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Diffstat (limited to 'clang/lib/Parse/ParseExpr.cpp')
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diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp new file mode 100644 index 00000000000..46714b73ea7 --- /dev/null +++ b/clang/lib/Parse/ParseExpr.cpp @@ -0,0 +1,1081 @@ +//===--- 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/Basic/Diagnostic.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 // *, /, % + }; +} + + +/// getBinOpPrecedence - Return the precedence of the specified binary operator +/// token. This returns: +/// +static prec::Level getBinOpPrecedence(tok::TokenKind Kind) { + switch (Kind) { + 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: + case tok::greater: 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; + } +} + + +/// 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. +/// +/// multiplicative-expression: [C99 6.5.5] +/// 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::ExprResult Parser::ParseExpression() { + if (Tok.is(tok::kw_throw)) + return ParseThrowExpression(); + + ExprResult LHS = ParseCastExpression(false); + if (LHS.isInvalid) return LHS; + + return ParseRHSOfBinaryExpression(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::ExprResult Parser::ParseExpressionWithLeadingAt(SourceLocation AtLoc) { + ExprResult LHS = ParseObjCAtExpression(AtLoc); + if (LHS.isInvalid) return LHS; + + return ParseRHSOfBinaryExpression(LHS, prec::Comma); +} + +/// ParseAssignmentExpression - Parse an expr that doesn't include commas. +/// +Parser::ExprResult Parser::ParseAssignmentExpression() { + if (Tok.is(tok::kw_throw)) + return ParseThrowExpression(); + + ExprResult LHS = ParseCastExpression(false); + if (LHS.isInvalid) return LHS; + + return ParseRHSOfBinaryExpression(LHS, prec::Assignment); +} + +Parser::ExprResult Parser::ParseConstantExpression() { + ExprResult LHS = ParseCastExpression(false); + if (LHS.isInvalid) return LHS; + + return ParseRHSOfBinaryExpression(LHS, prec::Conditional); +} + +/// ParseExpressionWithLeadingIdentifier - This special purpose method is used +/// in contexts where we have already consumed an identifier (which we saved in +/// 'IdTok'), then discovered that the identifier was really the leading token +/// of part of an expression. For example, in "A[1]+B", we consumed "A" (which +/// is now in 'IdTok') and the current token is "[". +Parser::ExprResult Parser:: +ParseExpressionWithLeadingIdentifier(const Token &IdTok) { + // We know that 'IdTok' must correspond to this production: + // primary-expression: identifier + + // Let the actions module handle the identifier. + ExprResult Res = Actions.ActOnIdentifierExpr(CurScope, IdTok.getLocation(), + *IdTok.getIdentifierInfo(), + Tok.is(tok::l_paren)); + + // Because we have to parse an entire cast-expression before starting the + // ParseRHSOfBinaryExpression method (which parses any trailing binops), we + // need to handle the 'postfix-expression' rules. We do this by invoking + // ParsePostfixExpressionSuffix to consume any postfix-expression suffixes: + Res = ParsePostfixExpressionSuffix(Res); + if (Res.isInvalid) return Res; + + // At this point, the "A[1]" part of "A[1]+B" has been consumed. Once this is + // done, we know we don't have to do anything for cast-expression, because the + // only non-postfix-expression production starts with a '(' token, and we know + // we have an identifier. As such, we can invoke ParseRHSOfBinaryExpression + // to consume any trailing operators (e.g. "+" in this example) and connected + // chunks of the expression. + return ParseRHSOfBinaryExpression(Res, prec::Comma); +} + +/// ParseExpressionWithLeadingIdentifier - This special purpose method is used +/// in contexts where we have already consumed an identifier (which we saved in +/// 'IdTok'), then discovered that the identifier was really the leading token +/// of part of an assignment-expression. For example, in "A[1]+B", we consumed +/// "A" (which is now in 'IdTok') and the current