SemaStmt.cpp revision 38c5ebd7b1b65304c7b5c7b9bf3f9162df22e77d
1//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for statements. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/APValue.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/Basic/TargetInfo.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 (Context) NullStmt(SemiLoc)); 38} 39 40Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, 41 SourceLocation StartLoc, 42 SourceLocation EndLoc) { 43 DeclGroupRef DG = dg.getAsVal<DeclGroupRef>(); 44 45 // If we have an invalid decl, just return an error. 46 if (DG.isNull()) return StmtError(); 47 48 return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); 49} 50 51Action::OwningStmtResult 52Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 53 MultiStmtArg elts, bool isStmtExpr) { 54 unsigned NumElts = elts.size(); 55 Stmt **Elts = reinterpret_cast<Stmt**>(elts.release()); 56 // If we're in C89 mode, check that we don't have any decls after stmts. If 57 // so, emit an extension diagnostic. 58 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 59 // Note that __extension__ can be around a decl. 60 unsigned i = 0; 61 // Skip over all declarations. 62 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 63 /*empty*/; 64 65 // We found the end of the list or a statement. Scan for another declstmt. 66 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 67 /*empty*/; 68 69 if (i != NumElts) { 70 Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); 71 Diag(D->getLocation(), diag::ext_mixed_decls_code); 72 } 73 } 74 // Warn about unused expressions in statements. 75 for (unsigned i = 0; i != NumElts; ++i) { 76 Expr *E = dyn_cast<Expr>(Elts[i]); 77 if (!E) continue; 78 79 // Warn about expressions with unused results if they are non-void and if 80 // this not the last stmt in a stmt expr. 81 if (E->getType()->isVoidType() || (isStmtExpr && i == NumElts-1)) 82 continue; 83 84 SourceLocation Loc; 85 SourceRange R1, R2; 86 if (!E->isUnusedResultAWarning(Loc, R1, R2)) 87 continue; 88 89 Diag(Loc, diag::warn_unused_expr) << R1 << R2; 90 } 91 92 return Owned(new (Context) CompoundStmt(Context, Elts, NumElts, L, R)); 93} 94 95Action::OwningStmtResult 96Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprArg lhsval, 97 SourceLocation DotDotDotLoc, ExprArg rhsval, 98 SourceLocation ColonLoc) { 99 assert((lhsval.get() != 0) && "missing expression in case statement"); 100 101 // C99 6.8.4.2p3: The expression shall be an integer constant. 102 // However, GCC allows any evaluatable integer expression. 103 Expr *LHSVal = static_cast<Expr*>(lhsval.get()); 104 if (VerifyIntegerConstantExpression(LHSVal)) 105 return StmtError(); 106 107 // GCC extension: The expression shall be an integer constant. 108 109 Expr *RHSVal = static_cast<Expr*>(rhsval.get()); 110 if (RHSVal && VerifyIntegerConstantExpression(RHSVal)) { 111 RHSVal = 0; // Recover by just forgetting about it. 112 rhsval = 0; 113 } 114 115 if (getSwitchStack().empty()) { 116 Diag(CaseLoc, diag::err_case_not_in_switch); 117 return StmtError(); 118 } 119 120 // Only now release the smart pointers. 121 lhsval.release(); 122 rhsval.release(); 123 CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc); 124 getSwitchStack().back()->addSwitchCase(CS); 125 return Owned(CS); 126} 127 128/// ActOnCaseStmtBody - This installs a statement as the body of a case. 129void Sema::ActOnCaseStmtBody(StmtTy *caseStmt, StmtArg subStmt) { 130 CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); 131 Stmt *SubStmt = static_cast<Stmt*>(subStmt.release()); 132 CS->setSubStmt(SubStmt); 133} 134 135Action::OwningStmtResult 136Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 137 StmtArg subStmt, Scope *CurScope) { 138 Stmt *SubStmt = static_cast<Stmt*>(subStmt.release()); 139 140 if (getSwitchStack().empty()) { 141 Diag(DefaultLoc, diag::err_default_not_in_switch); 142 return Owned(SubStmt); 143 } 144 145 DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, SubStmt); 146 getSwitchStack().back()->addSwitchCase(DS); 147 return Owned(DS); 148} 149 150Action::OwningStmtResult 151Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 152 SourceLocation ColonLoc, StmtArg subStmt) { 153 Stmt *SubStmt = static_cast<Stmt*>(subStmt.release()); 154 // Look up the record for this label identifier. 155 LabelStmt *&LabelDecl = getLabelMap()[II]; 156 157 // If not forward referenced or defined already, just create a new LabelStmt. 