CodeGenFunction.h

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//===-- CodeGenFunction.h - Per-Function state for LLVM CodeGen -*- C++ -*-===//
//
// 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 is the internal per-function state used for llvm translation.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
#define LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
 
#include "CGBuilder.h"
#include "CGDebugInfo.h"
#include "CGLoopInfo.h"
#include "CGValue.h"
#include "CodeGenModule.h"
#include "CodeGenPGO.h"
#include "EHScopeStack.h"
#include "VarBypassDetector.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/CurrentSourceLocExprScope.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprOpenMP.h"
#include "clang/AST/StmtOpenACC.h"
#include "clang/AST/StmtOpenMP.h"
#include "clang/AST/StmtSYCL.h"
#include "clang/AST/Type.h"
#include "clang/Basic/ABI.h"
#include "clang/Basic/CapturedStmt.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/OpenMPKinds.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Utils/SanitizerStats.h"
#include <optional>
 
namespace llvm {
class BasicBlock;
class LLVMContext;
class MDNode;
class SwitchInst;
class Twine;
class Value;
class CanonicalLoopInfo;
}
 
namespace clang {
class ASTContext;
class CXXDestructorDecl;
class CXXForRangeStmt;
class CXXTryStmt;
class Decl;
class LabelDecl;
class FunctionDecl;
class FunctionProtoType;
class LabelStmt;
class ObjCContainerDecl;
class ObjCInterfaceDecl;
class ObjCIvarDecl;
class ObjCMethodDecl;
class ObjCImplementationDecl;
class ObjCPropertyImplDecl;
class TargetInfo;
class VarDecl;
class ObjCForCollectionStmt;
class ObjCAtTryStmt;
class ObjCAtThrowStmt;
class ObjCAtSynchronizedStmt;
class ObjCAutoreleasePoolStmt;
class OMPUseDevicePtrClause;
class OMPUseDeviceAddrClause;
class SVETypeFlags;
class OMPExecutableDirective;
 
namespace analyze_os_log {
class OSLogBufferLayout;
}
 
namespace CodeGen {
class CodeGenTypes;
class CGCallee;
class CGFunctionInfo;
class CGBlockInfo;
class CGCXXABI;
class BlockByrefHelpers;
class BlockByrefInfo;
class BlockFieldFlags;
class RegionCodeGenTy;
class TargetCodeGenInfo;
struct OMPTaskDataTy;
struct CGCoroData;
 
/// The kind of evaluation to perform on values of a particular
/// type.  Basically, is the code in CGExprScalar, CGExprComplex, or
/// CGExprAgg?
///
/// TODO: should vectors maybe be split out into their own thing?
enum TypeEvaluationKind {
  TEK_Scalar,
  TEK_Complex,
  TEK_Aggregate
};
 
#define LIST_SANITIZER_CHECKS                                                  \
  SANITIZER_CHECK(AddOverflow, add_overflow, 0)                                \
  SANITIZER_CHECK(BuiltinUnreachable, builtin_unreachable, 0)                  \
  SANITIZER_CHECK(CFICheckFail, cfi_check_fail, 0)                             \
  SANITIZER_CHECK(DivremOverflow, divrem_overflow, 0)                          \
  SANITIZER_CHECK(DynamicTypeCacheMiss, dynamic_type_cache_miss, 0)            \
  SANITIZER_CHECK(FloatCastOverflow, float_cast_overflow, 0)                   \
  SANITIZER_CHECK(FunctionTypeMismatch, function_type_mismatch, 0)             \
  SANITIZER_CHECK(ImplicitConversion, implicit_conversion, 0)                  \
  SANITIZER_CHECK(InvalidBuiltin, invalid_builtin, 0)                          \
  SANITIZER_CHECK(InvalidObjCCast, invalid_objc_cast, 0)                       \
  SANITIZER_CHECK(LoadInvalidValue, load_invalid_value, 0)                     \
  SANITIZER_CHECK(MissingReturn, missing_return, 0)                            \
  SANITIZER_CHECK(MulOverflow, mul_overflow, 0)                                \
  SANITIZER_CHECK(NegateOverflow, negate_overflow, 0)                          \
  SANITIZER_CHECK(NullabilityArg, nullability_arg, 0)                          \
  SANITIZER_CHECK(NullabilityReturn, nullability_return, 1)                    \
  SANITIZER_CHECK(NonnullArg, nonnull_arg, 0)                                  \
  SANITIZER_CHECK(NonnullReturn, nonnull_return, 1)                            \
  SANITIZER_CHECK(OutOfBounds, out_of_bounds, 0)                               \
  SANITIZER_CHECK(PointerOverflow, pointer_overflow, 0)                        \
  SANITIZER_CHECK(ShiftOutOfBounds, shift_out_of_bounds, 0)                    \
  SANITIZER_CHECK(SubOverflow, sub_overflow, 0)                                \
  SANITIZER_CHECK(TypeMismatch, type_mismatch, 1)                              \
  SANITIZER_CHECK(AlignmentAssumption, alignment_assumption, 0)                \
  SANITIZER_CHECK(VLABoundNotPositive, vla_bound_not_positive, 0)              \
  SANITIZER_CHECK(BoundsSafety, bounds_safety, 0)
 
