SemaStmt.cpp revision 4b07b2968f87f3cd5a3d8c76145f1cbfd718d42d
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/Basic/TargetInfo.h" 20#include "clang/Basic/Diagnostic.h" 21using namespace clang; 22 23Sema::OwningStmtResult Sema::ActOnExprStmt(ExprArg expr) { 24 Expr *E = static_cast<Expr*>(expr.release()); 25 assert(E && "ActOnExprStmt(): missing expression"); 26 27 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 28 // void expression for its side effects. Conversion to void allows any 29 // operand, even incomplete types. 30 31 // Same thing in for stmt first clause (when expr) and third clause. 32 return Owned(static_cast<Stmt*>(E)); 33} 34 35 36Sema::OwningStmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 37 return Owned(new NullStmt(SemiLoc)); 38} 39 40Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclTy *decl, 41 SourceLocation StartLoc, 42 SourceLocation EndLoc) { 43 if (decl == 0) 44 return StmtError(); 45 46 ScopedDecl *SD = cast<ScopedDecl>(static_cast<Decl *>(decl)); 47 48 // This is a temporary hack until we are always passing around 49 // DeclGroupRefs. 50 llvm::SmallVector<Decl*, 10> decls; 51 while (SD) { 52 ScopedDecl* d = SD; 53 SD = SD->getNextDeclarator(); 54 d->setNextDeclarator(0); 55 decls.push_back(d); 56 } 57 58 assert (!decls.empty()); 59 60 if (decls.size() == 1) { 61 DeclGroupOwningRef DG(*decls.begin()); 62 return Owned(new DeclStmt(DG, StartLoc, EndLoc)); 63 } 64 else { 65 DeclGroupOwningRef DG(DeclGroup::Create(Context, decls.size(), &decls[0])); 66 return Owned(new DeclStmt(DG, StartLoc, EndLoc)); 67 } 68} 69 70Action::OwningStmtResult 71Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 72 MultiStmtArg elts, bool isStmtExpr) { 73 unsigned NumElts = elts.size(); 74 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 75 // If we're in C89 mode, check that we don't have any decls after stmts. If 76 // so, emit an extension diagnostic. 77 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 78 // Note that __extension__ can be around a decl. 79 unsigned i = 0; 80 // Skip over all declarations. 81 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 82 /*empty*/; 83 84 // We found the end of the list or a statement. Scan for another declstmt. 85 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 86 /*empty*/; 87 88 if (i != NumElts) { 89 ScopedDecl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 90 Diag(D->getLocation(), diag::ext_mixed_decls_code); 91 } 92 } 93 // Warn about unused expressions in statements. 94 for (unsigned i = 0; i != NumElts; ++i) { 95 Expr *E = dyn_cast<Expr>(Elts[i]); 96 if (!E) continue; 97 98 // Warn about expressions with unused results. 99 if (E->hasLocalSideEffect() || E->getType()->isVoidType()) 100 continue; 101 102 // The last expr in a stmt expr really is used. 103 if (isStmtExpr && i == NumElts-1) 104 continue; 105 106 /// DiagnoseDeadExpr - This expression is side-effect free and evaluated in 107 /// a context where the result is unused. Emit a diagnostic to warn about 108 /// this. 109 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) 110 Diag(BO->getOperatorLoc(), diag::warn_unused_expr) 111 << BO->getLHS()->getSourceRange() << BO->getRHS()->getSourceRange(); 112 else if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 113 Diag(UO->getOperatorLoc(), diag::warn_unused_expr) 114 << UO->getSubExpr()->getSourceRange(); 115 else 116 Diag(E->getExprLoc(), diag::warn_unused_expr) << E->getSourceRange(); 117 } 118 119 return Owned(new CompoundStmt(Elts, NumElts, L, R)); 120} 121 122Action::StmtResult 123Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprTy *lhsval, 124 SourceLocation DotDotDotLoc, ExprTy *rhsval, 125 SourceLocation ColonLoc, StmtTy *subStmt) { 126 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 127 Expr *LHSVal = ((Expr *)lhsval), *RHSVal = ((Expr *)rhsval); 128 assert((LHSVal != 0) && "missing expression in case statement"); 129 130 // C99 6.8.4.2p3: The expression shall be an integer constant. 131 // However, GCC allows any evaluatable integer expression. 132 133 if (VerifyIntegerConstantExpression(LHSVal)) 134 return SubStmt; 135 136 // GCC extension: The expression shall be an integer constant. 