SemaOpenACC.h

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//===----- SemaOpenACC.h - Semantic Analysis for OpenACC 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 declares semantic analysis for OpenACC constructs and
/// clauses.
///
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_SEMA_SEMAOPENACC_H
#define LLVM_CLANG_SEMA_SEMAOPENACC_H
 
#include "clang/AST/DeclGroup.h"
#include "clang/AST/StmtOpenACC.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/OpenACCKinds.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Sema/Ownership.h"
#include "clang/Sema/SemaBase.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Compiler.h"
#include <cassert>
#include <optional>
#include <utility>
#include <variant>
 
namespace clang {
class IdentifierInfo;
class OpenACCClause;
 
class SemaOpenACC : public SemaBase {
private:
  struct ComputeConstructInfo {
    /// Which type of compute construct we are inside of, which we can use to
    /// determine whether we should add loops to the above collection.  We can
    /// also use it to diagnose loop construct clauses.
    OpenACCDirectiveKind Kind = OpenACCDirectiveKind::Invalid;
    // If we have an active compute construct, stores the list of clauses we've
    // prepared for it, so that we can diagnose limitations on child constructs.
    ArrayRef<OpenACCClause *> Clauses;
  } ActiveComputeConstructInfo;
 
  bool isInComputeConstruct() const {
    return ActiveComputeConstructInfo.Kind != OpenACCDirectiveKind::Invalid;
  }
 
  /// Certain clauses care about the same things that aren't specific to the
  /// individual clause, but can be shared by a few, so store them here. All
  /// require a 'no intervening constructs' rule, so we know they are all from
  /// the same 'place'.
  struct LoopCheckingInfo {
    /// Records whether we've seen the top level 'for'. We already diagnose
    /// later that the 'top level' is a for loop, so we use this to suppress the
    /// 'collapse inner loop not a 'for' loop' diagnostic.
    LLVM_PREFERRED_TYPE(bool)
    unsigned TopLevelLoopSeen : 1;
 
    /// Records whether this 'tier' of the loop has already seen a 'for' loop,
    /// used to diagnose if there are multiple 'for' loops at any one level.
    LLVM_PREFERRED_TYPE(bool)
    unsigned CurLevelHasLoopAlready : 1;
 
  } LoopInfo{/*TopLevelLoopSeen=*/false, /*CurLevelHasLoopAlready=*/false};
 
  /// The 'collapse' clause requires quite a bit of checking while
  /// parsing/instantiating its body, so this structure/object keeps all of the
  /// necessary information as we do checking.  This should rarely be directly
  /// modified, and typically should be controlled by the RAII objects.
  ///
  /// Collapse has an 'N' count that makes it apply to a number of loops 'below'
  /// it.
  struct CollapseCheckingInfo {
    OpenACCCollapseClause *ActiveCollapse = nullptr;
 
    /// This is a value that maintains the current value of the 'N' on the
    /// current collapse, minus the depth that has already been traversed. When
    /// there is not an active collapse, or a collapse whose depth we don't know
    /// (for example, if it is a dependent value), this should be `nullopt`,
    /// else it should be 'N' minus the current depth traversed.
    std::optional<llvm::APSInt> CurCollapseCount;
 
    /// Records whether we've hit a CurCollapseCount of '0' on the way down,
    /// which allows us to diagnose if the value of 'N' is too large for the
    /// current number of 'for' loops.
    bool CollapseDepthSatisfied = true;
 
    /// Records the kind of the directive that this clause is attached to, which
    /// allows us to use it in diagnostics.
    OpenACCDirectiveKind DirectiveKind = OpenACCDirectiveKind::Invalid;
  } CollapseInfo;
 
  /// The 'tile' clause requires a bit of additional checking as well, so like
  /// the `CollapseCheckingInfo`, ensure we maintain information here too.
  struct TileCheckingInfo {
    OpenACCTileClause *ActiveTile = nullptr;
 
    /// This is the number of expressions on a 'tile' clause.  This doesn't have
    /// to be an APSInt because it isn't the result of a constexpr, just by our
    /// own counting of elements.
    std::optional<unsigned> CurTileCount;
 
    /// Records whether we've hit a 'CurTileCount' of '0' on the wya down,
    /// which allows us to diagnose if the number of arguments is too large for
    /// the current number of 'for' loops.
    bool TileDepthSatisfied = true;
 
    /// Records the kind of the directive that this clause is attached to, which
    /// allows us to use it in diagnostics.
    OpenACCDirectiveKind DirectiveKind = OpenACCDirectiveKind::Invalid;
  } TileInfo;
 
