//===--- ParseStmt.cpp - Statement and Block Parser -----------------------===// // // 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 Statement and Block portions of the Parser // interface. // //===----------------------------------------------------------------------===// #include "clang/Parse/Parser.h" #include "RAIIObjectsForParser.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/PrettyDeclStackTrace.h" #include "clang/Sema/Scope.h" #include "clang/Basic/Diagnostic.h" #include "clang/Basic/PrettyStackTrace.h" #include "clang/Basic/SourceManager.h" using namespace clang; //===----------------------------------------------------------------------===// // C99 6.8: Statements and Blocks. //===----------------------------------------------------------------------===// /// ParseStatementOrDeclaration - Read 'statement' or 'declaration'. /// StatementOrDeclaration: /// statement /// declaration /// /// statement: /// labeled-statement /// compound-statement /// expression-statement /// selection-statement /// iteration-statement /// jump-statement /// [C++] declaration-statement /// [C++] try-block /// [MS] seh-try-block /// [OBC] objc-throw-statement /// [OBC] objc-try-catch-statement /// [OBC] objc-synchronized-statement /// [GNU] asm-statement /// [OMP] openmp-construct [TODO] /// /// labeled-statement: /// identifier ':' statement /// 'case' constant-expression ':' statement /// 'default' ':' statement /// /// selection-statement: /// if-statement /// switch-statement /// /// iteration-statement: /// while-statement /// do-statement /// for-statement /// /// expression-statement: /// expression[opt] ';' /// /// jump-statement: /// 'goto' identifier ';' /// 'continue' ';' /// 'break' ';' /// 'return' expression[opt] ';' /// [GNU] 'goto' '*' expression ';' /// /// [OBC] objc-throw-statement: /// [OBC] '@' 'throw' expression ';' /// [OBC] '@' 'throw' ';' /// StmtResult Parser::ParseStatementOrDeclaration(StmtVector &Stmts, bool OnlyStatement, SourceLocation *TrailingElseLoc) { ParenBraceBracketBalancer BalancerRAIIObj(*this); ParsedAttributesWithRange Attrs(AttrFactory); MaybeParseCXX0XAttributes(Attrs, 0, /*MightBeObjCMessageSend*/ true); StmtResult Res = ParseStatementOrDeclarationAfterAttributes(Stmts, OnlyStatement, TrailingElseLoc, Attrs); assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) && "attributes on empty statement"); if (Attrs.empty() || Res.isInvalid()) return Res; return Actions.ProcessStmtAttributes(Res.get(), Attrs.getList(), Attrs.Range); } StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(StmtVector &Stmts, bool OnlyStatement, SourceLocation *TrailingElseLoc, ParsedAttributesWithRange &Attrs) { const char *SemiError = 0; StmtResult Res; // Cases in this switch statement should fall through if the parser expects // the token to end in a semicolon (in which case SemiError should be set), // or they directly 'return;' if not. Retry: tok::TokenKind Kind = Tok.getKind(); SourceLocation AtLoc; switch (Kind) { case tok::at: // May be a @try or @throw statement { ProhibitAttributes(Attrs); // TODO: is it correct? AtLoc = ConsumeToken(); // consume @ return ParseObjCAtStatement(AtLoc); } case tok::code_completion: Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement); cutOffParsing(); return StmtError(); case tok::identifier: { Token Next = NextToken(); if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement // identifier ':' statement return ParseLabeledStatement(Attrs); } if (Next.isNot(tok::coloncolon)) { CXXScopeSpec SS; IdentifierInfo *Name = Tok.getIdentifierInfo(); SourceLocation NameLoc = Tok.getLocation(); if (getLangOpts().CPlusPlus) CheckForTemplateAndDigraph(Next, ParsedType(), /*EnteringContext=*/false, *Name, SS); Sema::NameClassification Classification = Actions.ClassifyName(getCurScope(), SS, Name, NameLoc, Next); switch (Classification.getKind()) { case Sema::NC_Keyword: // The identifier was corrected to a keyword. Update the token // to this keyword, and try again. if (Name->getTokenID() != tok::identifier) { Tok.setIdentifierInfo(Name); Tok.setKind(Name->getTokenID()); goto Retry; } // Fall through via the normal error path. // FIXME: This seems like it could only happen for context-sensitive // keywords. case Sema::NC_Error: // Handle errors here by skipping up to the next semicolon or '}', and // eat the semicolon if that's what stopped us. SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true); if (Tok.is(tok::semi)) ConsumeToken(); return StmtError(); case Sema::NC_Unknown: // Either we don't know anything about this identifier, or we know that // we're in a syntactic context we haven't handled yet. break; case Sema::NC_Type: Tok.setKind(tok::annot_typename); setTypeAnnotation(Tok, Classification.getType()); Tok.setAnnotationEndLoc(NameLoc); PP.AnnotateCachedTokens(Tok); break; case Sema::NC_Expression: Tok.setKind(tok::annot_primary_expr); setExprAnnotation(Tok, Classification.getExpression()); Tok.setAnnotationEndLoc(NameLoc); PP.AnnotateCachedTokens(Tok); break; case Sema::NC_TypeTemplate: case Sema::NC_FunctionTemplate: { ConsumeToken(); // the identifier UnqualifiedId Id; Id.setIdentifier(Name, NameLoc); if (AnnotateTemplateIdToken( TemplateTy::make(Classification.getTemplateName()), Classification.getTemplateNameKind(), SS, SourceLocation(), Id, /*AllowTypeAnnotation=*/false)) { // Handle errors here by skipping up to the next semicolon or '}', and // eat the semicolon if that's what stopped us. SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true); if (Tok.is(tok::semi)) ConsumeToken(); return StmtError(); } // If the next token is '::', jump right into parsing a // nested-name-specifier. We don't want to leave the template-id // hanging. if (NextToken().is(tok::coloncolon) && TryAnnotateCXXScopeToken(false)){ // Handle errors here by skipping up to the next semicolon or '}', and // eat the semicolon if that's what stopped us. SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true); if (Tok.is(tok::semi)) ConsumeToken(); return StmtError(); } // We've annotated a template-id, so try again now. goto Retry; } case Sema::NC_NestedNameSpecifier: // FIXME: Implement this! break; } } // Fall through } default: { if ((getLangOpts().CPlusPlus || !OnlyStatement) && isDeclarationStatement()) { SourceLocation DeclStart = Tok.getLocation(), DeclEnd; DeclGroupPtrTy Decl = ParseDeclaration(Stmts, Declarator::BlockContext, DeclEnd, Attrs); return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd); } if (Tok.is(tok::r_brace)) { Diag(Tok, diag::err_expected_statement); return StmtError(); } return ParseExprStatement(); } case tok::kw_case: // C99 6.8.1: labeled-statement return ParseCaseStatement(); case tok::kw_default: // C99 6.8.1: labeled-statement return ParseDefaultStatement(); case tok::l_brace: // C99 6.8.2: compound-statement return ParseCompoundStatement(); case tok::semi: { // C99 6.8.3p3: expression[opt] ';' bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro(); return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro); } case tok::kw_if: // C99 6.8.4.1: if-statement return ParseIfStatement(TrailingElseLoc); case tok::kw_switch: // C99 6.8.4.2: switch-statement return ParseSwitchStatement(TrailingElseLoc); case tok::kw_while: // C99 6.8.5.1: while-statement return ParseWhileStatement(TrailingElseLoc); case tok::kw_do: // C99 6.8.5.2: do-statement Res = ParseDoStatement(); SemiError = "do/while"; break; case tok::kw_for: // C99 6.8.5.3: for-statement return ParseForStatement(TrailingElseLoc); case tok::kw_goto: // C99 6.8.6.1: goto-statement Res = ParseGotoStatement(); SemiError = "goto"; break; case tok::kw_continue: // C99 6.8.6.2: continue-statement Res = ParseContinueStatement(); SemiError = "continue"; break; case tok::kw_break: // C99 6.8.6.3: break-statement Res = ParseBreakStatement(); SemiError = "break"; break; case tok::kw_return: // C99 6.8.6.4: return-statement Res = ParseReturnStatement(); SemiError = "return"; break; case tok::kw_asm: { ProhibitAttributes(Attrs); bool msAsm = false; Res = ParseAsmStatement(msAsm); Res = Actions.ActOnFinishFullStmt(Res.get()); if (msAsm) return move(Res); SemiError = "asm"; break; } case tok::kw_try: // C++ 15: try-block return ParseCXXTryBlock(); case tok::kw___try: ProhibitAttributes(Attrs); // TODO: is it correct? return ParseSEHTryBlock(); case tok::annot_pragma_vis: ProhibitAttributes(Attrs); HandlePragmaVisibility(); return StmtEmpty(); case tok::annot_pragma_pack: ProhibitAttributes(Attrs); HandlePragmaPack(); return StmtEmpty(); } // If we reached this code, the statement must end in a semicolon. if (Tok.is(tok::semi)) { ConsumeToken(); } else if (!Res.isInvalid()) { // If the result was valid, then we do want to diagnose this. Use // ExpectAndConsume to emit the diagnostic, even though we know it won't // succeed. ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError); // Skip until we see a } or ;, but don't eat it. SkipUntil(tok::r_brace, true, true); } return move(Res); } /// \brief Parse an expression statement. StmtResult Parser::ParseExprStatement() { // If a case keyword is missing, this is where it should be inserted. Token OldToken = Tok; // expression[opt] ';' ExprResult Expr(ParseExpression()); if (Expr.isInvalid()) { // If the expression is invalid, skip ahead to the next semicolon or '}'. // Not doing this opens us up to the possibility of infinite loops if // ParseExpression does not consume any tokens. SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true); if (Tok.is(tok::semi)) ConsumeToken(); return StmtError(); } if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() && Actions.CheckCaseExpression(Expr.get())) { // If a constant expression is followed by a colon inside a switch block, // suggest a missing case keyword. Diag(OldToken, diag::err_expected_case_before_expression) << FixItHint::CreateInsertion(OldToken.getLocation(), "case "); // Recover parsing as a case statement. return ParseCaseStatement(/*MissingCase=*/true, Expr); } // Otherwise, eat the semicolon. ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); return Actions.ActOnExprStmt(Actions.MakeFullExpr(Expr.get())); } StmtResult Parser::ParseSEHTryBlock() { assert(Tok.is(tok::kw___try) && "Expected '__try'"); SourceLocation Loc = ConsumeToken(); return ParseSEHTryBlockCommon(Loc); } /// ParseSEHTryBlockCommon /// /// seh-try-block: /// '__try' compound-statement seh-handler /// /// seh-handler: /// seh-except-block /// seh-finally-block /// StmtResult Parser::ParseSEHTryBlockCommon(SourceLocation TryLoc) { if(Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok,diag::err_expected_lbrace)); StmtResult TryBlock(ParseCompoundStatement()); if(TryBlock.isInvalid()) return move(TryBlock); StmtResult Handler; if (Tok.is(tok::identifier) && Tok.getIdentifierInfo() == getSEHExceptKeyword()) { SourceLocation Loc = ConsumeToken(); Handler = ParseSEHExceptBlock(Loc); } else if (Tok.is(tok::kw___finally)) { SourceLocation Loc = ConsumeToken(); Handler = ParseSEHFinallyBlock(Loc); } else { return StmtError(Diag(Tok,diag::err_seh_expected_handler)); } if(Handler.isInvalid()) return move(Handler); return Actions.ActOnSEHTryBlock(false /* IsCXXTry */, TryLoc, TryBlock.take(), Handler.take()); } /// ParseSEHExceptBlock - Handle __except /// /// seh-except-block: /// '__except' '(' seh-filter-expression ')' compound-statement /// StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) { PoisonIdentifierRAIIObject raii(Ident__exception_code, false), raii2(Ident___exception_code, false), raii3(Ident_GetExceptionCode, false); if(ExpectAndConsume(tok::l_paren,diag::err_expected_lparen)) return StmtError(); ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope); if (getLangOpts().Borland) { Ident__exception_info->setIsPoisoned(false); Ident___exception_info->setIsPoisoned(false); Ident_GetExceptionInfo->setIsPoisoned(false); } ExprResult FilterExpr(ParseExpression()); if (getLangOpts().Borland) { Ident__exception_info->setIsPoisoned(true); Ident___exception_info->setIsPoisoned(true); Ident_GetExceptionInfo->setIsPoisoned(true); } if(FilterExpr.isInvalid()) return StmtError(); if(ExpectAndConsume(tok::r_paren,diag::err_expected_rparen)) return StmtError(); StmtResult Block(ParseCompoundStatement()); if(Block.isInvalid()) return move(Block); return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.take(), Block.take()); } /// ParseSEHFinallyBlock - Handle __finally /// /// seh-finally-block: /// '__finally' compound-statement /// StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyBlock) { PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false), raii2(Ident___abnormal_termination, false), raii3(Ident_AbnormalTermination, false); StmtResult Block(ParseCompoundStatement()); if(Block.isInvalid()) return move(Block); return Actions.ActOnSEHFinallyBlock(FinallyBlock,Block.take()); } /// ParseLabeledStatement - We have an identifier and a ':' after it. /// /// labeled-statement: /// identifier ':' statement /// [GNU] identifier ':' attributes[opt] statement /// StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) { assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() && "Not an identifier!"); Token IdentTok = Tok; // Save the whole token. ConsumeToken(); // eat the identifier. assert(Tok.is(tok::colon) && "Not a label!"); // identifier ':' statement SourceLocation ColonLoc = ConsumeToken(); // Read label attributes, if present. attrs will contain both C++11 and GNU // attributes (if present) after this point. MaybeParseGNUAttributes(attrs); StmtResult SubStmt(ParseStatement()); // Broken substmt shouldn't prevent the label from being added to the AST. if (SubStmt.isInvalid()) SubStmt = Actions.ActOnNullStmt(ColonLoc); LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(), IdentTok.getLocation()); if (AttributeList *Attrs = attrs.getList()) { Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs); attrs.clear(); } return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc, SubStmt.get()); } /// ParseCaseStatement /// labeled-statement: /// 'case' constant-expression ':' statement /// [GNU] 'case' constant-expression '...' constant-expression ':' statement /// StmtResult Parser::ParseCaseStatement(bool MissingCase, ExprResult Expr) { assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!"); // It is very very common for code to contain many case statements recursively // nested, as in (but usually without indentation): // case 1: // case 2: // case 3: // case 4: // case 5: etc. // // Parsing this naively works, but is both inefficient and can cause us to run // out of stack space in our recursive descent parser. As a special case, // flatten this recursion into an iterative loop. This is complex and gross, // but all the grossness is constrained to ParseCaseStatement (and some // wierdness in the actions), so this is just local grossness :). // TopLevelCase - This is the highest level we have parsed. 