CallEvent.cpp revision 4e45dba1c0234eec7b7c348dbbf568c5ac9fc471
1//===- Calls.cpp - Wrapper for all function and method calls ------*- C++ -*--// 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/// \file This file defines CallEvent and its subclasses, which represent path- 11/// sensitive instances of different kinds of function and method calls 12/// (C, C++, and Objective-C). 13// 14//===----------------------------------------------------------------------===// 15 16#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 17#include "clang/Analysis/ProgramPoint.h" 18#include "clang/AST/ParentMap.h" 19#include "llvm/ADT/SmallSet.h" 20#include "llvm/ADT/StringExtras.h" 21 22using namespace clang; 23using namespace ento; 24 25QualType CallEvent::getResultType() const { 26 const Expr *E = getOriginExpr(); 27 assert(E && "Calls without origin expressions do not have results"); 28 QualType ResultTy = E->getType(); 29 30 ASTContext &Ctx = getState()->getStateManager().getContext(); 31 32 // A function that returns a reference to 'int' will have a result type 33 // of simply 'int'. Check the origin expr's value kind to recover the 34 // proper type. 35 switch (E->getValueKind()) { 36 case VK_LValue: 37 ResultTy = Ctx.getLValueReferenceType(ResultTy); 38 break; 39 case VK_XValue: 40 ResultTy = Ctx.getRValueReferenceType(ResultTy); 41 break; 42 case VK_RValue: 43 // No adjustment is necessary. 44 break; 45 } 46 47 return ResultTy; 48} 49 50static bool isCallbackArg(SVal V, QualType T) { 51 // If the parameter is 0, it's harmless. 52 if (V.isZeroConstant()) 53 return false; 54 55 // If a parameter is a block or a callback, assume it can modify pointer. 56 if (T->isBlockPointerType() || 57 T->isFunctionPointerType() || 58 T->isObjCSelType()) 59 return true; 60 61 // Check if a callback is passed inside a struct (for both, struct passed by 62 // reference and by value). Dig just one level into the struct for now. 63 64 if (T->isAnyPointerType() || T->isReferenceType()) 65 T = T->getPointeeType(); 66 67 if (const RecordType *RT = T->getAsStructureType()) { 68 const RecordDecl *RD = RT->getDecl(); 69 for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); 70 I != E; ++I) { 71 QualType FieldT = I->getType(); 72 if (FieldT->isBlockPointerType() || FieldT->isFunctionPointerType()) 73 return true; 74 } 75 } 76 77 return false; 78} 79 80bool CallEvent::hasNonZeroCallbackArg() const { 81 unsigned NumOfArgs = getNumArgs(); 82 83 // If calling using a function pointer, assume the function does not 84 // have a callback. TODO: We could check the types of the arguments here. 85 if (!getDecl()) 86 return false; 87 88 unsigned Idx = 0; 89 for (CallEvent::param_type_iterator I = param_type_begin(), 90 E = param_type_end(); 91 I != E && Idx < NumOfArgs; ++I, ++Idx) { 92 if (NumOfArgs <= Idx) 93 break; 94 95 if (isCallbackArg(getArgSVal(Idx), *I)) 96 return true; 97 } 98 99 return false; 100} 101 102/// \brief Returns true if a type is a pointer-to-const or reference-to-const 103/// with no further indirection. 104static bool isPointerToConst(QualType Ty) { 105 QualType PointeeTy = Ty->getPointeeType(); 106 if (PointeeTy == QualType()) 107 return false; 108 if (!PointeeTy.isConstQualified()) 109 return false; 110 if (PointeeTy->isAnyPointerType()) 111 return false; 112 return true; 113} 114 115// Try to retrieve the function declaration and find the function parameter 116// types which are pointers/references to a non-pointer const. 117// We will not invalidate the corresponding argument regions. 