SemaStmt.cpp revision e878eb035b343d7d819c092102364ec9849716ae
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::StmtResult Sema::ActOnExprStmt(ExprTy *expr) { 24 Expr *E = static_cast<Expr*>(expr); 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 E; 33} 34 35 36Sema::StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 37 return new NullStmt(SemiLoc); 38} 39 40Sema::StmtResult Sema::ActOnDeclStmt(DeclTy *decl, SourceLocation StartLoc, 41 SourceLocation EndLoc) { 42 if (decl == 0) 43 return true; 44 45 ScopedDecl *SD = cast<ScopedDecl>(static_cast<Decl *>(decl)); 46 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 new DeclStmt(DG, StartLoc, EndLoc); 63 } 64 else { 65 DeclGroupOwningRef DG(DeclGroup::Create(Context, decls.size(), &decls[0])); 66 return new DeclStmt(DG, StartLoc, EndLoc); 67 } 68} 69 70Action::StmtResult 71Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 72 StmtTy **elts, unsigned NumElts, bool isStmtExpr) { 73 Stmt **Elts = reinterpret_cast<Stmt**>(elts); 74 // If we're in C89 mode, check that we don't have any decls after stmts. If 75 // so, emit an extension diagnostic. 76 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 77 // Note that __extension__ can be around a decl. 78 unsigned i = 0; 79 // Skip over all declarations. 80 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 81 /*empty*/; 82 83 // We found the end of the list or a statement. Scan for another declstmt. 84 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 85 /*empty*/; 86 87 if (i != NumElts) { 88 ScopedDecl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 89 Diag(D->getLocation(), diag::ext_mixed_decls_code); 90 } 91 } 92 // Warn about unused expressions in statements. 93 for (unsigned i = 0; i != NumElts; ++i) { 94 Expr *E = dyn_cast<Expr>(Elts[i]); 95 if (!E) continue; 96 97 // Warn about expressions with unused results. 98 if (E->hasLocalSideEffect() || E->getType()->isVoidType()) 99 continue; 100 101 // The last expr in a stmt expr really is used. 102 if (isStmtExpr && i == NumElts-1) 103 continue; 104 105 /// DiagnoseDeadExpr - This expression is side-effect free and evaluated in 106 /// a context where the result is unused. Emit a diagnostic to warn about 107 /// this. 108 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) 109 Diag(BO->getOperatorLoc(), diag::warn_unused_expr) 110 << BO->getLHS()->getSourceRange() << BO->getRHS()->getSourceRange(); 111 else if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 112 Diag(UO->getOperatorLoc(), diag::warn_unused_expr) 113 << UO->getSubExpr()->getSourceRange(); 114 else 115 Diag(E->getExprLoc(), diag::warn_unused_expr) << E->getSourceRange(); 116 } 117 118 return new CompoundStmt(Elts, NumElts, L, R); 119} 120 121Action::StmtResult 122Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprTy *lhsval, 123 SourceLocation DotDotDotLoc, ExprTy *rhsval, 124 SourceLocation ColonLoc, StmtTy *subStmt) { 125 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 126 Expr *LHSVal = ((Expr *)lhsval), *RHSVal = ((Expr *)rhsval); 127 assert((LHSVal != 0) && "missing expression in case statement"); 128 129 // C99 6.8.4.2p3: The expression shall be an integer constant. 130 // However, GCC allows any evaluatable integer expression. 131 132 if (VerifyIntegerConstantExpression(LHSVal)) 133 return SubStmt; 134 135 // GCC extension: The expression shall be an integer constant. 136 137 if (RHSVal && VerifyIntegerConstantExpression(RHSVal)) 138 RHSVal = 0; // Recover by just forgetting about it. 139 140 if (SwitchStack.empty()) { 141 Diag(CaseLoc, diag::err_case_not_in_switch); 142 return SubStmt; 143 } 144 145 CaseStmt *CS = new CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc); 146 SwitchStack.back()->addSwitchCase(CS); 147 return CS; 148} 149 150Action::StmtResult 151Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 152 StmtTy *subStmt, Scope *CurScope) { 153 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 154 155 if (SwitchStack.empty()) { 156 Diag(DefaultLoc, diag::err_default_not_in_switch); 157 return SubStmt; 158 } 159 160 DefaultStmt *DS = new DefaultStmt(DefaultLoc, SubStmt); 161 SwitchStack.back()->addSwitchCase(DS); 162 163 return DS; 164} 165 166Action::StmtResult 167Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 168 SourceLocation ColonLoc, StmtTy *subStmt) { 169 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 170 // Look up the record for this label identifier. 