Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 1 | //===--- CallAndMessageChecker.cpp ------------------------------*- C++ -*--==// |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 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 | // |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 10 | // This defines CallAndMessageChecker, a builtin checker that checks for various |
| 11 | // errors of call and objc message expressions. |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
Argyrios Kyrtzidis | d2592a3 | 2010-12-22 18:53:44 +0000 | [diff] [blame^] | 15 | #include "ExprEngineInternalChecks.h" |
Benjamin Kramer | 5e2d2c2 | 2010-03-27 21:19:47 +0000 | [diff] [blame] | 16 | #include "clang/AST/ParentMap.h" |
| 17 | #include "clang/Basic/TargetInfo.h" |
Argyrios Kyrtzidis | 98cabba | 2010-12-22 18:51:49 +0000 | [diff] [blame] | 18 | #include "clang/GR/BugReporter/BugType.h" |
| 19 | #include "clang/GR/PathSensitive/CheckerVisitor.h" |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 20 | |
| 21 | using namespace clang; |
Argyrios Kyrtzidis | 5a4f98f | 2010-12-22 18:53:20 +0000 | [diff] [blame] | 22 | using namespace GR; |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 23 | |
Ted Kremenek | f493f49 | 2009-11-11 05:50:44 +0000 | [diff] [blame] | 24 | namespace { |
Kovarththanan Rajaratnam | ba5fb5a | 2009-11-28 06:07:30 +0000 | [diff] [blame] | 25 | class CallAndMessageChecker |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 26 | : public CheckerVisitor<CallAndMessageChecker> { |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 27 | BugType *BT_call_null; |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 28 | BugType *BT_call_undef; |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 29 | BugType *BT_call_arg; |
| 30 | BugType *BT_msg_undef; |
| 31 | BugType *BT_msg_arg; |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 32 | BugType *BT_msg_ret; |
Ted Kremenek | f493f49 | 2009-11-11 05:50:44 +0000 | [diff] [blame] | 33 | public: |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 34 | CallAndMessageChecker() : |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 35 | BT_call_null(0), BT_call_undef(0), BT_call_arg(0), |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 36 | BT_msg_undef(0), BT_msg_arg(0), BT_msg_ret(0) {} |
Zhongxing Xu | 2055eff | 2009-11-24 07:06:39 +0000 | [diff] [blame] | 37 | |
Ted Kremenek | f493f49 | 2009-11-11 05:50:44 +0000 | [diff] [blame] | 38 | static void *getTag() { |
| 39 | static int x = 0; |
| 40 | return &x; |
| 41 | } |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 42 | |
Ted Kremenek | f493f49 | 2009-11-11 05:50:44 +0000 | [diff] [blame] | 43 | void PreVisitCallExpr(CheckerContext &C, const CallExpr *CE); |
Ted Kremenek | 64fa858 | 2009-11-21 00:49:41 +0000 | [diff] [blame] | 44 | void PreVisitObjCMessageExpr(CheckerContext &C, const ObjCMessageExpr *ME); |
Ted Kremenek | 9c14953 | 2010-12-01 21:57:22 +0000 | [diff] [blame] | 45 | bool evalNilReceiver(CheckerContext &C, const ObjCMessageExpr *ME); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 46 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 47 | private: |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 48 | bool PreVisitProcessArg(CheckerContext &C, const Expr *Ex, |
| 49 | const char *BT_desc, BugType *&BT); |
| 50 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 51 | void EmitBadCall(BugType *BT, CheckerContext &C, const CallExpr *CE); |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 52 | void emitNilReceiverBug(CheckerContext &C, const ObjCMessageExpr *ME, |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 53 | ExplodedNode *N); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 54 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 55 | void HandleNilReceiver(CheckerContext &C, const GRState *state, |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 56 | const ObjCMessageExpr *ME); |
| 57 | |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 58 | void LazyInit_BT(const char *desc, BugType *&BT) { |
| 59 | if (!BT) |
| 60 | BT = new BuiltinBug(desc); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 61 | } |
