path: root/lib/Sema/SemaType.cpp

//===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements type-related semantic analysis.
//
//===----------------------------------------------------------------------===//

#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/Parse/DeclSpec.h"
using namespace clang;

/// \brief Perform adjustment on the parameter type of a function.
///
/// This routine adjusts the given parameter type @p T to the actual
/// parameter type used by semantic analysis (C99 6.7.5.3p[7,8], 
/// C++ [dcl.fct]p3). The adjusted parameter type is returned. 
QualType Sema::adjustParameterType(QualType T) {
  // C99 6.7.5.3p7:
  if (T->isArrayType()) {
    // C99 6.7.5.3p7:
    //   A declaration of a parameter as "array of type" shall be
    //   adjusted to "qualified pointer to type", where the type
    //   qualifiers (if any) are those specified within the [ and ] of
    //   the array type derivation.
    return Context.getArrayDecayedType(T);
  } else if (T->isFunctionType())
    // C99 6.7.5.3p8:
    //   A declaration of a parameter as "function returning type"
    //   shall be adjusted to "pointer to function returning type", as
    //   in 6.3.2.1.
    return Context.getPointerType(T);

  return T;
}

/// \brief Convert the specified declspec to the appropriate type
/// object.
/// \param DS  the declaration specifiers
/// \param DeclLoc The location of the declarator identifier or invalid if none.
/// \returns The type described by the declaration specifiers.  This function
/// never returns null.
QualType Sema::ConvertDeclSpecToType(const DeclSpec &DS,
                                     SourceLocation DeclLoc,
                                     bool &isInvalid) {
  // FIXME: Should move the logic from DeclSpec::Finish to here for validity
  // checking.
  QualType Result;
  
  switch (DS.getTypeSpecType()) {
  case DeclSpec::TST_void:
    Result = Context.VoidTy;
    break;
  case DeclSpec::TST_char:
    if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
      Result = Context.CharTy;
    else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
      Result = Context.SignedCharTy;
    else {
      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
             "Unknown TSS value");
      Result = Context.UnsignedCharTy;
    }
    break;
  case DeclSpec::TST_wchar:
    if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
      Result = Context.WCharTy;
    else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed) {
      Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
        << DS.getSpecifierName(DS.getTypeSpecType());
      Result = Context.getSignedWCharType();
    } else {
      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
        "Unknown TSS value");
      Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
        << DS.getSpecifierName(DS.getTypeSpecType());
      Result = Context.getUnsignedWCharType();
    }
    break;
  case DeclSpec::TST_unspecified:
    // "<proto1,proto2>" is an objc qualified ID with a missing id.
    if (DeclSpec::ProtocolQualifierListTy PQ = DS.getProtocolQualifiers()) {
      Result = Context.getObjCQualifiedIdType((ObjCProtocolDecl**)PQ,
                                              DS.getNumProtocolQualifiers());
      break;
    }
      
    // Unspecified typespec defaults to int in C90.  However, the C90 grammar
    // [C90 6.5] only allows a decl-spec if there was *some* type-specifier,
    // type-qualifier, or storage-class-specifier.  If not, emit an extwarn.
    // Note that the one exception to this is function definitions, which are
    // allowed to be completely missing a declspec.  This is handled in the
    // parser already though by it pretending to have seen an 'int' in this
    // case.
    if (getLangOptions().ImplicitInt) {
      // In C89 mode, we only warn if there is a completely missing declspec
      // when one is not allowed.
      if (DS.isEmpty()) {
        if (DeclLoc.isInvalid())
          DeclLoc = DS.getSourceRange().getBegin();
        Diag(DeclLoc, diag::warn_missing_declspec)
          << DS.getSourceRange()