================
@@ -3068,11 +3110,195 @@ void MallocChecker::checkDeadSymbols(SymbolReaper
&SymReaper,
C.addTransition(state->set<RegionState>(RS), N);
}
+// Allowlist of owning smart pointers we want to recognize.
+// Start with unique_ptr and shared_ptr. (intentionally exclude weak_ptr)
+static bool isSmartOwningPtrType(QualType QT) {
+ QT = QT->getCanonicalTypeUnqualified();
+
+ auto isSmartPtrName = [](StringRef Name) {
+ return Name == "unique_ptr" || Name == "shared_ptr";
+ };
+
+ // First try TemplateSpecializationType (for std smart pointers)
+ if (const auto *TST = QT->getAs<TemplateSpecializationType>()) {
+ const TemplateDecl *TD = TST->getTemplateName().getAsTemplateDecl();
+ if (!TD)
+ return false;
+
+ const auto *ND = dyn_cast_or_null<NamedDecl>(TD->getTemplatedDecl());
+ if (!ND)
+ return false;
+
+ // Check if it's in std namespace
+ if (!isWithinStdNamespace(ND))
+ return false;
+
+ return isSmartPtrName(ND->getName());
+ }
+
+ // Also try RecordType (for custom smart pointer implementations)
+ if (const auto *RD = QT->getAsCXXRecordDecl()) {
+ // Accept any custom unique_ptr or shared_ptr implementation
+ return (isSmartPtrName(RD->getName()));
+ }
+
+ return false;
+}
+
+static bool hasSmartPtrField(const CXXRecordDecl *CRD) {
+ // Check direct fields
+ if (llvm::any_of(CRD->fields(), [](const FieldDecl *FD) {
+ return isSmartOwningPtrType(FD->getType());
+ }))
+ return true;
+
+ // Check fields from base classes
+ for (const CXXBaseSpecifier &Base : CRD->bases()) {
+ if (const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl()) {
+ if (hasSmartPtrField(BaseDecl))
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool isRvalueByValueRecord(const Expr *AE) {
+ if (AE->isGLValue())
+ return false;
+
+ QualType T = AE->getType();
+ if (!T->isRecordType() || T->isReferenceType())
+ return false;
+
+ // Accept common temp/construct forms but don't overfit.
+ return isa<CXXTemporaryObjectExpr, MaterializeTemporaryExpr,
CXXConstructExpr,
+ InitListExpr, ImplicitCastExpr, CXXBindTemporaryExpr>(AE);
+}
+
+static bool isRvalueByValueRecordWithSmartPtr(const Expr *AE) {
+ if (!isRvalueByValueRecord(AE))
+ return false;
+
+ const auto *CRD = AE->getType()->getAsCXXRecordDecl();
+ return CRD && hasSmartPtrField(CRD);
+}
+
+static ProgramStateRef escapeAllAllocatedSymbols(ProgramStateRef State) {
+ RegionStateTy RS = State->get<RegionState>();
+ ProgramStateRef NewState = State;
+ for (auto [Sym, RefSt] : RS) {
+ if (RefSt.isAllocated() || RefSt.isAllocatedOfSizeZero()) {
+ NewState = NewState->set<RegionState>(Sym, RefState::getEscaped(&RefSt));
+ }
+ }
+ return NewState;
+}
+
+static void collectDirectSmartOwningPtrFieldRegions(
+ const MemRegion *Base, QualType RecQT, CheckerContext &C,
+ SmallVectorImpl<const MemRegion *> &Out) {
+ if (!Base)
+ return;
+ const auto *CRD = RecQT->getAsCXXRecordDecl();
+ if (!CRD)
+ return;
+
+ // Collect direct fields
+ for (const FieldDecl *FD : CRD->fields()) {
+ if (!isSmartOwningPtrType(FD->getType()))
+ continue;
+ SVal L = C.getState()->getLValue(FD, loc::MemRegionVal(Base));
+ if (const MemRegion *FR = L.getAsRegion())
+ Out.push_back(FR);
+ }
+
+ // Collect fields from base classes
+ for (const CXXBaseSpecifier &BaseSpec : CRD->bases()) {
+ if (const CXXRecordDecl *BaseDecl =
+ BaseSpec.getType()->getAsCXXRecordDecl()) {
+ // Get the base class region
+ SVal BaseL = C.getState()->getLValue(BaseDecl, Base->getAs<SubRegion>(),
+ BaseSpec.isVirtual());
+ if (const MemRegion *BaseRegion = BaseL.getAsRegion()) {
+ // Recursively collect fields from this base class
+ collectDirectSmartOwningPtrFieldRegions(BaseRegion, BaseSpec.getType(),
+ C, Out);
+ }
+ }
+ }
+}
+
void MallocChecker::checkPostCall(const CallEvent &Call,
CheckerContext &C) const {
+ // Keep existing post-call handlers.
