SemaStmt.cpp revision 28be73f74c9e241a23ea24fe5756623de6bf1084
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/ASTContext.h" 16#include "clang/AST/Expr.h" 17#include "clang/AST/Stmt.h" 18#include "clang/Parse/Scope.h" 19#include "clang/Basic/TargetInfo.h" 20#include "clang/Basic/Diagnostic.h" 21#include "clang/Basic/LangOptions.h" 22#include "llvm/ADT/SmallString.h" 23using namespace clang; 24 25Sema::StmtResult Sema::ActOnExprStmt(ExprTy *expr) { 26 Expr *E = static_cast<Expr*>(expr); 27 assert(E && "ActOnExprStmt(): missing expression"); 28 29 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 30 // void expression for its side effects. Conversion to void allows any 31 // operand, even incomplete types. 32 33 // Same thing in for stmt first clause (when expr) and third clause. 34 return E; 35} 36 37 38Sema::StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 39 return new NullStmt(SemiLoc); 40} 41 42Sema::StmtResult Sema::ActOnDeclStmt(DeclTy *decl, SourceLocation StartLoc, 43 SourceLocation EndLoc) { 44 if (decl == 0) 45 return true; 46 47 ScopedDecl *SD = cast<ScopedDecl>(static_cast<Decl *>(decl)); 48 return new DeclStmt(SD, StartLoc, EndLoc); 49} 50 51Action::StmtResult 52Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 53 StmtTy **elts, unsigned NumElts, bool isStmtExpr) { 54 Stmt **Elts = reinterpret_cast<Stmt**>(elts); 55 // If we're in C89 mode, check that we don't have any decls after stmts. If 56 // so, emit an extension diagnostic. 57 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 58 // Note that __extension__ can be around a decl. 59 unsigned i = 0; 60 // Skip over all declarations. 61 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 62 /*empty*/; 63 64 // We found the end of the list or a statement. Scan for another declstmt. 65 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 66 /*empty*/; 67 68 if (i != NumElts) { 69 ScopedDecl *D = cast<DeclStmt>(Elts[i])->getDecl(); 70 Diag(D->getLocation(), diag::ext_mixed_decls_code); 71 } 72 } 73 // Warn about unused expressions in statements. 74 for (unsigned i = 0; i != NumElts; ++i) { 75 Expr *E = dyn_cast<Expr>(Elts[i]); 76 if (!E) continue; 77 78 // Warn about expressions with unused results. 79 if (E->hasLocalSideEffect() || E->getType()->isVoidType()) 80 continue; 81 82 // The last expr in a stmt expr really is used. 83 if (isStmtExpr && i == NumElts-1) 84 continue; 85 86 /// DiagnoseDeadExpr - This expression is side-effect free and evaluated in 87 /// a context where the result is unused. Emit a diagnostic to warn about 88 /// this. 89 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) 90 Diag(BO->getOperatorLoc(), diag::warn_unused_expr, 91 BO->getLHS()->getSourceRange(), BO->getRHS()->getSourceRange()); 92 else if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 93 Diag(UO->getOperatorLoc(), diag::warn_unused_expr, 94 UO->getSubExpr()->getSourceRange()); 95 else 96 Diag(E->getExprLoc(), diag::warn_unused_expr, E->getSourceRange()); 97 } 98 99 return new CompoundStmt(Elts, NumElts, L, R); 100} 101 102Action::StmtResult 103Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprTy *lhsval, 104 SourceLocation DotDotDotLoc, ExprTy *rhsval, 105 SourceLocation ColonLoc, StmtTy *subStmt) { 106 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 107 Expr *LHSVal = ((Expr *)lhsval), *RHSVal = ((Expr *)rhsval); 108 assert((LHSVal != 0) && "missing expression in case statement"); 109 110 SourceLocation ExpLoc; 111 // C99 6.8.4.2p3: The expression shall be an integer constant. 112 if (!LHSVal->isIntegerConstantExpr(Context, &ExpLoc)) { 113 Diag(ExpLoc, diag::err_case_label_not_integer_constant_expr, 114 LHSVal->getSourceRange()); 115 return SubStmt; 116 } 117 118 // GCC extension: The expression shall be an integer constant. 