//===--- ParseStmt.cpp - Statement and Block Parser -----------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file implements the Statement and Block portions of the Parser // interface. // //===----------------------------------------------------------------------===// #include "clang/AST/PrettyDeclStackTrace.h" #include "clang/Basic/Attributes.h" #include "clang/Basic/PrettyStackTrace.h" #include "clang/Parse/LoopHint.h" #include "clang/Parse/Parser.h" #include "clang/Parse/RAIIObjectsForParser.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Scope.h" #include "clang/Sema/TypoCorrection.h" using namespace clang; //===----------------------------------------------------------------------===// // C99 6.8: Statements and Blocks. //===----------------------------------------------------------------------===// /// Parse a standalone statement (for instance, as the body of an 'if', /// 'while', or 'for'). StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc, ParsedStmtContext StmtCtx) { StmtResult Res; // We may get back a null statement if we found a #pragma. Keep going until // we get an actual statement. do { StmtVector Stmts; Res = ParseStatementOrDeclaration(Stmts, StmtCtx, TrailingElseLoc); } while (!Res.isInvalid() && !Res.get()); return Res; } /// 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, ParsedStmtContext StmtCtx, SourceLocation *TrailingElseLoc) { ParenBraceBracketBalancer BalancerRAIIObj(*this); ParsedAttributesWithRange Attrs(AttrFactory); MaybeParseCXX11Attributes(Attrs, nullptr, /*MightBeObjCMessageSend*/ true); if (!MaybeParseOpenCLUnrollHintAttribute(Attrs)) return StmtError(); StmtResult Res = ParseStatementOrDeclarationAfterAttributes( Stmts, StmtCtx, 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, Attrs.Range); } namespace { class StatementFilterCCC final : public CorrectionCandidateCallback { public: StatementFilterCCC(Token nextTok) : NextToken(nextTok) { WantTypeSpecifiers = nextTok.isOneOf(tok::l_paren, tok::less, tok::l_square, tok::identifier, tok::star, tok::amp); WantExpressionKeywords = nextTok.isOneOf(tok::l_paren, tok::identifier, tok::arrow, tok::period); WantRemainingKeywords = nextTok.isOneOf(tok::l_paren, tok::semi, tok::identifier, tok::l_brace); WantCXXNamedCasts = false; } bool ValidateCandidate(const TypoCorrection &candidate) override { if (FieldDecl *FD = candidate.getCorrectionDeclAs()) return !candidate.getCorrectionSpecifier() || isa(FD); if (NextToken.is(tok::equal)) return candidate.getCorrectionDeclAs(); if (NextToken.is(tok::period) && candidate.getCorrectionDeclAs()) return false; return CorrectionCandidateCallback::ValidateCandidate(candidate); } std::unique_ptr clone() override { return std::make_unique(*this); } private: Token NextToken; }; } StmtResult Parser::ParseStatementOrDeclarationAfterAttributes( StmtVector &Stmts, ParsedStmtContext StmtCtx, SourceLocation *TrailingElseLoc, ParsedAttributesWithRange &Attrs) { const char *SemiError = nullptr; StmtResult Res; SourceLocation GNUAttributeLoc; // 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, StmtCtx); } 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, StmtCtx); } // Look up the identifier, and typo-correct it to a keyword if it's not // found. if (Next.isNot(tok::coloncolon)) { // Try to limit which sets of keywords should be included in typo // correction based on what the next token is. StatementFilterCCC CCC(Next); if (TryAnnotateName(/*IsAddressOfOperand*/ false, &CCC) == ANK_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 | StopBeforeMatch); if (Tok.is(tok::semi)) ConsumeToken(); return StmtError(); } // If the identifier was typo-corrected, try again. if (Tok.isNot(tok::identifier)) goto Retry; } // Fall through LLVM_FALLTHROUGH; } default: { if ((getLangOpts().CPlusPlus || getLangOpts().MicrosoftExt || (StmtCtx & ParsedStmtContext::AllowDeclarationsInC) != ParsedStmtContext()) && (GNUAttributeLoc.isValid() || isDeclarationStatement())) { SourceLocation DeclStart = Tok.getLocation(), DeclEnd; DeclGroupPtrTy Decl; if (GNUAttributeLoc.isValid()) { DeclStart = GNUAttributeLoc; Decl = ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, Attrs, &GNUAttributeLoc); } else { Decl = ParseDeclaration(DeclaratorContext::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(StmtCtx); } case tok::kw___attribute: { GNUAttributeLoc = Tok.getLocation(); ParseGNUAttributes(Attrs); goto Retry; } case tok::kw_case: // C99 6.8.1: labeled-statement return ParseCaseStatement(StmtCtx); case tok::kw_default: // C99 6.8.1: labeled-statement return ParseDefaultStatement(StmtCtx); 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_co_return: // C++ Coroutines: co_return statement Res = ParseReturnStatement(); SemiError = "co_return"; break; case tok::kw_asm: { ProhibitAttributes(Attrs); bool msAsm = false; Res = ParseAsmStatement(msAsm); Res = Actions.ActOnFinishFullStmt(Res.get()); if (msAsm) return Res; SemiError = "asm"; break; } case tok::kw___if_exists: case tok::kw___if_not_exists: ProhibitAttributes(Attrs); ParseMicrosoftIfExistsStatement(Stmts); // An __if_exists block is like a compound statement, but it doesn't create // a new scope. return StmtEmpty(); case tok::kw_try: // C++ 15: try-block return ParseCXXTryBlock(); case tok::kw___try: ProhibitAttributes(Attrs); // TODO: is it correct? return ParseSEHTryBlock(); case tok::kw___leave: Res = ParseSEHLeaveStatement(); SemiError = "__leave"; break; case tok::annot_pragma_vis: ProhibitAttributes(Attrs); HandlePragmaVisibility(); return StmtEmpty(); case