SemaStmt.cpp revision c1f3b28004a032f4cd13721d4d884c6dcec29c31
1//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 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 semantic analysis for statements. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/StmtObjC.h" 20#include "clang/AST/StmtCXX.h" 21#include "clang/Basic/TargetInfo.h" 22using namespace clang; 23 24Sema::OwningStmtResult Sema::ActOnExprStmt(ExprArg expr) { 25 Expr *E = expr.takeAs<Expr>(); 26 assert(E && "ActOnExprStmt(): missing expression"); 27 28 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 29 // void expression for its side effects. Conversion to void allows any 30 // operand, even incomplete types. 31 32 // Same thing in for stmt first clause (when expr) and third clause. 33 return Owned(static_cast<Stmt*>(E)); 34} 35 36 37Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 38 return Owned(new (Context) NullStmt(SemiLoc)); 39} 40 41Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, 42 SourceLocation StartLoc, 43 SourceLocation EndLoc) { 44 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 45 46 // If we have an invalid decl, just return an error. 47 if (DG.isNull()) return StmtError(); 48 49 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 50} 51 52Action::OwningStmtResult 53Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 54 MultiStmtArg elts, bool isStmtExpr) { 55 unsigned NumElts = elts.size(); 56 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 57 // If we're in C89 mode, check that we don't have any decls after stmts. If 58 // so, emit an extension diagnostic. 59 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 60 // Note that __extension__ can be around a decl. 61 unsigned i = 0; 62 // Skip over all declarations. 63 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 64 /*empty*/; 65 66 // We found the end of the list or a statement. Scan for another declstmt. 67 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 68 /*empty*/; 69 70 if (i != NumElts) { 71 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 72 Diag(D->getLocation(), diag::ext_mixed_decls_code); 73 } 74 } 75 // Warn about unused expressions in statements. 76 for (unsigned i = 0; i != NumElts; ++i) { 77 Expr *E = dyn_cast<Expr>(Elts[i]); 78 if (!E) continue; 79 80 // Warn about expressions with unused results if they are non-void and if 81 // this not the last stmt in a stmt expr. 82 if (E->getType()->isVoidType() || (isStmtExpr && i == NumElts-1)) 83 continue; 84 85 SourceLocation Loc; 86 SourceRange R1, R2; 87 if (!E->isUnusedResultAWarning(Loc, R1, R2)) 88 continue; 89 90 Diag(Loc, diag::warn_unused_expr) << R1 << R2; 91 } 92 93 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 94} 95 96Action::OwningStmtResult 97Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval, 98 SourceLocation DotDotDotLoc, ExprArg rhsval, 99 SourceLocation ColonLoc) { 100 assert((lhsval.get() != 0) && "missing expression in case statement"); 101 102 // C99 6.8.4.2p3: The expression shall be an integer constant. 103 // However, GCC allows any evaluatable integer expression. 104 Expr *LHSVal = static_cast<Expr*>(lhsval.get()); 105 if (VerifyIntegerConstantExpression(LHSVal)) 106 return StmtError(); 107 108 // GCC extension: The expression shall be an integer constant. 109 110 Expr *RHSVal = static_cast<Expr*>(rhsval.get()); 111 if (RHSVal && VerifyIntegerConstantExpression(RHSVal)) { 112 RHSVal = 0; // Recover by just forgetting about it. 113 rhsval = 0; 114 } 115 116 if (getSwitchStack().empty()) { 117 Diag(CaseLoc, diag::err_case_not_in_switch); 118 return StmtError(); 119 } 120 121 // Only now release the smart pointers. 122 lhsval.release(); 123 rhsval.release(); 124 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc); 125 getSwitchStack().back()->addSwitchCase(CS); 126 return Owned(CS); 127} 128 129/// ActOnCaseStmtBody - This installs a statement as the body of a case. 130void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) { 131 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 132 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 133 CS->setSubStmt(SubStmt); 134} 135 136Action::OwningStmtResult 137Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 138 StmtArg subStmt, Scope *CurScope) { 139 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 140 141 if (getSwitchStack().empty()) { 142 Diag(DefaultLoc, diag::err_default_not_in_switch); 143 return Owned(SubStmt); 144 } 145 146 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, SubStmt); 147 getSwitchStack().back()->addSwitchCase(DS); 148 return Owned(DS); 149} 150 151Action::OwningStmtResult 152Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 153 SourceLocation ColonLoc, StmtArg subStmt) { 154 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 155 // Look up the record for this label identifier. 156 LabelStmt *&LabelDecl = getLabelMap()[II]; 157 158 // If not forward referenced or defined already, just create a new LabelStmt. 