SemaStmt.cpp revision 4a2e2041edc63db687677325e113b39b9d123c40
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 if (!condExpr->isTypeDependent()) { 188 DefaultFunctionArrayConversion(condExpr); 189 // Take ownership again until we're past the error checking. 190 CondVal = condExpr; 191 QualType condType = condExpr->getType(); 192 193 if (getLangOptions().CPlusPlus) { 194 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 195 return StmtError(); 196 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 197 return StmtError(Diag(IfLoc, 198 diag::err_typecheck_statement_requires_scalar) 199 << condType << condExpr->getSourceRange()); 200 } 201 202 Stmt *thenStmt = ThenVal.takeAs<Stmt>(); 203 204 // Warn if the if block has a null body without an else value. 205 // this helps prevent bugs due to typos, such as 206 // if (condition); 207 // do_stuff(); 208 if (!ElseVal.get()) { 209 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 210 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 211 } 212 213 CondVal.release(); 214 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 215 ElseLoc, ElseVal.takeAs<Stmt>())); 216} 217 218Action::OwningStmtResult 219Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 220 Expr *Cond = cond.takeAs<Expr>(); 221 222 if (getLangOptions().CPlusPlus) { 223 // C++ 6.4.2.p2: 224 // The condition shall be of integral type, enumeration type, or of a class 225 // type for which a single conversion function to integral or enumeration 226 // type exists (12.3). If the condition is of class type, the condition is 227 // converted by calling that conversion function, and the result of the 228 // conversion is used in place of the original condition for the remainder 229 // of this section. Integral promotions are performed. 230 231 QualType Ty = Cond->getType(); 232 233 // FIXME: Handle class types. 234 235 // If the type is wrong a diagnostic will be emitted later at 236 // ActOnFinishSwitchStmt. 237 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 238 // Integral promotions are performed. 239 // FIXME: Integral promotions for C++ are not complete. 240 UsualUnaryConversions(Cond); 241 } 242 } else { 243 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 244 UsualUnaryConversions(Cond); 245 } 246 247 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 248 getSwitchStack().push_back(SS); 249 return Owned(SS); 250} 251 252/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 253/// the specified width and sign. If an overflow occurs, detect it and emit 254/// the specified diagnostic. 255void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 256 unsigned NewWidth, bool NewSign, 257 SourceLocation Loc, 258 unsigned DiagID) { 259 // Perform a conversion to the promoted condition type if needed. 260 if (NewWidth > Val.getBitWidth()) { 261 // If this is an extension, just do it. 262 llvm::APSInt OldVal(Val); 263 Val.extend(NewWidth); 264 265 // If the input was signed and negative and the output is unsigned, 266 // warn. 267 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 268 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 269 270 Val.setIsSigned(NewSign); 271 } else if (NewWidth < Val.getBitWidth()) { 272 // If this is a truncation, check for overflow. 273 llvm::APSInt ConvVal(Val); 274 ConvVal.trunc(NewWidth); 275 ConvVal.setIsSigned(NewSign); 276 ConvVal.extend(Val.getBitWidth()); 277 ConvVal.setIsSigned(Val.isSigned()); 278 if (ConvVal != Val) 279 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 280 281 // Regardless of whether a diagnostic was emitted, really do the 282 // truncation. 283 Val.trunc(NewWidth); 284 Val.setIsSigned(NewSign); 285 } else if (NewSign != Val.isSigned()) { 286 // Convert the sign to match the sign of the condition. This can cause 287 // overflow as well: unsigned(INTMIN) 288 llvm::APSInt OldVal(Val); 289 Val.setIsSigned(NewSign); 290 291 if (Val.isNegative()) // Sign bit changes meaning. 292 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 293 } 294} 295 296namespace { 297 struct CaseCompareFunctor { 298 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 299 const llvm::APSInt &RHS) { 300 return LHS.first < RHS; 301 } 302 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 303 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 304 return LHS.first < RHS.first; 305 } 306 bool operator()(const llvm::APSInt &LHS, 307 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 308 return LHS < RHS.first; 309 } 310 }; 311} 312 313/// CmpCaseVals - Comparison predicate for sorting case values. 