Ted Kremenek | f493f49 | 2009-11-11 05:50:44 +0000 | [diff] [blame] | 62 | }; |
| 63 | } // end anonymous namespace |
| 64 | |
Argyrios Kyrtzidis | d2592a3 | 2010-12-22 18:53:44 +0000 | [diff] [blame^] | 65 | void GR::RegisterCallAndMessageChecker(ExprEngine &Eng) { |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 66 | Eng.registerCheck(new CallAndMessageChecker()); |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 67 | } |
| 68 | |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 69 | void CallAndMessageChecker::EmitBadCall(BugType *BT, CheckerContext &C, |
| 70 | const CallExpr *CE) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 71 | ExplodedNode *N = C.generateSink(); |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 72 | if (!N) |
| 73 | return; |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 74 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 75 | EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N); |
| 76 | R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, |
| 77 | bugreporter::GetCalleeExpr(N)); |
| 78 | C.EmitReport(R); |
| 79 | } |
| 80 | |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 81 | bool CallAndMessageChecker::PreVisitProcessArg(CheckerContext &C, |
| 82 | const Expr *Ex, |
| 83 | const char *BT_desc, |
| 84 | BugType *&BT) { |
| 85 | |
| 86 | const SVal &V = C.getState()->getSVal(Ex); |
| 87 | |
| 88 | if (V.isUndef()) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 89 | if (ExplodedNode *N = C.generateSink()) { |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 90 | LazyInit_BT(BT_desc, BT); |
| 91 | |
| 92 | // Generate a report for this bug. |
| 93 | EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N); |
| 94 | R->addRange(Ex->getSourceRange()); |
| 95 | R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex); |
| 96 | C.EmitReport(R); |
| 97 | } |
| 98 | return true; |
| 99 | } |
| 100 | |
| 101 | if (const nonloc::LazyCompoundVal *LV = |
| 102 | dyn_cast<nonloc::LazyCompoundVal>(&V)) { |
| 103 | |
| 104 | class FindUninitializedField { |
| 105 | public: |
| 106 | llvm::SmallVector<const FieldDecl *, 10> FieldChain; |
| 107 | private: |
| 108 | ASTContext &C; |
| 109 | StoreManager &StoreMgr; |
| 110 | MemRegionManager &MrMgr; |
| 111 | Store store; |
| 112 | public: |
| 113 | FindUninitializedField(ASTContext &c, StoreManager &storeMgr, |
| 114 | MemRegionManager &mrMgr, Store s) |
| 115 | : C(c), StoreMgr(storeMgr), MrMgr(mrMgr), store(s) {} |
| 116 | |
| 117 | bool Find(const TypedRegion *R) { |
Zhongxing Xu | 018220c | 2010-08-11 06:10:55 +0000 | [diff] [blame] | 118 | QualType T = R->getValueType(); |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 119 | if (const RecordType *RT = T->getAsStructureType()) { |
| 120 | const RecordDecl *RD = RT->getDecl()->getDefinition(); |
| 121 | assert(RD && "Referred record has no definition"); |
| 122 | for (RecordDecl::field_iterator I = |
| 123 | RD->field_begin(), E = RD->field_end(); I!=E; ++I) { |
| 124 | const FieldRegion *FR = MrMgr.getFieldRegion(*I, R); |
| 125 | FieldChain.push_back(*I); |
| 126 | T = (*I)->getType(); |
| 127 | if (T->getAsStructureType()) { |
| 128 | if (Find(FR)) |
| 129 | return true; |
| 130 | } |
| 131 | else { |
| 132 | const SVal &V = StoreMgr.Retrieve(store, loc::MemRegionVal(FR)); |
| 133 | if (V.isUndef()) |
| 134 | return true; |
| 135 | } |
| 136 | FieldChain.pop_back(); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | return false; |
| 141 | } |
| 142 | }; |
| 143 | |
| 144 | const LazyCompoundValData *D = LV->getCVData(); |
| 145 | FindUninitializedField F(C.getASTContext(), |
| 146 | C.getState()->getStateManager().getStoreManager(), |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 147 | C.getSValBuilder().getRegionManager(), |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 148 | D->getStore()); |
| 149 | |
| 150 | if (F.Find(D->getRegion())) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 151 | if (ExplodedNode *N = C.generateSink()) { |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 152 | LazyInit_BT(BT_desc, BT); |
