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/Basic/Diagnostic.h"
18 #include "clang/Basic/PrettyStackTrace.h"
19 #include "clang/Basic/SourceManager.h"
20 #include "clang/Sema/DeclSpec.h"
21 #include "clang/Sema/PrettyDeclStackTrace.h"
22 #include "clang/Sema/Scope.h"
23 #include "clang/Sema/TypoCorrection.h"
24 #include "llvm/ADT/SmallString.h"
25 using namespace clang;
26
27 //===----------------------------------------------------------------------===//
28 // C99 6.8: Statements and Blocks.
29 //===----------------------------------------------------------------------===//
30
31 /// ParseStatementOrDeclaration - Read 'statement' or 'declaration'.
32 /// StatementOrDeclaration:
33 /// statement
34 /// declaration
35 ///
36 /// statement:
37 /// labeled-statement
38 /// compound-statement
39 /// expression-statement
40 /// selection-statement
41 /// iteration-statement
42 /// jump-statement
43 /// [C++] declaration-statement
44 /// [C++] try-block
45 /// [MS] seh-try-block
46 /// [OBC] objc-throw-statement
47 /// [OBC] objc-try-catch-statement
48 /// [OBC] objc-synchronized-statement
49 /// [GNU] asm-statement
50 /// [OMP] openmp-construct [TODO]
51 ///
52 /// labeled-statement:
53 /// identifier ':' statement
54 /// 'case' constant-expression ':' statement
55 /// 'default' ':' statement
56 ///
57 /// selection-statement:
58 /// if-statement
59 /// switch-statement
60 ///
61 /// iteration-statement:
62 /// while-statement
63 /// do-statement
64 /// for-statement
65 ///
66 /// expression-statement:
67 /// expression[opt] ';'
68 ///
69 /// jump-statement:
70 /// 'goto' identifier ';'
71 /// 'continue' ';'
72 /// 'break' ';'
73 /// 'return' expression[opt] ';'
74 /// [GNU] 'goto' '*' expression ';'
75 ///
76 /// [OBC] objc-throw-statement:
77 /// [OBC] '@' 'throw' expression ';'
78 /// [OBC] '@' 'throw' ';'
79 ///
80 StmtResult
ParseStatementOrDeclaration(StmtVector & Stmts,bool OnlyStatement,SourceLocation * TrailingElseLoc)81 Parser::ParseStatementOrDeclaration(StmtVector &Stmts, bool OnlyStatement,
82 SourceLocation *TrailingElseLoc) {
83
84 ParenBraceBracketBalancer BalancerRAIIObj(*this);
85
86 ParsedAttributesWithRange Attrs(AttrFactory);
87 MaybeParseCXX11Attributes(Attrs, 0, /*MightBeObjCMessageSend*/ true);
88
89 StmtResult Res = ParseStatementOrDeclarationAfterAttributes(Stmts,
90 OnlyStatement, TrailingElseLoc, Attrs);
91
92 assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) &&
93 "attributes on empty statement");
94
95 if (Attrs.empty() || Res.isInvalid())
96 return Res;
97
98 return Actions.ProcessStmtAttributes(Res.get(), Attrs.getList(), Attrs.Range);
99 }
100
101 StmtResult
ParseStatementOrDeclarationAfterAttributes(StmtVector & Stmts,bool OnlyStatement,SourceLocation * TrailingElseLoc,ParsedAttributesWithRange & Attrs)102 Parser::ParseStatementOrDeclarationAfterAttributes(StmtVector &Stmts,
103 bool OnlyStatement, SourceLocation *TrailingElseLoc,
104 ParsedAttributesWithRange &Attrs) {
105 const char *SemiError = 0;
106 StmtResult Res;
107
108 // Cases in this switch statement should fall through if the parser expects
109 // the token to end in a semicolon (in which case SemiError should be set),
110 // or they directly 'return;' if not.
111 Retry:
112 tok::TokenKind Kind = Tok.getKind();
113 SourceLocation AtLoc;
114 switch (Kind) {
115 case tok::at: // May be a @try or @throw statement
116 {
117 ProhibitAttributes(Attrs); // TODO: is it correct?
118 AtLoc = ConsumeToken(); // consume @
119 return ParseObjCAtStatement(AtLoc);
120 }
121
122 case tok::code_completion:
123 Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement);
124 cutOffParsing();
125 return StmtError();
126
127 case tok::identifier: {
128 Token Next = NextToken();
129 if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement
130 // identifier ':' statement
131 return ParseLabeledStatement(Attrs);
132 }
133
134 // Look up the identifier, and typo-correct it to a keyword if it's not
135 // found.
136 if (Next.isNot(tok::coloncolon)) {
137 // Try to limit which sets of keywords should be included in typo
138 // correction based on what the next token is.
139 // FIXME: Pass the next token into the CorrectionCandidateCallback and
140 // do this filtering in a more fine-grained manner.
141 CorrectionCandidateCallback DefaultValidator;
142 DefaultValidator.WantTypeSpecifiers =
143 Next.is(tok::l_paren) || Next.is(tok::less) ||
144 Next.is(tok::identifier) || Next.is(tok::star) ||
145 Next.is(tok::amp) || Next.is(tok::l_square);
146 DefaultValidator.WantExpressionKeywords =
147 Next.is(tok::l_paren) || Next.is(tok::identifier) ||
148 Next.is(tok::arrow) || Next.is(tok::period);
149 DefaultValidator.WantRemainingKeywords =
150 Next.is(tok::l_paren) || Next.is(tok::semi) ||
151 Next.is(tok::identifier) || Next.is(tok::l_brace);
152 DefaultValidator.WantCXXNamedCasts = false;
153 if (TryAnnotateName(/*IsAddressOfOperand*/false, &DefaultValidator)
154 == ANK_Error) {
155 // Handle errors here by skipping up to the next semicolon or '}', and
156 // eat the semicolon if that's what stopped us.
157 SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
158 if (Tok.is(tok::semi))
159 ConsumeToken();
160 return StmtError();
161 }
162
163 // If the identifier was typo-corrected, try again.
164 if (Tok.isNot(tok::identifier))
165 goto Retry;
166 }
167
168 // Fall through
169 }
170
171 default: {
172 if ((getLangOpts().CPlusPlus || !OnlyStatement) && isDeclarationStatement()) {
173 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
174 DeclGroupPtrTy Decl = ParseDeclaration(Stmts, Declarator::BlockContext,
175 DeclEnd, Attrs);
176 return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);
177 }
178
179 if (Tok.is(tok::r_brace)) {
180 Diag(Tok, diag::err_expected_statement);
181 return StmtError();
182 }
183
184 return ParseExprStatement();
185 }
186
187 case tok::kw_case: // C99 6.8.1: labeled-statement
188 return ParseCaseStatement();
189 case tok::kw_default: // C99 6.8.1: labeled-statement
190 return ParseDefaultStatement();
191
192 case tok::l_brace: // C99 6.8.2: compound-statement
193 return ParseCompoundStatement();
194 case tok::semi: { // C99 6.8.3p3: expression[opt] ';'
195 bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
196 return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro);
197 }
198
199 case tok::kw_if: // C99 6.8.4.1: if-statement
200 return ParseIfStatement(TrailingElseLoc);
201 case tok::kw_switch: // C99 6.8.4.2: switch-statement
202 return ParseSwitchStatement(TrailingElseLoc);
203
204 case tok::kw_while: // C99 6.8.5.1: while-statement
205 return ParseWhileStatement(TrailingElseLoc);
206 case tok::kw_do: // C99 6.8.5.2: do-statement
207 Res = ParseDoStatement();
208 SemiError = "do/while";
209 break;
210 case tok::kw_for: // C99 6.8.5.3: for-statement
211 return ParseForStatement(TrailingElseLoc);
212
213 case tok::kw_goto: // C99 6.8.6.1: goto-statement
214 Res = ParseGotoStatement();
215 SemiError = "goto";
216 break;
217 case tok::kw_continue: // C99 6.8.6.2: continue-statement
218 Res = ParseContinueStatement();
219 SemiError = "continue";
220 break;
221 case tok::kw_break: // C99 6.8.6.3: break-statement
222 Res = ParseBreakStatement();
223 SemiError = "break";
224 break;
225 case tok::kw_return: // C99 6.8.6.4: return-statement
226 Res = ParseReturnStatement();
227 SemiError = "return";
228 break;
229
230 case tok::kw_asm: {
231 ProhibitAttributes(Attrs);
232 bool msAsm = false;
233 Res = ParseAsmStatement(msAsm);
234 Res = Actions.ActOnFinishFullStmt(Res.get());
235 if (msAsm) return Res;
236 SemiError = "asm";
237 break;
238 }
239
240 case tok::kw_try: // C++ 15: try-block
241 return ParseCXXTryBlock();
242
243 case tok::kw___try:
244 ProhibitAttributes(Attrs); // TODO: is it correct?
245 return ParseSEHTryBlock();
246
247 case tok::annot_pragma_vis:
248 ProhibitAttributes(Attrs);
249 HandlePragmaVisibility();
250 return StmtEmpty();
251
252 case tok::annot_pragma_pack:
253 ProhibitAttributes(Attrs);
254 HandlePragmaPack();
255 return StmtEmpty();
256
257 case tok::annot_pragma_msstruct:
258 ProhibitAttributes(Attrs);
259 HandlePragmaMSStruct();
260 return StmtEmpty();
261
262 case tok::annot_pragma_align:
263 ProhibitAttributes(Attrs);
264 HandlePragmaAlign();
265 return StmtEmpty();
266
267 case tok::annot_pragma_weak:
268 ProhibitAttributes(Attrs);
269 HandlePragmaWeak();
270 return StmtEmpty();
271
272 case tok::annot_pragma_weakalias:
273 ProhibitAttributes(Attrs);
274 HandlePragmaWeakAlias();
275 return StmtEmpty();
276
277 case tok::annot_pragma_redefine_extname:
278 ProhibitAttributes(Attrs);
279 HandlePragmaRedefineExtname();
280 return StmtEmpty();
281
282 case tok::annot_pragma_fp_contract:
283 Diag(Tok, diag::err_pragma_fp_contract_scope);
284 ConsumeToken();
285 return StmtError();
286
287 case tok::annot_pragma_opencl_extension:
288 ProhibitAttributes(Attrs);
289 HandlePragmaOpenCLExtension();
290 return StmtEmpty();
291 }
292
293 // If we reached this code, the statement must end in a semicolon.
