tools/clang/lib/Sema/SemaOpenMP.cpp

reference, declaration → definition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced

//===--- SemaOpenMP.cpp - Semantic Analysis for OpenMP constructs ---------===//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements semantic analysis for OpenMP directives and
/// clauses.
///
//===----------------------------------------------------------------------===//

#include "TreeTransform.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclOpenMP.h"
#include "clang/AST/StmtCXX.h"
#include "clang/AST/StmtOpenMP.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeOrdering.h"
#include "clang/Basic/OpenMPKinds.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaInternal.h"
#include "llvm/ADT/PointerEmbeddedInt.h"
using namespace clang;

//===----------------------------------------------------------------------===//
// Stack of data-sharing attributes for variables
//===----------------------------------------------------------------------===//

static const Expr *checkMapClauseExpressionBase(
    Sema &SemaRef, Expr *E,
    OMPClauseMappableExprCommon::MappableExprComponentList &CurComponents,
    OpenMPClauseKind CKind, bool NoDiagnose);

namespace {
/// Default data sharing attributes, which can be applied to directive.
enum DefaultDataSharingAttributes {
  DSA_unspecified = 0, /// Data sharing attribute not specified.
  DSA_none = 1 << 0,   /// Default data sharing attribute 'none'.
  DSA_shared = 1 << 1, /// Default data sharing attribute 'shared'.
};

/// Attributes of the defaultmap clause.
enum DefaultMapAttributes {
  DMA_unspecified,   /// Default mapping is not specified.
  DMA_tofrom_scalar, /// Default mapping is 'tofrom:scalar'.
};

/// Stack for tracking declarations used in OpenMP directives and
/// clauses and their data-sharing attributes.
class DSAStackTy {
public:
  struct DSAVarData {
    OpenMPDirectiveKind DKind = OMPD_unknown;
    OpenMPClauseKind CKind = OMPC_unknown;
    const Expr *RefExpr = nullptr;
    DeclRefExpr *PrivateCopy = nullptr;
    SourceLocation ImplicitDSALoc;
    DSAVarData() = default;
    DSAVarData(OpenMPDirectiveKind DKind, OpenMPClauseKind CKind,
               const Expr *RefExpr, DeclRefExpr *PrivateCopy,
               SourceLocation ImplicitDSALoc)
        : DKind(DKind), CKind(CKind), RefExpr(RefExpr),
          PrivateCopy(PrivateCopy), ImplicitDSALoc(ImplicitDSALoc) {}
  };
  using OperatorOffsetTy =
      llvm::SmallVector<std::pair<Expr *, OverloadedOperatorKind>, 4>;
  using DoacrossDependMapTy =
      llvm::DenseMap<OMPDependClause *, OperatorOffsetTy>;

private:
  struct DSAInfo {
    OpenMPClauseKind Attributes = OMPC_unknown;
    /// Pointer to a reference expression and a flag which shows that the
    /// variable is marked as lastprivate(true) or not (false).
    llvm::PointerIntPair<const Expr *, 1, bool> RefExpr;
    DeclRefExpr *PrivateCopy = nullptr;
  };
  using DeclSAMapTy = llvm::SmallDenseMap<const ValueDecl *, DSAInfo, 8>;
  using AlignedMapTy = llvm::SmallDenseMap<const ValueDecl *, const Expr *, 8>;
  using LCDeclInfo = std::pair<unsigned, VarDecl *>;
  using LoopControlVariablesMapTy =
      llvm::SmallDenseMap<const ValueDecl *, LCDeclInfo, 8>;
  /// Struct that associates a component with the clause kind where they are
  /// found.
  struct MappedExprComponentTy {
    OMPClauseMappableExprCommon::MappableExprComponentLists Components;
    OpenMPClauseKind Kind = OMPC_unknown;
  };
  using MappedExprComponentsTy =
      llvm::DenseMap<const ValueDecl *, MappedExprComponentTy>;
  using CriticalsWithHintsTy =
      llvm::StringMap<std::pair<const OMPCriticalDirective *, llvm::APSInt>>;
  struct ReductionData {
    using BOKPtrType = llvm::PointerEmbeddedInt<BinaryOperatorKind, 16>;
    SourceRange ReductionRange;
    llvm::PointerUnion<const Expr *, BOKPtrType> ReductionOp;
    ReductionData() = default;
    void set(BinaryOperatorKind BO, SourceRange RR) {
      ReductionRange = RR;
      ReductionOp = BO;
    }
    void set(const Expr *RefExpr, SourceRange RR) {
      ReductionRange = RR;
      ReductionOp = RefExpr;
    }
  };
  using DeclReductionMapTy =
      llvm::SmallDenseMap<const ValueDecl *, ReductionData, 4>;

  struct SharingMapTy {
    DeclSAMapTy SharingMap;
    DeclReductionMapTy ReductionMap;
    AlignedMapTy AlignedMap;
    MappedExprComponentsTy MappedExprComponents;
    LoopControlVariablesMapTy LCVMap;
    DefaultDataSharingAttributes DefaultAttr = DSA_unspecified;
    SourceLocation DefaultAttrLoc;
    DefaultMapAttributes DefaultMapAttr = DMA_unspecified;
    SourceLocation DefaultMapAttrLoc;
    OpenMPDirectiveKind Directive = OMPD_unknown;
    DeclarationNameInfo DirectiveName;
    Scope *CurScope = nullptr;
    SourceLocation ConstructLoc;
    /// Set of 'depend' clauses with 'sink|source' dependence kind. Required to
    /// get the data (loop counters etc.) about enclosing loop-based construct.
    /// This data is required during codegen.
    DoacrossDependMapTy DoacrossDepends;
    /// First argument (Expr *) contains optional argument of the
    /// 'ordered' clause, the second one is true if the regions has 'ordered'
    /// clause, false otherwise.
    llvm::Optional<std::pair<const Expr *, OMPOrderedClause *>> OrderedRegion;
    unsigned AssociatedLoops = 1;
    bool HasMutipleLoops = false;
    const Decl *PossiblyLoopCounter = nullptr;
    bool NowaitRegion = false;
    bool CancelRegion = false;
    bool LoopStart = false;
    bool BodyComplete = false;
    SourceLocation InnerTeamsRegionLoc;
    /// Reference to the taskgroup task_reduction reference expression.
    Expr *TaskgroupReductionRef = nullptr;
    llvm::DenseSet<QualType> MappedClassesQualTypes;
    /// List of globals marked as declare target link in this target region
    /// (isOpenMPTargetExecutionDirective(Directive) == true).
    llvm::SmallVector<DeclRefExpr *, 4> DeclareTargetLinkVarDecls;
    SharingMapTy(OpenMPDirectiveKind DKind, DeclarationNameInfo Name,
                 Scope *CurScope, SourceLocation Loc)
        : Directive(DKind), DirectiveName(Name), CurScope(CurScope),
          ConstructLoc(Loc) {}
    SharingMapTy() = default;
  };

  using StackTy = SmallVector<SharingMapTy, 4>;

  /// Stack of used declaration and their data-sharing attributes.
  DeclSAMapTy Threadprivates;
  const FunctionScopeInfo *CurrentNonCapturingFunctionScope = nullptr;
  SmallVector<std::pair<StackTy, const FunctionScopeInfo *>, 4> Stack;
  /// true, if check for DSA must be from parent directive, false, if
  /// from current directive.
  OpenMPClauseKind ClauseKindMode = OMPC_unknown;
  Sema &SemaRef;
  bool ForceCapturing = false;
  /// true if all the variables in the target executable directives must be
  /// captured by reference.
  bool ForceCaptureByReferenceInTargetExecutable = false;
  CriticalsWithHintsTy Criticals;
  unsigned IgnoredStackElements = 0;

  /// Iterators over the stack iterate in order from innermost to outermost
  /// directive.
  using const_iterator = StackTy::const_reverse_iterator;
  const_iterator begin() const {
    return Stack.empty() ? const_iterator()
                         : Stack.back().first.rbegin() + IgnoredStackElements;
  }
  const_iterator end() const {
    return Stack.empty() ? const_iterator() : Stack.back().first.rend();
  }
  using iterator = StackTy::reverse_iterator;
  iterator begin() {
    return Stack.empty() ? iterator()
                         : Stack.back().first.rbegin() + IgnoredStackElements;
  }
  iterator end() {
    return Stack.empty() ? iterator() : Stack.back().first.rend();
  }

  // Convenience operations to get at the elements of the stack.

  bool isStackEmpty() const {
    return Stack.empty() ||
           Stack.back().second != CurrentNonCapturingFunctionScope ||
           Stack.back().first.size() <= IgnoredStackElements;
  }
  size_t getStackSize() const {
    return isStackEmpty() ? 0
                          : Stack.back().first.size() - IgnoredStackElements;
  }

  SharingMapTy *getTopOfStackOrNull() {
    size_t Size = getStackSize();
    if (Size == 0)
      return nullptr;
    return &Stack.back().first[Size - 1];
  }
  const SharingMapTy *getTopOfStackOrNull() const {
    return const_cast<DSAStackTy&>(*this).getTopOfStackOrNull();
  }
  SharingMapTy &getTopOfStack() {
    assert(!isStackEmpty() && "no current directive");
    return *getTopOfStackOrNull();
  }
  const SharingMapTy &getTopOfStack() const {
    return const_cast<DSAStackTy&>(*this).getTopOfStack();
  }

  SharingMapTy *getSecondOnStackOrNull() {
    size_t Size = getStackSize();
    if (Size <= 1)
      return nullptr;
    return &Stack.back().first[Size - 2];
  }
  const SharingMapTy *getSecondOnStackOrNull() const {
    return const_cast<DSAStackTy&>(*this).getSecondOnStackOrNull();
  }

  /// Get the stack element at a certain level (previously returned by
  /// \c getNestingLevel).
  ///
  /// Note that nesting levels count from outermost to innermost, and this is
  /// the reverse of our iteration order where new inner levels are pushed at
  /// the front of the stack.
  SharingMapTy &getStackElemAtLevel(unsigned Level) {
    assert(Level < getStackSize() && "no such stack element");
    return Stack.back().first[Level];
  }
  const SharingMapTy &getStackElemAtLevel(unsigned Level) const {
    return const_cast<DSAStackTy&>(*this).getStackElemAtLevel(Level);
  }

  DSAVarData getDSA(const_iterator &Iter, ValueDecl *D) const;

  /// Checks if the variable is a local for OpenMP region.
  bool isOpenMPLocal(VarDecl *D, const_iterator Iter) const;

