1 //===- ExprEngine.cpp - Path-Sensitive Expression-Level Dataflow ----------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file defines a meta-engine for path-sensitive dataflow analysis that
10 // is built on CoreEngine, but provides the boilerplate to execute transfer
11 // functions and build the ExplodedGraph at the expression level.
13 //===----------------------------------------------------------------------===//
15 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
16 #include "PrettyStackTraceLocationContext.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclBase.h"
20 #include "clang/AST/DeclCXX.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/ExprObjC.h"
25 #include "clang/AST/ParentMap.h"
26 #include "clang/AST/PrettyPrinter.h"
27 #include "clang/AST/Stmt.h"
28 #include "clang/AST/StmtCXX.h"
29 #include "clang/AST/StmtObjC.h"
30 #include "clang/AST/Type.h"
31 #include "clang/Analysis/AnalysisDeclContext.h"
32 #include "clang/Analysis/CFG.h"
33 #include "clang/Analysis/ConstructionContext.h"
34 #include "clang/Analysis/ProgramPoint.h"
35 #include "clang/Basic/IdentifierTable.h"
36 #include "clang/Basic/JsonSupport.h"
37 #include "clang/Basic/LLVM.h"
38 #include "clang/Basic/LangOptions.h"
39 #include "clang/Basic/PrettyStackTrace.h"
40 #include "clang/Basic/SourceLocation.h"
41 #include "clang/Basic/SourceManager.h"
42 #include "clang/Basic/Specifiers.h"
43 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
44 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
45 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
46 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
47 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
48 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
49 #include "clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h"
50 #include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
51 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
52 #include "clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h"
53 #include "clang/StaticAnalyzer/Core/PathSensitive/LoopWidening.h"
54 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
55 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
56 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
57 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
58 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
59 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
60 #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
61 #include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h"
62 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
63 #include "llvm/ADT/APSInt.h"
64 #include "llvm/ADT/DenseMap.h"
65 #include "llvm/ADT/ImmutableMap.h"
66 #include "llvm/ADT/ImmutableSet.h"
67 #include "llvm/ADT/Optional.h"
68 #include "llvm/ADT/SmallVector.h"
69 #include "llvm/ADT/Statistic.h"
70 #include "llvm/Support/Casting.h"
71 #include "llvm/Support/Compiler.h"
72 #include "llvm/Support/DOTGraphTraits.h"
73 #include "llvm/Support/ErrorHandling.h"
74 #include "llvm/Support/GraphWriter.h"
75 #include "llvm/Support/SaveAndRestore.h"
76 #include "llvm/Support/raw_ostream.h"
85 using namespace clang;
88 #define DEBUG_TYPE "ExprEngine"
90 STATISTIC(NumRemoveDeadBindings,
91 "The # of times RemoveDeadBindings is called");
92 STATISTIC(NumMaxBlockCountReached,
93 "The # of aborted paths due to reaching the maximum block count in "
94 "a top level function");
95 STATISTIC(NumMaxBlockCountReachedInInlined,
96 "The # of aborted paths due to reaching the maximum block count in "
97 "an inlined function");
98 STATISTIC(NumTimesRetriedWithoutInlining,
99 "The # of times we re-evaluated a call without inlining");
101 //===----------------------------------------------------------------------===//
102 // Internal program state traits.
103 //===----------------------------------------------------------------------===//
107 // When modeling a C++ constructor, for a variety of reasons we need to track
108 // the location of the object for the duration of its ConstructionContext.
109 // ObjectsUnderConstruction maps statements within the construction context
110 // to the object's location, so that on every such statement the location
111 // could have been retrieved.
113 /// ConstructedObjectKey is used for being able to find the path-sensitive
114 /// memory region of a freshly constructed object while modeling the AST node
115 /// that syntactically represents the object that is being constructed.
116 /// Semantics of such nodes may sometimes require access to the region that's
117 /// not otherwise present in the program state, or to the very fact that
118 /// the construction context was present and contained references to these
120 class ConstructedObjectKey {
121 using ConstructedObjectKeyImpl =
122 std::pair<ConstructionContextItem, const LocationContext *>;
123 const ConstructedObjectKeyImpl Impl;
126 explicit ConstructedObjectKey(const ConstructionContextItem &Item,
127 const LocationContext *LC)
130 const ConstructionContextItem &getItem() const { return Impl.first; }
131 const LocationContext *getLocationContext() const { return Impl.second; }
133 ASTContext &getASTContext() const {
134 return getLocationContext()->getDecl()->getASTContext();
137 void printJson(llvm::raw_ostream &Out, PrinterHelper *Helper,
138 PrintingPolicy &PP) const {
139 const Stmt *S = getItem().getStmtOrNull();
140 const CXXCtorInitializer *I = nullptr;
142 I = getItem().getCXXCtorInitializer();
145 Out << "\"stmt_id\": " << S->getID(getASTContext());
147 Out << "\"init_id\": " << I->getID(getASTContext());
150 Out << ", \"kind\": \"" << getItem().getKindAsString()
151 << "\", \"argument_index\": ";
153 if (getItem().getKind() == ConstructionContextItem::ArgumentKind)
154 Out << getItem().getIndex();
159 Out << ", \"pretty\": ";
162 S->printJson(Out, Helper, PP, /*AddQuotes=*/true);
164 Out << '\"' << I->getAnyMember()->getDeclName() << '\"';
168 void Profile(llvm::FoldingSetNodeID &ID) const {
170 ID.AddPointer(Impl.second);
173 bool operator==(const ConstructedObjectKey &RHS) const {
174 return Impl == RHS.Impl;
177 bool operator<(const ConstructedObjectKey &RHS) const {
178 return Impl < RHS.Impl;
183 typedef llvm::ImmutableMap<ConstructedObjectKey, SVal>
184 ObjectsUnderConstructionMap;
185 REGISTER_TRAIT_WITH_PROGRAMSTATE(ObjectsUnderConstruction,
186 ObjectsUnderConstructionMap)
188 //===----------------------------------------------------------------------===//
189 // Engine construction and deletion.
190 //===----------------------------------------------------------------------===//
192 static const char* TagProviderName = "ExprEngine";
194 ExprEngine::ExprEngine(cross_tu::CrossTranslationUnitContext &CTU,
195 AnalysisManager &mgr, SetOfConstDecls *VisitedCalleesIn,
196 FunctionSummariesTy *FS, InliningModes HowToInlineIn)
197 : CTU(CTU), IsCTUEnabled(mgr.getAnalyzerOptions().IsNaiveCTUEnabled),
198 AMgr(mgr), AnalysisDeclContexts(mgr.getAnalysisDeclContextManager()),
199 Engine(*this, FS, mgr.getAnalyzerOptions()), G(Engine.getGraph()),
200 StateMgr(getContext(), mgr.getStoreManagerCreator(),
201 mgr.getConstraintManagerCreator(), G.getAllocator(), this),
202 SymMgr(StateMgr.getSymbolManager()), MRMgr(StateMgr.getRegionManager()),
203 svalBuilder(StateMgr.getSValBuilder()), ObjCNoRet(mgr.getASTContext()),
204 BR(mgr, *this), VisitedCallees(VisitedCalleesIn),
205 HowToInline(HowToInlineIn) {
206 unsigned TrimInterval = mgr.options.GraphTrimInterval;
207 if (TrimInterval != 0) {
208 // Enable eager node reclamation when constructing the ExplodedGraph.
209 G.enableNodeReclamation(TrimInterval);
213 //===----------------------------------------------------------------------===//
215 //===----------------------------------------------------------------------===//
217 ProgramStateRef ExprEngine::getInitialState(const LocationContext *InitLoc) {
218 ProgramStateRef state = StateMgr.getInitialState(InitLoc);
219 const Decl *D = InitLoc->getDecl();
222 // FIXME: It would be nice if we had a more general mechanism to add
223 // such preconditions. Some day.
225 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
226 // Precondition: the first argument of 'main' is an integer guaranteed
228 const IdentifierInfo *II = FD->getIdentifier();
229 if (!II || !(II->getName() == "main" && FD->getNumParams() > 0))
232 const ParmVarDecl *PD = FD->getParamDecl(0);
233 QualType T = PD->getType();
234 const auto *BT = dyn_cast<BuiltinType>(T);
235 if (!BT || !BT->isInteger())
238 const MemRegion *R = state->getRegion(PD, InitLoc);
242 SVal V = state->getSVal(loc::MemRegionVal(R));
243 SVal Constraint_untested = evalBinOp(state, BO_GT, V,
244 svalBuilder.makeZeroVal(T),
245 svalBuilder.getConditionType());
247 Optional<DefinedOrUnknownSVal> Constraint =
248 Constraint_untested.getAs<DefinedOrUnknownSVal>();
253 if (ProgramStateRef newState = state->assume(*Constraint, true))
260 if (const auto *MD = dyn_cast<ObjCMethodDecl>(D)) {
261 // Precondition: 'self' is always non-null upon entry to an Objective-C
263 const ImplicitParamDecl *SelfD = MD->getSelfDecl();
264 const MemRegion *R = state->getRegion(SelfD, InitLoc);
265 SVal V = state->getSVal(loc::MemRegionVal(R));
267 if (Optional<Loc> LV = V.getAs<Loc>()) {
268 // Assume that the pointer value in 'self' is non-null.
269 state = state->assume(*LV, true);
270 assert(state && "'self' cannot be null");
274 if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
275 if (!MD->isStatic()) {
276 // Precondition: 'this' is always non-null upon entry to the
277 // top-level function. This is our starting assumption for
278 // analyzing an "open" program.
279 const StackFrameContext *SFC = InitLoc->getStackFrame();
280 if (SFC->getParent() == nullptr) {
281 loc::MemRegionVal L = svalBuilder.getCXXThis(MD, SFC);
282 SVal V = state->getSVal(L);
283 if (Optional<Loc> LV = V.getAs<Loc>()) {
284 state = state->assume(*LV, true);
285 assert(state && "'this' cannot be null");
294 ProgramStateRef ExprEngine::createTemporaryRegionIfNeeded(
295 ProgramStateRef State, const LocationContext *LC,
296 const Expr *InitWithAdjustments, const Expr *Result,
297 const SubRegion **OutRegionWithAdjustments) {
298 // FIXME: This function is a hack that works around the quirky AST
299 // we're often having with respect to C++ temporaries. If only we modelled
300 // the actual execution order of statements properly in the CFG,
301 // all the hassle with adjustments would not be necessary,
302 // and perhaps the whole function would be removed.
303 SVal InitValWithAdjustments = State->getSVal(InitWithAdjustments, LC);
305 // If we don't have an explicit result expression, we're in "if needed"
306 // mode. Only create a region if the current value is a NonLoc.
307 if (!isa<NonLoc>(InitValWithAdjustments)) {
308 if (OutRegionWithAdjustments)
309 *OutRegionWithAdjustments = nullptr;
312 Result = InitWithAdjustments;
314 // We need to create a region no matter what. Make sure we don't try to
315 // stuff a Loc into a non-pointer temporary region.
316 assert(!isa<Loc>(InitValWithAdjustments) ||
317 Loc::isLocType(Result->getType()) ||
318 Result->getType()->isMemberPointerType());
321 ProgramStateManager &StateMgr = State->getStateManager();
322 MemRegionManager &MRMgr = StateMgr.getRegionManager();
323 StoreManager &StoreMgr = StateMgr.getStoreManager();
325 // MaterializeTemporaryExpr may appear out of place, after a few field and
326 // base-class accesses have been made to the object, even though semantically
327 // it is the whole object that gets materialized and lifetime-extended.
331 // `-MaterializeTemporaryExpr
333 // `-CXXTemporaryObjectExpr
335 // instead of the more natural
338 // `-MaterializeTemporaryExpr
339 // `-CXXTemporaryObjectExpr
341 // Use the usual methods for obtaining the expression of the base object,
342 // and record the adjustments that we need to make to obtain the sub-object
343 // that the whole expression 'Ex' refers to. This trick is usual,
344 // in the sense that CodeGen takes a similar route.
346 SmallVector<const Expr *, 2> CommaLHSs;
347 SmallVector<SubobjectAdjustment, 2> Adjustments;
349 const Expr *Init = InitWithAdjustments->skipRValueSubobjectAdjustments(
350 CommaLHSs, Adjustments);
352 // Take the region for Init, i.e. for the whole object. If we do not remember
353 // the region in which the object originally was constructed, come up with
354 // a new temporary region out of thin air and copy the contents of the object
355 // (which are currently present in the Environment, because Init is an rvalue)
356 // into that region. This is not correct, but it is better than nothing.
357 const TypedValueRegion *TR = nullptr;
358 if (const auto *MT = dyn_cast<MaterializeTemporaryExpr>(Result)) {
359 if (Optional<SVal> V = getObjectUnderConstruction(State, MT, LC)) {
360 State = finishObjectConstruction(State, MT, LC);
361 State = State->BindExpr(Result, LC, *V);
364 StorageDuration SD = MT->getStorageDuration();
365 // If this object is bound to a reference with static storage duration, we
366 // put it in a different region to prevent "address leakage" warnings.
367 if (SD == SD_Static || SD == SD_Thread) {
368 TR = MRMgr.getCXXStaticTempObjectRegion(Init);
370 TR = MRMgr.getCXXTempObjectRegion(Init, LC);
374 TR = MRMgr.getCXXTempObjectRegion(Init, LC);
377 SVal Reg = loc::MemRegionVal(TR);
380 // Make the necessary adjustments to obtain the sub-object.
381 for (const SubobjectAdjustment &Adj : llvm::reverse(Adjustments)) {
383 case SubobjectAdjustment::DerivedToBaseAdjustment:
384 Reg = StoreMgr.evalDerivedToBase(Reg, Adj.DerivedToBase.BasePath);
386 case SubobjectAdjustment::FieldAdjustment:
387 Reg = StoreMgr.getLValueField(Adj.Field, Reg);
389 case SubobjectAdjustment::MemberPointerAdjustment:
390 // FIXME: Unimplemented.
391 State = State->invalidateRegions(Reg, InitWithAdjustments,
392 currBldrCtx->blockCount(), LC, true,
393 nullptr, nullptr, nullptr);
398 // What remains is to copy the value of the object to the new region.
399 // FIXME: In other words, what we should always do is copy value of the
400 // Init expression (which corresponds to the bigger object) to the whole
401 // temporary region TR. However, this value is often no longer present
402 // in the Environment. If it has disappeared, we instead invalidate TR.
403 // Still, what we can do is assign the value of expression Ex (which
404 // corresponds to the sub-object) to the TR's sub-region Reg. At least,
405 // values inside Reg would be correct.
406 SVal InitVal = State->getSVal(Init, LC);
407 if (InitVal.isUnknown()) {
408 InitVal = getSValBuilder().conjureSymbolVal(Result, LC, Init->getType(),
409 currBldrCtx->blockCount());
410 State = State->bindLoc(BaseReg.castAs<Loc>(), InitVal, LC, false);
412 // Then we'd need to take the value that certainly exists and bind it
414 if (InitValWithAdjustments.isUnknown()) {
415 // Try to recover some path sensitivity in case we couldn't
416 // compute the value.
417 InitValWithAdjustments = getSValBuilder().conjureSymbolVal(
418 Result, LC, InitWithAdjustments->getType(),
419 currBldrCtx->blockCount());
422 State->bindLoc(Reg.castAs<Loc>(), InitValWithAdjustments, LC, false);
424 State = State->bindLoc(BaseReg.castAs<Loc>(), InitVal, LC, false);
427 // The result expression would now point to the correct sub-region of the
428 // newly created temporary region. Do this last in order to getSVal of Init
429 // correctly in case (Result == Init).
430 if (Result->isGLValue()) {
431 State = State->BindExpr(Result, LC, Reg);
433 State = State->BindExpr(Result, LC, InitValWithAdjustments);
436 // Notify checkers once for two bindLoc()s.
437 State = processRegionChange(State, TR, LC);
439 if (OutRegionWithAdjustments)
440 *OutRegionWithAdjustments = cast<SubRegion>(Reg.getAsRegion());
445 ExprEngine::addObjectUnderConstruction(ProgramStateRef State,
446 const ConstructionContextItem &Item,
447 const LocationContext *LC, SVal V) {
448 ConstructedObjectKey Key(Item, LC->getStackFrame());
449 // FIXME: Currently the state might already contain the marker due to
450 // incorrect handling of temporaries bound to default parameters.
