CallAndMessageChecker.cpp revision e172e8b9e7fc67d7d03589af7e92fe777afcf33a
1e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber//===--- CallAndMessageChecker.cpp ------------------------------*- C++ -*--==// 2e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// 3e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// The LLVM Compiler Infrastructure 4e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// 5e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// This file is distributed under the University of Illinois Open Source 6e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// License. See LICENSE.TXT for details. 7e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// 8e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber//===----------------------------------------------------------------------===// 9e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// 10e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// This defines CallAndMessageChecker, a builtin checker that checks for various 11e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// errors of call and objc message expressions. 12e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber// 13e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber//===----------------------------------------------------------------------===// 14e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 15e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber#include "ClangSACheckers.h" 16e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber#include "clang/StaticAnalyzer/Core/Checker.h" 17a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn#include "clang/StaticAnalyzer/Core/CheckerManager.h" 18a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" 19a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 20a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn#include "clang/AST/ParentMap.h" 21a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn#include "clang/Basic/TargetInfo.h" 22a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn 23f1d5aa162c02a16b7195a43a9bcea4d592600ac4James Dongusing namespace clang; 24e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huberusing namespace ento; 25e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 26e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Hubernamespace { 27e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huberclass CallAndMessageChecker 28e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber : public Checker< check::PreStmt<CallExpr>, check::PreObjCMessage > { 29e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber mutable llvm::OwningPtr<BugType> BT_call_null; 30d599cd4573b5a2d5914c5040e0565ef866749b77James Dong mutable llvm::OwningPtr<BugType> BT_call_undef; 31e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber mutable llvm::OwningPtr<BugType> BT_call_arg; 32e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber mutable llvm::OwningPtr<BugType> BT_msg_undef; 33e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber mutable llvm::OwningPtr<BugType> BT_msg_arg; 34e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber mutable llvm::OwningPtr<BugType> BT_msg_ret; 35674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dongpublic: 36674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong 37a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong void checkPreStmt(const CallExpr *CE, CheckerContext &C) const; 38a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong void checkPreObjCMessage(ObjCMessage msg, CheckerContext &C) const; 39a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 40674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dongprivate: 41af8e8aa1ada2948972555592570ec9ad90cbf372Nick Kralevich static void PreVisitProcessArgs(CheckerContext &C,CallOrObjCMessage callOrMsg, 42674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong const char *BT_desc, llvm::OwningPtr<BugType> &BT); 43674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong static bool PreVisitProcessArg(CheckerContext &C, SVal V,SourceRange argRange, 44674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong const Expr *argEx, const char *BT_desc, llvm::OwningPtr<BugType> &BT); 45e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 46e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber static void EmitBadCall(BugType *BT, CheckerContext &C, const CallExpr *CE); 47e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber void emitNilReceiverBug(CheckerContext &C, const ObjCMessage &msg, 48674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong ExplodedNode *N) const; 49674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong 50a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong void HandleNilReceiver(CheckerContext &C, 51a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong const ProgramState *state, 52a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong ObjCMessage msg) const; 53e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 54e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber static void LazyInit_BT(const char *desc, llvm::OwningPtr<BugType> &BT) { 55e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (!BT) 56e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BT.reset(new BuiltinBug(desc)); 578bcc65c753085fe3328592cceda0cf0e8f8b0a45James Dong } 58e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber}; 59e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber} // end anonymous namespace 