  /// Vector of previously declared requires directives
  SmallVector<const OMPRequiresDecl *, 2> RequiresDecls;
  /// omp_allocator_handle_t type.
  QualType OMPAllocatorHandleT;
  /// Expression for the predefined allocators.
  Expr *OMPPredefinedAllocators[OMPAllocateDeclAttr::OMPUserDefinedMemAlloc] = {
      nullptr};
  /// Vector of previously encountered target directives
  SmallVector<SourceLocation, 2> TargetLocations;

public:
  explicit DSAStackTy(Sema &S) : SemaRef(S) {}

  /// Sets omp_allocator_handle_t type.
  void setOMPAllocatorHandleT(QualType Ty) { OMPAllocatorHandleT = Ty; }
  /// Gets omp_allocator_handle_t type.
  QualType getOMPAllocatorHandleT() const { return OMPAllocatorHandleT; }
  /// Sets the given default allocator.
  void setAllocator(OMPAllocateDeclAttr::AllocatorTypeTy AllocatorKind,
                    Expr *Allocator) {
    OMPPredefinedAllocators[AllocatorKind] = Allocator;
  }
  /// Returns the specified default allocator.
  Expr *getAllocator(OMPAllocateDeclAttr::AllocatorTypeTy AllocatorKind) const {
    return OMPPredefinedAllocators[AllocatorKind];
  }

  bool isClauseParsingMode() const { return ClauseKindMode != OMPC_unknown; }
  OpenMPClauseKind getClauseParsingMode() const {
    assert(isClauseParsingMode() && "Must be in clause parsing mode.");
    return ClauseKindMode;
  }
  void setClauseParsingMode(OpenMPClauseKind K) { ClauseKindMode = K; }

  bool isBodyComplete() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top && Top->BodyComplete;
  }
  void setBodyComplete() {
    getTopOfStack().BodyComplete = true;
  }

  bool isForceVarCapturing() const { return ForceCapturing; }
  void setForceVarCapturing(bool V) { ForceCapturing = V; }

  void setForceCaptureByReferenceInTargetExecutable(bool V) {
    ForceCaptureByReferenceInTargetExecutable = V;
  }
  bool isForceCaptureByReferenceInTargetExecutable() const {
    return ForceCaptureByReferenceInTargetExecutable;
  }

  void push(OpenMPDirectiveKind DKind, const DeclarationNameInfo &DirName,
            Scope *CurScope, SourceLocation Loc) {
    assert(!IgnoredStackElements &&
           "cannot change stack while ignoring elements");
    if (Stack.empty() ||
        Stack.back().second != CurrentNonCapturingFunctionScope)
      Stack.emplace_back(StackTy(), CurrentNonCapturingFunctionScope);
    Stack.back().first.emplace_back(DKind, DirName, CurScope, Loc);
    Stack.back().first.back().DefaultAttrLoc = Loc;
  }

  void pop() {
    assert(!IgnoredStackElements &&
           "cannot change stack while ignoring elements");
    assert(!Stack.back().first.empty() &&
           "Data-sharing attributes stack is empty!");
    Stack.back().first.pop_back();
  }

  /// RAII object to temporarily leave the scope of a directive when we want to
  /// logically operate in its parent.
  class ParentDirectiveScope {
    DSAStackTy &Self;
    bool Active;
  public:
    ParentDirectiveScope(DSAStackTy &Self, bool Activate)
        : Self(Self), Active(false) {
      if (Activate)
        enable();
    }
    ~ParentDirectiveScope() { disable(); }
    void disable() {
      if (Active) {
        --Self.IgnoredStackElements;
        Active = false;
      }
    }
    void enable() {
      if (!Active) {
        ++Self.IgnoredStackElements;
        Active = true;
      }
    }
  };

  /// Marks that we're started loop parsing.
  void loopInit() {
    assert(isOpenMPLoopDirective(getCurrentDirective()) &&
           "Expected loop-based directive.");
    getTopOfStack().LoopStart = true;
  }
  /// Start capturing of the variables in the loop context.
  void loopStart() {
    assert(isOpenMPLoopDirective(getCurrentDirective()) &&
           "Expected loop-based directive.");
    getTopOfStack().LoopStart = false;
  }
  /// true, if variables are captured, false otherwise.
  bool isLoopStarted() const {
    assert(isOpenMPLoopDirective(getCurrentDirective()) &&
           "Expected loop-based directive.");
    return !getTopOfStack().LoopStart;
  }
  /// Marks (or clears) declaration as possibly loop counter.
  void resetPossibleLoopCounter(const Decl *D = nullptr) {
    getTopOfStack().PossiblyLoopCounter =
        D ? D->getCanonicalDecl() : D;
  }
  /// Gets the possible loop counter decl.
  const Decl *getPossiblyLoopCunter() const {
    return getTopOfStack().PossiblyLoopCounter;
  }
  /// Start new OpenMP region stack in new non-capturing function.
  void pushFunction() {
    assert(!IgnoredStackElements &&
           "cannot change stack while ignoring elements");
    const FunctionScopeInfo *CurFnScope = SemaRef.getCurFunction();
    assert(!isa<CapturingScopeInfo>(CurFnScope));
    CurrentNonCapturingFunctionScope = CurFnScope;
  }
  /// Pop region stack for non-capturing function.
  void popFunction(const FunctionScopeInfo *OldFSI) {
    assert(!IgnoredStackElements &&
           "cannot change stack while ignoring elements");
    if (!Stack.empty() && Stack.back().second == OldFSI) {
      assert(Stack.back().first.empty());
      Stack.pop_back();
    }
    CurrentNonCapturingFunctionScope = nullptr;
    for (const FunctionScopeInfo *FSI : llvm::reverse(SemaRef.FunctionScopes)) {
      if (!isa<CapturingScopeInfo>(FSI)) {
        CurrentNonCapturingFunctionScope = FSI;
        break;
      }
    }
  }

  void addCriticalWithHint(const OMPCriticalDirective *D, llvm::APSInt Hint) {
    Criticals.try_emplace(D->getDirectiveName().getAsString(), D, Hint);
  }
  const std::pair<const OMPCriticalDirective *, llvm::APSInt>
  getCriticalWithHint(const DeclarationNameInfo &Name) const {
    auto I = Criticals.find(Name.getAsString());
    if (I != Criticals.end())
      return I->second;
    return std::make_pair(nullptr, llvm::APSInt());
  }
  /// If 'aligned' declaration for given variable \a D was not seen yet,
  /// add it and return NULL; otherwise return previous occurrence's expression
  /// for diagnostics.
  const Expr *addUniqueAligned(const ValueDecl *D, const Expr *NewDE);

  /// Register specified variable as loop control variable.
  void addLoopControlVariable(const ValueDecl *D, VarDecl *Capture);
  /// Check if the specified variable is a loop control variable for
  /// current region.
  /// \return The index of the loop control variable in the list of associated
  /// for-loops (from outer to inner).
  const LCDeclInfo isLoopControlVariable(const ValueDecl *D) const;
  /// Check if the specified variable is a loop control variable for
  /// parent region.
  /// \return The index of the loop control variable in the list of associated
  /// for-loops (from outer to inner).
  const LCDeclInfo isParentLoopControlVariable(const ValueDecl *D) const;
  /// Get the loop control variable for the I-th loop (or nullptr) in
  /// parent directive.
  const ValueDecl *getParentLoopControlVariable(unsigned I) const;

  /// Adds explicit data sharing attribute to the specified declaration.
  void addDSA(const ValueDecl *D, const Expr *E, OpenMPClauseKind A,
              DeclRefExpr *PrivateCopy = nullptr);

  /// Adds additional information for the reduction items with the reduction id
  /// represented as an operator.
  void addTaskgroupReductionData(const ValueDecl *D, SourceRange SR,
                                 BinaryOperatorKind BOK);
  /// Adds additional information for the reduction items with the reduction id
  /// represented as reduction identifier.
  void addTaskgroupReductionData(const ValueDecl *D, SourceRange SR,
                                 const Expr *ReductionRef);
  /// Returns the location and reduction operation from the innermost parent
  /// region for the given \p D.
  const DSAVarData
  getTopMostTaskgroupReductionData(const ValueDecl *D, SourceRange &SR,
                                   BinaryOperatorKind &BOK,
                                   Expr *&TaskgroupDescriptor) const;
  /// Returns the location and reduction operation from the innermost parent
  /// region for the given \p D.
  const DSAVarData
  getTopMostTaskgroupReductionData(const ValueDecl *D, SourceRange &SR,
                                   const Expr *&ReductionRef,
                                   Expr *&TaskgroupDescriptor) const;
  /// Return reduction reference expression for the current taskgroup.
  Expr *getTaskgroupReductionRef() const {
    assert(getTopOfStack().Directive == OMPD_taskgroup &&
           "taskgroup reference expression requested for non taskgroup "
           "directive.");
    return getTopOfStack().TaskgroupReductionRef;
  }
  /// Checks if the given \p VD declaration is actually a taskgroup reduction
  /// descriptor variable at the \p Level of OpenMP regions.
  bool isTaskgroupReductionRef(const ValueDecl *VD, unsigned Level) const {
    return getStackElemAtLevel(Level).TaskgroupReductionRef &&
           cast<DeclRefExpr>(getStackElemAtLevel(Level).TaskgroupReductionRef)
                   ->getDecl() == VD;
  }

  /// Returns data sharing attributes from top of the stack for the
  /// specified declaration.
  const DSAVarData getTopDSA(ValueDecl *D, bool FromParent);
  /// Returns data-sharing attributes for the specified declaration.
  const DSAVarData getImplicitDSA(ValueDecl *D, bool FromParent) const;
  /// Checks if the specified variables has data-sharing attributes which
  /// match specified \a CPred predicate in any directive which matches \a DPred
  /// predicate.
  const DSAVarData
  hasDSA(ValueDecl *D, const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
         const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
         bool FromParent) const;
  /// Checks if the specified variables has data-sharing attributes which
  /// match specified \a CPred predicate in any innermost directive which
  /// matches \a DPred predicate.
  const DSAVarData
  hasInnermostDSA(ValueDecl *D,
                  const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
                  const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
                  bool FromParent) const;
  /// Checks if the specified variables has explicit data-sharing
  /// attributes which match specified \a CPred predicate at the specified
  /// OpenMP region.
  bool hasExplicitDSA(const ValueDecl *D,
                      const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
                      unsigned Level, bool NotLastprivate = false) const;

  /// Returns true if the directive at level \Level matches in the
  /// specified \a DPred predicate.
  bool hasExplicitDirective(
      const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
      unsigned Level) const;

  /// Finds a directive which matches specified \a DPred predicate.
  bool hasDirective(
      const llvm::function_ref<bool(
          OpenMPDirectiveKind, const DeclarationNameInfo &, SourceLocation)>
          DPred,
      bool FromParent) const;

  /// Returns currently analyzed directive.
  OpenMPDirectiveKind getCurrentDirective() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->Directive : OMPD_unknown;
  }
  /// Returns directive kind at specified level.
  OpenMPDirectiveKind getDirective(unsigned Level) const {
    assert(!isStackEmpty() && "No directive at specified level.");
    return getStackElemAtLevel(Level).Directive;
  }
  /// Returns the capture region at the specified level.
  OpenMPDirectiveKind getCaptureRegion(unsigned Level,
                                       unsigned OpenMPCaptureLevel) const {
    SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
    getOpenMPCaptureRegions(CaptureRegions, getDirective(Level));
    return CaptureRegions[OpenMPCaptureLevel];
  }
  /// Returns parent directive.
  OpenMPDirectiveKind getParentDirective() const {
    const SharingMapTy *Parent = getSecondOnStackOrNull();
    return Parent ? Parent->Directive : OMPD_unknown;
  }

