SemaStmt.cpp revision 1401330b1c620dd8e14af4e2c1b1589cf68dc2c3
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 if (!condExpr->isTypeDependent()) { 549 DefaultFunctionArrayConversion(condExpr); 550 Cond = condExpr; 551 QualType condType = condExpr->getType(); 552 553 if (getLangOptions().CPlusPlus) { 554 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 555 return StmtError(); 556 } else if (!condType->isScalarType()) // C99 6.8.5p2 557 return StmtError(Diag(DoLoc, 558 diag::err_typecheck_statement_requires_scalar) 559 << condType << condExpr->getSourceRange()); 560 } 561 562 Cond.release(); 563 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, 564 WhileLoc)); 565} 566 567Action::OwningStmtResult 568Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 569 StmtArg first, ExprArg second, ExprArg third, 570 SourceLocation RParenLoc, StmtArg body) { 571 Stmt *First = static_cast<Stmt*>(first.get()); 572 Expr *Second = static_cast<Expr*>(second.get()); 573 Expr *Third = static_cast<Expr*>(third.get()); 574 Stmt *Body = static_cast<Stmt*>(body.get()); 575 576 if (!getLangOptions().CPlusPlus) { 577 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 578 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 579 // declare identifiers for objects having storage class 'auto' or 580 // 'register'. 581 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 582 DI!=DE; ++DI) { 583 VarDecl *VD = dyn_cast<VarDecl>(*DI); 584 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 585 VD = 0; 586 if (VD == 0) 587 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 588 // FIXME: mark decl erroneous! 589 } 590 } 591 } 592 if (Second && !Second->isTypeDependent()) { 593 DefaultFunctionArrayConversion(Second); 594 QualType SecondType = Second->getType(); 595 596 if (getLangOptions().CPlusPlus) { 597 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 598 return StmtError(); 599 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 600 return StmtError(Diag(ForLoc, 601 diag::err_typecheck_statement_requires_scalar) 602 << SecondType << Second->getSourceRange()); 603 } 604 first.release(); 605 second.release(); 606 third.release(); 607 body.release(); 608 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, 609 LParenLoc, RParenLoc)); 610} 611 612Action::OwningStmtResult 613Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 614 SourceLocation LParenLoc, 615 StmtArg first, ExprArg second, 616 SourceLocation RParenLoc, StmtArg body) { 617 Stmt *First = static_cast<Stmt*>(first.get()); 618 Expr *Second = static_cast<Expr*>(second.get()); 619 Stmt *Body = static_cast<Stmt*>(body.get()); 620 if (First) { 621 QualType FirstType; 622 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 623 if (!DS->isSingleDecl()) 624 return StmtError(Diag((*DS->decl_begin())->getLocation(), 625 diag::err_toomany_element_decls)); 626 627 Decl *D = DS->getSingleDecl(); 628 FirstType = cast<ValueDecl>(D)->getType(); 629 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 630 // declare identifiers for objects having storage class 'auto' or 631 // 'register'. 632 VarDecl *VD = cast<VarDecl>(D); 633 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 634 return StmtError(Diag(VD->getLocation(), 635 diag::err_non_variable_decl_in_for)); 636 } else { 637 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 638 return StmtError(Diag(First->getLocStart(), 639 diag::err_selector_element_not_lvalue) 640 << First->getSourceRange()); 641 642 FirstType = static_cast<Expr*>(First)->getType(); 643 } 644 if (!Context.isObjCObjectPointerType(FirstType)) 645 Diag(ForLoc, diag::err_selector_element_type) 646 << FirstType << First->getSourceRange(); 647 } 648 if (Second) { 649 DefaultFunctionArrayConversion(Second); 650 QualType SecondType = Second->getType(); 651 if (!Context.isObjCObjectPointerType(SecondType)) 652 Diag(ForLoc, diag::err_collection_expr_type) 653 << SecondType << Second->getSourceRange(); 654 } 655 first.release(); 656 second.release(); 657 body.release(); 658 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 659 ForLoc, RParenLoc)); 660} 661 662Action::OwningStmtResult 663Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 664 IdentifierInfo *LabelII) { 665 // If we are in a block, reject all gotos for now. 666 if (CurBlock) 667 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 668 669 // Look up the record for this label identifier. 670 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 671 672 // If we haven't seen this label yet, create a forward reference. 