1//===--- ParseStmt.cpp - Statement and Block Parser -----------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the Statement and Block portions of the Parser 11// interface. 12// 13//===----------------------------------------------------------------------===// 14 15#include "clang/Parse/Parser.h" 16#include "RAIIObjectsForParser.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/Basic/Attributes.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Basic/PrettyStackTrace.h" 21#include "clang/Sema/DeclSpec.h" 22#include "clang/Sema/LoopHint.h" 23#include "clang/Sema/PrettyDeclStackTrace.h" 24#include "clang/Sema/Scope.h" 25#include "clang/Sema/TypoCorrection.h" 26#include "llvm/ADT/SmallString.h" 27using namespace clang; 28 29//===----------------------------------------------------------------------===// 30// C99 6.8: Statements and Blocks. 31//===----------------------------------------------------------------------===// 32 33/// \brief Parse a standalone statement (for instance, as the body of an 'if', 34/// 'while', or 'for'). 35StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc) { 36 StmtResult Res; 37 38 // We may get back a null statement if we found a #pragma. Keep going until 39 // we get an actual statement. 40 do { 41 StmtVector Stmts; 42 Res = ParseStatementOrDeclaration(Stmts, true, TrailingElseLoc); 43 } while (!Res.isInvalid() && !Res.get()); 44 45 return Res; 46} 47 48/// ParseStatementOrDeclaration - Read 'statement' or 'declaration'. 49/// StatementOrDeclaration: 50/// statement 51/// declaration 52/// 53/// statement: 54/// labeled-statement 55/// compound-statement 56/// expression-statement 57/// selection-statement 58/// iteration-statement 59/// jump-statement 60/// [C++] declaration-statement 61/// [C++] try-block 62/// [MS] seh-try-block 63/// [OBC] objc-throw-statement 64/// [OBC] objc-try-catch-statement 65/// [OBC] objc-synchronized-statement 66/// [GNU] asm-statement 67/// [OMP] openmp-construct [TODO] 68/// 69/// labeled-statement: 70/// identifier ':' statement 71/// 'case' constant-expression ':' statement 72/// 'default' ':' statement 73/// 74/// selection-statement: 75/// if-statement 76/// switch-statement 77/// 78/// iteration-statement: 79/// while-statement 80/// do-statement 81/// for-statement 82/// 83/// expression-statement: 84/// expression[opt] ';' 85/// 86/// jump-statement: 87/// 'goto' identifier ';' 88/// 'continue' ';' 89/// 'break' ';' 90/// 'return' expression[opt] ';' 91/// [GNU] 'goto' '*' expression ';' 92/// 93/// [OBC] objc-throw-statement: 94/// [OBC] '@' 'throw' expression ';' 95/// [OBC] '@' 'throw' ';' 96/// 97StmtResult 98Parser::ParseStatementOrDeclaration(StmtVector &Stmts, bool OnlyStatement, 99 SourceLocation *TrailingElseLoc) { 100 101 ParenBraceBracketBalancer BalancerRAIIObj(*this); 102 103 ParsedAttributesWithRange Attrs(AttrFactory); 104 MaybeParseCXX11Attributes(Attrs, nullptr, /*MightBeObjCMessageSend*/ true); 105 106 StmtResult Res = ParseStatementOrDeclarationAfterAttributes(Stmts, 107 OnlyStatement, TrailingElseLoc, Attrs); 108 109 assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) && 110 "attributes on empty statement"); 111 112 if (Attrs.empty() || Res.isInvalid()) 113 return Res; 114 115 return Actions.ProcessStmtAttributes(Res.get(), Attrs.getList(), Attrs.Range); 116} 117 118namespace { 119class StatementFilterCCC : public CorrectionCandidateCallback { 120public: 121 StatementFilterCCC(Token nextTok) : NextToken(nextTok) { 122 WantTypeSpecifiers = nextTok.is(tok::l_paren) || nextTok.is(tok::less) || 123 nextTok.is(tok::identifier) || nextTok.is(tok::star) || 124 nextTok.is(tok::amp) || nextTok.is(tok::l_square); 125 WantExpressionKeywords = nextTok.is(tok::l_paren) || 126 nextTok.is(tok::identifier) || 127 nextTok.is(tok::arrow) || nextTok.is(tok::period); 128 WantRemainingKeywords = nextTok.is(tok::l_paren) || nextTok.is(tok::semi) || 129 nextTok.is(tok::identifier) || 130 nextTok.is(tok::l_brace); 131 WantCXXNamedCasts = false; 132 } 133 134 bool ValidateCandidate(const TypoCorrection &candidate) override { 135 if (FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>()) 136 return !candidate.getCorrectionSpecifier() || isa<ObjCIvarDecl>(FD); 137 if (NextToken.is(tok::equal)) 138 return candidate.getCorrectionDeclAs<VarDecl>(); 139 if (NextToken.is(tok::period) && 140 candidate.getCorrectionDeclAs<NamespaceDecl>()) 141 return false; 142 return CorrectionCandidateCallback::ValidateCandidate(candidate); 143 } 144 145private: 146 Token NextToken; 147}; 148} 149 150StmtResult 151Parser::ParseStatementOrDeclarationAfterAttributes(StmtVector &Stmts, 152 bool OnlyStatement, SourceLocation *TrailingElseLoc, 153 ParsedAttributesWithRange &Attrs) { 154 const char *SemiError = nullptr; 155 StmtResult Res; 156 157 // Cases in this switch statement should fall through if the parser expects 158 // the token to end in a semicolon (in which case SemiError should be set), 159 // or they directly 'return;' if not. 160Retry: 161 tok::TokenKind Kind = Tok.getKind(); 162 SourceLocation AtLoc; 163 switch (Kind) { 164 case tok::at: // May be a @try or @throw statement 165 { 166 ProhibitAttributes(Attrs); // TODO: is it correct? 167 AtLoc = ConsumeToken(); // consume @ 168 return ParseObjCAtStatement(AtLoc); 169 } 170 171 case tok::code_completion: 172 Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement); 173 cutOffParsing(); 174 return StmtError(); 175 176 case tok::identifier: { 177 Token Next = NextToken(); 178 if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement 179 // identifier ':' statement 180 return ParseLabeledStatement(Attrs); 181 } 182 183 // Look up the identifier, and typo-correct it to a keyword if it's not 184 // found. 185 if (Next.isNot(tok::coloncolon)) { 186 // Try to limit which sets of keywords should be included in typo 187 // correction based on what the next token is. 188 if (TryAnnotateName(/*IsAddressOfOperand*/ false, 189 llvm::make_unique<StatementFilterCCC>(Next)) == 190 ANK_Error) { 191 // Handle errors here by skipping up to the next semicolon or '}', and 192 // eat the semicolon if that's what stopped us. 193 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 194 if (Tok.is(tok::semi)) 195 ConsumeToken(); 196 return StmtError(); 197 } 198 199 // If the identifier was typo-corrected, try again. 200 if (Tok.isNot(tok::identifier)) 201 goto Retry; 202 } 203 204 // Fall through 205 } 206 207 default: { 208 if ((getLangOpts().CPlusPlus || !OnlyStatement) && isDeclarationStatement()) { 209 SourceLocation DeclStart = Tok.getLocation(), DeclEnd; 210 DeclGroupPtrTy Decl = ParseDeclaration(Declarator::BlockContext, 211 DeclEnd, Attrs); 212 return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd); 213 } 214 215 if (Tok.is(tok::r_brace)) { 216 Diag(Tok, diag::err_expected_statement); 217 return StmtError(); 218 } 219 220 return ParseExprStatement(); 221 } 222 223 case tok::kw_case: // C99 6.8.1: labeled-statement 224 return ParseCaseStatement(); 225 case tok::kw_default: // C99 6.8.1: labeled-statement 226 return ParseDefaultStatement(); 227 228 case tok::l_brace: // C99 6.8.2: compound-statement 229 return ParseCompoundStatement(); 230 case tok::semi: { // C99 6.8.3p3: expression[opt] ';' 231 bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro(); 232 return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro); 233 } 234 235 case tok::kw_if: // C99 6.8.4.1: if-statement 236 return ParseIfStatement(TrailingElseLoc); 237 case tok::kw_switch: // C99 6.8.4.2: switch-statement 238 return ParseSwitchStatement(TrailingElseLoc); 239 240 case tok::kw_while: // C99 6.8.5.1: while-statement 241 return ParseWhileStatement(TrailingElseLoc); 242 case tok::kw_do: // C99 6.8.5.2: do-statement 243 Res = ParseDoStatement(); 244 SemiError = "do/while"; 245 break; 246 case tok::kw_for: // C99 6.8.5.3: for-statement 247 return ParseForStatement(TrailingElseLoc); 248 249 case tok::kw_goto: // C99 6.8.6.1: goto-statement 250 Res = ParseGotoStatement(); 251 SemiError = "goto"; 252 break; 253 case tok::kw_continue: // C99 6.8.6.2: continue-statement 254 Res = ParseContinueStatement(); 255 SemiError = "continue"; 256 break; 257 case tok::kw_break: // C99 6.8.6.3: break-statement 258 Res = ParseBreakStatement(); 259 SemiError = "break"; 260 break; 261 case tok::kw_return: // C99 6.8.6.4: return-statement 262 Res = ParseReturnStatement(); 263 SemiError = "return"; 264 break; 265 266 case tok::kw_asm: { 267 ProhibitAttributes(Attrs); 268 bool msAsm = false; 269 Res = ParseAsmStatement(msAsm); 270 Res = Actions.ActOnFinishFullStmt(Res.get()); 271 if (msAsm) return Res; 272 SemiError = "asm"; 273 break; 274 } 275 276 case tok::kw___if_exists: 277 case tok::kw___if_not_exists: 278 ProhibitAttributes(Attrs); 279 ParseMicrosoftIfExistsStatement(Stmts); 280 // An __if_exists block is like a compound statement, but it doesn't create 281 // a new scope. 282 return StmtEmpty(); 283 284 case tok::kw_try: // C++ 15: try-block 285 return ParseCXXTryBlock(); 286 287 case tok::kw___try: 288 ProhibitAttributes(Attrs); // TODO: is it correct? 