  /// Add requires decl to internal vector
  void addRequiresDecl(OMPRequiresDecl *RD) {
    RequiresDecls.push_back(RD);
  }

  /// Checks if the defined 'requires' directive has specified type of clause.
  template <typename ClauseType>
  bool hasRequiresDeclWithClause() {
    return llvm::any_of(RequiresDecls, [](const OMPRequiresDecl *D) {
      return llvm::any_of(D->clauselists(), [](const OMPClause *C) {
        return isa<ClauseType>(C);
      });
    });
  }

  /// Checks for a duplicate clause amongst previously declared requires
  /// directives
  bool hasDuplicateRequiresClause(ArrayRef<OMPClause *> ClauseList) const {
    bool IsDuplicate = false;
    for (OMPClause *CNew : ClauseList) {
      for (const OMPRequiresDecl *D : RequiresDecls) {
        for (const OMPClause *CPrev : D->clauselists()) {
          if (CNew->getClauseKind() == CPrev->getClauseKind()) {
            SemaRef.Diag(CNew->getBeginLoc(),
                         diag::err_omp_requires_clause_redeclaration)
                << getOpenMPClauseName(CNew->getClauseKind());
            SemaRef.Diag(CPrev->getBeginLoc(),
                         diag::note_omp_requires_previous_clause)
                << getOpenMPClauseName(CPrev->getClauseKind());
            IsDuplicate = true;
          }
        }
      }
    }
    return IsDuplicate;
  }

  /// Add location of previously encountered target to internal vector
  void addTargetDirLocation(SourceLocation LocStart) {
    TargetLocations.push_back(LocStart);
  }

  // Return previously encountered target region locations.
  ArrayRef<SourceLocation> getEncounteredTargetLocs() const {
    return TargetLocations;
  }

  /// Set default data sharing attribute to none.
  void setDefaultDSANone(SourceLocation Loc) {
    getTopOfStack().DefaultAttr = DSA_none;
    getTopOfStack().DefaultAttrLoc = Loc;
  }
  /// Set default data sharing attribute to shared.
  void setDefaultDSAShared(SourceLocation Loc) {
    getTopOfStack().DefaultAttr = DSA_shared;
    getTopOfStack().DefaultAttrLoc = Loc;
  }
  /// Set default data mapping attribute to 'tofrom:scalar'.
  void setDefaultDMAToFromScalar(SourceLocation Loc) {
    getTopOfStack().DefaultMapAttr = DMA_tofrom_scalar;
    getTopOfStack().DefaultMapAttrLoc = Loc;
  }

  DefaultDataSharingAttributes getDefaultDSA() const {
    return isStackEmpty() ? DSA_unspecified
                          : getTopOfStack().DefaultAttr;
  }
  SourceLocation getDefaultDSALocation() const {
    return isStackEmpty() ? SourceLocation()
                          : getTopOfStack().DefaultAttrLoc;
  }
  DefaultMapAttributes getDefaultDMA() const {
    return isStackEmpty() ? DMA_unspecified
                          : getTopOfStack().DefaultMapAttr;
  }
  DefaultMapAttributes getDefaultDMAAtLevel(unsigned Level) const {
    return getStackElemAtLevel(Level).DefaultMapAttr;
  }
  SourceLocation getDefaultDMALocation() const {
    return isStackEmpty() ? SourceLocation()
                          : getTopOfStack().DefaultMapAttrLoc;
  }

  /// Checks if the specified variable is a threadprivate.
  bool isThreadPrivate(VarDecl *D) {
    const DSAVarData DVar = getTopDSA(D, false);
    return isOpenMPThreadPrivate(DVar.CKind);
  }

  /// Marks current region as ordered (it has an 'ordered' clause).
  void setOrderedRegion(bool IsOrdered, const Expr *Param,
                        OMPOrderedClause *Clause) {
    if (IsOrdered)
      getTopOfStack().OrderedRegion.emplace(Param, Clause);
    else
      getTopOfStack().OrderedRegion.reset();
  }
  /// Returns true, if region is ordered (has associated 'ordered' clause),
  /// false - otherwise.
  bool isOrderedRegion() const {
    if (const SharingMapTy *Top = getTopOfStackOrNull())
      return Top->OrderedRegion.hasValue();
    return false;
  }
  /// Returns optional parameter for the ordered region.
  std::pair<const Expr *, OMPOrderedClause *> getOrderedRegionParam() const {
    if (const SharingMapTy *Top = getTopOfStackOrNull())
      if (Top->OrderedRegion.hasValue())
        return Top->OrderedRegion.getValue();
    return std::make_pair(nullptr, nullptr);
  }
  /// Returns true, if parent region is ordered (has associated
  /// 'ordered' clause), false - otherwise.
  bool isParentOrderedRegion() const {
    if (const SharingMapTy *Parent = getSecondOnStackOrNull())
      return Parent->OrderedRegion.hasValue();
    return false;
  }
  /// Returns optional parameter for the ordered region.
  std::pair<const Expr *, OMPOrderedClause *>
  getParentOrderedRegionParam() const {
    if (const SharingMapTy *Parent = getSecondOnStackOrNull())
      if (Parent->OrderedRegion.hasValue())
        return Parent->OrderedRegion.getValue();
    return std::make_pair(nullptr, nullptr);
  }
  /// Marks current region as nowait (it has a 'nowait' clause).
  void setNowaitRegion(bool IsNowait = true) {
    getTopOfStack().NowaitRegion = IsNowait;
  }
  /// Returns true, if parent region is nowait (has associated
  /// 'nowait' clause), false - otherwise.
  bool isParentNowaitRegion() const {
    if (const SharingMapTy *Parent = getSecondOnStackOrNull())
      return Parent->NowaitRegion;
    return false;
  }
  /// Marks parent region as cancel region.
  void setParentCancelRegion(bool Cancel = true) {
    if (SharingMapTy *Parent = getSecondOnStackOrNull())
      Parent->CancelRegion |= Cancel;
  }
  /// Return true if current region has inner cancel construct.
  bool isCancelRegion() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->CancelRegion : false;
  }

  /// Set collapse value for the region.
  void setAssociatedLoops(unsigned Val) {
    getTopOfStack().AssociatedLoops = Val;
    if (Val > 1)
      getTopOfStack().HasMutipleLoops = true;
  }
  /// Return collapse value for region.
  unsigned getAssociatedLoops() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->AssociatedLoops : 0;
  }
  /// Returns true if the construct is associated with multiple loops.
  bool hasMutipleLoops() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->HasMutipleLoops : false;
  }

  /// Marks current target region as one with closely nested teams
  /// region.
  void setParentTeamsRegionLoc(SourceLocation TeamsRegionLoc) {
    if (SharingMapTy *Parent = getSecondOnStackOrNull())
      Parent->InnerTeamsRegionLoc = TeamsRegionLoc;
  }
  /// Returns true, if current region has closely nested teams region.
  bool hasInnerTeamsRegion() const {
    return getInnerTeamsRegionLoc().isValid();
  }
  /// Returns location of the nested teams region (if any).
  SourceLocation getInnerTeamsRegionLoc() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->InnerTeamsRegionLoc : SourceLocation();
  }

  Scope *getCurScope() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->CurScope : nullptr;
  }
  SourceLocation getConstructLoc() const {
    const SharingMapTy *Top = getTopOfStackOrNull();
    return Top ? Top->ConstructLoc : SourceLocation();
  }

  /// Do the check specified in \a Check to all component lists and return true
  /// if any issue is found.
  bool checkMappableExprComponentListsForDecl(
      const ValueDecl *VD, bool CurrentRegionOnly,
      const llvm::function_ref<
          bool(OMPClauseMappableExprCommon::MappableExprComponentListRef,
               OpenMPClauseKind)>
          Check) const {
    if (isStackEmpty())
      return false;
    auto SI = begin();
    auto SE = end();

    if (SI == SE)
      return false;

    if (CurrentRegionOnly)
      SE = std::next(SI);
    else
      std::advance(SI, 1);

    for (; SI != SE; ++SI) {
      auto MI = SI->MappedExprComponents.find(VD);
      if (MI != SI->MappedExprComponents.end())
        for (OMPClauseMappableExprCommon::MappableExprComponentListRef L :
             MI->second.Components)
          if (Check(L, MI->second.Kind))
            return true;
    }
    return false;
  }

  /// Do the check specified in \a Check to all component lists at a given level
  /// and return true if any issue is found.
  bool checkMappableExprComponentListsForDeclAtLevel(
      const ValueDecl *VD, unsigned Level,
      const llvm::function_ref<
          bool(OMPClauseMappableExprCommon::MappableExprComponentListRef,
               OpenMPClauseKind)>
          Check) const {
    if (getStackSize() <= Level)
      return false;

    const SharingMapTy &StackElem = getStackElemAtLevel(Level);
    auto MI = StackElem.MappedExprComponents.find(VD);
    if (MI != StackElem.MappedExprComponents.end())
      for (OMPClauseMappableExprCommon::MappableExprComponentListRef L :
           MI->second.Components)
        if (Check(L, MI->second.Kind))
          return true;
    return false;
  }

  /// Create a new mappable expression component list associated with a given
  /// declaration and initialize it with the provided list of components.
  void addMappableExpressionComponents(
      const ValueDecl *VD,
      OMPClauseMappableExprCommon::MappableExprComponentListRef Components,
      OpenMPClauseKind WhereFoundClauseKind) {
    MappedExprComponentTy &MEC = getTopOfStack().MappedExprComponents[VD];
    // Create new entry and append the new components there.
    MEC.Components.resize(MEC.Components.size() + 1);
    MEC.Components.back().append(Components.begin(), Components.end());
    MEC.Kind = WhereFoundClauseKind;
  }

  unsigned getNestingLevel() const {
    assert(!isStackEmpty());
    return getStackSize() - 1;
  }
  void addDoacrossDependClause(OMPDependClause *C,
                               const OperatorOffsetTy &OpsOffs) {
    SharingMapTy *Parent = getSecondOnStackOrNull();
    assert(Parent && isOpenMPWorksharingDirective(Parent->Directive));
    Parent->DoacrossDepends.try_emplace(C, OpsOffs);
  }
  llvm::iterator_range<DoacrossDependMapTy::const_iterator>
  getDoacrossDependClauses() const {
    const SharingMapTy &StackElem = getTopOfStack();
    if (isOpenMPWorksharingDirective(StackElem.Directive)) {
      const DoacrossDependMapTy &Ref = StackElem.DoacrossDepends;
      return llvm::make_range(Ref.begin(), Ref.end());
    }
    return llvm::make_range(StackElem.DoacrossDepends.end(),
                            StackElem.DoacrossDepends.end());
  }

  // Store types of classes which have been explicitly mapped
  void addMappedClassesQualTypes(QualType QT) {
    SharingMapTy &StackElem = getTopOfStack();
    StackElem.MappedClassesQualTypes.insert(QT);
  }