314/// 315static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 316 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 317 if (lhs.first < rhs.first) 318 return true; 319 320 if (lhs.first == rhs.first && 321 lhs.second->getCaseLoc().getRawEncoding() 322 < rhs.second->getCaseLoc().getRawEncoding()) 323 return true; 324 return false; 325} 326 327Action::OwningStmtResult 328Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 329 StmtArg Body) { 330 Stmt *BodyStmt = Body.takeAs<Stmt>(); 331 332 SwitchStmt *SS = getSwitchStack().back(); 333 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 334 335 SS->setBody(BodyStmt, SwitchLoc); 336 getSwitchStack().pop_back(); 337 338 Expr *CondExpr = SS->getCond(); 339 QualType CondType = CondExpr->getType(); 340 341 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 342 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 343 << CondType << CondExpr->getSourceRange(); 344 return StmtError(); 345 } 346 347 // Get the bitwidth of the switched-on value before promotions. We must 348 // convert the integer case values to this width before comparison. 349 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 350 bool CondIsSigned = CondType->isSignedIntegerType(); 351 352 // Accumulate all of the case values in a vector so that we can sort them 353 // and detect duplicates. This vector contains the APInt for the case after 354 // it has been converted to the condition type. 355 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 356 CaseValsTy CaseVals; 357 358 // Keep track of any GNU case ranges we see. The APSInt is the low value. 359 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 360 361 DefaultStmt *TheDefaultStmt = 0; 362 363 bool CaseListIsErroneous = false; 364 365 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 366 SC = SC->getNextSwitchCase()) { 367 368 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 369 if (TheDefaultStmt) { 370 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 371 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 372 373 // FIXME: Remove the default statement from the switch block so that 374 // we'll return a valid AST. This requires recursing down the 375 // AST and finding it, not something we are set up to do right now. For 376 // now, just lop the entire switch stmt out of the AST. 377 CaseListIsErroneous = true; 378 } 379 TheDefaultStmt = DS; 380 381 } else { 382 CaseStmt *CS = cast<CaseStmt>(SC); 383 384 // We already verified that the expression has a i-c-e value (C99 385 // 6.8.4.2p3) - get that value now. 386 Expr *Lo = CS->getLHS(); 387 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 388 389 // Convert the value to the same width/sign as the condition. 390 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 391 CS->getLHS()->getLocStart(), 392 diag::warn_case_value_overflow); 393 394 // If the LHS is not the same type as the condition, insert an implicit 395 // cast. 396 ImpCastExprToType(Lo, CondType); 397 CS->setLHS(Lo); 398 399 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 400 if (CS->getRHS()) 401 CaseRanges.push_back(std::make_pair(LoVal, CS)); 402 else 403 CaseVals.push_back(std::make_pair(LoVal, CS)); 404 } 405 } 406 407 // Sort all the scalar case values so we can easily detect duplicates. 408 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 409 410 if (!CaseVals.empty()) { 411 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 412 if (CaseVals[i].first == CaseVals[i+1].first) { 413 // If we have a duplicate, report it. 414 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 415 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 416 Diag(CaseVals[i].second->getLHS()->getLocStart(), 417 diag::note_duplicate_case_prev); 418 // FIXME: We really want to remove the bogus case stmt from the substmt, 419 // but we have no way to do this right now. 420 CaseListIsErroneous = true; 421 } 422 } 423 } 424 425 // Detect duplicate case ranges, which usually don't exist at all in the first 426 // place. 427 if (!CaseRanges.empty()) { 428 // Sort all the case ranges by their low value so we can easily detect 429 // overlaps between ranges. 430 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 431 432 // Scan the ranges, computing the high values and removing empty ranges. 433 std::vector<llvm::APSInt> HiVals; 434 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 435 CaseStmt *CR = CaseRanges[i].second; 436 Expr *Hi = CR->getRHS(); 437 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 438 439 // Convert the value to the same width/sign as the condition. 440 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 441 CR->getRHS()->getLocStart(), 442 diag::warn_case_value_overflow); 443 444 // If the LHS is not the same type as the condition, insert an implicit 445 // cast. 446 ImpCastExprToType(Hi, CondType); 447 CR->setRHS(Hi); 448 449 // If the low value is bigger than the high value, the case is empty. 