137 138 if (RHSVal && VerifyIntegerConstantExpression(RHSVal)) 139 RHSVal = 0; // Recover by just forgetting about it. 140 141 if (SwitchStack.empty()) { 142 Diag(CaseLoc, diag::err_case_not_in_switch); 143 return SubStmt; 144 } 145 146 CaseStmt *CS = new CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc); 147 SwitchStack.back()->addSwitchCase(CS); 148 return CS; 149} 150 151Action::StmtResult 152Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 153 StmtTy *subStmt, Scope *CurScope) { 154 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 155 156 if (SwitchStack.empty()) { 157 Diag(DefaultLoc, diag::err_default_not_in_switch); 158 return SubStmt; 159 } 160 161 DefaultStmt *DS = new DefaultStmt(DefaultLoc, SubStmt); 162 SwitchStack.back()->addSwitchCase(DS); 163 164 return DS; 165} 166 167Action::StmtResult 168Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 169 SourceLocation ColonLoc, StmtTy *subStmt) { 170 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 171 // Look up the record for this label identifier. 172 LabelStmt *&LabelDecl = LabelMap[II]; 173 174 // If not forward referenced or defined already, just create a new LabelStmt. 175 if (LabelDecl == 0) 176 return LabelDecl = new LabelStmt(IdentLoc, II, SubStmt); 177 178 assert(LabelDecl->getID() == II && "Label mismatch!"); 179 180 // Otherwise, this label was either forward reference or multiply defined. If 181 // multiply defined, reject it now. 182 if (LabelDecl->getSubStmt()) { 183 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 184 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 185 return SubStmt; 186 } 187 188 // Otherwise, this label was forward declared, and we just found its real 189 // definition. Fill in the forward definition and return it. 190 LabelDecl->setIdentLoc(IdentLoc); 191 LabelDecl->setSubStmt(SubStmt); 192 return LabelDecl; 193} 194 195Action::StmtResult 196Sema::ActOnIfStmt(SourceLocation IfLoc, ExprTy *CondVal, 197 StmtTy *ThenVal, SourceLocation ElseLoc, 198 StmtTy *ElseVal) { 199 Expr *condExpr = (Expr *)CondVal; 200 Stmt *thenStmt = (Stmt *)ThenVal; 201 202 assert(condExpr && "ActOnIfStmt(): missing expression"); 203 204 DefaultFunctionArrayConversion(condExpr); 205 QualType condType = condExpr->getType(); 206 207 if (getLangOptions().CPlusPlus) { 208 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 209 return true; 210 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 211 return Diag(IfLoc, diag::err_typecheck_statement_requires_scalar) 212 << condType << condExpr->getSourceRange(); 213 214 // Warn if the if block has a null body without an else value. 215 // this helps prevent bugs due to typos, such as 216 // if (condition); 217 // do_stuff(); 218 if (!ElseVal) { 219 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 220 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 221 } 222 223 return new IfStmt(IfLoc, condExpr, thenStmt, (Stmt*)ElseVal); 224} 225 226Action::StmtResult 227Sema::ActOnStartOfSwitchStmt(ExprTy *cond) { 228 Expr *Cond = static_cast<Expr*>(cond); 229 230 if (getLangOptions().CPlusPlus) { 231 // C++ 6.4.2.p2: 232 // The condition shall be of integral type, enumeration type, or of a class 233 // type for which a single conversion function to integral or enumeration 234 // type exists (12.3). If the condition is of class type, the condition is 235 // converted by calling that conversion function, and the result of the 236 // conversion is used in place of the original condition for the remainder 237 // of this section. Integral promotions are performed. 238 239 QualType Ty = Cond->getType(); 240 241 // FIXME: Handle class types. 242 243 // If the type is wrong a diagnostic will be emitted later at 244 // ActOnFinishSwitchStmt. 245 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 246 // Integral promotions are performed. 247 // FIXME: Integral promotions for C++ are not complete. 