| //===--- ParseExpr.cpp - Expression Parsing -------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by Chris Lattner and 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 "clang/Basic/TargetInfo.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| using namespace llvm; |
| 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 |
| /// |
| /// assignment-operator: one of |
| /// = *= /= %= += -= <<= >>= &= ^= |= |
| /// |
| /// expression: [C99 6.5.17] |
| /// assignment-expression |
| /// expression ',' assignment-expression |
| /// |
| Parser::ExprResult Parser::ParseExpression() { |
| ExprResult LHS = ParseCastExpression(false); |
| if (LHS.isInvalid) return LHS; |
| |
| return ParseRHSOfBinaryExpression(LHS, prec::Comma); |
| } |
| |
| /// ParseAssignmentExpression - Parse an expr that doesn't include commas. |
| /// |
| Parser::ExprResult Parser::ParseAssignmentExpression() { |
| 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; |
| |
| // TODO: Validate that this is a constant expr! |
| 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 |
| /// 'Tok'), 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 'Tok') and the current token is "[". |
| Parser::ExprResult Parser:: |
| ParseExpressionWithLeadingIdentifier(const LexerToken &Tok) { |
| // We know that 'Tok' must correspond to this production: |
| // primary-expression: identifier |
| |
| // Let the actions module handle the identifier. |
| ExprResult Res = Actions.ParseSimplePrimaryExpr(Tok.getLocation(), |
| Tok.getKind()); |
| |
| // 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 |
| /// 'Tok'), 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 'Tok') and the current token is "[". |
| Parser::ExprResult Parser:: |
| ParseAssignmentExprWithLeadingIdentifier(const LexerToken &Tok) { |
| // We know that 'Tok' must correspond to this production: |
| // primary-expression: identifier |
| |
| // Let the actions module handle the identifier. |
| ExprResult Res = Actions.ParseSimplePrimaryExpr(Tok.getLocation(), |
| Tok.getKind()); |
| |
| // 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 |
| /// 'Tok'), then discovered that the '*' was really the leading token of an |
| /// expression. For example, in "*(int*)P+B", we consumed "*" (which is |
| /// now in 'Tok') and the current token is "(". |
| Parser::ExprResult Parser:: |
| ParseAssignmentExpressionWithLeadingStar(const LexerToken &Tok) { |
| // We know that 'Tok' 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; |
| |
| // TODO: Combine Tok + Res to get the new AST. |
| |
| // 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. |
| LexerToken OpToken = Tok; |
| ConsumeToken(); |
| |
| // Special case handling for the ternary operator. |
| ExprResult TernaryMiddle(true); |
| if (NextTokPrec == prec::Conditional) { |
| if (Tok.getKind() != 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 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.getKind() != tok::colon) { |
| Diag(Tok, diag::err_expected_colon); |
| Diag(OpToken, diag::err_matching, "?"); |
| 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) 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 = NextTokPrec == prec::Conditional || |
| NextTokPrec == 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) return RHS; |
| |
| NextTokPrec = getBinOpPrecedence(Tok.getKind()); |
| } |
| assert(NextTokPrec <= ThisPrec && "Recursion didn't work!"); |
| |
| // Combine the LHS and RHS into the LHS (e.g. build AST). |
| if (TernaryMiddle.isInvalid) |
| LHS = Actions.ParseBinOp(OpToken.getLocation(), OpToken.getKind(), |