450 if (CaseRanges[i].first > HiVal) { 451 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 452 << SourceRange(CR->getLHS()->getLocStart(), 453 CR->getRHS()->getLocEnd()); 454 CaseRanges.erase(CaseRanges.begin()+i); 455 --i, --e; 456 continue; 457 } 458 HiVals.push_back(HiVal); 459 } 460 461 // Rescan the ranges, looking for overlap with singleton values and other 462 // ranges. Since the range list is sorted, we only need to compare case 463 // ranges with their neighbors. 464 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 465 llvm::APSInt &CRLo = CaseRanges[i].first; 466 llvm::APSInt &CRHi = HiVals[i]; 467 CaseStmt *CR = CaseRanges[i].second; 468 469 // Check to see whether the case range overlaps with any singleton cases. 470 CaseStmt *OverlapStmt = 0; 471 llvm::APSInt OverlapVal(32); 472 473 // Find the smallest value >= the lower bound. If I is in the case range, 474 // then we have overlap. 475 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 476 CaseVals.end(), CRLo, 477 CaseCompareFunctor()); 478 if (I != CaseVals.end() && I->first < CRHi) { 479 OverlapVal = I->first; // Found overlap with scalar. 480 OverlapStmt = I->second; 481 } 482 483 // Find the smallest value bigger than the upper bound. 484 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 485 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 486 OverlapVal = (I-1)->first; // Found overlap with scalar. 487 OverlapStmt = (I-1)->second; 488 } 489 490 // Check to see if this case stmt overlaps with the subsequent case range. 491 if (i && CRLo <= HiVals[i-1]) { 492 OverlapVal = HiVals[i-1]; // Found overlap with range. 493 OverlapStmt = CaseRanges[i-1].second; 494 } 495 496 if (OverlapStmt) { 497 // If we have a duplicate, report it. 498 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 499 << OverlapVal.toString(10); 500 Diag(OverlapStmt->getLHS()->getLocStart(), 501 diag::note_duplicate_case_prev); 502 // FIXME: We really want to remove the bogus case stmt from the substmt, 503 // but we have no way to do this right now. 504 CaseListIsErroneous = true; 505 } 506 } 507 } 508 509 // FIXME: If the case list was broken is some way, we don't have a good system 510 // to patch it up. Instead, just return the whole substmt as broken. 511 if (CaseListIsErroneous) 512 return StmtError(); 513 514 Switch.release(); 515 return Owned(SS); 516} 517 518Action::OwningStmtResult 519Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprArg Cond, StmtArg Body) { 520 Expr *condExpr = Cond.takeAs<Expr>(); 521 assert(condExpr && "ActOnWhileStmt(): missing expression"); 522 523 if (!condExpr->isTypeDependent()) { 524 DefaultFunctionArrayConversion(condExpr); 525 Cond = condExpr; 526 QualType condType = condExpr->getType(); 527 528 if (getLangOptions().CPlusPlus) { 529 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 530 return StmtError(); 531 } else if (!condType->isScalarType()) // C99 6.8.5p2 532 return StmtError(Diag(WhileLoc, 533 diag::err_typecheck_statement_requires_scalar) 534 << condType << condExpr->getSourceRange()); 535 } 536 537 Cond.release(); 538 return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 539 WhileLoc)); 540} 541 542Action::OwningStmtResult 543Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 544 SourceLocation WhileLoc, ExprArg Cond) { 545 Expr *condExpr = Cond.takeAs<Expr>(); 546 assert(condExpr && "ActOnDoStmt(): missing expression"); 547 548 DefaultFunctionArrayConversion(condExpr); 549 Cond = condExpr; 550 QualType condType = condExpr->getType(); 551 552 if (getLangOptions().CPlusPlus) { 553 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 554 return StmtError(); 555 } else if (!condType->isScalarType()) // C99 6.8.5p2 556 return StmtError(Diag(DoLoc, diag::err_typecheck_statement_requires_scalar) 557 << condType << condExpr->getSourceRange()); 558 559 Cond.release(); 560 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc)); 561} 562 563Action::OwningStmtResult 564Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 565 StmtArg first, ExprArg second, ExprArg third, 566 SourceLocation RParenLoc, StmtArg body) { 567 Stmt *First = static_cast<Stmt*>(first.get()); 568 Expr *Second = static_cast<Expr*>(second.get()); 569 Expr *Third = static_cast<Expr*>(third.get()); 570 Stmt *Body = static_cast<Stmt*>(body.get()); 571 572 if (!getLangOptions().CPlusPlus) { 573 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 574 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 575 // declare identifiers for objects having storage class 'auto' or 576 // 'register'. 577 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 578 DI!=DE; ++DI) { 579 VarDecl *VD = dyn_cast<VarDecl>(*DI); 580 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 581 VD = 0; 582 if (VD == 0) 583 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 584 // FIXME: mark decl erroneous! 