248 UsualUnaryConversions(Cond); 249 } 250 } else { 251 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 252 UsualUnaryConversions(Cond); 253 } 254 255 SwitchStmt *SS = new SwitchStmt(Cond); 256 SwitchStack.push_back(SS); 257 return SS; 258} 259 260/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 261/// the specified width and sign. If an overflow occurs, detect it and emit 262/// the specified diagnostic. 263void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 264 unsigned NewWidth, bool NewSign, 265 SourceLocation Loc, 266 unsigned DiagID) { 267 // Perform a conversion to the promoted condition type if needed. 268 if (NewWidth > Val.getBitWidth()) { 269 // If this is an extension, just do it. 270 llvm::APSInt OldVal(Val); 271 Val.extend(NewWidth); 272 273 // If the input was signed and negative and the output is unsigned, 274 // warn. 275 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 276 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 277 278 Val.setIsSigned(NewSign); 279 } else if (NewWidth < Val.getBitWidth()) { 280 // If this is a truncation, check for overflow. 281 llvm::APSInt ConvVal(Val); 282 ConvVal.trunc(NewWidth); 283 ConvVal.setIsSigned(NewSign); 284 ConvVal.extend(Val.getBitWidth()); 285 ConvVal.setIsSigned(Val.isSigned()); 286 if (ConvVal != Val) 287 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 288 289 // Regardless of whether a diagnostic was emitted, really do the 290 // truncation. 291 Val.trunc(NewWidth); 292 Val.setIsSigned(NewSign); 293 } else if (NewSign != Val.isSigned()) { 294 // Convert the sign to match the sign of the condition. This can cause 295 // overflow as well: unsigned(INTMIN) 296 llvm::APSInt OldVal(Val); 297 Val.setIsSigned(NewSign); 298 299 if (Val.isNegative()) // Sign bit changes meaning. 300 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 301 } 302} 303 304namespace { 305 struct CaseCompareFunctor { 306 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 307 const llvm::APSInt &RHS) { 308 return LHS.first < RHS; 309 } 310 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 311 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 312 return LHS.first < RHS.first; 313 } 314 bool operator()(const llvm::APSInt &LHS, 315 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 316 return LHS < RHS.first; 317 } 318 }; 319} 320 321/// CmpCaseVals - Comparison predicate for sorting case values. 322/// 323static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 324 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 325 if (lhs.first < rhs.first) 326 return true; 327 328 if (lhs.first == rhs.first && 329 lhs.second->getCaseLoc().getRawEncoding() 330 < rhs.second->getCaseLoc().getRawEncoding()) 331 return true; 332 return false; 333} 334 335Action::StmtResult 336Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch, 337 ExprTy *Body) { 338 Stmt *BodyStmt = (Stmt*)Body; 339 340 SwitchStmt *SS = SwitchStack.back(); 341 assert(SS == (SwitchStmt*)Switch && "switch stack missing push/pop!"); 342 343 SS->setBody(BodyStmt, SwitchLoc); 344 SwitchStack.pop_back(); 345 346 Expr *CondExpr = SS->getCond(); 347 QualType CondType = CondExpr->getType(); 348 349 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 350 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 351 << CondType << CondExpr->getSourceRange(); 352 return true; 353 } 354 355 // Get the bitwidth of the switched-on value before promotions. We must 356 // convert the integer case values to this width before comparison. 357 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 358 bool CondIsSigned = CondType->isSignedIntegerType(); 359 360 // Accumulate all of the case values in a vector so that we can sort them 361 // and detect duplicates. This vector contains the APInt for the case after 362 // it has been converted to the condition type. 363 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 364 CaseValsTy CaseVals; 365 366 // Keep track of any GNU case ranges we see. The APSInt is the low value. 