159 if (LabelDecl == 0) 160 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt)); 161 162 assert(LabelDecl->getID() == II && "Label mismatch!"); 163 164 // Otherwise, this label was either forward reference or multiply defined. If 165 // multiply defined, reject it now. 166 if (LabelDecl->getSubStmt()) { 167 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 168 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 169 return Owned(SubStmt); 170 } 171 172 // Otherwise, this label was forward declared, and we just found its real 173 // definition. Fill in the forward definition and return it. 174 LabelDecl->setIdentLoc(IdentLoc); 175 LabelDecl->setSubStmt(SubStmt); 176 return Owned(LabelDecl); 177} 178 179Action::OwningStmtResult 180Sema::ActOnIfStmt(SourceLocation IfLoc, ExprArg CondVal, 181 StmtArg ThenVal, SourceLocation ElseLoc, 182 StmtArg ElseVal) { 183 Expr *condExpr = CondVal.takeAs<Expr>(); 184 185 assert(condExpr && "ActOnIfStmt(): missing expression"); 186 187 DefaultFunctionArrayConversion(condExpr); 188 // Take ownership again until we're past the error checking. 189 CondVal = condExpr; 190 QualType condType = condExpr->getType(); 191 192 if (getLangOptions().CPlusPlus) { 193 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 194 return StmtError(); 195 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 196 return StmtError(Diag(IfLoc, diag::err_typecheck_statement_requires_scalar) 197 << condType << condExpr->getSourceRange()); 198 199 Stmt *thenStmt = ThenVal.takeAs<Stmt>(); 200 201 // Warn if the if block has a null body without an else value. 202 // this helps prevent bugs due to typos, such as 203 // if (condition); 204 // do_stuff(); 205 if (!ElseVal.get()) { 206 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 207 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 208 } 209 210 CondVal.release(); 211 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 212 ElseVal.takeAs<Stmt>())); 213} 214 215Action::OwningStmtResult 216Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 217 Expr *Cond = cond.takeAs<Expr>(); 218 219 if (getLangOptions().CPlusPlus) { 220 // C++ 6.4.2.p2: 221 // The condition shall be of integral type, enumeration type, or of a class 222 // type for which a single conversion function to integral or enumeration 223 // type exists (12.3). If the condition is of class type, the condition is 224 // converted by calling that conversion function, and the result of the 225 // conversion is used in place of the original condition for the remainder 226 // of this section. Integral promotions are performed. 227 228 QualType Ty = Cond->getType(); 229 230 // FIXME: Handle class types. 231 232 // If the type is wrong a diagnostic will be emitted later at 233 // ActOnFinishSwitchStmt. 234 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 235 // Integral promotions are performed. 236 // FIXME: Integral promotions for C++ are not complete. 237 UsualUnaryConversions(Cond); 238 } 239 } else { 240 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 241 UsualUnaryConversions(Cond); 242 } 243 244 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 245 getSwitchStack().push_back(SS); 246 return Owned(SS); 247} 248 249/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 250/// the specified width and sign. If an overflow occurs, detect it and emit 251/// the specified diagnostic. 252void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 253 unsigned NewWidth, bool NewSign, 254 SourceLocation Loc, 255 unsigned DiagID) { 256 // Perform a conversion to the promoted condition type if needed. 257 if (NewWidth > Val.getBitWidth()) { 258 // If this is an extension, just do it. 259 llvm::APSInt OldVal(Val); 260 Val.extend(NewWidth); 261 262 // If the input was signed and negative and the output is unsigned, 263 // warn. 264 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 265 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 266 267 Val.setIsSigned(NewSign); 268 } else if (NewWidth < Val.getBitWidth()) { 269 // If this is a truncation, check for overflow. 270 llvm::APSInt ConvVal(Val); 271 ConvVal.trunc(NewWidth); 272 ConvVal.setIsSigned(NewSign); 273 ConvVal.extend(Val.getBitWidth()); 274 ConvVal.setIsSigned(Val.isSigned()); 275 if (ConvVal != Val) 276 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 277 278 // Regardless of whether a diagnostic was emitted, really do the 279 // truncation. 280 Val.trunc(NewWidth); 281 Val.setIsSigned(NewSign); 282 } else if (NewSign != Val.isSigned()) { 283 // Convert the sign to match the sign of the condition. This can cause 284 // overflow as well: unsigned(INTMIN) 285 llvm::APSInt OldVal(Val); 286 Val.setIsSigned(NewSign); 287 288 if (Val.isNegative()) // Sign bit changes meaning. 289 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 290 } 291} 292 293namespace { 294 struct CaseCompareFunctor { 295 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 296 const llvm::APSInt &RHS) { 297 return LHS.first < RHS; 298 } 299 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 300 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 301 return LHS.first < RHS.first; 302 } 303 bool operator()(const llvm::APSInt &LHS, 304 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 305 return LHS < RHS.first; 306 } 307 }; 308} 309 310/// CmpCaseVals - Comparison predicate for sorting case values. 