  /// A list of the active reduction clauses, which allows us to check that all
  /// vars on nested constructs for the same reduction var have the same
  /// reduction operator. Currently this is enforced against all constructs
  /// despite the rule being in the 'loop' section. By current reading, this
  /// should apply to all anyway, but we may need to make this more like the
  /// 'loop' clause enforcement, where this is 'blocked' by a compute construct.
  llvm::SmallVector<OpenACCReductionClause *> ActiveReductionClauses;
 
  // Type to check the info about the 'for stmt'.
  struct ForStmtBeginChecker {
    SemaOpenACC &SemaRef;
    SourceLocation ForLoc;
    bool IsRangeFor = false;
    std::optional<const CXXForRangeStmt *> RangeFor = nullptr;
    const Stmt *Init = nullptr;
    bool InitChanged = false;
    std::optional<const Stmt *> Cond = nullptr;
    std::optional<const Stmt *> Inc = nullptr;
    // Prevent us from checking 2x, which can happen with collapse & tile.
    bool AlreadyChecked = false;
 
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        std::optional<const CXXForRangeStmt *> S)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsRangeFor(true), RangeFor(S) {}
 
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        const Stmt *I, bool InitChanged,
                        std::optional<const Stmt *> C,
                        std::optional<const Stmt *> Inc)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsRangeFor(false), Init(I),
          InitChanged(InitChanged), Cond(C), Inc(Inc) {}
    // Do the checking for the For/Range-For. Currently this implements the 'not
    // seq' restrictions only, and should be called either if we know we are a
    // top-level 'for' (the one associated via associated-stmt), or extended via
    // 'collapse'.
    void check();
 
    const ValueDecl *checkInit();
    void checkCond();
    void checkInc(const ValueDecl *Init);
  };
 
  /// Helper function for checking the 'for' and 'range for' stmts.
  void ForStmtBeginHelper(SourceLocation ForLoc, ForStmtBeginChecker &C);
 
public:
  ComputeConstructInfo &getActiveComputeConstructInfo() {
    return ActiveComputeConstructInfo;
  }
 
  /// If there is a current 'active' loop construct with a 'gang' clause on a
  /// 'kernel' construct, this will have the source location for it, and the
  /// 'kernel kind'. This permits us to implement the restriction of no further
  /// 'gang' clauses.
  struct LoopGangOnKernelTy {
    SourceLocation Loc;
    OpenACCDirectiveKind DirKind = OpenACCDirectiveKind::Invalid;
  } LoopGangClauseOnKernel;
 
  /// If there is a current 'active' loop construct with a 'worker' clause on it
  /// (on any sort of construct), this has the source location for it.  This
  /// permits us to implement the restriction of no further 'gang' or 'worker'
  /// clauses.
  SourceLocation LoopWorkerClauseLoc;
  /// If there is a current 'active' loop construct with a 'vector' clause on it
  /// (on any sort of construct), this has the source location for it.  This
  /// permits us to implement the restriction of no further 'gang', 'vector', or
  /// 'worker' clauses.
  SourceLocation LoopVectorClauseLoc;
  /// If there is a current 'active' loop construct that does NOT have a 'seq'
  /// clause on it, this has that source location and loop Directive 'kind'.
  /// This permits us to implement the 'loop' restrictions on the loop variable.
  /// This can be extended via 'collapse', so we need to keep this around for a
  /// while.
  struct LoopWithoutSeqCheckingInfo {
    OpenACCDirectiveKind Kind = OpenACCDirectiveKind::Invalid;
    SourceLocation Loc;
  } LoopWithoutSeqInfo;
 
  // Redeclaration of the version in OpenACCClause.h.
  using DeviceTypeArgument = std::pair<IdentifierInfo *, SourceLocation>;
 
  /// A type to represent all the data for an OpenACC Clause that has been
  /// parsed, but not yet created/semantically analyzed. This is effectively a
  /// discriminated union on the 'Clause Kind', with all of the individual
  /// clause details stored in a std::variant.
  class OpenACCParsedClause {
    OpenACCDirectiveKind DirKind;
    OpenACCClauseKind ClauseKind;
    SourceRange ClauseRange;
    SourceLocation LParenLoc;
 
    struct DefaultDetails {
      OpenACCDefaultClauseKind DefaultClauseKind;
    };
 
    struct ConditionDetails {
      Expr *ConditionExpr;
    };
 
    struct IntExprDetails {
      SmallVector<Expr *> IntExprs;
    };
 
    struct VarListDetails {
      SmallVector<Expr *> VarList;
      bool IsReadOnly;
      bool IsZero;
    };
 
