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