118static void findPtrToConstParams(llvm::SmallSet<unsigned, 1> &PreserveArgs, 119 const CallEvent &Call) { 120 unsigned Idx = 0; 121 for (CallEvent::param_type_iterator I = Call.param_type_begin(), 122 E = Call.param_type_end(); 123 I != E; ++I, ++Idx) { 124 if (isPointerToConst(*I)) 125 PreserveArgs.insert(Idx); 126 } 127} 128 129ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount, 130 ProgramStateRef Orig) const { 131 ProgramStateRef Result = (Orig ? Orig : getState()); 132 133 SmallVector<const MemRegion *, 8> RegionsToInvalidate; 134 getExtraInvalidatedRegions(RegionsToInvalidate); 135 136 // Indexes of arguments whose values will be preserved by the call. 137 llvm::SmallSet<unsigned, 1> PreserveArgs; 138 if (!argumentsMayEscape()) 139 findPtrToConstParams(PreserveArgs, *this); 140 141 for (unsigned Idx = 0, Count = getNumArgs(); Idx != Count; ++Idx) { 142 if (PreserveArgs.count(Idx)) 143 continue; 144 145 SVal V = getArgSVal(Idx); 146 147 // If we are passing a location wrapped as an integer, unwrap it and 148 // invalidate the values referred by the location. 149 if (nonloc::LocAsInteger *Wrapped = dyn_cast<nonloc::LocAsInteger>(&V)) 150 V = Wrapped->getLoc(); 151 else if (!isa<Loc>(V)) 152 continue; 153 154 if (const MemRegion *R = V.getAsRegion()) { 155 // Invalidate the value of the variable passed by reference. 156 157 // Are we dealing with an ElementRegion? If the element type is 158 // a basic integer type (e.g., char, int) and the underlying region 159 // is a variable region then strip off the ElementRegion. 160 // FIXME: We really need to think about this for the general case 161 // as sometimes we are reasoning about arrays and other times 162 // about (char*), etc., is just a form of passing raw bytes. 163 // e.g., void *p = alloca(); foo((char*)p); 164 if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) { 165 // Checking for 'integral type' is probably too promiscuous, but 166 // we'll leave it in for now until we have a systematic way of 167 // handling all of these cases. Eventually we need to come up 168 // with an interface to StoreManager so that this logic can be 169 // appropriately delegated to the respective StoreManagers while 170 // still allowing us to do checker-specific logic (e.g., 171 // invalidating reference counts), probably via callbacks. 172 if (ER->getElementType()->isIntegralOrEnumerationType()) { 173 const MemRegion *superReg = ER->getSuperRegion(); 174 if (isa<VarRegion>(superReg) || isa<FieldRegion>(superReg) || 175 isa<ObjCIvarRegion>(superReg)) 176 R = cast<TypedRegion>(superReg); 177 } 178 // FIXME: What about layers of ElementRegions? 179 } 180 181 // Mark this region for invalidation. We batch invalidate regions 182 // below for efficiency. 183 RegionsToInvalidate.push_back(R); 184 } 185 } 186 187 // Invalidate designated regions using the batch invalidation API. 188 // NOTE: Even if RegionsToInvalidate is empty, we may still invalidate 189 // global variables. 190 return Result->invalidateRegions(RegionsToInvalidate, getOriginExpr(), 191 BlockCount, getLocationContext(), 192 /*Symbols=*/0, this); 193} 194 195ProgramPoint CallEvent::getProgramPoint(bool IsPreVisit, 196 const ProgramPointTag *Tag) const { 197 if (const Expr *E = getOriginExpr()) { 198 if (IsPreVisit) 199 return PreStmt(E, getLocationContext(), Tag); 200 return PostStmt(E, getLocationContext(), Tag); 201 } 202 203 const Decl *D = getDecl(); 204 assert(D && "Cannot get a program point without a statement or decl"); 205 206 SourceLocation Loc = getSourceRange().getBegin(); 207 if (IsPreVisit) 208 return PreImplicitCall(D, Loc, getLocationContext(), Tag); 209 return PostImplicitCall(D, Loc, getLocationContext(), Tag); 210} 211 212SVal CallEvent::getArgSVal(unsigned Index) const { 213 const Expr *ArgE = getArgExpr(Index); 