171 LabelStmt *&LabelDecl = LabelMap[II]; 172 173 // If not forward referenced or defined already, just create a new LabelStmt. 174 if (LabelDecl == 0) 175 return LabelDecl = new LabelStmt(IdentLoc, II, SubStmt); 176 177 assert(LabelDecl->getID() == II && "Label mismatch!"); 178 179 // Otherwise, this label was either forward reference or multiply defined. If 180 // multiply defined, reject it now. 181 if (LabelDecl->getSubStmt()) { 182 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 183 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 184 return SubStmt; 185 } 186 187 // Otherwise, this label was forward declared, and we just found its real 188 // definition. Fill in the forward definition and return it. 189 LabelDecl->setIdentLoc(IdentLoc); 190 LabelDecl->setSubStmt(SubStmt); 191 return LabelDecl; 192} 193 194Action::StmtResult 195Sema::ActOnIfStmt(SourceLocation IfLoc, ExprTy *CondVal, 196 StmtTy *ThenVal, SourceLocation ElseLoc, 197 StmtTy *ElseVal) { 198 Expr *condExpr = (Expr *)CondVal; 199 Stmt *thenStmt = (Stmt *)ThenVal; 200 201 assert(condExpr && "ActOnIfStmt(): missing expression"); 202 203 DefaultFunctionArrayConversion(condExpr); 204 QualType condType = condExpr->getType(); 205 206 if (getLangOptions().CPlusPlus) { 207 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 208 return true; 209 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 210 return Diag(IfLoc, diag::err_typecheck_statement_requires_scalar) 211 << condType << condExpr->getSourceRange(); 212 213 // Warn if the if block has a null body without an else value. 214 // this helps prevent bugs due to typos, such as 215 // if (condition); 216 // do_stuff(); 217 if (!ElseVal) { 218 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 219 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 220 } 221 222 return new IfStmt(IfLoc, condExpr, thenStmt, (Stmt*)ElseVal); 223} 224 225Action::StmtResult 226Sema::ActOnStartOfSwitchStmt(ExprTy *cond) { 227 Expr *Cond = static_cast<Expr*>(cond); 228 229 if (getLangOptions().CPlusPlus) { 230 // C++ 6.4.2.p2: 231 // The condition shall be of integral type, enumeration type, or of a class 232 // type for which a single conversion function to integral or enumeration 233 // type exists (12.3). If the condition is of class type, the condition is 234 // converted by calling that conversion function, and the result of the 235 // conversion is used in place of the original condition for the remainder 236 // of this section. Integral promotions are performed. 237 238 QualType Ty = Cond->getType(); 239 240 // FIXME: Handle class types. 241 242 // If the type is wrong a diagnostic will be emitted later at 243 // ActOnFinishSwitchStmt. 244 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 245 // Integral promotions are performed. 246 // FIXME: Integral promotions for C++ are not complete. 247 UsualUnaryConversions(Cond); 248 } 249 } else { 250 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 251 UsualUnaryConversions(Cond); 252 } 253 254 SwitchStmt *SS = new SwitchStmt(Cond); 255 SwitchStack.push_back(SS); 256 return SS; 257} 258 259/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 260/// the specified width and sign. If an overflow occurs, detect it and emit 261/// the specified diagnostic. 262void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 263 unsigned NewWidth, bool NewSign, 264 SourceLocation Loc, 265 unsigned DiagID) { 266 // Perform a conversion to the promoted condition type if needed. 