Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===--- StmtCXX.h - Classes for representing C++ statements ----*- C++ -*-===//

//

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

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

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

//

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

//

// This file defines the C++ statement AST node classes.

//

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

#ifndef LLVM_CLANG_AST_STMTCXX_H

#define LLVM_CLANG_AST_STMTCXX_H

#include "clang/AST/DeclarationName.h"

#include "clang/AST/Expr.h"

#include "clang/AST/NestedNameSpecifier.h"

#include "clang/AST/Stmt.h"

#include "llvm/Support/Compiler.h"

namespace clang {

class VarDecl;

/// CXXCatchStmt - This represents a C++ catch block.

///

class CXXCatchStmt : public Stmt {

  SourceLocation CatchLoc;

  /// The exception-declaration of the type.

  VarDecl *ExceptionDecl;

  /// The handler block.

  Stmt *HandlerBlock;

public:

  CXXCatchStmt(SourceLocation catchLoc, VarDecl *exDecl, Stmt *handlerBlock)

  : Stmt(CXXCatchStmtClass), CatchLoc(catchLoc), ExceptionDecl(exDecl),

    HandlerBlock(handlerBlock) {}

  CXXCatchStmt(EmptyShell Empty)

  : Stmt(CXXCatchStmtClass), ExceptionDecl(nullptr), HandlerBlock(nullptr) {}

  SourceLocation getBeginLoc() const LLVM_READONLY { return CatchLoc; }

  SourceLocation getEndLoc() const LLVM_READONLY {

    return HandlerBlock->getEndLoc();

  }

  SourceLocation getCatchLoc() const { return CatchLoc; }

  VarDecl *getExceptionDecl() const { return ExceptionDecl; }

  QualType getCaughtType() const;

  Stmt *getHandlerBlock() const { return HandlerBlock; }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == CXXCatchStmtClass;

  }

  child_range children() { return child_range(&HandlerBlock, &HandlerBlock+1); }

  const_child_range children() const {

    return const_child_range(&HandlerBlock, &HandlerBlock + 1);

  }

  friend class ASTStmtReader;

};

/// CXXTryStmt - A C++ try block, including all handlers.

///

class CXXTryStmt final : public Stmt,

                         private llvm::TrailingObjects<CXXTryStmt, Stmt *> {

  friend TrailingObjects;

  friend class ASTStmtReader;

  SourceLocation TryLoc;

  unsigned NumHandlers;

  size_t numTrailingObjects(OverloadToken<Stmt *>) const { return NumHandlers; }

  CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock, ArrayRef<Stmt*> handlers);

  CXXTryStmt(EmptyShell Empty, unsigned numHandlers)

    : Stmt(CXXTryStmtClass), NumHandlers(numHandlers) { }

  Stmt *const *getStmts() const { return getTrailingObjects<Stmt *>(); }

  Stmt **getStmts() { return getTrailingObjects<Stmt *>(); }

public:

  static CXXTryStmt *Create(const ASTContext &C, SourceLocation tryLoc,

                            Stmt *tryBlock, ArrayRef<Stmt*> handlers);

  static CXXTryStmt *Create(const ASTContext &C, EmptyShell Empty,

                            unsigned numHandlers);

  SourceLocation getBeginLoc() const LLVM_READONLY { return getTryLoc(); }

  SourceLocation getTryLoc() const { return TryLoc; }

  SourceLocation getEndLoc() const {

    return getStmts()[NumHandlers]->getEndLoc();

  }

  CompoundStmt *getTryBlock() {

    return cast<CompoundStmt>(getStmts()[0]);

  }

  const CompoundStmt *getTryBlock() const {

    return cast<CompoundStmt>(getStmts()[0]);

  }

  unsigned getNumHandlers() const { return NumHandlers; }

  CXXCatchStmt *getHandler(unsigned i) {

    return cast<CXXCatchStmt>(getStmts()[i + 1]);

  }

  const CXXCatchStmt *getHandler(unsigned i) const {

    return cast<CXXCatchStmt>(getStmts()[i + 1]);

  }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == CXXTryStmtClass;

  }

  child_range children() {

    return child_range(getStmts(), getStmts() + getNumHandlers() + 1);

  }

  const_child_range children() const {

    return const_child_range(getStmts(), getStmts() + getNumHandlers() + 1);

  }

};

/// CXXForRangeStmt - This represents C++0x [stmt.ranged]'s ranged for

/// statement, represented as 'for (range-declarator : range-expression)'

/// or 'for (init-statement range-declarator : range-expression)'.

