1 //===--- ParseStmt.cpp - Statement and Block Parser -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the Statement and Block portions of the Parser
10 // interface.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/AST/PrettyDeclStackTrace.h"
15 #include "clang/Basic/Attributes.h"
16 #include "clang/Basic/PrettyStackTrace.h"
17 #include "clang/Parse/LoopHint.h"
18 #include "clang/Parse/Parser.h"
19 #include "clang/Parse/RAIIObjectsForParser.h"
20 #include "clang/Sema/DeclSpec.h"
21 #include "clang/Sema/Scope.h"
22 #include "clang/Sema/TypoCorrection.h"
23 using namespace clang;
24
25 //===----------------------------------------------------------------------===//
26 // C99 6.8: Statements and Blocks.
27 //===----------------------------------------------------------------------===//
28
29 /// Parse a standalone statement (for instance, as the body of an 'if',
30 /// 'while', or 'for').
ParseStatement(SourceLocation * TrailingElseLoc,ParsedStmtContext StmtCtx)31 StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc,
32 ParsedStmtContext StmtCtx) {
33 StmtResult Res;
34
35 // We may get back a null statement if we found a #pragma. Keep going until
36 // we get an actual statement.
37 do {
38 StmtVector Stmts;
39 Res = ParseStatementOrDeclaration(Stmts, StmtCtx, TrailingElseLoc);
40 } while (!Res.isInvalid() && !Res.get());
41
42 return Res;
43 }
44
45 /// ParseStatementOrDeclaration - Read 'statement' or 'declaration'.
46 /// StatementOrDeclaration:
47 /// statement
48 /// declaration
49 ///
50 /// statement:
51 /// labeled-statement
52 /// compound-statement
53 /// expression-statement
54 /// selection-statement
55 /// iteration-statement
56 /// jump-statement
57 /// [C++] declaration-statement
58 /// [C++] try-block
59 /// [MS] seh-try-block
60 /// [OBC] objc-throw-statement
61 /// [OBC] objc-try-catch-statement
62 /// [OBC] objc-synchronized-statement
63 /// [GNU] asm-statement
64 /// [OMP] openmp-construct [TODO]
65 ///
66 /// labeled-statement:
67 /// identifier ':' statement
68 /// 'case' constant-expression ':' statement
69 /// 'default' ':' statement
70 ///
71 /// selection-statement:
72 /// if-statement
73 /// switch-statement
74 ///
75 /// iteration-statement:
76 /// while-statement
77 /// do-statement
78 /// for-statement
79 ///
80 /// expression-statement:
81 /// expression[opt] ';'
82 ///
83 /// jump-statement:
84 /// 'goto' identifier ';'
85 /// 'continue' ';'
86 /// 'break' ';'
87 /// 'return' expression[opt] ';'
88 /// [GNU] 'goto' '*' expression ';'
89 ///
90 /// [OBC] objc-throw-statement:
91 /// [OBC] '@' 'throw' expression ';'
92 /// [OBC] '@' 'throw' ';'
93 ///
94 StmtResult
ParseStatementOrDeclaration(StmtVector & Stmts,ParsedStmtContext StmtCtx,SourceLocation * TrailingElseLoc)95 Parser::ParseStatementOrDeclaration(StmtVector &Stmts,
96 ParsedStmtContext StmtCtx,
97 SourceLocation *TrailingElseLoc) {
98
99 ParenBraceBracketBalancer BalancerRAIIObj(*this);
100
101 ParsedAttributesWithRange Attrs(AttrFactory);
102 MaybeParseCXX11Attributes(Attrs, nullptr, /*MightBeObjCMessageSend*/ true);
103 if (!MaybeParseOpenCLUnrollHintAttribute(Attrs))
104 return StmtError();
105
106 StmtResult Res = ParseStatementOrDeclarationAfterAttributes(
107 Stmts, StmtCtx, 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, Attrs.Range);
116 }
117
118 namespace {
119 class StatementFilterCCC final : public CorrectionCandidateCallback {
120 public:
StatementFilterCCC(Token nextTok)121 StatementFilterCCC(Token nextTok) : NextToken(nextTok) {
122 WantTypeSpecifiers = nextTok.isOneOf(tok::l_paren, tok::less, tok::l_square,
123 tok::identifier, tok::star, tok::amp);
124 WantExpressionKeywords =
125 nextTok.isOneOf(tok::l_paren, tok::identifier, tok::arrow, tok::period);
126 WantRemainingKeywords =
127 nextTok.isOneOf(tok::l_paren, tok::semi, tok::identifier, tok::l_brace);
128 WantCXXNamedCasts = false;
129 }
130
ValidateCandidate(const TypoCorrection & candidate)131 bool ValidateCandidate(const TypoCorrection &candidate) override {
132 if (FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>())
133 return !candidate.getCorrectionSpecifier() || isa<ObjCIvarDecl>(FD);
134 if (NextToken.is(tok::equal))
135 return candidate.getCorrectionDeclAs<VarDecl>();
136 if (NextToken.is(tok::period) &&
137 candidate.getCorrectionDeclAs<NamespaceDecl>())
138 return false;
139 return CorrectionCandidateCallback::ValidateCandidate(candidate);
140 }
141
clone()142 std::unique_ptr<CorrectionCandidateCallback> clone() override {
143 return std::make_unique<StatementFilterCCC>(*this);
144 }
145
146 private:
147 Token NextToken;
148 };
149 }
150
ParseStatementOrDeclarationAfterAttributes(StmtVector & Stmts,ParsedStmtContext StmtCtx,SourceLocation * TrailingElseLoc,ParsedAttributesWithRange & Attrs)151 StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(
152 StmtVector &Stmts, ParsedStmtContext StmtCtx,
153 SourceLocation *TrailingElseLoc, ParsedAttributesWithRange &Attrs) {
154 const char *SemiError = nullptr;
155 StmtResult Res;
156 SourceLocation GNUAttributeLoc;
157
158 // Cases in this switch statement should fall through if the parser expects
159 // the token to end in a semicolon (in which case SemiError should be set),
160 // or they directly 'return;' if not.
161 Retry:
162 tok::TokenKind Kind = Tok.getKind();
163 SourceLocation AtLoc;
164 switch (Kind) {
165 case tok::at: // May be a @try or @throw statement
166 {
167 ProhibitAttributes(Attrs); // TODO: is it correct?
168 AtLoc = ConsumeToken(); // consume @
169 return ParseObjCAtStatement(AtLoc, StmtCtx);
170 }
171
172 case tok::code_completion:
173 Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement);
174 cutOffParsing();
175 return StmtError();
176
177 case tok::identifier: {
178 Token Next = NextToken();
179 if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement
180 // identifier ':' statement
181 return ParseLabeledStatement(Attrs, StmtCtx);
182 }
183
184 // Look up the identifier, and typo-correct it to a keyword if it's not
185 // found.
186 if (Next.isNot(tok::coloncolon)) {
187 // Try to limit which sets of keywords should be included in typo
188 // correction based on what the next token is.
189 StatementFilterCCC CCC(Next);
190 if (TryAnnotateName(&CCC) == 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 LLVM_FALLTHROUGH;
206 }
207
208 default: {
209 if ((getLangOpts().CPlusPlus || getLangOpts().MicrosoftExt ||
210 (StmtCtx & ParsedStmtContext::AllowDeclarationsInC) !=
211 ParsedStmtContext()) &&
212 (GNUAttributeLoc.isValid() || isDeclarationStatement())) {
213 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
214 DeclGroupPtrTy Decl;
215 if (GNUAttributeLoc.isValid()) {
216 DeclStart = GNUAttributeLoc;
217 Decl = ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, Attrs,
218 &GNUAttributeLoc);
219 } else {
220 Decl =
221 ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, Attrs);
222 }
223 if (Attrs.Range.getBegin().isValid())
224 DeclStart = Attrs.Range.getBegin();
225 return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);
226 }
227
228 if (Tok.is(tok::r_brace)) {
229 Diag(Tok, diag::err_expected_statement);
230 return StmtError();
231 }
232
233 return ParseExprStatement(StmtCtx);
234 }
235
236 case tok::kw___attribute: {
237 GNUAttributeLoc = Tok.getLocation();
238 ParseGNUAttributes(Attrs);
239 goto Retry;
240 }
241
242 case tok::kw_case: // C99 6.8.1: labeled-statement
243 return ParseCaseStatement(StmtCtx);
244 case tok::kw_default: // C99 6.8.1: labeled-statement
245 return ParseDefaultStatement(StmtCtx);
246
247 case tok::l_brace: // C99 6.8.2: compound-statement
248 return ParseCompoundStatement();
249 case tok::semi: { // C99 6.8.3p3: expression[opt] ';'
250 bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
251 return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro);
252 }
253
254 case tok::kw_if: // C99 6.8.4.1: if-statement
255 return ParseIfStatement(TrailingElseLoc);
256 case tok::kw_switch: // C99 6.8.4.2: switch-statement
257 return ParseSwitchStatement(TrailingElseLoc);
258
259 case tok::kw_while: // C99 6.8.5.1: while-statement
260 return ParseWhileStatement(TrailingElseLoc);
261 case tok::kw_do: // C99 6.8.5.2: do-statement
262 Res = ParseDoStatement();
263 SemiError = "do/while";
264 break;
265 case tok::kw_for: // C99 6.8.5.3: for-statement
266 return ParseForStatement(TrailingElseLoc);
267
268 case tok::kw_goto: // C99 6.8.6.1: goto-statement
269 Res = ParseGotoStatement();
270 SemiError = "goto";
271 break;
272 case tok::kw_continue: // C99 6.8.6.2: continue-statement
273 Res = ParseContinueStatement();
274 SemiError = "continue";
275 break;
276 case tok::kw_break: // C99 6.8.6.3: break-statement
277 Res = ParseBreakStatement();
278 SemiError = "break";
279 break;
280 case tok::kw_return: // C99 6.8.6.4: return-statement
281 Res = ParseReturnStatement();
282 SemiError = "return";
283 break;
284 case tok::kw_co_return: // C++ Coroutines: co_return statement
285 Res = ParseReturnStatement();
286 SemiError = "co_return";
287 break;
288
289 case tok::kw_asm: {
290 ProhibitAttributes(Attrs);
291 bool msAsm = false;
292 Res = ParseAsmStatement(msAsm);
293 Res = Actions.ActOnFinishFullStmt(Res.get());
294 if (msAsm) return Res;
295 SemiError = "asm";
296 break;
297 }
298
299 case tok::kw___if_exists:
300 case tok::kw___if_not_exists:
301 ProhibitAttributes(Attrs);
302 ParseMicrosoftIfExistsStatement(Stmts);
303 // An __if_exists block is like a compound statement, but it doesn't create
304 // a new scope.