    struct WaitDetails {
      Expr *DevNumExpr;
      SourceLocation QueuesLoc;
      SmallVector<Expr *> QueueIdExprs;
    };
 
    struct DeviceTypeDetails {
      SmallVector<DeviceTypeArgument> Archs;
    };
    struct ReductionDetails {
      OpenACCReductionOperator Op;
      SmallVector<Expr *> VarList;
    };
 
    struct CollapseDetails {
      bool IsForce;
      Expr *LoopCount;
    };
 
    struct GangDetails {
      SmallVector<OpenACCGangKind> GangKinds;
      SmallVector<Expr *> IntExprs;
    };
 
    std::variant<std::monostate, DefaultDetails, ConditionDetails,
                 IntExprDetails, VarListDetails, WaitDetails, DeviceTypeDetails,
                 ReductionDetails, CollapseDetails, GangDetails>
        Details = std::monostate{};
 
  public:
    OpenACCParsedClause(OpenACCDirectiveKind DirKind,
                        OpenACCClauseKind ClauseKind, SourceLocation BeginLoc)
        : DirKind(DirKind), ClauseKind(ClauseKind), ClauseRange(BeginLoc, {}) {}
 
    OpenACCDirectiveKind getDirectiveKind() const { return DirKind; }
 
    OpenACCClauseKind getClauseKind() const { return ClauseKind; }
 
    SourceLocation getBeginLoc() const { return ClauseRange.getBegin(); }
 
    SourceLocation getLParenLoc() const { return LParenLoc; }
 
    SourceLocation getEndLoc() const { return ClauseRange.getEnd(); }
 
    OpenACCDefaultClauseKind getDefaultClauseKind() const {
      assert(ClauseKind == OpenACCClauseKind::Default &&
             "Parsed clause is not a default clause");
      return std::get<DefaultDetails>(Details).DefaultClauseKind;
    }
 
    const Expr *getConditionExpr() const {
      return const_cast<OpenACCParsedClause *>(this)->getConditionExpr();
    }
 
    Expr *getConditionExpr() {
      assert((ClauseKind == OpenACCClauseKind::If ||
              (ClauseKind == OpenACCClauseKind::Self &&
               DirKind != OpenACCDirectiveKind::Update)) &&
             "Parsed clause kind does not have a condition expr");
 
      // 'self' has an optional ConditionExpr, so be tolerant of that. This will
      // assert in variant otherwise.
      if (ClauseKind == OpenACCClauseKind::Self &&
          std::holds_alternative<std::monostate>(Details))
        return nullptr;
 
      return std::get<ConditionDetails>(Details).ConditionExpr;
    }
 
    unsigned getNumIntExprs() const {
      assert((ClauseKind == OpenACCClauseKind::NumGangs ||
              ClauseKind == OpenACCClauseKind::NumWorkers ||
              ClauseKind == OpenACCClauseKind::Async ||
              ClauseKind == OpenACCClauseKind::DeviceNum ||
              ClauseKind == OpenACCClauseKind::Tile ||
              ClauseKind == OpenACCClauseKind::Worker ||
              ClauseKind == OpenACCClauseKind::Vector ||
              ClauseKind == OpenACCClauseKind::VectorLength) &&
             "Parsed clause kind does not have a int exprs");
 
      // 'async', 'worker', 'vector', and 'wait' have an optional IntExpr, so be
      // tolerant of that.
      if ((ClauseKind == OpenACCClauseKind::Async ||
           ClauseKind == OpenACCClauseKind::Worker ||
           ClauseKind == OpenACCClauseKind::Vector ||
           ClauseKind == OpenACCClauseKind::Wait) &&
          std::holds_alternative<std::monostate>(Details))
        return 0;
      return std::get<IntExprDetails>(Details).IntExprs.size();
    }
 
    SourceLocation getQueuesLoc() const {
      assert(ClauseKind == OpenACCClauseKind::Wait &&
             "Parsed clause kind does not have a queues location");
 
      if (std::holds_alternative<std::monostate>(Details))
        return SourceLocation{};
 
      return std::get<WaitDetails>(Details).QueuesLoc;
    }
 
    Expr *getDevNumExpr() const {
      assert(ClauseKind == OpenACCClauseKind::Wait &&
             "Parsed clause kind does not have a device number expr");
 
      if (std::holds_alternative<std::monostate>(Details))
        return nullptr;
 
      return std::get<WaitDetails>(Details).DevNumExpr;
    }
 
    ArrayRef<Expr *> getQueueIdExprs() const {
      assert(ClauseKind == OpenACCClauseKind::Wait &&
             "Parsed clause kind does not have a queue id expr list");
 
      if (std::holds_alternative<std::monostate>(Details))
        return ArrayRef<Expr *>();
 