585 } 586 } 587 } 588 if (Second) { 589 DefaultFunctionArrayConversion(Second); 590 QualType SecondType = Second->getType(); 591 592 if (getLangOptions().CPlusPlus) { 593 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 594 return StmtError(); 595 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 596 return StmtError(Diag(ForLoc, 597 diag::err_typecheck_statement_requires_scalar) 598 << SecondType << Second->getSourceRange()); 599 } 600 first.release(); 601 second.release(); 602 third.release(); 603 body.release(); 604 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc)); 605} 606 607Action::OwningStmtResult 608Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 609 SourceLocation LParenLoc, 610 StmtArg first, ExprArg second, 611 SourceLocation RParenLoc, StmtArg body) { 612 Stmt *First = static_cast<Stmt*>(first.get()); 613 Expr *Second = static_cast<Expr*>(second.get()); 614 Stmt *Body = static_cast<Stmt*>(body.get()); 615 if (First) { 616 QualType FirstType; 617 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 618 if (!DS->isSingleDecl()) 619 return StmtError(Diag((*DS->decl_begin())->getLocation(), 620 diag::err_toomany_element_decls)); 621 622 Decl *D = DS->getSingleDecl(); 623 FirstType = cast<ValueDecl>(D)->getType(); 624 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 625 // declare identifiers for objects having storage class 'auto' or 626 // 'register'. 627 VarDecl *VD = cast<VarDecl>(D); 628 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 629 return StmtError(Diag(VD->getLocation(), 630 diag::err_non_variable_decl_in_for)); 631 } else { 632 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 633 return StmtError(Diag(First->getLocStart(), 634 diag::err_selector_element_not_lvalue) 635 << First->getSourceRange()); 636 637 FirstType = static_cast<Expr*>(First)->getType(); 638 } 639 if (!Context.isObjCObjectPointerType(FirstType)) 640 Diag(ForLoc, diag::err_selector_element_type) 641 << FirstType << First->getSourceRange(); 642 } 643 if (Second) { 644 DefaultFunctionArrayConversion(Second); 645 QualType SecondType = Second->getType(); 646 if (!Context.isObjCObjectPointerType(SecondType)) 647 Diag(ForLoc, diag::err_collection_expr_type) 648 << SecondType << Second->getSourceRange(); 649 } 650 first.release(); 651 second.release(); 652 body.release(); 653 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 654 ForLoc, RParenLoc)); 655} 656 657Action::OwningStmtResult 658Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 659 IdentifierInfo *LabelII) { 660 // If we are in a block, reject all gotos for now. 661 if (CurBlock) 662 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 663 664 // Look up the record for this label identifier. 665 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 666 667 // If we haven't seen this label yet, create a forward reference. 668 if (LabelDecl == 0) 669 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 670 671 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 672} 673 674Action::OwningStmtResult 675Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 676 ExprArg DestExp) { 677 // Convert operand to void* 678 Expr* E = DestExp.takeAs<Expr>(); 679 QualType ETy = E->getType(); 680 AssignConvertType ConvTy = 681 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 682 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 683 E, "passing")) 684 return StmtError(); 685 return Owned(new (Context) IndirectGotoStmt(GotoLoc, E)); 686} 687 688Action::OwningStmtResult 689Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 690 Scope *S = CurScope->getContinueParent(); 691 if (!S) { 692 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 693 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 694 } 695 696 return Owned(new (Context) ContinueStmt(ContinueLoc)); 697} 698 699Action::OwningStmtResult 700Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 701 Scope *S = CurScope->getBreakParent(); 702 if (!S) { 703 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 704 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 705 } 706 707 return Owned(new (Context) BreakStmt(BreakLoc)); 708} 709 710/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 711/// 712Action::OwningStmtResult 713Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 714 // If this is the first return we've seen in the block, infer the type of 715 // the block from it. 716 if (CurBlock->ReturnType == 0) { 717 if (RetValExp) { 718 // Don't call UsualUnaryConversions(), since we don't want to do 719 // integer promotions here. 720 DefaultFunctionArrayConversion(RetValExp); 721 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 