305 return StmtEmpty();
306
307 case tok::kw_try: // C++ 15: try-block
308 return ParseCXXTryBlock();
309
310 case tok::kw___try:
311 ProhibitAttributes(Attrs); // TODO: is it correct?
312 return ParseSEHTryBlock();
313
314 case tok::kw___leave:
315 Res = ParseSEHLeaveStatement();
316 SemiError = "__leave";
317 break;
318
319 case tok::annot_pragma_vis:
320 ProhibitAttributes(Attrs);
321 HandlePragmaVisibility();
322 return StmtEmpty();
323
324 case tok::annot_pragma_pack:
325 ProhibitAttributes(Attrs);
326 HandlePragmaPack();
327 return StmtEmpty();
328
329 case tok::annot_pragma_msstruct:
330 ProhibitAttributes(Attrs);
331 HandlePragmaMSStruct();
332 return StmtEmpty();
333
334 case tok::annot_pragma_align:
335 ProhibitAttributes(Attrs);
336 HandlePragmaAlign();
337 return StmtEmpty();
338
339 case tok::annot_pragma_weak:
340 ProhibitAttributes(Attrs);
341 HandlePragmaWeak();
342 return StmtEmpty();
343
344 case tok::annot_pragma_weakalias:
345 ProhibitAttributes(Attrs);
346 HandlePragmaWeakAlias();
347 return StmtEmpty();
348
349 case tok::annot_pragma_redefine_extname:
350 ProhibitAttributes(Attrs);
351 HandlePragmaRedefineExtname();
352 return StmtEmpty();
353
354 case tok::annot_pragma_fp_contract:
355 ProhibitAttributes(Attrs);
356 Diag(Tok, diag::err_pragma_fp_contract_scope);
357 ConsumeAnnotationToken();
358 return StmtError();
359
360 case tok::annot_pragma_fp:
361 ProhibitAttributes(Attrs);
362 Diag(Tok, diag::err_pragma_fp_scope);
363 ConsumeAnnotationToken();
364 return StmtError();
365
366 case tok::annot_pragma_fenv_access:
367 ProhibitAttributes(Attrs);
368 HandlePragmaFEnvAccess();
369 return StmtEmpty();
370
371 case tok::annot_pragma_opencl_extension:
372 ProhibitAttributes(Attrs);
373 HandlePragmaOpenCLExtension();
374 return StmtEmpty();
375
376 case tok::annot_pragma_captured:
377 ProhibitAttributes(Attrs);
378 return HandlePragmaCaptured();
379
380 case tok::annot_pragma_openmp:
381 ProhibitAttributes(Attrs);
382 return ParseOpenMPDeclarativeOrExecutableDirective(StmtCtx);
383
384 case tok::annot_pragma_ms_pointers_to_members:
385 ProhibitAttributes(Attrs);
386 HandlePragmaMSPointersToMembers();
387 return StmtEmpty();
388
389 case tok::annot_pragma_ms_pragma:
390 ProhibitAttributes(Attrs);
391 HandlePragmaMSPragma();
392 return StmtEmpty();
393
394 case tok::annot_pragma_ms_vtordisp:
395 ProhibitAttributes(Attrs);
396 HandlePragmaMSVtorDisp();
397 return StmtEmpty();
398
399 case tok::annot_pragma_loop_hint:
400 ProhibitAttributes(Attrs);
401 return ParsePragmaLoopHint(Stmts, StmtCtx, TrailingElseLoc, Attrs);
402
403 case tok::annot_pragma_dump:
404 HandlePragmaDump();
405 return StmtEmpty();
406
407 case tok::annot_pragma_attribute:
408 HandlePragmaAttribute();
409 return StmtEmpty();
410 }
411
412 // If we reached this code, the statement must end in a semicolon.
413 if (!TryConsumeToken(tok::semi) && !Res.isInvalid()) {
414 // If the result was valid, then we do want to diagnose this. Use
415 // ExpectAndConsume to emit the diagnostic, even though we know it won't
416 // succeed.
417 ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError);
418 // Skip until we see a } or ;, but don't eat it.
419 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
420 }
421
422 return Res;
423 }
424
425 /// Parse an expression statement.
ParseExprStatement(ParsedStmtContext StmtCtx)426 StmtResult Parser::ParseExprStatement(ParsedStmtContext StmtCtx) {
427 // If a case keyword is missing, this is where it should be inserted.
428 Token OldToken = Tok;
429
430 ExprStatementTokLoc = Tok.getLocation();
431
432 // expression[opt] ';'
433 ExprResult Expr(ParseExpression());
434 if (Expr.isInvalid()) {
435 // If the expression is invalid, skip ahead to the next semicolon or '}'.
436 // Not doing this opens us up to the possibility of infinite loops if
437 // ParseExpression does not consume any tokens.
438 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
439 if (Tok.is(tok::semi))
440 ConsumeToken();
441 return Actions.ActOnExprStmtError();
442 }
443
444 if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() &&
445 Actions.CheckCaseExpression(Expr.get())) {
446 // If a constant expression is followed by a colon inside a switch block,
447 // suggest a missing case keyword.
448 Diag(OldToken, diag::err_expected_case_before_expression)
449 << FixItHint::CreateInsertion(OldToken.getLocation(), "case ");
450
451 // Recover parsing as a case statement.
452 return ParseCaseStatement(StmtCtx, /*MissingCase=*/true, Expr);
453 }
454
455 // Otherwise, eat the semicolon.
456 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
457 return handleExprStmt(Expr, StmtCtx);
458 }
459
460 /// ParseSEHTryBlockCommon
461 ///
462 /// seh-try-block:
463 /// '__try' compound-statement seh-handler
464 ///
465 /// seh-handler:
466 /// seh-except-block
467 /// seh-finally-block
468 ///
ParseSEHTryBlock()469 StmtResult Parser::ParseSEHTryBlock() {
470 assert(Tok.is(tok::kw___try) && "Expected '__try'");
471 SourceLocation TryLoc = ConsumeToken();
472
473 if (Tok.isNot(tok::l_brace))
474 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
475
476 StmtResult TryBlock(ParseCompoundStatement(
477 /*isStmtExpr=*/false,
478 Scope::DeclScope | Scope::CompoundStmtScope | Scope::SEHTryScope));
479 if (TryBlock.isInvalid())
480 return TryBlock;
481
482 StmtResult Handler;
483 if (Tok.is(tok::identifier) &&
484 Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
485 SourceLocation Loc = ConsumeToken();
486 Handler = ParseSEHExceptBlock(Loc);
487 } else if (Tok.is(tok::kw___finally)) {
488 SourceLocation Loc = ConsumeToken();
489 Handler = ParseSEHFinallyBlock(Loc);
490 } else {
491 return StmtError(Diag(Tok, diag::err_seh_expected_handler));
492 }
493
494 if(Handler.isInvalid())
495 return Handler;
496
497 return Actions.ActOnSEHTryBlock(false /* IsCXXTry */,
498 TryLoc,
499 TryBlock.get(),
500 Handler.get());
501 }
502
503 /// ParseSEHExceptBlock - Handle __except
504 ///
505 /// seh-except-block:
506 /// '__except' '(' seh-filter-expression ')' compound-statement
507 ///
ParseSEHExceptBlock(SourceLocation ExceptLoc)508 StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
509 PoisonIdentifierRAIIObject raii(Ident__exception_code, false),
510 raii2(Ident___exception_code, false),
511 raii3(Ident_GetExceptionCode, false);
512
513 if (ExpectAndConsume(tok::l_paren))
514 return StmtError();
515
516 ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope |
517 Scope::SEHExceptScope);
518
519 if (getLangOpts().Borland) {
520 Ident__exception_info->setIsPoisoned(false);
521 Ident___exception_info->setIsPoisoned(false);
522 Ident_GetExceptionInfo->setIsPoisoned(false);
523 }
524
525 ExprResult FilterExpr;
526 {
527 ParseScopeFlags FilterScope(this, getCurScope()->getFlags() |
528 Scope::SEHFilterScope);
529 FilterExpr = Actions.CorrectDelayedTyposInExpr(ParseExpression());
530 }
531
532 if (getLangOpts().Borland) {
533 Ident__exception_info->setIsPoisoned(true);
534 Ident___exception_info->setIsPoisoned(true);
535 Ident_GetExceptionInfo->setIsPoisoned(true);
536 }
537
538 if(FilterExpr.isInvalid())
539 return StmtError();
540
541 if (ExpectAndConsume(tok::r_paren))
542 return StmtError();
543
544 if (Tok.isNot(tok::l_brace))
545 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
546
547 StmtResult Block(ParseCompoundStatement());
548
549 if(Block.isInvalid())
550 return Block;
551
552 return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.get(), Block.get());
553 }
554
555 /// ParseSEHFinallyBlock - Handle __finally
556 ///
557 /// seh-finally-block:
558 /// '__finally' compound-statement
559 ///
ParseSEHFinallyBlock(SourceLocation FinallyLoc)560 StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyLoc) {
561 PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false),
562 raii2(Ident___abnormal_termination, false),
563 raii3(Ident_AbnormalTermination, false);
564
565 if (Tok.isNot(tok::l_brace))
566 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
567
568 ParseScope FinallyScope(this, 0);
569 Actions.ActOnStartSEHFinallyBlock();
570
571 StmtResult Block(ParseCompoundStatement());
572 if(Block.isInvalid()) {
573 Actions.ActOnAbortSEHFinallyBlock();
574 return Block;
575 }
576
577 return Actions.ActOnFinishSEHFinallyBlock(FinallyLoc, Block.get());
578 }
579
580 /// Handle __leave
581 ///
582 /// seh-leave-statement:
583 /// '__leave' ';'
584 ///
ParseSEHLeaveStatement()585 StmtResult Parser::ParseSEHLeaveStatement() {
586 SourceLocation LeaveLoc = ConsumeToken(); // eat the '__leave'.
587 return Actions.ActOnSEHLeaveStmt(LeaveLoc, getCurScope());
588 }
589
590 /// ParseLabeledStatement - We have an identifier and a ':' after it.
591 ///
592 /// labeled-statement:
593 /// identifier ':' statement
594 /// [GNU] identifier ':' attributes[opt] statement
595 ///
ParseLabeledStatement(ParsedAttributesWithRange & attrs,ParsedStmtContext StmtCtx)596 StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs,
597 ParsedStmtContext StmtCtx) {
598 assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
599 "Not an identifier!");
600
601 // The substatement is always a 'statement', not a 'declaration', but is
602 // otherwise in the same context as the labeled-statement.
603 StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
604
605 Token IdentTok = Tok; // Save the whole token.
606 ConsumeToken(); // eat the identifier.
607
608 assert(Tok.is(tok::colon) && "Not a label!");
609
610 // identifier ':' statement
611 SourceLocation ColonLoc = ConsumeToken();
612
613 // Read label attributes, if present.
614 StmtResult SubStmt;
615 if (Tok.is(tok::kw___attribute)) {
616 ParsedAttributesWithRange TempAttrs(AttrFactory);
617 ParseGNUAttributes(TempAttrs);
618
619 // In C++, GNU attributes only apply to the label if they are followed by a
620 // semicolon, to disambiguate label attributes from attributes on a labeled
621 // declaration.
622 //
623 // This doesn't quite match what GCC does; if the attribute list is empty
624 // and followed by a semicolon, GCC will reject (it appears to parse the
625 // attributes as part of a statement in that case). That looks like a bug.
626 if (!getLangOpts().CPlusPlus || Tok.is(tok::semi))
627 attrs.takeAllFrom(TempAttrs);
628 else if (isDeclarationStatement()) {
629 StmtVector Stmts;
630 // FIXME: We should do this whether or not we have a declaration
631 // statement, but that doesn't work correctly (because ProhibitAttributes
632 // can't handle GNU attributes), so only call it in the one case where
633 // GNU attributes are allowed.
634 SubStmt = ParseStatementOrDeclarationAfterAttributes(Stmts, StmtCtx,
635 nullptr, TempAttrs);
636 if (!TempAttrs.empty() && !SubStmt.isInvalid())
637 SubStmt = Actions.ProcessStmtAttributes(SubStmt.get(), TempAttrs,
638 TempAttrs.Range);
639 } else {
640 Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi;
641 }
642 }
643
644 // If we've not parsed a statement yet, parse one now.
645 if (!SubStmt.isInvalid() && !SubStmt.isUsable())
646 SubStmt = ParseStatement(nullptr, StmtCtx);
647
648 // Broken substmt shouldn't prevent the label from being added to the AST.
649 if (SubStmt.isInvalid())
650 SubStmt = Actions.ActOnNullStmt(ColonLoc);
651
652 LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(),
653 IdentTok.getLocation());
654 Actions.ProcessDeclAttributeList(Actions.CurScope, LD, attrs);
655 attrs.clear();
656
657 return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc,
658 SubStmt.get());
659 }
660
661 /// ParseCaseStatement
662 /// labeled-statement:
663 /// 'case' constant-expression ':' statement
664 /// [GNU] 'case' constant-expression '...' constant-expression ':' statement
665 ///
ParseCaseStatement(ParsedStmtContext StmtCtx,bool MissingCase,ExprResult Expr)666 StmtResult Parser::ParseCaseStatement(ParsedStmtContext StmtCtx,
667 bool MissingCase, ExprResult Expr) {
668 assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!");
669
670 // The substatement is always a 'statement', not a 'declaration', but is
671 // otherwise in the same context as the labeled-statement.
