SemaStmt.cpp revision 7f537c18c7029e73f0bd555be3782c066e7e2c1e
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(FullExprArg 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, FullExprArg CondVal, 184 StmtArg ThenVal, SourceLocation ElseLoc, 185 StmtArg ElseVal) { 186 OwningExprResult CondResult(CondVal.release()); 187 188 Expr *condExpr = CondResult.takeAs<Expr>(); 189 190 assert(condExpr && "ActOnIfStmt(): missing expression"); 191 192 if (!condExpr->isTypeDependent()) { 193 DefaultFunctionArrayConversion(condExpr); 194 // Take ownership again until we're past the error checking. 195 CondResult = condExpr; 196 QualType condType = condExpr->getType(); 197 198 if (getLangOptions().CPlusPlus) { 199 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 200 return StmtError(); 201 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 202 return StmtError(Diag(IfLoc, 203 diag::err_typecheck_statement_requires_scalar) 204 << condType << condExpr->getSourceRange()); 205 } 206 207 Stmt *thenStmt = ThenVal.takeAs<Stmt>(); 208 209 // Warn if the if block has a null body without an else value. 210 // this helps prevent bugs due to typos, such as 211 // if (condition); 212 // do_stuff(); 213 if (!ElseVal.get()) { 214 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 215 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 216 } 217 218 CondResult.release(); 219 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 220 ElseLoc, ElseVal.takeAs<Stmt>())); 221} 222 223Action::OwningStmtResult 224Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 225 Expr *Cond = cond.takeAs<Expr>(); 226 227 if (getLangOptions().CPlusPlus) { 228 // C++ 6.4.2.p2: 229 // The condition shall be of integral type, enumeration type, or of a class 230 // type for which a single conversion function to integral or enumeration 231 // type exists (12.3). If the condition is of class type, the condition is 232 // converted by calling that conversion function, and the result of the 233 // conversion is used in place of the original condition for the remainder 234 // of this section. Integral promotions are performed. 235 if (!Cond->isTypeDependent()) { 236 QualType Ty = Cond->getType(); 237 238 // FIXME: Handle class types. 239 240 // If the type is wrong a diagnostic will be emitted later at 241 // ActOnFinishSwitchStmt. 242 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 243 // Integral promotions are performed. 244 // FIXME: Integral promotions for C++ are not complete. 245 UsualUnaryConversions(Cond); 246 } 247 } 248 } else { 249 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 250 UsualUnaryConversions(Cond); 251 } 252 253 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 254 getSwitchStack().push_back(SS); 255 return Owned(SS); 256} 257 258/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 259/// the specified width and sign. If an overflow occurs, detect it and emit 260/// the specified diagnostic. 261void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 262 unsigned NewWidth, bool NewSign, 263 SourceLocation Loc, 264 unsigned DiagID) { 265 // Perform a conversion to the promoted condition type if needed. 266 if (NewWidth > Val.getBitWidth()) { 267 // If this is an extension, just do it. 268 llvm::APSInt OldVal(Val); 269 Val.extend(NewWidth); 270 271 // If the input was signed and negative and the output is unsigned, 272 // warn. 273 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 274 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 275 276 Val.setIsSigned(NewSign); 277 } else if (NewWidth < Val.getBitWidth()) { 278 // If this is a truncation, check for overflow. 279 llvm::APSInt ConvVal(Val); 280 ConvVal.trunc(NewWidth); 281 ConvVal.setIsSigned(NewSign); 282 ConvVal.extend(Val.getBitWidth()); 283 ConvVal.setIsSigned(Val.isSigned()); 284 if (ConvVal != Val) 285 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 286 287 // Regardless of whether a diagnostic was emitted, really do the 288 // truncation. 289 Val.trunc(NewWidth); 290 Val.setIsSigned(NewSign); 291 } else if (NewSign != Val.isSigned()) { 292 // Convert the sign to match the sign of the condition. This can cause 293 // overflow as well: unsigned(INTMIN) 294 llvm::APSInt OldVal(Val); 295 Val.setIsSigned(NewSign); 296 297 if (Val.isNegative()) // Sign bit changes meaning. 298 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 299 } 300} 301 302namespace { 303 struct CaseCompareFunctor { 304 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 305 const llvm::APSInt &RHS) { 306 return LHS.first < RHS; 307 } 308 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 309 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 310 return LHS.first < RHS.first; 311 } 312 bool operator()(const llvm::APSInt &LHS, 313 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 314 return LHS < RHS.first; 315 } 316 }; 317} 318 319/// CmpCaseVals - Comparison predicate for sorting case values. 