;
  }
  case Intrinsic::call_preallocated_arg: {
    auto *Token = dyn_cast<CallBase>(Call.getArgOperand(0));
    Check(Token &&
              Token->getIntrinsicID() == Intrinsic::call_preallocated_setup,
          "llvm.call.preallocated.arg token argument must be a "
          "llvm.call.preallocated.setup");
    Check(Call.hasFnAttr(Attribute::Preallocated),
          "llvm.call.preallocated.arg must be called with a \"preallocated\" "
          "call site attribute");
    break;
  }
  case Intrinsic::call_preallocated_teardown: {
    auto *Token = dyn_cast<CallBase>(Call.getArgOperand(0));
    Check(Token &&
              Token->getIntrinsicID() == Intrinsic::call_preallocated_setup,
          "llvm.call.preallocated.teardown token argument must be a "
          "llvm.call.preallocated.setup");
    break;
  }
  case Intrinsic::gcroot:
  case Intrinsic::gcwrite:
  case Intrinsic::gcread:
    if (ID == Intrinsic::gcroot) {
      auto *AI =
          dyn_cast<AllocaInst>(Call.getArgOperand(0)->stripPointerCasts());
      Check(AI, "llvm.gcroot parameter #1 must be an alloca.", Call);
      Check(isa<Constant>(Call.getArgOperand(1)),
            "llvm.gcroot parameter #2 must be a constant.", Call);
      if (!AI->getAllocatedType()->isPointerTy()) {
        Check(!isa<ConstantPointerNull>(Call.getArgOperand(1)),
              "llvm.gcroot parameter #1 must either be a pointer alloca, "
              "or argument #2 must be a non-null constant.",
              Call);
      }
    }
 
    Check(Call.getParent()->getParent()->hasGC(),
          "Enclosing function does not use GC.", Call);
    break;
  case Intrinsic::init_trampoline:
    Check(isa<Function>(Call.getArgOperand(1)->stripPointerCasts()),
          "llvm.init_trampoline parameter #2 must resolve to a function.",
          Call);
    break;
  case Intrinsic::reloc_none: {
    Check(isa<MDString>(
              cast<MetadataAsValue>(Call.getArgOperand(0))->getMetadata()),
          "llvm.reloc.none argument must be a metadata string", &Call);
    break;
  }
  case Intrinsic::stackprotector:
    Check(isa<AllocaInst>(Call.getArgOperand(1)->stripPointerCasts()),
          "llvm.stackprotector parameter #2 must resolve to an alloca.", Call);
    break;
  case Intrinsic::localescape: {
    BasicBlock *BB = Call.getParent();
    Check(BB->isEntryBlock(), "llvm.localescape used outside of entry block",
          Call);
    Check(!SawFrameEscape, "multiple calls to llvm.localescape in one function",
          Call);
    for (Value *Arg : Call.args()) {
      if (isa<ConstantPointerNull>(Arg))
        continue; // Null values are allowed as placeholders.
      auto *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
      Check(AI && AI->isStaticAlloca(),
            "llvm.localescape only accepts static allocas", Call);
    }
    FrameEscapeInfo[BB->getParent()].first = Call.arg_size();
    SawFrameEscape = true;
    break;
  }
  case Intrinsic::localrecover: {
    Value *FnArg = Call.getArgOperand(0)->stripPointerCasts();
    auto *Fn = dyn_cast<Function>(FnArg);
    Check(Fn && !Fn->isDeclaration(),
          "llvm.localrecover first "
          "argument must be function defined in this module",
          Call);
    auto *IdxArg = cast<ConstantInt>(Call.getArgOperand(2));
    auto &Entry = FrameEscapeInfo[Fn];
    Entry.second = unsigned(
        std::max(uint64_t(Entry.second), IdxArg->getLimitedValue(~0U) + 1));
    break;
  }
 
  case Intrinsic::experimental_gc_statepoint:
    if (auto *CI = dyn_cast<CallInst>(&Call))
      Check(!CI->isInlineAsm(),
            "gc.statepoint support for inline assembly unimplemented", CI);
    Check(Call.getParent()->getParent()->hasGC(),
          "Enclosing function does not use GC.", Call);
 
    verifyStatepoint(Call);
    break;
  case Intrinsic::experimental_gc_result: {
    Check(Call.getParent()->getParent()->hasGC(),
          "Enclosing function does not use GC.", Call);
 
    auto *Statepoint = Call.getArgOperand(0);
    if (isa<UndefValue>(Statepoint))
      break;
 
    // Are we tied to a statepoint properly?
    const auto *StatepointCall = dyn_cast<CallBase>(Statepoint);
    Check(StatepointCall && StatepointCall->getIntrinsicID() ==
                                Intrinsic::experimental_gc_statepoint,
          "gc.result operand #1 must be from a statepoint", Call,
          Call.getArgOperand(0));
 
    // Check that result type matches wrapped callee.
    auto *TargetFuncType =
        cast<FunctionType>(StatepointCall->getParamElementType(2));
    Check(Call.getType() == TargetFuncType->getReturnType(),
          "gc.result result type does not match wrapped callee", Call);
    break;
  }
  case Intrinsic::experimental_gc_relocate: {
    Check(Call.arg_size() == 3, "wrong number of arguments", Call);
 
    Check(isa<PointerType>(Call.getType()->getScalarType()),
          "gc.relocate must return a pointer or a vector of pointers", Call);
 
    // Check that this relocate is correctly tied to the statepoint
 
    // This is case for relocate on the unwinding path of an invoke statepoint
    if (auto *LandingPad = dyn_cast<LandingPadInst>(Call.getArgOperand(0))) {
 
      const BasicBlock *InvokeBB =
          LandingPad->getParent()->getUniquePredecessor();
 
      // Landingpad relocates should have only one predecessor with invoke
      // statepoint terminator
      Check(InvokeBB, "safepoints should have unique landingpads",
            LandingPad->getParent());
      Check(InvokeBB->getTerminator(), "safepoint block should be well formed",
            InvokeBB);
      Check(isa<GCStatepointInst>(InvokeBB->getTerminator()),
            "gc relocate should be linked to a statepoint", InvokeBB);
    } else {
      // In all other cases relocate should be tied to the statepoint directly.
      // This covers relocates on a normal return path of invoke statepoint and
      // relocates of a call statepoint.
      auto *Token = Call.getArgOperand(0);
      Check(isa<GCStatepointInst>(Token) || isa<UndefValue>(Token),
            "gc relocate is incorrectly tied to the statepoint", Call, Token);
    }
 
    // Verify rest of the relocate arguments.
    const Value &StatepointCall = *cast<GCRelocateInst>(Call).getStatepoint();
 
    // Both the base and derived must be piped through the safepoint.
    Value *Base = Call.getArgOperand(1);
    Check(isa<ConstantInt>(Base),
          "gc.relocate operand #2 must be integer offset", Call);
 
    Value *Derived = Call.getArgOperand(2);
    Check(isa<ConstantInt>(Derived),
          "gc.relocate operand #3 must be integer offset", Call);
 
    const uint64_t BaseIndex = cast<ConstantInt>(Base)->getZExtValue();
    const uint64_t DerivedIndex = cast<ConstantInt>(Derived)->getZExtValue();
 
    // Check the bounds
    if (isa<UndefValue>(StatepointCall))
      break;
    if (auto Opt = cast<GCStatepointInst>(StatepointCall)
                       .getOperandBundle(LLVMContext::OB_gc_live)) {
      Check(BaseIndex < Opt->Inputs.size(),
            "gc.relocate: statepoint base index out of bounds", Call);
      Check(DerivedIndex < Opt->Inputs.size(),
            "gc.relocate: statepoint derived index out of bounds", Call);
    }
 
    // Relocated value must be either a pointer type or vector-of-pointer type,
    // but gc_relocate does not need to return the same pointer type as the
    // relocated pointer. It can be casted to the correct type later if it's
    // desired. However, they must have the same address space and 'vectorness'
    GCRelocateInst &Relocate = cast<GCRelocateInst>(Call);
    auto *ResultType = Call.getType();
    auto *DerivedType = Relocate.getDerivedPtr()->getType();
    auto *BaseType = Relocate.getBasePtr()->getType();
 
    Check(BaseType->isPtrOrPtrVectorTy(),
          "gc.relocate: relocated value must be a pointer", Call);
    Check(DerivedType->isPtrOrPtrVectorTy(),
          "gc.relocate: relocated value must be a pointer", Call);
 
