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 StatementFilterCCC Validator(Next);
189 if (TryAnnotateName(/*IsAddressOfOperand*/false, &Validator)
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(Stmts, 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();
349
350 case tok::annot_pragma_ms_pointers_to_members:
351 ProhibitAttributes(Attrs);
352 HandlePragmaMSPointersToMembers();
353 return StmtEmpty();
354
355 case tok::annot_pragma_ms_pragma:
356 ProhibitAttributes(Attrs);
357 HandlePragmaMSPragma();
358 return StmtEmpty();
359
360 case tok::annot_pragma_loop_hint:
361 ProhibitAttributes(Attrs);
362 return ParsePragmaLoopHint(Stmts, OnlyStatement, TrailingElseLoc, Attrs);
363 }
364
365 // If we reached this code, the statement must end in a semicolon.
366 if (!TryConsumeToken(tok::semi) && !Res.isInvalid()) {
367 // If the result was valid, then we do want to diagnose this. Use
368 // ExpectAndConsume to emit the diagnostic, even though we know it won't
369 // succeed.
370 ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError);
371 // Skip until we see a } or ;, but don't eat it.
372 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
373 }
374
375 return Res;
376 }
377
378 /// \brief Parse an expression statement.
ParseExprStatement()379 StmtResult Parser::ParseExprStatement() {
380 // If a case keyword is missing, this is where it should be inserted.
381 Token OldToken = Tok;
382
383 // expression[opt] ';'
384 ExprResult Expr(ParseExpression());
385 if (Expr.isInvalid()) {
386 // If the expression is invalid, skip ahead to the next semicolon or '}'.
387 // Not doing this opens us up to the possibility of infinite loops if
388 // ParseExpression does not consume any tokens.
389 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
390 if (Tok.is(tok::semi))
391 ConsumeToken();
392 return Actions.ActOnExprStmtError();
393 }
394
395 if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() &&
396 Actions.CheckCaseExpression(Expr.get())) {
397 // If a constant expression is followed by a colon inside a switch block,
398 // suggest a missing case keyword.
399 Diag(OldToken, diag::err_expected_case_before_expression)
400 << FixItHint::CreateInsertion(OldToken.getLocation(), "case ");
401
402 // Recover parsing as a case statement.
403 return ParseCaseStatement(/*MissingCase=*/true, Expr);
404 }
405
406 // Otherwise, eat the semicolon.
407 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
408 return Actions.ActOnExprStmt(Expr);
409 }
410
ParseSEHTryBlock()411 StmtResult Parser::ParseSEHTryBlock() {
412 assert(Tok.is(tok::kw___try) && "Expected '__try'");
413 SourceLocation Loc = ConsumeToken();
414 return ParseSEHTryBlockCommon(Loc);
415 }
416
417 /// ParseSEHTryBlockCommon
418 ///
419 /// seh-try-block:
420 /// '__try' compound-statement seh-handler
421 ///
422 /// seh-handler:
423 /// seh-except-block
424 /// seh-finally-block
425 ///
ParseSEHTryBlockCommon(SourceLocation TryLoc)426 StmtResult Parser::ParseSEHTryBlockCommon(SourceLocation TryLoc) {
427 if(Tok.isNot(tok::l_brace))
428 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
429
430 StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false,
431 Scope::DeclScope | Scope::SEHTryScope));
432 if(TryBlock.isInvalid())
433 return TryBlock;
434
435 StmtResult Handler;
436 if (Tok.is(tok::identifier) &&
437 Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
438 SourceLocation Loc = ConsumeToken();
439 Handler = ParseSEHExceptBlock(Loc);
440 } else if (Tok.is(tok::kw___finally)) {
441 SourceLocation Loc = ConsumeToken();
442 Handler = ParseSEHFinallyBlock(Loc);
443 } else {
444 return StmtError(Diag(Tok,diag::err_seh_expected_handler));
445 }
446
447 if(Handler.isInvalid())
448 return Handler;
449
450 return Actions.ActOnSEHTryBlock(false /* IsCXXTry */,
451 TryLoc,
452 TryBlock.get(),
453 Handler.get());
454 }
455
456 /// ParseSEHExceptBlock - Handle __except
457 ///
458 /// seh-except-block:
459 /// '__except' '(' seh-filter-expression ')' compound-statement
460 ///
ParseSEHExceptBlock(SourceLocation ExceptLoc)461 StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
462 PoisonIdentifierRAIIObject raii(Ident__exception_code, false),
463 raii2(Ident___exception_code, false),
464 raii3(Ident_GetExceptionCode, false);
465
466 if (ExpectAndConsume(tok::l_paren))
467 return StmtError();
468
469 ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope);
470
471 if (getLangOpts().Borland) {
472 Ident__exception_info->setIsPoisoned(false);
473 Ident___exception_info->setIsPoisoned(false);
474 Ident_GetExceptionInfo->setIsPoisoned(false);
475 }
476 ExprResult FilterExpr(ParseExpression());
477
478 if (getLangOpts().Borland) {
479 Ident__exception_info->setIsPoisoned(true);
480 Ident___exception_info->setIsPoisoned(true);
481 Ident_GetExceptionInfo->setIsPoisoned(true);
482 }
483
484 if(FilterExpr.isInvalid())
485 return StmtError();
486
487 if (ExpectAndConsume(tok::r_paren))
488 return StmtError();
489
490 StmtResult Block(ParseCompoundStatement());
491
492 if(Block.isInvalid())
493 return Block;
494
495 return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.get(), Block.get());
496 }
497
498 /// ParseSEHFinallyBlock - Handle __finally
499 ///
500 /// seh-finally-block:
501 /// '__finally' compound-statement
502 ///
ParseSEHFinallyBlock(SourceLocation FinallyBlock)503 StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyBlock) {
504 PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false),
505 raii2(Ident___abnormal_termination, false),
506 raii3(Ident_AbnormalTermination, false);
507
508 StmtResult Block(ParseCompoundStatement());
509 if(Block.isInvalid())
510 return Block;
511
512 return Actions.ActOnSEHFinallyBlock(FinallyBlock,Block.get());
513 }
514
515 /// Handle __leave
516 ///
517 /// seh-leave-statement:
518 /// '__leave' ';'
519 ///
ParseSEHLeaveStatement()520 StmtResult Parser::ParseSEHLeaveStatement() {
521 SourceLocation LeaveLoc = ConsumeToken(); // eat the '__leave'.
522 return Actions.ActOnSEHLeaveStmt(LeaveLoc, getCurScope());
523 }
524
525 /// ParseLabeledStatement - We have an identifier and a ':' after it.
526 ///
527 /// labeled-statement:
528 /// identifier ':' statement
529 /// [GNU] identifier ':' attributes[opt] statement
530 ///
ParseLabeledStatement(ParsedAttributesWithRange & attrs)531 StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs) {
532 assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
533 "Not an identifier!");
534
535 Token IdentTok = Tok; // Save the whole token.
536 ConsumeToken(); // eat the identifier.
537
538 assert(Tok.is(tok::colon) && "Not a label!");
539
540 // identifier ':' statement
541 SourceLocation ColonLoc = ConsumeToken();
542
543 // Read label attributes, if present.
544 StmtResult SubStmt;
545 if (Tok.is(tok::kw___attribute)) {
546 ParsedAttributesWithRange TempAttrs(AttrFactory);
547 ParseGNUAttributes(TempAttrs);
548
549 // In C++, GNU attributes only apply to the label if they are followed by a
550 // semicolon, to disambiguate label attributes from attributes on a labeled
551 // declaration.
552 //
553 // This doesn't quite match what GCC does; if the attribute list is empty
554 // and followed by a semicolon, GCC will reject (it appears to parse the
555 // attributes as part of a statement in that case). That looks like a bug.
556 if (!getLangOpts().CPlusPlus || Tok.is(tok::semi))
557 attrs.takeAllFrom(TempAttrs);
558 else if (isDeclarationStatement()) {
559 StmtVector Stmts;
560 // FIXME: We should do this whether or not we have a declaration
561 // statement, but that doesn't work correctly (because ProhibitAttributes
562 // can't handle GNU attributes), so only call it in the one case where
563 // GNU attributes are allowed.