'case 1' in the // example above. StmtResult TopLevelCase(true); // DeepestParsedCaseStmt - This is the deepest statement we have parsed, which // gets updated each time a new case is parsed, and whose body is unset so // far. When parsing 'case 4', this is the 'case 3' node. Stmt *DeepestParsedCaseStmt = 0; // While we have case statements, eat and stack them. SourceLocation ColonLoc; do { SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() : ConsumeToken(); // eat the 'case'. if (Tok.is(tok::code_completion)) { Actions.CodeCompleteCase(getCurScope()); cutOffParsing(); return StmtError(); } /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'. /// Disable this form of error recovery while we're parsing the case /// expression. ColonProtectionRAIIObject ColonProtection(*this); ExprResult LHS(MissingCase ? Expr : ParseConstantExpression()); MissingCase = false; if (LHS.isInvalid()) { SkipUntil(tok::colon); return StmtError(); } // GNU case range extension. SourceLocation DotDotDotLoc; ExprResult RHS; if (Tok.is(tok::ellipsis)) { Diag(Tok, diag::ext_gnu_case_range); DotDotDotLoc = ConsumeToken(); RHS = ParseConstantExpression(); if (RHS.isInvalid()) { SkipUntil(tok::colon); return StmtError(); } } ColonProtection.restore(); if (Tok.is(tok::colon)) { ColonLoc = ConsumeToken(); // Treat "case blah;" as a typo for "case blah:". } else if (Tok.is(tok::semi)) { ColonLoc = ConsumeToken(); Diag(ColonLoc, diag::err_expected_colon_after) << "'case'" << FixItHint::CreateReplacement(ColonLoc, ":"); } else { SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); Diag(ExpectedLoc, diag::err_expected_colon_after) << "'case'" << FixItHint::CreateInsertion(ExpectedLoc, ":"); ColonLoc = ExpectedLoc; } StmtResult Case = Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc, RHS.get(), ColonLoc); // If we had a sema error parsing this case, then just ignore it and // continue parsing the sub-stmt. if (Case.isInvalid()) { if (TopLevelCase.isInvalid()) // No parsed case stmts. return ParseStatement(); // Otherwise, just don't add it as a nested case. } else { // If this is the first case statement we parsed, it becomes TopLevelCase. // Otherwise we link it into the current chain. Stmt *NextDeepest = Case.get(); if (TopLevelCase.isInvalid()) TopLevelCase = move(Case); else Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get()); DeepestParsedCaseStmt = NextDeepest; } // Handle all case statements. } while (Tok.is(tok::kw_case)); assert(!TopLevelCase.isInvalid() && "Should have parsed at least one case!"); // If we found a non-case statement, start by parsing it. StmtResult SubStmt; if (Tok.isNot(tok::r_brace)) { SubStmt = ParseStatement(); } else { // Nicely diagnose the common error "switch (X) { case 4: }", which is // not valid. SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc); Diag(AfterColonLoc, diag::err_label_end_of_compound_statement) << FixItHint::CreateInsertion(AfterColonLoc, " ;"); SubStmt = true; } // Broken sub-stmt shouldn't prevent forming the case statement properly. if (SubStmt.isInvalid()) SubStmt = Actions.ActOnNullStmt(SourceLocation()); // Install the body into the most deeply-nested case. Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get()); // Return the top level parsed statement tree. return move(TopLevelCase); } /// ParseDefaultStatement /// labeled-statement: /// 'default' ':' statement /// Note that this does not parse the 'statement' at the end. /// StmtResult Parser::ParseDefaultStatement() { assert(Tok.is(tok::kw_default) && "Not a default stmt!"); SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'. SourceLocation ColonLoc; if (Tok.is(tok::colon)) { ColonLoc = ConsumeToken(); // Treat "default;" as a typo for "default:". } else if (Tok.is(tok::semi)) { ColonLoc = ConsumeToken(); Diag(ColonLoc, diag::err_expected_colon_after) << "'default'" << FixItHint::CreateReplacement(ColonLoc, ":"); } else { SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); Diag(ExpectedLoc, diag::err_expected_colon_after) << "'default'" << FixItHint::CreateInsertion(ExpectedLoc, ":"); ColonLoc = ExpectedLoc; } StmtResult SubStmt; if (Tok.isNot(tok::r_brace)) { SubStmt = ParseStatement(); } else { // Diagnose the common error "switch (X) {... default: }", which is // not valid. SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc); Diag(AfterColonLoc, diag::err_label_end_of_compound_statement) << FixItHint::CreateInsertion(AfterColonLoc, " ;"); SubStmt = true; } // Broken sub-stmt shouldn't prevent forming the case statement properly. if (SubStmt.isInvalid()) SubStmt = Actions.ActOnNullStmt(ColonLoc); return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc, SubStmt.get(), getCurScope()); } StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) { return ParseCompoundStatement(isStmtExpr, Scope::DeclScope); } /// ParseCompoundStatement - Parse a "{}" block. /// /// compound-statement: [C99 6.8.2] /// { block-item-list[opt] } /// [GNU] { label-declarations block-item-list } [TODO] /// /// block-item-list: /// block-item /// block-item-list block-item /// /// block-item: /// declaration /// [GNU] '__extension__' declaration /// statement /// [OMP] openmp-directive [TODO] /// /// [GNU] label-declarations: /// [GNU] label-declaration /// [GNU] label-declarations label-declaration /// /// [GNU] label-declaration: /// [GNU] '__label__' identifier-list ';' /// /// [OMP] openmp-directive: [TODO] /// [OMP] barrier-directive /// [OMP] flush-directive /// StmtResult Parser::ParseCompoundStatement(bool isStmtExpr, unsigned ScopeFlags) { assert(Tok.is(tok::l_brace) && "Not a compount stmt!"); // Enter a scope to hold everything within the compound stmt. Compound // statements can always hold declarations. ParseScope CompoundScope(this, ScopeFlags); // Parse the statements in the body. return ParseCompoundStatementBody(isStmtExpr); } /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the /// ActOnCompoundStmt action. This expects the '{' to be the current token, and /// consume the '}' at the end of the block. It does not manipulate the scope /// stack. StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) { PrettyStackTraceLoc CrashInfo(PP.getSourceManager(), Tok.getLocation(), "in compound statement ('{}')"); InMessageExpressionRAIIObject InMessage(*this, false); BalancedDelimiterTracker T(*this, tok::l_brace); if (T.consumeOpen()) return StmtError(); Sema::CompoundScopeRAII CompoundScope(Actions); StmtVector Stmts(Actions); // "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are // only allowed at the start of a compound stmt regardless of the language. while (Tok.is(tok::kw___label__)) { SourceLocation LabelLoc = ConsumeToken(); Diag(LabelLoc, diag::ext_gnu_local_label); SmallVector DeclsInGroup; while (1) { if (Tok.isNot(tok::identifier)) { Diag(Tok, diag::err_expected_ident); break; } IdentifierInfo *II = Tok.getIdentifierInfo(); SourceLocation IdLoc = ConsumeToken(); DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc)); if (!Tok.is(tok::comma)) break; ConsumeToken(); } DeclSpec DS(AttrFactory); DeclGroupPtrTy Res = Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup.data(), DeclsInGroup.size()); StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation()); ExpectAndConsume(tok::semi, diag::err_expected_semi_declaration); if (R.isUsable()) Stmts.push_back(R.release()); } while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) { if (Tok.is(tok::annot_pragma_unused)) { HandlePragmaUnused(); continue; } if (getLangOpts().MicrosoftExt && (Tok.is(tok::kw___if_exists) || Tok.is(tok::kw___if_not_exists))) { ParseMicrosoftIfExistsStatement(Stmts); continue; } StmtResult R; if (Tok.isNot(tok::kw___extension__)) { R = ParseStatementOrDeclaration(Stmts, false); } else { // __extension__ can start declarations and it can also be a unary // operator for expressions. Consume multiple __extension__ markers here // until we can determine which is which. // FIXME: This loses extension expressions in the AST! SourceLocation ExtLoc = ConsumeToken(); while (Tok.is(tok::kw___extension__)) ConsumeToken(); ParsedAttributesWithRange attrs(AttrFactory); MaybeParseCXX0XAttributes(attrs, 0, /*MightBeObjCMessageSend*/ true); // If this is the start of a declaration, parse it as such. if (isDeclarationStatement()) { // __extension__ silences extension warnings in the subdeclaration. // FIXME: Save the __extension__ on the decl as a node somehow? ExtensionRAIIObject O(Diags); SourceLocation DeclStart = Tok.getLocation(), DeclEnd; DeclGroupPtrTy Res = ParseDeclaration(Stmts, Declarator::BlockContext, DeclEnd, attrs); R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd); } else { // Otherwise this was a unary __extension__ marker. ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc)); if (Res.isInvalid()) { SkipUntil(tok::semi); continue; } // FIXME: Use attributes? // Eat the semicolon at the end of stmt and convert the expr into a // statement. ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); R = Actions.ActOnExprStmt(Actions.MakeFullExpr(Res.get())); } } if (R.isUsable()) Stmts.push_back(R.release()); } SourceLocation CloseLoc = Tok.getLocation(); // We broke out of the while loop because we found a '}' or EOF. if (Tok.isNot(tok::r_brace)) { Diag(Tok, diag::err_expected_rbrace); Diag(T.getOpenLocation(), diag::note_matching) << "{"; // Recover by creating a compound statement with what we parsed so far, // instead of dropping everything and returning StmtError(); } else { if (!T.consumeClose()) CloseLoc = T.getCloseLocation(); } return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc, move_arg(Stmts), isStmtExpr); } /// ParseParenExprOrCondition: /// [C ] '(' expression ')' /// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true] /// /// This function parses and performs error recovery on the specified condition /// or expression (depending on whether we're in C++ or C mode). This function /// goes out of its way to recover well. It returns true if there was a parser /// error (the right paren couldn't be found), which indicates that the caller /// should try to recover harder. It returns false if the condition is /// successfully parsed. Note that a successful parse can still have semantic /// errors in the condition. bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult, Decl *&DeclResult, SourceLocation Loc, bool ConvertToBoolean) { BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); if (getLangOpts().CPlusPlus) ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean); else { ExprResult = ParseExpression(); DeclResult = 0; // If required, convert to a boolean value. if (!ExprResult.isInvalid() && ConvertToBoolean) ExprResult = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get()); } // If the parser was confused by the condition and we don't have a ')', try to // recover by skipping ahead to a semi and bailing out. If condexp is // semantically invalid but we have well formed code, keep going. if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) { SkipUntil(tok::semi); // Skipping may have stopped if it found the containing ')'. If so, we can // continue parsing the if statement. if (Tok.isNot(tok::r_paren)) return true; } // Otherwise the condition is valid or the rparen is present. T.consumeClose(); return false; } /// ParseIfStatement /// if-statement: [C99 6.8.4.1] /// 'if' '(' expression ')' statement /// 'if' '(' expression ')' statement 'else' statement /// [C++] 'if' '(' condition ')' statement /// [C++] 'if' '(' condition ')' statement 'else' statement /// StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) { assert(Tok.is(tok::kw_if) && "Not an if stmt!"); SourceLocation IfLoc = ConsumeToken(); // eat the 'if'. if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "if"; SkipUntil(tok::semi); return StmtError(); } bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; // C99 6.8.4p3 - In C99, the if statement is a block. This is not // the case for C90. // // C++ 6.4p3: // A name introduced by a declaration in a condition is in scope from its // point of declaration until the end of the substatements controlled by the // condition. // C++ 3.3.2p4: // Names declared in the for-init-statement, and in the condition of if, // while, for, and switch statements are local to the if, while, for, or // switch statement (including the controlled statement). // ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX); // Parse the condition. ExprResult CondExp; Decl *CondVar = 0; if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true)) return StmtError(); FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get())); // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do this // if the body isn't a compound statement to avoid push/pop in common cases. // // C++ 6.4p1: // The substatement in a selection-statement (each substatement, in the else // form of the if statement) implicitly defines a local scope. // // For C++ we create a scope for the condition and a new scope for // substatements because: // -When the 'then' scope exits, we want the condition declaration to still be // active for the 'else' scope too. // -Sema will detect name clashes by considering declarations of a // 'ControlScope' as part of its direct subscope. // -If we wanted the condition and substatement to be in the same scope, we // would have to notify ParseStatement not to create a new scope. It's // simpler to let it create a new scope. // ParseScope InnerScope(this, Scope::DeclScope, C99orCXX && Tok.isNot(tok::l_brace)); // Read the 'then' stmt. SourceLocation ThenStmtLoc = Tok.getLocation(); SourceLocation InnerStatementTrailingElseLoc; StmtResult ThenStmt(ParseStatement(&InnerStatementTrailingElseLoc)); // Pop the 'if' scope if needed. InnerScope.Exit(); // If it has an else, parse it. SourceLocation ElseLoc; SourceLocation ElseStmtLoc; StmtResult ElseStmt; if (Tok.is(tok::kw_else)) { if (TrailingElseLoc) *TrailingElseLoc = Tok.getLocation(); ElseLoc = ConsumeToken(); ElseStmtLoc = Tok.getLocation(); // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do // this if the body isn't a compound statement to avoid push/pop in common // cases. // // C++ 6.4p1: // The substatement in a selection-statement (each substatement, in the else // form of the if statement) implicitly defines a local scope. // ParseScope InnerScope(this, Scope::DeclScope, C99orCXX && Tok.isNot(tok::l_brace)); ElseStmt = ParseStatement(); // Pop the 'else' scope if needed. InnerScope.Exit(); } else if (Tok.is(tok::code_completion)) { Actions.CodeCompleteAfterIf(getCurScope()); cutOffParsing(); return StmtError(); } else if (InnerStatementTrailingElseLoc.isValid()) { Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else); } IfScope.Exit(); // If the condition was invalid, discard the if statement. We could recover // better by replacing it with a valid expr, but don't do that yet. if (CondExp.isInvalid() && !CondVar) return StmtError(); // If the then or else stmt is invalid and the other is valid (and present), // make turn the invalid one into a null stmt to avoid dropping the other // part. If both are invalid, return error. if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) || (ThenStmt.isInvalid() && ElseStmt.get() == 0) || (ThenStmt.get() == 0 && ElseStmt.isInvalid())) { // Both invalid, or one is invalid and other is non-present: return error. return StmtError(); } // Now if either are invalid, replace with a ';'. if (ThenStmt.isInvalid()) ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc); if (ElseStmt.isInvalid()) ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc); return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(), ElseLoc, ElseStmt.get()); } /// ParseSwitchStatement /// switch-statement: /// 'switch' '(' expression ')' statement /// [C++] 'switch' '(' condition ')' statement StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) { assert(Tok.is(tok::kw_switch) && "Not a switch stmt!"); SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'. if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "switch"; SkipUntil(tok::semi); return StmtError(); } bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; // C99 6.8.4p3 - In C99, the switch statement is a block. This is // not the case for C90. Start the switch scope. // // C++ 6.4p3: // A name introduced by a declaration in a condition is in scope from its // point of declaration until the end of the substatements controlled by the // condition. // C++ 3.3.2p4: // Names declared in the for-init-statement, and in the condition of if, // while, for, and switch statements are local to the if, while, for, or // switch statement (including the controlled statement). // unsigned ScopeFlags = Scope::BreakScope | Scope::SwitchScope; if (C99orCXX) ScopeFlags |= Scope::DeclScope | Scope::ControlScope; ParseScope SwitchScope(this, ScopeFlags); // Parse the condition. ExprResult Cond; Decl *CondVar = 0; if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false)) return StmtError(); StmtResult Switch = Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar); if (Switch.isInvalid()) { // Skip the switch body. // FIXME: This is not optimal recovery, but parsing the body is more // dangerous due to the presence of case and default statements, which // will