119 if (RHSVal && !RHSVal->isIntegerConstantExpr(Context, &ExpLoc)) { 120 Diag(ExpLoc, diag::err_case_label_not_integer_constant_expr, 121 RHSVal->getSourceRange()); 122 RHSVal = 0; // Recover by just forgetting about it. 123 } 124 125 if (SwitchStack.empty()) { 126 Diag(CaseLoc, diag::err_case_not_in_switch); 127 return SubStmt; 128 } 129 130 CaseStmt *CS = new CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc); 131 SwitchStack.back()->addSwitchCase(CS); 132 return CS; 133} 134 135Action::StmtResult 136Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 137 StmtTy *subStmt, Scope *CurScope) { 138 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 139 140 if (SwitchStack.empty()) { 141 Diag(DefaultLoc, diag::err_default_not_in_switch); 142 return SubStmt; 143 } 144 145 DefaultStmt *DS = new DefaultStmt(DefaultLoc, SubStmt); 146 SwitchStack.back()->addSwitchCase(DS); 147 148 return DS; 149} 150 151Action::StmtResult 152Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 153 SourceLocation ColonLoc, StmtTy *subStmt) { 154 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 155 // Look up the record for this label identifier. 156 LabelStmt *&LabelDecl = LabelMap[II]; 157 158 // If not forward referenced or defined already, just create a new LabelStmt. 159 if (LabelDecl == 0) 160 return LabelDecl = new LabelStmt(IdentLoc, II, SubStmt); 161 162 assert(LabelDecl->getID() == II && "Label mismatch!"); 163 164 // Otherwise, this label was either forward reference or multiply defined. If 165 // multiply defined, reject it now. 166 if (LabelDecl->getSubStmt()) { 167 Diag(IdentLoc, diag::err_redefinition_of_label, LabelDecl->getName()); 168 Diag(LabelDecl->getIdentLoc(), diag::err_previous_definition); 169 return SubStmt; 170 } 171 172 // Otherwise, this label was forward declared, and we just found its real 173 // definition. Fill in the forward definition and return it. 174 LabelDecl->setIdentLoc(IdentLoc); 175 LabelDecl->setSubStmt(SubStmt); 176 return LabelDecl; 177} 178 179Action::StmtResult 180Sema::ActOnIfStmt(SourceLocation IfLoc, ExprTy *CondVal, 181 StmtTy *ThenVal, SourceLocation ElseLoc, 182 StmtTy *ElseVal) { 183 Expr *condExpr = (Expr *)CondVal; 184 Stmt *thenStmt = (Stmt *)ThenVal; 185 186 assert(condExpr && "ActOnIfStmt(): missing expression"); 187 188 DefaultFunctionArrayConversion(condExpr); 189 QualType condType = condExpr->getType(); 190 191 if (!condType->isScalarType()) // C99 6.8.4.1p1 192 return Diag(IfLoc, diag::err_typecheck_statement_requires_scalar, 193 condType.getAsString(), condExpr->getSourceRange()); 194 195 // Warn if the if block has a null body without an else value. 196 // this helps prevent bugs due to typos, such as 197 // if (condition); 198 // do_stuff(); 199 if (!ElseVal) { 200 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 201 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 202 } 203 204 return new IfStmt(IfLoc, condExpr, thenStmt, (Stmt*)ElseVal); 205} 206 207Action::StmtResult 208Sema::ActOnStartOfSwitchStmt(ExprTy *cond) { 209 Expr *Cond = static_cast<Expr*>(cond); 210 211 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 212 UsualUnaryConversions(Cond); 213 214 SwitchStmt *SS = new SwitchStmt(Cond); 215 SwitchStack.push_back(SS); 216 return SS; 217} 218 219/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 220/// the specified width and sign. If an overflow occurs, detect it and emit 221/// the specified diagnostic. 222void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 223 unsigned NewWidth, bool NewSign, 224 SourceLocation Loc, 225 unsigned DiagID) { 226 // Perform a conversion to the promoted condition type if needed. 227 if (NewWidth > Val.getBitWidth()) { 228 // If this is an extension, just do it. 229 llvm::APSInt OldVal(Val); 230 Val.extend(NewWidth); 231 232 // If the input was signed and negative and the output is unsigned, 233 // warn. 234 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 235 Diag(Loc, DiagID, OldVal.toString(), Val.toString()); 236 237 Val.setIsSigned(NewSign); 238 } else if (NewWidth < Val.getBitWidth()) { 239 // If this is a truncation, check for overflow. 240 llvm::APSInt ConvVal(Val); 241 ConvVal.trunc(NewWidth); 242 ConvVal.setIsSigned(NewSign); 243 ConvVal.extend(Val.getBitWidth()); 244 ConvVal.setIsSigned(Val.isSigned()); 245 if (ConvVal != Val) 246 Diag(Loc, DiagID, Val.toString(), ConvVal.toString()); 247 248 // Regardless of whether a diagnostic was emitted, really do the 249 // truncation. 