564 SubStmt = ParseStatementOrDeclarationAfterAttributes(
565 Stmts, /*OnlyStmts*/ true, nullptr, TempAttrs);
566 if (!TempAttrs.empty() && !SubStmt.isInvalid())
567 SubStmt = Actions.ProcessStmtAttributes(
568 SubStmt.get(), TempAttrs.getList(), TempAttrs.Range);
569 } else {
570 Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi;
571 }
572 }
573
574 // If we've not parsed a statement yet, parse one now.
575 if (!SubStmt.isInvalid() && !SubStmt.isUsable())
576 SubStmt = ParseStatement();
577
578 // Broken substmt shouldn't prevent the label from being added to the AST.
579 if (SubStmt.isInvalid())
580 SubStmt = Actions.ActOnNullStmt(ColonLoc);
581
582 LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(),
583 IdentTok.getLocation());
584 if (AttributeList *Attrs = attrs.getList()) {
585 Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs);
586 attrs.clear();
587 }
588
589 return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc,
590 SubStmt.get());
591 }
592
593 /// ParseCaseStatement
594 /// labeled-statement:
595 /// 'case' constant-expression ':' statement
596 /// [GNU] 'case' constant-expression '...' constant-expression ':' statement
597 ///
ParseCaseStatement(bool MissingCase,ExprResult Expr)598 StmtResult Parser::ParseCaseStatement(bool MissingCase, ExprResult Expr) {
599 assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!");
600
601 // It is very very common for code to contain many case statements recursively
602 // nested, as in (but usually without indentation):
603 // case 1:
604 // case 2:
605 // case 3:
606 // case 4:
607 // case 5: etc.
608 //
609 // Parsing this naively works, but is both inefficient and can cause us to run
610 // out of stack space in our recursive descent parser. As a special case,
611 // flatten this recursion into an iterative loop. This is complex and gross,
612 // but all the grossness is constrained to ParseCaseStatement (and some
613 // weirdness in the actions), so this is just local grossness :).
614
615 // TopLevelCase - This is the highest level we have parsed. 'case 1' in the
616 // example above.
617 StmtResult TopLevelCase(true);
618
619 // DeepestParsedCaseStmt - This is the deepest statement we have parsed, which
620 // gets updated each time a new case is parsed, and whose body is unset so
621 // far. When parsing 'case 4', this is the 'case 3' node.
622 Stmt *DeepestParsedCaseStmt = nullptr;
623
624 // While we have case statements, eat and stack them.
625 SourceLocation ColonLoc;
626 do {
627 SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() :
628 ConsumeToken(); // eat the 'case'.
629 ColonLoc = SourceLocation();
630
631 if (Tok.is(tok::code_completion)) {
632 Actions.CodeCompleteCase(getCurScope());
633 cutOffParsing();
634 return StmtError();
635 }
636
637 /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
638 /// Disable this form of error recovery while we're parsing the case
639 /// expression.
640 ColonProtectionRAIIObject ColonProtection(*this);
641
642 ExprResult LHS;
643 if (!MissingCase) {
644 LHS = ParseConstantExpression();
645 if (LHS.isInvalid()) {
646 // If constant-expression is parsed unsuccessfully, recover by skipping
647 // current case statement (moving to the colon that ends it).
648 if (SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) {
649 TryConsumeToken(tok::colon, ColonLoc);
650 continue;
651 }
652 return StmtError();
653 }
654 } else {
655 LHS = Expr;
656 MissingCase = false;
657 }
658
659 // GNU case range extension.
660 SourceLocation DotDotDotLoc;
661 ExprResult RHS;
662 if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) {
663 Diag(DotDotDotLoc, diag::ext_gnu_case_range);
664 RHS = ParseConstantExpression();
665 if (RHS.isInvalid()) {
666 if (SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch)) {
667 TryConsumeToken(tok::colon, ColonLoc);
668 continue;
669 }
670 return StmtError();
671 }
672 }
673
674 ColonProtection.restore();
675
676 if (TryConsumeToken(tok::colon, ColonLoc)) {
677 } else if (TryConsumeToken(tok::semi, ColonLoc) ||
678 TryConsumeToken(tok::coloncolon, ColonLoc)) {
679 // Treat "case blah;" or "case blah::" as a typo for "case blah:".
680 Diag(ColonLoc, diag::err_expected_after)
681 << "'case'" << tok::colon
682 << FixItHint::CreateReplacement(ColonLoc, ":");
683 } else {
684 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
685 Diag(ExpectedLoc, diag::err_expected_after)
686 << "'case'" << tok::colon
687 << FixItHint::CreateInsertion(ExpectedLoc, ":");
688 ColonLoc = ExpectedLoc;
689 }
690
691 StmtResult Case =
692 Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc,
693 RHS.get(), ColonLoc);
694
695 // If we had a sema error parsing this case, then just ignore it and
696 // continue parsing the sub-stmt.
697 if (Case.isInvalid()) {
698 if (TopLevelCase.isInvalid()) // No parsed case stmts.
699 return ParseStatement();
700 // Otherwise, just don't add it as a nested case.
701 } else {
702 // If this is the first case statement we parsed, it becomes TopLevelCase.
703 // Otherwise we link it into the current chain.
704 Stmt *NextDeepest = Case.get();
705 if (TopLevelCase.isInvalid())
706 TopLevelCase = Case;
707 else
708 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
709 DeepestParsedCaseStmt = NextDeepest;
710 }
711
712 // Handle all case statements.
713 } while (Tok.is(tok::kw_case));
714
715 // If we found a non-case statement, start by parsing it.
716 StmtResult SubStmt;
717
718 if (Tok.isNot(tok::r_brace)) {
719 SubStmt = ParseStatement();
720 } else {
721 // Nicely diagnose the common error "switch (X) { case 4: }", which is
722 // not valid. If ColonLoc doesn't point to a valid text location, there was
723 // another parsing error, so avoid producing extra diagnostics.
724 if (ColonLoc.isValid()) {
725 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
726 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
727 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
728 }
729 SubStmt = StmtError();
730 }
731
732 // Install the body into the most deeply-nested case.
733 if (DeepestParsedCaseStmt) {
734 // Broken sub-stmt shouldn't prevent forming the case statement properly.
735 if (SubStmt.isInvalid())
736 SubStmt = Actions.ActOnNullStmt(SourceLocation());
737 Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
738 }
739
740 // Return the top level parsed statement tree.
741 return TopLevelCase;
742 }
743
744 /// ParseDefaultStatement
745 /// labeled-statement:
746 /// 'default' ':' statement
747 /// Note that this does not parse the 'statement' at the end.
748 ///
ParseDefaultStatement()749 StmtResult Parser::ParseDefaultStatement() {
750 assert(Tok.is(tok::kw_default) && "Not a default stmt!");
751 SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
752
753 SourceLocation ColonLoc;
754 if (TryConsumeToken(tok::colon, ColonLoc)) {
755 } else if (TryConsumeToken(tok::semi, ColonLoc)) {
756 // Treat "default;" as a typo for "default:".
757 Diag(ColonLoc, diag::err_expected_after)
758 << "'default'" << tok::colon
759 << FixItHint::CreateReplacement(ColonLoc, ":");
760 } else {
761 SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
762 Diag(ExpectedLoc, diag::err_expected_after)
763 << "'default'" << tok::colon
764 << FixItHint::CreateInsertion(ExpectedLoc, ":");
765 ColonLoc = ExpectedLoc;
766 }
767
768 StmtResult SubStmt;
769
770 if (Tok.isNot(tok::r_brace)) {
771 SubStmt = ParseStatement();
772 } else {
773 // Diagnose the common error "switch (X) {... default: }", which is
774 // not valid.
775 SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
776 Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
777 << FixItHint::CreateInsertion(AfterColonLoc, " ;");
778 SubStmt = true;
779 }
780
781 // Broken sub-stmt shouldn't prevent forming the case statement properly.
782 if (SubStmt.isInvalid())
783 SubStmt = Actions.ActOnNullStmt(ColonLoc);
784
785 return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
786 SubStmt.get(), getCurScope());
787 }
788
ParseCompoundStatement(bool isStmtExpr)789 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) {
790 return ParseCompoundStatement(isStmtExpr, Scope::DeclScope);
791 }
792
793 /// ParseCompoundStatement - Parse a "{}" block.