294 if (Tok.is(tok::semi)) {
295 ConsumeToken();
296 } else if (!Res.isInvalid()) {
297 // If the result was valid, then we do want to diagnose this. Use
298 // ExpectAndConsume to emit the diagnostic, even though we know it won't
299 // succeed.
300 ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError);
301 // Skip until we see a } or ;, but don't eat it.
302 SkipUntil(tok::r_brace, true, true);
303 }
304
305 return Res;
306 }
307
308 /// \brief Parse an expression statement.
ParseExprStatement()309 StmtResult Parser::ParseExprStatement() {
310 // If a case keyword is missing, this is where it should be inserted.
311 Token OldToken = Tok;
312
313 // expression[opt] ';'
314 ExprResult Expr(ParseExpression());
315 if (Expr.isInvalid()) {
316 // If the expression is invalid, skip ahead to the next semicolon or '}'.
317 // Not doing this opens us up to the possibility of infinite loops if
318 // ParseExpression does not consume any tokens.
319 SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
320 if (Tok.is(tok::semi))
321 ConsumeToken();
322 return StmtError();
323 }
324
325 if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() &&
326 Actions.CheckCaseExpression(Expr.get())) {
327 // If a constant expression is followed by a colon inside a switch block,
328 // suggest a missing case keyword.
329 Diag(OldToken, diag::err_expected_case_before_expression)
330 << FixItHint::CreateInsertion(OldToken.getLocation(), "case ");
331
332 // Recover parsing as a case statement.
333 return ParseCaseStatement(/*MissingCase=*/true, Expr);
334 }
335
336 // Otherwise, eat the semicolon.
337 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
338 return Actions.ActOnExprStmt(Expr);
339 }
340
ParseSEHTryBlock()341 StmtResult Parser::ParseSEHTryBlock() {
342 assert(Tok.is(tok::kw___try) && "Expected '__try'");
343 SourceLocation Loc = ConsumeToken();
344 return ParseSEHTryBlockCommon(Loc);
345 }
346
347 /// ParseSEHTryBlockCommon
348 ///
349 /// seh-try-block:
350 /// '__try' compound-statement seh-handler
351 ///
352 /// seh-handler:
353 /// seh-except-block
354 /// seh-finally-block
355 ///
ParseSEHTryBlockCommon(SourceLocation TryLoc)356 StmtResult Parser::ParseSEHTryBlockCommon(SourceLocation TryLoc) {
357 if(Tok.isNot(tok::l_brace))
358 return StmtError(Diag(Tok,diag::err_expected_lbrace));
359
360 StmtResult TryBlock(ParseCompoundStatement());
361 if(TryBlock.isInvalid())
362 return TryBlock;
363
364 StmtResult Handler;
365 if (Tok.is(tok::identifier) &&
366 Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
367 SourceLocation Loc = ConsumeToken();
368 Handler = ParseSEHExceptBlock(Loc);
369 } else if (Tok.is(tok::kw___finally)) {
370 SourceLocation Loc = ConsumeToken();
371 Handler = ParseSEHFinallyBlock(Loc);
372 } else {
373 return StmtError(Diag(Tok,diag::err_seh_expected_handler));
374 }
375
376 if(Handler.isInvalid())
377 return Handler;
378
379 return Actions.ActOnSEHTryBlock(false /* IsCXXTry */,
380 TryLoc,
381 TryBlock.take(),
382 Handler.take());
383 }
384
385 /// ParseSEHExceptBlock - Handle __except
386 ///
387 /// seh-except-block:
388 /// '__except' '(' seh-filter-expression ')' compound-statement
389 ///
ParseSEHExceptBlock(SourceLocation ExceptLoc)390 StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
391 PoisonIdentifierRAIIObject raii(Ident__exception_code, false),
392 raii2(Ident___exception_code, false),
393 raii3(Ident_GetExceptionCode, false);
394
395 if(ExpectAndConsume(tok::l_paren,diag::err_expected_lparen))
396 return StmtError();
397
398 ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope);
399
400 if (getLangOpts().Borland) {
401 Ident__exception_info->setIsPoisoned(false);
402 Ident___exception_info->setIsPoisoned(false);
403 Ident_GetExceptionInfo->setIsPoisoned(false);
404 }
405 ExprResult FilterExpr(ParseExpression());
406
407 if (getLangOpts().Borland) {
408 Ident__exception_info->setIsPoisoned(true);
409 Ident___exception_info->setIsPoisoned(true);
410 Ident_GetExceptionInfo->setIsPoisoned(true);
411 }
412
413 if(FilterExpr.isInvalid())
414 return StmtError();
415
416 if(ExpectAndConsume(tok::r_paren,diag::err_expected_rparen))
417 return StmtError();
418
419 StmtResult Block(ParseCompoundStatement());
420
421 if(Block.isInvalid())
422 return Block;
423
424 return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.take(), Block.take());
425 }
426
427 /// ParseSEHFinallyBlock - Handle __finally
428 ///
429 /// seh-finally-block:
430 /// '__finally' compound-statement
431 ///
ParseSEHFinallyBlock(SourceLocation FinallyBlock)432 StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyBlock) {
433 PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false),
434 raii2(Ident___abnormal_termination, false),
435 raii3(Ident_AbnormalTermination, false);
436
437 StmtResult Block(ParseCompoundStatement());
438 if(Block.isInvalid())
439 return Block;
440
441 return Actions.ActOnSEHFinallyBlock(FinallyBlock,Block.take());
442 }
443
444 /// ParseLabeledStatement - We have an identifier and a ':' after it.
445 ///
446 /// labeled-statement:
447 /// identifier ':' statement
448 /// [GNU] identifier ':' attributes[opt] statement
449 ///
ParseLabeledStatement(ParsedAttributesWithRange & attrs)450 StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) {
451 assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
452 "Not an identifier!");
453
454 Token IdentTok = Tok; // Save the whole token.
455 ConsumeToken(); // eat the identifier.
456
457 assert(Tok.is(tok::colon) && "Not a label!");
458
459 // identifier ':' statement
460 SourceLocation ColonLoc = ConsumeToken();
461
462 // Read label attributes, if present. attrs will contain both C++11 and GNU
463 // attributes (if present) after this point.
464 MaybeParseGNUAttributes(attrs);
465
466 StmtResult SubStmt(ParseStatement());
467
468 // Broken substmt shouldn't prevent the label from being added to the AST.
469 if (SubStmt.isInvalid())
470 SubStmt = Actions.ActOnNullStmt(ColonLoc);
471
472 LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(),
473 IdentTok.getLocation());
474 if (AttributeList *Attrs = attrs.getList()) {
475 Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs);
476 attrs.clear();
477 }
478
479 return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc,
480 SubStmt.get());
481 }
482
483 /// ParseCaseStatement
484 /// labeled-statement:
485 /// 'case' constant-expression ':' statement
486 /// [GNU] 'case' constant-expression '...' constant-expression ':' statement
487 ///
ParseCaseStatement(bool MissingCase,ExprResult Expr)488 StmtResult Parser::ParseCaseStatement(bool MissingCase, ExprResult Expr) {
489 assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!");
490
491 // It is very very common for code to contain many case statements recursively
492 // nested, as in (but usually without indentation):
493 // case 1:
494 // case 2:
495 // case 3:
496 // case 4:
497 // case 5: etc.
498 //
499 // Parsing this naively works, but is both inefficient and can cause us to run
500 // out of stack space in our recursive descent parser. As a special case,
501 // flatten this recursion into an iterative loop. This is complex and gross,
502 // but all the grossness is constrained to ParseCaseStatement (and some
503 // wierdness in the actions), so this is just local grossness :).
504
505 // TopLevelCase - This is the highest level we have parsed. 'case 1' in the
506 // example above.
507 StmtResult TopLevelCase(true);
508
509 // DeepestParsedCaseStmt - This is the deepest statement we have parsed, which
510 // gets updated each time a new case is parsed, and whose body is unset so
511 // far. When parsing 'case 4', this is the 'case 3' node.
512 Stmt *DeepestParsedCaseStmt = 0;
513
514 // While we have case statements, eat and stack them.
515 SourceLocation ColonLoc;
516 do {
517 SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() :
518 ConsumeToken(); // eat the 'case'.
519
520 if (Tok.is(tok::code_completion)) {
521 Actions.CodeCompleteCase(getCurScope());
522 cutOffParsing();
523 return StmtError();
524 }
525
526 /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
527 /// Disable this form of error recovery while we're parsing the case
528 /// expression.
529 ColonProtectionRAIIObject ColonProtection(*this);
530
531 ExprResult LHS(MissingCase ? Expr : ParseConstantExpression());
532 MissingCase = false;
533 if (LHS.isInvalid()) {
534 SkipUntil(tok::colon);
535 return StmtError();
536 }
537
538 // GNU case range extension.
539 SourceLocation DotDotDotLoc;
540 ExprResult RHS;
541 if (Tok.is(tok::ellipsis)) {
542 Diag(Tok, diag::ext_gnu_case_range);
543 DotDotDotLoc = ConsumeToken();
544
545 RHS = ParseConstantExpression();
546 if (RHS.isInvalid()) {
547 SkipUntil(tok::colon);
548 return StmtError();
549 }
550 }
551
552 ColonProtection.restore();
553
554 if (Tok.is(tok::colon)) {
555 ColonLoc = ConsumeToken();
556
557 // Treat "case blah;" as a typo for "case blah:".
558 } else if (Tok.is(tok::semi)) {
559 ColonLoc = ConsumeToken();
560 Diag(ColonLoc, diag::err_expected_colon_after) << "'case'"
561 << FixItHint::CreateReplacement(ColonLoc, ":");
562 } else {
563 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
564 Diag(ExpectedLoc, diag::err_expected_colon_after) << "'case'"
565 << FixItHint::CreateInsertion(ExpectedLoc, ":");
566 ColonLoc = ExpectedLoc;
567 }
568
569 StmtResult Case =
570 Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc,
571 RHS.get(), ColonLoc);
572
573 // If we had a sema error parsing this case, then just ignore it and
574 // continue parsing the sub-stmt.
575 if (Case.isInvalid()) {
576 if (TopLevelCase.isInvalid()) // No parsed case stmts.
577 return ParseStatement();
578 // Otherwise, just don't add it as a nested case.
579 } else {
580 // If this is the first case statement we parsed, it becomes TopLevelCase.
581 // Otherwise we link it into the current chain.
582 Stmt *NextDeepest = Case.get();
583 if (TopLevelCase.isInvalid())
584 TopLevelCase = Case;
585 else
586 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
587 DeepestParsedCaseStmt = NextDeepest;
588 }
589
590 // Handle all case statements.
