Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===--- ASTConcept.h - Concepts Related AST Data Structures ----*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

///

/// \file

/// \brief This file provides AST data structures related to concepts.

///

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_ASTCONCEPT_H

#define LLVM_CLANG_AST_ASTCONCEPT_H

#include "clang/AST/Expr.h"

#include "clang/Basic/SourceLocation.h"

#include "llvm/ADT/PointerUnion.h"

#include "llvm/ADT/SmallVector.h"

#include <utility>

namespace clang {

class ConceptDecl;

/// The result of a constraint satisfaction check, containing the necessary

/// information to diagnose an unsatisfied constraint.

class ConstraintSatisfaction : public llvm::FoldingSetNode {

  // The template-like entity that 'owns' the constraint checked here (can be a

  // constrained entity or a concept).

  const NamedDecl *ConstraintOwner = nullptr;

  llvm::SmallVector<TemplateArgument, 4> TemplateArgs;

public:

  ConstraintSatisfaction() = default;

  ConstraintSatisfaction(const NamedDecl *ConstraintOwner,

                         ArrayRef<TemplateArgument> TemplateArgs) :

      ConstraintOwner(ConstraintOwner), TemplateArgs(TemplateArgs.begin(),

                                                     TemplateArgs.end()) { }

  using SubstitutionDiagnostic = std::pair<SourceLocation, StringRef>;

  using Detail = llvm::PointerUnion<Expr *, SubstitutionDiagnostic *>;

  bool IsSatisfied = false;

  bool ContainsErrors = false;

  /// \brief Pairs of unsatisfied atomic constraint expressions along with the

  /// substituted constraint expr, if the template arguments could be

  /// substituted into them, or a diagnostic if substitution resulted in an

  /// invalid expression.

  llvm::SmallVector<std::pair<const Expr *, Detail>, 4> Details;

  void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &C) {

    Profile(ID, C, ConstraintOwner, TemplateArgs);

  }

  static void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &C,

                      const NamedDecl *ConstraintOwner,

                      ArrayRef<TemplateArgument> TemplateArgs);

  bool HasSubstitutionFailure() {

    for (const auto &Detail : Details)

      if (Detail.second.dyn_cast<SubstitutionDiagnostic *>())

        return true;

    return false;

  }

};

/// Pairs of unsatisfied atomic constraint expressions along with the

/// substituted constraint expr, if the template arguments could be

/// substituted into them, or a diagnostic if substitution resulted in

/// an invalid expression.

using UnsatisfiedConstraintRecord =

    std::pair<const Expr *,

              llvm::PointerUnion<Expr *,

                                 std::pair<SourceLocation, StringRef> *>>;

/// \brief The result of a constraint satisfaction check, containing the

/// necessary information to diagnose an unsatisfied constraint.

///

/// This is safe to store in an AST node, as opposed to ConstraintSatisfaction.

struct ASTConstraintSatisfaction final :

    llvm::TrailingObjects<ASTConstraintSatisfaction,

                          UnsatisfiedConstraintRecord> {

  std::size_t NumRecords;

  bool IsSatisfied : 1;

  bool ContainsErrors : 1;

  const UnsatisfiedConstraintRecord *begin() const {

    return getTrailingObjects<UnsatisfiedConstraintRecord>();

  }

  const UnsatisfiedConstraintRecord *end() const {

    return getTrailingObjects<UnsatisfiedConstraintRecord>() + NumRecords;

  }

  ASTConstraintSatisfaction(const ASTContext &C,

                            const ConstraintSatisfaction &Satisfaction);

  ASTConstraintSatisfaction(const ASTContext &C,

                            const ASTConstraintSatisfaction &Satisfaction);

  static ASTConstraintSatisfaction *

  Create(const ASTContext &C, const ConstraintSatisfaction &Satisfaction);

  static ASTConstraintSatisfaction *

  Rebuild(const ASTContext &C, const ASTConstraintSatisfaction &Satisfaction);

};

/// \brief Common data class for constructs that reference concepts with

/// template arguments.

class ConceptReference {

protected:

  // \brief The optional nested name specifier used when naming the concept.

