//===----- 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 Scope;

class SemaOpenACC : public SemaBase {
public:
  using DeclGroupPtrTy = OpaquePtr<DeclGroupRef>;

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 {
    const 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.
    UnsignedOrNone CurTileCount = std::nullopt;

    /// Records whether we've hit a 'CurTileCount' of '0' on the way 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;

  /// The 'cache' var-list requires some additional work to track variable
  /// references to make sure they are on the 'other' side of a `loop`. This
  /// structure is used during parse time to track vardecl use while parsing a
  /// cache var list.
  struct CacheParseInfo {
    bool ParsingCacheVarList = false;
    bool IsInvalidCacheRef = false;
  } CacheInfo;

  /// 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 'for' (or range-for) statement for compatibility with the
  // 'loop' directive.
  class ForStmtBeginChecker {
    SemaOpenACC &SemaRef;
    SourceLocation ForLoc;
    bool IsInstantiation = false;

    struct RangeForInfo {
      const CXXForRangeStmt *Uninstantiated = nullptr;
      const CXXForRangeStmt *CurrentVersion = nullptr;
      // GCC 7.x requires this constructor, else the construction of variant
      // doesn't work correctly.
      RangeForInfo() : Uninstantiated{nullptr}, CurrentVersion{nullptr} {}
      RangeForInfo(const CXXForRangeStmt *Uninst, const CXXForRangeStmt *Cur)
          : Uninstantiated{Uninst}, CurrentVersion{Cur} {}
    };

    struct ForInfo {
      const Stmt *Init = nullptr;
      const Stmt *Condition = nullptr;
      const Stmt *Increment = nullptr;
    };

    struct CheckForInfo {
      ForInfo Uninst;
      ForInfo Current;
    };

    std::variant<RangeForInfo, CheckForInfo> Info;
    // Prevent us from checking 2x, which can happen with collapse & tile.
    bool AlreadyChecked = false;

    void checkRangeFor();

    bool checkForInit(const Stmt *InitStmt, const ValueDecl *&InitVar,
                      bool Diag);
    bool checkForCond(const Stmt *CondStmt, const ValueDecl *InitVar,
                      bool Diag);
    bool checkForInc(const Stmt *IncStmt, const ValueDecl *InitVar, bool Diag);

    void checkFor();

    //  void checkRangeFor(); ?? ERICH
    //  const ValueDecl *checkInit();
    //  void checkCond(const ValueDecl *Init);
    //  void checkInc(const ValueDecl *Init);
  public:
    // Checking for non-instantiation version of a Range-for.
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        const CXXForRangeStmt *RangeFor)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsInstantiation(false),
          Info(RangeForInfo{nullptr, RangeFor}) {}
    // Checking for an instantiation of the range-for.
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        const CXXForRangeStmt *OldRangeFor,
                        const CXXForRangeStmt *RangeFor)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsInstantiation(true),
          Info(RangeForInfo{OldRangeFor, RangeFor}) {}
    // Checking for a non-instantiation version of a traditional for.
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        const Stmt *Init, const Stmt *Cond, const Stmt *Inc)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsInstantiation(false),
          Info(CheckForInfo{{}, {Init, Cond, Inc}}) {}
    // Checking for an instantiation version of a traditional for.
    ForStmtBeginChecker(SemaOpenACC &SemaRef, SourceLocation ForLoc,
                        const Stmt *OldInit, const Stmt *OldCond,
                        const Stmt *OldInc, const Stmt *Init, const Stmt *Cond,
                        const Stmt *Inc)
        : SemaRef(SemaRef), ForLoc(ForLoc), IsInstantiation(true),
          Info(CheckForInfo{{OldInit, OldCond, OldInc}, {Init, Cond, Inc}}) {}

    void check();
  };

  /// Helper function for checking the 'for' and 'range for' stmts.
  void ForStmtBeginHelper(SourceLocation ForLoc, ForStmtBeginChecker &C);

  // The 'declare' construct requires only a single reference among ALL declare
  // directives in a context. We store existing references to check. Because the
  // rules prevent referencing the same variable from multiple declaration
  // contexts, we can just store the declaration and location of the reference.
  llvm::DenseMap<const clang::DeclaratorDecl *, SourceLocation>
      DeclareVarReferences;
  // The 'routine' construct disallows magic-statics in a function referred to
  // by a 'routine' directive.  So record any of these that we see so we can
  // check them later.
  llvm::SmallDenseMap<const clang::FunctionDecl *, SourceLocation>
      MagicStaticLocs;
  OpenACCRoutineDecl *LastRoutineDecl = nullptr;

  void CheckLastRoutineDeclNameConflict(const NamedDecl *ND);

  bool DiagnoseRequiredClauses(OpenACCDirectiveKind DK, SourceLocation DirLoc,
                               ArrayRef<const OpenACCClause *> Clauses);

  bool DiagnoseAllowedClauses(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                              SourceLocation ClauseLoc);

public:
  // Needed from the visitor, so should be public.
  bool DiagnoseAllowedOnceClauses(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                                  SourceLocation ClauseLoc,
                                  ArrayRef<const OpenACCClause *> Clauses);
  bool DiagnoseExclusiveClauses(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                                SourceLocation ClauseLoc,
                                ArrayRef<const OpenACCClause *> Clauses);