| LHS.Val, RHS.Val); |
| else |
| LHS = Actions.ParseConditionalOp(OpToken.getLocation(), ColonLoc, |
| LHS.Val, TernaryMiddle.Val, 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 |
| /// '(' 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 ')' |
| /// [OBC] '[' objc-receiver objc-message-args ']' [TODO] |
| /// [OBC] '@selector' '(' objc-selector-arg ')' [TODO] |
| /// [OBC] '@protocol' '(' identifier ')' [TODO] |
| /// [OBC] '@encode' '(' type-name ')' [TODO] |
| /// [OBC] objc-string-literal [TODO] |
| /// |
| /// 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.ParseCastExpr(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 |
| |
| // TODO: Validate whether this is an integer or floating-constant or |
| // neither. |
| if (1) { |
| Res = Actions.ParseIntegerConstant(Tok.getLocation()); |
| } else { |
| Res = Actions.ParseFloatingConstant(Tok.getLocation()); |
| } |
| ConsumeToken(); |
| |
| // These can be followed by postfix-expr pieces. |
| return ParsePostfixExpressionSuffix(Res); |
| |
| case tok::identifier: // primary-expression: identifier |
| // constant: enumeration-constant |
| case tok::char_constant: // constant: character-constant |
| 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.ParseSimplePrimaryExpr(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_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.ParseUnaryOp(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] |
| case tok::kw___extension__:{//unary-expression:'__extension__' cast-expr [GNU] |
| // FIXME: Extension not handled correctly here! |
| SourceLocation SavedLoc = ConsumeToken(); |
| Res = ParseCastExpression(false); |
| if (!Res.isInvalid) |
| Res = Actions.ParseUnaryOp(SavedLoc, SavedKind, Res.Val); |
| 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 |
| Diag(Tok, diag::ext_gnu_address_of_label); |
| SourceLocation SavedLoc = ConsumeToken(); |
| |
| if (Tok.getKind() != tok::identifier) { |
| Diag(Tok, diag::err_expected_ident); |
| return ExprResult(true); |
| } |
| // FIXME: Create a label ref for Tok.Ident. |
| Res = Actions.ParseUnaryOp(SavedLoc, SavedKind, 0); |
| ConsumeToken(); |
| |
| return Res; |
| } |
| 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.getKind() == tok::r_square) |
| LHS = Actions.ParseArraySubscriptExpr(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] ')' |
| SmallVector<ExprTy*, 8> ArgExprs; |
| SmallVector<SourceLocation, 8> CommaLocs; |
| bool ArgExprsOk = true; |
| |
| Loc = ConsumeParen(); |
| |
| if (Tok.getKind() != tok::r_paren) { |
| while (1) { |
| ExprResult ArgExpr = ParseAssignmentExpression(); |
| if (ArgExpr.isInvalid) |
| ArgExprsOk = false; |
| else |
| ArgExprs.push_back(ArgExpr.Val); |
| |
| if (Tok.getKind() != tok::comma) |
| break; |
| // Move to the next argument, remember where the comma was. |
| CommaLocs.push_back(ConsumeToken()); |
| } |
| } |
| |
| // Match the ')'. |
| if (!LHS.isInvalid && ArgExprsOk && Tok.getKind() == tok::r_paren) { |
| assert((ArgExprs.size() == 0 || ArgExprs.size()-1 == CommaLocs.size())&& |
| "Unexpected number of commas!"); |
| LHS = Actions.ParseCallExpr(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.getKind() != tok::identifier) { |
| Diag(Tok, diag::err_expected_ident); |
| return ExprResult(true); |
| } |
| |
| if (!LHS.isInvalid) |
| LHS = Actions.ParseMemberReferenceExpr(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.ParsePostfixUnaryOp(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.getKind() == tok::kw_sizeof || |
| Tok.getKind() == tok::kw___alignof) && |
| "Not a sizeof/alignof expression!"); |