673 if (LabelDecl == 0) 674 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 675 676 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 677} 678 679Action::OwningStmtResult 680Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 681 ExprArg DestExp) { 682 // Convert operand to void* 683 Expr* E = DestExp.takeAs<Expr>(); 684 QualType ETy = E->getType(); 685 AssignConvertType ConvTy = 686 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 687 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 688 E, "passing")) 689 return StmtError(); 690 return Owned(new (Context) IndirectGotoStmt(GotoLoc, E)); 691} 692 693Action::OwningStmtResult 694Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 695 Scope *S = CurScope->getContinueParent(); 696 if (!S) { 697 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 698 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 699 } 700 701 return Owned(new (Context) ContinueStmt(ContinueLoc)); 702} 703 704Action::OwningStmtResult 705Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 706 Scope *S = CurScope->getBreakParent(); 707 if (!S) { 708 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 709 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 710 } 711 712 return Owned(new (Context) BreakStmt(BreakLoc)); 713} 714 715/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 716/// 717Action::OwningStmtResult 718Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 719 // If this is the first return we've seen in the block, infer the type of 720 // the block from it. 721 if (CurBlock->ReturnType == 0) { 722 if (RetValExp) { 723 // Don't call UsualUnaryConversions(), since we don't want to do 724 // integer promotions here. 725 DefaultFunctionArrayConversion(RetValExp); 726 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 727 } else 728 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 729 } 730 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 731 732 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 733 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 734 << getCurFunctionOrMethodDecl()->getDeclName(); 735 return StmtError(); 736 } 737 738 // Otherwise, verify that this result type matches the previous one. We are 739 // pickier with blocks than for normal functions because we don't have GCC 740 // compatibility to worry about here. 741 if (CurBlock->ReturnType->isVoidType()) { 742 if (RetValExp) { 743 Diag(ReturnLoc, diag::err_return_block_has_expr); 744 RetValExp->Destroy(Context); 745 RetValExp = 0; 746 } 747 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 748 } 749 750 if (!RetValExp) 751 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 752 753 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 754 // we have a non-void block with an expression, continue checking 755 QualType RetValType = RetValExp->getType(); 756 757 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 758 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 759 // function return. 760 761 // In C++ the return statement is handled via a copy initialization. 762 // the C version of which boils down to CheckSingleAssignmentConstraints. 763 // FIXME: Leaks RetValExp. 764 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 765 return StmtError(); 766 767 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 768 } 769 770 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 771} 772 773/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 774/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 775static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 776 Expr *RetExpr) { 777 QualType ExprType = RetExpr->getType(); 778 // - in a return statement in a function with ... 779 // ... a class return type ... 780 if (!RetType->isRecordType()) 781 return false; 782 // ... the same cv-unqualified type as the function return type ... 783 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 784 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 785 return false; 786 // ... the expression is the name of a non-volatile automatic object ... 787 // We ignore parentheses here. 788 // FIXME: Is this compliant? 789 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 790 if (!DR) 791 return false; 792 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 793 if (!VD) 794 return false; 795 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 796 && !VD->getType().isVolatileQualified(); 797} 798 799Action::OwningStmtResult 800Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 801 Expr *RetValExp = rex.takeAs<Expr>(); 802 if (CurBlock) 803 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 804 805 QualType FnRetType; 806 if (const FunctionDecl *FD = getCurFunctionDecl()) { 807 FnRetType = FD->getResultType(); 808 if (FD->hasAttr<NoReturnAttr>()) { 809 Diag(ReturnLoc, diag::err_noreturn_function_has_return_expr) 810 << getCurFunctionOrMethodDecl()->getDeclName(); 811 return StmtError(); 812 } 813 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 814 FnRetType = MD->getResultType(); 815 else // If we don't have a function/method context, bail. 816 return StmtError(); 817 818 if (FnRetType->isVoidType()) { 819 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 820 unsigned D = diag::ext_return_has_expr; 821 if (RetValExp->getType()->isVoidType()) 822 D = diag::ext_return_has_void_expr; 823 824 // return (some void expression); is legal in C++. 