SemaStmt.cpp revision 636463e4c43be15e2f0fd0b8a08667f3066d8af7
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" 22#include "llvm/ADT/STLExtras.h" 23#include "llvm/ADT/SmallVector.h" 24using namespace clang; 25 26Sema::OwningStmtResult Sema::ActOnExprStmt(FullExprArg expr) { 27 Expr *E = expr->takeAs<Expr>(); 28 assert(E && "ActOnExprStmt(): missing expression"); 29 30 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 31 // void expression for its side effects. Conversion to void allows any 32 // operand, even incomplete types. 33 34 // Same thing in for stmt first clause (when expr) and third clause. 35 return Owned(static_cast<Stmt*>(E)); 36} 37 38 39Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 40 return Owned(new (Context) NullStmt(SemiLoc)); 41} 42 43Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, 44 SourceLocation StartLoc, 45 SourceLocation EndLoc) { 46 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 47 48 // If we have an invalid decl, just return an error. 49 if (DG.isNull()) return StmtError(); 50 51 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 52} 53 54void Sema::DiagnoseUnusedExprResult(const Stmt *S) { 55 const Expr *E = dyn_cast<Expr>(S); 56 if (!E) 57 return; 58 59 // Ignore expressions that have void type. 60 if (E->getType()->isVoidType()) 61 return; 62 63 SourceLocation Loc; 64 SourceRange R1, R2; 65 if (!E->isUnusedResultAWarning(Loc, R1, R2)) 66 return; 67 68 Diag(Loc, diag::warn_unused_expr) << R1 << R2; 69} 70 71Action::OwningStmtResult 72Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 73 MultiStmtArg elts, bool isStmtExpr) { 74 unsigned NumElts = elts.size(); 75 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 76 // If we're in C89 mode, check that we don't have any decls after stmts. If 77 // so, emit an extension diagnostic. 78 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 79 // Note that __extension__ can be around a decl. 80 unsigned i = 0; 81 // Skip over all declarations. 82 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 83 /*empty*/; 84 85 // We found the end of the list or a statement. Scan for another declstmt. 86 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 87 /*empty*/; 88 89 if (i != NumElts) { 90 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 91 Diag(D->getLocation(), diag::ext_mixed_decls_code); 92 } 93 } 94 // Warn about unused expressions in statements. 95 for (unsigned i = 0; i != NumElts; ++i) { 96 // Ignore statements that are last in a statement expression. 97 if (isStmtExpr && i == NumElts - 1) 98 continue; 99 100 DiagnoseUnusedExprResult(Elts[i]); 101 } 102 103 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 104} 105 106Action::OwningStmtResult 107Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval, 108 SourceLocation DotDotDotLoc, ExprArg rhsval, 109 SourceLocation ColonLoc) { 110 assert((lhsval.get() != 0) && "missing expression in case statement"); 111 112 // C99 6.8.4.2p3: The expression shall be an integer constant. 113 // However, GCC allows any evaluatable integer expression. 114 Expr *LHSVal = static_cast<Expr*>(lhsval.get()); 115 if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent() && 116 VerifyIntegerConstantExpression(LHSVal)) 117 return StmtError(); 118 119 // GCC extension: The expression shall be an integer constant. 120 121 Expr *RHSVal = static_cast<Expr*>(rhsval.get()); 122 if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent() && 123 VerifyIntegerConstantExpression(RHSVal)) { 124 RHSVal = 0; // Recover by just forgetting about it. 125 rhsval = 0; 126 } 127 128 if (getSwitchStack().empty()) { 129 Diag(CaseLoc, diag::err_case_not_in_switch); 130 return StmtError(); 131 } 132 133 // Only now release the smart pointers. 134 lhsval.release(); 135 rhsval.release(); 136 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, 137 ColonLoc); 138 getSwitchStack().back()->addSwitchCase(CS); 139 return Owned(CS); 140} 141 142/// ActOnCaseStmtBody - This installs a statement as the body of a case. 143void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) { 144 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 145 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 146 CS->setSubStmt(SubStmt); 147} 148 149Action::OwningStmtResult 150Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 151 StmtArg subStmt, Scope *CurScope) { 152 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 153 154 if (getSwitchStack().empty()) { 155 Diag(DefaultLoc, diag::err_default_not_in_switch); 156 return Owned(SubStmt); 157 } 158 159 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); 160 getSwitchStack().back()->addSwitchCase(DS); 161 return Owned(DS); 162} 163 164Action::OwningStmtResult 165Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 166 SourceLocation ColonLoc, StmtArg subStmt) { 167 Stmt *SubStmt = subStmt.takeAs<Stmt>(); 168 // Look up the record for this label identifier. 169 LabelStmt *&LabelDecl = getLabelMap()[II]; 170 171 // If not forward referenced or defined already, just create a new LabelStmt. 172 if (LabelDecl == 0) 173 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt)); 174 175 assert(LabelDecl->getID() == II && "Label mismatch!"); 176 177 // Otherwise, this label was either forward reference or multiply defined. If 178 // multiply defined, reject it now. 179 if (LabelDecl->getSubStmt()) { 180 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 181 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 182 return Owned(SubStmt); 183 } 184 185 // Otherwise, this label was forward declared, and we just found its real 186 // definition. Fill in the forward definition and return it. 187 LabelDecl->setIdentLoc(IdentLoc); 188 LabelDecl->setSubStmt(SubStmt); 189 return Owned(LabelDecl); 190} 191 192Action::OwningStmtResult 193Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, 194 StmtArg ThenVal, SourceLocation ElseLoc, 195 StmtArg ElseVal) { 196 OwningExprResult CondResult(CondVal.release()); 197 198 Expr *condExpr = CondResult.takeAs<Expr>(); 199 200 assert(condExpr && "ActOnIfStmt(): missing expression"); 201 202 if (!condExpr->isTypeDependent()) { 203 DefaultFunctionArrayConversion(condExpr); 204 // Take ownership again until we're past the error checking. 