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//===--- ParseExpr.cpp - 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. Expressions in
// C99 basically consist of a bunch of binary operators with unary operators and
// other random stuff at the leaves.
//
// In the C99 grammar, these unary operators bind tightest and are represented
// as the 'cast-expression' production. Everything else is either a binary
// operator (e.g. '/') or a ternary operator ("?:"). The unary leaves are
// handled by ParseCastExpression, the higher level pieces are handled by
// ParseBinaryExpression.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Parse/Scope.h"
#include "ExtensionRAIIObject.h"
#include "AstGuard.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/SmallString.h"
using namespace clang;
/// PrecedenceLevels - These are precedences for the binary/ternary operators in
/// the C99 grammar. These have been named to relate with the C99 grammar
/// productions. Low precedences numbers bind more weakly than high numbers.
namespace prec {
enum Level {
Unknown = 0, // Not binary operator.
Comma = 1, // ,
Assignment = 2, // =, *=, /=, %=, +=, -=, <<=, >>=, &=, ^=, |=
Conditional = 3, // ?
LogicalOr = 4, // ||
LogicalAnd = 5, // &&
InclusiveOr = 6, // |
ExclusiveOr = 7, // ^
And = 8, // &
Equality = 9, // ==, !=
Relational = 10, // >=, <=, >, <
Shift = 11, // <<, >>
Additive = 12, // -, +
Multiplicative = 13, // *, /, %
PointerToMember = 14 // .*, ->*
};
}
/// getBinOpPrecedence - Return the precedence of the specified binary operator
/// token. This returns:
///
static prec::Level getBinOpPrecedence(tok::TokenKind Kind,
bool GreaterThanIsOperator) {
switch (Kind) {
case tok::greater:
// The '>' token can act as either an operator or as the ending
// token for a template argument list.
// FIXME: '>>' is similar, for error recovery and C++0x.
if (GreaterThanIsOperator)
return prec::Relational;
return prec::Unknown;
default: return prec::Unknown;
case tok::comma: return prec::Comma;
case tok::equal:
case tok::starequal:
case tok::slashequal:
case tok::percentequal:
case tok::plusequal:
case tok::minusequal:
case tok::lesslessequal:
case tok::greatergreaterequal:
case tok::ampequal:
case tok::caretequal:
case tok::pipeequal: return prec::Assignment;
case tok::question: return prec::Conditional;
case tok::pipepipe: return prec::LogicalOr;
case tok::ampamp: return prec::LogicalAnd;
case tok::pipe: return prec::InclusiveOr;
case tok::caret: return prec::ExclusiveOr;
case tok::amp: return prec::And;
case tok::exclaimequal:
case tok::equalequal: return prec::Equality;
case tok::lessequal:
case tok::less:
case tok::greaterequal: return prec::Relational;
case tok::lessless:
case tok::greatergreater: return prec::Shift;
case tok::plus:
case tok::minus: return prec::Additive;
case tok::percent:
case tok::slash:
case tok::star: return prec::Multiplicative;
case tok::periodstar:
case tok::arrowstar: return prec::PointerToMember;
}
}
/// ParseExpression - Simple precedence-based parser for binary/ternary
/// operators.
///
/// Note: we diverge from the C99 grammar when parsing the assignment-expression
/// production. C99 specifies that the LHS of an assignment operator should be
/// parsed as a unary-expression, but consistency dictates that it be a
/// conditional-expession. In practice, the important thing here is that the
/// LHS of an assignment has to be an l-value, which productions between
/// unary-expression and conditional-expression don't produce. Because we want
/// consistency, we parse the LHS as a conditional-expression, then check for
/// l-value-ness in semantic analysis stages.
///
/// pm-expression: [C++ 5.5]
/// cast-expression
/// pm-expression '.*' cast-expression
/// pm-expression '->*' cast-expression
///
/// multiplicative-expression: [C99 6.5.5]
/// Note: in C++, apply pm-expression instead of cast-expression
/// cast-expression
/// multiplicative-expression '*' cast-expression
/// multiplicative-expression '/' cast-expression
/// multiplicative-expression '%' cast-expression
///
/// additive-expression: [C99 6.5.6]
/// multiplicative-expression
/// additive-expression '+' multiplicative-expression
/// additive-expression '-' multiplicative-expression
///
/// shift-expression: [C99 6.5.7]
/// additive-expression
/// shift-expression '<<' additive-expression
/// shift-expression '>>' additive-expression
///
/// relational-expression: [C99 6.5.8]
/// shift-expression
/// relational-expression '<' shift-expression
/// relational-expression '>' shift-expression
/// relational-expression '<=' shift-expression
/// relational-expression '>=' shift-expression
///
/// equality-expression: [C99 6.5.9]
/// relational-expression
/// equality-expression '==' relational-expression
/// equality-expression '!=' relational-expression
///
/// AND-expression: [C99 6.5.10]
/// equality-expression
/// AND-expression '&' equality-expression
///
/// exclusive-OR-expression: [C99 6.5.11]
/// AND-expression
/// exclusive-OR-expression '^' AND-expression
///
/// inclusive-OR-expression: [C99 6.5.12]
/// exclusive-OR-expression
/// inclusive-OR-expression '|' exclusive-OR-expression
///
/// logical-AND-expression: [C99 6.5.13]
/// inclusive-OR-expression
/// logical-AND-expression '&&' inclusive-OR-expression
///
/// logical-OR-expression: [C99 6.5.14]
/// logical-AND-expression
/// logical-OR-expression '||' logical-AND-expression
///
/// conditional-expression: [C99 6.5.15]
/// logical-OR-expression
/// logical-OR-expression '?' expression ':' conditional-expression
/// [GNU] logical-OR-expression '?' ':' conditional-expression
///
/// assignment-expression: [C99 6.5.16]
/// conditional-expression
/// unary-expression assignment-operator assignment-expression
/// [C++] throw-expression [C++ 15]
///
/// assignment-operator: one of
/// = *= /= %= += -= <<= >>= &= ^= |=
///
/// expression: [C99 6.5.17]
/// assignment-expression
/// expression ',' assignment-expression
///
Parser::OwningExprResult Parser::ParseExpression() {
if (Tok.is(tok::kw_throw))
return ParseThrowExpression();
OwningExprResult LHS(ParseCastExpression(false));
if (LHS.isInvalid()) return move(LHS);
return ParseRHSOfBinaryExpression(move(LHS), prec::Comma);
}
/// This routine is called when the '@' is seen and consumed.