311/// 312static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 313 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 314 if (lhs.first < rhs.first) 315 return true; 316 317 if (lhs.first == rhs.first && 318 lhs.second->getCaseLoc().getRawEncoding() 319 < rhs.second->getCaseLoc().getRawEncoding()) 320 return true; 321 return false; 322} 323 324Action::OwningStmtResult 325Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 326 StmtArg Body) { 327 Stmt *BodyStmt = Body.takeAs<Stmt>(); 328 329 SwitchStmt *SS = getSwitchStack().back(); 330 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 331 332 SS->setBody(BodyStmt, SwitchLoc); 333 getSwitchStack().pop_back(); 334 335 Expr *CondExpr = SS->getCond(); 336 QualType CondType = CondExpr->getType(); 337 338 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 339 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 340 << CondType << CondExpr->getSourceRange(); 341 return StmtError(); 342 } 343 344 // Get the bitwidth of the switched-on value before promotions. We must 345 // convert the integer case values to this width before comparison. 346 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 347 bool CondIsSigned = CondType->isSignedIntegerType(); 348 349 // Accumulate all of the case values in a vector so that we can sort them 350 // and detect duplicates. This vector contains the APInt for the case after 351 // it has been converted to the condition type. 352 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 353 CaseValsTy CaseVals; 354 355 // Keep track of any GNU case ranges we see. The APSInt is the low value. 356 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 357 358 DefaultStmt *TheDefaultStmt = 0; 359 360 bool CaseListIsErroneous = false; 361 362 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 363 SC = SC->getNextSwitchCase()) { 364 365 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 366 if (TheDefaultStmt) { 367 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 368 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 369 370 // FIXME: Remove the default statement from the switch block so that 371 // we'll return a valid AST. This requires recursing down the 372 // AST and finding it, not something we are set up to do right now. For 373 // now, just lop the entire switch stmt out of the AST. 374 CaseListIsErroneous = true; 375 } 376 TheDefaultStmt = DS; 377 378 } else { 379 CaseStmt *CS = cast<CaseStmt>(SC); 380 381 // We already verified that the expression has a i-c-e value (C99 382 // 6.8.4.2p3) - get that value now. 383 Expr *Lo = CS->getLHS(); 384 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 385 386 // Convert the value to the same width/sign as the condition. 387 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 388 CS->getLHS()->getLocStart(), 389 diag::warn_case_value_overflow); 390 391 // If the LHS is not the same type as the condition, insert an implicit 392 // cast. 393 ImpCastExprToType(Lo, CondType); 394 CS->setLHS(Lo); 395 396 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 397 if (CS->getRHS()) 398 CaseRanges.push_back(std::make_pair(LoVal, CS)); 399 else 400 CaseVals.push_back(std::make_pair(LoVal, CS)); 401 } 402 } 403 404 // Sort all the scalar case values so we can easily detect duplicates. 405 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 406 407 if (!CaseVals.empty()) { 408 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 409 if (CaseVals[i].first == CaseVals[i+1].first) { 410 // If we have a duplicate, report it. 411 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 412 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 413 Diag(CaseVals[i].second->getLHS()->getLocStart(), 414 diag::note_duplicate_case_prev); 415 // FIXME: We really want to remove the bogus case stmt from the substmt, 416 // but we have no way to do this right now. 417 CaseListIsErroneous = true; 418 } 419 } 420 } 421 422 // Detect duplicate case ranges, which usually don't exist at all in the first 423 // place. 424 if (!CaseRanges.empty()) { 425 // Sort all the case ranges by their low value so we can easily detect 426 // overlaps between ranges. 427 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 428 429 // Scan the ranges, computing the high values and removing empty ranges. 430 std::vector<llvm::APSInt> HiVals; 431 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 432 CaseStmt *CR = CaseRanges[i].second; 433 Expr *Hi = CR->getRHS(); 434 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 435 436 // Convert the value to the same width/sign as the condition. 437 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 438 CR->getRHS()->getLocStart(), 439 diag::warn_case_value_overflow); 440 441 // If the LHS is not the same type as the condition, insert an implicit 442 // cast. 443 ImpCastExprToType(Hi, CondType); 444 CR->setRHS(Hi); 445 446 // If the low value is bigger than the high value, the case is empty. 447 if (CaseRanges[i].first > HiVal) { 448 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 449 << SourceRange(CR->getLHS()->getLocStart(), 450 CR->getRHS()->getLocEnd()); 451 CaseRanges.erase(CaseRanges.begin()+i); 452 --i, --e; 453 continue; 454 } 455 HiVals.push_back(HiVal); 456 } 457 458 // Rescan the ranges, looking for overlap with singleton values and other 459 // ranges. Since the range list is sorted, we only need to compare case 460 // ranges with their neighbors. 461 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 462 llvm::APSInt &CRLo = CaseRanges[i].first; 463 llvm::APSInt &CRHi = HiVals[i]; 464 CaseStmt *CR = CaseRanges[i].second; 465 466 // Check to see whether the case range overlaps with any singleton cases. 