205 CondResult = condExpr; 206 QualType condType = condExpr->getType(); 207 208 if (getLangOptions().CPlusPlus) { 209 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 210 return StmtError(); 211 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 212 return StmtError(Diag(IfLoc, 213 diag::err_typecheck_statement_requires_scalar) 214 << condType << condExpr->getSourceRange()); 215 } 216 217 Stmt *thenStmt = ThenVal.takeAs<Stmt>(); 218 219 // Warn if the if block has a null body without an else value. 220 // this helps prevent bugs due to typos, such as 221 // if (condition); 222 // do_stuff(); 223 if (!ElseVal.get()) { 224 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 225 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 226 } 227 228 CondResult.release(); 229 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 230 ElseLoc, ElseVal.takeAs<Stmt>())); 231} 232 233Action::OwningStmtResult 234Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 235 Expr *Cond = cond.takeAs<Expr>(); 236 237 if (getLangOptions().CPlusPlus) { 238 // C++ 6.4.2.p2: 239 // The condition shall be of integral type, enumeration type, or of a class 240 // type for which a single conversion function to integral or enumeration 241 // type exists (12.3). If the condition is of class type, the condition is 242 // converted by calling that conversion function, and the result of the 243 // conversion is used in place of the original condition for the remainder 244 // of this section. Integral promotions are performed. 245 if (!Cond->isTypeDependent()) { 246 QualType Ty = Cond->getType(); 247 248 // FIXME: Handle class types. 249 250 // If the type is wrong a diagnostic will be emitted later at 251 // ActOnFinishSwitchStmt. 252 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 253 // Integral promotions are performed. 254 // FIXME: Integral promotions for C++ are not complete. 255 UsualUnaryConversions(Cond); 256 } 257 } 258 } else { 259 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 260 UsualUnaryConversions(Cond); 261 } 262 263 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 264 getSwitchStack().push_back(SS); 265 return Owned(SS); 266} 267 268/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 269/// the specified width and sign. If an overflow occurs, detect it and emit 270/// the specified diagnostic. 271void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 272 unsigned NewWidth, bool NewSign, 273 SourceLocation Loc, 274 unsigned DiagID) { 275 // Perform a conversion to the promoted condition type if needed. 276 if (NewWidth > Val.getBitWidth()) { 277 // If this is an extension, just do it. 278 llvm::APSInt OldVal(Val); 279 Val.extend(NewWidth); 280 281 // If the input was signed and negative and the output is unsigned, 282 // warn. 283 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 284 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 285 286 Val.setIsSigned(NewSign); 287 } else if (NewWidth < Val.getBitWidth()) { 288 // If this is a truncation, check for overflow. 289 llvm::APSInt ConvVal(Val); 290 ConvVal.trunc(NewWidth); 291 ConvVal.setIsSigned(NewSign); 292 ConvVal.extend(Val.getBitWidth()); 293 ConvVal.setIsSigned(Val.isSigned()); 294 if (ConvVal != Val) 295 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 296 297 // Regardless of whether a diagnostic was emitted, really do the 298 // truncation. 299 Val.trunc(NewWidth); 300 Val.setIsSigned(NewSign); 301 } else if (NewSign != Val.isSigned()) { 302 // Convert the sign to match the sign of the condition. This can cause 303 // overflow as well: unsigned(INTMIN) 304 llvm::APSInt OldVal(Val); 305 Val.setIsSigned(NewSign); 306 307 if (Val.isNegative()) // Sign bit changes meaning. 308 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 309 } 310} 311 312namespace { 313 struct CaseCompareFunctor { 314 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 315 const llvm::APSInt &RHS) { 316 return LHS.first < RHS; 317 } 318 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 319 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 320 return LHS.first < RHS.first; 321 } 322 bool operator()(const llvm::APSInt &LHS, 323 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 324 return LHS < RHS.first; 325 } 326 }; 327} 328 329/// CmpCaseVals - Comparison predicate for sorting case values. 330/// 331static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 332 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 333 if (lhs.first < rhs.first) 334 return true; 335 336 if (lhs.first == rhs.first && 337 lhs.second->getCaseLoc().getRawEncoding() 338 < rhs.second->getCaseLoc().getRawEncoding()) 339 return true; 340 return false; 341} 342 343Action::OwningStmtResult 344Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 345 StmtArg Body) { 346 Stmt *BodyStmt = Body.takeAs<Stmt>(); 347 348 SwitchStmt *SS = getSwitchStack().back(); 349 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 350 351 SS->setBody(BodyStmt, SwitchLoc); 352 getSwitchStack().pop_back(); 353 354 Expr *CondExpr = SS->getCond(); 355 QualType CondType = CondExpr->getType(); 356 357 if (!CondExpr->isTypeDependent() && 358 !CondType->isIntegerType()) { // C99 6.8.4.2p1 359 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 360 << CondType << CondExpr->getSourceRange(); 361 return StmtError(); 362 } 363 364 // Get the bitwidth of the switched-on value before promotions. We must 365 // convert the integer case values to this width before comparison. 