tok::annot_pragma_pack: ProhibitAttributes(Attrs); HandlePragmaPack(); return StmtEmpty(); case tok::annot_pragma_msstruct: ProhibitAttributes(Attrs); HandlePragmaMSStruct(); return StmtEmpty(); case tok::annot_pragma_align: ProhibitAttributes(Attrs); HandlePragmaAlign(); return StmtEmpty(); case tok::annot_pragma_weak: ProhibitAttributes(Attrs); HandlePragmaWeak(); return StmtEmpty(); case tok::annot_pragma_weakalias: ProhibitAttributes(Attrs); HandlePragmaWeakAlias(); return StmtEmpty(); case tok::annot_pragma_redefine_extname: ProhibitAttributes(Attrs); HandlePragmaRedefineExtname(); return StmtEmpty(); case tok::annot_pragma_fp_contract: ProhibitAttributes(Attrs); Diag(Tok, diag::err_pragma_fp_contract_scope); ConsumeAnnotationToken(); return StmtError(); case tok::annot_pragma_fp: ProhibitAttributes(Attrs); Diag(Tok, diag::err_pragma_fp_scope); ConsumeAnnotationToken(); return StmtError(); case tok::annot_pragma_fenv_access: ProhibitAttributes(Attrs); HandlePragmaFEnvAccess(); return StmtEmpty(); case tok::annot_pragma_opencl_extension: ProhibitAttributes(Attrs); HandlePragmaOpenCLExtension(); return StmtEmpty(); case tok::annot_pragma_captured: ProhibitAttributes(Attrs); return HandlePragmaCaptured(); case tok::annot_pragma_openmp: ProhibitAttributes(Attrs); return ParseOpenMPDeclarativeOrExecutableDirective(StmtCtx); case tok::annot_pragma_ms_pointers_to_members: ProhibitAttributes(Attrs); HandlePragmaMSPointersToMembers(); return StmtEmpty(); case tok::annot_pragma_ms_pragma: ProhibitAttributes(Attrs); HandlePragmaMSPragma(); return StmtEmpty(); case tok::annot_pragma_ms_vtordisp: ProhibitAttributes(Attrs); HandlePragmaMSVtorDisp(); return StmtEmpty(); case tok::annot_pragma_loop_hint: ProhibitAttributes(Attrs); return ParsePragmaLoopHint(Stmts, StmtCtx, TrailingElseLoc, Attrs); case tok::annot_pragma_dump: HandlePragmaDump(); return StmtEmpty(); case tok::annot_pragma_attribute: HandlePragmaAttribute(); return StmtEmpty(); } // If we reached this code, the statement must end in a semicolon. if (!TryConsumeToken(tok::semi) && !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, StopAtSemi | StopBeforeMatch); } return Res; } /// Parse an expression statement. StmtResult Parser::ParseExprStatement(ParsedStmtContext StmtCtx) { // If a case keyword is missing, this is where it should be inserted. Token OldToken = Tok; ExprStatementTokLoc = Tok.getLocation(); // 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 | StopBeforeMatch); if (Tok.is(tok::semi)) ConsumeToken(); return Actions.ActOnExprStmtError(); } 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(StmtCtx, /*MissingCase=*/true, Expr); } // Otherwise, eat the semicolon. ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); return handleExprStmt(Expr, StmtCtx); } /// ParseSEHTryBlockCommon /// /// seh-try-block: /// '__try' compound-statement seh-handler /// /// seh-handler: /// seh-except-block /// seh-finally-block /// StmtResult Parser::ParseSEHTryBlock() { assert(Tok.is(tok::kw___try) && "Expected '__try'"); SourceLocation TryLoc = ConsumeToken(); if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); StmtResult TryBlock(ParseCompoundStatement( /*isStmtExpr=*/false, Scope::DeclScope | Scope::CompoundStmtScope | Scope::SEHTryScope)); if (TryBlock.isInvalid()) return 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 Handler; return Actions.ActOnSEHTryBlock(false /* IsCXXTry */, TryLoc, TryBlock.get(), Handler.get()); } /// 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)) return StmtError(); ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope | Scope::SEHExceptScope); if (getLangOpts().Borland) { Ident__exception_info->setIsPoisoned(false); Ident___exception_info->setIsPoisoned(false); Ident_GetExceptionInfo->setIsPoisoned(false); } ExprResult FilterExpr; { ParseScopeFlags FilterScope(this, getCurScope()->getFlags() | Scope::SEHFilterScope); FilterExpr = Actions.CorrectDelayedTyposInExpr(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)) return StmtError(); if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); StmtResult Block(ParseCompoundStatement()); if(Block.isInvalid()) return Block; return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.get(), Block.get()); } /// ParseSEHFinallyBlock - Handle __finally /// /// seh-finally-block: /// '__finally' compound-statement /// StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyLoc) { PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false), raii2(Ident___abnormal_termination, false), raii3(Ident_AbnormalTermination, false); if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); ParseScope FinallyScope(this, 0); Actions.ActOnStartSEHFinallyBlock(); StmtResult Block(ParseCompoundStatement()); if(Block.isInvalid()) { Actions.ActOnAbortSEHFinallyBlock(); return Block; } return Actions.ActOnFinishSEHFinallyBlock(FinallyLoc, Block.get()); } /// Handle __leave /// /// seh-leave-statement: /// '__leave' ';' /// StmtResult Parser::ParseSEHLeaveStatement() { SourceLocation LeaveLoc = ConsumeToken(); // eat the '__leave'. return Actions.ActOnSEHLeaveStmt(LeaveLoc, getCurScope()); } /// ParseLabeledStatement - We have an identifier and a ':' after it. /// /// labeled-statement: /// identifier ':' statement /// [GNU] identifier ':' attributes[opt] statement /// StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs, ParsedStmtContext StmtCtx) { assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() && "Not an identifier!"); // The substatement is always a 'statement', not a 'declaration', but is // otherwise