/// Current token is an Identifier and is not a 'try'. This
/// routine is necessary to disambiguate @try-statement from,
/// for example, @encode-expression.
///
Parser::OwningExprResult
Parser::ParseExpressionWithLeadingAt(SourceLocation AtLoc) {
OwningExprResult LHS(ParseObjCAtExpression(AtLoc));
if (LHS.isInvalid()) return move(LHS);
return ParseRHSOfBinaryExpression(move(LHS), prec::Comma);
}
/// This routine is called when a leading '__extension__' is seen and
/// consumed. This is necessary because the token gets consumed in the
/// process of disambiguating between an expression and a declaration.
Parser::OwningExprResult
Parser::ParseExpressionWithLeadingExtension(SourceLocation ExtLoc) {
// FIXME: The handling for throw is almost certainly wrong.
if (Tok.is(tok::kw_throw))
return ParseThrowExpression();
OwningExprResult LHS(ParseCastExpression(false));
if (LHS.isInvalid()) return move(LHS);
LHS = Actions.ActOnUnaryOp(CurScope, ExtLoc, tok::kw___extension__,
move(LHS));
if (LHS.isInvalid()) return move(LHS);
return ParseRHSOfBinaryExpression(move(LHS), prec::Comma);
}
/// ParseAssignmentExpression - Parse an expr that doesn't include commas.
///
Parser::OwningExprResult Parser::ParseAssignmentExpression() {
if (Tok.is(tok::kw_throw))
return ParseThrowExpression();
OwningExprResult LHS(ParseCastExpression(false));
if (LHS.isInvalid()) return move(LHS);
return ParseRHSOfBinaryExpression(move(LHS), prec::Assignment);
}
/// ParseAssignmentExprWithObjCMessageExprStart - Parse an assignment expression
/// where part of an objc message send has already been parsed. In this case
/// LBracLoc indicates the location of the '[' of the message send, and either
/// ReceiverName or ReceiverExpr is non-null indicating the receiver of the
/// message.
///
/// Since this handles full assignment-expression's, it handles postfix
/// expressions and other binary operators for these expressions as well.
Parser::OwningExprResult
Parser::ParseAssignmentExprWithObjCMessageExprStart(SourceLocation LBracLoc,
SourceLocation NameLoc,
IdentifierInfo *ReceiverName,
ExprArg ReceiverExpr) {
OwningExprResult R(ParseObjCMessageExpressionBody(LBracLoc, NameLoc,
ReceiverName,
move(ReceiverExpr)));
if (R.isInvalid()) return move(R);
R = ParsePostfixExpressionSuffix(move(R));
if (R.isInvalid()) return move(R);
return ParseRHSOfBinaryExpression(move(R), prec::Assignment);
}
Parser::OwningExprResult Parser::ParseConstantExpression() {
OwningExprResult LHS(ParseCastExpression(false));
if (LHS.isInvalid()) return move(LHS);
return ParseRHSOfBinaryExpression(move(LHS), prec::Conditional);
}
/// ParseRHSOfBinaryExpression - Parse a binary expression that starts with
/// LHS and has a precedence of at least MinPrec.
Parser::OwningExprResult
Parser::ParseRHSOfBinaryExpression(OwningExprResult LHS, unsigned MinPrec) {
unsigned NextTokPrec = getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator);
SourceLocation ColonLoc;
while (1) {
// If this token has a lower precedence than we are allowed to parse (e.g.
// because we are called recursively, or because the token is not a binop),
// then we are done!
if (NextTokPrec < MinPrec)
return move(LHS);
// Consume the operator, saving the operator token for error reporting.
Token OpToken = Tok;
ConsumeToken();
// Special case handling for the ternary operator.
OwningExprResult TernaryMiddle(Actions, true);
if (NextTokPrec == prec::Conditional) {
if (Tok.isNot(tok::colon)) {
// Handle this production specially:
// logical-OR-expression '?' expression ':' conditional-expression
// In particular, the RHS of the '?' is 'expression', not
// 'logical-OR-expression' as we might expect.
TernaryMiddle = ParseExpression();
if (TernaryMiddle.isInvalid())
return move(TernaryMiddle);
} else {
// Special case handling of "X ? Y : Z" where Y is empty:
// logical-OR-expression '?' ':' conditional-expression [GNU]
TernaryMiddle = 0;
Diag(Tok, diag::ext_gnu_conditional_expr);
}
if (Tok.isNot(tok::colon)) {
Diag(Tok, diag::err_expected_colon);
Diag(OpToken, diag::note_matching) << "?";
return ExprError();
}
// Eat the colon.
ColonLoc = ConsumeToken();
}
// Parse another leaf here for the RHS of the operator.
OwningExprResult RHS(ParseCastExpression(false));
if (RHS.isInvalid())
return move(RHS);
// Remember the precedence of this operator and get the precedence of the
// operator immediately to the right of the RHS.
unsigned ThisPrec = NextTokPrec;
NextTokPrec = getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator);
// Assignment and conditional expressions are right-associative.
bool isRightAssoc = ThisPrec == prec::Conditional ||
ThisPrec == prec::Assignment;
// Get the precedence of the operator to the right of the RHS. If it binds
// more tightly with RHS than we do, evaluate it completely first.
if (ThisPrec < NextTokPrec ||
(ThisPrec == NextTokPrec && isRightAssoc)) {
// If this is left-associative, only parse things on the RHS that bind
// more tightly than the current operator. If it is left-associative, it
// is okay, to bind exactly as tightly. For example, compile A=B=C=D as
// A=(B=(C=D)), where each paren is a level of recursion here.