289 return ParseSEHTryBlock(); 290 291 case tok::kw___leave: 292 Res = ParseSEHLeaveStatement(); 293 SemiError = "__leave"; 294 break; 295 296 case tok::annot_pragma_vis: 297 ProhibitAttributes(Attrs); 298 HandlePragmaVisibility(); 299 return StmtEmpty(); 300 301 case tok::annot_pragma_pack: 302 ProhibitAttributes(Attrs); 303 HandlePragmaPack(); 304 return StmtEmpty(); 305 306 case tok::annot_pragma_msstruct: 307 ProhibitAttributes(Attrs); 308 HandlePragmaMSStruct(); 309 return StmtEmpty(); 310 311 case tok::annot_pragma_align: 312 ProhibitAttributes(Attrs); 313 HandlePragmaAlign(); 314 return StmtEmpty(); 315 316 case tok::annot_pragma_weak: 317 ProhibitAttributes(Attrs); 318 HandlePragmaWeak(); 319 return StmtEmpty(); 320 321 case tok::annot_pragma_weakalias: 322 ProhibitAttributes(Attrs); 323 HandlePragmaWeakAlias(); 324 return StmtEmpty(); 325 326 case tok::annot_pragma_redefine_extname: 327 ProhibitAttributes(Attrs); 328 HandlePragmaRedefineExtname(); 329 return StmtEmpty(); 330 331 case tok::annot_pragma_fp_contract: 332 ProhibitAttributes(Attrs); 333 Diag(Tok, diag::err_pragma_fp_contract_scope); 334 ConsumeToken(); 335 return StmtError(); 336 337 case tok::annot_pragma_opencl_extension: 338 ProhibitAttributes(Attrs); 339 HandlePragmaOpenCLExtension(); 340 return StmtEmpty(); 341 342 case tok::annot_pragma_captured: 343 ProhibitAttributes(Attrs); 344 return HandlePragmaCaptured(); 345 346 case tok::annot_pragma_openmp: 347 ProhibitAttributes(Attrs); 348 return ParseOpenMPDeclarativeOrExecutableDirective(!OnlyStatement); 349 350 case tok::annot_pragma_ms_pointers_to_members: 351 ProhibitAttributes(Attrs); 352 HandlePragmaMSPointersToMembers(); 353 return StmtEmpty(); 354 355 case tok::annot_pragma_ms_pragma: 356 ProhibitAttributes(Attrs); 357 HandlePragmaMSPragma(); 358 return StmtEmpty(); 359 360 case tok::annot_pragma_loop_hint: 361 ProhibitAttributes(Attrs); 362 return ParsePragmaLoopHint(Stmts, OnlyStatement, TrailingElseLoc, Attrs); 363 } 364 365 // If we reached this code, the statement must end in a semicolon. 366 if (!TryConsumeToken(tok::semi) && !Res.isInvalid()) { 367 // If the result was valid, then we do want to diagnose this. Use 368 // ExpectAndConsume to emit the diagnostic, even though we know it won't 369 // succeed. 370 ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError); 371 // Skip until we see a } or ;, but don't eat it. 372 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 373 } 374 375 return Res; 376} 377 378/// \brief Parse an expression statement. 379StmtResult Parser::ParseExprStatement() { 380 // If a case keyword is missing, this is where it should be inserted. 381 Token OldToken = Tok; 382 383 // expression[opt] ';' 384 ExprResult Expr(ParseExpression()); 385 if (Expr.isInvalid()) { 386 // If the expression is invalid, skip ahead to the next semicolon or '}'. 387 // Not doing this opens us up to the possibility of infinite loops if 388 // ParseExpression does not consume any tokens. 389 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 390 if (Tok.is(tok::semi)) 391 ConsumeToken(); 392 return Actions.ActOnExprStmtError(); 393 } 394 395 if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() && 396 Actions.CheckCaseExpression(Expr.get())) { 397 // If a constant expression is followed by a colon inside a switch block, 398 // suggest a missing case keyword. 399 Diag(OldToken, diag::err_expected_case_before_expression) 400 << FixItHint::CreateInsertion(OldToken.getLocation(), "case "); 401 402 // Recover parsing as a case statement. 403 return ParseCaseStatement(/*MissingCase=*/true, Expr); 404 } 405 406 // Otherwise, eat the semicolon. 407 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); 408 return Actions.ActOnExprStmt(Expr); 409} 410 411/// ParseSEHTryBlockCommon 412/// 413/// seh-try-block: 414/// '__try' compound-statement seh-handler 415/// 416/// seh-handler: 417/// seh-except-block 418/// seh-finally-block 419/// 420StmtResult Parser::ParseSEHTryBlock() { 421 assert(Tok.is(tok::kw___try) && "Expected '__try'"); 422 SourceLocation TryLoc = ConsumeToken(); 423 424 if (Tok.isNot(tok::l_brace)) 425 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); 426 427 StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false, 428 Scope::DeclScope | Scope::SEHTryScope)); 429 if(TryBlock.isInvalid()) 430 return TryBlock; 431 432 StmtResult Handler; 433 if (Tok.is(tok::identifier) && 434 Tok.getIdentifierInfo() == getSEHExceptKeyword()) { 435 SourceLocation Loc = ConsumeToken(); 436 Handler = ParseSEHExceptBlock(Loc); 437 } else if (Tok.is(tok::kw___finally)) { 438 SourceLocation Loc = ConsumeToken(); 439 Handler = ParseSEHFinallyBlock(Loc); 440 } else { 441 return StmtError(Diag(Tok, diag::err_seh_expected_handler)); 442 } 443 444 if(Handler.isInvalid()) 445 return Handler; 446 447 return Actions.ActOnSEHTryBlock(false /* IsCXXTry */, 448 TryLoc, 449 TryBlock.get(), 450 Handler.get()); 451} 452 453/// ParseSEHExceptBlock - Handle __except 454/// 455/// seh-except-block: 456/// '__except' '(' seh-filter-expression ')' compound-statement 457/// 458StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) { 459 PoisonIdentifierRAIIObject raii(Ident__exception_code, false), 460 raii2(Ident___exception_code, false), 461 raii3(Ident_GetExceptionCode, false); 462 463 if (ExpectAndConsume(tok::l_paren)) 464 return StmtError(); 465 466 ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope | 467 Scope::SEHExceptScope); 468 469 if (getLangOpts().Borland) { 470 Ident__exception_info->setIsPoisoned(false); 471 Ident___exception_info->setIsPoisoned(false); 472 Ident_GetExceptionInfo->setIsPoisoned(false); 473 } 474 475 ExprResult FilterExpr; 476 { 477 ParseScopeFlags FilterScope(this, getCurScope()->getFlags() | 478 Scope::SEHFilterScope); 479 FilterExpr = Actions.CorrectDelayedTyposInExpr(ParseExpression()); 480 } 481 482 if (getLangOpts().Borland) { 483 Ident__exception_info->setIsPoisoned(true); 484 Ident___exception_info->setIsPoisoned(true); 485 Ident_GetExceptionInfo->setIsPoisoned(true); 486 } 487 488 if(FilterExpr.isInvalid()) 489 return StmtError(); 490 491 if (ExpectAndConsume(tok::r_paren)) 492 return StmtError(); 493 494 if (Tok.isNot(tok::l_brace)) 495 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); 496 497 StmtResult Block(ParseCompoundStatement()); 498 499 if(Block.isInvalid()) 500 return Block; 501 502 return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.get(), Block.get()); 503} 504 505/// ParseSEHFinallyBlock - Handle __finally 506/// 507/// seh-finally-block: 508/// '__finally' compound-statement 509/// 510StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyLoc) { 511 PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false), 512 raii2(Ident___abnormal_termination, false), 513 raii3(Ident_AbnormalTermination, false); 514 515 if (Tok.isNot(tok::l_brace)) 516 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); 517 518 ParseScope FinallyScope(this, 0); 519 Actions.ActOnStartSEHFinallyBlock(); 520 521 StmtResult Block(ParseCompoundStatement()); 522 if(Block.isInvalid()) { 523 Actions.ActOnAbortSEHFinallyBlock(); 524 return Block; 525 } 526 527 return Actions.ActOnFinishSEHFinallyBlock(FinallyLoc, Block.get()); 528} 529 530/// Handle __leave 531/// 532/// seh-leave-statement: 533/// '__leave' ';' 534/// 535StmtResult Parser::ParseSEHLeaveStatement() { 536 SourceLocation LeaveLoc = ConsumeToken(); // eat the '__leave'. 537 return Actions.ActOnSEHLeaveStmt(LeaveLoc, getCurScope()); 538} 539 540/// ParseLabeledStatement - We have an identifier and a ':' after it. 541/// 542/// labeled-statement: 543/// identifier ':' statement 544/// [GNU] identifier ':' attributes[opt] statement 545/// 546StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) { 547 assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() && 548 "Not an identifier!"); 549 550 Token IdentTok = Tok; // Save the whole token. 551 ConsumeToken(); // eat the identifier. 552 553 assert(Tok.is(tok::colon) && "Not a label!"); 554 555 // identifier ':' statement 556 SourceLocation ColonLoc = ConsumeToken(); 557 558 // Read label attributes, if present. 559 StmtResult SubStmt; 560 if (Tok.is(tok::kw___attribute)) { 561 ParsedAttributesWithRange TempAttrs(AttrFactory); 562 ParseGNUAttributes(TempAttrs); 563 564 // In C++, GNU attributes only apply to the label if they are followed by a 565 // semicolon, to disambiguate label attributes from attributes on a labeled 566 // declaration. 567 // 568 // This doesn't quite match what GCC does; if the attribute list is empty 569 // and followed by a semicolon, GCC will reject (it appears to parse the 570 // attributes as part of a statement in that case). That looks like a bug. 571 if (!getLangOpts().CPlusPlus || Tok.is(tok::semi)) 572 attrs.takeAllFrom(TempAttrs); 573 else if (isDeclarationStatement()) { 574 StmtVector Stmts; 575 // FIXME: We should do this whether or not we have a declaration 576 // statement, but that doesn't work correctly (because ProhibitAttributes 577 // can't handle GNU attributes), so only call it in the one case where 578 // GNU attributes are allowed. 