672 StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
673
674 // It is very very common for code to contain many case statements recursively
675 // nested, as in (but usually without indentation):
676 // case 1:
677 // case 2:
678 // case 3:
679 // case 4:
680 // case 5: etc.
681 //
682 // Parsing this naively works, but is both inefficient and can cause us to run
683 // out of stack space in our recursive descent parser. As a special case,
684 // flatten this recursion into an iterative loop. This is complex and gross,
685 // but all the grossness is constrained to ParseCaseStatement (and some
686 // weirdness in the actions), so this is just local grossness :).
687
688 // TopLevelCase - This is the highest level we have parsed. 'case 1' in the
689 // example above.
690 StmtResult TopLevelCase(true);
691
692 // DeepestParsedCaseStmt - This is the deepest statement we have parsed, which
693 // gets updated each time a new case is parsed, and whose body is unset so
694 // far. When parsing 'case 4', this is the 'case 3' node.
695 Stmt *DeepestParsedCaseStmt = nullptr;
696
697 // While we have case statements, eat and stack them.
698 SourceLocation ColonLoc;
699 do {
700 SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() :
701 ConsumeToken(); // eat the 'case'.
702 ColonLoc = SourceLocation();
703
704 if (Tok.is(tok::code_completion)) {
705 Actions.CodeCompleteCase(getCurScope());
706 cutOffParsing();
707 return StmtError();
708 }
709
710 /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
711 /// Disable this form of error recovery while we're parsing the case
712 /// expression.
713 ColonProtectionRAIIObject ColonProtection(*this);
714
715 ExprResult LHS;
716 if (!MissingCase) {
717 LHS = ParseCaseExpression(CaseLoc);
718 if (LHS.isInvalid()) {
719 // If constant-expression is parsed unsuccessfully, recover by skipping
720 // current case statement (moving to the colon that ends it).
721 if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch))
722 return StmtError();
723 }
724 } else {
725 LHS = Expr;
726 MissingCase = false;
727 }
728
729 // GNU case range extension.
730 SourceLocation DotDotDotLoc;
731 ExprResult RHS;
732 if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) {
733 Diag(DotDotDotLoc, diag::ext_gnu_case_range);
734 RHS = ParseCaseExpression(CaseLoc);
735 if (RHS.isInvalid()) {
736 if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch))
737 return StmtError();
738 }
739 }
740
741 ColonProtection.restore();
742
743 if (TryConsumeToken(tok::colon, ColonLoc)) {
744 } else if (TryConsumeToken(tok::semi, ColonLoc) ||
745 TryConsumeToken(tok::coloncolon, ColonLoc)) {
746 // Treat "case blah;" or "case blah::" as a typo for "case blah:".
747 Diag(ColonLoc, diag::err_expected_after)
748 << "'case'" << tok::colon
749 << FixItHint::CreateReplacement(ColonLoc, ":");
750 } else {
751 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
752 Diag(ExpectedLoc, diag::err_expected_after)
753 << "'case'" << tok::colon
754 << FixItHint::CreateInsertion(ExpectedLoc, ":");
755 ColonLoc = ExpectedLoc;
756 }
757
758 StmtResult Case =
759 Actions.ActOnCaseStmt(CaseLoc, LHS, DotDotDotLoc, RHS, ColonLoc);
760
761 // If we had a sema error parsing this case, then just ignore it and
762 // continue parsing the sub-stmt.
763 if (Case.isInvalid()) {
764 if (TopLevelCase.isInvalid()) // No parsed case stmts.
765 return ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx);
766 // Otherwise, just don't add it as a nested case.
767 } else {
768 // If this is the first case statement we parsed, it becomes TopLevelCase.
769 // Otherwise we link it into the current chain.
770 Stmt *NextDeepest = Case.get();
771 if (TopLevelCase.isInvalid())
772 TopLevelCase = Case;
773 else
774 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
775 DeepestParsedCaseStmt = NextDeepest;
776 }
777
778 // Handle all case statements.
779 } while (Tok.is(tok::kw_case));
780
781 // If we found a non-case statement, start by parsing it.
782 StmtResult SubStmt;
783
784 if (Tok.isNot(tok::r_brace)) {
785 SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx);
786 } else {
787 // Nicely diagnose the common error "switch (X) { case 4: }", which is
788 // not valid. If ColonLoc doesn't point to a valid text location, there was
789 // another parsing error, so avoid producing extra diagnostics.
790 if (ColonLoc.isValid()) {
791 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
792 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
793 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
794 }
795 SubStmt = StmtError();
796 }
797
798 // Install the body into the most deeply-nested case.
799 if (DeepestParsedCaseStmt) {
800 // Broken sub-stmt shouldn't prevent forming the case statement properly.
801 if (SubStmt.isInvalid())
802 SubStmt = Actions.ActOnNullStmt(SourceLocation());
803 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
804 }
805
806 // Return the top level parsed statement tree.
807 return TopLevelCase;
808 }
809
810 /// ParseDefaultStatement
811 /// labeled-statement:
812 /// 'default' ':' statement
813 /// Note that this does not parse the 'statement' at the end.
814 ///
ParseDefaultStatement(ParsedStmtContext StmtCtx)815 StmtResult Parser::ParseDefaultStatement(ParsedStmtContext StmtCtx) {
816 assert(Tok.is(tok::kw_default) && "Not a default stmt!");
817
818 // The substatement is always a 'statement', not a 'declaration', but is
819 // otherwise in the same context as the labeled-statement.
820 StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
821
822 SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
823
824 SourceLocation ColonLoc;
825 if (TryConsumeToken(tok::colon, ColonLoc)) {
826 } else if (TryConsumeToken(tok::semi, ColonLoc)) {
827 // Treat "default;" as a typo for "default:".
828 Diag(ColonLoc, diag::err_expected_after)
829 << "'default'" << tok::colon
830 << FixItHint::CreateReplacement(ColonLoc, ":");
831 } else {
832 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
833 Diag(ExpectedLoc, diag::err_expected_after)
834 << "'default'" << tok::colon
835 << FixItHint::CreateInsertion(ExpectedLoc, ":");
836 ColonLoc = ExpectedLoc;
837 }
838
839 StmtResult SubStmt;
840
841 if (Tok.isNot(tok::r_brace)) {
842 SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx);
843 } else {
844 // Diagnose the common error "switch (X) {... default: }", which is
845 // not valid.
846 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
847 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
848 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
849 SubStmt = true;
850 }
851
852 // Broken sub-stmt shouldn't prevent forming the case statement properly.
853 if (SubStmt.isInvalid())
854 SubStmt = Actions.ActOnNullStmt(ColonLoc);
855
856 return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
857 SubStmt.get(), getCurScope());
858 }
859
ParseCompoundStatement(bool isStmtExpr)860 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) {
861 return ParseCompoundStatement(isStmtExpr,
862 Scope::DeclScope | Scope::CompoundStmtScope);
863 }
864
865 /// ParseCompoundStatement - Parse a "{}" block.
866 ///
867 /// compound-statement: [C99 6.8.2]
868 /// { block-item-list[opt] }
869 /// [GNU] { label-declarations block-item-list } [TODO]
870 ///
871 /// block-item-list:
872 /// block-item
873 /// block-item-list block-item
874 ///
875 /// block-item:
876 /// declaration
877 /// [GNU] '__extension__' declaration
878 /// statement
879 ///
880 /// [GNU] label-declarations:
881 /// [GNU] label-declaration
882 /// [GNU] label-declarations label-declaration
883 ///
884 /// [GNU] label-declaration:
885 /// [GNU] '__label__' identifier-list ';'
886 ///
ParseCompoundStatement(bool isStmtExpr,unsigned ScopeFlags)887 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr,
888 unsigned ScopeFlags) {
889 assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
890
891 // Enter a scope to hold everything within the compound stmt. Compound
892 // statements can always hold declarations.
893 ParseScope CompoundScope(this, ScopeFlags);
894
895 // Parse the statements in the body.
896 return ParseCompoundStatementBody(isStmtExpr);
897 }
898
899 /// Parse any pragmas at the start of the compound expression. We handle these
900 /// separately since some pragmas (FP_CONTRACT) must appear before any C
901 /// statement in the compound, but may be intermingled with other pragmas.
ParseCompoundStatementLeadingPragmas()902 void Parser::ParseCompoundStatementLeadingPragmas() {
903 bool checkForPragmas = true;
904 while (checkForPragmas) {
905 switch (Tok.getKind()) {
906 case tok::annot_pragma_vis:
907 HandlePragmaVisibility();
908 break;
909 case tok::annot_pragma_pack:
910 HandlePragmaPack();
911 break;
912 case tok::annot_pragma_msstruct:
913 HandlePragmaMSStruct();
914 break;
915 case tok::annot_pragma_align:
916 HandlePragmaAlign();
917 break;
918 case tok::annot_pragma_weak:
919 HandlePragmaWeak();
920 break;
921 case tok::annot_pragma_weakalias:
922 HandlePragmaWeakAlias();
923 break;
924 case tok::annot_pragma_redefine_extname:
925 HandlePragmaRedefineExtname();
926 break;
927 case tok::annot_pragma_opencl_extension:
928 HandlePragmaOpenCLExtension();
929 break;
930 case tok::annot_pragma_fp_contract:
931 HandlePragmaFPContract();
932 break;
933 case tok::annot_pragma_fp:
934 HandlePragmaFP();
935 break;
936 case tok::annot_pragma_fenv_access:
937 HandlePragmaFEnvAccess();
938 break;
939 case tok::annot_pragma_ms_pointers_to_members:
940 HandlePragmaMSPointersToMembers();
941 break;
942 case tok::annot_pragma_ms_pragma:
943 HandlePragmaMSPragma();
944 break;
945 case tok::annot_pragma_ms_vtordisp:
946 HandlePragmaMSVtorDisp();
947 break;
948 case tok::annot_pragma_dump:
949 HandlePragmaDump();
950 break;
951 default:
952 checkForPragmas = false;
953 break;
954 }
955 }
956
957 }
958
959 /// Consume any extra semi-colons resulting in null statements,
960 /// returning true if any tok::semi were consumed.
ConsumeNullStmt(StmtVector & Stmts)961 bool Parser::ConsumeNullStmt(StmtVector &Stmts) {
962 if (!Tok.is(tok::semi))
963 return false;
964
965 SourceLocation StartLoc = Tok.getLocation();
966 SourceLocation EndLoc;
967
968 while (Tok.is(tok::semi) && !Tok.hasLeadingEmptyMacro() &&
969 Tok.getLocation().isValid() && !Tok.getLocation().isMacroID()) {
970 EndLoc = Tok.getLocation();
971
972 // Don't just ConsumeToken() this tok::semi, do store it in AST.
973 StmtResult R =
974 ParseStatementOrDeclaration(Stmts, ParsedStmtContext::SubStmt);
975 if (R.isUsable())
976 Stmts.push_back(R.get());
977 }
978
979 // Did not consume any extra semi.
980 if (EndLoc.isInvalid())
981 return false;
982
983 Diag(StartLoc, diag::warn_null_statement)
984 << FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
985 return true;
986 }
987
handleExprStmt(ExprResult E,ParsedStmtContext StmtCtx)988 StmtResult Parser::handleExprStmt(ExprResult E, ParsedStmtContext StmtCtx) {
989 bool IsStmtExprResult = false;
990 if ((StmtCtx & ParsedStmtContext::InStmtExpr) != ParsedStmtContext()) {
991 // For GCC compatibility we skip past NullStmts.
992 unsigned LookAhead = 0;
993 while (GetLookAheadToken(LookAhead).is(tok::semi)) {
994 ++LookAhead;
995 }
996 // Then look to see if the next two tokens close the statement expression;
997 // if so, this expression statement is the last statement in a statment
998 // expression.
999 IsStmtExprResult = GetLookAheadToken(LookAhead).is(tok::r_brace) &&
1000 GetLookAheadToken(LookAhead + 1).is(tok::r_paren);
1001 }
1002
1003 if (IsStmtExprResult)
1004 E = Actions.ActOnStmtExprResult(E);
1005 return Actions.ActOnExprStmt(E, /*DiscardedValue=*/!IsStmtExprResult);
1006 }
1007
1008 /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
1009 /// ActOnCompoundStmt action. This expects the '{' to be the current token, and
1010 /// consume the '}' at the end of the block. It does not manipulate the scope
1011 /// stack.