794 ///
795 /// compound-statement: [C99 6.8.2]
796 /// { block-item-list[opt] }
797 /// [GNU] { label-declarations block-item-list } [TODO]
798 ///
799 /// block-item-list:
800 /// block-item
801 /// block-item-list block-item
802 ///
803 /// block-item:
804 /// declaration
805 /// [GNU] '__extension__' declaration
806 /// statement
807 /// [OMP] openmp-directive [TODO]
808 ///
809 /// [GNU] label-declarations:
810 /// [GNU] label-declaration
811 /// [GNU] label-declarations label-declaration
812 ///
813 /// [GNU] label-declaration:
814 /// [GNU] '__label__' identifier-list ';'
815 ///
816 /// [OMP] openmp-directive: [TODO]
817 /// [OMP] barrier-directive
818 /// [OMP] flush-directive
819 ///
ParseCompoundStatement(bool isStmtExpr,unsigned ScopeFlags)820 StmtResult Parser::ParseCompoundStatement(bool isStmtExpr,
821 unsigned ScopeFlags) {
822 assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
823
824 // Enter a scope to hold everything within the compound stmt. Compound
825 // statements can always hold declarations.
826 ParseScope CompoundScope(this, ScopeFlags);
827
828 // Parse the statements in the body.
829 return ParseCompoundStatementBody(isStmtExpr);
830 }
831
832 /// Parse any pragmas at the start of the compound expression. We handle these
833 /// separately since some pragmas (FP_CONTRACT) must appear before any C
834 /// statement in the compound, but may be intermingled with other pragmas.
ParseCompoundStatementLeadingPragmas()835 void Parser::ParseCompoundStatementLeadingPragmas() {
836 bool checkForPragmas = true;
837 while (checkForPragmas) {
838 switch (Tok.getKind()) {
839 case tok::annot_pragma_vis:
840 HandlePragmaVisibility();
841 break;
842 case tok::annot_pragma_pack:
843 HandlePragmaPack();
844 break;
845 case tok::annot_pragma_msstruct:
846 HandlePragmaMSStruct();
847 break;
848 case tok::annot_pragma_align:
849 HandlePragmaAlign();
850 break;
851 case tok::annot_pragma_weak:
852 HandlePragmaWeak();
853 break;
854 case tok::annot_pragma_weakalias:
855 HandlePragmaWeakAlias();
856 break;
857 case tok::annot_pragma_redefine_extname:
858 HandlePragmaRedefineExtname();
859 break;
860 case tok::annot_pragma_opencl_extension:
861 HandlePragmaOpenCLExtension();
862 break;
863 case tok::annot_pragma_fp_contract:
864 HandlePragmaFPContract();
865 break;
866 case tok::annot_pragma_ms_pointers_to_members:
867 HandlePragmaMSPointersToMembers();
868 break;
869 case tok::annot_pragma_ms_pragma:
870 HandlePragmaMSPragma();
871 break;
872 default:
873 checkForPragmas = false;
874 break;
875 }
876 }
877
878 }
879
880 /// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
881 /// ActOnCompoundStmt action. This expects the '{' to be the current token, and
882 /// consume the '}' at the end of the block. It does not manipulate the scope
883 /// stack.
ParseCompoundStatementBody(bool isStmtExpr)884 StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
885 PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
886 Tok.getLocation(),
887 "in compound statement ('{}')");
888
889 // Record the state of the FP_CONTRACT pragma, restore on leaving the
890 // compound statement.
891 Sema::FPContractStateRAII SaveFPContractState(Actions);
892
893 InMessageExpressionRAIIObject InMessage(*this, false);
894 BalancedDelimiterTracker T(*this, tok::l_brace);
895 if (T.consumeOpen())
896 return StmtError();
897
898 Sema::CompoundScopeRAII CompoundScope(Actions);
899
900 // Parse any pragmas at the beginning of the compound statement.
901 ParseCompoundStatementLeadingPragmas();
902
903 StmtVector Stmts;
904
905 // "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are
906 // only allowed at the start of a compound stmt regardless of the language.
907 while (Tok.is(tok::kw___label__)) {
908 SourceLocation LabelLoc = ConsumeToken();
909
910 SmallVector<Decl *, 8> DeclsInGroup;
911 while (1) {
912 if (Tok.isNot(tok::identifier)) {
913 Diag(Tok, diag::err_expected) << tok::identifier;
914 break;
915 }
916
917 IdentifierInfo *II = Tok.getIdentifierInfo();
918 SourceLocation IdLoc = ConsumeToken();
919 DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
920
921 if (!TryConsumeToken(tok::comma))
922 break;
923 }
924
925 DeclSpec DS(AttrFactory);
926 DeclGroupPtrTy Res =
927 Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup);
928 StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
929
930 ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
931 if (R.isUsable())
932 Stmts.push_back(R.get());
933 }
934
935 while (Tok.isNot(tok::r_brace) && !isEofOrEom()) {
936 if (Tok.is(tok::annot_pragma_unused)) {
937 HandlePragmaUnused();
938 continue;
939 }
940
941 StmtResult R;
942 if (Tok.isNot(tok::kw___extension__)) {
943 R = ParseStatementOrDeclaration(Stmts, false);
944 } else {
945 // __extension__ can start declarations and it can also be a unary
946 // operator for expressions. Consume multiple __extension__ markers here
947 // until we can determine which is which.
948 // FIXME: This loses extension expressions in the AST!
949 SourceLocation ExtLoc = ConsumeToken();
950 while (Tok.is(tok::kw___extension__))
951 ConsumeToken();
952
953 ParsedAttributesWithRange attrs(AttrFactory);
954 MaybeParseCXX11Attributes(attrs, nullptr,
955 /*MightBeObjCMessageSend*/ true);
956
957 // If this is the start of a declaration, parse it as such.
958 if (isDeclarationStatement()) {
959 // __extension__ silences extension warnings in the subdeclaration.
960 // FIXME: Save the __extension__ on the decl as a node somehow?
961 ExtensionRAIIObject O(Diags);
962
963 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
964 DeclGroupPtrTy Res = ParseDeclaration(Stmts,
965 Declarator::BlockContext, DeclEnd,
966 attrs);
967 R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd);
968 } else {
969 // Otherwise this was a unary __extension__ marker.
970 ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
971
972 if (Res.isInvalid()) {
973 SkipUntil(tok::semi);
974 continue;
975 }
976
977 // FIXME: Use attributes?
978 // Eat the semicolon at the end of stmt and convert the expr into a
979 // statement.
980 ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
981 R = Actions.ActOnExprStmt(Res);
982 }
983 }
984
985 if (R.isUsable())
986 Stmts.push_back(R.get());
987 }
988
989 SourceLocation CloseLoc = Tok.getLocation();
990
991 // We broke out of the while loop because we found a '}' or EOF.
992 if (!T.consumeClose())
993 // Recover by creating a compound statement with what we parsed so far,
994 // instead of dropping everything and returning StmtError();
995 CloseLoc = T.getCloseLocation();
996
997 return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc,
998 Stmts, isStmtExpr);
999 }
1000
1001 /// ParseParenExprOrCondition:
1002 /// [C ] '(' expression ')'
1003 /// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true]
1004 ///
1005 /// This function parses and performs error recovery on the specified condition
1006 /// or expression (depending on whether we're in C++ or C mode). This function
1007 /// goes out of its way to recover well. It returns true if there was a parser
1008 /// error (the right paren couldn't be found), which indicates that the caller
1009 /// should try to recover harder. It returns false if the condition is
1010 /// successfully parsed. Note that a successful parse can still have semantic
1011 /// errors in the condition.
ParseParenExprOrCondition(ExprResult & ExprResult,Decl * & DeclResult,SourceLocation Loc,bool ConvertToBoolean)1012 bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult,
1013 Decl *&DeclResult,
1014 SourceLocation Loc,
1015 bool ConvertToBoolean) {
1016 BalancedDelimiterTracker T(*this, tok::l_paren);
1017 T.consumeOpen();
1018
1019 if (getLangOpts().CPlusPlus)
1020 ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean);
1021 else {
1022 ExprResult = ParseExpression();
1023 DeclResult = nullptr;
1024
1025 // If required, convert to a boolean value.
1026 if (!ExprResult.isInvalid() && ConvertToBoolean)
1027 ExprResult
1028 = Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get());
1029 }
1030
1031 // If the parser was confused by the condition and we don't have a ')', try to
1032 // recover by skipping ahead to a semi and bailing out. If condexp is
1033 // semantically invalid but we have well formed code, keep going.
1034 if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) {
1035 SkipUntil(tok::semi);
1036 // Skipping may have stopped if it found the containing ')'. If so, we can
1037 // continue parsing the if statement.
