SemaStmt.cpp revision dbb26db1d426fb6caaaf1b4fa47b46d1947c12c9
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 (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && 106 VerifyIntegerConstantExpression(LHSVal)) 107 return StmtError(); 108 109 // GCC extension: The expression shall be an integer constant. 110 111 Expr *RHSVal = static_cast<Expr*>(rhsval.get()); 112 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && 113 VerifyIntegerConstantExpression(RHSVal)) { 114 RHSVal = 0; // Recover by just forgetting about it. 115 rhsval = 0; 116 } 117 118 if (getSwitchStack().empty()) { 119 Diag(CaseLoc, diag::err_case_not_in_switch); 120 return StmtError(); 121 } 122 123 // Only now release the smart pointers. 124 lhsval.release(); 125 rhsval.release(); 126 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 127 ColonLoc); 128 getSwitchStack().back()->addSwitchCase(CS); 129 return Owned(CS); 130} 131 132/// ActOnCaseStmtBody - This installs a statement as the body of a case. 133void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) { 134 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 135 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 136 CS->setSubStmt(SubStmt); 137} 138 139Action::OwningStmtResult 140Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 141 StmtArg subStmt, Scope *CurScope) { 142 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 143 144 if (getSwitchStack().empty()) { 145 Diag(DefaultLoc, diag::err_default_not_in_switch); 146 return Owned(SubStmt); 147 } 148 149 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 150 getSwitchStack().back()->addSwitchCase(DS); 151 return Owned(DS); 152} 153 154Action::OwningStmtResult 155Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 156 SourceLocation ColonLoc, StmtArg subStmt) { 157 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 158 // Look up the record for this label identifier. 159 LabelStmt *&LabelDecl = getLabelMap()[II]; 160 161 // If not forward referenced or defined already, just create a new LabelStmt. 162 if (LabelDecl == 0) 163 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt)); 164 165 assert(LabelDecl->getID() == II && "Label mismatch!"); 166 167 // Otherwise, this label was either forward reference or multiply defined. If 168 // multiply defined, reject it now. 169 if (LabelDecl->getSubStmt()) { 170 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 171 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 172 return Owned(SubStmt); 173 } 174 175 // Otherwise, this label was forward declared, and we just found its real 176 // definition. Fill in the forward definition and return it. 177 LabelDecl->setIdentLoc(IdentLoc); 178 LabelDecl->setSubStmt(SubStmt); 179 return Owned(LabelDecl); 180} 181 182Action::OwningStmtResult 183Sema::ActOnIfStmt(SourceLocation IfLoc, ExprArg CondVal, 184 StmtArg ThenVal, SourceLocation ElseLoc, 185 StmtArg ElseVal) { 186 Expr *condExpr = CondVal.takeAs<Expr>(); 187 188 assert(condExpr && "ActOnIfStmt(): missing expression"); 189 190 if (!condExpr->isTypeDependent()) { 191 DefaultFunctionArrayConversion(condExpr); 192 // Take ownership again until we're past the error checking. 193 CondVal = condExpr; 194 QualType condType = condExpr->getType(); 195 196 if (getLangOptions().CPlusPlus) { 197 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 198 return StmtError(); 199 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 200 return StmtError(Diag(IfLoc, 201 diag::err_typecheck_statement_requires_scalar) 202 << condType << condExpr->getSourceRange()); 203 } 204 205 Stmt *thenStmt = ThenVal.takeAs<Stmt>(); 206 207 // Warn if the if block has a null body without an else value. 208 // this helps prevent bugs due to typos, such as 209 // if (condition); 210 // do_stuff(); 211 if (!ElseVal.get()) { 212 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 213 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 214 } 215 216 CondVal.release(); 217 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 218 ElseLoc, ElseVal.takeAs<Stmt>())); 219} 220 221Action::OwningStmtResult 222Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 223 Expr *Cond = cond.takeAs<Expr>(); 224 225 if (getLangOptions().CPlusPlus) { 226 // C++ 6.4.2.p2: 227 // The condition shall be of integral type, enumeration type, or of a class 228 // type for which a single conversion function to integral or enumeration 229 // type exists (12.3). If the condition is of class type, the condition is 230 // converted by calling that conversion function, and the result of the 231 // conversion is used in place of the original condition for the remainder 232 // of this section. Integral promotions are performed. 233 if (!Cond->isTypeDependent()) { 234 QualType Ty = Cond->getType(); 235 236 // FIXME: Handle class types. 237 238 // If the type is wrong a diagnostic will be emitted later at 239 // ActOnFinishSwitchStmt. 240 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 241 // Integral promotions are performed. 242 // FIXME: Integral promotions for C++ are not complete. 