SemaStmt.cpp revision 194179
152243Sdfr//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 2139731Simp// 340713Swollman// The LLVM Compiler Infrastructure 440713Swollman// 540713Swollman// This file is distributed under the University of Illinois Open Source 640713Swollman// License. See LICENSE.TXT for details. 740713Swollman// 840713Swollman//===----------------------------------------------------------------------===// 940713Swollman// 1040713Swollman// This file implements semantic analysis for statements. 1140713Swollman// 1240713Swollman//===----------------------------------------------------------------------===// 1340713Swollman 1440713Swollman#include "Sema.h" 1540713Swollman#include "clang/AST/APValue.h" 1640713Swollman#include "clang/AST/ASTContext.h" 1740713Swollman#include "clang/AST/DeclObjC.h" 1840713Swollman#include "clang/AST/Expr.h" 1940713Swollman#include "clang/AST/StmtObjC.h" 2040713Swollman#include "clang/AST/StmtCXX.h" 2140713Swollman#include "clang/Basic/TargetInfo.h" 2240713Swollmanusing namespace clang; 2340713Swollman 2440713SwollmanSema::OwningStmtResult Sema::ActOnExprStmt(FullExprArg expr) { 2540713Swollman Expr *E = expr->takeAs<Expr>(); 2640713Swollman assert(E && "ActOnExprStmt(): missing expression"); 2740713Swollman 2840713Swollman // C99 6.8.3p2: The expression in an expression statement is evaluated as a 2940713Swollman // void expression for its side effects. Conversion to void allows any 3040713Swollman // operand, even incomplete types. 3140713Swollman 3240713Swollman // Same thing in for stmt first clause (when expr) and third clause. 3340713Swollman return Owned(static_cast<Stmt*>(E)); 3440713Swollman} 3540713Swollman 3640713Swollman 3740713SwollmanSema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 3840713Swollman return Owned(new (Context) NullStmt(SemiLoc)); 3949157Sdfr} 4049157Sdfr 4149157SdfrSema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, 4249157Sdfr SourceLocation StartLoc, 4340713Swollman SourceLocation EndLoc) { 4440713Swollman 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, SourceLocation CondLParen, 572 ExprArg Cond, SourceLocation CondRParen) { 573 Expr *condExpr = Cond.takeAs<Expr>(); 574 assert(condExpr && "ActOnDoStmt(): missing expression"); 575 576 if (!condExpr->isTypeDependent()) { 577 DefaultFunctionArrayConversion(condExpr); 578 Cond = condExpr; 579 QualType condType = condExpr->getType(); 580 581 if (getLangOptions().CPlusPlus) { 582 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 583 return StmtError(); 584 } else if (!condType->isScalarType()) // C99 6.8.5p2 585 return StmtError(Diag(DoLoc, 586 diag::err_typecheck_statement_requires_scalar) 587 << condType << condExpr->getSourceRange()); 588 } 589 590 Cond.release(); 591 return Owned(new (Context) DoStmt(Body.takeAs<Stmt>(), condExpr, DoLoc, 592 WhileLoc, CondRParen)); 593} 594 595Action::OwningStmtResult 596Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 597 StmtArg first, ExprArg second, ExprArg third, 598 SourceLocation RParenLoc, StmtArg body) { 599 Stmt *First = static_cast<Stmt*>(first.get()); 600 Expr *Second = static_cast<Expr*>(second.get()); 601 Expr *Third = static_cast<Expr*>(third.get()); 602 Stmt *Body = static_cast<Stmt*>(body.get()); 603 604 if (!getLangOptions().CPlusPlus) { 605 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 606 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 607 // declare identifiers for objects having storage class 'auto' or 608 // 'register'. 609 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 610 DI!=DE; ++DI) { 611 VarDecl *VD = dyn_cast<VarDecl>(*DI); 612 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 613 VD = 0; 614 if (VD == 0) 615 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 616 // FIXME: mark decl erroneous! 617 } 618 } 619 } 620 if (Second && !Second->isTypeDependent()) { 621 DefaultFunctionArrayConversion(Second); 622 QualType SecondType = Second->getType(); 623 624 if (getLangOptions().CPlusPlus) { 625 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 626 return StmtError(); 627 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 628 return StmtError(Diag(ForLoc, 629 diag::err_typecheck_statement_requires_scalar) 630 << SecondType << Second->getSourceRange()); 631 } 632 first.release(); 633 second.release(); 634 third.release(); 635 body.release(); 636 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc, 637 LParenLoc, RParenLoc)); 638} 639 640Action::OwningStmtResult 641Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 642 SourceLocation LParenLoc, 643 StmtArg first, ExprArg second, 644 SourceLocation RParenLoc, StmtArg body) { 645 Stmt *First = static_cast<Stmt*>(first.get()); 646 Expr *Second = static_cast<Expr*>(second.get()); 647 Stmt *Body = static_cast<Stmt*>(body.get()); 648 if (First) { 649 QualType FirstType; 650 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 651 if (!DS->isSingleDecl()) 652 return StmtError(Diag((*DS->decl_begin())->getLocation(), 653 diag::err_toomany_element_decls)); 654 655 Decl *D = DS->getSingleDecl(); 656 FirstType = cast<ValueDecl>(D)->getType(); 657 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 658 // declare identifiers for objects having storage class 'auto' or 659 // 'register'. 