token is "[". +Parser::ExprResult Parser:: +ParseAssignmentExprWithLeadingIdentifier(const Token &IdTok) { + // We know that 'IdTok' must correspond to this production: + // primary-expression: identifier + + // Let the actions module handle the identifier. + ExprResult Res = Actions.ActOnIdentifierExpr(CurScope, IdTok.getLocation(), + *IdTok.getIdentifierInfo(), + Tok.is(tok::l_paren)); + + // Because we have to parse an entire cast-expression before starting the + // ParseRHSOfBinaryExpression method (which parses any trailing binops), we + // need to handle the 'postfix-expression' rules. We do this by invoking + // ParsePostfixExpressionSuffix to consume any postfix-expression suffixes: + Res = ParsePostfixExpressionSuffix(Res); + if (Res.isInvalid) return Res; + + // At this point, the "A[1]" part of "A[1]+B" has been consumed. Once this is + // done, we know we don't have to do anything for cast-expression, because the + // only non-postfix-expression production starts with a '(' token, and we know + // we have an identifier. As such, we can invoke ParseRHSOfBinaryExpression + // to consume any trailing operators (e.g. "+" in this example) and connected + // chunks of the expression. + return ParseRHSOfBinaryExpression(Res, prec::Assignment); +} + + +/// ParseAssignmentExpressionWithLeadingStar - This special purpose method is +/// used in contexts where we have already consumed a '*' (which we saved in +/// 'StarTok'), then discovered that the '*' was really the leading token of an +/// expression. For example, in "*(int*)P+B", we consumed "*" (which is +/// now in 'StarTok') and the current token is "(". +Parser::ExprResult Parser:: +ParseAssignmentExpressionWithLeadingStar(const Token &StarTok) { + // We know that 'StarTok' must correspond to this production: + // unary-expression: unary-operator cast-expression + // where 'unary-operator' is '*'. + + // Parse the cast-expression that follows the '*'. This will parse the + // "*(int*)P" part of "*(int*)P+B". + ExprResult Res = ParseCastExpression(false); + if (Res.isInvalid) return Res; + + // Combine StarTok + Res to get the new AST for the combined expression.. + Res = Actions.ActOnUnaryOp(StarTok.getLocation(), tok::star, Res.Val); + if (Res.isInvalid) return Res; + + + // We have to parse an entire cast-expression before starting the + // ParseRHSOfBinaryExpression method (which parses any trailing binops). Since + // we know that the only production above us is the cast-expression + // production, and because the only alternative productions start with a '(' + // token (we know we had a '*'), there is no work to do to get a whole + // cast-expression. + + // At this point, the "*(int*)P" part of "*(int*)P+B" has been consumed. Once + // this is done, we can invoke ParseRHSOfBinaryExpression to consume any + // trailing operators (e.g. "+" in this example) and connected chunks of the + // assignment-expression. + return ParseRHSOfBinaryExpression(Res, prec::Assignment); +} + + +/// ParseRHSOfBinaryExpression - Parse a binary expression that starts with +/// LHS and has a precedence of at least MinPrec. +Parser::ExprResult +Parser::ParseRHSOfBinaryExpression(ExprResult LHS, unsigned MinPrec) { + unsigned NextTokPrec = getBinOpPrecedence(Tok.getKind()); + 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 LHS; + + // Consume the operator, saving the operator token for error reporting. + Token OpToken = Tok; + ConsumeToken(); + + // Special case handling for the ternary operator. + ExprResult TernaryMiddle(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) { + Actions.DeleteExpr(LHS.Val); + return TernaryMiddle; + } + } else { + // Special case handling of "X ? Y : Z" where Y is empty: + // logical-OR-expression '?' ':' conditional-expression [GNU] + TernaryMiddle = ExprResult(false); + Diag(Tok, diag::ext_gnu_conditional_expr); + } + + if (Tok.isNot(tok::colon)) { + Diag(Tok, diag::err_expected_colon); + Diag(OpToken, diag::err_matching, "?"); + Actions.DeleteExpr(LHS.Val); + Actions.DeleteExpr(TernaryMiddle.Val); + return