267 if (NewWidth > Val.getBitWidth()) { 268 // If this is an extension, just do it. 269 llvm::APSInt OldVal(Val); 270 Val.extend(NewWidth); 271 272 // If the input was signed and negative and the output is unsigned, 273 // warn. 274 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 275 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 276 277 Val.setIsSigned(NewSign); 278 } else if (NewWidth < Val.getBitWidth()) { 279 // If this is a truncation, check for overflow. 280 llvm::APSInt ConvVal(Val); 281 ConvVal.trunc(NewWidth); 282 ConvVal.setIsSigned(NewSign); 283 ConvVal.extend(Val.getBitWidth()); 284 ConvVal.setIsSigned(Val.isSigned()); 285 if (ConvVal != Val) 286 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 287 288 // Regardless of whether a diagnostic was emitted, really do the 289 // truncation. 290 Val.trunc(NewWidth); 291 Val.setIsSigned(NewSign); 292 } else if (NewSign != Val.isSigned()) { 293 // Convert the sign to match the sign of the condition. This can cause 294 // overflow as well: unsigned(INTMIN) 295 llvm::APSInt OldVal(Val); 296 Val.setIsSigned(NewSign); 297 298 if (Val.isNegative()) // Sign bit changes meaning. 299 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 300 } 301} 302 303namespace { 304 struct CaseCompareFunctor { 305 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 306 const llvm::APSInt &RHS) { 307 return LHS.first < RHS; 308 } 309 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 310 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 311 return LHS.first < RHS.first; 312 } 313 bool operator()(const llvm::APSInt &LHS, 314 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 315 return LHS < RHS.first; 316 } 317 }; 318} 319 320/// CmpCaseVals - Comparison predicate for sorting case values. 321/// 322static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 323 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 324 if (lhs.first < rhs.first) 325 return true; 326 327 if (lhs.first == rhs.first && 328 lhs.second->getCaseLoc().getRawEncoding() 329 < rhs.second->getCaseLoc().getRawEncoding()) 330 return true; 331 return false; 332} 333 334Action::StmtResult 335Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch, 336 ExprTy *Body) { 337 Stmt *BodyStmt = (Stmt*)Body; 338 339 SwitchStmt *SS = SwitchStack.back(); 340 assert(SS == (SwitchStmt*)Switch && "switch stack missing push/pop!"); 341 342 SS->setBody(BodyStmt, SwitchLoc); 343 SwitchStack.pop_back(); 344 345 Expr *CondExpr = SS->getCond(); 346 QualType CondType = CondExpr->getType(); 347 348 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 349 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 350 << CondType << CondExpr->getSourceRange(); 351 return true; 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 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 357 bool CondIsSigned = CondType->isSignedIntegerType(); 358 359 // Accumulate all of the case values in a vector so that we can sort them 360 // and detect duplicates. This vector contains the APInt for the case after 361 // it has been converted to the condition type. 362 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 363 CaseValsTy CaseVals; 364 365 // Keep track of any GNU case ranges we see. The APSInt is the low value. 366 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 367 368 DefaultStmt *TheDefaultStmt = 0; 369 370 bool CaseListIsErroneous = false; 371 372 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 373 SC = SC->getNextSwitchCase()) { 374 375 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 376 if (TheDefaultStmt) { 377 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 378 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 379 380 // FIXME: Remove the default statement from the switch block so that 381 // we'll return a valid AST. This requires recursing down the 382 // AST and finding it, not something we are set up to do right now. For 383 // now, just lop the entire switch stmt out of the AST. 384 CaseListIsErroneous = true; 385 } 386 TheDefaultStmt = DS; 387 388 } else { 389 CaseStmt *CS = cast<CaseStmt>(SC); 390 391 // We already verified that the expression has a i-c-e value (C99 392 // 6.8.4.2p3) - get that value now. 393 Expr *Lo = CS->getLHS(); 394 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 395 396 // Convert the value to the same width/sign as the condition. 