243 UsualUnaryConversions(Cond); 244 } 245 } 246 } else { 247 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 248 UsualUnaryConversions(Cond); 249 } 250 251 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 252 getSwitchStack().push_back(SS); 253 return Owned(SS); 254} 255 256/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 257/// the specified width and sign. If an overflow occurs, detect it and emit 258/// the specified diagnostic. 259void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 260 unsigned NewWidth, bool NewSign, 261 SourceLocation Loc, 262 unsigned DiagID) { 263 // Perform a conversion to the promoted condition type if needed. 264 if (NewWidth > Val.getBitWidth()) { 265 // If this is an extension, just do it. 266 llvm::APSInt OldVal(Val); 267 Val.extend(NewWidth); 268 269 // If the input was signed and negative and the output is unsigned, 270 // warn. 271 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 272 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 273 274 Val.setIsSigned(NewSign); 275 } else if (NewWidth < Val.getBitWidth()) { 276 // If this is a truncation, check for overflow. 277 llvm::APSInt ConvVal(Val); 278 ConvVal.trunc(NewWidth); 279 ConvVal.setIsSigned(NewSign); 280 ConvVal.extend(Val.getBitWidth()); 281 ConvVal.setIsSigned(Val.isSigned()); 282 if (ConvVal != Val) 283 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 284 285 // Regardless of whether a diagnostic was emitted, really do the 286 // truncation. 287 Val.trunc(NewWidth); 288 Val.setIsSigned(NewSign); 289 } else if (NewSign != Val.isSigned()) { 290 // Convert the sign to match the sign of the condition. This can cause 291 // overflow as well: unsigned(INTMIN) 292 llvm::APSInt OldVal(Val); 293 Val.setIsSigned(NewSign); 294 295 if (Val.isNegative()) // Sign bit changes meaning. 296 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 297 } 298} 299 300namespace { 301 struct CaseCompareFunctor { 302 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 303 const llvm::APSInt &RHS) { 304 return LHS.first < RHS; 305 } 306 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 307 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 308 return LHS.first < RHS.first; 309 } 310 bool operator()(const llvm::APSInt &LHS, 311 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 312 return LHS < RHS.first; 313 } 314 }; 315} 316 317/// CmpCaseVals - Comparison predicate for sorting case values. 318/// 319static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 320 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 321 if (lhs.first < rhs.first) 322 return true; 323 324 if (lhs.first == rhs.first && 325 lhs.second->getCaseLoc().getRawEncoding() 326 < rhs.second->getCaseLoc().getRawEncoding()) 327 return true; 328 return false; 329} 330 331Action::OwningStmtResult 332Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 333 StmtArg Body) { 334 Stmt *BodyStmt = Body.takeAs<Stmt>(); 335 336 SwitchStmt *SS = getSwitchStack().back(); 337 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 338 339 SS->setBody(BodyStmt, SwitchLoc); 340 getSwitchStack().pop_back(); 341 342 Expr *CondExpr = SS->getCond(); 343 QualType CondType = CondExpr->getType(); 344 345 if (!CondExpr->isTypeDependent() && 346 !CondType->isIntegerType()) { // C99 6.8.4.2p1 347 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 348 << CondType << CondExpr->getSourceRange(); 349 return StmtError(); 350 } 351 352 // Get the bitwidth of the switched-on value before promotions. We must 353 // convert the integer case values to this width before comparison. 354 bool HasDependentValue 355 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 356 unsigned CondWidth 357 = HasDependentValue? 0 358 : static_cast<unsigned>(Context.getTypeSize(CondType)); 359 bool CondIsSigned = CondType->isSignedIntegerType(); 360 361 // Accumulate all of the case values in a vector so that we can sort them 362 // and detect duplicates. This vector contains the APInt for the case after 363 // it has been converted to the condition type. 364 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 365 CaseValsTy CaseVals; 366 367 // Keep track of any GNU case ranges we see. The APSInt is the low value. 368 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 369 370 DefaultStmt *TheDefaultStmt = 0; 371 372 bool CaseListIsErroneous = false; 373 374 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 375 SC = SC->getNextSwitchCase()) { 376 377 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 378 if (TheDefaultStmt) { 379 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 380 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 381 382 // FIXME: Remove the default statement from the switch block so that 383 // we'll return a valid AST. This requires recursing down the 384 // AST and finding it, not something we are set up to do right now. For 385 // now, just lop the entire switch stmt out of the AST. 386 CaseListIsErroneous = true; 387 } 388 TheDefaultStmt = DS; 389 390 } else { 391 CaseStmt *CS = cast<CaseStmt>(SC); 392 393 // We already verified that the expression has a i-c-e value (C99 394 // 6.8.4.2p3) - get that value now. 395 Expr *Lo = CS->getLHS(); 396 397 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 398 HasDependentValue = true; 399 break; 400 } 401 402 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 403 404 // Convert the value to the same width/sign as the condition. 