451 assert(!State->get<ObjectsUnderConstruction>(Key) ||
452 Key.getItem().getKind() ==
453 ConstructionContextItem::TemporaryDestructorKind);
454 return State->set<ObjectsUnderConstruction>(Key, V);
458 ExprEngine::getObjectUnderConstruction(ProgramStateRef State,
459 const ConstructionContextItem &Item,
460 const LocationContext *LC) {
461 ConstructedObjectKey Key(Item, LC->getStackFrame());
462 return Optional<SVal>::create(State->get<ObjectsUnderConstruction>(Key));
466 ExprEngine::finishObjectConstruction(ProgramStateRef State,
467 const ConstructionContextItem &Item,
468 const LocationContext *LC) {
469 ConstructedObjectKey Key(Item, LC->getStackFrame());
470 assert(State->contains<ObjectsUnderConstruction>(Key));
471 return State->remove<ObjectsUnderConstruction>(Key);
474 ProgramStateRef ExprEngine::elideDestructor(ProgramStateRef State,
475 const CXXBindTemporaryExpr *BTE,
476 const LocationContext *LC) {
477 ConstructedObjectKey Key({BTE, /*IsElided=*/true}, LC);
478 // FIXME: Currently the state might already contain the marker due to
479 // incorrect handling of temporaries bound to default parameters.
480 return State->set<ObjectsUnderConstruction>(Key, UnknownVal());
484 ExprEngine::cleanupElidedDestructor(ProgramStateRef State,
485 const CXXBindTemporaryExpr *BTE,
486 const LocationContext *LC) {
487 ConstructedObjectKey Key({BTE, /*IsElided=*/true}, LC);
488 assert(State->contains<ObjectsUnderConstruction>(Key));
489 return State->remove<ObjectsUnderConstruction>(Key);
492 bool ExprEngine::isDestructorElided(ProgramStateRef State,
493 const CXXBindTemporaryExpr *BTE,
494 const LocationContext *LC) {
495 ConstructedObjectKey Key({BTE, /*IsElided=*/true}, LC);
496 return State->contains<ObjectsUnderConstruction>(Key);
499 bool ExprEngine::areAllObjectsFullyConstructed(ProgramStateRef State,
500 const LocationContext *FromLC,
501 const LocationContext *ToLC) {
502 const LocationContext *LC = FromLC;
504 assert(LC && "ToLC must be a parent of FromLC!");
505 for (auto I : State->get<ObjectsUnderConstruction>())
506 if (I.first.getLocationContext() == LC)
509 LC = LC->getParent();
515 //===----------------------------------------------------------------------===//
516 // Top-level transfer function logic (Dispatcher).
517 //===----------------------------------------------------------------------===//
519 /// evalAssume - Called by ConstraintManager. Used to call checker-specific
520 /// logic for handling assumptions on symbolic values.
521 ProgramStateRef ExprEngine::processAssume(ProgramStateRef state,
522 SVal cond, bool assumption) {
523 return getCheckerManager().runCheckersForEvalAssume(state, cond, assumption);
527 ExprEngine::processRegionChanges(ProgramStateRef state,
528 const InvalidatedSymbols *invalidated,
529 ArrayRef<const MemRegion *> Explicits,
530 ArrayRef<const MemRegion *> Regions,
531 const LocationContext *LCtx,
532 const CallEvent *Call) {
533 return getCheckerManager().runCheckersForRegionChanges(state, invalidated,
539 printObjectsUnderConstructionJson(raw_ostream &Out, ProgramStateRef State,
540 const char *NL, const LocationContext *LCtx,
541 unsigned int Space = 0, bool IsDot = false) {
543 LCtx->getAnalysisDeclContext()->getASTContext().getPrintingPolicy();
546 bool HasItem = false;
548 // Store the last key.
549 const ConstructedObjectKey *LastKey = nullptr;
550 for (const auto &I : State->get<ObjectsUnderConstruction>()) {
551 const ConstructedObjectKey &Key = I.first;
552 if (Key.getLocationContext() != LCtx)
563 for (const auto &I : State->get<ObjectsUnderConstruction>()) {
564 const ConstructedObjectKey &Key = I.first;
565 SVal Value = I.second;
566 if (Key.getLocationContext() != LCtx)
569 Indent(Out, Space, IsDot) << "{ ";
570 Key.printJson(Out, nullptr, PP);
571 Out << ", \"value\": \"" << Value << "\" }";
579 Indent(Out, --Space, IsDot) << ']'; // End of "location_context".
585 void ExprEngine::printJson(raw_ostream &Out, ProgramStateRef State,
586 const LocationContext *LCtx, const char *NL,
587 unsigned int Space, bool IsDot) const {
588 Indent(Out, Space, IsDot) << "\"constructing_objects\": ";
590 if (LCtx && !State->get<ObjectsUnderConstruction>().isEmpty()) {
593 LCtx->printJson(Out, NL, Space, IsDot, [&](const LocationContext *LC) {
594 printObjectsUnderConstructionJson(Out, State, NL, LC, Space, IsDot);
598 Indent(Out, Space, IsDot) << "]," << NL; // End of "constructing_objects".
600 Out << "null," << NL;
603 getCheckerManager().runCheckersForPrintStateJson(Out, State, NL, Space,
607 void ExprEngine::processEndWorklist() {
608 // This prints the name of the top-level function if we crash.
609 PrettyStackTraceLocationContext CrashInfo(getRootLocationContext());
610 getCheckerManager().runCheckersForEndAnalysis(G, BR, *this);
613 void ExprEngine::processCFGElement(const CFGElement E, ExplodedNode *Pred,
614 unsigned StmtIdx, NodeBuilderContext *Ctx) {
615 PrettyStackTraceLocationContext CrashInfo(Pred->getLocationContext());
616 currStmtIdx = StmtIdx;
619 switch (E.getKind()) {
620 case CFGElement::Statement:
621 case CFGElement::Constructor:
622 case CFGElement::CXXRecordTypedCall:
623 ProcessStmt(E.castAs<CFGStmt>().getStmt(), Pred);
625 case CFGElement::Initializer:
626 ProcessInitializer(E.castAs<CFGInitializer>(), Pred);
628 case CFGElement::NewAllocator:
629 ProcessNewAllocator(E.castAs<CFGNewAllocator>().getAllocatorExpr(),
632 case CFGElement::AutomaticObjectDtor:
633 case CFGElement::DeleteDtor:
634 case CFGElement::BaseDtor:
635 case CFGElement::MemberDtor:
636 case CFGElement::TemporaryDtor:
637 ProcessImplicitDtor(E.castAs<CFGImplicitDtor>(), Pred);
639 case CFGElement::LoopExit:
640 ProcessLoopExit(E.castAs<CFGLoopExit>().getLoopStmt(), Pred);
642 case CFGElement::LifetimeEnds:
643 case CFGElement::ScopeBegin:
644 case CFGElement::ScopeEnd:
649 static bool shouldRemoveDeadBindings(AnalysisManager &AMgr,
651 const ExplodedNode *Pred,
652 const LocationContext *LC) {
653 // Are we never purging state values?
654 if (AMgr.options.AnalysisPurgeOpt == PurgeNone)
657 // Is this the beginning of a basic block?
658 if (Pred->getLocation().getAs<BlockEntrance>())
661 // Is this on a non-expression?
665 // Run before processing a call.
666 if (CallEvent::isCallStmt(S))
669 // Is this an expression that is consumed by another expression? If so,
670 // postpone cleaning out the state.
671 ParentMap &PM = LC->getAnalysisDeclContext()->getParentMap();
672 return !PM.isConsumedExpr(cast<Expr>(S));
675 void ExprEngine::removeDead(ExplodedNode *Pred, ExplodedNodeSet &Out,
676 const Stmt *ReferenceStmt,
677 const LocationContext *LC,
678 const Stmt *DiagnosticStmt,
679 ProgramPoint::Kind K) {
680 assert((K == ProgramPoint::PreStmtPurgeDeadSymbolsKind ||
681 ReferenceStmt == nullptr || isa<ReturnStmt>(ReferenceStmt))
682 && "PostStmt is not generally supported by the SymbolReaper yet");
683 assert(LC && "Must pass the current (or expiring) LocationContext");
685 if (!DiagnosticStmt) {
686 DiagnosticStmt = ReferenceStmt;
687 assert(DiagnosticStmt && "Required for clearing a LocationContext");
690 NumRemoveDeadBindings++;
691 ProgramStateRef CleanedState = Pred->getState();
693 // LC is the location context being destroyed, but SymbolReaper wants a
694 // location context that is still live. (If this is the top-level stack
695 // frame, this will be null.)
696 if (!ReferenceStmt) {
697 assert(K == ProgramPoint::PostStmtPurgeDeadSymbolsKind &&
698 "Use PostStmtPurgeDeadSymbolsKind for clearing a LocationContext");
699 LC = LC->getParent();
702 const StackFrameContext *SFC = LC ? LC->getStackFrame() : nullptr;
703 SymbolReaper SymReaper(SFC, ReferenceStmt, SymMgr, getStoreManager());
705 for (auto I : CleanedState->get<ObjectsUnderConstruction>()) {
706 if (SymbolRef Sym = I.second.getAsSymbol())
707 SymReaper.markLive(Sym);
708 if (const MemRegion *MR = I.second.getAsRegion())
709 SymReaper.markLive(MR);
712 getCheckerManager().runCheckersForLiveSymbols(CleanedState, SymReaper);
714 // Create a state in which dead bindings are removed from the environment
715 // and the store. TODO: The function should just return new env and store,
717 CleanedState = StateMgr.removeDeadBindingsFromEnvironmentAndStore(
718 CleanedState, SFC, SymReaper);
720 // Process any special transfer function for dead symbols.
721 // A tag to track convenience transitions, which can be removed at cleanup.
722 static SimpleProgramPointTag cleanupTag(TagProviderName, "Clean Node");
723 // Call checkers with the non-cleaned state so that they could query the
724 // values of the soon to be dead symbols.
725 ExplodedNodeSet CheckedSet;
726 getCheckerManager().runCheckersForDeadSymbols(CheckedSet, Pred, SymReaper,
727 DiagnosticStmt, *this, K);
729 // For each node in CheckedSet, generate CleanedNodes that have the
730 // environment, the store, and the constraints cleaned up but have the
731 // user-supplied states as the predecessors.
732 StmtNodeBuilder Bldr(CheckedSet, Out, *currBldrCtx);
733 for (const auto I : CheckedSet) {
734 ProgramStateRef CheckerState = I->getState();
736 // The constraint manager has not been cleaned up yet, so clean up now.
738 getConstraintManager().removeDeadBindings(CheckerState, SymReaper);
740 assert(StateMgr.haveEqualEnvironments(CheckerState, Pred->getState()) &&
741 "Checkers are not allowed to modify the Environment as a part of "
742 "checkDeadSymbols processing.");
743 assert(StateMgr.haveEqualStores(CheckerState, Pred->getState()) &&
744 "Checkers are not allowed to modify the Store as a part of "
745 "checkDeadSymbols processing.");
747 // Create a state based on CleanedState with CheckerState GDM and
748 // generate a transition to that state.
749 ProgramStateRef CleanedCheckerSt =
750 StateMgr.getPersistentStateWithGDM(CleanedState, CheckerState);
751 Bldr.generateNode(DiagnosticStmt, I, CleanedCheckerSt, &cleanupTag, K);
755 void ExprEngine::ProcessStmt(const Stmt *currStmt, ExplodedNode *Pred) {
756 // Reclaim any unnecessary nodes in the ExplodedGraph.
757 G.reclaimRecentlyAllocatedNodes();
759 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
760 currStmt->getBeginLoc(),
761 "Error evaluating statement");
763 // Remove dead bindings and symbols.
764 ExplodedNodeSet CleanedStates;
765 if (shouldRemoveDeadBindings(AMgr, currStmt, Pred,
766 Pred->getLocationContext())) {
767 removeDead(Pred, CleanedStates, currStmt,
768 Pred->getLocationContext());
770 CleanedStates.Add(Pred);
772 // Visit the statement.
774 for (const auto I : CleanedStates) {
775 ExplodedNodeSet DstI;
776 // Visit the statement.
777 Visit(currStmt, I, DstI);
781 // Enqueue the new nodes onto the work list.
782 Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
785 void ExprEngine::ProcessLoopExit(const Stmt* S, ExplodedNode *Pred) {
786 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
788 "Error evaluating end of the loop");
791 NodeBuilder Bldr(Pred, Dst, *currBldrCtx);
792 ProgramStateRef NewState = Pred->getState();
794 if(AMgr.options.ShouldUnrollLoops)
795 NewState = processLoopEnd(S, NewState);
797 LoopExit PP(S, Pred->getLocationContext());
798 Bldr.generateNode(PP, NewState, Pred);
799 // Enqueue the new nodes onto the work list.
800 Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
803 void ExprEngine::ProcessInitializer(const CFGInitializer CFGInit,
804 ExplodedNode *Pred) {
805 const CXXCtorInitializer *BMI = CFGInit.getInitializer();
806 const Expr *Init = BMI->getInit()->IgnoreImplicit();
807 const LocationContext *LC = Pred->getLocationContext();
809 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
810 BMI->getSourceLocation(),
811 "Error evaluating initializer");
813 // We don't clean up dead bindings here.
814 const auto *stackFrame = cast<StackFrameContext>(Pred->getLocationContext());
815 const auto *decl = cast<CXXConstructorDecl>(stackFrame->getDecl());
817 ProgramStateRef State = Pred->getState();
818 SVal thisVal = State->getSVal(svalBuilder.getCXXThis(decl, stackFrame));
823 // Evaluate the initializer, if necessary
824 if (BMI->isAnyMemberInitializer()) {
825 // Constructors build the object directly in the field,
826 // but non-objects must be copied in from the initializer.
827 if (getObjectUnderConstruction(State, BMI, LC)) {
828 // The field was directly constructed, so there is no need to bind.
829 // But we still need to stop tracking the object under construction.
830 State = finishObjectConstruction(State, BMI, LC);
831 NodeBuilder Bldr(Pred, Tmp, *currBldrCtx);
832 PostStore PS(Init, LC, /*Loc*/ nullptr, /*tag*/ nullptr);
833 Bldr.generateNode(PS, State, Pred);
835 const ValueDecl *Field;
836 if (BMI->isIndirectMemberInitializer()) {
837 Field = BMI->getIndirectMember();
838 FieldLoc = State->getLValue(BMI->getIndirectMember(), thisVal);
840 Field = BMI->getMember();
841 FieldLoc = State->getLValue(BMI->getMember(), thisVal);
845 if (Init->getType()->isArrayType()) {
846 // Handle arrays of trivial type. We can represent this with a
847 // primitive load/copy from the base array region.
848 const ArraySubscriptExpr *ASE;
849 while ((ASE = dyn_cast<ArraySubscriptExpr>(Init)))
850 Init = ASE->getBase()->IgnoreImplicit();
852 SVal LValue = State->getSVal(Init, stackFrame);
853 if (!Field->getType()->isReferenceType())
854 if (Optional<Loc> LValueLoc = LValue.getAs<Loc>())
855 InitVal = State->getSVal(*LValueLoc);
857 // If we fail to get the value for some reason, use a symbolic value.
858 if (InitVal.isUnknownOrUndef()) {
859 SValBuilder &SVB = getSValBuilder();
860 InitVal = SVB.conjureSymbolVal(BMI->getInit(), stackFrame,
862 currBldrCtx->blockCount());
865 InitVal = State->getSVal(BMI->getInit(), stackFrame);
868 PostInitializer PP(BMI, FieldLoc.getAsRegion(), stackFrame);
869 evalBind(Tmp, Init, Pred, FieldLoc, InitVal, /*isInit=*/true, &PP);
872 assert(BMI->isBaseInitializer() || BMI->isDelegatingInitializer());
874 // We already did all the work when visiting the CXXConstructExpr.
877 // Construct PostInitializer nodes whether the state changed or not,
878 // so that the diagnostics don't get confused.
879 PostInitializer PP(BMI, FieldLoc.getAsRegion(), stackFrame);
881 NodeBuilder Bldr(Tmp, Dst, *currBldrCtx);
882 for (const auto I : Tmp) {
883 ProgramStateRef State = I->getState();
884 Bldr.generateNode(PP, State, I);
887 // Enqueue the new nodes onto the work list.