214 if (!ArgE) 215 return UnknownVal(); 216 return getSVal(ArgE); 217} 218 219SourceRange CallEvent::getArgSourceRange(unsigned Index) const { 220 const Expr *ArgE = getArgExpr(Index); 221 if (!ArgE) 222 return SourceRange(); 223 return ArgE->getSourceRange(); 224} 225 226void CallEvent::dump() const { 227 dump(llvm::errs()); 228} 229 230void CallEvent::dump(raw_ostream &Out) const { 231 ASTContext &Ctx = getState()->getStateManager().getContext(); 232 if (const Expr *E = getOriginExpr()) { 233 E->printPretty(Out, 0, Ctx.getPrintingPolicy()); 234 Out << "\n"; 235 return; 236 } 237 238 if (const Decl *D = getDecl()) { 239 Out << "Call to "; 240 D->print(Out, Ctx.getPrintingPolicy()); 241 return; 242 } 243 244 // FIXME: a string representation of the kind would be nice. 245 Out << "Unknown call (type " << getKind() << ")"; 246} 247 248 249bool CallEvent::isCallStmt(const Stmt *S) { 250 return isa<CallExpr>(S) || isa<ObjCMessageExpr>(S) 251 || isa<CXXConstructExpr>(S) 252 || isa<CXXNewExpr>(S); 253} 254 255static void addParameterValuesToBindings(const StackFrameContext *CalleeCtx, 256 CallEvent::BindingsTy &Bindings, 257 SValBuilder &SVB, 258 const CallEvent &Call, 259 CallEvent::param_iterator I, 260 CallEvent::param_iterator E) { 261 MemRegionManager &MRMgr = SVB.getRegionManager(); 262 263 unsigned Idx = 0; 264 for (; I != E; ++I, ++Idx) { 265 const ParmVarDecl *ParamDecl = *I; 266 assert(ParamDecl && "Formal parameter has no decl?"); 267 268 SVal ArgVal = Call.getArgSVal(Idx); 269 if (!ArgVal.isUnknown()) { 270 Loc ParamLoc = SVB.makeLoc(MRMgr.getVarRegion(ParamDecl, CalleeCtx)); 271 Bindings.push_back(std::make_pair(ParamLoc, ArgVal)); 272 } 273 } 274 275 // FIXME: Variadic arguments are not handled at all right now. 276} 277 278 279CallEvent::param_iterator AnyFunctionCall::param_begin() const { 280 const FunctionDecl *D = getDecl(); 281 if (!D) 282 return 0; 283 284 return D->param_begin(); 285} 286 287CallEvent::param_iterator AnyFunctionCall::param_end() const { 288 const FunctionDecl *D = getDecl(); 289 if (!D) 290 return 0; 291 292 return D->param_end(); 293} 294 295void AnyFunctionCall::getInitialStackFrameContents( 296 const StackFrameContext *CalleeCtx, 297 BindingsTy &Bindings) const { 298 const FunctionDecl *D = cast<FunctionDecl>(CalleeCtx->getDecl()); 299 SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); 300 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, 301 D->param_begin(), D->param_end()); 302} 303 304bool AnyFunctionCall::argumentsMayEscape() const { 305 if (hasNonZeroCallbackArg()) 306 return true; 307 308 const FunctionDecl *D = getDecl(); 309 if (!D) 310 return true; 311 312 const IdentifierInfo *II = D->getIdentifier(); 313 if (!II) 314 return true; 315 316 // This set of "escaping" APIs is 317 318 // - 'int pthread_setspecific(ptheread_key k, const void *)' stores a 319 // value into thread local storage. The value can later be retrieved with 320 // 'void *ptheread_getspecific(pthread_key)'. So even thought the 321 // parameter is 'const void *', the region escapes through the call. 322 if (II->isStr("pthread_setspecific")) 323 return true; 324 325 // - xpc_connection_set_context stores a value which can be retrieved later 326 // with xpc_connection_get_context. 327 if (II->isStr("xpc_connection_set_context")) 328 return true; 329 330 // - funopen - sets a buffer for future IO calls. 331 if (II->isStr("funopen")) 332 return true; 333 334 StringRef FName = II->getName(); 335 336 // - CoreFoundation functions that end with "NoCopy" can free a passed-in 337 // buffer even if it is const. 