250 Val.trunc(NewWidth); 251 Val.setIsSigned(NewSign); 252 } else if (NewSign != Val.isSigned()) { 253 // Convert the sign to match the sign of the condition. This can cause 254 // overflow as well: unsigned(INTMIN) 255 llvm::APSInt OldVal(Val); 256 Val.setIsSigned(NewSign); 257 258 if (Val.isNegative()) // Sign bit changes meaning. 259 Diag(Loc, DiagID, OldVal.toString(), Val.toString()); 260 } 261} 262 263namespace { 264 struct CaseCompareFunctor { 265 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 266 const llvm::APSInt &RHS) { 267 return LHS.first < RHS; 268 } 269 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 270 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 271 return LHS.first < RHS.first; 272 } 273 bool operator()(const llvm::APSInt &LHS, 274 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 275 return LHS < RHS.first; 276 } 277 }; 278} 279 280/// CmpCaseVals - Comparison predicate for sorting case values. 281/// 282static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 283 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 284 if (lhs.first < rhs.first) 285 return true; 286 287 if (lhs.first == rhs.first && 288 lhs.second->getCaseLoc().getRawEncoding() 289 < rhs.second->getCaseLoc().getRawEncoding()) 290 return true; 291 return false; 292} 293 294Action::StmtResult 295Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch, 296 ExprTy *Body) { 297 Stmt *BodyStmt = (Stmt*)Body; 298 299 SwitchStmt *SS = SwitchStack.back(); 300 assert(SS == (SwitchStmt*)Switch && "switch stack missing push/pop!"); 301 302 SS->setBody(BodyStmt, SwitchLoc); 303 SwitchStack.pop_back(); 304 305 Expr *CondExpr = SS->getCond(); 306 QualType CondType = CondExpr->getType(); 307 308 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 309 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer, 310 CondType.getAsString(), CondExpr->getSourceRange()); 311 return true; 312 } 313 314 // Get the bitwidth of the switched-on value before promotions. We must 315 // convert the integer case values to this width before comparison. 316 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 317 bool CondIsSigned = CondType->isSignedIntegerType(); 318 319 // Accumulate all of the case values in a vector so that we can sort them 320 // and detect duplicates. This vector contains the APInt for the case after 321 // it has been converted to the condition type. 322 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 323 CaseValsTy CaseVals; 324 325 // Keep track of any GNU case ranges we see. The APSInt is the low value. 326 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 327 328 DefaultStmt *TheDefaultStmt = 0; 329 330 bool CaseListIsErroneous = false; 331 332 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 333 SC = SC->getNextSwitchCase()) { 334 335 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 336 if (TheDefaultStmt) { 337 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 338 Diag(TheDefaultStmt->getDefaultLoc(), diag::err_first_label); 339 340 // FIXME: Remove the default statement from the switch block so that 341 // we'll return a valid AST. This requires recursing down the 342 // AST and finding it, not something we are set up to do right now. For 343 // now, just lop the entire switch stmt out of the AST. 344 CaseListIsErroneous = true; 345 } 346 TheDefaultStmt = DS; 347 348 } else { 349 CaseStmt *CS = cast<CaseStmt>(SC); 350 351 // We already verified that the expression has a i-c-e value (C99 352 // 6.8.4.2p3) - get that value now. 353 llvm::APSInt LoVal(32); 354 Expr *Lo = CS->getLHS(); 355 Lo->isIntegerConstantExpr(LoVal, Context); 356 357 // Convert the value to the same width/sign as the condition. 358 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 359 CS->getLHS()->getLocStart(), 360 diag::warn_case_value_overflow); 361 362 // If the LHS is not the same type as the condition, insert an implicit 363 // cast. 364 ImpCastExprToType(Lo, CondType); 365 CS->setLHS(Lo); 366 367 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 368 if (CS->getRHS()) 369 CaseRanges.push_back(std::make_pair(LoVal, CS)); 370 else 371 CaseVals.push_back(std::make_pair(LoVal, CS)); 372 } 373 } 374 375 // Sort all the scalar case values so we can easily detect duplicates. 