888 Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
891 void ExprEngine::ProcessImplicitDtor(const CFGImplicitDtor D,
892 ExplodedNode *Pred) {
894 switch (D.getKind()) {
895 case CFGElement::AutomaticObjectDtor:
896 ProcessAutomaticObjDtor(D.castAs<CFGAutomaticObjDtor>(), Pred, Dst);
898 case CFGElement::BaseDtor:
899 ProcessBaseDtor(D.castAs<CFGBaseDtor>(), Pred, Dst);
901 case CFGElement::MemberDtor:
902 ProcessMemberDtor(D.castAs<CFGMemberDtor>(), Pred, Dst);
904 case CFGElement::TemporaryDtor:
905 ProcessTemporaryDtor(D.castAs<CFGTemporaryDtor>(), Pred, Dst);
907 case CFGElement::DeleteDtor:
908 ProcessDeleteDtor(D.castAs<CFGDeleteDtor>(), Pred, Dst);
911 llvm_unreachable("Unexpected dtor kind.");
914 // Enqueue the new nodes onto the work list.
915 Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
918 void ExprEngine::ProcessNewAllocator(const CXXNewExpr *NE,
919 ExplodedNode *Pred) {
921 AnalysisManager &AMgr = getAnalysisManager();
922 AnalyzerOptions &Opts = AMgr.options;
923 // TODO: We're not evaluating allocators for all cases just yet as
924 // we're not handling the return value correctly, which causes false
925 // positives when the alpha.cplusplus.NewDeleteLeaks check is on.
926 if (Opts.MayInlineCXXAllocator)
927 VisitCXXNewAllocatorCall(NE, Pred, Dst);
929 NodeBuilder Bldr(Pred, Dst, *currBldrCtx);
930 const LocationContext *LCtx = Pred->getLocationContext();
931 PostImplicitCall PP(NE->getOperatorNew(), NE->getBeginLoc(), LCtx);
932 Bldr.generateNode(PP, Pred->getState(), Pred);
934 Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
937 void ExprEngine::ProcessAutomaticObjDtor(const CFGAutomaticObjDtor Dtor,
939 ExplodedNodeSet &Dst) {
940 const VarDecl *varDecl = Dtor.getVarDecl();
941 QualType varType = varDecl->getType();
943 ProgramStateRef state = Pred->getState();
944 SVal dest = state->getLValue(varDecl, Pred->getLocationContext());
945 const MemRegion *Region = dest.castAs<loc::MemRegionVal>().getRegion();
947 if (varType->isReferenceType()) {
948 const MemRegion *ValueRegion = state->getSVal(Region).getAsRegion();
950 // FIXME: This should not happen. The language guarantees a presence
951 // of a valid initializer here, so the reference shall not be undefined.
952 // It seems that we're calling destructors over variables that
953 // were not initialized yet.
956 Region = ValueRegion->getBaseRegion();
957 varType = cast<TypedValueRegion>(Region)->getValueType();
960 // FIXME: We need to run the same destructor on every element of the array.
961 // This workaround will just run the first destructor (which will still
962 // invalidate the entire array).
963 EvalCallOptions CallOpts;
964 Region = makeZeroElementRegion(state, loc::MemRegionVal(Region), varType,
965 CallOpts.IsArrayCtorOrDtor).getAsRegion();
967 VisitCXXDestructor(varType, Region, Dtor.getTriggerStmt(),
968 /*IsBase=*/false, Pred, Dst, CallOpts);
971 void ExprEngine::ProcessDeleteDtor(const CFGDeleteDtor Dtor,
973 ExplodedNodeSet &Dst) {
974 ProgramStateRef State = Pred->getState();
975 const LocationContext *LCtx = Pred->getLocationContext();
976 const CXXDeleteExpr *DE = Dtor.getDeleteExpr();
977 const Stmt *Arg = DE->getArgument();
978 QualType DTy = DE->getDestroyedType();
979 SVal ArgVal = State->getSVal(Arg, LCtx);
981 // If the argument to delete is known to be a null value,
982 // don't run destructor.
983 if (State->isNull(ArgVal).isConstrainedTrue()) {
984 QualType BTy = getContext().getBaseElementType(DTy);
985 const CXXRecordDecl *RD = BTy->getAsCXXRecordDecl();
986 const CXXDestructorDecl *Dtor = RD->getDestructor();
988 PostImplicitCall PP(Dtor, DE->getBeginLoc(), LCtx);
989 NodeBuilder Bldr(Pred, Dst, *currBldrCtx);
990 Bldr.generateNode(PP, Pred->getState(), Pred);
994 EvalCallOptions CallOpts;
995 const MemRegion *ArgR = ArgVal.getAsRegion();
996 if (DE->isArrayForm()) {
997 // FIXME: We need to run the same destructor on every element of the array.
998 // This workaround will just run the first destructor (which will still
999 // invalidate the entire array).
1000 CallOpts.IsArrayCtorOrDtor = true;
1001 // Yes, it may even be a multi-dimensional array.
1002 while (const auto *AT = getContext().getAsArrayType(DTy))
1003 DTy = AT->getElementType();
1005 ArgR = getStoreManager().GetElementZeroRegion(cast<SubRegion>(ArgR), DTy);
1008 VisitCXXDestructor(DTy, ArgR, DE, /*IsBase=*/false, Pred, Dst, CallOpts);
1011 void ExprEngine::ProcessBaseDtor(const CFGBaseDtor D,
1012 ExplodedNode *Pred, ExplodedNodeSet &Dst) {
1013 const LocationContext *LCtx = Pred->getLocationContext();
1015 const auto *CurDtor = cast<CXXDestructorDecl>(LCtx->getDecl());
1016 Loc ThisPtr = getSValBuilder().getCXXThis(CurDtor,
1017 LCtx->getStackFrame());
1018 SVal ThisVal = Pred->getState()->getSVal(ThisPtr);
1020 // Create the base object region.
1021 const CXXBaseSpecifier *Base = D.getBaseSpecifier();
1022 QualType BaseTy = Base->getType();
1023 SVal BaseVal = getStoreManager().evalDerivedToBase(ThisVal, BaseTy,
1026 EvalCallOptions CallOpts;
1027 VisitCXXDestructor(BaseTy, BaseVal.getAsRegion(), CurDtor->getBody(),
1028 /*IsBase=*/true, Pred, Dst, CallOpts);
1031 void ExprEngine::ProcessMemberDtor(const CFGMemberDtor D,
1032 ExplodedNode *Pred, ExplodedNodeSet &Dst) {
1033 const FieldDecl *Member = D.getFieldDecl();
1034 QualType T = Member->getType();
1035 ProgramStateRef State = Pred->getState();
1036 const LocationContext *LCtx = Pred->getLocationContext();
1038 const auto *CurDtor = cast<CXXDestructorDecl>(LCtx->getDecl());
1039 Loc ThisStorageLoc =
1040 getSValBuilder().getCXXThis(CurDtor, LCtx->getStackFrame());
1041 Loc ThisLoc = State->getSVal(ThisStorageLoc).castAs<Loc>();
1042 SVal FieldVal = State->getLValue(Member, ThisLoc);
1044 // FIXME: We need to run the same destructor on every element of the array.
1045 // This workaround will just run the first destructor (which will still
1046 // invalidate the entire array).
1047 EvalCallOptions CallOpts;
1048 FieldVal = makeZeroElementRegion(State, FieldVal, T,
1049 CallOpts.IsArrayCtorOrDtor);
1051 VisitCXXDestructor(T, FieldVal.getAsRegion(), CurDtor->getBody(),
1052 /*IsBase=*/false, Pred, Dst, CallOpts);
1055 void ExprEngine::ProcessTemporaryDtor(const CFGTemporaryDtor D,
1057 ExplodedNodeSet &Dst) {
1058 const CXXBindTemporaryExpr *BTE = D.getBindTemporaryExpr();
1059 ProgramStateRef State = Pred->getState();
1060 const LocationContext *LC = Pred->getLocationContext();
1061 const MemRegion *MR = nullptr;
1063 if (Optional<SVal> V =
1064 getObjectUnderConstruction(State, D.getBindTemporaryExpr(),
1065 Pred->getLocationContext())) {
1066 // FIXME: Currently we insert temporary destructors for default parameters,
1067 // but we don't insert the constructors, so the entry in
1068 // ObjectsUnderConstruction may be missing.
1069 State = finishObjectConstruction(State, D.getBindTemporaryExpr(),
1070 Pred->getLocationContext());
1071 MR = V->getAsRegion();
1074 // If copy elision has occurred, and the constructor corresponding to the
1075 // destructor was elided, we need to skip the destructor as well.
1076 if (isDestructorElided(State, BTE, LC)) {
1077 State = cleanupElidedDestructor(State, BTE, LC);
1078 NodeBuilder Bldr(Pred, Dst, *currBldrCtx);
1079 PostImplicitCall PP(D.getDestructorDecl(getContext()),
1080 D.getBindTemporaryExpr()->getBeginLoc(),
1081 Pred->getLocationContext());
1082 Bldr.generateNode(PP, State, Pred);
1086 ExplodedNodeSet CleanDtorState;
1087 StmtNodeBuilder StmtBldr(Pred, CleanDtorState, *currBldrCtx);
1088 StmtBldr.generateNode(D.getBindTemporaryExpr(), Pred, State);
1090 QualType T = D.getBindTemporaryExpr()->getSubExpr()->getType();
1091 // FIXME: Currently CleanDtorState can be empty here due to temporaries being
1092 // bound to default parameters.
1093 assert(CleanDtorState.size() <= 1);
1094 ExplodedNode *CleanPred =
1095 CleanDtorState.empty() ? Pred : *CleanDtorState.begin();
1097 EvalCallOptions CallOpts;
1098 CallOpts.IsTemporaryCtorOrDtor = true;
1100 // If we have no MR, we still need to unwrap the array to avoid destroying
1101 // the whole array at once. Regardless, we'd eventually need to model array
1102 // destructors properly, element-by-element.
1103 while (const ArrayType *AT = getContext().getAsArrayType(T)) {
1104 T = AT->getElementType();
1105 CallOpts.IsArrayCtorOrDtor = true;
1108 // We'd eventually need to makeZeroElementRegion() trick here,
1109 // but for now we don't have the respective construction contexts,
1110 // so MR would always be null in this case. Do nothing for now.
1112 VisitCXXDestructor(T, MR, D.getBindTemporaryExpr(),
1113 /*IsBase=*/false, CleanPred, Dst, CallOpts);
1116 void ExprEngine::processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
1117 NodeBuilderContext &BldCtx,
1119 ExplodedNodeSet &Dst,
1120 const CFGBlock *DstT,
1121 const CFGBlock *DstF) {
1122 BranchNodeBuilder TempDtorBuilder(Pred, Dst, BldCtx, DstT, DstF);
1123 ProgramStateRef State = Pred->getState();
1124 const LocationContext *LC = Pred->getLocationContext();
1125 if (getObjectUnderConstruction(State, BTE, LC)) {
1126 TempDtorBuilder.markInfeasible(false);
1127 TempDtorBuilder.generateNode(State, true, Pred);
1129 TempDtorBuilder.markInfeasible(true);
1130 TempDtorBuilder.generateNode(State, false, Pred);
1134 void ExprEngine::VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
1135 ExplodedNodeSet &PreVisit,
1136 ExplodedNodeSet &Dst) {
1137 // This is a fallback solution in case we didn't have a construction
1138 // context when we were constructing the temporary. Otherwise the map should
1139 // have been populated there.
1140 if (!getAnalysisManager().options.ShouldIncludeTemporaryDtorsInCFG) {
1141 // In case we don't have temporary destructors in the CFG, do not mark
1142 // the initialization - we would otherwise never clean it up.
1146 StmtNodeBuilder StmtBldr(PreVisit, Dst, *currBldrCtx);
1147 for (ExplodedNode *Node : PreVisit) {
1148 ProgramStateRef State = Node->getState();
1149 const LocationContext *LC = Node->getLocationContext();
1150 if (!getObjectUnderConstruction(State, BTE, LC)) {
1151 // FIXME: Currently the state might also already contain the marker due to
1152 // incorrect handling of temporaries bound to default parameters; for
1153 // those, we currently skip the CXXBindTemporaryExpr but rely on adding
1154 // temporary destructor nodes.
1155 State = addObjectUnderConstruction(State, BTE, LC, UnknownVal());
1157 StmtBldr.generateNode(BTE, Node, State);
1161 ProgramStateRef ExprEngine::escapeValues(ProgramStateRef State,
1163 PointerEscapeKind K,
1164 const CallEvent *Call) const {
1165 class CollectReachableSymbolsCallback final : public SymbolVisitor {
1166 InvalidatedSymbols &Symbols;
1169 explicit CollectReachableSymbolsCallback(InvalidatedSymbols &Symbols)
1170 : Symbols(Symbols) {}
1172 const InvalidatedSymbols &getSymbols() const { return Symbols; }
1174 bool VisitSymbol(SymbolRef Sym) override {
1175 Symbols.insert(Sym);
1179 InvalidatedSymbols Symbols;
1180 CollectReachableSymbolsCallback CallBack(Symbols);
1182 State->scanReachableSymbols(V, CallBack);
1184 return getCheckerManager().runCheckersForPointerEscape(
1185 State, CallBack.getSymbols(), Call, K, nullptr);
1188 void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
1189 ExplodedNodeSet &DstTop) {
1190 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
1191 S->getBeginLoc(), "Error evaluating statement");
1192 ExplodedNodeSet Dst;
1193 StmtNodeBuilder Bldr(Pred, DstTop, *currBldrCtx);
1195 assert(!isa<Expr>(S) || S == cast<Expr>(S)->IgnoreParens());
1197 switch (S->getStmtClass()) {
1198 // C++, OpenMP and ARC stuff we don't support yet.