591 } while (Tok.is(tok::kw_case));
592
593 assert(!TopLevelCase.isInvalid() && "Should have parsed at least one case!");
594
595 // If we found a non-case statement, start by parsing it.
596 StmtResult SubStmt;
597
598 if (Tok.isNot(tok::r_brace)) {
599 SubStmt = ParseStatement();
600 } else {
601 // Nicely diagnose the common error "switch (X) { case 4: }", which is
602 // not valid.
603 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
604 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
605 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
606 SubStmt = true;
607 }
608
609 // Broken sub-stmt shouldn't prevent forming the case statement properly.
610 if (SubStmt.isInvalid())
611 SubStmt = Actions.ActOnNullStmt(SourceLocation());
612
613 // Install the body into the most deeply-nested case.
614 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
615
616 // Return the top level parsed statement tree.
617 return TopLevelCase;
618 }
619
620 /// ParseDefaultStatement
621 /// labeled-statement:
622 /// 'default' ':' statement
623 /// Note that this does not parse the 'statement' at the end.
624 ///
ParseDefaultStatement()625 StmtResult Parser::ParseDefaultStatement() {
626 assert(Tok.is(tok::kw_default) && "Not a default stmt!");
627 SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
628
629 SourceLocation ColonLoc;
630 if (Tok.is(tok::colon)) {
631 ColonLoc = ConsumeToken();
632
633 // Treat "default;" as a typo for "default:".
634 } else if (Tok.is(tok::semi)) {
635 ColonLoc = ConsumeToken();
636 Diag(ColonLoc, diag::err_expected_colon_after) << "'default'"
637 << FixItHint::CreateReplacement(ColonLoc, ":");
638 } else {
639 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
640 Diag(ExpectedLoc, diag::err_expected_colon_after) << "'default'"
641 << FixItHint::CreateInsertion(ExpectedLoc, ":");
642 ColonLoc = ExpectedLoc;
643 }
644
645 StmtResult SubStmt;
646
647 if (Tok.isNot(tok::r_brace)) {
648 SubStmt = ParseStatement();
649 } else {
650 // Diagnose the common error "switch (X) {... default: }", which is
651 // not valid.
652 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
653 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
654 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
655 SubStmt = true;
656 }
657
658 // Broken sub-stmt shouldn't prevent forming the case statement properly.
659 if (SubStmt.isInvalid())
660 SubStmt = Actions.ActOnNullStmt(ColonLoc);
661
662 return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
663 SubStmt.get(), getCurScope());
664 }
665
ParseCompoundStatement(bool isStmtExpr)666 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) {
667 return ParseCompoundStatement(isStmtExpr, Scope::DeclScope);
668 }
669
670 /// ParseCompoundStatement - Parse a "{}" block.
671 ///
672 /// compound-statement: [C99 6.8.2]
673 /// { block-item-list[opt] }
674 /// [GNU] { label-declarations block-item-list } [TODO]
675 ///
676 /// block-item-list:
677 /// block-item
678 /// block-item-list block-item
679 ///
680 /// block-item:
681 /// declaration
682 /// [GNU] '__extension__' declaration
683 /// statement
684 /// [OMP] openmp-directive [TODO]
685 ///
686 /// [GNU] label-declarations:
687 /// [GNU] label-declaration
688 /// [GNU] label-declarations label-declaration
689 ///
690 /// [GNU] label-declaration:
691 /// [GNU] '__label__' identifier-list ';'
692 ///
693 /// [OMP] openmp-directive: [TODO]
694 /// [OMP] barrier-directive
695 /// [OMP] flush-directive
696 ///
ParseCompoundStatement(bool isStmtExpr,unsigned ScopeFlags)697 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr,
698 unsigned ScopeFlags) {
699 assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
700
701 // Enter a scope to hold everything within the compound stmt. Compound
702 // statements can always hold declarations.
703 ParseScope CompoundScope(this, ScopeFlags);
704
705 // Parse the statements in the body.
706 return ParseCompoundStatementBody(isStmtExpr);
707 }
708
709 /// Parse any pragmas at the start of the compound expression. We handle these
710 /// separately since some pragmas (FP_CONTRACT) must appear before any C
711 /// statement in the compound, but may be intermingled with other pragmas.
ParseCompoundStatementLeadingPragmas()712 void Parser::ParseCompoundStatementLeadingPragmas() {
713 bool checkForPragmas = true;
714 while (checkForPragmas) {
715 switch (Tok.getKind()) {
716 case tok::annot_pragma_vis:
717 HandlePragmaVisibility();
718 break;
719 case tok::annot_pragma_pack:
720 HandlePragmaPack();
721 break;
722 case tok::annot_pragma_msstruct:
723 HandlePragmaMSStruct();
724 break;
725 case tok::annot_pragma_align:
726 HandlePragmaAlign();
727 break;
728 case tok::annot_pragma_weak:
729 HandlePragmaWeak();
730 break;
731 case tok::annot_pragma_weakalias:
732 HandlePragmaWeakAlias();
733 break;
734 case tok::annot_pragma_redefine_extname:
735 HandlePragmaRedefineExtname();
736 break;
737 case tok::annot_pragma_opencl_extension:
738 HandlePragmaOpenCLExtension();
739 break;
740 case tok::annot_pragma_fp_contract:
741 HandlePragmaFPContract();
742 break;
743 default:
744 checkForPragmas = false;
745 break;
746 }
747 }
748
749 }
750
751 /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
752 /// ActOnCompoundStmt action. This expects the '{' to be the current token, and
753 /// consume the '}' at the end of the block. It does not manipulate the scope
754 /// stack.
ParseCompoundStatementBody(bool isStmtExpr)755 StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
756 PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
757 Tok.getLocation(),
758 "in compound statement ('{}')");
759
760 // Record the state of the FP_CONTRACT pragma, restore on leaving the
761 // compound statement.
762 Sema::FPContractStateRAII SaveFPContractState(Actions);
763
764 InMessageExpressionRAIIObject InMessage(*this, false);
765 BalancedDelimiterTracker T(*this, tok::l_brace);
766 if (T.consumeOpen())
767 return StmtError();
768
769 Sema::CompoundScopeRAII CompoundScope(Actions);
770
771 // Parse any pragmas at the beginning of the compound statement.
772 ParseCompoundStatementLeadingPragmas();
773
774 StmtVector Stmts;
775
776 // "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are
777 // only allowed at the start of a compound stmt regardless of the language.
778 while (Tok.is(tok::kw___label__)) {
779 SourceLocation LabelLoc = ConsumeToken();
780 Diag(LabelLoc, diag::ext_gnu_local_label);
781
782 SmallVector<Decl *, 8> DeclsInGroup;
783 while (1) {
784 if (Tok.isNot(tok::identifier)) {
785 Diag(Tok, diag::err_expected_ident);
786 break;
787 }
788
789 IdentifierInfo *II = Tok.getIdentifierInfo();
790 SourceLocation IdLoc = ConsumeToken();
791 DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
792
793 if (!Tok.is(tok::comma))
794 break;
795 ConsumeToken();
796 }
797
798 DeclSpec DS(AttrFactory);
799 DeclGroupPtrTy Res = Actions.FinalizeDeclaratorGroup(getCurScope(), DS,
800 DeclsInGroup.data(), DeclsInGroup.size());
801 StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
802
803 ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
804 if (R.isUsable())
805 Stmts.push_back(R.release());
806 }
807
808 while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
809 if (Tok.is(tok::annot_pragma_unused)) {
810 HandlePragmaUnused();
811 continue;
812 }
813
814 if (getLangOpts().MicrosoftExt && (Tok.is(tok::kw___if_exists) ||
815 Tok.is(tok::kw___if_not_exists))) {
816 ParseMicrosoftIfExistsStatement(Stmts);
817 continue;
818 }
819
820 StmtResult R;
821 if (Tok.isNot(tok::kw___extension__)) {
822 R = ParseStatementOrDeclaration(Stmts, false);
823 } else {
824 // __extension__ can start declarations and it can also be a unary
825 // operator for expressions. Consume multiple __extension__ markers here
826 // until we can determine which is which.
827 // FIXME: This loses extension expressions in the AST!
828 SourceLocation ExtLoc = ConsumeToken();
829 while (Tok.is(tok::kw___extension__))
830 ConsumeToken();
831
832 ParsedAttributesWithRange attrs(AttrFactory);
833 MaybeParseCXX11Attributes(attrs, 0, /*MightBeObjCMessageSend*/ true);
834
835 // If this is the start of a declaration, parse it as such.
836 if (isDeclarationStatement()) {
837 // __extension__ silences extension warnings in the subdeclaration.
838 // FIXME: Save the __extension__ on the decl as a node somehow?
839 ExtensionRAIIObject O(Diags);
840
841 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
842 DeclGroupPtrTy Res = ParseDeclaration(Stmts,
843 Declarator::BlockContext, DeclEnd,
844 attrs);
845 R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd);
846 } else {
847 // Otherwise this was a unary __extension__ marker.
848 ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
849
850 if (Res.isInvalid()) {
851 SkipUntil(tok::semi);
852 continue;
853 }
854
855 // FIXME: Use attributes?
856 // Eat the semicolon at the end of stmt and convert the expr into a
857 // statement.
858 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
859 R = Actions.ActOnExprStmt(Res);
860 }
861 }
862
863 if (R.isUsable())
864 Stmts.push_back(R.release());
865 }
866
867 SourceLocation CloseLoc = Tok.getLocation();
868
869 // We broke out of the while loop because we found a '}' or EOF.
870 if (!T.consumeClose())
871 // Recover by creating a compound statement with what we parsed so far,
872 // instead of dropping everything and returning StmtError();
873 CloseLoc = T.getCloseLocation();
874
875 return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc,
876 Stmts, isStmtExpr);
877 }
878
879 /// ParseParenExprOrCondition:
880 /// [C ] '(' expression ')'
881 /// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true]
882 ///
883 /// This function parses and performs error recovery on the specified condition
884 /// or expression (depending on whether we're in C++ or C mode). This function
885 /// goes out of its way to recover well. It returns true if there was a parser
886 /// error (the right paren couldn't be found), which indicates that the caller
887 /// should try to recover harder. It returns false if the condition is
888 /// successfully parsed. Note that a successful parse can still have semantic
889 /// errors in the condition.