enum SanitizerHandler {
#define SANITIZER_CHECK(Enum, Name, Version) Enum,
  LIST_SANITIZER_CHECKS
#undef SANITIZER_CHECK
};
 
/// Helper class with most of the code for saving a value for a
/// conditional expression cleanup.
struct DominatingLLVMValue {
  typedef llvm::PointerIntPair<llvm::Value*, 1, bool> saved_type;
 
  /// Answer whether the given value needs extra work to be saved.
  static bool needsSaving(llvm::Value *value) {
    if (!value)
      return false;
 
    // If it's not an instruction, we don't need to save.
    if (!isa<llvm::Instruction>(value)) return false;
 
    // If it's an instruction in the entry block, we don't need to save.
    llvm::BasicBlock *block = cast<llvm::Instruction>(value)->getParent();
    return (block != &block->getParent()->getEntryBlock());
  }
 
  static saved_type save(CodeGenFunction &CGF, llvm::Value *value);
  static llvm::Value *restore(CodeGenFunction &CGF, saved_type value);
};
 
/// A partial specialization of DominatingValue for llvm::Values that
/// might be llvm::Instructions.
template <class T> struct DominatingPointer<T,true> : DominatingLLVMValue {
  typedef T *type;
  static type restore(CodeGenFunction &CGF, saved_type value) {
    return static_cast<T*>(DominatingLLVMValue::restore(CGF, value));
  }
};
 
/// A specialization of DominatingValue for Address.
template <> struct DominatingValue<Address> {
  typedef Address type;
 
  struct saved_type {
    DominatingLLVMValue::saved_type BasePtr;
    llvm::Type *ElementType;
    CharUnits Alignment;
    DominatingLLVMValue::saved_type Offset;
    llvm::PointerType *EffectiveType;
  };
 
  static bool needsSaving(type value) {
    if (DominatingLLVMValue::needsSaving(value.getBasePointer()) ||
        DominatingLLVMValue::needsSaving(value.getOffset()))
      return true;
    return false;
  }
  static saved_type save(CodeGenFunction &CGF, type value) {
    return {DominatingLLVMValue::save(CGF, value.getBasePointer()),
            value.getElementType(), value.getAlignment(),
            DominatingLLVMValue::save(CGF, value.getOffset()), value.getType()};
  }
  static type restore(CodeGenFunction &CGF, saved_type value) {
    return Address(DominatingLLVMValue::restore(CGF, value.BasePtr),
                   value.ElementType, value.Alignment, CGPointerAuthInfo(),
                   DominatingLLVMValue::restore(CGF, value.Offset));
  }
};
 