367 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 368 369 DefaultStmt *TheDefaultStmt = 0; 370 371 bool CaseListIsErroneous = false; 372 373 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 374 SC = SC->getNextSwitchCase()) { 375 376 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 377 if (TheDefaultStmt) { 378 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 379 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 380 381 // FIXME: Remove the default statement from the switch block so that 382 // we'll return a valid AST. This requires recursing down the 383 // AST and finding it, not something we are set up to do right now. For 384 // now, just lop the entire switch stmt out of the AST. 385 CaseListIsErroneous = true; 386 } 387 TheDefaultStmt = DS; 388 389 } else { 390 CaseStmt *CS = cast<CaseStmt>(SC); 391 392 // We already verified that the expression has a i-c-e value (C99 393 // 6.8.4.2p3) - get that value now. 394 Expr *Lo = CS->getLHS(); 395 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 396 397 // Convert the value to the same width/sign as the condition. 398 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 399 CS->getLHS()->getLocStart(), 400 diag::warn_case_value_overflow); 401 402 // If the LHS is not the same type as the condition, insert an implicit 403 // cast. 404 ImpCastExprToType(Lo, CondType); 405 CS->setLHS(Lo); 406 407 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 408 if (CS->getRHS()) 409 CaseRanges.push_back(std::make_pair(LoVal, CS)); 410 else 411 CaseVals.push_back(std::make_pair(LoVal, CS)); 412 } 413 } 414 415 // Sort all the scalar case values so we can easily detect duplicates. 416 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 417 418 if (!CaseVals.empty()) { 419 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 420 if (CaseVals[i].first == CaseVals[i+1].first) { 421 // If we have a duplicate, report it. 422 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 423 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 424 Diag(CaseVals[i].second->getLHS()->getLocStart(), 425 diag::note_duplicate_case_prev); 426 // FIXME: We really want to remove the bogus case stmt from the substmt, 427 // but we have no way to do this right now. 428 CaseListIsErroneous = true; 429 } 430 } 431 } 432 433 // Detect duplicate case ranges, which usually don't exist at all in the first 434 // place. 435 if (!CaseRanges.empty()) { 436 // Sort all the case ranges by their low value so we can easily detect 437 // overlaps between ranges. 438 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 439 440 // Scan the ranges, computing the high values and removing empty ranges. 441 std::vector<llvm::APSInt> HiVals; 442 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 443 CaseStmt *CR = CaseRanges[i].second; 444 Expr *Hi = CR->getRHS(); 445 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 446 447 // Convert the value to the same width/sign as the condition. 448 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 449 CR->getRHS()->getLocStart(), 450 diag::warn_case_value_overflow); 451 452 // If the LHS is not the same type as the condition, insert an implicit 453 // cast. 454 ImpCastExprToType(Hi, CondType); 455 CR->setRHS(Hi); 456 457 // If the low value is bigger than the high value, the case is empty. 458 if (CaseRanges[i].first > HiVal) { 459 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 460 << SourceRange(CR->getLHS()->getLocStart(), 461 CR->getRHS()->getLocEnd()); 462 CaseRanges.erase(CaseRanges.begin()+i); 463 --i, --e; 464 continue; 465 } 466 HiVals.push_back(HiVal); 467 } 468 469 // Rescan the ranges, looking for overlap with singleton values and other 470 // ranges. Since the range list is sorted, we only need to compare case 471 // ranges with their neighbors. 472 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 473 llvm::APSInt &CRLo = CaseRanges[i].first; 474 llvm::APSInt &CRHi = HiVals[i]; 475 CaseStmt *CR = CaseRanges[i].second; 476 477 // Check to see whether the case range overlaps with any singleton cases. 478 CaseStmt *OverlapStmt = 0; 479 llvm::APSInt OverlapVal(32); 480 481 // Find the smallest value >= the lower bound. If I is in the case range, 482 // then we have overlap. 483 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 484 CaseVals.end(), CRLo, 485 CaseCompareFunctor()); 486 if (I != CaseVals.end() && I->first < CRHi) { 487 OverlapVal = I->first; // Found overlap with scalar. 