ParseCompoundStatementBody(bool isStmtExpr)1012 StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
1013 PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
1014 Tok.getLocation(),
1015 "in compound statement ('{}')");
1016
1017 // Record the state of the FP_CONTRACT pragma, restore on leaving the
1018 // compound statement.
1019 Sema::FPContractStateRAII SaveFPContractState(Actions);
1020
1021 InMessageExpressionRAIIObject InMessage(*this, false);
1022 BalancedDelimiterTracker T(*this, tok::l_brace);
1023 if (T.consumeOpen())
1024 return StmtError();
1025
1026 Sema::CompoundScopeRAII CompoundScope(Actions, isStmtExpr);
1027
1028 // Parse any pragmas at the beginning of the compound statement.
1029 ParseCompoundStatementLeadingPragmas();
1030
1031 StmtVector Stmts;
1032
1033 // "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are
1034 // only allowed at the start of a compound stmt regardless of the language.
1035 while (Tok.is(tok::kw___label__)) {
1036 SourceLocation LabelLoc = ConsumeToken();
1037
1038 SmallVector<Decl *, 8> DeclsInGroup;
1039 while (1) {
1040 if (Tok.isNot(tok::identifier)) {
1041 Diag(Tok, diag::err_expected) << tok::identifier;
1042 break;
1043 }
1044
1045 IdentifierInfo *II = Tok.getIdentifierInfo();
1046 SourceLocation IdLoc = ConsumeToken();
1047 DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
1048
1049 if (!TryConsumeToken(tok::comma))
1050 break;
1051 }
1052
1053 DeclSpec DS(AttrFactory);
1054 DeclGroupPtrTy Res =
1055 Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup);
1056 StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
1057
1058 ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
1059 if (R.isUsable())
1060 Stmts.push_back(R.get());
1061 }
1062
1063 ParsedStmtContext SubStmtCtx =
1064 ParsedStmtContext::Compound |
1065 (isStmtExpr ? ParsedStmtContext::InStmtExpr : ParsedStmtContext());
1066
1067 while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
1068 Tok.isNot(tok::eof)) {
1069 if (Tok.is(tok::annot_pragma_unused)) {
1070 HandlePragmaUnused();
1071 continue;
1072 }
1073
1074 if (ConsumeNullStmt(Stmts))
1075 continue;
1076
1077 StmtResult R;
1078 if (Tok.isNot(tok::kw___extension__)) {
1079 R = ParseStatementOrDeclaration(Stmts, SubStmtCtx);
1080 } else {
1081 // __extension__ can start declarations and it can also be a unary
1082 // operator for expressions. Consume multiple __extension__ markers here
1083 // until we can determine which is which.
1084 // FIXME: This loses extension expressions in the AST!
1085 SourceLocation ExtLoc = ConsumeToken();
1086 while (Tok.is(tok::kw___extension__))
1087 ConsumeToken();
1088
1089 ParsedAttributesWithRange attrs(AttrFactory);
1090 MaybeParseCXX11Attributes(attrs, nullptr,
1091 /*MightBeObjCMessageSend*/ true);
1092
1093 // If this is the start of a declaration, parse it as such.
1094 if (isDeclarationStatement()) {
1095 // __extension__ silences extension warnings in the subdeclaration.
1096 // FIXME: Save the __extension__ on the decl as a node somehow?
1097 ExtensionRAIIObject O(Diags);
1098
1099 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1100 DeclGroupPtrTy Res =
1101 ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, attrs);
1102 R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd);
1103 } else {
1104 // Otherwise this was a unary __extension__ marker.
1105 ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
1106
1107 if (Res.isInvalid()) {
1108 SkipUntil(tok::semi);
1109 continue;
1110 }
1111
1112 // Eat the semicolon at the end of stmt and convert the expr into a
1113 // statement.
1114 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
1115 R = handleExprStmt(Res, SubStmtCtx);
1116 if (R.isUsable())
1117 R = Actions.ProcessStmtAttributes(R.get(), attrs, attrs.Range);
1118 }
1119 }
1120
1121 if (R.isUsable())
1122 Stmts.push_back(R.get());
1123 }
1124
1125 SourceLocation CloseLoc = Tok.getLocation();
1126
1127 // We broke out of the while loop because we found a '}' or EOF.
1128 if (!T.consumeClose())
1129 // Recover by creating a compound statement with what we parsed so far,
1130 // instead of dropping everything and returning StmtError();
1131 CloseLoc = T.getCloseLocation();
1132
1133 return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc,
1134 Stmts, isStmtExpr);
1135 }
1136
1137 /// ParseParenExprOrCondition:
1138 /// [C ] '(' expression ')'
1139 /// [C++] '(' condition ')'
1140 /// [C++1z] '(' init-statement[opt] condition ')'
1141 ///
1142 /// This function parses and performs error recovery on the specified condition
1143 /// or expression (depending on whether we're in C++ or C mode). This function
1144 /// goes out of its way to recover well. It returns true if there was a parser
1145 /// error (the right paren couldn't be found), which indicates that the caller
1146 /// should try to recover harder. It returns false if the condition is
1147 /// successfully parsed. Note that a successful parse can still have semantic
1148 /// errors in the condition.
ParseParenExprOrCondition(StmtResult * InitStmt,Sema::ConditionResult & Cond,SourceLocation Loc,Sema::ConditionKind CK)1149 bool Parser::ParseParenExprOrCondition(StmtResult *InitStmt,
1150 Sema::ConditionResult &Cond,
1151 SourceLocation Loc,
1152 Sema::ConditionKind CK) {
1153 BalancedDelimiterTracker T(*this, tok::l_paren);
1154 T.consumeOpen();
1155
1156 if (getLangOpts().CPlusPlus)
1157 Cond = ParseCXXCondition(InitStmt, Loc, CK);
1158 else {
1159 ExprResult CondExpr = ParseExpression();
1160
1161 // If required, convert to a boolean value.
1162 if (CondExpr.isInvalid())
1163 Cond = Sema::ConditionError();
1164 else
1165 Cond = Actions.ActOnCondition(getCurScope(), Loc, CondExpr.get(), CK);
1166 }
1167
1168 // If the parser was confused by the condition and we don't have a ')', try to
1169 // recover by skipping ahead to a semi and bailing out. If condexp is
1170 // semantically invalid but we have well formed code, keep going.
1171 if (Cond.isInvalid() && Tok.isNot(tok::r_paren)) {
1172 SkipUntil(tok::semi);
1173 // Skipping may have stopped if it found the containing ')'. If so, we can
1174 // continue parsing the if statement.
1175 if (Tok.isNot(tok::r_paren))
1176 return true;
1177 }
1178
1179 // Otherwise the condition is valid or the rparen is present.
1180 T.consumeClose();
1181
1182 // Check for extraneous ')'s to catch things like "if (foo())) {". We know
1183 // that all callers are looking for a statement after the condition, so ")"
1184 // isn't valid.
1185 while (Tok.is(tok::r_paren)) {
1186 Diag(Tok, diag::err_extraneous_rparen_in_condition)
1187 << FixItHint::CreateRemoval(Tok.getLocation());
1188 ConsumeParen();
1189 }
1190
1191 return false;
1192 }
1193
1194 namespace {
1195
1196 enum MisleadingStatementKind { MSK_if, MSK_else, MSK_for, MSK_while };
1197
1198 struct MisleadingIndentationChecker {
1199 Parser &P;
1200 SourceLocation StmtLoc;
1201 SourceLocation PrevLoc;
1202 unsigned NumDirectives;
1203 MisleadingStatementKind Kind;
1204 bool ShouldSkip;
MisleadingIndentationChecker__anon8ef062900211::MisleadingIndentationChecker1205 MisleadingIndentationChecker(Parser &P, MisleadingStatementKind K,
1206 SourceLocation SL)
1207 : P(P), StmtLoc(SL), PrevLoc(P.getCurToken().getLocation()),
1208 NumDirectives(P.getPreprocessor().getNumDirectives()), Kind(K),
1209 ShouldSkip(P.getCurToken().is(tok::l_brace)) {
1210 if (!P.MisleadingIndentationElseLoc.isInvalid()) {
1211 StmtLoc = P.MisleadingIndentationElseLoc;
1212 P.MisleadingIndentationElseLoc = SourceLocation();
1213 }
1214 if (Kind == MSK_else && !ShouldSkip)
1215 P.MisleadingIndentationElseLoc = SL;
1216 }
1217
1218 /// Compute the column number will aligning tabs on TabStop (-ftabstop), this
1219 /// gives the visual indentation of the SourceLocation.
getVisualIndentation__anon8ef062900211::MisleadingIndentationChecker1220 static unsigned getVisualIndentation(SourceManager &SM, SourceLocation Loc) {
1221 unsigned TabStop = SM.getDiagnostics().getDiagnosticOptions().TabStop;
1222
1223 unsigned ColNo = SM.getSpellingColumnNumber(Loc);
1224 if (ColNo == 0 || TabStop == 1)
1225 return ColNo;
1226
1227 std::pair<FileID, unsigned> FIDAndOffset = SM.getDecomposedLoc(Loc);
1228
1229 bool Invalid;
1230 StringRef BufData = SM.getBufferData(FIDAndOffset.first, &Invalid);
1231 if (Invalid)
1232 return 0;
1233
1234 const char *EndPos = BufData.data() + FIDAndOffset.second;
1235 // FileOffset are 0-based and Column numbers are 1-based
1236 assert(FIDAndOffset.second + 1 >= ColNo &&
1237 "Column number smaller than file offset?");
1238
1239 unsigned VisualColumn = 0; // Stored as 0-based column, here.
1240 // Loop from beginning of line up to Loc's file position, counting columns,
1241 // expanding tabs.
1242 for (const char *CurPos = EndPos - (ColNo - 1); CurPos != EndPos;
1243 ++CurPos) {
1244 if (*CurPos == '\t')
1245 // Advance visual column to next tabstop.
1246 VisualColumn += (TabStop - VisualColumn % TabStop);
1247 else
1248 VisualColumn++;
1249 }
1250 return VisualColumn + 1;
1251 }
1252
Check__anon8ef062900211::MisleadingIndentationChecker1253 void Check() {
1254 Token Tok = P.getCurToken();
1255 if (P.getActions().getDiagnostics().isIgnored(
1256 diag::warn_misleading_indentation, Tok.getLocation()) ||
1257 ShouldSkip || NumDirectives != P.getPreprocessor().getNumDirectives() ||
1258 Tok.isOneOf(tok::semi, tok::r_brace) || Tok.isAnnotation() ||
1259 Tok.getLocation().isMacroID() || PrevLoc.isMacroID() ||
1260 StmtLoc.isMacroID() ||
1261 (Kind == MSK_else && P.MisleadingIndentationElseLoc.isInvalid())) {
1262 P.MisleadingIndentationElseLoc = SourceLocation();
1263 return;
1264 }
1265 if (Kind == MSK_else)
1266 P.MisleadingIndentationElseLoc = SourceLocation();
1267
1268 SourceManager &SM = P.getPreprocessor().getSourceManager();
1269 unsigned PrevColNum = getVisualIndentation(SM, PrevLoc);
1270 unsigned CurColNum = getVisualIndentation(SM, Tok.getLocation());
1271 unsigned StmtColNum = getVisualIndentation(SM, StmtLoc);
1272
1273 if (PrevColNum != 0 && CurColNum != 0 && StmtColNum != 0 &&
1274 ((PrevColNum > StmtColNum && PrevColNum == CurColNum) ||
1275 !Tok.isAtStartOfLine()) &&
1276 SM.getPresumedLineNumber(StmtLoc) !=
1277 SM.getPresumedLineNumber(Tok.getLocation()) &&
1278 (Tok.isNot(tok::identifier) ||
1279 P.getPreprocessor().LookAhead(0).isNot(tok::colon))) {
1280 P.Diag(Tok.getLocation(), diag::warn_misleading_indentation) << Kind;
1281 P.Diag(StmtLoc, diag::note_previous_statement);
1282 }
1283 }
1284 };
1285
1286 }
1287
1288 /// ParseIfStatement
1289 /// if-statement: [C99 6.8.4.1]
1290 /// 'if' '(' expression ')' statement
1291 /// 'if' '(' expression ')' statement 'else' statement
1292 /// [C++] 'if' '(' condition ')' statement
1293 /// [C++] 'if' '(' condition ')' statement 'else' statement
1294 ///
ParseIfStatement(SourceLocation * TrailingElseLoc)1295 StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
1296 assert(Tok.is(tok::kw_if) && "Not an if stmt!");
1297 SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
1298
1299 bool IsConstexpr = false;
1300 if (Tok.is(tok::kw_constexpr)) {
1301 Diag(Tok, getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_constexpr_if
1302 : diag::ext_constexpr_if);
1303 IsConstexpr = true;
1304 ConsumeToken();
1305 }
1306
1307 if (Tok.isNot(tok::l_paren)) {
1308 Diag(Tok, diag::err_expected_lparen_after) << "if";
1309 SkipUntil(tok::semi);
1310 return StmtError();
1311 }
1312
1313 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1314
1315 // C99 6.8.4p3 - In C99, the if statement is a block. This is not
1316 // the case for C90.