/// A specialization of DominatingValue for RValue.
template <> struct DominatingValue<RValue> {
  typedef RValue type;
  class saved_type {
    enum Kind { ScalarLiteral, ScalarAddress, AggregateLiteral,
                AggregateAddress, ComplexAddress };
    union {
      struct {
        DominatingLLVMValue::saved_type first, second;
      } Vals;
      DominatingValue<Address>::saved_type AggregateAddr;
    };
    LLVM_PREFERRED_TYPE(Kind)
    unsigned K : 3;
 
    saved_type(DominatingLLVMValue::saved_type Val1, unsigned K)
        : Vals{Val1, DominatingLLVMValue::saved_type()}, K(K) {}
 
    saved_type(DominatingLLVMValue::saved_type Val1,
               DominatingLLVMValue::saved_type Val2)
        : Vals{Val1, Val2}, K(ComplexAddress) {}
 
    saved_type(DominatingValue<Address>::saved_type AggregateAddr, unsigned K)
        : AggregateAddr(AggregateAddr), K(K) {}
 
  public:
    static bool needsSaving(RValue value);
    static saved_type save(CodeGenFunction &CGF, RValue value);
    RValue restore(CodeGenFunction &CGF);
 
    // implementations in CGCleanup.cpp
  };
 
  static bool needsSaving(type value) {
    return saved_type::needsSaving(value);
  }
  static saved_type save(CodeGenFunction &CGF, type value) {
    return saved_type::save(CGF, value);
  }
  static type restore(CodeGenFunction &CGF, saved_type value) {
    return value.restore(CGF);
  }
};
 
/// CodeGenFunction - This class organizes the per-function state that is used
/// while generating LLVM code.
class CodeGenFunction : public CodeGenTypeCache {
  CodeGenFunction(const CodeGenFunction &) = delete;
  void operator=(const CodeGenFunction &) = delete;
 
  friend class CGCXXABI;
public:
  /// A jump destination is an abstract label, branching to which may
  /// require a jump out through normal cleanups.
  struct JumpDest {
    JumpDest() : Block(nullptr), Index(0) {}
    JumpDest(llvm::BasicBlock *Block, EHScopeStack::stable_iterator Depth,
             unsigned Index)
        : Block(Block), ScopeDepth(Depth), Index(Index) {}
 
    bool isValid() const { return Block != nullptr; }
    llvm::BasicBlock *getBlock() const { return Block; }
    EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
    unsigned getDestIndex() const { return Index; }
 
    // This should be used cautiously.
    void setScopeDepth(EHScopeStack::stable_iterator depth) {
      ScopeDepth = depth;
    }
 
  private:
    llvm::BasicBlock *Block;
    EHScopeStack::stable_iterator ScopeDepth;
    unsigned Index;
  };
 
  CodeGenModule &CGM;  // Per-module state.
  const TargetInfo &Target;
 
  // For EH/SEH outlined funclets, this field points to parent's CGF
  CodeGenFunction *ParentCGF = nullptr;
 
  typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
  LoopInfoStack LoopStack;
  CGBuilderTy Builder;
 
  // Stores variables for which we can't generate correct lifetime markers
  // because of jumps.
  VarBypassDetector Bypasses;
 
  /// List of recently emitted OMPCanonicalLoops.
  ///
  /// Since OMPCanonicalLoops are nested inside other statements (in particular
  /// CapturedStmt generated by OMPExecutableDirective and non-perfectly nested
  /// loops), we cannot directly call OMPEmitOMPCanonicalLoop and receive its
  /// llvm::CanonicalLoopInfo. Instead, we call EmitStmt and any
  /// OMPEmitOMPCanonicalLoop called by it will add its CanonicalLoopInfo to
  /// this stack when done. Entering a new loop requires clearing this list; it
  /// either means we start parsing a new loop nest (in which case the previous
  /// loop nest goes out of scope) or a second loop in the same level in which
  /// case it would be ambiguous into which of the two (or more) loops the loop
  /// nest would extend.
  SmallVector<llvm::CanonicalLoopInfo *, 4> OMPLoopNestStack;
 
  /// Stack to track the Logical Operator recursion nest for MC/DC.
  SmallVector<const BinaryOperator *, 16> MCDCLogOpStack;
 