366 bool HasDependentValue 367 = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); 368 unsigned CondWidth 369 = HasDependentValue? 0 370 : static_cast<unsigned>(Context.getTypeSize(CondType)); 371 bool CondIsSigned = CondType->isSignedIntegerType(); 372 373 // Accumulate all of the case values in a vector so that we can sort them 374 // and detect duplicates. This vector contains the APInt for the case after 375 // it has been converted to the condition type. 376 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 377 CaseValsTy CaseVals; 378 379 // Keep track of any GNU case ranges we see. The APSInt is the low value. 380 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 381 382 DefaultStmt *TheDefaultStmt = 0; 383 384 bool CaseListIsErroneous = false; 385 386 for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; 387 SC = SC->getNextSwitchCase()) { 388 389 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 390 if (TheDefaultStmt) { 391 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 392 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 393 394 // FIXME: Remove the default statement from the switch block so that 395 // we'll return a valid AST. This requires recursing down the AST and 396 // finding it, not something we are set up to do right now. For now, 397 // just lop the entire switch stmt out of the AST. 398 CaseListIsErroneous = true; 399 } 400 TheDefaultStmt = DS; 401 402 } else { 403 CaseStmt *CS = cast<CaseStmt>(SC); 404 405 // We already verified that the expression has a i-c-e value (C99 406 // 6.8.4.2p3) - get that value now. 407 Expr *Lo = CS->getLHS(); 408 409 if (Lo->isTypeDependent() || Lo->isValueDependent()) { 410 HasDependentValue = true; 411 break; 412 } 413 414 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 415 416 // Convert the value to the same width/sign as the condition. 417 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 418 CS->getLHS()->getLocStart(), 419 diag::warn_case_value_overflow); 420 421 // If the LHS is not the same type as the condition, insert an implicit 422 // cast. 423 ImpCastExprToType(Lo, CondType); 424 CS->setLHS(Lo); 425 426 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 427 if (CS->getRHS()) { 428 if (CS->getRHS()->isTypeDependent() || 429 CS->getRHS()->isValueDependent()) { 430 HasDependentValue = true; 431 break; 432 } 433 CaseRanges.push_back(std::make_pair(LoVal, CS)); 434 } else 435 CaseVals.push_back(std::make_pair(LoVal, CS)); 436 } 437 } 438 439 if (!HasDependentValue) { 440 // Sort all the scalar case values so we can easily detect duplicates. 441 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 442 443 if (!CaseVals.empty()) { 444 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 445 if (CaseVals[i].first == CaseVals[i+1].first) { 446 // If we have a duplicate, report it. 447 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 448 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 449 Diag(CaseVals[i].second->getLHS()->getLocStart(), 450 diag::note_duplicate_case_prev); 451 // FIXME: We really want to remove the bogus case stmt from the 452 // substmt, but we have no way to do this right now. 453 CaseListIsErroneous = true; 454 } 455 } 456 } 457 458 // Detect duplicate case ranges, which usually don't exist at all in 459 // the first place. 460 if (!CaseRanges.empty()) { 461 // Sort all the case ranges by their low value so we can easily detect 462 // overlaps between ranges. 463 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 464 465 // Scan the ranges, computing the high values and removing empty ranges. 466 std::vector<llvm::APSInt> HiVals; 467 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 468 CaseStmt *CR = CaseRanges[i].second; 469 Expr *Hi = CR->getRHS(); 470 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 471 472 // Convert the value to the same width/sign as the condition. 473 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 474 CR->getRHS()->getLocStart(), 475 diag::warn_case_value_overflow); 476 477 // If the LHS is not the same type as the condition, insert an implicit 478 // cast. 479 ImpCastExprToType(Hi, CondType); 480 CR->setRHS(Hi); 481 482 // If the low value is bigger than the high value, the case is empty. 483 if (CaseRanges[i].first > HiVal) { 484 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 485 << SourceRange(CR->getLHS()->getLocStart(), 486 CR->getRHS()->getLocEnd()); 487 CaseRanges.erase(CaseRanges.begin()+i); 488 --i, --e; 489 continue; 490 } 491 HiVals.push_back(HiVal); 492 } 493 494 // Rescan the ranges, looking for overlap with singleton values and other 495 // ranges. Since the range list is sorted, we only need to compare case 496 // ranges with their neighbors. 497 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 498 llvm::APSInt &CRLo = CaseRanges[i].first; 499 llvm::APSInt &CRHi = HiVals[i]; 500 CaseStmt *CR = CaseRanges[i].second; 501 502 // Check to see whether the case range overlaps with any 503 // singleton cases. 504 CaseStmt *OverlapStmt = 0; 505 llvm::APSInt OverlapVal(32); 506 507 // Find the smallest value >= the lower bound. If I is in the 508 // case range, then we have overlap. 509 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 510 CaseVals.end(), CRLo, 511 CaseCompareFunctor()); 512 if (I != CaseVals.end() && I->first < CRHi) { 513 OverlapVal = I->first; // Found overlap with scalar. 514 OverlapStmt = I->second; 515 } 516 517 // Find the smallest value bigger than the upper bound. 518 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 519 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 520 OverlapVal = (I-1)->first; // Found overlap with scalar. 521 OverlapStmt = (I-1)->second; 522 } 523 524 // Check to see if this case stmt overlaps with the subsequent 525 // case range. 526 if (i && CRLo <= HiVals[i-1]) { 527 OverlapVal = HiVals[i-1]; // Found overlap with range. 