spaits updated this revision to Diff 504062.
spaits added a comment.
As @Szelethus has mentioned in his reply I tried to improve on the comment. I
hope now it describes correctly what the new visitor is good for.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D145069/new/
https://reviews.llvm.org/D145069
Files:
clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
Index: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -452,29 +452,8 @@
CallEventRef<> Call =
BR.getStateManager().getCallEventManager().getCaller(SCtx, State);
- // Optimistically suppress uninitialized value bugs that result
- // from system headers having a chance to initialize the value
- // but failing to do so. It's too unlikely a system header's fault.
- // It's much more likely a situation in which the function has a failure
- // mode that the user decided not to check. If we want to hunt such
- // omitted checks, we should provide an explicit function-specific note
- // describing the precondition under which the function isn't supposed to
- // initialize its out-parameter, and additionally check that such
- // precondition can actually be fulfilled on the current path.
- if (Call->isInSystemHeader()) {
- // We make an exception for system header functions that have no branches.
- // Such functions unconditionally fail to initialize the variable.
- // If they call other functions that have more paths within them,
- // this suppression would still apply when we visit these inner functions.
- // One common example of a standard function that doesn't ever initialize
- // its out parameter is operator placement new; it's up to the follow-up
- // constructor (if any) to initialize the memory.
- if (!N->getStackFrame()->getCFG()->isLinear()) {
- static int i = 0;
- R.markInvalid(&i, nullptr);
- }
+ if (Call->isInSystemHeader())
return nullptr;
- }
if (const auto *MC = dyn_cast<ObjCMethodCall>(Call)) {
// If we failed to construct a piece for self, we still want to check
@@ -492,6 +471,70 @@
return maybeEmitNoteForParameters(R, *Call, N);
}
+//===----------------------------------------------------------------------===//
+// Implementation of SuppressSystemHeaderWarningVistor.
+//===----------------------------------------------------------------------===//
+
+// This visitor suppresses warnings coming from inlined system
+// headers functions when we exit the call that have no branches.
+// This is a very primitive visitor. It flat-out suppresses every report that
+// have a node that matches all the conditions above.
+// It should be used carefully!
+//
+// A good example for the usage of this visitor is when we want to suppress
+// warnings when a system header function does not initialize their arguments.
+// It's too unlikely a system header's fault.
+// It's much more likely a situation in which the function has a failure
+// mode that the user decided not to check. If we want to hunt such
+// omitted checks, we should provide an explicit function-specific note
+// describing the precondition under which the function isn't supposed to
+// initialize its out-parameter, and additionally check that such
+// precondition can actually be fulfilled on the current path.
+//
+// System header functions that have no branches unconditionally fail to
+// initialize the variable.
+// If they call other functions that have more paths within them,
+// this suppression would still apply when we visit these inner functions.
+// One common example of a standard function that doesn't ever initialize
+// its out parameter is operator placement new; it's up to the follow-up
+// constructor (if any) to initialize the memory
+namespace {
+class SuppressSystemHeaderWarningVisitor : public BugReporterVisitor {
+public:
+ virtual PathDiagnosticPieceRef VisitNode(const ExplodedNode *,
+ BugReporterContext &,
+ PathSensitiveBugReport &) override;
+ void Profile(llvm::FoldingSetNodeID &ID) const override {
+ static int Tag = 0;
+ ID.AddPointer(&Tag);
+ }
+};
+} // namespace
+
+PathDiagnosticPieceRef
+SuppressSystemHeaderWarningVisitor::VisitNode(const ExplodedNode *Succ,
+ BugReporterContext &BRC,
+ PathSensitiveBugReport &BR) {
+ const LocationContext *Ctx = Succ->getLocationContext();
+ const StackFrameContext *SCtx = Ctx->getStackFrame();
+ ProgramStateRef State = Succ->getState();
+ auto CallExitLoc = Succ->getLocationAs<CallExitBegin>();
+
+ if (!CallExitLoc)
+ return nullptr;
+
+ CallEventRef<> Call =
+ BRC.getStateManager().getCallEventManager().getCaller(SCtx, State);
+
+ if (Call->isInSystemHeader()) {
+ if (!Succ->getStackFrame()->getCFG()->isLinear()) {
+ static int i = 0;
+ BR.markInvalid(&i, nullptr);
+ }
+ }
+ return nullptr;
+}
+
//===----------------------------------------------------------------------===//
// Implementation of NoStoreFuncVisitor.
//===----------------------------------------------------------------------===//
@@ -2350,7 +2393,7 @@
// Mark both the variable region and its contents as interesting.
SVal V = LVState->getRawSVal(loc::MemRegionVal(R));
Report.addVisitor<NoStoreFuncVisitor>(cast<SubRegion>(R), Opts.Kind);
-
+ Report.addVisitor<SuppressSystemHeaderWarningVisitor>();
// When we got here, we do have something to track, and we will
// interrupt.
Result.FoundSomethingToTrack = true;
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