  /// Stack to track the controlled convergence tokens.
  SmallVector<llvm::ConvergenceControlInst *, 4> ConvergenceTokenStack;
 
  /// Number of nested loop to be consumed by the last surrounding
  /// loop-associated directive.
  int ExpectedOMPLoopDepth = 0;
 
  // CodeGen lambda for loops and support for ordered clause
  typedef llvm::function_ref<void(CodeGenFunction &, const OMPLoopDirective &,
                                  JumpDest)>
      CodeGenLoopTy;
  typedef llvm::function_ref<void(CodeGenFunction &, SourceLocation,
                                  const unsigned, const bool)>
      CodeGenOrderedTy;
 
  // Codegen lambda for loop bounds in worksharing loop constructs
  typedef llvm::function_ref<std::pair<LValue, LValue>(
      CodeGenFunction &, const OMPExecutableDirective &S)>
      CodeGenLoopBoundsTy;
 
  // Codegen lambda for loop bounds in dispatch-based loop implementation
  typedef llvm::function_ref<std::pair<llvm::Value *, llvm::Value *>(
      CodeGenFunction &, const OMPExecutableDirective &S, Address LB,
      Address UB)>
      CodeGenDispatchBoundsTy;
 
  /// CGBuilder insert helper. This function is called after an
  /// instruction is created using Builder.
  void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
                    llvm::BasicBlock::iterator InsertPt) const;
 
  /// CurFuncDecl - Holds the Decl for the current outermost
  /// non-closure context.
  const Decl *CurFuncDecl = nullptr;
  /// CurCodeDecl - This is the inner-most code context, which includes blocks.
  const Decl *CurCodeDecl = nullptr;
  const CGFunctionInfo *CurFnInfo = nullptr;
  QualType FnRetTy;
  llvm::Function *CurFn = nullptr;
 
  /// Save Parameter Decl for coroutine.
  llvm::SmallVector<const ParmVarDecl *, 4> FnArgs;
 
  // Holds coroutine data if the current function is a coroutine. We use a
  // wrapper to manage its lifetime, so that we don't have to define CGCoroData
  // in this header.
  struct CGCoroInfo {
    std::unique_ptr<CGCoroData> Data;
    bool InSuspendBlock = false;
    CGCoroInfo();
    ~CGCoroInfo();
  };
  CGCoroInfo CurCoro;
 
  bool isCoroutine() const {
    return CurCoro.Data != nullptr;
  }
 
  bool inSuspendBlock() const {
    return isCoroutine() && CurCoro.InSuspendBlock;
  }
 
  // Holds FramePtr for await_suspend wrapper generation,
  // so that __builtin_coro_frame call can be lowered
  // directly to value of its second argument
  struct AwaitSuspendWrapperInfo {
    llvm::Value *FramePtr = nullptr;
  };
  AwaitSuspendWrapperInfo CurAwaitSuspendWrapper;
 
  // Generates wrapper function for `llvm.coro.await.suspend.*` intrinisics.
  // It encapsulates SuspendExpr in a function, to separate it's body
  // from the main coroutine to avoid miscompilations. Intrinisic
  // is lowered to this function call in CoroSplit pass
  // Function signature is:
  // <type> __await_suspend_wrapper_<name>(ptr %awaiter, ptr %hdl)
  // where type is one of (void, i1, ptr)
  llvm::Function *generateAwaitSuspendWrapper(Twine const &CoroName,
                                              Twine const &SuspendPointName,
                                              CoroutineSuspendExpr const &S);
 
  /// CurGD - The GlobalDecl for the current function being compiled.
  GlobalDecl CurGD;
 
  /// PrologueCleanupDepth - The cleanup depth enclosing all the
  /// cleanups associated with the parameters.
  EHScopeStack::stable_iterator PrologueCleanupDepth;
 
  /// ReturnBlock - Unified return block.
  JumpDest ReturnBlock;
 
  /// ReturnValue - The temporary alloca to hold the return
  /// value. This is invalid iff the function has no return value.
  Address ReturnValue = Address::invalid();
 