ParseParenExprOrCondition(ExprResult & ExprResult,Decl * & DeclResult,SourceLocation Loc,bool ConvertToBoolean)890 bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult,
891 Decl *&DeclResult,
892 SourceLocation Loc,
893 bool ConvertToBoolean) {
894 BalancedDelimiterTracker T(*this, tok::l_paren);
895 T.consumeOpen();
896
897 if (getLangOpts().CPlusPlus)
898 ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean);
899 else {
900 ExprResult = ParseExpression();
901 DeclResult = 0;
902
903 // If required, convert to a boolean value.
904 if (!ExprResult.isInvalid() && ConvertToBoolean)
905 ExprResult
906 = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get());
907 }
908
909 // If the parser was confused by the condition and we don't have a ')', try to
910 // recover by skipping ahead to a semi and bailing out. If condexp is
911 // semantically invalid but we have well formed code, keep going.
912 if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) {
913 SkipUntil(tok::semi);
914 // Skipping may have stopped if it found the containing ')'. If so, we can
915 // continue parsing the if statement.
916 if (Tok.isNot(tok::r_paren))
917 return true;
918 }
919
920 // Otherwise the condition is valid or the rparen is present.
921 T.consumeClose();
922
923 // Check for extraneous ')'s to catch things like "if (foo())) {". We know
924 // that all callers are looking for a statement after the condition, so ")"
925 // isn't valid.
926 while (Tok.is(tok::r_paren)) {
927 Diag(Tok, diag::err_extraneous_rparen_in_condition)
928 << FixItHint::CreateRemoval(Tok.getLocation());
929 ConsumeParen();
930 }
931
932 return false;
933 }
934
935
936 /// ParseIfStatement
937 /// if-statement: [C99 6.8.4.1]
938 /// 'if' '(' expression ')' statement
939 /// 'if' '(' expression ')' statement 'else' statement
940 /// [C++] 'if' '(' condition ')' statement
941 /// [C++] 'if' '(' condition ')' statement 'else' statement
942 ///
ParseIfStatement(SourceLocation * TrailingElseLoc)943 StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
944 assert(Tok.is(tok::kw_if) && "Not an if stmt!");
945 SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
946
947 if (Tok.isNot(tok::l_paren)) {
948 Diag(Tok, diag::err_expected_lparen_after) << "if";
949 SkipUntil(tok::semi);
950 return StmtError();
951 }
952
953 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
954
955 // C99 6.8.4p3 - In C99, the if statement is a block. This is not
956 // the case for C90.
957 //
958 // C++ 6.4p3:
959 // A name introduced by a declaration in a condition is in scope from its
960 // point of declaration until the end of the substatements controlled by the
961 // condition.
962 // C++ 3.3.2p4:
963 // Names declared in the for-init-statement, and in the condition of if,
964 // while, for, and switch statements are local to the if, while, for, or
965 // switch statement (including the controlled statement).
966 //
967 ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX);
968
969 // Parse the condition.
970 ExprResult CondExp;
971 Decl *CondVar = 0;
972 if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true))
973 return StmtError();
974
975 FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get(), IfLoc));
976
977 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
978 // there is no compound stmt. C90 does not have this clause. We only do this
979 // if the body isn't a compound statement to avoid push/pop in common cases.
980 //
981 // C++ 6.4p1:
982 // The substatement in a selection-statement (each substatement, in the else
983 // form of the if statement) implicitly defines a local scope.
984 //
985 // For C++ we create a scope for the condition and a new scope for
986 // substatements because:
987 // -When the 'then' scope exits, we want the condition declaration to still be
988 // active for the 'else' scope too.
989 // -Sema will detect name clashes by considering declarations of a
990 // 'ControlScope' as part of its direct subscope.
991 // -If we wanted the condition and substatement to be in the same scope, we
992 // would have to notify ParseStatement not to create a new scope. It's
993 // simpler to let it create a new scope.
994 //
995 ParseScope InnerScope(this, Scope::DeclScope,
996 C99orCXX && Tok.isNot(tok::l_brace));
997
998 // Read the 'then' stmt.
999 SourceLocation ThenStmtLoc = Tok.getLocation();
1000
1001 SourceLocation InnerStatementTrailingElseLoc;
1002 StmtResult ThenStmt(ParseStatement(&InnerStatementTrailingElseLoc));
1003
1004 // Pop the 'if' scope if needed.
1005 InnerScope.Exit();
1006
1007 // If it has an else, parse it.
1008 SourceLocation ElseLoc;
1009 SourceLocation ElseStmtLoc;
1010 StmtResult ElseStmt;
1011
1012 if (Tok.is(tok::kw_else)) {
1013 if (TrailingElseLoc)
1014 *TrailingElseLoc = Tok.getLocation();
1015
1016 ElseLoc = ConsumeToken();
1017 ElseStmtLoc = Tok.getLocation();
1018
1019 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
1020 // there is no compound stmt. C90 does not have this clause. We only do
1021 // this if the body isn't a compound statement to avoid push/pop in common
1022 // cases.
1023 //
1024 // C++ 6.4p1:
1025 // The substatement in a selection-statement (each substatement, in the else
1026 // form of the if statement) implicitly defines a local scope.
1027 //
1028 ParseScope InnerScope(this, Scope::DeclScope,
1029 C99orCXX && Tok.isNot(tok::l_brace));
1030
1031 ElseStmt = ParseStatement();
1032
1033 // Pop the 'else' scope if needed.
1034 InnerScope.Exit();
1035 } else if (Tok.is(tok::code_completion)) {
1036 Actions.CodeCompleteAfterIf(getCurScope());
1037 cutOffParsing();
1038 return StmtError();
1039 } else if (InnerStatementTrailingElseLoc.isValid()) {
1040 Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else);
1041 }
1042
1043 IfScope.Exit();
1044
1045 // If the then or else stmt is invalid and the other is valid (and present),
1046 // make turn the invalid one into a null stmt to avoid dropping the other
1047 // part. If both are invalid, return error.
1048 if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) ||
1049 (ThenStmt.isInvalid() && ElseStmt.get() == 0) ||
1050 (ThenStmt.get() == 0 && ElseStmt.isInvalid())) {
1051 // Both invalid, or one is invalid and other is non-present: return error.
1052 return StmtError();
1053 }
1054
1055 // Now if either are invalid, replace with a ';'.
1056 if (ThenStmt.isInvalid())
1057 ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc);
1058 if (ElseStmt.isInvalid())
1059 ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc);
1060
1061 return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(),
1062 ElseLoc, ElseStmt.get());
1063 }
1064
1065 /// ParseSwitchStatement
1066 /// switch-statement:
1067 /// 'switch' '(' expression ')' statement
1068 /// [C++] 'switch' '(' condition ')' statement
ParseSwitchStatement(SourceLocation * TrailingElseLoc)1069 StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
1070 assert(Tok.is(tok::kw_switch) && "Not a switch stmt!");
1071 SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'.
1072
1073 if (Tok.isNot(tok::l_paren)) {
1074 Diag(Tok, diag::err_expected_lparen_after) << "switch";
1075 SkipUntil(tok::semi);
1076 return StmtError();
1077 }
1078
1079 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1080
1081 // C99 6.8.4p3 - In C99, the switch statement is a block. This is
1082 // not the case for C90. Start the switch scope.
1083 //
1084 // C++ 6.4p3:
1085 // A name introduced by a declaration in a condition is in scope from its
1086 // point of declaration until the end of the substatements controlled by the
1087 // condition.
1088 // C++ 3.3.2p4:
1089 // Names declared in the for-init-statement, and in the condition of if,
1090 // while, for, and switch statements are local to the if, while, for, or
1091 // switch statement (including the controlled statement).
1092 //
1093 unsigned ScopeFlags = Scope::BreakScope | Scope::SwitchScope;
1094 if (C99orCXX)
1095 ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
1096 ParseScope SwitchScope(this, ScopeFlags);
1097
1098 // Parse the condition.
1099 ExprResult Cond;
1100 Decl *CondVar = 0;
1101 if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false))
1102 return StmtError();
1103
1104 StmtResult Switch
1105 = Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar);
1106
1107 if (Switch.isInvalid()) {
1108 // Skip the switch body.
1109 // FIXME: This is not optimal recovery, but parsing the body is more
1110 // dangerous due to the presence of case and default statements, which
1111 // will have no place to connect back with the switch.
1112 if (Tok.is(tok::l_brace)) {
1113 ConsumeBrace();
1114 SkipUntil(tok::r_brace, false, false);
1115 } else
1116 SkipUntil(tok::semi);
1117 return Switch;
1118 }
1119
1120 // C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
1121 // there is no compound stmt. C90 does not have this clause. We only do this
1122 // if the body isn't a compound statement to avoid push/pop in common cases.
1123 //
1124 // C++ 6.4p1:
1125 // The substatement in a selection-statement (each substatement, in the else
1126 // form of the if statement) implicitly defines a local scope.
1127 //
1128 // See comments in ParseIfStatement for why we create a scope for the
1129 // condition and a new scope for substatement in C++.
1130 //
1131 ParseScope InnerScope(this, Scope::DeclScope,
1132 C99orCXX && Tok.isNot(tok::l_brace));
1133
1134 // Read the body statement.
1135 StmtResult Body(ParseStatement(TrailingElseLoc));
1136
1137 // Pop the scopes.
1138 InnerScope.Exit();
1139 SwitchScope.Exit();
1140
1141 if (Body.isInvalid()) {
1142 // FIXME: Remove the case statement list from the Switch statement.
1143
1144 // Put the synthesized null statement on the same line as the end of switch
1145 // condition.
1146 SourceLocation SynthesizedNullStmtLocation = Cond.get()->getLocEnd();
1147 Body = Actions.ActOnNullStmt(SynthesizedNullStmtLocation);
1148 }
1149
1150 return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get());
1151 }
1152
1153 /// ParseWhileStatement
1154 /// while-statement: [C99 6.8.5.1]
1155 /// 'while' '(' expression ')' statement
1156 /// [C++] 'while' '(' condition ')' statement
ParseWhileStatement(SourceLocation * TrailingElseLoc)1157 StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
1158 assert(Tok.is(tok::kw_while) && "Not a while stmt!");
1159 SourceLocation WhileLoc = Tok.getLocation();
1160 ConsumeToken(); // eat the 'while'.
1161
1162 if (Tok.isNot(tok::l_paren)) {
1163 Diag(Tok, diag::err_expected_lparen_after) << "while";
1164 SkipUntil(tok::semi);
1165 return StmtError();
1166 }
1167
1168 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1169
1170 // C99 6.8.5p5 - In C99, the while statement is a block. This is not
1171 // the case for C90. Start the loop scope.