405 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 406 CS->getLHS()->getLocStart(), 407 diag::warn_case_value_overflow); 408 409 // If the LHS is not the same type as the condition, insert an implicit 410 // cast. 411 ImpCastExprToType(Lo, CondType); 412 CS->setLHS(Lo); 413 414 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 415 if (CS->getRHS()) { 416 if (CS->getRHS()->isTypeDependent() || 417 CS->getRHS()->isValueDependent()) { 418 HasDependentValue = true; 419 break; 420 } 421 CaseRanges.push_back(std::make_pair(LoVal, CS)); 422 } else 423 CaseVals.push_back(std::make_pair(LoVal, CS)); 424 } 425 } 426 427 if (!HasDependentValue) { 428 // Sort all the scalar case values so we can easily detect duplicates. 429 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 430 431 if (!CaseVals.empty()) { 432 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 433 if (CaseVals[i].first == CaseVals[i+1].first) { 434 // If we have a duplicate, report it. 435 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 436 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 437 Diag(CaseVals[i].second->getLHS()->getLocStart(), 438 diag::note_duplicate_case_prev); 439 // FIXME: We really want to remove the bogus case stmt from 440 // the substmt, but we have no way to do this right now. 441 CaseListIsErroneous = true; 442 } 443 } 444 } 445 446 // Detect duplicate case ranges, which usually don't exist at all in 447 // the first place. 448 if (!CaseRanges.empty()) { 449 // Sort all the case ranges by their low value so we can easily detect 450 // overlaps between ranges. 451 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 452 453 // Scan the ranges, computing the high values and removing empty ranges. 454 std::vector<llvm::APSInt> HiVals; 455 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 456 CaseStmt *CR = CaseRanges[i].second; 457 Expr *Hi = CR->getRHS(); 458 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 459 460 // Convert the value to the same width/sign as the condition. 461 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 462 CR->getRHS()->getLocStart(), 463 diag::warn_case_value_overflow); 464 465 // If the LHS is not the same type as the condition, insert an implicit 466 // cast. 467 ImpCastExprToType(Hi, CondType); 468 CR->setRHS(Hi); 469 470 // If the low value is bigger than the high value, the case is empty. 471 if (CaseRanges[i].first > HiVal) { 472 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 473 << SourceRange(CR->getLHS()->getLocStart(), 474 CR->getRHS()->getLocEnd()); 475 CaseRanges.erase(CaseRanges.begin()+i); 476 --i, --e; 477 continue; 478 } 479 HiVals.push_back(HiVal); 480 } 481 482 // Rescan the ranges, looking for overlap with singleton values and other 483 // ranges. Since the range list is sorted, we only need to compare case 484 // ranges with their neighbors. 485 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 486 llvm::APSInt &CRLo = CaseRanges[i].first; 487 llvm::APSInt &CRHi = HiVals[i]; 488 CaseStmt *CR = CaseRanges[i].second; 489 490 // Check to see whether the case range overlaps with any 491 // singleton cases. 492 CaseStmt *OverlapStmt = 0; 493 llvm::APSInt OverlapVal(32); 494 495 // Find the smallest value >= the lower bound. If I is in the 496 // case range, then we have overlap. 497 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 498 CaseVals.end(), CRLo, 499 CaseCompareFunctor()); 500 if (I != CaseVals.end() && I->first < CRHi) { 501 OverlapVal = I->first; // Found overlap with scalar. 502 OverlapStmt = I->second; 503 } 504 505 // Find the smallest value bigger than the upper bound. 506 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 507 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 508 OverlapVal = (I-1)->first; // Found overlap with scalar. 509 OverlapStmt = (I-1)->second; 510 } 511 512 // Check to see if this case stmt overlaps with the subsequent 513 // case range. 514 if (i && CRLo <= HiVals[i-1]) { 515 OverlapVal = HiVals[i-1]; // Found overlap with range. 516 OverlapStmt = CaseRanges[i-1].second; 517 } 518 519 if (OverlapStmt) { 520 // If we have a duplicate, report it. 521 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 522 << OverlapVal.toString(10); 523 Diag(OverlapStmt->getLHS()->getLocStart(), 524 diag::note_duplicate_case_prev); 525 // FIXME: We really want to remove the bogus case stmt from 526 // the substmt, but we have no way to do this right now. 527 CaseListIsErroneous = true; 528 } 529 } 530 } 531 } 532 533 // FIXME: If the case list was broken is some way, we don't have a 534 // good system to patch it up. Instead, just return the whole 535 // substmt as broken. 