in the same context as the labeled-statement. StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC; 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. StmtResult SubStmt; if (Tok.is(tok::kw___attribute)) { ParsedAttributesWithRange TempAttrs(AttrFactory); ParseGNUAttributes(TempAttrs); // In C++, GNU attributes only apply to the label if they are followed by a // semicolon, to disambiguate label attributes from attributes on a labeled // declaration. // // This doesn't quite match what GCC does; if the attribute list is empty // and followed by a semicolon, GCC will reject (it appears to parse the // attributes as part of a statement in that case). That looks like a bug. if (!getLangOpts().CPlusPlus || Tok.is(tok::semi)) attrs.takeAllFrom(TempAttrs); else if (isDeclarationStatement()) { StmtVector Stmts; // FIXME: We should do this whether or not we have a declaration // statement, but that doesn't work correctly (because ProhibitAttributes // can't handle GNU attributes), so only call it in the one case where // GNU attributes are allowed. SubStmt = ParseStatementOrDeclarationAfterAttributes(Stmts, StmtCtx, nullptr, TempAttrs); if (!TempAttrs.empty() && !SubStmt.isInvalid()) SubStmt = Actions.ProcessStmtAttributes(SubStmt.get(), TempAttrs, TempAttrs.Range); } else { Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi; } } // If we've not parsed a statement yet, parse one now. if (!SubStmt.isInvalid() && !SubStmt.isUsable()) SubStmt = ParseStatement(nullptr, StmtCtx); // 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()); 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(ParsedStmtContext StmtCtx, bool MissingCase, ExprResult Expr) { assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!"); // The substatement is always a 'statement', not a 'declaration', but is // otherwise in the same context as the labeled-statement. StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC; // 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 // weirdness 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 = nullptr; // While we have case statements, eat and stack them. SourceLocation ColonLoc; do { SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() : ConsumeToken(); // eat the 'case'. ColonLoc = SourceLocation(); 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; if (!MissingCase) { LHS = ParseCaseExpression(CaseLoc); if (LHS.isInvalid()) { // If constant-expression is parsed unsuccessfully, recover by skipping // current case statement (moving to the colon that ends it). if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) return StmtError(); } } else { LHS = Expr; MissingCase = false; } // GNU case range extension. SourceLocation DotDotDotLoc; ExprResult RHS; if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) { Diag(DotDotDotLoc, diag::ext_gnu_case_range); RHS = ParseCaseExpression(CaseLoc); if (RHS.isInvalid()) { if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) return StmtError(); } } ColonProtection.restore(); if (TryConsumeToken(tok::colon, ColonLoc)) { } else if (TryConsumeToken(tok::semi, ColonLoc) || TryConsumeToken(tok::coloncolon, ColonLoc)) { // Treat "case blah;" or "case blah::" as a typo for "case blah:". Diag(ColonLoc, diag::err_expected_after) << "'case'" << tok::colon << FixItHint::CreateReplacement(ColonLoc, ":"); } else { SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); Diag(ExpectedLoc, diag::err_expected_after) << "'case'" << tok::colon << FixItHint::CreateInsertion(ExpectedLoc, ":"); ColonLoc = ExpectedLoc; } StmtResult Case = Actions.ActOnCaseStmt(CaseLoc, LHS, DotDotDotLoc, RHS, 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(/*TrailingElseLoc=*/nullptr, StmtCtx); // 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 = Case; else Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get()); DeepestParsedCaseStmt = NextDeepest; } // Handle all case statements. } while (Tok.is(tok::kw_case)); // If we found a non-case statement, start by parsing it. StmtResult SubStmt; if (Tok.isNot(tok::r_brace)) { SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx); } else { // Nicely diagnose the common error "switch (X) { case 4: }", which is // not valid. If ColonLoc doesn't point to a valid text location, there was // another parsing error, so avoid producing extra diagnostics. if (ColonLoc.isValid()) { SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc); Diag(AfterColonLoc, diag::err_label_end_of_compound_statement) << FixItHint::CreateInsertion(AfterColonLoc, " ;"); } SubStmt = StmtError(); } // Install the body into the most deeply-nested case. if (DeepestParsedCaseStmt) { // Broken sub-stmt shouldn't prevent forming the case statement properly. if (SubStmt.isInvalid()) SubStmt = Actions.ActOnNullStmt(SourceLocation()); Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get()); } // Return the top level parsed statement tree. return TopLevelCase; } /// ParseDefaultStatement /// labeled-statement: /// 'default' ':' statement /// Note that this does not parse the 'statement' at the end. /// StmtResult Parser::ParseDefaultStatement(ParsedStmtContext StmtCtx) { assert(Tok.is(tok::kw_default) && "Not a default stmt!"); // The substatement is always a 'statement', not a 'declaration', but is // otherwise in the same context as the labeled-statement. StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC; SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'. SourceLocation ColonLoc; if (TryConsumeToken(tok::colon, ColonLoc)) { } else if (TryConsumeToken(tok::semi, ColonLoc)) { // Treat "default;" as a typo for "default:". Diag(ColonLoc, diag::err_expected_after) << "'default'" << tok::colon << FixItHint::CreateReplacement(ColonLoc, ":"); } else { SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); Diag(ExpectedLoc, diag::err_expected_after) << "'default'" << tok::colon << FixItHint::CreateInsertion(ExpectedLoc, ":"); ColonLoc = ExpectedLoc; } StmtResult SubStmt; if (Tok.isNot(tok::r_brace)) { SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx); } 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 | Scope::CompoundStmtScope); } /// 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 /// /// [GNU] label-declarations: /// [GNU] label-declaration /// [GNU] label-declarations label-declaration /// /// [GNU] label-declaration: /// [GNU] '__label__' identifier-list ';' /// 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); } /// Parse any pragmas at the start of the compound expression. We handle these /// separately since some pragmas (FP_CONTRACT) must appear before any C /// statement in the compound, but may be intermingled with other pragmas. void Parser::ParseCompoundStatementLeadingPragmas() { bool checkForPragmas = true; while (checkForPragmas) { switch (Tok.getKind()) { case tok::annot_pragma_vis: HandlePragmaVisibility(); break; case tok::annot_pragma_pack: HandlePragmaPack(); break; case tok::annot_pragma_msstruct: HandlePragmaMSStruct(); break; case tok::annot_pragma_align: HandlePragmaAlign(); break; case tok::annot_pragma_weak: HandlePragmaWeak(); break; case tok::annot_pragma_weakalias: HandlePragmaWeakAlias(); break; case tok::annot_pragma_redefine_extname: HandlePragmaRedefineExtname(); break; case tok::annot_pragma_opencl_extension: HandlePragmaOpenCLExtension(); break; case tok::annot_pragma_fp_contract: HandlePragmaFPContract(); break; case tok::annot_pragma_fp: HandlePragmaFP(); break; case tok::annot_pragma_fenv_access: HandlePragmaFEnvAccess(); break; case tok::annot_pragma_ms_pointers_to_members: HandlePragmaMSPointersToMembers(); break; case tok::annot_pragma_ms_pragma: HandlePragmaMSPragma(); break; case tok::annot_pragma_ms_vtordisp: HandlePragmaMSVtorDisp(); break; case tok::annot_pragma_dump: HandlePragmaDump(); break; default: checkForPragmas = false; break; } } } /// Consume any extra semi-colons resulting in null statements, /// returning true if any tok::semi were consumed. bool Parser::ConsumeNullStmt(StmtVector &Stmts) { if (!Tok.is(tok::semi)) return false; SourceLocation StartLoc = Tok.getLocation(); SourceLocation EndLoc; while (Tok.is(tok::semi) && !Tok.hasLeadingEmptyMacro() && Tok.getLocation().isValid() && !Tok.getLocation().isMacroID()) { EndLoc = Tok.getLocation(); // Don't just ConsumeToken() this tok::semi, do store it in AST. StmtResult R = ParseStatementOrDeclaration(Stmts, ParsedStmtContext::SubStmt); if (R.isUsable()) Stmts.push_back(R.get()); } // Did not consume any extra semi. if (EndLoc.isInvalid()) return false; Diag(StartLoc, diag::warn_null_statement) << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc)); return true; } StmtResult Parser::handleExprStmt(ExprResult E, ParsedStmtContext StmtCtx) { bool IsStmtExprResult = false; if ((StmtCtx & ParsedStmtContext::InStmtExpr) != ParsedStmtContext()) { // For GCC compatibility we skip past NullStmts. unsigned LookAhead = 0; while (GetLookAheadToken(LookAhead).is(tok::semi)) { ++LookAhead; } // Then look to see if the next two tokens close the statement expression; // if so, this expression statement is the last statement in a statment // expression. IsStmtExprResult = GetLookAheadToken(LookAhead).is(tok::r_brace) && GetLookAheadToken(LookAhead + 1).is(tok::r_paren); } if (IsStmtExprResult) E = Actions.ActOnStmtExprResult(E); return Actions.ActOnExprStmt(E, /*DiscardedValue=*/!IsStmtExprResult); } /// 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 ('{}')"); // Record the state of the FP_CONTRACT pragma, restore on leaving the // compound statement. Sema::FPContractStateRAII SaveFPContractState(Actions); InMessageExpressionRAIIObject InMessage(*this, false); BalancedDelimiterTracker T(*this, tok::l_brace); if (T.consumeOpen()) return StmtError(); Sema::CompoundScopeRAII CompoundScope(Actions, isStmtExpr); // Parse any pragmas at the beginning of the compound statement. ParseCompoundStatementLeadingPragmas(); StmtVector Stmts; // "__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(); SmallVector DeclsInGroup; while (1) { if (Tok.isNot(tok::identifier)) { Diag(Tok, diag::err_expected) << tok::identifier; break; } IdentifierInfo *II = Tok.getIdentifierInfo(); SourceLocation IdLoc = ConsumeToken(); DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc)); if (!TryConsumeToken(tok::comma)) break; } DeclSpec DS(AttrFactory); DeclGroupPtrTy Res = Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup); StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation()); ExpectAndConsumeSemi(diag::err_expected_semi_declaration); if (R.isUsable()) Stmts.push_back(R.get()); } ParsedStmtContext SubStmtCtx = ParsedStmtContext::Compound | (isStmtExpr ? ParsedStmtContext::InStmtExpr : ParsedStmtContext()); while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) { if (Tok.is(tok::annot_pragma_unused)) { HandlePragmaUnused(); continue; } if (ConsumeNullStmt(Stmts)) continue; StmtResult R; if (Tok.isNot(tok::kw___extension__)) { R = ParseStatementOrDeclaration(Stmts, SubStmtCtx); } 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); MaybeParseCXX11Attributes(attrs, nullptr, /*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(DeclaratorContext::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; } // Eat the semicolon at the end of stmt and convert the expr into a // statement. ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); R = handleExprStmt(Res, SubStmtCtx); if (R.isUsable()) R = Actions.ProcessStmtAttributes(R.get(), attrs, attrs.Range); } } if (R.isUsable()) Stmts.push_back(R.get()); } SourceLocation CloseLoc = Tok.getLocation(); // We broke out of the while loop because we found a '}' or EOF. if (!T.consumeClose()) // Recover by creating a compound statement with what we parsed so far, // instead of dropping everything and returning StmtError(); CloseLoc = T.getCloseLocation(); return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc, Stmts, isStmtExpr); } /// ParseParenExprOrCondition: /// [C ] '(' expression ')' /// [C++] '(' condition ')' /// [C++1z] '(' init-statement[opt] condition ')' /// /// 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(StmtResult *InitStmt, Sema::ConditionResult &Cond, SourceLocation Loc, Sema::ConditionKind CK) { BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); if (getLangOpts().CPlusPlus) Cond = ParseCXXCondition(InitStmt, Loc, CK); else { ExprResult CondExpr = ParseExpression(); // If required, convert to a boolean value. if (CondExpr.isInvalid()) Cond = Sema::ConditionError(); else Cond = Actions.ActOnCondition(getCurScope(), Loc, CondExpr.get(), CK); } // 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 (Cond.isInvalid() && 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(); // Check for extraneous ')'s to catch things like "if (foo())) {". We know // that all callers are looking for a statement after the condition, so ")" // isn't valid. while (Tok.is(tok::r_paren)) { Diag(Tok, diag::err_extraneous_rparen_in_condition) << FixItHint::CreateRemoval(Tok.getLocation()); ConsumeParen(); } 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'. bool IsConstexpr = false; if (Tok.is(tok::kw_constexpr)) { Diag(Tok, getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_constexpr_if : diag::ext_constexpr_if); IsConstexpr = true; ConsumeToken(); } 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. StmtResult InitStmt; Sema::ConditionResult Cond; if (ParseParenExprOrCondition(&InitStmt, Cond, IfLoc, IsConstexpr ? Sema::ConditionKind::ConstexprIf : Sema::ConditionKind::Boolean)) return StmtError(); llvm::Optional ConstexprCondition; if (IsConstexpr) ConstexprCondition = Cond.getKnownValue(); // 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.is(tok::l_brace)); // Read the 'then' stmt. SourceLocation ThenStmtLoc = Tok.getLocation(); SourceLocation InnerStatementTrailingElseLoc; StmtResult ThenStmt; { EnterExpressionEvaluationContext PotentiallyDiscarded( Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr, Sema::ExpressionEvaluationContextRecord::EK_Other, /*ShouldEnter=*/ConstexprCondition && !*ConstexprCondition); 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.is(tok::l_brace)); EnterExpressionEvaluationContext PotentiallyDiscarded( Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr, Sema::ExpressionEvaluationContextRecord::EK_Other, /*ShouldEnter=*/ConstexprCondition && *ConstexprCondition); 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 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() == nullptr) || (ThenStmt.get() == nullptr && 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, IsConstexpr, InitStmt.get(), Cond, 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::SwitchScope; if (C99orCXX) ScopeFlags |= Scope::DeclScope | Scope::ControlScope; ParseScope SwitchScope(this, ScopeFlags); // Parse the condition. StmtResult InitStmt; Sema::ConditionResult Cond; if (ParseParenExprOrCondition(&InitStmt, Cond, SwitchLoc, Sema::ConditionKind::Switch)) return StmtError(); StmtResult Switch = Actions.ActOnStartOfSwitchStmt(SwitchLoc, InitStmt.get(), Cond); 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); } else SkipUntil(tok::semi); return 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++. // getCurScope()->AddFlags(Scope::BreakScope); ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); // We have incremented the mangling number for the SwitchScope and the // InnerScope, which is one too many. if (C99orCXX) getCurScope()->decrementMSManglingNumber(); // Read the body statement. StmtResult Body(ParseStatement(TrailingElseLoc)); // Pop the scopes. InnerScope.Exit(); SwitchScope.Exit(); 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. Sema::ConditionResult Cond; if (ParseParenExprOrCondition(nullptr, Cond, WhileLoc, Sema::ConditionKind::Boolean)) return StmtError(); // C99 6.8.5p5 - In C99, the body of the while 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.is(tok::l_brace)); // Read the body statement. StmtResult Body(ParseStatement(TrailingElseLoc)); // Pop the body scope if needed. InnerScope.Exit(); WhileScope.Exit(); if (Cond.isInvalid() || Body.isInvalid()) return StmtError(); return Actions.ActOnWhileStmt(WhileLoc, Cond, 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 do 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. // bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(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, StopBeforeMatch); } return StmtError(); } SourceLocation WhileLoc = ConsumeToken(); if (Tok.isNot(tok::l_paren)) { Diag(Tok, diag::err_expected_lparen_after) << "do/while"; SkipUntil(tok::semi, StopBeforeMatch); return StmtError(); } // Parse the parenthesized