825 if (D != diag::ext_return_has_void_expr || 826 !getLangOptions().CPlusPlus) { 827 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 828 Diag(ReturnLoc, D) 829 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 830 << RetValExp->getSourceRange(); 831 } 832 } 833 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 834 } 835 836 if (!RetValExp && !FnRetType->isDependentType()) { 837 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 838 // C99 6.8.6.4p1 (ext_ since GCC warns) 839 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 840 841 if (FunctionDecl *FD = getCurFunctionDecl()) 842 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 843 else 844 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 845 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 846 } 847 848 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 849 // we have a non-void function with an expression, continue checking 850 851 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 852 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 853 // function return. 854 855 // C++0x 12.8p15: When certain criteria are met, an implementation is 856 // allowed to omit the copy construction of a class object, [...] 857 // - in a return statement in a function with a class return type, when 858 // the expression is the name of a non-volatile automatic object with 859 // the same cv-unqualified type as the function return type, the copy 860 // operation can be omitted [...] 861 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 862 // and the object to be copied is designated by an lvalue, overload 863 // resolution to select the constructor for the copy is first performed 864 // as if the object were designated by an rvalue. 865 // Note that we only compute Elidable if we're in C++0x, since we don't 866 // care otherwise. 867 bool Elidable = getLangOptions().CPlusPlus0x ? 868 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 869 false; 870 871 // In C++ the return statement is handled via a copy initialization. 872 // the C version of which boils down to CheckSingleAssignmentConstraints. 873 // FIXME: Leaks RetValExp on error. 874 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 875 return StmtError(); 876 877 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 878 } 879 880 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 881} 882 883/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 884/// ignore "noop" casts in places where an lvalue is required by an inline asm. 885/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 886/// provide a strong guidance to not use it. 887/// 888/// This method checks to see if the argument is an acceptable l-value and 889/// returns false if it is a case we can handle. 890static bool CheckAsmLValue(const Expr *E, Sema &S) { 891 if (E->isLvalue(S.Context) == Expr::LV_Valid) 892 return false; // Cool, this is an lvalue. 893 894 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 895 // are supposed to allow. 896 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 897 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 898 if (!S.getLangOptions().HeinousExtensions) 899 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 900 << E->getSourceRange(); 901 else 902 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 903 << E->getSourceRange(); 904 // Accept, even if we emitted an error diagnostic. 905 return false; 906 } 907 908 // None of the above, just randomly invalid non-lvalue. 909 return true; 910} 911 912 913Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 914 bool IsSimple, 915 bool IsVolatile, 916 unsigned NumOutputs, 917 unsigned NumInputs, 918 std::string *Names, 919 MultiExprArg constraints, 920 MultiExprArg exprs, 921 ExprArg asmString, 922 MultiExprArg clobbers, 923 SourceLocation RParenLoc) { 924 unsigned NumClobbers = clobbers.size(); 925 StringLiteral **Constraints = 926 reinterpret_cast<StringLiteral**>(constraints.get()); 927 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 928 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 929 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 930 931 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 932 933 // The parser verifies that there is a string literal here. 934 if (AsmString->isWide()) 935 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 936 << AsmString->getSourceRange()); 937 938 for (unsigned i = 0; i != NumOutputs; i++) { 939 StringLiteral *Literal = Constraints[i]; 940 if (Literal->isWide()) 941 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 942 << Literal->getSourceRange()); 943 944 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 945 Literal->getByteLength(), 946 Names[i]); 947 if (!Context.Target.validateOutputConstraint(Info)) 948 return StmtError(Diag(Literal->getLocStart(), 949 diag::err_asm_invalid_output_constraint) 950 << Info.getConstraintStr()); 951 952 // Check that the output exprs are valid lvalues. 