338 if (FName.endswith("NoCopy")) 339 return true; 340 341 // - NSXXInsertXX, for example NSMapInsertIfAbsent, since they can 342 // be deallocated by NSMapRemove. 343 if (FName.startswith("NS") && (FName.find("Insert") != StringRef::npos)) 344 return true; 345 346 // - Many CF containers allow objects to escape through custom 347 // allocators/deallocators upon container construction. (PR12101) 348 if (FName.startswith("CF") || FName.startswith("CG")) { 349 return StrInStrNoCase(FName, "InsertValue") != StringRef::npos || 350 StrInStrNoCase(FName, "AddValue") != StringRef::npos || 351 StrInStrNoCase(FName, "SetValue") != StringRef::npos || 352 StrInStrNoCase(FName, "WithData") != StringRef::npos || 353 StrInStrNoCase(FName, "AppendValue") != StringRef::npos || 354 StrInStrNoCase(FName, "SetAttribute") != StringRef::npos; 355 } 356 357 return false; 358} 359 360 361const FunctionDecl *SimpleCall::getDecl() const { 362 const FunctionDecl *D = getOriginExpr()->getDirectCallee(); 363 if (D) 364 return D; 365 366 return getSVal(getOriginExpr()->getCallee()).getAsFunctionDecl(); 367} 368 369 370const FunctionDecl *CXXInstanceCall::getDecl() const { 371 const CallExpr *CE = cast_or_null<CallExpr>(getOriginExpr()); 372 if (!CE) 373 return AnyFunctionCall::getDecl(); 374 375 const FunctionDecl *D = CE->getDirectCallee(); 376 if (D) 377 return D; 378 379 return getSVal(CE->getCallee()).getAsFunctionDecl(); 380} 381 382void CXXInstanceCall::getExtraInvalidatedRegions(RegionList &Regions) const { 383 if (const MemRegion *R = getCXXThisVal().getAsRegion()) 384 Regions.push_back(R); 385} 386 387 388RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const { 389 // Do we have a decl at all? 390 const Decl *D = getDecl(); 391 if (!D) 392 return RuntimeDefinition(); 393 394 // If the method is non-virtual, we know we can inline it. 395 const CXXMethodDecl *MD = cast<CXXMethodDecl>(D); 396 if (!MD->isVirtual()) 397 return AnyFunctionCall::getRuntimeDefinition(); 398 399 // Do we know the implicit 'this' object being called? 400 const MemRegion *R = getCXXThisVal().getAsRegion(); 401 if (!R) 402 return RuntimeDefinition(); 403 404 // Do we know anything about the type of 'this'? 405 DynamicTypeInfo DynType = getState()->getDynamicTypeInfo(R); 406 if (!DynType.isValid()) 407 return RuntimeDefinition(); 408 409 // Is the type a C++ class? (This is mostly a defensive check.) 410 QualType RegionType = DynType.getType()->getPointeeType(); 411 assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer."); 412 413 const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl(); 414 if (!RD || !RD->hasDefinition()) 415 return RuntimeDefinition(); 416 417 // Find the decl for this method in that class. 418 const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true); 419 assert(Result && "At the very least the static decl should show up."); 420 421 // Does the decl that we found have an implementation? 422 const FunctionDecl *Definition; 423 if (!Result->hasBody(Definition)) 424 return RuntimeDefinition(); 425 426 // We found a definition. If we're not sure that this devirtualization is 427 // actually what will happen at runtime, make sure to provide the region so 428 // that ExprEngine can decide what to do with it. 429 if (DynType.canBeASubClass()) 430 return RuntimeDefinition(Definition, R->StripCasts()); 431 return RuntimeDefinition(Definition, /*DispatchRegion=*/0); 432} 433 434void CXXInstanceCall::getInitialStackFrameContents( 435 const StackFrameContext *CalleeCtx, 436 BindingsTy &Bindings) const { 437 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings); 438 439 // Handle the binding of 'this' in the new stack frame. 