376 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 377 378 if (!CaseVals.empty()) { 379 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 380 if (CaseVals[i].first == CaseVals[i+1].first) { 381 // If we have a duplicate, report it. 382 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 383 diag::err_duplicate_case, CaseVals[i].first.toString()); 384 Diag(CaseVals[i].second->getLHS()->getLocStart(), 385 diag::err_duplicate_case_prev); 386 // FIXME: We really want to remove the bogus case stmt from the substmt, 387 // but we have no way to do this right now. 388 CaseListIsErroneous = true; 389 } 390 } 391 } 392 393 // Detect duplicate case ranges, which usually don't exist at all in the first 394 // place. 395 if (!CaseRanges.empty()) { 396 // Sort all the case ranges by their low value so we can easily detect 397 // overlaps between ranges. 398 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 399 400 // Scan the ranges, computing the high values and removing empty ranges. 401 std::vector<llvm::APSInt> HiVals; 402 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 403 CaseStmt *CR = CaseRanges[i].second; 404 llvm::APSInt HiVal(32); 405 Expr *Hi = CR->getRHS(); 406 Hi->isIntegerConstantExpr(HiVal, Context); 407 408 // Convert the value to the same width/sign as the condition. 409 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 410 CR->getRHS()->getLocStart(), 411 diag::warn_case_value_overflow); 412 413 // If the LHS is not the same type as the condition, insert an implicit 414 // cast. 415 ImpCastExprToType(Hi, CondType); 416 CR->setRHS(Hi); 417 418 // If the low value is bigger than the high value, the case is empty. 419 if (CaseRanges[i].first > HiVal) { 420 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range, 421 SourceRange(CR->getLHS()->getLocStart(), 422 CR->getRHS()->getLocEnd())); 423 CaseRanges.erase(CaseRanges.begin()+i); 424 --i, --e; 425 continue; 426 } 427 HiVals.push_back(HiVal); 428 } 429 430 // Rescan the ranges, looking for overlap with singleton values and other 431 // ranges. Since the range list is sorted, we only need to compare case 432 // ranges with their neighbors. 433 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 434 llvm::APSInt &CRLo = CaseRanges[i].first; 435 llvm::APSInt &CRHi = HiVals[i]; 436 CaseStmt *CR = CaseRanges[i].second; 437 438 // Check to see whether the case range overlaps with any singleton cases. 439 CaseStmt *OverlapStmt = 0; 440 llvm::APSInt OverlapVal(32); 441 442 // Find the smallest value >= the lower bound. If I is in the case range, 443 // then we have overlap. 444 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 445 CaseVals.end(), CRLo, 446 CaseCompareFunctor()); 447 if (I != CaseVals.end() && I->first < CRHi) { 448 OverlapVal = I->first; // Found overlap with scalar. 449 OverlapStmt = I->second; 450 } 451 452 // Find the smallest value bigger than the upper bound. 453 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 454 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 455 OverlapVal = (I-1)->first; // Found overlap with scalar. 456 OverlapStmt = (I-1)->second; 457 } 458 459 // Check to see if this case stmt overlaps with the subsequent case range. 460 if (i && CRLo <= HiVals[i-1]) { 461 OverlapVal = HiVals[i-1]; // Found overlap with range. 462 OverlapStmt = CaseRanges[i-1].second; 463 } 464 465 if (OverlapStmt) { 466 // If we have a duplicate, report it. 467 Diag(CR->getLHS()->getLocStart(), 468 diag::err_duplicate_case, OverlapVal.toString()); 469 Diag(OverlapStmt->getLHS()->getLocStart(), 470 diag::err_duplicate_case_prev); 471 // FIXME: We really want to remove the bogus case stmt from the substmt, 472 // but we have no way to do this right now. 473 CaseListIsErroneous = true; 474 } 475 } 476 } 477 478 // FIXME: If the case list was broken is some way, we don't have a good system 479 // to patch it up. Instead, just return the whole substmt as broken. 