158 if (LabelDecl == 0) 159 return Owned(LabelDecl = new (Context) LabelStmt(IdentLoc, II, SubStmt)); 160 161 assert(LabelDecl->getID() == II && "Label mismatch!"); 162 163 // Otherwise, this label was either forward reference or multiply defined. If 164 // multiply defined, reject it now. 165 if (LabelDecl->getSubStmt()) { 166 Diag(IdentLoc, diag::err_redefinition_of_label) << LabelDecl->getID(); 167 Diag(LabelDecl->getIdentLoc(), diag::note_previous_definition); 168 return Owned(SubStmt); 169 } 170 171 // Otherwise, this label was forward declared, and we just found its real 172 // definition. Fill in the forward definition and return it. 173 LabelDecl->setIdentLoc(IdentLoc); 174 LabelDecl->setSubStmt(SubStmt); 175 return Owned(LabelDecl); 176} 177 178Action::OwningStmtResult 179Sema::ActOnIfStmt(SourceLocation IfLoc, ExprArg CondVal, 180 StmtArg ThenVal, SourceLocation ElseLoc, 181 StmtArg ElseVal) { 182 Expr *condExpr = (Expr *)CondVal.release(); 183 184 assert(condExpr && "ActOnIfStmt(): missing expression"); 185 186 DefaultFunctionArrayConversion(condExpr); 187 // Take ownership again until we're past the error checking. 188 CondVal = condExpr; 189 QualType condType = condExpr->getType(); 190 191 if (getLangOptions().CPlusPlus) { 192 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 193 return StmtError(); 194 } else if (!condType->isScalarType()) // C99 6.8.4.1p1 195 return StmtError(Diag(IfLoc, diag::err_typecheck_statement_requires_scalar) 196 << condType << condExpr->getSourceRange()); 197 198 Stmt *thenStmt = (Stmt *)ThenVal.release(); 199 200 // Warn if the if block has a null body without an else value. 201 // this helps prevent bugs due to typos, such as 202 // if (condition); 203 // do_stuff(); 204 if (!ElseVal.get()) { 205 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 206 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 207 } 208 209 CondVal.release(); 210 return Owned(new (Context) IfStmt(IfLoc, condExpr, thenStmt, 211 (Stmt*)ElseVal.release())); 212} 213 214Action::OwningStmtResult 215Sema::ActOnStartOfSwitchStmt(ExprArg cond) { 216 Expr *Cond = static_cast<Expr*>(cond.release()); 217 218 if (getLangOptions().CPlusPlus) { 219 // C++ 6.4.2.p2: 220 // The condition shall be of integral type, enumeration type, or of a class 221 // type for which a single conversion function to integral or enumeration 222 // type exists (12.3). If the condition is of class type, the condition is 223 // converted by calling that conversion function, and the result of the 224 // conversion is used in place of the original condition for the remainder 225 // of this section. Integral promotions are performed. 226 227 QualType Ty = Cond->getType(); 228 229 // FIXME: Handle class types. 230 231 // If the type is wrong a diagnostic will be emitted later at 232 // ActOnFinishSwitchStmt. 233 if (Ty->isIntegralType() || Ty->isEnumeralType()) { 234 // Integral promotions are performed. 235 // FIXME: Integral promotions for C++ are not complete. 236 UsualUnaryConversions(Cond); 237 } 238 } else { 239 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 240 UsualUnaryConversions(Cond); 241 } 242 243 SwitchStmt *SS = new (Context) SwitchStmt(Cond); 244 getSwitchStack().push_back(SS); 245 return Owned(SS); 246} 247 248/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 249/// the specified width and sign. If an overflow occurs, detect it and emit 250/// the specified diagnostic. 251void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 252 unsigned NewWidth, bool NewSign, 253 SourceLocation Loc, 254 unsigned DiagID) { 255 // Perform a conversion to the promoted condition type if needed. 256 if (NewWidth > Val.getBitWidth()) { 257 // If this is an extension, just do it. 258 llvm::APSInt OldVal(Val); 259 Val.extend(NewWidth); 260 261 // If the input was signed and negative and the output is unsigned, 262 // warn. 263 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 264 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 265 266 Val.setIsSigned(NewSign); 267 } else if (NewWidth < Val.getBitWidth()) { 268 // If this is a truncation, check for overflow. 269 llvm::APSInt ConvVal(Val); 270 ConvVal.trunc(NewWidth); 271 ConvVal.setIsSigned(NewSign); 272 ConvVal.extend(Val.getBitWidth()); 273 ConvVal.setIsSigned(Val.isSigned()); 274 if (ConvVal != Val) 275 Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); 276 277 // Regardless of whether a diagnostic was emitted, really do the 278 // truncation. 279 Val.trunc(NewWidth); 280 Val.setIsSigned(NewSign); 281 } else if (NewSign != Val.isSigned()) { 282 // Convert the sign to match the sign of the condition. This can cause 283 // overflow as well: unsigned(INTMIN) 284 llvm::APSInt OldVal(Val); 285 Val.setIsSigned(NewSign); 286 287 if (Val.isNegative()) // Sign bit changes meaning. 288 Diag(Loc, DiagID) << OldVal.toString(10) << Val.toString(10); 289 } 290} 291 292namespace { 293 struct CaseCompareFunctor { 294 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 295 const llvm::APSInt &RHS) { 296 return LHS.first < RHS; 297 } 298 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 299 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 300 return LHS.first < RHS.first; 301 } 302 bool operator()(const llvm::APSInt &LHS, 303 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 304 return LHS < RHS.first; 305 } 306 }; 307} 308 309/// CmpCaseVals - Comparison predicate for sorting case values. 