467 CaseStmt *OverlapStmt = 0; 468 llvm::APSInt OverlapVal(32); 469 470 // Find the smallest value >= the lower bound. If I is in the case range, 471 // then we have overlap. 472 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 473 CaseVals.end(), CRLo, 474 CaseCompareFunctor()); 475 if (I != CaseVals.end() && I->first < CRHi) { 476 OverlapVal = I->first; // Found overlap with scalar. 477 OverlapStmt = I->second; 478 } 479 480 // Find the smallest value bigger than the upper bound. 481 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 482 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 483 OverlapVal = (I-1)->first; // Found overlap with scalar. 484 OverlapStmt = (I-1)->second; 485 } 486 487 // Check to see if this case stmt overlaps with the subsequent case range. 488 if (i && CRLo <= HiVals[i-1]) { 489 OverlapVal = HiVals[i-1]; // Found overlap with range. 490 OverlapStmt = CaseRanges[i-1].second; 491 } 492 493 if (OverlapStmt) { 494 // If we have a duplicate, report it. 495 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 496 << OverlapVal.toString(10); 497 Diag(OverlapStmt->getLHS()->getLocStart(), 498 diag::note_duplicate_case_prev); 499 // FIXME: We really want to remove the bogus case stmt from the substmt, 500 // but we have no way to do this right now. 501 CaseListIsErroneous = true; 502 } 503 } 504 } 505 506 // FIXME: If the case list was broken is some way, we don't have a good system 507 // to patch it up. Instead, just return the whole substmt as broken. 508 if (CaseListIsErroneous) 509 return StmtError(); 510 511 Switch.release(); 512 return Owned(SS); 513} 514 515Action::OwningStmtResult 516Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprArg Cond, StmtArg Body) { 517 Expr *condExpr = Cond.takeAs<Expr>(); 518 assert(condExpr && "ActOnWhileStmt(): missing expression"); 519 520 DefaultFunctionArrayConversion(condExpr); 521 Cond = condExpr; 522 QualType condType = condExpr->getType(); 523 524 if (getLangOptions().CPlusPlus) { 525 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 526 return StmtError(); 527 } else if (!condType->isScalarType()) // C99 6.8.5p2 528 return StmtError(Diag(WhileLoc, 529 diag::err_typecheck_statement_requires_scalar) 530 << condType << condExpr->getSourceRange()); 531 532 Cond.release(); 533 return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 534 WhileLoc)); 535} 536 537Action::OwningStmtResult 538Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 539 SourceLocation WhileLoc, ExprArg Cond) { 540 Expr *condExpr = Cond.takeAs<Expr>(); 541 assert(condExpr && "ActOnDoStmt(): missing expression"); 542 543 DefaultFunctionArrayConversion(condExpr); 544 Cond = condExpr; 545 QualType condType = condExpr->getType(); 546 547 if (getLangOptions().CPlusPlus) { 548 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 549 return StmtError(); 550 } else if (!condType->isScalarType()) // C99 6.8.5p2 551 return StmtError(Diag(DoLoc, diag::err_typecheck_statement_requires_scalar) 552 << condType << condExpr->getSourceRange()); 553 554 Cond.release(); 555 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc)); 556} 557 558Action::OwningStmtResult 559Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 560 StmtArg first, ExprArg second, ExprArg third, 561 SourceLocation RParenLoc, StmtArg body) { 562 Stmt *First = static_cast<Stmt*>(first.get()); 563 Expr *Second = static_cast<Expr*>(second.get()); 564 Expr *Third = static_cast<Expr*>(third.get()); 565 Stmt *Body = static_cast<Stmt*>(body.get()); 566 567 if (!getLangOptions().CPlusPlus) { 568 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 569 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 570 // declare identifiers for objects having storage class 'auto' or 571 // 'register'. 572 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 573 DI!=DE; ++DI) { 574 VarDecl *VD = dyn_cast<VarDecl>(*DI); 575 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 576 VD = 0; 577 if (VD == 0) 578 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 579 // FIXME: mark decl erroneous! 580 } 581 } 582 } 583 if (Second) { 584 DefaultFunctionArrayConversion(Second); 585 QualType SecondType = Second->getType(); 586 587 if (getLangOptions().CPlusPlus) { 588 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 589 return StmtError(); 590 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 591 return StmtError(Diag(ForLoc, 592 diag::err_typecheck_statement_requires_scalar) 593 << SecondType << Second->getSourceRange()); 594 } 595 first.release(); 596 second.release(); 597 third.release(); 598 body.release(); 599 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc)); 600} 601 602Action::OwningStmtResult 603Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 604 SourceLocation LParenLoc, 605 StmtArg first, ExprArg second, 606 SourceLocation RParenLoc, StmtArg body) { 607 Stmt *First = static_cast<Stmt*>(first.get()); 608 Expr *Second = static_cast<Expr*>(second.get()); 609 Stmt *Body = static_cast<Stmt*>(body.get()); 610 if (First) { 611 QualType FirstType; 612 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 613 if (!DS->isSingleDecl()) 614 return StmtError(Diag((*DS->decl_begin())->getLocation(), 615 diag::err_toomany_element_decls)); 616 617 Decl *D = DS->getSingleDecl(); 618 FirstType = cast<ValueDecl>(D)->getType(); 619 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 620 // declare identifiers for objects having storage class 'auto' or 621 // 'register'. 