have no place to connect back with the switch. if (Tok.is(tok::l_brace)) { ConsumeBrace(); SkipUntil(tok::r_brace, false, false); } else SkipUntil(tok::semi); return move(Switch); } // C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do this // if the body isn't a compound statement to avoid push/pop in common cases. // // C++ 6.4p1: // The substatement in a selection-statement (each substatement, in the else // form of the if statement) implicitly defines a local scope. // // See comments in ParseIfStatement for why we create a scope for the // condition and a new scope for substatement in C++. // ParseScope InnerScope(this, Scope::DeclScope, C99orCXX && Tok.isNot(tok::l_brace)); // Read the body statement. StmtResult Body(ParseStatement(TrailingElseLoc)); // Pop the scopes. InnerScope.Exit(); SwitchScope.Exit(); if (Body.isInvalid()) { // FIXME: Remove the case statement list from the Switch statement. // Put the synthesized null statement on the same line as the end of switch // condition. SourceLocation SynthesizedNullStmtLocation = Cond.get()->getLocEnd(); Body = Actions.ActOnNullStmt(SynthesizedNullStmtLocation); } return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get()); } /// ParseWhileStatement /// while-statement: [C99 6.8.5.1] /// 'while' '(' expression ')' statement /// [C++] 'while' '(' condition ')' statement StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) { assert(Tok.is(tok::kw_while) && "Not a while stmt!"); SourceLocation WhileLoc = Tok.getLocation(); ConsumeToken(); // eat the 'while'. if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "while"; SkipUntil(tok::semi); return StmtError(); } bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; // C99 6.8.5p5 - In C99, the while statement is a block. This is not // the case for C90. Start the loop scope. // // C++ 6.4p3: // A name introduced by a declaration in a condition is in scope from its // point of declaration until the end of the substatements controlled by the // condition. // C++ 3.3.2p4: // Names declared in the for-init-statement, and in the condition of if, // while, for, and switch statements are local to the if, while, for, or // switch statement (including the controlled statement). // unsigned ScopeFlags; if (C99orCXX) ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope | Scope::ControlScope; else ScopeFlags = Scope::BreakScope | Scope::ContinueScope; ParseScope WhileScope(this, ScopeFlags); // Parse the condition. ExprResult Cond; Decl *CondVar = 0; if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true)) return StmtError(); FullExprArg FullCond(Actions.MakeFullExpr(Cond.get())); // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do this // if the body isn't a compound statement to avoid push/pop in common cases. // // C++ 6.5p2: // The substatement in an iteration-statement implicitly defines a local scope // which is entered and exited each time through the loop. // // See comments in ParseIfStatement for why we create a scope for the // condition and a new scope for substatement in C++. // ParseScope InnerScope(this, Scope::DeclScope, C99orCXX && Tok.isNot(tok::l_brace)); // Read the body statement. StmtResult Body(ParseStatement(TrailingElseLoc)); // Pop the body scope if needed. InnerScope.Exit(); WhileScope.Exit(); if ((Cond.isInvalid() && !CondVar) || Body.isInvalid()) return StmtError(); return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get()); } /// ParseDoStatement /// do-statement: [C99 6.8.5.2] /// 'do' statement 'while' '(' expression ')' ';' /// Note: this lets the caller parse the end ';'. StmtResult Parser::ParseDoStatement() { assert(Tok.is(tok::kw_do) && "Not a do stmt!"); SourceLocation DoLoc = ConsumeToken(); // eat the 'do'. // C99 6.8.5p5 - In C99, the do statement is a block. This is not // the case for C90. Start the loop scope. unsigned ScopeFlags; if (getLangOpts().C99) ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope; else ScopeFlags = Scope::BreakScope | Scope::ContinueScope; ParseScope DoScope(this, ScopeFlags); // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do this // if the body isn't a compound statement to avoid push/pop in common cases. // // C++ 6.5p2: // The substatement in an iteration-statement implicitly defines a local scope // which is entered and exited each time through the loop. // ParseScope InnerScope(this, Scope::DeclScope, (getLangOpts().C99 || getLangOpts().CPlusPlus) && Tok.isNot(tok::l_brace)); // Read the body statement. StmtResult Body(ParseStatement()); // Pop the body scope if needed. InnerScope.Exit(); if (Tok.isNot(tok::kw_while)) { if (!Body.isInvalid()) { Diag(Tok, diag::err_expected_while); Diag(DoLoc, diag::note_matching) << "do"; SkipUntil(tok::semi, false, true); } return StmtError(); } SourceLocation WhileLoc = ConsumeToken(); if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "do/while"; SkipUntil(tok::semi, false, true); return StmtError(); } // Parse the parenthesized condition. BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); ExprResult Cond = ParseExpression(); T.consumeClose(); DoScope.Exit(); if (Cond.isInvalid() || Body.isInvalid()) return StmtError(); return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(), Cond.get(), T.getCloseLocation()); } /// ParseForStatement /// for-statement: [C99 6.8.5.3] /// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement /// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement /// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')' /// [C++] statement /// [C++0x] 'for' '(' for-range-declaration : for-range-initializer ) statement /// [OBJC2] 'for' '(' declaration 'in' expr ')' statement /// [OBJC2] 'for' '(' expr 'in' expr ')' statement /// /// [C++] for-init-statement: /// [C++] expression-statement /// [C++] simple-declaration /// /// [C++0x] for-range-declaration: /// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator /// [C++0x] for-range-initializer: /// [C++0x] expression /// [C++0x] braced-init-list [TODO] StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) { assert(Tok.is(tok::kw_for) && "Not a for stmt!"); SourceLocation ForLoc = ConsumeToken(); // eat the 'for'. if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "for"; SkipUntil(tok::semi); return StmtError(); } bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus || getLangOpts().ObjC1; // C99 6.8.5p5 - In C99, the for statement is a block. This is not // the case for C90. Start the loop scope. // // C++ 6.4p3: // A name introduced by a declaration in a condition is in scope from its // point of declaration until the end of the substatements controlled by the // condition. // C++ 3.3.2p4: // Names declared in the for-init-statement, and in the condition of if, // while, for, and switch statements are local to the if, while, for, or // switch statement (including the controlled statement). // C++ 6.5.3p1: // Names declared in the for-init-statement are in the same declarative-region // as those declared in the condition. // unsigned ScopeFlags; if (C99orCXXorObjC) ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope | Scope::ControlScope; else ScopeFlags = Scope::BreakScope | Scope::ContinueScope; ParseScope ForScope(this, ScopeFlags); BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); ExprResult Value; bool ForEach = false, ForRange = false; StmtResult FirstPart; bool SecondPartIsInvalid = false; FullExprArg SecondPart(Actions); ExprResult Collection; ForRangeInit ForRangeInit; FullExprArg ThirdPart(Actions); Decl *SecondVar = 0; if (Tok.is(tok::code_completion)) { Actions.CodeCompleteOrdinaryName(getCurScope(), C99orCXXorObjC? Sema::PCC_ForInit : Sema::PCC_Expression); cutOffParsing(); return StmtError(); } // Parse the first part of the for specifier. if (Tok.is(tok::semi)) { // for (; // no first part, eat the ';'. ConsumeToken(); } else if (isForInitDeclaration()) { // for (int X = 4; // Parse declaration, which eats the ';'. if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode? Diag(Tok, diag::ext_c99_variable_decl_in_for_loop); ParsedAttributesWithRange