310/// 311static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 312 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 313 if (lhs.first < rhs.first) 314 return true; 315 316 if (lhs.first == rhs.first && 317 lhs.second->getCaseLoc().getRawEncoding() 318 < rhs.second->getCaseLoc().getRawEncoding()) 319 return true; 320 return false; 321} 322 323Action::OwningStmtResult 324Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtArg Switch, 325 StmtArg Body) { 326 Stmt *BodyStmt = (Stmt*)Body.release(); 327 328 SwitchStmt *SS = getSwitchStack().back(); 329 assert(SS == (SwitchStmt*)Switch.get() && "switch stack missing push/pop!"); 330 331 SS->setBody(BodyStmt, SwitchLoc); 332 getSwitchStack().pop_back(); 333 334 Expr *CondExpr = SS->getCond(); 335 QualType CondType = CondExpr->getType(); 336 337 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 338 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer) 339 << CondType << CondExpr->getSourceRange(); 340 return StmtError(); 341 } 342 343 // Get the bitwidth of the switched-on value before promotions. We must 344 // convert the integer case values to this width before comparison. 345 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 346 bool CondIsSigned = CondType->isSignedIntegerType(); 347 348 // Accumulate all of the case values in a vector so that we can sort them 349 // and detect duplicates. This vector contains the APInt for the case after 350 // it has been converted to the condition type. 351 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 352 CaseValsTy CaseVals; 353 354 // Keep track of any GNU case ranges we see. The APSInt is the low value. 355 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 356 357 DefaultStmt *TheDefaultStmt = 0; 358 359 bool CaseListIsErroneous = false; 360 361 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 362 SC = SC->getNextSwitchCase()) { 363 364 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 365 if (TheDefaultStmt) { 366 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 367 Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); 368 369 // FIXME: Remove the default statement from the switch block so that 370 // we'll return a valid AST. This requires recursing down the 371 // AST and finding it, not something we are set up to do right now. For 372 // now, just lop the entire switch stmt out of the AST. 373 CaseListIsErroneous = true; 374 } 375 TheDefaultStmt = DS; 376 377 } else { 378 CaseStmt *CS = cast<CaseStmt>(SC); 379 380 // We already verified that the expression has a i-c-e value (C99 381 // 6.8.4.2p3) - get that value now. 382 Expr *Lo = CS->getLHS(); 383 llvm::APSInt LoVal = Lo->EvaluateAsInt(Context); 384 385 // Convert the value to the same width/sign as the condition. 386 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 387 CS->getLHS()->getLocStart(), 388 diag::warn_case_value_overflow); 389 390 // If the LHS is not the same type as the condition, insert an implicit 391 // cast. 392 ImpCastExprToType(Lo, CondType); 393 CS->setLHS(Lo); 394 395 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 396 if (CS->getRHS()) 397 CaseRanges.push_back(std::make_pair(LoVal, CS)); 398 else 399 CaseVals.push_back(std::make_pair(LoVal, CS)); 400 } 401 } 402 403 // Sort all the scalar case values so we can easily detect duplicates. 404 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 405 406 if (!CaseVals.empty()) { 407 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 408 if (CaseVals[i].first == CaseVals[i+1].first) { 409 // If we have a duplicate, report it. 410 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 411 diag::err_duplicate_case) << CaseVals[i].first.toString(10); 412 Diag(CaseVals[i].second->getLHS()->getLocStart(), 413 diag::note_duplicate_case_prev); 414 // FIXME: We really want to remove the bogus case stmt from the substmt, 415 // but we have no way to do this right now. 416 CaseListIsErroneous = true; 417 } 418 } 419 } 420 421 // Detect duplicate case ranges, which usually don't exist at all in the first 422 // place. 423 if (!CaseRanges.empty()) { 424 // Sort all the case ranges by their low value so we can easily detect 425 // overlaps between ranges. 426 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 427 428 // Scan the ranges, computing the high values and removing empty ranges. 429 std::vector<llvm::APSInt> HiVals; 430 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 431 CaseStmt *CR = CaseRanges[i].second; 432 Expr *Hi = CR->getRHS(); 433 llvm::APSInt HiVal = Hi->EvaluateAsInt(Context); 434 435 // Convert the value to the same width/sign as the condition. 436 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 437 CR->getRHS()->getLocStart(), 438 diag::warn_case_value_overflow); 439 440 // If the LHS is not the same type as the condition, insert an implicit 441 // cast. 442 ImpCastExprToType(Hi, CondType); 443 CR->setRHS(Hi); 444 445 // If the low value is bigger than the high value, the case is empty. 