579 SubStmt = ParseStatementOrDeclarationAfterAttributes( 580 Stmts, /*OnlyStmts*/ true, nullptr, TempAttrs); 581 if (!TempAttrs.empty() && !SubStmt.isInvalid()) 582 SubStmt = Actions.ProcessStmtAttributes( 583 SubStmt.get(), TempAttrs.getList(), TempAttrs.Range); 584 } else { 585 Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi; 586 } 587 } 588 589 // If we've not parsed a statement yet, parse one now. 590 if (!SubStmt.isInvalid() && !SubStmt.isUsable()) 591 SubStmt = ParseStatement(); 592 593 // Broken substmt shouldn't prevent the label from being added to the AST. 594 if (SubStmt.isInvalid()) 595 SubStmt = Actions.ActOnNullStmt(ColonLoc); 596 597 LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(), 598 IdentTok.getLocation()); 599 if (AttributeList *Attrs = attrs.getList()) { 600 Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs); 601 attrs.clear(); 602 } 603 604 return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc, 605 SubStmt.get()); 606} 607 608/// ParseCaseStatement 609/// labeled-statement: 610/// 'case' constant-expression ':' statement 611/// [GNU] 'case' constant-expression '...' constant-expression ':' statement 612/// 613StmtResult Parser::ParseCaseStatement(bool MissingCase, ExprResult Expr) { 614 assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!"); 615 616 // It is very very common for code to contain many case statements recursively 617 // nested, as in (but usually without indentation): 618 // case 1: 619 // case 2: 620 // case 3: 621 // case 4: 622 // case 5: etc. 623 // 624 // Parsing this naively works, but is both inefficient and can cause us to run 625 // out of stack space in our recursive descent parser. As a special case, 626 // flatten this recursion into an iterative loop. This is complex and gross, 627 // but all the grossness is constrained to ParseCaseStatement (and some 628 // weirdness in the actions), so this is just local grossness :). 629 630 // TopLevelCase - This is the highest level we have parsed. 'case 1' in the 631 // example above. 632 StmtResult TopLevelCase(true); 633 634 // DeepestParsedCaseStmt - This is the deepest statement we have parsed, which 635 // gets updated each time a new case is parsed, and whose body is unset so 636 // far. When parsing 'case 4', this is the 'case 3' node. 637 Stmt *DeepestParsedCaseStmt = nullptr; 638 639 // While we have case statements, eat and stack them. 640 SourceLocation ColonLoc; 641 do { 642 SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() : 643 ConsumeToken(); // eat the 'case'. 644 ColonLoc = SourceLocation(); 645 646 if (Tok.is(tok::code_completion)) { 647 Actions.CodeCompleteCase(getCurScope()); 648 cutOffParsing(); 649 return StmtError(); 650 } 651 652 /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'. 653 /// Disable this form of error recovery while we're parsing the case 654 /// expression. 655 ColonProtectionRAIIObject ColonProtection(*this); 656 657 ExprResult LHS; 658 if (!MissingCase) { 659 LHS = ParseConstantExpression(); 660 if (!getLangOpts().CPlusPlus11) { 661 LHS = Actions.CorrectDelayedTyposInExpr(LHS, [this](class Expr *E) { 662 return Actions.VerifyIntegerConstantExpression(E); 663 }); 664 } 665 if (LHS.isInvalid()) { 666 // If constant-expression is parsed unsuccessfully, recover by skipping 667 // current case statement (moving to the colon that ends it). 668 if (SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) { 669 TryConsumeToken(tok::colon, ColonLoc); 670 continue; 671 } 672 return StmtError(); 673 } 674 } else { 675 LHS = Expr; 676 MissingCase = false; 677 } 678 679 // GNU case range extension. 680 SourceLocation DotDotDotLoc; 681 ExprResult RHS; 682 if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) { 683 Diag(DotDotDotLoc, diag::ext_gnu_case_range); 684 RHS = ParseConstantExpression(); 685 if (RHS.isInvalid()) { 686 if (SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) { 687 TryConsumeToken(tok::colon, ColonLoc); 688 continue; 689 } 690 return StmtError(); 691 } 692 } 693 694 ColonProtection.restore(); 695 696 if (TryConsumeToken(tok::colon, ColonLoc)) { 697 } else if (TryConsumeToken(tok::semi, ColonLoc) || 698 TryConsumeToken(tok::coloncolon, ColonLoc)) { 699 // Treat "case blah;" or "case blah::" as a typo for "case blah:". 700 Diag(ColonLoc, diag::err_expected_after) 701 << "'case'" << tok::colon 702 << FixItHint::CreateReplacement(ColonLoc, ":"); 703 } else { 704 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); 705 Diag(ExpectedLoc, diag::err_expected_after) 706 << "'case'" << tok::colon 707 << FixItHint::CreateInsertion(ExpectedLoc, ":"); 708 ColonLoc = ExpectedLoc; 709 } 710 711 StmtResult Case = 712 Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc, 713 RHS.get(), ColonLoc); 714 715 // If we had a sema error parsing this case, then just ignore it and 716 // continue parsing the sub-stmt. 717 if (Case.isInvalid()) { 718 if (TopLevelCase.isInvalid()) // No parsed case stmts. 719 return ParseStatement(); 720 // Otherwise, just don't add it as a nested case. 721 } else { 722 // If this is the first case statement we parsed, it becomes TopLevelCase. 723 // Otherwise we link it into the current chain. 724 Stmt *NextDeepest = Case.get(); 725 if (TopLevelCase.isInvalid()) 726 TopLevelCase = Case; 727 else 728 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get()); 729 DeepestParsedCaseStmt = NextDeepest; 730 } 731 732 // Handle all case statements. 733 } while (Tok.is(tok::kw_case)); 734 735 // If we found a non-case statement, start by parsing it. 736 StmtResult SubStmt; 737 738 if (Tok.isNot(tok::r_brace)) { 739 SubStmt = ParseStatement(); 740 } else { 741 // Nicely diagnose the common error "switch (X) { case 4: }", which is 742 // not valid. If ColonLoc doesn't point to a valid text location, there was 743 // another parsing error, so avoid producing extra diagnostics. 744 if (ColonLoc.isValid()) { 745 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc); 746 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement) 747 << FixItHint::CreateInsertion(AfterColonLoc, " ;"); 748 } 749 SubStmt = StmtError(); 750 } 751 752 // Install the body into the most deeply-nested case. 753 if (DeepestParsedCaseStmt) { 754 // Broken sub-stmt shouldn't prevent forming the case statement properly. 755 if (SubStmt.isInvalid()) 756 SubStmt = Actions.ActOnNullStmt(SourceLocation()); 757 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get()); 758 } 759 760 // Return the top level parsed statement tree. 761 return TopLevelCase; 762} 763 764/// ParseDefaultStatement 765/// labeled-statement: 766/// 'default' ':' statement 767/// Note that this does not parse the 'statement' at the end. 768/// 769StmtResult Parser::ParseDefaultStatement() { 770 assert(Tok.is(tok::kw_default) && "Not a default stmt!"); 771 SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'. 772 773 SourceLocation ColonLoc; 774 if (TryConsumeToken(tok::colon, ColonLoc)) { 775 } else if (TryConsumeToken(tok::semi, ColonLoc)) { 776 // Treat "default;" as a typo for "default:". 777 Diag(ColonLoc, diag::err_expected_after) 778 << "'default'" << tok::colon 779 << FixItHint::CreateReplacement(ColonLoc, ":"); 780 } else { 781 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation); 782 Diag(ExpectedLoc, diag::err_expected_after) 783 << "'default'" << tok::colon 784 << FixItHint::CreateInsertion(ExpectedLoc, ":"); 785 ColonLoc = ExpectedLoc; 786 } 787 788 StmtResult SubStmt; 789 790 if (Tok.isNot(tok::r_brace)) { 791 SubStmt = ParseStatement(); 792 } else { 793 // Diagnose the common error "switch (X) {... default: }", which is 794 // not valid. 795 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc); 796 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement) 797 << FixItHint::CreateInsertion(AfterColonLoc, " ;"); 798 SubStmt = true; 799 } 800 801 // Broken sub-stmt shouldn't prevent forming the case statement properly. 802 if (SubStmt.isInvalid()) 803 SubStmt = Actions.ActOnNullStmt(ColonLoc); 804 805 return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc, 806 SubStmt.get(), getCurScope()); 807} 808 809StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) { 810 return ParseCompoundStatement(isStmtExpr, Scope::DeclScope); 811} 812 813/// ParseCompoundStatement - Parse a "{}" block. 814/// 815/// compound-statement: [C99 6.8.2] 816/// { block-item-list[opt] } 817/// [GNU] { label-declarations block-item-list } [TODO] 818/// 819/// block-item-list: 820/// block-item 821/// block-item-list block-item 822/// 823/// block-item: 824/// declaration 825/// [GNU] '__extension__' declaration 826/// statement 827/// 828/// [GNU] label-declarations: 829/// [GNU] label-declaration 830/// [GNU] label-declarations label-declaration 831/// 832/// [GNU] label-declaration: 833/// [GNU] '__label__' identifier-list ';' 834/// 835StmtResult Parser::ParseCompoundStatement(bool isStmtExpr, 836 unsigned ScopeFlags) { 837 assert(Tok.is(tok::l_brace) && "Not a compount stmt!"); 838 839 // Enter a scope to hold everything within the compound stmt. Compound 840 // statements can always hold declarations. 