expression. BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); // A do-while expression is not a condition, so can't have attributes. DiagnoseAndSkipCXX11Attributes(); ExprResult Cond = ParseExpression(); // Correct the typos in condition before closing the scope. if (Cond.isUsable()) Cond = Actions.CorrectDelayedTyposInExpr(Cond); T.consumeClose(); DoScope.Exit(); if (Cond.isInvalid() || Body.isInvalid()) return StmtError(); return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(), Cond.get(), T.getCloseLocation()); } bool Parser::isForRangeIdentifier() { assert(Tok.is(tok::identifier)); const Token &Next = NextToken(); if (Next.is(tok::colon)) return true; if (Next.isOneOf(tok::l_square, tok::kw_alignas)) { TentativeParsingAction PA(*this); ConsumeToken(); SkipCXX11Attributes(); bool Result = Tok.is(tok::colon); PA.Revert(); return Result; } return false; } /// 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' /// 'co_await'[opt] [Coroutines] /// '(' 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'. SourceLocation CoawaitLoc; if (Tok.is(tok::kw_co_await)) CoawaitLoc = ConsumeToken(); 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().ObjC; // 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 = 0; if (C99orCXXorObjC) ScopeFlags = Scope::DeclScope | Scope::ControlScope; ParseScope ForScope(this, ScopeFlags); BalancedDelimiterTracker T(*this, tok::l_paren); T.consumeOpen(); ExprResult Value; bool ForEach = false; StmtResult FirstPart; Sema::ConditionResult SecondPart; ExprResult Collection; ForRangeInfo ForRangeInfo; FullExprArg ThirdPart(Actions); if (Tok.is(tok::code_completion)) { Actions.CodeCompleteOrdinaryName(getCurScope(), C99orCXXorObjC? Sema::PCC_ForInit : Sema::PCC_Expression); cutOffParsing(); return StmtError(); } ParsedAttributesWithRange attrs(AttrFactory); MaybeParseCXX11Attributes(attrs); SourceLocation EmptyInitStmtSemiLoc; // Parse the first part of the for specifier. if (Tok.is(tok::semi)) { // for (; ProhibitAttributes(attrs); // no first part, eat the ';'. SourceLocation SemiLoc = Tok.getLocation(); if (!Tok.hasLeadingEmptyMacro() && !SemiLoc.isMacroID()) EmptyInitStmtSemiLoc = SemiLoc; ConsumeToken(); } else if (getLangOpts().CPlusPlus && Tok.is(tok::identifier) && isForRangeIdentifier()) { ProhibitAttributes(attrs); IdentifierInfo *Name = Tok.getIdentifierInfo(); SourceLocation Loc = ConsumeToken(); MaybeParseCXX11Attributes(attrs); ForRangeInfo.ColonLoc = ConsumeToken(); if (Tok.is(tok::l_brace)) ForRangeInfo.RangeExpr = ParseBraceInitializer(); else ForRangeInfo.RangeExpr = ParseExpression(); Diag(Loc, diag::err_for_range_identifier) << ((getLangOpts().CPlusPlus11 && !getLangOpts().CPlusPlus17) ? FixItHint::CreateInsertion(Loc, "auto &&") : FixItHint()); ForRangeInfo.LoopVar = Actions.ActOnCXXForRangeIdentifier( getCurScope(), Loc, Name, attrs, attrs.Range.getEnd()); } else if (isForInitDeclaration()) { // for (int X = 4; ParenBraceBracketBalancer BalancerRAIIObj(*this); // 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); Diag(Tok, diag::warn_gcc_variable_decl_in_for_loop); } // 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; DeclGroupPtrTy DG = ParseSimpleDeclaration( DeclaratorContext::ForContext, DeclEnd, attrs, false, MightBeForRangeStmt ? &ForRangeInfo : nullptr); FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation()); if (ForRangeInfo.ParsedForRangeDecl()) { Diag(ForRangeInfo.ColonLoc, getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_for_range : diag::ext_for_range); ForRangeInfo.LoopVar = FirstPart; FirstPart = StmtResult(); } 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 { ProhibitAttributes(attrs); Value = Actions.CorrectDelayedTyposInExpr(ParseExpression()); ForEach = isTokIdentifier_in(); // Turn the expression into a stmt. if (!Value.isInvalid()) { if (ForEach) FirstPart = Actions.ActOnForEachLValueExpr(Value.get()); else { // We already know this is not an init-statement within a for loop, so // if we are parsing a C++11 range-based for loop, we should treat this // expression statement as being a discarded value expression because // we will err below. This way we do not warn on an unused expression // that was an error in the first place, like with: for (expr : expr); bool IsRangeBasedFor = getLangOpts().CPlusPlus11 && !ForEach && Tok.is(tok::colon); FirstPart = Actions.ActOnExprStmt(Value, !IsRangeBasedFor); } } if (Tok.is(tok::semi)) { ConsumeToken(); } else if (ForEach) { ConsumeToken(); // consume 'in' if (Tok.is(tok::code_completion)) { Actions.CodeCompleteObjCForCollection(getCurScope(), nullptr); cutOffParsing(); return StmtError(); } Collection = ParseExpression(); } else if (getLangOpts().CPlusPlus11 && 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, StopBeforeMatch); SecondPart = Sema::ConditionError(); } 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, StopAtSemi | StopBeforeMatch); if (Tok.is(tok::semi)) ConsumeToken(); } } } // Parse the second part of the for specifier. getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope); if (!ForEach && !ForRangeInfo.ParsedForRangeDecl() && !SecondPart.isInvalid()) { // 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 { if (getLangOpts().CPlusPlus) { // C++2a: We've parsed an init-statement; we might have a // for-range-declaration next. bool MightBeForRangeStmt = !ForRangeInfo.ParsedForRangeDecl(); ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt); SecondPart = ParseCXXCondition(nullptr, ForLoc, Sema::ConditionKind::Boolean, MightBeForRangeStmt ? &ForRangeInfo : nullptr); if (ForRangeInfo.ParsedForRangeDecl()) { Diag(FirstPart.get() ? FirstPart.get()->getBeginLoc() : ForRangeInfo.ColonLoc, getLangOpts().CPlusPlus2a ? diag::warn_cxx17_compat_for_range_init_stmt : diag::ext_for_range_init_stmt) << (FirstPart.get() ? FirstPart.get()->getSourceRange() : SourceRange()); if (EmptyInitStmtSemiLoc.isValid()) { Diag(EmptyInitStmtSemiLoc, diag::warn_empty_init_statement) << /*for-loop*/ 2 << FixItHint::CreateRemoval(EmptyInitStmtSemiLoc); } } } else { ExprResult SecondExpr = ParseExpression(); if (SecondExpr.isInvalid()) SecondPart = Sema::ConditionError(); else SecondPart = Actions.ActOnCondition(getCurScope(), ForLoc, SecondExpr.get(), Sema::ConditionKind::Boolean); } } } // Parse the third part of the for statement. if (!ForEach && !ForRangeInfo.ParsedForRangeDecl()) { if (Tok.isNot(tok::semi)) { if (!SecondPart.isInvalid()) Diag(Tok, diag::err_expected_semi_for); else // Skip until semicolon or rparen, don't consume it. SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch); } if (Tok.is(tok::semi)) { ConsumeToken(); } if (Tok.isNot(tok::r_paren)) { // for (...;...;) ExprResult Third = ParseExpression(); // FIXME: The C++11 standard doesn't actually say that this is a // discarded-value expression, but it clearly should be. ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.get()); } } // Match the ')'. T.consumeClose(); // C++ Coroutines [stmt.iter]: // 'co_await' can only be used for a range-based for statement. if (CoawaitLoc.isValid() && !ForRangeInfo.ParsedForRangeDecl()) { Diag(CoawaitLoc, diag::err_for_co_await_not_range_for); CoawaitLoc = SourceLocation(); } // 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; StmtResult ForEachStmt; if (ForRangeInfo.ParsedForRangeDecl()) { ExprResult CorrectedRange = Actions.CorrectDelayedTyposInExpr(ForRangeInfo.RangeExpr.get()); ForRangeStmt = Actions.ActOnCXXForRangeStmt( getCurScope(), ForLoc, CoawaitLoc, FirstPart.get(), ForRangeInfo.LoopVar.get(), ForRangeInfo.ColonLoc, CorrectedRange.get(), T.getCloseLocation(), Sema::BFRK_Build); // Similarly, we need to do the semantic analysis for a for-range // statement immediately in order to close over temporaries correctly. } else if (ForEach) { ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc, FirstPart.get(), Collection.get(), T.getCloseLocation()); } else { // In OpenMP loop region loop control variable must be captured and be // private. Perform analysis of first part (if any). if (getLangOpts().OpenMP && FirstPart.isUsable()) { Actions.ActOnOpenMPLoopInitialization(ForLoc, FirstPart.get()); } } // C99 6.8.5p5 - In C99, the body of the for 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.is(tok::l_brace)); // The body of the for loop has the same local mangling number as the // for-init-statement. // It will only be incremented if the body contains other things that would // normally increment the mangling number (like a compound statement). if (C99orCXXorObjC) getCurScope()->decrementMSManglingNumber(); // 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.FinishObjCForCollectionStmt(ForEachStmt.get(), Body.get()); if (ForRangeInfo.ParsedForRangeDecl()) return Actions.FinishCXXForRangeStmt(ForRangeStmt.get(), Body.get()); return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.get(), SecondPart, ThirdPart, T.getCloseLocation(), Body.get()); } /// 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, StopBeforeMatch); return StmtError(); } Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.get()); } else { Diag(Tok, diag::err_expected) << tok::identifier; return StmtError(); } return 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] ';' /// 'return' braced-init-list ';' /// 'co_return' expression[opt] ';' /// 'co_return' braced-init-list ';' StmtResult Parser::ParseReturnStatement() { assert((Tok.is(tok::kw_return) || Tok.is(tok::kw_co_return)) && "Not a return stmt!"); bool IsCoreturn = Tok.is(tok::kw_co_return); SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'. ExprResult R; if (Tok.isNot(tok::semi)) { if (!IsCoreturn) PreferredType.enterReturn(Actions, Tok.getLocation()); // FIXME: Code completion for co_return. if (Tok.is(tok::code_completion) && !IsCoreturn) { Actions.CodeCompleteExpression(getCurScope(), PreferredType.get(Tok.getLocation())); cutOffParsing(); return StmtError(); } if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) { R = ParseInitializer(); if (R.isUsable()) Diag(R.get()->getBeginLoc(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_generalized_initializer_lists : diag::ext_generalized_initializer_lists) << R.get()->getSourceRange(); } else R = ParseExpression(); if (R.isInvalid()) { SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); return StmtError(); } } if (IsCoreturn) return Actions.ActOnCoreturnStmt(getCurScope(), ReturnLoc, R.get()); return Actions.ActOnReturnStmt(ReturnLoc, R.get(), getCurScope()); } StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts, ParsedStmtContext StmtCtx, SourceLocation *TrailingElseLoc, ParsedAttributesWithRange &Attrs) { // Create temporary attribute list. ParsedAttributesWithRange TempAttrs(AttrFactory); // Get loop hints and consume annotated token. while (Tok.is(tok::annot_pragma_loop_hint)) { LoopHint Hint; if (!HandlePragmaLoopHint(Hint)) continue; ArgsUnion ArgHints[] = {Hint.PragmaNameLoc, Hint.OptionLoc, Hint.StateLoc, ArgsUnion(Hint.ValueExpr)}; TempAttrs.addNew(Hint.PragmaNameLoc->Ident, Hint.Range, nullptr, Hint.PragmaNameLoc->Loc, ArgHints, 4, ParsedAttr::AS_Pragma); } // Get the next statement. MaybeParseCXX11Attributes(Attrs); StmtResult