446 if (CaseRanges[i].first > HiVal) { 447 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) 448 << SourceRange(CR->getLHS()->getLocStart(), 449 CR->getRHS()->getLocEnd()); 450 CaseRanges.erase(CaseRanges.begin()+i); 451 --i, --e; 452 continue; 453 } 454 HiVals.push_back(HiVal); 455 } 456 457 // Rescan the ranges, looking for overlap with singleton values and other 458 // ranges. Since the range list is sorted, we only need to compare case 459 // ranges with their neighbors. 460 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 461 llvm::APSInt &CRLo = CaseRanges[i].first; 462 llvm::APSInt &CRHi = HiVals[i]; 463 CaseStmt *CR = CaseRanges[i].second; 464 465 // Check to see whether the case range overlaps with any singleton cases. 466 CaseStmt *OverlapStmt = 0; 467 llvm::APSInt OverlapVal(32); 468 469 // Find the smallest value >= the lower bound. If I is in the case range, 470 // then we have overlap. 471 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 472 CaseVals.end(), CRLo, 473 CaseCompareFunctor()); 474 if (I != CaseVals.end() && I->first < CRHi) { 475 OverlapVal = I->first; // Found overlap with scalar. 476 OverlapStmt = I->second; 477 } 478 479 // Find the smallest value bigger than the upper bound. 480 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 481 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 482 OverlapVal = (I-1)->first; // Found overlap with scalar. 483 OverlapStmt = (I-1)->second; 484 } 485 486 // Check to see if this case stmt overlaps with the subsequent case range. 487 if (i && CRLo <= HiVals[i-1]) { 488 OverlapVal = HiVals[i-1]; // Found overlap with range. 489 OverlapStmt = CaseRanges[i-1].second; 490 } 491 492 if (OverlapStmt) { 493 // If we have a duplicate, report it. 494 Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) 495 << OverlapVal.toString(10); 496 Diag(OverlapStmt->getLHS()->getLocStart(), 497 diag::note_duplicate_case_prev); 498 // FIXME: We really want to remove the bogus case stmt from the substmt, 499 // but we have no way to do this right now. 500 CaseListIsErroneous = true; 501 } 502 } 503 } 504 505 // FIXME: If the case list was broken is some way, we don't have a good system 506 // to patch it up. Instead, just return the whole substmt as broken. 507 if (CaseListIsErroneous) 508 return StmtError(); 509 510 Switch.release(); 511 return Owned(SS); 512} 513 514Action::OwningStmtResult 515Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprArg Cond, StmtArg Body) { 516 Expr *condExpr = (Expr *)Cond.release(); 517 assert(condExpr && "ActOnWhileStmt(): missing expression"); 518 519 DefaultFunctionArrayConversion(condExpr); 520 Cond = condExpr; 521 QualType condType = condExpr->getType(); 522 523 if (getLangOptions().CPlusPlus) { 524 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 525 return StmtError(); 526 } else if (!condType->isScalarType()) // C99 6.8.5p2 527 return StmtError(Diag(WhileLoc, 528 diag::err_typecheck_statement_requires_scalar) 529 << condType << condExpr->getSourceRange()); 530 531 Cond.release(); 532 return Owned(new (Context) WhileStmt(condExpr, (Stmt*)Body.release(), 533 WhileLoc)); 534} 535 536Action::OwningStmtResult 537Sema::ActOnDoStmt(SourceLocation DoLoc, StmtArg Body, 538 SourceLocation WhileLoc, ExprArg Cond) { 539 Expr *condExpr = (Expr *)Cond.release(); 540 assert(condExpr && "ActOnDoStmt(): missing expression"); 541 542 DefaultFunctionArrayConversion(condExpr); 543 Cond = condExpr; 544 QualType condType = condExpr->getType(); 545 546 if (getLangOptions().CPlusPlus) { 547 if (CheckCXXBooleanCondition(condExpr)) // C++ 6.4p4 548 return StmtError(); 549 } else if (!condType->isScalarType()) // C99 6.8.5p2 550 return StmtError(Diag(DoLoc, diag::err_typecheck_statement_requires_scalar) 551 << condType << condExpr->getSourceRange()); 552 553 Cond.release(); 554 return Owned(new (Context) DoStmt((Stmt*)Body.release(), condExpr, DoLoc)); 555} 556 557Action::OwningStmtResult 558Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 559 StmtArg first, ExprArg second, ExprArg third, 560 SourceLocation RParenLoc, StmtArg body) { 561 Stmt *First = static_cast<Stmt*>(first.get()); 562 Expr *Second = static_cast<Expr*>(second.get()); 563 Expr *Third = static_cast<Expr*>(third.get()); 564 Stmt *Body = static_cast<Stmt*>(body.get()); 565 566 if (!getLangOptions().CPlusPlus) { 567 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 568 // C99 6.8.5p3: The declaration part of a 'for' statement shall only 569 // declare identifiers for objects having storage class 'auto' or 570 // 'register'. 571 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 572 DI!=DE; ++DI) { 573 VarDecl *VD = dyn_cast<VarDecl>(*DI); 574 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 575 VD = 0; 576 if (VD == 0) 577 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 578 // FIXME: mark decl erroneous! 