1317 //
1318 // C++ 6.4p3:
1319 // A name introduced by a declaration in a condition is in scope from its
1320 // point of declaration until the end of the substatements controlled by the
1321 // condition.
1322 // C++ 3.3.2p4:
1323 // Names declared in the for-init-statement, and in the condition of if,
1324 // while, for, and switch statements are local to the if, while, for, or
1325 // switch statement (including the controlled statement).
1326 //
1327 ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX);
1328
1329 // Parse the condition.
1330 StmtResult InitStmt;
1331 Sema::ConditionResult Cond;
1332 if (ParseParenExprOrCondition(&InitStmt, Cond, IfLoc,
1333 IsConstexpr ? Sema::ConditionKind::ConstexprIf
1334 : Sema::ConditionKind::Boolean))
1335 return StmtError();
1336
1337 llvm::Optional<bool> ConstexprCondition;
1338 if (IsConstexpr)
1339 ConstexprCondition = Cond.getKnownValue();
1340
1341 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
1342 // there is no compound stmt. C90 does not have this clause. We only do this
1343 // if the body isn't a compound statement to avoid push/pop in common cases.
1344 //
1345 // C++ 6.4p1:
1346 // The substatement in a selection-statement (each substatement, in the else
1347 // form of the if statement) implicitly defines a local scope.
1348 //
1349 // For C++ we create a scope for the condition and a new scope for
1350 // substatements because:
1351 // -When the 'then' scope exits, we want the condition declaration to still be
1352 // active for the 'else' scope too.
1353 // -Sema will detect name clashes by considering declarations of a
1354 // 'ControlScope' as part of its direct subscope.
1355 // -If we wanted the condition and substatement to be in the same scope, we
1356 // would have to notify ParseStatement not to create a new scope. It's
1357 // simpler to let it create a new scope.
1358 //
1359 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1360
1361 MisleadingIndentationChecker MIChecker(*this, MSK_if, IfLoc);
1362
1363 // Read the 'then' stmt.
1364 SourceLocation ThenStmtLoc = Tok.getLocation();
1365
1366 SourceLocation InnerStatementTrailingElseLoc;
1367 StmtResult ThenStmt;
1368 {
1369 EnterExpressionEvaluationContext PotentiallyDiscarded(
1370 Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr,
1371 Sema::ExpressionEvaluationContextRecord::EK_Other,
1372 /*ShouldEnter=*/ConstexprCondition && !*ConstexprCondition);
1373 ThenStmt = ParseStatement(&InnerStatementTrailingElseLoc);
1374 }
1375
1376 if (Tok.isNot(tok::kw_else))
1377 MIChecker.Check();
1378
1379 // Pop the 'if' scope if needed.
1380 InnerScope.Exit();
1381
1382 // If it has an else, parse it.
1383 SourceLocation ElseLoc;
1384 SourceLocation ElseStmtLoc;
1385 StmtResult ElseStmt;
1386
1387 if (Tok.is(tok::kw_else)) {
1388 if (TrailingElseLoc)
1389 *TrailingElseLoc = Tok.getLocation();
1390
1391 ElseLoc = ConsumeToken();
1392 ElseStmtLoc = Tok.getLocation();
1393
1394 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
1395 // there is no compound stmt. C90 does not have this clause. We only do
1396 // this if the body isn't a compound statement to avoid push/pop in common
1397 // cases.
1398 //
1399 // C++ 6.4p1:
1400 // The substatement in a selection-statement (each substatement, in the else
1401 // form of the if statement) implicitly defines a local scope.
1402 //
1403 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX,
1404 Tok.is(tok::l_brace));
1405
1406 MisleadingIndentationChecker MIChecker(*this, MSK_else, ElseLoc);
1407
1408 EnterExpressionEvaluationContext PotentiallyDiscarded(
1409 Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr,
1410 Sema::ExpressionEvaluationContextRecord::EK_Other,
1411 /*ShouldEnter=*/ConstexprCondition && *ConstexprCondition);
1412 ElseStmt = ParseStatement();
1413
1414 if (ElseStmt.isUsable())
1415 MIChecker.Check();
1416
1417 // Pop the 'else' scope if needed.
1418 InnerScope.Exit();
1419 } else if (Tok.is(tok::code_completion)) {
1420 Actions.CodeCompleteAfterIf(getCurScope());
1421 cutOffParsing();
1422 return StmtError();
1423 } else if (InnerStatementTrailingElseLoc.isValid()) {
1424 Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else);
1425 }
1426
1427 IfScope.Exit();
1428
1429 // If the then or else stmt is invalid and the other is valid (and present),
1430 // make turn the invalid one into a null stmt to avoid dropping the other
1431 // part. If both are invalid, return error.
1432 if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) ||
1433 (ThenStmt.isInvalid() && ElseStmt.get() == nullptr) ||
1434 (ThenStmt.get() == nullptr && ElseStmt.isInvalid())) {
1435 // Both invalid, or one is invalid and other is non-present: return error.
1436 return StmtError();
1437 }
1438
1439 // Now if either are invalid, replace with a ';'.
1440 if (ThenStmt.isInvalid())
1441 ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc);
1442 if (ElseStmt.isInvalid())
1443 ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc);
1444
1445 return Actions.ActOnIfStmt(IfLoc, IsConstexpr, InitStmt.get(), Cond,
1446 ThenStmt.get(), ElseLoc, ElseStmt.get());
1447 }
1448
1449 /// ParseSwitchStatement
1450 /// switch-statement:
1451 /// 'switch' '(' expression ')' statement
1452 /// [C++] 'switch' '(' condition ')' statement
ParseSwitchStatement(SourceLocation * TrailingElseLoc)1453 StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
1454 assert(Tok.is(tok::kw_switch) && "Not a switch stmt!");
1455 SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'.
1456
1457 if (Tok.isNot(tok::l_paren)) {
1458 Diag(Tok, diag::err_expected_lparen_after) << "switch";
1459 SkipUntil(tok::semi);
1460 return StmtError();
1461 }
1462
1463 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1464
1465 // C99 6.8.4p3 - In C99, the switch statement is a block. This is
1466 // not the case for C90. Start the switch scope.
1467 //
1468 // C++ 6.4p3:
1469 // A name introduced by a declaration in a condition is in scope from its
1470 // point of declaration until the end of the substatements controlled by the
1471 // condition.
1472 // C++ 3.3.2p4:
1473 // Names declared in the for-init-statement, and in the condition of if,
1474 // while, for, and switch statements are local to the if, while, for, or
1475 // switch statement (including the controlled statement).
1476 //
1477 unsigned ScopeFlags = Scope::SwitchScope;
1478 if (C99orCXX)
1479 ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
1480 ParseScope SwitchScope(this, ScopeFlags);
1481
1482 // Parse the condition.
1483 StmtResult InitStmt;
1484 Sema::ConditionResult Cond;
1485 if (ParseParenExprOrCondition(&InitStmt, Cond, SwitchLoc,
1486 Sema::ConditionKind::Switch))
1487 return StmtError();
1488
1489 StmtResult Switch =
1490 Actions.ActOnStartOfSwitchStmt(SwitchLoc, InitStmt.get(), Cond);
1491
1492 if (Switch.isInvalid()) {
1493 // Skip the switch body.
1494 // FIXME: This is not optimal recovery, but parsing the body is more
1495 // dangerous due to the presence of case and default statements, which
1496 // will have no place to connect back with the switch.
1497 if (Tok.is(tok::l_brace)) {
1498 ConsumeBrace();
1499 SkipUntil(tok::r_brace);
1500 } else
1501 SkipUntil(tok::semi);
1502 return Switch;
1503 }
1504
1505 // C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
1506 // there is no compound stmt. C90 does not have this clause. We only do this
1507 // if the body isn't a compound statement to avoid push/pop in common cases.
1508 //
1509 // C++ 6.4p1:
1510 // The substatement in a selection-statement (each substatement, in the else
1511 // form of the if statement) implicitly defines a local scope.
1512 //
1513 // See comments in ParseIfStatement for why we create a scope for the
1514 // condition and a new scope for substatement in C++.
1515 //
1516 getCurScope()->AddFlags(Scope::BreakScope);
1517 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1518
1519 // We have incremented the mangling number for the SwitchScope and the
1520 // InnerScope, which is one too many.
1521 if (C99orCXX)
1522 getCurScope()->decrementMSManglingNumber();
1523
1524 // Read the body statement.
1525 StmtResult Body(ParseStatement(TrailingElseLoc));
1526
1527 // Pop the scopes.
1528 InnerScope.Exit();
1529 SwitchScope.Exit();
1530
1531 return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get());
1532 }
1533
1534 /// ParseWhileStatement
1535 /// while-statement: [C99 6.8.5.1]
1536 /// 'while' '(' expression ')' statement
1537 /// [C++] 'while' '(' condition ')' statement
ParseWhileStatement(SourceLocation * TrailingElseLoc)1538 StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
1539 assert(Tok.is(tok::kw_while) && "Not a while stmt!");
1540 SourceLocation WhileLoc = Tok.getLocation();
1541 ConsumeToken(); // eat the 'while'.
1542
1543 if (Tok.isNot(tok::l_paren)) {
1544 Diag(Tok, diag::err_expected_lparen_after) << "while";
1545 SkipUntil(tok::semi);
1546 return StmtError();
1547 }
1548
1549 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1550
1551 // C99 6.8.5p5 - In C99, the while statement is a block. This is not
1552 // the case for C90. Start the loop scope.
1553 //
1554 // C++ 6.4p3:
1555 // A name introduced by a declaration in a condition is in scope from its
1556 // point of declaration until the end of the substatements controlled by the
1557 // condition.
1558 // C++ 3.3.2p4:
1559 // Names declared in the for-init-statement, and in the condition of if,
1560 // while, for, and switch statements are local to the if, while, for, or
1561 // switch statement (including the controlled statement).
1562 //
1563 unsigned ScopeFlags;
1564 if (C99orCXX)
1565 ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
1566 Scope::DeclScope | Scope::ControlScope;
1567 else
1568 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1569 ParseScope WhileScope(this, ScopeFlags);
1570
1571 // Parse the condition.
1572 Sema::ConditionResult Cond;
1573 if (ParseParenExprOrCondition(nullptr, Cond, WhileLoc,
1574 Sema::ConditionKind::Boolean))
1575 return StmtError();
1576
1577 // C99 6.8.5p5 - In C99, the body of the while statement is a scope, even if
1578 // there is no compound stmt. C90 does not have this clause. We only do this
1579 // if the body isn't a compound statement to avoid push/pop in common cases.
1580 //
1581 // C++ 6.5p2:
1582 // The substatement in an iteration-statement implicitly defines a local scope
1583 // which is entered and exited each time through the loop.
1584 //
1585 // See comments in ParseIfStatement for why we create a scope for the
1586 // condition and a new scope for substatement in C++.
1587 //
1588 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1589
1590 MisleadingIndentationChecker MIChecker(*this, MSK_while, WhileLoc);
1591
1592 // Read the body statement.