      return std::get<WaitDetails>(Details).QueueIdExprs;
    }
 
    ArrayRef<Expr *> getIntExprs() {
      assert((ClauseKind == OpenACCClauseKind::NumGangs ||
              ClauseKind == OpenACCClauseKind::NumWorkers ||
              ClauseKind == OpenACCClauseKind::Async ||
              ClauseKind == OpenACCClauseKind::DeviceNum ||
              ClauseKind == OpenACCClauseKind::Tile ||
              ClauseKind == OpenACCClauseKind::Gang ||
              ClauseKind == OpenACCClauseKind::Worker ||
              ClauseKind == OpenACCClauseKind::Vector ||
              ClauseKind == OpenACCClauseKind::VectorLength) &&
             "Parsed clause kind does not have a int exprs");
 
      if (ClauseKind == OpenACCClauseKind::Gang) {
        // There might not be any gang int exprs, as this is an optional
        // argument.
        if (std::holds_alternative<std::monostate>(Details))
          return {};
        return std::get<GangDetails>(Details).IntExprs;
      }
 
      return std::get<IntExprDetails>(Details).IntExprs;
    }
 
    ArrayRef<Expr *> getIntExprs() const {
      return const_cast<OpenACCParsedClause *>(this)->getIntExprs();
    }
 
    OpenACCReductionOperator getReductionOp() const {
      return std::get<ReductionDetails>(Details).Op;
    }
 
    ArrayRef<OpenACCGangKind> getGangKinds() const {
      assert(ClauseKind == OpenACCClauseKind::Gang &&
             "Parsed clause kind does not have gang kind");
      // The args on gang are optional, so this might not actually hold
      // anything.
      if (std::holds_alternative<std::monostate>(Details))
        return {};
      return std::get<GangDetails>(Details).GangKinds;
    }
 
    ArrayRef<Expr *> getVarList() {
      assert((ClauseKind == OpenACCClauseKind::Private ||
              ClauseKind == OpenACCClauseKind::NoCreate ||
              ClauseKind == OpenACCClauseKind::Present ||
              ClauseKind == OpenACCClauseKind::Copy ||
              ClauseKind == OpenACCClauseKind::PCopy ||
              ClauseKind == OpenACCClauseKind::PresentOrCopy ||
              ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn ||
              ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate ||
              ClauseKind == OpenACCClauseKind::Attach ||
              ClauseKind == OpenACCClauseKind::Delete ||
              ClauseKind == OpenACCClauseKind::UseDevice ||
              ClauseKind == OpenACCClauseKind::Detach ||
              ClauseKind == OpenACCClauseKind::DevicePtr ||
              ClauseKind == OpenACCClauseKind::Reduction ||
              ClauseKind == OpenACCClauseKind::FirstPrivate) &&
             "Parsed clause kind does not have a var-list");
 
      if (ClauseKind == OpenACCClauseKind::Reduction)
        return std::get<ReductionDetails>(Details).VarList;
 
      return std::get<VarListDetails>(Details).VarList;
    }
 
    ArrayRef<Expr *> getVarList() const {
      return const_cast<OpenACCParsedClause *>(this)->getVarList();
    }
 
    bool isReadOnly() const {
      assert((ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn) &&
             "Only copyin accepts 'readonly:' tag");
      return std::get<VarListDetails>(Details).IsReadOnly;
    }
 
    bool isZero() const {
      assert((ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate) &&
             "Only copyout/create accepts 'zero' tag");
      return std::get<VarListDetails>(Details).IsZero;
    }
 
    bool isForce() const {
      assert(ClauseKind == OpenACCClauseKind::Collapse &&
             "Only 'collapse' has a force tag");
      return std::get<CollapseDetails>(Details).IsForce;
    }
 
    Expr *getLoopCount() const {
      assert(ClauseKind == OpenACCClauseKind::Collapse &&
             "Only 'collapse' has a loop count");
      return std::get<CollapseDetails>(Details).LoopCount;
    }
 
