[analyzer] Malloc: unique leak reports by allocation site.
When we find two leak reports with the same allocation site, report only
one of them.
Provide a helper method to BugReporter to facilitate this.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151287 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 4ae1dd8..d6dc97a 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -186,6 +186,11 @@
static bool SummarizeRegion(raw_ostream &os, const MemRegion *MR);
void ReportBadFree(CheckerContext &C, SVal ArgVal, SourceRange range) const;
+ /// Find the location of the allocation for Sym on the path leading to the
+ /// exploded node N.
+ const Stmt *getAllocationSite(const ExplodedNode *N, SymbolRef Sym,
+ CheckerContext &C) const;
+
void reportLeak(SymbolRef Sym, ExplodedNode *N, CheckerContext &C) const;
/// The bug visitor which allows us to print extra diagnostics along the
@@ -766,6 +771,24 @@
return MallocMemAux(C, CE, TotalSize, zeroVal, state);
}
+const Stmt *
+MallocChecker::getAllocationSite(const ExplodedNode *N, SymbolRef Sym,
+ CheckerContext &C) const {
+ // Walk the ExplodedGraph backwards and find the first node that referred to
+ // the tracked symbol.
+ const ExplodedNode *AllocNode = N;
+
+ while (N) {
+ if (!N->getState()->get<RegionState>(Sym))
+ break;
+ AllocNode = N;
+ N = N->pred_empty() ? NULL : *(N->pred_begin());
+ }
+
+ ProgramPoint P = AllocNode->getLocation();
+ return cast<clang::PostStmt>(P).getStmt();
+}
+
void MallocChecker::reportLeak(SymbolRef Sym, ExplodedNode *N,
CheckerContext &C) const {
assert(N);
@@ -779,8 +802,16 @@
BT_Leak->setSuppressOnSink(true);
}
+ // Most bug reports are cached at the location where they occurred.
+ // With leaks, we want to unique them by the location where they were
+ // allocated, and only report a single path.
+ const Stmt *AllocStmt = getAllocationSite(N, Sym, C);
+ PathDiagnosticLocation LocUsedForUniqueing =
+ PathDiagnosticLocation::createBegin(AllocStmt, C.getSourceManager(),
+ N->getLocationContext());
+
BugReport *R = new BugReport(*BT_Leak,
- "Memory is never released; potential memory leak", N);
+ "Memory is never released; potential memory leak", N, LocUsedForUniqueing);
R->addVisitor(new MallocBugVisitor(Sym));
C.EmitReport(R);
}
@@ -818,14 +849,17 @@
}
}
- ExplodedNode *N = C.addTransition(state->set<RegionState>(RS));
+ // Generate leak node.
+ static SimpleProgramPointTag Tag("MallocChecker : DeadSymbolsLeak");
+ ExplodedNode *N = C.addTransition(C.getState(), C.getPredecessor(), &Tag);
- if (N && generateReport) {
+ if (generateReport) {
for (llvm::SmallVector<SymbolRef, 2>::iterator
I = Errors.begin(), E = Errors.end(); I != E; ++I) {
reportLeak(*I, N, C);
}
}
+ C.addTransition(state->set<RegionState>(RS), N);
}
void MallocChecker::checkEndPath(CheckerContext &C) const {
diff --git a/lib/StaticAnalyzer/Core/BugReporter.cpp b/lib/StaticAnalyzer/Core/BugReporter.cpp
index 0df71f2..0dbc7f1 100644
--- a/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -1270,7 +1270,9 @@
void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
hash.AddPointer(&BT);
hash.AddString(Description);
- if (Location.isValid()) {
+ if (UniqueingLocation.isValid()) {
+ UniqueingLocation.Profile(hash);
+ } else if (Location.isValid()) {
Location.Profile(hash);
} else {
assert(ErrorNode);