  NestedNameSpecifierLoc NestedNameSpec;

  /// \brief The location of the template keyword, if specified when naming the

  /// concept.

  SourceLocation TemplateKWLoc;

  /// \brief The concept name used.

  DeclarationNameInfo ConceptName;

  /// \brief The declaration found by name lookup when the expression was

  /// created.

  /// Can differ from NamedConcept when, for example, the concept was found

  /// through a UsingShadowDecl.

  NamedDecl *FoundDecl;

  /// \brief The concept named.

  ConceptDecl *NamedConcept;

  /// \brief The template argument list source info used to specialize the

  /// concept.

  const ASTTemplateArgumentListInfo *ArgsAsWritten;

public:

  ConceptReference(NestedNameSpecifierLoc NNS, SourceLocation TemplateKWLoc,

                   DeclarationNameInfo ConceptNameInfo, NamedDecl *FoundDecl,

                   ConceptDecl *NamedConcept,

                   const ASTTemplateArgumentListInfo *ArgsAsWritten)

      : NestedNameSpec(NNS), TemplateKWLoc(TemplateKWLoc),

        ConceptName(ConceptNameInfo), FoundDecl(FoundDecl),

        NamedConcept(NamedConcept), ArgsAsWritten(ArgsAsWritten) {}

  ConceptReference()

      : FoundDecl(nullptr), NamedConcept(nullptr), ArgsAsWritten(nullptr) {}

  const NestedNameSpecifierLoc &getNestedNameSpecifierLoc() const {

    return NestedNameSpec;

  }

  const DeclarationNameInfo &getConceptNameInfo() const { return ConceptName; }

  SourceLocation getConceptNameLoc() const {

    return getConceptNameInfo().getLoc();

  }

  SourceLocation getTemplateKWLoc() const { return TemplateKWLoc; }

  NamedDecl *getFoundDecl() const {

    return FoundDecl;

  }

  ConceptDecl *getNamedConcept() const {

    return NamedConcept;

  }

  const ASTTemplateArgumentListInfo *getTemplateArgsAsWritten() const {

    return ArgsAsWritten;

  }

  /// \brief Whether or not template arguments were explicitly specified in the

  /// concept reference (they might not be in type constraints, for example)

  bool hasExplicitTemplateArgs() const {

    return ArgsAsWritten != nullptr;

  }

};

class TypeConstraint : public ConceptReference {

  /// \brief The immediately-declared constraint expression introduced by this

  /// type-constraint.

  Expr *ImmediatelyDeclaredConstraint = nullptr;

public:

  TypeConstraint(NestedNameSpecifierLoc NNS,

                 DeclarationNameInfo ConceptNameInfo, NamedDecl *FoundDecl,

                 ConceptDecl *NamedConcept,

                 const ASTTemplateArgumentListInfo *ArgsAsWritten,

                 Expr *ImmediatelyDeclaredConstraint) :

      ConceptReference(NNS, /*TemplateKWLoc=*/SourceLocation(), ConceptNameInfo,

                       FoundDecl, NamedConcept, ArgsAsWritten),

      ImmediatelyDeclaredConstraint(ImmediatelyDeclaredConstraint) {}

  /// \brief Get the immediately-declared constraint expression introduced by

  /// this type-constraint, that is - the constraint expression that is added to

  /// the associated constraints of the enclosing declaration in practice.

  Expr *getImmediatelyDeclaredConstraint() const {

    return ImmediatelyDeclaredConstraint;

  }

  void print(llvm::raw_ostream &OS, PrintingPolicy Policy) const;

};

} // clang

#endif // LLVM_CLANG_AST_ASTCONCEPT_H