1172 //
1173 // C++ 6.4p3:
1174 // A name introduced by a declaration in a condition is in scope from its
1175 // point of declaration until the end of the substatements controlled by the
1176 // condition.
1177 // C++ 3.3.2p4:
1178 // Names declared in the for-init-statement, and in the condition of if,
1179 // while, for, and switch statements are local to the if, while, for, or
1180 // switch statement (including the controlled statement).
1181 //
1182 unsigned ScopeFlags;
1183 if (C99orCXX)
1184 ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
1185 Scope::DeclScope | Scope::ControlScope;
1186 else
1187 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1188 ParseScope WhileScope(this, ScopeFlags);
1189
1190 // Parse the condition.
1191 ExprResult Cond;
1192 Decl *CondVar = 0;
1193 if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true))
1194 return StmtError();
1195
1196 FullExprArg FullCond(Actions.MakeFullExpr(Cond.get(), WhileLoc));
1197
1198 // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
1199 // there is no compound stmt. C90 does not have this clause. We only do this
1200 // if the body isn't a compound statement to avoid push/pop in common cases.
1201 //
1202 // C++ 6.5p2:
1203 // The substatement in an iteration-statement implicitly defines a local scope
1204 // which is entered and exited each time through the loop.
1205 //
1206 // See comments in ParseIfStatement for why we create a scope for the
1207 // condition and a new scope for substatement in C++.
1208 //
1209 ParseScope InnerScope(this, Scope::DeclScope,
1210 C99orCXX && Tok.isNot(tok::l_brace));
1211
1212 // Read the body statement.
1213 StmtResult Body(ParseStatement(TrailingElseLoc));
1214
1215 // Pop the body scope if needed.
1216 InnerScope.Exit();
1217 WhileScope.Exit();
1218
1219 if ((Cond.isInvalid() && !CondVar) || Body.isInvalid())
1220 return StmtError();
1221
1222 return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get());
1223 }
1224
1225 /// ParseDoStatement
1226 /// do-statement: [C99 6.8.5.2]
1227 /// 'do' statement 'while' '(' expression ')' ';'
1228 /// Note: this lets the caller parse the end ';'.
ParseDoStatement()1229 StmtResult Parser::ParseDoStatement() {
1230 assert(Tok.is(tok::kw_do) && "Not a do stmt!");
1231 SourceLocation DoLoc = ConsumeToken(); // eat the 'do'.
1232
1233 // C99 6.8.5p5 - In C99, the do statement is a block. This is not
1234 // the case for C90. Start the loop scope.
1235 unsigned ScopeFlags;
1236 if (getLangOpts().C99)
1237 ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope;
1238 else
1239 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1240
1241 ParseScope DoScope(this, ScopeFlags);
1242
1243 // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
1244 // there is no compound stmt. C90 does not have this clause. We only do this
1245 // if the body isn't a compound statement to avoid push/pop in common cases.
1246 //
1247 // C++ 6.5p2:
1248 // The substatement in an iteration-statement implicitly defines a local scope
1249 // which is entered and exited each time through the loop.
1250 //
1251 ParseScope InnerScope(this, Scope::DeclScope,
1252 (getLangOpts().C99 || getLangOpts().CPlusPlus) &&
1253 Tok.isNot(tok::l_brace));
1254
1255 // Read the body statement.
1256 StmtResult Body(ParseStatement());
1257
1258 // Pop the body scope if needed.
1259 InnerScope.Exit();
1260
1261 if (Tok.isNot(tok::kw_while)) {
1262 if (!Body.isInvalid()) {
1263 Diag(Tok, diag::err_expected_while);
1264 Diag(DoLoc, diag::note_matching) << "do";
1265 SkipUntil(tok::semi, false, true);
1266 }
1267 return StmtError();
1268 }
1269 SourceLocation WhileLoc = ConsumeToken();
1270
1271 if (Tok.isNot(tok::l_paren)) {
1272 Diag(Tok, diag::err_expected_lparen_after) << "do/while";
1273 SkipUntil(tok::semi, false, true);
1274 return StmtError();
1275 }
1276
1277 // Parse the parenthesized condition.
1278 BalancedDelimiterTracker T(*this, tok::l_paren);
1279 T.consumeOpen();
1280
1281 // FIXME: Do not just parse the attribute contents and throw them away
1282 ParsedAttributesWithRange attrs(AttrFactory);
1283 MaybeParseCXX11Attributes(attrs);
1284 ProhibitAttributes(attrs);
1285
1286 ExprResult Cond = ParseExpression();
1287 T.consumeClose();
1288 DoScope.Exit();
1289
1290 if (Cond.isInvalid() || Body.isInvalid())
1291 return StmtError();
1292
1293 return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(),
1294 Cond.get(), T.getCloseLocation());
1295 }
1296
1297 /// ParseForStatement
1298 /// for-statement: [C99 6.8.5.3]
1299 /// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement
1300 /// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement
1301 /// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')'
1302 /// [C++] statement
1303 /// [C++0x] 'for' '(' for-range-declaration : for-range-initializer ) statement
1304 /// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
1305 /// [OBJC2] 'for' '(' expr 'in' expr ')' statement
1306 ///
1307 /// [C++] for-init-statement:
1308 /// [C++] expression-statement
1309 /// [C++] simple-declaration
1310 ///
1311 /// [C++0x] for-range-declaration:
1312 /// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator
1313 /// [C++0x] for-range-initializer:
1314 /// [C++0x] expression
1315 /// [C++0x] braced-init-list [TODO]
ParseForStatement(SourceLocation * TrailingElseLoc)1316 StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
1317 assert(Tok.is(tok::kw_for) && "Not a for stmt!");
1318 SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
1319
1320 if (Tok.isNot(tok::l_paren)) {
1321 Diag(Tok, diag::err_expected_lparen_after) << "for";
1322 SkipUntil(tok::semi);
1323 return StmtError();
1324 }
1325
1326 bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus ||
1327 getLangOpts().ObjC1;
1328
1329 // C99 6.8.5p5 - In C99, the for statement is a block. This is not
1330 // the case for C90. Start the loop scope.
1331 //
1332 // C++ 6.4p3:
1333 // A name introduced by a declaration in a condition is in scope from its
1334 // point of declaration until the end of the substatements controlled by the
1335 // condition.
1336 // C++ 3.3.2p4:
1337 // Names declared in the for-init-statement, and in the condition of if,
1338 // while, for, and switch statements are local to the if, while, for, or
1339 // switch statement (including the controlled statement).
1340 // C++ 6.5.3p1:
1341 // Names declared in the for-init-statement are in the same declarative-region
1342 // as those declared in the condition.
1343 //
1344 unsigned ScopeFlags;
1345 if (C99orCXXorObjC)
1346 ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
1347 Scope::DeclScope | Scope::ControlScope;
1348 else
1349 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1350
1351 ParseScope ForScope(this, ScopeFlags);
1352
1353 BalancedDelimiterTracker T(*this, tok::l_paren);
1354 T.consumeOpen();
1355
1356 ExprResult Value;
1357
1358 bool ForEach = false, ForRange = false;
1359 StmtResult FirstPart;
1360 bool SecondPartIsInvalid = false;
1361 FullExprArg SecondPart(Actions);
1362 ExprResult Collection;
1363 ForRangeInit ForRangeInit;
1364 FullExprArg ThirdPart(Actions);
1365 Decl *SecondVar = 0;
1366
1367 if (Tok.is(tok::code_completion)) {
1368 Actions.CodeCompleteOrdinaryName(getCurScope(),
1369 C99orCXXorObjC? Sema::PCC_ForInit
1370 : Sema::PCC_Expression);
1371 cutOffParsing();
1372 return StmtError();
1373 }
1374
1375 ParsedAttributesWithRange attrs(AttrFactory);
1376 MaybeParseCXX11Attributes(attrs);
1377
1378 // Parse the first part of the for specifier.
1379 if (Tok.is(tok::semi)) { // for (;
1380 ProhibitAttributes(attrs);
1381 // no first part, eat the ';'.
1382 ConsumeToken();
1383 } else if (isForInitDeclaration()) { // for (int X = 4;
1384 // Parse declaration, which eats the ';'.
1385 if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode?
1386 Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
1387
1388 // In C++0x, "for (T NS:a" might not be a typo for ::
1389 bool MightBeForRangeStmt = getLangOpts().CPlusPlus;
1390 ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
1391
1392 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1393 StmtVector Stmts;
1394 DeclGroupPtrTy DG = ParseSimpleDeclaration(Stmts, Declarator::ForContext,
1395 DeclEnd, attrs, false,
1396 MightBeForRangeStmt ?
1397 &ForRangeInit : 0);
1398 FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
1399
1400 if (ForRangeInit.ParsedForRangeDecl()) {
1401 Diag(ForRangeInit.ColonLoc, getLangOpts().CPlusPlus11 ?
1402 diag::warn_cxx98_compat_for_range : diag::ext_for_range);
1403
1404 ForRange = true;
1405 } else if (Tok.is(tok::semi)) { // for (int x = 4;
1406 ConsumeToken();
1407 } else if ((ForEach = isTokIdentifier_in())) {
1408 Actions.ActOnForEachDeclStmt(DG);
1409 // ObjC: for (id x in expr)
1410 ConsumeToken(); // consume 'in'
1411
1412 if (Tok.is(tok::code_completion)) {
1413 Actions.CodeCompleteObjCForCollection(getCurScope(), DG);
1414 cutOffParsing();
1415 return StmtError();
1416 }
1417 Collection = ParseExpression();
1418 } else {
1419 Diag(Tok, diag::err_expected_semi_for);
1420 }
1421 } else {
1422 ProhibitAttributes(attrs);
1423 Value = ParseExpression();
1424
1425 ForEach = isTokIdentifier_in();
1426
1427 // Turn the expression into a stmt.
1428 if (!Value.isInvalid()) {
1429 if (ForEach)
1430 FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
1431 else
1432 FirstPart = Actions.ActOnExprStmt(Value);
1433 }
1434
1435 if (Tok.is(tok::semi)) {
1436 ConsumeToken();
1437 } else if (ForEach) {
1438 ConsumeToken(); // consume 'in'
1439
1440 if (Tok.is(tok::code_completion)) {
1441 Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy());
1442 cutOffParsing();
1443 return StmtError();
1444 }
1445 Collection = ParseExpression();
1446 } else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) {
1447 // User tried to write the reasonable, but ill-formed, for-range-statement
1448 // for (expr : expr) { ... }
1449 Diag(Tok, diag::err_for_range_expected_decl)
1450 << FirstPart.get()->getSourceRange();
1451 SkipUntil(tok::r_paren, false, true);
1452 SecondPartIsInvalid = true;
1453 } else {
1454 if (!Value.isInvalid()) {
1455 Diag(Tok, diag::err_expected_semi_for);
1456 } else {
1457 // Skip until semicolon or rparen, don't consume it.