ExprResult(true); + } + + // Eat the colon. + ColonLoc = ConsumeToken(); + } + + // Parse another leaf here for the RHS of the operator. + ExprResult RHS = ParseCastExpression(false); + if (RHS.isInvalid) { + Actions.DeleteExpr(LHS.Val); + Actions.DeleteExpr(TernaryMiddle.Val); + return 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()); + + // 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. + RHS = ParseRHSOfBinaryExpression(RHS, ThisPrec + !isRightAssoc); + if (RHS.isInvalid) { + Actions.DeleteExpr(LHS.Val); + Actions.DeleteExpr(TernaryMiddle.Val); + return RHS; + } + + NextTokPrec = getBinOpPrecedence(Tok.getKind()); + } + 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(OpToken.getLocation(), OpToken.getKind(), + LHS.Val, RHS.Val); + else + LHS = Actions.ActOnConditionalOp(OpToken.getLocation(), ColonLoc, + LHS.Val, TernaryMiddle.Val, RHS.Val); + } else { + // We had a semantic error on the LHS. Just free the RHS and continue. + Actions.DeleteExpr(TernaryMiddle.Val); + Actions.DeleteExpr(RHS.Val); + } + } +} + +/// ParseCastExpression - Parse a cast-expression, or, if isUnaryExpression is +/// true, parse a unary-expression. +/// +/// 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 ')' +/// [GNU] '&&' identifier +/// +/// unary-operator: one of +/// '&' '*' '+' '-' '~' '!' +/// [GNU] '__extension__' '__real' '__imag' +/// +/// primary-expression: [C99 6.5.1] +/// identifier +/// 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 ')' +/// [OBJC] '[' objc-message-expr ']' +/// [OBJC] '@selector' '(' objc-selector-arg ')' +/// [OBJC] '@protocol' '(' identifier ')' +/// [OBJC] '@encode' '(' type-name ')' +/// [OBJC] objc-string-literal +/// [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] +/// +/// constant: [C99 6.4.4] +/// integer-constant +/// floating-constant +/// enumeration-constant -> identifier +/// character-constant +/// +Parser::ExprResult Parser::ParseCastExpression(bool isUnaryExpression) { + ExprResult Res; + 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 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, Res.Val); + return Res; + } + + // These can be followed by postfix-expr pieces. + return ParsePostfixExpressionSuffix(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(Res); + + case tok::kw_true: + case tok::kw_false: + return ParseCXXBoolLiteral(); + + case tok::identifier: { // primary-expression: identifier + // constant: enumeration-constant + // 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(Res); + } + case tok::char_constant: // constant: character-constant + Res = Actions.ActOnCharacterConstant(Tok); + ConsumeToken(); + // These can be followed by postfix-expr pieces. + return ParsePostfixExpressionSuffix(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(Res); + case tok::string_literal: // primary-expression: string-literal + case tok::wide_string_literal: + Res = ParseStringLiteralExpression(); + if (Res.isInvalid) return Res; + // This can be followed by postfix-expr pieces (e.g. "foo"[1]). + return ParsePostfixExpressionSuffix(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::plusplus: // unary-expression: '++' unary-expression + case tok::minusminus: { // unary-expression: '--' unary-expression + SourceLocation SavedLoc = ConsumeToken(); + Res = ParseCastExpression(true); + if (!Res.isInvalid) + Res = Actions.ActOnUnaryOp(SavedLoc, SavedKind, Res.Val); + return Res; + } + case tok::amp: // unary-expression: '&' cast-expression + 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(SavedLoc, SavedKind, Res.Val); + return Res; + } + + case tok::kw___extension__:{//unary-expression:'__extension__' cast-expr [GNU] + // __extension__ silences extension warnings in the subexpression. + bool SavedExtWarn = Diags.getWarnOnExtensions(); + Diags.setWarnOnExtensions(false); + SourceLocation SavedLoc = ConsumeToken(); + Res = ParseCastExpression(false); + if (!Res.isInvalid) + Res = Actions.ActOnUnaryOp(SavedLoc, SavedKind, Res.Val); + Diags.setWarnOnExtensions(SavedExtWarn); + return