841 ParseScope CompoundScope(this, ScopeFlags); 842 843 // Parse the statements in the body. 844 return ParseCompoundStatementBody(isStmtExpr); 845} 846 847/// Parse any pragmas at the start of the compound expression. We handle these 848/// separately since some pragmas (FP_CONTRACT) must appear before any C 849/// statement in the compound, but may be intermingled with other pragmas. 850void Parser::ParseCompoundStatementLeadingPragmas() { 851 bool checkForPragmas = true; 852 while (checkForPragmas) { 853 switch (Tok.getKind()) { 854 case tok::annot_pragma_vis: 855 HandlePragmaVisibility(); 856 break; 857 case tok::annot_pragma_pack: 858 HandlePragmaPack(); 859 break; 860 case tok::annot_pragma_msstruct: 861 HandlePragmaMSStruct(); 862 break; 863 case tok::annot_pragma_align: 864 HandlePragmaAlign(); 865 break; 866 case tok::annot_pragma_weak: 867 HandlePragmaWeak(); 868 break; 869 case tok::annot_pragma_weakalias: 870 HandlePragmaWeakAlias(); 871 break; 872 case tok::annot_pragma_redefine_extname: 873 HandlePragmaRedefineExtname(); 874 break; 875 case tok::annot_pragma_opencl_extension: 876 HandlePragmaOpenCLExtension(); 877 break; 878 case tok::annot_pragma_fp_contract: 879 HandlePragmaFPContract(); 880 break; 881 case tok::annot_pragma_ms_pointers_to_members: 882 HandlePragmaMSPointersToMembers(); 883 break; 884 case tok::annot_pragma_ms_pragma: 885 HandlePragmaMSPragma(); 886 break; 887 default: 888 checkForPragmas = false; 889 break; 890 } 891 } 892 893} 894 895/// ParseCompoundStatementBody - Parse a sequence of statements and invoke the 896/// ActOnCompoundStmt action. This expects the '{' to be the current token, and 897/// consume the '}' at the end of the block. It does not manipulate the scope 898/// stack. 899StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) { 900 PrettyStackTraceLoc CrashInfo(PP.getSourceManager(), 901 Tok.getLocation(), 902 "in compound statement ('{}')"); 903 904 // Record the state of the FP_CONTRACT pragma, restore on leaving the 905 // compound statement. 906 Sema::FPContractStateRAII SaveFPContractState(Actions); 907 908 InMessageExpressionRAIIObject InMessage(*this, false); 909 BalancedDelimiterTracker T(*this, tok::l_brace); 910 if (T.consumeOpen()) 911 return StmtError(); 912 913 Sema::CompoundScopeRAII CompoundScope(Actions); 914 915 // Parse any pragmas at the beginning of the compound statement. 916 ParseCompoundStatementLeadingPragmas(); 917 918 StmtVector Stmts; 919 920 // "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are 921 // only allowed at the start of a compound stmt regardless of the language. 922 while (Tok.is(tok::kw___label__)) { 923 SourceLocation LabelLoc = ConsumeToken(); 924 925 SmallVector<Decl *, 8> DeclsInGroup; 926 while (1) { 927 if (Tok.isNot(tok::identifier)) { 928 Diag(Tok, diag::err_expected) << tok::identifier; 929 break; 930 } 931 932 IdentifierInfo *II = Tok.getIdentifierInfo(); 933 SourceLocation IdLoc = ConsumeToken(); 934 DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc)); 935 936 if (!TryConsumeToken(tok::comma)) 937 break; 938 } 939 940 DeclSpec DS(AttrFactory); 941 DeclGroupPtrTy Res = 942 Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup); 943 StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation()); 944 945 ExpectAndConsumeSemi(diag::err_expected_semi_declaration); 946 if (R.isUsable()) 947 Stmts.push_back(R.get()); 948 } 949 950 while (Tok.isNot(tok::r_brace) && !isEofOrEom()) { 951 if (Tok.is(tok::annot_pragma_unused)) { 952 HandlePragmaUnused(); 953 continue; 954 } 955 956 StmtResult R; 957 if (Tok.isNot(tok::kw___extension__)) { 958 R = ParseStatementOrDeclaration(Stmts, false); 959 } else { 960 // __extension__ can start declarations and it can also be a unary 961 // operator for expressions. Consume multiple __extension__ markers here 962 // until we can determine which is which. 963 // FIXME: This loses extension expressions in the AST! 964 SourceLocation ExtLoc = ConsumeToken(); 965 while (Tok.is(tok::kw___extension__)) 966 ConsumeToken(); 967 968 ParsedAttributesWithRange attrs(AttrFactory); 969 MaybeParseCXX11Attributes(attrs, nullptr, 970 /*MightBeObjCMessageSend*/ true); 971 972 // If this is the start of a declaration, parse it as such. 973 if (isDeclarationStatement()) { 974 // __extension__ silences extension warnings in the subdeclaration. 975 // FIXME: Save the __extension__ on the decl as a node somehow? 976 ExtensionRAIIObject O(Diags); 977 978 SourceLocation DeclStart = Tok.getLocation(), DeclEnd; 979 DeclGroupPtrTy Res = ParseDeclaration(Declarator::BlockContext, DeclEnd, 980 attrs); 981 R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd); 982 } else { 983 // Otherwise this was a unary __extension__ marker. 984 ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc)); 985 986 if (Res.isInvalid()) { 987 SkipUntil(tok::semi); 988 continue; 989 } 990 991 // FIXME: Use attributes? 992 // Eat the semicolon at the end of stmt and convert the expr into a 993 // statement. 994 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr); 995 R = Actions.ActOnExprStmt(Res); 996 } 997 } 998 999 if (R.isUsable()) 1000 Stmts.push_back(R.get()); 1001 } 1002 1003 SourceLocation CloseLoc = Tok.getLocation(); 1004 1005 // We broke out of the while loop because we found a '}' or EOF. 1006 if (!T.consumeClose()) 1007 // Recover by creating a compound statement with what we parsed so far, 1008 // instead of dropping everything and returning StmtError(); 1009 CloseLoc = T.getCloseLocation(); 1010 1011 return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc, 1012 Stmts, isStmtExpr); 1013} 1014 1015/// ParseParenExprOrCondition: 1016/// [C ] '(' expression ')' 1017/// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true] 1018/// 1019/// This function parses and performs error recovery on the specified condition 1020/// or expression (depending on whether we're in C++ or C mode). This function 1021/// goes out of its way to recover well. It returns true if there was a parser 1022/// error (the right paren couldn't be found), which indicates that the caller 1023/// should try to recover harder. It returns false if the condition is 1024/// successfully parsed. Note that a successful parse can still have semantic 1025/// errors in the condition. 1026bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult, 1027 Decl *&DeclResult, 1028 SourceLocation Loc, 1029 bool ConvertToBoolean) { 1030 BalancedDelimiterTracker T(*this, tok::l_paren); 1031 T.consumeOpen(); 1032 1033 if (getLangOpts().CPlusPlus) 1034 ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean); 1035 else { 1036 ExprResult = ParseExpression(); 1037 DeclResult = nullptr; 1038 1039 // If required, convert to a boolean value. 1040 if (!ExprResult.isInvalid() && ConvertToBoolean) 1041 ExprResult 1042 = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get()); 1043 } 1044 1045 // If the parser was confused by the condition and we don't have a ')', try to 1046 // recover by skipping ahead to a semi and bailing out. If condexp is 1047 // semantically invalid but we have well formed code, keep going. 1048 if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) { 1049 SkipUntil(tok::semi); 1050 // Skipping may have stopped if it found the containing ')'. If so, we can 1051 // continue parsing the if statement. 1052 if (Tok.isNot(tok::r_paren)) 1053 return true; 1054 } 1055 1056 // Otherwise the condition is valid or the rparen is present. 1057 T.consumeClose(); 1058 1059 // Check for extraneous ')'s to catch things like "if (foo())) {". We know 1060 // that all callers are looking for a statement after the condition, so ")" 1061 // isn't valid. 1062 while (Tok.is(tok::r_paren)) { 1063 Diag(Tok, diag::err_extraneous_rparen_in_condition) 1064 << FixItHint::CreateRemoval(Tok.getLocation()); 1065 ConsumeParen(); 1066 } 1067 1068 return false; 1069} 1070 1071 1072/// ParseIfStatement 1073/// if-statement: [C99 6.8.4.1] 1074/// 'if' '(' expression ')' statement 1075/// 'if' '(' expression ')' statement 'else' statement 1076/// [C++] 'if' '(' condition ')' statement 1077/// [C++] 'if' '(' condition ')' statement 'else' statement 1078/// 1079StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) { 1080 assert(Tok.is(tok::kw_if) && "Not an if stmt!"); 1081 SourceLocation IfLoc = ConsumeToken(); // eat the 'if'. 1082 1083 if (Tok.isNot(tok::l_paren)) { 1084 Diag(Tok, diag::err_expected_lparen_after) << "if"; 1085 SkipUntil(tok::semi); 1086 return StmtError(); 1087 } 1088 1089 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; 1090 1091 // C99 6.8.4p3 - In C99, the if statement is a block. This is not 1092 // the case for C90. 1093 // 1094 // C++ 6.4p3: 1095 // A name introduced by a declaration in a condition is in scope from its 1096 // point of declaration until the end of the substatements controlled by the 1097 // condition. 