[analyzer] Do not run visitors until the fixpoint, run only once.
In the current implementation, we run visitors until the fixed point is
reached.
That is, if a visitor adds another visitor, the currently processed path
is destroyed, all diagnostics is discarded, and it is regenerated again,
until it's no longer modified.
This pattern has a few negative implications:
- This loop does not even guarantee to terminate.
E.g. just imagine two visitors bouncing a diagnostics around.
- Performance-wise, e.g. for sqlite3 all visitors are being re-run at
least 10 times for some bugs.
We have already seen a few reports where it leads to timeouts.
- If we want to add more computationally intense visitors, this will
become worse.
- From architectural standpoint, the current layout requires copying
visitors, which is conceptually wrong, and can be annoying (e.g. no
unique_ptr on visitors allowed).
The proposed change is a much simpler architecture: the outer loop
processes nodes upwards, and whenever the visitor is added it only
processes current nodes and above, thus guaranteeing termination.
Differential Revision: https://reviews.llvm.org/D47856
llvm-svn: 335666
diff --git a/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
index c5010f5..71703d6 100644
--- a/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/VirtualCallChecker.cpp
@@ -57,7 +57,7 @@
void reportBug(StringRef Msg, bool PureError, const MemRegion *Reg,
CheckerContext &C) const;
- class VirtualBugVisitor : public BugReporterVisitorImpl<VirtualBugVisitor> {
+ class VirtualBugVisitor : public BugReporterVisitor {
private:
const MemRegion *ObjectRegion;
bool Found;