// The function takes ownership of the RHS.
RHS = ParseRHSOfBinaryExpression(move(RHS), ThisPrec + !isRightAssoc);
if (RHS.isInvalid())
return move(RHS);
NextTokPrec = getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator);
}
assert(NextTokPrec <= ThisPrec && "Recursion didn't work!");
if (!LHS.isInvalid()) {
// Combine the LHS and RHS into the LHS (e.g. build AST).
if (TernaryMiddle.isInvalid())
LHS = Actions.ActOnBinOp(CurScope, OpToken.getLocation(),
OpToken.getKind(), move(LHS), move(RHS));
else
LHS = Actions.ActOnConditionalOp(OpToken.getLocation(), ColonLoc,
move(LHS), move(TernaryMiddle),
move(RHS));
}
}
}
/// ParseCastExpression - Parse a cast-expression, or, if isUnaryExpression is
/// true, parse a unary-expression. isAddressOfOperand exists because an
/// id-expression that is the operand of address-of gets special treatment
/// due to member pointers.
///
/// cast-expression: [C99 6.5.4]
/// unary-expression
/// '(' type-name ')' cast-expression
///
/// unary-expression: [C99 6.5.3]
/// postfix-expression
/// '++' unary-expression
/// '--' unary-expression
/// unary-operator cast-expression
/// 'sizeof' unary-expression
/// 'sizeof' '(' type-name ')'
/// [GNU] '__alignof' unary-expression
/// [GNU] '__alignof' '(' type-name ')'
/// [C++0x] 'alignof' '(' type-id ')'
/// [GNU] '&&' identifier
/// [C++] new-expression
/// [C++] delete-expression
///
/// unary-operator: one of
/// '&' '*' '+' '-' '~' '!'
/// [GNU] '__extension__' '__real' '__imag'
///
/// primary-expression: [C99 6.5.1]
/// [C99] identifier
/// [C++] id-expression
/// constant
/// string-literal
/// [C++] boolean-literal [C++ 2.13.5]
/// '(' expression ')'
/// '__func__' [C99 6.4.2.2]
/// [GNU] '__FUNCTION__'
/// [GNU] '__PRETTY_FUNCTION__'
/// [GNU] '(' compound-statement ')'
/// [GNU] '__builtin_va_arg' '(' assignment-expression ',' type-name ')'
/// [GNU] '__builtin_offsetof' '(' type-name ',' offsetof-member-designator')'
/// [GNU] '__builtin_choose_expr' '(' assign-expr ',' assign-expr ','
/// assign-expr ')'
/// [GNU] '__builtin_types_compatible_p' '(' type-name ',' type-name ')'
/// [GNU] '__null'
/// [OBJC] '[' objc-message-expr ']'
/// [OBJC] '@selector' '(' objc-selector-arg ')'
/// [OBJC] '@protocol' '(' identifier ')'
/// [OBJC] '@encode' '(' type-name ')'
/// [OBJC] objc-string-literal
/// [C++] simple-type-specifier '(' expression-list[opt] ')' [C++ 5.2.3]
/// [C++] typename-specifier '(' expression-list[opt] ')' [TODO]
/// [C++] 'const_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]
/// [C++] 'dynamic_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]
/// [C++] 'reinterpret_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]
/// [C++] 'static_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]
/// [C++] 'typeid' '(' expression ')' [C++ 5.2p1]
/// [C++] 'typeid' '(' type-id ')' [C++ 5.2p1]
/// [C++] 'this' [C++ 9.3.2]
/// [G++] unary-type-trait '(' type-id ')'
/// [G++] binary-type-trait '(' type-id ',' type-id ')' [TODO]
/// [clang] '^' block-literal
///
/// constant: [C99 6.4.4]
/// integer-constant
/// floating-constant
/// enumeration-constant -> identifier
/// character-constant
///
/// id-expression: [C++ 5.1]
/// unqualified-id
/// qualified-id [TODO]
///
/// unqualified-id: [C++ 5.1]
/// identifier
/// operator-function-id
/// conversion-function-id [TODO]
/// '~' class-name [TODO]
/// template-id [TODO]
///
/// new-expression: [C++ 5.3.4]
/// '::'[opt] 'new' new-placement[opt] new-type-id
/// new-initializer[opt]
/// '::'[opt] 'new' new-placement[opt] '(' type-id ')'
/// new-initializer[opt]
///
/// delete-expression: [C++ 5.3.5]
/// '::'[opt] 'delete' cast-expression
/// '::'[opt] 'delete' '[' ']' cast-expression
///
/// [GNU] unary-type-trait:
/// '__has_nothrow_assign' [TODO]
/// '__has_nothrow_copy' [TODO]
/// '__has_nothrow_constructor' [TODO]
/// '__has_trivial_assign' [TODO]
/// '__has_trivial_copy' [TODO]
/// '__has_trivial_constructor' [TODO]
/// '__has_trivial_destructor' [TODO]
/// '__has_virtual_destructor' [TODO]
/// '__is_abstract' [TODO]
/// '__is_class'
/// '__is_empty' [TODO]
/// '__is_enum'
/// '__is_pod'
/// '__is_polymorphic'
/// '__is_union'
///
/// [GNU] binary-type-trait:
/// '__is_base_of' [TODO]
///
Parser::OwningExprResult Parser::ParseCastExpression(bool isUnaryExpression,
bool isAddressOfOperand) {
OwningExprResult Res(Actions);
tok::TokenKind SavedKind = Tok.getKind();
// This handles all of cast-expression, unary-expression, postfix-expression,
// and primary-expression. We handle them together like this for efficiency
// and to simplify handling of an expression starting with a '(' token: which
// may be one of a parenthesized expression, cast-expression, compound literal
// expression, or statement expression.
//
// If the parsed tokens consist of a primary-expression, the cases below
// call ParsePostfixExpressionSuffix to handle the postfix expression
// suffixes. Cases that cannot be followed by postfix exprs should
// return without invoking ParsePostfixExpressionSuffix.
switch (SavedKind) {
case tok::l_paren: {
// If this expression is limited to being a unary-expression, the parent can
// not start a cast expression.