440 SVal ThisVal = getCXXThisVal(); 441 if (!ThisVal.isUnknown()) { 442 ProgramStateManager &StateMgr = getState()->getStateManager(); 443 SValBuilder &SVB = StateMgr.getSValBuilder(); 444 445 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl()); 446 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx); 447 448 // If we devirtualized to a different member function, we need to make sure 449 // we have the proper layering of CXXBaseObjectRegions. 450 if (MD->getCanonicalDecl() != getDecl()->getCanonicalDecl()) { 451 ASTContext &Ctx = SVB.getContext(); 452 const CXXRecordDecl *Class = MD->getParent(); 453 QualType Ty = Ctx.getPointerType(Ctx.getRecordType(Class)); 454 455 // FIXME: CallEvent maybe shouldn't be directly accessing StoreManager. 456 bool Failed; 457 ThisVal = StateMgr.getStoreManager().evalDynamicCast(ThisVal, Ty, Failed); 458 assert(!Failed && "Calling an incorrectly devirtualized method"); 459 } 460 461 if (!ThisVal.isUnknown()) 462 Bindings.push_back(std::make_pair(ThisLoc, ThisVal)); 463 } 464} 465 466 467 468const Expr *CXXMemberCall::getCXXThisExpr() const { 469 return getOriginExpr()->getImplicitObjectArgument(); 470} 471 472 473const Expr *CXXMemberOperatorCall::getCXXThisExpr() const { 474 return getOriginExpr()->getArg(0); 475} 476 477 478const BlockDataRegion *BlockCall::getBlockRegion() const { 479 const Expr *Callee = getOriginExpr()->getCallee(); 480 const MemRegion *DataReg = getSVal(Callee).getAsRegion(); 481 482 return dyn_cast_or_null<BlockDataRegion>(DataReg); 483} 484 485CallEvent::param_iterator BlockCall::param_begin() const { 486 const BlockDecl *D = getBlockDecl(); 487 if (!D) 488 return 0; 489 return D->param_begin(); 490} 491 492CallEvent::param_iterator BlockCall::param_end() const { 493 const BlockDecl *D = getBlockDecl(); 494 if (!D) 495 return 0; 496 return D->param_end(); 497} 498 499void BlockCall::getExtraInvalidatedRegions(RegionList &Regions) const { 500 // FIXME: This also needs to invalidate captured globals. 501 if (const MemRegion *R = getBlockRegion()) 502 Regions.push_back(R); 503} 504 505void BlockCall::getInitialStackFrameContents(const StackFrameContext *CalleeCtx, 506 BindingsTy &Bindings) const { 507 const BlockDecl *D = cast<BlockDecl>(CalleeCtx->getDecl()); 508 SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); 509 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, 510 D->param_begin(), D->param_end()); 511} 512 513 514SVal CXXConstructorCall::getCXXThisVal() const { 515 if (Data) 516 return loc::MemRegionVal(static_cast<const MemRegion *>(Data)); 517 return UnknownVal(); 518} 519 520void CXXConstructorCall::getExtraInvalidatedRegions(RegionList &Regions) const { 521 if (Data) 522 Regions.push_back(static_cast<const MemRegion *>(Data)); 523} 524 525void CXXConstructorCall::getInitialStackFrameContents( 526 const StackFrameContext *CalleeCtx, 527 BindingsTy &Bindings) const { 528 AnyFunctionCall::getInitialStackFrameContents(CalleeCtx, Bindings); 529 530 SVal ThisVal = getCXXThisVal(); 531 if (!ThisVal.isUnknown()) { 532 SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); 533 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CalleeCtx->getDecl()); 534 Loc ThisLoc = SVB.getCXXThis(MD, CalleeCtx); 535 Bindings.push_back(std::make_pair(ThisLoc, ThisVal)); 536 } 537} 538 539 540 541SVal CXXDestructorCall::getCXXThisVal() const { 542 if (Data) 543 return loc::MemRegionVal(static_cast<const MemRegion *>(Data)); 544 return UnknownVal(); 545} 546 547 548CallEvent::param_iterator ObjCMethodCall::param_begin() const { 549 const ObjCMethodDecl *D = getDecl(); 550 if (!D) 551 return 0; 552 553 return D->param_begin(); 554} 555 556CallEvent::param_iterator ObjCMethodCall::param_end() const { 557 const ObjCMethodDecl *D = getDecl(); 558 if (!D) 559 return 0; 560 561 return D->param_end(); 562} 563 564void 565ObjCMethodCall::getExtraInvalidatedRegions(RegionList &Regions) const { 566 if (const MemRegion *R = getReceiverSVal().getAsRegion()) 567 Regions.push_back(R); 568} 569 570SVal ObjCMethodCall::getSelfSVal() const { 571 const LocationContext *LCtx = getLocationContext(); 572 const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl(); 573 if (!SelfDecl) 574 return SVal(); 575 return getState()->getSVal(getState()->getRegion(SelfDecl, LCtx)); 576} 577 578SVal ObjCMethodCall::getReceiverSVal() const { 579 // FIXME: Is this the best way to handle class receivers? 580 if (!isInstanceMessage()) 581 return UnknownVal(); 582 583 if (const Expr *RecE = getOriginExpr()->getInstanceReceiver()) 584 return getSVal(RecE); 585 586 // An instance message with no expression means we are sending to super. 587 // In this case the object reference is the same as 'self'. 588 assert(getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance); 589 SVal SelfVal = getSelfSVal(); 590 assert(SelfVal.isValid() && "Calling super but not in ObjC method"); 591 return SelfVal; 592} 593 594bool ObjCMethodCall::isReceiverSelfOrSuper() const { 595 if (getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperInstance || 596 getOriginExpr()->getReceiverKind() == ObjCMessageExpr::SuperClass) 597 return true; 598 599 if (!isInstanceMessage()) 600 return false; 601 602 SVal RecVal = getSVal(getOriginExpr()->getInstanceReceiver()); 603 604 return (RecVal == getSelfSVal()); 605} 606 607SourceRange ObjCMethodCall::getSourceRange() const { 608 switch (getMessageKind()) { 609 case OCM_Message: 610 return getOriginExpr()->getSourceRange(); 611 case OCM_PropertyAccess: 612 case OCM_Subscript: 613 return getContainingPseudoObjectExpr()->getSourceRange(); 614 } 615 llvm_unreachable("unknown message kind"); 616} 617 618typedef llvm::PointerIntPair<const PseudoObjectExpr *, 2> ObjCMessageDataTy; 619 620const PseudoObjectExpr *ObjCMethodCall::getContainingPseudoObjectExpr() const { 621 assert(Data != 0 && "Lazy lookup not yet performed."); 622 assert(getMessageKind() != OCM_Message && "Explicit message send."); 623 return ObjCMessageDataTy::getFromOpaqueValue(Data).getPointer(); 624} 625 626ObjCMessageKind ObjCMethodCall::getMessageKind() const { 627 if (Data == 0) { 628 ParentMap &PM = getLocationContext()->getParentMap(); 629 const Stmt *S = PM.getParent(getOriginExpr()); 630 if (const PseudoObjectExpr *POE = dyn_cast_or_null<PseudoObjectExpr>(S)) { 631 const Expr *Syntactic = POE->getSyntacticForm(); 632 633 // This handles the funny case of assigning to the result of a getter. 634 // This can happen if the getter returns a non-const reference. 635 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(Syntactic)) 636 Syntactic = BO->getLHS(); 637 638 ObjCMessageKind K; 639 switch (Syntactic->getStmtClass()) { 640 case Stmt::ObjCPropertyRefExprClass: 641 K = OCM_PropertyAccess; 642 break; 643 case Stmt::ObjCSubscriptRefExprClass: 644 K = OCM_Subscript; 645 break; 646 default: 647 // FIXME: Can this ever happen? 648 K = OCM_Message; 649 break; 650 } 651 652 if (K != OCM_Message) { 653 const_cast<ObjCMethodCall *>(this)->Data 654 = ObjCMessageDataTy(POE, K).getOpaqueValue(); 655 assert(getMessageKind() == K); 656 return K; 657 } 658 } 659 660 const_cast<ObjCMethodCall *>(this)->Data 661 = ObjCMessageDataTy(0, 1).getOpaqueValue(); 662 assert(getMessageKind() == OCM_Message); 663 return OCM_Message; 664 } 665 666 ObjCMessageDataTy Info = ObjCMessageDataTy::getFromOpaqueValue(Data); 667 if (!Info.getPointer()) 668 return OCM_Message; 669 return static_cast<ObjCMessageKind>(Info.getInt()); 670} 671 672 673bool ObjCMethodCall::canBeOverridenInSubclass(ObjCInterfaceDecl *IDecl, 674 Selector Sel) const { 675 assert(IDecl); 676 const SourceManager &SM = 677 getState()->getStateManager().getContext().getSourceManager(); 678 679 // If the class interface is declared inside the main file, assume it is not 680 // subcassed. 