480 if (CaseListIsErroneous) 481 return true; 482 483 return SS; 484} 485 486Action::StmtResult 487Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprTy *Cond, StmtTy *Body) { 488 Expr *condExpr = (Expr *)Cond; 489 assert(condExpr && "ActOnWhileStmt(): missing expression"); 490 491 DefaultFunctionArrayConversion(condExpr); 492 QualType condType = condExpr->getType(); 493 494 if (!condType->isScalarType()) // C99 6.8.5p2 495 return Diag(WhileLoc, diag::err_typecheck_statement_requires_scalar, 496 condType.getAsString(), condExpr->getSourceRange()); 497 498 return new WhileStmt(condExpr, (Stmt*)Body, WhileLoc); 499} 500 501Action::StmtResult 502Sema::ActOnDoStmt(SourceLocation DoLoc, StmtTy *Body, 503 SourceLocation WhileLoc, ExprTy *Cond) { 504 Expr *condExpr = (Expr *)Cond; 505 assert(condExpr && "ActOnDoStmt(): missing expression"); 506 507 DefaultFunctionArrayConversion(condExpr); 508 QualType condType = condExpr->getType(); 509 510 if (!condType->isScalarType()) // C99 6.8.5p2 511 return Diag(DoLoc, diag::err_typecheck_statement_requires_scalar, 512 condType.getAsString(), condExpr->getSourceRange()); 513 514 return new DoStmt((Stmt*)Body, condExpr, DoLoc); 515} 516 517Action::StmtResult 518Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 519 StmtTy *first, ExprTy *second, ExprTy *third, 520 SourceLocation RParenLoc, StmtTy *body) { 521 Stmt *First = static_cast<Stmt*>(first); 522 Expr *Second = static_cast<Expr*>(second); 523 Expr *Third = static_cast<Expr*>(third); 524 Stmt *Body = static_cast<Stmt*>(body); 525 526 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 527 // C99 6.8.5p3: The declaration part of a 'for' statement shall only declare 528 // identifiers for objects having storage class 'auto' or 'register'. 529 for (ScopedDecl *D = DS->getDecl(); D; D = D->getNextDeclarator()) { 530 VarDecl *VD = dyn_cast<VarDecl>(D); 531 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 532 VD = 0; 533 if (VD == 0) 534 Diag(dyn_cast<ScopedDecl>(D)->getLocation(), 535 diag::err_non_variable_decl_in_for); 536 // FIXME: mark decl erroneous! 537 } 538 } 539 if (Second) { 540 DefaultFunctionArrayConversion(Second); 541 QualType SecondType = Second->getType(); 542 543 if (!SecondType->isScalarType()) // C99 6.8.5p2 544 return Diag(ForLoc, diag::err_typecheck_statement_requires_scalar, 545 SecondType.getAsString(), Second->getSourceRange()); 546 } 547 return new ForStmt(First, Second, Third, Body, ForLoc); 548} 549 550Action::StmtResult 551Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 552 SourceLocation LParenLoc, 553 StmtTy *first, ExprTy *second, 554 SourceLocation RParenLoc, StmtTy *body) { 555 Stmt *First = static_cast<Stmt*>(first); 556 Expr *Second = static_cast<Expr*>(second); 557 Stmt *Body = static_cast<Stmt*>(body); 558 if (First) { 559 QualType FirstType; 560 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 561 FirstType = cast<ValueDecl>(DS->getDecl())->getType(); 562 // C99 6.8.5p3: The declaration part of a 'for' statement shall only declare 563 // identifiers for objects having storage class 'auto' or 'register'. 564 ScopedDecl *D = DS->getDecl(); 565 VarDecl *VD = cast<VarDecl>(D); 566 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 567 return Diag(VD->getLocation(), diag::err_non_variable_decl_in_for); 568 if (D->getNextDeclarator()) 569 return Diag(D->getLocation(), diag::err_toomany_element_decls); 570 } else 571 FirstType = static_cast<Expr*>(first)->getType(); 572 if (!Context.isObjCObjectPointerType(FirstType)) 573 Diag(ForLoc, diag::err_selector_element_type, 574 FirstType.getAsString(), First->getSourceRange()); 575 } 576 if (Second) { 577 DefaultFunctionArrayConversion(Second); 578 QualType SecondType = Second->getType(); 579 if (!Context.isObjCObjectPointerType(SecondType)) 580 Diag(ForLoc, diag::err_collection_expr_type, 581 SecondType.getAsString(), Second->getSourceRange()); 582 } 583 return new ObjCForCollectionStmt(First, Second, Body, ForLoc, RParenLoc); 584} 585 586Action::StmtResult 587Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 588 IdentifierInfo *LabelII) { 589 // Look up the record for this label identifier. 