536 if (CaseListIsErroneous) 537 return StmtError(); 538 539 Switch.release(); 540 return Owned(SS); 541} 542 543Action::OwningStmtResult 544Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprArg Cond, StmtArg Body) { 545 Expr *condExpr = Cond.takeAs<Expr>(); 546 assert(condExpr && "ActOnWhileStmt(): 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(WhileLoc, 558 diag::err_typecheck_statement_requires_scalar) 559 << condType << condExpr->getSourceRange()); 560 } 561 562 Cond.release(); 563 return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 564 WhileLoc)); 565} 566 567Action::OwningStmtResult 568Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 569 SourceLocation WhileLoc, ExprArg Cond) { 570 Expr *condExpr = Cond.takeAs<Expr>(); 571 assert(condExpr && "ActOnDoStmt(): missing expression"); 572 573 if (!condExpr->isTypeDependent()) { 574 DefaultFunctionArrayConversion(condExpr); 575 Cond = condExpr; 576 QualType condType = condExpr->getType(); 577 578 if (getLangOptions().CPlusPlus) { 579 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 580 return StmtError(); 581 } else if (!condType->isScalarType()) // C99 6.8.5p2 582 return StmtError(Diag(DoLoc, 583 diag::err_typecheck_statement_requires_scalar) 584 << condType << condExpr->getSourceRange()); 585 } 586 587 Cond.release(); 588 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, 589 WhileLoc)); 590} 591 592Action::OwningStmtResult 593Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 594 StmtArg first, ExprArg second, ExprArg third, 595 SourceLocation RParenLoc, StmtArg body) { 596 Stmt *First = static_cast<Stmt*>(first.get()); 597 Expr *Second = static_cast<Expr*>(second.get()); 598 Expr *Third = static_cast<Expr*>(third.get()); 599 Stmt *Body = static_cast<Stmt*>(body.get()); 600 601 if (!getLangOptions().CPlusPlus) { 602 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 603 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 604 // declare identifiers for objects having storage class 'auto' or 605 // 'register'. 606 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 607 DI!=DE; ++DI) { 608 VarDecl *VD = dyn_cast<VarDecl>(*DI); 609 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 610 VD = 0; 611 if (VD == 0) 612 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 613 // FIXME: mark decl erroneous! 614 } 615 } 616 } 617 if (Second && !Second->isTypeDependent()) { 618 DefaultFunctionArrayConversion(Second); 619 QualType SecondType = Second->getType(); 620 621 if (getLangOptions().CPlusPlus) { 622 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 623 return StmtError(); 624 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 625 return StmtError(Diag(ForLoc, 626 diag::err_typecheck_statement_requires_scalar) 627 << SecondType << Second->getSourceRange()); 628 } 629 first.release(); 630 second.release(); 631 third.release(); 632 body.release(); 633 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, 634 LParenLoc, RParenLoc)); 635} 636 637Action::OwningStmtResult 638Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 639 SourceLocation LParenLoc, 640 StmtArg first, ExprArg second, 641 SourceLocation RParenLoc, StmtArg body) { 642 Stmt *First = static_cast<Stmt*>(first.get()); 643 Expr *Second = static_cast<Expr*>(second.get()); 644 Stmt *Body = static_cast<Stmt*>(body.get()); 645 if (First) { 646 QualType FirstType; 647 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 648 if (!DS->isSingleDecl()) 649 return StmtError(Diag((*DS->decl_begin())->getLocation(), 650 diag::err_toomany_element_decls)); 651 652 Decl *D = DS->getSingleDecl(); 653 FirstType = cast<ValueDecl>(D)->getType(); 654 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 655 // declare identifiers for objects having storage class 'auto' or 656 // 'register'. 657 VarDecl *VD = cast<VarDecl>(D); 658 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 659 return StmtError(Diag(VD->getLocation(), 660 diag::err_non_variable_decl_in_for)); 661 } else { 662 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 663 return StmtError(Diag(First->getLocStart(), 664 diag::err_selector_element_not_lvalue) 665 << First->getSourceRange()); 666 667 FirstType = static_cast<Expr*>(First)->getType(); 668 } 669 if (!Context.isObjCObjectPointerType(FirstType)) 670 Diag(ForLoc, diag::err_selector_element_type) 671 << FirstType << First->getSourceRange(); 672 } 673 if (Second) { 674 DefaultFunctionArrayConversion(Second); 675 QualType SecondType = Second->getType(); 676 if (!Context.isObjCObjectPointerType(SecondType)) 677 Diag(ForLoc, diag::err_collection_expr_type) 678 << SecondType << Second->getSourceRange(); 679 } 680 first.release(); 681 second.release(); 682 body.release(); 683 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 684 ForLoc, RParenLoc)); 685} 686 687Action::OwningStmtResult 688Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 689 IdentifierInfo *LabelII) { 690 // If we are in a block, reject all gotos for now. 691 if (CurBlock) 692 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 693 694 // Look up the record for this label identifier. 695 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 696 697 // If we haven't seen this label yet, create a forward reference. 