622 VarDecl *VD = cast<VarDecl>(D); 623 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 624 return StmtError(Diag(VD->getLocation(), 625 diag::err_non_variable_decl_in_for)); 626 } else { 627 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 628 return StmtError(Diag(First->getLocStart(), 629 diag::err_selector_element_not_lvalue) 630 << First->getSourceRange()); 631 632 FirstType = static_cast<Expr*>(First)->getType(); 633 } 634 if (!Context.isObjCObjectPointerType(FirstType)) 635 Diag(ForLoc, diag::err_selector_element_type) 636 << FirstType << First->getSourceRange(); 637 } 638 if (Second) { 639 DefaultFunctionArrayConversion(Second); 640 QualType SecondType = Second->getType(); 641 if (!Context.isObjCObjectPointerType(SecondType)) 642 Diag(ForLoc, diag::err_collection_expr_type) 643 << SecondType << Second->getSourceRange(); 644 } 645 first.release(); 646 second.release(); 647 body.release(); 648 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 649 ForLoc, RParenLoc)); 650} 651 652Action::OwningStmtResult 653Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 654 IdentifierInfo *LabelII) { 655 // If we are in a block, reject all gotos for now. 656 if (CurBlock) 657 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 658 659 // Look up the record for this label identifier. 660 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 661 662 // If we haven't seen this label yet, create a forward reference. 663 if (LabelDecl == 0) 664 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 665 666 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 667} 668 669Action::OwningStmtResult 670Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 671 ExprArg DestExp) { 672 // Convert operand to void* 673 Expr* E = DestExp.takeAs<Expr>(); 674 QualType ETy = E->getType(); 675 AssignConvertType ConvTy = 676 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 677 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 678 E, "passing")) 679 return StmtError(); 680 return Owned(new (Context) IndirectGotoStmt(GotoLoc, E)); 681} 682 683Action::OwningStmtResult 684Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 685 Scope *S = CurScope->getContinueParent(); 686 if (!S) { 687 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 688 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 689 } 690 691 return Owned(new (Context) ContinueStmt(ContinueLoc)); 692} 693 694Action::OwningStmtResult 695Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 696 Scope *S = CurScope->getBreakParent(); 697 if (!S) { 698 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 699 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 700 } 701 702 return Owned(new (Context) BreakStmt(BreakLoc)); 703} 704 705/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 706/// 707Action::OwningStmtResult 708Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 709 // If this is the first return we've seen in the block, infer the type of 710 // the block from it. 711 if (CurBlock->ReturnType == 0) { 712 if (RetValExp) { 713 // Don't call UsualUnaryConversions(), since we don't want to do 714 // integer promotions here. 715 DefaultFunctionArrayConversion(RetValExp); 716 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 717 } else 718 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 719 } 720 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 721 722 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 723 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 724 << getCurFunctionOrMethodDecl()->getDeclName(); 725 return StmtError(); 726 } 727 728 // Otherwise, verify that this result type matches the previous one. We are 729 // pickier with blocks than for normal functions because we don't have GCC 730 // compatibility to worry about here. 731 if (CurBlock->ReturnType->isVoidType()) { 732 if (RetValExp) { 733 Diag(ReturnLoc, diag::err_return_block_has_expr); 734 RetValExp->Destroy(Context); 735 RetValExp = 0; 736 } 737 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 738 } 739 740 if (!RetValExp) 741 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 742 743 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 744 // we have a non-void block with an expression, continue checking 745 QualType RetValType = RetValExp->getType(); 746 747 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 748 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 749 // function return. 750 751 // In C++ the return statement is handled via a copy initialization. 752 // the C version of which boils down to CheckSingleAssignmentConstraints. 753 // FIXME: Leaks RetValExp. 754 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 755 return StmtError(); 756 757 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 758 } 759 760 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 761} 762 763/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 764/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 765static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 766 Expr *RetExpr) { 767 QualType ExprType = RetExpr->getType(); 768 // - in a return statement in a function with ... 769 // ... a class return type ... 