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 = IdentifierLoc;

  /// 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;
      OpenACCModifierKind ModifierKind;
    };

    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;
    };
    struct BindDetails {
      std::variant<std::monostate, clang::StringLiteral *, IdentifierInfo *>
          Argument;
    };

    std::variant<std::monostate, DefaultDetails, ConditionDetails,
                 IntExprDetails, VarListDetails, WaitDetails, DeviceTypeDetails,
                 ReductionDetails, CollapseDetails, GangDetails, BindDetails>
        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::DefaultAsync ||
              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::DefaultAsync ||
              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::Host ||
              ClauseKind == OpenACCClauseKind::Device ||
              ClauseKind == OpenACCClauseKind::DeviceResident ||
              ClauseKind == OpenACCClauseKind::Link ||
              (ClauseKind == OpenACCClauseKind::Self &&
               DirKind == OpenACCDirectiveKind::Update) ||
              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();
    }

    OpenACCModifierKind getModifierList() const {
      return std::get<VarListDetails>(Details).ModifierKind;
    }

    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;
    }

    std::variant<std::monostate, clang::StringLiteral *, IdentifierInfo *>
    getBindDetails() const {
      assert(ClauseKind == OpenACCClauseKind::Bind &&
             "Only 'bind' has bind details");
      return std::get<BindDetails>(Details).Argument;
    }

    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::DefaultAsync ||
              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::DefaultAsync ||
              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,
                           OpenACCModifierKind ModKind) {
      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::Host ||
              ClauseKind == OpenACCClauseKind::Device ||
              ClauseKind == OpenACCClauseKind::DeviceResident ||
              ClauseKind == OpenACCClauseKind::Link ||
              (ClauseKind == OpenACCClauseKind::Self &&
               DirKind == OpenACCDirectiveKind::Update) ||
              ClauseKind == OpenACCClauseKind::FirstPrivate) &&
             "Parsed clause kind does not have a var-list");
      assert((ModKind == OpenACCModifierKind::Invalid ||
              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) &&
             "Modifier Kind only valid on copy, copyin, copyout, create");
      Details = VarListDetails{{VarList.begin(), VarList.end()}, ModKind};
    }

    void setVarListDetails(llvm::SmallVector<Expr *> &&VarList,
                           OpenACCModifierKind ModKind) {
      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::Host ||
              ClauseKind == OpenACCClauseKind::Device ||
              ClauseKind == OpenACCClauseKind::DeviceResident ||
              ClauseKind == OpenACCClauseKind::Link ||
              (ClauseKind == OpenACCClauseKind::Self &&
               DirKind == OpenACCDirectiveKind::Update) ||
              ClauseKind == OpenACCClauseKind::FirstPrivate) &&
             "Parsed clause kind does not have a var-list");
      assert((ModKind == OpenACCModifierKind::Invalid ||
              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) &&
             "Modifier Kind only valid on copy, copyin, copyout, create");
      Details = VarListDetails{std::move(VarList), ModKind};
    }

    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};
    }

    void setBindDetails(
        std::variant<std::monostate, clang::StringLiteral *, IdentifierInfo *>
            Arg) {
      assert(ClauseKind == OpenACCClauseKind::Bind &&
             "Only 'bind' has bind details");
      Details = BindDetails{Arg};
    }
  };

  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,
                               ArrayRef<const OpenACCClause *> Clauses);
  /// 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,
                                 OpenACCAtomicKind AtKind,
                                 ArrayRef<const OpenACCClause *> Clauses,
                                 StmtResult AssocStmt);

  StmtResult ActOnAssociatedStmt(SourceLocation DirectiveLoc,
                                 OpenACCDirectiveKind K,
                                 ArrayRef<const OpenACCClause *> Clauses,
                                 StmtResult AssocStmt) {
    return ActOnAssociatedStmt(DirectiveLoc, K, OpenACCAtomicKind::None,
                               Clauses, AssocStmt);
  }
  /// Called to check the form of the `atomic` construct which has some fairly
  /// sizable restrictions.
  StmtResult CheckAtomicAssociatedStmt(SourceLocation AtomicDirLoc,
                                       OpenACCAtomicKind AtKind,
                                       StmtResult AssocStmt);