698 if (LabelDecl == 0) 699 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 700 701 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 702} 703 704Action::OwningStmtResult 705Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 706 ExprArg DestExp) { 707 // Convert operand to void* 708 Expr* E = DestExp.takeAs<Expr>(); 709 QualType ETy = E->getType(); 710 AssignConvertType ConvTy = 711 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 712 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 713 E, "passing")) 714 return StmtError(); 715 return Owned(new (Context) IndirectGotoStmt(GotoLoc, E)); 716} 717 718Action::OwningStmtResult 719Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 720 Scope *S = CurScope->getContinueParent(); 721 if (!S) { 722 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 723 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 724 } 725 726 return Owned(new (Context) ContinueStmt(ContinueLoc)); 727} 728 729Action::OwningStmtResult 730Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 731 Scope *S = CurScope->getBreakParent(); 732 if (!S) { 733 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 734 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 735 } 736 737 return Owned(new (Context) BreakStmt(BreakLoc)); 738} 739 740/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 741/// 742Action::OwningStmtResult 743Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 744 // If this is the first return we've seen in the block, infer the type of 745 // the block from it. 746 if (CurBlock->ReturnType == 0) { 747 if (RetValExp) { 748 // Don't call UsualUnaryConversions(), since we don't want to do 749 // integer promotions here. 750 DefaultFunctionArrayConversion(RetValExp); 751 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 752 } else 753 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 754 } 755 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 756 757 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 758 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 759 << getCurFunctionOrMethodDecl()->getDeclName(); 760 return StmtError(); 761 } 762 763 // Otherwise, verify that this result type matches the previous one. We are 764 // pickier with blocks than for normal functions because we don't have GCC 765 // compatibility to worry about here. 766 if (CurBlock->ReturnType->isVoidType()) { 767 if (RetValExp) { 768 Diag(ReturnLoc, diag::err_return_block_has_expr); 769 RetValExp->Destroy(Context); 770 RetValExp = 0; 771 } 772 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 773 } 774 775 if (!RetValExp) 776 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 777 778 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 779 // we have a non-void block with an expression, continue checking 780 QualType RetValType = RetValExp->getType(); 781 782 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 783 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 784 // function return. 785 786 // In C++ the return statement is handled via a copy initialization. 787 // the C version of which boils down to CheckSingleAssignmentConstraints. 788 // FIXME: Leaks RetValExp. 789 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 790 return StmtError(); 791 792 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 793 } 794 795 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 796} 797 798/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 799/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 800static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 801 Expr *RetExpr) { 802 QualType ExprType = RetExpr->getType(); 803 // - in a return statement in a function with ... 804 // ... a class return type ... 805 if (!RetType->isRecordType()) 806 return false; 807 // ... the same cv-unqualified type as the function return type ... 808 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 809 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 810 return false; 811 // ... the expression is the name of a non-volatile automatic object ... 812 // We ignore parentheses here. 813 // FIXME: Is this compliant? 814 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 815 if (!DR) 816 return false; 817 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 818 if (!VD) 819 return false; 820 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 821 && !VD->getType().isVolatileQualified(); 822} 823 824Action::OwningStmtResult 825Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 826 Expr *RetValExp = rex.takeAs<Expr>(); 827 if (CurBlock) 828 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 829 830 QualType FnRetType; 831 if (const FunctionDecl *FD = getCurFunctionDecl()) { 832 FnRetType = FD->getResultType(); 833 if (FD->hasAttr<NoReturnAttr>()) { 834 Diag(ReturnLoc, diag::err_noreturn_function_has_return_expr) 835 << getCurFunctionOrMethodDecl()->getDeclName(); 836 return StmtError(); 837 } 838 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 839 FnRetType = MD->getResultType(); 840 else // If we don't have a function/method context, bail. 841 return StmtError(); 842 843 if (FnRetType->isVoidType()) { 844 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 845 unsigned D = diag::ext_return_has_expr; 846 if (RetValExp->getType()->isVoidType()) 847 D = diag::ext_return_has_void_expr; 848 849 // return (some void expression); is legal in C++. 