Res; + } + case tok::kw_sizeof: // unary-expression: 'sizeof' unary-expression + // unary-expression: 'sizeof' '(' type-name ')' + case tok::kw___alignof: // unary-expression: '__alignof' unary-expression + // unary-expression: '__alignof' '(' type-name ')' + return ParseSizeofAlignofExpression(); + case tok::ampamp: { // unary-expression: '&&' identifier + SourceLocation AmpAmpLoc = ConsumeToken(); + if (Tok.isNot(tok::identifier)) { + Diag(Tok, diag::err_expected_ident); + return ExprResult(true); + } + + Diag(AmpAmpLoc, diag::ext_gnu_address_of_label); + Res = Actions.ActOnAddrLabel(AmpAmpLoc, Tok.getLocation(), + Tok.getIdentifierInfo()); + ConsumeToken(); + return Res; + } + case tok::kw_const_cast: + case tok::kw_dynamic_cast: + case tok::kw_reinterpret_cast: + case tok::kw_static_cast: + return ParseCXXCasts(); + case tok::at: { + SourceLocation AtLoc = ConsumeToken(); + return ParseObjCAtExpression(AtLoc); + } + case tok::l_square: + // These can be followed by postfix-expr pieces. + return ParsePostfixExpressionSuffix(ParseObjCMessageExpression()); + default: + Diag(Tok, diag::err_expected_expression); + return ExprResult(true); + } + + // 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::ExprResult Parser::ParsePostfixExpressionSuffix(ExprResult 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 LHS; + case tok::l_square: { // postfix-expression: p-e '[' expression ']' + Loc = ConsumeBracket(); + ExprResult Idx = ParseExpression(); + + SourceLocation RLoc = Tok.getLocation(); + + if (!LHS.isInvalid && !Idx.isInvalid && Tok.is(tok::r_square)) + LHS = Actions.ActOnArraySubscriptExpr(LHS.Val, Loc, Idx.Val, RLoc); + else + LHS = ExprResult(true); + + // Match the ']'. + MatchRHSPunctuation(tok::r_square, Loc); + break; + } + + case tok::l_paren: { // p-e: p-e '(' argument-expression-list[opt] ')' + llvm::SmallVector<ExprTy*, 8> ArgExprs; + llvm::SmallVector<SourceLocation, 8> CommaLocs; + + Loc = ConsumeParen(); + + if (Tok.isNot(tok::r_paren)) { + while (1) { + ExprResult ArgExpr = ParseAssignmentExpression(); + if (ArgExpr.isInvalid) { + SkipUntil(tok::r_paren); + return ExprResult(true); + } else + ArgExprs.push_back(ArgExpr.Val); + + if (Tok.isNot(tok::comma)) + break; + // Move to the next argument, remember where the comma was. + CommaLocs.push_back(ConsumeToken()); + } + } + + // 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(LHS.Val, Loc, &ArgExprs[0], ArgExprs.size(), + &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 ExprResult(true); + } + + if (!LHS.isInvalid) + LHS = Actions.ActOnMemberReferenceExpr(LHS.Val, 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(Tok.getLocation(), Tok.getKind(), + LHS.Val); + 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 ')' +Parser::ExprResult Parser::ParseSizeofAlignofExpression() { + assert((Tok.is(tok::kw_sizeof) || 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. + ExprResult Operand; + 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.ActOnSizeOfAlignOfTypeExpr(OpTok.getLocation(), + OpTok.is(tok::kw_sizeof), + LParenLoc, CastTy, 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(Operand); + } + + // If we get here, the operand to the sizeof/alignof was an expresion. + if (!Operand.isInvalid) + Operand = Actions.ActOnUnaryOp(OpTok.getLocation(), OpTok.getKind(), + Operand.Val); + return 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::ExprResult Parser::ParseBuiltinPrimaryExpression() { + ExprResult Res(false); + 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)) { + Diag(Tok, diag::err_expected_lparen_after, BuiltinII->getName()); + return ExprResult(true); + } + + SourceLocation LParenLoc = ConsumeParen(); + // TODO: Build AST. + + switch (T) { + default: assert(0 && "Not a builtin primary expression!"); + case tok::kw___builtin_va_arg: { + ExprResult Expr = ParseAssignmentExpression(); + if (Expr.isInvalid) { + SkipUntil(tok::r_paren); + return Res; + } + + if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) + return