1199 case Stmt::CXXDependentScopeMemberExprClass:
1200 case Stmt::CXXTryStmtClass:
1201 case Stmt::CXXTypeidExprClass:
1202 case Stmt::CXXUuidofExprClass:
1203 case Stmt::CXXFoldExprClass:
1204 case Stmt::MSPropertyRefExprClass:
1205 case Stmt::MSPropertySubscriptExprClass:
1206 case Stmt::CXXUnresolvedConstructExprClass:
1207 case Stmt::DependentScopeDeclRefExprClass:
1208 case Stmt::ArrayTypeTraitExprClass:
1209 case Stmt::ExpressionTraitExprClass:
1210 case Stmt::UnresolvedLookupExprClass:
1211 case Stmt::UnresolvedMemberExprClass:
1212 case Stmt::TypoExprClass:
1213 case Stmt::RecoveryExprClass:
1214 case Stmt::CXXNoexceptExprClass:
1215 case Stmt::PackExpansionExprClass:
1216 case Stmt::SubstNonTypeTemplateParmPackExprClass:
1217 case Stmt::FunctionParmPackExprClass:
1218 case Stmt::CoroutineBodyStmtClass:
1219 case Stmt::CoawaitExprClass:
1220 case Stmt::DependentCoawaitExprClass:
1221 case Stmt::CoreturnStmtClass:
1222 case Stmt::CoyieldExprClass:
1223 case Stmt::SEHTryStmtClass:
1224 case Stmt::SEHExceptStmtClass:
1225 case Stmt::SEHLeaveStmtClass:
1226 case Stmt::SEHFinallyStmtClass:
1227 case Stmt::OMPCanonicalLoopClass:
1228 case Stmt::OMPParallelDirectiveClass:
1229 case Stmt::OMPSimdDirectiveClass:
1230 case Stmt::OMPForDirectiveClass:
1231 case Stmt::OMPForSimdDirectiveClass:
1232 case Stmt::OMPSectionsDirectiveClass:
1233 case Stmt::OMPSectionDirectiveClass:
1234 case Stmt::OMPSingleDirectiveClass:
1235 case Stmt::OMPMasterDirectiveClass:
1236 case Stmt::OMPCriticalDirectiveClass:
1237 case Stmt::OMPParallelForDirectiveClass:
1238 case Stmt::OMPParallelForSimdDirectiveClass:
1239 case Stmt::OMPParallelSectionsDirectiveClass:
1240 case Stmt::OMPParallelMasterDirectiveClass:
1241 case Stmt::OMPParallelMaskedDirectiveClass:
1242 case Stmt::OMPTaskDirectiveClass:
1243 case Stmt::OMPTaskyieldDirectiveClass:
1244 case Stmt::OMPBarrierDirectiveClass:
1245 case Stmt::OMPTaskwaitDirectiveClass:
1246 case Stmt::OMPTaskgroupDirectiveClass:
1247 case Stmt::OMPFlushDirectiveClass:
1248 case Stmt::OMPDepobjDirectiveClass:
1249 case Stmt::OMPScanDirectiveClass:
1250 case Stmt::OMPOrderedDirectiveClass:
1251 case Stmt::OMPAtomicDirectiveClass:
1252 case Stmt::OMPTargetDirectiveClass:
1253 case Stmt::OMPTargetDataDirectiveClass:
1254 case Stmt::OMPTargetEnterDataDirectiveClass:
1255 case Stmt::OMPTargetExitDataDirectiveClass:
1256 case Stmt::OMPTargetParallelDirectiveClass:
1257 case Stmt::OMPTargetParallelForDirectiveClass:
1258 case Stmt::OMPTargetUpdateDirectiveClass:
1259 case Stmt::OMPTeamsDirectiveClass:
1260 case Stmt::OMPCancellationPointDirectiveClass:
1261 case Stmt::OMPCancelDirectiveClass:
1262 case Stmt::OMPTaskLoopDirectiveClass:
1263 case Stmt::OMPTaskLoopSimdDirectiveClass:
1264 case Stmt::OMPMasterTaskLoopDirectiveClass:
1265 case Stmt::OMPMaskedTaskLoopDirectiveClass:
1266 case Stmt::OMPMasterTaskLoopSimdDirectiveClass:
1267 case Stmt::OMPMaskedTaskLoopSimdDirectiveClass:
1268 case Stmt::OMPParallelMasterTaskLoopDirectiveClass:
1269 case Stmt::OMPParallelMaskedTaskLoopDirectiveClass:
1270 case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass:
1271 case Stmt::OMPParallelMaskedTaskLoopSimdDirectiveClass:
1272 case Stmt::OMPDistributeDirectiveClass:
1273 case Stmt::OMPDistributeParallelForDirectiveClass:
1274 case Stmt::OMPDistributeParallelForSimdDirectiveClass:
1275 case Stmt::OMPDistributeSimdDirectiveClass:
1276 case Stmt::OMPTargetParallelForSimdDirectiveClass:
1277 case Stmt::OMPTargetSimdDirectiveClass:
1278 case Stmt::OMPTeamsDistributeDirectiveClass:
1279 case Stmt::OMPTeamsDistributeSimdDirectiveClass:
1280 case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass:
1281 case Stmt::OMPTeamsDistributeParallelForDirectiveClass:
1282 case Stmt::OMPTargetTeamsDirectiveClass:
1283 case Stmt::OMPTargetTeamsDistributeDirectiveClass:
1284 case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass:
1285 case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass:
1286 case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass:
1287 case Stmt::OMPTileDirectiveClass:
1288 case Stmt::OMPInteropDirectiveClass:
1289 case Stmt::OMPDispatchDirectiveClass:
1290 case Stmt::OMPMaskedDirectiveClass:
1291 case Stmt::OMPGenericLoopDirectiveClass:
1292 case Stmt::OMPTeamsGenericLoopDirectiveClass:
1293 case Stmt::OMPTargetTeamsGenericLoopDirectiveClass:
1294 case Stmt::OMPParallelGenericLoopDirectiveClass:
1295 case Stmt::OMPTargetParallelGenericLoopDirectiveClass:
1296 case Stmt::CapturedStmtClass:
1297 case Stmt::OMPUnrollDirectiveClass:
1298 case Stmt::OMPMetaDirectiveClass: {
1299 const ExplodedNode *node = Bldr.generateSink(S, Pred, Pred->getState());
1300 Engine.addAbortedBlock(node, currBldrCtx->getBlock());
1304 case Stmt::ParenExprClass:
1305 llvm_unreachable("ParenExprs already handled.");
1306 case Stmt::GenericSelectionExprClass:
1307 llvm_unreachable("GenericSelectionExprs already handled.");
1308 // Cases that should never be evaluated simply because they shouldn't
1309 // appear in the CFG.
1310 case Stmt::BreakStmtClass:
1311 case Stmt::CaseStmtClass:
1312 case Stmt::CompoundStmtClass:
1313 case Stmt::ContinueStmtClass:
1314 case Stmt::CXXForRangeStmtClass:
1315 case Stmt::DefaultStmtClass:
1316 case Stmt::DoStmtClass:
1317 case Stmt::ForStmtClass:
1318 case Stmt::GotoStmtClass:
1319 case Stmt::IfStmtClass:
1320 case Stmt::IndirectGotoStmtClass:
1321 case Stmt::LabelStmtClass:
1322 case Stmt::NoStmtClass:
1323 case Stmt::NullStmtClass:
1324 case Stmt::SwitchStmtClass:
1325 case Stmt::WhileStmtClass:
1326 case Expr::MSDependentExistsStmtClass:
1327 llvm_unreachable("Stmt should not be in analyzer evaluation loop");
1328 case Stmt::ImplicitValueInitExprClass:
1329 // These nodes are shared in the CFG and would case caching out.
1330 // Moreover, no additional evaluation required for them, the
1331 // analyzer can reconstruct these values from the AST.
1332 llvm_unreachable("Should be pruned from CFG");
1334 case Stmt::ObjCSubscriptRefExprClass:
1335 case Stmt::ObjCPropertyRefExprClass:
1336 llvm_unreachable("These are handled by PseudoObjectExpr");
1338 case Stmt::GNUNullExprClass: {
1339 // GNU __null is a pointer-width integer, not an actual pointer.
1340 ProgramStateRef state = Pred->getState();
1341 state = state->BindExpr(
1342 S, Pred->getLocationContext(),
1343 svalBuilder.makeIntValWithWidth(getContext().VoidPtrTy, 0));
1344 Bldr.generateNode(S, Pred, state);
1348 case Stmt::ObjCAtSynchronizedStmtClass:
1349 Bldr.takeNodes(Pred);
1350 VisitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(S), Pred, Dst);
1354 case Expr::ConstantExprClass:
1355 case Stmt::ExprWithCleanupsClass:
1356 // Handled due to fully linearised CFG.
1359 case Stmt::CXXBindTemporaryExprClass: {
1360 Bldr.takeNodes(Pred);
1361 ExplodedNodeSet PreVisit;
1362 getCheckerManager().runCheckersForPreStmt(PreVisit, Pred, S, *this);
1363 ExplodedNodeSet Next;
1364 VisitCXXBindTemporaryExpr(cast<CXXBindTemporaryExpr>(S), PreVisit, Next);
1365 getCheckerManager().runCheckersForPostStmt(Dst, Next, S, *this);
1370 case Stmt::ArrayInitLoopExprClass:
1371 Bldr.takeNodes(Pred);
1372 VisitArrayInitLoopExpr(cast<ArrayInitLoopExpr>(S), Pred, Dst);
1375 // Cases not handled yet; but will handle some day.
1376 case Stmt::DesignatedInitExprClass:
1377 case Stmt::DesignatedInitUpdateExprClass:
1378 case Stmt::ArrayInitIndexExprClass:
1379 case Stmt::ExtVectorElementExprClass:
1380 case Stmt::ImaginaryLiteralClass:
1381 case Stmt::ObjCAtCatchStmtClass:
1382 case Stmt::ObjCAtFinallyStmtClass:
1383 case Stmt::ObjCAtTryStmtClass:
1384 case Stmt::ObjCAutoreleasePoolStmtClass:
1385 case Stmt::ObjCEncodeExprClass:
1386 case Stmt::ObjCIsaExprClass:
1387 case Stmt::ObjCProtocolExprClass:
1388 case Stmt::ObjCSelectorExprClass:
1389 case Stmt::ParenListExprClass:
1390 case Stmt::ShuffleVectorExprClass:
1391 case Stmt::ConvertVectorExprClass:
1392 case Stmt::VAArgExprClass:
1393 case Stmt::CUDAKernelCallExprClass:
1394 case Stmt::OpaqueValueExprClass:
1395 case Stmt::AsTypeExprClass:
1396 case Stmt::ConceptSpecializationExprClass:
1397 case Stmt::CXXRewrittenBinaryOperatorClass:
1398 case Stmt::RequiresExprClass:
1401 // Cases we intentionally don't evaluate, since they don't need
1402 // to be explicitly evaluated.
1403 case Stmt::PredefinedExprClass:
1404 case Stmt::AddrLabelExprClass:
1405 case Stmt::AttributedStmtClass:
1406 case Stmt::IntegerLiteralClass:
1407 case Stmt::FixedPointLiteralClass:
1408 case Stmt::CharacterLiteralClass:
1409 case Stmt::CXXScalarValueInitExprClass:
1410 case Stmt::CXXBoolLiteralExprClass:
1411 case Stmt::ObjCBoolLiteralExprClass:
1412 case Stmt::ObjCAvailabilityCheckExprClass:
1413 case Stmt::FloatingLiteralClass:
1414 case Stmt::NoInitExprClass:
1415 case Stmt::SizeOfPackExprClass:
1416 case Stmt::StringLiteralClass:
1417 case Stmt::SourceLocExprClass:
1418 case Stmt::ObjCStringLiteralClass:
1419 case Stmt::CXXPseudoDestructorExprClass:
1420 case Stmt::SubstNonTypeTemplateParmExprClass:
1421 case Stmt::CXXNullPtrLiteralExprClass:
1422 case Stmt::OMPArraySectionExprClass:
1423 case Stmt::OMPArrayShapingExprClass:
1424 case Stmt::OMPIteratorExprClass:
1425 case Stmt::SYCLUniqueStableNameExprClass:
1426 case Stmt::TypeTraitExprClass: {
1427 Bldr.takeNodes(Pred);
1428 ExplodedNodeSet preVisit;
1429 getCheckerManager().runCheckersForPreStmt(preVisit, Pred, S, *this);
1430 getCheckerManager().runCheckersForPostStmt(Dst, preVisit, S, *this);
1435 case Stmt::CXXDefaultArgExprClass:
1436 case Stmt::CXXDefaultInitExprClass: {
1437 Bldr.takeNodes(Pred);
1438 ExplodedNodeSet PreVisit;
1439 getCheckerManager().runCheckersForPreStmt(PreVisit, Pred, S, *this);
1441 ExplodedNodeSet Tmp;
1442 StmtNodeBuilder Bldr2(PreVisit, Tmp, *currBldrCtx);
1445 if (const auto *DefE = dyn_cast<CXXDefaultArgExpr>(S))
1446 ArgE = DefE->getExpr();
1447 else if (const auto *DefE = dyn_cast<CXXDefaultInitExpr>(S))
1448 ArgE = DefE->getExpr();
1450 llvm_unreachable("unknown constant wrapper kind");
1452 bool IsTemporary = false;
1453 if (const auto *MTE = dyn_cast<MaterializeTemporaryExpr>(ArgE)) {
1454 ArgE = MTE->getSubExpr();
1458 Optional<SVal> ConstantVal = svalBuilder.getConstantVal(ArgE);
1460 ConstantVal = UnknownVal();
1462 const LocationContext *LCtx = Pred->getLocationContext();
1463 for (const auto I : PreVisit) {
1464 ProgramStateRef State = I->getState();
1465 State = State->BindExpr(S, LCtx, *ConstantVal);
1467 State = createTemporaryRegionIfNeeded(State, LCtx,
1470 Bldr2.generateNode(S, I, State);
1473 getCheckerManager().runCheckersForPostStmt(Dst, Tmp, S, *this);
1478 // Cases we evaluate as opaque expressions, conjuring a symbol.
1479 case Stmt::CXXStdInitializerListExprClass:
1480 case Expr::ObjCArrayLiteralClass:
1481 case Expr::ObjCDictionaryLiteralClass:
1482 case Expr::ObjCBoxedExprClass: {
1483 Bldr.takeNodes(Pred);
1485 ExplodedNodeSet preVisit;
1486 getCheckerManager().runCheckersForPreStmt(preVisit, Pred, S, *this);
1488 ExplodedNodeSet Tmp;
1489 StmtNodeBuilder Bldr2(preVisit, Tmp, *currBldrCtx);
1491 const auto *Ex = cast<Expr>(S);
1492 QualType resultType = Ex->getType();
1494 for (const auto N : preVisit) {
1495 const LocationContext *LCtx = N->getLocationContext();
1496 SVal result = svalBuilder.conjureSymbolVal(nullptr, Ex, LCtx,
1498 currBldrCtx->blockCount());
1499 ProgramStateRef State = N->getState()->BindExpr(Ex, LCtx, result);
1501 // Escape pointers passed into the list, unless it's an ObjC boxed
1502 // expression which is not a boxable C structure.
1503 if (!(isa<ObjCBoxedExpr>(Ex) &&
1504 !cast<ObjCBoxedExpr>(Ex)->getSubExpr()
1505 ->getType()->isRecordType()))
1506 for (auto Child : Ex->children()) {
1508 SVal Val = State->getSVal(Child, LCtx);
1509 State = escapeValues(State, Val, PSK_EscapeOther);
1512 Bldr2.generateNode(S, N, State);
1515 getCheckerManager().runCheckersForPostStmt(Dst, Tmp, S, *this);
1520 case Stmt::ArraySubscriptExprClass:
1521 Bldr.takeNodes(Pred);
1522 VisitArraySubscriptExpr(cast<ArraySubscriptExpr>(S), Pred, Dst);
1526 case Stmt::MatrixSubscriptExprClass:
1527 llvm_unreachable("Support for MatrixSubscriptExpr is not implemented.");
1530 case Stmt::GCCAsmStmtClass:
1531 Bldr.takeNodes(Pred);
1532 VisitGCCAsmStmt(cast<GCCAsmStmt>(S), Pred, Dst);
1536 case Stmt::MSAsmStmtClass:
1537 Bldr.takeNodes(Pred);
1538 VisitMSAsmStmt(cast<MSAsmStmt>(S), Pred, Dst);
1542 case Stmt::BlockExprClass:
1543 Bldr.takeNodes(Pred);
1544 VisitBlockExpr(cast<BlockExpr>(S), Pred, Dst);
1548 case Stmt::LambdaExprClass:
1549 if (AMgr.options.ShouldInlineLambdas) {
1550 Bldr.takeNodes(Pred);
1551 VisitLambdaExpr(cast<LambdaExpr>(S), Pred, Dst);
1554 const ExplodedNode *node = Bldr.generateSink(S, Pred, Pred->getState());
1555 Engine.addAbortedBlock(node, currBldrCtx->getBlock());
1559 case Stmt::BinaryOperatorClass: {
1560 const auto *B = cast<BinaryOperator>(S);
1561 if (B->isLogicalOp()) {
1562 Bldr.takeNodes(Pred);
1563 VisitLogicalExpr(B, Pred, Dst);
1567 else if (B->getOpcode() == BO_Comma) {
1568 ProgramStateRef state = Pred->getState();
1569 Bldr.generateNode(B, Pred,
1570 state->BindExpr(B, Pred->getLocationContext(),
1571 state->getSVal(B->getRHS(),
1572 Pred->getLocationContext())));
1576 Bldr.takeNodes(Pred);
1578 if (AMgr.options.ShouldEagerlyAssume &&
1579 (B->isRelationalOp() || B->isEqualityOp())) {
1580 ExplodedNodeSet Tmp;
1581 VisitBinaryOperator(cast<BinaryOperator>(S), Pred, Tmp);
1582 evalEagerlyAssumeBinOpBifurcation(Dst, Tmp, cast<Expr>(S));
1585 VisitBinaryOperator(cast<BinaryOperator>(S), Pred, Dst);
1591 case Stmt::CXXOperatorCallExprClass: {
1592 const auto *OCE = cast<CXXOperatorCallExpr>(S);
1594 // For instance method operators, make sure the 'this' argument has a
1596 const Decl *Callee = OCE->getCalleeDecl();
1597 if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(Callee)) {
1598 if (MD->isInstance()) {
1599 ProgramStateRef State = Pred->getState();
1600 const LocationContext *LCtx = Pred->getLocationContext();
1601 ProgramStateRef NewState =
1602 createTemporaryRegionIfNeeded(State, LCtx, OCE->getArg(0));
1603 if (NewState != State) {
1604 Pred = Bldr.generateNode(OCE, Pred, NewState, /*tag=*/nullptr,
1605 ProgramPoint::PreStmtKind);
1606 // Did we cache out?