1038 if (Tok.isNot(tok::r_paren))
1039 return true;
1040 }
1041
1042 // Otherwise the condition is valid or the rparen is present.
1043 T.consumeClose();
1044
1045 // Check for extraneous ')'s to catch things like "if (foo())) {". We know
1046 // that all callers are looking for a statement after the condition, so ")"
1047 // isn't valid.
1048 while (Tok.is(tok::r_paren)) {
1049 Diag(Tok, diag::err_extraneous_rparen_in_condition)
1050 << FixItHint::CreateRemoval(Tok.getLocation());
1051 ConsumeParen();
1052 }
1053
1054 return false;
1055 }
1056
1057
1058 /// ParseIfStatement
1059 /// if-statement: [C99 6.8.4.1]
1060 /// 'if' '(' expression ')' statement
1061 /// 'if' '(' expression ')' statement 'else' statement
1062 /// [C++] 'if' '(' condition ')' statement
1063 /// [C++] 'if' '(' condition ')' statement 'else' statement
1064 ///
ParseIfStatement(SourceLocation * TrailingElseLoc)1065 StmtResult Parser::ParseIfStatement(SourceLocation *TrailingElseLoc) {
1066 assert(Tok.is(tok::kw_if) && "Not an if stmt!");
1067 SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
1068
1069 if (Tok.isNot(tok::l_paren)) {
1070 Diag(Tok, diag::err_expected_lparen_after) << "if";
1071 SkipUntil(tok::semi);
1072 return StmtError();
1073 }
1074
1075 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1076
1077 // C99 6.8.4p3 - In C99, the if statement is a block. This is not
1078 // the case for C90.
1079 //
1080 // C++ 6.4p3:
1081 // A name introduced by a declaration in a condition is in scope from its
1082 // point of declaration until the end of the substatements controlled by the
1083 // condition.
1084 // C++ 3.3.2p4:
1085 // Names declared in the for-init-statement, and in the condition of if,
1086 // while, for, and switch statements are local to the if, while, for, or
1087 // switch statement (including the controlled statement).
1088 //
1089 ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX);
1090
1091 // Parse the condition.
1092 ExprResult CondExp;
1093 Decl *CondVar = nullptr;
1094 if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true))
1095 return StmtError();
1096
1097 FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get(), IfLoc));
1098
1099 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
1100 // there is no compound stmt. C90 does not have this clause. We only do this
1101 // if the body isn't a compound statement to avoid push/pop in common cases.
1102 //
1103 // C++ 6.4p1:
1104 // The substatement in a selection-statement (each substatement, in the else
1105 // form of the if statement) implicitly defines a local scope.
1106 //
1107 // For C++ we create a scope for the condition and a new scope for
1108 // substatements because:
1109 // -When the 'then' scope exits, we want the condition declaration to still be
1110 // active for the 'else' scope too.
1111 // -Sema will detect name clashes by considering declarations of a
1112 // 'ControlScope' as part of its direct subscope.
1113 // -If we wanted the condition and substatement to be in the same scope, we
1114 // would have to notify ParseStatement not to create a new scope. It's
1115 // simpler to let it create a new scope.
1116 //
1117 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1118
1119 // Read the 'then' stmt.
1120 SourceLocation ThenStmtLoc = Tok.getLocation();
1121
1122 SourceLocation InnerStatementTrailingElseLoc;
1123 StmtResult ThenStmt(ParseStatement(&InnerStatementTrailingElseLoc));
1124
1125 // Pop the 'if' scope if needed.
1126 InnerScope.Exit();
1127
1128 // If it has an else, parse it.
1129 SourceLocation ElseLoc;
1130 SourceLocation ElseStmtLoc;
1131 StmtResult ElseStmt;
1132
1133 if (Tok.is(tok::kw_else)) {
1134 if (TrailingElseLoc)
1135 *TrailingElseLoc = Tok.getLocation();
1136
1137 ElseLoc = ConsumeToken();
1138 ElseStmtLoc = Tok.getLocation();
1139
1140 // C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
1141 // there is no compound stmt. C90 does not have this clause. We only do
1142 // this if the body isn't a compound statement to avoid push/pop in common
1143 // cases.
1144 //
1145 // C++ 6.4p1:
1146 // The substatement in a selection-statement (each substatement, in the else
1147 // form of the if statement) implicitly defines a local scope.
1148 //
1149 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1150
1151 ElseStmt = ParseStatement();
1152
1153 // Pop the 'else' scope if needed.
1154 InnerScope.Exit();
1155 } else if (Tok.is(tok::code_completion)) {
1156 Actions.CodeCompleteAfterIf(getCurScope());
1157 cutOffParsing();
1158 return StmtError();
1159 } else if (InnerStatementTrailingElseLoc.isValid()) {
1160 Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else);
1161 }
1162
1163 IfScope.Exit();
1164
1165 // If the then or else stmt is invalid and the other is valid (and present),
1166 // make turn the invalid one into a null stmt to avoid dropping the other
1167 // part. If both are invalid, return error.
1168 if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) ||
1169 (ThenStmt.isInvalid() && ElseStmt.get() == nullptr) ||
1170 (ThenStmt.get() == nullptr && ElseStmt.isInvalid())) {
1171 // Both invalid, or one is invalid and other is non-present: return error.
1172 return StmtError();
1173 }
1174
1175 // Now if either are invalid, replace with a ';'.
1176 if (ThenStmt.isInvalid())
1177 ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc);
1178 if (ElseStmt.isInvalid())
1179 ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc);
1180
1181 return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(),
1182 ElseLoc, ElseStmt.get());
1183 }
1184
1185 /// ParseSwitchStatement
1186 /// switch-statement:
1187 /// 'switch' '(' expression ')' statement
1188 /// [C++] 'switch' '(' condition ')' statement
ParseSwitchStatement(SourceLocation * TrailingElseLoc)1189 StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
1190 assert(Tok.is(tok::kw_switch) && "Not a switch stmt!");
1191 SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'.
1192
1193 if (Tok.isNot(tok::l_paren)) {
1194 Diag(Tok, diag::err_expected_lparen_after) << "switch";
1195 SkipUntil(tok::semi);
1196 return StmtError();
1197 }
1198
1199 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1200
1201 // C99 6.8.4p3 - In C99, the switch statement is a block. This is
1202 // not the case for C90. Start the switch scope.
1203 //
1204 // C++ 6.4p3:
1205 // A name introduced by a declaration in a condition is in scope from its
1206 // point of declaration until the end of the substatements controlled by the
1207 // condition.
1208 // C++ 3.3.2p4:
1209 // Names declared in the for-init-statement, and in the condition of if,
1210 // while, for, and switch statements are local to the if, while, for, or
1211 // switch statement (including the controlled statement).
1212 //
1213 unsigned ScopeFlags = Scope::SwitchScope;
1214 if (C99orCXX)
1215 ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
1216 ParseScope SwitchScope(this, ScopeFlags);
1217
1218 // Parse the condition.
1219 ExprResult Cond;
1220 Decl *CondVar = nullptr;
1221 if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false))
1222 return StmtError();
1223
1224 StmtResult Switch
1225 = Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar);
1226
1227 if (Switch.isInvalid()) {
1228 // Skip the switch body.
1229 // FIXME: This is not optimal recovery, but parsing the body is more
1230 // dangerous due to the presence of case and default statements, which
1231 // will have no place to connect back with the switch.
1232 if (Tok.is(tok::l_brace)) {
1233 ConsumeBrace();
1234 SkipUntil(tok::r_brace);
1235 } else
1236 SkipUntil(tok::semi);
1237 return Switch;
1238 }
1239
1240 // C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
1241 // there is no compound stmt. C90 does not have this clause. We only do this
1242 // if the body isn't a compound statement to avoid push/pop in common cases.
1243 //
1244 // C++ 6.4p1:
1245 // The substatement in a selection-statement (each substatement, in the else
1246 // form of the if statement) implicitly defines a local scope.
1247 //
1248 // See comments in ParseIfStatement for why we create a scope for the
1249 // condition and a new scope for substatement in C++.
1250 //
1251 getCurScope()->AddFlags(Scope::BreakScope);
1252 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1253
1254 // We have incremented the mangling number for the SwitchScope and the
1255 // InnerScope, which is one too many.