ParenParseOption ParenExprType =
isUnaryExpression ? CompoundLiteral : CastExpr;
TypeTy *CastTy;
SourceLocation LParenLoc = Tok.getLocation();
SourceLocation RParenLoc;
Res = ParseParenExpression(ParenExprType, CastTy, RParenLoc);
if (Res.isInvalid()) return move(Res);
switch (ParenExprType) {
case SimpleExpr: break; // Nothing else to do.
case CompoundStmt: break; // Nothing else to do.
case CompoundLiteral:
// We parsed '(' type-name ')' '{' ... '}'. If any suffixes of
// postfix-expression exist, parse them now.
break;
case CastExpr:
// We parsed '(' type-name ')' and the thing after it wasn't a '{'. Parse
// the cast-expression that follows it next.
// TODO: For cast expression with CastTy.
Res = ParseCastExpression(false);
if (!Res.isInvalid())
Res = Actions.ActOnCastExpr(LParenLoc, CastTy, RParenLoc, move(Res));
return move(Res);
}
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
}
// primary-expression
case tok::numeric_constant:
// constant: integer-constant
// constant: floating-constant
Res = Actions.ActOnNumericConstant(Tok);
ConsumeToken();
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw_true:
case tok::kw_false:
return ParseCXXBoolLiteral();
case tok::identifier: { // primary-expression: identifier
// unqualified-id: identifier
// constant: enumeration-constant
// Turn a potentially qualified name into a annot_typename or
// annot_cxxscope if it would be valid. This handles things like x::y, etc.
if (getLang().CPlusPlus) {
// If TryAnnotateTypeOrScopeToken annotates the token, tail recurse.
if (TryAnnotateTypeOrScopeToken())
return ParseCastExpression(isUnaryExpression, isAddressOfOperand);
}
// Consume the identifier so that we can see if it is followed by a '('.
// Function designators are allowed to be undeclared (C99 6.5.1p2), so we
// need to know whether or not this identifier is a function designator or
// not.
IdentifierInfo &II = *Tok.getIdentifierInfo();
SourceLocation L = ConsumeToken();
Res = Actions.ActOnIdentifierExpr(CurScope, L, II, Tok.is(tok::l_paren));
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
}
case tok::char_constant: // constant: character-constant
Res = Actions.ActOnCharacterConstant(Tok);
ConsumeToken();
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw___func__: // primary-expression: __func__ [C99 6.4.2.2]
case tok::kw___FUNCTION__: // primary-expression: __FUNCTION__ [GNU]
case tok::kw___PRETTY_FUNCTION__: // primary-expression: __P..Y_F..N__ [GNU]
Res = Actions.ActOnPredefinedExpr(Tok.getLocation(), SavedKind);
ConsumeToken();
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::string_literal: // primary-expression: string-literal
case tok::wide_string_literal:
Res = ParseStringLiteralExpression();
if (Res.isInvalid()) return move(Res);
// This can be followed by postfix-expr pieces (e.g. "foo"[1]).
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw___builtin_va_arg:
case tok::kw___builtin_offsetof:
case tok::kw___builtin_choose_expr:
case tok::kw___builtin_overload:
case tok::kw___builtin_types_compatible_p:
return ParseBuiltinPrimaryExpression();
case tok::kw___null:
return Owned(Actions.ActOnGNUNullExpr(ConsumeToken()));
break;
case tok::plusplus: // unary-expression: '++' unary-expression
case tok::minusminus: { // unary-expression: '--' unary-expression
SourceLocation SavedLoc = ConsumeToken();
Res = ParseCastExpression(true);
if (!Res.isInvalid())
Res = Actions.ActOnUnaryOp(CurScope, SavedLoc, SavedKind, move(Res));
return move(Res);
}
case tok::amp: { // unary-expression: '&' cast-expression
// Special treatment because of member pointers
SourceLocation SavedLoc = ConsumeToken();
Res = ParseCastExpression(false, true);
if (!Res.isInvalid())
Res = Actions.ActOnUnaryOp(CurScope, SavedLoc, SavedKind, move(Res));
return move(Res);
}
case tok::star: // unary-expression: '*' cast-expression
case tok::plus: // unary-expression: '+' cast-expression
case tok::minus: // unary-expression: '-' cast-expression
case tok::tilde: // unary-expression: '~' cast-expression
case tok::exclaim: // unary-expression: '!' cast-expression
case tok::kw___real: // unary-expression: '__real' cast-expression [GNU]
case tok::kw___imag: { // unary-expression: '__imag' cast-expression [GNU]
SourceLocation SavedLoc = ConsumeToken();
Res = ParseCastExpression(false);
if (!Res.isInvalid())
Res = Actions.ActOnUnaryOp(CurScope, SavedLoc, SavedKind, move(Res));
return move(Res);
}
case tok::kw___extension__:{//unary-expression:'__extension__' cast-expr [GNU]
// __extension__ silences extension warnings in the subexpression.
ExtensionRAIIObject O(Diags); // Use RAII to do this.