    Check(ResultType->isVectorTy() == DerivedType->isVectorTy(),
          "gc.relocate: vector relocates to vector and pointer to pointer",
          Call);
    Check(
        ResultType->getPointerAddressSpace() ==
            DerivedType->getPointerAddressSpace(),
        "gc.relocate: relocating a pointer shouldn't change its address space",
        Call);
 
    auto GC = llvm::getGCStrategy(Relocate.getFunction()->getGC());
    Check(GC, "gc.relocate: calling function must have GCStrategy",
          Call.getFunction());
    if (GC) {
      auto isGCPtr = [&GC](Type *PTy) {
        return GC->isGCManagedPointer(PTy->getScalarType()).value_or(true);
      };
      Check(isGCPtr(ResultType), "gc.relocate: must return gc pointer", Call);
      Check(isGCPtr(BaseType),
            "gc.relocate: relocated value must be a gc pointer", Call);
      Check(isGCPtr(DerivedType),
            "gc.relocate: relocated value must be a gc pointer", Call);
    }
    break;
  }
  case Intrinsic::experimental_patchpoint: {
    if (Call.getCallingConv() == CallingConv::AnyReg) {
      Check(Call.getType()->isSingleValueType(),
            "patchpoint: invalid return type used with anyregcc", Call);
    }
    break;
  }
  case Intrinsic::eh_exceptioncode:
  case Intrinsic::eh_exceptionpointer: {
    Check(isa<CatchPadInst>(Call.getArgOperand(0)),
          "eh.exceptionpointer argument must be a catchpad", Call);
    break;
  }
  case Intrinsic::get_active_lane_mask: {
    Type *ElemTy = Call.getType()->getScalarType();
    Check(ElemTy->isIntegerTy(1),
          "get_active_lane_mask: element type is not i1", Call);
    break;
  }
  case Intrinsic::experimental_get_vector_length: {
    auto *VF = cast<ConstantInt>(Call.getArgOperand(1));
    Check(!VF->isNegative() && !VF->isZero(),
          "get_vector_length: VF must be positive", Call);
    break;
  }
  case Intrinsic::experimental_guard: {
    Check(isa<CallInst>(Call), "experimental_guard cannot be invoked", Call);
    Check(Call.countOperandBundlesOfType(LLVMContext::OB_deopt) == 1,
          "experimental_guard must have exactly one "
          "\"deopt\" operand bundle");
    break;
  }
 
  case Intrinsic::experimental_deoptimize: {
    Check(isa<CallInst>(Call), "experimental_deoptimize cannot be invoked",
          Call);
    Check(Call.countOperandBundlesOfType(LLVMContext::OB_deopt) == 1,
          "experimental_deoptimize must have exactly one "
          "\"deopt\" operand bundle");
    Check(Call.getType() == Call.getFunction()->getReturnType(),
          "experimental_deoptimize return type must match caller return type");
 
    if (isa<CallInst>(Call)) {
      auto *RI = dyn_cast<ReturnInst>(Call.getNextNode());
      Check(RI,
            "calls to experimental_deoptimize must be followed by a return");
 
      if (!Call.getType()->isVoidTy() && RI)
        Check(RI->getReturnValue() == &Call,
              "calls to experimental_deoptimize must be followed by a return "
              "of the value computed by experimental_deoptimize");
    }
 
    break;
  }
  case Intrinsic::vastart: {
    Check(Call.getFunction()->isVarArg(),
          "va_start called in a non-varargs function");
    break;
  }
  case Intrinsic::get_dynamic_area_offset: {
    auto *IntTy = dyn_cast<IntegerType>(Call.getType());
    Check(IntTy && DL.getPointerSizeInBits(DL.getAllocaAddrSpace()) ==
                       IntTy->getBitWidth(),
          "get_dynamic_area_offset result type must be scalar integer matching "
          "alloca address space width",
          Call);
    break;
  }
  case Intrinsic::smul_fix:
  case Intrinsic::smul_fix_sat:
  case Intrinsic::umul_fix:
  case Intrinsic::umul_fix_sat:
  case Intrinsic::sdiv_fix:
  case Intrinsic::sdiv_fix_sat:
  case Intrinsic::udiv_fix:
  case Intrinsic::udiv_fix_sat: {
    Value *Op1 = Call.getArgOperand(0);
    auto *Op3 = cast<ConstantInt>(Call.getArgOperand(2));
 
    if (ID == Intrinsic::smul_fix || ID == Intrinsic::smul_fix_sat ||
        ID == Intrinsic::sdiv_fix || ID == Intrinsic::sdiv_fix_sat) {
      Check(Op3->getZExtValue() < Op1->getType()->getScalarSizeInBits(),
            "the scale of s[mul|div]_fix[_sat] must be less than the width of "
            "the operands");
    } else {
      Check(Op3->getZExtValue() <= Op1->getType()->getScalarSizeInBits(),
            "the scale of u[mul|div]_fix[_sat] must be less than or equal "
            "to the width of the operands");
    }
    break;
  }
  case Intrinsic::lrint:
  case Intrinsic::llrint:
  case Intrinsic::lround:
  case Intrinsic::llround: {
    Type *ValTy = Call.getArgOperand(0)->getType();
    Type *ResultTy = Call.getType();
    Check(ValTy->isVectorTy() == ResultTy->isVectorTy(),
          IF->getName() + ": argument and result disagree on vector use",
          &Call);
    if (auto *VTy = dyn_cast<VectorType>(ValTy)) {
      auto *RTy = dyn_cast<VectorType>(ResultTy);
      Check(VTy->getElementCount() == RTy->getElementCount(),
            IF->getName() + ": argument must be same length as result", &Call);
    }
    break;
  }
  case Intrinsic::bswap: {
    Type *Ty = Call.getType();
    unsigned Size = Ty->getScalarSizeInBits();
    Check(Size % 16 == 0, "bswap must be an even number of bytes", &Call);
    break;
  }
  case Intrinsic::invariant_start: {
    auto *InvariantSize = dyn_cast<ConstantInt>(Call.getArgOperand(0));
    Check(InvariantSize &&
              (!InvariantSize->isNegative() || InvariantSize->isMinusOne()),
          "invariant_start parameter must be -1, 0 or a positive number",
          &Call);
    break;
  }
  case Intrinsic::matrix_multiply:
  case Intrinsic::matrix_transpose:
  case Intrinsic::matrix_column_major_load:
  case Intrinsic::matrix_column_major_store: {
    Function *IF = Call.getCalledFunction();
    Value *Stride = nullptr;
    ConstantInt *NumRows;
    ConstantInt *NumColumns;
    VectorType *ResultTy;
    Type *Op0ElemTy = nullptr;
    Type *Op1ElemTy = nullptr;
    switch (ID) {
    case Intrinsic::matrix_multiply: {
      NumRows = cast<ConstantInt>(Call.getArgOperand(2));
      ConstantInt *N = cast<ConstantInt>(Call.getArgOperand(3));
      NumColumns = cast<ConstantInt>(Call.getArgOperand(4));
      Check(cast<FixedVectorType>(Call.getArgOperand(0)->getType())
                    ->getNumElements() ==
                NumRows->getZExtValue() * N->getZExtValue(),
            "First argument of a matrix operation does not match specified "
            "shape!");
      Check(cast<FixedVectorType>(Call.getArgOperand(1)->getType())
                    ->getNumElements() ==
                N->getZExtValue() * NumColumns->getZExtValue(),
            "Second argument of a matrix operation does not match specified "
            "shape!");
 
      ResultTy = cast<VectorType>(Call.getType());
      Op0ElemTy =
          cast<VectorType>(Call.getArgOperand(0)->getType())->getElementType();
      Op1ElemTy =
          cast<VectorType>(Call.getArgOperand(1)->getType())->getElementType();
      break;
    }
    case Intrinsic::matrix_transpose:
      NumRows = cast<ConstantInt>(Call.getArgOperand(1));
      NumColumns = cast<ConstantInt>(Call.getArgOperand(2));
      ResultTy = cast<VectorType>(Call.getType());
      Op0ElemTy =
          cast<VectorType>(Call.getArgOperand(0)->getType())->getElementType();
      break;
    case Intrinsic::matrix_column_major_load: {
      Stride = Call.getArgOperand(1);
      NumRows = cast<ConstantInt>(Call.getArgOperand(3));
      NumColumns = cast<ConstantInt>(Call.getArgOperand(4));
      ResultTy = cast<VectorType>(Call.getType());
      break;
    }
    case Intrinsic::matrix_column_major_store: {
      Stride = Call.getArgOperand(2);
      NumRows = cast<ConstantInt>(Call.getArgOperand(4));
      NumColumns = cast<ConstantInt>(Call.getArgOperand(5));
      ResultTy = cast<VectorType>(Call.getArgOperand(0)->getType());
      Op0ElemTy =
          cast<VectorType>(Call.getArgOperand(0)->getType())->getElementType();
      break;
    }
    default:
      llvm_unreachable("unexpected intrinsic");
    }
 
    Check(ResultTy->getElementType()->isIntegerTy() ||
              ResultTy->getElementType()->isFloatingPointTy(),
          "Result type must be an integer or floating-point type!", IF);
 
    if (Op0ElemTy)
      Check(ResultTy->getElementType() == Op0ElemTy,
            "Vector element type mismatch of the result and first operand "
            "vector!",
            IF);
 
    if (Op1ElemTy)
      Check(ResultTy->getElementType() == Op1ElemTy,
            "Vector element type mismatch of the result and second operand "
            "vector!",
            IF);
 
    Check(cast<FixedVectorType>(ResultTy)->getNumElements() ==
              NumRows->getZExtValue() * NumColumns->getZExtValue(),
          "Result of a matrix operation does not fit in the returned vector!");
 
    if (Stride)
      Check(Stride->getType()->getIntegerBitWidth() <= 64,
            "Stride bitwidth cannot exceed 64!", IF);
 
    break;
  }
  case Intrinsic::stepvector: {
    auto *VecTy = dyn_cast<VectorType>(Call.getType());
    Check(VecTy && VecTy->getScalarType()->isIntegerTy() &&
              VecTy->getScalarSizeInBits() >= 8,
          "stepvector only supported for vectors of integers "
          "with a bitwidth of at least 8.",
          &Call);
    break;
  }
  case Intrinsic::experimental_vector_match: {
    Value *Op1 = Call.getArgOperand(0);
    Value *Op2 = Call.getArgOperand(1);
    Value *Mask = Call.getArgOperand(2);
 
    auto *Op1Ty = dyn_cast<VectorType>(Op1->getType());
    auto *Op2Ty = dyn_cast<VectorType>(Op2->getType());
    auto *MaskTy = dyn_cast<VectorType>(Mask->getType());
 