///

/// This is stored in a partially-desugared form to allow full semantic

/// analysis of the constituent components. The original syntactic components

/// can be extracted using getLoopVariable and getRangeInit.

class CXXForRangeStmt : public Stmt {

  SourceLocation ForLoc;

  enum { INIT, RANGE, BEGINSTMT, ENDSTMT, COND, INC, LOOPVAR, BODY, END };

  // SubExprs[RANGE] is an expression or declstmt.

  // SubExprs[COND] and SubExprs[INC] are expressions.

  Stmt *SubExprs[END];

  SourceLocation CoawaitLoc;

  SourceLocation ColonLoc;

  SourceLocation RParenLoc;

  friend class ASTStmtReader;

public:

  CXXForRangeStmt(Stmt *InitStmt, DeclStmt *Range, DeclStmt *Begin,

                  DeclStmt *End, Expr *Cond, Expr *Inc, DeclStmt *LoopVar,

                  Stmt *Body, SourceLocation FL, SourceLocation CAL,

                  SourceLocation CL, SourceLocation RPL);

  CXXForRangeStmt(EmptyShell Empty) : Stmt(CXXForRangeStmtClass, Empty) { }

  Stmt *getInit() { return SubExprs[INIT]; }

  VarDecl *getLoopVariable();

  Expr *getRangeInit();

  const Stmt *getInit() const { return SubExprs[INIT]; }

  const VarDecl *getLoopVariable() const;

  const Expr *getRangeInit() const;

  DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }

  DeclStmt *getBeginStmt() {

    return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);

  }

  DeclStmt *getEndStmt() { return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]); }

  Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }

  Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }

  DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }

  Stmt *getBody() { return SubExprs[BODY]; }

  const DeclStmt *getRangeStmt() const {

    return cast<DeclStmt>(SubExprs[RANGE]);

  }

  const DeclStmt *getBeginStmt() const {

    return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);

  }

  const DeclStmt *getEndStmt() const {

    return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]);

  }

  const Expr *getCond() const {

    return cast_or_null<Expr>(SubExprs[COND]);

  }

  const Expr *getInc() const {

    return cast_or_null<Expr>(SubExprs[INC]);

  }

  const DeclStmt *getLoopVarStmt() const {

    return cast<DeclStmt>(SubExprs[LOOPVAR]);

  }

  const Stmt *getBody() const { return SubExprs[BODY]; }

  void setInit(Stmt *S) { SubExprs[INIT] = S; }

  void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }

  void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }

  void setBeginStmt(Stmt *S) { SubExprs[BEGINSTMT] = S; }

  void setEndStmt(Stmt *S) { SubExprs[ENDSTMT] = S; }

  void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }

  void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }

  void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }

  void setBody(Stmt *S) { SubExprs[BODY] = S; }

  SourceLocation getForLoc() const { return ForLoc; }

  SourceLocation getCoawaitLoc() const { return CoawaitLoc; }

  SourceLocation getColonLoc() const { return ColonLoc; }

  SourceLocation getRParenLoc() const { return RParenLoc; }

  SourceLocation getBeginLoc() const LLVM_READONLY { return ForLoc; }

  SourceLocation getEndLoc() const LLVM_READONLY {

    return SubExprs[BODY]->getEndLoc();

  }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == CXXForRangeStmtClass;

  }

  // Iterators

  child_range children() {

    return child_range(&SubExprs[0], &SubExprs[END]);

  }

  const_child_range children() const {

    return const_child_range(&SubExprs[0], &SubExprs[END]);

  }

};

/// Representation of a Microsoft __if_exists or __if_not_exists

/// statement with a dependent name.

///

/// The __if_exists statement can be used to include a sequence of statements

/// in the program only when a particular dependent name does not exist. For

/// example:

///

/// \code

/// template<typename T>

/// void call_foo(T &t) {

///   __if_exists (T::foo) {

///     t.foo(); // okay: only called when T::foo exists.

///   }

/// }

/// \endcode

///

/// Similarly, the __if_not_exists statement can be used to include the

/// statements when a particular name does not exist.