1616 case Stmt::CallExprClass:
1617 case Stmt::CXXMemberCallExprClass:
1618 case Stmt::UserDefinedLiteralClass:
1619 Bldr.takeNodes(Pred);
1620 VisitCallExpr(cast<CallExpr>(S), Pred, Dst);
1624 case Stmt::CXXCatchStmtClass:
1625 Bldr.takeNodes(Pred);
1626 VisitCXXCatchStmt(cast<CXXCatchStmt>(S), Pred, Dst);
1630 case Stmt::CXXTemporaryObjectExprClass:
1631 case Stmt::CXXConstructExprClass:
1632 Bldr.takeNodes(Pred);
1633 VisitCXXConstructExpr(cast<CXXConstructExpr>(S), Pred, Dst);
1637 case Stmt::CXXInheritedCtorInitExprClass:
1638 Bldr.takeNodes(Pred);
1639 VisitCXXInheritedCtorInitExpr(cast<CXXInheritedCtorInitExpr>(S), Pred,
1644 case Stmt::CXXNewExprClass: {
1645 Bldr.takeNodes(Pred);
1647 ExplodedNodeSet PreVisit;
1648 getCheckerManager().runCheckersForPreStmt(PreVisit, Pred, S, *this);
1650 ExplodedNodeSet PostVisit;
1651 for (const auto i : PreVisit)
1652 VisitCXXNewExpr(cast<CXXNewExpr>(S), i, PostVisit);
1654 getCheckerManager().runCheckersForPostStmt(Dst, PostVisit, S, *this);
1659 case Stmt::CXXDeleteExprClass: {
1660 Bldr.takeNodes(Pred);
1661 ExplodedNodeSet PreVisit;
1662 const auto *CDE = cast<CXXDeleteExpr>(S);
1663 getCheckerManager().runCheckersForPreStmt(PreVisit, Pred, S, *this);
1664 ExplodedNodeSet PostVisit;
1665 getCheckerManager().runCheckersForPostStmt(PostVisit, PreVisit, S, *this);
1667 for (const auto i : PostVisit)
1668 VisitCXXDeleteExpr(CDE, i, Dst);
1673 // FIXME: ChooseExpr is really a constant. We need to fix
1674 // the CFG do not model them as explicit control-flow.
1676 case Stmt::ChooseExprClass: { // __builtin_choose_expr
1677 Bldr.takeNodes(Pred);
1678 const auto *C = cast<ChooseExpr>(S);
1679 VisitGuardedExpr(C, C->getLHS(), C->getRHS(), Pred, Dst);
1684 case Stmt::CompoundAssignOperatorClass:
1685 Bldr.takeNodes(Pred);
1686 VisitBinaryOperator(cast<BinaryOperator>(S), Pred, Dst);
1690 case Stmt::CompoundLiteralExprClass:
1691 Bldr.takeNodes(Pred);
1692 VisitCompoundLiteralExpr(cast<CompoundLiteralExpr>(S), Pred, Dst);
1696 case Stmt::BinaryConditionalOperatorClass:
1697 case Stmt::ConditionalOperatorClass: { // '?' operator
1698 Bldr.takeNodes(Pred);
1699 const auto *C = cast<AbstractConditionalOperator>(S);
1700 VisitGuardedExpr(C, C->getTrueExpr(), C->getFalseExpr(), Pred, Dst);
1705 case Stmt::CXXThisExprClass:
1706 Bldr.takeNodes(Pred);
1707 VisitCXXThisExpr(cast<CXXThisExpr>(S), Pred, Dst);
1711 case Stmt::DeclRefExprClass: {
1712 Bldr.takeNodes(Pred);
1713 const auto *DE = cast<DeclRefExpr>(S);
1714 VisitCommonDeclRefExpr(DE, DE->getDecl(), Pred, Dst);
1719 case Stmt::DeclStmtClass:
1720 Bldr.takeNodes(Pred);
1721 VisitDeclStmt(cast<DeclStmt>(S), Pred, Dst);
1725 case Stmt::ImplicitCastExprClass:
1726 case Stmt::CStyleCastExprClass:
1727 case Stmt::CXXStaticCastExprClass:
1728 case Stmt::CXXDynamicCastExprClass:
1729 case Stmt::CXXReinterpretCastExprClass:
1730 case Stmt::CXXConstCastExprClass:
1731 case Stmt::CXXFunctionalCastExprClass:
1732 case Stmt::BuiltinBitCastExprClass:
1733 case Stmt::ObjCBridgedCastExprClass:
1734 case Stmt::CXXAddrspaceCastExprClass: {
1735 Bldr.takeNodes(Pred);
1736 const auto *C = cast<CastExpr>(S);
1737 ExplodedNodeSet dstExpr;
1738 VisitCast(C, C->getSubExpr(), Pred, dstExpr);
1740 // Handle the postvisit checks.
1741 getCheckerManager().runCheckersForPostStmt(Dst, dstExpr, C, *this);
1746 case Expr::MaterializeTemporaryExprClass: {
1747 Bldr.takeNodes(Pred);
1748 const auto *MTE = cast<MaterializeTemporaryExpr>(S);
1749 ExplodedNodeSet dstPrevisit;
1750 getCheckerManager().runCheckersForPreStmt(dstPrevisit, Pred, MTE, *this);
1751 ExplodedNodeSet dstExpr;
1752 for (const auto i : dstPrevisit)
1753 CreateCXXTemporaryObject(MTE, i, dstExpr);
1754 getCheckerManager().runCheckersForPostStmt(Dst, dstExpr, MTE, *this);
1759 case Stmt::InitListExprClass:
1760 Bldr.takeNodes(Pred);
1761 VisitInitListExpr(cast<InitListExpr>(S), Pred, Dst);
1765 case Stmt::MemberExprClass:
1766 Bldr.takeNodes(Pred);
1767 VisitMemberExpr(cast<MemberExpr>(S), Pred, Dst);
1771 case Stmt::AtomicExprClass:
1772 Bldr.takeNodes(Pred);
1773 VisitAtomicExpr(cast<AtomicExpr>(S), Pred, Dst);
1777 case Stmt::ObjCIvarRefExprClass:
1778 Bldr.takeNodes(Pred);
1779 VisitLvalObjCIvarRefExpr(cast<ObjCIvarRefExpr>(S), Pred, Dst);
1783 case Stmt::ObjCForCollectionStmtClass:
1784 Bldr.takeNodes(Pred);
1785 VisitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(S), Pred, Dst);
1789 case Stmt::ObjCMessageExprClass:
1790 Bldr.takeNodes(Pred);
1791 VisitObjCMessage(cast<ObjCMessageExpr>(S), Pred, Dst);
1795 case Stmt::ObjCAtThrowStmtClass:
1796 case Stmt::CXXThrowExprClass:
1797 // FIXME: This is not complete. We basically treat @throw as
1799 Bldr.generateSink(S, Pred, Pred->getState());
1802 case Stmt::ReturnStmtClass:
1803 Bldr.takeNodes(Pred);
1804 VisitReturnStmt(cast<ReturnStmt>(S), Pred, Dst);
1808 case Stmt::OffsetOfExprClass: {
1809 Bldr.takeNodes(Pred);
1810 ExplodedNodeSet PreVisit;
1811 getCheckerManager().runCheckersForPreStmt(PreVisit, Pred, S, *this);
1813 ExplodedNodeSet PostVisit;
1814 for (const auto Node : PreVisit)
1815 VisitOffsetOfExpr(cast<OffsetOfExpr>(S), Node, PostVisit);
1817 getCheckerManager().runCheckersForPostStmt(Dst, PostVisit, S, *this);
1822 case Stmt::UnaryExprOrTypeTraitExprClass:
1823 Bldr.takeNodes(Pred);
1824 VisitUnaryExprOrTypeTraitExpr(cast<UnaryExprOrTypeTraitExpr>(S),
1829 case Stmt::StmtExprClass: {
1830 const auto *SE = cast<StmtExpr>(S);
1832 if (SE->getSubStmt()->body_empty()) {
1833 // Empty statement expression.
1834 assert(SE->getType() == getContext().VoidTy
1835 && "Empty statement expression must have void type.");
1839 if (const auto *LastExpr =
1840 dyn_cast<Expr>(*SE->getSubStmt()->body_rbegin())) {
1841 ProgramStateRef state = Pred->getState();
1842 Bldr.generateNode(SE, Pred,
1843 state->BindExpr(SE, Pred->getLocationContext(),
1844 state->getSVal(LastExpr,
1845 Pred->getLocationContext())));
1850 case Stmt::UnaryOperatorClass: {
1851 Bldr.takeNodes(Pred);
1852 const auto *U = cast<UnaryOperator>(S);
1853 if (AMgr.options.ShouldEagerlyAssume && (U->getOpcode() == UO_LNot)) {
1854 ExplodedNodeSet Tmp;
1855 VisitUnaryOperator(U, Pred, Tmp);
1856 evalEagerlyAssumeBinOpBifurcation(Dst, Tmp, U);
1859 VisitUnaryOperator(U, Pred, Dst);
1864 case Stmt::PseudoObjectExprClass: {
1865 Bldr.takeNodes(Pred);
1866 ProgramStateRef state = Pred->getState();
1867 const auto *PE = cast<PseudoObjectExpr>(S);
1868 if (const Expr *Result = PE->getResultExpr()) {
1869 SVal V = state->getSVal(Result, Pred->getLocationContext());
1870 Bldr.generateNode(S, Pred,
1871 state->BindExpr(S, Pred->getLocationContext(), V));
1874 Bldr.generateNode(S, Pred,
1875 state->BindExpr(S, Pred->getLocationContext(),
1882 case Expr::ObjCIndirectCopyRestoreExprClass: {
1883 // ObjCIndirectCopyRestoreExpr implies passing a temporary for
1884 // correctness of lifetime management. Due to limited analysis
1885 // of ARC, this is implemented as direct arg passing.
1886 Bldr.takeNodes(Pred);
1887 ProgramStateRef state = Pred->getState();
1888 const auto *OIE = cast<ObjCIndirectCopyRestoreExpr>(S);
1889 const Expr *E = OIE->getSubExpr();
1890 SVal V = state->getSVal(E, Pred->getLocationContext());
1891 Bldr.generateNode(S, Pred,
1892 state->BindExpr(S, Pred->getLocationContext(), V));
1899 bool ExprEngine::replayWithoutInlining(ExplodedNode *N,
1900 const LocationContext *CalleeLC) {
1901 const StackFrameContext *CalleeSF = CalleeLC->getStackFrame();
1902 const StackFrameContext *CallerSF = CalleeSF->getParent()->getStackFrame();
1903 assert(CalleeSF && CallerSF);
1904 ExplodedNode *BeforeProcessingCall = nullptr;
1905 const Stmt *CE = CalleeSF->getCallSite();
1907 // Find the first node before we started processing the call expression.
1909 ProgramPoint L = N->getLocation();
1910 BeforeProcessingCall = N;
1911 N = N->pred_empty() ? nullptr : *(N->pred_begin());
1913 // Skip the nodes corresponding to the inlined code.
1914 if (L.getStackFrame() != CallerSF)
1916 // We reached the caller. Find the node right before we started
1917 // processing the call.
1918 if (L.isPurgeKind())
1920 if (L.getAs<PreImplicitCall>())
1922 if (L.getAs<CallEnter>())
1924 if (Optional<StmtPoint> SP = L.getAs<StmtPoint>())
1925 if (SP->getStmt() == CE)
1930 if (!BeforeProcessingCall)
1933 // TODO: Clean up the unneeded nodes.
1935 // Build an Epsilon node from which we will restart the analyzes.
1936 // Note that CE is permitted to be NULL!
1937 ProgramPoint NewNodeLoc =
1938 EpsilonPoint(BeforeProcessingCall->getLocationContext(), CE);
1939 // Add the special flag to GDM to signal retrying with no inlining.
1940 // Note, changing the state ensures that we are not going to cache out.
1941 ProgramStateRef NewNodeState = BeforeProcessingCall->getState();
1943 NewNodeState->set<ReplayWithoutInlining>(const_cast<Stmt *>(CE));
1945 // Make the new node a successor of BeforeProcessingCall.
1947 ExplodedNode *NewNode = G.getNode(NewNodeLoc, NewNodeState, false, &IsNew);
1948 // We cached out at this point. Caching out is common due to us backtracking
1949 // from the inlined function, which might spawn several paths.
1953 NewNode->addPredecessor(BeforeProcessingCall, G);
1955 // Add the new node to the work list.
1956 Engine.enqueueStmtNode(NewNode, CalleeSF->getCallSiteBlock(),
1957 CalleeSF->getIndex());
1958 NumTimesRetriedWithoutInlining++;
1962 /// Block entrance. (Update counters).
1963 void ExprEngine::processCFGBlockEntrance(const BlockEdge &L,
1964 NodeBuilderWithSinks &nodeBuilder,
1965 ExplodedNode *Pred) {
1966 PrettyStackTraceLocationContext CrashInfo(Pred->getLocationContext());
1967 // If we reach a loop which has a known bound (and meets
1968 // other constraints) then consider completely unrolling it.
1969 if(AMgr.options.ShouldUnrollLoops) {
1970 unsigned maxBlockVisitOnPath = AMgr.options.maxBlockVisitOnPath;
1971 const Stmt *Term = nodeBuilder.getContext().getBlock()->getTerminatorStmt();
1973 ProgramStateRef NewState = updateLoopStack(Term, AMgr.getASTContext(),
1974 Pred, maxBlockVisitOnPath);
1975 if (NewState != Pred->getState()) {
1976 ExplodedNode *UpdatedNode = nodeBuilder.generateNode(NewState, Pred);
1982 // Is we are inside an unrolled loop then no need the check the counters.
1983 if(isUnrolledState(Pred->getState()))
1987 // If this block is terminated by a loop and it has already been visited the
1988 // maximum number of times, widen the loop.
1989 unsigned int BlockCount = nodeBuilder.getContext().blockCount();
1990 if (BlockCount == AMgr.options.maxBlockVisitOnPath - 1 &&
1991 AMgr.options.ShouldWidenLoops) {
1992 const Stmt *Term = nodeBuilder.getContext().getBlock()->getTerminatorStmt();
1993 if (!isa_and_nonnull<ForStmt, WhileStmt, DoStmt>(Term))
1996 const LocationContext *LCtx = Pred->getLocationContext();
1997 ProgramStateRef WidenedState =
1998 getWidenedLoopState(Pred->getState(), LCtx, BlockCount, Term);
1999 nodeBuilder.generateNode(WidenedState, Pred);
2003 // FIXME: Refactor this into a checker.
2004 if (BlockCount >= AMgr.options.maxBlockVisitOnPath) {
2005 static SimpleProgramPointTag tag(TagProviderName, "Block count exceeded");
2006 const ExplodedNode *Sink =
2007 nodeBuilder.generateSink(Pred->getState(), Pred, &tag);
2009 // Check if we stopped at the top level function or not.
2010 // Root node should have the location context of the top most function.
2011 const LocationContext *CalleeLC = Pred->getLocation().getLocationContext();
2012 const LocationContext *CalleeSF = CalleeLC->getStackFrame();
2013 const LocationContext *RootLC =
2014 (*G.roots_begin())->getLocation().getLocationContext();
2015 if (RootLC->getStackFrame() != CalleeSF) {
2016 Engine.FunctionSummaries->markReachedMaxBlockCount(CalleeSF->getDecl());
2018 // Re-run the call evaluation without inlining it, by storing the
2019 // no-inlining policy in the state and enqueuing the new work item on
2020 // the list. Replay should almost never fail. Use the stats to catch it
2022 if ((!AMgr.options.NoRetryExhausted &&
2023 replayWithoutInlining(Pred, CalleeLC)))
2025 NumMaxBlockCountReachedInInlined++;
2027 NumMaxBlockCountReached++;
2029 // Make sink nodes as exhausted(for stats) only if retry failed.
2030 Engine.blocksExhausted.push_back(std::make_pair(L, Sink));
2034 //===----------------------------------------------------------------------===//
2035 // Branch processing.
2036 //===----------------------------------------------------------------------===//
2038 /// RecoverCastedSymbol - A helper function for ProcessBranch that is used
2039 /// to try to recover some path-sensitivity for casts of symbolic
2040 /// integers that promote their values (which are currently not tracked well).
2041 /// This function returns the SVal bound to Condition->IgnoreCasts if all the
2042 // cast(s) did was sign-extend the original value.
2043 static SVal RecoverCastedSymbol(ProgramStateRef state,
2044 const Stmt *Condition,
2045 const LocationContext *LCtx,
2048 const auto *Ex = dyn_cast<Expr>(Condition);
2050 return UnknownVal();
2053 bool bitsInit = false;
2055 while (const auto *CE = dyn_cast<CastExpr>(Ex)) {
2056 QualType T = CE->getType();
2058 if (!T->isIntegralOrEnumerationType())
2059 return UnknownVal();
2061 uint64_t newBits = Ctx.getTypeSize(T);
2062 if (!bitsInit || newBits < bits) {
2067 Ex = CE->getSubExpr();
2070 // We reached a non-cast. Is it a symbolic value?