488 OverlapStmt = I->second; 489 } 490 491 // Find the smallest value bigger than the upper bound. 492 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 493 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 494 OverlapVal = (I-1)->first; // Found overlap with scalar. 495 OverlapStmt = (I-1)->second; 496 } 497 498 // Check to see if this case stmt overlaps with the subsequent case range. 499 if (i && CRLo <= HiVals[i-1]) { 500 OverlapVal = HiVals[i-1]; // Found overlap with range. 501 OverlapStmt = CaseRanges[i-1].second; 502 } 503 504 if (OverlapStmt) { 505 // If we have a duplicate, report it. 506 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 507 << OverlapVal.toString(10); 508 Diag(OverlapStmt->getLHS()->getLocStart(), 509 diag::note_duplicate_case_prev); 510 // FIXME: We really want to remove the bogus case stmt from the substmt, 511 // but we have no way to do this right now. 512 CaseListIsErroneous = true; 513 } 514 } 515 } 516 517 // FIXME: If the case list was broken is some way, we don't have a good system 518 // to patch it up. Instead, just return the whole substmt as broken. 519 if (CaseListIsErroneous) 520 return true; 521 522 return SS; 523} 524 525Action::StmtResult 526Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprTy *Cond, StmtTy *Body) { 527 Expr *condExpr = (Expr *)Cond; 528 assert(condExpr && "ActOnWhileStmt(): missing expression"); 529 530 DefaultFunctionArrayConversion(condExpr); 531 QualType condType = condExpr->getType(); 532 533 if (getLangOptions().CPlusPlus) { 534 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 535 return true; 536 } else if (!condType->isScalarType()) // C99 6.8.5p2 537 return Diag(WhileLoc, diag::err_typecheck_statement_requires_scalar) 538 << condType << condExpr->getSourceRange(); 539 540 return new WhileStmt(condExpr, (Stmt*)Body, WhileLoc); 541} 542 543Action::StmtResult 544Sema::ActOnDoStmt(SourceLocation DoLoc, StmtTy *Body, 545 SourceLocation WhileLoc, ExprTy *Cond) { 546 Expr *condExpr = (Expr *)Cond; 547 assert(condExpr && "ActOnDoStmt(): missing expression"); 548 549 DefaultFunctionArrayConversion(condExpr); 550 QualType condType = condExpr->getType(); 551 552 if (getLangOptions().CPlusPlus) { 553 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 554 return true; 555 } else if (!condType->isScalarType()) // C99 6.8.5p2 556 return Diag(DoLoc, diag::err_typecheck_statement_requires_scalar) 557 << condType << condExpr->getSourceRange(); 558 559 return new DoStmt((Stmt*)Body, condExpr, DoLoc); 560} 561 562Action::StmtResult 563Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 564 StmtTy *first, ExprTy *second, ExprTy *third, 565 SourceLocation RParenLoc, StmtTy *body) { 566 Stmt *First = static_cast<Stmt*>(first); 567 Expr *Second = static_cast<Expr*>(second); 568 Expr *Third = static_cast<Expr*>(third); 569 Stmt *Body = static_cast<Stmt*>(body); 570 571 if (!getLangOptions().CPlusPlus) { 572 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 573 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 574 // declare identifiers for objects having storage class 'auto' or 575 // 'register'. 576 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 577 DI!=DE; ++DI) { 578 VarDecl *VD = dyn_cast<VarDecl>(*DI); 579 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 580 VD = 0; 581 if (VD == 0) 582 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 583 // FIXME: mark decl erroneous! 584 } 585 } 586 } 587 if (Second) { 588 DefaultFunctionArrayConversion(Second); 589 QualType SecondType = Second->getType(); 590 591 if (getLangOptions().CPlusPlus) { 592 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 593 return true; 594 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 595 return Diag(ForLoc, diag::err_typecheck_statement_requires_scalar) 596 << SecondType << Second->getSourceRange(); 597 } 598 return new ForStmt(First, Second, Third, Body, ForLoc); 599} 600 601Action::StmtResult 602Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 603 SourceLocation LParenLoc, 604 StmtTy *first, ExprTy *second, 605 SourceLocation RParenLoc, StmtTy *body) { 606 Stmt *First = static_cast<Stmt*>(first); 607 Expr *Second = static_cast<Expr*>(second); 608 Stmt *Body = static_cast<Stmt*>(body); 609 if (First) { 610 QualType FirstType; 611 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 612 if (!DS->hasSolitaryDecl()) 613 return Diag((*DS->decl_begin())->getLocation(), 614 diag::err_toomany_element_decls); 615 616 ScopedDecl *D = DS->getSolitaryDecl(); 617 FirstType = cast<ValueDecl>(D)->getType(); 618 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 619 // declare identifiers for objects having storage class 'auto' or 620 // 'register'. 