1593 StmtResult Body(ParseStatement(TrailingElseLoc));
1594
1595 if (Body.isUsable())
1596 MIChecker.Check();
1597 // Pop the body scope if needed.
1598 InnerScope.Exit();
1599 WhileScope.Exit();
1600
1601 if (Cond.isInvalid() || Body.isInvalid())
1602 return StmtError();
1603
1604 return Actions.ActOnWhileStmt(WhileLoc, Cond, Body.get());
1605 }
1606
1607 /// ParseDoStatement
1608 /// do-statement: [C99 6.8.5.2]
1609 /// 'do' statement 'while' '(' expression ')' ';'
1610 /// Note: this lets the caller parse the end ';'.
ParseDoStatement()1611 StmtResult Parser::ParseDoStatement() {
1612 assert(Tok.is(tok::kw_do) && "Not a do stmt!");
1613 SourceLocation DoLoc = ConsumeToken(); // eat the 'do'.
1614
1615 // C99 6.8.5p5 - In C99, the do statement is a block. This is not
1616 // the case for C90. Start the loop scope.
1617 unsigned ScopeFlags;
1618 if (getLangOpts().C99)
1619 ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope;
1620 else
1621 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1622
1623 ParseScope DoScope(this, ScopeFlags);
1624
1625 // C99 6.8.5p5 - In C99, the body of the do statement is a scope, even if
1626 // there is no compound stmt. C90 does not have this clause. We only do this
1627 // if the body isn't a compound statement to avoid push/pop in common cases.
1628 //
1629 // C++ 6.5p2:
1630 // The substatement in an iteration-statement implicitly defines a local scope
1631 // which is entered and exited each time through the loop.
1632 //
1633 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1634 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1635
1636 // Read the body statement.
1637 StmtResult Body(ParseStatement());
1638
1639 // Pop the body scope if needed.
1640 InnerScope.Exit();
1641
1642 if (Tok.isNot(tok::kw_while)) {
1643 if (!Body.isInvalid()) {
1644 Diag(Tok, diag::err_expected_while);
1645 Diag(DoLoc, diag::note_matching) << "'do'";
1646 SkipUntil(tok::semi, StopBeforeMatch);
1647 }
1648 return StmtError();
1649 }
1650 SourceLocation WhileLoc = ConsumeToken();
1651
1652 if (Tok.isNot(tok::l_paren)) {
1653 Diag(Tok, diag::err_expected_lparen_after) << "do/while";
1654 SkipUntil(tok::semi, StopBeforeMatch);
1655 return StmtError();
1656 }
1657
1658 // Parse the parenthesized expression.
1659 BalancedDelimiterTracker T(*this, tok::l_paren);
1660 T.consumeOpen();
1661
1662 // A do-while expression is not a condition, so can't have attributes.
1663 DiagnoseAndSkipCXX11Attributes();
1664
1665 ExprResult Cond = ParseExpression();
1666 // Correct the typos in condition before closing the scope.
1667 if (Cond.isUsable())
1668 Cond = Actions.CorrectDelayedTyposInExpr(Cond);
1669 T.consumeClose();
1670 DoScope.Exit();
1671
1672 if (Cond.isInvalid() || Body.isInvalid())
1673 return StmtError();
1674
1675 return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(),
1676 Cond.get(), T.getCloseLocation());
1677 }
1678
isForRangeIdentifier()1679 bool Parser::isForRangeIdentifier() {
1680 assert(Tok.is(tok::identifier));
1681
1682 const Token &Next = NextToken();
1683 if (Next.is(tok::colon))
1684 return true;
1685
1686 if (Next.isOneOf(tok::l_square, tok::kw_alignas)) {
1687 TentativeParsingAction PA(*this);
1688 ConsumeToken();
1689 SkipCXX11Attributes();
1690 bool Result = Tok.is(tok::colon);
1691 PA.Revert();
1692 return Result;
1693 }
1694
1695 return false;
1696 }
1697
1698 /// ParseForStatement
1699 /// for-statement: [C99 6.8.5.3]
1700 /// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement
1701 /// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement
1702 /// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')'
1703 /// [C++] statement
1704 /// [C++0x] 'for'
1705 /// 'co_await'[opt] [Coroutines]
1706 /// '(' for-range-declaration ':' for-range-initializer ')'
1707 /// statement
1708 /// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
1709 /// [OBJC2] 'for' '(' expr 'in' expr ')' statement
1710 ///
1711 /// [C++] for-init-statement:
1712 /// [C++] expression-statement
1713 /// [C++] simple-declaration
1714 ///
1715 /// [C++0x] for-range-declaration:
1716 /// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator
1717 /// [C++0x] for-range-initializer:
1718 /// [C++0x] expression
1719 /// [C++0x] braced-init-list [TODO]
ParseForStatement(SourceLocation * TrailingElseLoc)1720 StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
1721 assert(Tok.is(tok::kw_for) && "Not a for stmt!");
1722 SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
1723
1724 SourceLocation CoawaitLoc;
1725 if (Tok.is(tok::kw_co_await))
1726 CoawaitLoc = ConsumeToken();
1727
1728 if (Tok.isNot(tok::l_paren)) {
1729 Diag(Tok, diag::err_expected_lparen_after) << "for";
1730 SkipUntil(tok::semi);
1731 return StmtError();
1732 }
1733
1734 bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus ||
1735 getLangOpts().ObjC;
1736
1737 // C99 6.8.5p5 - In C99, the for statement is a block. This is not
1738 // the case for C90. Start the loop scope.
1739 //
1740 // C++ 6.4p3:
1741 // A name introduced by a declaration in a condition is in scope from its
1742 // point of declaration until the end of the substatements controlled by the
1743 // condition.
1744 // C++ 3.3.2p4:
1745 // Names declared in the for-init-statement, and in the condition of if,
1746 // while, for, and switch statements are local to the if, while, for, or
1747 // switch statement (including the controlled statement).
1748 // C++ 6.5.3p1:
1749 // Names declared in the for-init-statement are in the same declarative-region
1750 // as those declared in the condition.
1751 //
1752 unsigned ScopeFlags = 0;
1753 if (C99orCXXorObjC)
1754 ScopeFlags = Scope::DeclScope | Scope::ControlScope;
1755
1756 ParseScope ForScope(this, ScopeFlags);
1757
1758 BalancedDelimiterTracker T(*this, tok::l_paren);
1759 T.consumeOpen();
1760
1761 ExprResult Value;
1762
1763 bool ForEach = false;
1764 StmtResult FirstPart;
1765 Sema::ConditionResult SecondPart;
1766 ExprResult Collection;
1767 ForRangeInfo ForRangeInfo;
1768 FullExprArg ThirdPart(Actions);
1769
1770 if (Tok.is(tok::code_completion)) {
1771 Actions.CodeCompleteOrdinaryName(getCurScope(),
1772 C99orCXXorObjC? Sema::PCC_ForInit
1773 : Sema::PCC_Expression);
1774 cutOffParsing();
1775 return StmtError();
1776 }
1777
1778 ParsedAttributesWithRange attrs(AttrFactory);
1779 MaybeParseCXX11Attributes(attrs);
1780
1781 SourceLocation EmptyInitStmtSemiLoc;
1782
1783 // Parse the first part of the for specifier.
1784 if (Tok.is(tok::semi)) { // for (;
1785 ProhibitAttributes(attrs);
1786 // no first part, eat the ';'.
1787 SourceLocation SemiLoc = Tok.getLocation();
1788 if (!Tok.hasLeadingEmptyMacro() && !SemiLoc.isMacroID())
1789 EmptyInitStmtSemiLoc = SemiLoc;
1790 ConsumeToken();
1791 } else if (getLangOpts().CPlusPlus && Tok.is(tok::identifier) &&
1792 isForRangeIdentifier()) {
1793 ProhibitAttributes(attrs);
1794 IdentifierInfo *Name = Tok.getIdentifierInfo();
1795 SourceLocation Loc = ConsumeToken();
1796 MaybeParseCXX11Attributes(attrs);
1797
1798 ForRangeInfo.ColonLoc = ConsumeToken();
1799 if (Tok.is(tok::l_brace))
1800 ForRangeInfo.RangeExpr = ParseBraceInitializer();
1801 else
1802 ForRangeInfo.RangeExpr = ParseExpression();
1803
1804 Diag(Loc, diag::err_for_range_identifier)
1805 << ((getLangOpts().CPlusPlus11 && !getLangOpts().CPlusPlus17)
1806 ? FixItHint::CreateInsertion(Loc, "auto &&")
1807 : FixItHint());
1808
1809 ForRangeInfo.LoopVar = Actions.ActOnCXXForRangeIdentifier(
1810 getCurScope(), Loc, Name, attrs, attrs.Range.getEnd());
1811 } else if (isForInitDeclaration()) { // for (int X = 4;
1812 ParenBraceBracketBalancer BalancerRAIIObj(*this);
1813
1814 // Parse declaration, which eats the ';'.
1815 if (!C99orCXXorObjC) { // Use of C99-style for loops in C90 mode?
1816 Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
1817 Diag(Tok, diag::warn_gcc_variable_decl_in_for_loop);
1818 }
1819
1820 // In C++0x, "for (T NS:a" might not be a typo for ::
1821 bool MightBeForRangeStmt = getLangOpts().CPlusPlus;
1822 ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
1823
1824 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1825 DeclGroupPtrTy DG = ParseSimpleDeclaration(
1826 DeclaratorContext::ForContext, DeclEnd, attrs, false,
1827 MightBeForRangeStmt ? &ForRangeInfo : nullptr);
1828 FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
1829 if (ForRangeInfo.ParsedForRangeDecl()) {
1830 Diag(ForRangeInfo.ColonLoc, getLangOpts().CPlusPlus11 ?
1831 diag::warn_cxx98_compat_for_range : diag::ext_for_range);
1832 ForRangeInfo.LoopVar = FirstPart;
1833 FirstPart = StmtResult();
1834 } else if (Tok.is(tok::semi)) { // for (int x = 4;
1835 ConsumeToken();
1836 } else if ((ForEach = isTokIdentifier_in())) {
1837 Actions.ActOnForEachDeclStmt(DG);
1838 // ObjC: for (id x in expr)
1839 ConsumeToken(); // consume 'in'
1840
1841 if (Tok.is(tok::code_completion)) {
1842 Actions.CodeCompleteObjCForCollection(getCurScope(), DG);
1843 cutOffParsing();
1844 return StmtError();
1845 }
1846 Collection = ParseExpression();
1847 } else {
1848 Diag(Tok, diag::err_expected_semi_for);
1849 }
1850 } else {
1851 ProhibitAttributes(attrs);
1852 Value = Actions.CorrectDelayedTyposInExpr(ParseExpression());
1853
1854 ForEach = isTokIdentifier_in();
1855
1856 // Turn the expression into a stmt.
1857 if (!Value.isInvalid()) {
1858 if (ForEach)
1859 FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
1860 else {
1861 // We already know this is not an init-statement within a for loop, so
1862 // if we are parsing a C++11 range-based for loop, we should treat this
1863 // expression statement as being a discarded value expression because
1864 // we will err below. This way we do not warn on an unused expression
1865 // that was an error in the first place, like with: for (expr : expr);
1866 bool IsRangeBasedFor =
1867 getLangOpts().CPlusPlus11 && !ForEach && Tok.is(tok::colon);
1868 FirstPart = Actions.ActOnExprStmt(Value, !IsRangeBasedFor);
1869 }
1870 }
1871
1872 if (Tok.is(tok::semi)) {
1873 ConsumeToken();
1874 } else if (ForEach) {
1875 ConsumeToken(); // consume 'in'
1876
1877 if (Tok.is(tok::code_completion)) {
1878 Actions.CodeCompleteObjCForCollection(getCurScope(), nullptr);
1879 cutOffParsing();
1880 return StmtError();
1881 }
1882 Collection = ParseExpression();
1883 } else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) {
1884 // User tried to write the reasonable, but ill-formed, for-range-statement
1885 // for (expr : expr) { ... }
1886 Diag(Tok, diag::err_for_range_expected_decl)
1887 << FirstPart.get()->getSourceRange();
1888 SkipUntil(tok::r_paren, StopBeforeMatch);
1889 SecondPart = Sema::ConditionError();
1890 } else {
1891 if (!Value.isInvalid()) {
1892 Diag(Tok, diag::err_expected_semi_for);
1893 } else {
1894 // Skip until semicolon or rparen, don't consume it.