320/// 321static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 322 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 323 if (lhs.first < rhs.first) 324 return true; 325 326 if (lhs.first == rhs.first && 327 lhs.second->getCaseLoc().getRawEncoding() 328 < rhs.second->getCaseLoc().getRawEncoding()) 329 return true; 330 return false; 331} 332 333Action::OwningStmtResult 334Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 335 StmtArg Body) { 336 Stmt *BodyStmt = Body.takeAs<Stmt>(); 337 338 SwitchStmt *SS = getSwitchStack().back(); 339 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 340 341 SS->setBody(BodyStmt, SwitchLoc); 342 getSwitchStack().pop_back(); 343 344 Expr *CondExpr = SS->getCond(); 345 QualType CondType = CondExpr->getType(); 346 347 if (!CondExpr->isTypeDependent() && 348 !CondType->isIntegerType()) { // C99 6.8.4.2p1 349 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 350 << CondType << CondExpr->getSourceRange(); 351 return StmtError(); 352 } 353 354 // Get the bitwidth of the switched-on value before promotions. We must 355 // convert the integer case values to this width before comparison. 356 bool HasDependentValue 357 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 358 unsigned CondWidth 359 = HasDependentValue? 0 360 : static_cast<unsigned>(Context.getTypeSize(CondType)); 361 bool CondIsSigned = CondType->isSignedIntegerType(); 362 363 // Accumulate all of the case values in a vector so that we can sort them 364 // and detect duplicates. This vector contains the APInt for the case after 365 // it has been converted to the condition type. 366 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 367 CaseValsTy CaseVals; 368 369 // Keep track of any GNU case ranges we see. The APSInt is the low value. 370 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 371 372 DefaultStmt *TheDefaultStmt = 0; 373 374 bool CaseListIsErroneous = false; 375 376 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 377 SC = SC->getNextSwitchCase()) { 378 379 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 380 if (TheDefaultStmt) { 381 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 382 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 383 384 // FIXME: Remove the default statement from the switch block so that 385 // we'll return a valid AST. This requires recursing down the AST and 386 // finding it, not something we are set up to do right now. For now, 387 // just lop the entire switch stmt out of the AST. 388 CaseListIsErroneous = true; 389 } 390 TheDefaultStmt = DS; 391 392 } else { 393 CaseStmt *CS = cast<CaseStmt>(SC); 394 395 // We already verified that the expression has a i-c-e value (C99 396 // 6.8.4.2p3) - get that value now. 397 Expr *Lo = CS->getLHS(); 398 399 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 400 HasDependentValue = true; 401 break; 402 } 403 404 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 405 406 // Convert the value to the same width/sign as the condition. 407 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 408 CS->getLHS()->getLocStart(), 409 diag::warn_case_value_overflow); 410 411 // If the LHS is not the same type as the condition, insert an implicit 412 // cast. 413 ImpCastExprToType(Lo, CondType); 414 CS->setLHS(Lo); 415 416 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 417 if (CS->getRHS()) { 418 if (CS->getRHS()->isTypeDependent() || 419 CS->getRHS()->isValueDependent()) { 420 HasDependentValue = true; 421 break; 422 } 423 CaseRanges.push_back(std::make_pair(LoVal, CS)); 424 } else 425 CaseVals.push_back(std::make_pair(LoVal, CS)); 426 } 427 } 428 429 if (!HasDependentValue) { 430 // Sort all the scalar case values so we can easily detect duplicates. 431 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 432 433 if (!CaseVals.empty()) { 434 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 435 if (CaseVals[i].first == CaseVals[i+1].first) { 436 // If we have a duplicate, report it. 437 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 438 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 439 Diag(CaseVals[i].second->getLHS()->getLocStart(), 440 diag::note_duplicate_case_prev); 441 // FIXME: We really want to remove the bogus case stmt from the 442 // substmt, but we have no way to do this right now. 443 CaseListIsErroneous = true; 444 } 445 } 446 } 447 448 // Detect duplicate case ranges, which usually don't exist at all in 449 // the first place. 450 if (!CaseRanges.empty()) { 451 // Sort all the case ranges by their low value so we can easily detect 452 // overlaps between ranges. 453 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 454 455 // Scan the ranges, computing the high values and removing empty ranges. 