770 if (!RetType->isRecordType()) 771 return false; 772 // ... the same cv-unqualified type as the function return type ... 773 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 774 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 775 return false; 776 // ... the expression is the name of a non-volatile automatic object ... 777 // We ignore parentheses here. 778 // FIXME: Is this compliant? 779 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 780 if (!DR) 781 return false; 782 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 783 if (!VD) 784 return false; 785 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 786 && !VD->getType().isVolatileQualified(); 787} 788 789Action::OwningStmtResult 790Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 791 Expr *RetValExp = rex.takeAs<Expr>(); 792 if (CurBlock) 793 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 794 795 QualType FnRetType; 796 if (const FunctionDecl *FD = getCurFunctionDecl()) { 797 FnRetType = FD->getResultType(); 798 if (FD->hasAttr<NoReturnAttr>()) { 799 Diag(ReturnLoc, diag::err_noreturn_function_has_return_expr) 800 << getCurFunctionOrMethodDecl()->getDeclName(); 801 return StmtError(); 802 } 803 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 804 FnRetType = MD->getResultType(); 805 else // If we don't have a function/method context, bail. 806 return StmtError(); 807 808 if (FnRetType->isVoidType()) { 809 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 810 unsigned D = diag::ext_return_has_expr; 811 if (RetValExp->getType()->isVoidType()) 812 D = diag::ext_return_has_void_expr; 813 814 // return (some void expression); is legal in C++. 815 if (D != diag::ext_return_has_void_expr || 816 !getLangOptions().CPlusPlus) { 817 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 818 Diag(ReturnLoc, D) 819 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 820 << RetValExp->getSourceRange(); 821 } 822 } 823 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 824 } 825 826 if (!RetValExp) { 827 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 828 // C99 6.8.6.4p1 (ext_ since GCC warns) 829 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 830 831 if (FunctionDecl *FD = getCurFunctionDecl()) 832 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 833 else 834 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 835 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 836 } 837 838 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 839 // we have a non-void function with an expression, continue checking 840 841 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 842 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 843 // function return. 844 845 // C++0x 12.8p15: When certain criteria are met, an implementation is 846 // allowed to omit the copy construction of a class object, [...] 847 // - in a return statement in a function with a class return type, when 848 // the expression is the name of a non-volatile automatic object with 849 // the same cv-unqualified type as the function return type, the copy 850 // operation can be omitted [...] 851 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 852 // and the object to be copied is designated by an lvalue, overload 853 // resolution to select the constructor for the copy is first performed 854 // as if the object were designated by an rvalue. 855 // Note that we only compute Elidable if we're in C++0x, since we don't 856 // care otherwise. 857 bool Elidable = getLangOptions().CPlusPlus0x ? 858 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 859 false; 860 861 // In C++ the return statement is handled via a copy initialization. 862 // the C version of which boils down to CheckSingleAssignmentConstraints. 863 // FIXME: Leaks RetValExp on error. 864 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 865 return StmtError(); 866 867 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 868 } 869 870 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 871} 872 873/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 874/// ignore "noop" casts in places where an lvalue is required by an inline asm. 875/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 876/// provide a strong guidance to not use it. 877/// 878/// This method checks to see if the argument is an acceptable l-value and 879/// returns false if it is a case we can handle. 880static bool CheckAsmLValue(const Expr *E, Sema &S) { 881 if (E->isLvalue(S.Context) == Expr::LV_Valid) 882 return false; // Cool, this is an lvalue. 883 884 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 885 // are supposed to allow. 886 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 887 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 888 if (!S.getLangOptions().HeinousExtensions) 889 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 890 << E->getSourceRange(); 891 else 892 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 893 << E->getSourceRange(); 894 // Accept, even if we emitted an error diagnostic. 895 return false; 896 } 897 898 // None of the above, just randomly invalid non-lvalue. 