60674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong 61674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dongvoid CallAndMessageChecker::EmitBadCall(BugType *BT, CheckerContext &C, 62674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong const CallExpr *CE) { 63e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber ExplodedNode *N = C.generateSink(); 64e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (!N) 65e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return; 66e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 67e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BugReport *R = new BugReport(*BT, BT->getName(), N); 68e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, 69e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber bugreporter::GetCalleeExpr(N)); 70e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber C.EmitReport(R); 71e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber} 72e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 73e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Hubervoid CallAndMessageChecker::PreVisitProcessArgs(CheckerContext &C, 74e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber CallOrObjCMessage callOrMsg, 75e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const char *BT_desc, 76e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber llvm::OwningPtr<BugType> &BT) { 77e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber for (unsigned i = 0, e = callOrMsg.getNumArgs(); i != e; ++i) 78e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (PreVisitProcessArg(C, callOrMsg.getArgSVal(i), 79e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber callOrMsg.getArgSourceRange(i), callOrMsg.getArg(i), 80e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BT_desc, BT)) 81e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return; 82e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber} 83e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 84e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huberbool CallAndMessageChecker::PreVisitProcessArg(CheckerContext &C, 85e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber SVal V, SourceRange argRange, 86e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const Expr *argEx, 87e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const char *BT_desc, 88e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber llvm::OwningPtr<BugType> &BT) { 89e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 90e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (V.isUndef()) { 91e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (ExplodedNode *N = C.generateSink()) { 92e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber LazyInit_BT(BT_desc, BT); 93e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 94e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber // Generate a report for this bug. 95e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BugReport *R = new BugReport(*BT, BT->getName(), N); 96e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber R->addRange(argRange); 97e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (argEx) 98e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, argEx); 99e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber C.EmitReport(R); 100e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber } 101e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return true; 102674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong } 103c7fc37a3dab9bd1f96713649f351b5990e6316ffJames Dong 104e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (const nonloc::LazyCompoundVal *LV = 105e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber dyn_cast<nonloc::LazyCompoundVal>(&V)) { 106e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 107e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber class FindUninitializedField { 108e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber public: 109e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber SmallVector<const FieldDecl *, 10> FieldChain; 11084333e0475bc911adc16417f4ca327c975cf6c36Andreas Huber private: 111e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber ASTContext &C; 112e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber StoreManager &StoreMgr; 113e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber MemRegionManager &MrMgr; 114e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber Store store; 115a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong public: 116e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber FindUninitializedField(ASTContext &c, StoreManager &storeMgr, 117e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber MemRegionManager &mrMgr, Store s) 118e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber : C(c), StoreMgr(storeMgr), MrMgr(mrMgr), store(s) {} 119a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 120a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong bool Find(const TypedValueRegion *R) { 121a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong QualType T = R->getValueType(); 122a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong if (const RecordType *RT = T->getAsStructureType()) { 123a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong const RecordDecl *RD = RT->getDecl()->getDefinition(); 124a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong assert(RD && "Referred record has no definition"); 125a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong for (RecordDecl::field_iterator I = 126a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong RD->field_begin(), E = RD->field_end(); I!