456 std::vector<llvm::APSInt> HiVals; 457 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 458 CaseStmt *CR = CaseRanges[i].second; 459 Expr *Hi = CR->getRHS(); 460 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 461 462 // Convert the value to the same width/sign as the condition. 463 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 464 CR->getRHS()->getLocStart(), 465 diag::warn_case_value_overflow); 466 467 // If the LHS is not the same type as the condition, insert an implicit 468 // cast. 469 ImpCastExprToType(Hi, CondType); 470 CR->setRHS(Hi); 471 472 // If the low value is bigger than the high value, the case is empty. 473 if (CaseRanges[i].first > HiVal) { 474 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 475 << SourceRange(CR->getLHS()->getLocStart(), 476 CR->getRHS()->getLocEnd()); 477 CaseRanges.erase(CaseRanges.begin()+i); 478 --i, --e; 479 continue; 480 } 481 HiVals.push_back(HiVal); 482 } 483 484 // Rescan the ranges, looking for overlap with singleton values and other 485 // ranges. Since the range list is sorted, we only need to compare case 486 // ranges with their neighbors. 487 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 488 llvm::APSInt &CRLo = CaseRanges[i].first; 489 llvm::APSInt &CRHi = HiVals[i]; 490 CaseStmt *CR = CaseRanges[i].second; 491 492 // Check to see whether the case range overlaps with any 493 // singleton cases. 494 CaseStmt *OverlapStmt = 0; 495 llvm::APSInt OverlapVal(32); 496 497 // Find the smallest value >= the lower bound. If I is in the 498 // case range, then we have overlap. 499 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 500 CaseVals.end(), CRLo, 501 CaseCompareFunctor()); 502 if (I != CaseVals.end() && I->first < CRHi) { 503 OverlapVal = I->first; // Found overlap with scalar. 504 OverlapStmt = I->second; 505 } 506 507 // Find the smallest value bigger than the upper bound. 508 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 509 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 510 OverlapVal = (I-1)->first; // Found overlap with scalar. 511 OverlapStmt = (I-1)->second; 512 } 513 514 // Check to see if this case stmt overlaps with the subsequent 515 // case range. 516 if (i && CRLo <= HiVals[i-1]) { 517 OverlapVal = HiVals[i-1]; // Found overlap with range. 518 OverlapStmt = CaseRanges[i-1].second; 519 } 520 521 if (OverlapStmt) { 522 // If we have a duplicate, report it. 523 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 524 << OverlapVal.toString(10); 525 Diag(OverlapStmt->getLHS()->getLocStart(), 526 diag::note_duplicate_case_prev); 527 // FIXME: We really want to remove the bogus case stmt from the 528 // substmt, but we have no way to do this right now. 529 CaseListIsErroneous = true; 530 } 531 } 532 } 533 } 534 535 // FIXME: If the case list was broken is some way, we don't have a good system 536 // to patch it up. Instead, just return the whole substmt as broken. 537 if (CaseListIsErroneous) 538 return StmtError(); 539 540 Switch.release(); 541 return Owned(SS); 542} 543 544Action::OwningStmtResult 545Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, StmtArg Body) { 546 ExprArg CondArg(Cond.release()); 547 Expr *condExpr = CondArg.takeAs<Expr>(); 548 assert(condExpr && "ActOnWhileStmt(): missing expression"); 549 550 if (!condExpr->isTypeDependent()) { 551 DefaultFunctionArrayConversion(condExpr); 552 CondArg = condExpr; 553 QualType condType = condExpr->getType(); 554 555 if (getLangOptions().CPlusPlus) { 556 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 557 return StmtError(); 558 } else if (!condType->isScalarType()) // C99 6.8.5p2 559 return StmtError(Diag(WhileLoc, 560 diag::err_typecheck_statement_requires_scalar) 561 << condType << condExpr->getSourceRange()); 562 } 563 564 CondArg.release(); 565 return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 566 WhileLoc)); 567} 568 569Action::OwningStmtResult 570Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 571 SourceLocation WhileLoc, ExprArg Cond) { 572 Expr *condExpr = Cond.takeAs<Expr>(); 573 assert(condExpr && "ActOnDoStmt(): missing expression"); 574 575 if (!condExpr->isTypeDependent()) { 576 DefaultFunctionArrayConversion(condExpr); 577 Cond = condExpr; 578 QualType condType = condExpr->getType(); 579 580 if (getLangOptions().CPlusPlus) { 581 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 582 return StmtError(); 583 } else if (!condType->isScalarType()) // C99 6.8.5p2 584 return StmtError(Diag(DoLoc, 585 diag::err_typecheck_statement_requires_scalar) 586 << condType << condExpr->getSourceRange()); 587 } 588 589 Cond.release(); 590 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, 591 WhileLoc)); 592} 593 594Action::OwningStmtResult 595Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 596 StmtArg first, ExprArg second, ExprArg third, 597 SourceLocation RParenLoc, StmtArg body) { 598 Stmt *First = static_cast<Stmt*>(first.get()); 599 Expr *Second = static_cast<Expr*>(second.get()); 600 Expr *Third = static_cast<Expr*>(third.get()); 601 Stmt *Body = static_cast<Stmt*>(body.get()); 602 603 if (!getLangOptions().CPlusPlus) { 604 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 605 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 606 // declare identifiers for objects having storage class 'auto' or 607 // 'register'. 