397 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 398 CS->getLHS()->getLocStart(), 399 diag::warn_case_value_overflow); 400 401 // If the LHS is not the same type as the condition, insert an implicit 402 // cast. 403 ImpCastExprToType(Lo, CondType); 404 CS->setLHS(Lo); 405 406 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 407 if (CS->getRHS()) 408 CaseRanges.push_back(std::make_pair(LoVal, CS)); 409 else 410 CaseVals.push_back(std::make_pair(LoVal, CS)); 411 } 412 } 413 414 // Sort all the scalar case values so we can easily detect duplicates. 415 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 416 417 if (!CaseVals.empty()) { 418 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 419 if (CaseVals[i].first == CaseVals[i+1].first) { 420 // If we have a duplicate, report it. 421 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 422 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 423 Diag(CaseVals[i].second->getLHS()->getLocStart(), 424 diag::note_duplicate_case_prev); 425 // FIXME: We really want to remove the bogus case stmt from the substmt, 426 // but we have no way to do this right now. 427 CaseListIsErroneous = true; 428 } 429 } 430 } 431 432 // Detect duplicate case ranges, which usually don't exist at all in the first 433 // place. 434 if (!CaseRanges.empty()) { 435 // Sort all the case ranges by their low value so we can easily detect 436 // overlaps between ranges. 437 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 438 439 // Scan the ranges, computing the high values and removing empty ranges. 440 std::vector<llvm::APSInt> HiVals; 441 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 442 CaseStmt *CR = CaseRanges[i].second; 443 Expr *Hi = CR->getRHS(); 444 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 445 446 // Convert the value to the same width/sign as the condition. 447 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 448 CR->getRHS()->getLocStart(), 449 diag::warn_case_value_overflow); 450 451 // If the LHS is not the same type as the condition, insert an implicit 452 // cast. 453 ImpCastExprToType(Hi, CondType); 454 CR->setRHS(Hi); 455 456 // If the low value is bigger than the high value, the case is empty. 457 if (CaseRanges[i].first > HiVal) { 458 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 459 << SourceRange(CR->getLHS()->getLocStart(), 460 CR->getRHS()->getLocEnd()); 461 CaseRanges.erase(CaseRanges.begin()+i); 462 --i, --e; 463 continue; 464 } 465 HiVals.push_back(HiVal); 466 } 467 468 // Rescan the ranges, looking for overlap with singleton values and other 469 // ranges. Since the range list is sorted, we only need to compare case 470 // ranges with their neighbors. 471 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 472 llvm::APSInt &CRLo = CaseRanges[i].first; 473 llvm::APSInt &CRHi = HiVals[i]; 474 CaseStmt *CR = CaseRanges[i].second; 475 476 // Check to see whether the case range overlaps with any singleton cases. 477 CaseStmt *OverlapStmt = 0; 478 llvm::APSInt OverlapVal(32); 479 480 // Find the smallest value >= the lower bound. If I is in the case range, 481 // then we have overlap. 482 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 483 CaseVals.end(), CRLo, 484 CaseCompareFunctor()); 485 if (I != CaseVals.end() && I->first < CRHi) { 486 OverlapVal = I->first; // Found overlap with scalar. 487 OverlapStmt = I->second; 488 } 489 490 // Find the smallest value bigger than the upper bound. 491 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 492 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 493 OverlapVal = (I-1)->first; // Found overlap with scalar. 