  /// ReturnValuePointer - The temporary alloca to hold a pointer to sret.
  /// This is invalid if sret is not in use.
  Address ReturnValuePointer = Address::invalid();
 
  /// If a return statement is being visited, this holds the return statment's
  /// result expression.
  const Expr *RetExpr = nullptr;
 
  /// Return true if a label was seen in the current scope.
  bool hasLabelBeenSeenInCurrentScope() const {
    if (CurLexicalScope)
      return CurLexicalScope->hasLabels();
    return !LabelMap.empty();
  }
 
  /// AllocaInsertPoint - This is an instruction in the entry block before which
  /// we prefer to insert allocas.
  llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
 
private:
  /// PostAllocaInsertPt - This is a place in the prologue where code can be
  /// inserted that will be dominated by all the static allocas. This helps
  /// achieve two things:
  ///   1. Contiguity of all static allocas (within the prologue) is maintained.
  ///   2. All other prologue code (which are dominated by static allocas) do
  ///      appear in the source order immediately after all static allocas.
  ///
  /// PostAllocaInsertPt will be lazily created when it is *really* required.
  llvm::AssertingVH<llvm::Instruction> PostAllocaInsertPt = nullptr;
 
public:
  /// Return PostAllocaInsertPt. If it is not yet created, then insert it
  /// immediately after AllocaInsertPt.
  llvm::Instruction *getPostAllocaInsertPoint() {
    if (!PostAllocaInsertPt) {
      assert(AllocaInsertPt &&
             "Expected static alloca insertion point at function prologue");
      assert(AllocaInsertPt->getParent()->isEntryBlock() &&
             "EBB should be entry block of the current code gen function");
      PostAllocaInsertPt = AllocaInsertPt->clone();
      PostAllocaInsertPt->setName("postallocapt");
      PostAllocaInsertPt->insertAfter(AllocaInsertPt);
    }
 
    return PostAllocaInsertPt;
  }
 
  /// API for captured statement code generation.
  class CGCapturedStmtInfo {
  public:
    explicit CGCapturedStmtInfo(CapturedRegionKind K = CR_Default)
        : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {}
    explicit CGCapturedStmtInfo(const CapturedStmt &S,
                                CapturedRegionKind K = CR_Default)
      : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {
 
      RecordDecl::field_iterator Field =
        S.getCapturedRecordDecl()->field_begin();
      for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
                                                E = S.capture_end();
           I != E; ++I, ++Field) {
        if (I->capturesThis())
          CXXThisFieldDecl = *Field;
        else if (I->capturesVariable())
          CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
        else if (I->capturesVariableByCopy())
          CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
      }
    }
 
    virtual ~CGCapturedStmtInfo();
 
    CapturedRegionKind getKind() const { return Kind; }
 
    virtual void setContextValue(llvm::Value *V) { ThisValue = V; }
    // Retrieve the value of the context parameter.
    virtual llvm::Value *getContextValue() const { return ThisValue; }
 
    /// Lookup the captured field decl for a variable.
    virtual const FieldDecl *lookup(const VarDecl *VD) const {
      return CaptureFields.lookup(VD->getCanonicalDecl());
    }
 
    bool isCXXThisExprCaptured() const { return getThisFieldDecl() != nullptr; }
    virtual FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
 
    static bool classof(const CGCapturedStmtInfo *) {
      return true;
    }
 
    /// Emit the captured statement body.
    virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) {
      CGF.incrementProfileCounter(S);
      CGF.EmitStmt(S);
    }
 
    /// Get the name of the capture helper.
    virtual StringRef getHelperName() const { return "__captured_stmt"; }
 
    /// Get the CaptureFields
    llvm::SmallDenseMap<const VarDecl *, FieldDecl *> getCaptureFields() {
      return CaptureFields;
    }
 
  private:
    /// The kind of captured statement being generated.
    CapturedRegionKind Kind;
 
    /// Keep the map between VarDecl and FieldDecl.
    llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
 