    ArrayRef<DeviceTypeArgument> getDeviceTypeArchitectures() const {
      assert((ClauseKind == OpenACCClauseKind::DeviceType ||
              ClauseKind == OpenACCClauseKind::DType) &&
             "Only 'device_type'/'dtype' has a device-type-arg list");
      return std::get<DeviceTypeDetails>(Details).Archs;
    }
 
    void setLParenLoc(SourceLocation EndLoc) { LParenLoc = EndLoc; }
    void setEndLoc(SourceLocation EndLoc) { ClauseRange.setEnd(EndLoc); }
 
    void setDefaultDetails(OpenACCDefaultClauseKind DefKind) {
      assert(ClauseKind == OpenACCClauseKind::Default &&
             "Parsed clause is not a default clause");
      Details = DefaultDetails{DefKind};
    }
 
    void setConditionDetails(Expr *ConditionExpr) {
      assert((ClauseKind == OpenACCClauseKind::If ||
              (ClauseKind == OpenACCClauseKind::Self &&
               DirKind != OpenACCDirectiveKind::Update)) &&
             "Parsed clause kind does not have a condition expr");
      // In C++ we can count on this being a 'bool', but in C this gets left as
      // some sort of scalar that codegen will have to take care of converting.
      assert((!ConditionExpr || ConditionExpr->isInstantiationDependent() ||
              ConditionExpr->getType()->isScalarType()) &&
             "Condition expression type not scalar/dependent");
 
      Details = ConditionDetails{ConditionExpr};
    }
 
    void setIntExprDetails(ArrayRef<Expr *> IntExprs) {
      assert((ClauseKind == OpenACCClauseKind::NumGangs ||
              ClauseKind == OpenACCClauseKind::NumWorkers ||
              ClauseKind == OpenACCClauseKind::Async ||
              ClauseKind == OpenACCClauseKind::DeviceNum ||
              ClauseKind == OpenACCClauseKind::Tile ||
              ClauseKind == OpenACCClauseKind::Worker ||
              ClauseKind == OpenACCClauseKind::Vector ||
              ClauseKind == OpenACCClauseKind::VectorLength) &&
             "Parsed clause kind does not have a int exprs");
      Details = IntExprDetails{{IntExprs.begin(), IntExprs.end()}};
    }
    void setIntExprDetails(llvm::SmallVector<Expr *> &&IntExprs) {
      assert((ClauseKind == OpenACCClauseKind::NumGangs ||
              ClauseKind == OpenACCClauseKind::NumWorkers ||
              ClauseKind == OpenACCClauseKind::Async ||
              ClauseKind == OpenACCClauseKind::DeviceNum ||
              ClauseKind == OpenACCClauseKind::Tile ||
              ClauseKind == OpenACCClauseKind::Worker ||
              ClauseKind == OpenACCClauseKind::Vector ||
              ClauseKind == OpenACCClauseKind::VectorLength) &&
             "Parsed clause kind does not have a int exprs");
      Details = IntExprDetails{std::move(IntExprs)};
    }
 
    void setGangDetails(ArrayRef<OpenACCGangKind> GKs,
                        ArrayRef<Expr *> IntExprs) {
      assert(ClauseKind == OpenACCClauseKind::Gang &&
             "Parsed Clause kind does not have gang details");
      assert(GKs.size() == IntExprs.size() && "Mismatched kind/size?");
 
      Details = GangDetails{{GKs.begin(), GKs.end()},
                            {IntExprs.begin(), IntExprs.end()}};
    }
 
    void setGangDetails(llvm::SmallVector<OpenACCGangKind> &&GKs,
                        llvm::SmallVector<Expr *> &&IntExprs) {
      assert(ClauseKind == OpenACCClauseKind::Gang &&
             "Parsed Clause kind does not have gang details");
      assert(GKs.size() == IntExprs.size() && "Mismatched kind/size?");
 
      Details = GangDetails{std::move(GKs), std::move(IntExprs)};
    }
 
    void setVarListDetails(ArrayRef<Expr *> VarList, bool IsReadOnly,
                           bool IsZero) {
      assert((ClauseKind == OpenACCClauseKind::Private ||
              ClauseKind == OpenACCClauseKind::NoCreate ||
              ClauseKind == OpenACCClauseKind::Present ||
              ClauseKind == OpenACCClauseKind::Copy ||
              ClauseKind == OpenACCClauseKind::PCopy ||
              ClauseKind == OpenACCClauseKind::PresentOrCopy ||
              ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn ||
              ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate ||
              ClauseKind == OpenACCClauseKind::Attach ||
              ClauseKind == OpenACCClauseKind::Delete ||
              ClauseKind == OpenACCClauseKind::UseDevice ||
              ClauseKind == OpenACCClauseKind::Detach ||
              ClauseKind == OpenACCClauseKind::DevicePtr ||
              ClauseKind == OpenACCClauseKind::FirstPrivate) &&
             "Parsed clause kind does not have a var-list");
      assert((!IsReadOnly || ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn) &&
             "readonly: tag only valid on copyin");
      assert((!IsZero || ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate) &&
             "zero: tag only valid on copyout/create");
      Details =
          VarListDetails{{VarList.begin(), VarList.end()}, IsReadOnly, IsZero};
    }
 
