rnkovacs updated this revision to Diff 152604.
rnkovacs marked an inline comment as done.
rnkovacs added a comment.
Um, sorry, I totally forgot about that. Added your case to the tests.
https://reviews.llvm.org/D48522
Files:
lib/StaticAnalyzer/Checkers/AllocationState.h
lib/StaticAnalyzer/Checkers/DanglingInternalBufferChecker.cpp
lib/StaticAnalyzer/Checkers/MallocChecker.cpp
test/Analysis/dangling-internal-buffer.cpp
Index: test/Analysis/dangling-internal-buffer.cpp
===================================================================
--- test/Analysis/dangling-internal-buffer.cpp
+++ test/Analysis/dangling-internal-buffer.cpp
@@ -25,17 +25,29 @@
const char *c;
{
std::string s;
- c = s.c_str();
+ c = s.c_str(); // expected-note {{Dangling buffer was obtained here}}
+ } // expected-note {{Internal buffer is released because the object was destroyed}}
+ consume(c); // expected-warning {{Use of memory after it is freed}}
+ // expected-note@-1 {{Use of memory after it is freed}}
+}
+
+void deref_after_scope_char2() {
+ const char *c;
+ {
+ std::string s;
+ c = s.c_str(); // expected-note {{Dangling buffer was obtained here}}
} // expected-note {{Internal buffer is released because the object was destroyed}}
+ std::string s;
+ const char *c2 = s.c_str();
consume(c); // expected-warning {{Use of memory after it is freed}}
// expected-note@-1 {{Use of memory after it is freed}}
}
void deref_after_scope_wchar_t() {
const wchar_t *w;
{
std::wstring ws;
- w = ws.c_str();
+ w = ws.c_str(); // expected-note {{Dangling buffer was obtained here}}
} // expected-note {{Internal buffer is released because the object was destroyed}}
consume(w); // expected-warning {{Use of memory after it is freed}}
// expected-note@-1 {{Use of memory after it is freed}}
@@ -45,7 +57,7 @@
const char16_t *c16;
{
std::u16string s16;
- c16 = s16.c_str();
+ c16 = s16.c_str(); // expected-note {{Dangling buffer was obtained here}}
} // expected-note {{Internal buffer is released because the object was destroyed}}
consume(c16); // expected-warning {{Use of memory after it is freed}}
// expected-note@-1 {{Use of memory after it is freed}}
@@ -55,7 +67,7 @@
const char32_t *c32;
{
std::u32string s32;
- c32 = s32.c_str();
+ c32 = s32.c_str(); // expected-note {{Dangling buffer was obtained here}}
} // expected-note {{Internal buffer is released because the object was destroyed}}
consume(c32); // expected-warning {{Use of memory after it is freed}}
// expected-note@-1 {{Use of memory after it is freed}}
Index: lib/StaticAnalyzer/Checkers/MallocChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -1988,6 +1988,11 @@
R->markInteresting(Sym);
R->addRange(Range);
R->addVisitor(llvm::make_unique<MallocBugVisitor>(Sym));
+
+ const RefState *RS = C.getState()->get<RegionState>(Sym);
+ if (RS->getAllocationFamily() == AF_InternalBuffer)
+ R->addVisitor(allocation_state::getDanglingBufferBRVisitor(Sym));
+
C.emitReport(std::move(R));
}
}
Index: lib/StaticAnalyzer/Checkers/DanglingInternalBufferChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/DanglingInternalBufferChecker.cpp
+++ lib/StaticAnalyzer/Checkers/DanglingInternalBufferChecker.cpp
@@ -24,13 +24,51 @@
using namespace clang;
using namespace ento;
+// FIXME: c_str() may be called on a string object many times, so it should
+// have a list of symbols associated with it.
+REGISTER_MAP_WITH_PROGRAMSTATE(RawPtrMap, const MemRegion *, SymbolRef)
+
namespace {
class DanglingInternalBufferChecker : public Checker<check::DeadSymbols,
check::PostCall> {
CallDescription CStrFn;
public:
+ class DanglingBufferBRVisitor
+ : public BugReporterVisitorImpl<DanglingBufferBRVisitor> {
+ // Tracked pointer to a buffer.