1098 // C++ 3.3.2p4: 1099 // Names declared in the for-init-statement, and in the condition of if, 1100 // while, for, and switch statements are local to the if, while, for, or 1101 // switch statement (including the controlled statement). 1102 // 1103 ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX); 1104 1105 // Parse the condition. 1106 ExprResult CondExp; 1107 Decl *CondVar = nullptr; 1108 if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true)) 1109 return StmtError(); 1110 1111 FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get(), IfLoc)); 1112 1113 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if 1114 // there is no compound stmt. C90 does not have this clause. We only do this 1115 // if the body isn't a compound statement to avoid push/pop in common cases. 1116 // 1117 // C++ 6.4p1: 1118 // The substatement in a selection-statement (each substatement, in the else 1119 // form of the if statement) implicitly defines a local scope. 1120 // 1121 // For C++ we create a scope for the condition and a new scope for 1122 // substatements because: 1123 // -When the 'then' scope exits, we want the condition declaration to still be 1124 // active for the 'else' scope too. 1125 // -Sema will detect name clashes by considering declarations of a 1126 // 'ControlScope' as part of its direct subscope. 1127 // -If we wanted the condition and substatement to be in the same scope, we 1128 // would have to notify ParseStatement not to create a new scope. It's 1129 // simpler to let it create a new scope. 1130 // 1131 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); 1132 1133 // Read the 'then' stmt. 1134 SourceLocation ThenStmtLoc = Tok.getLocation(); 1135 1136 SourceLocation InnerStatementTrailingElseLoc; 1137 StmtResult ThenStmt(ParseStatement(&InnerStatementTrailingElseLoc)); 1138 1139 // Pop the 'if' scope if needed. 1140 InnerScope.Exit(); 1141 1142 // If it has an else, parse it. 1143 SourceLocation ElseLoc; 1144 SourceLocation ElseStmtLoc; 1145 StmtResult ElseStmt; 1146 1147 if (Tok.is(tok::kw_else)) { 1148 if (TrailingElseLoc) 1149 *TrailingElseLoc = Tok.getLocation(); 1150 1151 ElseLoc = ConsumeToken(); 1152 ElseStmtLoc = Tok.getLocation(); 1153 1154 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if 1155 // there is no compound stmt. C90 does not have this clause. We only do 1156 // this if the body isn't a compound statement to avoid push/pop in common 1157 // cases. 1158 // 1159 // C++ 6.4p1: 1160 // The substatement in a selection-statement (each substatement, in the else 1161 // form of the if statement) implicitly defines a local scope. 1162 // 1163 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); 1164 1165 ElseStmt = ParseStatement(); 1166 1167 // Pop the 'else' scope if needed. 1168 InnerScope.Exit(); 1169 } else if (Tok.is(tok::code_completion)) { 1170 Actions.CodeCompleteAfterIf(getCurScope()); 1171 cutOffParsing(); 1172 return StmtError(); 1173 } else if (InnerStatementTrailingElseLoc.isValid()) { 1174 Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else); 1175 } 1176 1177 IfScope.Exit(); 1178 1179 // If the then or else stmt is invalid and the other is valid (and present), 1180 // make turn the invalid one into a null stmt to avoid dropping the other 1181 // part. If both are invalid, return error. 1182 if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) || 1183 (ThenStmt.isInvalid() && ElseStmt.get() == nullptr) || 1184 (ThenStmt.get() == nullptr && ElseStmt.isInvalid())) { 1185 // Both invalid, or one is invalid and other is non-present: return error. 1186 return StmtError(); 1187 } 1188 1189 // Now if either are invalid, replace with a ';'. 1190 if (ThenStmt.isInvalid()) 1191 ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc); 1192 if (ElseStmt.isInvalid()) 1193 ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc); 1194 1195 return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(), 1196 ElseLoc, ElseStmt.get()); 1197} 1198 1199/// ParseSwitchStatement 1200/// switch-statement: 1201/// 'switch' '(' expression ')' statement 1202/// [C++] 'switch' '(' condition ')' statement 1203StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) { 1204 assert(Tok.is(tok::kw_switch) && "Not a switch stmt!"); 1205 SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'. 1206 1207 if (Tok.isNot(tok::l_paren)) { 1208 Diag(Tok, diag::err_expected_lparen_after) << "switch"; 1209 SkipUntil(tok::semi); 1210 return StmtError(); 1211 } 1212 1213 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; 1214 1215 // C99 6.8.4p3 - In C99, the switch statement is a block. This is 1216 // not the case for C90. Start the switch scope. 1217 // 1218 // C++ 6.4p3: 1219 // A name introduced by a declaration in a condition is in scope from its 1220 // point of declaration until the end of the substatements controlled by the 1221 // condition. 1222 // C++ 3.3.2p4: 1223 // Names declared in the for-init-statement, and in the condition of if, 1224 // while, for, and switch statements are local to the if, while, for, or 1225 // switch statement (including the controlled statement). 1226 // 1227 unsigned ScopeFlags = Scope::SwitchScope; 1228 if (C99orCXX) 1229 ScopeFlags |= Scope::DeclScope | Scope::ControlScope; 1230 ParseScope SwitchScope(this, ScopeFlags); 1231 1232 // Parse the condition. 1233 ExprResult Cond; 1234 Decl *CondVar = nullptr; 1235 if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false)) 1236 return StmtError(); 1237 1238 StmtResult Switch 1239 = Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar); 1240 1241 if (Switch.isInvalid()) { 1242 // Skip the switch body. 1243 // FIXME: This is not optimal recovery, but parsing the body is more 1244 // dangerous due to the presence of case and default statements, which 1245 // will have no place to connect back with the switch. 1246 if (Tok.is(tok::l_brace)) { 1247 ConsumeBrace(); 1248 SkipUntil(tok::r_brace); 1249 } else 1250 SkipUntil(tok::semi); 1251 return Switch; 1252 } 1253 1254 // C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if 1255 // there is no compound stmt. C90 does not have this clause. We only do this 1256 // if the body isn't a compound statement to avoid push/pop in common cases. 1257 // 1258 // C++ 6.4p1: 1259 // The substatement in a selection-statement (each substatement, in the else 1260 // form of the if statement) implicitly defines a local scope. 1261 // 1262 // See comments in ParseIfStatement for why we create a scope for the 1263 // condition and a new scope for substatement in C++. 1264 // 1265 getCurScope()->AddFlags(Scope::BreakScope); 1266 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); 1267 1268 // We have incremented the mangling number for the SwitchScope and the 1269 // InnerScope, which is one too many. 1270 if (C99orCXX) 1271 getCurScope()->decrementMSManglingNumber(); 1272 1273 // Read the body statement. 1274 StmtResult Body(ParseStatement(TrailingElseLoc)); 1275 1276 // Pop the scopes. 1277 InnerScope.Exit(); 1278 SwitchScope.Exit(); 1279 1280 return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get()); 1281} 1282 1283/// ParseWhileStatement 1284/// while-statement: [C99 6.8.5.1] 1285/// 'while' '(' expression ')' statement 1286/// [C++] 'while' '(' condition ')' statement 1287StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) { 1288 assert(Tok.is(tok::kw_while) && "Not a while stmt!"); 1289 SourceLocation WhileLoc = Tok.getLocation(); 1290 ConsumeToken(); // eat the 'while'. 1291 1292 if (Tok.isNot(tok::l_paren)) { 1293 Diag(Tok, diag::err_expected_lparen_after) << "while"; 1294 SkipUntil(tok::semi); 1295 return StmtError(); 1296 } 1297 1298 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; 1299 1300 // C99 6.8.5p5 - In C99, the while statement is a block. This is not 1301 // the case for C90. Start the loop scope. 1302 // 1303 // C++ 6.4p3: 1304 // A name introduced by a declaration in a condition is in scope from its 1305 // point of declaration until the end of the substatements controlled by the 1306 // condition. 1307 // C++ 3.3.2p4: 1308 // Names declared in the for-init-statement, and in the condition of if, 1309 // while, for, and switch statements are local to the if, while, for, or 1310 // switch statement (including the controlled statement). 1311 // 1312 unsigned ScopeFlags; 1313 if (C99orCXX) 1314 ScopeFlags = Scope::BreakScope | Scope::ContinueScope | 1315 Scope::DeclScope | Scope::ControlScope; 1316 else 1317 ScopeFlags = Scope::BreakScope | Scope::ContinueScope; 1318 ParseScope WhileScope(this, ScopeFlags); 1319 1320 // Parse the condition. 1321 ExprResult Cond; 1322 Decl *CondVar = nullptr; 1323 if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true)) 1324 return StmtError(); 1325 1326 FullExprArg FullCond(Actions.MakeFullExpr(Cond.get(), WhileLoc)); 1327 1328 // C99 6.8.5p5 - In C99, the body of the while statement is a scope, even if 1329 // there is no compound stmt. C90 does not have this clause. We only do this 1330 // if the body isn't a compound statement to avoid push/pop in common cases. 