899 return true; 900} 901 902 903Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 904 bool IsSimple, 905 bool IsVolatile, 906 unsigned NumOutputs, 907 unsigned NumInputs, 908 std::string *Names, 909 MultiExprArg constraints, 910 MultiExprArg exprs, 911 ExprArg asmString, 912 MultiExprArg clobbers, 913 SourceLocation RParenLoc) { 914 unsigned NumClobbers = clobbers.size(); 915 StringLiteral **Constraints = 916 reinterpret_cast<StringLiteral**>(constraints.get()); 917 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 918 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 919 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 920 921 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 922 923 // The parser verifies that there is a string literal here. 924 if (AsmString->isWide()) 925 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 926 << AsmString->getSourceRange()); 927 928 for (unsigned i = 0; i != NumOutputs; i++) { 929 StringLiteral *Literal = Constraints[i]; 930 if (Literal->isWide()) 931 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 932 << Literal->getSourceRange()); 933 934 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 935 Literal->getByteLength(), 936 Names[i]); 937 if (!Context.Target.validateOutputConstraint(Info)) 938 return StmtError(Diag(Literal->getLocStart(), 939 diag::err_asm_invalid_output_constraint) 940 << Info.getConstraintStr()); 941 942 // Check that the output exprs are valid lvalues. 943 // FIXME: Operands to asms should not be parsed as ParenExprs. 944 ParenExpr *OutputExpr = cast<ParenExpr>(Exprs[i]); 945 if (CheckAsmLValue(OutputExpr, *this)) { 946 return StmtError(Diag(OutputExpr->getSubExpr()->getLocStart(), 947 diag::err_asm_invalid_lvalue_in_output) 948 << OutputExpr->getSubExpr()->getSourceRange()); 949 } 950 951 OutputConstraintInfos.push_back(Info); 952 } 953 954 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 955 956 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 957 StringLiteral *Literal = Constraints[i]; 958 if (Literal->isWide()) 959 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 960 << Literal->getSourceRange()); 961 962 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 963 Literal->getByteLength(), 964 Names[i]); 965 if (!Context.Target.validateInputConstraint(&OutputConstraintInfos[0], 966 NumOutputs, Info)) { 967 return StmtError(Diag(Literal->getLocStart(), 968 diag::err_asm_invalid_input_constraint) 969 << Info.getConstraintStr()); 970 } 971 972 ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]); 973 974 // Only allow void types for memory constraints. 975 if (Info.allowsMemory() && !Info.allowsRegister()) { 976 if (CheckAsmLValue(InputExpr, *this)) 977 return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(), 978 diag::err_asm_invalid_lvalue_in_input) 979 << Info.getConstraintStr() 980 << InputExpr->getSubExpr()->getSourceRange()); 981 } 982 983 if (Info.allowsRegister()) { 984 if (InputExpr->getType()->isVoidType()) { 985 return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(), 986 diag::err_asm_invalid_type_in_input) 987 << InputExpr->getType() << Info.getConstraintStr() 988 << InputExpr->getSubExpr()->getSourceRange()); 989 } 990 } 991 992 DefaultFunctionArrayConversion(Exprs[i]); 993 994 InputConstraintInfos.push_back(Info); 995 } 996 997 // Check that the clobbers are valid. 998 for (unsigned i = 0; i != NumClobbers; i++) { 999 StringLiteral *Literal = Clobbers[i]; 1000 if (Literal->isWide()) 1001 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1002 << Literal->getSourceRange()); 1003 1004 llvm::SmallString<16> Clobber(Literal->getStrData(), 1005 Literal->getStrData() + 1006 Literal->getByteLength()); 1007 1008 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1009 return StmtError(Diag(Literal->getLocStart(), 1010 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1011 } 1012 1013 constraints.release(); 1014 exprs.release(); 1015 asmString.release(); 1016 clobbers.release(); 1017 AsmStmt *NS = 1018 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1019 Names, Constraints, Exprs, AsmString, NumClobbers, 1020 Clobbers, RParenLoc); 1021 // Validate the asm string, ensuring it makes sense given the operands we 1022 // have. 1023 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1024 unsigned DiagOffs; 1025 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1026 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1027 << AsmString->getSourceRange(); 1028 DeleteStmt(NS); 1029 return StmtError(); 1030 } 1031 1032 // Validate tied input operands for type mismatches. 1033 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1034 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1035 1036 // If this is a tied constraint, verify that the output and input have 1037 // either exactly the same type, or that they are int/ptr operands with the 1038 // same size (int/long, int*/long, are ok etc). 1039 if (!Info.hasTiedOperand()) continue; 1040 1041 unsigned TiedTo = Info.getTiedOperand(); 1042 Expr *OutputExpr = Exprs[TiedTo]; 1043 Expr *InputExpr = Exprs[i+NumOutputs]; 1044 QualType InTy = InputExpr->getType(); 1045 QualType OutTy = OutputExpr->getType(); 1046 if (Context.hasSameType(InTy, OutTy)) 1047 continue; // All types can be tied to themselves. 1048 1049 // Int/ptr operands have some special cases that we allow. 1050 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1051 (InTy->isIntegerType() || InTy->isPointerType())) { 1052 1053 // They are ok if they are the same size. Tying void* to int is ok if 1054 // they are the same size, for example. This also allows tying void* to 1055 // int*. 