  // Return set of mapped classes types
  bool isClassPreviouslyMapped(QualType QT) const {
    const SharingMapTy &StackElem = getTopOfStack();
    return StackElem.MappedClassesQualTypes.count(QT) != 0;
  }

  /// Adds global declare target to the parent target region.
  void addToParentTargetRegionLinkGlobals(DeclRefExpr *E) {
    assert(*OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(
               E->getDecl()) == OMPDeclareTargetDeclAttr::MT_Link &&
           "Expected declare target link global.");
    for (auto &Elem : *this) {
      if (isOpenMPTargetExecutionDirective(Elem.Directive)) {
        Elem.DeclareTargetLinkVarDecls.push_back(E);
        return;
      }
    }
  }

  /// Returns the list of globals with declare target link if current directive
  /// is target.
  ArrayRef<DeclRefExpr *> getLinkGlobals() const {
    assert(isOpenMPTargetExecutionDirective(getCurrentDirective()) &&
           "Expected target executable directive.");
    return getTopOfStack().DeclareTargetLinkVarDecls;
  }
};

bool isImplicitTaskingRegion(OpenMPDirectiveKind DKind) {
  return isOpenMPParallelDirective(DKind) || isOpenMPTeamsDirective(DKind);
}

bool isImplicitOrExplicitTaskingRegion(OpenMPDirectiveKind DKind) {
  return isImplicitTaskingRegion(DKind) || isOpenMPTaskingDirective(DKind) ||
         DKind == OMPD_unknown;
}

} // namespace

static const Expr *getExprAsWritten(const Expr *E) {
  if (const auto *FE = dyn_cast<FullExpr>(E))
    E = FE->getSubExpr();

  if (const auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
    E = MTE->GetTemporaryExpr();

  while (const auto *Binder = dyn_cast<CXXBindTemporaryExpr>(E))
    E = Binder->getSubExpr();

  if (const auto *ICE = dyn_cast<ImplicitCastExpr>(E))
    E = ICE->getSubExprAsWritten();
  return E->IgnoreParens();
}

static Expr *getExprAsWritten(Expr *E) {
  return const_cast<Expr *>(getExprAsWritten(const_cast<const Expr *>(E)));
}

static const ValueDecl *getCanonicalDecl(const ValueDecl *D) {
  if (const auto *CED = dyn_cast<OMPCapturedExprDecl>(D))
    if (const auto *ME = dyn_cast<MemberExpr>(getExprAsWritten(CED->getInit())))
      D = ME->getMemberDecl();
  const auto *VD = dyn_cast<VarDecl>(D);
  const auto *FD = dyn_cast<FieldDecl>(D);
  if (VD != nullptr) {
    VD = VD->getCanonicalDecl();
    D = VD;
  } else {
    assert(FD);
    FD = FD->getCanonicalDecl();
    D = FD;
  }
  return D;
}

static ValueDecl *getCanonicalDecl(ValueDecl *D) {
  return const_cast<ValueDecl *>(
      getCanonicalDecl(const_cast<const ValueDecl *>(D)));
}

DSAStackTy::DSAVarData DSAStackTy::getDSA(const_iterator &Iter,
                                          ValueDecl *D) const {
  D = getCanonicalDecl(D);
  auto *VD = dyn_cast<VarDecl>(D);
  const auto *FD = dyn_cast<FieldDecl>(D);
  DSAVarData DVar;
  if (Iter == end()) {
    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
    // in a region but not in construct]
    //  File-scope or namespace-scope variables referenced in called routines
    //  in the region are shared unless they appear in a threadprivate
    //  directive.
    if (VD && !VD->isFunctionOrMethodVarDecl() && !isa<ParmVarDecl>(VD))
      DVar.CKind = OMPC_shared;

    // OpenMP [2.9.1.2, Data-sharing Attribute Rules for Variables Referenced
    // in a region but not in construct]
    //  Variables with static storage duration that are declared in called
    //  routines in the region are shared.
    if (VD && VD->hasGlobalStorage())
      DVar.CKind = OMPC_shared;

    // Non-static data members are shared by default.
    if (FD)
      DVar.CKind = OMPC_shared;

    return DVar;
  }

  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, C/C++, predetermined, p.1]
  // Variables with automatic storage duration that are declared in a scope
  // inside the construct are private.
  if (VD && isOpenMPLocal(VD, Iter) && VD->isLocalVarDecl() &&
      (VD->getStorageClass() == SC_Auto || VD->getStorageClass() == SC_None)) {
    DVar.CKind = OMPC_private;
    return DVar;
  }

  DVar.DKind = Iter->Directive;
  // Explicitly specified attributes and local variables with predetermined
  // attributes.
  if (Iter->SharingMap.count(D)) {
    const DSAInfo &Data = Iter->SharingMap.lookup(D);
    DVar.RefExpr = Data.RefExpr.getPointer();
    DVar.PrivateCopy = Data.PrivateCopy;
    DVar.CKind = Data.Attributes;
    DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
    return DVar;
  }

  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, C/C++, implicitly determined, p.1]
  //  In a parallel or task construct, the data-sharing attributes of these
  //  variables are determined by the default clause, if present.
  switch (Iter->DefaultAttr) {
  case DSA_shared:
    DVar.CKind = OMPC_shared;
    DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
    return DVar;
  case DSA_none:
    return DVar;
  case DSA_unspecified:
    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
    // in a Construct, implicitly determined, p.2]
    //  In a parallel construct, if no default clause is present, these
    //  variables are shared.
    DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
    if ((isOpenMPParallelDirective(DVar.DKind) &&
         !isOpenMPTaskLoopDirective(DVar.DKind)) ||
        isOpenMPTeamsDirective(DVar.DKind)) {
      DVar.CKind = OMPC_shared;
      return DVar;
    }

    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
    // in a Construct, implicitly determined, p.4]
    //  In a task construct, if no default clause is present, a variable that in
    //  the enclosing context is determined to be shared by all implicit tasks
    //  bound to the current team is shared.
    if (isOpenMPTaskingDirective(DVar.DKind)) {
      DSAVarData DVarTemp;
      const_iterator I = Iter, E = end();
      do {
        ++I;
        // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables
        // Referenced in a Construct, implicitly determined, p.6]
        //  In a task construct, if no default clause is present, a variable
        //  whose data-sharing attribute is not determined by the rules above is
        //  firstprivate.
        DVarTemp = getDSA(I, D);
        if (DVarTemp.CKind != OMPC_shared) {
          DVar.RefExpr = nullptr;
          DVar.CKind = OMPC_firstprivate;
          return DVar;
        }
      } while (I != E && !isImplicitTaskingRegion(I->Directive));
      DVar.CKind =
          (DVarTemp.CKind == OMPC_unknown) ? OMPC_firstprivate : OMPC_shared;
      return DVar;
    }
  }
  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, implicitly determined, p.3]
  //  For constructs other than task, if no default clause is present, these
  //  variables inherit their data-sharing attributes from the enclosing
  //  context.
  return getDSA(++Iter, D);
}

const Expr *DSAStackTy::addUniqueAligned(const ValueDecl *D,
                                         const Expr *NewDE) {
  assert(!isStackEmpty() && "Data sharing attributes stack is empty");
  D = getCanonicalDecl(D);
  SharingMapTy &StackElem = getTopOfStack();
  auto It = StackElem.AlignedMap.find(D);
  if (It == StackElem.AlignedMap.end()) {
    assert(NewDE && "Unexpected nullptr expr to be added into aligned map");
    StackElem.AlignedMap[D] = NewDE;
    return nullptr;
  }
  assert(It->second && "Unexpected nullptr expr in the aligned map");
  return It->second;
}

void DSAStackTy::addLoopControlVariable(const ValueDecl *D, VarDecl *Capture) {
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
  D = getCanonicalDecl(D);
  SharingMapTy &StackElem = getTopOfStack();
  StackElem.LCVMap.try_emplace(
      D, LCDeclInfo(StackElem.LCVMap.size() + 1, Capture));
}

const DSAStackTy::LCDeclInfo
DSAStackTy::isLoopControlVariable(const ValueDecl *D) const {
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
  D = getCanonicalDecl(D);
  const SharingMapTy &StackElem = getTopOfStack();
  auto It = StackElem.LCVMap.find(D);
  if (It != StackElem.LCVMap.end())
    return It->second;
  return {0, nullptr};
}

const DSAStackTy::LCDeclInfo
DSAStackTy::isParentLoopControlVariable(const ValueDecl *D) const {
  const SharingMapTy *Parent = getSecondOnStackOrNull();
  assert(Parent && "Data-sharing attributes stack is empty");
  D = getCanonicalDecl(D);
  auto It = Parent->LCVMap.find(D);
  if (It != Parent->LCVMap.end())
    return It->second;
  return {0, nullptr};
}

const ValueDecl *DSAStackTy::getParentLoopControlVariable(unsigned I) const {
  const SharingMapTy *Parent = getSecondOnStackOrNull();
  assert(Parent && "Data-sharing attributes stack is empty");
  if (Parent->LCVMap.size() < I)
    return nullptr;
  for (const auto &Pair : Parent->LCVMap)
    if (Pair.second.first == I)
      return Pair.first;
  return nullptr;
}

void DSAStackTy::addDSA(const ValueDecl *D, const Expr *E, OpenMPClauseKind A,
                        DeclRefExpr *PrivateCopy) {
  D = getCanonicalDecl(D);
  if (A == OMPC_threadprivate) {
    DSAInfo &Data = Threadprivates[D];
    Data.Attributes = A;
    Data.RefExpr.setPointer(E);
    Data.PrivateCopy = nullptr;
  } else {
    DSAInfo &Data = getTopOfStack().SharingMap[D];
    assert(Data.Attributes == OMPC_unknown || (A == Data.Attributes) ||
           (A == OMPC_firstprivate && Data.Attributes == OMPC_lastprivate) ||
           (A == OMPC_lastprivate && Data.Attributes == OMPC_firstprivate) ||
           (isLoopControlVariable(D).first && A == OMPC_private));
    if (A == OMPC_lastprivate && Data.Attributes == OMPC_firstprivate) {
      Data.RefExpr.setInt(/*IntVal=*/true);
      return;
    }
    const bool IsLastprivate =
        A == OMPC_lastprivate || Data.Attributes == OMPC_lastprivate;
    Data.Attributes = A;
    Data.RefExpr.setPointerAndInt(E, IsLastprivate);
    Data.PrivateCopy = PrivateCopy;
    if (PrivateCopy) {
      DSAInfo &Data = getTopOfStack().SharingMap[PrivateCopy->getDecl()];
      Data.Attributes = A;
      Data.RefExpr.setPointerAndInt(PrivateCopy, IsLastprivate);
      Data.PrivateCopy = nullptr;
    }
  }
}