| 153 | llvm::SmallString<512> Str; |
| 154 | llvm::raw_svector_ostream os(Str); |
| 155 | os << "Passed-by-value struct argument contains uninitialized data"; |
| 156 | |
| 157 | if (F.FieldChain.size() == 1) |
Benjamin Kramer | 900fc63 | 2010-04-17 09:33:03 +0000 | [diff] [blame] | 158 | os << " (e.g., field: '" << F.FieldChain[0] << "')"; |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 159 | else { |
| 160 | os << " (e.g., via the field chain: '"; |
| 161 | bool first = true; |
| 162 | for (llvm::SmallVectorImpl<const FieldDecl *>::iterator |
| 163 | DI = F.FieldChain.begin(), DE = F.FieldChain.end(); DI!=DE;++DI){ |
| 164 | if (first) |
| 165 | first = false; |
| 166 | else |
| 167 | os << '.'; |
Benjamin Kramer | 900fc63 | 2010-04-17 09:33:03 +0000 | [diff] [blame] | 168 | os << *DI; |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 169 | } |
| 170 | os << "')"; |
| 171 | } |
| 172 | |
| 173 | // Generate a report for this bug. |
| 174 | EnhancedBugReport *R = new EnhancedBugReport(*BT, os.str(), N); |
| 175 | R->addRange(Ex->getSourceRange()); |
| 176 | |
| 177 | // FIXME: enhance track back for uninitialized value for arbitrary |
| 178 | // memregions |
| 179 | C.EmitReport(R); |
| 180 | } |
| 181 | return true; |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | return false; |
| 186 | } |
| 187 | |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 188 | void CallAndMessageChecker::PreVisitCallExpr(CheckerContext &C, |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 189 | const CallExpr *CE){ |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 190 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 191 | const Expr *Callee = CE->getCallee()->IgnoreParens(); |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 192 | SVal L = C.getState()->getSVal(Callee); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 193 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 194 | if (L.isUndef()) { |
| 195 | if (!BT_call_undef) |
| 196 | BT_call_undef = |
Ted Kremenek | 818b433 | 2010-09-09 22:51:55 +0000 | [diff] [blame] | 197 | new BuiltinBug("Called function pointer is an uninitalized pointer value"); |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 198 | EmitBadCall(BT_call_undef, C, CE); |
| 199 | return; |
| 200 | } |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 201 | |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 202 | if (isa<loc::ConcreteInt>(L)) { |
| 203 | if (!BT_call_null) |
| 204 | BT_call_null = |
| 205 | new BuiltinBug("Called function pointer is null (null dereference)"); |
| 206 | EmitBadCall(BT_call_null, C, CE); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 207 | } |
| 208 | |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 209 | for (CallExpr::const_arg_iterator I = CE->arg_begin(), E = CE->arg_end(); |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 210 | I != E; ++I) |
| 211 | if (PreVisitProcessArg(C, *I, |
Ted Kremenek | 818b433 | 2010-09-09 22:51:55 +0000 | [diff] [blame] | 212 | "Function call argument is an uninitialized value", |
| 213 | BT_call_arg)) |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 214 | return; |
Ted Kremenek | 64fa858 | 2009-11-21 00:49:41 +0000 | [diff] [blame] | 215 | } |
| 216 | |
Zhongxing Xu | d02174c | 2009-11-24 04:45:44 +0000 | [diff] [blame] | 217 | void CallAndMessageChecker::PreVisitObjCMessageExpr(CheckerContext &C, |
| 218 | const ObjCMessageExpr *ME) { |
Ted Kremenek | 64fa858 | 2009-11-21 00:49:41 +0000 | [diff] [blame] | 219 | |
Ted Kremenek | 64fa858 | 2009-11-21 00:49:41 +0000 | [diff] [blame] | 220 | const GRState *state = C.getState(); |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 221 | |
Douglas Gregor | 04badcf | 2010-04-21 00:45:42 +0000 | [diff] [blame] | 222 | // FIXME: Handle 'super'? |
| 223 | if (const Expr *receiver = ME->getInstanceReceiver()) |
Ted Kremenek | 1397663 | 2010-02-08 16:18:51 +0000 | [diff] [blame] | 224 | if (state->getSVal(receiver).isUndef()) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 225 | if (ExplodedNode *N = C.generateSink()) { |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 226 | if (!BT_msg_undef) |