621 VarDecl *VD = cast<VarDecl>(D); 622 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 623 return Diag(VD->getLocation(), diag::err_non_variable_decl_in_for); 624 } else { 625 Expr::isLvalueResult lval = cast<Expr>(First)->isLvalue(Context); 626 627 if (lval != Expr::LV_Valid) 628 return Diag(First->getLocStart(), diag::err_selector_element_not_lvalue) 629 << First->getSourceRange(); 630 631 FirstType = static_cast<Expr*>(first)->getType(); 632 } 633 if (!Context.isObjCObjectPointerType(FirstType)) 634 Diag(ForLoc, diag::err_selector_element_type) 635 << FirstType << First->getSourceRange(); 636 } 637 if (Second) { 638 DefaultFunctionArrayConversion(Second); 639 QualType SecondType = Second->getType(); 640 if (!Context.isObjCObjectPointerType(SecondType)) 641 Diag(ForLoc, diag::err_collection_expr_type) 642 << SecondType << Second->getSourceRange(); 643 } 644 return new ObjCForCollectionStmt(First, Second, Body, ForLoc, RParenLoc); 645} 646 647Action::StmtResult 648Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 649 IdentifierInfo *LabelII) { 650 // If we are in a block, reject all gotos for now. 651 if (CurBlock) 652 return Diag(GotoLoc, diag::err_goto_in_block); 653 654 // Look up the record for this label identifier. 655 LabelStmt *&LabelDecl = LabelMap[LabelII]; 656 657 // If we haven't seen this label yet, create a forward reference. 658 if (LabelDecl == 0) 659 LabelDecl = new LabelStmt(LabelLoc, LabelII, 0); 660 661 return new GotoStmt(LabelDecl, GotoLoc, LabelLoc); 662} 663 664Action::StmtResult 665Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc,SourceLocation StarLoc, 666 ExprTy *DestExp) { 667 // FIXME: Verify that the operand is convertible to void*. 668 669 return new IndirectGotoStmt((Expr*)DestExp); 670} 671 672Action::StmtResult 673Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 674 Scope *S = CurScope->getContinueParent(); 675 if (!S) { 676 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 677 Diag(ContinueLoc, diag::err_continue_not_in_loop); 678 return true; 679 } 680 681 return new ContinueStmt(ContinueLoc); 682} 683 684Action::StmtResult 685Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 686 Scope *S = CurScope->getBreakParent(); 687 if (!S) { 688 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 689 Diag(BreakLoc, diag::err_break_not_in_loop_or_switch); 690 return true; 691 } 692 693 return new BreakStmt(BreakLoc); 694} 695 696/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 697/// 698Action::StmtResult 699Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 700 701 // If this is the first return we've seen in the block, infer the type of 702 // the block from it. 703 if (CurBlock->ReturnType == 0) { 704 if (RetValExp) { 705 // Don't call UsualUnaryConversions(), since we don't want to do 706 // integer promotions here. 707 DefaultFunctionArrayConversion(RetValExp); 708 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 709 } else 710 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 711 return new ReturnStmt(ReturnLoc, RetValExp); 712 } 713 714 // Otherwise, verify that this result type matches the previous one. We are 715 // pickier with blocks than for normal functions because we don't have GCC 716 // compatibility to worry about here. 717 if (CurBlock->ReturnType->isVoidType()) { 718 if (RetValExp) { 719 Diag(ReturnLoc, diag::err_return_block_has_expr); 720 delete RetValExp; 721 RetValExp = 0; 722 } 723 return new ReturnStmt(ReturnLoc, RetValExp); 724 } 725 726 if (!RetValExp) { 727 Diag(ReturnLoc, diag::err_block_return_missing_expr); 728 return true; 729 } 730 731 // we have a non-void