722 } else 723 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 724 } 725 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 726 727 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 728 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 729 << getCurFunctionOrMethodDecl()->getDeclName(); 730 return StmtError(); 731 } 732 733 // Otherwise, verify that this result type matches the previous one. We are 734 // pickier with blocks than for normal functions because we don't have GCC 735 // compatibility to worry about here. 736 if (CurBlock->ReturnType->isVoidType()) { 737 if (RetValExp) { 738 Diag(ReturnLoc, diag::err_return_block_has_expr); 739 RetValExp->Destroy(Context); 740 RetValExp = 0; 741 } 742 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 743 } 744 745 if (!RetValExp) 746 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 747 748 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 749 // we have a non-void block with an expression, continue checking 750 QualType RetValType = RetValExp->getType(); 751 752 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 753 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 754 // function return. 755 756 // In C++ the return statement is handled via a copy initialization. 757 // the C version of which boils down to CheckSingleAssignmentConstraints. 758 // FIXME: Leaks RetValExp. 759 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 760 return StmtError(); 761 762 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 763 } 764 765 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 766} 767 768/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 769/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 770static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 771 Expr *RetExpr) { 772 QualType ExprType = RetExpr->getType(); 773 // - in a return statement in a function with ... 774 // ... a class return type ... 775 if (!RetType->isRecordType()) 776 return false; 777 // ... the same cv-unqualified type as the function return type ... 778 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 779 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 780 return false; 781 // ... the expression is the name of a non-volatile automatic object ... 782 // We ignore parentheses here. 783 // FIXME: Is this compliant? 784 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 785 if (!DR) 786 return false; 787 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 788 if (!VD) 789 return false; 790 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 791 && !VD->getType().isVolatileQualified(); 792} 793 794Action::OwningStmtResult 795Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 796 Expr *RetValExp = rex.takeAs<Expr>(); 797 if (CurBlock) 798 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 799 800 QualType FnRetType; 801 if (const FunctionDecl *FD = getCurFunctionDecl()) { 802 FnRetType = FD->getResultType(); 803 if (FD->hasAttr<NoReturnAttr>()) { 804 Diag(ReturnLoc, diag::err_noreturn_function_has_return_expr) 805 << getCurFunctionOrMethodDecl()->getDeclName(); 806 return StmtError(); 807 } 808 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 809 FnRetType = MD->getResultType(); 810 else // If we don't have a function/method context, bail. 811 return StmtError(); 812 813 if (FnRetType->isVoidType()) { 814 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 815 unsigned D = diag::ext_return_has_expr; 816 if (RetValExp->getType()->isVoidType()) 817 D = diag::ext_return_has_void_expr; 818 819 // return (some void expression); is legal in C++. 820 if (D != diag::ext_return_has_void_expr || 821 !getLangOptions().CPlusPlus) { 822 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 823 Diag(ReturnLoc, D) 824 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 825 << RetValExp->getSourceRange(); 826 } 827 } 828 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 829 } 830 831 if (!RetValExp && !FnRetType->isDependentType()) { 832 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 833 // C99 6.8.6.4p1 (ext_ since GCC warns) 834 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 835 836 if (FunctionDecl *FD = getCurFunctionDecl()) 837 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 838 else 839 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 840 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 841 } 842 843 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 844 // we have a non-void function with an expression, continue checking 845 846 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 847 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 848 // function return. 849 850 // C++0x 12.8p15: When certain criteria are met, an implementation is 851 // allowed to omit the copy construction of a class object, [...] 