953 Expr *OutputExpr = Exprs[i]; 954 if (CheckAsmLValue(OutputExpr, *this)) { 955 return StmtError(Diag(OutputExpr->getLocStart(), 956 diag::err_asm_invalid_lvalue_in_output) 957 << OutputExpr->getSourceRange()); 958 } 959 960 OutputConstraintInfos.push_back(Info); 961 } 962 963 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 964 965 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 966 StringLiteral *Literal = Constraints[i]; 967 if (Literal->isWide()) 968 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 969 << Literal->getSourceRange()); 970 971 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 972 Literal->getByteLength(), 973 Names[i]); 974 if (!Context.Target.validateInputConstraint(&OutputConstraintInfos[0], 975 NumOutputs, Info)) { 976 return StmtError(Diag(Literal->getLocStart(), 977 diag::err_asm_invalid_input_constraint) 978 << Info.getConstraintStr()); 979 } 980 981 Expr *InputExpr = Exprs[i]; 982 983 // Only allow void types for memory constraints. 984 if (Info.allowsMemory() && !Info.allowsRegister()) { 985 if (CheckAsmLValue(InputExpr, *this)) 986 return StmtError(Diag(InputExpr->getLocStart(), 987 diag::err_asm_invalid_lvalue_in_input) 988 << Info.getConstraintStr() 989 << InputExpr->getSourceRange()); 990 } 991 992 if (Info.allowsRegister()) { 993 if (InputExpr->getType()->isVoidType()) { 994 return StmtError(Diag(InputExpr->getLocStart(), 995 diag::err_asm_invalid_type_in_input) 996 << InputExpr->getType() << Info.getConstraintStr() 997 << InputExpr->getSourceRange()); 998 } 999 } 1000 1001 DefaultFunctionArrayConversion(Exprs[i]); 1002 1003 InputConstraintInfos.push_back(Info); 1004 } 1005 1006 // Check that the clobbers are valid. 1007 for (unsigned i = 0; i != NumClobbers; i++) { 1008 StringLiteral *Literal = Clobbers[i]; 1009 if (Literal->isWide()) 1010 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1011 << Literal->getSourceRange()); 1012 1013 llvm::SmallString<16> Clobber(Literal->getStrData(), 1014 Literal->getStrData() + 1015 Literal->getByteLength()); 1016 1017 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1018 return StmtError(Diag(Literal->getLocStart(), 1019 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1020 } 1021 1022 constraints.release(); 1023 exprs.release(); 1024 asmString.release(); 1025 clobbers.release(); 1026 AsmStmt *NS = 1027 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1028 Names, Constraints, Exprs, AsmString, NumClobbers, 1029 Clobbers, RParenLoc); 1030 // Validate the asm string, ensuring it makes sense given the operands we 1031 // have. 1032 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1033 unsigned DiagOffs; 1034 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1035 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1036 << AsmString->getSourceRange(); 1037 DeleteStmt(NS); 1038 return StmtError(); 1039 } 1040 1041 // Validate tied input operands for type mismatches. 1042 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1043 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1044 1045 // If this is a tied constraint, verify that the output and input have 1046 // either exactly the same type, or that they are int/ptr operands with the 1047 // same size (int/long, int*/long, are ok etc). 1048 if (!Info.hasTiedOperand()) continue; 1049 1050 unsigned TiedTo = Info.getTiedOperand(); 1051 Expr *OutputExpr = Exprs[TiedTo]; 1052 Expr *InputExpr = Exprs[i+NumOutputs]; 1053 QualType InTy = InputExpr->getType(); 1054 QualType OutTy = OutputExpr->getType(); 1055 if (Context.hasSameType(InTy, OutTy)) 1056 continue; // All types can be tied to themselves. 1057 1058 // Int/ptr operands have some special cases that we allow. 1059 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1060 (InTy->isIntegerType() || InTy->isPointerType())) { 1061 1062 // They are ok if they are the same size. Tying void* to int is ok if 1063 // they are the same size, for example. This also allows tying void* to 1064 // int*. 1065 uint64_t OutSize = Context.getTypeSize(OutTy); 1066 uint64_t InSize = Context.getTypeSize(InTy); 1067 if (OutSize == InSize) 1068 continue; 1069 1070 // If the smaller input/output operand is not mentioned in the asm string, 1071 // then we can promote it and the asm string won't notice. Check this 1072 // case now. 1073 bool SmallerValueMentioned = false; 1074 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1075 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1076 if (!Piece.isOperand()) continue; 1077 1078 // If this is a reference to the input and if the input was the smaller 1079 // one, then we have to reject this asm. 1080 if (Piece.getOperandNo() == i+NumOutputs) { 1081 if (InSize < OutSize) { 1082 SmallerValueMentioned = true; 1083 break; 1084 } 1085 } 1086 1087 // If this is a reference to the input and if the input was the smaller 1088 // one, then we have to reject this asm. 1089 if (Piece.getOperandNo() == TiedTo) { 1090 if (InSize > OutSize) { 1091 SmallerValueMentioned = true; 1092 break; 1093 } 1094 } 1095 } 1096 1097 // If the smaller value wasn't mentioned in the asm string, and if the 1098 // output was a register, just extend the shorter one to the size of the 1099 // larger one. 1100 if (!SmallerValueMentioned && 1101 OutputConstraintInfos[TiedTo].allowsRegister()) 1102 continue; 1103 } 1104 1105 Diag(InputExpr->getLocStart(), 1106 diag::err_asm_tying_incompatible_types) 1107 << InTy << OutTy << OutputExpr->getSourceRange() 1108 << InputExpr->getSourceRange(); 1109 DeleteStmt(NS); 1110 return StmtError(); 1111 } 1112 1113 return Owned(NS); 1114} 1115 1116Action::OwningStmtResult 1117Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1118 SourceLocation RParen, DeclPtrTy Parm, 1119 StmtArg Body, StmtArg catchList) { 1120 Stmt *CatchList = catchList.takeAs<Stmt>(); 1121 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1122 1123 // PVD == 0 implies @catch(...). 