528 OverlapStmt = CaseRanges[i-1].second; 529 } 530 531 if (OverlapStmt) { 532 // If we have a duplicate, report it. 533 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 534 << OverlapVal.toString(10); 535 Diag(OverlapStmt->getLHS()->getLocStart(), 536 diag::note_duplicate_case_prev); 537 // FIXME: We really want to remove the bogus case stmt from the 538 // substmt, but we have no way to do this right now. 539 CaseListIsErroneous = true; 540 } 541 } 542 } 543 } 544 545 // FIXME: If the case list was broken is some way, we don't have a good system 546 // to patch it up. Instead, just return the whole substmt as broken. 547 if (CaseListIsErroneous) 548 return StmtError(); 549 550 Switch.release(); 551 return Owned(SS); 552} 553 554Action::OwningStmtResult 555Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, StmtArg Body) { 556 ExprArg CondArg(Cond.release()); 557 Expr *condExpr = CondArg.takeAs<Expr>(); 558 assert(condExpr && "ActOnWhileStmt(): missing expression"); 559 560 if (!condExpr->isTypeDependent()) { 561 DefaultFunctionArrayConversion(condExpr); 562 CondArg = condExpr; 563 QualType condType = condExpr->getType(); 564 565 if (getLangOptions().CPlusPlus) { 566 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 567 return StmtError(); 568 } else if (!condType->isScalarType()) // C99 6.8.5p2 569 return StmtError(Diag(WhileLoc, 570 diag::err_typecheck_statement_requires_scalar) 571 << condType << condExpr->getSourceRange()); 572 } 573 574 CondArg.release(); 575 return Owned(new (Context) WhileStmt(condExpr, Body.takeAs<Stmt>(), 576 WhileLoc)); 577} 578 579Action::OwningStmtResult 580Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 581 SourceLocation WhileLoc, SourceLocation CondLParen, 582 ExprArg Cond, SourceLocation CondRParen) { 583 Expr *condExpr = Cond.takeAs<Expr>(); 584 assert(condExpr && "ActOnDoStmt(): missing expression"); 585 586 if (!condExpr->isTypeDependent()) { 587 DefaultFunctionArrayConversion(condExpr); 588 Cond = condExpr; 589 QualType condType = condExpr->getType(); 590 591 if (getLangOptions().CPlusPlus) { 592 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 593 return StmtError(); 594 } else if (!condType->isScalarType()) // C99 6.8.5p2 595 return StmtError(Diag(DoLoc, 596 diag::err_typecheck_statement_requires_scalar) 597 << condType << condExpr->getSourceRange()); 598 } 599 600 Cond.release(); 601 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, 602 WhileLoc, CondRParen)); 603} 604 605Action::OwningStmtResult 606Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 607 StmtArg first, ExprArg second, ExprArg third, 608 SourceLocation RParenLoc, StmtArg body) { 609 Stmt *First = static_cast<Stmt*>(first.get()); 610 Expr *Second = static_cast<Expr*>(second.get()); 611 Expr *Third = static_cast<Expr*>(third.get()); 612 Stmt *Body = static_cast<Stmt*>(body.get()); 613 614 if (!getLangOptions().CPlusPlus) { 615 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 616 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 617 // declare identifiers for objects having storage class 'auto' or 618 // 'register'. 619 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 620 DI!=DE; ++DI) { 621 VarDecl *VD = dyn_cast<VarDecl>(*DI); 622 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 623 VD = 0; 624 if (VD == 0) 625 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 626 // FIXME: mark decl erroneous! 627 } 628 } 629 } 630 if (Second && !Second->isTypeDependent()) { 631 DefaultFunctionArrayConversion(Second); 632 QualType SecondType = Second->getType(); 633 634 if (getLangOptions().CPlusPlus) { 635 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 636 return StmtError(); 637 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 638 return StmtError(Diag(ForLoc, 639 diag::err_typecheck_statement_requires_scalar) 640 << SecondType << Second->getSourceRange()); 641 } 642 first.release(); 643 second.release(); 644 third.release(); 645 body.release(); 646 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, 647 LParenLoc, RParenLoc)); 648} 649 650Action::OwningStmtResult 651Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 652 SourceLocation LParenLoc, 653 StmtArg first, ExprArg second, 654 SourceLocation RParenLoc, StmtArg body) { 655 Stmt *First = static_cast<Stmt*>(first.get()); 656 Expr *Second = static_cast<Expr*>(second.get()); 657 Stmt *Body = static_cast<Stmt*>(body.get()); 658 if (First) { 659 QualType FirstType; 660 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 661 if (!DS->isSingleDecl()) 662 return StmtError(Diag((*DS->decl_begin())->getLocation(), 663 diag::err_toomany_element_decls)); 664 665 Decl *D = DS->getSingleDecl(); 666 FirstType = cast<ValueDecl>(D)->getType(); 667 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 668 // declare identifiers for objects having storage class 'auto' or 669 // 'register'. 670 VarDecl *VD = cast<VarDecl>(D); 671 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 672 return StmtError(Diag(VD->getLocation(), 673 diag::err_non_variable_decl_in_for)); 674 } else { 675 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 676 return StmtError(Diag(First->getLocStart(), 677 diag::err_selector_element_not_lvalue) 678 << First->getSourceRange()); 679 680 FirstType = static_cast<Expr*>(First)->getType(); 681 } 682 if (!FirstType->isObjCObjectPointerType()) 683 Diag(ForLoc, diag::err_selector_element_type) 684 << FirstType << First->getSourceRange(); 685 } 686 if (Second) { 687 DefaultFunctionArrayConversion(Second); 688 QualType SecondType = Second->getType(); 689 if (!SecondType->isObjCObjectPointerType()) 690 Diag(ForLoc, diag::err_collection_expr_type) 691 << SecondType << Second->getSourceRange(); 692 } 693 first.release(); 694 second.release(); 695 body.release(); 696 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 697 ForLoc, RParenLoc)); 698} 699 700Action::OwningStmtResult 701Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 702 IdentifierInfo *LabelII) { 703 // If we are in a block, reject all gotos for now. 704 if (CurBlock) 705 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 706 707 // Look up the record for this label identifier. 