SourceLocation SavedLoc = ConsumeToken();
Res = ParseCastExpression(false);
if (!Res.isInvalid())
Res = Actions.ActOnUnaryOp(CurScope, SavedLoc, SavedKind, move(Res));
return move(Res);
}
case tok::kw_sizeof: // unary-expression: 'sizeof' unary-expression
// unary-expression: 'sizeof' '(' type-name ')'
case tok::kw_alignof:
case tok::kw___alignof: // unary-expression: '__alignof' unary-expression
// unary-expression: '__alignof' '(' type-name ')'
// unary-expression: 'alignof' '(' type-id ')'
return ParseSizeofAlignofExpression();
case tok::ampamp: { // unary-expression: '&&' identifier
SourceLocation AmpAmpLoc = ConsumeToken();
if (Tok.isNot(tok::identifier))
return ExprError(Diag(Tok, diag::err_expected_ident));
Diag(AmpAmpLoc, diag::ext_gnu_address_of_label);
Res = Actions.ActOnAddrLabel(AmpAmpLoc, Tok.getLocation(),
Tok.getIdentifierInfo());
ConsumeToken();
return move(Res);
}
case tok::kw_const_cast:
case tok::kw_dynamic_cast:
case tok::kw_reinterpret_cast:
case tok::kw_static_cast:
Res = ParseCXXCasts();
// These can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw_typeid:
Res = ParseCXXTypeid();
// This can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw_this:
Res = ParseCXXThis();
// This can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
case tok::kw_char:
case tok::kw_wchar_t:
case tok::kw_bool:
case tok::kw_short:
case tok::kw_int:
case tok::kw_long:
case tok::kw_signed:
case tok::kw_unsigned:
case tok::kw_float:
case tok::kw_double:
case tok::kw_void:
case tok::kw_typeof:
case tok::annot_typename: {
if (!getLang().CPlusPlus) {
Diag(Tok, diag::err_expected_expression);
return ExprError();
}
// postfix-expression: simple-type-specifier '(' expression-list[opt] ')'
//
DeclSpec DS;
ParseCXXSimpleTypeSpecifier(DS);
if (Tok.isNot(tok::l_paren))
return ExprError(Diag(Tok, diag::err_expected_lparen_after_type)
<< DS.getSourceRange());
Res = ParseCXXTypeConstructExpression(DS);
// This can be followed by postfix-expr pieces.
return ParsePostfixExpressionSuffix(move(Res));
}
case tok::annot_cxxscope: // [C++] id-expression: qualified-id
case tok::kw_operator: // [C++] id-expression: operator/conversion-function-id
// template-id
Res = ParseCXXIdExpression(isAddressOfOperand);
return ParsePostfixExpressionSuffix(move(Res));
case tok::coloncolon: {
// ::foo::bar -> global qualified name etc. If TryAnnotateTypeOrScopeToken
// annotates the token, tail recurse.
if (TryAnnotateTypeOrScopeToken())
return ParseCastExpression(isUnaryExpression, isAddressOfOperand);
// ::new -> [C++] new-expression
// ::delete -> [C++] delete-expression
SourceLocation CCLoc = ConsumeToken();
if (Tok.is(tok::kw_new))
return ParseCXXNewExpression(true, CCLoc);
if (Tok.is(tok::kw_delete))
return ParseCXXDeleteExpression(true, CCLoc);
// This is not a type name or scope specifier, it is an invalid expression.
Diag(CCLoc, diag::err_expected_expression);
return ExprError();
}
case tok::kw_new: // [C++] new-expression
return ParseCXXNewExpression(false, Tok.getLocation());
case tok::kw_delete: // [C++] delete-expression
return ParseCXXDeleteExpression(false, Tok.getLocation());
case tok::kw___is_pod: // [GNU] unary-type-trait
case tok::kw___is_class:
case tok::kw___is_enum:
case tok::kw___is_union:
case tok::kw___is_polymorphic:
return ParseUnaryTypeTrait();
case tok::at: {
SourceLocation AtLoc = ConsumeToken();
return ParseObjCAtExpression(AtLoc);
}
case tok::caret:
if (getLang().Blocks)
return ParsePostfixExpressionSuffix(ParseBlockLiteralExpression());
Diag(Tok, diag::err_expected_expression);
return ExprError();
case tok::l_square:
// These can be followed by postfix-expr pieces.
if (getLang().ObjC1)
return ParsePostfixExpressionSuffix(ParseObjCMessageExpression());
// FALL THROUGH.
default:
Diag(Tok, diag::err_expected_expression);
return ExprError();
}
// unreachable.
abort();
}
/// ParsePostfixExpressionSuffix - Once the leading part of a postfix-expression
/// is parsed, this method parses any suffixes that apply.
///
/// postfix-expression: [C99 6.5.2]
/// primary-expression
/// postfix-expression '[' expression ']'
/// postfix-expression '(' argument-expression-list[opt] ')'
/// postfix-expression '.' identifier
/// postfix-expression '->' identifier
/// postfix-expression '++'
/// postfix-expression '--'
/// '(' type-name ')' '{' initializer-list '}'
/// '(' type-name ')' '{' initializer-list ',' '}'
///
/// argument-expression-list: [C99 6.5.2]
/// argument-expression
/// argument-expression-list ',' assignment-expression
///
Parser::OwningExprResult
Parser::ParsePostfixExpressionSuffix(OwningExprResult LHS) {
// Now that the primary-expression piece of the postfix-expression has been
// parsed, see if there are any postfix-expression pieces here.
SourceLocation Loc;
while (1) {
switch (Tok.getKind()) {
default: // Not a postfix-expression suffix.
return move(LHS);
case tok::l_square: { // postfix-expression: p-e '[' expression ']'
Loc = ConsumeBracket();
OwningExprResult Idx(ParseExpression());
SourceLocation RLoc = Tok.getLocation();
if (!LHS.isInvalid() && !Idx.isInvalid() && Tok.is(tok::r_square)) {
LHS = Actions.ActOnArraySubscriptExpr(CurScope, move(LHS), Loc,
move(Idx), RLoc);
} else
LHS = ExprError();
// Match the ']'.
MatchRHSPunctuation(tok::r_square, Loc);
break;
}
case tok::l_paren: { // p-e: p-e '(' argument-expression-list[opt] ')'
ExprVector ArgExprs(Actions);
CommaLocsTy CommaLocs;
Loc = ConsumeParen();
if (Tok.isNot(tok::r_paren)) {
if (ParseExpressionList(ArgExprs, CommaLocs)) {
SkipUntil(tok::r_paren);
return ExprError();
}
}
// Match the ')'.
if (!LHS.isInvalid() && Tok.is(tok::r_paren)) {
assert((ArgExprs.size() == 0 || ArgExprs.size()-1 == CommaLocs.size())&&
"Unexpected number of commas!");
LHS = Actions.ActOnCallExpr(CurScope, move(LHS), Loc,
move_arg(ArgExprs), &CommaLocs[0],
Tok.getLocation());
}
MatchRHSPunctuation(tok::r_paren, Loc);
break;
}
case tok::arrow: // postfix-expression: p-e '->' identifier
case tok::period: { // postfix-expression: p-e '.' identifier
tok::TokenKind OpKind = Tok.getKind();
SourceLocation OpLoc = ConsumeToken(); // Eat the "." or "->" token.
