clang-1/lib/Parse/ParseExprCXX.cpp

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//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expression parsing implementation for C++.
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/Diagnostic.h"
#include "clang/Parse/Parser.h"
#include "clang/Parse/DeclSpec.h"
using namespace clang;
/// ParseCXXScopeSpecifier - Parse global scope or nested-name-specifier.
///
/// '::'[opt] nested-name-specifier
/// '::'
///
/// nested-name-specifier:
/// type-name '::'
/// namespace-name '::'
/// nested-name-specifier identifier '::'
/// nested-name-specifier 'template'[opt] simple-template-id '::' [TODO]
///
void Parser::ParseCXXScopeSpecifier(CXXScopeSpec &SS) {
assert(isTokenCXXScopeSpecifier() && "Not scope specifier!");
if (Tok.is(tok::annot_cxxscope)) {
SS.setScopeRep(Tok.getAnnotationValue());
SS.setRange(Tok.getAnnotationRange());
ConsumeToken();
return;
}
SS.setBeginLoc(Tok.getLocation());
// '::'
if (Tok.is(tok::coloncolon)) {
// Global scope.
SourceLocation CCLoc = ConsumeToken();
SS.setScopeRep(Actions.ActOnCXXGlobalScopeSpecifier(CurScope, CCLoc));
SS.setEndLoc(CCLoc);
}
// nested-name-specifier:
// type-name '::'
// namespace-name '::'
// nested-name-specifier identifier '::'
// nested-name-specifier 'template'[opt] simple-template-id '::' [TODO]
while (Tok.is(tok::identifier) && NextToken().is(tok::coloncolon)) {
IdentifierInfo *II = Tok.getIdentifierInfo();
SourceLocation IdLoc = ConsumeToken();
assert(Tok.is(tok::coloncolon) &&
"NextToken() not working properly!");
SourceLocation CCLoc = ConsumeToken();
if (SS.isInvalid())
continue;
SS.setScopeRep(
Actions.ActOnCXXNestedNameSpecifier(CurScope, SS, IdLoc, CCLoc, *II) );
SS.setEndLoc(CCLoc);
}
}
/// ParseCXXIdExpression - Handle id-expression.
///
/// id-expression:
/// unqualified-id
/// qualified-id
///
/// unqualified-id:
/// identifier
/// operator-function-id
/// conversion-function-id [TODO]
/// '~' class-name [TODO]
/// template-id [TODO]
///
/// qualified-id:
/// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
/// '::' identifier
/// '::' operator-function-id
/// '::' template-id [TODO]
///
/// nested-name-specifier:
/// type-name '::'
/// namespace-name '::'
/// nested-name-specifier identifier '::'
/// nested-name-specifier 'template'[opt] simple-template-id '::' [TODO]
///
/// NOTE: The standard specifies that, for qualified-id, the parser does not
/// expect:
///
/// '::' conversion-function-id
/// '::' '~' class-name
///
/// This may cause a slight inconsistency on diagnostics:
///
/// class C {};
/// namespace A {}
/// void f() {
/// :: A :: ~ C(); // Some Sema error about using destructor with a
/// // namespace.
/// :: ~ C(); // Some Parser error like 'unexpected ~'.
/// }
///
/// We simplify the parser a bit and make it work like:
///
/// qualified-id:
/// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
/// '::' unqualified-id
///
/// That way Sema can handle and report similar errors for namespaces and the
/// global scope.
///
Parser::ExprResult Parser::ParseCXXIdExpression() {
// qualified-id:
// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
// '::' unqualified-id
//
CXXScopeSpec SS;
if (isTokenCXXScopeSpecifier())
ParseCXXScopeSpecifier(SS);
// unqualified-id:
// identifier
// operator-function-id
// conversion-function-id [TODO]
// '~' class-name [TODO]
// template-id [TODO]
//
switch (Tok.getKind()) {
default:
return Diag(Tok, diag::err_expected_unqualified_id);
case tok::identifier: {
// Consume the identifier so that we can see if it is followed by a '('.
IdentifierInfo &II = *Tok.getIdentifierInfo();
SourceLocation L = ConsumeToken();
return Actions.ActOnIdentifierExpr(CurScope, L, II,
Tok.is(tok::l_paren), &SS);
}
case tok::kw_operator: {
SourceLocation OperatorLoc = Tok.getLocation();
if (IdentifierInfo *II = MaybeParseOperatorFunctionId()) {
return Actions.ActOnIdentifierExpr(CurScope, OperatorLoc, *II,
Tok.is(tok::l_paren), &SS);
}
// FIXME: Handle conversion-function-id.
unsigned DiagID = PP.getDiagnostics().getCustomDiagID(Diagnostic::Error,
"expected operator-function-id");
return Diag(Tok, DiagID);
}
} // switch.
assert(0 && "The switch was supposed to take care everything.");
}
/// ParseCXXCasts - This handles the various ways to cast expressions to another
/// type.