708 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 709 710 // If we haven't seen this label yet, create a forward reference. 711 if (LabelDecl == 0) 712 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 713 714 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 715} 716 717Action::OwningStmtResult 718Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 719 ExprArg DestExp) { 720 // Convert operand to void* 721 Expr* E = DestExp.takeAs<Expr>(); 722 if (!E->isTypeDependent()) { 723 QualType ETy = E->getType(); 724 AssignConvertType ConvTy = 725 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 726 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 727 E, "passing")) 728 return StmtError(); 729 } 730 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 731} 732 733Action::OwningStmtResult 734Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 735 Scope *S = CurScope->getContinueParent(); 736 if (!S) { 737 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 738 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 739 } 740 741 return Owned(new (Context) ContinueStmt(ContinueLoc)); 742} 743 744Action::OwningStmtResult 745Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 746 Scope *S = CurScope->getBreakParent(); 747 if (!S) { 748 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 749 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 750 } 751 752 return Owned(new (Context) BreakStmt(BreakLoc)); 753} 754 755/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 756/// 757Action::OwningStmtResult 758Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 759 // If this is the first return we've seen in the block, infer the type of 760 // the block from it. 761 if (CurBlock->ReturnType.isNull()) { 762 if (RetValExp) { 763 // Don't call UsualUnaryConversions(), since we don't want to do 764 // integer promotions here. 765 DefaultFunctionArrayConversion(RetValExp); 766 CurBlock->ReturnType = RetValExp->getType(); 767 if (BlockDeclRefExpr *CDRE = dyn_cast<BlockDeclRefExpr>(RetValExp)) { 768 // We have to remove a 'const' added to copied-in variable which was 769 // part of the implementation spec. and not the actual qualifier for 770 // the variable. 771 if (CDRE->isConstQualAdded()) 772 CurBlock->ReturnType.removeConst(); 773 } 774 } else 775 CurBlock->ReturnType = Context.VoidTy; 776 } 777 QualType FnRetType = CurBlock->ReturnType; 778 779 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 780 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 781 << getCurFunctionOrMethodDecl()->getDeclName(); 782 return StmtError(); 783 } 784 785 // Otherwise, verify that this result type matches the previous one. We are 786 // pickier with blocks than for normal functions because we don't have GCC 787 // compatibility to worry about here. 788 if (CurBlock->ReturnType->isVoidType()) { 789 if (RetValExp) { 790 Diag(ReturnLoc, diag::err_return_block_has_expr); 791 RetValExp->Destroy(Context); 792 RetValExp = 0; 793 } 794 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 795 } 796 797 if (!RetValExp) 798 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 799 800 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 801 // we have a non-void block with an expression, continue checking 802 QualType RetValType = RetValExp->getType(); 803 804 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 805 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 806 // function return. 807 808 // In C++ the return statement is handled via a copy initialization. 809 // the C version of which boils down to CheckSingleAssignmentConstraints. 810 // FIXME: Leaks RetValExp. 811 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 812 return StmtError(); 813 814 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 815 } 816 817 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 818} 819 820/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 821/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 822static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 823 Expr *RetExpr) { 824 QualType ExprType = RetExpr->getType(); 825 // - in a return statement in a function with ... 826 // ... a class return type ... 827 if (!RetType->isRecordType()) 828 return false; 829 // ... the same cv-unqualified type as the function return type ... 830 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 831 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 832 return false; 833 // ... the expression is the name of a non-volatile automatic object ... 834 // We ignore parentheses here. 835 // FIXME: Is this compliant? 836 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 837 if (!DR) 838 return false; 839 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 840 if (!VD) 841 return false; 842 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 843 && !VD->getType().isVolatileQualified(); 844} 845 846Action::OwningStmtResult 847Sema::ActOnReturnStmt(SourceLocation ReturnLoc, FullExprArg rex) { 848 Expr *RetValExp = rex->takeAs<Expr>(); 849 if (CurBlock) 850 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 851 852 QualType FnRetType; 853 if (const FunctionDecl *FD = getCurFunctionDecl()) { 854 FnRetType = FD->getResultType(); 855 if (FD->hasAttr<NoReturnAttr>()) 856 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 857 << getCurFunctionOrMethodDecl()->getDeclName(); 858 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 859 FnRetType = MD->getResultType(); 860 else // If we don't have a function/method context, bail. 861 return StmtError(); 862 863 if (FnRetType->isVoidType()) { 864 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 865 unsigned D = diag::ext_return_has_expr; 866 if (RetValExp->getType()->isVoidType()) 867 D = diag::ext_return_has_void_expr; 868 869 // return (some void expression); is legal in C++. 