attrs(AttrFactory); MaybeParseCXX0XAttributes(attrs); // In C++0x, "for (T NS:a" might not be a typo for :: bool MightBeForRangeStmt = getLangOpts().CPlusPlus; ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt); SourceLocation DeclStart = Tok.getLocation(), DeclEnd; StmtVector Stmts(Actions); DeclGroupPtrTy DG = ParseSimpleDeclaration(Stmts, Declarator::ForContext, DeclEnd, attrs, false, MightBeForRangeStmt ? &ForRangeInit : 0); FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation()); if (ForRangeInit.ParsedForRangeDecl()) { Diag(ForRangeInit.ColonLoc, getLangOpts().CPlusPlus0x ? diag::warn_cxx98_compat_for_range : diag::ext_for_range); ForRange = true; } else if (Tok.is(tok::semi)) { // for (int x = 4; ConsumeToken(); } else if ((ForEach = isTokIdentifier_in())) { Actions.ActOnForEachDeclStmt(DG); // ObjC: for (id x in expr) ConsumeToken(); // consume 'in' if (Tok.is(tok::code_completion)) { Actions.CodeCompleteObjCForCollection(getCurScope(), DG); cutOffParsing(); return StmtError(); } Collection = ParseExpression(); } else { Diag(Tok, diag::err_expected_semi_for); } } else { Value = ParseExpression(); ForEach = isTokIdentifier_in(); // Turn the expression into a stmt. if (!Value.isInvalid()) { if (ForEach) FirstPart = Actions.ActOnForEachLValueExpr(Value.get()); else FirstPart = Actions.ActOnExprStmt(Actions.MakeFullExpr(Value.get())); } if (Tok.is(tok::semi)) { ConsumeToken(); } else if (ForEach) { ConsumeToken(); // consume 'in' if (Tok.is(tok::code_completion)) { Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy()); cutOffParsing(); return StmtError(); } Collection = ParseExpression(); } else if (getLangOpts().CPlusPlus0x && Tok.is(tok::colon) && FirstPart.get()) { // User tried to write the reasonable, but ill-formed, for-range-statement // for (expr : expr) { ... } Diag(Tok, diag::err_for_range_expected_decl) << FirstPart.get()->getSourceRange(); SkipUntil(tok::r_paren, false, true); SecondPartIsInvalid = true; } else { if (!Value.isInvalid()) { Diag(Tok, diag::err_expected_semi_for); } else { // Skip until semicolon or rparen, don't consume it. SkipUntil(tok::r_paren, true, true); if (Tok.is(tok::semi)) ConsumeToken(); } } } if (!ForEach && !ForRange) { assert(!SecondPart.get() && "Shouldn't have a second expression yet."); // Parse the second part of the for specifier. if (Tok.is(tok::semi)) { // for (...;; // no second part. } else if (Tok.is(tok::r_paren)) { // missing both semicolons. } else { ExprResult Second; if (getLangOpts().CPlusPlus) ParseCXXCondition(Second, SecondVar, ForLoc, true); else { Second = ParseExpression(); if (!Second.isInvalid()) Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc, Second.get()); } SecondPartIsInvalid = Second.isInvalid(); SecondPart = Actions.MakeFullExpr(Second.get()); } if (Tok.isNot(tok::semi)) { if (!SecondPartIsInvalid || SecondVar) Diag(Tok, diag::err_expected_semi_for); else // Skip until semicolon or rparen, don't consume it. SkipUntil(tok::r_paren, true, true); } if (Tok.is(tok::semi)) { ConsumeToken(); } // Parse the third part of the for specifier. if (Tok.isNot(tok::r_paren)) { // for (...;...;) ExprResult Third = ParseExpression(); ThirdPart = Actions.MakeFullExpr(Third.take()); } } // Match the ')'. T.consumeClose(); // We need to perform most of the semantic analysis for a C++0x for-range // statememt before parsing the body, in order to be able to deduce the type // of an auto-typed loop variable. StmtResult ForRangeStmt; if (ForRange) { ForRangeStmt = Actions.ActOnCXXForRangeStmt(ForLoc, T.getOpenLocation(), FirstPart.take(), ForRangeInit.ColonLoc, ForRangeInit.RangeExpr.get(), T.getCloseLocation()); // Similarly, we need to do the semantic analysis for a for-range // statement immediately in order to close over temporaries correctly. } else if (ForEach) { if (!Collection.isInvalid()) Collection = Actions.ActOnObjCForCollectionOperand(ForLoc, Collection.take()); } // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if // there is no compound stmt. C90 does not have this clause. We only do this // if the body isn't a compound statement to avoid push/pop in common cases. // // C++ 6.5p2: // The substatement in an iteration-statement implicitly defines a local scope // which is entered and exited each time through the loop. // // See comments in ParseIfStatement for why we create a scope for // for-init-statement/condition and a new scope for substatement in C++. // ParseScope InnerScope(this, Scope::DeclScope, C99orCXXorObjC && Tok.isNot(tok::l_brace)); // Read the body statement. StmtResult Body(ParseStatement(TrailingElseLoc)); // Pop the body scope if needed. InnerScope.Exit(); // Leave the for-scope. ForScope.Exit(); if (Body.isInvalid()) return StmtError(); if (ForEach) return Actions.ActOnObjCForCollectionStmt(ForLoc, T.getOpenLocation(), FirstPart.take(), Collection.take(), T.getCloseLocation(), Body.take()); if (ForRange) return Actions.FinishCXXForRangeStmt(ForRangeStmt.take(), Body.take()); return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.take(), SecondPart, SecondVar, ThirdPart, T.getCloseLocation(), Body.take()); } /// ParseGotoStatement /// jump-statement: /// 'goto' identifier ';' /// [GNU] 'goto' '*' expression ';' /// /// Note: this lets the caller parse the end ';'. /// StmtResult Parser::ParseGotoStatement() { assert(Tok.is(tok::kw_goto) && "Not a goto stmt!"); SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'. StmtResult Res; if (Tok.is(tok::identifier)) { LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(), Tok.getLocation()); Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD); ConsumeToken(); } else if (Tok.is(tok::star)) { // GNU indirect goto extension. Diag(Tok, diag::ext_gnu_indirect_goto); SourceLocation StarLoc = ConsumeToken(); ExprResult R(ParseExpression()); if (R.isInvalid()) { // Skip to the semicolon, but don't consume it. SkipUntil(tok::semi, false, true); return StmtError(); } Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.take()); } else { Diag(Tok, diag::err_expected_ident); return StmtError(); } return move(Res); } /// ParseContinueStatement /// jump-statement: /// 'continue' ';' /// /// Note: this lets the caller parse the end ';'. /// StmtResult Parser::ParseContinueStatement() { SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'. return Actions.ActOnContinueStmt(ContinueLoc, getCurScope()); } /// ParseBreakStatement /// jump-statement: /// 'break' ';' /// /// Note: this lets the caller parse the end ';'. /// StmtResult Parser::ParseBreakStatement() { SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'. return Actions.ActOnBreakStmt(BreakLoc, getCurScope()); } /// ParseReturnStatement /// jump-statement: /// 'return' expression[opt] ';' StmtResult Parser::ParseReturnStatement() { assert(Tok.is(tok::kw_return) && "Not a return stmt!"); SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'. ExprResult R; if (Tok.isNot(tok::semi)) { if (Tok.is(tok::code_completion)) { Actions.CodeCompleteReturn(getCurScope()); cutOffParsing(); return StmtError(); } if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) { R = ParseInitializer(); if (R.isUsable()) Diag(R.get()->getLocStart(), getLangOpts().CPlusPlus0x ? diag::warn_cxx98_compat_generalized_initializer_lists : diag::ext_generalized_initializer_lists) << R.get()->getSourceRange(); } else R = ParseExpression(); if (R.isInvalid()) { // Skip to the semicolon, but don't consume it. SkipUntil(tok::semi, false, true); return StmtError(); } } return Actions.ActOnReturnStmt(ReturnLoc, R.take()); } /// ParseMicrosoftAsmStatement. When -fms-extensions/-fasm-blocks is enabled, /// this routine is called to collect the tokens for an MS asm statement. StmtResult Parser::ParseMicrosoftAsmStatement(SourceLocation AsmLoc) { SourceManager &SrcMgr = PP.getSourceManager(); SourceLocation EndLoc = AsmLoc; do { bool InBraces = false; unsigned short savedBraceCount = 0; bool InAsmComment = false; FileID FID; unsigned LineNo = 0; unsigned NumTokensRead = 0; SourceLocation