/// Build a variable declaration for OpenMP loop iteration variable.
static VarDecl *buildVarDecl(Sema &SemaRef, SourceLocation Loc, QualType Type,
                             StringRef Name, const AttrVec *Attrs = nullptr,
                             DeclRefExpr *OrigRef = nullptr) {
  DeclContext *DC = SemaRef.CurContext;
  IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
  TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
  auto *Decl =
      VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, TInfo, SC_None);
  if (Attrs) {
    for (specific_attr_iterator<AlignedAttr> I(Attrs->begin()), E(Attrs->end());
         I != E; ++I)
      Decl->addAttr(*I);
  }
  Decl->setImplicit();
  if (OrigRef) {
    Decl->addAttr(
        OMPReferencedVarAttr::CreateImplicit(SemaRef.Context, OrigRef));
  }
  return Decl;
}

static DeclRefExpr *buildDeclRefExpr(Sema &S, VarDecl *D, QualType Ty,
                                     SourceLocation Loc,
                                     bool RefersToCapture = false) {
  D->setReferenced();
  D->markUsed(S.Context);
  return DeclRefExpr::Create(S.getASTContext(), NestedNameSpecifierLoc(),
                             SourceLocation(), D, RefersToCapture, Loc, Ty,
                             VK_LValue);
}

void DSAStackTy::addTaskgroupReductionData(const ValueDecl *D, SourceRange SR,
                                           BinaryOperatorKind BOK) {
  D = getCanonicalDecl(D);
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
  assert(
      getTopOfStack().SharingMap[D].Attributes == OMPC_reduction &&
      "Additional reduction info may be specified only for reduction items.");
  ReductionData &ReductionData = getTopOfStack().ReductionMap[D];
  assert(ReductionData.ReductionRange.isInvalid() &&
         getTopOfStack().Directive == OMPD_taskgroup &&
         "Additional reduction info may be specified only once for reduction "
         "items.");
  ReductionData.set(BOK, SR);
  Expr *&TaskgroupReductionRef =
      getTopOfStack().TaskgroupReductionRef;
  if (!TaskgroupReductionRef) {
    VarDecl *VD = buildVarDecl(SemaRef, SR.getBegin(),
                               SemaRef.Context.VoidPtrTy, ".task_red.");
    TaskgroupReductionRef =
        buildDeclRefExpr(SemaRef, VD, SemaRef.Context.VoidPtrTy, SR.getBegin());
  }
}

void DSAStackTy::addTaskgroupReductionData(const ValueDecl *D, SourceRange SR,
                                           const Expr *ReductionRef) {
  D = getCanonicalDecl(D);
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty");
  assert(
      getTopOfStack().SharingMap[D].Attributes == OMPC_reduction &&
      "Additional reduction info may be specified only for reduction items.");
  ReductionData &ReductionData = getTopOfStack().ReductionMap[D];
  assert(ReductionData.ReductionRange.isInvalid() &&
         getTopOfStack().Directive == OMPD_taskgroup &&
         "Additional reduction info may be specified only once for reduction "
         "items.");
  ReductionData.set(ReductionRef, SR);
  Expr *&TaskgroupReductionRef =
      getTopOfStack().TaskgroupReductionRef;
  if (!TaskgroupReductionRef) {
    VarDecl *VD = buildVarDecl(SemaRef, SR.getBegin(),
                               SemaRef.Context.VoidPtrTy, ".task_red.");
    TaskgroupReductionRef =
        buildDeclRefExpr(SemaRef, VD, SemaRef.Context.VoidPtrTy, SR.getBegin());
  }
}

const DSAStackTy::DSAVarData DSAStackTy::getTopMostTaskgroupReductionData(
    const ValueDecl *D, SourceRange &SR, BinaryOperatorKind &BOK,
    Expr *&TaskgroupDescriptor) const {
  D = getCanonicalDecl(D);
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty.");
  for (const_iterator I = begin() + 1, E = end(); I != E; ++I) {
    const DSAInfo &Data = I->SharingMap.lookup(D);
    if (Data.Attributes != OMPC_reduction || I->Directive != OMPD_taskgroup)
      continue;
    const ReductionData &ReductionData = I->ReductionMap.lookup(D);
    if (!ReductionData.ReductionOp ||
        ReductionData.ReductionOp.is<const Expr *>())
      return DSAVarData();
    SR = ReductionData.ReductionRange;
    BOK = ReductionData.ReductionOp.get<ReductionData::BOKPtrType>();
    assert(I->TaskgroupReductionRef && "taskgroup reduction reference "
                                       "expression for the descriptor is not "
                                       "set.");
    TaskgroupDescriptor = I->TaskgroupReductionRef;
    return DSAVarData(OMPD_taskgroup, OMPC_reduction, Data.RefExpr.getPointer(),
                      Data.PrivateCopy, I->DefaultAttrLoc);
  }
  return DSAVarData();
}

const DSAStackTy::DSAVarData DSAStackTy::getTopMostTaskgroupReductionData(
    const ValueDecl *D, SourceRange &SR, const Expr *&ReductionRef,
    Expr *&TaskgroupDescriptor) const {
  D = getCanonicalDecl(D);
  assert(!isStackEmpty() && "Data-sharing attributes stack is empty.");
  for (const_iterator I = begin() + 1, E = end(); I != E; ++I) {
    const DSAInfo &Data = I->SharingMap.lookup(D);
    if (Data.Attributes != OMPC_reduction || I->Directive != OMPD_taskgroup)
      continue;
    const ReductionData &ReductionData = I->ReductionMap.lookup(D);
    if (!ReductionData.ReductionOp ||
        !ReductionData.ReductionOp.is<const Expr *>())
      return DSAVarData();
    SR = ReductionData.ReductionRange;
    ReductionRef = ReductionData.ReductionOp.get<const Expr *>();
    assert(I->TaskgroupReductionRef && "taskgroup reduction reference "
                                       "expression for the descriptor is not "
                                       "set.");
    TaskgroupDescriptor = I->TaskgroupReductionRef;
    return DSAVarData(OMPD_taskgroup, OMPC_reduction, Data.RefExpr.getPointer(),
                      Data.PrivateCopy, I->DefaultAttrLoc);
  }
  return DSAVarData();
}

bool DSAStackTy::isOpenMPLocal(VarDecl *D, const_iterator I) const {
  D = D->getCanonicalDecl();
  for (const_iterator E = end(); I != E; ++I) {
    if (isImplicitOrExplicitTaskingRegion(I->Directive) ||
        isOpenMPTargetExecutionDirective(I->Directive)) {
      Scope *TopScope = I->CurScope ? I->CurScope->getParent() : nullptr;
      Scope *CurScope = getCurScope();
      while (CurScope && CurScope != TopScope && !CurScope->isDeclScope(D))
        CurScope = CurScope->getParent();
      return CurScope != TopScope;
    }
  }
  return false;
}

static bool isConstNotMutableType(Sema &SemaRef, QualType Type,
                                  bool AcceptIfMutable = true,
                                  bool *IsClassType = nullptr) {
  ASTContext &Context = SemaRef.getASTContext();
  Type = Type.getNonReferenceType().getCanonicalType();
  bool IsConstant = Type.isConstant(Context);
  Type = Context.getBaseElementType(Type);
  const CXXRecordDecl *RD = AcceptIfMutable && SemaRef.getLangOpts().CPlusPlus
                                ? Type->getAsCXXRecordDecl()
                                : nullptr;
  if (const auto *CTSD = dyn_cast_or_null<ClassTemplateSpecializationDecl>(RD))
    if (const ClassTemplateDecl *CTD = CTSD->getSpecializedTemplate())
      RD = CTD->getTemplatedDecl();
  if (IsClassType)
    *IsClassType = RD;
  return IsConstant && !(SemaRef.getLangOpts().CPlusPlus && RD &&
                         RD->hasDefinition() && RD->hasMutableFields());
}

static bool rejectConstNotMutableType(Sema &SemaRef, const ValueDecl *D,
                                      QualType Type, OpenMPClauseKind CKind,
                                      SourceLocation ELoc,
                                      bool AcceptIfMutable = true,
                                      bool ListItemNotVar = false) {
  ASTContext &Context = SemaRef.getASTContext();
  bool IsClassType;
  if (isConstNotMutableType(SemaRef, Type, AcceptIfMutable, &IsClassType)) {
    unsigned Diag = ListItemNotVar
                        ? diag::err_omp_const_list_item
                        : IsClassType ? diag::err_omp_const_not_mutable_variable
                                      : diag::err_omp_const_variable;
    SemaRef.Diag(ELoc, Diag) << getOpenMPClauseName(CKind);
    if (!ListItemNotVar && D) {
      const VarDecl *VD = dyn_cast<VarDecl>(D);
      bool IsDecl = !VD || VD->isThisDeclarationADefinition(Context) ==
                               VarDecl::DeclarationOnly;
      SemaRef.Diag(D->getLocation(),
                   IsDecl ? diag::note_previous_decl : diag::note_defined_here)
          << D;
    }
    return true;
  }
  return false;
}

const DSAStackTy::DSAVarData DSAStackTy::getTopDSA(ValueDecl *D,
                                                   bool FromParent) {
  D = getCanonicalDecl(D);
  DSAVarData DVar;

  auto *VD = dyn_cast<VarDecl>(D);
  auto TI = Threadprivates.find(D);
  if (TI != Threadprivates.end()) {
    DVar.RefExpr = TI->getSecond().RefExpr.getPointer();
    DVar.CKind = OMPC_threadprivate;
    return DVar;
  }
  if (VD && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
    DVar.RefExpr = buildDeclRefExpr(
        SemaRef, VD, D->getType().getNonReferenceType(),
        VD->getAttr<OMPThreadPrivateDeclAttr>()->getLocation());
    DVar.CKind = OMPC_threadprivate;
    addDSA(D, DVar.RefExpr, OMPC_threadprivate);
    return DVar;
  }
  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, C/C++, predetermined, p.1]
  //  Variables appearing in threadprivate directives are threadprivate.
  if ((VD && VD->getTLSKind() != VarDecl::TLS_None &&
       !(VD->hasAttr<OMPThreadPrivateDeclAttr>() &&
         SemaRef.getLangOpts().OpenMPUseTLS &&
         SemaRef.getASTContext().getTargetInfo().isTLSSupported())) ||
      (VD && VD->getStorageClass() == SC_Register &&
       VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())) {
    DVar.RefExpr = buildDeclRefExpr(
        SemaRef, VD, D->getType().getNonReferenceType(), D->getLocation());
    DVar.CKind = OMPC_threadprivate;
    addDSA(D, DVar.RefExpr, OMPC_threadprivate);
    return DVar;
  }
  if (SemaRef.getLangOpts().OpenMPCUDAMode && VD &&
      VD->isLocalVarDeclOrParm() && !isStackEmpty() &&
      !isLoopControlVariable(D).first) {
    const_iterator IterTarget =
        std::find_if(begin(), end(), [](const SharingMapTy &Data) {
          return isOpenMPTargetExecutionDirective(Data.Directive);
        });
    if (IterTarget != end()) {
      const_iterator ParentIterTarget = IterTarget + 1;
      for (const_iterator Iter = begin();
           Iter != ParentIterTarget; ++Iter) {
        if (isOpenMPLocal(VD, Iter)) {
          DVar.RefExpr =
              buildDeclRefExpr(SemaRef, VD, D->getType().getNonReferenceType(),
                               D->getLocation());
          DVar.CKind = OMPC_threadprivate;
          return DVar;
        }
      }
      if (!isClauseParsingMode() || IterTarget != begin()) {
        auto DSAIter = IterTarget->SharingMap.find(D);
        if (DSAIter != IterTarget->SharingMap.end() &&
            isOpenMPPrivate(DSAIter->getSecond().Attributes)) {
          DVar.RefExpr = DSAIter->getSecond().RefExpr.getPointer();
          DVar.CKind = OMPC_threadprivate;
          return DVar;
        }
        const_iterator End = end();
        if (!SemaRef.isOpenMPCapturedByRef(
                D, std::distance(ParentIterTarget, End),
                /*OpenMPCaptureLevel=*/0)) {
          DVar.RefExpr =
              buildDeclRefExpr(SemaRef, VD, D->getType().getNonReferenceType(),
                               IterTarget->ConstructLoc);
          DVar.CKind = OMPC_threadprivate;
          return DVar;
        }
      }
    }
  }

  if (isStackEmpty())
    // Not in OpenMP execution region and top scope was already checked.
    return DVar;