///
/// postfix-expression: [C++ 5.2p1]
/// 'dynamic_cast' '<' type-name '>' '(' expression ')'
/// 'static_cast' '<' type-name '>' '(' expression ')'
/// 'reinterpret_cast' '<' type-name '>' '(' expression ')'
/// 'const_cast' '<' type-name '>' '(' expression ')'
///
Parser::ExprResult Parser::ParseCXXCasts() {
tok::TokenKind Kind = Tok.getKind();
const char *CastName = 0; // For error messages
switch (Kind) {
default: assert(0 && "Unknown C++ cast!"); abort();
case tok::kw_const_cast: CastName = "const_cast"; break;
case tok::kw_dynamic_cast: CastName = "dynamic_cast"; break;
case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
case tok::kw_static_cast: CastName = "static_cast"; break;
}
SourceLocation OpLoc = ConsumeToken();
SourceLocation LAngleBracketLoc = Tok.getLocation();
if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
return ExprResult(true);
TypeTy *CastTy = ParseTypeName();
SourceLocation RAngleBracketLoc = Tok.getLocation();
if (ExpectAndConsume(tok::greater, diag::err_expected_greater)) {
Diag(LAngleBracketLoc, diag::err_matching, "<");
return ExprResult(true);
}
SourceLocation LParenLoc = Tok.getLocation(), RParenLoc;
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after, CastName);
return ExprResult(true);
}
ExprResult Result = ParseSimpleParenExpression(RParenLoc);
if (!Result.isInvalid)
Result = Actions.ActOnCXXNamedCast(OpLoc, Kind,
LAngleBracketLoc, CastTy, RAngleBracketLoc,
LParenLoc, Result.Val, RParenLoc);
return Result;
}
/// ParseCXXBoolLiteral - This handles the C++ Boolean literals.
///
/// boolean-literal: [C++ 2.13.5]
/// 'true'
/// 'false'
Parser::ExprResult Parser::ParseCXXBoolLiteral() {
tok::TokenKind Kind = Tok.getKind();
return Actions.ActOnCXXBoolLiteral(ConsumeToken(), Kind);
}
/// ParseThrowExpression - This handles the C++ throw expression.
///
/// throw-expression: [C++ 15]
/// 'throw' assignment-expression[opt]
Parser::ExprResult Parser::ParseThrowExpression() {
assert(Tok.is(tok::kw_throw) && "Not throw!");
SourceLocation ThrowLoc = ConsumeToken(); // Eat the throw token.
// If the current token isn't the start of an assignment-expression,
// then the expression is not present. This handles things like:
// "C ? throw : (void)42", which is crazy but legal.
switch (Tok.getKind()) { // FIXME: move this predicate somewhere common.
case tok::semi:
case tok::r_paren:
case tok::r_square:
case tok::r_brace:
case tok::colon:
case tok::comma:
return Actions.ActOnCXXThrow(ThrowLoc);
default:
ExprResult Expr = ParseAssignmentExpression();
if (Expr.isInvalid) return Expr;
return Actions.ActOnCXXThrow(ThrowLoc, Expr.Val);
}
}
/// ParseCXXThis - This handles the C++ 'this' pointer.
///
/// 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.
Parser::ExprResult Parser::ParseCXXThis() {
assert(Tok.is(tok::kw_this) && "Not 'this'!");
SourceLocation ThisLoc = ConsumeToken();
return Actions.ActOnCXXThis(ThisLoc);
}
/// ParseCXXTypeConstructExpression - 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()").
///
/// postfix-expression: [C++ 5.2p1]
/// simple-type-specifier '(' expression-list[opt] ')' [C++ 5.2.3]
/// typename-specifier '(' expression-list[opt] ')' [TODO]
///
Parser::ExprResult Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
Declarator DeclaratorInfo(DS, Declarator::TypeNameContext);
TypeTy *TypeRep = Actions.ActOnTypeName(CurScope, DeclaratorInfo).Val;
assert(Tok.is(tok::l_paren) && "Expected '('!");
SourceLocation LParenLoc = ConsumeParen();
ExprListTy Exprs;
CommaLocsTy CommaLocs;
if (Tok.isNot(tok::r_paren)) {
if (ParseExpressionList(Exprs, CommaLocs)) {
SkipUntil(tok::r_paren);
return ExprResult(true);
}
}
// Match the ')'.