608 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 609 DI!=DE; ++DI) { 610 VarDecl *VD = dyn_cast<VarDecl>(*DI); 611 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 612 VD = 0; 613 if (VD == 0) 614 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 615 // FIXME: mark decl erroneous! 616 } 617 } 618 } 619 if (Second && !Second->isTypeDependent()) { 620 DefaultFunctionArrayConversion(Second); 621 QualType SecondType = Second->getType(); 622 623 if (getLangOptions().CPlusPlus) { 624 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 625 return StmtError(); 626 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 627 return StmtError(Diag(ForLoc, 628 diag::err_typecheck_statement_requires_scalar) 629 << SecondType << Second->getSourceRange()); 630 } 631 first.release(); 632 second.release(); 633 third.release(); 634 body.release(); 635 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, 636 LParenLoc, RParenLoc)); 637} 638 639Action::OwningStmtResult 640Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 641 SourceLocation LParenLoc, 642 StmtArg first, ExprArg second, 643 SourceLocation RParenLoc, StmtArg body) { 644 Stmt *First = static_cast<Stmt*>(first.get()); 645 Expr *Second = static_cast<Expr*>(second.get()); 646 Stmt *Body = static_cast<Stmt*>(body.get()); 647 if (First) { 648 QualType FirstType; 649 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 650 if (!DS->isSingleDecl()) 651 return StmtError(Diag((*DS->decl_begin())->getLocation(), 652 diag::err_toomany_element_decls)); 653 654 Decl *D = DS->getSingleDecl(); 655 FirstType = cast<ValueDecl>(D)->getType(); 656 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 657 // declare identifiers for objects having storage class 'auto' or 658 // 'register'. 659 VarDecl *VD = cast<VarDecl>(D); 660 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 661 return StmtError(Diag(VD->getLocation(), 662 diag::err_non_variable_decl_in_for)); 663 } else { 664 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 665 return StmtError(Diag(First->getLocStart(), 666 diag::err_selector_element_not_lvalue) 667 << First->getSourceRange()); 668 669 FirstType = static_cast<Expr*>(First)->getType(); 670 } 671 if (!Context.isObjCObjectPointerType(FirstType)) 672 Diag(ForLoc, diag::err_selector_element_type) 673 << FirstType << First->getSourceRange(); 674 } 675 if (Second) { 676 DefaultFunctionArrayConversion(Second); 677 QualType SecondType = Second->getType(); 678 if (!Context.isObjCObjectPointerType(SecondType)) 679 Diag(ForLoc, diag::err_collection_expr_type) 680 << SecondType << Second->getSourceRange(); 681 } 682 first.release(); 683 second.release(); 684 body.release(); 685 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 686 ForLoc, RParenLoc)); 687} 688 689Action::OwningStmtResult 690Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 691 IdentifierInfo *LabelII) { 692 // If we are in a block, reject all gotos for now. 693 if (CurBlock) 694 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 695 696 // Look up the record for this label identifier. 697 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 698 699 // If we haven't seen this label yet, create a forward reference. 700 if (LabelDecl == 0) 701 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 702 703 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 704} 705 706Action::OwningStmtResult 707Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 708 ExprArg DestExp) { 709 // Convert operand to void* 710 Expr* E = DestExp.takeAs<Expr>(); 711 if (!E->isTypeDependent()) { 712 QualType ETy = E->getType(); 713 AssignConvertType ConvTy = 714 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 715 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 716 E, "passing")) 717 return StmtError(); 718 } 719 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 720} 721 722Action::OwningStmtResult 723Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 724 Scope *S = CurScope->getContinueParent(); 725 if (!S) { 726 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 727 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 728 } 729 730 return Owned(new (Context) ContinueStmt(ContinueLoc)); 731} 732 733Action::OwningStmtResult 734Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 735 Scope *S = CurScope->getBreakParent(); 736 if (!S) { 737 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 738 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 739 } 740 741 return Owned(new (Context) BreakStmt(BreakLoc)); 742} 743 