block with an expression, continue checking 732 QualType RetValType = RetValExp->getType(); 733 734 // For now, restrict multiple return statements in a block to have 735 // strict compatible types only. 736 QualType BlockQT = QualType(CurBlock->ReturnType, 0); 737 if (Context.getCanonicalType(BlockQT).getTypePtr() 738 != Context.getCanonicalType(RetValType).getTypePtr()) { 739 DiagnoseAssignmentResult(Incompatible, ReturnLoc, BlockQT, 740 RetValType, RetValExp, "returning"); 741 return true; 742 } 743 744 if (RetValExp) CheckReturnStackAddr(RetValExp, BlockQT, ReturnLoc); 745 746 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 747} 748 749Action::StmtResult 750Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprTy *rex) { 751 Expr *RetValExp = static_cast<Expr *>(rex); 752 if (CurBlock) 753 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 754 755 QualType FnRetType; 756 if (FunctionDecl *FD = getCurFunctionDecl()) 757 FnRetType = FD->getResultType(); 758 else 759 FnRetType = getCurMethodDecl()->getResultType(); 760 761 if (FnRetType->isVoidType()) { 762 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 763 unsigned D = diag::ext_return_has_expr; 764 if (RetValExp->getType()->isVoidType()) 765 D = diag::ext_return_has_void_expr; 766 767 // return (some void expression); is legal in C++. 768 if (D != diag::ext_return_has_void_expr || 769 !getLangOptions().CPlusPlus) { 770 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 771 Diag(ReturnLoc, D) 772 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 773 << RetValExp->getSourceRange(); 774 } 775 } 776 return new ReturnStmt(ReturnLoc, RetValExp); 777 } 778 779 if (!RetValExp) { 780 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 781 // C99 6.8.6.4p1 (ext_ since GCC warns) 782 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 783 784 if (FunctionDecl *FD = getCurFunctionDecl()) 785 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 786 else 787 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 788 return new ReturnStmt(ReturnLoc, (Expr*)0); 789 } 790 791 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 792 // we have a non-void function with an expression, continue checking 793 QualType RetValType = RetValExp->getType(); 794 795 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 796 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 797 // function return. 798 799 // In C++ the return statement is handled via a copy initialization. 800 // the C version of which boils down to 801 // CheckSingleAssignmentConstraints. 802 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 803 return true; 804 805 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 806 } 807 808 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 809} 810 811Sema::StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 812 bool IsSimple, 813 bool IsVolatile, 814 unsigned NumOutputs, 815 unsigned NumInputs, 816 std::string *Names, 817 ExprTy **constraints, 818 ExprTy **exprs, 819 ExprTy *asmString, 820 unsigned NumClobbers, 821 ExprTy **clobbers, 822 SourceLocation RParenLoc) { 823 StringLiteral **Constraints = reinterpret_cast<StringLiteral**>(constraints); 824 Expr **Exprs = reinterpret_cast<Expr **>(exprs); 825 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString); 826 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers); 827 828 // The parser verifies that there is a string literal here. 829 if (AsmString->isWide()) 830 // FIXME: We currently leak memory here. 831 return Diag(AsmString->getLocStart(), diag::err_asm_wide_character) 832 << AsmString->getSourceRange(); 833 834 835 for (unsigned i = 0; i != NumOutputs; i++) { 836 StringLiteral *Literal = Constraints[i]; 837 if (Literal->isWide()) 838 // FIXME: We currently leak memory here. 839 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 840 << Literal->getSourceRange(); 841 842 std::string OutputConstraint(Literal->getStrData(), 843 Literal->getByteLength()); 844 845 TargetInfo::ConstraintInfo info; 846 if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info)) 847 // FIXME: We currently leak memory here. 848 return Diag(Literal->getLocStart(), 849 diag::err_asm_invalid_output_constraint) << OutputConstraint; 850 851 // Check that the output exprs are valid lvalues. 