C++ ASTContext::getArrayDecayedType方法代码示例

/// GetBuiltinType - Return the type for the specified builtin.
QualType Builtin::Context::GetBuiltinType(unsigned id, ASTContext &Context,
                                          GetBuiltinTypeError &Error) const {
  const char *TypeStr = GetRecord(id).Type;
  
  llvm::SmallVector<QualType, 8> ArgTypes;
  
  Error = GE_None;
  QualType ResType = DecodeTypeFromStr(TypeStr, Context, Error);
  if (Error != GE_None)
    return QualType();
  while (TypeStr[0] && TypeStr[0] != '.') {
    QualType Ty = DecodeTypeFromStr(TypeStr, Context, Error);
    if (Error != GE_None)
      return QualType();

    // Do array -> pointer decay.  The builtin should use the decayed type.
    if (Ty->isArrayType())
      Ty = Context.getArrayDecayedType(Ty);
   
    ArgTypes.push_back(Ty);
  }

  assert((TypeStr[0] != '.' || TypeStr[1] == 0) &&
         "'.' should only occur at end of builtin type list!");

  // handle untyped/variadic arguments "T c99Style();" or "T cppStyle(...);".
  if (ArgTypes.size() == 0 && TypeStr[0] == '.')
    return Context.getFunctionNoProtoType(ResType);
  return Context.getFunctionType(ResType, ArgTypes.data(), ArgTypes.size(),
                                 TypeStr[0] == '.', 0);
}

//.........这里部分代码省略.........
  case 'i':
    if (HowLong == 3)
      Type = Unsigned ? Context.UnsignedInt128Ty : Context.Int128Ty;
    else if (HowLong == 2)
      Type = Unsigned ? Context.UnsignedLongLongTy : Context.LongLongTy;
    else if (HowLong == 1)
      Type = Unsigned ? Context.UnsignedLongTy : Context.LongTy;
    else
      Type = Unsigned ? Context.UnsignedIntTy : Context.IntTy;
    break;
  case 'c':
    assert(HowLong == 0 && "Bad modifiers used with 'c'!");
    if (Signed)
      Type = Context.SignedCharTy;
    else if (Unsigned)
      Type = Context.UnsignedCharTy;
    else
      Type = Context.CharTy;
    break;
  case 'b': // boolean
    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'b'!");
    Type = Context.BoolTy;
    break;
  case 'z':  // size_t.
    assert(HowLong == 0 && !Signed && !Unsigned && "Bad modifiers for 'z'!");
    Type = Context.getSizeType();
    break;
  case 'F':
    Type = Context.getCFConstantStringType();
    break;
  case 'a':
    Type = Context.getBuiltinVaListType();
    assert(!Type.isNull() && "builtin va list type not initialized!");
    break;
  case 'A':
    // This is a "reference" to a va_list; however, what exactly
    // this means depends on how va_list is defined. There are two
    // different kinds of va_list: ones passed by value, and ones
    // passed by reference.  An example of a by-value va_list is
    // x86, where va_list is a char*. An example of by-ref va_list
    // is x86-64, where va_list is a __va_list_tag[1]. For x86,
    // we want this argument to be a char*&; for x86-64, we want
    // it to be a __va_list_tag*.
    Type = Context.getBuiltinVaListType();
    assert(!Type.isNull() && "builtin va list type not initialized!");
    if (Type->isArrayType()) {
      Type = Context.getArrayDecayedType(Type);
    } else {
      Type = Context.getLValueReferenceType(Type);
    }
    break;
  case 'V': {
    char *End;
    
    unsigned NumElements = strtoul(Str, &End, 10);
    assert(End != Str && "Missing vector size");
    
    Str = End;
    
    QualType ElementType = DecodeTypeFromStr(Str, Context, Error, false);
    Type = Context.getVectorType(ElementType, NumElements);
    break;
  }
  case 'P': {
    IdentifierInfo *II = &Context.Idents.get("FILE");
    DeclContext::lookup_result Lookup 
      = Context.getTranslationUnitDecl()->lookup(Context, II);
    if (Lookup.first != Lookup.second && isa<TypeDecl>(*Lookup.first)) {
      Type = Context.getTypeDeclType(cast<TypeDecl>(*Lookup.first));
      break;
    }
    else {
      Error = Builtin::Context::GE_Missing_FILE;
      return QualType();
    }
  }
  }
  
  if (!AllowTypeModifiers)
    return Type;
  
  Done = false;
  while (!Done) {
    switch (*Str++) {
      default: Done = true; --Str; break;
      case '*':
        Type = Context.getPointerType(Type);
        break;
      case '&':
        Type = Context.getLValueReferenceType(Type);
        break;
      // FIXME: There's no way to have a built-in with an rvalue ref arg.
      case 'C':
        Type = Type.getQualifiedType(QualType::Const);
        break;
    }
  }
  
  return Type;
}