[PATCH] D127389: [analyzer] Print the offending function at EndAnalysis crash

[Balázs Benics via Phabricator via cfe-commits]

steakhal created this revision.
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I've faced crashes in the past multiple times when some
`check::EndAnalysis` callback caused some crash.
It's really anoying that it doesn't tell which function triggered this
callback.

This patch adds the well-known trace for that situation as well.
Example:

1. <eof> parser at end of file
2. While analyzing stack: #0 Calling test11

Note that this does not have tests.
I've considered `unittests` for this purpose, by using the
`ASSERT_DEATH()` similarly how we check double eval called functions in
`ConflictingEvalCallsTest.cpp`, however, that the testsuite won't invoke
the custom handlers. Only the message of the `llvm_unreachable()` will
be printed. Consequently, it's not applicable for us testing this
feature.

I've also considered using an end-to-end LIT test for this.
For that, we would need to somehow overload the `clang_analyzer_crash()`
`ExprInspection` handler, to get triggered by other events than the
`EvalCall`. I'm not saying that we could not come up with a generic way
of causing crash in a specific checker callback, but I'm not sure if
that would worth the effort.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D127389

Files:
  clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
  clang/lib/StaticAnalyzer/Core/ExprEngine.cpp


Index: clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -613,6 +613,7 @@
 }
 
 void ExprEngine::processEndWorklist() {
+  PrettyStackTraceLocationContext CrashInfo(getRootLocationContext());
   getCheckerManager().runCheckersForEndAnalysis(G, BR, *this);
 }
 
Index: clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
===================================================================
--- clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
+++ clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
@@ -228,6 +228,11 @@
 
   const Stmt *getStmt() const;
 
+  const LocationContext *getRootLocationContext() const {
+    assert(G.roots_begin() != G.roots_end());
+    return (*G.roots_begin())->getLocation().getLocationContext();
+  }
+
   void GenerateAutoTransition(ExplodedNode *N);
   void enqueueEndOfPath(ExplodedNodeSet &S);
   void GenerateCallExitNode(ExplodedNode *N);


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