681 // TODO: It could actually be subclassed if the subclass is private as well. 682 // This is probably very rare. 683 SourceLocation InterfLoc = IDecl->getEndOfDefinitionLoc(); 684 if (InterfLoc.isValid() && SM.isFromMainFile(InterfLoc)) 685 return false; 686 687 // Assume that property accessors are not overridden. 688 if (getMessageKind() == OCM_PropertyAccess) 689 return false; 690 691 // We assume that if the method is public (declared outside of main file) or 692 // has a parent which publicly declares the method, the method could be 693 // overridden in a subclass. 694 695 // Find the first declaration in the class hierarchy that declares 696 // the selector. 697 ObjCMethodDecl *D = 0; 698 while (true) { 699 D = IDecl->lookupMethod(Sel, true); 700 701 // Cannot find a public definition. 702 if (!D) 703 return false; 704 705 // If outside the main file, 706 if (D->getLocation().isValid() && !SM.isFromMainFile(D->getLocation())) 707 return true; 708 709 if (D->isOverriding()) { 710 // Search in the superclass on the next iteration. 711 IDecl = D->getClassInterface(); 712 if (!IDecl) 713 return false; 714 715 IDecl = IDecl->getSuperClass(); 716 if (!IDecl) 717 return false; 718 719 continue; 720 } 721 722 return false; 723 }; 724 725 llvm_unreachable("The while loop should always terminate."); 726} 727 728RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const { 729 const ObjCMessageExpr *E = getOriginExpr(); 730 assert(E); 731 Selector Sel = E->getSelector(); 732 733 if (E->isInstanceMessage()) { 734 735 // Find the the receiver type. 736 const ObjCObjectPointerType *ReceiverT = 0; 737 bool CanBeSubClassed = false; 738 QualType SupersType = E->getSuperType(); 739 const MemRegion *Receiver = 0; 740 741 if (!SupersType.isNull()) { 742 // Super always means the type of immediate predecessor to the method 743 // where the call occurs. 744 ReceiverT = cast<ObjCObjectPointerType>(SupersType); 745 } else { 746 Receiver = getReceiverSVal().getAsRegion(); 747 if (!Receiver) 748 return RuntimeDefinition(); 749 750 DynamicTypeInfo DTI = getState()->getDynamicTypeInfo(Receiver); 751 QualType DynType = DTI.getType(); 752 CanBeSubClassed = DTI.canBeASubClass(); 753 ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType); 754 755 if (ReceiverT && CanBeSubClassed) 756 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) 757 if (!canBeOverridenInSubclass(IDecl, Sel)) 758 CanBeSubClassed = false; 759 } 760 761 // Lookup the method implementation. 762 if (ReceiverT) 763 if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) { 764 const ObjCMethodDecl *MD = IDecl->lookupPrivateMethod(Sel); 765 if (CanBeSubClassed) 766 return RuntimeDefinition(MD, Receiver); 767 else 768 return RuntimeDefinition(MD, 0); 769 } 770 771 } else { 772 // This is a class method. 773 // If we have type info for the receiver class, we are calling via 774 // class name. 775 if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) { 776 // Find/Return the method implementation. 