    void setVarListDetails(llvm::SmallVector<Expr *> &&VarList, bool IsReadOnly,
                           bool IsZero) {
      assert((ClauseKind == OpenACCClauseKind::Private ||
              ClauseKind == OpenACCClauseKind::NoCreate ||
              ClauseKind == OpenACCClauseKind::Present ||
              ClauseKind == OpenACCClauseKind::Copy ||
              ClauseKind == OpenACCClauseKind::PCopy ||
              ClauseKind == OpenACCClauseKind::PresentOrCopy ||
              ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn ||
              ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate ||
              ClauseKind == OpenACCClauseKind::Attach ||
              ClauseKind == OpenACCClauseKind::Delete ||
              ClauseKind == OpenACCClauseKind::UseDevice ||
              ClauseKind == OpenACCClauseKind::Detach ||
              ClauseKind == OpenACCClauseKind::DevicePtr ||
              ClauseKind == OpenACCClauseKind::FirstPrivate) &&
             "Parsed clause kind does not have a var-list");
      assert((!IsReadOnly || ClauseKind == OpenACCClauseKind::CopyIn ||
              ClauseKind == OpenACCClauseKind::PCopyIn ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyIn) &&
             "readonly: tag only valid on copyin");
      assert((!IsZero || ClauseKind == OpenACCClauseKind::CopyOut ||
              ClauseKind == OpenACCClauseKind::PCopyOut ||
              ClauseKind == OpenACCClauseKind::PresentOrCopyOut ||
              ClauseKind == OpenACCClauseKind::Create ||
              ClauseKind == OpenACCClauseKind::PCreate ||
              ClauseKind == OpenACCClauseKind::PresentOrCreate) &&
             "zero: tag only valid on copyout/create");
      Details = VarListDetails{std::move(VarList), IsReadOnly, IsZero};
    }
 
    void setReductionDetails(OpenACCReductionOperator Op,
                             llvm::SmallVector<Expr *> &&VarList) {
      assert(ClauseKind == OpenACCClauseKind::Reduction &&
             "reduction details only valid on reduction");
      Details = ReductionDetails{Op, std::move(VarList)};
    }
 
    void setWaitDetails(Expr *DevNum, SourceLocation QueuesLoc,
                        llvm::SmallVector<Expr *> &&IntExprs) {
      assert(ClauseKind == OpenACCClauseKind::Wait &&
             "Parsed clause kind does not have a wait-details");
      Details = WaitDetails{DevNum, QueuesLoc, std::move(IntExprs)};
    }
 
    void setDeviceTypeDetails(llvm::SmallVector<DeviceTypeArgument> &&Archs) {
      assert((ClauseKind == OpenACCClauseKind::DeviceType ||
              ClauseKind == OpenACCClauseKind::DType) &&
             "Only 'device_type'/'dtype' has a device-type-arg list");
      Details = DeviceTypeDetails{std::move(Archs)};
    }
 
    void setCollapseDetails(bool IsForce, Expr *LoopCount) {
      assert(ClauseKind == OpenACCClauseKind::Collapse &&
             "Only 'collapse' has collapse details");
      Details = CollapseDetails{IsForce, LoopCount};
    }
  };
 
  SemaOpenACC(Sema &S);
 
  // Called when we encounter a 'while' statement, before looking at its 'body'.
  void ActOnWhileStmt(SourceLocation WhileLoc);
  // Called when we encounter a 'do' statement, before looking at its 'body'.
  void ActOnDoStmt(SourceLocation DoLoc);
  // Called when we encounter a 'for' statement, before looking at its 'body',
  // for the 'range-for'. 'ActOnForStmtEnd' is used after the body.
  void ActOnRangeForStmtBegin(SourceLocation ForLoc, const Stmt *OldRangeFor,
                              const Stmt *RangeFor);
  void ActOnRangeForStmtBegin(SourceLocation ForLoc, const Stmt *RangeFor);
  // Called when we encounter a 'for' statement, before looking at its 'body'.
  // 'ActOnForStmtEnd' is used after the body.
  void ActOnForStmtBegin(SourceLocation ForLoc, const Stmt *First,
                         const Stmt *Second, const Stmt *Third);
  void ActOnForStmtBegin(SourceLocation ForLoc, const Stmt *OldFirst,
                         const Stmt *First, const Stmt *OldSecond,
                         const Stmt *Second, const Stmt *OldThird,
                         const Stmt *Third);
  // Called when we encounter a 'for' statement, after we've consumed/checked
  // the body. This is necessary for a number of checks on the contents of the
  // 'for' statement.
  void ActOnForStmtEnd(SourceLocation ForLoc, StmtResult Body);
 