1331 // 1332 // C++ 6.5p2: 1333 // The substatement in an iteration-statement implicitly defines a local scope 1334 // which is entered and exited each time through the loop. 1335 // 1336 // See comments in ParseIfStatement for why we create a scope for the 1337 // condition and a new scope for substatement in C++. 1338 // 1339 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); 1340 1341 // Read the body statement. 1342 StmtResult Body(ParseStatement(TrailingElseLoc)); 1343 1344 // Pop the body scope if needed. 1345 InnerScope.Exit(); 1346 WhileScope.Exit(); 1347 1348 if ((Cond.isInvalid() && !CondVar) || Body.isInvalid()) 1349 return StmtError(); 1350 1351 return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get()); 1352} 1353 1354/// ParseDoStatement 1355/// do-statement: [C99 6.8.5.2] 1356/// 'do' statement 'while' '(' expression ')' ';' 1357/// Note: this lets the caller parse the end ';'. 1358StmtResult Parser::ParseDoStatement() { 1359 assert(Tok.is(tok::kw_do) && "Not a do stmt!"); 1360 SourceLocation DoLoc = ConsumeToken(); // eat the 'do'. 1361 1362 // C99 6.8.5p5 - In C99, the do statement is a block. This is not 1363 // the case for C90. Start the loop scope. 1364 unsigned ScopeFlags; 1365 if (getLangOpts().C99) 1366 ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope; 1367 else 1368 ScopeFlags = Scope::BreakScope | Scope::ContinueScope; 1369 1370 ParseScope DoScope(this, ScopeFlags); 1371 1372 // C99 6.8.5p5 - In C99, the body of the do statement is a scope, even if 1373 // there is no compound stmt. C90 does not have this clause. We only do this 1374 // if the body isn't a compound statement to avoid push/pop in common cases. 1375 // 1376 // C++ 6.5p2: 1377 // The substatement in an iteration-statement implicitly defines a local scope 1378 // which is entered and exited each time through the loop. 1379 // 1380 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus; 1381 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace)); 1382 1383 // Read the body statement. 1384 StmtResult Body(ParseStatement()); 1385 1386 // Pop the body scope if needed. 1387 InnerScope.Exit(); 1388 1389 if (Tok.isNot(tok::kw_while)) { 1390 if (!Body.isInvalid()) { 1391 Diag(Tok, diag::err_expected_while); 1392 Diag(DoLoc, diag::note_matching) << "'do'"; 1393 SkipUntil(tok::semi, StopBeforeMatch); 1394 } 1395 return StmtError(); 1396 } 1397 SourceLocation WhileLoc = ConsumeToken(); 1398 1399 if (Tok.isNot(tok::l_paren)) { 1400 Diag(Tok, diag::err_expected_lparen_after) << "do/while"; 1401 SkipUntil(tok::semi, StopBeforeMatch); 1402 return StmtError(); 1403 } 1404 1405 // Parse the parenthesized expression. 1406 BalancedDelimiterTracker T(*this, tok::l_paren); 1407 T.consumeOpen(); 1408 1409 // A do-while expression is not a condition, so can't have attributes. 1410 DiagnoseAndSkipCXX11Attributes(); 1411 1412 ExprResult Cond = ParseExpression(); 1413 T.consumeClose(); 1414 DoScope.Exit(); 1415 1416 if (Cond.isInvalid() || Body.isInvalid()) 1417 return StmtError(); 1418 1419 return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(), 1420 Cond.get(), T.getCloseLocation()); 1421} 1422 1423bool Parser::isForRangeIdentifier() { 1424 assert(Tok.is(tok::identifier)); 1425 1426 const Token &Next = NextToken(); 1427 if (Next.is(tok::colon)) 1428 return true; 1429 1430 if (Next.is(tok::l_square) || Next.is(tok::kw_alignas)) { 1431 TentativeParsingAction PA(*this); 1432 ConsumeToken(); 1433 SkipCXX11Attributes(); 1434 bool Result = Tok.is(tok::colon); 1435 PA.Revert(); 1436 return Result; 1437 } 1438 1439 return false; 1440} 1441 1442/// ParseForStatement 1443/// for-statement: [C99 6.8.5.3] 1444/// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement 1445/// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement 1446/// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')' 1447/// [C++] statement 1448/// [C++0x] 'for' '(' for-range-declaration : for-range-initializer ) statement 1449/// [OBJC2] 'for' '(' declaration 'in' expr ')' statement 1450/// [OBJC2] 'for' '(' expr 'in' expr ')' statement 1451/// 1452/// [C++] for-init-statement: 1453/// [C++] expression-statement 1454/// [C++] simple-declaration 1455/// 1456/// [C++0x] for-range-declaration: 1457/// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator 1458/// [C++0x] for-range-initializer: 1459/// [C++0x] expression 1460/// [C++0x] braced-init-list [TODO] 1461StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) { 1462 assert(Tok.is(tok::kw_for) && "Not a for stmt!"); 1463 SourceLocation ForLoc = ConsumeToken(); // eat the 'for'. 1464 1465 if (Tok.isNot(tok::l_paren)) { 1466 Diag(Tok, diag::err_expected_lparen_after) << "for"; 1467 SkipUntil(tok::semi); 1468 return StmtError(); 1469 } 1470 1471 bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus || 1472 getLangOpts().ObjC1; 1473 1474 // C99 6.8.5p5 - In C99, the for statement is a block. This is not 1475 // the case for C90. Start the loop scope. 1476 // 1477 // C++ 6.4p3: 1478 // A name introduced by a declaration in a condition is in scope from its 1479 // point of declaration until the end of the substatements controlled by the 1480 // condition. 1481 // C++ 3.3.2p4: 1482 // Names declared in the for-init-statement, and in the condition of if, 1483 // while, for, and switch statements are local to the if, while, for, or 1484 // switch statement (including the controlled statement). 1485 // C++ 6.5.3p1: 1486 // Names declared in the for-init-statement are in the same declarative-region 1487 // as those declared in the condition. 1488 // 1489 unsigned ScopeFlags = 0; 1490 if (C99orCXXorObjC) 1491 ScopeFlags = Scope::DeclScope | Scope::ControlScope; 1492 1493 ParseScope ForScope(this, ScopeFlags); 1494 1495 BalancedDelimiterTracker T(*this, tok::l_paren); 1496 T.consumeOpen(); 1497 1498 ExprResult Value; 1499 1500 bool ForEach = false, ForRange = false; 1501 StmtResult FirstPart; 1502 bool SecondPartIsInvalid = false; 1503 FullExprArg SecondPart(Actions); 1504 ExprResult Collection; 1505 ForRangeInit ForRangeInit; 1506 FullExprArg ThirdPart(Actions); 1507 Decl *SecondVar = nullptr; 1508 1509 if (Tok.is(tok::code_completion)) { 1510 Actions.CodeCompleteOrdinaryName(getCurScope(), 1511 C99orCXXorObjC? Sema::PCC_ForInit 1512 : Sema::PCC_Expression); 1513 cutOffParsing(); 1514 return StmtError(); 1515 } 1516 1517 ParsedAttributesWithRange attrs(AttrFactory); 1518 MaybeParseCXX11Attributes(attrs); 1519 1520 // Parse the first part of the for specifier. 1521 if (Tok.is(tok::semi)) { // for (; 1522 ProhibitAttributes(attrs); 1523 // no first part, eat the ';'. 1524 ConsumeToken(); 1525 } else if (getLangOpts().CPlusPlus && Tok.is(tok::identifier) && 1526 isForRangeIdentifier()) { 1527 ProhibitAttributes(attrs); 1528 IdentifierInfo *Name = Tok.getIdentifierInfo(); 1529 SourceLocation Loc = ConsumeToken(); 1530 MaybeParseCXX11Attributes(attrs); 1531 1532 ForRangeInit.ColonLoc = ConsumeToken(); 1533 if (Tok.is(tok::l_brace)) 1534 ForRangeInit.RangeExpr = ParseBraceInitializer(); 1535 else 1536 ForRangeInit.RangeExpr = ParseExpression(); 1537 1538 Diag(Loc, diag::err_for_range_identifier) 1539 << ((getLangOpts().CPlusPlus11 && !getLangOpts().CPlusPlus1z) 1540 ? FixItHint::CreateInsertion(Loc, "auto &&") 1541 : FixItHint()); 1542 1543 FirstPart = Actions.ActOnCXXForRangeIdentifier(getCurScope(), Loc, Name, 1544 attrs, attrs.Range.getEnd()); 1545 ForRange = true; 1546 } else if (isForInitDeclaration()) { // for (int X = 4; 1547 // Parse declaration, which eats the ';'. 1548 if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode? 1549 Diag(Tok, diag::ext_c99_variable_decl_in_for_loop); 1550 1551 // In C++0x, "for (T NS:a" might not be a typo for :: 1552 bool MightBeForRangeStmt = getLangOpts().CPlusPlus; 1553 ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt); 1554 1555 SourceLocation DeclStart = Tok.getLocation(), DeclEnd; 1556 DeclGroupPtrTy DG = ParseSimpleDeclaration( 1557 Declarator::ForContext, DeclEnd, attrs, false, 1558 MightBeForRangeStmt ? &ForRangeInit : nullptr); 1559 FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation()); 1560 if (ForRangeInit.ParsedForRangeDecl()) { 1561 Diag(ForRangeInit.ColonLoc, getLangOpts().CPlusPlus11 ? 