494 OverlapStmt = (I-1)->second; 495 } 496 497 // Check to see if this case stmt overlaps with the subsequent case range. 498 if (i && CRLo <= HiVals[i-1]) { 499 OverlapVal = HiVals[i-1]; // Found overlap with range. 500 OverlapStmt = CaseRanges[i-1].second; 501 } 502 503 if (OverlapStmt) { 504 // If we have a duplicate, report it. 505 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 506 << OverlapVal.toString(10); 507 Diag(OverlapStmt->getLHS()->getLocStart(), 508 diag::note_duplicate_case_prev); 509 // FIXME: We really want to remove the bogus case stmt from the substmt, 510 // but we have no way to do this right now. 511 CaseListIsErroneous = true; 512 } 513 } 514 } 515 516 // FIXME: If the case list was broken is some way, we don't have a good system 517 // to patch it up. Instead, just return the whole substmt as broken. 518 if (CaseListIsErroneous) 519 return true; 520 521 return SS; 522} 523 524Action::StmtResult 525Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprTy *Cond, StmtTy *Body) { 526 Expr *condExpr = (Expr *)Cond; 527 assert(condExpr && "ActOnWhileStmt(): missing expression"); 528 529 DefaultFunctionArrayConversion(condExpr); 530 QualType condType = condExpr->getType(); 531 532 if (getLangOptions().CPlusPlus) { 533 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 534 return true; 535 } else if (!condType->isScalarType()) // C99 6.8.5p2 536 return Diag(WhileLoc, diag::err_typecheck_statement_requires_scalar) 537 << condType << condExpr->getSourceRange(); 538 539 return new WhileStmt(condExpr, (Stmt*)Body, WhileLoc); 540} 541 542Action::StmtResult 543Sema::ActOnDoStmt(SourceLocation DoLoc, StmtTy *Body, 544 SourceLocation WhileLoc, ExprTy *Cond) { 545 Expr *condExpr = (Expr *)Cond; 546 assert(condExpr && "ActOnDoStmt(): missing expression"); 547 548 DefaultFunctionArrayConversion(condExpr); 549 QualType condType = condExpr->getType(); 550 551 if (getLangOptions().CPlusPlus) { 552 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 553 return true; 554 } else if (!condType->isScalarType()) // C99 6.8.5p2 555 return Diag(DoLoc, diag::err_typecheck_statement_requires_scalar) 556 << condType << condExpr->getSourceRange(); 557 558 return new DoStmt((Stmt*)Body, condExpr, DoLoc); 559} 560 561Action::StmtResult 562Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 563 StmtTy *first, ExprTy *second, ExprTy *third, 564 SourceLocation RParenLoc, StmtTy *body) { 565 Stmt *First = static_cast<Stmt*>(first); 566 Expr *Second = static_cast<Expr*>(second); 567 Expr *Third = static_cast<Expr*>(third); 568 Stmt *Body = static_cast<Stmt*>(body); 569 570 if (!getLangOptions().CPlusPlus) { 571 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 572 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 573 // declare identifiers for objects having storage class 'auto' or 574 // 'register'. 575 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 576 DI!=DE; ++DI) { 577 VarDecl *VD = dyn_cast<VarDecl>(*DI); 578 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 579 VD = 0; 580 if (VD == 0) 581 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 582 // FIXME: mark decl erroneous! 583 } 584 } 585 } 586 if (Second) { 587 DefaultFunctionArrayConversion(Second); 588 QualType SecondType = Second->getType(); 589 590 if (getLangOptions().CPlusPlus) { 591 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 592 return true; 593 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 594 return Diag(ForLoc, diag::err_typecheck_statement_requires_scalar) 595 << SecondType << Second->getSourceRange(); 596 } 597 return new ForStmt(First, Second, Third, Body, ForLoc); 598} 599 600Action::StmtResult 601Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 602 SourceLocation LParenLoc, 603 StmtTy *first, ExprTy *second, 604 SourceLocation RParenLoc, StmtTy *body) { 605 Stmt *First = static_cast<Stmt*>(first); 606 Expr *Second = static_cast<Expr*>(second); 607 Stmt *Body = static_cast<Stmt*>(body); 608 if (First) { 609 QualType FirstType; 610 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 611 if (!DS->hasSolitaryDecl()) 612 return Diag((*DS->decl_begin())->getLocation(), 613 diag::err_toomany_element_decls); 614 615 ScopedDecl *D = DS->getSolitaryDecl(); 616 FirstType = cast<ValueDecl>(D)->getType(); 617 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 618 // declare identifiers for objects having storage class 'auto' or 619 // 'register'. 