if (const auto *PostFN = PostFnMap.lookup(Call)) {
(*PostFN)(this, C.getState(), Call, C);
- return;
+ }
+
+ SmallVector<const MemRegion *, 8> SmartPtrFieldRoots;
+ ProgramStateRef State = C.getState();
+ bool needsStateUpdate = false;
+
+ for (unsigned I = 0, E = Call.getNumArgs(); I != E; ++I) {
+ const Expr *AE = Call.getArgExpr(I);
+ if (!AE)
+ continue;
+ AE = AE->IgnoreParenImpCasts();
+
+ if (!isRvalueByValueRecordWithSmartPtr(AE))
+ continue;
+
+ // Find a region for the argument.
+ SVal ArgVal = Call.getArgSVal(I);
+ const MemRegion *ArgRegion = ArgVal.getAsRegion();
+ if (!ArgRegion) {
+ // Fallback: if we have a by-value record with smart pointer fields but
no
+ // region, mark all allocated symbols as escaped
+ State = escapeAllAllocatedSymbols(State);
+ needsStateUpdate = true;
+ continue;
+ }
+
+ // Push direct smart owning pointer field regions only (precise root set).
+ collectDirectSmartOwningPtrFieldRegions(ArgRegion, AE->getType(), C,
+ SmartPtrFieldRoots);
+ }
+
+ // Escape only from those field roots; do nothing if empty.
+ if (!SmartPtrFieldRoots.empty()) {
+ ProgramStateRef NewState =
+ EscapeTrackedCallback::EscapeTrackedRegionsReachableFrom(
+ SmartPtrFieldRoots, State);
+ if (NewState != State) {
+ State = NewState;
+ needsStateUpdate = true;
+ } else {
+ // Fallback: if we have by-value record arguments but no smart pointer
+ // fields detected, check if any of the arguments are by-value records
+ // with smart pointer fields
+ bool hasByValueRecordWithSmartPtr = false;
+ for (unsigned I = 0, E = Call.getNumArgs(); I != E; ++I) {
+ const Expr *AE = Call.getArgExpr(I);
+ if (!AE)
+ continue;
+ AE = AE->IgnoreParenImpCasts();
+
+ if (isRvalueByValueRecordWithSmartPtr(AE)) {
+ hasByValueRecordWithSmartPtr = true;
+ break;
+ }
+ }
+
+ if (hasByValueRecordWithSmartPtr) {
+ State = escapeAllAllocatedSymbols(State);
----------------
ivanmurashko wrote:
At 10th commit I did the following:
- Added a test case verifying that `MallocChecker` correctly reports leaks for
malloc when smart pointers are passed to functions.
- Fixed `checkPostCall` by removing fallback logic that indiscriminately
escaped all allocated symbols on encountering smart pointers. Now only memory
managed by smart pointers is escaped, enabling correct leak detection for
regular malloc calls.
- Simplified code by removing the `needsStateUpdate` flag; always call
`C.addTransition(State)` since it internally checks for state changes.
- Added clarifying comment about `addTransition` behaviour.
https://github.com/llvm/llvm-project/pull/152751
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