    Check(Op1Ty && Op2Ty && MaskTy, "Operands must be vectors.", &Call);
    Check(isa<FixedVectorType>(Op2Ty),
          "Second operand must be a fixed length vector.", &Call);
    Check(Op1Ty->getElementType()->isIntegerTy(),
          "First operand must be a vector of integers.", &Call);
    Check(Op1Ty->getElementType() == Op2Ty->getElementType(),
          "First two operands must have the same element type.", &Call);
    Check(Op1Ty->getElementCount() == MaskTy->getElementCount(),
          "First operand and mask must have the same number of elements.",
          &Call);
    Check(MaskTy->getElementType()->isIntegerTy(1),
          "Mask must be a vector of i1's.", &Call);
    Check(Call.getType() == MaskTy, "Return type must match the mask type.",
          &Call);
    break;
  }
  case Intrinsic::vector_insert: {
    Value *Vec = Call.getArgOperand(0);
    Value *SubVec = Call.getArgOperand(1);
    Value *Idx = Call.getArgOperand(2);
    unsigned IdxN = cast<ConstantInt>(Idx)->getZExtValue();
 
    VectorType *VecTy = cast<VectorType>(Vec->getType());
    VectorType *SubVecTy = cast<VectorType>(SubVec->getType());
 
    ElementCount VecEC = VecTy->getElementCount();
    ElementCount SubVecEC = SubVecTy->getElementCount();
    Check(VecTy->getElementType() == SubVecTy->getElementType(),
          "vector_insert parameters must have the same element "
          "type.",
          &Call);
    Check(IdxN % SubVecEC.getKnownMinValue() == 0,
          "vector_insert index must be a constant multiple of "
          "the subvector's known minimum vector length.");
 
    // The only allowed 'mixed' case is inserting a fixed vector into a
    // scalable vector.
    if (SubVecEC.isScalable()) {
      Check(VecEC.isScalable(), "cannot vector_insert a scalable vector into "
                                "a fixed vector.");
    }
 
    // If this insertion is not the 'mixed' case where a fixed vector is
    // inserted into a scalable vector, ensure that the insertion of the
    // subvector does not overrun the parent vector.
    if (VecEC.isScalable() == SubVecEC.isScalable()) {
      Check(IdxN < VecEC.getKnownMinValue() &&
                IdxN + SubVecEC.getKnownMinValue() <= VecEC.getKnownMinValue(),
            "subvector operand of vector_insert would overrun the "
            "vector being inserted into.");
    }
    break;
  }
  case Intrinsic::vector_extract: {
    Value *Vec = Call.getArgOperand(0);
    Value *Idx = Call.getArgOperand(1);
    unsigned IdxN = cast<ConstantInt>(Idx)->getZExtValue();
 
    VectorType *ResultTy = cast<VectorType>(Call.getType());
    VectorType *VecTy = cast<VectorType>(Vec->getType());
 
    ElementCount VecEC = VecTy->getElementCount();
    ElementCount ResultEC = ResultTy->getElementCount();
 
    Check(ResultTy->getElementType() == VecTy->getElementType(),
          "vector_extract result must have the same element "
          "type as the input vector.",
          &Call);
    Check(IdxN % ResultEC.getKnownMinValue() == 0,
          "vector_extract index must be a constant multiple of "
          "the result type's known minimum vector length.");
 
    // The only allowed 'mixed' case is extracting a fixed vector from a
    // scalable vector.
    if (ResultEC.isScalable()) {
      Check(VecEC.isScalable(), "cannot vector_extract a scalable vector from "
                                "a fixed vector.");
    }
 
    // If this extraction is not the 'mixed' case where a fixed vector is
    // extracted from a scalable vector, ensure that the extraction does not
    // overrun the parent vector.
    if (VecEC.isScalable() == ResultEC.isScalable()) {
      Check(IdxN < VecEC.getKnownMinValue() &&
                IdxN + ResultEC.getKnownMinValue() <= VecEC.getKnownMinValue(),
            "vector_extract would overrun.");
    }
    break;
  }
  case Intrinsic::vector_partial_reduce_fadd:
  case Intrinsic::vector_partial_reduce_add: {
    VectorType *AccTy = cast<VectorType>(Call.getArgOperand(0)->getType());
    VectorType *VecTy = cast<VectorType>(Call.getArgOperand(1)->getType());
 
    unsigned VecWidth = VecTy->getElementCount().getKnownMinValue();
    unsigned AccWidth = AccTy->getElementCount().getKnownMinValue();
 
    Check((VecWidth % AccWidth) == 0,
          "Invalid vector widths for partial "
          "reduction. The width of the input vector "
          "must be a positive integer multiple of "
          "the width of the accumulator vector.");
    break;
  }
  case Intrinsic::experimental_noalias_scope_decl: {
    NoAliasScopeDecls.push_back(cast<IntrinsicInst>(&Call));
    break;
  }
  case Intrinsic::preserve_array_access_index:
  case Intrinsic::preserve_struct_access_index:
  case Intrinsic::aarch64_ldaxr:
  case Intrinsic::aarch64_ldxr:
  case Intrinsic::arm_ldaex:
  case Intrinsic::arm_ldrex: {
    Type *ElemTy = Call.getParamElementType(0);
    Check(ElemTy, "Intrinsic requires elementtype attribute on first argument.",
          &Call);
    break;
  }
  case Intrinsic::aarch64_stlxr:
  case Intrinsic::aarch64_stxr:
  case Intrinsic::arm_stlex:
  case Intrinsic::arm_strex: {
    Type *ElemTy = Call.getAttributes().getParamElementType(1);
    Check(ElemTy,
          "Intrinsic requires elementtype attribute on second argument.",
          &Call);
    break;
  }
  case Intrinsic::aarch64_prefetch: {
    Check(cast<ConstantInt>(Call.getArgOperand(1))->getZExtValue() < 2,
          "write argument to llvm.aarch64.prefetch must be 0 or 1", Call);
    Check(cast<ConstantInt>(Call.getArgOperand(2))->getZExtValue() < 4,
          "target argument to llvm.aarch64.prefetch must be 0-3", Call);
    Check(cast<ConstantInt>(Call.getArgOperand(3))->getZExtValue() < 2,
          "stream argument to llvm.aarch64.prefetch must be 0 or 1", Call);
    Check(cast<ConstantInt>(Call.getArgOperand(4))->getZExtValue() < 2,
          "isdata argument to llvm.aarch64.prefetch must be 0 or 1", Call);
    break;
  }
  case Intrinsic::aarch64_range_prefetch: {
    Check(cast<ConstantInt>(Call.getArgOperand(1))->getZExtValue() < 2,
          "write argument to llvm.aarch64.range.prefetch must be 0 or 1", Call);
    Check(cast<ConstantInt>(Call.getArgOperand(2))->getZExtValue() < 2,
          "stream argument to llvm.aarch64.range.prefetch must be 0 or 1",
          Call);
    break;
  }
  case Intrinsic::riscv_vsetvli:
  case Intrinsic::riscv_vsetvlimax: {
    // The result models VLMAX (or a VL bounded by it) and is only defined for
    // XLen (i32/i64). Narrower types cannot represent the architectural VLMAX
    // range of [1, 65536], which value analyses rely on.
    Check(Call.getType()->isIntegerTy(32) || Call.getType()->isIntegerTy(64),
          "llvm.riscv.vsetvli/vsetvlimax result must be i32 or i64", &Call);
 
    // VSEW and VLMUL select the vtype and must encode a valid SEW/LMUL pair.
    bool HasAVL = ID == Intrinsic::riscv_vsetvli;
    unsigned Offset = HasAVL ? 1 : 0;
    uint64_t VSEW =
        cast<ConstantInt>(Call.getArgOperand(Offset))->getZExtValue();
    uint64_t VLMUL =
        cast<ConstantInt>(Call.getArgOperand(Offset + 1))->getZExtValue();
    Check(VSEW <= 3, "llvm.riscv.vsetvli/vsetvlimax VSEW must be 0-3", &Call);
    Check(VLMUL <= 7 && VLMUL != RISCVVType::LMUL_RESERVED,
          "llvm.riscv.vsetvli/vsetvlimax VLMUL is reserved", &Call);
    break;
  }
  case Intrinsic::callbr_landingpad: {
    const auto *CBR = dyn_cast<CallBrInst>(Call.getOperand(0));
    Check(CBR, "intrinstic requires callbr operand", &Call);
    if (!CBR)
      break;
 
    const BasicBlock *LandingPadBB = Call.getParent();
    const BasicBlock *PredBB = LandingPadBB->getUniquePredecessor();
    if (!PredBB) {
      CheckFailed("Intrinsic in block must have 1 unique predecessor", &Call);
      break;
    }
    if (!isa<CallBrInst>(PredBB->getTerminator())) {
      CheckFailed("Intrinsic must have corresponding callbr in predecessor",
                  &Call);
      break;
    }
    Check(llvm::is_contained(CBR->getIndirectDests(), LandingPadBB),
          "Intrinsic's corresponding callbr must have intrinsic's parent basic "
          "block in indirect destination list",
          &Call);
    const Instruction &First = *LandingPadBB->begin();
    Check(&First == &Call, "No other instructions may proceed intrinsic",
          &Call);
    break;
  }
  case Intrinsic::structured_gep: {
    // Parser should refuse those 2 cases.
    assert(Call.arg_size() >= 1);
    assert(Call.getOperand(0)->getType()->isPointerTy());
 
    Check(Call.paramHasAttr(0, Attribute::ElementType),
          "Intrinsic first parameter is missing an ElementType attribute",
          &Call);
 