| LexerToken OpTok = Tok; |
| ConsumeToken(); |
| |
| // If the operand doesn't start with an '(', it must be an expression. |
| ExprResult Operand; |
| if (Tok.getKind() != 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.ParseSizeOfAlignOfTypeExpr(OpTok.getLocation(), |
| OpTok.getKind() == tok::kw_sizeof, |
| LParenLoc, CastTy, RParenLoc); |
| } |
| } |
| |
| // If we get here, the operand to the sizeof/alignof was an expresion. |
| if (!Operand.isInvalid) |
| Operand = Actions.ParseUnaryOp(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 ')' |
| /// |
| /// [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.getKind() != 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: |
| Res = ParseAssignmentExpression(); |
| if (Res.isInvalid) { |
| SkipUntil(tok::r_paren); |
| return Res; |
| } |
| |
| if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) |
| return ExprResult(true); |
| |
| ParseTypeName(); |
| break; |
| |
| case tok::kw___builtin_offsetof: |
| ParseTypeName(); |
| |
| if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) |
| return ExprResult(true); |
| |
| // We must have at least one identifier here. |
| if (ExpectAndConsume(tok::identifier, diag::err_expected_ident, "", |
| tok::r_paren)) |
| return ExprResult(true); |
| |
| while (1) { |
| if (Tok.getKind() == tok::period) { |
| // offsetof-member-designator: offsetof-member-designator '.' identifier |
| ConsumeToken(); |
| |
| if (ExpectAndConsume(tok::identifier, diag::err_expected_ident, "", |
| tok::r_paren)) |
| return ExprResult(true); |
| } else if (Tok.getKind() == tok::l_square) { |
| // offsetof-member-designator: offsetof-member-design '[' expression ']' |
| SourceLocation LSquareLoc = ConsumeBracket(); |
| Res = ParseExpression(); |
| if (Res.isInvalid) { |
| SkipUntil(tok::r_paren); |
| return Res; |
| } |
| |
| MatchRHSPunctuation(tok::r_square, LSquareLoc); |
| } else { |
| break; |
| } |
| } |
| break; |
| case tok::kw___builtin_choose_expr: |
| Res = ParseAssignmentExpression(); |
| |
| if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) |
| return ExprResult(true); |
| |
| Res = ParseAssignmentExpression(); |
| |
| if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) |
| return ExprResult(true); |
| |
| Res = ParseAssignmentExpression(); |
| break; |
| case tok::kw___builtin_types_compatible_p: |
| ParseTypeName(); |
| |
| if (ExpectAndConsume(tok::comma, diag::err_expected_comma, "",tok::r_paren)) |
| return ExprResult(true); |
| |
| ParseTypeName(); |
| break; |
| } |
| |
| MatchRHSPunctuation(tok::r_paren, LParenLoc); |
| |
| // 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.getKind() == tok::l_paren && "Not a paren expr!"); |
| SourceLocation OpenLoc = ConsumeParen(); |
| ExprResult Result(false); |
| CastTy = 0; |
| |
| if (ExprType >= CompoundStmt && Tok.getKind() == tok::l_brace && |
| !getLang().NoExtensions) { |
| Diag(Tok, diag::ext_gnu_statement_expr); |
| ParseCompoundStatement(); |
| ExprType = CompoundStmt; |
| // TODO: Build AST for GNU compound stmt. |
| } else if (ExprType >= CompoundLiteral && isTypeSpecifierQualifier()) { |
| // Otherwise, this is a compound literal expression or cast expression. |
| TypeTy *Ty = ParseTypeName(); |
| |
| // Match the ')'. |
| if (Tok.getKind() == tok::r_paren) |
| RParenLoc = ConsumeParen(); |
| else |
| MatchRHSPunctuation(tok::r_paren, OpenLoc); |
| |
| if (Tok.getKind() == tok::l_brace) { |
| if (!getLang().C99) // Compound literals don't exist in C90. |
| Diag(OpenLoc, diag::ext_c99_compound_literal); |
| Result = ParseInitializer(); |