1458 SkipUntil(tok::r_paren, true, true);
1459 if (Tok.is(tok::semi))
1460 ConsumeToken();
1461 }
1462 }
1463 }
1464 if (!ForEach && !ForRange) {
1465 assert(!SecondPart.get() && "Shouldn't have a second expression yet.");
1466 // Parse the second part of the for specifier.
1467 if (Tok.is(tok::semi)) { // for (...;;
1468 // no second part.
1469 } else if (Tok.is(tok::r_paren)) {
1470 // missing both semicolons.
1471 } else {
1472 ExprResult Second;
1473 if (getLangOpts().CPlusPlus)
1474 ParseCXXCondition(Second, SecondVar, ForLoc, true);
1475 else {
1476 Second = ParseExpression();
1477 if (!Second.isInvalid())
1478 Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc,
1479 Second.get());
1480 }
1481 SecondPartIsInvalid = Second.isInvalid();
1482 SecondPart = Actions.MakeFullExpr(Second.get(), ForLoc);
1483 }
1484
1485 if (Tok.isNot(tok::semi)) {
1486 if (!SecondPartIsInvalid || SecondVar)
1487 Diag(Tok, diag::err_expected_semi_for);
1488 else
1489 // Skip until semicolon or rparen, don't consume it.
1490 SkipUntil(tok::r_paren, true, true);
1491 }
1492
1493 if (Tok.is(tok::semi)) {
1494 ConsumeToken();
1495 }
1496
1497 // Parse the third part of the for specifier.
1498 if (Tok.isNot(tok::r_paren)) { // for (...;...;)
1499 ExprResult Third = ParseExpression();
1500 // FIXME: The C++11 standard doesn't actually say that this is a
1501 // discarded-value expression, but it clearly should be.
1502 ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.take());
1503 }
1504 }
1505 // Match the ')'.
1506 T.consumeClose();
1507
1508 // We need to perform most of the semantic analysis for a C++0x for-range
1509 // statememt before parsing the body, in order to be able to deduce the type
1510 // of an auto-typed loop variable.
1511 StmtResult ForRangeStmt;
1512 StmtResult ForEachStmt;
1513
1514 if (ForRange) {
1515 ForRangeStmt = Actions.ActOnCXXForRangeStmt(ForLoc, FirstPart.take(),
1516 ForRangeInit.ColonLoc,
1517 ForRangeInit.RangeExpr.get(),
1518 T.getCloseLocation(),
1519 Sema::BFRK_Build);
1520
1521
1522 // Similarly, we need to do the semantic analysis for a for-range
1523 // statement immediately in order to close over temporaries correctly.
1524 } else if (ForEach) {
1525 ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc,
1526 FirstPart.take(),
1527 Collection.take(),
1528 T.getCloseLocation());
1529 }
1530
1531 // C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
1532 // there is no compound stmt. C90 does not have this clause. We only do this
1533 // if the body isn't a compound statement to avoid push/pop in common cases.
1534 //
1535 // C++ 6.5p2:
1536 // The substatement in an iteration-statement implicitly defines a local scope
1537 // which is entered and exited each time through the loop.
1538 //
1539 // See comments in ParseIfStatement for why we create a scope for
1540 // for-init-statement/condition and a new scope for substatement in C++.
1541 //
1542 ParseScope InnerScope(this, Scope::DeclScope,
1543 C99orCXXorObjC && Tok.isNot(tok::l_brace));
1544
1545 // Read the body statement.
1546 StmtResult Body(ParseStatement(TrailingElseLoc));
1547
1548 // Pop the body scope if needed.
1549 InnerScope.Exit();
1550
1551 // Leave the for-scope.
1552 ForScope.Exit();
1553
1554 if (Body.isInvalid())
1555 return StmtError();
1556
1557 if (ForEach)
1558 return Actions.FinishObjCForCollectionStmt(ForEachStmt.take(),
1559 Body.take());
1560
1561 if (ForRange)
1562 return Actions.FinishCXXForRangeStmt(ForRangeStmt.take(), Body.take());
1563
1564 return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.take(),
1565 SecondPart, SecondVar, ThirdPart,
1566 T.getCloseLocation(), Body.take());
1567 }
1568
1569 /// ParseGotoStatement
1570 /// jump-statement:
1571 /// 'goto' identifier ';'
1572 /// [GNU] 'goto' '*' expression ';'
1573 ///
1574 /// Note: this lets the caller parse the end ';'.
1575 ///
ParseGotoStatement()1576 StmtResult Parser::ParseGotoStatement() {
1577 assert(Tok.is(tok::kw_goto) && "Not a goto stmt!");
1578 SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'.
1579
1580 StmtResult Res;
1581 if (Tok.is(tok::identifier)) {
1582 LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
1583 Tok.getLocation());
1584 Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD);
1585 ConsumeToken();
1586 } else if (Tok.is(tok::star)) {
1587 // GNU indirect goto extension.
1588 Diag(Tok, diag::ext_gnu_indirect_goto);
1589 SourceLocation StarLoc = ConsumeToken();
1590 ExprResult R(ParseExpression());
1591 if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
1592 SkipUntil(tok::semi, false, true);
1593 return StmtError();
1594 }
1595 Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.take());
1596 } else {
1597 Diag(Tok, diag::err_expected_ident);
1598 return StmtError();
1599 }
1600
1601 return Res;
1602 }
1603
1604 /// ParseContinueStatement
1605 /// jump-statement:
1606 /// 'continue' ';'
1607 ///
1608 /// Note: this lets the caller parse the end ';'.
1609 ///
ParseContinueStatement()1610 StmtResult Parser::ParseContinueStatement() {
1611 SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'.
1612 return Actions.ActOnContinueStmt(ContinueLoc, getCurScope());
1613 }
1614
1615 /// ParseBreakStatement
1616 /// jump-statement:
1617 /// 'break' ';'
1618 ///
1619 /// Note: this lets the caller parse the end ';'.
1620 ///
ParseBreakStatement()1621 StmtResult Parser::ParseBreakStatement() {
1622 SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
1623 return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
1624 }
1625
1626 /// ParseReturnStatement
1627 /// jump-statement:
1628 /// 'return' expression[opt] ';'
ParseReturnStatement()1629 StmtResult Parser::ParseReturnStatement() {
1630 assert(Tok.is(tok::kw_return) && "Not a return stmt!");
1631 SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
1632
1633 ExprResult R;
1634 if (Tok.isNot(tok::semi)) {
1635 if (Tok.is(tok::code_completion)) {
1636 Actions.CodeCompleteReturn(getCurScope());
1637 cutOffParsing();
1638 return StmtError();
1639 }
1640
1641 if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) {
1642 R = ParseInitializer();
1643 if (R.isUsable())
1644 Diag(R.get()->getLocStart(), getLangOpts().CPlusPlus11 ?
1645 diag::warn_cxx98_compat_generalized_initializer_lists :
1646 diag::ext_generalized_initializer_lists)
1647 << R.get()->getSourceRange();
1648 } else
1649 R = ParseExpression();
1650 if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
1651 SkipUntil(tok::semi, false, true);
1652 return StmtError();
1653 }
1654 }
1655 return Actions.ActOnReturnStmt(ReturnLoc, R.take());
1656 }
1657
1658 /// ParseMicrosoftAsmStatement. When -fms-extensions/-fasm-blocks is enabled,
1659 /// this routine is called to collect the tokens for an MS asm statement.
1660 ///
1661 /// [MS] ms-asm-statement:
1662 /// ms-asm-block
1663 /// ms-asm-block ms-asm-statement
1664 ///
1665 /// [MS] ms-asm-block:
1666 /// '__asm' ms-asm-line '\n'
1667 /// '__asm' '{' ms-asm-instruction-block[opt] '}' ';'[opt]
1668 ///
1669 /// [MS] ms-asm-instruction-block
1670 /// ms-asm-line
1671 /// ms-asm-line '\n' ms-asm-instruction-block
1672 ///
ParseMicrosoftAsmStatement(SourceLocation AsmLoc)1673 StmtResult Parser::ParseMicrosoftAsmStatement(SourceLocation AsmLoc) {
1674 SourceManager &SrcMgr = PP.getSourceManager();
1675 SourceLocation EndLoc = AsmLoc;
1676 SmallVector<Token, 4> AsmToks;
1677
1678 bool InBraces = false;
1679 unsigned short savedBraceCount = 0;
1680 bool InAsmComment = false;
1681 FileID FID;
1682 unsigned LineNo = 0;
1683 unsigned NumTokensRead = 0;
1684 SourceLocation LBraceLoc;
1685
1686 if (Tok.is(tok::l_brace)) {
1687 // Braced inline asm: consume the opening brace.
1688 InBraces = true;
1689 savedBraceCount = BraceCount;
1690 EndLoc = LBraceLoc = ConsumeBrace();
1691 ++NumTokensRead;
1692 } else {
1693 // Single-line inline asm; compute which line it is on.
1694 std::pair<FileID, unsigned> ExpAsmLoc =
1695 SrcMgr.getDecomposedExpansionLoc(EndLoc);
1696 FID = ExpAsmLoc.first;
1697 LineNo = SrcMgr.getLineNumber(FID, ExpAsmLoc.second);
1698 }
1699
1700 SourceLocation TokLoc = Tok.getLocation();
1701 do {
1702 // If we hit EOF, we're done, period.
1703 if (Tok.is(tok::eof))
1704 break;
1705
1706 if (!InAsmComment && Tok.is(tok::semi)) {
1707 // A semicolon in an asm is the start of a comment.
1708 InAsmComment = true;
1709 if (InBraces) {
1710 // Compute which line the comment is on.
1711 std::pair<FileID, unsigned> ExpSemiLoc =
1712 SrcMgr.getDecomposedExpansionLoc(TokLoc);
1713 FID = ExpSemiLoc.first;
1714 LineNo = SrcMgr.getLineNumber(FID, ExpSemiLoc.second);
1715 }
1716 } else if (!InBraces || InAsmComment) {
1717 // If end-of-line is significant, check whether this token is on a
1718 // new line.