S = ParseStatementOrDeclarationAfterAttributes( Stmts, StmtCtx, TrailingElseLoc, Attrs); Attrs.takeAllFrom(TempAttrs); return S; } Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) { assert(Tok.is(tok::l_brace)); SourceLocation LBraceLoc = Tok.getLocation(); PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, LBraceLoc, "parsing function body"); // Save and reset current vtordisp stack if we have entered a C++ method body. bool IsCXXMethod = getLangOpts().CPlusPlus && Decl && isa(Decl); Sema::PragmaStackSentinelRAII PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod); // 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, None, false); } BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, FnBody.get()); } /// 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.Context, Decl, TryLoc, "parsing function try block"); // Constructor initializer list? if (Tok.is(tok::colon)) ParseConstructorInitializer(Decl); else Actions.ActOnDefaultCtorInitializers(Decl); // Save and reset current vtordisp stack if we have entered a C++ method body. bool IsCXXMethod = getLangOpts().CPlusPlus && Decl && isa(Decl); Sema::PragmaStackSentinelRAII PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod); SourceLocation LBraceLoc = Tok.getLocation(); StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true)); // 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, None, false); } BodyScope.Exit(); return Actions.ActOnFinishFunctionBody(Decl, FnBody.get()); } bool Parser::trySkippingFunctionBody() { assert(SkipFunctionBodies && "Should only be called when SkipFunctionBodies is enabled"); if (!PP.isCodeCompletionEnabled()) { SkipFunctionBody(); return true; } // We're in code-completion mode. Skip parsing for all function bodies unless // the body contains the code-completion point. TentativeParsingAction PA(*this); bool IsTryCatch = Tok.is(tok::kw_try); CachedTokens Toks; bool ErrorInPrologue = ConsumeAndStoreFunctionPrologue(Toks); if (llvm::any_of(Toks, [](const Token &Tok) { return Tok.is(tok::code_completion); })) { PA.Revert(); return false; } if (ErrorInPrologue) { PA.Commit(); SkipMalformedDecl(); return true; } if (!SkipUntil(tok::r_brace, StopAtCodeCompletion)) { PA.Revert(); return false; } while (IsTryCatch && Tok.is(tok::kw_catch)) { if (!SkipUntil(tok::l_brace, StopAtCodeCompletion) || !SkipUntil(tok::r_brace, StopAtCodeCompletion)) { PA.Revert(); return false; } } PA.Commit(); return true; } /// 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-statement seh-finally-block /// StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) { if (Tok.isNot(tok::l_brace)) return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); StmtResult TryBlock(ParseCompoundStatement( /*isStmtExpr=*/false, Scope::DeclScope | Scope::TryScope | Scope::CompoundStmtScope | (FnTry ? Scope::FnTryCatchScope : 0))); if (TryBlock.isInvalid()) return 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 Handler; return Actions.ActOnSEHTryBlock(true /* IsCXXTry */, TryLoc, TryBlock.get(), Handler.get()); } else { StmtVector Handlers; // C++11 attributes can't appear here, despite this context seeming // statement-like. DiagnoseAndSkipCXX11Attributes(); if (Tok.isNot(tok::kw_catch)) return StmtError(Diag(Tok, diag::err_expected_catch)); while (Tok.is(tok::kw_catch)) { StmtResult Handler(ParseCXXCatchBlock(FnTry)); if (!Handler.isInvalid()) Handlers.push_back(Handler.get()); } // 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.get(), Handlers); } } /// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard /// /// handler: /// 'catch' '(' exception-declaration ')' compound-statement /// /// exception-declaration: /// attribute-specifier-seq[opt] type-specifier-seq declarator /// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt] /// '...' /// StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) { assert(Tok.is(tok::kw_catch) && "Expected 'catch'"); SourceLocation CatchLoc = ConsumeToken(); BalancedDelimiterTracker T(*this, tok::l_paren); if (T.expectAndConsume()) 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 | Scope::CatchScope | (FnCatch ? Scope::FnTryCatchScope : 0)); // exception-declaration is equivalent to '...' or a parameter-declaration // without default arguments. Decl *ExceptionDecl = nullptr; if (Tok.isNot(tok::ellipsis)) { ParsedAttributesWithRange Attributes(AttrFactory); MaybeParseCXX11Attributes(Attributes); DeclSpec DS(AttrFactory); DS.takeAttributesFrom(Attributes); if (ParseCXXTypeSpecifierSeq(DS)) return StmtError(); Declarator ExDecl(DS, DeclaratorContext::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) << tok::l_brace); // FIXME: Possible draft standard bug: attribute-specifier should be allowed? StmtResult Block(ParseCompoundStatement()); if (Block.isInvalid()) return Block; return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.get()); } 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) << tok::l_brace; 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) << tok::l_brace; 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, ParsedStmtContext::Compound); if (R.isUsable()) Stmts.push_back(R.get()); } Braces.consumeClose(); } bool Parser::ParseOpenCLUnrollHintAttribute(ParsedAttributes &Attrs) { MaybeParseGNUAttributes(Attrs); if (Attrs.empty()) return true; if (Attrs.begin()->getKind() != ParsedAttr::AT_OpenCLUnrollHint) return true; if (!(Tok.is(tok::kw_for) || Tok.is(tok::kw_while) || Tok.is(tok::kw_do))) { Diag(Tok, diag::err_opencl_unroll_hint_on_non_loop); return false; } return true; }