660 VarDecl *VD = cast<VarDecl>(D); 661 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 662 return StmtError(Diag(VD->getLocation(), 663 diag::err_non_variable_decl_in_for)); 664 } else { 665 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 666 return StmtError(Diag(First->getLocStart(), 667 diag::err_selector_element_not_lvalue) 668 << First->getSourceRange()); 669 670 FirstType = static_cast<Expr*>(First)->getType(); 671 } 672 if (!Context.isObjCObjectPointerType(FirstType)) 673 Diag(ForLoc, diag::err_selector_element_type) 674 << FirstType << First->getSourceRange(); 675 } 676 if (Second) { 677 DefaultFunctionArrayConversion(Second); 678 QualType SecondType = Second->getType(); 679 if (!Context.isObjCObjectPointerType(SecondType)) 680 Diag(ForLoc, diag::err_collection_expr_type) 681 << SecondType << Second->getSourceRange(); 682 } 683 first.release(); 684 second.release(); 685 body.release(); 686 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 687 ForLoc, RParenLoc)); 688} 689 690Action::OwningStmtResult 691Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 692 IdentifierInfo *LabelII) { 693 // If we are in a block, reject all gotos for now. 694 if (CurBlock) 695 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 696 697 // Look up the record for this label identifier. 698 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 699 700 // If we haven't seen this label yet, create a forward reference. 701 if (LabelDecl == 0) 702 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 703 704 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 705} 706 707Action::OwningStmtResult 708Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 709 ExprArg DestExp) { 710 // Convert operand to void* 711 Expr* E = DestExp.takeAs<Expr>(); 712 if (!E->isTypeDependent()) { 713 QualType ETy = E->getType(); 714 AssignConvertType ConvTy = 715 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 716 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 717 E, "passing")) 718 return StmtError(); 719 } 720 return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); 721} 722 723Action::OwningStmtResult 724Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 725 Scope *S = CurScope->getContinueParent(); 726 if (!S) { 727 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 728 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 729 } 730 731 return Owned(new (Context) ContinueStmt(ContinueLoc)); 732} 733 734Action::OwningStmtResult 735Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 736 Scope *S = CurScope->getBreakParent(); 737 if (!S) { 738 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 739 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 740 } 741 742 return Owned(new (Context) BreakStmt(BreakLoc)); 743} 744 745/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 746/// 747Action::OwningStmtResult 748Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 749 // If this is the first return we've seen in the block, infer the type of 750 // the block from it. 751 if (CurBlock->ReturnType == 0) { 752 if (RetValExp) { 753 // Don't call UsualUnaryConversions(), since we don't want to do 754 // integer promotions here. 755 DefaultFunctionArrayConversion(RetValExp); 756 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 757 } else 758 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 759 } 760 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 761 762 if (CurBlock->TheDecl->hasAttr<NoReturnAttr>()) { 763 Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr) 764 << getCurFunctionOrMethodDecl()->getDeclName(); 765 return StmtError(); 766 } 767 768 // Otherwise, verify that this result type matches the previous one. We are 769 // pickier with blocks than for normal functions because we don't have GCC 770 // compatibility to worry about here. 771 if (CurBlock->ReturnType->isVoidType()) { 772 if (RetValExp) { 773 Diag(ReturnLoc, diag::err_return_block_has_expr); 774 RetValExp->Destroy(Context); 775 RetValExp = 0; 776 } 777 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 778 } 779 780 if (!RetValExp) 781 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 782 783 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 784 // we have a non-void block with an expression, continue checking 785 QualType RetValType = RetValExp->getType(); 786 787 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 788 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 789 // function return. 