777 return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel)); 778 } 779 } 780 781 return RuntimeDefinition(); 782} 783 784void ObjCMethodCall::getInitialStackFrameContents( 785 const StackFrameContext *CalleeCtx, 786 BindingsTy &Bindings) const { 787 const ObjCMethodDecl *D = cast<ObjCMethodDecl>(CalleeCtx->getDecl()); 788 SValBuilder &SVB = getState()->getStateManager().getSValBuilder(); 789 addParameterValuesToBindings(CalleeCtx, Bindings, SVB, *this, 790 D->param_begin(), D->param_end()); 791 792 SVal SelfVal = getReceiverSVal(); 793 if (!SelfVal.isUnknown()) { 794 const VarDecl *SelfD = CalleeCtx->getAnalysisDeclContext()->getSelfDecl(); 795 MemRegionManager &MRMgr = SVB.getRegionManager(); 796 Loc SelfLoc = SVB.makeLoc(MRMgr.getVarRegion(SelfD, CalleeCtx)); 797 Bindings.push_back(std::make_pair(SelfLoc, SelfVal)); 798 } 799} 800 801CallEventRef<> 802CallEventManager::getSimpleCall(const CallExpr *CE, ProgramStateRef State, 803 const LocationContext *LCtx) { 804 if (const CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(CE)) 805 return create<CXXMemberCall>(MCE, State, LCtx); 806 807 if (const CXXOperatorCallExpr *OpCE = dyn_cast<CXXOperatorCallExpr>(CE)) { 808 const FunctionDecl *DirectCallee = OpCE->getDirectCallee(); 809 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DirectCallee)) 810 if (MD->isInstance()) 811 return create<CXXMemberOperatorCall>(OpCE, State, LCtx); 812 813 } else if (CE->getCallee()->getType()->isBlockPointerType()) { 814 return create<BlockCall>(CE, State, LCtx); 815 } 816 817 // Otherwise, it's a normal function call, static member function call, or 818 // something we can't reason about. 819 return create<FunctionCall>(CE, State, LCtx); 820} 821 822 823CallEventRef<> 824CallEventManager::getCaller(const StackFrameContext *CalleeCtx, 825 ProgramStateRef State) { 826 const LocationContext *ParentCtx = CalleeCtx->getParent(); 827 const LocationContext *CallerCtx = ParentCtx->getCurrentStackFrame(); 828 assert(CallerCtx && "This should not be used for top-level stack frames"); 829 830 const Stmt *CallSite = CalleeCtx->getCallSite(); 831 832 if (CallSite) { 833 if (const CallExpr *CE = dyn_cast<CallExpr>(CallSite)) 834 return getSimpleCall(CE, State, CallerCtx); 835 836 switch (CallSite->getStmtClass()) { 837 case Stmt::CXXConstructExprClass: 838 case Stmt::CXXTemporaryObjectExprClass: { 839 SValBuilder &SVB = State->getStateManager().getSValBuilder(); 840 const CXXMethodDecl *Ctor = cast<CXXMethodDecl>(CalleeCtx->getDecl()); 841 Loc ThisPtr = SVB.getCXXThis(Ctor, CalleeCtx); 842 SVal ThisVal = State->getSVal(ThisPtr); 843 844 return getCXXConstructorCall(cast<CXXConstructExpr>(CallSite), 845 ThisVal.getAsRegion(), State, CallerCtx); 846 } 847 case Stmt::CXXNewExprClass: 848 return getCXXAllocatorCall(cast<CXXNewExpr>(CallSite), State, CallerCtx); 849 case Stmt::ObjCMessageExprClass: 850 return getObjCMethodCall(cast<ObjCMessageExpr>(CallSite), 851 State, CallerCtx); 852 default: 853 llvm_unreachable("This is not an inlineable statement."); 854 } 855 } 856 857 // Fall back to the CFG. The only thing we haven't handled yet is 858 // destructors, though this could change in the future. 859 const CFGBlock *B = CalleeCtx->getCallSiteBlock(); 860 CFGElement E = (*B)[CalleeCtx->getIndex()]; 861 assert(isa<CFGImplicitDtor>(E) && "All other CFG elements should have exprs"); 862 assert(!isa<CFGTemporaryDtor>(E) && "We don't handle temporaries yet"); 863 864 SValBuilder &SVB = State->getStateManager().getSValBuilder(); 865 const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CalleeCtx->getDecl()); 866 Loc ThisPtr = SVB.getCXXThis(Dtor, CalleeCtx); 867 SVal ThisVal = State->getSVal(ThisPtr); 868 869 const Stmt *Trigger; 870 if (const CFGAutomaticObjDtor *AutoDtor = dyn_cast<CFGAutomaticObjDtor>(&E)) 871 Trigger = AutoDtor->getTriggerStmt(); 872 else 873 Trigger = Dtor->getBody(); 874 875 return getCXXDestructorCall(Dtor, Trigger, ThisVal.getAsRegion(), 876 State, CallerCtx); 877} 878