[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/MallocChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 2ab817a..b008bcd 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -431,8 +431,7 @@
/// The bug visitor which allows us to print extra diagnostics along the
/// BugReport path. For example, showing the allocation site of the leaked
/// region.
- class MallocBugVisitor final
- : public BugReporterVisitorImpl<MallocBugVisitor> {
+ class MallocBugVisitor final : public BugReporterVisitor {
protected:
enum NotificationMode {
Normal,
@@ -511,7 +510,7 @@
BugReporterContext &BRC,
BugReport &BR) override;
- std::unique_ptr<PathDiagnosticPiece>
+ std::shared_ptr<PathDiagnosticPiece>
getEndPath(BugReporterContext &BRC, const ExplodedNode *EndPathNode,
BugReport &BR) override {
if (!IsLeak)
@@ -521,7 +520,7 @@
PathDiagnosticLocation::createEndOfPath(EndPathNode,
BRC.getSourceManager());
// Do not add the statement itself as a range in case of leak.
- return llvm::make_unique<PathDiagnosticEventPiece>(L, BR.getDescription(),
+ return std::make_shared<PathDiagnosticEventPiece>(L, BR.getDescription(),
false);
}