1256 if (C99orCXX)
1257 getCurScope()->decrementMSLocalManglingNumber();
1258
1259 // Read the body statement.
1260 StmtResult Body(ParseStatement(TrailingElseLoc));
1261
1262 // Pop the scopes.
1263 InnerScope.Exit();
1264 SwitchScope.Exit();
1265
1266 return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get());
1267 }
1268
1269 /// ParseWhileStatement
1270 /// while-statement: [C99 6.8.5.1]
1271 /// 'while' '(' expression ')' statement
1272 /// [C++] 'while' '(' condition ')' statement
ParseWhileStatement(SourceLocation * TrailingElseLoc)1273 StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
1274 assert(Tok.is(tok::kw_while) && "Not a while stmt!");
1275 SourceLocation WhileLoc = Tok.getLocation();
1276 ConsumeToken(); // eat the 'while'.
1277
1278 if (Tok.isNot(tok::l_paren)) {
1279 Diag(Tok, diag::err_expected_lparen_after) << "while";
1280 SkipUntil(tok::semi);
1281 return StmtError();
1282 }
1283
1284 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1285
1286 // C99 6.8.5p5 - In C99, the while statement is a block. This is not
1287 // the case for C90. Start the loop scope.
1288 //
1289 // C++ 6.4p3:
1290 // A name introduced by a declaration in a condition is in scope from its
1291 // point of declaration until the end of the substatements controlled by the
1292 // condition.
1293 // C++ 3.3.2p4:
1294 // Names declared in the for-init-statement, and in the condition of if,
1295 // while, for, and switch statements are local to the if, while, for, or
1296 // switch statement (including the controlled statement).
1297 //
1298 unsigned ScopeFlags;
1299 if (C99orCXX)
1300 ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
1301 Scope::DeclScope | Scope::ControlScope;
1302 else
1303 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1304 ParseScope WhileScope(this, ScopeFlags);
1305
1306 // Parse the condition.
1307 ExprResult Cond;
1308 Decl *CondVar = nullptr;
1309 if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true))
1310 return StmtError();
1311
1312 FullExprArg FullCond(Actions.MakeFullExpr(Cond.get(), WhileLoc));
1313
1314 // C99 6.8.5p5 - In C99, the body of the while statement is a scope, even if
1315 // there is no compound stmt. C90 does not have this clause. We only do this
1316 // if the body isn't a compound statement to avoid push/pop in common cases.
1317 //
1318 // C++ 6.5p2:
1319 // The substatement in an iteration-statement implicitly defines a local scope
1320 // which is entered and exited each time through the loop.
1321 //
1322 // See comments in ParseIfStatement for why we create a scope for the
1323 // condition and a new scope for substatement in C++.
1324 //
1325 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1326
1327 // Read the body statement.
1328 StmtResult Body(ParseStatement(TrailingElseLoc));
1329
1330 // Pop the body scope if needed.
1331 InnerScope.Exit();
1332 WhileScope.Exit();
1333
1334 if ((Cond.isInvalid() && !CondVar) || Body.isInvalid())
1335 return StmtError();
1336
1337 return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get());
1338 }
1339
1340 /// ParseDoStatement
1341 /// do-statement: [C99 6.8.5.2]
1342 /// 'do' statement 'while' '(' expression ')' ';'
1343 /// Note: this lets the caller parse the end ';'.
ParseDoStatement()1344 StmtResult Parser::ParseDoStatement() {
1345 assert(Tok.is(tok::kw_do) && "Not a do stmt!");
1346 SourceLocation DoLoc = ConsumeToken(); // eat the 'do'.
1347
1348 // C99 6.8.5p5 - In C99, the do statement is a block. This is not
1349 // the case for C90. Start the loop scope.
1350 unsigned ScopeFlags;
1351 if (getLangOpts().C99)
1352 ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope;
1353 else
1354 ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
1355
1356 ParseScope DoScope(this, ScopeFlags);
1357
1358 // C99 6.8.5p5 - In C99, the body of the do statement is a scope, even if
1359 // there is no compound stmt. C90 does not have this clause. We only do this
1360 // if the body isn't a compound statement to avoid push/pop in common cases.
1361 //
1362 // C++ 6.5p2:
1363 // The substatement in an iteration-statement implicitly defines a local scope
1364 // which is entered and exited each time through the loop.
1365 //
1366 bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
1367 ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
1368
1369 // Read the body statement.
1370 StmtResult Body(ParseStatement());
1371
1372 // Pop the body scope if needed.
1373 InnerScope.Exit();
1374
1375 if (Tok.isNot(tok::kw_while)) {
1376 if (!Body.isInvalid()) {
1377 Diag(Tok, diag::err_expected_while);
1378 Diag(DoLoc, diag::note_matching) << "'do'";
1379 SkipUntil(tok::semi, StopBeforeMatch);
1380 }
1381 return StmtError();
1382 }
1383 SourceLocation WhileLoc = ConsumeToken();
1384
1385 if (Tok.isNot(tok::l_paren)) {
1386 Diag(Tok, diag::err_expected_lparen_after) << "do/while";
1387 SkipUntil(tok::semi, StopBeforeMatch);
1388 return StmtError();
1389 }
1390
1391 // Parse the parenthesized expression.
1392 BalancedDelimiterTracker T(*this, tok::l_paren);
1393 T.consumeOpen();
1394
1395 // A do-while expression is not a condition, so can't have attributes.
1396 DiagnoseAndSkipCXX11Attributes();
1397
1398 ExprResult Cond = ParseExpression();
1399 T.consumeClose();
1400 DoScope.Exit();
1401
1402 if (Cond.isInvalid() || Body.isInvalid())
1403 return StmtError();
1404
1405 return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(),
1406 Cond.get(), T.getCloseLocation());
1407 }
1408
isForRangeIdentifier()1409 bool Parser::isForRangeIdentifier() {
1410 assert(Tok.is(tok::identifier));
1411
1412 const Token &Next = NextToken();
1413 if (Next.is(tok::colon))
1414 return true;
1415
1416 if (Next.is(tok::l_square) || Next.is(tok::kw_alignas)) {
1417 TentativeParsingAction PA(*this);
1418 ConsumeToken();
1419 SkipCXX11Attributes();
1420 bool Result = Tok.is(tok::colon);
1421 PA.Revert();
1422 return Result;
1423 }
1424
1425 return false;
1426 }
1427
1428 /// ParseForStatement
1429 /// for-statement: [C99 6.8.5.3]
1430 /// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement
1431 /// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement
1432 /// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')'
1433 /// [C++] statement
1434 /// [C++0x] 'for' '(' for-range-declaration : for-range-initializer ) statement
1435 /// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
1436 /// [OBJC2] 'for' '(' expr 'in' expr ')' statement
1437 ///
1438 /// [C++] for-init-statement:
1439 /// [C++] expression-statement
1440 /// [C++] simple-declaration
1441 ///
1442 /// [C++0x] for-range-declaration:
1443 /// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator
1444 /// [C++0x] for-range-initializer:
1445 /// [C++0x] expression
1446 /// [C++0x] braced-init-list [TODO]
ParseForStatement(SourceLocation * TrailingElseLoc)1447 StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
1448 assert(Tok.is(tok::kw_for) && "Not a for stmt!");
1449 SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
1450
1451 if (Tok.isNot(tok::l_paren)) {
1452 Diag(Tok, diag::err_expected_lparen_after) << "for";
1453 SkipUntil(tok::semi);
1454 return StmtError();
1455 }
1456
1457 bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus ||
1458 getLangOpts().ObjC1;
1459
1460 // C99 6.8.5p5 - In C99, the for statement is a block. This is not
1461 // the case for C90. Start the loop scope.
1462 //
1463 // C++ 6.4p3:
1464 // A name introduced by a declaration in a condition is in scope from its
1465 // point of declaration until the end of the substatements controlled by the
1466 // condition.
1467 // C++ 3.3.2p4:
1468 // Names declared in the for-init-statement, and in the condition of if,
1469 // while, for, and switch statements are local to the if, while, for, or
1470 // switch statement (including the controlled statement).
1471 // C++ 6.5.3p1:
1472 // Names declared in the for-init-statement are in the same declarative-region
1473 // as those declared in the condition.