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected_ident);
return ExprError();
}
if (!LHS.isInvalid()) {
LHS = Actions.ActOnMemberReferenceExpr(CurScope, move(LHS), OpLoc,
OpKind, Tok.getLocation(),
*Tok.getIdentifierInfo());
}
ConsumeToken();
break;
}
case tok::plusplus: // postfix-expression: postfix-expression '++'
case tok::minusminus: // postfix-expression: postfix-expression '--'
if (!LHS.isInvalid()) {
LHS = Actions.ActOnPostfixUnaryOp(CurScope, Tok.getLocation(),
Tok.getKind(), move(LHS));
}
ConsumeToken();
break;
}
}
}
/// ParseSizeofAlignofExpression - Parse a sizeof or alignof expression.
/// unary-expression: [C99 6.5.3]
/// 'sizeof' unary-expression
/// 'sizeof' '(' type-name ')'
/// [GNU] '__alignof' unary-expression
/// [GNU] '__alignof' '(' type-name ')'
/// [C++0x] 'alignof' '(' type-id ')'
Parser::OwningExprResult Parser::ParseSizeofAlignofExpression() {
assert((Tok.is(tok::kw_sizeof) || Tok.is(tok::kw___alignof)
|| Tok.is(tok::kw_alignof)) &&
"Not a sizeof/alignof expression!");
Token OpTok = Tok;
ConsumeToken();
// If the operand doesn't start with an '(', it must be an expression.
OwningExprResult Operand(Actions);
if (Tok.isNot(tok::l_paren)) {
Operand = ParseCastExpression(true);
} else {
// If it starts with a '(', we know that it is either a parenthesized
// type-name, or it is a unary-expression that starts with a compound
// literal, or starts with a primary-expression that is a parenthesized
// expression.
ParenParseOption ExprType = CastExpr;
TypeTy *CastTy;
SourceLocation LParenLoc = Tok.getLocation(), RParenLoc;
Operand = ParseParenExpression(ExprType, CastTy, RParenLoc);
// If ParseParenExpression parsed a '(typename)' sequence only, the this is
// sizeof/alignof a type. Otherwise, it is sizeof/alignof an expression.
if (ExprType == CastExpr)
return Actions.ActOnSizeOfAlignOfExpr(OpTok.getLocation(),
OpTok.is(tok::kw_sizeof),
/*isType=*/true, CastTy,
SourceRange(LParenLoc, RParenLoc));
// If this is a parenthesized expression, it is the start of a
// unary-expression, but doesn't include any postfix pieces. Parse these
// now if present.
Operand = ParsePostfixExpressionSuffix(move(Operand));
}
// If we get here, the operand to the sizeof/alignof was an expresion.
if (!Operand.isInvalid())
Operand = Actions.ActOnSizeOfAlignOfExpr(OpTok.getLocation(),
OpTok.is(tok::kw_sizeof),
/*isType=*/false,
Operand.release(), SourceRange());
return move(Operand);
}
/// ParseBuiltinPrimaryExpression
///
/// primary-expression: [C99 6.5.1]
/// [GNU] '__builtin_va_arg' '(' assignment-expression ',' type-name ')'
/// [GNU] '__builtin_offsetof' '(' type-name ',' offsetof-member-designator')'
/// [GNU] '__builtin_choose_expr' '(' assign-expr ',' assign-expr ','
/// assign-expr ')'
/// [GNU] '__builtin_types_compatible_p' '(' type-name ',' type-name ')'
/// [CLANG] '__builtin_overload' '(' expr (',' expr)* ')'
///
/// [GNU] offsetof-member-designator:
/// [GNU] identifier
/// [GNU] offsetof-member-designator '.' identifier
/// [GNU] offsetof-member-designator '[' expression ']'
///
Parser::OwningExprResult Parser::ParseBuiltinPrimaryExpression() {
OwningExprResult Res(Actions);
const IdentifierInfo *BuiltinII = Tok.getIdentifierInfo();
tok::TokenKind T = Tok.getKind();
SourceLocation StartLoc = ConsumeToken(); // Eat the builtin identifier.
// All of these start with an open paren.
if (Tok.isNot(tok::l_paren))
return ExprError(Diag(Tok, diag::err_expected_lparen_after_id)
<< BuiltinII);
SourceLocation LParenLoc = ConsumeParen();
// TODO: Build AST.
switch (T) {
default: assert(0 && "Not a builtin primary expression!");
case tok::kw___builtin_va_arg: {
OwningExprResult Expr(ParseAssignmentExpression());
if (Expr.isInvalid()) {
SkipUntil(tok::r_paren);
return ExprError();
}
if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
return ExprError();
TypeTy *Ty = ParseTypeName();
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_expected_rparen);
return ExprError();
}
Res = Actions.ActOnVAArg(StartLoc, Expr.release(), Ty, ConsumeParen());
break;
}
case tok::kw___builtin_offsetof: {
SourceLocation TypeLoc = Tok.getLocation();
TypeTy *Ty = ParseTypeName();
if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
return ExprError();
// We must have at least one identifier here.