2071 QualType T = Ex->getType();
2073 if (!bitsInit || !T->isIntegralOrEnumerationType() ||
2074 Ctx.getTypeSize(T) > bits)
2075 return UnknownVal();
2077 return state->getSVal(Ex, LCtx);
2081 static const Stmt *getRightmostLeaf(const Stmt *Condition) {
2083 const auto *BO = dyn_cast<BinaryOperator>(Condition);
2084 if (!BO || !BO->isLogicalOp()) {
2087 Condition = BO->getRHS()->IgnoreParens();
2093 // Returns the condition the branch at the end of 'B' depends on and whose value
2094 // has been evaluated within 'B'.
2095 // In most cases, the terminator condition of 'B' will be evaluated fully in
2096 // the last statement of 'B'; in those cases, the resolved condition is the
2097 // given 'Condition'.
2098 // If the condition of the branch is a logical binary operator tree, the CFG is
2099 // optimized: in that case, we know that the expression formed by all but the
2100 // rightmost leaf of the logical binary operator tree must be true, and thus
2101 // the branch condition is at this point equivalent to the truth value of that
2102 // rightmost leaf; the CFG block thus only evaluates this rightmost leaf
2103 // expression in its final statement. As the full condition in that case was
2104 // not evaluated, and is thus not in the SVal cache, we need to use that leaf
2105 // expression to evaluate the truth value of the condition in the current state
2107 static const Stmt *ResolveCondition(const Stmt *Condition,
2108 const CFGBlock *B) {
2109 if (const auto *Ex = dyn_cast<Expr>(Condition))
2110 Condition = Ex->IgnoreParens();
2112 const auto *BO = dyn_cast<BinaryOperator>(Condition);
2113 if (!BO || !BO->isLogicalOp())
2116 assert(B->getTerminator().isStmtBranch() &&
2117 "Other kinds of branches are handled separately!");
2119 // For logical operations, we still have the case where some branches
2120 // use the traditional "merge" approach and others sink the branch
2121 // directly into the basic blocks representing the logical operation.
2122 // We need to distinguish between those two cases here.
2124 // The invariants are still shifting, but it is possible that the
2125 // last element in a CFGBlock is not a CFGStmt. Look for the last
2126 // CFGStmt as the value of the condition.
2127 CFGBlock::const_reverse_iterator I = B->rbegin(), E = B->rend();
2128 for (; I != E; ++I) {
2129 CFGElement Elem = *I;
2130 Optional<CFGStmt> CS = Elem.getAs<CFGStmt>();
2133 const Stmt *LastStmt = CS->getStmt();
2134 assert(LastStmt == Condition || LastStmt == getRightmostLeaf(Condition));
2137 llvm_unreachable("could not resolve condition");
2140 using ObjCForLctxPair =
2141 std::pair<const ObjCForCollectionStmt *, const LocationContext *>;
2143 REGISTER_MAP_WITH_PROGRAMSTATE(ObjCForHasMoreIterations, ObjCForLctxPair, bool)
2145 ProgramStateRef ExprEngine::setWhetherHasMoreIteration(
2146 ProgramStateRef State, const ObjCForCollectionStmt *O,
2147 const LocationContext *LC, bool HasMoreIteraton) {
2148 assert(!State->contains<ObjCForHasMoreIterations>({O, LC}));
2149 return State->set<ObjCForHasMoreIterations>({O, LC}, HasMoreIteraton);
2153 ExprEngine::removeIterationState(ProgramStateRef State,
2154 const ObjCForCollectionStmt *O,
2155 const LocationContext *LC) {
2156 assert(State->contains<ObjCForHasMoreIterations>({O, LC}));
2157 return State->remove<ObjCForHasMoreIterations>({O, LC});
2160 bool ExprEngine::hasMoreIteration(ProgramStateRef State,
2161 const ObjCForCollectionStmt *O,
2162 const LocationContext *LC) {
2163 assert(State->contains<ObjCForHasMoreIterations>({O, LC}));
2164 return *State->get<ObjCForHasMoreIterations>({O, LC});
2167 /// Split the state on whether there are any more iterations left for this loop.
2168 /// Returns a (HasMoreIteration, HasNoMoreIteration) pair, or None when the
2169 /// acquisition of the loop condition value failed.
2170 static Optional<std::pair<ProgramStateRef, ProgramStateRef>>
2171 assumeCondition(const Stmt *Condition, ExplodedNode *N) {
2172 ProgramStateRef State = N->getState();
2173 if (const auto *ObjCFor = dyn_cast<ObjCForCollectionStmt>(Condition)) {
2174 bool HasMoreIteraton =
2175 ExprEngine::hasMoreIteration(State, ObjCFor, N->getLocationContext());
2176 // Checkers have already ran on branch conditions, so the current
2177 // information as to whether the loop has more iteration becomes outdated
2178 // after this point.
2179 State = ExprEngine::removeIterationState(State, ObjCFor,
2180 N->getLocationContext());
2181 if (HasMoreIteraton)
2182 return std::pair<ProgramStateRef, ProgramStateRef>{State, nullptr};
2184 return std::pair<ProgramStateRef, ProgramStateRef>{nullptr, State};
2186 SVal X = State->getSVal(Condition, N->getLocationContext());
2188 if (X.isUnknownOrUndef()) {
2189 // Give it a chance to recover from unknown.
2190 if (const auto *Ex = dyn_cast<Expr>(Condition)) {
2191 if (Ex->getType()->isIntegralOrEnumerationType()) {
2192 // Try to recover some path-sensitivity. Right now casts of symbolic
2193 // integers that promote their values are currently not tracked well.
2194 // If 'Condition' is such an expression, try and recover the
2195 // underlying value and use that instead.
2197 RecoverCastedSymbol(State, Condition, N->getLocationContext(),
2198 N->getState()->getStateManager().getContext());
2200 if (!recovered.isUnknown()) {
2207 // If the condition is still unknown, give up.
2208 if (X.isUnknownOrUndef())
2211 DefinedSVal V = X.castAs<DefinedSVal>();
2213 ProgramStateRef StTrue, StFalse;
2214 return State->assume(V);
2217 void ExprEngine::processBranch(const Stmt *Condition,
2218 NodeBuilderContext& BldCtx,
2220 ExplodedNodeSet &Dst,
2221 const CFGBlock *DstT,
2222 const CFGBlock *DstF) {
2223 assert((!Condition || !isa<CXXBindTemporaryExpr>(Condition)) &&
2224 "CXXBindTemporaryExprs are handled by processBindTemporary.");
2225 const LocationContext *LCtx = Pred->getLocationContext();
2226 PrettyStackTraceLocationContext StackCrashInfo(LCtx);
2227 currBldrCtx = &BldCtx;
2229 // Check for NULL conditions; e.g. "for(;;)"
2231 BranchNodeBuilder NullCondBldr(Pred, Dst, BldCtx, DstT, DstF);
2232 NullCondBldr.markInfeasible(false);
2233 NullCondBldr.generateNode(Pred->getState(), true, Pred);
2237 if (const auto *Ex = dyn_cast<Expr>(Condition))
2238 Condition = Ex->IgnoreParens();
2240 Condition = ResolveCondition(Condition, BldCtx.getBlock());
2241 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
2242 Condition->getBeginLoc(),
2243 "Error evaluating branch");
2245 ExplodedNodeSet CheckersOutSet;
2246 getCheckerManager().runCheckersForBranchCondition(Condition, CheckersOutSet,
2248 // We generated only sinks.
2249 if (CheckersOutSet.empty())
2252 BranchNodeBuilder builder(CheckersOutSet, Dst, BldCtx, DstT, DstF);
2253 for (ExplodedNode *PredN : CheckersOutSet) {
2254 if (PredN->isSink())
2257 ProgramStateRef PrevState = PredN->getState();
2259 ProgramStateRef StTrue, StFalse;
2260 if (const auto KnownCondValueAssumption = assumeCondition(Condition, PredN))
2261 std::tie(StTrue, StFalse) = *KnownCondValueAssumption;
2263 assert(!isa<ObjCForCollectionStmt>(Condition));
2264 builder.generateNode(PrevState, true, PredN);
2265 builder.generateNode(PrevState, false, PredN);
2268 if (StTrue && StFalse)
2269 assert(!isa<ObjCForCollectionStmt>(Condition));
2271 // Process the true branch.
2272 if (builder.isFeasible(true)) {
2274 builder.generateNode(StTrue, true, PredN);
2276 builder.markInfeasible(true);
2279 // Process the false branch.
2280 if (builder.isFeasible(false)) {
2282 builder.generateNode(StFalse, false, PredN);
2284 builder.markInfeasible(false);
2287 currBldrCtx = nullptr;
2290 /// The GDM component containing the set of global variables which have been
2291 /// previously initialized with explicit initializers.
2292 REGISTER_TRAIT_WITH_PROGRAMSTATE(InitializedGlobalsSet,
2293 llvm::ImmutableSet<const VarDecl *>)
2295 void ExprEngine::processStaticInitializer(const DeclStmt *DS,
2296 NodeBuilderContext &BuilderCtx,
2298 ExplodedNodeSet &Dst,
2299 const CFGBlock *DstT,
2300 const CFGBlock *DstF) {
2301 PrettyStackTraceLocationContext CrashInfo(Pred->getLocationContext());
2302 currBldrCtx = &BuilderCtx;
2304 const auto *VD = cast<VarDecl>(DS->getSingleDecl());
2305 ProgramStateRef state = Pred->getState();
2306 bool initHasRun = state->contains<InitializedGlobalsSet>(VD);
2307 BranchNodeBuilder builder(Pred, Dst, BuilderCtx, DstT, DstF);
2310 state = state->add<InitializedGlobalsSet>(VD);
2313 builder.generateNode(state, initHasRun, Pred);
2314 builder.markInfeasible(!initHasRun);
2316 currBldrCtx = nullptr;
2319 /// processIndirectGoto - Called by CoreEngine. Used to generate successor
2320 /// nodes by processing the 'effects' of a computed goto jump.
2321 void ExprEngine::processIndirectGoto(IndirectGotoNodeBuilder &builder) {
2322 ProgramStateRef state = builder.getState();
2323 SVal V = state->getSVal(builder.getTarget(), builder.getLocationContext());
2325 // Three possibilities:
2327 // (1) We know the computed label.
2328 // (2) The label is NULL (or some other constant), or Undefined.
2329 // (3) We have no clue about the label. Dispatch to all targets.
2332 using iterator = IndirectGotoNodeBuilder::iterator;
2334 if (Optional<loc::GotoLabel> LV = V.getAs<loc::GotoLabel>()) {
2335 const LabelDecl *L = LV->getLabel();
2337 for (iterator I = builder.begin(), E = builder.end(); I != E; ++I) {
2338 if (I.getLabel() == L) {
2339 builder.generateNode(I, state);
2344 llvm_unreachable("No block with label.");
2347 if (isa<UndefinedVal, loc::ConcreteInt>(V)) {
2348 // Dispatch to the first target and mark it as a sink.
2349 //ExplodedNode* N = builder.generateNode(builder.begin(), state, true);
2350 // FIXME: add checker visit.
2351 // UndefBranches.insert(N);
2355 // This is really a catch-all. We don't support symbolics yet.
2356 // FIXME: Implement dispatch for symbolic pointers.
2358 for (iterator I = builder.begin(), E = builder.end(); I != E; ++I)
2359 builder.generateNode(I, state);
2362 void ExprEngine::processBeginOfFunction(NodeBuilderContext &BC,
2364 ExplodedNodeSet &Dst,
2365 const BlockEdge &L) {
2366 SaveAndRestore<const NodeBuilderContext *> NodeContextRAII(currBldrCtx, &BC);
2367 getCheckerManager().runCheckersForBeginFunction(Dst, L, Pred, *this);
2370 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path
2371 /// nodes when the control reaches the end of a function.
2372 void ExprEngine::processEndOfFunction(NodeBuilderContext& BC,
2374 const ReturnStmt *RS) {
2375 ProgramStateRef State = Pred->getState();
2377 if (!Pred->getStackFrame()->inTopFrame())
2378 State = finishArgumentConstruction(
2379 State, *getStateManager().getCallEventManager().getCaller(
2380 Pred->getStackFrame(), Pred->getState()));
2382 // FIXME: We currently cannot assert that temporaries are clear, because
2383 // lifetime extended temporaries are not always modelled correctly. In some
2384 // cases when we materialize the temporary, we do
2385 // createTemporaryRegionIfNeeded(), and the region changes, and also the
2386 // respective destructor becomes automatic from temporary. So for now clean up
2387 // the state manually before asserting. Ideally, this braced block of code
2390 const LocationContext *FromLC = Pred->getLocationContext();
2391 const LocationContext *ToLC = FromLC->getStackFrame()->getParent();
2392 const LocationContext *LC = FromLC;
2393 while (LC != ToLC) {
2394 assert(LC && "ToLC must be a parent of FromLC!");
2395 for (auto I : State->get<ObjectsUnderConstruction>())
2396 if (I.first.getLocationContext() == LC) {
2397 // The comment above only pardons us for not cleaning up a
2398 // temporary destructor. If any other statements are found here,
2399 // it must be a separate problem.
2400 assert(I.first.getItem().getKind() ==
2401 ConstructionContextItem::TemporaryDestructorKind ||
2402 I.first.getItem().getKind() ==
2403 ConstructionContextItem::ElidedDestructorKind);
2404 State = State->remove<ObjectsUnderConstruction>(I.first);
2406 LC = LC->getParent();
2410 // Perform the transition with cleanups.
2411 if (State != Pred->getState()) {
2412 ExplodedNodeSet PostCleanup;
2413 NodeBuilder Bldr(Pred, PostCleanup, BC);
2414 Pred = Bldr.generateNode(Pred->getLocation(), State, Pred);
2416 // The node with clean temporaries already exists. We might have reached
2417 // it on a path on which we initialize different temporaries.
2422 assert(areAllObjectsFullyConstructed(Pred->getState(),
2423 Pred->getLocationContext(),
2424 Pred->getStackFrame()->getParent()));
2426 PrettyStackTraceLocationContext CrashInfo(Pred->getLocationContext());
2428 ExplodedNodeSet Dst;
2429 if (Pred->getLocationContext()->inTopFrame()) {
2430 // Remove dead symbols.
2431 ExplodedNodeSet AfterRemovedDead;
2432 removeDeadOnEndOfFunction(BC, Pred, AfterRemovedDead);
2435 for (const auto I : AfterRemovedDead)
2436 getCheckerManager().runCheckersForEndFunction(BC, Dst, I, *this, RS);
2438 getCheckerManager().runCheckersForEndFunction(BC, Dst, Pred, *this, RS);
2441 Engine.enqueueEndOfFunction(Dst, RS);
2444 /// ProcessSwitch - Called by CoreEngine. Used to generate successor
2445 /// nodes by processing the 'effects' of a switch statement.
2446 void ExprEngine::processSwitch(SwitchNodeBuilder& builder) {
2447 using iterator = SwitchNodeBuilder::iterator;
2449 ProgramStateRef state = builder.getState();
2450 const Expr *CondE = builder.getCondition();
2451 SVal CondV_untested = state->getSVal(CondE, builder.getLocationContext());
2453 if (CondV_untested.isUndef()) {
2454 //ExplodedNode* N = builder.generateDefaultCaseNode(state, true);
2455 // FIXME: add checker
2456 //UndefBranches.insert(N);
2460 DefinedOrUnknownSVal CondV = CondV_untested.castAs<DefinedOrUnknownSVal>();
2462 ProgramStateRef DefaultSt = state;
2464 iterator I = builder.begin(), EI = builder.end();
2465 bool defaultIsFeasible = I == EI;
2467 for ( ; I != EI; ++I) {
2468 // Successor may be pruned out during CFG construction.
2472 const CaseStmt *Case = I.getCase();
2474 // Evaluate the LHS of the case value.
2475 llvm::APSInt V1 = Case->getLHS()->EvaluateKnownConstInt(getContext());
2476 assert(V1.getBitWidth() == getContext().getIntWidth(CondE->getType()));
2478 // Get the RHS of the case, if it exists.
2480 if (const Expr *E = Case->getRHS())
2481 V2 = E->EvaluateKnownConstInt(getContext());
2485 ProgramStateRef StateCase;
2486 if (Optional<NonLoc> NL = CondV.getAs<NonLoc>())
2487 std::tie(StateCase, DefaultSt) =
2488 DefaultSt->assumeInclusiveRange(*NL, V1, V2);
2490 StateCase = DefaultSt;
2493 builder.generateCaseStmtNode(I, StateCase);
2495 // Now "assume" that the case doesn't match. Add this state
2496 // to the default state (if it is feasible).