744/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 745/// 746Action::OwningStmtResult 747Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 748 // If this is the first return we've seen in the block, infer the type of 749 // the block from it. 750 if (CurBlock->ReturnType == 0) { 751 if (RetValExp) { 752 // Don't call UsualUnaryConversions(), since we don't want to do 753 // integer promotions here. 754 DefaultFunctionArrayConversion(RetValExp); 755 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 756 } else 757 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 758 } 759 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 760 761 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 762 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 763 << getCurFunctionOrMethodDecl()->getDeclName(); 764 return StmtError(); 765 } 766 767 // Otherwise, verify that this result type matches the previous one. We are 768 // pickier with blocks than for normal functions because we don't have GCC 769 // compatibility to worry about here. 770 if (CurBlock->ReturnType->isVoidType()) { 771 if (RetValExp) { 772 Diag(ReturnLoc, diag::err_return_block_has_expr); 773 RetValExp->Destroy(Context); 774 RetValExp = 0; 775 } 776 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 777 } 778 779 if (!RetValExp) 780 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 781 782 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 783 // we have a non-void block with an expression, continue checking 784 QualType RetValType = RetValExp->getType(); 785 786 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 787 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 788 // function return. 789 790 // In C++ the return statement is handled via a copy initialization. 791 // the C version of which boils down to CheckSingleAssignmentConstraints. 792 // FIXME: Leaks RetValExp. 793 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 794 return StmtError(); 795 796 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 797 } 798 799 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 800} 801 802/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 803/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 804static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 805 Expr *RetExpr) { 806 QualType ExprType = RetExpr->getType(); 807 // - in a return statement in a function with ... 808 // ... a class return type ... 809 if (!RetType->isRecordType()) 810 return false; 811 // ... the same cv-unqualified type as the function return type ... 812 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 813 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 814 return false; 815 // ... the expression is the name of a non-volatile automatic object ... 816 // We ignore parentheses here. 817 // FIXME: Is this compliant? 818 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 819 if (!DR) 820 return false; 821 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 822 if (!VD) 823 return false; 824 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 825 && !VD->getType().isVolatileQualified(); 826} 827 828Action::OwningStmtResult 829Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 830 Expr *RetValExp = rex.takeAs<Expr>(); 831 if (CurBlock) 832 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 833 834 QualType FnRetType; 835 if (const FunctionDecl *FD = getCurFunctionDecl()) { 836 FnRetType = FD->getResultType(); 837 if (FD->hasAttr<NoReturnAttr>()) { 838 Diag(ReturnLoc, diag::err_noreturn_function_has_return_expr) 839 << getCurFunctionOrMethodDecl()->getDeclName(); 840 return StmtError(); 841 } 842 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 843 FnRetType = MD->getResultType(); 844 else // If we don't have a function/method context, bail. 845 return StmtError(); 846 847 if (FnRetType->isVoidType()) { 848 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 849 unsigned D = diag::ext_return_has_expr; 850 if (RetValExp->getType()->isVoidType()) 851 D = diag::ext_return_has_void_expr; 852 853 // return (some void expression); is legal in C++. 854 if (D != diag::ext_return_has_void_expr || 855 !getLangOptions().CPlusPlus) { 856 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 857 Diag(ReturnLoc, D) 858 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 859 << RetValExp->getSourceRange(); 860 } 861 } 862 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 863 } 864 865 if (!RetValExp && !FnRetType->isDependentType()) { 866 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 867 // C99 6.8.6.4p1 (ext_ since GCC warns) 868 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 869 870 if (FunctionDecl *FD = getCurFunctionDecl()) 871 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 872 else 873 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 874 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 875 } 876 877 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 878 // we have a non-void function with an expression, continue checking 879 880 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 881 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 882 // function return. 