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected_ident);
SkipUntil(tok::r_paren);
return ExprError();
}
// Keep track of the various subcomponents we see.
llvm::SmallVector<Action::OffsetOfComponent, 4> Comps;
Comps.push_back(Action::OffsetOfComponent());
Comps.back().isBrackets = false;
Comps.back().U.IdentInfo = Tok.getIdentifierInfo();
Comps.back().LocStart = Comps.back().LocEnd = ConsumeToken();
// FIXME: This loop leaks the index expressions on error.
while (1) {
if (Tok.is(tok::period)) {
// offsetof-member-designator: offsetof-member-designator '.' identifier
Comps.push_back(Action::OffsetOfComponent());
Comps.back().isBrackets = false;
Comps.back().LocStart = ConsumeToken();
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected_ident);
SkipUntil(tok::r_paren);
return ExprError();
}
Comps.back().U.IdentInfo = Tok.getIdentifierInfo();
Comps.back().LocEnd = ConsumeToken();
} else if (Tok.is(tok::l_square)) {
// offsetof-member-designator: offsetof-member-design '[' expression ']'
Comps.push_back(Action::OffsetOfComponent());
Comps.back().isBrackets = true;
Comps.back().LocStart = ConsumeBracket();
Res = ParseExpression();
if (Res.isInvalid()) {
SkipUntil(tok::r_paren);
return move(Res);
}
Comps.back().U.E = Res.release();
Comps.back().LocEnd =
MatchRHSPunctuation(tok::r_square, Comps.back().LocStart);
} else if (Tok.is(tok::r_paren)) {
Res = Actions.ActOnBuiltinOffsetOf(CurScope, StartLoc, TypeLoc, Ty,
&Comps[0], Comps.size(),
ConsumeParen());
break;
} else {
// Error occurred.
return ExprError();
}
}
break;
}
case tok::kw___builtin_choose_expr: {
OwningExprResult Cond(ParseAssignmentExpression());
if (Cond.isInvalid()) {
SkipUntil(tok::r_paren);
return move(Cond);
}
if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
return ExprError();
OwningExprResult Expr1(ParseAssignmentExpression());
if (Expr1.isInvalid()) {
SkipUntil(tok::r_paren);
return move(Expr1);
}
if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
return ExprError();
OwningExprResult Expr2(ParseAssignmentExpression());
if (Expr2.isInvalid()) {
SkipUntil(tok::r_paren);
return move(Expr2);
}
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_expected_rparen);
return ExprError();
}
Res = Actions.ActOnChooseExpr(StartLoc, Cond.release(), Expr1.release(),
Expr2.release(), ConsumeParen());
break;
}
case tok::kw___builtin_overload: {
ExprVector ArgExprs(Actions);
llvm::SmallVector<SourceLocation, 8> CommaLocs;
// For each iteration through the loop look for assign-expr followed by a
// comma. If there is no comma, break and attempt to match r-paren.
if (Tok.isNot(tok::r_paren)) {
while (1) {
OwningExprResult ArgExpr(ParseAssignmentExpression());
if (ArgExpr.isInvalid()) {
SkipUntil(tok::r_paren);
return ExprError();
} else
ArgExprs.push_back(ArgExpr.release());
if (Tok.isNot(tok::comma))
break;
// Move to the next argument, remember where the comma was.
CommaLocs.push_back(ConsumeToken());
}
}
// Attempt to consume the r-paren
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_expected_rparen);
SkipUntil(tok::r_paren);
return ExprError();
}
Res = Actions.ActOnOverloadExpr(ArgExprs.take(), ArgExprs.size(),
&CommaLocs[0], StartLoc, ConsumeParen());
break;
}
case tok::kw___builtin_types_compatible_p:
TypeTy *Ty1 = ParseTypeName();
if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren))
return ExprError();
TypeTy *Ty2 = ParseTypeName();
if (Tok.isNot(tok::r_paren)) {
Diag(Tok, diag::err_expected_rparen);
return ExprError();
}
Res = Actions.ActOnTypesCompatibleExpr(StartLoc, Ty1, Ty2, ConsumeParen());
break;
}
// These can be followed by postfix-expr pieces because they are
// primary-expressions.
return ParsePostfixExpressionSuffix(move(Res));
}
/// ParseParenExpression - This parses the unit that starts with a '(' token,
/// based on what is allowed by ExprType. The actual thing parsed is returned
/// in ExprType.
///
/// primary-expression: [C99 6.5.1]
/// '(' expression ')'
/// [GNU] '(' compound-statement ')' (if !ParenExprOnly)
/// postfix-expression: [C99 6.5.2]
/// '(' type-name ')' '{' initializer-list '}'
/// '(' type-name ')' '{' initializer-list ',' '}'
/// cast-expression: [C99 6.5.4]
/// '(' type-name ')' cast-expression
///
Parser::OwningExprResult
Parser::ParseParenExpression(ParenParseOption &ExprType,
TypeTy *&CastTy, SourceLocation &RParenLoc) {
assert(Tok.is(tok::l_paren) && "Not a paren expr!");
GreaterThanIsOperatorScope G(GreaterThanIsOperator, true);
SourceLocation OpenLoc = ConsumeParen();
OwningExprResult Result(Actions, true);
CastTy = 0;
if (ExprType >= CompoundStmt && Tok.is(tok::l_brace)) {
Diag(Tok, diag::ext_gnu_statement_expr);
OwningStmtResult Stmt(ParseCompoundStatement(true));
ExprType = CompoundStmt;
// If the substmt parsed correctly, build the AST node.
if (!Stmt.isInvalid() && Tok.is(tok::r_paren))
Result = Actions.ActOnStmtExpr(
OpenLoc, Stmt.release(), Tok.getLocation());
} else if (ExprType >= CompoundLiteral && isTypeIdInParens()) {
// Otherwise, this is a compound literal expression or cast expression.
TypeTy *Ty = ParseTypeName();
// Match the ')'.
if (Tok.is(tok::r_paren))
RParenLoc = ConsumeParen();
else
MatchRHSPunctuation(tok::r_paren, OpenLoc);
if (Tok.is(tok::l_brace)) {
if (!getLang().C99) // Compound literals don't exist in C90.
Diag(OpenLoc, diag::ext_c99_compound_literal);
Result = ParseInitializer();
ExprType = CompoundLiteral;
if (!Result.isInvalid())
return Actions.ActOnCompoundLiteral(OpenLoc, Ty, RParenLoc,
move(Result));
return move(Result);
}
if (ExprType == CastExpr) {
// Note that this doesn't parse the subsequence cast-expression, it just
// returns the parsed type to the callee.