850 if (D != diag::ext_return_has_void_expr || 851 !getLangOptions().CPlusPlus) { 852 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 853 Diag(ReturnLoc, D) 854 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 855 << RetValExp->getSourceRange(); 856 } 857 } 858 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 859 } 860 861 if (!RetValExp && !FnRetType->isDependentType()) { 862 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 863 // C99 6.8.6.4p1 (ext_ since GCC warns) 864 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 865 866 if (FunctionDecl *FD = getCurFunctionDecl()) 867 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 868 else 869 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 870 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 871 } 872 873 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 874 // we have a non-void function with an expression, continue checking 875 876 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 877 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 878 // function return. 879 880 // C++0x 12.8p15: When certain criteria are met, an implementation is 881 // allowed to omit the copy construction of a class object, [...] 882 // - in a return statement in a function with a class return type, when 883 // the expression is the name of a non-volatile automatic object with 884 // the same cv-unqualified type as the function return type, the copy 885 // operation can be omitted [...] 886 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 887 // and the object to be copied is designated by an lvalue, overload 888 // resolution to select the constructor for the copy is first performed 889 // as if the object were designated by an rvalue. 890 // Note that we only compute Elidable if we're in C++0x, since we don't 891 // care otherwise. 892 bool Elidable = getLangOptions().CPlusPlus0x ? 893 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 894 false; 895 896 // In C++ the return statement is handled via a copy initialization. 897 // the C version of which boils down to CheckSingleAssignmentConstraints. 898 // FIXME: Leaks RetValExp on error. 899 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 900 return StmtError(); 901 902 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 903 } 904 905 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 906} 907 908/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 909/// ignore "noop" casts in places where an lvalue is required by an inline asm. 910/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 911/// provide a strong guidance to not use it. 912/// 913/// This method checks to see if the argument is an acceptable l-value and 914/// returns false if it is a case we can handle. 915static bool CheckAsmLValue(const Expr *E, Sema &S) { 916 if (E->isLvalue(S.Context) == Expr::LV_Valid) 917 return false; // Cool, this is an lvalue. 918 919 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 920 // are supposed to allow. 921 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 922 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 923 if (!S.getLangOptions().HeinousExtensions) 924 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 925 << E->getSourceRange(); 926 else 927 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 928 << E->getSourceRange(); 929 // Accept, even if we emitted an error diagnostic. 930 return false; 931 } 932 933 // None of the above, just randomly invalid non-lvalue. 934 return true; 935} 936 937 938Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 939 bool IsSimple, 940 bool IsVolatile, 941 unsigned NumOutputs, 942 unsigned NumInputs, 943 std::string *Names, 944 MultiExprArg constraints, 945 MultiExprArg exprs, 946 ExprArg asmString, 947 MultiExprArg clobbers, 948 SourceLocation RParenLoc) { 949 unsigned NumClobbers = clobbers.size(); 950 StringLiteral **Constraints = 951 reinterpret_cast<StringLiteral**>(constraints.get()); 952 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 953 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 954 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 955 956 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 957 958 // The parser verifies that there is a string literal here. 959 if (AsmString->isWide()) 960 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 961 << AsmString->getSourceRange()); 962 963 for (unsigned i = 0; i != NumOutputs; i++) { 964 StringLiteral *Literal = Constraints[i]; 965 if (Literal->isWide()) 966 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 967 << Literal->getSourceRange()); 968 969 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 970 Literal->getByteLength(), 971 Names[i]); 972 if (!Context.Target.validateOutputConstraint(Info)) 973 return StmtError(Diag(Literal->getLocStart(), 974 diag::err_asm_invalid_output_constraint) 975 << Info.getConstraintStr()); 976 977 // Check that the output exprs are valid lvalues. 