    Type *T = Call.getParamAttr(0, Attribute::ElementType).getValueAsType();
    for (unsigned I = 1; I < Call.arg_size(); ++I) {
      Value *Index = Call.getOperand(I);
      auto *CI = dyn_cast<ConstantInt>(Index);
      Check(Index->getType()->isIntegerTy(),
            "Index operand type must be an integer", &Call);
 
      if (auto *AT = dyn_cast<ArrayType>(T)) {
        T = AT->getElementType();
      } else if (auto *ST = dyn_cast<StructType>(T)) {
        Check(CI, "Indexing into a struct requires a constant int", &Call);
        Check(CI->getZExtValue() < ST->getNumElements(),
              "Indexing in a struct should be inbounds", &Call);
        T = ST->getElementType(CI->getZExtValue());
      } else if (auto *VT = dyn_cast<VectorType>(T)) {
        T = VT->getElementType();
      } else {
        CheckFailed("Reached a non-composite type with more indices to process",
                    &Call);
      }
    }
    break;
  }
  case Intrinsic::structured_alloca:
    Check(Call.hasRetAttr(Attribute::ElementType),
          "@llvm.structured.alloca calls require elementtype attribute.",
          &Call);
    break;
  case Intrinsic::nvvm_setmaxnreg_inc_sync_aligned_u32:
  case Intrinsic::nvvm_setmaxnreg_dec_sync_aligned_u32: {
    Value *V = Call.getArgOperand(0);
    unsigned RegCount = cast<ConstantInt>(V)->getZExtValue();
    Check(RegCount % 8 == 0,
          "reg_count argument to nvvm.setmaxnreg must be in multiples of 8");
    break;
  }
  case Intrinsic::experimental_convergence_entry:
  case Intrinsic::experimental_convergence_anchor:
    break;
  case Intrinsic::experimental_convergence_loop:
    break;
  case Intrinsic::ptrmask: {
    Type *Ty0 = Call.getArgOperand(0)->getType();
    Type *Ty1 = Call.getArgOperand(1)->getType();
    Check(Ty0->isPtrOrPtrVectorTy(),
          "llvm.ptrmask intrinsic first argument must be pointer or vector "
          "of pointers",
          &Call);
    Check(
        Ty0->isVectorTy() == Ty1->isVectorTy(),
        "llvm.ptrmask intrinsic arguments must be both scalars or both vectors",
        &Call);
    if (Ty0->isVectorTy())
      Check(cast<VectorType>(Ty0)->getElementCount() ==
                cast<VectorType>(Ty1)->getElementCount(),
            "llvm.ptrmask intrinsic arguments must have the same number of "
            "elements",
            &Call);
    Check(DL.getIndexTypeSizeInBits(Ty0) == Ty1->getScalarSizeInBits(),
          "llvm.ptrmask intrinsic second argument bitwidth must match "
          "pointer index type size of first argument",
          &Call);
    break;
  }
  case Intrinsic::thread_pointer: {
    Check(Call.getType()->getPointerAddressSpace() ==
              DL.getDefaultGlobalsAddressSpace(),
          "llvm.thread.pointer intrinsic return type must be for the globals "
          "address space",
          &Call);
    break;
  }
  case Intrinsic::threadlocal_address: {
    const Value &Arg0 = *Call.getArgOperand(0);
    Check(isa<GlobalValue>(Arg0),
          "llvm.threadlocal.address first argument must be a GlobalValue");
    Check(cast<GlobalValue>(Arg0).isThreadLocal(),
          "llvm.threadlocal.address operand isThreadLocal() must be true");
    break;
  }
  case Intrinsic::lifetime_start:
  case Intrinsic::lifetime_end: {
    Value *Ptr = Call.getArgOperand(0);
    auto *II = dyn_cast<IntrinsicInst>(Ptr);
    Check(isa<AllocaInst>(Ptr) || isa<PoisonValue>(Ptr) ||
              (II && II->getIntrinsicID() == Intrinsic::structured_alloca),
          "llvm.lifetime.start/end can only be used on alloca or poison",
          &Call);
    break;
  }
  case Intrinsic::sponentry: {
    const unsigned StackAS = DL.getAllocaAddrSpace();
    const Type *RetTy = Call.getFunctionType()->getReturnType();
    Check(RetTy->getPointerAddressSpace() == StackAS,
          "llvm.sponentry must return a pointer to the stack", &Call);
    break;
  }
  case Intrinsic::write_volatile_register: {
    auto *MD = cast<MDNode>(
        cast<MetadataAsValue>(Call.getArgOperand(0))->getMetadata());
    Check(MD->getNumOperands() == 1 && isa<MDString>(MD->getOperand(0)),
          "llvm.write_volatile_register metadata must be a single MDString",
          &Call);
    break;
  }
  case Intrinsic::ptrauth_auth_with_pc_and_resign: {
    // Verify that the auth key is IA (0) or IB (1), not DA (2) or DB (3)
    auto *AuthKey = cast<ConstantInt>(Call.getArgOperand(1));
    uint64_t Key = AuthKey->getZExtValue();
    Check(Key == 0 || Key == 1,
          "ptrauth.auth.with.pc.and.resign key must be IA (0) or IB (1)",
          &Call);
    break;
  }
  };
 
  // Verify that there aren't any unmediated control transfers between funclets.
  if (IntrinsicInst::mayLowerToFunctionCall(ID)) {
    Function *F = Call.getParent()->getParent();
    if (F->hasPersonalityFn() &&
        isScopedEHPersonality(classifyEHPersonality(F->getPersonalityFn()))) {
      // Run EH funclet coloring on-demand and cache results for other intrinsic
      // calls in this function
      if (BlockEHFuncletColors.empty())
        BlockEHFuncletColors = colorEHFunclets(*F);
 
      // Check for catch-/cleanup-pad in first funclet block
      bool InEHFunclet = false;
      BasicBlock *CallBB = Call.getParent();
      const ColorVector &CV = BlockEHFuncletColors.find(CallBB)->second;
      assert(CV.size() > 0 && "Uncolored block");
      for (BasicBlock *ColorFirstBB : CV)
        if (auto It = ColorFirstBB->getFirstNonPHIIt();
            It != ColorFirstBB->end())
          if (isa_and_nonnull<FuncletPadInst>(&*It))
            InEHFunclet = true;
 
      // Check for funclet operand bundle
      bool HasToken = false;
      for (unsigned I = 0, E = Call.getNumOperandBundles(); I != E; ++I)
        if (Call.getOperandBundleAt(I).getTagID() == LLVMContext::OB_funclet)
          HasToken = true;
 
      // This would cause silent code truncation in WinEHPrepare
      if (InEHFunclet)
        Check(HasToken, "Missing funclet token on intrinsic call", &Call);
    }
  }
 
  // Target-specific intrinsic call checks.
  verifyAMDGPUIntrinsicCall(*this, ID, Call);
}
 
/// Carefully grab the subprogram from a local scope.
///
/// This carefully grabs the subprogram from a local scope, avoiding the
/// built-in assertions that would typically fire.
DISubprogram *Verifier::getSubprogram(Metadata *LocalScope) {
  if (hasDIScopeCycle(LocalScope))
    return nullptr;
 
  if (!LocalScope)
    return nullptr;
 
  if (auto *SP = dyn_cast<DISubprogram>(LocalScope))
    return SP;
 
  if (auto *LB = dyn_cast<DILexicalBlockBase>(LocalScope))
    return getSubprogram(LB->getRawScope());
 
  // Just return null; broken scope chains are checked elsewhere.
  assert(!isa<DILocalScope>(LocalScope) && "Unknown type of local scope");
  return nullptr;
}
 
void Verifier::visit(DbgLabelRecord &DLR) {
  CheckDI(isa<DILabel>(DLR.getRawLabel()),
          "invalid #dbg_label intrinsic variable", &DLR, DLR.getRawLabel());
 
  // Ignore broken !dbg attachments; they're checked elsewhere.
  if (MDNode *N = DLR.getDebugLoc().getAsMDNode())
    if (!isa<DILocation>(N))
      return;
 
  BasicBlock *BB = DLR.getParent();
  Function *F = BB ? BB->getParent() : nullptr;
 
  // The scopes for variables and !dbg attachments must agree.
  DILabel *Label = DLR.getLabel();
  DILocation *Loc = DLR.getDebugLoc();
  CheckDI(Loc, "#dbg_label record requires a !dbg attachment", &DLR, BB, F);
 
  DISubprogram *LabelSP = getSubprogram(Label->getRawScope());
  DISubprogram *LocSP = getSubprogram(Loc->getRawScope());
  if (!LabelSP || !LocSP)
    return;
 
  CheckDI(LabelSP == LocSP,
          "mismatched subprogram between #dbg_label label and !dbg attachment",
          &DLR, BB, F, Label, Label->getScope()->getSubprogram(), Loc,
          Loc->getScope()->getSubprogram());
}
 
void Verifier::visit(DbgVariableRecord &DVR) {
  BasicBlock *BB = DVR.getParent();
  Function *F = BB->getParent();
 
  CheckDI(DVR.getType() == DbgVariableRecord::LocationType::Value ||
              DVR.getType() == DbgVariableRecord::LocationType::Declare ||
              DVR.getType() == DbgVariableRecord::LocationType::DeclareValue ||
              DVR.getType() == DbgVariableRecord::LocationType::Assign,
          "invalid #dbg record type", &DVR, DVR.getType(), BB, F);
 