883 884 // C++0x 12.8p15: When certain criteria are met, an implementation is 885 // allowed to omit the copy construction of a class object, [...] 886 // - in a return statement in a function with a class return type, when 887 // the expression is the name of a non-volatile automatic object with 888 // the same cv-unqualified type as the function return type, the copy 889 // operation can be omitted [...] 890 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 891 // and the object to be copied is designated by an lvalue, overload 892 // resolution to select the constructor for the copy is first performed 893 // as if the object were designated by an rvalue. 894 // Note that we only compute Elidable if we're in C++0x, since we don't 895 // care otherwise. 896 bool Elidable = getLangOptions().CPlusPlus0x ? 897 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 898 false; 899 900 // In C++ the return statement is handled via a copy initialization. 901 // the C version of which boils down to CheckSingleAssignmentConstraints. 902 // FIXME: Leaks RetValExp on error. 903 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 904 return StmtError(); 905 906 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 907 } 908 909 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 910} 911 912/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 913/// ignore "noop" casts in places where an lvalue is required by an inline asm. 914/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 915/// provide a strong guidance to not use it. 916/// 917/// This method checks to see if the argument is an acceptable l-value and 918/// returns false if it is a case we can handle. 919static bool CheckAsmLValue(const Expr *E, Sema &S) { 920 if (E->isLvalue(S.Context) == Expr::LV_Valid) 921 return false; // Cool, this is an lvalue. 922 923 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 924 // are supposed to allow. 925 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 926 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 927 if (!S.getLangOptions().HeinousExtensions) 928 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 929 << E->getSourceRange(); 930 else 931 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 932 << E->getSourceRange(); 933 // Accept, even if we emitted an error diagnostic. 934 return false; 935 } 936 937 // None of the above, just randomly invalid non-lvalue. 938 return true; 939} 940 941 942Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 943 bool IsSimple, 944 bool IsVolatile, 945 unsigned NumOutputs, 946 unsigned NumInputs, 947 std::string *Names, 948 MultiExprArg constraints, 949 MultiExprArg exprs, 950 ExprArg asmString, 951 MultiExprArg clobbers, 952 SourceLocation RParenLoc) { 953 unsigned NumClobbers = clobbers.size(); 954 StringLiteral **Constraints = 955 reinterpret_cast<StringLiteral**>(constraints.get()); 956 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 957 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 958 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 959 960 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 961 962 // The parser verifies that there is a string literal here. 963 if (AsmString->isWide()) 964 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 965 << AsmString->getSourceRange()); 966 967 for (unsigned i = 0; i != NumOutputs; i++) { 968 StringLiteral *Literal = Constraints[i]; 969 if (Literal->isWide()) 970 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 971 << Literal->getSourceRange()); 972 973 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 974 Literal->getByteLength(), 975 Names[i]); 976 if (!Context.Target.validateOutputConstraint(Info)) 977 return StmtError(Diag(Literal->getLocStart(), 978 diag::err_asm_invalid_output_constraint) 979 << Info.getConstraintStr()); 980 981 // Check that the output exprs are valid lvalues. 982 Expr *OutputExpr = Exprs[i]; 983 if (CheckAsmLValue(OutputExpr, *this)) { 984 return StmtError(Diag(OutputExpr->getLocStart(), 985 diag::err_asm_invalid_lvalue_in_output) 986 << OutputExpr->getSourceRange()); 987 } 988 989 OutputConstraintInfos.push_back(Info); 990 } 991 992 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 993 994 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 995 StringLiteral *Literal = Constraints[i]; 996 if (Literal->isWide()) 997 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 998 << Literal->getSourceRange()); 999 1000 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 1001 Literal->getByteLength(), 1002 Names[i]); 1003 if (!Context.Target.validateInputConstraint(&OutputConstraintInfos[0], 1004 NumOutputs, Info)) { 1005 return StmtError(Diag(Literal->getLocStart(), 1006 diag::err_asm_invalid_input_constraint) 1007 << Info.getConstraintStr()); 1008 } 1009 1010 Expr *InputExpr = Exprs[i]; 1011 1012 // Only allow void types for memory constraints. 