| 227 | BT_msg_undef = |
Ted Kremenek | 818b433 | 2010-09-09 22:51:55 +0000 | [diff] [blame] | 228 | new BuiltinBug("Receiver in message expression is an uninitialized value"); |
Ted Kremenek | c79d7d4 | 2009-11-21 01:25:37 +0000 | [diff] [blame] | 229 | EnhancedBugReport *R = |
| 230 | new EnhancedBugReport(*BT_msg_undef, BT_msg_undef->getName(), N); |
| 231 | R->addRange(receiver->getSourceRange()); |
| 232 | R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, |
| 233 | receiver); |
| 234 | C.EmitReport(R); |
| 235 | } |
| 236 | return; |
| 237 | } |
| 238 | |
| 239 | // Check for any arguments that are uninitialized/undefined. |
Zhongxing Xu | 2055eff | 2009-11-24 07:06:39 +0000 | [diff] [blame] | 240 | for (ObjCMessageExpr::const_arg_iterator I = ME->arg_begin(), |
Ted Kremenek | 8133716 | 2010-03-18 03:22:29 +0000 | [diff] [blame] | 241 | E = ME->arg_end(); I != E; ++I) |
| 242 | if (PreVisitProcessArg(C, *I, |
Ted Kremenek | 818b433 | 2010-09-09 22:51:55 +0000 | [diff] [blame] | 243 | "Argument in message expression " |
| 244 | "is an uninitialized value", BT_msg_arg)) |
Ted Kremenek | 64fa858 | 2009-11-21 00:49:41 +0000 | [diff] [blame] | 245 | return; |
Zhongxing Xu | a46e4d9 | 2009-12-02 05:49:12 +0000 | [diff] [blame] | 246 | } |
Zhongxing Xu | 2055eff | 2009-11-24 07:06:39 +0000 | [diff] [blame] | 247 | |
Ted Kremenek | 9c14953 | 2010-12-01 21:57:22 +0000 | [diff] [blame] | 248 | bool CallAndMessageChecker::evalNilReceiver(CheckerContext &C, |
Zhongxing Xu | a46e4d9 | 2009-12-02 05:49:12 +0000 | [diff] [blame] | 249 | const ObjCMessageExpr *ME) { |
| 250 | HandleNilReceiver(C, C.getState(), ME); |
| 251 | return true; // Nil receiver is not handled elsewhere. |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 252 | } |
| 253 | |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 254 | void CallAndMessageChecker::emitNilReceiverBug(CheckerContext &C, |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 255 | const ObjCMessageExpr *ME, |
| 256 | ExplodedNode *N) { |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 257 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 258 | if (!BT_msg_ret) |
| 259 | BT_msg_ret = |
| 260 | new BuiltinBug("Receiver in message expression is " |
| 261 | "'nil' and returns a garbage value"); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 262 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 263 | llvm::SmallString<200> buf; |
| 264 | llvm::raw_svector_ostream os(buf); |
| 265 | os << "The receiver of message '" << ME->getSelector().getAsString() |
| 266 | << "' is nil and returns a value of type '" |
| 267 | << ME->getType().getAsString() << "' that will be garbage"; |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 268 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 269 | EnhancedBugReport *report = new EnhancedBugReport(*BT_msg_ret, os.str(), N); |
Douglas Gregor | 04badcf | 2010-04-21 00:45:42 +0000 | [diff] [blame] | 270 | if (const Expr *receiver = ME->getInstanceReceiver()) { |
| 271 | report->addRange(receiver->getSourceRange()); |
| 272 | report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, |
| 273 | receiver); |
| 274 | } |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 275 | C.EmitReport(report); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 276 | } |
| 277 | |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 278 | static bool supportsNilWithFloatRet(const llvm::Triple &triple) { |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 279 | return triple.getVendor() == llvm::Triple::Apple && |
Ted Kremenek | 6123874 | 2010-09-30 00:37:10 +0000 | [diff] [blame] | 280 | (triple.getDarwinMajorNumber() >= 9 || |
| 281 | triple.getArch() == llvm::Triple::arm || |
| 282 | triple.getArch() == llvm::Triple::thumb); |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 283 | } |
| 284 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 285 | void CallAndMessageChecker::HandleNilReceiver(CheckerContext &C, |
| 286 | const GRState *state, |