620 VarDecl *VD = cast<VarDecl>(D); 621 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 622 return Diag(VD->getLocation(), diag::err_non_variable_decl_in_for); 623 } else { 624 Expr::isLvalueResult lval = cast<Expr>(First)->isLvalue(Context); 625 626 if (lval != Expr::LV_Valid) 627 return Diag(First->getLocStart(), diag::err_selector_element_not_lvalue) 628 << First->getSourceRange(); 629 630 FirstType = static_cast<Expr*>(first)->getType(); 631 } 632 if (!Context.isObjCObjectPointerType(FirstType)) 633 Diag(ForLoc, diag::err_selector_element_type) 634 << FirstType << First->getSourceRange(); 635 } 636 if (Second) { 637 DefaultFunctionArrayConversion(Second); 638 QualType SecondType = Second->getType(); 639 if (!Context.isObjCObjectPointerType(SecondType)) 640 Diag(ForLoc, diag::err_collection_expr_type) 641 << SecondType << Second->getSourceRange(); 642 } 643 return new ObjCForCollectionStmt(First, Second, Body, ForLoc, RParenLoc); 644} 645 646Action::StmtResult 647Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 648 IdentifierInfo *LabelII) { 649 // If we are in a block, reject all gotos for now. 650 if (CurBlock) 651 return Diag(GotoLoc, diag::err_goto_in_block); 652 653 // Look up the record for this label identifier. 654 LabelStmt *&LabelDecl = LabelMap[LabelII]; 655 656 // If we haven't seen this label yet, create a forward reference. 657 if (LabelDecl == 0) 658 LabelDecl = new LabelStmt(LabelLoc, LabelII, 0); 659 660 return new GotoStmt(LabelDecl, GotoLoc, LabelLoc); 661} 662 663Action::StmtResult 664Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc,SourceLocation StarLoc, 665 ExprTy *DestExp) { 666 // FIXME: Verify that the operand is convertible to void*. 667 668 return new IndirectGotoStmt((Expr*)DestExp); 669} 670 671Action::StmtResult 672Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 673 Scope *S = CurScope->getContinueParent(); 674 if (!S) { 675 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 676 Diag(ContinueLoc, diag::err_continue_not_in_loop); 677 return true; 678 } 679 680 return new ContinueStmt(ContinueLoc); 681} 682 683Action::StmtResult 684Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 685 Scope *S = CurScope->getBreakParent(); 686 if (!S) { 687 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 688 Diag(BreakLoc, diag::err_break_not_in_loop_or_switch); 689 return true; 690 } 691 692 return new BreakStmt(BreakLoc); 693} 694 695/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 696/// 697Action::StmtResult 698Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 699 700 // If this is the first return we've seen in the block, infer the type of 701 // the block from it. 702 if (CurBlock->ReturnType == 0) { 703 if (RetValExp) { 704 // Don't call UsualUnaryConversions(), since we don't want to do 705 // integer promotions here. 706 DefaultFunctionArrayConversion(RetValExp); 707 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 708 } else 709 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 710 return new ReturnStmt(ReturnLoc, RetValExp); 711 } 712 713 // Otherwise, verify that this result type matches the previous one. We are 714 // pickier with blocks than for normal functions because we don't have GCC 715 // compatibility to worry about here. 716 if (CurBlock->ReturnType->isVoidType()) { 717 if (RetValExp) { 718 Diag(ReturnLoc, diag::err_return_block_has_expr); 719 delete RetValExp; 720 RetValExp = 0; 721 } 722 return new ReturnStmt(ReturnLoc, RetValExp); 723 } 724 725 if (!RetValExp) { 726 