579 } 580 } 581 } 582 if (Second) { 583 DefaultFunctionArrayConversion(Second); 584 QualType SecondType = Second->getType(); 585 586 if (getLangOptions().CPlusPlus) { 587 if (CheckCXXBooleanCondition(Second)) // C++ 6.4p4 588 return StmtError(); 589 } else if (!SecondType->isScalarType()) // C99 6.8.5p2 590 return StmtError(Diag(ForLoc, 591 diag::err_typecheck_statement_requires_scalar) 592 << SecondType << Second->getSourceRange()); 593 } 594 first.release(); 595 second.release(); 596 third.release(); 597 body.release(); 598 return Owned(new (Context) ForStmt(First, Second, Third, Body, ForLoc)); 599} 600 601Action::OwningStmtResult 602Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 603 SourceLocation LParenLoc, 604 StmtArg first, ExprArg second, 605 SourceLocation RParenLoc, StmtArg body) { 606 Stmt *First = static_cast<Stmt*>(first.get()); 607 Expr *Second = static_cast<Expr*>(second.get()); 608 Stmt *Body = static_cast<Stmt*>(body.get()); 609 if (First) { 610 QualType FirstType; 611 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 612 if (!DS->isSingleDecl()) 613 return StmtError(Diag((*DS->decl_begin())->getLocation(), 614 diag::err_toomany_element_decls)); 615 616 Decl *D = DS->getSingleDecl(); 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 StmtError(Diag(VD->getLocation(), 624 diag::err_non_variable_decl_in_for)); 625 } else { 626 if (cast<Expr>(First)->isLvalue(Context) != Expr::LV_Valid) 627 return StmtError(Diag(First->getLocStart(), 628 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 first.release(); 645 second.release(); 646 body.release(); 647 return Owned(new (Context) ObjCForCollectionStmt(First, Second, Body, 648 ForLoc, RParenLoc)); 649} 650 651Action::OwningStmtResult 652Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 653 IdentifierInfo *LabelII) { 654 // If we are in a block, reject all gotos for now. 655 if (CurBlock) 656 return StmtError(Diag(GotoLoc, diag::err_goto_in_block)); 657 658 // Look up the record for this label identifier. 659 LabelStmt *&LabelDecl = getLabelMap()[LabelII]; 660 661 // If we haven't seen this label yet, create a forward reference. 662 if (LabelDecl == 0) 663 LabelDecl = new (Context) LabelStmt(LabelLoc, LabelII, 0); 664 665 return Owned(new (Context) GotoStmt(LabelDecl, GotoLoc, LabelLoc)); 666} 667 668Action::OwningStmtResult 669Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, 670 ExprArg DestExp) { 671 // Convert operand to void* 672 Expr* E = DestExp.takeAs<Expr>(); 673 QualType ETy = E->getType(); 674 AssignConvertType ConvTy = 675 CheckSingleAssignmentConstraints(Context.VoidPtrTy, E); 676 if (DiagnoseAssignmentResult(ConvTy, StarLoc, Context.VoidPtrTy, ETy, 677 E, "passing")) 678 return StmtError(); 679 return Owned(new (Context) IndirectGotoStmt(GotoLoc, E)); 680} 681 682Action::OwningStmtResult 683Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 684 Scope *S = CurScope->getContinueParent(); 685 if (!S) { 686 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 687 return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); 688 } 689 690 return Owned(new (Context) ContinueStmt(ContinueLoc)); 691} 692 693Action::OwningStmtResult 694Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 695 Scope *S = CurScope->getBreakParent(); 696 if (!S) { 697 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 698 return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); 699 } 700 701 return Owned(new (Context) BreakStmt(BreakLoc)); 702} 703 704/// ActOnBlockReturnStmt - Utility routine to figure out block's return type. 705/// 706Action::OwningStmtResult 707Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { 708 709 // If this is the first return we've seen in the block, infer the type of 710 // the block from it. 711 if (CurBlock->ReturnType == 0) { 712 if (RetValExp) { 713 // Don't call UsualUnaryConversions(), since we don't want to do 714 // integer promotions here. 715 DefaultFunctionArrayConversion(RetValExp); 716 CurBlock->ReturnType = RetValExp->getType().getTypePtr(); 717 } else 718 CurBlock->ReturnType = Context.VoidTy.getTypePtr(); 719 } 720 QualType FnRetType = QualType(CurBlock->ReturnType, 0); 721 722 // Otherwise, verify that this result type matches the previous one. We are 723 // pickier with blocks than for normal functions because we don't have GCC 724 // compatibility to worry about here. 725 if (CurBlock->ReturnType->isVoidType()) { 726 if (RetValExp) { 727 Diag(ReturnLoc, diag::err_return_block_has_expr); 728 RetValExp->Destroy(Context); 729 RetValExp = 0; 730 } 731 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 732 } 733 734 if (!RetValExp) 735 return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); 736 737 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 738 // we have a non-void block with an expression, continue checking 739 QualType RetValType = RetValExp->getType(); 740 741 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 742 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 743 // function return. 744 745 // In C++ the return statement is handled via a copy initialization. 746 // the C version of which boils down to CheckSingleAssignmentConstraints. 747 // FIXME: Leaks RetValExp. 