870 if (D != diag::ext_return_has_void_expr || 871 !getLangOptions().CPlusPlus) { 872 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 873 Diag(ReturnLoc, D) 874 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 875 << RetValExp->getSourceRange(); 876 } 877 } 878 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 879 } 880 881 if (!RetValExp && !FnRetType->isDependentType()) { 882 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 883 // C99 6.8.6.4p1 (ext_ since GCC warns) 884 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 885 886 if (FunctionDecl *FD = getCurFunctionDecl()) 887 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 888 else 889 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 890 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 891 } 892 893 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 894 // we have a non-void function with an expression, continue checking 895 896 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 897 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 898 // function return. 899 900 // C++0x 12.8p15: When certain criteria are met, an implementation is 901 // allowed to omit the copy construction of a class object, [...] 902 // - in a return statement in a function with a class return type, when 903 // the expression is the name of a non-volatile automatic object with 904 // the same cv-unqualified type as the function return type, the copy 905 // operation can be omitted [...] 906 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 907 // and the object to be copied is designated by an lvalue, overload 908 // resolution to select the constructor for the copy is first performed 909 // as if the object were designated by an rvalue. 910 // Note that we only compute Elidable if we're in C++0x, since we don't 911 // care otherwise. 912 bool Elidable = getLangOptions().CPlusPlus0x ? 913 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 914 false; 915 916 // In C++ the return statement is handled via a copy initialization. 917 // the C version of which boils down to CheckSingleAssignmentConstraints. 918 // FIXME: Leaks RetValExp on error. 919 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 920 return StmtError(); 921 922 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 923 } 924 925 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 926} 927 928/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 929/// ignore "noop" casts in places where an lvalue is required by an inline asm. 930/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 931/// provide a strong guidance to not use it. 932/// 933/// This method checks to see if the argument is an acceptable l-value and 934/// returns false if it is a case we can handle. 935static bool CheckAsmLValue(const Expr *E, Sema &S) { 936 if (E->isLvalue(S.Context) == Expr::LV_Valid) 937 return false; // Cool, this is an lvalue. 938 939 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 940 // are supposed to allow. 941 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 942 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 943 if (!S.getLangOptions().HeinousExtensions) 944 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 945 << E->getSourceRange(); 946 else 947 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 948 << E->getSourceRange(); 949 // Accept, even if we emitted an error diagnostic. 950 return false; 951 } 952 953 // None of the above, just randomly invalid non-lvalue. 954 return true; 955} 956 957 958Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 959 bool IsSimple, 960 bool IsVolatile, 961 unsigned NumOutputs, 962 unsigned NumInputs, 963 std::string *Names, 964 MultiExprArg constraints, 965 MultiExprArg exprs, 966 ExprArg asmString, 967 MultiExprArg clobbers, 968 SourceLocation RParenLoc) { 969 unsigned NumClobbers = clobbers.size(); 970 StringLiteral **Constraints = 971 reinterpret_cast<StringLiteral**>(constraints.get()); 972 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 973 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 974 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 975 976 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 977 978 // The parser verifies that there is a string literal here. 979 if (AsmString->isWide()) 980 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 981 << AsmString->getSourceRange()); 982 983 for (unsigned i = 0; i != NumOutputs; i++) { 984 StringLiteral *Literal = Constraints[i]; 985 if (Literal->isWide()) 986 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 987 << Literal->getSourceRange()); 988 989 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 990 Literal->getByteLength(), 991 Names[i]); 992 if (!Context.Target.validateOutputConstraint(Info)) 993 return StmtError(Diag(Literal->getLocStart(), 994 diag::err_asm_invalid_output_constraint) 995 << Info.getConstraintStr()); 996 997 // Check that the output exprs are valid lvalues. 998 Expr *OutputExpr = Exprs[i]; 999 if (CheckAsmLValue(OutputExpr, *this)) { 1000 return StmtError(Diag(OutputExpr->getLocStart(), 1001 diag::err_asm_invalid_lvalue_in_output) 1002 << OutputExpr->getSourceRange()); 1003 } 1004 1005 OutputConstraintInfos.push_back(Info); 1006 } 1007 1008 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 1009 1010 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 1011 StringLiteral *Literal = Constraints[i]; 1012 if (Literal->isWide()) 1013 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1014 << Literal->getSourceRange()); 1015 1016 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 1017 Literal->getByteLength(), 1018 Names[i]); 1019 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(), 1020 NumOutputs, Info)) { 1021 return StmtError(Diag(Literal->getLocStart(), 1022 diag::err_asm_invalid_input_constraint) 1023 << Info.getConstraintStr()); 1024 } 1025 1026 Expr *InputExpr = Exprs[i]; 1027 1028 // Only allow void types for memory constraints. 