+ SymbolRef Sym;
+
+ public:
+ DanglingBufferBRVisitor(SymbolRef Sym) : Sym(Sym) {}
+
+ static void *getTag() {
+ static int Tag = 0;
+ return &Tag;
+ }
+
+ void Profile(llvm::FoldingSetNodeID &ID) const override {
+ ID.AddPointer(getTag());
+ }
+
+ std::shared_ptr<PathDiagnosticPiece> VisitNode(const ExplodedNode *N,
+ const ExplodedNode *PrevN,
+ BugReporterContext &BRC,
+ BugReport &BR) override;
+
+ bool isSymbolTracked(ProgramStateRef State, SymbolRef Sym) {
+ bool Found = false;
+ RawPtrMapTy Map = State->get<RawPtrMap>();
+ for (const auto Entry : Map) {
+ if (Entry.second == Sym)
+ Found = true;
+ }
+ return Found;
+ }
+
+ };
+
DanglingInternalBufferChecker() : CStrFn("c_str") {}
/// Record the connection between the symbol returned by c_str() and the
@@ -44,10 +82,6 @@
} // end anonymous namespace
-// FIXME: c_str() may be called on a string object many times, so it should
-// have a list of symbols associated with it.
-REGISTER_MAP_WITH_PROGRAMSTATE(RawPtrMap, const MemRegion *, SymbolRef)
-
void DanglingInternalBufferChecker::checkPostCall(const CallEvent &Call,
CheckerContext &C) const {
const auto *ICall = dyn_cast<CXXInstanceCall>(&Call);
@@ -103,6 +137,41 @@
C.addTransition(State);
}
+std::shared_ptr<PathDiagnosticPiece>
+DanglingInternalBufferChecker::DanglingBufferBRVisitor::VisitNode(
+ const ExplodedNode *N, const ExplodedNode *PrevN,
+ BugReporterContext &BRC, BugReport &BR) {
+
+ if (!isSymbolTracked(N->getState(), Sym) ||
+ isSymbolTracked(PrevN->getState(), Sym))
+ return nullptr;
+
+ const Stmt *S = PathDiagnosticLocation::getStmt(N);
+ if (!S)
+ return nullptr;
+
+ SmallString<256> Buf;
+ llvm::raw_svector_ostream OS(Buf);
+ OS << "Dangling buffer was obtained here";
+ PathDiagnosticLocation Pos(S, BRC.getSourceManager(),
+ N->getLocationContext());
+ return std::make_shared<PathDiagnosticEventPiece>(Pos, OS.str(),
+ true, nullptr);
+}
+
+namespace clang {
+namespace ento {
+namespace allocation_state {
+
+std::unique_ptr<BugReporterVisitor>
+getDanglingBufferBRVisitor(SymbolRef Sym) {
+ return llvm::make_unique<DanglingInternalBufferChecker::DanglingBufferBRVisitor>(Sym);
+}
+
+} // end namespace allocation_state
+} // end namespace ento
+} // end namespace clang
+
void ento::registerDanglingInternalBufferChecker(CheckerManager &Mgr) {
registerNewDeleteChecker(Mgr);
Mgr.registerChecker<DanglingInternalBufferChecker>();
Index: lib/StaticAnalyzer/Checkers/AllocationState.h
===================================================================
--- lib/StaticAnalyzer/Checkers/AllocationState.h
+++ lib/StaticAnalyzer/Checkers/AllocationState.h
@@ -20,6 +20,9 @@
ProgramStateRef markReleased(ProgramStateRef State, SymbolRef Sym,
const Expr *Origin);
+std::unique_ptr<BugReporterVisitor>
+getDanglingBufferBRVisitor(SymbolRef Sym);
+
} // end namespace allocation_state
} // end namespace ento
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