2498 defaultIsFeasible = true;
2500 defaultIsFeasible = false;
2505 if (!defaultIsFeasible)
2508 // If we have switch(enum value), the default branch is not
2509 // feasible if all of the enum constants not covered by 'case:' statements
2510 // are not feasible values for the switch condition.
2512 // Note that this isn't as accurate as it could be. Even if there isn't
2513 // a case for a particular enum value as long as that enum value isn't
2514 // feasible then it shouldn't be considered for making 'default:' reachable.
2515 const SwitchStmt *SS = builder.getSwitch();
2516 const Expr *CondExpr = SS->getCond()->IgnoreParenImpCasts();
2517 if (CondExpr->getType()->getAs<EnumType>()) {
2518 if (SS->isAllEnumCasesCovered())
2522 builder.generateDefaultCaseNode(DefaultSt);
2525 //===----------------------------------------------------------------------===//
2526 // Transfer functions: Loads and stores.
2527 //===----------------------------------------------------------------------===//
2529 void ExprEngine::VisitCommonDeclRefExpr(const Expr *Ex, const NamedDecl *D,
2531 ExplodedNodeSet &Dst) {
2532 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
2534 ProgramStateRef state = Pred->getState();
2535 const LocationContext *LCtx = Pred->getLocationContext();
2537 if (const auto *VD = dyn_cast<VarDecl>(D)) {
2538 // C permits "extern void v", and if you cast the address to a valid type,
2539 // you can even do things with it. We simply pretend
2540 assert(Ex->isGLValue() || VD->getType()->isVoidType());
2541 const LocationContext *LocCtxt = Pred->getLocationContext();
2542 const Decl *D = LocCtxt->getDecl();
2543 const auto *MD = dyn_cast_or_null<CXXMethodDecl>(D);
2544 const auto *DeclRefEx = dyn_cast<DeclRefExpr>(Ex);
2545 Optional<std::pair<SVal, QualType>> VInfo;
2547 if (AMgr.options.ShouldInlineLambdas && DeclRefEx &&
2548 DeclRefEx->refersToEnclosingVariableOrCapture() && MD &&
2549 MD->getParent()->isLambda()) {
2550 // Lookup the field of the lambda.
2551 const CXXRecordDecl *CXXRec = MD->getParent();
2552 llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
2553 FieldDecl *LambdaThisCaptureField;
2554 CXXRec->getCaptureFields(LambdaCaptureFields, LambdaThisCaptureField);
2556 // Sema follows a sequence of complex rules to determine whether the
2557 // variable should be captured.
2558 if (const FieldDecl *FD = LambdaCaptureFields[VD]) {
2560 svalBuilder.getCXXThis(MD, LocCtxt->getStackFrame());
2561 SVal CXXThisVal = state->getSVal(CXXThis);
2562 VInfo = std::make_pair(state->getLValue(FD, CXXThisVal), FD->getType());
2567 VInfo = std::make_pair(state->getLValue(VD, LocCtxt), VD->getType());
2569 SVal V = VInfo->first;
2570 bool IsReference = VInfo->second->isReferenceType();
2572 // For references, the 'lvalue' is the pointer address stored in the
2573 // reference region.
2575 if (const MemRegion *R = V.getAsRegion())
2576 V = state->getSVal(R);
2581 Bldr.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V), nullptr,
2582 ProgramPoint::PostLValueKind);
2585 if (const auto *ED = dyn_cast<EnumConstantDecl>(D)) {
2586 assert(!Ex->isGLValue());
2587 SVal V = svalBuilder.makeIntVal(ED->getInitVal());
2588 Bldr.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V));
2591 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2592 SVal V = svalBuilder.getFunctionPointer(FD);
2593 Bldr.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V), nullptr,
2594 ProgramPoint::PostLValueKind);
2597 if (isa<FieldDecl, IndirectFieldDecl>(D)) {
2598 // Delegate all work related to pointer to members to the surrounding
2602 if (const auto *BD = dyn_cast<BindingDecl>(D)) {
2603 const auto *DD = cast<DecompositionDecl>(BD->getDecomposedDecl());
2605 SVal Base = state->getLValue(DD, LCtx);
2606 if (DD->getType()->isReferenceType()) {
2607 Base = state->getSVal(Base.getAsRegion());
2610 SVal V = UnknownVal();
2612 // Handle binding to data members
2613 if (const auto *ME = dyn_cast<MemberExpr>(BD->getBinding())) {
2614 const auto *Field = cast<FieldDecl>(ME->getMemberDecl());
2615 V = state->getLValue(Field, Base);
2617 // Handle binding to arrays
2618 else if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(BD->getBinding())) {
2619 SVal Idx = state->getSVal(ASE->getIdx(), LCtx);
2621 // Note: the index of an element in a structured binding is automatically
2622 // created and it is a unique identifier of the specific element. Thus it
2623 // cannot be a value that varies at runtime.
2624 assert(Idx.isConstant() && "BindingDecl array index is not a constant!");
2626 V = state->getLValue(BD->getType(), Idx, Base);
2628 // Handle binding to tuple-like strcutures
2629 else if (BD->getHoldingVar()) {
2630 // FIXME: handle tuples
2633 llvm_unreachable("An unknown case of structured binding encountered!");
2635 if (BD->getType()->isReferenceType())
2636 V = state->getSVal(V.getAsRegion());
2638 Bldr.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V), nullptr,
2639 ProgramPoint::PostLValueKind);
2644 llvm_unreachable("Support for this Decl not implemented.");
2647 /// VisitArrayInitLoopExpr - Transfer function for array init loop.
2648 void ExprEngine::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *Ex,
2650 ExplodedNodeSet &Dst) {
2651 ExplodedNodeSet CheckerPreStmt;
2652 getCheckerManager().runCheckersForPreStmt(CheckerPreStmt, Pred, Ex, *this);
2654 ExplodedNodeSet EvalSet;
2655 StmtNodeBuilder Bldr(CheckerPreStmt, EvalSet, *currBldrCtx);
2657 const Expr *Arr = Ex->getCommonExpr()->getSourceExpr();
2659 for (auto *Node : CheckerPreStmt) {
2660 const LocationContext *LCtx = Node->getLocationContext();
2661 ProgramStateRef state = Node->getState();
2663 SVal Base = UnknownVal();
2665 // As in case of this expression the sub-expressions are not visited by any
2666 // other transfer functions, they are handled by matching their AST.
2668 // Case of implicit copy or move ctor of object with array member
2670 // Note: ExprEngine::VisitMemberExpr is not able to bind the array to the
2681 // The AST in case of a *copy constructor* looks like this:
2682 // ArrayInitLoopExpr
2683 // |-OpaqueValueExpr
2684 // | `-MemberExpr <-- match this
2690 // S d = std::move(d);
2692 // In case of a *move constructor* the resulting AST looks like:
2693 // ArrayInitLoopExpr
2694 // |-OpaqueValueExpr
2695 // | `-MemberExpr <-- match this first
2696 // | `-CXXStaticCastExpr <-- match this after
2699 if (const auto *ME = dyn_cast<MemberExpr>(Arr)) {
2700 Expr *MEBase = ME->getBase();
2703 if (auto CXXSCE = dyn_cast<CXXStaticCastExpr>(MEBase)) {
2704 MEBase = CXXSCE->getSubExpr();
2707 auto ObjDeclExpr = cast<DeclRefExpr>(MEBase);
2708 SVal Obj = state->getLValue(cast<VarDecl>(ObjDeclExpr->getDecl()), LCtx);
2710 Base = state->getLValue(cast<FieldDecl>(ME->getMemberDecl()), Obj);
2713 // Case of lambda capture and decomposition declaration
2717 // [arr]{ int a = arr[0]; }();
2718 // auto[a, b] = arr;
2720 // In both of these cases the AST looks like the following:
2721 // ArrayInitLoopExpr
2722 // |-OpaqueValueExpr
2723 // | `-DeclRefExpr <-- match this
2725 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arr))
2726 Base = state->getLValue(cast<VarDecl>(DRE->getDecl()), LCtx);
2728 // Create a lazy compound value to the original array
2729 if (const MemRegion *R = Base.getAsRegion())
2730 Base = state->getSVal(R);
2732 Base = UnknownVal();
2734 Bldr.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, Base));
2737 getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, Ex, *this);
2740 /// VisitArraySubscriptExpr - Transfer function for array accesses
2741 void ExprEngine::VisitArraySubscriptExpr(const ArraySubscriptExpr *A,
2743 ExplodedNodeSet &Dst){
2744 const Expr *Base = A->getBase()->IgnoreParens();
2745 const Expr *Idx = A->getIdx()->IgnoreParens();
2747 ExplodedNodeSet CheckerPreStmt;
2748 getCheckerManager().runCheckersForPreStmt(CheckerPreStmt, Pred, A, *this);
2750 ExplodedNodeSet EvalSet;
2751 StmtNodeBuilder Bldr(CheckerPreStmt, EvalSet, *currBldrCtx);
2753 bool IsVectorType = A->getBase()->getType()->isVectorType();
2755 // The "like" case is for situations where C standard prohibits the type to
2756 // be an lvalue, e.g. taking the address of a subscript of an expression of
2758 bool IsGLValueLike = A->isGLValue() ||
2759 (A->getType().isCForbiddenLValueType() && !AMgr.getLangOpts().CPlusPlus);
2761 for (auto *Node : CheckerPreStmt) {
2762 const LocationContext *LCtx = Node->getLocationContext();
2763 ProgramStateRef state = Node->getState();
2765 if (IsGLValueLike) {
2766 QualType T = A->getType();
2768 // One of the forbidden LValue types! We still need to have sensible
2769 // symbolic locations to represent this stuff. Note that arithmetic on
2770 // void pointers is a GCC extension.
2771 if (T->isVoidType())
2772 T = getContext().CharTy;
2774 SVal V = state->getLValue(T,
2775 state->getSVal(Idx, LCtx),
2776 state->getSVal(Base, LCtx));
2777 Bldr.generateNode(A, Node, state->BindExpr(A, LCtx, V), nullptr,
2778 ProgramPoint::PostLValueKind);
2779 } else if (IsVectorType) {
2780 // FIXME: non-glvalue vector reads are not modelled.
2781 Bldr.generateNode(A, Node, state, nullptr);
2783 llvm_unreachable("Array subscript should be an lValue when not \
2784 a vector and not a forbidden lvalue type");
2788 getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, A, *this);
2791 /// VisitMemberExpr - Transfer function for member expressions.
2792 void ExprEngine::VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
2793 ExplodedNodeSet &Dst) {
2794 // FIXME: Prechecks eventually go in ::Visit().
2795 ExplodedNodeSet CheckedSet;
2796 getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, M, *this);
2798 ExplodedNodeSet EvalSet;
2799 ValueDecl *Member = M->getMemberDecl();
2801 // Handle static member variables and enum constants accessed via
2803 if (isa<VarDecl, EnumConstantDecl>(Member)) {
2804 for (const auto I : CheckedSet)
2805 VisitCommonDeclRefExpr(M, Member, I, EvalSet);
2807 StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
2808 ExplodedNodeSet Tmp;
2810 for (const auto I : CheckedSet) {
2811 ProgramStateRef state = I->getState();
2812 const LocationContext *LCtx = I->getLocationContext();
2813 Expr *BaseExpr = M->getBase();
2815 // Handle C++ method calls.
2816 if (const auto *MD = dyn_cast<CXXMethodDecl>(Member)) {
2817 if (MD->isInstance())
2818 state = createTemporaryRegionIfNeeded(state, LCtx, BaseExpr);
2820 SVal MDVal = svalBuilder.getFunctionPointer(MD);
2821 state = state->BindExpr(M, LCtx, MDVal);
2823 Bldr.generateNode(M, I, state);
2827 // Handle regular struct fields / member variables.
2828 const SubRegion *MR = nullptr;
2829 state = createTemporaryRegionIfNeeded(state, LCtx, BaseExpr,
2831 /*OutRegionWithAdjustments=*/&MR);
2833 MR ? loc::MemRegionVal(MR) : state->getSVal(BaseExpr, LCtx);
2835 const auto *field = cast<FieldDecl>(Member);
2836 SVal L = state->getLValue(field, baseExprVal);
2838 if (M->isGLValue() || M->getType()->isArrayType()) {
2839 // We special-case rvalues of array type because the analyzer cannot
2840 // reason about them, since we expect all regions to be wrapped in Locs.
2841 // We instead treat these as lvalues and assume that they will decay to
2842 // pointers as soon as they are used.
2843 if (!M->isGLValue()) {
2844 assert(M->getType()->isArrayType());
2846 dyn_cast<ImplicitCastExpr>(I->getParentMap().getParentIgnoreParens(M));
2847 if (!PE || PE->getCastKind() != CK_ArrayToPointerDecay) {
2848 llvm_unreachable("should always be wrapped in ArrayToPointerDecay");
2852 if (field->getType()->isReferenceType()) {
2853 if (const MemRegion *R = L.getAsRegion())
2854 L = state->getSVal(R);
2859 Bldr.generateNode(M, I, state->BindExpr(M, LCtx, L), nullptr,
2860 ProgramPoint::PostLValueKind);
2863 evalLoad(Tmp, M, M, I, state, L);
2869 getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, M, *this);
2872 void ExprEngine::VisitAtomicExpr(const AtomicExpr *AE, ExplodedNode *Pred,
2873 ExplodedNodeSet &Dst) {
2874 ExplodedNodeSet AfterPreSet;
2875 getCheckerManager().runCheckersForPreStmt(AfterPreSet, Pred, AE, *this);
2877 // For now, treat all the arguments to C11 atomics as escaping.
2878 // FIXME: Ideally we should model the behavior of the atomics precisely here.
2880 ExplodedNodeSet AfterInvalidateSet;
2881 StmtNodeBuilder Bldr(AfterPreSet, AfterInvalidateSet, *currBldrCtx);
2883 for (const auto I : AfterPreSet) {
2884 ProgramStateRef State = I->getState();
2885 const LocationContext *LCtx = I->getLocationContext();
2887 SmallVector<SVal, 8> ValuesToInvalidate;
2888 for (unsigned SI = 0, Count = AE->getNumSubExprs(); SI != Count; SI++) {
2889 const Expr *SubExpr = AE->getSubExprs()[SI];
2890 SVal SubExprVal = State->getSVal(SubExpr, LCtx);
2891 ValuesToInvalidate.push_back(SubExprVal);
2894 State = State->invalidateRegions(ValuesToInvalidate, AE,
2895 currBldrCtx->blockCount(),
2897 /*CausedByPointerEscape*/true,
2898 /*Symbols=*/nullptr);
2900 SVal ResultVal = UnknownVal();
2901 State = State->BindExpr(AE, LCtx, ResultVal);
2902 Bldr.generateNode(AE, I, State, nullptr,
2903 ProgramPoint::PostStmtKind);
2906 getCheckerManager().runCheckersForPostStmt(Dst, AfterInvalidateSet, AE, *this);
2909 // A value escapes in four possible cases:
2910 // (1) We are binding to something that is not a memory region.
2911 // (2) We are binding to a MemRegion that does not have stack storage.
2912 // (3) We are binding to a top-level parameter region with a non-trivial
2913 // destructor. We won't see the destructor during analysis, but it's there.
2914 // (4) We are binding to a MemRegion with stack storage that the store
2915 // does not understand.
2916 ProgramStateRef ExprEngine::processPointerEscapedOnBind(
2917 ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals,
2918 const LocationContext *LCtx, PointerEscapeKind Kind,
2919 const CallEvent *Call) {
2920 SmallVector<SVal, 8> Escaped;
2921 for (const std::pair<SVal, SVal> &LocAndVal : LocAndVals) {
2922 // Cases (1) and (2).
2923 const MemRegion *MR = LocAndVal.first.getAsRegion();
2924 if (!MR || !MR->hasStackStorage()) {
2925 Escaped.push_back(LocAndVal.second);
2930 if (const auto *VR = dyn_cast<VarRegion>(MR->getBaseRegion()))
2931 if (VR->hasStackParametersStorage() && VR->getStackFrame()->inTopFrame())
2932 if (const auto *RD = VR->getValueType()->getAsCXXRecordDecl())
2933 if (!RD->hasTrivialDestructor()) {
2934 Escaped.push_back(LocAndVal.second);
2938 // Case (4): in order to test that, generate a new state with the binding
2939 // added. If it is the same state, then it escapes (since the store cannot
2940 // represent the binding).