=E; ++I) { 127a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong const FieldRegion *FR = MrMgr.getFieldRegion(*I, R); 128e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber FieldChain.push_back(*I); 129e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber T = (*I)->getType(); 130e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (T->getAsStructureType()) { 131e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (Find(FR)) 132e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return true; 133e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber } 134e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber else { 135e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const SVal &V = StoreMgr.Retrieve(store, loc::MemRegionVal(FR)); 136e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (V.isUndef()) 137e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return true; 1382dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber } 139e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber FieldChain.pop_back(); 140e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber } 141e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber } 142e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 143e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber return false; 144e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber } 145e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber }; 146e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 147e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const LazyCompoundValData *D = LV->getCVData(); 148e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber FindUninitializedField F(C.getASTContext(), 14937187916a486504acaf83bea30147eb5fbf46ae5James Dong C.getState()->getStateManager().getStoreManager(), 150a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong C.getSValBuilder().getRegionManager(), 15137187916a486504acaf83bea30147eb5fbf46ae5James Dong D->getStore()); 152a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 153a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong if (F.Find(D->getRegion())) { 15437187916a486504acaf83bea30147eb5fbf46ae5James Dong if (ExplodedNode *N = C.generateSink()) { 155a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong LazyInit_BT(BT_desc, BT); 156a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong llvm::SmallString<512> Str; 1578bcc65c753085fe3328592cceda0cf0e8f8b0a45James Dong llvm::raw_svector_ostream os(Str); 158ebe87f32e442c9a8fb2931632311d6c5a126eddbAndreas Huber os << "Passed-by-value struct argument contains uninitialized data"; 15937187916a486504acaf83bea30147eb5fbf46ae5James Dong 160e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (F.FieldChain.size() == 1) 161e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber os << " (e.g., field: '" << F.FieldChain[0] << "')"; 162ebe87f32e442c9a8fb2931632311d6c5a126eddbAndreas Huber else { 163ebe87f32e442c9a8fb2931632311d6c5a126eddbAndreas Huber os << " (e.g., via the field chain: '"; 164e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber bool first = true; 165e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber for (SmallVectorImpl<const FieldDecl *>::iterator 166e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber DI = F.FieldChain.begin(), DE = F.FieldChain.end(); DI!=DE;++DI){ 167377b2ec9a2885f9b6405b07ba900a9e3f4349c38Kévin PETIT if (first) 16837187916a486504acaf83bea30147eb5fbf46ae5James Dong first = false; 16937187916a486504acaf83bea30147eb5fbf46ae5James Dong else 17037187916a486504acaf83bea30147eb5fbf46ae5James Dong os << '.'; 17137187916a486504acaf83bea30147eb5fbf46ae5James Dong os << *DI; 17237187916a486504acaf83bea30147eb5fbf46ae5James Dong } 17337187916a486504acaf83bea30147eb5fbf46ae5James Dong os << "')"; 17437187916a486504acaf83bea30147eb5fbf46ae5James Dong } 175e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 176e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber // Generate a report for this bug. 17737187916a486504acaf83bea30147eb5fbf46ae5James Dong BugReport *R = new BugReport(*BT, os.str(), N); 178e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber R->addRange(argRange); 179e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 180d599cd4573b5a2d5914c5040e0565ef866749b77James Dong // FIXME: enhance track back for uninitialized value for arbitrary 181d599cd4573b5a2d5914c5040e0565ef866749b77James Dong // memregions 182d599cd4573b5a2d5914c5040e0565ef866749b77James Dong C.EmitReport(R); 183d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 184d599cd4573b5a2d5914c5040e0565ef866749b77James Dong return true; 185d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 186d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 187d599cd4573b5a2d5914c5040e0565ef866749b77James Dong 188d599cd4573b5a2d5914c5040e0565ef866749b77James Dong return false; 189d599cd4573b5a2d5914c5040e0565ef866749b77James Dong} 190d599cd4573b5a2d5914c5040e0565ef866749b77James Dong 191d599cd4573b5a2d5914c5040e0565ef866749b77James Dongvoid CallAndMessageChecker::checkPreStmt(const CallExpr *CE, 192d599cd4573b5a2d5914c5040e0565ef866749b77James Dong CheckerContext &C) const{ 193d599cd4573b5a2d5914c5040e0565ef866749b77James Dong 194e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const Expr *Callee = CE->getCallee()->IgnoreParens(); 