ExprType = CastExpr;
CastTy = Ty;
return OwningExprResult(Actions);
}
Diag(Tok, diag::err_expected_lbrace_in_compound_literal);
return ExprError();
} else {
Result = ParseExpression();
ExprType = SimpleExpr;
if (!Result.isInvalid() && Tok.is(tok::r_paren))
Result = Actions.ActOnParenExpr(OpenLoc, Tok.getLocation(), move(Result));
}
// Match the ')'.
if (Result.isInvalid()) {
SkipUntil(tok::r_paren);
return ExprError();
}
if (Tok.is(tok::r_paren))
RParenLoc = ConsumeParen();
else
MatchRHSPunctuation(tok::r_paren, OpenLoc);
return move(Result);
}
/// ParseStringLiteralExpression - This handles the various token types that
/// form string literals, and also handles string concatenation [C99 5.1.1.2,
/// translation phase #6].
///
/// primary-expression: [C99 6.5.1]
/// string-literal
Parser::OwningExprResult Parser::ParseStringLiteralExpression() {
assert(isTokenStringLiteral() && "Not a string literal!");
// String concat. Note that keywords like __func__ and __FUNCTION__ are not
// considered to be strings for concatenation purposes.
llvm::SmallVector<Token, 4> StringToks;
do {
StringToks.push_back(Tok);
ConsumeStringToken();
} while (isTokenStringLiteral());
// Pass the set of string tokens, ready for concatenation, to the actions.
return Actions.ActOnStringLiteral(&StringToks[0], StringToks.size());
}
/// ParseExpressionList - Used for C/C++ (argument-)expression-list.
///
/// argument-expression-list:
/// assignment-expression
/// argument-expression-list , assignment-expression
///
/// [C++] expression-list:
/// [C++] assignment-expression
/// [C++] expression-list , assignment-expression
///
bool Parser::ParseExpressionList(ExprListTy &Exprs, CommaLocsTy &CommaLocs) {
while (1) {
OwningExprResult Expr(ParseAssignmentExpression());
if (Expr.isInvalid())
return true;
Exprs.push_back(Expr.release());
if (Tok.isNot(tok::comma))
return false;
// Move to the next argument, remember where the comma was.
CommaLocs.push_back(ConsumeToken());
}
}
/// ParseBlockId - Parse a block-id, which roughly looks like int (int x).
///
/// [clang] block-id:
/// [clang] specifier-qualifier-list block-declarator
///
void Parser::ParseBlockId() {
// Parse the specifier-qualifier-list piece.
DeclSpec DS;
ParseSpecifierQualifierList(DS);
// Parse the block-declarator.
Declarator DeclaratorInfo(DS, Declarator::BlockLiteralContext);
ParseDeclarator(DeclaratorInfo);
// Inform sema that we are starting a block.
Actions.ActOnBlockArguments(DeclaratorInfo, CurScope);
}
/// ParseBlockLiteralExpression - Parse a block literal, which roughly looks
/// like ^(int x){ return x+1; }
///
/// block-literal:
/// [clang] '^' block-args[opt] compound-statement
/// [clang] '^' block-id compound-statement
/// [clang] block-args:
/// [clang] '(' parameter-list ')'
///
Parser::OwningExprResult Parser::ParseBlockLiteralExpression() {
assert(Tok.is(tok::caret) && "block literal starts with ^");
SourceLocation CaretLoc = ConsumeToken();
// Enter a scope to hold everything within the block. This includes the
// argument decls, decls within the compound expression, etc. This also
// allows determining whether a variable reference inside the block is
// within or outside of the block.
ParseScope BlockScope(this, Scope::BlockScope | Scope::FnScope |
Scope::BreakScope | Scope::ContinueScope |
Scope::DeclScope);
// Inform sema that we are starting a block.
Actions.ActOnBlockStart(CaretLoc, CurScope);
// Parse the return type if present.
DeclSpec DS;
Declarator ParamInfo(DS, Declarator::BlockLiteralContext);
// FIXME: Since the return type isn't actually parsed, it can't be used to
// fill ParamInfo with an initial valid range, so do it manually.
ParamInfo.SetSourceRange(SourceRange(Tok.getLocation(), Tok.getLocation()));
// If this block has arguments, parse them. There is no ambiguity here with
// the expression case, because the expression case requires a parameter list.
if (Tok.is(tok::l_paren)) {
ParseParenDeclarator(ParamInfo);
// Parse the pieces after the identifier as if we had "int(...)".
// SetIdentifier sets the source range end, but in this case we're past
// that location.
SourceLocation Tmp = ParamInfo.getSourceRange().getEnd();
ParamInfo.SetIdentifier(0, CaretLoc);
ParamInfo.SetRangeEnd(Tmp);
if (ParamInfo.getInvalidType()) {
// If there was an error parsing the arguments, they may have
// tried to use ^(x+y) which requires an argument list. Just
// skip the whole block literal.
return ExprError();
}
// Inform sema that we are starting a block.
Actions.ActOnBlockArguments(ParamInfo, CurScope);
} else if (! Tok.is(tok::l_brace)) {
ParseBlockId();
} else {
// Otherwise, pretend we saw (void).
ParamInfo.AddTypeInfo(DeclaratorChunk::getFunction(true, false,
0, 0, 0, CaretLoc,
ParamInfo),
CaretLoc);
// Inform sema that we are starting a block.
Actions.ActOnBlockArguments(ParamInfo, CurScope);
}
OwningExprResult Result(Actions, true);
if (Tok.is(tok::l_brace)) {
OwningStmtResult Stmt(ParseCompoundStatementBody());
if (!Stmt.isInvalid()) {
Result = Actions.ActOnBlockStmtExpr(CaretLoc, Stmt.release(), CurScope);
} else {
Actions.ActOnBlockError(CaretLoc, CurScope);
}
} else {
// Saw something like: ^expr
Diag(Tok, diag::err_expected_expression);
return ExprError();
}
return move(Result);
}