852 // - in a return statement in a function with a class return type, when 853 // the expression is the name of a non-volatile automatic object with 854 // the same cv-unqualified type as the function return type, the copy 855 // operation can be omitted [...] 856 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 857 // and the object to be copied is designated by an lvalue, overload 858 // resolution to select the constructor for the copy is first performed 859 // as if the object were designated by an rvalue. 860 // Note that we only compute Elidable if we're in C++0x, since we don't 861 // care otherwise. 862 bool Elidable = getLangOptions().CPlusPlus0x ? 863 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 864 false; 865 866 // In C++ the return statement is handled via a copy initialization. 867 // the C version of which boils down to CheckSingleAssignmentConstraints. 868 // FIXME: Leaks RetValExp on error. 869 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 870 return StmtError(); 871 872 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 873 } 874 875 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 876} 877 878/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 879/// ignore "noop" casts in places where an lvalue is required by an inline asm. 880/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 881/// provide a strong guidance to not use it. 882/// 883/// This method checks to see if the argument is an acceptable l-value and 884/// returns false if it is a case we can handle. 885static bool CheckAsmLValue(const Expr *E, Sema &S) { 886 if (E->isLvalue(S.Context) == Expr::LV_Valid) 887 return false; // Cool, this is an lvalue. 888 889 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 890 // are supposed to allow. 891 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 892 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 893 if (!S.getLangOptions().HeinousExtensions) 894 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 895 << E->getSourceRange(); 896 else 897 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 898 << E->getSourceRange(); 899 // Accept, even if we emitted an error diagnostic. 900 return false; 901 } 902 903 // None of the above, just randomly invalid non-lvalue. 904 return true; 905} 906 907 908Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 909 bool IsSimple, 910 bool IsVolatile, 911 unsigned NumOutputs, 912 unsigned NumInputs, 913 std::string *Names, 914 MultiExprArg constraints, 915 MultiExprArg exprs, 916 ExprArg asmString, 917 MultiExprArg clobbers, 918 SourceLocation RParenLoc) { 919 unsigned NumClobbers = clobbers.size(); 920 StringLiteral **Constraints = 921 reinterpret_cast<StringLiteral**>(constraints.get()); 922 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 923 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 924 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 925 926 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 927 928 // The parser verifies that there is a string literal here. 929 if (AsmString->isWide()) 930 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 931 << AsmString->getSourceRange()); 932 933 for (unsigned i = 0; i != NumOutputs; i++) { 934 StringLiteral *Literal = Constraints[i]; 935 if (Literal->isWide()) 936 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 937 << Literal->getSourceRange()); 938 939 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 940 Literal->getByteLength(), 941 Names[i]); 942 if (!Context.Target.validateOutputConstraint(Info)) 943 return StmtError(Diag(Literal->getLocStart(), 944 diag::err_asm_invalid_output_constraint) 945 << Info.getConstraintStr()); 946 947 // Check that the output exprs are valid lvalues. 948 Expr *OutputExpr = Exprs[i]; 949 if (CheckAsmLValue(OutputExpr, *this)) { 950 return StmtError(Diag(OutputExpr->getLocStart(), 951 diag::err_asm_invalid_lvalue_in_output) 952 << OutputExpr->getSourceRange()); 953 } 954 955 OutputConstraintInfos.push_back(Info); 956 } 957 958 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 959 960 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 961 StringLiteral *Literal = Constraints[i]; 962 if (Literal->isWide()) 963 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 964 << Literal->getSourceRange()); 965 966 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 967 Literal->getByteLength(), 968 Names[i]); 969 if (!Context.Target.validateInputConstraint(&OutputConstraintInfos[0], 970 NumOutputs, Info)) { 971 return StmtError(Diag(Literal->getLocStart(), 972 diag::err_asm_invalid_input_constraint) 973 << Info.getConstraintStr()); 974 } 975 976 Expr *InputExpr = Exprs[i]; 977 978 // Only allow void types for memory constraints. 