  // The location for a DbgVariableRecord must be either a ValueAsMetadata,
  // DIArgList, or an empty MDNode (which is a legacy representation for an
  // "undef" location).
  auto *MD = DVR.getRawLocation();
  CheckDI(MD && (isa<ValueAsMetadata>(MD) || isa<DIArgList>(MD) ||
                 (isa<MDNode>(MD) && !cast<MDNode>(MD)->getNumOperands())),
          "invalid #dbg record address/value", &DVR, MD, BB, F);
  if (auto *VAM = dyn_cast<ValueAsMetadata>(MD)) {
    visitValueAsMetadata(*VAM, F);
    if (DVR.isDbgDeclare()) {
      // Allow integers here to support inttoptr salvage.
      Type *Ty = VAM->getValue()->getType();
      CheckDI(Ty->isPointerTy() || Ty->isIntegerTy(),
              "location of #dbg_declare must be a pointer or int", &DVR, MD, BB,
              F);
    }
  } else if (auto *AL = dyn_cast<DIArgList>(MD)) {
    visitDIArgList(*AL, F);
  }
 
  CheckDI(isa_and_nonnull<DILocalVariable>(DVR.getRawVariable()),
          "invalid #dbg record variable", &DVR, DVR.getRawVariable(), BB, F);
  visitMDNode(*DVR.getRawVariable(), AreDebugLocsAllowed::No);
 
  CheckDI(isa_and_nonnull<DIExpression>(DVR.getRawExpression()),
          "invalid #dbg record expression", &DVR, DVR.getRawExpression(), BB,
          F);
  visitMDNode(*DVR.getExpression(), AreDebugLocsAllowed::No);
 
  if (DVR.isDbgAssign()) {
    CheckDI(isa_and_nonnull<DIAssignID>(DVR.getRawAssignID()),
            "invalid #dbg_assign DIAssignID", &DVR, DVR.getRawAssignID(), BB,
            F);
    visitMDNode(*cast<DIAssignID>(DVR.getRawAssignID()),
                AreDebugLocsAllowed::No);
 
    const auto *RawAddr = DVR.getRawAddress();
    // Similarly to the location above, the address for an assign
    // DbgVariableRecord must be a ValueAsMetadata or an empty MDNode, which
    // represents an undef address.
    CheckDI(
        isa<ValueAsMetadata>(RawAddr) ||
            (isa<MDNode>(RawAddr) && !cast<MDNode>(RawAddr)->getNumOperands()),
        "invalid #dbg_assign address", &DVR, DVR.getRawAddress(), BB, F);
    if (auto *VAM = dyn_cast<ValueAsMetadata>(RawAddr))
      visitValueAsMetadata(*VAM, F);
 
    CheckDI(isa_and_nonnull<DIExpression>(DVR.getRawAddressExpression()),
            "invalid #dbg_assign address expression", &DVR,
            DVR.getRawAddressExpression(), BB, F);
    visitMDNode(*DVR.getAddressExpression(), AreDebugLocsAllowed::No);
 
    // All of the linked instructions should be in the same function as DVR.
    for (Instruction *I : at::getAssignmentInsts(&DVR))
      CheckDI(DVR.getFunction() == I->getFunction(),
              "inst not in same function as #dbg_assign", I, &DVR, BB, F);
  }
 
  // This check is redundant with one in visitLocalVariable().
  DILocalVariable *Var = DVR.getVariable();
  CheckDI(isType(Var->getRawType()), "invalid type ref", Var, Var->getRawType(),
          BB, F);
 
  auto *DLNode = DVR.getDebugLoc().getAsMDNode();
  CheckDI(isa_and_nonnull<DILocation>(DLNode), "invalid #dbg record DILocation",
          &DVR, DLNode, BB, F);
  DILocation *Loc = DVR.getDebugLoc();
 
  // The scopes for variables and !dbg attachments must agree.
  DISubprogram *VarSP = getSubprogram(Var->getRawScope());
  DISubprogram *LocSP = getSubprogram(Loc->getRawScope());
  if (!VarSP || !LocSP)
    return; // Broken scope chains are checked elsewhere.
 
  CheckDI(VarSP == LocSP,
          "mismatched subprogram between #dbg record variable and DILocation",
          &DVR, BB, F, Var, Var->getScope()->getSubprogram(), Loc,
          Loc->getScope()->getSubprogram(), BB, F);
 
  verifyFnArgs(DVR);
}
 
void Verifier::visitVPIntrinsic(VPIntrinsic &VPI) {
  switch (VPI.getIntrinsicID()) {
  case Intrinsic::experimental_vp_splice: {
    VectorType *VecTy = cast<VectorType>(VPI.getType());
    int64_t Idx = cast<ConstantInt>(VPI.getArgOperand(2))->getSExtValue();
    int64_t KnownMinNumElements = VecTy->getElementCount().getKnownMinValue();
    if (VPI.getParent() && VPI.getParent()->getParent()) {
      AttributeList Attrs = VPI.getParent()->getParent()->getAttributes();
      if (Attrs.hasFnAttr(Attribute::VScaleRange))
        KnownMinNumElements *= Attrs.getFnAttrs().getVScaleRangeMin();
    }
    Check((Idx < 0 && std::abs(Idx) <= KnownMinNumElements) ||
              (Idx >= 0 && Idx < KnownMinNumElements),
          "The splice index exceeds the range [-VL, VL-1] where VL is the "
          "known minimum number of elements in the vector. For scalable "
          "vectors the minimum number of elements is determined from "
          "vscale_range.",
          &VPI);
    break;
  }
  }
}
 
void Verifier::visitConstrainedFPIntrinsic(ConstrainedFPIntrinsic &FPI) {
  unsigned NumOperands = FPI.getNonMetadataArgCount();
  bool HasRoundingMD =
      Intrinsic::hasConstrainedFPRoundingModeOperand(FPI.getIntrinsicID());
 
  // Add the expected number of metadata operands.
  NumOperands += (1 + HasRoundingMD);
 
  // Compare intrinsics carry an extra predicate metadata operand.
  if (isa<ConstrainedFPCmpIntrinsic>(FPI))
    NumOperands += 1;
  Check((FPI.arg_size() == NumOperands),
        "invalid arguments for constrained FP intrinsic", &FPI);
 
  switch (FPI.getIntrinsicID()) {
  case Intrinsic::experimental_constrained_fcmp:
  case Intrinsic::experimental_constrained_fcmps: {
    auto Pred = cast<ConstrainedFPCmpIntrinsic>(&FPI)->getPredicate();
    Check(CmpInst::isFPPredicate(Pred),
          "invalid predicate for constrained FP comparison intrinsic", &FPI);
    break;
  }
 
  case Intrinsic::experimental_constrained_fptosi:
  case Intrinsic::experimental_constrained_fptoui: {
    Value *Operand = FPI.getArgOperand(0);
    ElementCount SrcEC;
    Check(Operand->getType()->isFPOrFPVectorTy(),
          "Intrinsic first argument must be floating point", &FPI);
    if (auto *OperandT = dyn_cast<VectorType>(Operand->getType())) {
      SrcEC = cast<VectorType>(OperandT)->getElementCount();
    }
 
    Operand = &FPI;
    Check(SrcEC.isNonZero() == Operand->getType()->isVectorTy(),
          "Intrinsic first argument and result disagree on vector use", &FPI);
    Check(Operand->getType()->isIntOrIntVectorTy(),
          "Intrinsic result must be an integer", &FPI);
    if (auto *OperandT = dyn_cast<VectorType>(Operand->getType())) {
      Check(SrcEC == cast<VectorType>(OperandT)->getElementCount(),
            "Intrinsic first argument and result vector lengths must be equal",
            &FPI);
    }
    break;
  }
 
  case Intrinsic::experimental_constrained_sitofp:
  case Intrinsic::experimental_constrained_uitofp: {
    Value *Operand = FPI.getArgOperand(0);
    ElementCount SrcEC;
    Check(Operand->getType()->isIntOrIntVectorTy(),
          "Intrinsic first argument must be integer", &FPI);
    if (auto *OperandT = dyn_cast<VectorType>(Operand->getType())) {
      SrcEC = cast<VectorType>(OperandT)->getElementCount();
    }
 
    Operand = &FPI;
    Check(SrcEC.isNonZero() == Operand->getType()->isVectorTy(),
          "Intrinsic first argument and result disagree on vector use", &FPI);
    Check(Operand->getType()->isFPOrFPVectorTy(),
          "Intrinsic result must be a floating point", &FPI);
    if (auto *OperandT = dyn_cast<VectorType>(Operand->getType())) {
      Check(SrcEC == cast<VectorType>(OperandT)->getElementCount(),
            "Intrinsic first argument and result vector lengths must be equal",
            &FPI);
    }
    break;
  }
 
  case Intrinsic::experimental_constrained_fptrunc:
  case Intrinsic::experimental_constrained_fpext: {
    Value *Operand = FPI.getArgOperand(0);
    Type *OperandTy = Operand->getType();
    Value *Result = &FPI;
    Type *ResultTy = Result->getType();
    Check(OperandTy->isFPOrFPVectorTy(),
          "Intrinsic first argument must be FP or FP vector", &FPI);
    Check(ResultTy->isFPOrFPVectorTy(),
          "Intrinsic result must be FP or FP vector", &FPI);
    Check(OperandTy->isVectorTy() == ResultTy->isVectorTy(),
          "Intrinsic first argument and result disagree on vector use", &FPI);
    if (OperandTy->isVectorTy()) {
      Check(cast<VectorType>(OperandTy)->getElementCount() ==
                cast<VectorType>(ResultTy)->getElementCount(),
            "Intrinsic first argument and result vector lengths must be equal",
            &FPI);
    }
    if (FPI.getIntrinsicID() == Intrinsic::experimental_constrained_fptrunc) {
      Check(OperandTy->getScalarSizeInBits() > ResultTy->getScalarSizeInBits(),
            "Intrinsic first argument's type must be larger than result type",
            &FPI);
    } else {
      Check(OperandTy->getScalarSizeInBits() < ResultTy->getScalarSizeInBits(),
            "Intrinsic first argument's type must be smaller than result type",
            &FPI);
    }
    break;
  }
 
  default:
    break;
  }
 
  // If a non-metadata argument is passed in a metadata slot then the
  // error will be caught earlier when the incorrect argument doesn't
  // match the specification in the intrinsic call table. Thus, no
  // argument type check is needed here.
 