590 LabelStmt *&LabelDecl = LabelMap[LabelII]; 591 592 // If we haven't seen this label yet, create a forward reference. 593 if (LabelDecl == 0) 594 LabelDecl = new LabelStmt(LabelLoc, LabelII, 0); 595 596 return new GotoStmt(LabelDecl, GotoLoc, LabelLoc); 597} 598 599Action::StmtResult 600Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc,SourceLocation StarLoc, 601 ExprTy *DestExp) { 602 // FIXME: Verify that the operand is convertible to void*. 603 604 return new IndirectGotoStmt((Expr*)DestExp); 605} 606 607Action::StmtResult 608Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 609 Scope *S = CurScope->getContinueParent(); 610 if (!S) { 611 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 612 Diag(ContinueLoc, diag::err_continue_not_in_loop); 613 return true; 614 } 615 616 return new ContinueStmt(ContinueLoc); 617} 618 619Action::StmtResult 620Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 621 Scope *S = CurScope->getBreakParent(); 622 if (!S) { 623 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 624 Diag(BreakLoc, diag::err_break_not_in_loop_or_switch); 625 return true; 626 } 627 628 return new BreakStmt(BreakLoc); 629} 630 631 632Action::StmtResult 633Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprTy *rex) { 634 Expr *RetValExp = static_cast<Expr *>(rex); 635 QualType FnRetType = 636 getCurFunctionDecl() ? getCurFunctionDecl()->getResultType() : 637 getCurMethodDecl()->getResultType(); 638 639 if (FnRetType->isVoidType()) { 640 if (RetValExp) // C99 6.8.6.4p1 (ext_ since GCC warns) 641 Diag(ReturnLoc, diag::ext_return_has_expr, 642 ( getCurFunctionDecl() ? 643 getCurFunctionDecl()->getIdentifier()->getName() : 644 getCurMethodDecl()->getSelector().getName() ), 645 RetValExp->getSourceRange()); 646 return new ReturnStmt(ReturnLoc, RetValExp); 647 } else { 648 if (!RetValExp) { 649 const char *funcName = 650 getCurFunctionDecl() ? 651 getCurFunctionDecl()->getIdentifier()->getName() : 652 getCurMethodDecl()->getSelector().getName().c_str(); 653 if (getLangOptions().C99) // C99 6.8.6.4p1 (ext_ since GCC warns) 654 Diag(ReturnLoc, diag::ext_return_missing_expr, funcName); 655 else // C90 6.6.6.4p4 656 Diag(ReturnLoc, diag::warn_return_missing_expr, funcName); 657 return new ReturnStmt(ReturnLoc, (Expr*)0); 658 } 659 } 660 // we have a non-void function with an expression, continue checking 661 QualType RetValType = RetValExp->getType(); 662 663 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 664 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 665 // function return. 666 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(FnRetType, 667 RetValExp); 668 if (DiagnoseAssignmentResult(ConvTy, ReturnLoc, FnRetType, 669 RetValType, RetValExp, "returning")) 670 return true; 671 672 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 673 674 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 675} 676 677Sema::StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 678 bool IsSimple, 679 bool IsVolatile, 680 unsigned NumOutputs, 681 unsigned NumInputs, 682 std::string *Names, 683 ExprTy **Constraints, 684 ExprTy **Exprs, 685 ExprTy *asmString, 686 unsigned NumClobbers, 687 ExprTy **Clobbers, 688 SourceLocation RParenLoc) { 689 // The parser verifies that there is a string literal here. 690 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString); 691 if (AsmString->isWide()) 692 // FIXME: We currently leak memory here. 693 return Diag(AsmString->getLocStart(), diag::err_asm_wide_character, 694 AsmString->getSourceRange()); 695 696 697 for (unsigned i = 0; i < NumOutputs; i++) { 698 StringLiteral *Literal = cast<StringLiteral>((Expr *)Constraints[i]); 699 if (Literal->isWide()) 700 // FIXME: We currently leak memory here. 701 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 702 Literal->getSourceRange()); 703 704 std::string OutputConstraint(Literal->getStrData(), 705 Literal->getByteLength()); 706 707 TargetInfo::ConstraintInfo info; 708 if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info)) 709 // FIXME: We currently leak memory here. 710 return Diag(Literal->getLocStart(), 711 diag::err_invalid_output_constraint_in_asm); 712 713 // Check that the output exprs are valid lvalues. 