    /// The base address of the captured record, passed in as the first
    /// argument of the parallel region function.
    llvm::Value *ThisValue;
 
    /// Captured 'this' type.
    FieldDecl *CXXThisFieldDecl;
  };
  CGCapturedStmtInfo *CapturedStmtInfo = nullptr;
 
  /// RAII for correct setting/restoring of CapturedStmtInfo.
  class CGCapturedStmtRAII {
  private:
    CodeGenFunction &CGF;
    CGCapturedStmtInfo *PrevCapturedStmtInfo;
  public:
    CGCapturedStmtRAII(CodeGenFunction &CGF,
                       CGCapturedStmtInfo *NewCapturedStmtInfo)
        : CGF(CGF), PrevCapturedStmtInfo(CGF.CapturedStmtInfo) {
      CGF.CapturedStmtInfo = NewCapturedStmtInfo;
    }
    ~CGCapturedStmtRAII() { CGF.CapturedStmtInfo = PrevCapturedStmtInfo; }
  };
 
  /// An abstract representation of regular/ObjC call/message targets.
  class AbstractCallee {
    /// The function declaration of the callee.
    const Decl *CalleeDecl;
 
  public:
    AbstractCallee() : CalleeDecl(nullptr) {}
    AbstractCallee(const FunctionDecl *FD) : CalleeDecl(FD) {}
    AbstractCallee(const ObjCMethodDecl *OMD) : CalleeDecl(OMD) {}
    bool hasFunctionDecl() const {
      return isa_and_nonnull<FunctionDecl>(CalleeDecl);
    }
    const Decl *getDecl() const { return CalleeDecl; }
    unsigned getNumParams() const {
      if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
        return FD->getNumParams();
      return cast<ObjCMethodDecl>(CalleeDecl)->param_size();
    }
    const ParmVarDecl *getParamDecl(unsigned I) const {
      if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
        return FD->getParamDecl(I);
      return *(cast<ObjCMethodDecl>(CalleeDecl)->param_begin() + I);
    }
  };
 
  /// Sanitizers enabled for this function.
  SanitizerSet SanOpts;
 
  /// True if CodeGen currently emits code implementing sanitizer checks.
  bool IsSanitizerScope = false;
 
  /// RAII object to set/unset CodeGenFunction::IsSanitizerScope.
  class SanitizerScope {
    CodeGenFunction *CGF;
  public:
    SanitizerScope(CodeGenFunction *CGF);
    ~SanitizerScope();
  };
 
  /// In C++, whether we are code generating a thunk.  This controls whether we
  /// should emit cleanups.
  bool CurFuncIsThunk = false;
 
  /// In ARC, whether we should autorelease the return value.
  bool AutoreleaseResult = false;
 
  /// Whether we processed a Microsoft-style asm block during CodeGen. These can
  /// potentially set the return value.
  bool SawAsmBlock = false;
 
  GlobalDecl CurSEHParent;
 
  /// True if the current function is an outlined SEH helper. This can be a
  /// finally block or filter expression.
  bool IsOutlinedSEHHelper = false;
 
  /// True if CodeGen currently emits code inside presereved access index
  /// region.
  bool IsInPreservedAIRegion = false;
 
  /// True if the current statement has nomerge attribute.
  bool InNoMergeAttributedStmt = false;
 
  /// True if the current statement has noinline attribute.
  bool InNoInlineAttributedStmt = false;
 
  /// True if the current statement has always_inline attribute.
  bool InAlwaysInlineAttributedStmt = false;
 
  /// True if the current statement has noconvergent attribute.
  bool InNoConvergentAttributedStmt = false;
 
  /// HLSL Branch attribute.
  HLSLControlFlowHintAttr::Spelling HLSLControlFlowAttr =
      HLSLControlFlowHintAttr::SpellingNotCalculated;
 
  // The CallExpr within the current statement that the musttail attribute
  // applies to.  nullptr if there is no 'musttail' on the current statement.
  const CallExpr *MustTailCall = nullptr;
 
  /// Returns true if a function must make progress, which means the
  /// mustprogress attribute can be added.
  bool