LBraceLoc; if (Tok.is(tok::l_brace)) { // Braced inline asm: consume the opening brace. InBraces = true; savedBraceCount = BraceCount; EndLoc = LBraceLoc = ConsumeBrace(); ++NumTokensRead; } else { // Single-line inline asm; compute which line it is on. std::pair ExpAsmLoc = SrcMgr.getDecomposedExpansionLoc(EndLoc); FID = ExpAsmLoc.first; LineNo = SrcMgr.getLineNumber(FID, ExpAsmLoc.second); } SourceLocation TokLoc = Tok.getLocation(); do { // If we hit EOF, we're done, period. if (Tok.is(tok::eof)) break; // When we consume the closing brace, we're done. if (InBraces && BraceCount == savedBraceCount) break; if (!InAsmComment && Tok.is(tok::semi)) { // A semicolon in an asm is the start of a comment. InAsmComment = true; if (InBraces) { // Compute which line the comment is on. std::pair ExpSemiLoc = SrcMgr.getDecomposedExpansionLoc(TokLoc); FID = ExpSemiLoc.first; LineNo = SrcMgr.getLineNumber(FID, ExpSemiLoc.second); } } else if (!InBraces || InAsmComment) { // If end-of-line is significant, check whether this token is on a // new line. std::pair ExpLoc = SrcMgr.getDecomposedExpansionLoc(TokLoc); if (ExpLoc.first != FID || SrcMgr.getLineNumber(ExpLoc.first, ExpLoc.second) != LineNo) { // If this is a single-line __asm, we're done. if (!InBraces) break; // We're no longer in a comment. InAsmComment = false; } else if (!InAsmComment && Tok.is(tok::r_brace)) { // Single-line asm always ends when a closing brace is seen. // FIXME: This is compatible with Apple gcc's -fasm-blocks; what // does MSVC do here? break; } } // Consume the next token; make sure we don't modify the brace count etc. // if we are in a comment. EndLoc = TokLoc; if (InAsmComment) PP.Lex(Tok); else ConsumeAnyToken(); TokLoc = Tok.getLocation(); ++NumTokensRead; } while (1); if (InBraces && BraceCount != savedBraceCount) { // __asm without closing brace (this can happen at EOF). Diag(Tok, diag::err_expected_rbrace); Diag(LBraceLoc, diag::note_matching) << "{"; return StmtError(); } else if (NumTokensRead == 0) { // Empty __asm. Diag(Tok, diag::err_expected_lbrace); return StmtError(); } // Multiple adjacent asm's form together into a single asm statement // in the AST. if (!Tok.is(tok::kw_asm)) break; EndLoc = ConsumeToken(); } while (1); // FIXME: Need to actually grab the data and pass it on to Sema. Ideally, // what Sema wants is a string of the entire inline asm, with one instruction // per line and all the __asm keywords stripped out, and a way of mapping // from any character of that string to its location in the original source // code. I'm not entirely sure how to go about that, though. Token t; t.setKind(tok::string_literal); t.setLiteralData("\"/*FIXME: not done*/\""); t.clearFlag(Token::NeedsCleaning); t.setLength(21); ExprResult AsmString(Actions.ActOnStringLiteral(&t, 1)); ExprVector Constraints(Actions); ExprVector Exprs(Actions); ExprVector Clobbers(Actions); return Actions.ActOnAsmStmt(AsmLoc, true, true, 0, 0, 0, move_arg(Constraints), move_arg(Exprs), AsmString.take(), move_arg(Clobbers), EndLoc, true); } /// ParseAsmStatement - Parse a GNU extended asm statement. /// asm-statement: /// gnu-asm-statement /// ms-asm-statement /// /// [GNU] gnu-asm-statement: /// 'asm' type-qualifier[opt] '(' asm-argument ')' ';' /// /// [GNU] asm-argument: /// asm-string-literal /// asm-string-literal ':' asm-operands[opt] /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt] /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt] /// ':' asm-clobbers /// /// [GNU] asm-clobbers: /// asm-string-literal /// asm-clobbers ',' asm-string-literal /// /// [MS] ms-asm-statement: /// ms-asm-block /// ms-asm-block ms-asm-statement /// /// [MS] ms-asm-block: /// '__asm' ms-asm-line '\n' /// '__asm' '{' ms-asm-instruction-block[opt] '}' ';'[opt] /// /// [MS] ms-asm-instruction-block /// ms-asm-line /// ms-asm-line '\n' ms-asm-instruction-block /// StmtResult Parser::ParseAsmStatement(bool &msAsm) { assert(Tok.is(tok::kw_asm) && "Not an asm stmt"); SourceLocation AsmLoc = ConsumeToken(); if (getLangOpts().MicrosoftExt && Tok.isNot(tok::l_paren) && !isTypeQualifier()) { msAsm = true; return ParseMicrosoftAsmStatement(AsmLoc); } DeclSpec DS(AttrFactory); SourceLocation Loc = Tok.getLocation(); ParseTypeQualifierListOpt(DS, true, false); // GNU asms accept, but warn, about type-qualifiers other than volatile. if (DS.getTypeQualifiers() & DeclSpec::TQ_const) Diag(Loc, diag::w_asm_qualifier_ignored) << "const"; if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict) Diag(Loc, diag::w_asm_qualifier_ignored) << "restrict"; // Remember if this was a volatile asm. bool isVolatile = DS.getTypeQualifiers() & DeclSpec::TQ_volatile; if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "asm"; SkipUntil(tok::r_paren); return StmtError(); } BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); ExprResult AsmString(ParseAsmStringLiteral()); if (AsmString.isInvalid()) { // Consume up to and including the closing paren. T.skipToEnd(); return StmtError(); } SmallVector Names; ExprVector Constraints(Actions); ExprVector Exprs(Actions); ExprVector Clobbers(Actions); if (Tok.is(tok::r_paren)) { // We have a simple asm expression like 'asm("foo")'. T.consumeClose(); return Actions.ActOnAsmStmt(AsmLoc, /*isSimple*/ true, isVolatile, /*NumOutputs*/ 0, /*NumInputs*/ 0, 0, move_arg(Constraints), move_arg(Exprs), AsmString.take(), move_arg(Clobbers), T.getCloseLocation()); } // Parse Outputs, if present. bool AteExtraColon = false; if (Tok.is(tok::colon) || Tok.is(tok::coloncolon)) { // In C++ mode, parse "::" like ": :". AteExtraColon = Tok.is(tok::coloncolon); ConsumeToken(); if (!AteExtraColon && ParseAsmOperandsOpt(Names, Constraints, Exprs)) return StmtError(); } unsigned NumOutputs = Names.size(); // Parse Inputs, if present. if (AteExtraColon || Tok.is(tok::colon) || Tok.is(tok::coloncolon)) { // In C++ mode, parse "::" like ": :". if (AteExtraColon) AteExtraColon = false; else { AteExtraColon = Tok.is(tok::coloncolon); ConsumeToken(); } if (!AteExtraColon && ParseAsmOperandsOpt(Names, Constraints, Exprs)) return StmtError(); } assert(Names.size() == Constraints.size() && Constraints.size() == Exprs.size() && "Input operand size mismatch!"); unsigned NumInputs = Names.size() - NumOutputs; // Parse the clobbers, if present. if (AteExtraColon || Tok.is(tok::colon)) { if (!AteExtraColon) ConsumeToken(); // Parse the asm-string list for clobbers if present. if (Tok.isNot(tok::r_paren)) { while (1) { ExprResult Clobber(ParseAsmStringLiteral()); if (Clobber.isInvalid()) break; Clobbers.push_back(Clobber.release()); if (Tok.isNot(tok::comma)) break; ConsumeToken(); } } } T.consumeClose(); return Actions.ActOnAsmStmt(AsmLoc, false, isVolatile, NumOutputs, NumInputs, Names.data(), move_arg(Constraints), move_arg(Exprs), AsmString.take(), move_arg(Clobbers), T.getCloseLocation()); } /// ParseAsmOperands - Parse the asm-operands production as used by /// asm-statement, assuming the leading ':' token was eaten. /// /// [GNU] asm-operands: /// asm-operand /// asm-operands ',' asm-operand /// /// [GNU] asm-operand: /// asm-string-literal '(' expression ')' /// '[' identifier ']' asm-string-literal '(' expression ')' /// // // FIXME: Avoid unnecessary std::string trashing. bool Parser::ParseAsmOperandsOpt(SmallVectorImpl &Names, SmallVectorImpl &Constraints, SmallVectorImpl &Exprs) { // 'asm-operands' isn't present? if (!isTokenStringLiteral() && Tok.isNot(tok::l_square)) return false; while (1) { // Read the [id] if present. if (Tok.is(tok::l_square)) { BalancedDelimiterTracker T(*this, tok::l_square); T.consumeOpen(); if (Tok.isNot(tok::identifier)) { Diag(Tok, diag::err_expected_ident); SkipUntil(tok::r_paren); return true; } IdentifierInfo *II = Tok.getIdentifierInfo(); ConsumeToken(); Names.push_back(II); T.consumeClose(); } else Names.push_back(0); ExprResult Constraint(ParseAsmStringLiteral()); if (Constraint.isInvalid()) { SkipUntil(tok::r_paren); return true; } Constraints.push_back(Constraint.release()); if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "asm