1474 //
1475 unsigned ScopeFlags = 0;
1476 if (C99orCXXorObjC)
1477 ScopeFlags = Scope::DeclScope | Scope::ControlScope;
1478
1479 ParseScope ForScope(this, ScopeFlags);
1480
1481 BalancedDelimiterTracker T(*this, tok::l_paren);
1482 T.consumeOpen();
1483
1484 ExprResult Value;
1485
1486 bool ForEach = false, ForRange = false;
1487 StmtResult FirstPart;
1488 bool SecondPartIsInvalid = false;
1489 FullExprArg SecondPart(Actions);
1490 ExprResult Collection;
1491 ForRangeInit ForRangeInit;
1492 FullExprArg ThirdPart(Actions);
1493 Decl *SecondVar = nullptr;
1494
1495 if (Tok.is(tok::code_completion)) {
1496 Actions.CodeCompleteOrdinaryName(getCurScope(),
1497 C99orCXXorObjC? Sema::PCC_ForInit
1498 : Sema::PCC_Expression);
1499 cutOffParsing();
1500 return StmtError();
1501 }
1502
1503 ParsedAttributesWithRange attrs(AttrFactory);
1504 MaybeParseCXX11Attributes(attrs);
1505
1506 // Parse the first part of the for specifier.
1507 if (Tok.is(tok::semi)) { // for (;
1508 ProhibitAttributes(attrs);
1509 // no first part, eat the ';'.
1510 ConsumeToken();
1511 } else if (getLangOpts().CPlusPlus && Tok.is(tok::identifier) &&
1512 isForRangeIdentifier()) {
1513 ProhibitAttributes(attrs);
1514 IdentifierInfo *Name = Tok.getIdentifierInfo();
1515 SourceLocation Loc = ConsumeToken();
1516 MaybeParseCXX11Attributes(attrs);
1517
1518 ForRangeInit.ColonLoc = ConsumeToken();
1519 if (Tok.is(tok::l_brace))
1520 ForRangeInit.RangeExpr = ParseBraceInitializer();
1521 else
1522 ForRangeInit.RangeExpr = ParseExpression();
1523
1524 Diag(Loc, getLangOpts().CPlusPlus1z
1525 ? diag::warn_cxx1y_compat_for_range_identifier
1526 : diag::ext_for_range_identifier)
1527 << ((getLangOpts().CPlusPlus11 && !getLangOpts().CPlusPlus1z)
1528 ? FixItHint::CreateInsertion(Loc, "auto &&")
1529 : FixItHint());
1530
1531 FirstPart = Actions.ActOnCXXForRangeIdentifier(getCurScope(), Loc, Name,
1532 attrs, attrs.Range.getEnd());
1533 ForRange = true;
1534 } else if (isForInitDeclaration()) { // for (int X = 4;
1535 // Parse declaration, which eats the ';'.
1536 if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode?
1537 Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
1538
1539 // In C++0x, "for (T NS:a" might not be a typo for ::
1540 bool MightBeForRangeStmt = getLangOpts().CPlusPlus;
1541 ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
1542
1543 SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
1544 StmtVector Stmts;
1545 DeclGroupPtrTy DG = ParseSimpleDeclaration(
1546 Stmts, Declarator::ForContext, DeclEnd, attrs, false,
1547 MightBeForRangeStmt ? &ForRangeInit : nullptr);
1548 FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
1549 if (ForRangeInit.ParsedForRangeDecl()) {
1550 Diag(ForRangeInit.ColonLoc, getLangOpts().CPlusPlus11 ?
1551 diag::warn_cxx98_compat_for_range : diag::ext_for_range);
1552
1553 ForRange = true;
1554 } else if (Tok.is(tok::semi)) { // for (int x = 4;
1555 ConsumeToken();
1556 } else if ((ForEach = isTokIdentifier_in())) {
1557 Actions.ActOnForEachDeclStmt(DG);
1558 // ObjC: for (id x in expr)
1559 ConsumeToken(); // consume 'in'
1560
1561 if (Tok.is(tok::code_completion)) {
1562 Actions.CodeCompleteObjCForCollection(getCurScope(), DG);
1563 cutOffParsing();
1564 return StmtError();
1565 }
1566 Collection = ParseExpression();
1567 } else {
1568 Diag(Tok, diag::err_expected_semi_for);
1569 }
1570 } else {
1571 ProhibitAttributes(attrs);
1572 Value = ParseExpression();
1573
1574 ForEach = isTokIdentifier_in();
1575
1576 // Turn the expression into a stmt.
1577 if (!Value.isInvalid()) {
1578 if (ForEach)
1579 FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
1580 else
1581 FirstPart = Actions.ActOnExprStmt(Value);
1582 }
1583
1584 if (Tok.is(tok::semi)) {
1585 ConsumeToken();
1586 } else if (ForEach) {
1587 ConsumeToken(); // consume 'in'
1588
1589 if (Tok.is(tok::code_completion)) {
1590 Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy());
1591 cutOffParsing();
1592 return StmtError();
1593 }
1594 Collection = ParseExpression();
1595 } else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) {
1596 // User tried to write the reasonable, but ill-formed, for-range-statement
1597 // for (expr : expr) { ... }
1598 Diag(Tok, diag::err_for_range_expected_decl)
1599 << FirstPart.get()->getSourceRange();
1600 SkipUntil(tok::r_paren, StopBeforeMatch);
1601 SecondPartIsInvalid = true;
1602 } else {
1603 if (!Value.isInvalid()) {
1604 Diag(Tok, diag::err_expected_semi_for);
1605 } else {
1606 // Skip until semicolon or rparen, don't consume it.
1607 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
1608 if (Tok.is(tok::semi))
1609 ConsumeToken();
1610 }
1611 }
1612 }
1613
1614 // Parse the second part of the for specifier.
1615 getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope);
1616 if (!ForEach && !ForRange) {
1617 assert(!SecondPart.get() && "Shouldn't have a second expression yet.");
1618 // Parse the second part of the for specifier.
1619 if (Tok.is(tok::semi)) { // for (...;;
1620 // no second part.
1621 } else if (Tok.is(tok::r_paren)) {
1622 // missing both semicolons.
1623 } else {
1624 ExprResult Second;
1625 if (getLangOpts().CPlusPlus)
1626 ParseCXXCondition(Second, SecondVar, ForLoc, true);
1627 else {
1628 Second = ParseExpression();
1629 if (!Second.isInvalid())
1630 Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc,
1631 Second.get());
1632 }
1633 SecondPartIsInvalid = Second.isInvalid();
1634 SecondPart = Actions.MakeFullExpr(Second.get(), ForLoc);
1635 }
1636
1637 if (Tok.isNot(tok::semi)) {
1638 if (!SecondPartIsInvalid || SecondVar)
1639 Diag(Tok, diag::err_expected_semi_for);
1640 else
1641 // Skip until semicolon or rparen, don't consume it.
1642 SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
1643 }
1644
1645 if (Tok.is(tok::semi)) {
1646 ConsumeToken();
1647 }
1648
1649 // Parse the third part of the for specifier.
1650 if (Tok.isNot(tok::r_paren)) { // for (...;...;)
1651 ExprResult Third = ParseExpression();
1652 // FIXME: The C++11 standard doesn't actually say that this is a
1653 // discarded-value expression, but it clearly should be.
1654 ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.get());
1655 }
1656 }
1657 // Match the ')'.
1658 T.consumeClose();
1659
1660 // We need to perform most of the semantic analysis for a C++0x for-range
1661 // statememt before parsing the body, in order to be able to deduce the type
1662 // of an auto-typed loop variable.
1663 StmtResult ForRangeStmt;
1664 StmtResult ForEachStmt;
1665
1666 if (ForRange) {
1667 ForRangeStmt = Actions.ActOnCXXForRangeStmt(ForLoc, FirstPart.get(),
1668 ForRangeInit.ColonLoc,
1669 ForRangeInit.RangeExpr.get(),
1670 T.getCloseLocation(),
1671 Sema::BFRK_Build);
1672
1673
1674 // Similarly, we need to do the semantic analysis for a for-range
1675 // statement immediately in order to close over temporaries correctly.
1676 } else if (ForEach) {
1677 ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc,
1678 FirstPart.get(),
1679 Collection.get(),
1680 T.getCloseLocation());
1681 }
1682
1683 // C99 6.8.5p5 - In C99, the body of the for statement is a scope, even if
1684 // there is no compound stmt. C90 does not have this clause. We only do this
1685 // if the body isn't a compound statement to avoid push/pop in common cases.