2941 // Do this only if we know that the store is not supposed to generate the
2943 SVal StoredVal = State->getSVal(MR);
2944 if (StoredVal != LocAndVal.second)
2946 (State->bindLoc(loc::MemRegionVal(MR), LocAndVal.second, LCtx)))
2947 Escaped.push_back(LocAndVal.second);
2950 if (Escaped.empty())
2953 return escapeValues(State, Escaped, Kind, Call);
2957 ExprEngine::processPointerEscapedOnBind(ProgramStateRef State, SVal Loc,
2958 SVal Val, const LocationContext *LCtx) {
2959 std::pair<SVal, SVal> LocAndVal(Loc, Val);
2960 return processPointerEscapedOnBind(State, LocAndVal, LCtx, PSK_EscapeOnBind,
2965 ExprEngine::notifyCheckersOfPointerEscape(ProgramStateRef State,
2966 const InvalidatedSymbols *Invalidated,
2967 ArrayRef<const MemRegion *> ExplicitRegions,
2968 const CallEvent *Call,
2969 RegionAndSymbolInvalidationTraits &ITraits) {
2970 if (!Invalidated || Invalidated->empty())
2974 return getCheckerManager().runCheckersForPointerEscape(State,
2980 // If the symbols were invalidated by a call, we want to find out which ones
2981 // were invalidated directly due to being arguments to the call.
2982 InvalidatedSymbols SymbolsDirectlyInvalidated;
2983 for (const auto I : ExplicitRegions) {
2984 if (const SymbolicRegion *R = I->StripCasts()->getAs<SymbolicRegion>())
2985 SymbolsDirectlyInvalidated.insert(R->getSymbol());
2988 InvalidatedSymbols SymbolsIndirectlyInvalidated;
2989 for (const auto &sym : *Invalidated) {
2990 if (SymbolsDirectlyInvalidated.count(sym))
2992 SymbolsIndirectlyInvalidated.insert(sym);
2995 if (!SymbolsDirectlyInvalidated.empty())
2996 State = getCheckerManager().runCheckersForPointerEscape(State,
2997 SymbolsDirectlyInvalidated, Call, PSK_DirectEscapeOnCall, &ITraits);
2999 // Notify about the symbols that get indirectly invalidated by the call.
3000 if (!SymbolsIndirectlyInvalidated.empty())
3001 State = getCheckerManager().runCheckersForPointerEscape(State,
3002 SymbolsIndirectlyInvalidated, Call, PSK_IndirectEscapeOnCall, &ITraits);
3007 /// evalBind - Handle the semantics of binding a value to a specific location.
3008 /// This method is used by evalStore and (soon) VisitDeclStmt, and others.
3009 void ExprEngine::evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE,
3011 SVal location, SVal Val,
3012 bool atDeclInit, const ProgramPoint *PP) {
3013 const LocationContext *LC = Pred->getLocationContext();
3014 PostStmt PS(StoreE, LC);
3018 // Do a previsit of the bind.
3019 ExplodedNodeSet CheckedSet;
3020 getCheckerManager().runCheckersForBind(CheckedSet, Pred, location, Val,
3021 StoreE, *this, *PP);
3023 StmtNodeBuilder Bldr(CheckedSet, Dst, *currBldrCtx);
3025 // If the location is not a 'Loc', it will already be handled by
3026 // the checkers. There is nothing left to do.
3027 if (!isa<Loc>(location)) {
3028 const ProgramPoint L = PostStore(StoreE, LC, /*Loc*/nullptr,
3030 ProgramStateRef state = Pred->getState();
3031 state = processPointerEscapedOnBind(state, location, Val, LC);
3032 Bldr.generateNode(L, state, Pred);
3036 for (const auto PredI : CheckedSet) {
3037 ProgramStateRef state = PredI->getState();
3039 state = processPointerEscapedOnBind(state, location, Val, LC);
3041 // When binding the value, pass on the hint that this is a initialization.
3042 // For initializations, we do not need to inform clients of region
3044 state = state->bindLoc(location.castAs<Loc>(),
3045 Val, LC, /* notifyChanges = */ !atDeclInit);
3047 const MemRegion *LocReg = nullptr;
3048 if (Optional<loc::MemRegionVal> LocRegVal =
3049 location.getAs<loc::MemRegionVal>()) {
3050 LocReg = LocRegVal->getRegion();
3053 const ProgramPoint L = PostStore(StoreE, LC, LocReg, nullptr);
3054 Bldr.generateNode(L, state, PredI);
3058 /// evalStore - Handle the semantics of a store via an assignment.
3059 /// @param Dst The node set to store generated state nodes
3060 /// @param AssignE The assignment expression if the store happens in an
3062 /// @param LocationE The location expression that is stored to.
3063 /// @param state The current simulation state
3064 /// @param location The location to store the value
3065 /// @param Val The value to be stored
3066 void ExprEngine::evalStore(ExplodedNodeSet &Dst, const Expr *AssignE,
3067 const Expr *LocationE,
3069 ProgramStateRef state, SVal location, SVal Val,
3070 const ProgramPointTag *tag) {
3071 // Proceed with the store. We use AssignE as the anchor for the PostStore
3072 // ProgramPoint if it is non-NULL, and LocationE otherwise.
3073 const Expr *StoreE = AssignE ? AssignE : LocationE;
3075 // Evaluate the location (checks for bad dereferences).
3076 ExplodedNodeSet Tmp;
3077 evalLocation(Tmp, AssignE, LocationE, Pred, state, location, false);
3082 if (location.isUndef())
3085 for (const auto I : Tmp)
3086 evalBind(Dst, StoreE, I, location, Val, false);
3089 void ExprEngine::evalLoad(ExplodedNodeSet &Dst,
3091 const Expr *BoundEx,
3093 ProgramStateRef state,
3095 const ProgramPointTag *tag,
3097 assert(!isa<NonLoc>(location) && "location cannot be a NonLoc.");
3100 // Evaluate the location (checks for bad dereferences).
3101 ExplodedNodeSet Tmp;
3102 evalLocation(Tmp, NodeEx, BoundEx, Pred, state, location, true);
3106 StmtNodeBuilder Bldr(Tmp, Dst, *currBldrCtx);
3107 if (location.isUndef())
3110 // Proceed with the load.
3111 for (const auto I : Tmp) {
3112 state = I->getState();
3113 const LocationContext *LCtx = I->getLocationContext();
3115 SVal V = UnknownVal();
3116 if (location.isValid()) {
3117 if (LoadTy.isNull())
3118 LoadTy = BoundEx->getType();
3119 V = state->getSVal(location.castAs<Loc>(), LoadTy);
3122 Bldr.generateNode(NodeEx, I, state->BindExpr(BoundEx, LCtx, V), tag,
3123 ProgramPoint::PostLoadKind);
3127 void ExprEngine::evalLocation(ExplodedNodeSet &Dst,
3129 const Stmt *BoundEx,
3131 ProgramStateRef state,
3134 StmtNodeBuilder BldrTop(Pred, Dst, *currBldrCtx);
3135 // Early checks for performance reason.
3136 if (location.isUnknown()) {
3140 ExplodedNodeSet Src;
3141 BldrTop.takeNodes(Pred);
3142 StmtNodeBuilder Bldr(Pred, Src, *currBldrCtx);
3143 if (Pred->getState() != state) {
3144 // Associate this new state with an ExplodedNode.
3145 // FIXME: If I pass null tag, the graph is incorrect, e.g for
3149 // "p = 0" is not noted as "Null pointer value stored to 'p'" but
3150 // instead "int *p" is noted as
3151 // "Variable 'p' initialized to a null pointer value"
3153 static SimpleProgramPointTag tag(TagProviderName, "Location");
3154 Bldr.generateNode(NodeEx, Pred, state, &tag);
3156 ExplodedNodeSet Tmp;
3157 getCheckerManager().runCheckersForLocation(Tmp, Src, location, isLoad,
3158 NodeEx, BoundEx, *this);
3159 BldrTop.addNodes(Tmp);
3162 std::pair<const ProgramPointTag *, const ProgramPointTag*>
3163 ExprEngine::geteagerlyAssumeBinOpBifurcationTags() {
3164 static SimpleProgramPointTag
3165 eagerlyAssumeBinOpBifurcationTrue(TagProviderName,
3166 "Eagerly Assume True"),
3167 eagerlyAssumeBinOpBifurcationFalse(TagProviderName,
3168 "Eagerly Assume False");
3169 return std::make_pair(&eagerlyAssumeBinOpBifurcationTrue,
3170 &eagerlyAssumeBinOpBifurcationFalse);
3173 void ExprEngine::evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst,
3174 ExplodedNodeSet &Src,
3176 StmtNodeBuilder Bldr(Src, Dst, *currBldrCtx);
3178 for (const auto Pred : Src) {
3179 // Test if the previous node was as the same expression. This can happen
3180 // when the expression fails to evaluate to anything meaningful and
3181 // (as an optimization) we don't generate a node.
3182 ProgramPoint P = Pred->getLocation();
3183 if (!P.getAs<PostStmt>() || P.castAs<PostStmt>().getStmt() != Ex) {
3187 ProgramStateRef state = Pred->getState();
3188 SVal V = state->getSVal(Ex, Pred->getLocationContext());
3189 Optional<nonloc::SymbolVal> SEV = V.getAs<nonloc::SymbolVal>();
3190 if (SEV && SEV->isExpression()) {
3191 const std::pair<const ProgramPointTag *, const ProgramPointTag*> &tags =
3192 geteagerlyAssumeBinOpBifurcationTags();
3194 ProgramStateRef StateTrue, StateFalse;
3195 std::tie(StateTrue, StateFalse) = state->assume(*SEV);
3197 // First assume that the condition is true.
3199 SVal Val = svalBuilder.makeIntVal(1U, Ex->getType());
3200 StateTrue = StateTrue->BindExpr(Ex, Pred->getLocationContext(), Val);
3201 Bldr.generateNode(Ex, Pred, StateTrue, tags.first);
3204 // Next, assume that the condition is false.
3206 SVal Val = svalBuilder.makeIntVal(0U, Ex->getType());
3207 StateFalse = StateFalse->BindExpr(Ex, Pred->getLocationContext(), Val);
3208 Bldr.generateNode(Ex, Pred, StateFalse, tags.second);
3214 void ExprEngine::VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
3215 ExplodedNodeSet &Dst) {
3216 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
3217 // We have processed both the inputs and the outputs. All of the outputs
3218 // should evaluate to Locs. Nuke all of their values.
3220 // FIXME: Some day in the future it would be nice to allow a "plug-in"
3221 // which interprets the inline asm and stores proper results in the
3224 ProgramStateRef state = Pred->getState();
3226 for (const Expr *O : A->outputs()) {
3227 SVal X = state->getSVal(O, Pred->getLocationContext());
3228 assert(!isa<NonLoc>(X)); // Should be an Lval, or unknown, undef.
3230 if (Optional<Loc> LV = X.getAs<Loc>())
3231 state = state->bindLoc(*LV, UnknownVal(), Pred->getLocationContext());
3234 Bldr.generateNode(A, Pred, state);
3237 void ExprEngine::VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
3238 ExplodedNodeSet &Dst) {
3239 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
3240 Bldr.generateNode(A, Pred, Pred->getState());
3243 //===----------------------------------------------------------------------===//
3245 //===----------------------------------------------------------------------===//
3250 struct DOTGraphTraits<ExplodedGraph*> : public DefaultDOTGraphTraits {
3251 DOTGraphTraits (bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
3253 static bool nodeHasBugReport(const ExplodedNode *N) {
3254 BugReporter &BR = static_cast<ExprEngine &>(
3255 N->getState()->getStateManager().getOwningEngine()).getBugReporter();
3257 const auto EQClasses =
3258 llvm::make_range(BR.EQClasses_begin(), BR.EQClasses_end());
3260 for (const auto &EQ : EQClasses) {
3261 for (const auto &I : EQ.getReports()) {
3262 const auto *PR = dyn_cast<PathSensitiveBugReport>(I.get());
3265 const ExplodedNode *EN = PR->getErrorNode();
3266 if (EN->getState() == N->getState() &&
3267 EN->getLocation() == N->getLocation())
3274 /// \p PreCallback: callback before break.
3275 /// \p PostCallback: callback after break.
3276 /// \p Stop: stop iteration if returns @c true
3277 /// \return Whether @c Stop ever returned @c true.
3278 static bool traverseHiddenNodes(
3279 const ExplodedNode *N,
3280 llvm::function_ref<void(const ExplodedNode *)> PreCallback,
3281 llvm::function_ref<void(const ExplodedNode *)> PostCallback,
3282 llvm::function_ref<bool(const ExplodedNode *)> Stop) {
3288 if (N->succ_size() != 1 || !isNodeHidden(N->getFirstSucc(), nullptr))
3292 N = N->getFirstSucc();
3297 static bool isNodeHidden(const ExplodedNode *N, const ExplodedGraph *G) {
3298 return N->isTrivial();
3301 static std::string getNodeLabel(const ExplodedNode *N, ExplodedGraph *G){
3303 llvm::raw_string_ostream Out(Buf);
3305 const bool IsDot = true;
3306 const unsigned int Space = 1;
3307 ProgramStateRef State = N->getState();
3309 Out << "{ \"state_id\": " << State->getID()
3312 Indent(Out, Space, IsDot) << "\"program_points\": [\\l";
3314 // Dump program point for all the previously skipped nodes.
3315 traverseHiddenNodes(
3317 [&](const ExplodedNode *OtherNode) {
3318 Indent(Out, Space + 1, IsDot) << "{ ";
3319 OtherNode->getLocation().printJson(Out, /*NL=*/"\\l");
3320 Out << ", \"tag\": ";
3321 if (const ProgramPointTag *Tag = OtherNode->getLocation().getTag())
3322 Out << '\"' << Tag->getTagDescription() << "\"";
3325 Out << ", \"node_id\": " << OtherNode->getID() <<
3326 ", \"is_sink\": " << OtherNode->isSink() <<
3327 ", \"has_report\": " << nodeHasBugReport(OtherNode) << " }";
3329 // Adds a comma and a new-line between each program point.
3330 [&](const ExplodedNode *) { Out << ",\\l"; },
3331 [&](const ExplodedNode *) { return false; });
3333 Out << "\\l"; // Adds a new-line to the last program point.
3334 Indent(Out, Space, IsDot) << "],\\l";
3336 State->printDOT(Out, N->getLocationContext(), Space);
3345 void ExprEngine::ViewGraph(bool trim) {
3346 std::string Filename = DumpGraph(trim);
3347 llvm::DisplayGraph(Filename, false, llvm::GraphProgram::DOT);
3350 void ExprEngine::ViewGraph(ArrayRef<const ExplodedNode *> Nodes) {
3351 std::string Filename = DumpGraph(Nodes);
3352 llvm::DisplayGraph(Filename, false, llvm::GraphProgram::DOT);
3355 std::string ExprEngine::DumpGraph(bool trim, StringRef Filename) {
3357 std::vector<const ExplodedNode *> Src;
3359 // Iterate through the reports and get their nodes.
3360 for (BugReporter::EQClasses_iterator
3361 EI = BR.EQClasses_begin(), EE = BR.EQClasses_end(); EI != EE; ++EI) {
3363 dyn_cast<PathSensitiveBugReport>(EI->getReports()[0].get());
3366 const auto *N = const_cast<ExplodedNode *>(R->getErrorNode());
3369 return DumpGraph(Src, Filename);
3372 return llvm::WriteGraph(&G, "ExprEngine", /*ShortNames=*/false,
3373 /*Title=*/"Exploded Graph",
3374 /*Filename=*/std::string(Filename));
3377 std::string ExprEngine::DumpGraph(ArrayRef<const ExplodedNode *> Nodes,
3378 StringRef Filename) {
3379 std::unique_ptr<ExplodedGraph> TrimmedG(G.trim(Nodes));
3381 if (!TrimmedG.get()) {
3382 llvm::errs() << "warning: Trimmed ExplodedGraph is empty.\n";
3386 return llvm::WriteGraph(TrimmedG.get(), "TrimmedExprEngine",
3387 /*ShortNames=*/false,
3388 /*Title=*/"Trimmed Exploded Graph",
3389 /*Filename=*/std::string(Filename));
3392 void *ProgramStateTrait<ReplayWithoutInlining>::GDMIndex() {
3393 static int index = 0;
3397 void ExprEngine::anchor() { }