790 791 // In C++ the return statement is handled via a copy initialization. 792 // the C version of which boils down to CheckSingleAssignmentConstraints. 793 // FIXME: Leaks RetValExp. 794 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 795 return StmtError(); 796 797 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 798 } 799 800 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 801} 802 803/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 804/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 805static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 806 Expr *RetExpr) { 807 QualType ExprType = RetExpr->getType(); 808 // - in a return statement in a function with ... 809 // ... a class return type ... 810 if (!RetType->isRecordType()) 811 return false; 812 // ... the same cv-unqualified type as the function return type ... 813 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 814 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 815 return false; 816 // ... the expression is the name of a non-volatile automatic object ... 817 // We ignore parentheses here. 818 // FIXME: Is this compliant? 819 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 820 if (!DR) 821 return false; 822 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 823 if (!VD) 824 return false; 825 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 826 && !VD->getType().isVolatileQualified(); 827} 828 829Action::OwningStmtResult 830Sema::ActOnReturnStmt(SourceLocation ReturnLoc, FullExprArg rex) { 831 Expr *RetValExp = rex->takeAs<Expr>(); 832 if (CurBlock) 833 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 834 835 QualType FnRetType; 836 if (const FunctionDecl *FD = getCurFunctionDecl()) { 837 FnRetType = FD->getResultType(); 838 if (FD->hasAttr<NoReturnAttr>()) 839 Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) 840 << getCurFunctionOrMethodDecl()->getDeclName(); 841 } else if (ObjCMethodDecl *MD = getCurMethodDecl()) 842 FnRetType = MD->getResultType(); 843 else // If we don't have a function/method context, bail. 844 return StmtError(); 845 846 if (FnRetType->isVoidType()) { 847 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 848 unsigned D = diag::ext_return_has_expr; 849 if (RetValExp->getType()->isVoidType()) 850 D = diag::ext_return_has_void_expr; 851 852 // return (some void expression); is legal in C++. 853 if (D != diag::ext_return_has_void_expr || 854 !getLangOptions().CPlusPlus) { 855 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 856 Diag(ReturnLoc, D) 857 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 858 << RetValExp->getSourceRange(); 859 } 860 } 861 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 862 } 863 864 if (!RetValExp && !FnRetType->isDependentType()) { 865 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 866 // C99 6.8.6.4p1 (ext_ since GCC warns) 867 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 868 869 if (FunctionDecl *FD = getCurFunctionDecl()) 870 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 871 else 872 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 873 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 874 } 875 876 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 877 // we have a non-void function with an expression, continue checking 878 879 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 880 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 881 // function return. 882 883 // C++0x 12.8p15: When certain criteria are met, an implementation is 884 // allowed to omit the copy construction of a class object, [...] 885 // - in a return statement in a function with a class return type, when 886 // the expression is the name of a non-volatile automatic object with 887 // the same cv-unqualified type as the function return type, the copy 888 // operation can be omitted [...] 889 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 890 // and the object to be copied is designated by an lvalue, overload 891 // resolution to select the constructor for the copy is first performed 892 // as if the object were designated by an rvalue. 