1124 if (PVD) { 1125 // If we already know the decl is invalid, reject it. 1126 if (PVD->isInvalidDecl()) 1127 return StmtError(); 1128 1129 if (!Context.isObjCObjectPointerType(PVD->getType())) 1130 return StmtError(Diag(PVD->getLocation(), 1131 diag::err_catch_param_not_objc_type)); 1132 if (PVD->getType()->isObjCQualifiedIdType()) 1133 return StmtError(Diag(PVD->getLocation(), 1134 diag::err_illegal_qualifiers_on_catch_parm)); 1135 } 1136 1137 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1138 PVD, Body.takeAs<Stmt>(), CatchList); 1139 return Owned(CatchList ? CatchList : CS); 1140} 1141 1142Action::OwningStmtResult 1143Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1144 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1145 static_cast<Stmt*>(Body.release()))); 1146} 1147 1148Action::OwningStmtResult 1149Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1150 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1151 CurFunctionNeedsScopeChecking = true; 1152 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1153 Catch.takeAs<Stmt>(), 1154 Finally.takeAs<Stmt>())); 1155} 1156 1157Action::OwningStmtResult 1158Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1159 Expr *ThrowExpr = expr.takeAs<Expr>(); 1160 if (!ThrowExpr) { 1161 // @throw without an expression designates a rethrow (which much occur 1162 // in the context of an @catch clause). 1163 Scope *AtCatchParent = CurScope; 1164 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1165 AtCatchParent = AtCatchParent->getParent(); 1166 if (!AtCatchParent) 1167 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1168 } else { 1169 QualType ThrowType = ThrowExpr->getType(); 1170 // Make sure the expression type is an ObjC pointer or "void *". 1171 if (!Context.isObjCObjectPointerType(ThrowType)) { 1172 const PointerType *PT = ThrowType->getAsPointerType(); 1173 if (!PT || !PT->getPointeeType()->isVoidType()) 1174 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1175 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1176 } 1177 } 1178 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1179} 1180 1181Action::OwningStmtResult 1182Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1183 StmtArg SynchBody) { 1184 CurFunctionNeedsScopeChecking = true; 1185 1186 // Make sure the expression type is an ObjC pointer or "void *". 1187 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1188 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1189 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1190 if (!PT || !PT->getPointeeType()->isVoidType()) 1191 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1192 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1193 } 1194 1195 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1196 SynchExpr.takeAs<Stmt>(), 1197 SynchBody.takeAs<Stmt>())); 1198} 1199 1200/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1201/// and creates a proper catch handler from them. 1202Action::OwningStmtResult 1203Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1204 StmtArg HandlerBlock) { 1205 // There's nothing to test that ActOnExceptionDecl didn't already test. 1206 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1207 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1208 HandlerBlock.takeAs<Stmt>())); 1209} 1210 1211/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1212/// handlers and creates a try statement from them. 1213Action::OwningStmtResult 1214Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1215 MultiStmtArg RawHandlers) { 1216 unsigned NumHandlers = RawHandlers.size(); 1217 assert(NumHandlers > 0 && 1218 "The parser shouldn't call this if there are no handlers."); 1219 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1220 1221 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1222 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1223 if (!Handler->getExceptionDecl()) 1224 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1225 } 1226 // FIXME: We should detect handlers for the same type as an earlier one. 1227 // This one is rather easy. 1228 // FIXME: We should detect handlers that cannot catch anything because an 1229 // earlier handler catches a superclass. Need to find a method that is not 1230 // quadratic for this. 1231 // Neither of these are explicitly forbidden, but every compiler detects them 1232 // and warns. 1233 1234 CurFunctionNeedsScopeChecking = true; 1235 RawHandlers.release(); 1236 return Owned(new (Context) CXXTryStmt(TryLoc, 1237 static_cast<Stmt*>(TryBlock.release()), 1238 Handlers, NumHandlers)); 1239} 1240