path: root/lib/Sema/SemaExprCXX.cpp

//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements semantic analysis for C++ expressions.
//
//===----------------------------------------------------------------------===//

#include "SemaInherit.h"
#include "Sema.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ASTContext.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/ADT/STLExtras.h"
using namespace clang;

/// ActOnCXXConversionFunctionExpr - Parse a C++ conversion function
/// name (e.g., operator void const *) as an expression. This is
/// very similar to ActOnIdentifierExpr, except that instead of
/// providing an identifier the parser provides the type of the
/// conversion function.
Sema::OwningExprResult
Sema::ActOnCXXConversionFunctionExpr(Scope *S, SourceLocation OperatorLoc,
                                     TypeTy *Ty, bool HasTrailingLParen,
                                     const CXXScopeSpec &SS,
                                     bool isAddressOfOperand) {
  QualType ConvType = QualType::getFromOpaquePtr(Ty);
  QualType ConvTypeCanon = Context.getCanonicalType(ConvType);
  DeclarationName ConvName 
    = Context.DeclarationNames.getCXXConversionFunctionName(ConvTypeCanon);
  return ActOnDeclarationNameExpr(S, OperatorLoc, ConvName, HasTrailingLParen,
                                  &SS, isAddressOfOperand);
}

/// ActOnCXXOperatorFunctionIdExpr - Parse a C++ overloaded operator
/// name (e.g., @c operator+ ) as an expression. This is very
/// similar to ActOnIdentifierExpr, except that instead of providing
/// an identifier the parser provides the kind of overloaded
/// operator that was parsed.
Sema::OwningExprResult
Sema::ActOnCXXOperatorFunctionIdExpr(Scope *S, SourceLocation OperatorLoc,
                                     OverloadedOperatorKind Op,
                                     bool HasTrailingLParen,
                                     const CXXScopeSpec &SS,
                                     bool isAddressOfOperand) {
  DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(Op);
  return ActOnDeclarationNameExpr(S, OperatorLoc, Name, HasTrailingLParen, &SS,
                                  isAddressOfOperand);
}

/// ActOnCXXTypeidOfType - Parse typeid( type-id ).
Action::OwningExprResult
Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
                     bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
  NamespaceDecl *StdNs = GetStdNamespace();
  if (!StdNs)
    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
  
  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
  Decl *TypeInfoDecl = LookupQualifiedName(StdNs, TypeInfoII, LookupTagName);
  RecordDecl *TypeInfoRecordDecl = dyn_cast_or_null<RecordDecl>(TypeInfoDecl);
  if (!TypeInfoRecordDecl)
    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));

  QualType TypeInfoType = Context.getTypeDeclType(TypeInfoRecordDecl);

  return Owned(new (Context) CXXTypeidExpr(isType, TyOrExpr,
                                           TypeInfoType.withConst(),
                                           SourceRange(OpLoc, RParenLoc)));
}

/// ActOnCXXBoolLiteral - Parse {true,false} literals.
Action::OwningExprResult
Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
  assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
         "Unknown C++ Boolean value!");
  return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true,
                                                Context.BoolTy, OpLoc));
}

/// ActOnCXXThrow - Parse throw expressions.
Action::OwningExprResult
Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprArg E) {
  return Owned(new (Context) CXXThrowExpr((Expr*)E.release(), Context.VoidTy,
                                          OpLoc));
}

Action::OwningExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) {
  /// C++ 9.3.2: In the body of a non-static member function, the keyword this
  /// is a non-lvalue expression whose value is the address of the object for
  /// which the function is called.

  if (!isa<FunctionDecl>(CurContext))
    return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));

  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext))
    if (MD->isInstance())
      return Owned(new (Context) CXXThisExpr(ThisLoc,
                                             MD->getThisType(Context)));

  return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));
}

/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
Action::OwningExprResult
Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep,
                                SourceLocation LParenLoc,
                                MultiExprArg exprs,
                                SourceLocation *CommaLocs,
                                SourceLocation RParenLoc) {
  assert(TypeRep && "Missing type!");
  QualType Ty = QualType::getFromOpaquePtr(TypeRep);
  unsigned NumExprs = exprs.size();
  Expr **Exprs = (Expr**)exprs.get();