979 if (Info.allowsMemory() && !Info.allowsRegister()) { 980 if (CheckAsmLValue(InputExpr, *this)) 981 return StmtError(Diag(InputExpr->getLocStart(), 982 diag::err_asm_invalid_lvalue_in_input) 983 << Info.getConstraintStr() 984 << InputExpr->getSourceRange()); 985 } 986 987 if (Info.allowsRegister()) { 988 if (InputExpr->getType()->isVoidType()) { 989 return StmtError(Diag(InputExpr->getLocStart(), 990 diag::err_asm_invalid_type_in_input) 991 << InputExpr->getType() << Info.getConstraintStr() 992 << InputExpr->getSourceRange()); 993 } 994 } 995 996 DefaultFunctionArrayConversion(Exprs[i]); 997 998 InputConstraintInfos.push_back(Info); 999 } 1000 1001 // Check that the clobbers are valid. 1002 for (unsigned i = 0; i != NumClobbers; i++) { 1003 StringLiteral *Literal = Clobbers[i]; 1004 if (Literal->isWide()) 1005 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1006 << Literal->getSourceRange()); 1007 1008 llvm::SmallString<16> Clobber(Literal->getStrData(), 1009 Literal->getStrData() + 1010 Literal->getByteLength()); 1011 1012 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1013 return StmtError(Diag(Literal->getLocStart(), 1014 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1015 } 1016 1017 constraints.release(); 1018 exprs.release(); 1019 asmString.release(); 1020 clobbers.release(); 1021 AsmStmt *NS = 1022 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1023 Names, Constraints, Exprs, AsmString, NumClobbers, 1024 Clobbers, RParenLoc); 1025 // Validate the asm string, ensuring it makes sense given the operands we 1026 // have. 1027 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1028 unsigned DiagOffs; 1029 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1030 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1031 << AsmString->getSourceRange(); 1032 DeleteStmt(NS); 1033 return StmtError(); 1034 } 1035 1036 // Validate tied input operands for type mismatches. 1037 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1038 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1039 1040 // If this is a tied constraint, verify that the output and input have 1041 // either exactly the same type, or that they are int/ptr operands with the 1042 // same size (int/long, int*/long, are ok etc). 1043 if (!Info.hasTiedOperand()) continue; 1044 1045 unsigned TiedTo = Info.getTiedOperand(); 1046 Expr *OutputExpr = Exprs[TiedTo]; 1047 Expr *InputExpr = Exprs[i+NumOutputs]; 1048 QualType InTy = InputExpr->getType(); 1049 QualType OutTy = OutputExpr->getType(); 1050 if (Context.hasSameType(InTy, OutTy)) 1051 continue; // All types can be tied to themselves. 1052 1053 // Int/ptr operands have some special cases that we allow. 1054 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1055 (InTy->isIntegerType() || InTy->isPointerType())) { 1056 1057 // They are ok if they are the same size. Tying void* to int is ok if 1058 // they are the same size, for example. This also allows tying void* to 1059 // int*. 1060 uint64_t OutSize = Context.getTypeSize(OutTy); 1061 uint64_t InSize = Context.getTypeSize(InTy); 1062 if (OutSize == InSize) 1063 continue; 1064 1065 // If the smaller input/output operand is not mentioned in the asm string, 1066 // then we can promote it and the asm string won't notice. Check this 1067 // case now. 1068 bool SmallerValueMentioned = false; 1069 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1070 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1071 if (!Piece.isOperand()) continue; 1072 1073 // If this is a reference to the input and if the input was the smaller 1074 // one, then we have to reject this asm. 1075 if (Piece.getOperandNo() == i+NumOutputs) { 1076 if (InSize < OutSize) { 1077 SmallerValueMentioned = true; 1078 break; 1079 } 1080 } 1081 1082 // If this is a reference to the input and if the input was the smaller 1083 // one, then we have to reject this asm. 1084 if (Piece.getOperandNo() == TiedTo) { 1085 if (InSize > OutSize) { 1086 SmallerValueMentioned = true; 1087 break; 1088 } 1089 } 1090 } 1091 1092 // If the smaller value wasn't mentioned in the asm string, and if the 1093 // output was a register, just extend the shorter one to the size of the 1094 // larger one. 1095 if (!SmallerValueMentioned && 1096 OutputConstraintInfos[TiedTo].allowsRegister()) 1097 continue; 1098 } 1099 1100 Diag(InputExpr->getLocStart(), 1101 diag::err_asm_tying_incompatible_types) 1102 << InTy << OutTy << OutputExpr->getSourceRange() 1103 << InputExpr->getSourceRange(); 1104 DeleteStmt(NS); 1105 return StmtError(); 1106 } 1107 1108 return Owned(NS); 1109} 1110 1111Action::OwningStmtResult 1112Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1113 SourceLocation RParen, DeclPtrTy Parm, 1114 StmtArg Body, StmtArg catchList) { 1115 Stmt *CatchList = catchList.takeAs<Stmt>(); 1116 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1117 1118 // PVD == 0 implies @catch(...). 