893 // Note that we only compute Elidable if we're in C++0x, since we don't 894 // care otherwise. 895 bool Elidable = getLangOptions().CPlusPlus0x ? 896 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 897 false; 898 899 // In C++ the return statement is handled via a copy initialization. 900 // the C version of which boils down to CheckSingleAssignmentConstraints. 901 // FIXME: Leaks RetValExp on error. 902 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 903 return StmtError(); 904 905 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 906 } 907 908 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 909} 910 911/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 912/// ignore "noop" casts in places where an lvalue is required by an inline asm. 913/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 914/// provide a strong guidance to not use it. 915/// 916/// This method checks to see if the argument is an acceptable l-value and 917/// returns false if it is a case we can handle. 918static bool CheckAsmLValue(const Expr *E, Sema &S) { 919 if (E->isLvalue(S.Context) == Expr::LV_Valid) 920 return false; // Cool, this is an lvalue. 921 922 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 923 // are supposed to allow. 924 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 925 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 926 if (!S.getLangOptions().HeinousExtensions) 927 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 928 << E->getSourceRange(); 929 else 930 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 931 << E->getSourceRange(); 932 // Accept, even if we emitted an error diagnostic. 933 return false; 934 } 935 936 // None of the above, just randomly invalid non-lvalue. 937 return true; 938} 939 940 941Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 942 bool IsSimple, 943 bool IsVolatile, 944 unsigned NumOutputs, 945 unsigned NumInputs, 946 std::string *Names, 947 MultiExprArg constraints, 948 MultiExprArg exprs, 949 ExprArg asmString, 950 MultiExprArg clobbers, 951 SourceLocation RParenLoc) { 952 unsigned NumClobbers = clobbers.size(); 953 StringLiteral **Constraints = 954 reinterpret_cast<StringLiteral**>(constraints.get()); 955 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 956 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 957 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 958 959 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 960 961 // The parser verifies that there is a string literal here. 962 if (AsmString->isWide()) 963 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 964 << AsmString->getSourceRange()); 965 966 for (unsigned i = 0; i != NumOutputs; i++) { 967 StringLiteral *Literal = Constraints[i]; 968 if (Literal->isWide()) 969 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 970 << Literal->getSourceRange()); 971 972 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 973 Literal->getByteLength(), 974 Names[i]); 975 if (!Context.Target.validateOutputConstraint(Info)) 976 return StmtError(Diag(Literal->getLocStart(), 977 diag::err_asm_invalid_output_constraint) 978 << Info.getConstraintStr()); 979 980 // Check that the output exprs are valid lvalues. 981 Expr *OutputExpr = Exprs[i]; 982 if (CheckAsmLValue(OutputExpr, *this)) { 983 return StmtError(Diag(OutputExpr->getLocStart(), 984 diag::err_asm_invalid_lvalue_in_output) 985 << OutputExpr->getSourceRange()); 986 } 987 988 OutputConstraintInfos.push_back(Info); 989 } 990 991 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; 992 993 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 994 StringLiteral *Literal = Constraints[i]; 995 if (Literal->isWide()) 996 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 997 << Literal->getSourceRange()); 998 999 TargetInfo::ConstraintInfo Info(Literal->getStrData(), 1000 Literal->getByteLength(), 1001 Names[i]); 1002 if (!Context.Target.validateInputConstraint(OutputConstraintInfos.data(), 1003 NumOutputs, Info)) { 1004 return StmtError(Diag(Literal->getLocStart(), 1005 diag::err_asm_invalid_input_constraint) 1006 << Info.getConstraintStr()); 1007 } 1008 1009 Expr *InputExpr = Exprs[i]; 1010 1011 // Only allow void types for memory constraints. 