748 if (PerformCopyInitialization(RetValExp, FnRetType, "returning")) 749 return StmtError(); 750 751 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 752 } 753 754 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 755} 756 757/// IsReturnCopyElidable - Whether returning @p RetExpr from a function that 758/// returns a @p RetType fulfills the criteria for copy elision (C++0x 12.8p15). 759static bool IsReturnCopyElidable(ASTContext &Ctx, QualType RetType, 760 Expr *RetExpr) { 761 QualType ExprType = RetExpr->getType(); 762 // - in a return statement in a function with ... 763 // ... a class return type ... 764 if (!RetType->isRecordType()) 765 return false; 766 // ... the same cv-unqualified type as the function return type ... 767 if (Ctx.getCanonicalType(RetType).getUnqualifiedType() != 768 Ctx.getCanonicalType(ExprType).getUnqualifiedType()) 769 return false; 770 // ... the expression is the name of a non-volatile automatic object ... 771 // We ignore parentheses here. 772 // FIXME: Is this compliant? 773 const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(RetExpr->IgnoreParens()); 774 if (!DR) 775 return false; 776 const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); 777 if (!VD) 778 return false; 779 return VD->hasLocalStorage() && !VD->getType()->isReferenceType() 780 && !VD->getType().isVolatileQualified(); 781} 782 783Action::OwningStmtResult 784Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprArg rex) { 785 Expr *RetValExp = static_cast<Expr *>(rex.release()); 786 if (CurBlock) 787 return ActOnBlockReturnStmt(ReturnLoc, RetValExp); 788 789 QualType FnRetType; 790 if (FunctionDecl *FD = getCurFunctionDecl()) 791 FnRetType = FD->getResultType(); 792 else if (ObjCMethodDecl *MD = getCurMethodDecl()) 793 FnRetType = MD->getResultType(); 794 else // If we don't have a function/method context, bail. 795 return StmtError(); 796 797 if (FnRetType->isVoidType()) { 798 if (RetValExp) {// C99 6.8.6.4p1 (ext_ since GCC warns) 799 unsigned D = diag::ext_return_has_expr; 800 if (RetValExp->getType()->isVoidType()) 801 D = diag::ext_return_has_void_expr; 802 803 // return (some void expression); is legal in C++. 804 if (D != diag::ext_return_has_void_expr || 805 !getLangOptions().CPlusPlus) { 806 NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); 807 Diag(ReturnLoc, D) 808 << CurDecl->getDeclName() << isa<ObjCMethodDecl>(CurDecl) 809 << RetValExp->getSourceRange(); 810 } 811 } 812 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 813 } 814 815 if (!RetValExp) { 816 unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 817 // C99 6.8.6.4p1 (ext_ since GCC warns) 818 if (getLangOptions().C99) DiagID = diag::ext_return_missing_expr; 819 820 if (FunctionDecl *FD = getCurFunctionDecl()) 821 Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; 822 else 823 Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; 824 return Owned(new (Context) ReturnStmt(ReturnLoc, (Expr*)0)); 825 } 826 827 if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { 828 // we have a non-void function with an expression, continue checking 829 830 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 831 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 832 // function return. 833 834 // C++0x 12.8p15: When certain criteria are met, an implementation is 835 // allowed to omit the copy construction of a class object, [...] 836 // - in a return statement in a function with a class return type, when 837 // the expression is the name of a non-volatile automatic object with 838 // the same cv-unqualified type as the function return type, the copy 839 // operation can be omitted [...] 840 // C++0x 12.8p16: When the criteria for elision of a copy operation are met 841 // and the object to be copied is designated by an lvalue, overload 842 // resolution to select the constructor for the copy is first performed 843 // as if the object were designated by an rvalue. 844 // Note that we only compute Elidable if we're in C++0x, since we don't 845 // care otherwise. 846 bool Elidable = getLangOptions().CPlusPlus0x ? 847 IsReturnCopyElidable(Context, FnRetType, RetValExp) : 848 false; 849 850 // In C++ the return statement is handled via a copy initialization. 851 // the C version of which boils down to CheckSingleAssignmentConstraints. 852 // FIXME: Leaks RetValExp on error. 853 if (PerformCopyInitialization(RetValExp, FnRetType, "returning", Elidable)) 854 return StmtError(); 855 856 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 857 } 858 859 return Owned(new (Context) ReturnStmt(ReturnLoc, RetValExp)); 860} 861 862/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently 863/// ignore "noop" casts in places where an lvalue is required by an inline asm. 864/// We emulate this behavior when -fheinous-gnu-extensions is specified, but 865/// provide a strong guidance to not use it. 866/// 867/// This method checks to see if the argument is an acceptable l-value and 868/// returns false if it is a case we can handle. 