| ExprType = CompoundLiteral; |
| // TODO: Build AST for compound literal. |
| } 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.getKind() == tok::r_paren) |
| Result = Actions.ParseParenExpr(OpenLoc, Tok.getLocation(), Result.Val); |
| } |
| |
| // Match the ')'. |
| if (Result.isInvalid) |
| SkipUntil(tok::r_paren); |
| else { |
| if (Tok.getKind() == tok::r_paren) |
| RParenLoc = ConsumeParen(); |
| else |
| MatchRHSPunctuation(tok::r_paren, OpenLoc); |
| } |
| |
| return Result; |
| } |
| |
| /// HexDigitValue - Return the value of the specified hex digit, or -1 if it's |
| /// not valid. |
| static int HexDigitValue(char C) { |
| if (C >= '0' && C <= '9') return C-'0'; |
| if (C >= 'a' && C <= 'f') return C-'a'+10; |
| if (C >= 'A' && C <= 'F') return C-'A'+10; |
| return -1; |
| } |
| |
| /// 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. |
| SmallVector<LexerToken, 4> StringToks; |
| |
| // While we're looking at all of the string portions, remember the max |
| // individual token length, computing a bound on the concatenated string |
| // length, and see whether any piece is a wide-string. If any of the string |
| // portions is a wide-string literal, the result is also a wide-string literal |
| // [C99 6.4.5p4]. |
| unsigned SizeBound = 0, MaxTokenLength = 0; |
| bool AnyWide = false; |
| do { |
| // The string could be shorter than this if it needs cleaning, but this is a |
| // reasonable bound, which is all we need. |
| SizeBound += Tok.getLength()-2; // -2 for "". |
| |
| // Find maximum string piece length. |
| if (Tok.getLength() > MaxTokenLength) |
| MaxTokenLength = Tok.getLength(); |
| |
| // Remember if we see any wide strings. |
| AnyWide |= Tok.getKind() == tok::wide_string_literal; |
| |
| // Remember the string token. |
| StringToks.push_back(Tok); |
| ConsumeStringToken(); |
| } while (isTokenStringLiteral()); |
| |
| // Include space for the null terminator. |
| ++SizeBound; |
| |
| // TODO: K&R warning: "traditional C rejects string constant concatenation" |
| |
| // Get the width in bytes of wchar_t. If no wchar_t strings are used, do not |
| // query the target. As such, wchar_tByteWidth is only valid if AnyWide=true. |
| unsigned wchar_tByteWidth = ~0U; |
| if (AnyWide) |
| wchar_tByteWidth=getTargetInfo().getWCharWidth(StringToks[0].getLocation()); |
| |
| // The output buffer size needs to be large enough to hold wide characters. |
| // This is a worst-case assumption which basically corresponds to L"" "long". |
| if (AnyWide) |
| SizeBound *= wchar_tByteWidth; |
| |
| // Create a temporary buffer to hold the result string data. |
| SmallString<512> ResultBuf; |
| ResultBuf.resize(SizeBound); |
| |
| // Likewise, but for each string piece. |
| SmallString<512> TokenBuf; |
| TokenBuf.resize(MaxTokenLength); |
| |
| // Loop over all the strings, getting their spelling, and expanding them to |
| // wide strings as appropriate. |
| char *ResultPtr = &ResultBuf[0]; // Next byte to fill in. |
| |
| for (unsigned i = 0, e = StringToks.size(); i != e; ++i) { |
| const char *ThisTokBuf = &TokenBuf[0]; |
| // Get the spelling of the token, which eliminates trigraphs, etc. We know |
| // that ThisTokBuf points to a buffer that is big enough for the whole token |
| // and 'spelled' tokens can only shrink. |
| unsigned ThisTokLen = PP.getSpelling(StringToks[i], ThisTokBuf); |
| const char *ThisTokEnd = ThisTokBuf+ThisTokLen-1; // Skip end quote. |
| |
| // TODO: Input character set mapping support. |
| |
| // Skip L marker for wide strings. |
| if (ThisTokBuf[0] == 'L') ++ThisTokBuf; |
| |