1119 if (PVD) { 1120 // If we already know the decl is invalid, reject it. 1121 if (PVD->isInvalidDecl()) 1122 return StmtError(); 1123 1124 if (!Context.isObjCObjectPointerType(PVD->getType())) 1125 return StmtError(Diag(PVD->getLocation(), 1126 diag::err_catch_param_not_objc_type)); 1127 if (PVD->getType()->isObjCQualifiedIdType()) 1128 return StmtError(Diag(PVD->getLocation(), 1129 diag::err_illegal_qualifiers_on_catch_parm)); 1130 } 1131 1132 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1133 PVD, Body.takeAs<Stmt>(), CatchList); 1134 return Owned(CatchList ? CatchList : CS); 1135} 1136 1137Action::OwningStmtResult 1138Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1139 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1140 static_cast<Stmt*>(Body.release()))); 1141} 1142 1143Action::OwningStmtResult 1144Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1145 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1146 CurFunctionNeedsScopeChecking = true; 1147 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1148 Catch.takeAs<Stmt>(), 1149 Finally.takeAs<Stmt>())); 1150} 1151 1152Action::OwningStmtResult 1153Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1154 Expr *ThrowExpr = expr.takeAs<Expr>(); 1155 if (!ThrowExpr) { 1156 // @throw without an expression designates a rethrow (which much occur 1157 // in the context of an @catch clause). 1158 Scope *AtCatchParent = CurScope; 1159 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1160 AtCatchParent = AtCatchParent->getParent(); 1161 if (!AtCatchParent) 1162 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1163 } else { 1164 QualType ThrowType = ThrowExpr->getType(); 1165 // Make sure the expression type is an ObjC pointer or "void *". 1166 if (!Context.isObjCObjectPointerType(ThrowType)) { 1167 const PointerType *PT = ThrowType->getAsPointerType(); 1168 if (!PT || !PT->getPointeeType()->isVoidType()) 1169 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1170 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1171 } 1172 } 1173 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1174} 1175 1176Action::OwningStmtResult 1177Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1178 StmtArg SynchBody) { 1179 CurFunctionNeedsScopeChecking = true; 1180 1181 // Make sure the expression type is an ObjC pointer or "void *". 1182 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1183 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1184 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1185 if (!PT || !PT->getPointeeType()->isVoidType()) 1186 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1187 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1188 } 1189 1190 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1191 SynchExpr.takeAs<Stmt>(), 1192 SynchBody.takeAs<Stmt>())); 1193} 1194 1195/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1196/// and creates a proper catch handler from them. 1197Action::OwningStmtResult 1198Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1199 StmtArg HandlerBlock) { 1200 // There's nothing to test that ActOnExceptionDecl didn't already test. 1201 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1202 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1203 HandlerBlock.takeAs<Stmt>())); 1204} 1205 1206/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1207/// handlers and creates a try statement from them. 1208Action::OwningStmtResult 1209Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1210 MultiStmtArg RawHandlers) { 1211 unsigned NumHandlers = RawHandlers.size(); 1212 assert(NumHandlers > 0 && 1213 "The parser shouldn't call this if there are no handlers."); 1214 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1215 1216 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1217 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1218 if (!Handler->getExceptionDecl()) 1219 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1220 } 1221 // FIXME: We should detect handlers for the same type as an earlier one. 1222 // This one is rather easy. 1223 // FIXME: We should detect handlers that cannot catch anything because an 1224 // earlier handler catches a superclass. Need to find a method that is not 1225 // quadratic for this. 1226 // Neither of these are explicitly forbidden, but every compiler detects them 1227 // and warns. 1228 1229 CurFunctionNeedsScopeChecking = true; 1230 RawHandlers.release(); 1231 return Owned(new (Context) CXXTryStmt(TryLoc, 1232 static_cast<Stmt*>(TryBlock.release()), 1233 Handlers, NumHandlers)); 1234} 1235