1686 //
1687 // C++ 6.5p2:
1688 // The substatement in an iteration-statement implicitly defines a local scope
1689 // which is entered and exited each time through the loop.
1690 //
1691 // See comments in ParseIfStatement for why we create a scope for
1692 // for-init-statement/condition and a new scope for substatement in C++.
1693 //
1694 ParseScope InnerScope(this, Scope::DeclScope, C99orCXXorObjC,
1695 Tok.is(tok::l_brace));
1696
1697 // The body of the for loop has the same local mangling number as the
1698 // for-init-statement.
1699 // It will only be incremented if the body contains other things that would
1700 // normally increment the mangling number (like a compound statement).
1701 if (C99orCXXorObjC)
1702 getCurScope()->decrementMSLocalManglingNumber();
1703
1704 // Read the body statement.
1705 StmtResult Body(ParseStatement(TrailingElseLoc));
1706
1707 // Pop the body scope if needed.
1708 InnerScope.Exit();
1709
1710 // Leave the for-scope.
1711 ForScope.Exit();
1712
1713 if (Body.isInvalid())
1714 return StmtError();
1715
1716 if (ForEach)
1717 return Actions.FinishObjCForCollectionStmt(ForEachStmt.get(),
1718 Body.get());
1719
1720 if (ForRange)
1721 return Actions.FinishCXXForRangeStmt(ForRangeStmt.get(), Body.get());
1722
1723 return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.get(),
1724 SecondPart, SecondVar, ThirdPart,
1725 T.getCloseLocation(), Body.get());
1726 }
1727
1728 /// ParseGotoStatement
1729 /// jump-statement:
1730 /// 'goto' identifier ';'
1731 /// [GNU] 'goto' '*' expression ';'
1732 ///
1733 /// Note: this lets the caller parse the end ';'.
1734 ///
ParseGotoStatement()1735 StmtResult Parser::ParseGotoStatement() {
1736 assert(Tok.is(tok::kw_goto) && "Not a goto stmt!");
1737 SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'.
1738
1739 StmtResult Res;
1740 if (Tok.is(tok::identifier)) {
1741 LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
1742 Tok.getLocation());
1743 Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD);
1744 ConsumeToken();
1745 } else if (Tok.is(tok::star)) {
1746 // GNU indirect goto extension.
1747 Diag(Tok, diag::ext_gnu_indirect_goto);
1748 SourceLocation StarLoc = ConsumeToken();
1749 ExprResult R(ParseExpression());
1750 if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
1751 SkipUntil(tok::semi, StopBeforeMatch);
1752 return StmtError();
1753 }
1754 Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.get());
1755 } else {
1756 Diag(Tok, diag::err_expected) << tok::identifier;
1757 return StmtError();
1758 }
1759
1760 return Res;
1761 }
1762
1763 /// ParseContinueStatement
1764 /// jump-statement:
1765 /// 'continue' ';'
1766 ///
1767 /// Note: this lets the caller parse the end ';'.
1768 ///
ParseContinueStatement()1769 StmtResult Parser::ParseContinueStatement() {
1770 SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'.
1771 return Actions.ActOnContinueStmt(ContinueLoc, getCurScope());
1772 }
1773
1774 /// ParseBreakStatement
1775 /// jump-statement:
1776 /// 'break' ';'
1777 ///
1778 /// Note: this lets the caller parse the end ';'.
1779 ///
ParseBreakStatement()1780 StmtResult Parser::ParseBreakStatement() {
1781 SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
1782 return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
1783 }
1784
1785 /// ParseReturnStatement
1786 /// jump-statement:
1787 /// 'return' expression[opt] ';'
ParseReturnStatement()1788 StmtResult Parser::ParseReturnStatement() {
1789 assert(Tok.is(tok::kw_return) && "Not a return stmt!");
1790 SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
1791
1792 ExprResult R;
1793 if (Tok.isNot(tok::semi)) {
1794 if (Tok.is(tok::code_completion)) {
1795 Actions.CodeCompleteReturn(getCurScope());
1796 cutOffParsing();
1797 return StmtError();
1798 }
1799
1800 if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) {
1801 R = ParseInitializer();
1802 if (R.isUsable())
1803 Diag(R.get()->getLocStart(), getLangOpts().CPlusPlus11 ?
1804 diag::warn_cxx98_compat_generalized_initializer_lists :
1805 diag::ext_generalized_initializer_lists)
1806 << R.get()->getSourceRange();
1807 } else
1808 R = ParseExpression();
1809 if (R.isInvalid()) {
1810 SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
1811 return StmtError();
1812 }
1813 }
1814 return Actions.ActOnReturnStmt(ReturnLoc, R.get(), getCurScope());
1815 }
1816
ParsePragmaLoopHint(StmtVector & Stmts,bool OnlyStatement,SourceLocation * TrailingElseLoc,ParsedAttributesWithRange & Attrs)1817 StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts, bool OnlyStatement,
1818 SourceLocation *TrailingElseLoc,
1819 ParsedAttributesWithRange &Attrs) {
1820 // Create temporary attribute list.
1821 ParsedAttributesWithRange TempAttrs(AttrFactory);
1822
1823 // Get vectorize hints and consume annotated token.
1824 while (Tok.is(tok::annot_pragma_loop_hint)) {
1825 LoopHint Hint = HandlePragmaLoopHint();
1826 ConsumeToken();
1827
1828 if (!Hint.LoopLoc || !Hint.OptionLoc || !Hint.ValueLoc)
1829 continue;
1830
1831 ArgsUnion ArgHints[] = {Hint.OptionLoc, Hint.ValueLoc,
1832 ArgsUnion(Hint.ValueExpr)};
1833 TempAttrs.addNew(Hint.LoopLoc->Ident, Hint.Range, nullptr,
1834 Hint.LoopLoc->Loc, ArgHints, 3, AttributeList::AS_Pragma);
1835 }
1836
1837 // Get the next statement.
1838 MaybeParseCXX11Attributes(Attrs);
1839
1840 StmtResult S = ParseStatementOrDeclarationAfterAttributes(
1841 Stmts, OnlyStatement, TrailingElseLoc, Attrs);
1842
1843 Attrs.takeAllFrom(TempAttrs);
1844 return S;
1845 }
1846
ParseFunctionStatementBody(Decl * Decl,ParseScope & BodyScope)1847 Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
1848 assert(Tok.is(tok::l_brace));
1849 SourceLocation LBraceLoc = Tok.getLocation();
1850
1851 if (SkipFunctionBodies && (!Decl || Actions.canSkipFunctionBody(Decl)) &&
1852 trySkippingFunctionBody()) {
1853 BodyScope.Exit();
1854 return Actions.ActOnSkippedFunctionBody(Decl);
1855 }
1856
1857 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc,
1858 "parsing function body");
1859
1860 // Do not enter a scope for the brace, as the arguments are in the same scope
1861 // (the function body) as the body itself. Instead, just read the statement
1862 // list and put it into a CompoundStmt for safe keeping.
1863 StmtResult FnBody(ParseCompoundStatementBody());
1864
1865 // If the function body could not be parsed, make a bogus compoundstmt.
1866 if (FnBody.isInvalid()) {
1867 Sema::CompoundScopeRAII CompoundScope(Actions);
1868 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
1869 }
1870
1871 BodyScope.Exit();
1872 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
1873 }
1874
1875 /// ParseFunctionTryBlock - Parse a C++ function-try-block.
1876 ///
1877 /// function-try-block:
1878 /// 'try' ctor-initializer[opt] compound-statement handler-seq
1879 ///
ParseFunctionTryBlock(Decl * Decl,ParseScope & BodyScope)1880 Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
1881 assert(Tok.is(tok::kw_try) && "Expected 'try'");
1882 SourceLocation TryLoc = ConsumeToken();
1883
1884 PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc,
1885 "parsing function try block");
1886
1887 // Constructor initializer list?
1888 if (Tok.is(tok::colon))
1889 ParseConstructorInitializer(Decl);
1890 else
1891 Actions.ActOnDefaultCtorInitializers(Decl);
1892
1893 if (SkipFunctionBodies && Actions.canSkipFunctionBody(Decl) &&
1894 trySkippingFunctionBody()) {
1895 BodyScope.Exit();
1896 return Actions.ActOnSkippedFunctionBody(Decl);
1897 }
1898
1899 SourceLocation LBraceLoc = Tok.getLocation();
1900 StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));
1901 // If we failed to parse the try-catch, we just give the function an empty
1902 // compound statement as the body.