  Check(FPI.getExceptionBehavior().has_value(),
        "invalid exception behavior argument", &FPI);
  if (HasRoundingMD) {
    Check(FPI.getRoundingMode().has_value(), "invalid rounding mode argument",
          &FPI);
  }
}
 
void Verifier::verifyFragmentExpression(const DbgVariableRecord &DVR) {
  DILocalVariable *V = dyn_cast_or_null<DILocalVariable>(DVR.getRawVariable());
  DIExpression *E = dyn_cast_or_null<DIExpression>(DVR.getRawExpression());
 
  // We don't know whether this intrinsic verified correctly.
  if (!V || !E || !E->isValid())
    return;
 
  // Nothing to do if this isn't a DW_OP_LLVM_fragment expression.
  auto Fragment = E->getFragmentInfo();
  if (!Fragment)
    return;
 
  // The frontend helps out GDB by emitting the members of local anonymous
  // unions as artificial local variables with shared storage. When SROA splits
  // the storage for artificial local variables that are smaller than the entire
  // union, the overhang piece will be outside of the allotted space for the
  // variable and this check fails.
  // FIXME: Remove this check as soon as clang stops doing this; it hides bugs.
  if (V->isArtificial())
    return;
 
  verifyFragmentExpression(*V, *Fragment, &DVR);
}
 
template <typename ValueOrMetadata>
void Verifier::verifyFragmentExpression(const DIVariable &V,
                                        DIExpression::FragmentInfo Fragment,
                                        ValueOrMetadata *Desc) {
  // If there's no size, the type is broken, but that should be checked
  // elsewhere.
  auto VarSize = V.getSizeInBits();
  if (!VarSize)
    return;
 
  unsigned FragSize = Fragment.SizeInBits;
  unsigned FragOffset = Fragment.OffsetInBits;
  CheckDI(FragSize + FragOffset <= *VarSize,
          "fragment is larger than or outside of variable", Desc, &V);
  CheckDI(FragSize != *VarSize, "fragment covers entire variable", Desc, &V);
}
 
void Verifier::verifyFnArgs(const DbgVariableRecord &DVR) {
  // This function does not take the scope of noninlined function arguments into
  // account. Don't run it if current function is nodebug, because it may
  // contain inlined debug intrinsics.
  if (!HasDebugInfo)
    return;
 
  // For performance reasons only check non-inlined ones.
  if (DVR.getDebugLoc()->getInlinedAt())
    return;
 
  DILocalVariable *Var = DVR.getVariable();
  CheckDI(Var, "#dbg record without variable");
 
  unsigned ArgNo = Var->getArg();
  if (!ArgNo)
    return;
 
  // Verify there are no duplicate function argument debug info entries.
  // These will cause hard-to-debug assertions in the DWARF backend.
  if (DebugFnArgs.size() < ArgNo)
    DebugFnArgs.resize(ArgNo, nullptr);
 
  auto *Prev = DebugFnArgs[ArgNo - 1];
  DebugFnArgs[ArgNo - 1] = Var;
  CheckDI(!Prev || (Prev == Var), "conflicting debug info for argument", &DVR,
          Prev, Var);
}
 
void Verifier::verifyNotEntryValue(const DbgVariableRecord &DVR) {
  DIExpression *E = dyn_cast_or_null<DIExpression>(DVR.getRawExpression());
 
  // We don't know whether this intrinsic verified correctly.
  if (!E || !E->isValid())
    return;
 
  if (isa<ValueAsMetadata>(DVR.getRawLocation())) {
    Value *VarValue = DVR.getVariableLocationOp(0);
    if (isa<UndefValue>(VarValue) || isa<PoisonValue>(VarValue))
      return;
    // We allow EntryValues for swift async arguments, as they have an
    // ABI-guarantee to be turned into a specific register.
    if (auto *ArgLoc = dyn_cast_or_null<Argument>(VarValue);
        ArgLoc && ArgLoc->hasAttribute(Attribute::SwiftAsync))
      return;
  }
 
  CheckDI(!E->isEntryValue(),
          "Entry values are only allowed in MIR unless they target a "
          "swiftasync Argument",
          &DVR);
}
 
void Verifier::verifyCompileUnits() {
  // When more than one Module is imported into the same context, such as during
  // an LTO build before linking the modules, ODR type uniquing may cause types
  // to point to a different CU. This check does not make sense in this case.
  if (M.getContext().isODRUniquingDebugTypes())
    return;
  auto *CUs = M.getNamedMetadata("llvm.dbg.cu");
  SmallPtrSet<const Metadata *, 2> Listed;
  if (CUs)
    Listed.insert_range(CUs->operands());
  for (const auto *CU : CUVisited)
    CheckDI(Listed.count(CU), "DICompileUnit not listed in llvm.dbg.cu", CU);
  CUVisited.clear();
}
 
void Verifier::verifyDeoptimizeCallingConvs() {
  if (DeoptimizeDeclarations.empty())
    return;
 
  const Function *First = DeoptimizeDeclarations[0];
  for (const auto *F : ArrayRef(DeoptimizeDeclarations).slice(1)) {
    Check(First->getCallingConv() == F->getCallingConv(),
          "All llvm.experimental.deoptimize declarations must have the same "
          "calling convention",
          First, F);
  }
}
 
void Verifier::verifyAttachedCallBundle(const CallBase &Call,
                                        const OperandBundleUse &BU) {
  FunctionType *FTy = Call.getFunctionType();
 
  Check((FTy->getReturnType()->isPointerTy() ||
         (Call.doesNotReturn() && FTy->getReturnType()->isVoidTy())),
        "a call with operand bundle \"clang.arc.attachedcall\" must call a "
        "function returning a pointer or a non-returning function that has a "
        "void return type",
        Call);
 
  Check(BU.Inputs.size() == 1 && isa<Function>(BU.Inputs.front()),
        "operand bundle \"clang.arc.attachedcall\" requires one function as "
        "an argument",
        Call);
 
  auto *Fn = cast<Function>(BU.Inputs.front());
  Intrinsic::ID IID = Fn->getIntrinsicID();
 
  if (IID) {
    Check((IID == Intrinsic::objc_retainAutoreleasedReturnValue ||
           IID == Intrinsic::objc_claimAutoreleasedReturnValue ||
           IID == Intrinsic::objc_unsafeClaimAutoreleasedReturnValue),
          "invalid function argument", Call);
  } else {
    StringRef FnName = Fn->getName();
    Check((FnName == "objc_retainAutoreleasedReturnValue" ||
           FnName == "objc_claimAutoreleasedReturnValue" ||
           FnName == "objc_unsafeClaimAutoreleasedReturnValue"),
          "invalid function argument", Call);
  }
}
 
void Verifier::verifyNoAliasScopeDecl() {
  if (NoAliasScopeDecls.empty())
    return;
 
  // only a single scope must be declared at a time.
  for (auto *II : NoAliasScopeDecls) {
    assert(II->getIntrinsicID() == Intrinsic::experimental_noalias_scope_decl &&
           "Not a llvm.experimental.noalias.scope.decl ?");
    const auto *ScopeListMV = dyn_cast<MetadataAsValue>(
        II->getOperand(Intrinsic::NoAliasScopeDeclScopeArg));
    Check(ScopeListMV != nullptr,
          "llvm.experimental.noalias.scope.decl must have a MetadataAsValue "
          "argument",
          II);
 
    const auto *ScopeListMD = dyn_cast<MDNode>(ScopeListMV->getMetadata());
    Check(ScopeListMD != nullptr, "!id.scope.list must point to an MDNode", II);
    Check(ScopeListMD->getNumOperands() == 1,
          "!id.scope.list must point to a list with a single scope", II);
    visitAliasScopeListMetadata(ScopeListMD);
  }
 
  // Only check the domination rule when requested. Once all passes have been
  // adapted this option can go away.
  if (!VerifyNoAliasScopeDomination)
    return;
 
  // Now sort the intrinsics based on the scope MDNode so that declarations of
  // the same scopes are next to each other.
  auto GetScope = [](IntrinsicInst *II) {
    const auto *ScopeListMV = cast<MetadataAsValue>(
        II->getOperand(Intrinsic::NoAliasScopeDeclScopeArg));
    return &cast<MDNode>(ScopeListMV->getMetadata())->getOperand(0);
  };
 
  // We are sorting on MDNode pointers here. For valid input IR this is ok.
  // TODO: Sort on Metadata ID to avoid non-deterministic error messages.
  auto Compare = [GetScope](IntrinsicInst *Lhs, IntrinsicInst *Rhs) {
    return GetScope(Lhs) < GetScope(Rhs);
  };
 
  llvm::sort(NoAliasScopeDecls, Compare);
 