  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, C/C++, predetermined, p.4]
  //  Static data members are shared.
  // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
  // in a Construct, C/C++, predetermined, p.7]
  //  Variables with static storage duration that are declared in a scope
  //  inside the construct are shared.
  if (VD && VD->isStaticDataMember()) {
    // Check for explicitly specified attributes.
    const_iterator I = begin();
    const_iterator EndI = end();
    if (FromParent && I != EndI)
      ++I;
    auto It = I->SharingMap.find(D);
    if (It != I->SharingMap.end()) {
      const DSAInfo &Data = It->getSecond();
      DVar.RefExpr = Data.RefExpr.getPointer();
      DVar.PrivateCopy = Data.PrivateCopy;
      DVar.CKind = Data.Attributes;
      DVar.ImplicitDSALoc = I->DefaultAttrLoc;
      DVar.DKind = I->Directive;
      return DVar;
    }

    DVar.CKind = OMPC_shared;
    return DVar;
  }

  auto &&MatchesAlways = [](OpenMPDirectiveKind) { return true; };
  // The predetermined shared attribute for const-qualified types having no
  // mutable members was removed after OpenMP 3.1.
  if (SemaRef.LangOpts.OpenMP <= 31) {
    // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
    // in a Construct, C/C++, predetermined, p.6]
    //  Variables with const qualified type having no mutable member are
    //  shared.
    if (isConstNotMutableType(SemaRef, D->getType())) {
      // Variables with const-qualified type having no mutable member may be
      // listed in a firstprivate clause, even if they are static data members.
      DSAVarData DVarTemp = hasInnermostDSA(
          D,
          [](OpenMPClauseKind C) {
            return C == OMPC_firstprivate || C == OMPC_shared;
          },
          MatchesAlways, FromParent);
      if (DVarTemp.CKind != OMPC_unknown && DVarTemp.RefExpr)
        return DVarTemp;

      DVar.CKind = OMPC_shared;
      return DVar;
    }
  }

  // Explicitly specified attributes and local variables with predetermined
  // attributes.
  const_iterator I = begin();
  const_iterator EndI = end();
  if (FromParent && I != EndI)
    ++I;
  auto It = I->SharingMap.find(D);
  if (It != I->SharingMap.end()) {
    const DSAInfo &Data = It->getSecond();
    DVar.RefExpr = Data.RefExpr.getPointer();
    DVar.PrivateCopy = Data.PrivateCopy;
    DVar.CKind = Data.Attributes;
    DVar.ImplicitDSALoc = I->DefaultAttrLoc;
    DVar.DKind = I->Directive;
  }

  return DVar;
}

const DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(ValueDecl *D,
                                                        bool FromParent) const {
  if (isStackEmpty()) {
    const_iterator I;
    return getDSA(I, D);
  }
  D = getCanonicalDecl(D);
  const_iterator StartI = begin();
  const_iterator EndI = end();
  if (FromParent && StartI != EndI)
    ++StartI;
  return getDSA(StartI, D);
}

const DSAStackTy::DSAVarData
DSAStackTy::hasDSA(ValueDecl *D,
                   const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
                   const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
                   bool FromParent) const {
  if (isStackEmpty())
    return {};
  D = getCanonicalDecl(D);
  const_iterator I = begin();
  const_iterator EndI = end();
  if (FromParent && I != EndI)
    ++I;
  for (; I != EndI; ++I) {
    if (!DPred(I->Directive) &&
        !isImplicitOrExplicitTaskingRegion(I->Directive))
      continue;
    const_iterator NewI = I;
    DSAVarData DVar = getDSA(NewI, D);
    if (I == NewI && CPred(DVar.CKind))
      return DVar;
  }
  return {};
}

const DSAStackTy::DSAVarData DSAStackTy::hasInnermostDSA(
    ValueDecl *D, const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
    const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
    bool FromParent) const {
  if (isStackEmpty())
    return {};
  D = getCanonicalDecl(D);
  const_iterator StartI = begin();
  const_iterator EndI = end();
  if (FromParent && StartI != EndI)
    ++StartI;
  if (StartI == EndI || !DPred(StartI->Directive))
    return {};
  const_iterator NewI = StartI;
  DSAVarData DVar = getDSA(NewI, D);
  return (NewI == StartI && CPred(DVar.CKind)) ? DVar : DSAVarData();
}

bool DSAStackTy::hasExplicitDSA(
    const ValueDecl *D, const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
    unsigned Level, bool NotLastprivate) const {
  if (getStackSize() <= Level)
    return false;
  D = getCanonicalDecl(D);
  const SharingMapTy &StackElem = getStackElemAtLevel(Level);
  auto I = StackElem.SharingMap.find(D);
  if (I != StackElem.SharingMap.end() &&
      I->getSecond().RefExpr.getPointer() &&
      CPred(I->getSecond().Attributes) &&
      (!NotLastprivate || !I->getSecond().RefExpr.getInt()))
    return true;
  // Check predetermined rules for the loop control variables.
  auto LI = StackElem.LCVMap.find(D);
  if (LI != StackElem.LCVMap.end())
    return CPred(OMPC_private);
  return false;
}

bool DSAStackTy::hasExplicitDirective(
    const llvm::function_ref<bool(OpenMPDirectiveKind)> DPred,
    unsigned Level) const {
  if (getStackSize() <= Level)
    return false;
  const SharingMapTy &StackElem = getStackElemAtLevel(Level);
  return DPred(StackElem.Directive);
}

bool DSAStackTy::hasDirective(
    const llvm::function_ref<bool(OpenMPDirectiveKind,
                                  const DeclarationNameInfo &, SourceLocation)>
        DPred,
    bool FromParent) const {
  // We look only in the enclosing region.
  size_t Skip = FromParent ? 2 : 1;
  for (const_iterator I = begin() + std::min(Skip, getStackSize()), E = end();
       I != E; ++I) {
    if (DPred(I->Directive, I->DirectiveName, I->ConstructLoc))
      return true;
  }
  return false;
}

void Sema::InitDataSharingAttributesStack() {
  VarDataSharingAttributesStack = new DSAStackTy(*this);
}

#define DSAStack static_cast<DSAStackTy *>(VarDataSharingAttributesStack)

void Sema::pushOpenMPFunctionRegion() {
  DSAStack->pushFunction();
}

void Sema::popOpenMPFunctionRegion(const FunctionScopeInfo *OldFSI) {
  DSAStack->popFunction(OldFSI);
}

static bool isOpenMPDeviceDelayedContext(Sema &S) {
  assert(S.LangOpts.OpenMP && S.LangOpts.OpenMPIsDevice &&
         "Expected OpenMP device compilation.");
  return !S.isInOpenMPTargetExecutionDirective() &&
         !S.isInOpenMPDeclareTargetContext();
}

namespace {
/// Status of the function emission on the host/device.
enum class FunctionEmissionStatus {
  Emitted,
  Discarded,
  Unknown,
};
} // anonymous namespace

Sema::DeviceDiagBuilder Sema::diagIfOpenMPDeviceCode(SourceLocation Loc,
                                                     unsigned DiagID) {
  assert(LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
         "Expected OpenMP device compilation.");
  FunctionEmissionStatus FES = getEmissionStatus(getCurFunctionDecl());
  DeviceDiagBuilder::Kind Kind = DeviceDiagBuilder::K_Nop;
  switch (FES) {
  case FunctionEmissionStatus::Emitted:
    Kind = DeviceDiagBuilder::K_Immediate;
    break;
  case FunctionEmissionStatus::Unknown:
    Kind = isOpenMPDeviceDelayedContext(*this) ? DeviceDiagBuilder::K_Deferred
                                               : DeviceDiagBuilder::K_Immediate;
    break;
  case FunctionEmissionStatus::TemplateDiscarded:
  case FunctionEmissionStatus::OMPDiscarded:
    Kind = DeviceDiagBuilder::K_Nop;
    break;
  case FunctionEmissionStatus::CUDADiscarded:
    llvm_unreachable("CUDADiscarded unexpected in OpenMP device compilation");
    break;
  }

  return DeviceDiagBuilder(Kind, Loc, DiagID, getCurFunctionDecl(), *this);
}

Sema::DeviceDiagBuilder Sema::diagIfOpenMPHostCode(SourceLocation Loc,
                                                   unsigned DiagID) {
  assert(LangOpts.OpenMP && !LangOpts.OpenMPIsDevice &&
         "Expected OpenMP host compilation.");
  FunctionEmissionStatus FES = getEmissionStatus(getCurFunctionDecl());
  DeviceDiagBuilder::Kind Kind = DeviceDiagBuilder::K_Nop;
  switch (FES) {
  case FunctionEmissionStatus::Emitted:
    Kind = DeviceDiagBuilder::K_Immediate;
    break;
  case FunctionEmissionStatus::Unknown:
    Kind = DeviceDiagBuilder::K_Deferred;
    break;
  case FunctionEmissionStatus::TemplateDiscarded:
  case FunctionEmissionStatus::OMPDiscarded:
  case FunctionEmissionStatus::CUDADiscarded:
    Kind = DeviceDiagBuilder::K_Nop;
    break;
  }

  return DeviceDiagBuilder(Kind, Loc, DiagID, getCurFunctionDecl(), *this);
}

void Sema::checkOpenMPDeviceFunction(SourceLocation Loc, FunctionDecl *Callee,
                                     bool CheckForDelayedContext) {
  assert(LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
         "Expected OpenMP device compilation.");
  assert(Callee && "Callee may not be null.");
  Callee = Callee->getMostRecentDecl();
  FunctionDecl *Caller = getCurFunctionDecl();