1903 if (FnBody.isInvalid()) {
1904 Sema::CompoundScopeRAII CompoundScope(Actions);
1905 FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
1906 }
1907
1908 BodyScope.Exit();
1909 return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
1910 }
1911
trySkippingFunctionBody()1912 bool Parser::trySkippingFunctionBody() {
1913 assert(Tok.is(tok::l_brace));
1914 assert(SkipFunctionBodies &&
1915 "Should only be called when SkipFunctionBodies is enabled");
1916
1917 if (!PP.isCodeCompletionEnabled()) {
1918 ConsumeBrace();
1919 SkipUntil(tok::r_brace);
1920 return true;
1921 }
1922
1923 // We're in code-completion mode. Skip parsing for all function bodies unless
1924 // the body contains the code-completion point.
1925 TentativeParsingAction PA(*this);
1926 ConsumeBrace();
1927 if (SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
1928 PA.Commit();
1929 return true;
1930 }
1931
1932 PA.Revert();
1933 return false;
1934 }
1935
1936 /// ParseCXXTryBlock - Parse a C++ try-block.
1937 ///
1938 /// try-block:
1939 /// 'try' compound-statement handler-seq
1940 ///
ParseCXXTryBlock()1941 StmtResult Parser::ParseCXXTryBlock() {
1942 assert(Tok.is(tok::kw_try) && "Expected 'try'");
1943
1944 SourceLocation TryLoc = ConsumeToken();
1945 return ParseCXXTryBlockCommon(TryLoc);
1946 }
1947
1948 /// ParseCXXTryBlockCommon - Parse the common part of try-block and
1949 /// function-try-block.
1950 ///
1951 /// try-block:
1952 /// 'try' compound-statement handler-seq
1953 ///
1954 /// function-try-block:
1955 /// 'try' ctor-initializer[opt] compound-statement handler-seq
1956 ///
1957 /// handler-seq:
1958 /// handler handler-seq[opt]
1959 ///
1960 /// [Borland] try-block:
1961 /// 'try' compound-statement seh-except-block
1962 /// 'try' compound-statement seh-finally-block
1963 ///
ParseCXXTryBlockCommon(SourceLocation TryLoc,bool FnTry)1964 StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
1965 if (Tok.isNot(tok::l_brace))
1966 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
1967 // FIXME: Possible draft standard bug: attribute-specifier should be allowed?
1968
1969 StmtResult TryBlock(ParseCompoundStatement(/*isStmtExpr=*/false,
1970 Scope::DeclScope | Scope::TryScope |
1971 (FnTry ? Scope::FnTryCatchScope : 0)));
1972 if (TryBlock.isInvalid())
1973 return TryBlock;
1974
1975 // Borland allows SEH-handlers with 'try'
1976
1977 if ((Tok.is(tok::identifier) &&
1978 Tok.getIdentifierInfo() == getSEHExceptKeyword()) ||
1979 Tok.is(tok::kw___finally)) {
1980 // TODO: Factor into common return ParseSEHHandlerCommon(...)
1981 StmtResult Handler;
1982 if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
1983 SourceLocation Loc = ConsumeToken();
1984 Handler = ParseSEHExceptBlock(Loc);
1985 }
1986 else {
1987 SourceLocation Loc = ConsumeToken();
1988 Handler = ParseSEHFinallyBlock(Loc);
1989 }
1990 if(Handler.isInvalid())
1991 return Handler;
1992
1993 return Actions.ActOnSEHTryBlock(true /* IsCXXTry */,
1994 TryLoc,
1995 TryBlock.get(),
1996 Handler.get());
1997 }
1998 else {
1999 StmtVector Handlers;
2000
2001 // C++11 attributes can't appear here, despite this context seeming
2002 // statement-like.
2003 DiagnoseAndSkipCXX11Attributes();
2004
2005 if (Tok.isNot(tok::kw_catch))
2006 return StmtError(Diag(Tok, diag::err_expected_catch));
2007 while (Tok.is(tok::kw_catch)) {
2008 StmtResult Handler(ParseCXXCatchBlock(FnTry));
2009 if (!Handler.isInvalid())
2010 Handlers.push_back(Handler.get());
2011 }
2012 // Don't bother creating the full statement if we don't have any usable
2013 // handlers.
2014 if (Handlers.empty())
2015 return StmtError();
2016
2017 return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.get(), Handlers);
2018 }
2019 }
2020
2021 /// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
2022 ///
2023 /// handler:
2024 /// 'catch' '(' exception-declaration ')' compound-statement
2025 ///
2026 /// exception-declaration:
2027 /// attribute-specifier-seq[opt] type-specifier-seq declarator
2028 /// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt]
2029 /// '...'
2030 ///
ParseCXXCatchBlock(bool FnCatch)2031 StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
2032 assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
2033
2034 SourceLocation CatchLoc = ConsumeToken();
2035
2036 BalancedDelimiterTracker T(*this, tok::l_paren);
2037 if (T.expectAndConsume())
2038 return StmtError();
2039
2040 // C++ 3.3.2p3:
2041 // The name in a catch exception-declaration is local to the handler and
2042 // shall not be redeclared in the outermost block of the handler.
2043 ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope |
2044 (FnCatch ? Scope::FnTryCatchScope : 0));
2045
2046 // exception-declaration is equivalent to '...' or a parameter-declaration
2047 // without default arguments.
2048 Decl *ExceptionDecl = nullptr;
2049 if (Tok.isNot(tok::ellipsis)) {
2050 ParsedAttributesWithRange Attributes(AttrFactory);
2051 MaybeParseCXX11Attributes(Attributes);
2052
2053 DeclSpec DS(AttrFactory);
2054 DS.takeAttributesFrom(Attributes);
2055
2056 if (ParseCXXTypeSpecifierSeq(DS))
2057 return StmtError();
2058
2059 Declarator ExDecl(DS, Declarator::CXXCatchContext);
2060 ParseDeclarator(ExDecl);
2061 ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
2062 } else
2063 ConsumeToken();
2064
2065 T.consumeClose();
2066 if (T.getCloseLocation().isInvalid())
2067 return StmtError();
2068
2069 if (Tok.isNot(tok::l_brace))
2070 return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
2071
2072 // FIXME: Possible draft standard bug: attribute-specifier should be allowed?
2073 StmtResult Block(ParseCompoundStatement());
2074 if (Block.isInvalid())
2075 return Block;
2076
2077 return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.get());
2078 }
2079
ParseMicrosoftIfExistsStatement(StmtVector & Stmts)2080 void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
2081 IfExistsCondition Result;
2082 if (ParseMicrosoftIfExistsCondition(Result))
2083 return;
2084
2085 // Handle dependent statements by parsing the braces as a compound statement.
2086 // This is not the same behavior as Visual C++, which don't treat this as a
2087 // compound statement, but for Clang's type checking we can't have anything
2088 // inside these braces escaping to the surrounding code.
2089 if (Result.Behavior == IEB_Dependent) {
2090 if (!Tok.is(tok::l_brace)) {
2091 Diag(Tok, diag::err_expected) << tok::l_brace;
2092 return;
2093 }
2094
2095 StmtResult Compound = ParseCompoundStatement();
2096 if (Compound.isInvalid())
2097 return;
2098
2099 StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc,
2100 Result.IsIfExists,
2101 Result.SS,
2102 Result.Name,
2103 Compound.get());
2104 if (DepResult.isUsable())
2105 Stmts.push_back(DepResult.get());
2106 return;
2107 }
2108
2109 BalancedDelimiterTracker Braces(*this, tok::l_brace);
2110 if (Braces.consumeOpen()) {
2111 Diag(Tok, diag::err_expected) << tok::l_brace;
2112 return;
2113 }
2114
2115 switch (Result.Behavior) {
2116 case IEB_Parse:
2117 // Parse the statements below.
2118 break;
2119
2120 case IEB_Dependent:
2121 llvm_unreachable("Dependent case handled above");
2122
2123 case IEB_Skip:
2124 Braces.skipToEnd();
2125 return;
2126 }
2127
2128 // Condition is true, parse the statements.
2129 while (Tok.isNot(tok::r_brace)) {
2130 StmtResult R = ParseStatementOrDeclaration(Stmts, false);
2131 if (R.isUsable())
2132 Stmts.push_back(R.get());
2133 }
2134 Braces.consumeClose();
2135 }
2136