  /// Called after parsing an OpenACC Clause so that it can be checked.
  OpenACCClause *ActOnClause(ArrayRef<const OpenACCClause *> ExistingClauses,
                             OpenACCParsedClause &Clause);
 
  /// Called after the construct has been parsed, but clauses haven't been
  /// parsed.  This allows us to diagnose not-implemented, as well as set up any
  /// state required for parsing the clauses.
  void ActOnConstruct(OpenACCDirectiveKind K, SourceLocation DirLoc);
 
  /// Called after the directive, including its clauses, have been parsed and
  /// parsing has consumed the 'annot_pragma_openacc_end' token. This DOES
  /// happen before any associated declarations or statements have been parsed.
  /// This function is only called when we are parsing a 'statement' context.
  bool ActOnStartStmtDirective(OpenACCDirectiveKind K, SourceLocation StartLoc,
                               ArrayRef<const OpenACCClause *> Clauses);
 
  /// Called after the directive, including its clauses, have been parsed and
  /// parsing has consumed the 'annot_pragma_openacc_end' token. This DOES
  /// happen before any associated declarations or statements have been parsed.
  /// This function is only called when we are parsing a 'Decl' context.
  bool ActOnStartDeclDirective(OpenACCDirectiveKind K, SourceLocation StartLoc);
  /// Called when we encounter an associated statement for our construct, this
  /// should check legality of the statement as it appertains to this Construct.
  StmtResult ActOnAssociatedStmt(SourceLocation DirectiveLoc,
                                 OpenACCDirectiveKind K,
                                 ArrayRef<const OpenACCClause *> Clauses,
                                 StmtResult AssocStmt);
 
  /// Called after the directive has been completely parsed, including the
  /// declaration group or associated statement.
  /// LParenLoc: Location of the left paren, if it exists (not on all
  /// constructs).
  /// MiscLoc: First misc location, if necessary (not all constructs).
  /// Exprs: List of expressions on the construct itself, if necessary (not all
  /// constructs).
  /// RParenLoc: Location of the right paren, if it exists (not on all
  /// constructs).
  StmtResult ActOnEndStmtDirective(
      OpenACCDirectiveKind K, SourceLocation StartLoc, SourceLocation DirLoc,
      SourceLocation LParenLoc, SourceLocation MiscLoc, ArrayRef<Expr *> Exprs,
      SourceLocation RParenLoc, SourceLocation EndLoc,
      ArrayRef<OpenACCClause *> Clauses, StmtResult AssocStmt);
 
  /// Called after the directive has been completely parsed, including the
  /// declaration group or associated statement.
  DeclGroupRef ActOnEndDeclDirective();
 
  /// Called when encountering an 'int-expr' for OpenACC, and manages
  /// conversions and diagnostics to 'int'.
  ExprResult ActOnIntExpr(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                          SourceLocation Loc, Expr *IntExpr);
 
  /// Called when encountering a 'var' for OpenACC, ensures it is actually a
  /// declaration reference to a variable of the correct type.
  ExprResult ActOnVar(OpenACCClauseKind CK, Expr *VarExpr);
 
  /// Called while semantically analyzing the reduction clause, ensuring the var
  /// is the correct kind of reference.
  ExprResult CheckReductionVar(OpenACCDirectiveKind DirectiveKind,
                               OpenACCReductionOperator ReductionOp,
                               Expr *VarExpr);
 
  /// Called to check the 'var' type is a variable of pointer type, necessary
  /// for 'deviceptr' and 'attach' clauses. Returns true on success.
  bool CheckVarIsPointerType(OpenACCClauseKind ClauseKind, Expr *VarExpr);
 
  /// Checks and creates an Array Section used in an OpenACC construct/clause.
  ExprResult ActOnArraySectionExpr(Expr *Base, SourceLocation LBLoc,
                                   Expr *LowerBound,
                                   SourceLocation ColonLocFirst, Expr *Length,
                                   SourceLocation RBLoc);
  /// Checks the loop depth value for a collapse clause.
  ExprResult CheckCollapseLoopCount(Expr *LoopCount);
  /// Checks a single size expr for a tile clause.
  ExprResult CheckTileSizeExpr(Expr *SizeExpr);
 
  // Check a single expression on a gang clause.
  ExprResult CheckGangExpr(ArrayRef<const OpenACCClause *> ExistingClauses,
                           OpenACCDirectiveKind DK, OpenACCGangKind GK,
                           Expr *E);
 