  // host only function are not available on the device.
  if (Caller) {
    FunctionEmissionStatus CallerS = getEmissionStatus(Caller);
    FunctionEmissionStatus CalleeS = getEmissionStatus(Callee);
    assert(CallerS != FunctionEmissionStatus::CUDADiscarded &&
           CalleeS != FunctionEmissionStatus::CUDADiscarded &&
           "CUDADiscarded unexpected in OpenMP device function check");
    if ((CallerS == FunctionEmissionStatus::Emitted ||
         (!isOpenMPDeviceDelayedContext(*this) &&
          CallerS == FunctionEmissionStatus::Unknown)) &&
        CalleeS == FunctionEmissionStatus::OMPDiscarded) {
      StringRef HostDevTy = getOpenMPSimpleClauseTypeName(
          OMPC_device_type, OMPC_DEVICE_TYPE_host);
      Diag(Loc, diag::err_omp_wrong_device_function_call) << HostDevTy << 0;
      Diag(Callee->getAttr<OMPDeclareTargetDeclAttr>()->getLocation(),
           diag::note_omp_marked_device_type_here)
          << HostDevTy;
      return;
    }
  }
  // If the caller is known-emitted, mark the callee as known-emitted.
  // Otherwise, mark the call in our call graph so we can traverse it later.
  if ((CheckForDelayedContext && !isOpenMPDeviceDelayedContext(*this)) ||
      (!Caller && !CheckForDelayedContext) ||
      (Caller && getEmissionStatus(Caller) == FunctionEmissionStatus::Emitted))
    markKnownEmitted(*this, Caller, Callee, Loc,
                     [CheckForDelayedContext](Sema &S, FunctionDecl *FD) {
                       return CheckForDelayedContext &&
                              S.getEmissionStatus(FD) ==
                                  FunctionEmissionStatus::Emitted;
                     });
  else if (Caller)
    DeviceCallGraph[Caller].insert({Callee, Loc});
}

void Sema::checkOpenMPHostFunction(SourceLocation Loc, FunctionDecl *Callee,
                                   bool CheckCaller) {
  assert(LangOpts.OpenMP && !LangOpts.OpenMPIsDevice &&
         "Expected OpenMP host compilation.");
  assert(Callee && "Callee may not be null.");
  Callee = Callee->getMostRecentDecl();
  FunctionDecl *Caller = getCurFunctionDecl();

  // device only function are not available on the host.
  if (Caller) {
    FunctionEmissionStatus CallerS = getEmissionStatus(Caller);
    FunctionEmissionStatus CalleeS = getEmissionStatus(Callee);
    assert(
        (LangOpts.CUDA || (CallerS != FunctionEmissionStatus::CUDADiscarded &&
                           CalleeS != FunctionEmissionStatus::CUDADiscarded)) &&
        "CUDADiscarded unexpected in OpenMP host function check");
    if (CallerS == FunctionEmissionStatus::Emitted &&
        CalleeS == FunctionEmissionStatus::OMPDiscarded) {
      StringRef NoHostDevTy = getOpenMPSimpleClauseTypeName(
          OMPC_device_type, OMPC_DEVICE_TYPE_nohost);
      Diag(Loc, diag::err_omp_wrong_device_function_call) << NoHostDevTy << 1;
      Diag(Callee->getAttr<OMPDeclareTargetDeclAttr>()->getLocation(),
           diag::note_omp_marked_device_type_here)
          << NoHostDevTy;
      return;
    }
  }
  // If the caller is known-emitted, mark the callee as known-emitted.
  // Otherwise, mark the call in our call graph so we can traverse it later.
  if (!shouldIgnoreInHostDeviceCheck(Callee)) {
    if ((!CheckCaller && !Caller) ||
        (Caller &&
         getEmissionStatus(Caller) == FunctionEmissionStatus::Emitted))
      markKnownEmitted(
          *this, Caller, Callee, Loc, [CheckCaller](Sema &S, FunctionDecl *FD) {
            return CheckCaller &&
                   S.getEmissionStatus(FD) == FunctionEmissionStatus::Emitted;
          });
    else if (Caller)
      DeviceCallGraph[Caller].insert({Callee, Loc});
  }
}

void Sema::checkOpenMPDeviceExpr(const Expr *E) {
  assert(getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
         "OpenMP device compilation mode is expected.");
  QualType Ty = E->getType();
  if ((Ty->isFloat16Type() && !Context.getTargetInfo().hasFloat16Type()) ||
      ((Ty->isFloat128Type() ||
        (Ty->isRealFloatingType() && Context.getTypeSize(Ty) == 128)) &&
       !Context.getTargetInfo().hasFloat128Type()) ||
      (Ty->isIntegerType() && Context.getTypeSize(Ty) == 128 &&
       !Context.getTargetInfo().hasInt128Type()))
    targetDiag(E->getExprLoc(), diag::err_omp_unsupported_type)
        << static_cast<unsigned>(Context.getTypeSize(Ty)) << Ty
        << Context.getTargetInfo().getTriple().str() << E->getSourceRange();
}

bool Sema::isOpenMPCapturedByRef(const ValueDecl *D, unsigned Level,
                                 unsigned OpenMPCaptureLevel) const {
  assert(LangOpts.OpenMP && "OpenMP is not allowed");

  ASTContext &Ctx = getASTContext();
  bool IsByRef = true;

  // Find the directive that is associated with the provided scope.
  D = cast<ValueDecl>(D->getCanonicalDecl());
  QualType Ty = D->getType();

  bool IsVariableUsedInMapClause = false;
  if (DSAStack->hasExplicitDirective(isOpenMPTargetExecutionDirective, Level)) {
    // This table summarizes how a given variable should be passed to the device
    // given its type and the clauses where it appears. This table is based on
    // the description in OpenMP 4.5 [2.10.4, target Construct] and
    // OpenMP 4.5 [2.15.5, Data-mapping Attribute Rules and Clauses].
    //
    // =========================================================================
    // | type |  defaultmap   | pvt | first | is_device_ptr |    map   | res.  |
    // |      |(tofrom:scalar)|     |  pvt  |               |          |       |
    // =========================================================================
    // | scl  |               |     |       |       -       |          | bycopy|
    // | scl  |               |  -  |   x   |       -       |     -    | bycopy|
    // | scl  |               |  x  |   -   |       -       |     -    | null  |
    // | scl  |       x       |     |       |       -       |          | byref |
    // | scl  |       x       |  -  |   x   |       -       |     -    | bycopy|
    // | scl  |       x       |  x  |   -   |       -       |     -    | null  |
    // | scl  |               |  -  |   -   |       -       |     x    | byref |
    // | scl  |       x       |  -  |   -   |       -       |     x    | byref |
    //
    // | agg  |      n.a.     |     |       |       -       |          | byref |
    // | agg  |      n.a.     |  -  |   x   |       -       |     -    | byref |
    // | agg  |      n.a.     |  x  |   -   |       -       |     -    | null  |
    // | agg  |      n.a.     |  -  |   -   |       -       |     x    | byref |
    // | agg  |      n.a.     |  -  |   -   |       -       |    x[]   | byref |
    //
    // | ptr  |      n.a.     |     |       |       -       |          | bycopy|
    // | ptr  |      n.a.     |  -  |   x   |       -       |     -    | bycopy|
    // | ptr  |      n.a.     |  x  |   -   |       -       |     -    | null  |
    // | ptr  |      n.a.     |  -  |   -   |       -       |     x    | byref |
    // | ptr  |      n.a.     |  -  |   -   |       -       |    x[]   | bycopy|
    // | ptr  |      n.a.     |  -  |   -   |       x       |          | bycopy|
    // | ptr  |      n.a.     |  -  |   -   |       x       |     x    | bycopy|
    // | ptr  |      n.a.     |  -  |   -   |       x       |    x[]   | bycopy|
    // =========================================================================
    // Legend:
    //  scl - scalar
    //  ptr - pointer
    //  agg - aggregate
    //  x - applies
    //  - - invalid in this combination
    //  [] - mapped with an array section
    //  byref - should be mapped by reference
    //  byval - should be mapped by value
    //  null - initialize a local variable to null on the device
    //
    // Observations:
    //  - All scalar declarations that show up in a map clause have to be passed
    //    by reference, because they may have been mapped in the enclosing data
    //    environment.
    //  - If the scalar value does not fit the size of uintptr, it has to be
    //    passed by reference, regardless the result in the table above.
    //  - For pointers mapped by value that have either an implicit map or an
    //    array section, the runtime library may pass the NULL value to the
    //    device instead of the value passed to it by the compiler.

    if (Ty->isReferenceType())
      Ty = Ty->castAs<ReferenceType>()->getPointeeType();

    // Locate map clauses and see if the variable being captured is referred to
    // in any of those clauses. Here we only care about variables, not fields,
    // because fields are part of aggregates.
    bool IsVariableAssociatedWithSection = false;

    DSAStack->checkMappableExprComponentListsForDeclAtLevel(
        D, Level,
        [&IsVariableUsedInMapClause, &IsVariableAssociatedWithSection, D](
            OMPClauseMappableExprCommon::MappableExprComponentListRef
                MapExprComponents,
            OpenMPClauseKind WhereFoundClauseKind) {
          // Only the map clause information influences how a variable is
          // captured. E.g. is_device_ptr does not require changing the default
          // behavior.
          if (WhereFoundClauseKind != OMPC_map)
            return false;

          auto EI = MapExprComponents.rbegin();
          auto EE = MapExprComponents.rend();

          assert(EI != EE && "Invalid map expression!");

          if (isa<DeclRefExpr>(EI->getAssociatedExpression()))
            IsVariableUsedInMapClause |= EI->getAssociatedDeclaration() == D;

          ++EI;
          if (EI == EE)
            return false;

          if (isa<ArraySubscriptExpr>(EI->getAssociatedExpression()) ||
              isa<OMPArraySectionExpr>(EI->getAssociatedExpression()) ||
              isa<MemberExpr>(EI->getAssociatedExpression())) {
            IsVariableAssociatedWithSection = true;
            // There is nothing more we need to know about this variable.
            return true;
          }

          // Keep looking for more map info.
          return false;
        });

    if (IsVariableUsedInMapClause) {
      // If variable is identified in a map clause it is always captured by
      // reference except if it is a pointer that is dereferenced somehow.
      IsByRef = !(Ty->isPointerType() && IsVariableAssociatedWithSection);
    } else {
      // By default, all the data that has a scalar type is mapped by copy
      // (except for reduction variables).
      IsByRef =
          (DSAStack->isForceCaptureByReferenceInTargetExecutable() &&
           !Ty->isAnyPointerType()) ||
          !Ty->isScalarType() ||
          DSAStack->getDefaultDMAAtLevel(Level) == DMA_tofrom_scalar ||
          DSAStack->hasExplicitDSA(
              D, [](OpenMPClauseKind K) { return K == OMPC_reduction; }, Level);
    }
  }

  if (IsByRef && Ty.getNonReferenceType()->isScalarType()) {
    IsByRef =
        ((IsVariableUsedInMapClause &&
          DSAStack->getCaptureRegion(Level, OpenMPCaptureLevel) ==
              OMPD_target) ||
         !DSAStack->hasExplicitDSA(
             D,
             [](OpenMPClauseKind K) -> bool { return K == OMPC_firstprivate; },
             Level, /*NotLastprivate=*/true)) &&
        // If the variable is artificial and must be captured by value - try to
        // capture by value.
        !(isa<OMPCapturedExprDecl>(D) && !D->hasAttr<OMPCaptureNoInitAttr>() &&
          !cast<OMPCapturedExprDecl>(D)->getInit()->isGLValue());
  }