///

/// Note that this statement only captures __if_exists and __if_not_exists

/// statements whose name is dependent. All non-dependent cases are handled

/// directly in the parser, so that they don't introduce a new scope. Clang

/// introduces scopes in the dependent case to keep names inside the compound

/// statement from leaking out into the surround statements, which would

/// compromise the template instantiation model. This behavior differs from

/// Visual C++ (which never introduces a scope), but is a fairly reasonable

/// approximation of the VC++ behavior.

class MSDependentExistsStmt : public Stmt {

  SourceLocation KeywordLoc;

  bool IsIfExists;

  NestedNameSpecifierLoc QualifierLoc;

  DeclarationNameInfo NameInfo;

  Stmt *SubStmt;

  friend class ASTReader;

  friend class ASTStmtReader;

public:

  MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,

                        NestedNameSpecifierLoc QualifierLoc,

                        DeclarationNameInfo NameInfo,

                        CompoundStmt *SubStmt)

  : Stmt(MSDependentExistsStmtClass),

    KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),

    QualifierLoc(QualifierLoc), NameInfo(NameInfo),

    SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }

  /// Retrieve the location of the __if_exists or __if_not_exists

  /// keyword.

  SourceLocation getKeywordLoc() const { return KeywordLoc; }

  /// Determine whether this is an __if_exists statement.

  bool isIfExists() const { return IsIfExists; }

  /// Determine whether this is an __if_exists statement.

  bool isIfNotExists() const { return !IsIfExists; }

  /// Retrieve the nested-name-specifier that qualifies this name, if

  /// any.

  NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }

  /// Retrieve the name of the entity we're testing for, along with

  /// location information

  DeclarationNameInfo getNameInfo() const { return NameInfo; }

  /// Retrieve the compound statement that will be included in the

  /// program only if the existence of the symbol matches the initial keyword.

  CompoundStmt *getSubStmt() const {

    return reinterpret_cast<CompoundStmt *>(SubStmt);

  }

  SourceLocation getBeginLoc() const LLVM_READONLY { return KeywordLoc; }

  SourceLocation getEndLoc() const LLVM_READONLY {

    return SubStmt->getEndLoc();

  }

  child_range children() {

    return child_range(&SubStmt, &SubStmt+1);

  }

  const_child_range children() const {

    return const_child_range(&SubStmt, &SubStmt + 1);

  }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == MSDependentExistsStmtClass;

  }

};

/// Represents the body of a coroutine. This wraps the normal function

/// body and holds the additional semantic context required to set up and tear

/// down the coroutine frame.

class CoroutineBodyStmt final

    : public Stmt,

      private llvm::TrailingObjects<CoroutineBodyStmt, Stmt *> {

  enum SubStmt {

    Body,          ///< The body of the coroutine.

    Promise,       ///< The promise statement.

    InitSuspend,   ///< The initial suspend statement, run before the body.

    FinalSuspend,  ///< The final suspend statement, run after the body.

    OnException,   ///< Handler for exceptions thrown in the body.

    OnFallthrough, ///< Handler for control flow falling off the body.

    Allocate,      ///< Coroutine frame memory allocation.

    Deallocate,    ///< Coroutine frame memory deallocation.

    ReturnValue,   ///< Return value for thunk function: p.get_return_object().

    ReturnStmt,    ///< Return statement for the thunk function.

    ReturnStmtOnAllocFailure, ///< Return statement if allocation failed.

    FirstParamMove ///< First offset for move construction of parameter copies.

  };

  unsigned NumParams;

  friend class ASTStmtReader;

  friend class ASTReader;

  friend TrailingObjects;

  Stmt **getStoredStmts() { return getTrailingObjects<Stmt *>(); }

  Stmt *const *getStoredStmts() const { return getTrailingObjects<Stmt *>(); }

public:

  struct CtorArgs {

    Stmt *Body = nullptr;

    Stmt *Promise = nullptr;

    Expr *InitialSuspend = nullptr;

    Expr *FinalSuspend = nullptr;

    Stmt *OnException = nullptr;

    Stmt *OnFallthrough = nullptr;

    Expr *Allocate = nullptr;

    Expr *Deallocate = nullptr;

    Expr *ReturnValue = nullptr;

    Stmt *ReturnStmt = nullptr;

    Stmt *ReturnStmtOnAllocFailure = nullptr;

    ArrayRef<Stmt *> ParamMoves;

  };

private:

  CoroutineBodyStmt(CtorArgs const& Args);

public:

  static CoroutineBodyStmt *Create(const ASTContext &C, CtorArgs const &Args);

  static CoroutineBodyStmt *Create(const ASTContext &C, EmptyShell,

                                   unsigned NumParams);

  bool hasDependentPromiseType() const {

    return getPromiseDecl()->getType()->isDependentType();

  }

  /// Retrieve the body of the coroutine as written. This will be either

  /// a CompoundStmt or a TryStmt.