1562 diag::warn_cxx98_compat_for_range : diag::ext_for_range); 1563 1564 ForRange = true; 1565 } else if (Tok.is(tok::semi)) { // for (int x = 4; 1566 ConsumeToken(); 1567 } else if ((ForEach = isTokIdentifier_in())) { 1568 Actions.ActOnForEachDeclStmt(DG); 1569 // ObjC: for (id x in expr) 1570 ConsumeToken(); // consume 'in' 1571 1572 if (Tok.is(tok::code_completion)) { 1573 Actions.CodeCompleteObjCForCollection(getCurScope(), DG); 1574 cutOffParsing(); 1575 return StmtError(); 1576 } 1577 Collection = ParseExpression(); 1578 } else { 1579 Diag(Tok, diag::err_expected_semi_for); 1580 } 1581 } else { 1582 ProhibitAttributes(attrs); 1583 Value = Actions.CorrectDelayedTyposInExpr(ParseExpression()); 1584 1585 ForEach = isTokIdentifier_in(); 1586 1587 // Turn the expression into a stmt. 1588 if (!Value.isInvalid()) { 1589 if (ForEach) 1590 FirstPart = Actions.ActOnForEachLValueExpr(Value.get()); 1591 else 1592 FirstPart = Actions.ActOnExprStmt(Value); 1593 } 1594 1595 if (Tok.is(tok::semi)) { 1596 ConsumeToken(); 1597 } else if (ForEach) { 1598 ConsumeToken(); // consume 'in' 1599 1600 if (Tok.is(tok::code_completion)) { 1601 Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy()); 1602 cutOffParsing(); 1603 return StmtError(); 1604 } 1605 Collection = ParseExpression(); 1606 } else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) { 1607 // User tried to write the reasonable, but ill-formed, for-range-statement 1608 // for (expr : expr) { ... } 1609 Diag(Tok, diag::err_for_range_expected_decl) 1610 << FirstPart.get()->getSourceRange(); 1611 SkipUntil(tok::r_paren, StopBeforeMatch); 1612 SecondPartIsInvalid = true; 1613 } else { 1614 if (!Value.isInvalid()) { 1615 Diag(Tok, diag::err_expected_semi_for); 1616 } else { 1617 // Skip until semicolon or rparen, don't consume it. 1618 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch); 1619 if (Tok.is(tok::semi)) 1620 ConsumeToken(); 1621 } 1622 } 1623 } 1624 1625 // Parse the second part of the for specifier. 1626 getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope); 1627 if (!ForEach && !ForRange) { 1628 assert(!SecondPart.get() && "Shouldn't have a second expression yet."); 1629 // Parse the second part of the for specifier. 1630 if (Tok.is(tok::semi)) { // for (...;; 1631 // no second part. 1632 } else if (Tok.is(tok::r_paren)) { 1633 // missing both semicolons. 1634 } else { 1635 ExprResult Second; 1636 if (getLangOpts().CPlusPlus) 1637 ParseCXXCondition(Second, SecondVar, ForLoc, true); 1638 else { 1639 Second = ParseExpression(); 1640 if (!Second.isInvalid()) 1641 Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc, 1642 Second.get()); 1643 } 1644 SecondPartIsInvalid = Second.isInvalid(); 1645 SecondPart = Actions.MakeFullExpr(Second.get(), ForLoc); 1646 } 1647 1648 if (Tok.isNot(tok::semi)) { 1649 if (!SecondPartIsInvalid || SecondVar) 1650 Diag(Tok, diag::err_expected_semi_for); 1651 else 1652 // Skip until semicolon or rparen, don't consume it. 1653 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch); 1654 } 1655 1656 if (Tok.is(tok::semi)) { 1657 ConsumeToken(); 1658 } 1659 1660 // Parse the third part of the for specifier. 1661 if (Tok.isNot(tok::r_paren)) { // for (...;...;) 1662 ExprResult Third = ParseExpression(); 1663 // FIXME: The C++11 standard doesn't actually say that this is a 1664 // discarded-value expression, but it clearly should be. 1665 ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.get()); 1666 } 1667 } 1668 // Match the ')'. 1669 T.consumeClose(); 1670 1671 // We need to perform most of the semantic analysis for a C++0x for-range 1672 // statememt before parsing the body, in order to be able to deduce the type 1673 // of an auto-typed loop variable. 1674 StmtResult ForRangeStmt; 1675 StmtResult ForEachStmt; 1676 1677 if (ForRange) { 1678 ForRangeStmt = Actions.ActOnCXXForRangeStmt(ForLoc, FirstPart.get(), 1679 ForRangeInit.ColonLoc, 1680 ForRangeInit.RangeExpr.get(), 1681 T.getCloseLocation(), 1682 Sema::BFRK_Build); 1683 1684 1685 // Similarly, we need to do the semantic analysis for a for-range 1686 // statement immediately in order to close over temporaries correctly. 1687 } else if (ForEach) { 1688 ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc, 1689 FirstPart.get(), 1690 Collection.get(), 1691 T.getCloseLocation()); 1692 } 1693 1694 // C99 6.8.5p5 - In C99, the body of the for statement is a scope, even if 1695 // there is no compound stmt. C90 does not have this clause. We only do this 1696 // if the body isn't a compound statement to avoid push/pop in common cases. 1697 // 1698 // C++ 6.5p2: 1699 // The substatement in an iteration-statement implicitly defines a local scope 1700 // which is entered and exited each time through the loop. 1701 // 1702 // See comments in ParseIfStatement for why we create a scope for 1703 // for-init-statement/condition and a new scope for substatement in C++. 1704 // 1705 ParseScope InnerScope(this, Scope::DeclScope, C99orCXXorObjC, 1706 Tok.is(tok::l_brace)); 1707 1708 // The body of the for loop has the same local mangling number as the 1709 // for-init-statement. 1710 // It will only be incremented if the body contains other things that would 1711 // normally increment the mangling number (like a compound statement). 1712 if (C99orCXXorObjC) 1713 getCurScope()->decrementMSManglingNumber(); 1714 1715 // Read the body statement. 1716 StmtResult Body(ParseStatement(TrailingElseLoc)); 1717 1718 // Pop the body scope if needed. 1719 InnerScope.Exit(); 1720 1721 // Leave the for-scope. 1722 ForScope.Exit(); 1723 1724 if (Body.isInvalid()) 1725 return StmtError(); 1726 1727 if (ForEach) 1728 return Actions.FinishObjCForCollectionStmt(ForEachStmt.get(), 1729 Body.get()); 1730 1731 if (ForRange) 1732 return Actions.FinishCXXForRangeStmt(ForRangeStmt.get(), Body.get()); 1733 1734 return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.get(), 1735 SecondPart, SecondVar, ThirdPart, 1736 T.getCloseLocation(), Body.get()); 1737} 1738 1739/// ParseGotoStatement 1740/// jump-statement: 1741/// 'goto' identifier ';' 1742/// [GNU] 'goto' '*' expression ';' 1743/// 1744/// Note: this lets the caller parse the end ';'. 1745/// 1746StmtResult Parser::ParseGotoStatement() { 1747 assert(Tok.is(tok::kw_goto) && "Not a goto stmt!"); 1748 SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'. 1749 1750 StmtResult Res; 1751 if (Tok.is(tok::identifier)) { 1752 LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(), 1753 Tok.getLocation()); 1754 Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD); 1755 ConsumeToken(); 1756 } else if (Tok.is(tok::star)) { 1757 // GNU indirect goto extension. 1758 Diag(Tok, diag::ext_gnu_indirect_goto); 1759 SourceLocation StarLoc = ConsumeToken(); 1760 ExprResult R(ParseExpression()); 1761 if (R.isInvalid()) { // Skip to the semicolon, but don't consume it. 1762 SkipUntil(tok::semi, StopBeforeMatch); 1763 return StmtError(); 1764 } 1765 Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.get()); 1766 } else { 1767 Diag(Tok, diag::err_expected) << tok::identifier; 1768 return StmtError(); 1769 } 1770 1771 return Res; 1772} 1773 1774/// ParseContinueStatement 1775/// jump-statement: 1776/// 'continue' ';' 1777/// 1778/// Note: this lets the caller parse the end ';'. 1779/// 1780StmtResult Parser::ParseContinueStatement() { 1781 SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'. 1782 return Actions.ActOnContinueStmt(ContinueLoc, getCurScope()); 1783} 1784 1785/// ParseBreakStatement 1786/// jump-statement: 1787/// 'break' ';' 1788/// 1789/// Note: this lets the caller parse the end ';'. 1790/// 1791StmtResult Parser::ParseBreakStatement() { 1792 SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'. 1793 return Actions.ActOnBreakStmt(BreakLoc, getCurScope()); 1794} 1795 1796/// ParseReturnStatement 1797/// jump-statement: 1798/// 'return' expression[opt] ';' 1799StmtResult Parser::ParseReturnStatement() { 1800 assert(Tok.is(tok::kw_return) && "Not a return stmt!"); 1801 SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'. 1802 1803 ExprResult R; 1804 if (Tok.isNot(tok::semi)) { 1805 if (Tok.is(tok::code_completion)) { 1806 Actions.CodeCompleteReturn(getCurScope()); 1807 cutOffParsing(); 1808 return StmtError(); 1809 } 1810 1811 if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) { 1812 R = ParseInitializer(); 1813 if (R.isUsable()) 1814 Diag(R.get()->getLocStart(), getLangOpts().CPlusPlus11 ? 1815 diag::warn_cxx98_compat_generalized_initializer_lists : 1816 diag::ext_generalized_initializer_lists) 1817 << R.get()->getSourceRange(); 1818 } else 1819 R = ParseExpression(); 1820 if (R.isInvalid()) { 1821 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch); 1822 return StmtError(); 1823 } 1824 } 1825 return Actions.ActOnReturnStmt(ReturnLoc, R.get(), getCurScope()); 1826} 1827 1828StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts, bool OnlyStatement, 1829 SourceLocation *TrailingElseLoc, 1830 ParsedAttributesWithRange &Attrs) { 1831 // Create temporary attribute list. 1832 ParsedAttributesWithRange TempAttrs(AttrFactory); 1833 1834 // Get loop hints and consume annotated token. 1835 while (Tok.is(tok::annot_pragma_loop_hint)) { 1836 LoopHint Hint; 1837 if (!HandlePragmaLoopHint(Hint)) 1838 continue; 1839 1840 ArgsUnion ArgHints[] = {Hint.PragmaNameLoc, Hint.OptionLoc, Hint.StateLoc, 1841 ArgsUnion(Hint.ValueExpr)}; 1842 TempAttrs.addNew(Hint.PragmaNameLoc->Ident, Hint.Range, nullptr, 1843 Hint.PragmaNameLoc->Loc, ArgHints, 4, 1844 AttributeList::AS_Pragma); 1845 } 1846 1847 // Get the next statement. 