869static bool CheckAsmLValue(const Expr *E, Sema &S) { 870 if (E->isLvalue(S.Context) == Expr::LV_Valid) 871 return false; // Cool, this is an lvalue. 872 873 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we 874 // are supposed to allow. 875 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); 876 if (E != E2 && E2->isLvalue(S.Context) == Expr::LV_Valid) { 877 if (!S.getLangOptions().HeinousExtensions) 878 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) 879 << E->getSourceRange(); 880 else 881 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) 882 << E->getSourceRange(); 883 // Accept, even if we emitted an error diagnostic. 884 return false; 885 } 886 887 // None of the above, just randomly invalid non-lvalue. 888 return true; 889} 890 891 892Sema::OwningStmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 893 bool IsSimple, 894 bool IsVolatile, 895 unsigned NumOutputs, 896 unsigned NumInputs, 897 std::string *Names, 898 MultiExprArg constraints, 899 MultiExprArg exprs, 900 ExprArg asmString, 901 MultiExprArg clobbers, 902 SourceLocation RParenLoc) { 903 unsigned NumClobbers = clobbers.size(); 904 StringLiteral **Constraints = 905 reinterpret_cast<StringLiteral**>(constraints.get()); 906 Expr **Exprs = reinterpret_cast<Expr **>(exprs.get()); 907 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString.get()); 908 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.get()); 909 910 llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; 911 912 // The parser verifies that there is a string literal here. 913 if (AsmString->isWide()) 914 return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) 915 << AsmString->getSourceRange()); 916 917 918 for (unsigned i = 0; i != NumOutputs; i++) { 919 StringLiteral *Literal = Constraints[i]; 920 if (Literal->isWide()) 921 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 922 << Literal->getSourceRange()); 923 924 std::string OutputConstraint(Literal->getStrData(), 925 Literal->getByteLength()); 926 927 TargetInfo::ConstraintInfo info; 928 if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info)) 929 return StmtError(Diag(Literal->getLocStart(), 930 diag::err_asm_invalid_output_constraint) << OutputConstraint); 931 932 // Check that the output exprs are valid lvalues. 933 ParenExpr *OutputExpr = cast<ParenExpr>(Exprs[i]); 934 if (CheckAsmLValue(OutputExpr, *this)) { 935 return StmtError(Diag(OutputExpr->getSubExpr()->getLocStart(), 936 diag::err_asm_invalid_lvalue_in_output) 937 << OutputExpr->getSubExpr()->getSourceRange()); 938 } 939 940 OutputConstraintInfos.push_back(info); 941 } 942 943 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 944 StringLiteral *Literal = Constraints[i]; 945 if (Literal->isWide()) 946 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 947 << Literal->getSourceRange()); 948 949 std::string InputConstraint(Literal->getStrData(), 950 Literal->getByteLength()); 951 952 TargetInfo::ConstraintInfo info; 953 if (!Context.Target.validateInputConstraint(InputConstraint.c_str(), 954 &Names[0], 955 &Names[0] + NumOutputs, 956 &OutputConstraintInfos[0], 957 info)) { 958 return StmtError(Diag(Literal->getLocStart(), 959 diag::err_asm_invalid_input_constraint) << InputConstraint); 960 } 961 962 ParenExpr *InputExpr = cast<ParenExpr>(Exprs[i]); 963 964 // Only allow void types for memory constraints. 965 if ((info & TargetInfo::CI_AllowsMemory) 966 && !(info & TargetInfo::CI_AllowsRegister)) { 967 if (CheckAsmLValue(InputExpr, *this)) 968 return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(), 969 diag::err_asm_invalid_lvalue_in_input) 970 << InputConstraint << InputExpr->getSubExpr()->getSourceRange()); 971 } 972 973 if (info & TargetInfo::CI_AllowsRegister) { 974 if (InputExpr->getType()->isVoidType()) { 975 return StmtError(Diag(InputExpr->getSubExpr()->getLocStart(), 976 diag::err_asm_invalid_type_in_input) 977 << InputExpr->getType() << InputConstraint 978 << InputExpr->getSubExpr()->getSourceRange()); 979 } 980 } 981 982 DefaultFunctionArrayConversion(Exprs[i]); 983 } 984 985 // Check that the clobbers are valid. 986 for (unsigned i = 0; i != NumClobbers; i++) { 987 StringLiteral *Literal = Clobbers[i]; 988 if (Literal->isWide()) 989 return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) 990 << Literal->getSourceRange()); 991 992 llvm::SmallString<16> Clobber(Literal->getStrData(), 993 Literal->getStrData() + 994 Literal->getByteLength()); 995 996 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 997 return StmtError(Diag(Literal->getLocStart(), 998 diag::err_asm_unknown_register_name) << Clobber.c_str()); 999 } 1000 1001 constraints.release(); 1002 exprs.release(); 1003 asmString.release(); 1004 clobbers.release(); 1005 AsmStmt *NS = 1006 new (Context) AsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, 1007 Names, Constraints, Exprs, AsmString, NumClobbers, 1008 Clobbers, RParenLoc); 1009 // Validate the asm string, ensuring it makes sense given the operands we 1010 // have. 1011 llvm::SmallVector<AsmStmt::AsmStringPiece, 8> Pieces; 1012 unsigned DiagOffs; 1013 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { 1014 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) 1015 << AsmString->getSourceRange(); 1016 DeleteStmt(NS); 1017 return StmtError(); 1018 } 1019 1020 1021 return Owned(NS); 1022} 1023 1024Action::OwningStmtResult 1025Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 1026 SourceLocation RParen, DeclPtrTy Parm, 1027 StmtArg Body, StmtArg catchList) { 1028 Stmt *CatchList = static_cast<Stmt*>(catchList.release()); 1029 ParmVarDecl *PVD = cast_or_null<ParmVarDecl>(Parm.getAs<Decl>()); 1030 1031 // PVD == 0 implies @catch(...). 