1029 if (Info.allowsMemory() && !Info.allowsRegister()) { 1030 if (CheckAsmLValue(InputExpr, *this)) 1031 return StmtError(Diag(InputExpr->getLocStart(), 1032 diag::err_asm_invalid_lvalue_in_input) 1033 << Info.getConstraintStr() 1034 << InputExpr->getSourceRange()); 1035 } 1036 1037 if (Info.allowsRegister()) { 1038 if (InputExpr->getType()->isVoidType()) { 1039 return StmtError(Diag(InputExpr->getLocStart(), 1040 diag::err_asm_invalid_type_in_input) 1041 << InputExpr->getType() << Info.getConstraintStr() 1042 << InputExpr->getSourceRange()); 1043 } 1044 } 1045 1046 DefaultFunctionArrayConversion(Exprs[i]); 1047 1048 InputConstraintInfos.push_back(Info); 1049 } 1050 1051 // Check that the clobbers are valid. 1052 for (unsigned i = 0; i != NumClobbers; i++) { 1053 StringLiteral *Literal = Clobbers[i]; 1054 if (Literal->isWide()) 1055 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1056 << Literal->getSourceRange()); 1057 1058 llvm::SmallString<16> Clobber(Literal->getStrData(), 1059 Literal->getStrData() + 1060 Literal->getByteLength()); 1061 1062 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1063 return StmtError(Diag(Literal->getLocStart(), 1064 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1065 } 1066 1067 constraints.release(); 1068 exprs.release(); 1069 asmString.release(); 1070 clobbers.release(); 1071 AsmStmt *NS = 1072 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1073 Names, Constraints, Exprs, AsmString, NumClobbers, 1074 Clobbers, RParenLoc); 1075 // Validate the asm string, ensuring it makes sense given the operands we 1076 // have. 1077 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1078 unsigned DiagOffs; 1079 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1080 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1081 << AsmString->getSourceRange(); 1082 DeleteStmt(NS); 1083 return StmtError(); 1084 } 1085 1086 // Validate tied input operands for type mismatches. 1087 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1088 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1089 1090 // If this is a tied constraint, verify that the output and input have 1091 // either exactly the same type, or that they are int/ptr operands with the 1092 // same size (int/long, int*/long, are ok etc). 1093 if (!Info.hasTiedOperand()) continue; 1094 1095 unsigned TiedTo = Info.getTiedOperand(); 1096 Expr *OutputExpr = Exprs[TiedTo]; 1097 Expr *InputExpr = Exprs[i+NumOutputs]; 1098 QualType InTy = InputExpr->getType(); 1099 QualType OutTy = OutputExpr->getType(); 1100 if (Context.hasSameType(InTy, OutTy)) 1101 continue; // All types can be tied to themselves. 1102 1103 // Int/ptr operands have some special cases that we allow. 1104 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1105 (InTy->isIntegerType() || InTy->isPointerType())) { 1106 1107 // They are ok if they are the same size. Tying void* to int is ok if 1108 // they are the same size, for example. This also allows tying void* to 1109 // int*. 1110 uint64_t OutSize = Context.getTypeSize(OutTy); 1111 uint64_t InSize = Context.getTypeSize(InTy); 1112 if (OutSize == InSize) 1113 continue; 1114 1115 // If the smaller input/output operand is not mentioned in the asm string, 1116 // then we can promote it and the asm string won't notice. Check this 1117 // case now. 1118 bool SmallerValueMentioned = false; 1119 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1120 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1121 if (!Piece.isOperand()) continue; 1122 1123 // If this is a reference to the input and if the input was the smaller 1124 // one, then we have to reject this asm. 1125 if (Piece.getOperandNo() == i+NumOutputs) { 1126 if (InSize < OutSize) { 1127 SmallerValueMentioned = true; 1128 break; 1129 } 1130 } 1131 1132 // If this is a reference to the input and if the input was the smaller 1133 // one, then we have to reject this asm. 1134 if (Piece.getOperandNo() == TiedTo) { 1135 if (InSize > OutSize) { 1136 SmallerValueMentioned = true; 1137 break; 1138 } 1139 } 1140 } 1141 1142 // If the smaller value wasn't mentioned in the asm string, and if the 1143 // output was a register, just extend the shorter one to the size of the 1144 // larger one. 1145 if (!SmallerValueMentioned && 1146 OutputConstraintInfos[TiedTo].allowsRegister()) 1147 continue; 1148 } 1149 1150 Diag(InputExpr->getLocStart(), 1151 diag::err_asm_tying_incompatible_types) 1152 << InTy << OutTy << OutputExpr->getSourceRange() 1153 << InputExpr->getSourceRange(); 1154 DeleteStmt(NS); 1155 return StmtError(); 1156 } 1157 1158 return Owned(NS); 1159} 1160 1161Action::OwningStmtResult 1162Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1163 SourceLocation RParen, DeclPtrTy Parm, 1164 StmtArg Body, StmtArg catchList) { 1165 Stmt *CatchList = catchList.takeAs<Stmt>(); 1166 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1167 1168 // PVD == 0 implies @catch(...). 