978 Expr *OutputExpr = Exprs[i]; 979 if (CheckAsmLValue(OutputExpr, *this)) { 980 return StmtError(Diag(OutputExpr->getLocStart(), 981 diag::err_asm_invalid_lvalue_in_output) 982 << OutputExpr->getSourceRange()); 983 } 984 985 OutputConstraintInfos.push_back(Info); 986 } 987 988 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 989 990 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 991 StringLiteral *Literal = Constraints[i]; 992 if (Literal->isWide()) 993 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 994 << Literal->getSourceRange()); 995 996 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 997 Literal->getByteLength(), 998 Names[i]); 999 if (!Context.Target.validateInputConstraint(&OutputConstraintInfos[0], 1000 NumOutputs, Info)) { 1001 return StmtError(Diag(Literal->getLocStart(), 1002 diag::err_asm_invalid_input_constraint) 1003 << Info.getConstraintStr()); 1004 } 1005 1006 Expr *InputExpr = Exprs[i]; 1007 1008 // Only allow void types for memory constraints. 1009 if (Info.allowsMemory() && !Info.allowsRegister()) { 1010 if (CheckAsmLValue(InputExpr, *this)) 1011 return StmtError(Diag(InputExpr->getLocStart(), 1012 diag::err_asm_invalid_lvalue_in_input) 1013 << Info.getConstraintStr() 1014 << InputExpr->getSourceRange()); 1015 } 1016 1017 if (Info.allowsRegister()) { 1018 if (InputExpr->getType()->isVoidType()) { 1019 return StmtError(Diag(InputExpr->getLocStart(), 1020 diag::err_asm_invalid_type_in_input) 1021 << InputExpr->getType() << Info.getConstraintStr() 1022 << InputExpr->getSourceRange()); 1023 } 1024 } 1025 1026 DefaultFunctionArrayConversion(Exprs[i]); 1027 1028 InputConstraintInfos.push_back(Info); 1029 } 1030 1031 // Check that the clobbers are valid. 1032 for (unsigned i = 0; i != NumClobbers; i++) { 1033 StringLiteral *Literal = Clobbers[i]; 1034 if (Literal->isWide()) 1035 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1036 << Literal->getSourceRange()); 1037 1038 llvm::SmallString<16> Clobber(Literal->getStrData(), 1039 Literal->getStrData() + 1040 Literal->getByteLength()); 1041 1042 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1043 return StmtError(Diag(Literal->getLocStart(), 1044 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1045 } 1046 1047 constraints.release(); 1048 exprs.release(); 1049 asmString.release(); 1050 clobbers.release(); 1051 AsmStmt *NS = 1052 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1053 Names, Constraints, Exprs, AsmString, NumClobbers, 1054 Clobbers, RParenLoc); 1055 // Validate the asm string, ensuring it makes sense given the operands we 1056 // have. 1057 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1058 unsigned DiagOffs; 1059 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1060 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1061 << AsmString->getSourceRange(); 1062 DeleteStmt(NS); 1063 return StmtError(); 1064 } 1065 1066 // Validate tied input operands for type mismatches. 1067 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1068 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1069 1070 // If this is a tied constraint, verify that the output and input have 1071 // either exactly the same type, or that they are int/ptr operands with the 1072 // same size (int/long, int*/long, are ok etc). 1073 if (!Info.hasTiedOperand()) continue; 1074 1075 unsigned TiedTo = Info.getTiedOperand(); 1076 Expr *OutputExpr = Exprs[TiedTo]; 1077 Expr *InputExpr = Exprs[i+NumOutputs]; 1078 QualType InTy = InputExpr->getType(); 1079 QualType OutTy = OutputExpr->getType(); 1080 if (Context.hasSameType(InTy, OutTy)) 1081 continue; // All types can be tied to themselves. 1082 1083 // Int/ptr operands have some special cases that we allow. 1084 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1085 (InTy->isIntegerType() || InTy->isPointerType())) { 1086 1087 // They are ok if they are the same size. Tying void* to int is ok if 1088 // they are the same size, for example. This also allows tying void* to 1089 // int*. 1090 uint64_t OutSize = Context.getTypeSize(OutTy); 1091 uint64_t InSize = Context.getTypeSize(InTy); 1092 if (OutSize == InSize) 1093 continue; 1094 1095 // If the smaller input/output operand is not mentioned in the asm string, 1096 // then we can promote it and the asm string won't notice. Check this 1097 // case now. 1098 bool SmallerValueMentioned = false; 1099 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1100 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1101 if (!Piece.isOperand()) continue; 1102 1103 // If this is a reference to the input and if the input was the smaller 1104 // one, then we have to reject this asm. 1105 if (Piece.getOperandNo() == i+NumOutputs) { 1106 if (InSize < OutSize) { 1107 SmallerValueMentioned = true; 1108 break; 1109 } 1110 } 1111 1112 // If this is a reference to the input and if the input was the smaller 1113 // one, then we have to reject this asm. 1114 if (Piece.getOperandNo() == TiedTo) { 1115 if (InSize > OutSize) { 1116 SmallerValueMentioned = true; 1117 break; 1118 } 1119 } 1120 } 1121 1122 // If the smaller value wasn't mentioned in the asm string, and if the 1123 // output was a register, just extend the shorter one to the size of the 1124 // larger one. 1125 if (!SmallerValueMentioned && 1126 OutputConstraintInfos[TiedTo].allowsRegister()) 1127 continue; 1128 } 1129 1130 Diag(InputExpr->getLocStart(), 1131 diag::err_asm_tying_incompatible_types) 1132 << InTy << OutTy << OutputExpr->getSourceRange() 1133 << InputExpr->getSourceRange(); 1134 DeleteStmt(NS); 1135 return StmtError(); 1136 } 1137 1138 return Owned(NS); 1139} 1140 1141Action::OwningStmtResult 1142Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1143 SourceLocation RParen, DeclPtrTy Parm, 1144 StmtArg Body, StmtArg catchList) { 1145 Stmt *CatchList = catchList.takeAs<Stmt>(); 1146 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1147 1148 // PVD == 0 implies @catch(...). 