1032 if (PVD) { 1033 // If we already know the decl is invalid, reject it. 1034 if (PVD->isInvalidDecl()) 1035 return StmtError(); 1036 1037 if (!Context.isObjCObjectPointerType(PVD->getType())) 1038 return StmtError(Diag(PVD->getLocation(), 1039 diag::err_catch_param_not_objc_type)); 1040 if (PVD->getType()->isObjCQualifiedIdType()) 1041 return StmtError(Diag(PVD->getLocation(), 1042 diag::err_illegal_qualifiers_on_catch_parm)); 1043 } 1044 1045 ObjCAtCatchStmt *CS = new (Context) ObjCAtCatchStmt(AtLoc, RParen, 1046 PVD, static_cast<Stmt*>(Body.release()), CatchList); 1047 return Owned(CatchList ? CatchList : CS); 1048} 1049 1050Action::OwningStmtResult 1051Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtArg Body) { 1052 return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, 1053 static_cast<Stmt*>(Body.release()))); 1054} 1055 1056Action::OwningStmtResult 1057Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 1058 StmtArg Try, StmtArg Catch, StmtArg Finally) { 1059 CurFunctionNeedsScopeChecking = true; 1060 return Owned(new (Context) ObjCAtTryStmt(AtLoc, 1061 static_cast<Stmt*>(Try.release()), 1062 static_cast<Stmt*>(Catch.release()), 1063 static_cast<Stmt*>(Finally.release()))); 1064} 1065 1066Action::OwningStmtResult 1067Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, ExprArg expr,Scope *CurScope) { 1068 Expr *ThrowExpr = static_cast<Expr*>(expr.release()); 1069 if (!ThrowExpr) { 1070 // @throw without an expression designates a rethrow (which much occur 1071 // in the context of an @catch clause). 1072 Scope *AtCatchParent = CurScope; 1073 while (AtCatchParent && !AtCatchParent->isAtCatchScope()) 1074 AtCatchParent = AtCatchParent->getParent(); 1075 if (!AtCatchParent) 1076 return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); 1077 } else { 1078 QualType ThrowType = ThrowExpr->getType(); 1079 // Make sure the expression type is an ObjC pointer or "void *". 1080 if (!Context.isObjCObjectPointerType(ThrowType)) { 1081 const PointerType *PT = ThrowType->getAsPointerType(); 1082 if (!PT || !PT->getPointeeType()->isVoidType()) 1083 return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) 1084 << ThrowExpr->getType() << ThrowExpr->getSourceRange()); 1085 } 1086 } 1087 return Owned(new (Context) ObjCAtThrowStmt(AtLoc, ThrowExpr)); 1088} 1089 1090Action::OwningStmtResult 1091Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprArg SynchExpr, 1092 StmtArg SynchBody) { 1093 return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, 1094 static_cast<Stmt*>(SynchExpr.release()), 1095 static_cast<Stmt*>(SynchBody.release()))); 1096} 1097 1098/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block 1099/// and creates a proper catch handler from them. 1100Action::OwningStmtResult 1101Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, DeclPtrTy ExDecl, 1102 StmtArg HandlerBlock) { 1103 // There's nothing to test that ActOnExceptionDecl didn't already test. 1104 return Owned(new (Context) CXXCatchStmt(CatchLoc, 1105 cast_or_null<VarDecl>(ExDecl.getAs<Decl>()), 1106 static_cast<Stmt*>(HandlerBlock.release()))); 1107} 1108 1109/// ActOnCXXTryBlock - Takes a try compound-statement and a number of 1110/// handlers and creates a try statement from them. 1111Action::OwningStmtResult 1112Sema::ActOnCXXTryBlock(SourceLocation TryLoc, StmtArg TryBlock, 1113 MultiStmtArg RawHandlers) { 1114 unsigned NumHandlers = RawHandlers.size(); 1115 assert(NumHandlers > 0 && 1116 "The parser shouldn't call this if there are no handlers."); 1117 Stmt **Handlers = reinterpret_cast<Stmt**>(RawHandlers.get()); 1118 1119 for(unsigned i = 0; i < NumHandlers - 1; ++i) { 1120 CXXCatchStmt *Handler = llvm::cast<CXXCatchStmt>(Handlers[i]); 1121 if (!Handler->getExceptionDecl()) 1122 return StmtError(Diag(Handler->getLocStart(), diag::err_early_catch_all)); 1123 } 1124 // FIXME: We should detect handlers for the same type as an earlier one. 1125 // This one is rather easy. 1126 // FIXME: We should detect handlers that cannot catch anything because an 1127 // earlier handler catches a superclass. Need to find a method that is not 1128 // quadratic for this. 1129 // Neither of these are explicitly forbidden, but every compiler detects them 1130 // and warns. 1131 1132 RawHandlers.release(); 1133 return Owned(new (Context) CXXTryStmt(TryLoc, 1134 static_cast<Stmt*>(TryBlock.release()), 1135 Handlers, NumHandlers)); 1136} 1137