1012 if (Info.allowsMemory() && !Info.allowsRegister()) { 1013 if (CheckAsmLValue(InputExpr, *this)) 1014 return StmtError(Diag(InputExpr->getLocStart(), 1015 diag::err_asm_invalid_lvalue_in_input) 1016 << Info.getConstraintStr() 1017 << InputExpr->getSourceRange()); 1018 } 1019 1020 if (Info.allowsRegister()) { 1021 if (InputExpr->getType()->isVoidType()) { 1022 return StmtError(Diag(InputExpr->getLocStart(), 1023 diag::err_asm_invalid_type_in_input) 1024 << InputExpr->getType() << Info.getConstraintStr() 1025 << InputExpr->getSourceRange()); 1026 } 1027 } 1028 1029 DefaultFunctionArrayConversion(Exprs[i]); 1030 1031 InputConstraintInfos.push_back(Info); 1032 } 1033 1034 // Check that the clobbers are valid. 1035 for (unsigned i = 0; i != NumClobbers; i++) { 1036 StringLiteral *Literal = Clobbers[i]; 1037 if (Literal->isWide()) 1038 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 1039 << Literal->getSourceRange()); 1040 1041 llvm::SmallString<16> Clobber(Literal->getStrData(), 1042 Literal->getStrData() + 1043 Literal->getByteLength()); 1044 1045 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 1046 return StmtError(Diag(Literal->getLocStart(), 1047 diag::err_asm_unknown_register_name) << Clobber.c_str()); 1048 } 1049 1050 constraints.release(); 1051 exprs.release(); 1052 asmString.release(); 1053 clobbers.release(); 1054 AsmStmt *NS = 1055 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1056 Names, Constraints, Exprs, AsmString, NumClobbers, 1057 Clobbers, RParenLoc); 1058 // Validate the asm string, ensuring it makes sense given the operands we 1059 // have. 1060 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1061 unsigned DiagOffs; 1062 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1063 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1064 << AsmString->getSourceRange(); 1065 DeleteStmt(NS); 1066 return StmtError(); 1067 } 1068 1069 // Validate tied input operands for type mismatches. 1070 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { 1071 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; 1072 1073 // If this is a tied constraint, verify that the output and input have 1074 // either exactly the same type, or that they are int/ptr operands with the 1075 // same size (int/long, int*/long, are ok etc). 1076 if (!Info.hasTiedOperand()) continue; 1077 1078 unsigned TiedTo = Info.getTiedOperand(); 1079 Expr *OutputExpr = Exprs[TiedTo]; 1080 Expr *InputExpr = Exprs[i+NumOutputs]; 1081 QualType InTy = InputExpr->getType(); 1082 QualType OutTy = OutputExpr->getType(); 1083 if (Context.hasSameType(InTy, OutTy)) 1084 continue; // All types can be tied to themselves. 1085 1086 // Int/ptr operands have some special cases that we allow. 1087 if ((OutTy->isIntegerType() || OutTy->isPointerType()) && 1088 (InTy->isIntegerType() || InTy->isPointerType())) { 1089 1090 // They are ok if they are the same size. Tying void* to int is ok if 1091 // they are the same size, for example. This also allows tying void* to 1092 // int*. 1093 uint64_t OutSize = Context.getTypeSize(OutTy); 1094 uint64_t InSize = Context.getTypeSize(InTy); 1095 if (OutSize == InSize) 1096 continue; 1097 1098 // If the smaller input/output operand is not mentioned in the asm string, 1099 // then we can promote it and the asm string won't notice. Check this 1100 // case now. 1101 bool SmallerValueMentioned = false; 1102 for (unsigned p = 0, e = Pieces.size(); p != e; ++p) { 1103 AsmStmt::AsmStringPiece &Piece = Pieces[p]; 1104 if (!Piece.isOperand()) continue; 1105 1106 // If this is a reference to the input and if the input was the smaller 1107 // one, then we have to reject this asm. 1108 if (Piece.getOperandNo() == i+NumOutputs) { 1109 if (InSize < OutSize) { 1110 SmallerValueMentioned = true; 1111 break; 1112 } 1113 } 1114 1115 // If this is a reference to the input and if the input was the smaller 1116 // one, then we have to reject this asm. 1117 if (Piece.getOperandNo() == TiedTo) { 1118 if (InSize > OutSize) { 1119 SmallerValueMentioned = true; 1120 break; 1121 } 1122 } 1123 } 1124 1125 // If the smaller value wasn't mentioned in the asm string, and if the 1126 // output was a register, just extend the shorter one to the size of the 1127 // larger one. 1128 if (!SmallerValueMentioned && 1129 OutputConstraintInfos[TiedTo].allowsRegister()) 1130 continue; 1131 } 1132 1133 Diag(InputExpr->getLocStart(), 1134 diag::err_asm_tying_incompatible_types) 1135 << InTy << OutTy << OutputExpr->getSourceRange() 1136 << InputExpr->getSourceRange(); 1137 DeleteStmt(NS); 1138 return StmtError(); 1139 } 1140 1141 return Owned(NS); 1142} 1143 1144Action::OwningStmtResult 1145Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1146 SourceLocation RParen, DeclPtrTy Parm, 1147 StmtArg Body, StmtArg catchList) { 1148 Stmt *CatchList = catchList.takeAs<Stmt>(); 1149 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1150 1151 // PVD == 0 implies @catch(...). 