1149 if (PVD) { 1150 // If we already know the decl is invalid, reject it. 1151 if (PVD->isInvalidDecl()) 1152 return StmtError(); 1153 1154 if (!Context.isObjCObjectPointerType(PVD->getType())) 1155 return StmtError(Diag(PVD->getLocation(), 1156 diag::err_catch_param_not_objc_type)); 1157 if (PVD->getType()->isObjCQualifiedIdType()) 1158 return StmtError(Diag(PVD->getLocation(), 1159 diag::err_illegal_qualifiers_on_catch_parm)); 1160 } 1161 1162 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1163 PVD, Body.takeAs<Stmt>(), CatchList); 1164 return Owned(CatchList ? CatchList : CS); 1165} 1166 1167Action::OwningStmtResult 1168Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1169 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1170 static_cast<Stmt*>(Body.release()))); 1171} 1172 1173Action::OwningStmtResult 1174Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1175 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1176 CurFunctionNeedsScopeChecking = true; 1177 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1178 Catch.takeAs<Stmt>(), 1179 Finally.takeAs<Stmt>())); 1180} 1181 1182Action::OwningStmtResult 1183Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1184 Expr *ThrowExpr = expr.takeAs<Expr>(); 1185 if (!ThrowExpr) { 1186 // @throw without an expression designates a rethrow (which much occur 1187 // in the context of an @catch clause). 1188 Scope *AtCatchParent = CurScope; 1189 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1190 AtCatchParent = AtCatchParent->getParent(); 1191 if (!AtCatchParent) 1192 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1193 } else { 1194 QualType ThrowType = ThrowExpr->getType(); 1195 // Make sure the expression type is an ObjC pointer or "void *". 1196 if (!Context.isObjCObjectPointerType(ThrowType)) { 1197 const PointerType *PT = ThrowType->getAsPointerType(); 1198 if (!PT || !PT->getPointeeType()->isVoidType()) 1199 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1200 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1201 } 1202 } 1203 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1204} 1205 1206Action::OwningStmtResult 1207Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1208 StmtArg SynchBody) { 1209 CurFunctionNeedsScopeChecking = true; 1210 1211 // Make sure the expression type is an ObjC pointer or "void *". 1212 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1213 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1214 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1215 if (!PT || !PT->getPointeeType()->isVoidType()) 1216 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1217 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1218 } 1219 1220 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1221 SynchExpr.takeAs<Stmt>(), 1222 SynchBody.takeAs<Stmt>())); 1223} 1224 1225/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1226/// and creates a proper catch handler from them. 1227Action::OwningStmtResult 1228Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1229 StmtArg HandlerBlock) { 1230 // There's nothing to test that ActOnExceptionDecl didn't already test. 1231 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1232 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1233 HandlerBlock.takeAs<Stmt>())); 1234} 1235 1236/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1237/// handlers and creates a try statement from them. 1238Action::OwningStmtResult 1239Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1240 MultiStmtArg RawHandlers) { 1241 unsigned NumHandlers = RawHandlers.size(); 1242 assert(NumHandlers > 0 && 1243 "The parser shouldn't call this if there are no handlers."); 1244 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1245 1246 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1247 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1248 if (!Handler->getExceptionDecl()) 1249 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1250 } 1251 // FIXME: We should detect handlers for the same type as an earlier one. 1252 // This one is rather easy. 1253 // FIXME: We should detect handlers that cannot catch anything because an 1254 // earlier handler catches a superclass. Need to find a method that is not 1255 // quadratic for this. 1256 // Neither of these are explicitly forbidden, but every compiler detects them 1257 // and warns. 1258 1259 CurFunctionNeedsScopeChecking = true; 1260 RawHandlers.release(); 1261 return Owned(new (Context) CXXTryStmt(TryLoc, 1262 static_cast<Stmt*>(TryBlock.release()), 1263 Handlers, NumHandlers)); 1264} 1265