714 Expr *OutputExpr = (Expr *)Exprs[i]; 715 Expr::isLvalueResult Result = OutputExpr->isLvalue(Context); 716 if (Result != Expr::LV_Valid) { 717 ParenExpr *PE = cast<ParenExpr>(OutputExpr); 718 719 // FIXME: We currently leak memory here. 720 return Diag(PE->getSubExpr()->getLocStart(), 721 diag::err_invalid_lvalue_in_asm_output, 722 PE->getSubExpr()->getSourceRange()); 723 } 724 } 725 726 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 727 StringLiteral *Literal = cast<StringLiteral>((Expr *)Constraints[i]); 728 if (Literal->isWide()) 729 // FIXME: We currently leak memory here. 730 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 731 Literal->getSourceRange()); 732 733 std::string InputConstraint(Literal->getStrData(), 734 Literal->getByteLength()); 735 736 TargetInfo::ConstraintInfo info; 737 if (!Context.Target.validateInputConstraint(InputConstraint.c_str(), 738 NumOutputs, 739 info)) { 740 // FIXME: We currently leak memory here. 741 return Diag(Literal->getLocStart(), 742 diag::err_invalid_input_constraint_in_asm); 743 } 744 745 // Check that the input exprs aren't of type void. 746 Expr *InputExpr = (Expr *)Exprs[i]; 747 if (InputExpr->getType()->isVoidType()) { 748 ParenExpr *PE = cast<ParenExpr>(InputExpr); 749 750 // FIXME: We currently leak memory here. 751 return Diag(PE->getSubExpr()->getLocStart(), 752 diag::err_invalid_type_in_asm_input, 753 PE->getType().getAsString(), 754 PE->getSubExpr()->getSourceRange()); 755 } 756 } 757 758 // Check that the clobbers are valid. 759 for (unsigned i = 0; i < NumClobbers; i++) { 760 StringLiteral *Literal = cast<StringLiteral>((Expr *)Clobbers[i]); 761 if (Literal->isWide()) 762 // FIXME: We currently leak memory here. 763 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 764 Literal->getSourceRange()); 765 766 llvm::SmallString<16> Clobber(Literal->getStrData(), 767 Literal->getStrData() + 768 Literal->getByteLength()); 769 770 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 771 // FIXME: We currently leak memory here. 772 return Diag(Literal->getLocStart(), 773 diag::err_unknown_register_name_in_asm, Clobber.c_str()); 774 } 775 776 return new AsmStmt(AsmLoc, 777 IsSimple, 778 IsVolatile, 779 NumOutputs, 780 NumInputs, 781 Names, 782 reinterpret_cast<StringLiteral**>(Constraints), 783 reinterpret_cast<Expr**>(Exprs), 784 AsmString, NumClobbers, 785 reinterpret_cast<StringLiteral**>(Clobbers), 786 RParenLoc); 787} 788 789Action::StmtResult 790Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 791 SourceLocation RParen, StmtTy *Parm, 792 StmtTy *Body, StmtTy *CatchList) { 793 ObjCAtCatchStmt *CS = new ObjCAtCatchStmt(AtLoc, RParen, 794 static_cast<Stmt*>(Parm), static_cast<Stmt*>(Body), 795 static_cast<Stmt*>(CatchList)); 796 return CatchList ? CatchList : CS; 797} 798 799Action::StmtResult 800Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtTy *Body) { 801 ObjCAtFinallyStmt *FS = new ObjCAtFinallyStmt(AtLoc, 802 static_cast<Stmt*>(Body)); 803 return FS; 804} 805 806Action::StmtResult 807Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 808 StmtTy *Try, StmtTy *Catch, StmtTy *Finally) { 809 ObjCAtTryStmt *TS = new ObjCAtTryStmt(AtLoc, static_cast<Stmt*>(Try), 810 static_cast<Stmt*>(Catch), 811 static_cast<Stmt*>(Finally)); 812 return TS; 813} 814 815Action::StmtResult 816Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, StmtTy *Throw) { 817 ObjCAtThrowStmt *TS = new ObjCAtThrowStmt(AtLoc, static_cast<Stmt*>(Throw)); 818 return TS; 819} 820 821Action::StmtResult 822Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprTy *SynchExpr, 823 StmtTy *SynchBody) { 824 ObjCAtSynchronizedStmt *SS = new ObjCAtSynchronizedStmt(AtLoc, 825 static_cast<Stmt*>(SynchExpr), static_cast<Stmt*>(SynchBody)); 826 return SS; 827} 828