SourceLocation RParenLoc = MatchRHSPunctuation(tok::r_paren, LParenLoc);
assert((Exprs.size() == 0 || Exprs.size()-1 == CommaLocs.size())&&
"Unexpected number of commas!");
return Actions.ActOnCXXTypeConstructExpr(DS.getSourceRange(), TypeRep,
LParenLoc,
&Exprs[0], Exprs.size(),
&CommaLocs[0], RParenLoc);
}
/// ParseCXXCondition - if/switch/while/for condition expression.
///
/// condition:
/// expression
/// type-specifier-seq declarator '=' assignment-expression
/// [GNU] type-specifier-seq declarator simple-asm-expr[opt] attributes[opt]
/// '=' assignment-expression
///
Parser::ExprResult Parser::ParseCXXCondition() {
if (!isCXXConditionDeclaration())
return ParseExpression(); // expression
SourceLocation StartLoc = Tok.getLocation();
// type-specifier-seq
DeclSpec DS;
ParseSpecifierQualifierList(DS);
// declarator
Declarator DeclaratorInfo(DS, Declarator::ConditionContext);
ParseDeclarator(DeclaratorInfo);
// simple-asm-expr[opt]
if (Tok.is(tok::kw_asm)) {
ExprResult AsmLabel = ParseSimpleAsm();
if (AsmLabel.isInvalid) {
SkipUntil(tok::semi);
return true;
}
DeclaratorInfo.setAsmLabel(AsmLabel.Val);
}
// If attributes are present, parse them.
if (Tok.is(tok::kw___attribute))
DeclaratorInfo.AddAttributes(ParseAttributes());
// '=' assignment-expression
if (Tok.isNot(tok::equal))
return Diag(Tok, diag::err_expected_equal_after_declarator);
SourceLocation EqualLoc = ConsumeToken();
ExprResult AssignExpr = ParseAssignmentExpression();
if (AssignExpr.isInvalid)
return true;
return Actions.ActOnCXXConditionDeclarationExpr(CurScope, StartLoc,
DeclaratorInfo,
EqualLoc, AssignExpr.Val);
}
/// ParseCXXSimpleTypeSpecifier - [C++ 7.1.5.2] Simple type specifiers.
/// This should only be called when the current token is known to be part of
/// simple-type-specifier.
///
/// simple-type-specifier:
/// '::'[opt] nested-name-specifier[opt] type-name
/// '::'[opt] nested-name-specifier 'template' simple-template-id [TODO]
/// char
/// wchar_t
/// bool
/// short
/// int
/// long
/// signed
/// unsigned
/// float
/// double
/// void
/// [GNU] typeof-specifier
/// [C++0x] auto [TODO]
///
/// type-name:
/// class-name
/// enum-name
/// typedef-name
///
void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
// Annotate typenames and C++ scope specifiers.
TryAnnotateTypeOrScopeToken();
DS.SetRangeStart(Tok.getLocation());
const char *PrevSpec;
SourceLocation Loc = Tok.getLocation();
switch (Tok.getKind()) {
default:
assert(0 && "Not a simple-type-specifier token!");
abort();
// type-name
case tok::annot_qualtypename: {
DS.SetTypeSpecType(DeclSpec::TST_typedef, Loc, PrevSpec,
Tok.getAnnotationValue());
break;
}
// builtin types
case tok::kw_short:
DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec);
break;
case tok::kw_long:
DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec);
break;
case tok::kw_signed:
DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec);
break;
case tok::kw_unsigned:
DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec);
break;
case tok::kw_void:
DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec);
break;
case tok::kw_char:
DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec);
break;
case tok::kw_int:
DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec);
break;
case tok::kw_float:
DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec);
break;
case tok::kw_double:
DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec);
break;
case tok::kw_wchar_t:
DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec);
break;
case tok::kw_bool:
DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec);
break;
// GNU typeof support.
case tok::kw_typeof:
ParseTypeofSpecifier(DS);
DS.Finish(Diags, PP.getSourceManager(), getLang());
return;
}
if (Tok.is(tok::annot_qualtypename))
DS.SetRangeEnd(Tok.getAnnotationEndLoc());
else
DS.SetRangeEnd(Tok.getLocation());
ConsumeToken();
DS.Finish(Diags, PP.getSourceManager(), getLang());
}
/// ParseCXXTypeSpecifierSeq - Parse a C++ type-specifier-seq (C++
/// [dcl.name]), which is a non-empty sequence of type-specifiers,
/// e.g., "const short int". Note that the DeclSpec is *not* finished
/// by parsing the type-specifier-seq, because these sequences are
/// typically followed by some form of declarator. Returns true and
/// emits diagnostics if this is not a type-specifier-seq, false
/// otherwise.