| assert(ThisTokBuf[0] == '"' && "Expected quote, lexer broken?"); |
| ++ThisTokBuf; |
| |
| while (ThisTokBuf != ThisTokEnd) { |
| // Is this a span of non-escape characters? |
| if (ThisTokBuf[0] != '\\') { |
| const char *InStart = ThisTokBuf; |
| do { |
| ++ThisTokBuf; |
| } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\'); |
| |
| // Copy the character span over. |
| unsigned Len = ThisTokBuf-InStart; |
| if (!AnyWide) { |
| memcpy(ResultPtr, InStart, Len); |
| ResultPtr += Len; |
| } else { |
| // Note: our internal rep of wide char tokens is always little-endian. |
| for (; Len; --Len, ++InStart) { |
| *ResultPtr++ = InStart[0]; |
| // Add zeros at the end. |
| for (unsigned i = 1, e = wchar_tByteWidth; i != e; ++i) |
| *ResultPtr++ = 0; |
| } |
| } |
| continue; |
| } |
| |
| // Otherwise, this is an escape character. Skip the '\' char. |
| ++ThisTokBuf; |
| |
| // We know that this character can't be off the end of the buffer, because |
| // that would have been \", which would not have been the end of string. |
| unsigned ResultChar = *ThisTokBuf++; |
| switch (ResultChar) { |
| // These map to themselves. |
| case '\\': case '\'': case '"': case '?': break; |
| |
| // These have fixed mappings. |
| case 'a': |
| // TODO: K&R: the meaning of '\\a' is different in traditional C |
| ResultChar = 7; |
| break; |
| case 'b': |
| ResultChar = 8; |
| break; |
| case 'e': |
| PP.Diag(StringToks[i], diag::ext_nonstandard_escape, "e"); |
| ResultChar = 27; |
| break; |
| case 'f': |
| ResultChar = 12; |
| break; |
| case 'n': |
| ResultChar = 10; |
| break; |
| case 'r': |
| ResultChar = 13; |
| break; |
| case 't': |
| ResultChar = 9; |
| break; |
| case 'v': |
| ResultChar = 11; |
| break; |
| |
| //case 'u': case 'U': // FIXME: UCNs. |
| case 'x': // Hex escape. |
| if (ThisTokBuf == ThisTokEnd || |
| (ResultChar = HexDigitValue(*ThisTokBuf)) == ~0U) { |
| PP.Diag(StringToks[i], diag::err_hex_escape_no_digits); |
| ResultChar = 0; |
| break; |
| } |
| ++ThisTokBuf; // Consumed one hex digit. |
| |
| assert(0 && "hex escape: unimp!"); |
| break; |
| case '0': case '1': case '2': case '3': |
| case '4': case '5': case '6': case '7': |
| // Octal escapes. |
| assert(0 && "octal escape: unimp!"); |
| break; |
| |
| // Otherwise, these are not valid escapes. |
| case '(': case '{': case '[': case '%': |
| // GCC accepts these as extensions. We warn about them as such though. |
| if (!PP.getLangOptions().NoExtensions) { |
| PP.Diag(StringToks[i], diag::ext_nonstandard_escape, |
| std::string()+(char)ResultChar); |
| break; |
| } |
| // FALL THROUGH. |
| default: |
| if (isgraph(ThisTokBuf[0])) { |
| PP.Diag(StringToks[i], diag::ext_unknown_escape, |
| std::string()+(char)ResultChar); |
| } else { |
| PP.Diag(StringToks[i], diag::ext_unknown_escape, |
| "x"+utohexstr(ResultChar)); |
| } |
| } |
| |
| // Note: our internal rep of wide char tokens is always little-endian. |
| *ResultPtr++ = ResultChar & 0xFF; |
| |
| if (AnyWide) { |
| for (unsigned i = 1, e = wchar_tByteWidth; i != e; ++i) |
| *ResultPtr++ = ResultChar >> i*8; |
| } |
| } |
| } |
| |
| // Add zero terminator. |
| *ResultPtr = 0; |
| if (AnyWide) { |
| for (unsigned i = 1, e = wchar_tByteWidth; i != e; ++i) |
| *ResultPtr++ = 0; |
| } |
| |
| SmallVector<SourceLocation, 4> StringTokLocs; |
| for (unsigned i = 0; i != StringToks.size(); ++i) |
| StringTokLocs.push_back(StringToks[i].getLocation()); |
| |
| // Hand this off to the Actions. |
| return Actions.ParseStringExpr(&ResultBuf[0], ResultPtr-&ResultBuf[0], |
| AnyWide, &StringTokLocs[0], |
| StringTokLocs.size()); |
| } |
| |