| 287 | const ObjCMessageExpr *ME) { |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 288 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 289 | // Check the return type of the message expression. A message to nil will |
| 290 | // return different values depending on the return type and the architecture. |
| 291 | QualType RetTy = ME->getType(); |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 292 | |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 293 | ASTContext &Ctx = C.getASTContext(); |
| 294 | CanQualType CanRetTy = Ctx.getCanonicalType(RetTy); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 295 | |
Douglas Gregor | fb87b89 | 2010-04-26 21:31:17 +0000 | [diff] [blame] | 296 | if (CanRetTy->isStructureOrClassType()) { |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 297 | // FIXME: At some point we shouldn't rely on isConsumedExpr(), but instead |
| 298 | // have the "use of undefined value" be smarter about where the |
| 299 | // undefined value came from. |
| 300 | if (C.getPredecessor()->getParentMap().isConsumedExpr(ME)) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 301 | if (ExplodedNode* N = C.generateSink(state)) |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 302 | emitNilReceiverBug(C, ME, N); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 303 | return; |
| 304 | } |
| 305 | |
| 306 | // The result is not consumed by a surrounding expression. Just propagate |
| 307 | // the current state. |
| 308 | C.addTransition(state); |
| 309 | return; |
| 310 | } |
| 311 | |
| 312 | // Other cases: check if the return type is smaller than void*. |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 313 | if (CanRetTy != Ctx.VoidTy && |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 314 | C.getPredecessor()->getParentMap().isConsumedExpr(ME)) { |
| 315 | // Compute: sizeof(void *) and sizeof(return type) |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 316 | const uint64_t voidPtrSize = Ctx.getTypeSize(Ctx.VoidPtrTy); |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 317 | const uint64_t returnTypeSize = Ctx.getTypeSize(CanRetTy); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 318 | |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 319 | if (voidPtrSize < returnTypeSize && |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 320 | !(supportsNilWithFloatRet(Ctx.Target.getTriple()) && |
Ted Kremenek | f81330c | 2009-11-24 22:48:18 +0000 | [diff] [blame] | 321 | (Ctx.FloatTy == CanRetTy || |
| 322 | Ctx.DoubleTy == CanRetTy || |
| 323 | Ctx.LongDoubleTy == CanRetTy || |
Ted Kremenek | 6123874 | 2010-09-30 00:37:10 +0000 | [diff] [blame] | 324 | Ctx.LongLongTy == CanRetTy || |
| 325 | Ctx.UnsignedLongLongTy == CanRetTy))) { |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 326 | if (ExplodedNode* N = C.generateSink(state)) |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 327 | emitNilReceiverBug(C, ME, N); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 328 | return; |
| 329 | } |
| 330 | |
| 331 | // Handle the safe cases where the return value is 0 if the |
| 332 | // receiver is nil. |
| 333 | // |
| 334 | // FIXME: For now take the conservative approach that we only |
| 335 | // return null values if we *know* that the receiver is nil. |
| 336 | // This is because we can have surprises like: |
| 337 | // |
| 338 | // ... = [[NSScreens screens] objectAtIndex:0]; |
| 339 | // |
| 340 | // What can happen is that [... screens] could return nil, but |
| 341 | // it most likely isn't nil. We should assume the semantics |
| 342 | // of this case unless we have *a lot* more knowledge. |
| 343 | // |
Ted Kremenek | c8413fd | 2010-12-02 07:49:45 +0000 | [diff] [blame] | 344 | SVal V = C.getSValBuilder().makeZeroVal(ME->getType()); |
Ted Kremenek | d048c6e | 2010-12-20 21:19:09 +0000 | [diff] [blame] | 345 | C.generateNode(state->BindExpr(ME, V)); |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 346 | return; |
| 347 | } |
Ted Kremenek | 091b588 | 2010-03-18 02:17:27 +0000 | [diff] [blame] | 348 | |
Ted Kremenek | fee96e0 | 2009-11-24 21:41:28 +0000 | [diff] [blame] | 349 | C.addTransition(state); |
Zhongxing Xu | 8958fff | 2009-11-03 06:46:03 +0000 | [diff] [blame] | 350 | } |