1013 if (Info.allowsMemory() && !Info.allowsRegister()) { 1014 if (CheckAsmLValue(InputExpr, *this)) 1015 return StmtError(Diag(InputExpr->getLocStart(), 1016 diag::err_asm_invalid_lvalue_in_input) 1017 << Info.getConstraintStr() 1018 << InputExpr->getSourceRange()); 1019 } 1020 1021 if (Info.allowsRegister()) { 1022 if (InputExpr->getType()->isVoidType()) { 1023 return StmtError(Diag(InputExpr->getLocStart(), 1024 diag::err_asm_invalid_type_in_input) 1025 << InputExpr->getType() << Info.getConstraintStr() 1026 << InputExpr->getSourceRange()); 1027 } 1028 } 1029 1030 DefaultFunctionArrayConversion(Exprs[i]); 1031 1032 InputConstraintInfos.push_back(Info); 1033 } 1034 1035 // Check that the clobbers are valid. 1036 for (unsigned i = 0; i != NumClobbers; i++) { 1037 StringLiteral *Literal = Clobbers[i]; 1038 if (Literal->isWide()) 1039 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1040 << Literal->getSourceRange()); 1041 1042 llvm::SmallString<16> Clobber(Literal->getStrData(), 1043 Literal->getStrData() + 1044 Literal->getByteLength()); 1045 1046 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1047 return StmtError(Diag(Literal->getLocStart(), 1048 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1049 } 1050 1051 constraints.release(); 1052 exprs.release(); 1053 asmString.release(); 1054 clobbers.release(); 1055 AsmStmt *NS = 1056 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1057 Names, Constraints, Exprs, AsmString, NumClobbers, 1058 Clobbers, RParenLoc); 1059 // Validate the asm string, ensuring it makes sense given the operands we 1060 // have. 1061 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1062 unsigned DiagOffs; 1063 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1064 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1065 << AsmString->getSourceRange(); 1066 DeleteStmt(NS); 1067 return StmtError(); 1068 } 1069 1070 // Validate tied input operands for type mismatches. 1071 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1072 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1073 1074 // If this is a tied constraint, verify that the output and input have 1075 // either exactly the same type, or that they are int/ptr operands with the 1076 // same size (int/long, int*/long, are ok etc). 1077 if (!Info.hasTiedOperand()) continue; 1078 1079 unsigned TiedTo = Info.getTiedOperand(); 1080 Expr *OutputExpr = Exprs[TiedTo]; 1081 Expr *InputExpr = Exprs[i+NumOutputs]; 1082 QualType InTy = InputExpr->getType(); 1083 QualType OutTy = OutputExpr->getType(); 1084 if (Context.hasSameType(InTy, OutTy)) 1085 continue; // All types can be tied to themselves. 1086 1087 // Int/ptr operands have some special cases that we allow. 1088 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1089 (InTy->isIntegerType() || InTy->isPointerType())) { 1090 1091 // They are ok if they are the same size. Tying void* to int is ok if 1092 // they are the same size, for example. This also allows tying void* to 1093 // int*. 1094 uint64_t OutSize = Context.getTypeSize(OutTy); 1095 uint64_t InSize = Context.getTypeSize(InTy); 1096 if (OutSize == InSize) 1097 continue; 1098 1099 // If the smaller input/output operand is not mentioned in the asm string, 1100 // then we can promote it and the asm string won't notice. Check this 1101 // case now. 1102 bool SmallerValueMentioned = false; 1103 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1104 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1105 if (!Piece.isOperand()) continue; 1106 1107 // If this is a reference to the input and if the input was the smaller 1108 // one, then we have to reject this asm. 1109 if (Piece.getOperandNo() == i+NumOutputs) { 1110 if (InSize < OutSize) { 1111 SmallerValueMentioned = true; 1112 break; 1113 } 1114 } 1115 1116 // If this is a reference to the input and if the input was the smaller 1117 // one, then we have to reject this asm. 1118 if (Piece.getOperandNo() == TiedTo) { 1119 if (InSize > OutSize) { 1120 SmallerValueMentioned = true; 1121 break; 1122 } 1123 } 1124 } 1125 1126 // If the smaller value wasn't mentioned in the asm string, and if the 1127 // output was a register, just extend the shorter one to the size of the 1128 // larger one. 1129 if (!SmallerValueMentioned && 1130 OutputConstraintInfos[TiedTo].allowsRegister()) 1131 continue; 1132 } 1133 1134 Diag(InputExpr->getLocStart(), 1135 diag::err_asm_tying_incompatible_types) 1136 << InTy << OutTy << OutputExpr->getSourceRange() 1137 << InputExpr->getSourceRange(); 1138 DeleteStmt(NS); 1139 return StmtError(); 1140 } 1141 1142 return Owned(NS); 1143} 1144 1145Action::OwningStmtResult 1146Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1147 SourceLocation RParen, DeclPtrTy Parm, 1148 StmtArg Body, StmtArg catchList) { 1149 Stmt *CatchList = catchList.takeAs<Stmt>(); 1150 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1151 1152 // PVD == 0 implies @catch(...). 