1719 std::pair<FileID, unsigned> ExpLoc =
1720 SrcMgr.getDecomposedExpansionLoc(TokLoc);
1721 if (ExpLoc.first != FID ||
1722 SrcMgr.getLineNumber(ExpLoc.first, ExpLoc.second) != LineNo) {
1723 // If this is a single-line __asm, we're done.
1724 if (!InBraces)
1725 break;
1726 // We're no longer in a comment.
1727 InAsmComment = false;
1728 } else if (!InAsmComment && Tok.is(tok::r_brace)) {
1729 // Single-line asm always ends when a closing brace is seen.
1730 // FIXME: This is compatible with Apple gcc's -fasm-blocks; what
1731 // does MSVC do here?
1732 break;
1733 }
1734 }
1735 if (!InAsmComment && InBraces && Tok.is(tok::r_brace) &&
1736 BraceCount == (savedBraceCount + 1)) {
1737 // Consume the closing brace, and finish
1738 EndLoc = ConsumeBrace();
1739 break;
1740 }
1741
1742 // Consume the next token; make sure we don't modify the brace count etc.
1743 // if we are in a comment.
1744 EndLoc = TokLoc;
1745 if (InAsmComment)
1746 PP.Lex(Tok);
1747 else {
1748 AsmToks.push_back(Tok);
1749 ConsumeAnyToken();
1750 }
1751 TokLoc = Tok.getLocation();
1752 ++NumTokensRead;
1753 } while (1);
1754
1755 if (InBraces && BraceCount != savedBraceCount) {
1756 // __asm without closing brace (this can happen at EOF).
1757 Diag(Tok, diag::err_expected_rbrace);
1758 Diag(LBraceLoc, diag::note_matching) << "{";
1759 return StmtError();
1760 } else if (NumTokensRead == 0) {
1761 // Empty __asm.
1762 Diag(Tok, diag::err_expected_lbrace);
1763 return StmtError();
1764 }
1765
1766 // FIXME: We should be passing source locations for better diagnostics.
1767 return Actions.ActOnMSAsmStmt(AsmLoc, LBraceLoc,
1768 llvm::makeArrayRef(AsmToks), EndLoc);
1769 }
1770
1771 /// ParseAsmStatement - Parse a GNU extended asm statement.
1772 /// asm-statement:
1773 /// gnu-asm-statement
1774 /// ms-asm-statement
1775 ///
1776 /// [GNU] gnu-asm-statement:
1777 /// 'asm' type-qualifier[opt] '(' asm-argument ')' ';'
1778 ///
1779 /// [GNU] asm-argument:
1780 /// asm-string-literal
1781 /// asm-string-literal ':' asm-operands[opt]
1782 /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
1783 /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
1784 /// ':' asm-clobbers
1785 ///
1786 /// [GNU] asm-clobbers:
1787 /// asm-string-literal
1788 /// asm-clobbers ',' asm-string-literal
1789 ///
ParseAsmStatement(bool & msAsm)1790 StmtResult Parser::ParseAsmStatement(bool &msAsm) {
1791 assert(Tok.is(tok::kw_asm) && "Not an asm stmt");
1792 SourceLocation AsmLoc = ConsumeToken();
1793
1794 if (getLangOpts().AsmBlocks && Tok.isNot(tok::l_paren) &&
1795 !isTypeQualifier()) {
1796 msAsm = true;
1797 return ParseMicrosoftAsmStatement(AsmLoc);
1798 }
1799 DeclSpec DS(AttrFactory);
1800 SourceLocation Loc = Tok.getLocation();
1801 ParseTypeQualifierListOpt(DS, true, false);
1802
1803 // GNU asms accept, but warn, about type-qualifiers other than volatile.
1804 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
1805 Diag(Loc, diag::w_asm_qualifier_ignored) << "const";
1806 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
1807 Diag(Loc, diag::w_asm_qualifier_ignored) << "restrict";
1808
1809 // Remember if this was a volatile asm.
1810 bool isVolatile = DS.getTypeQualifiers() & DeclSpec::TQ_volatile;
1811 if (Tok.isNot(tok::l_paren)) {
1812 Diag(Tok, diag::err_expected_lparen_after) << "asm";
1813 SkipUntil(tok::r_paren);
1814 return StmtError();
1815 }
1816 BalancedDelimiterTracker T(*this, tok::l_paren);
1817 T.consumeOpen();
1818
1819 ExprResult AsmString(ParseAsmStringLiteral());
1820 if (AsmString.isInvalid()) {
1821 // Consume up to and including the closing paren.
1822 T.skipToEnd();
1823 return StmtError();
1824 }
1825
1826 SmallVector<IdentifierInfo *, 4> Names;
1827 ExprVector Constraints;
1828 ExprVector Exprs;
1829 ExprVector Clobbers;
1830
1831 if (Tok.is(tok::r_paren)) {
1832 // We have a simple asm expression like 'asm("foo")'.
1833 T.consumeClose();
1834 return Actions.ActOnGCCAsmStmt(AsmLoc, /*isSimple*/ true, isVolatile,
1835 /*NumOutputs*/ 0, /*NumInputs*/ 0, 0,
1836 Constraints, Exprs, AsmString.take(),
1837 Clobbers, T.getCloseLocation());
1838 }
1839
1840 // Parse Outputs, if present.
1841 bool AteExtraColon = false;
1842 if (Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
1843 // In C++ mode, parse "::" like ": :".
1844 AteExtraColon = Tok.is(tok::coloncolon);
1845 ConsumeToken();
1846
1847 if (!AteExtraColon &&
1848 ParseAsmOperandsOpt(Names, Constraints, Exprs))
1849 return StmtError();
1850 }
1851
1852 unsigned NumOutputs = Names.size();
1853
1854 // Parse Inputs, if present.
1855 if (AteExtraColon ||
1856 Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
1857 // In C++ mode, parse "::" like ": :".
1858 if (AteExtraColon)
1859 AteExtraColon = false;
1860 else {
1861 AteExtraColon = Tok.is(tok::coloncolon);
1862 ConsumeToken();
1863 }
1864
1865 if (!AteExtraColon &&
1866 ParseAsmOperandsOpt(Names, Constraints, Exprs))
1867 return StmtError();
1868 }
1869
1870 assert(Names.size() == Constraints.size() &&
1871 Constraints.size() == Exprs.size() &&
1872 "Input operand size mismatch!");
1873
1874 unsigned NumInputs = Names.size() - NumOutputs;
1875
1876 // Parse the clobbers, if present.
1877 if (AteExtraColon || Tok.is(tok::colon)) {
1878 if (!AteExtraColon)
1879 ConsumeToken();
1880
1881 // Parse the asm-string list for clobbers if present.
1882 if (Tok.isNot(tok::r_paren)) {
1883 while (1) {
1884 ExprResult Clobber(ParseAsmStringLiteral());
1885
1886 if (Clobber.isInvalid())
1887 break;
1888
1889 Clobbers.push_back(Clobber.release());
1890
1891 if (Tok.isNot(tok::comma)) break;
1892 ConsumeToken();
1893 }
1894 }
1895 }
1896
1897 T.consumeClose();
1898 return Actions.ActOnGCCAsmStmt(AsmLoc, false, isVolatile, NumOutputs,
1899 NumInputs, Names.data(), Constraints, Exprs,
1900 AsmString.take(), Clobbers,
1901 T.getCloseLocation());
1902 }
1903
1904 /// ParseAsmOperands - Parse the asm-operands production as used by
1905 /// asm-statement, assuming the leading ':' token was eaten.
1906 ///
1907 /// [GNU] asm-operands:
1908 /// asm-operand
1909 /// asm-operands ',' asm-operand
1910 ///
1911 /// [GNU] asm-operand:
1912 /// asm-string-literal '(' expression ')'
1913 /// '[' identifier ']' asm-string-literal '(' expression ')'
1914 ///
1915 //
1916 // FIXME: Avoid unnecessary std::string trashing.
ParseAsmOperandsOpt(SmallVectorImpl<IdentifierInfo * > & Names,SmallVectorImpl<Expr * > & Constraints,SmallVectorImpl<Expr * > & Exprs)1917 bool Parser::ParseAsmOperandsOpt(SmallVectorImpl<IdentifierInfo *> &Names,
1918 SmallVectorImpl<Expr *> &Constraints,
1919 SmallVectorImpl<Expr *> &Exprs) {
1920 // 'asm-operands' isn't present?
1921 if (!isTokenStringLiteral() && Tok.isNot(tok::l_square))
1922 return false;
1923
1924 while (1) {
1925 // Read the [id] if present.
1926 if (Tok.is(tok::l_square)) {
1927 BalancedDelimiterTracker T(*this, tok::l_square);
1928 T.consumeOpen();
1929
1930 if (Tok.isNot(tok::identifier)) {
1931 Diag(Tok, diag::err_expected_ident);
1932 SkipUntil(tok::r_paren);
1933 return true;
1934 }
1935
1936 IdentifierInfo *II = Tok.getIdentifierInfo();
1937 ConsumeToken();
1938
1939 Names.push_back(II);
1940 T.consumeClose();
1941 } else
1942 Names.push_back(0);
1943
1944 ExprResult Constraint(ParseAsmStringLiteral());
1945 if (Constraint.isInvalid()) {
1946 SkipUntil(tok::r_paren);
1947 return true;
1948 }
1949 Constraints.push_back(Constraint.release());
1950
1951 if (Tok.isNot(tok::l_paren)) {
1952 Diag(Tok, diag::err_expected_lparen_after) << "asm operand";
1953 SkipUntil(tok::r_paren);
1954 return true;
1955 }
1956
1957 // Read the parenthesized expression.
1958 BalancedDelimiterTracker T(*this, tok::l_paren);
1959 T.consumeOpen();
1960 ExprResult Res(ParseExpression());
1961 T.consumeClose();
1962 if (Res.isInvalid()) {
1963 SkipUntil(tok::r_paren);
1964 return true;
1965 }
1966 Exprs.push_back(Res.release());
1967 // Eat the comma and continue parsing if it exists.
1968 if (Tok.isNot(tok::comma)) return false;
1969 ConsumeToken();
1970 }
1971 }
1972
ParseFunctionStatementBody(Decl * Decl,ParseScope & BodyScope)1973 Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
1974 assert(Tok.is(tok::l_brace));
1975 SourceLocation LBraceLoc = Tok.getLocation();
1976
1977 if (SkipFunctionBodies && (!Decl || Actions.canSkipFunctionBody(Decl)) &&
1978 trySkippingFunctionBody()) {
1979 BodyScope.Exit();
1980 return Actions.ActOnSkippedFunctionBody(Decl);
1981 }
1982
1983 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc,
1984 "parsing function body");
1985
1986 // Do not enter a scope for the brace, as the arguments are in the same scope
1987 // (the function body) as the body itself. Instead, just read the statement
1988 // list and put it into a CompoundStmt for safe keeping.