  // When passing data by copy, we need to make sure it fits the uintptr size
  // and alignment, because the runtime library only deals with uintptr types.
  // If it does not fit the uintptr size, we need to pass the data by reference
  // instead.
  if (!IsByRef &&
      (Ctx.getTypeSizeInChars(Ty) >
           Ctx.getTypeSizeInChars(Ctx.getUIntPtrType()) ||
       Ctx.getDeclAlign(D) > Ctx.getTypeAlignInChars(Ctx.getUIntPtrType()))) {
    IsByRef = true;
  }

  return IsByRef;
}

unsigned Sema::getOpenMPNestingLevel() const {
  assert(getLangOpts().OpenMP);
  return DSAStack->getNestingLevel();
}

bool Sema::isInOpenMPTargetExecutionDirective() const {
  return (isOpenMPTargetExecutionDirective(DSAStack->getCurrentDirective()) &&
          !DSAStack->isClauseParsingMode()) ||
         DSAStack->hasDirective(
             [](OpenMPDirectiveKind K, const DeclarationNameInfo &,
                SourceLocation) -> bool {
               return isOpenMPTargetExecutionDirective(K);
             },
             false);
}

VarDecl *Sema::isOpenMPCapturedDecl(ValueDecl *D, bool CheckScopeInfo,
                                    unsigned StopAt) {
  assert(LangOpts.OpenMP && "OpenMP is not allowed");
  D = getCanonicalDecl(D);

  auto *VD = dyn_cast<VarDecl>(D);
  // Do not capture constexpr variables.
  if (VD && VD->isConstexpr())
    return nullptr;

  // If we want to determine whether the variable should be captured from the
  // perspective of the current capturing scope, and we've already left all the
  // capturing scopes of the top directive on the stack, check from the
  // perspective of its parent directive (if any) instead.
  DSAStackTy::ParentDirectiveScope InParentDirectiveRAII(
      *DSAStack, CheckScopeInfo && DSAStack->isBodyComplete());

  // If we are attempting to capture a global variable in a directive with
  // 'target' we return true so that this global is also mapped to the device.
  //
  if (VD && !VD->hasLocalStorage() &&
      (getCurCapturedRegion() || getCurBlock() || getCurLambda())) {
    if (isInOpenMPDeclareTargetContext()) {
      // Try to mark variable as declare target if it is used in capturing
      // regions.
      if (LangOpts.OpenMP <= 45 &&
          !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD))
        checkDeclIsAllowedInOpenMPTarget(nullptr, VD);
      return nullptr;
    } else if (isInOpenMPTargetExecutionDirective()) {
      // If the declaration is enclosed in a 'declare target' directive,
      // then it should not be captured.
      //
      if (OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD))
        return nullptr;
      return VD;
    }
  }

  if (CheckScopeInfo) {
    bool OpenMPFound = false;
    for (unsigned I = StopAt + 1; I > 0; --I) {
      FunctionScopeInfo *FSI = FunctionScopes[I - 1];
      if(!isa<CapturingScopeInfo>(FSI))
        return nullptr;
      if (auto *RSI = dyn_cast<CapturedRegionScopeInfo>(FSI))
        if (RSI->CapRegionKind == CR_OpenMP) {
          OpenMPFound = true;
          break;
        }
    }
    if (!OpenMPFound)
      return nullptr;
  }

  if (DSAStack->getCurrentDirective() != OMPD_unknown &&
      (!DSAStack->isClauseParsingMode() ||
       DSAStack->getParentDirective() != OMPD_unknown)) {
    auto &&Info = DSAStack->isLoopControlVariable(D);
    if (Info.first ||
        (VD && VD->hasLocalStorage() &&
         isImplicitOrExplicitTaskingRegion(DSAStack->getCurrentDirective())) ||
        (VD && DSAStack->isForceVarCapturing()))
      return VD ? VD : Info.second;
    DSAStackTy::DSAVarData DVarPrivate =
        DSAStack->getTopDSA(D, DSAStack->isClauseParsingMode());
    if (DVarPrivate.CKind != OMPC_unknown && isOpenMPPrivate(DVarPrivate.CKind))
      return VD ? VD : cast<VarDecl>(DVarPrivate.PrivateCopy->getDecl());
    // Threadprivate variables must not be captured.
    if (isOpenMPThreadPrivate(DVarPrivate.CKind))
      return nullptr;
    // The variable is not private or it is the variable in the directive with
    // default(none) clause and not used in any clause.
    DVarPrivate = DSAStack->hasDSA(D, isOpenMPPrivate,
                                   [](OpenMPDirectiveKind) { return true; },
                                   DSAStack->isClauseParsingMode());
    if (DVarPrivate.CKind != OMPC_unknown ||
        (VD && DSAStack->getDefaultDSA() == DSA_none))
      return VD ? VD : cast<VarDecl>(DVarPrivate.PrivateCopy->getDecl());
  }
  return nullptr;
}

void Sema::adjustOpenMPTargetScopeIndex(unsigned &FunctionScopesIndex,
                                        unsigned Level) const {
  SmallVector<OpenMPDirectiveKind, 4> Regions;
  getOpenMPCaptureRegions(Regions, DSAStack->getDirective(Level));
  FunctionScopesIndex -= Regions.size();
}

void Sema::startOpenMPLoop() {
  assert(LangOpts.OpenMP && "OpenMP must be enabled.");
  if (isOpenMPLoopDirective(DSAStack->getCurrentDirective()))
    DSAStack->loopInit();
}

void Sema::startOpenMPCXXRangeFor() {
  assert(LangOpts.OpenMP && "OpenMP must be enabled.");
  if (isOpenMPLoopDirective(DSAStack->getCurrentDirective())) {
    DSAStack->resetPossibleLoopCounter();
    DSAStack->loopStart();
  }
}

bool Sema::isOpenMPPrivateDecl(const ValueDecl *D, unsigned Level) const {
  assert(LangOpts.OpenMP && "OpenMP is not allowed");
  if (isOpenMPLoopDirective(DSAStack->getCurrentDirective())) {
    if (DSAStack->getAssociatedLoops() > 0 &&
        !DSAStack->isLoopStarted()) {
      DSAStack->resetPossibleLoopCounter(D);
      DSAStack->loopStart();
      return true;
    }
    if ((DSAStack->getPossiblyLoopCunter() == D->getCanonicalDecl() ||
         DSAStack->isLoopControlVariable(D).first) &&
        !DSAStack->hasExplicitDSA(
            D, [](OpenMPClauseKind K) { return K != OMPC_private; }, Level) &&
        !isOpenMPSimdDirective(DSAStack->getCurrentDirective()))
      return true;
  }
  if (const auto *VD = dyn_cast<VarDecl>(D)) {
    if (DSAStack->isThreadPrivate(const_cast<VarDecl *>(VD)) &&
        DSAStack->isForceVarCapturing() &&
        !DSAStack->hasExplicitDSA(
            D, [](OpenMPClauseKind K) { return K == OMPC_copyin; }, Level))
      return true;
  }
  return DSAStack->hasExplicitDSA(
             D, [](OpenMPClauseKind K) { return K == OMPC_private; }, Level) ||
         (DSAStack->isClauseParsingMode() &&
          DSAStack->getClauseParsingMode() == OMPC_private) ||
         // Consider taskgroup reduction descriptor variable a private to avoid
         // possible capture in the region.
         (DSAStack->hasExplicitDirective(
              [](OpenMPDirectiveKind K) { return K == OMPD_taskgroup; },
              Level) &&
          DSAStack->isTaskgroupReductionRef(D, Level));
}

void Sema::setOpenMPCaptureKind(FieldDecl *FD, const ValueDecl *D,
                                unsigned Level) {
  assert(LangOpts.OpenMP && "OpenMP is not allowed");
  D = getCanonicalDecl(D);
  OpenMPClauseKind OMPC = OMPC_unknown;
  for (unsigned I = DSAStack->getNestingLevel() + 1; I > Level; --I) {
    const unsigned NewLevel = I - 1;
    if (DSAStack->hasExplicitDSA(D,
                                 [&OMPC](const OpenMPClauseKind K) {
                                   if (isOpenMPPrivate(K)) {
                                     OMPC = K;
                                     return true;
                                   }
                                   return false;
                                 },
                                 NewLevel))
      break;
    if (DSAStack->checkMappableExprComponentListsForDeclAtLevel(
            D, NewLevel,
            [](OMPClauseMappableExprCommon::MappableExprComponentListRef,
               OpenMPClauseKind) { return true; })) {
      OMPC = OMPC_map;
      break;
    }
    if (DSAStack->hasExplicitDirective(isOpenMPTargetExecutionDirective,
                                       NewLevel)) {
      OMPC = OMPC_map;
      if (D->getType()->isScalarType() &&
          DSAStack->getDefaultDMAAtLevel(NewLevel) !=
              DefaultMapAttributes::DMA_tofrom_scalar)
        OMPC = OMPC_firstprivate;
      break;
    }
  }
  if (OMPC != OMPC_unknown)
    FD->addAttr(OMPCaptureKindAttr::CreateImplicit(Context, OMPC));
}

bool Sema::isOpenMPTargetCapturedDecl(const ValueDecl *D,
                                      unsigned Level) const {
  assert(LangOpts.OpenMP && "OpenMP is not allowed");
  // Return true if the current level is no longer enclosed in a target region.

  const auto *VD = dyn_cast<VarDecl>(D);
  return VD && !VD->hasLocalStorage() &&
         DSAStack->hasExplicitDirective(isOpenMPTargetExecutionDirective,
                                        Level);
}

void Sema::DestroyDataSharingAttributesStack() { delete DSAStack; }

void Sema::finalizeOpenMPDelayedAnalysis() {
  assert(LangOpts.OpenMP && "Expected OpenMP compilation mode.");
  // Diagnose implicit declare target functions and their callees.
  for (const auto &CallerCallees : DeviceCallGraph) {
    Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
        OMPDeclareTargetDeclAttr::getDeviceType(
            CallerCallees.getFirst()->getMostRecentDecl());
    // Ignore host functions during device analyzis.
    if (LangOpts.OpenMPIsDevice && DevTy &&
        *DevTy == OMPDeclareTargetDeclAttr::DT_Host)
      continue;
    // Ignore nohost functions during host analyzis.
    if (!LangOpts.OpenMPIsDevice && DevTy &&
        *DevTy == OMPDeclareTargetDeclAttr::DT_NoHost)
      continue;
    for (const std::pair<CanonicalDeclPtr<FunctionDecl>, SourceLocation>
             &Callee : CallerCallees.getSecond()) {
      const FunctionDecl *FD = Callee.first->getMostRecentDecl();
      Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
          OMPDeclareTargetDeclAttr::getDeviceType(FD);
      if (LangOpts.OpenMPIsDevice && DevTy &&
          *DevTy == OMPDeclareTargetDeclAttr::DT_Host) {
        // Diagnose host function called during device codegen.
        StringRef