1153 if (PVD) { 1154 // If we already know the decl is invalid, reject it. 1155 if (PVD->isInvalidDecl()) 1156 return StmtError(); 1157 1158 if (!Context.isObjCObjectPointerType(PVD->getType())) 1159 return StmtError(Diag(PVD->getLocation(), 1160 diag::err_catch_param_not_objc_type)); 1161 if (PVD->getType()->isObjCQualifiedIdType()) 1162 return StmtError(Diag(PVD->getLocation(), 1163 diag::err_illegal_qualifiers_on_catch_parm)); 1164 } 1165 1166 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1167 PVD, Body.takeAs<Stmt>(), CatchList); 1168 return Owned(CatchList ? CatchList : CS); 1169} 1170 1171Action::OwningStmtResult 1172Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1173 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1174 static_cast<Stmt*>(Body.release()))); 1175} 1176 1177Action::OwningStmtResult 1178Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1179 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1180 CurFunctionNeedsScopeChecking = true; 1181 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1182 Catch.takeAs<Stmt>(), 1183 Finally.takeAs<Stmt>())); 1184} 1185 1186Action::OwningStmtResult 1187Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1188 Expr *ThrowExpr = expr.takeAs<Expr>(); 1189 if (!ThrowExpr) { 1190 // @throw without an expression designates a rethrow (which much occur 1191 // in the context of an @catch clause). 1192 Scope *AtCatchParent = CurScope; 1193 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1194 AtCatchParent = AtCatchParent->getParent(); 1195 if (!AtCatchParent) 1196 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1197 } else { 1198 QualType ThrowType = ThrowExpr->getType(); 1199 // Make sure the expression type is an ObjC pointer or "void *". 1200 if (!Context.isObjCObjectPointerType(ThrowType)) { 1201 const PointerType *PT = ThrowType->getAsPointerType(); 1202 if (!PT || !PT->getPointeeType()->isVoidType()) 1203 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1204 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1205 } 1206 } 1207 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1208} 1209 1210Action::OwningStmtResult 1211Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1212 StmtArg SynchBody) { 1213 CurFunctionNeedsScopeChecking = true; 1214 1215 // Make sure the expression type is an ObjC pointer or "void *". 1216 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1217 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1218 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1219 if (!PT || !PT->getPointeeType()->isVoidType()) 1220 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1221 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1222 } 1223 1224 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1225 SynchExpr.takeAs<Stmt>(), 1226 SynchBody.takeAs<Stmt>())); 1227} 1228 1229/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1230/// and creates a proper catch handler from them. 1231Action::OwningStmtResult 1232Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1233 StmtArg HandlerBlock) { 1234 // There's nothing to test that ActOnExceptionDecl didn't already test. 1235 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1236 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1237 HandlerBlock.takeAs<Stmt>())); 1238} 1239 1240/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1241/// handlers and creates a try statement from them. 1242Action::OwningStmtResult 1243Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1244 MultiStmtArg RawHandlers) { 1245 unsigned NumHandlers = RawHandlers.size(); 1246 assert(NumHandlers > 0 && 1247 "The parser shouldn't call this if there are no handlers."); 1248 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1249 1250 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1251 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1252 if (!Handler->getExceptionDecl()) 1253 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1254 } 1255 // FIXME: We should detect handlers for the same type as an earlier one. 1256 // This one is rather easy. 1257 // FIXME: We should detect handlers that cannot catch anything because an 1258 // earlier handler catches a superclass. Need to find a method that is not 1259 // quadratic for this. 1260 // Neither of these are explicitly forbidden, but every compiler detects them 1261 // and warns. 1262 1263 CurFunctionNeedsScopeChecking = true; 1264 RawHandlers.release(); 1265 return Owned(new (Context) CXXTryStmt(TryLoc, 1266 static_cast<Stmt*>(TryBlock.release()), 1267 Handlers, NumHandlers)); 1268} 1269