1895 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
1896 if (Tok.is(tok::semi))
1897 ConsumeToken();
1898 }
1899 }
1900 }
1901
1902 // Parse the second part of the for specifier.
1903 getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope);
1904 if (!ForEach && !ForRangeInfo.ParsedForRangeDecl() &&
1905 !SecondPart.isInvalid()) {
1906 // Parse the second part of the for specifier.
1907 if (Tok.is(tok::semi)) { // for (...;;
1908 // no second part.
1909 } else if (Tok.is(tok::r_paren)) {
1910 // missing both semicolons.
1911 } else {
1912 if (getLangOpts().CPlusPlus) {
1913 // C++2a: We've parsed an init-statement; we might have a
1914 // for-range-declaration next.
1915 bool MightBeForRangeStmt = !ForRangeInfo.ParsedForRangeDecl();
1916 ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
1917 SecondPart =
1918 ParseCXXCondition(nullptr, ForLoc, Sema::ConditionKind::Boolean,
1919 MightBeForRangeStmt ? &ForRangeInfo : nullptr);
1920
1921 if (ForRangeInfo.ParsedForRangeDecl()) {
1922 Diag(FirstPart.get() ? FirstPart.get()->getBeginLoc()
1923 : ForRangeInfo.ColonLoc,
1924 getLangOpts().CPlusPlus2a
1925 ? diag::warn_cxx17_compat_for_range_init_stmt
1926 : diag::ext_for_range_init_stmt)
1927 << (FirstPart.get() ? FirstPart.get()->getSourceRange()
1928 : SourceRange());
1929 if (EmptyInitStmtSemiLoc.isValid()) {
1930 Diag(EmptyInitStmtSemiLoc, diag::warn_empty_init_statement)
1931 << /*for-loop*/ 2
1932 << FixItHint::CreateRemoval(EmptyInitStmtSemiLoc);
1933 }
1934 }
1935 } else {
1936 ExprResult SecondExpr = ParseExpression();
1937 if (SecondExpr.isInvalid())
1938 SecondPart = Sema::ConditionError();
1939 else
1940 SecondPart =
1941 Actions.ActOnCondition(getCurScope(), ForLoc, SecondExpr.get(),
1942 Sema::ConditionKind::Boolean);
1943 }
1944 }
1945 }
1946
1947 // Parse the third part of the for statement.
1948 if (!ForEach && !ForRangeInfo.ParsedForRangeDecl()) {
1949 if (Tok.isNot(tok::semi)) {
1950 if (!SecondPart.isInvalid())
1951 Diag(Tok, diag::err_expected_semi_for);
1952 else
1953 // Skip until semicolon or rparen, don't consume it.
1954 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
1955 }
1956
1957 if (Tok.is(tok::semi)) {
1958 ConsumeToken();
1959 }
1960
1961 if (Tok.isNot(tok::r_paren)) { // for (...;...;)
1962 ExprResult Third = ParseExpression();
1963 // FIXME: The C++11 standard doesn't actually say that this is a
1964 // discarded-value expression, but it clearly should be.
1965 ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.get());
1966 }
1967 }
1968 // Match the ')'.
1969 T.consumeClose();
1970
1971 // C++ Coroutines [stmt.iter]:
1972 // 'co_await' can only be used for a range-based for statement.
1973 if (CoawaitLoc.isValid() && !ForRangeInfo.ParsedForRangeDecl()) {
1974 Diag(CoawaitLoc, diag::err_for_co_await_not_range_for);
1975 CoawaitLoc = SourceLocation();
1976 }
1977
1978 // We need to perform most of the semantic analysis for a C++0x for-range
1979 // statememt before parsing the body, in order to be able to deduce the type
1980 // of an auto-typed loop variable.
1981 StmtResult ForRangeStmt;
1982 StmtResult ForEachStmt;
1983
1984 if (ForRangeInfo.ParsedForRangeDecl()) {
1985 ExprResult CorrectedRange =
1986 Actions.CorrectDelayedTyposInExpr(ForRangeInfo.RangeExpr.get());
1987 ForRangeStmt = Actions.ActOnCXXForRangeStmt(
1988 getCurScope(), ForLoc, CoawaitLoc, FirstPart.get(),
1989 ForRangeInfo.LoopVar.get(), ForRangeInfo.ColonLoc, CorrectedRange.get(),
1990 T.getCloseLocation(), Sema::BFRK_Build);
1991
1992 // Similarly, we need to do the semantic analysis for a for-range
1993 // statement immediately in order to close over temporaries correctly.
1994 } else if (ForEach) {
1995 ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc,
1996 FirstPart.get(),
1997 Collection.get(),
1998 T.getCloseLocation());
1999 } else {
2000 // In OpenMP loop region loop control variable must be captured and be
2001 // private. Perform analysis of first part (if any).
2002 if (getLangOpts().OpenMP && FirstPart.isUsable()) {
2003 Actions.ActOnOpenMPLoopInitialization(ForLoc, FirstPart.get());
2004 }
2005 }
2006
2007 // C99 6.8.5p5 - In C99, the body of the for statement is a scope, even if
2008 // there is no compound stmt. C90 does not have this clause. We only do this
2009 // if the body isn't a compound statement to avoid push/pop in common cases.
2010 //
2011 // C++ 6.5p2:
2012 // The substatement in an iteration-statement implicitly defines a local scope
2013 // which is entered and exited each time through the loop.
2014 //
2015 // See comments in ParseIfStatement for why we create a scope for
2016 // for-init-statement/condition and a new scope for substatement in C++.
2017 //
2018 ParseScope InnerScope(this, Scope::DeclScope, C99orCXXorObjC,
2019 Tok.is(tok::l_brace));
2020
2021 // The body of the for loop has the same local mangling number as the
2022 // for-init-statement.
2023 // It will only be incremented if the body contains other things that would
2024 // normally increment the mangling number (like a compound statement).
2025 if (C99orCXXorObjC)
2026 getCurScope()->decrementMSManglingNumber();
2027
2028 MisleadingIndentationChecker MIChecker(*this, MSK_for, ForLoc);
2029
2030 // Read the body statement.
2031 StmtResult Body(ParseStatement(TrailingElseLoc));
2032
2033 if (Body.isUsable())
2034 MIChecker.Check();
2035
2036 // Pop the body scope if needed.
2037 InnerScope.Exit();
2038
2039 // Leave the for-scope.
2040 ForScope.Exit();
2041
2042 if (Body.isInvalid())
2043 return StmtError();
2044
2045 if (ForEach)
2046 return Actions.FinishObjCForCollectionStmt(ForEachStmt.get(),
2047 Body.get());
2048
2049 if (ForRangeInfo.ParsedForRangeDecl())
2050 return Actions.FinishCXXForRangeStmt(ForRangeStmt.get(), Body.get());
2051
2052 return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.get(),
2053 SecondPart, ThirdPart, T.getCloseLocation(),
2054 Body.get());
2055 }
2056
2057 /// ParseGotoStatement
2058 /// jump-statement:
2059 /// 'goto' identifier ';'
2060 /// [GNU] 'goto' '*' expression ';'
2061 ///
2062 /// Note: this lets the caller parse the end ';'.
2063 ///
ParseGotoStatement()2064 StmtResult Parser::ParseGotoStatement() {
2065 assert(Tok.is(tok::kw_goto) && "Not a goto stmt!");
2066 SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'.
2067
2068 StmtResult Res;
2069 if (Tok.is(tok::identifier)) {
2070 LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
2071 Tok.getLocation());
2072 Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD);
2073 ConsumeToken();
2074 } else if (Tok.is(tok::star)) {
2075 // GNU indirect goto extension.
2076 Diag(Tok, diag::ext_gnu_indirect_goto);
2077 SourceLocation StarLoc = ConsumeToken();
2078 ExprResult R(ParseExpression());
2079 if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
2080 SkipUntil(tok::semi, StopBeforeMatch);
2081 return StmtError();
2082 }
2083 Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.get());
2084 } else {
2085 Diag(Tok, diag::err_expected) << tok::identifier;
2086 return StmtError();
2087 }
2088
2089 return Res;
2090 }
2091
2092 /// ParseContinueStatement
2093 /// jump-statement:
2094 /// 'continue' ';'
2095 ///
2096 /// Note: this lets the caller parse the end ';'.
2097 ///
ParseContinueStatement()2098 StmtResult Parser::ParseContinueStatement() {
2099 SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'.
2100 return Actions.ActOnContinueStmt(ContinueLoc, getCurScope());
2101 }
2102
2103 /// ParseBreakStatement
2104 /// jump-statement:
2105 /// 'break' ';'
2106 ///
2107 /// Note: this lets the caller parse the end ';'.
2108 ///
ParseBreakStatement()2109 StmtResult Parser::ParseBreakStatement() {
2110 SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
2111 return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
2112 }
2113
2114 /// ParseReturnStatement
2115 /// jump-statement:
2116 /// 'return' expression[opt] ';'
2117 /// 'return' braced-init-list ';'
2118 /// 'co_return' expression[opt] ';'
2119 /// 'co_return' braced-init-list ';'
ParseReturnStatement()2120 StmtResult Parser::ParseReturnStatement() {
2121 assert((Tok.is(tok::kw_return) || Tok.is(tok::kw_co_return)) &&
2122 "Not a return stmt!");
2123 bool IsCoreturn = Tok.is(tok::kw_co_return);
2124 SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
2125
2126 ExprResult R;
2127 if (Tok.isNot(tok::semi)) {
2128 if (!IsCoreturn)
2129 PreferredType.enterReturn(Actions, Tok.getLocation());
2130 // FIXME: Code completion for co_return.
2131 if (Tok.is(tok::code_completion) && !IsCoreturn) {
2132 Actions.CodeCompleteExpression(getCurScope(),
2133 PreferredType.get(Tok.getLocation()));
2134 cutOffParsing();
2135 return StmtError();
2136 }
2137
2138 if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) {
2139 R = ParseInitializer();
2140 if (R.isUsable())
2141 Diag(R.get()->getBeginLoc(),
2142 getLangOpts().CPlusPlus11
2143 ? diag::warn_cxx98_compat_generalized_initializer_lists
2144 : diag::ext_generalized_initializer_lists)
2145 << R.get()->getSourceRange();
2146 } else
2147 R = ParseExpression();
2148 if (R.isInvalid()) {
2149 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
2150 return StmtError();
2151 }
2152 }
2153 if (IsCoreturn)
2154 return Actions.ActOnCoreturnStmt(getCurScope(), ReturnLoc, R.get());
2155 return Actions.ActOnReturnStmt(ReturnLoc, R.get(), getCurScope());
2156 }
2157
ParsePragmaLoopHint(StmtVector & Stmts,ParsedStmtContext StmtCtx,SourceLocation * TrailingElseLoc,ParsedAttributesWithRange & Attrs)2158 StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts,
2159 ParsedStmtContext StmtCtx,
2160 SourceLocation *TrailingElseLoc,
2161 ParsedAttributesWithRange &Attrs) {
2162 // Create temporary attribute list.
2163 ParsedAttributesWithRange TempAttrs(AttrFactory);
2164
2165 // Get loop hints and consume annotated token.
2166 while (Tok.is(tok::annot_pragma_loop_hint)) {
2167 LoopHint Hint;
2168 if (!HandlePragmaLoopHint(Hint))
2169 continue;
2170
2171 ArgsUnion ArgHints[] = {Hint.PragmaNameLoc, Hint.OptionLoc, Hint.StateLoc,
2172 ArgsUnion(Hint.ValueExpr)};
2173 TempAttrs.addNew(Hint.PragmaNameLoc->Ident, Hint.Range, nullptr,
2174 Hint.PragmaNameLoc->Loc, ArgHints, 4,
2175 ParsedAttr::AS_Pragma);
2176 }
2177
2178 // Get the next statement.