852 ParenExpr *OutputExpr = cast<ParenExpr>(Exprs[i]); 853 Expr::isLvalueResult Result = OutputExpr->isLvalue(Context); 854 if (Result != Expr::LV_Valid) { 855 // FIXME: We currently leak memory here. 856 return Diag(OutputExpr->getSubExpr()->getLocStart(), 857 diag::err_asm_invalid_lvalue_in_output) 858 << OutputExpr->getSubExpr()->getSourceRange(); 859 } 860 } 861 862 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 863 StringLiteral *Literal = Constraints[i]; 864 if (Literal->isWide()) 865 // FIXME: We currently leak memory here. 866 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 867 << Literal->getSourceRange(); 868 869 std::string InputConstraint(Literal->getStrData(), 870 Literal->getByteLength()); 871 872 TargetInfo::ConstraintInfo info; 873 if (!Context.Target.validateInputConstraint(InputConstraint.c_str(), 874 NumOutputs, info)) { 875 // FIXME: We currently leak memory here. 876 return Diag(Literal->getLocStart(), 877 diag::err_asm_invalid_input_constraint) << InputConstraint; 878 } 879 880 // Check that the input exprs aren't of type void. 881 ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]); 882 if (InputExpr->getType()->isVoidType()) { 883 884 // FIXME: We currently leak memory here. 885 return Diag(InputExpr->getSubExpr()->getLocStart(), 886 diag::err_asm_invalid_type_in_input) 887 << InputExpr->getType() << InputConstraint 888 << InputExpr->getSubExpr()->getSourceRange(); 889 } 890 } 891 892 // Check that the clobbers are valid. 893 for (unsigned i = 0; i != NumClobbers; i++) { 894 StringLiteral *Literal = Clobbers[i]; 895 if (Literal->isWide()) 896 // FIXME: We currently leak memory here. 897 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 898 << Literal->getSourceRange(); 899 900 llvm::SmallString<16> Clobber(Literal->getStrData(), 901 Literal->getStrData() + 902 Literal->getByteLength()); 903 904 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 905 // FIXME: We currently leak memory here. 906 return Diag(Literal->getLocStart(), 907 diag::err_asm_unknown_register_name) << Clobber.c_str(); 908 } 909 910 return new AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 911 Names, Constraints, Exprs, AsmString, NumClobbers, 912 Clobbers, RParenLoc); 913} 914 915Action::StmtResult 916Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 917 SourceLocation RParen, StmtTy *Parm, 918 StmtTy *Body, StmtTy *CatchList) { 919 ObjCAtCatchStmt *CS = new ObjCAtCatchStmt(AtLoc, RParen, 920 static_cast<Stmt*>(Parm), static_cast<Stmt*>(Body), 921 static_cast<Stmt*>(CatchList)); 922 return CatchList ? CatchList : CS; 923} 924 925Action::StmtResult 926Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtTy *Body) { 927 ObjCAtFinallyStmt *FS = new ObjCAtFinallyStmt(AtLoc, 928 static_cast<Stmt*>(Body)); 929 return FS; 930} 931 932Action::StmtResult 933Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 934 StmtTy *Try, StmtTy *Catch, StmtTy *Finally) { 935 ObjCAtTryStmt *TS = new ObjCAtTryStmt(AtLoc, static_cast<Stmt*>(Try), 936 static_cast<Stmt*>(Catch), 937 static_cast<Stmt*>(Finally)); 938 return TS; 939} 940 941Action::StmtResult 942Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, StmtTy *Throw) { 943 ObjCAtThrowStmt *TS = new ObjCAtThrowStmt(AtLoc, static_cast<Stmt*>(Throw)); 944 return TS; 945} 946 947Action::StmtResult 948Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprTy *SynchExpr, 949 StmtTy *SynchBody) { 950 ObjCAtSynchronizedStmt *SS = new ObjCAtSynchronizedStmt(AtLoc, 951 static_cast<Stmt*>(SynchExpr), static_cast<Stmt*>(SynchBody)); 952 return SS; 953} 954 955/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 956/// and creates a proper catch handler from them. 957Action::OwningStmtResult 958Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclTy *ExDecl, 959 StmtArg HandlerBlock) { 960 // There's nothing to test that ActOnExceptionDecl didn't already test. 961 return Owned(new CXXCatchStmt(CatchLoc, static_cast<VarDecl*>(ExDecl), 962 static_cast<Stmt*>(HandlerBlock.release()))); 963} 964