  /// Called after the directive has been completely parsed, including the
  /// declaration group or associated statement.
  /// DirLoc: Location of the actual directive keyword.
  /// 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).
  /// FuncRef: used only for Routine, this is the function being referenced.
  /// AK: The atomic kind of the directive, if necessary (atomic only)
  /// RParenLoc: Location of the right paren, if it exists (not on all
  /// constructs).
  /// EndLoc: The last source location of the driective.
  /// Clauses: The list of clauses for the directive, if present.
  /// AssocStmt: The associated statement for this construct, if necessary.
  StmtResult ActOnEndStmtDirective(
      OpenACCDirectiveKind K, SourceLocation StartLoc, SourceLocation DirLoc,
      SourceLocation LParenLoc, SourceLocation MiscLoc, ArrayRef<Expr *> Exprs,
      OpenACCAtomicKind AK, 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(OpenACCDirectiveKind K, SourceLocation StartLoc,
                        SourceLocation DirLoc, SourceLocation LParenLoc,
                        SourceLocation RParenLoc, SourceLocation EndLoc,
                        ArrayRef<OpenACCClause *> Clauses);

  // Helper functions for ActOnEndRoutine*Directive, which does all the checking
  // given the proper list of declarations.
  void CheckRoutineDecl(SourceLocation DirLoc,
                        ArrayRef<const OpenACCClause *> Clauses,
                        Decl *NextParsedDecl);
  OpenACCRoutineDecl *CheckRoutineDecl(SourceLocation StartLoc,
                                       SourceLocation DirLoc,
                                       SourceLocation LParenLoc, Expr *FuncRef,
                                       SourceLocation RParenLoc,
                                       ArrayRef<const OpenACCClause *> Clauses,
                                       SourceLocation EndLoc);
  OpenACCRoutineDeclAttr *
  mergeRoutineDeclAttr(const OpenACCRoutineDeclAttr &Old);
  DeclGroupRef
  ActOnEndRoutineDeclDirective(SourceLocation StartLoc, SourceLocation DirLoc,
                               SourceLocation LParenLoc, Expr *ReferencedFunc,
                               SourceLocation RParenLoc,
                               ArrayRef<const OpenACCClause *> Clauses,
                               SourceLocation EndLoc, DeclGroupPtrTy NextDecl);
  StmtResult
  ActOnEndRoutineStmtDirective(SourceLocation StartLoc, SourceLocation DirLoc,
                               SourceLocation LParenLoc, Expr *ReferencedFunc,
                               SourceLocation RParenLoc,
                               ArrayRef<const OpenACCClause *> Clauses,
                               SourceLocation EndLoc, Stmt *NextStmt);

  /// 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 right before a 'var' is parsed, so we can set the state for parsing
  /// a 'cache' var.
  void ActOnStartParseVar(OpenACCDirectiveKind DK, OpenACCClauseKind CK);
  /// Called only if the parse of a 'var' was invalid, else 'ActOnVar' should be
  /// called.
  void ActOnInvalidParseVar();
  /// Called when encountering a 'var' for OpenACC, ensures it is actually a
  /// declaration reference to a variable of the correct type.
  ExprResult ActOnVar(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                      Expr *VarExpr);
  /// Helper function called by ActonVar that is used to check a 'cache' var.
  ExprResult ActOnCacheVar(Expr *VarExpr);
  /// Function called when a variable declarator is created, which lets us
  /// implement the 'routine' 'function static variables' restriction.
  void ActOnVariableDeclarator(VarDecl *VD);
  /// Called when a function decl is created, which lets us implement the
  /// 'routine' 'doesn't match next thing' warning.
  void ActOnFunctionDeclarator(FunctionDecl *FD);
  /// Called when a variable is initialized, so we can implement the 'routine
  /// 'doesn't match the next thing' warning for lambda init.
  void ActOnVariableInit(VarDecl *VD, QualType InitType);

  // Called after 'ActOnVar' specifically for a 'link' clause, which has to do
  // some minor additional checks.
  llvm::SmallVector<Expr *> CheckLinkClauseVarList(ArrayRef<Expr *> VarExpr);

  // Checking for the arguments specific to the declare-clause that need to be
  // checked during both phases of template translation.
  bool CheckDeclareClause(SemaOpenACC::OpenACCParsedClause &Clause,
                          OpenACCModifierKind Mods);

  ExprResult ActOnRoutineName(Expr *RoutineName);

  /// 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);

  // Called when a declaration is referenced, so that we can make sure certain
  // clauses don't do the 'wrong' thing/have incorrect references.
  void CheckDeclReference(SourceLocation Loc, Expr *E, Decl *D);

  // 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