1152 if (PVD) { 1153 // If we already know the decl is invalid, reject it. 1154 if (PVD->isInvalidDecl()) 1155 return StmtError(); 1156 1157 if (!Context.isObjCObjectPointerType(PVD->getType())) 1158 return StmtError(Diag(PVD->getLocation(), 1159 diag::err_catch_param_not_objc_type)); 1160 if (PVD->getType()->isObjCQualifiedIdType()) 1161 return StmtError(Diag(PVD->getLocation(), 1162 diag::err_illegal_qualifiers_on_catch_parm)); 1163 } 1164 1165 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1166 PVD, Body.takeAs<Stmt>(), CatchList); 1167 return Owned(CatchList ? CatchList : CS); 1168} 1169 1170Action::OwningStmtResult 1171Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1172 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1173 static_cast<Stmt*>(Body.release()))); 1174} 1175 1176Action::OwningStmtResult 1177Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1178 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1179 CurFunctionNeedsScopeChecking = true; 1180 return Owned(new (Context) ObjCAtTryStmt(AtLoc, Try.takeAs<Stmt>(), 1181 Catch.takeAs<Stmt>(), 1182 Finally.takeAs<Stmt>())); 1183} 1184 1185Action::OwningStmtResult 1186Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1187 Expr *ThrowExpr = expr.takeAs<Expr>(); 1188 if (!ThrowExpr) { 1189 // @throw without an expression designates a rethrow (which much occur 1190 // in the context of an @catch clause). 1191 Scope *AtCatchParent = CurScope; 1192 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1193 AtCatchParent = AtCatchParent->getParent(); 1194 if (!AtCatchParent) 1195 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1196 } else { 1197 QualType ThrowType = ThrowExpr->getType(); 1198 // Make sure the expression type is an ObjC pointer or "void *". 1199 if (!Context.isObjCObjectPointerType(ThrowType)) { 1200 const PointerType *PT = ThrowType->getAsPointerType(); 1201 if (!PT || !PT->getPointeeType()->isVoidType()) 1202 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1203 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1204 } 1205 } 1206 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1207} 1208 1209Action::OwningStmtResult 1210Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1211 StmtArg SynchBody) { 1212 CurFunctionNeedsScopeChecking = true; 1213 1214 // Make sure the expression type is an ObjC pointer or "void *". 1215 Expr *SyncExpr = static_cast<Expr*>(SynchExpr.get()); 1216 if (!Context.isObjCObjectPointerType(SyncExpr->getType())) { 1217 const PointerType *PT = SyncExpr->getType()->getAsPointerType(); 1218 if (!PT || !PT->getPointeeType()->isVoidType()) 1219 return StmtError(Diag(AtLoc, diag::error_objc_synchronized_expects_object) 1220 << SyncExpr->getType() << SyncExpr->getSourceRange()); 1221 } 1222 1223 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1224 SynchExpr.takeAs<Stmt>(), 1225 SynchBody.takeAs<Stmt>())); 1226} 1227 1228/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1229/// and creates a proper catch handler from them. 1230Action::OwningStmtResult 1231Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1232 StmtArg HandlerBlock) { 1233 // There's nothing to test that ActOnExceptionDecl didn't already test. 1234 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1235 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1236 HandlerBlock.takeAs<Stmt>())); 1237} 1238 1239/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1240/// handlers and creates a try statement from them. 1241Action::OwningStmtResult 1242Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1243 MultiStmtArg RawHandlers) { 1244 unsigned NumHandlers = RawHandlers.size(); 1245 assert(NumHandlers > 0 && 1246 "The parser shouldn't call this if there are no handlers."); 1247 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1248 1249 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1250 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1251 if (!Handler->getExceptionDecl()) 1252 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1253 } 1254 // FIXME: We should detect handlers for the same type as an earlier one. 1255 // This one is rather easy. 1256 // FIXME: We should detect handlers that cannot catch anything because an 1257 // earlier handler catches a superclass. Need to find a method that is not 1258 // quadratic for this. 1259 // Neither of these are explicitly forbidden, but every compiler detects them 1260 // and warns. 1261 1262 CurFunctionNeedsScopeChecking = true; 1263 RawHandlers.release(); 1264 return Owned(new (Context) CXXTryStmt(TryLoc, 1265 static_cast<Stmt*>(TryBlock.release()), 1266 Handlers, NumHandlers)); 1267} 1268