1989 StmtResult FnBody(ParseCompoundStatementBody());
1990
1991 // If the function body could not be parsed, make a bogus compoundstmt.
1992 if (FnBody.isInvalid()) {
1993 Sema::CompoundScopeRAII CompoundScope(Actions);
1994 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc,
1995 MultiStmtArg(), false);
1996 }
1997
1998 BodyScope.Exit();
1999 return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
2000 }
2001
2002 /// ParseFunctionTryBlock - Parse a C++ function-try-block.
2003 ///
2004 /// function-try-block:
2005 /// 'try' ctor-initializer[opt] compound-statement handler-seq
2006 ///
ParseFunctionTryBlock(Decl * Decl,ParseScope & BodyScope)2007 Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
2008 assert(Tok.is(tok::kw_try) && "Expected 'try'");
2009 SourceLocation TryLoc = ConsumeToken();
2010
2011 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc,
2012 "parsing function try block");
2013
2014 // Constructor initializer list?
2015 if (Tok.is(tok::colon))
2016 ParseConstructorInitializer(Decl);
2017 else
2018 Actions.ActOnDefaultCtorInitializers(Decl);
2019
2020 if (SkipFunctionBodies && Actions.canSkipFunctionBody(Decl) &&
2021 trySkippingFunctionBody()) {
2022 BodyScope.Exit();
2023 return Actions.ActOnSkippedFunctionBody(Decl);
2024 }
2025
2026 SourceLocation LBraceLoc = Tok.getLocation();
2027 StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));
2028 // If we failed to parse the try-catch, we just give the function an empty
2029 // compound statement as the body.
2030 if (FnBody.isInvalid()) {
2031 Sema::CompoundScopeRAII CompoundScope(Actions);
2032 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc,
2033 MultiStmtArg(), false);
2034 }
2035
2036 BodyScope.Exit();
2037 return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
2038 }
2039
trySkippingFunctionBody()2040 bool Parser::trySkippingFunctionBody() {
2041 assert(Tok.is(tok::l_brace));
2042 assert(SkipFunctionBodies &&
2043 "Should only be called when SkipFunctionBodies is enabled");
2044
2045 if (!PP.isCodeCompletionEnabled()) {
2046 ConsumeBrace();
2047 SkipUntil(tok::r_brace, /*StopAtSemi=*/false, /*DontConsume=*/false);
2048 return true;
2049 }
2050
2051 // We're in code-completion mode. Skip parsing for all function bodies unless
2052 // the body contains the code-completion point.
2053 TentativeParsingAction PA(*this);
2054 ConsumeBrace();
2055 if (SkipUntil(tok::r_brace, /*StopAtSemi=*/false, /*DontConsume=*/false,
2056 /*StopAtCodeCompletion=*/true)) {
2057 PA.Commit();
2058 return true;
2059 }
2060
2061 PA.Revert();
2062 return false;
2063 }
2064
2065 /// ParseCXXTryBlock - Parse a C++ try-block.
2066 ///
2067 /// try-block:
2068 /// 'try' compound-statement handler-seq
2069 ///
ParseCXXTryBlock()2070 StmtResult Parser::ParseCXXTryBlock() {
2071 assert(Tok.is(tok::kw_try) && "Expected 'try'");
2072
2073 SourceLocation TryLoc = ConsumeToken();
2074 return ParseCXXTryBlockCommon(TryLoc);
2075 }
2076
2077 /// ParseCXXTryBlockCommon - Parse the common part of try-block and
2078 /// function-try-block.
2079 ///
2080 /// try-block:
2081 /// 'try' compound-statement handler-seq
2082 ///
2083 /// function-try-block:
2084 /// 'try' ctor-initializer[opt] compound-statement handler-seq
2085 ///
2086 /// handler-seq:
2087 /// handler handler-seq[opt]
2088 ///
2089 /// [Borland] try-block:
2090 /// 'try' compound-statement seh-except-block
2091 /// 'try' compound-statment seh-finally-block
2092 ///
ParseCXXTryBlockCommon(SourceLocation TryLoc,bool FnTry)2093 StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
2094 if (Tok.isNot(tok::l_brace))
2095 return StmtError(Diag(Tok, diag::err_expected_lbrace));
2096 // FIXME: Possible draft standard bug: attribute-specifier should be allowed?
2097
2098 StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false,
2099 Scope::DeclScope | Scope::TryScope |
2100 (FnTry ? Scope::FnTryCatchScope : 0)));
2101 if (TryBlock.isInvalid())
2102 return TryBlock;
2103
2104 // Borland allows SEH-handlers with 'try'
2105
2106 if ((Tok.is(tok::identifier) &&
2107 Tok.getIdentifierInfo() == getSEHExceptKeyword()) ||
2108 Tok.is(tok::kw___finally)) {
2109 // TODO: Factor into common return ParseSEHHandlerCommon(...)
2110 StmtResult Handler;
2111 if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
2112 SourceLocation Loc = ConsumeToken();
2113 Handler = ParseSEHExceptBlock(Loc);
2114 }
2115 else {
2116 SourceLocation Loc = ConsumeToken();
2117 Handler = ParseSEHFinallyBlock(Loc);
2118 }
2119 if(Handler.isInvalid())
2120 return Handler;
2121
2122 return Actions.ActOnSEHTryBlock(true /* IsCXXTry */,
2123 TryLoc,
2124 TryBlock.take(),
2125 Handler.take());
2126 }
2127 else {
2128 StmtVector Handlers;
2129 ParsedAttributesWithRange attrs(AttrFactory);
2130 MaybeParseCXX11Attributes(attrs);
2131 ProhibitAttributes(attrs);
2132
2133 if (Tok.isNot(tok::kw_catch))
2134 return StmtError(Diag(Tok, diag::err_expected_catch));
2135 while (Tok.is(tok::kw_catch)) {
2136 StmtResult Handler(ParseCXXCatchBlock(FnTry));
2137 if (!Handler.isInvalid())
2138 Handlers.push_back(Handler.release());
2139 }
2140 // Don't bother creating the full statement if we don't have any usable
2141 // handlers.
2142 if (Handlers.empty())
2143 return StmtError();
2144
2145 return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.take(),Handlers);
2146 }
2147 }
2148
2149 /// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
2150 ///
2151 /// handler:
2152 /// 'catch' '(' exception-declaration ')' compound-statement
2153 ///
2154 /// exception-declaration:
2155 /// attribute-specifier-seq[opt] type-specifier-seq declarator
2156 /// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt]
2157 /// '...'
2158 ///
ParseCXXCatchBlock(bool FnCatch)2159 StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
2160 assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
2161
2162 SourceLocation CatchLoc = ConsumeToken();
2163
2164 BalancedDelimiterTracker T(*this, tok::l_paren);
2165 if (T.expectAndConsume(diag::err_expected_lparen))
2166 return StmtError();
2167
2168 // C++ 3.3.2p3:
2169 // The name in a catch exception-declaration is local to the handler and
2170 // shall not be redeclared in the outermost block of the handler.
2171 ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope |
2172 (FnCatch ? Scope::FnTryCatchScope : 0));
2173
2174 // exception-declaration is equivalent to '...' or a parameter-declaration
2175 // without default arguments.
2176 Decl *ExceptionDecl = 0;
2177 if (Tok.isNot(tok::ellipsis)) {
2178 ParsedAttributesWithRange Attributes(AttrFactory);
2179 MaybeParseCXX11Attributes(Attributes);
2180
2181 DeclSpec DS(AttrFactory);
2182 DS.takeAttributesFrom(Attributes);
2183
2184 if (ParseCXXTypeSpecifierSeq(DS))
2185 return StmtError();
2186
2187 Declarator ExDecl(DS, Declarator::CXXCatchContext);
2188 ParseDeclarator(ExDecl);
2189 ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
2190 } else
2191 ConsumeToken();
2192
2193 T.consumeClose();
2194 if (T.getCloseLocation().isInvalid())
2195 return StmtError();
2196
2197 if (Tok.isNot(tok::l_brace))
2198 return StmtError(Diag(Tok, diag::err_expected_lbrace));
2199
2200 // FIXME: Possible draft standard bug: attribute-specifier should be allowed?
2201 StmtResult Block(ParseCompoundStatement());
2202 if (Block.isInvalid())
2203 return Block;
2204
2205 return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.take());
2206 }
2207
ParseMicrosoftIfExistsStatement(StmtVector & Stmts)2208 void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
2209 IfExistsCondition Result;
2210 if (ParseMicrosoftIfExistsCondition(Result))
2211 return;
2212
2213 // Handle dependent statements by parsing the braces as a compound statement.
2214 // This is not the same behavior as Visual C++, which don't treat this as a
2215 // compound statement, but for Clang's type checking we can't have anything
2216 // inside these braces escaping to the surrounding code.
2217 if (Result.Behavior == IEB_Dependent) {
2218 if (!Tok.is(tok::l_brace)) {
2219 Diag(Tok, diag::err_expected_lbrace);
2220 return;
2221 }
2222
2223 StmtResult Compound = ParseCompoundStatement();
2224 if (Compound.isInvalid())
2225 return;
2226
2227 StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc,
2228 Result.IsIfExists,
2229 Result.SS,
2230 Result.Name,
2231 Compound.get());
2232 if (DepResult.isUsable())
2233 Stmts.push_back(DepResult.get());
2234 return;
2235 }
2236
2237 BalancedDelimiterTracker Braces(*this, tok::l_brace);
2238 if (Braces.consumeOpen()) {
2239 Diag(Tok, diag::err_expected_lbrace);
2240 return;
2241 }
2242
2243 switch (Result.Behavior) {
2244 case IEB_Parse:
2245 // Parse the statements below.
2246 break;
2247
2248 case IEB_Dependent:
2249 llvm_unreachable("Dependent case handled above");
2250
2251 case IEB_Skip:
2252 Braces.skipToEnd();
2253 return;
2254 }
2255
2256 // Condition is true, parse the statements.
2257 while (Tok.isNot(tok::r_brace)) {
2258 StmtResult R = ParseStatementOrDeclaration(Stmts, false);
2259 if (R.isUsable())
2260 Stmts.push_back(R.release());
2261 }
2262 Braces.consumeClose();
2263 }
2264