Diag(ReturnLoc, diag::err_block_return_missing_expr); 727 return true; 728 } 729 730 // we have a non-void block with an expression, continue checking 731 QualType RetValType = RetValExp->getType(); 732 733 // For now, restrict multiple return statements in a block to have 734 // strict compatible types only. 735 QualType BlockQT = QualType(CurBlock->ReturnType, 0); 736 if (Context.getCanonicalType(BlockQT).getTypePtr() 737 != Context.getCanonicalType(RetValType).getTypePtr()) { 738 DiagnoseAssignmentResult(Incompatible, ReturnLoc, BlockQT, 739 RetValType, RetValExp, "returning"); 740 return true; 741 } 742 743 if (RetValExp) CheckReturnStackAddr(RetValExp, BlockQT, ReturnLoc); 744 745 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 746} 747 748Action::StmtResult 749Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprTy *rex) { 750 Expr *RetValExp = static_cast<Expr *>(rex); 751 if (CurBlock) 752 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 753 754 QualType FnRetType; 755 if (FunctionDecl *FD = getCurFunctionDecl()) 756 FnRetType = FD->getResultType(); 757 else 758 FnRetType = getCurMethodDecl()->getResultType(); 759 760 if (FnRetType->isVoidType()) { 761 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 762 unsigned D = diag::ext_return_has_expr; 763 if (RetValExp->getType()->isVoidType()) 764 D = diag::ext_return_has_void_expr; 765 766 // return (some void expression); is legal in C++. 767 if (D != diag::ext_return_has_void_expr || 768 !getLangOptions().CPlusPlus) { 769 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 770 Diag(ReturnLoc, D) 771 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 772 << RetValExp->getSourceRange(); 773 } 774 } 775 return new ReturnStmt(ReturnLoc, RetValExp); 776 } 777 778 if (!RetValExp) { 779 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 780 // C99 6.8.6.4p1 (ext_ since GCC warns) 781 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 782 783 if (FunctionDecl *FD = getCurFunctionDecl()) 784 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 785 else 786 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 787 return new ReturnStmt(ReturnLoc, (Expr*)0); 788 } 789 790 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 791 // we have a non-void function with an expression, continue checking 792 QualType RetValType = RetValExp->getType(); 793 794 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 795 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 796 // function return. 797 798 // In C++ the return statement is handled via a copy initialization. 799 // the C version of which boils down to 800 // CheckSingleAssignmentConstraints. 801 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 802 return true; 803 804 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 805 } 806 807 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 808} 809 810Sema::StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 811 bool IsSimple, 812 bool IsVolatile, 813 unsigned NumOutputs, 814 unsigned NumInputs, 815 std::string *Names, 816 ExprTy **constraints, 817 ExprTy **exprs, 818 ExprTy *asmString, 819 unsigned NumClobbers, 820 ExprTy **clobbers, 821 SourceLocation RParenLoc) { 822 StringLiteral **Constraints = reinterpret_cast<StringLiteral**>(constraints); 823 Expr **Exprs = reinterpret_cast<Expr **>(exprs); 824 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString); 825 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers); 826 827 // The parser verifies that there is a string literal here. 828 if (AsmString->isWide()) 829 // FIXME: We currently leak memory here. 830 return Diag(AsmString->getLocStart(), diag::err_asm_wide_character) 831 << AsmString->getSourceRange(); 832 833 834 for (unsigned i = 0; i != NumOutputs; i++) { 835 StringLiteral *Literal = Constraints[i]; 836 if (Literal->isWide()) 837 // FIXME: We currently leak memory here. 838 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 839 << Literal->getSourceRange(); 840 841 std::string OutputConstraint(Literal->getStrData(), 842 Literal->getByteLength()); 843 844 TargetInfo::ConstraintInfo info; 845 if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info)) 846 // FIXME: We currently leak memory here. 847 return Diag(Literal->getLocStart(), 848 diag::err_asm_invalid_output_constraint) << OutputConstraint; 849 850 // Check that the output exprs are valid lvalues. 