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