1848 MaybeParseCXX11Attributes(Attrs); 1849 1850 StmtResult S = ParseStatementOrDeclarationAfterAttributes( 1851 Stmts, OnlyStatement, TrailingElseLoc, Attrs); 1852 1853 Attrs.takeAllFrom(TempAttrs); 1854 return S; 1855} 1856 1857Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) { 1858 assert(Tok.is(tok::l_brace)); 1859 SourceLocation LBraceLoc = Tok.getLocation(); 1860 1861 if (SkipFunctionBodies && (!Decl || Actions.canSkipFunctionBody(Decl)) && 1862 trySkippingFunctionBody()) { 1863 BodyScope.Exit(); 1864 return Actions.ActOnSkippedFunctionBody(Decl); 1865 } 1866 1867 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc, 1868 "parsing function body"); 1869 1870 // Do not enter a scope for the brace, as the arguments are in the same scope 1871 // (the function body) as the body itself. Instead, just read the statement 1872 // list and put it into a CompoundStmt for safe keeping. 1873 StmtResult FnBody(ParseCompoundStatementBody()); 1874 1875 // If the function body could not be parsed, make a bogus compoundstmt. 1876 if (FnBody.isInvalid()) { 1877 Sema::CompoundScopeRAII CompoundScope(Actions); 1878 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false); 1879 } 1880 1881 BodyScope.Exit(); 1882 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get()); 1883} 1884 1885/// ParseFunctionTryBlock - Parse a C++ function-try-block. 1886/// 1887/// function-try-block: 1888/// 'try' ctor-initializer[opt] compound-statement handler-seq 1889/// 1890Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) { 1891 assert(Tok.is(tok::kw_try) && "Expected 'try'"); 1892 SourceLocation TryLoc = ConsumeToken(); 1893 1894 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc, 1895 "parsing function try block"); 1896 1897 // Constructor initializer list? 1898 if (Tok.is(tok::colon)) 1899 ParseConstructorInitializer(Decl); 1900 else 1901 Actions.ActOnDefaultCtorInitializers(Decl); 1902 1903 if (SkipFunctionBodies && Actions.canSkipFunctionBody(Decl) && 1904 trySkippingFunctionBody()) { 1905 BodyScope.Exit(); 1906 return Actions.ActOnSkippedFunctionBody(Decl); 1907 } 1908 1909 SourceLocation LBraceLoc = Tok.getLocation(); 1910 StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true)); 1911 // If we failed to parse the try-catch, we just give the function an empty 1912 // compound statement as the body. 1913 if (FnBody.isInvalid()) { 1914 Sema::CompoundScopeRAII CompoundScope(Actions); 1915 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false); 1916 } 1917 1918 BodyScope.Exit(); 1919 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get()); 1920} 1921 1922bool Parser::trySkippingFunctionBody() { 1923 assert(Tok.is(tok::l_brace)); 1924 assert(SkipFunctionBodies && 1925 "Should only be called when SkipFunctionBodies is enabled"); 1926 1927 if (!PP.isCodeCompletionEnabled()) { 1928 ConsumeBrace(); 1929 SkipUntil(tok::r_brace); 1930 return true; 1931 } 1932 1933 // We're in code-completion mode. Skip parsing for all function bodies unless 1934 // the body contains the code-completion point. 1935 TentativeParsingAction PA(*this); 1936 ConsumeBrace(); 1937 if (SkipUntil(tok::r_brace, StopAtCodeCompletion)) { 1938 PA.Commit(); 1939 return true; 1940 } 1941 1942 PA.Revert(); 1943 return false; 1944} 1945 1946/// ParseCXXTryBlock - Parse a C++ try-block. 1947/// 1948/// try-block: 1949/// 'try' compound-statement handler-seq 1950/// 1951StmtResult Parser::ParseCXXTryBlock() { 1952 assert(Tok.is(tok::kw_try) && "Expected 'try'"); 1953 1954 SourceLocation TryLoc = ConsumeToken(); 1955 return ParseCXXTryBlockCommon(TryLoc); 1956} 1957 1958/// ParseCXXTryBlockCommon - Parse the common part of try-block and 1959/// function-try-block. 1960/// 1961/// try-block: 1962/// 'try' compound-statement handler-seq 1963/// 1964/// function-try-block: 1965/// 'try' ctor-initializer[opt] compound-statement handler-seq 1966/// 1967/// handler-seq: 1968/// handler handler-seq[opt] 1969/// 1970/// [Borland] try-block: 1971/// 'try' compound-statement seh-except-block 1972/// 'try' compound-statement seh-finally-block 1973/// 1974StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) { 1975 if (Tok.isNot(tok::l_brace)) 1976 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); 1977 1978 StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false, 1979 Scope::DeclScope | Scope::TryScope | 1980 (FnTry ? Scope::FnTryCatchScope : 0))); 1981 if (TryBlock.isInvalid()) 1982 return TryBlock; 1983 1984 // Borland allows SEH-handlers with 'try' 1985 1986 if ((Tok.is(tok::identifier) && 1987 Tok.getIdentifierInfo() == getSEHExceptKeyword()) || 1988 Tok.is(tok::kw___finally)) { 1989 // TODO: Factor into common return ParseSEHHandlerCommon(...) 1990 StmtResult Handler; 1991 if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) { 1992 SourceLocation Loc = ConsumeToken(); 1993 Handler = ParseSEHExceptBlock(Loc); 1994 } 1995 else { 1996 SourceLocation Loc = ConsumeToken(); 1997 Handler = ParseSEHFinallyBlock(Loc); 1998 } 1999 if(Handler.isInvalid()) 2000 return Handler; 2001 2002 return Actions.ActOnSEHTryBlock(true /* IsCXXTry */, 2003 TryLoc, 2004 TryBlock.get(), 2005 Handler.get()); 2006 } 2007 else { 2008 StmtVector Handlers; 2009 2010 // C++11 attributes can't appear here, despite this context seeming 2011 // statement-like. 2012 DiagnoseAndSkipCXX11Attributes(); 2013 2014 if (Tok.isNot(tok::kw_catch)) 2015 return StmtError(Diag(Tok, diag::err_expected_catch)); 2016 while (Tok.is(tok::kw_catch)) { 2017 StmtResult Handler(ParseCXXCatchBlock(FnTry)); 2018 if (!Handler.isInvalid()) 2019 Handlers.push_back(Handler.get()); 2020 } 2021 // Don't bother creating the full statement if we don't have any usable 2022 // handlers. 2023 if (Handlers.empty()) 2024 return StmtError(); 2025 2026 return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.get(), Handlers); 2027 } 2028} 2029 2030/// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard 2031/// 2032/// handler: 2033/// 'catch' '(' exception-declaration ')' compound-statement 2034/// 2035/// exception-declaration: 2036/// attribute-specifier-seq[opt] type-specifier-seq declarator 2037/// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt] 2038/// '...' 2039/// 2040StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) { 2041 assert(Tok.is(tok::kw_catch) && "Expected 'catch'"); 2042 2043 SourceLocation CatchLoc = ConsumeToken(); 2044 2045 BalancedDelimiterTracker T(*this, tok::l_paren); 2046 if (T.expectAndConsume()) 2047 return StmtError(); 2048 2049 // C++ 3.3.2p3: 2050 // The name in a catch exception-declaration is local to the handler and 2051 // shall not be redeclared in the outermost block of the handler. 2052 ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope | 2053 (FnCatch ? Scope::FnTryCatchScope : 0)); 2054 2055 // exception-declaration is equivalent to '...' or a parameter-declaration 2056 // without default arguments. 2057 Decl *ExceptionDecl = nullptr; 2058 if (Tok.isNot(tok::ellipsis)) { 2059 ParsedAttributesWithRange Attributes(AttrFactory); 2060 MaybeParseCXX11Attributes(Attributes); 2061 2062 DeclSpec DS(AttrFactory); 2063 DS.takeAttributesFrom(Attributes); 2064 2065 if (ParseCXXTypeSpecifierSeq(DS)) 2066 return StmtError(); 2067 2068 Declarator ExDecl(DS, Declarator::CXXCatchContext); 2069 ParseDeclarator(ExDecl); 2070 ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl); 2071 } else 2072 ConsumeToken(); 2073 2074 T.consumeClose(); 2075 if (T.getCloseLocation().isInvalid()) 2076 return StmtError(); 2077 2078 if (Tok.isNot(tok::l_brace)) 2079 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace); 2080 2081 // FIXME: Possible draft standard bug: attribute-specifier should be allowed? 2082 StmtResult Block(ParseCompoundStatement()); 2083 if (Block.isInvalid()) 2084 return Block; 2085 2086 return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.get()); 2087} 2088 2089void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) { 2090 IfExistsCondition Result; 2091 if (ParseMicrosoftIfExistsCondition(Result)) 2092 return; 2093 2094 // Handle dependent statements by parsing the braces as a compound statement. 2095 // This is not the same behavior as Visual C++, which don't treat this as a 2096 // compound statement, but for Clang's type checking we can't have anything 2097 // inside these braces escaping to the surrounding code. 2098 if (Result.Behavior == IEB_Dependent) { 2099 if (!Tok.is(tok::l_brace)) { 2100 Diag(Tok, diag::err_expected) << tok::l_brace; 2101 return; 2102 } 2103 2104 StmtResult Compound = ParseCompoundStatement(); 2105 if (Compound.isInvalid()) 2106 return; 2107 2108 StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc, 2109 Result.IsIfExists, 2110 Result.SS, 2111 Result.Name, 2112 Compound.get()); 2113 if (DepResult.isUsable()) 2114 Stmts.push_back(DepResult.get()); 2115 return; 2116 } 2117 2118 BalancedDelimiterTracker Braces(*this, tok::l_brace); 2119 if (Braces.consumeOpen()) { 2120 Diag(Tok, diag::err_expected) << tok::l_brace; 2121 return; 2122 } 2123 2124 switch (Result.Behavior) { 2125 case IEB_Parse: 2126 // Parse the statements below. 2127 break; 2128 2129 case IEB_Dependent: 2130 llvm_unreachable("Dependent case handled above"); 2131 2132 case IEB_Skip: 2133 Braces.skipToEnd(); 2134 return; 2135 } 2136 2137 // Condition is true, parse the statements. 2138 while (Tok.isNot(tok::r_brace)) { 2139 StmtResult R = ParseStatementOrDeclaration(Stmts, false); 2140 if (R.isUsable()) 2141 Stmts.push_back(R.get()); 2142 } 2143 Braces.consumeClose(); 2144} 2145