ExprResult(true); + + TypeTy *Ty = ParseTypeName(); + + if (Tok.isNot(tok::r_paren)) { + Diag(Tok, diag::err_expected_rparen); + return ExprResult(true); + } + Res = Actions.ActOnVAArg(StartLoc, Expr.Val, 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 ExprResult(true); + + // We must have at least one identifier here. + if (Tok.isNot(tok::identifier)) { + Diag(Tok, diag::err_expected_ident); + SkipUntil(tok::r_paren); + return true; + } + + // 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(); + + 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 true; + } + 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 Res; + } + Comps.back().U.E = Res.Val; + + Comps.back().LocEnd = + MatchRHSPunctuation(tok::r_square, Comps.back().LocStart); + } else if (Tok.is(tok::r_paren)) { + Res = Actions.ActOnBuiltinOffsetOf(StartLoc, TypeLoc, Ty, &Comps[0], + Comps.size(), ConsumeParen()); + break; + } else { + // Error occurred. + return ExprResult(true); + } + } + break; + } + case tok::kw___builtin_choose_expr: { + ExprResult Cond = ParseAssignmentExpression(); + if (Cond.isInvalid) { + SkipUntil(tok::r_paren); + return Cond; + } + if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) + return ExprResult(true); + + ExprResult Expr1 = ParseAssignmentExpression(); + if (Expr1.isInvalid) { + SkipUntil(tok::r_paren); + return Expr1; + } + if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) + return ExprResult(true); + + ExprResult Expr2 = ParseAssignmentExpression(); + if (Expr2.isInvalid) { + SkipUntil(tok::r_paren); + return Expr2; + } + if (Tok.isNot(tok::r_paren)) { + Diag(Tok, diag::err_expected_rparen); + return ExprResult(true); + } + Res = Actions.ActOnChooseExpr(StartLoc, Cond.Val, Expr1.Val, Expr2.Val, + ConsumeParen()); + break; + } + case tok::kw___builtin_overload: { + llvm::SmallVector<ExprTy*, 8> ArgExprs; + 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) { + ExprResult ArgExpr = ParseAssignmentExpression(); + if (ArgExpr.isInvalid) { + SkipUntil(tok::r_paren); + return ExprResult(true); + } else + ArgExprs.push_back(ArgExpr.Val); + + 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 ExprResult(true); + } + Res = Actions.ActOnOverloadExpr(&ArgExprs[0], 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 ExprResult(true); + + TypeTy *Ty2 = ParseTypeName(); + + if (Tok.isNot(tok::r_paren)) { + Diag(Tok, diag::err_expected_rparen); + return ExprResult(true); + } + Res = Actions.ActOnTypesCompatibleExpr(StartLoc, Ty1, Ty2, ConsumeParen()); + break; + } + + // These can be followed by postfix-expr pieces because they are + // primary-expressions. + return ParsePostfixExpressionSuffix(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::ExprResult Parser::ParseParenExpression(ParenParseOption &ExprType, + TypeTy *&CastTy, + SourceLocation &RParenLoc) { + assert(Tok.is(tok::l_paren) && "Not a paren expr!"); + SourceLocation OpenLoc = ConsumeParen(); + ExprResult Result(true); + CastTy = 0; + + if (ExprType >= CompoundStmt && Tok.is(tok::l_brace)) { + Diag(Tok, diag::ext_gnu_statement_expr); + Parser::StmtResult 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.Val, Tok.getLocation()); + + } else if (ExprType >= CompoundLiteral && isTypeSpecifierQualifier()) { + // 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, Result.Val); + } else 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 ExprResult(false); + } else { + Diag(Tok, diag::err_expected_lbrace_in_compound_literal); + return ExprResult(true); + } + return Result; + } else { + Result = ParseExpression(); + ExprType = SimpleExpr; + if (!Result.isInvalid && Tok.is(tok::r_paren)) + Result = Actions.ActOnParenExpr(OpenLoc, Tok.getLocation(), Result.Val); + } + + // Match the ')'. + if (Result.isInvalid) + SkipUntil(tok::r_paren); + else { + if (Tok.is(tok::r_paren)) + RParenLoc = ConsumeParen(); + else + MatchRHSPunctuation(tok::r_paren, OpenLoc); + } + + return 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::ExprResult 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()); +} |