  // Go over the intrinsics and check that for the same scope, they are not
  // dominating each other.
  auto ItCurrent = NoAliasScopeDecls.begin();
  while (ItCurrent != NoAliasScopeDecls.end()) {
    auto CurScope = GetScope(*ItCurrent);
    auto ItNext = ItCurrent;
    do {
      ++ItNext;
    } while (ItNext != NoAliasScopeDecls.end() &&
             GetScope(*ItNext) == CurScope);
 
    // [ItCurrent, ItNext) represents the declarations for the same scope.
    // Ensure they are not dominating each other.. but only if it is not too
    // expensive.
    if (ItNext - ItCurrent < 32)
      for (auto *I : llvm::make_range(ItCurrent, ItNext))
        for (auto *J : llvm::make_range(ItCurrent, ItNext))
          if (I != J)
            Check(!DT.dominates(I, J),
                  "llvm.experimental.noalias.scope.decl dominates another one "
                  "with the same scope",
                  I);
    ItCurrent = ItNext;
  }
}
 
//===----------------------------------------------------------------------===//
//  Implement the public interfaces to this file...
//===----------------------------------------------------------------------===//
 
bool llvm::verifyFunction(const Function &f, raw_ostream *OS) {
  Function &F = const_cast<Function &>(f);
 
  // Don't use a raw_null_ostream.  Printing IR is expensive.
  Verifier V(OS, /*ShouldTreatBrokenDebugInfoAsError=*/true, *f.getParent());
 
  // Note that this function's return value is inverted from what you would
  // expect of a function called "verify".
  return !V.verify(F);
}
 
bool llvm::verifyModule(const Module &M, raw_ostream *OS,
                        bool *BrokenDebugInfo) {
  // Don't use a raw_null_ostream.  Printing IR is expensive.
  Verifier V(OS, /*ShouldTreatBrokenDebugInfoAsError=*/!BrokenDebugInfo, M);
 
  bool Broken = false;
  for (const Function &F : M)
    Broken |= !V.verify(F);
 
  Broken |= !V.verify();
  if (BrokenDebugInfo)
    *BrokenDebugInfo = V.hasBrokenDebugInfo();
  // Note that this function's return value is inverted from what you would
  // expect of a function called "verify".
  return Broken;
}
 
namespace {
 
struct VerifierLegacyPass : public FunctionPass {
  static char ID;
 
  std::unique_ptr<Verifier> V;
  bool FatalErrors = true;
 
  VerifierLegacyPass() : FunctionPass(ID) {}
  explicit VerifierLegacyPass(bool FatalErrors)
      : FunctionPass(ID), FatalErrors(FatalErrors) {}
 
  bool doInitialization(Module &M) override {
    V = std::make_unique<Verifier>(
        &dbgs(), /*ShouldTreatBrokenDebugInfoAsError=*/false, M);
    return false;
  }
 
  bool runOnFunction(Function &F) override {
    if (!V->verify(F) && FatalErrors) {
      errs() << "in function " << F.getName() << '\n';
      report_fatal_error("Broken function found, compilation aborted!");
    }
    return false;
  }
 
  bool doFinalization(Module &M) override {
    bool HasErrors = false;
    for (Function &F : M)
      if (F.isDeclaration())
        HasErrors |= !V->verify(F);
 
    HasErrors |= !V->verify();
    if (FatalErrors && (HasErrors || V->hasBrokenDebugInfo()))
      report_fatal_error("Broken module found, compilation aborted!");
    return false;
  }
 
  void getAnalysisUsage(AnalysisUsage &AU) const override {
    AU.setPreservesAll();
  }
};
 
} // end anonymous namespace
 
/// Helper to issue failure from the TBAA verification
template <typename... Tys> void TBAAVerifier::CheckFailed(Tys &&... Args) {
  if (Diagnostic)
    return Diagnostic->CheckFailed(Args...);
}
 
#define CheckTBAA(C, ...)                                                      \
  do {                                                                         \
    if (!(C)) {                                                                \
      CheckFailed(__VA_ARGS__);                                                \
      return false;                                                            \
    }                                                                          \
  } while (false)
 
/// Verify that \p BaseNode can be used as the "base type" in the struct-path
/// TBAA scheme.  This means \p BaseNode is either a scalar node, or a
/// struct-type node describing an aggregate data structure (like a struct).
TBAAVerifier::TBAABaseNodeSummary
TBAAVerifier::verifyTBAABaseNode(const Instruction *I, const MDNode *BaseNode,
                                 bool IsNewFormat) {
  if (BaseNode->getNumOperands() < 2) {
    CheckFailed("Base nodes must have at least two operands", I, BaseNode);
    return {true, ~0u};
  }
 
  auto Itr = TBAABaseNodes.find(BaseNode);
  if (Itr != TBAABaseNodes.end())
    return Itr->second;
 
  auto Result = verifyTBAABaseNodeImpl(I, BaseNode, IsNewFormat);
  auto InsertResult = TBAABaseNodes.insert({BaseNode, Result});
  (void)InsertResult;
  assert(InsertResult.second && "We just checked!");
  return Result;
}
 
TBAAVerifier::TBAABaseNodeSummary
TBAAVerifier::verifyTBAABaseNodeImpl(const Instruction *I,
                                     const MDNode *BaseNode, bool IsNewFormat) {
  const TBAAVerifier::TBAABaseNodeSummary InvalidNode = {true, ~0u};
 
  if (BaseNode->getNumOperands() == 2) {
    // Scalar nodes can only be accessed at offset 0.
    return isValidScalarTBAANode(BaseNode)
               ? TBAAVerifier::TBAABaseNodeSummary({false, 0})
               : InvalidNode;
  }
 
  if (IsNewFormat) {
    if (BaseNode->getNumOperands() % 3 != 0) {
      CheckFailed("Access tag nodes must have the number of operands that is a "
                  "multiple of 3!", BaseNode);
      return InvalidNode;
    }
  } else {
    if (BaseNode->getNumOperands() % 2 != 1) {
      CheckFailed("Struct tag nodes must have an odd number of operands!",
                  BaseNode);
      return InvalidNode;
    }
  }
 
  // Check the type size field.
  if (IsNewFormat) {
    auto *TypeSizeNode = mdconst::dyn_extract_or_null<ConstantInt>(
        BaseNode->getOperand(1));
    if (!TypeSizeNode) {
      CheckFailed("Type size nodes must be constants!", I, BaseNode);
      return InvalidNode;
    }
  }
 
  // Check the type name field. In the new format it can be anything.
  if (!IsNewFormat && !isa<MDString>(BaseNode->getOperand(0))) {
    CheckFailed("Struct tag nodes have a string as their first operand",
                BaseNode);
    return InvalidNode;
  }
 
  bool Failed = false;
 
  std::optional<APInt> PrevOffset;
  unsigned BitWidth = ~0u;
 
  // We've already checked that BaseNode is not a degenerate root node with one
  // operand in \c verifyTBAABaseNode, so this loop should run at least once.
  unsigned FirstFieldOpNo = IsNewFormat ? 3 : 1;
  unsigned NumOpsPerField = IsNewFormat ? 3 : 2;
  for (unsigned Idx = FirstFieldOpNo; Idx < BaseNode->getNumOperands();
           Idx += NumOpsPerField) {
    const MDOperand &FieldTy = BaseNode->getOperand(Idx);
    const MDOperand &FieldOffset = BaseNode->getOperand(Idx + 1);
    if (!isa<MDNode>(FieldTy)) {
      CheckFailed("Incorrect field entry in struct type node!", I, BaseNode);
      Failed = true;
      continue;
    }
 
    auto *OffsetEntryCI =
        mdconst::dyn_extract_or_null<ConstantInt>(FieldOffset);
    if (!OffsetEntryCI) {
      CheckFailed("Offset entries must be constants!", I, BaseNode);
      Failed = true;
      continue;
    }
 
    if (BitWidth == ~0u)
      BitWidth = OffsetEntryCI->getBitWidth();
 
    if (OffsetEntryCI->getBitWidth() != BitWidth) {
      CheckFailed(
          "Bitwidth between the offsets and struct type entries must match", I,
          BaseNode);
      Failed = true;
      continue;
    }
 
    // NB! As far as I can tell, we generate a non-strictly increasing offset
    // sequence only from structs that have zero size bit fields.  When
    // recursing into a contained struct in \c getFieldNodeFromTBAABaseNode we
    // pick the field lexically the latest in struct type metadata node.  This
    // mirrors the actual behavior of the alias analysis implementation.
    bool IsAscending =
        !PrevOffset || PrevOffset->ule(OffsetEntryCI->getValue());
 
    if (!IsAscending) {
      CheckFailed("Offsets must be increasing!", I, BaseNode);
      Failed = true;
    }
 
    PrevOffset = OffsetEntryCI->getValue();
 
    if (IsNewFormat) {
      auto *MemberSizeNode = mdconst::dyn_extract_or_null<ConstantInt>(
          BaseNode->getOperand(Idx + 2));
      if (!MemberSizeNode) {
        CheckFailed("Member size entries must be constants!", I, BaseNode);
        Failed = true;
        continue;
      }
    }
  }
 
  return Failed ? InvalidNode
                : TBAAVerifier::TBAABaseNodeSummary(false, BitWidth);
}
 
static bool IsRootTBAANode(const MDNode *MD) {
  return MD->getNumOperands() < 2;
}
 
static bool IsScalarTBAANodeImpl(const MDNode *MD,
                                 SmallPtrSetImpl<const MDNode *> &Visited) {
  if (MD->getNumOperands() != 2 && MD->getNumOperands() != 3)
    return false;
 
  if (!isa<MDString>(MD->getOperand(0)))
    return false;
 
  if (MD->getNumOperands() == 3) {
    auto *Offset = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
    if (!(Offset && Offset->isZero() && isa<MDString>(MD->getOperand(0))))
      return false;
  }
 
  auto *Parent = dyn_cast_or_null<MDNode>(MD->getOperand(1));
  return Parent && Visited.insert(Parent).second &&
         (IsRootTBAANode(Parent) || IsScalarTBAANodeImpl(Parent, Visited));
}
 
bool TBAAVerifier::isValidScalarTBAANode(const MDNode *MD) {
  auto ResultIt = TBAAScalarNodes.find(MD);
  if (ResultIt != TBAAScalarNodes.end())
    return ResultIt->second;
 