operand"; SkipUntil(tok::r_paren); return true; } // Read the parenthesized expression. BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); ExprResult Res(ParseExpression()); T.consumeClose(); if (Res.isInvalid()) { SkipUntil(tok::r_paren); return true; } Exprs.push_back(Res.release()); // Eat the comma and continue parsing if it exists. if (Tok.isNot(tok::comma)) return false; ConsumeToken(); } } Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) { assert(Tok.is(tok::l_brace)); SourceLocation LBraceLoc = Tok.getLocation(); if (SkipFunctionBodies && trySkippingFunctionBody()) { BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, 0); } PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc, "parsing function body"); // Do not enter a scope for the brace, as the arguments are in the same scope // (the function body) as the body itself. Instead, just read the statement // list and put it into a CompoundStmt for safe keeping. StmtResult FnBody(ParseCompoundStatementBody()); // If the function body could not be parsed, make a bogus compoundstmt. if (FnBody.isInvalid()) { Sema::CompoundScopeRAII CompoundScope(Actions); FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, MultiStmtArg(Actions), false); } BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, FnBody.take()); } /// ParseFunctionTryBlock - Parse a C++ function-try-block. /// /// function-try-block: /// 'try' ctor-initializer[opt] compound-statement handler-seq /// Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) { assert(Tok.is(tok::kw_try) && "Expected 'try'"); SourceLocation TryLoc = ConsumeToken(); PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc, "parsing function try block"); // Constructor initializer list? if (Tok.is(tok::colon)) ParseConstructorInitializer(Decl); else Actions.ActOnDefaultCtorInitializers(Decl); if (SkipFunctionBodies && trySkippingFunctionBody()) { BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, 0); } SourceLocation LBraceLoc = Tok.getLocation(); StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc)); // If we failed to parse the try-catch, we just give the function an empty // compound statement as the body. if (FnBody.isInvalid()) { Sema::CompoundScopeRAII CompoundScope(Actions); FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, MultiStmtArg(Actions), false); } BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, FnBody.take()); } bool Parser::trySkippingFunctionBody() { assert(Tok.is(tok::l_brace)); assert(SkipFunctionBodies && "Should only be called when SkipFunctionBodies is enabled"); // We're in code-completion mode. Skip parsing for all function bodies unless // the body contains the code-completion point. TentativeParsingAction PA(*this); ConsumeBrace(); if (SkipUntil(tok::r_brace, /*StopAtSemi=*/false, /*DontConsume=*/false, /*StopAtCodeCompletion=*/PP.isCodeCompletionEnabled())) { PA.Commit(); return true; } PA.Revert(); return false; } /// ParseCXXTryBlock - Parse a C++ try-block. /// /// try-block: /// 'try' compound-statement handler-seq /// StmtResult Parser::ParseCXXTryBlock() { assert(Tok.is(tok::kw_try) && "Expected 'try'"); SourceLocation TryLoc = ConsumeToken(); return ParseCXXTryBlockCommon(TryLoc); } /// ParseCXXTryBlockCommon - Parse the common part of try-block and /// function-try-block. /// /// try-block: /// 'try' compound-statement handler-seq /// /// function-try-block: /// 'try' ctor-initializer[opt] compound-statement handler-seq /// /// handler-seq: /// handler handler-seq[opt] /// /// [Borland] try-block: /// 'try' compound-statement seh-except-block /// 'try' compound-statment seh-finally-block /// StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc) { if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected_lbrace)); // FIXME: Possible draft standard bug: attribute-specifier should be allowed? StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false, Scope::DeclScope|Scope::TryScope)); if (TryBlock.isInvalid()) return move(TryBlock); // Borland allows SEH-handlers with 'try' if ((Tok.is(tok::identifier) && Tok.getIdentifierInfo() == getSEHExceptKeyword()) || Tok.is(tok::kw___finally)) { // TODO: Factor into common return ParseSEHHandlerCommon(...) StmtResult Handler; if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) { SourceLocation Loc = ConsumeToken(); Handler = ParseSEHExceptBlock(Loc); } else { SourceLocation Loc = ConsumeToken(); Handler = ParseSEHFinallyBlock(Loc); } if(Handler.isInvalid()) return move(Handler); return Actions.ActOnSEHTryBlock(true /* IsCXXTry */, TryLoc, TryBlock.take(), Handler.take()); } else { StmtVector Handlers(Actions); ParsedAttributesWithRange attrs(AttrFactory); MaybeParseCXX0XAttributes(attrs); ProhibitAttributes(attrs); if (Tok.isNot(tok::kw_catch)) return StmtError(Diag(Tok, diag::err_expected_catch)); while (Tok.is(tok::kw_catch)) { StmtResult Handler(ParseCXXCatchBlock()); if (!Handler.isInvalid()) Handlers.push_back(Handler.release()); } // Don't bother creating the full statement if we don't have any usable // handlers. if (Handlers.empty()) return StmtError(); return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.take(), move_arg(Handlers)); } } /// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard /// /// handler: /// 'catch' '(' exception-declaration ')' compound-statement /// /// exception-declaration: /// type-specifier-seq declarator /// type-specifier-seq abstract-declarator /// type-specifier-seq /// '...' /// StmtResult Parser::ParseCXXCatchBlock() { assert(Tok.is(tok::kw_catch) && "Expected 'catch'"); SourceLocation CatchLoc = ConsumeToken(); BalancedDelimiterTracker T(*this, tok::l_paren); if (T.expectAndConsume(diag::err_expected_lparen)) return StmtError(); // C++ 3.3.2p3: // The name in a catch exception-declaration is local to the handler and // shall not be redeclared in the outermost block of the handler. ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope); // exception-declaration is equivalent to '...' or a parameter-declaration // without default arguments. Decl *ExceptionDecl = 0; if (Tok.isNot(tok::ellipsis)) { DeclSpec DS(AttrFactory); if (ParseCXXTypeSpecifierSeq(DS)) return StmtError(); Declarator ExDecl(DS, Declarator::CXXCatchContext); ParseDeclarator(ExDecl); ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl); } else ConsumeToken(); T.consumeClose(); if (T.getCloseLocation().isInvalid()) return StmtError(); if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected_lbrace)); // FIXME: Possible draft standard bug: attribute-specifier should be allowed? StmtResult Block(ParseCompoundStatement()); if (Block.isInvalid()) return move(Block); return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.take()); } void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) { IfExistsCondition Result; if (ParseMicrosoftIfExistsCondition(Result)) return; // Handle dependent statements by parsing the braces as a compound statement. // This is not the same behavior as Visual C++, which don't treat this as a // compound statement, but for Clang's type checking we can't have anything // inside these braces escaping to the surrounding code. if (Result.Behavior == IEB_Dependent) { if (!Tok.is(tok::l_brace)) { Diag(Tok, diag::err_expected_lbrace); return; } StmtResult Compound = ParseCompoundStatement(); if (Compound.isInvalid()) return; StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc, Result.IsIfExists, Result.SS, Result.Name, Compound.get()); if (DepResult.isUsable()) Stmts.push_back(DepResult.get()); return; } BalancedDelimiterTracker Braces(*this, tok::l_brace); if (Braces.consumeOpen()) { Diag(Tok, diag::err_expected_lbrace); return; } switch (Result.Behavior) { case IEB_Parse: // Parse the statements below. break; case IEB_Dependent: llvm_unreachable("Dependent case handled above"); case IEB_Skip: Braces.skipToEnd(); return; } // Condition is true, parse the statements. while (Tok.isNot(tok::r_brace)) { StmtResult R = ParseStatementOrDeclaration(Stmts, false); if (R.isUsable()) Stmts.push_back(R.release()); } Braces.consumeClose(); }