195e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber SVal L = C.getState()->getSVal(Callee); 196377b2ec9a2885f9b6405b07ba900a9e3f4349c38Kévin PETIT 197e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (L.isUndef()) { 198e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (!BT_call_undef) 19937187916a486504acaf83bea30147eb5fbf46ae5James Dong BT_call_undef.reset(new BuiltinBug("Called function pointer is an " 200d599cd4573b5a2d5914c5040e0565ef866749b77James Dong "uninitalized pointer value")); 201d599cd4573b5a2d5914c5040e0565ef866749b77James Dong EmitBadCall(BT_call_undef.get(), C, CE); 202f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong return; 203a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong } 204a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 20537187916a486504acaf83bea30147eb5fbf46ae5James Dong if (isa<loc::ConcreteInt>(L)) { 206a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong if (!BT_call_null) 207a6f61fc8e3d06373c17f0a38ff600e2b71c414faJames Dong BT_call_null.reset( 208ebe87f32e442c9a8fb2931632311d6c5a126eddbAndreas Huber new BuiltinBug("Called function pointer is null (null dereference)")); 209e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber EmitBadCall(BT_call_null.get(), C, CE); 21037187916a486504acaf83bea30147eb5fbf46ae5James Dong } 211e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 212e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber PreVisitProcessArgs(C, CallOrObjCMessage(CE, C.getState()), 213e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber "Function call argument is an uninitialized value", 214e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BT_call_arg); 215e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber} 216a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 217a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dongvoid CallAndMessageChecker::checkPreObjCMessage(ObjCMessage msg, 218a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong CheckerContext &C) const { 219a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 220a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong const ProgramState *state = C.getState(); 221a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 222d599cd4573b5a2d5914c5040e0565ef866749b77James Dong // FIXME: Handle 'super'? 223d599cd4573b5a2d5914c5040e0565ef866749b77James Dong if (const Expr *receiver = msg.getInstanceReceiver()) { 224d599cd4573b5a2d5914c5040e0565ef866749b77James Dong SVal recVal = state->getSVal(receiver); 225d599cd4573b5a2d5914c5040e0565ef866749b77James Dong if (recVal.isUndef()) { 226d599cd4573b5a2d5914c5040e0565ef866749b77James Dong if (ExplodedNode *N = C.generateSink()) { 227d599cd4573b5a2d5914c5040e0565ef866749b77James Dong if (!BT_msg_undef) 228d599cd4573b5a2d5914c5040e0565ef866749b77James Dong BT_msg_undef.reset(new BuiltinBug("Receiver in message expression is " 229d599cd4573b5a2d5914c5040e0565ef866749b77James Dong "an uninitialized value")); 230d599cd4573b5a2d5914c5040e0565ef866749b77James Dong BugReport *R = 231d599cd4573b5a2d5914c5040e0565ef866749b77James Dong new BugReport(*BT_msg_undef, BT_msg_undef->getName(), N); 232d599cd4573b5a2d5914c5040e0565ef866749b77James Dong R->addRange(receiver->getSourceRange()); 233d599cd4573b5a2d5914c5040e0565ef866749b77James Dong R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, 234d599cd4573b5a2d5914c5040e0565ef866749b77James Dong receiver); 235a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong C.EmitReport(R); 236a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong } 237a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong return; 238a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong } else { 239a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong // Bifurcate the state into nil and non-nil ones. 240a5750e0dad9e90f2195ce36f2c4457fa04b2b83eMark Salyzyn DefinedOrUnknownSVal receiverVal = cast<DefinedOrUnknownSVal>(recVal); 241a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 242a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong const ProgramState *notNilState, *nilState; 243a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong llvm::tie(notNilState, nilState) = state->assume(receiverVal); 244a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong 245a7d1a2dd776bf356c228785a94ba8e0ff6a2ec7fJames Dong // Handle receiver must be nil. 246d599cd4573b5a2d5914c5040e0565ef866749b77James Dong if (nilState && !notNilState) { 247d599cd4573b5a2d5914c5040e0565ef866749b77James Dong HandleNilReceiver(C, state, msg); 248d599cd4573b5a2d5914c5040e0565ef866749b77James Dong return; 249d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 250d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 251d599cd4573b5a2d5914c5040e0565ef866749b77James Dong } 252c7fc37a3dab9bd1f96713649f351b5990e6316ffJames Dong 253c7fc37a3dab9bd1f96713649f351b5990e6316ffJames Dong const char *bugDesc = msg.isPropertySetter() ? 254c7fc37a3dab9bd1f96713649f351b5990e6316ffJames Dong "Argument for property setter is an uninitialized value" 255e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber : "Argument in message expression is an uninitialized value"; 256e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber // Check for any arguments that are uninitialized/undefined. 