851 ParenExpr *OutputExpr = cast<ParenExpr>(Exprs[i]); 852 Expr::isLvalueResult Result = OutputExpr->isLvalue(Context); 853 if (Result != Expr::LV_Valid) { 854 // FIXME: We currently leak memory here. 855 return Diag(OutputExpr->getSubExpr()->getLocStart(), 856 diag::err_asm_invalid_lvalue_in_output) 857 << OutputExpr->getSubExpr()->getSourceRange(); 858 } 859 } 860 861 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 862 StringLiteral *Literal = Constraints[i]; 863 if (Literal->isWide()) 864 // FIXME: We currently leak memory here. 865 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 866 << Literal->getSourceRange(); 867 868 std::string InputConstraint(Literal->getStrData(), 869 Literal->getByteLength()); 870 871 TargetInfo::ConstraintInfo info; 872 if (!Context.Target.validateInputConstraint(InputConstraint.c_str(), 873 NumOutputs, info)) { 874 // FIXME: We currently leak memory here. 875 return Diag(Literal->getLocStart(), 876 diag::err_asm_invalid_input_constraint) << InputConstraint; 877 } 878 879 // Check that the input exprs aren't of type void. 880 ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]); 881 if (InputExpr->getType()->isVoidType()) { 882 883 // FIXME: We currently leak memory here. 884 return Diag(InputExpr->getSubExpr()->getLocStart(), 885 diag::err_asm_invalid_type_in_input) 886 << InputExpr->getType() << InputConstraint 887 << InputExpr->getSubExpr()->getSourceRange(); 888 } 889 } 890 891 // Check that the clobbers are valid. 892 for (unsigned i = 0; i != NumClobbers; i++) { 893 StringLiteral *Literal = Clobbers[i]; 894 if (Literal->isWide()) 895 // FIXME: We currently leak memory here. 896 return Diag(Literal->getLocStart(), diag::err_asm_wide_character) 897 << Literal->getSourceRange(); 898 899 llvm::SmallString<16> Clobber(Literal->getStrData(), 900 Literal->getStrData() + 901 Literal->getByteLength()); 902 903 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 904 // FIXME: We currently leak memory here. 905 return Diag(Literal->getLocStart(), 906 diag::err_asm_unknown_register_name) << Clobber.c_str(); 907 } 908 909 return new AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 910 Names, Constraints, Exprs, AsmString, NumClobbers, 911 Clobbers, RParenLoc); 912} 913 914Action::StmtResult 915Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 916 SourceLocation RParen, StmtTy *Parm, 917 StmtTy *Body, StmtTy *CatchList) { 918 ObjCAtCatchStmt *CS = new ObjCAtCatchStmt(AtLoc, RParen, 919 static_cast<Stmt*>(Parm), static_cast<Stmt*>(Body), 920 static_cast<Stmt*>(CatchList)); 921 return CatchList ? CatchList : CS; 922} 923 924Action::StmtResult 925Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtTy *Body) { 926 ObjCAtFinallyStmt *FS = new ObjCAtFinallyStmt(AtLoc, 927 static_cast<Stmt*>(Body)); 928 return FS; 929} 930 931Action::StmtResult 932Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 933 StmtTy *Try, StmtTy *Catch, StmtTy *Finally) { 934 ObjCAtTryStmt *TS = new ObjCAtTryStmt(AtLoc, static_cast<Stmt*>(Try), 935 static_cast<Stmt*>(Catch), 936 static_cast<Stmt*>(Finally)); 937 return TS; 938} 939 940Action::StmtResult 941Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, StmtTy *Throw) { 942 ObjCAtThrowStmt *TS = new ObjCAtThrowStmt(AtLoc, static_cast<Stmt*>(Throw)); 943 return TS; 944} 945 946Action::StmtResult 947Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprTy *SynchExpr, 948 StmtTy *SynchBody) { 949 ObjCAtSynchronizedStmt *SS = new ObjCAtSynchronizedStmt(AtLoc, 950 static_cast<Stmt*>(SynchExpr), static_cast<Stmt*>(SynchBody)); 951 return SS; 952} 953