  // Does the checking for a 'gang' clause that needs to be done in dependent
  // and not dependent cases.
  OpenACCClause *
  CheckGangClause(OpenACCDirectiveKind DirKind,
                  ArrayRef<const OpenACCClause *> ExistingClauses,
                  SourceLocation BeginLoc, SourceLocation LParenLoc,
                  ArrayRef<OpenACCGangKind> GangKinds,
                  ArrayRef<Expr *> IntExprs, SourceLocation EndLoc);
  // Does the checking for a 'reduction ' clause that needs to be done in
  // dependent and not dependent cases.
  OpenACCClause *
  CheckReductionClause(ArrayRef<const OpenACCClause *> ExistingClauses,
                       OpenACCDirectiveKind DirectiveKind,
                       SourceLocation BeginLoc, SourceLocation LParenLoc,
                       OpenACCReductionOperator ReductionOp,
                       ArrayRef<Expr *> Vars, SourceLocation EndLoc);
 
  ExprResult BuildOpenACCAsteriskSizeExpr(SourceLocation AsteriskLoc);
  ExprResult ActOnOpenACCAsteriskSizeExpr(SourceLocation AsteriskLoc);
 
  /// Helper type to restore the state of various 'loop' constructs when we run
  /// into a loop (for, etc) inside the construct.
  class LoopInConstructRAII {
    SemaOpenACC &SemaRef;
    LoopCheckingInfo OldLoopInfo;
    CollapseCheckingInfo OldCollapseInfo;
    TileCheckingInfo OldTileInfo;
    bool PreserveDepth;
 
  public:
    LoopInConstructRAII(SemaOpenACC &SemaRef, bool PreserveDepth = true)
        : SemaRef(SemaRef), OldLoopInfo(SemaRef.LoopInfo),
          OldCollapseInfo(SemaRef.CollapseInfo), OldTileInfo(SemaRef.TileInfo),
          PreserveDepth(PreserveDepth) {}
    ~LoopInConstructRAII() {
      // The associated-statement level of this should NOT preserve this, as it
      // is a new construct, but other loop uses need to preserve the depth so
      // it makes it to the 'top level' for diagnostics.
      bool CollapseDepthSatisified =
          PreserveDepth ? SemaRef.CollapseInfo.CollapseDepthSatisfied
                        : OldCollapseInfo.CollapseDepthSatisfied;
      bool TileDepthSatisfied = PreserveDepth
                                    ? SemaRef.TileInfo.TileDepthSatisfied
                                    : OldTileInfo.TileDepthSatisfied;
      bool CurLevelHasLoopAlready =
          PreserveDepth ? SemaRef.LoopInfo.CurLevelHasLoopAlready
                        : OldLoopInfo.CurLevelHasLoopAlready;
 
      SemaRef.LoopInfo = OldLoopInfo;
      SemaRef.CollapseInfo = OldCollapseInfo;
      SemaRef.TileInfo = OldTileInfo;
 
      SemaRef.CollapseInfo.CollapseDepthSatisfied = CollapseDepthSatisified;
      SemaRef.TileInfo.TileDepthSatisfied = TileDepthSatisfied;
      SemaRef.LoopInfo.CurLevelHasLoopAlready = CurLevelHasLoopAlready;
    }
  };
 
  /// Helper type for the registration/assignment of constructs that need to
  /// 'know' about their parent constructs and hold a reference to them, such as
  /// Loop needing its parent construct.
  class AssociatedStmtRAII {
    SemaOpenACC &SemaRef;
    ComputeConstructInfo OldActiveComputeConstructInfo;
    OpenACCDirectiveKind DirKind;
    LoopGangOnKernelTy OldLoopGangClauseOnKernel;
    SourceLocation OldLoopWorkerClauseLoc;
    SourceLocation OldLoopVectorClauseLoc;
    LoopWithoutSeqCheckingInfo OldLoopWithoutSeqInfo;
    llvm::SmallVector<OpenACCReductionClause *> ActiveReductionClauses;
    LoopInConstructRAII LoopRAII;
 
  public:
    AssociatedStmtRAII(SemaOpenACC &, OpenACCDirectiveKind, SourceLocation,
                       ArrayRef<const OpenACCClause *>,
                       ArrayRef<OpenACCClause *>);
    void SetCollapseInfoBeforeAssociatedStmt(
        ArrayRef<const OpenACCClause *> UnInstClauses,
        ArrayRef<OpenACCClause *> Clauses);
    void SetTileInfoBeforeAssociatedStmt(
        ArrayRef<const OpenACCClause *> UnInstClauses,
        ArrayRef<OpenACCClause *> Clauses);
    ~AssociatedStmtRAII();
  };
};
 
} // namespace clang
 
#endif // LLVM_CLANG_SEMA_SEMAOPENACC_H