257b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber PreVisitProcessArgs(C, CallOrObjCMessage(msg, state), bugDesc, BT_msg_arg); 258b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber} 259fa514f007bd144eb99cdd68f2fe5302a4508db28James Dong 260fa514f007bd144eb99cdd68f2fe5302a4508db28James Dongvoid CallAndMessageChecker::emitNilReceiverBug(CheckerContext &C, 261fa514f007bd144eb99cdd68f2fe5302a4508db28James Dong const ObjCMessage &msg, 262b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber ExplodedNode *N) const { 263fa514f007bd144eb99cdd68f2fe5302a4508db28James Dong 264e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber if (!BT_msg_ret) 265e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber BT_msg_ret.reset( 266b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber new BuiltinBug("Receiver in message expression is " 267f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong "'nil' and returns a garbage value")); 268f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong 269f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong llvm::SmallString<200> buf; 270f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong llvm::raw_svector_ostream os(buf); 271b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber os << "The receiver of message '" << msg.getSelector().getAsString() 272b45c62c8e9b05c2703bdae18cc298ae55550db8aAndreas Huber << "' is nil and returns a value of type '" 273e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber << msg.getType(C.getASTContext()).getAsString() << "' that will be garbage"; 2742dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber 275fa514f007bd144eb99cdd68f2fe5302a4508db28James Dong BugReport *report = new BugReport(*BT_msg_ret, os.str(), N); 276fa514f007bd144eb99cdd68f2fe5302a4508db28James Dong if (const Expr *receiver = msg.getInstanceReceiver()) { 277f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong report->addRange(receiver->getSourceRange()); 278f0ce2fb0c7bf3a414279e5aba61105f3d9025c0eJames Dong report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, 279674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong receiver); 280674ebd0b4e1143e38392a4e3bb38b4679a4577bcJames Dong } 2812dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber C.EmitReport(report); 28237187916a486504acaf83bea30147eb5fbf46ae5James Dong} 28337187916a486504acaf83bea30147eb5fbf46ae5James Dong 28437187916a486504acaf83bea30147eb5fbf46ae5James Dongstatic bool supportsNilWithFloatRet(const llvm::Triple &triple) { 28537187916a486504acaf83bea30147eb5fbf46ae5James Dong return triple.getVendor() == llvm::Triple::Apple && 2862dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber (!triple.isMacOSXVersionLT(10,5) || 2872dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber triple.getArch() == llvm::Triple::arm || 2882dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber triple.getArch() == llvm::Triple::thumb); 2892dce41ad26cb3e9e15c9e456a84bcf5309548ca0Andreas Huber} 290e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber 291e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Hubervoid CallAndMessageChecker::HandleNilReceiver(CheckerContext &C, 292e7c9cb48fec02697227bd847cd2e69432659adfdAndreas Huber const ProgramState *state, 293 ObjCMessage msg) const { 294 ASTContext &Ctx = C.getASTContext(); 295 296 // Check the return type of the message expression. A message to nil will 297 // return different values depending on the return type and the architecture. 298 QualType RetTy = msg.getType(Ctx); 299 300 CanQualType CanRetTy = Ctx.getCanonicalType(RetTy); 301 302 if (CanRetTy->isStructureOrClassType()) { 303 // FIXME: At some point we shouldn't rely on isConsumedExpr(), but instead 304 // have the "use of undefined value" be smarter about where the 305 // undefined value came from. 306 if (C.getPredecessor()->getParentMap().isConsumedExpr(msg.getOriginExpr())){ 307 if (ExplodedNode *N = C.generateSink(state)) 308 emitNilReceiverBug(C, msg, N); 309 return; 310 } 311 312 // The result is not consumed by a surrounding expression. Just propagate 313 // the current state. 314 C.addTransition(state); 315 return; 316 } 317 318 // Other cases: check if the return type is smaller than void*. 319 if (CanRetTy != Ctx.VoidTy && 320 C.getPredecessor()->getParentMap().isConsumedExpr(msg.getOriginExpr())) { 321 // Compute: sizeof(void *) and sizeof(return type) 322 const uint64_t voidPtrSize = Ctx.getTypeSize(Ctx.VoidPtrTy); 323 const uint64_t returnTypeSize = Ctx.getTypeSize(CanRetTy); 324 325 if (voidPtrSize < returnTypeSize && 326 !(supportsNilWithFloatRet(Ctx.Target.getTriple()) && 327 (Ctx.FloatTy == CanRetTy || 328 Ctx.DoubleTy == CanRetTy || 329 Ctx.LongDoubleTy == CanRetTy || 330 Ctx.LongLongTy == CanRetTy || 331 Ctx.UnsignedLongLongTy == CanRetTy))) { 332 if (ExplodedNode *N = C.generateSink(state)) 333 emitNilReceiverBug(C, msg, N); 334 return; 335 } 336 337 // Handle the safe cases where the return value is 0 if the 338 // receiver is nil. 339 // 340 // FIXME: For now take the conservative approach that we only 341 // return null values if we *know* that the receiver is nil. 342 // This is because we can have surprises like: 343 // 344 // ... = [[NSScreens screens] objectAtIndex:0]; 345 // 346 // What can happen is that [... screens] could return nil, but 347 // it most likely isn't nil. We should assume the semantics 348 // of this case unless we have *a lot* more knowledge. 349 // 350 SVal V = C.getSValBuilder().makeZeroVal(msg.getType(Ctx)); 351 C.generateNode(state->BindExpr(msg.getOriginExpr(), V)); 352 return; 353 } 354 355 C.addTransition(state); 356} 357 358void ento::registerCallAndMessageChecker(CheckerManager &mgr) { 359 mgr.registerChecker<CallAndMessageChecker>(); 360} 361