  Stmt *getBody() const {

    return getStoredStmts()[SubStmt::Body];

  }

  Stmt *getPromiseDeclStmt() const {

    return getStoredStmts()[SubStmt::Promise];

  }

  VarDecl *getPromiseDecl() const {

    return cast<VarDecl>(cast<DeclStmt>(getPromiseDeclStmt())->getSingleDecl());

  }

  Stmt *getInitSuspendStmt() const {

    return getStoredStmts()[SubStmt::InitSuspend];

  }

  Stmt *getFinalSuspendStmt() const {

    return getStoredStmts()[SubStmt::FinalSuspend];

  }

  Stmt *getExceptionHandler() const {

    return getStoredStmts()[SubStmt::OnException];

  }

  Stmt *getFallthroughHandler() const {

    return getStoredStmts()[SubStmt::OnFallthrough];

  }

  Expr *getAllocate() const {

    return cast_or_null<Expr>(getStoredStmts()[SubStmt::Allocate]);

  }

  Expr *getDeallocate() const {

    return cast_or_null<Expr>(getStoredStmts()[SubStmt::Deallocate]);

  }

  Expr *getReturnValueInit() const {

    return cast<Expr>(getStoredStmts()[SubStmt::ReturnValue]);

  }

  Expr *getReturnValue() const {

    assert(getReturnStmt());

    auto *RS = cast<clang::ReturnStmt>(getReturnStmt());

    return RS->getRetValue();

  }

  Stmt *getReturnStmt() const { return getStoredStmts()[SubStmt::ReturnStmt]; }

  Stmt *getReturnStmtOnAllocFailure() const {

    return getStoredStmts()[SubStmt::ReturnStmtOnAllocFailure];

  }

  ArrayRef<Stmt const *> getParamMoves() const {

    return {getStoredStmts() + SubStmt::FirstParamMove, NumParams};

  }

  SourceLocation getBeginLoc() const LLVM_READONLY {

    return getBody() ? getBody()->getBeginLoc()

                     : getPromiseDecl()->getBeginLoc();

  }

  SourceLocation getEndLoc() const LLVM_READONLY {

    return getBody() ? getBody()->getEndLoc() : getPromiseDecl()->getEndLoc();

  }

  child_range children() {

    return child_range(getStoredStmts(),

                       getStoredStmts() + SubStmt::FirstParamMove + NumParams);

  }

  const_child_range children() const {

    return const_child_range(getStoredStmts(), getStoredStmts() +

                                                   SubStmt::FirstParamMove +

                                                   NumParams);

  }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == CoroutineBodyStmtClass;

  }

};

/// Represents a 'co_return' statement in the C++ Coroutines TS.

///

/// This statament models the initialization of the coroutine promise

/// (encapsulating the eventual notional return value) from an expression

/// (or braced-init-list), followed by termination of the coroutine.

///

/// This initialization is modeled by the evaluation of the operand

/// followed by a call to one of:

///   <promise>.return_value(<operand>)

///   <promise>.return_void()

/// which we name the "promise call".

class CoreturnStmt : public Stmt {

  SourceLocation CoreturnLoc;

  enum SubStmt { Operand, PromiseCall, Count };

  Stmt *SubStmts[SubStmt::Count];

  bool IsImplicit : 1;

  friend class ASTStmtReader;

public:

  CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall,

               bool IsImplicit = false)

      : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc),

        IsImplicit(IsImplicit) {

    SubStmts[SubStmt::Operand] = Operand;

    SubStmts[SubStmt::PromiseCall] = PromiseCall;

  }

  CoreturnStmt(EmptyShell) : CoreturnStmt({}, {}, {}) {}

  SourceLocation getKeywordLoc() const { return CoreturnLoc; }

  /// Retrieve the operand of the 'co_return' statement. Will be nullptr

  /// if none was specified.

  Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }

  /// Retrieve the promise call that results from this 'co_return'

  /// statement. Will be nullptr if either the coroutine has not yet been

  /// finalized or the coroutine has no eventual return type.

  Expr *getPromiseCall() const {

    return static_cast<Expr*>(SubStmts[PromiseCall]);

  }

  bool isImplicit() const { return IsImplicit; }

  void setIsImplicit(bool value = true) { IsImplicit = value; }

  SourceLocation getBeginLoc() const LLVM_READONLY { return CoreturnLoc; }

  SourceLocation getEndLoc() const LLVM_READONLY {

    return getOperand() ? getOperand()->getEndLoc() : getBeginLoc();

  }

  child_range children() {

    return child_range(SubStmts, SubStmts + SubStmt::Count);

  }

  const_child_range children() const {

    return const_child_range(SubStmts, SubStmts + SubStmt::Count);

  }

  static bool classof(const Stmt *T) {

    return T->getStmtClass() == CoreturnStmtClass;

  }

};

}  // end namespace clang

#endif