///
/// type-specifier-seq: [C++ 8.1]
/// type-specifier type-specifier-seq[opt]
///
bool Parser::ParseCXXTypeSpecifierSeq(DeclSpec &DS) {
DS.SetRangeStart(Tok.getLocation());
const char *PrevSpec = 0;
int isInvalid = 0;
// Parse one or more of the type specifiers.
if (!MaybeParseTypeSpecifier(DS, isInvalid, PrevSpec)) {
Diag(Tok.getLocation(), diag::err_operator_missing_type_specifier);
return true;
}
while (MaybeParseTypeSpecifier(DS, isInvalid, PrevSpec)) ;
return false;
}
/// MaybeParseOperatorFunctionId - Attempts to parse a C++ overloaded
/// operator name (C++ [over.oper]). If successful, returns the
/// predefined identifier that corresponds to that overloaded
/// operator. Otherwise, returns NULL and does not consume any tokens.
///
/// operator-function-id: [C++ 13.5]
/// 'operator' operator
///
/// operator: one of
/// new delete new[] delete[]
/// + - * / % ^ & | ~
/// ! = < > += -= *= /= %=
/// ^= &= |= << >> >>= <<= == !=
/// <= >= && || ++ -- , ->* ->
/// () []
IdentifierInfo *Parser::MaybeParseOperatorFunctionId() {
assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
OverloadedOperatorKind Op = OO_None;
switch (NextToken().getKind()) {
case tok::kw_new:
ConsumeToken(); // 'operator'
ConsumeToken(); // 'new'
if (Tok.is(tok::l_square)) {
ConsumeBracket(); // '['
ExpectAndConsume(tok::r_square, diag::err_expected_rsquare); // ']'
Op = OO_Array_New;
} else {
Op = OO_New;
}
return &PP.getIdentifierTable().getOverloadedOperator(Op);
case tok::kw_delete:
ConsumeToken(); // 'operator'
ConsumeToken(); // 'delete'
if (Tok.is(tok::l_square)) {
ConsumeBracket(); // '['
ExpectAndConsume(tok::r_square, diag::err_expected_rsquare); // ']'
Op = OO_Array_Delete;
} else {
Op = OO_Delete;
}
return &PP.getIdentifierTable().getOverloadedOperator(Op);
#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
case tok::Token: Op = OO_##Name; break;
#define OVERLOADED_OPERATOR_MULTI(Name,Spelling,Unary,Binary,MemberOnly)
#include "clang/Basic/OperatorKinds.def"
case tok::l_paren:
ConsumeToken(); // 'operator'
ConsumeParen(); // '('
ExpectAndConsume(tok::r_paren, diag::err_expected_rparen); // ')'
return &PP.getIdentifierTable().getOverloadedOperator(OO_Call);
case tok::l_square:
ConsumeToken(); // 'operator'
ConsumeBracket(); // '['
ExpectAndConsume(tok::r_square, diag::err_expected_rsquare); // ']'
return &PP.getIdentifierTable().getOverloadedOperator(OO_Subscript);
default:
break;
}
if (Op == OO_None)
return 0;
else {
ConsumeToken(); // 'operator'
ConsumeAnyToken(); // the operator itself
return &PP.getIdentifierTable().getOverloadedOperator(Op);
}
}
/// ParseConversionFunctionId - Parse a C++ conversion-function-id,
/// which expresses the name of a user-defined conversion operator
/// (C++ [class.conv.fct]p1). Returns the type that this operator is
/// specifying a conversion for, or NULL if there was an error.
///
/// conversion-function-id: [C++ 12.3.2]
/// operator conversion-type-id
///
/// conversion-type-id:
/// type-specifier-seq conversion-declarator[opt]
///
/// conversion-declarator:
/// ptr-operator conversion-declarator[opt]
Parser::TypeTy *Parser::ParseConversionFunctionId() {
assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
ConsumeToken(); // 'operator'
// Parse the type-specifier-seq.
DeclSpec DS;
if (ParseCXXTypeSpecifierSeq(DS))
return 0;
// Parse the conversion-declarator, which is merely a sequence of
// ptr-operators.
Declarator D(DS, Declarator::TypeNameContext);
ParseDeclaratorInternal(D, /*PtrOperator=*/true);
// Finish up the type.
Action::TypeResult Result = Actions.ActOnTypeName(CurScope, D);
if (Result.isInvalid)
return 0;
else
return Result.Val;
}