2179 MaybeParseCXX11Attributes(Attrs);
2180
2181 StmtResult S = ParseStatementOrDeclarationAfterAttributes(
2182 Stmts, StmtCtx, TrailingElseLoc, Attrs);
2183
2184 Attrs.takeAllFrom(TempAttrs);
2185 return S;
2186 }
2187
ParseFunctionStatementBody(Decl * Decl,ParseScope & BodyScope)2188 Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
2189 assert(Tok.is(tok::l_brace));
2190 SourceLocation LBraceLoc = Tok.getLocation();
2191
2192 PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, LBraceLoc,
2193 "parsing function body");
2194
2195 // Save and reset current vtordisp stack if we have entered a C++ method body.
2196 bool IsCXXMethod =
2197 getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
2198 Sema::PragmaStackSentinelRAII
2199 PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
2200
2201 // Do not enter a scope for the brace, as the arguments are in the same scope
2202 // (the function body) as the body itself. Instead, just read the statement
2203 // list and put it into a CompoundStmt for safe keeping.
2204 StmtResult FnBody(ParseCompoundStatementBody());
2205
2206 // If the function body could not be parsed, make a bogus compoundstmt.
2207 if (FnBody.isInvalid()) {
2208 Sema::CompoundScopeRAII CompoundScope(Actions);
2209 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
2210 }
2211
2212 BodyScope.Exit();
2213 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
2214 }
2215
2216 /// ParseFunctionTryBlock - Parse a C++ function-try-block.
2217 ///
2218 /// function-try-block:
2219 /// 'try' ctor-initializer[opt] compound-statement handler-seq
2220 ///
ParseFunctionTryBlock(Decl * Decl,ParseScope & BodyScope)2221 Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
2222 assert(Tok.is(tok::kw_try) && "Expected 'try'");
2223 SourceLocation TryLoc = ConsumeToken();
2224
2225 PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, TryLoc,
2226 "parsing function try block");
2227
2228 // Constructor initializer list?
2229 if (Tok.is(tok::colon))
2230 ParseConstructorInitializer(Decl);
2231 else
2232 Actions.ActOnDefaultCtorInitializers(Decl);
2233
2234 // Save and reset current vtordisp stack if we have entered a C++ method body.
2235 bool IsCXXMethod =
2236 getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
2237 Sema::PragmaStackSentinelRAII
2238 PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
2239
2240 SourceLocation LBraceLoc = Tok.getLocation();
2241 StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));
2242 // If we failed to parse the try-catch, we just give the function an empty
2243 // compound statement as the body.
2244 if (FnBody.isInvalid()) {
2245 Sema::CompoundScopeRAII CompoundScope(Actions);
2246 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
2247 }
2248
2249 BodyScope.Exit();
2250 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
2251 }
2252
trySkippingFunctionBody()2253 bool Parser::trySkippingFunctionBody() {
2254 assert(SkipFunctionBodies &&
2255 "Should only be called when SkipFunctionBodies is enabled");
2256 if (!PP.isCodeCompletionEnabled()) {
2257 SkipFunctionBody();
2258 return true;
2259 }
2260
2261 // We're in code-completion mode. Skip parsing for all function bodies unless
2262 // the body contains the code-completion point.
2263 TentativeParsingAction PA(*this);
2264 bool IsTryCatch = Tok.is(tok::kw_try);
2265 CachedTokens Toks;
2266 bool ErrorInPrologue = ConsumeAndStoreFunctionPrologue(Toks);
2267 if (llvm::any_of(Toks, [](const Token &Tok) {
2268 return Tok.is(tok::code_completion);
2269 })) {
2270 PA.Revert();
2271 return false;
2272 }
2273 if (ErrorInPrologue) {
2274 PA.Commit();
2275 SkipMalformedDecl();
2276 return true;
2277 }
2278 if (!SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
2279 PA.Revert();
2280 return false;
2281 }
2282 while (IsTryCatch && Tok.is(tok::kw_catch)) {
2283 if (!SkipUntil(tok::l_brace, StopAtCodeCompletion) ||
2284 !SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
2285 PA.Revert();
2286 return false;
2287 }
2288 }
2289 PA.Commit();
2290 return true;
2291 }
2292
2293 /// ParseCXXTryBlock - Parse a C++ try-block.
2294 ///
2295 /// try-block:
2296 /// 'try' compound-statement handler-seq
2297 ///
ParseCXXTryBlock()2298 StmtResult Parser::ParseCXXTryBlock() {
2299 assert(Tok.is(tok::kw_try) && "Expected 'try'");
2300
2301 SourceLocation TryLoc = ConsumeToken();
2302 return ParseCXXTryBlockCommon(TryLoc);
2303 }
2304
2305 /// ParseCXXTryBlockCommon - Parse the common part of try-block and
2306 /// function-try-block.
2307 ///
2308 /// try-block:
2309 /// 'try' compound-statement handler-seq
2310 ///
2311 /// function-try-block:
2312 /// 'try' ctor-initializer[opt] compound-statement handler-seq
2313 ///
2314 /// handler-seq:
2315 /// handler handler-seq[opt]
2316 ///
2317 /// [Borland] try-block:
2318 /// 'try' compound-statement seh-except-block
2319 /// 'try' compound-statement seh-finally-block
2320 ///
ParseCXXTryBlockCommon(SourceLocation TryLoc,bool FnTry)2321 StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
2322 if (Tok.isNot(tok::l_brace))
2323 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
2324
2325 StmtResult TryBlock(ParseCompoundStatement(
2326 /*isStmtExpr=*/false, Scope::DeclScope | Scope::TryScope |
2327 Scope::CompoundStmtScope |
2328 (FnTry ? Scope::FnTryCatchScope : 0)));
2329 if (TryBlock.isInvalid())
2330 return TryBlock;
2331
2332 // Borland allows SEH-handlers with 'try'
2333
2334 if ((Tok.is(tok::identifier) &&
2335 Tok.getIdentifierInfo() == getSEHExceptKeyword()) ||
2336 Tok.is(tok::kw___finally)) {
2337 // TODO: Factor into common return ParseSEHHandlerCommon(...)
2338 StmtResult Handler;
2339 if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
2340 SourceLocation Loc = ConsumeToken();
2341 Handler = ParseSEHExceptBlock(Loc);
2342 }
2343 else {
2344 SourceLocation Loc = ConsumeToken();
2345 Handler = ParseSEHFinallyBlock(Loc);
2346 }
2347 if(Handler.isInvalid())
2348 return Handler;
2349
2350 return Actions.ActOnSEHTryBlock(true /* IsCXXTry */,
2351 TryLoc,
2352 TryBlock.get(),
2353 Handler.get());
2354 }
2355 else {
2356 StmtVector Handlers;
2357
2358 // C++11 attributes can't appear here, despite this context seeming
2359 // statement-like.
2360 DiagnoseAndSkipCXX11Attributes();
2361
2362 if (Tok.isNot(tok::kw_catch))
2363 return StmtError(Diag(Tok, diag::err_expected_catch));
2364 while (Tok.is(tok::kw_catch)) {
2365 StmtResult Handler(ParseCXXCatchBlock(FnTry));
2366 if (!Handler.isInvalid())
2367 Handlers.push_back(Handler.get());
2368 }
2369 // Don't bother creating the full statement if we don't have any usable
2370 // handlers.
2371 if (Handlers.empty())
2372 return StmtError();
2373
2374 return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.get(), Handlers);
2375 }
2376 }
2377
2378 /// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
2379 ///
2380 /// handler:
2381 /// 'catch' '(' exception-declaration ')' compound-statement
2382 ///
2383 /// exception-declaration:
2384 /// attribute-specifier-seq[opt] type-specifier-seq declarator
2385 /// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt]
2386 /// '...'
2387 ///
ParseCXXCatchBlock(bool FnCatch)2388 StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
2389 assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
2390
2391 SourceLocation CatchLoc = ConsumeToken();
2392
2393 BalancedDelimiterTracker T(*this, tok::l_paren);
2394 if (T.expectAndConsume())
2395 return StmtError();
2396
2397 // C++ 3.3.2p3:
2398 // The name in a catch exception-declaration is local to the handler and
2399 // shall not be redeclared in the outermost block of the handler.
2400 ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope |
2401 Scope::CatchScope |
2402 (FnCatch ? Scope::FnTryCatchScope : 0));
2403
2404 // exception-declaration is equivalent to '...' or a parameter-declaration
2405 // without default arguments.
2406 Decl *ExceptionDecl = nullptr;
2407 if (Tok.isNot(tok::ellipsis)) {
2408 ParsedAttributesWithRange Attributes(AttrFactory);
2409 MaybeParseCXX11Attributes(Attributes);
2410
2411 DeclSpec DS(AttrFactory);
2412 DS.takeAttributesFrom(Attributes);
2413
2414 if (ParseCXXTypeSpecifierSeq(DS))
2415 return StmtError();
2416
2417 Declarator ExDecl(DS, DeclaratorContext::CXXCatchContext);
2418 ParseDeclarator(ExDecl);
2419 ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
2420 } else
2421 ConsumeToken();
2422
2423 T.consumeClose();
2424 if (T.getCloseLocation().isInvalid())
2425 return StmtError();
2426
2427 if (Tok.isNot(tok::l_brace))
2428 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
2429
2430 // FIXME: Possible draft standard bug: attribute-specifier should be allowed?
2431 StmtResult Block(ParseCompoundStatement());
2432 if (Block.isInvalid())
2433 return Block;
2434
2435 return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.get());
2436 }
2437
ParseMicrosoftIfExistsStatement(StmtVector & Stmts)2438 void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
2439 IfExistsCondition Result;
2440 if (ParseMicrosoftIfExistsCondition(Result))
2441 return;
2442
2443 // Handle dependent statements by parsing the braces as a compound statement.
2444 // This is not the same behavior as Visual C++, which don't treat this as a
2445 // compound statement, but for Clang's type checking we can't have anything
2446 // inside these braces escaping to the surrounding code.
2447 if (Result.Behavior == IEB_Dependent) {
2448 if (!Tok.is(tok::l_brace)) {
2449 Diag(Tok, diag::err_expected) << tok::l_brace;
2450 return;
2451 }
2452
2453 StmtResult Compound = ParseCompoundStatement();
2454 if (Compound.isInvalid())
2455 return;
2456
2457 StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc,
2458 Result.IsIfExists,
2459 Result.SS,
2460 Result.Name,
2461 Compound.get());
2462 if (DepResult.isUsable())
2463 Stmts.push_back(DepResult.get());
2464 return;
2465 }
2466
2467 BalancedDelimiterTracker Braces(*this, tok::l_brace);
2468 if (Braces.consumeOpen()) {
2469 Diag(Tok, diag::err_expected) << tok::l_brace;
2470 return;
2471 }
2472
2473 switch (Result.Behavior) {
2474 case IEB_Parse:
2475 // Parse the statements below.
2476 break;
2477
2478 case IEB_Dependent:
2479 llvm_unreachable("Dependent case handled above");
2480
2481 case IEB_Skip:
2482 Braces.skipToEnd();
2483 return;
2484 }
2485
2486 // Condition is true, parse the statements.
2487 while (Tok.isNot(tok::r_brace)) {
2488 StmtResult R =
2489 ParseStatementOrDeclaration(Stmts, ParsedStmtContext::Compound);
2490 if (R.isUsable())
2491 Stmts.push_back(R.get());
2492 }
2493 Braces.consumeClose();
2494 }
2495
ParseOpenCLUnrollHintAttribute(ParsedAttributes & Attrs)2496 bool Parser::ParseOpenCLUnrollHintAttribute(ParsedAttributes &Attrs) {
2497 MaybeParseGNUAttributes(Attrs);
2498
2499 if (Attrs.empty())
2500 return true;
2501
2502 if (Attrs.begin()->getKind() != ParsedAttr::AT_OpenCLUnrollHint)
2503 return true;
2504
2505 if (!(Tok.is(tok::kw_for) || Tok.is(tok::kw_while) || Tok.is(tok::kw_do))) {
2506 Diag(Tok, diag::err_opencl_unroll_hint_on_non_loop);
2507 return false;
2508 }
2509 return true;
2510 }
2511