1169 if (PVD) { 1170 // If we already know the decl is invalid, reject it. 1171 if (PVD->isInvalidDecl()) 1172 return StmtError(); 1173 1174 if (!PVD->getType()->isObjCObjectPointerType()) 1175 return StmtError(Diag(PVD->getLocation(), 1176 diag::err_catch_param_not_objc_type)); 1177 if (PVD->getType()->isObjCQualifiedIdType()) 1178 return StmtError(Diag(PVD->getLocation(), 1179 diag::err_illegal_qualifiers_on_catch_parm)); 1180 } 1181 1182 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1183 PVD, Body.takeAs<Stmt>(), CatchList); 1184 return Owned(CatchList ? CatchList : CS); 1185} 1186 1187Action::OwningStmtResult 1188Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1189 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1190 static_cast<Stmt*>(Body.release()))); 1191} 1192 1193Action::OwningStmtResult 1194Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1195 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1196 CurFunctionNeedsScopeChecking = true; 1197 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1198 Catch.takeAs<Stmt>(), 1199 Finally.takeAs<Stmt>())); 1200} 1201 1202Action::OwningStmtResult 1203Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1204 Expr *ThrowExpr = expr.takeAs<Expr>(); 1205 if (!ThrowExpr) { 1206 // @throw without an expression designates a rethrow (which much occur 1207 // in the context of an @catch clause). 1208 Scope *AtCatchParent = CurScope; 1209 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1210 AtCatchParent = AtCatchParent->getParent(); 1211 if (!AtCatchParent) 1212 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1213 } else { 1214 QualType ThrowType = ThrowExpr->getType(); 1215 // Make sure the expression type is an ObjC pointer or "void *". 1216 if (!ThrowType->isObjCObjectPointerType()) { 1217 const PointerType *PT = ThrowType->getAs<PointerType>(); 1218 if (!PT || !PT->getPointeeType()->isVoidType()) 1219 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1220 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1221 } 1222 } 1223 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1224} 1225 1226Action::OwningStmtResult 1227Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1228 StmtArg SynchBody) { 1229 CurFunctionNeedsScopeChecking = true; 1230 1231 // Make sure the expression type is an ObjC pointer or "void *". 1232 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1233 if (!SyncExpr->getType()->isObjCObjectPointerType()) { 1234 const PointerType *PT = SyncExpr->getType()->getAs<PointerType>(); 1235 if (!PT || !PT->getPointeeType()->isVoidType()) 1236 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1237 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1238 } 1239 1240 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1241 SynchExpr.takeAs<Stmt>(), 1242 SynchBody.takeAs<Stmt>())); 1243} 1244 1245/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1246/// and creates a proper catch handler from them. 1247Action::OwningStmtResult 1248Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1249 StmtArg HandlerBlock) { 1250 // There's nothing to test that ActOnExceptionDecl didn't already test. 1251 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1252 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1253 HandlerBlock.takeAs<Stmt>())); 1254} 1255 1256class TypeWithHandler { 1257 QualType t; 1258 CXXCatchStmt *stmt; 1259public: 1260 TypeWithHandler(const QualType &type, CXXCatchStmt *statement) 1261 : t(type), stmt(statement) {} 1262 1263 bool operator<(const TypeWithHandler &y) const { 1264 if (t.getTypePtr() < y.t.getTypePtr()) 1265 return true; 1266 else if (t.getTypePtr() > y.t.getTypePtr()) 1267 return false; 1268 else if (t.getCVRQualifiers() < y.t.getCVRQualifiers()) 1269 return true; 1270 else if (t.getCVRQualifiers() < y.t.getCVRQualifiers()) 1271 return false; 1272 else 1273 return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); 1274 } 1275 1276 bool operator==(const TypeWithHandler& other) const { 1277 return t.getTypePtr() == other.t.getTypePtr() 1278 && t.getCVRQualifiers() == other.t.getCVRQualifiers(); 1279 } 1280 1281 QualType getQualType() const { return t; } 1282 CXXCatchStmt *getCatchStmt() const { return stmt; } 1283 SourceLocation getTypeSpecStartLoc() const { 1284 return stmt->getExceptionDecl()->getTypeSpecStartLoc(); 1285 } 1286}; 1287 1288/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1289/// handlers and creates a try statement from them. 1290Action::OwningStmtResult 1291Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1292 MultiStmtArg RawHandlers) { 1293 unsigned NumHandlers = RawHandlers.size(); 1294 assert(NumHandlers > 0 && 1295 "The parser shouldn't call this if there are no handlers."); 1296 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1297 1298 llvm::SmallVector<TypeWithHandler, 8> TypesWithHandlers; 1299 1300 for(unsigned i = 0; i < NumHandlers; ++i) { 1301 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1302 if (!Handler->getExceptionDecl()) { 1303 if (i < NumHandlers - 1) 1304 return StmtError(Diag(Handler->getLocStart(), 1305 diag::err_early_catch_all)); 1306 1307 continue; 1308 } 1309 1310 const QualType CaughtType = Handler->getCaughtType(); 1311 const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); 1312 TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); 1313 } 1314 1315 // Detect handlers for the same type as an earlier one. 1316 if (NumHandlers > 1) { 1317 llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); 1318 1319 TypeWithHandler prev = TypesWithHandlers[0]; 1320 for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { 1321 TypeWithHandler curr = TypesWithHandlers[i]; 1322 1323 if (curr == prev) { 1324 Diag(curr.getTypeSpecStartLoc(), 1325 diag::warn_exception_caught_by_earlier_handler) 1326 << curr.getCatchStmt()->getCaughtType().getAsString(); 1327 Diag(prev.getTypeSpecStartLoc(), 1328 diag::note_previous_exception_handler) 1329 << prev.getCatchStmt()->getCaughtType().getAsString(); 1330 } 1331 1332 prev = curr; 1333 } 1334 } 1335 1336 // FIXME: We should detect handlers that cannot catch anything because an 1337 // earlier handler catches a superclass. Need to find a method that is not 1338 // quadratic for this. 1339 // Neither of these are explicitly forbidden, but every compiler detects them 1340 // and warns. 1341 1342 CurFunctionNeedsScopeChecking = true; 1343 RawHandlers.release(); 1344 return Owned(new (Context) CXXTryStmt(TryLoc, 1345 static_cast<Stmt*>(TryBlock.release()), 1346 Handlers, NumHandlers)); 1347} 1348