  SmallPtrSet<const MDNode *, 4> Visited;
  bool Result = IsScalarTBAANodeImpl(MD, Visited);
  auto InsertResult = TBAAScalarNodes.insert({MD, Result});
  (void)InsertResult;
  assert(InsertResult.second && "Just checked!");
 
  return Result;
}
 
/// Returns the field node at the offset \p Offset in \p BaseNode.  Update \p
/// Offset in place to be the offset within the field node returned.
///
/// We assume we've okayed \p BaseNode via \c verifyTBAABaseNode.
MDNode *TBAAVerifier::getFieldNodeFromTBAABaseNode(const Instruction *I,
                                                   const MDNode *BaseNode,
                                                   APInt &Offset,
                                                   bool IsNewFormat) {
  assert(BaseNode->getNumOperands() >= 2 && "Invalid base node!");
 
  // Scalar nodes have only one possible "field" -- their parent in the access
  // hierarchy.  Offset must be zero at this point, but our caller is supposed
  // to check that.
  if (BaseNode->getNumOperands() == 2)
    return cast<MDNode>(BaseNode->getOperand(1));
 
  unsigned FirstFieldOpNo = IsNewFormat ? 3 : 1;
  unsigned NumOpsPerField = IsNewFormat ? 3 : 2;
  for (unsigned Idx = FirstFieldOpNo; Idx < BaseNode->getNumOperands();
           Idx += NumOpsPerField) {
    auto *OffsetEntryCI =
        mdconst::extract<ConstantInt>(BaseNode->getOperand(Idx + 1));
    if (OffsetEntryCI->getValue().ugt(Offset)) {
      if (Idx == FirstFieldOpNo) {
        CheckFailed("Could not find TBAA parent in struct type node", I,
                    BaseNode, &Offset);
        return nullptr;
      }
 
      unsigned PrevIdx = Idx - NumOpsPerField;
      auto *PrevOffsetEntryCI =
          mdconst::extract<ConstantInt>(BaseNode->getOperand(PrevIdx + 1));
      Offset -= PrevOffsetEntryCI->getValue();
      return cast<MDNode>(BaseNode->getOperand(PrevIdx));
    }
  }
 
  unsigned LastIdx = BaseNode->getNumOperands() - NumOpsPerField;
  auto *LastOffsetEntryCI = mdconst::extract<ConstantInt>(
      BaseNode->getOperand(LastIdx + 1));
  Offset -= LastOffsetEntryCI->getValue();
  return cast<MDNode>(BaseNode->getOperand(LastIdx));
}
 
static bool isNewFormatTBAATypeNode(llvm::MDNode *Type) {
  if (!Type || Type->getNumOperands() < 3)
    return false;
 
  // In the new format type nodes shall have a reference to the parent type as
  // its first operand.
  return isa_and_nonnull<MDNode>(Type->getOperand(0));
}
 
bool TBAAVerifier::visitTBAAMetadata(const Instruction *I, const MDNode *MD) {
  CheckTBAA(MD->getNumOperands() > 0, "TBAA metadata cannot have 0 operands", I,
            MD);
 
  if (I)
    CheckTBAA(isa<LoadInst>(I) || isa<StoreInst>(I) || isa<CallInst>(I) ||
                  isa<VAArgInst>(I) || isa<AtomicRMWInst>(I) ||
                  isa<AtomicCmpXchgInst>(I),
              "This instruction shall not have a TBAA access tag!", I);
 
  bool IsStructPathTBAA =
      isa<MDNode>(MD->getOperand(0)) && MD->getNumOperands() >= 3;
 
  CheckTBAA(IsStructPathTBAA,
            "Old-style TBAA is no longer allowed, use struct-path TBAA instead",
            I);
 
  auto *BaseNode = dyn_cast_or_null<MDNode>(MD->getOperand(0));
  auto *AccessType = dyn_cast_or_null<MDNode>(MD->getOperand(1));
 
  bool IsNewFormat = isNewFormatTBAATypeNode(AccessType);
 
  if (IsNewFormat) {
    CheckTBAA(MD->getNumOperands() == 4 || MD->getNumOperands() == 5,
              "Access tag metadata must have either 4 or 5 operands", I, MD);
  } else {
    CheckTBAA(MD->getNumOperands() < 5,
              "Struct tag metadata must have either 3 or 4 operands", I, MD);
  }
 
  // Check the access size field.
  if (IsNewFormat) {
    auto *AccessSizeNode = mdconst::dyn_extract_or_null<ConstantInt>(
        MD->getOperand(3));
    CheckTBAA(AccessSizeNode, "Access size field must be a constant", I, MD);
  }
 
  // Check the immutability flag.
  unsigned ImmutabilityFlagOpNo = IsNewFormat ? 4 : 3;
  if (MD->getNumOperands() == ImmutabilityFlagOpNo + 1) {
    auto *IsImmutableCI = mdconst::dyn_extract_or_null<ConstantInt>(
        MD->getOperand(ImmutabilityFlagOpNo));
    CheckTBAA(IsImmutableCI,
              "Immutability tag on struct tag metadata must be a constant", I,
              MD);
    CheckTBAA(
        IsImmutableCI->isZero() || IsImmutableCI->isOne(),
        "Immutability part of the struct tag metadata must be either 0 or 1", I,
        MD);
  }
 
  CheckTBAA(BaseNode && AccessType,
            "Malformed struct tag metadata: base and access-type "
            "should be non-null and point to Metadata nodes",
            I, MD, BaseNode, AccessType);
 
  if (!IsNewFormat) {
    CheckTBAA(isValidScalarTBAANode(AccessType),
              "Access type node must be a valid scalar type", I, MD,
              AccessType);
  }
 
  auto *OffsetCI = mdconst::dyn_extract_or_null<ConstantInt>(MD->getOperand(2));
  CheckTBAA(OffsetCI, "Offset must be constant integer", I, MD);
 
  APInt Offset = OffsetCI->getValue();
  bool SeenAccessTypeInPath = false;
 
  SmallPtrSet<MDNode *, 4> StructPath;
 
  for (/* empty */; BaseNode && !IsRootTBAANode(BaseNode);
       BaseNode =
           getFieldNodeFromTBAABaseNode(I, BaseNode, Offset, IsNewFormat)) {
    if (!StructPath.insert(BaseNode).second) {
      CheckFailed("Cycle detected in struct path", I, MD);
      return false;
    }
 
    bool Invalid;
    unsigned BaseNodeBitWidth;
    std::tie(Invalid, BaseNodeBitWidth) =
        verifyTBAABaseNode(I, BaseNode, IsNewFormat);
 
    // If the base node is invalid in itself, then we've already printed all the
    // errors we wanted to print.
    if (Invalid)
      return false;
 
    SeenAccessTypeInPath |= BaseNode == AccessType;
 
    if (isValidScalarTBAANode(BaseNode) || BaseNode == AccessType)
      CheckTBAA(Offset == 0, "Offset not zero at the point of scalar access", I,
                MD, &Offset);
 
    CheckTBAA(BaseNodeBitWidth == Offset.getBitWidth() ||
                  (BaseNodeBitWidth == 0 && Offset == 0) ||
                  (IsNewFormat && BaseNodeBitWidth == ~0u),
              "Access bit-width not the same as description bit-width", I, MD,
              BaseNodeBitWidth, Offset.getBitWidth());
 
    if (IsNewFormat && SeenAccessTypeInPath)
      break;
  }
 
  CheckTBAA(SeenAccessTypeInPath, "Did not see access type in access path!", I,
            MD);
  return true;
}
 
char VerifierLegacyPass::ID = 0;
INITIALIZE_PASS(VerifierLegacyPass, "verify", "Module Verifier", false, false)
 
FunctionPass *llvm::createVerifierPass(bool FatalErrors) {
  return new VerifierLegacyPass(FatalErrors);
}
 
AnalysisKey VerifierAnalysis::Key;
VerifierAnalysis::Result VerifierAnalysis::run(Module &M,
                                               ModuleAnalysisManager &) {
  Result Res;
  Res.IRBroken = llvm::verifyModule(M, &dbgs(), &Res.DebugInfoBroken);
  return Res;
}
 
VerifierAnalysis::Result VerifierAnalysis::run(Function &F,
                                               FunctionAnalysisManager &) {
  return { llvm::verifyFunction(F, &dbgs()), false };
}
 
PreservedAnalyses VerifierPass::run(Module &M, ModuleAnalysisManager &AM) {
  auto Res = AM.getResult<VerifierAnalysis>(M);
  if (FatalErrors && (Res.IRBroken || Res.DebugInfoBroken))
    report_fatal_error("Broken module found, compilation aborted!");
 
  return PreservedAnalyses::all();
}
 
PreservedAnalyses VerifierPass::run(Function &F, FunctionAnalysisManager &AM) {
  auto res = AM.getResult<VerifierAnalysis>(F);
  if (res.IRBroken && FatalErrors)
    report_fatal_error("Broken function found, compilation aborted!");
 
  return PreservedAnalyses::all();
}