1056 if (Context.getTypeSize(OutTy) == Context.getTypeSize(InTy)) 1057 continue; 1058 } 1059 1060 Diag(InputExpr->getLocStart(), 1061 diag::err_asm_tying_incompatible_types) 1062 << InTy << OutTy << OutputExpr->getSourceRange() 1063 << InputExpr->getSourceRange(); 1064 DeleteStmt(NS); 1065 return StmtError(); 1066 } 1067 1068 return Owned(NS); 1069} 1070 1071Action::OwningStmtResult 1072Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1073 SourceLocation RParen, DeclPtrTy Parm, 1074 StmtArg Body, StmtArg catchList) { 1075 Stmt *CatchList = catchList.takeAs<Stmt>(); 1076 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1077 1078 // PVD == 0 implies @catch(...). 1079 if (PVD) { 1080 // If we already know the decl is invalid, reject it. 1081 if (PVD->isInvalidDecl()) 1082 return StmtError(); 1083 1084 if (!Context.isObjCObjectPointerType(PVD->getType())) 1085 return StmtError(Diag(PVD->getLocation(), 1086 diag::err_catch_param_not_objc_type)); 1087 if (PVD->getType()->isObjCQualifiedIdType()) 1088 return StmtError(Diag(PVD->getLocation(), 1089 diag::err_illegal_qualifiers_on_catch_parm)); 1090 } 1091 1092 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1093 PVD, Body.takeAs<Stmt>(), CatchList); 1094 return Owned(CatchList ? CatchList : CS); 1095} 1096 1097Action::OwningStmtResult 1098Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1099 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1100 static_cast<Stmt*>(Body.release()))); 1101} 1102 1103Action::OwningStmtResult 1104Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1105 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1106 CurFunctionNeedsScopeChecking = true; 1107 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1108 Catch.takeAs<Stmt>(), 1109 Finally.takeAs<Stmt>())); 1110} 1111 1112Action::OwningStmtResult 1113Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1114 Expr *ThrowExpr = expr.takeAs<Expr>(); 1115 if (!ThrowExpr) { 1116 // @throw without an expression designates a rethrow (which much occur 1117 // in the context of an @catch clause). 1118 Scope *AtCatchParent = CurScope; 1119 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1120 AtCatchParent = AtCatchParent->getParent(); 1121 if (!AtCatchParent) 1122 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1123 } else { 1124 QualType ThrowType = ThrowExpr->getType(); 1125 // Make sure the expression type is an ObjC pointer or "void *". 1126 if (!Context.isObjCObjectPointerType(ThrowType)) { 1127 const PointerType *PT = ThrowType->getAsPointerType(); 1128 if (!PT || !PT->getPointeeType()->isVoidType()) 1129 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1130 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1131 } 1132 } 1133 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1134} 1135 1136Action::OwningStmtResult 1137Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1138 StmtArg SynchBody) { 1139 CurFunctionNeedsScopeChecking = true; 1140 1141 // Make sure the expression type is an ObjC pointer or "void *". 1142 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1143 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1144 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1145 if (!PT || !PT->getPointeeType()->isVoidType()) 1146 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1147 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1148 } 1149 1150 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1151 SynchExpr.takeAs<Stmt>(), 1152 SynchBody.takeAs<Stmt>())); 1153} 1154 1155/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1156/// and creates a proper catch handler from them. 1157Action::OwningStmtResult 1158Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1159 StmtArg HandlerBlock) { 1160 // There's nothing to test that ActOnExceptionDecl didn't already test. 1161 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1162 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1163 HandlerBlock.takeAs<Stmt>())); 1164} 1165 1166/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1167/// handlers and creates a try statement from them. 1168Action::OwningStmtResult 1169Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1170 MultiStmtArg RawHandlers) { 1171 unsigned NumHandlers = RawHandlers.size(); 1172 assert(NumHandlers > 0 && 1173 "The parser shouldn't call this if there are no handlers."); 1174 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1175 1176 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1177 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1178 if (!Handler->getExceptionDecl()) 1179 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1180 } 1181 // FIXME: We should detect handlers for the same type as an earlier one. 1182 // This one is rather easy. 1183 // FIXME: We should detect handlers that cannot catch anything because an 1184 // earlier handler catches a superclass. Need to find a method that is not 1185 // quadratic for this. 1186 // Neither of these are explicitly forbidden, but every compiler detects them 1187 // and warns. 1188 1189 CurFunctionNeedsScopeChecking = true; 1190 RawHandlers.release(); 1191 return Owned(new (Context) CXXTryStmt(TryLoc, 1192 static_cast<Stmt*>(TryBlock.release()), 1193 Handlers, NumHandlers)); 1194} 1195