[PATCH] D105553: [analyzer][NFC] Split the main logic of NoStoreFuncVisitor to an abstract NoStateChangeVisitor class

[Artem Dergachev via Phabricator via cfe-commits]

NoQ accepted this revision.
NoQ added a comment.
This revision is now accepted and ready to land.

This looks perfectly sensible to me.

In the mailing list I seem to have made a mistake about how this works: we don't explicitly scan the AST for potential statements that could cause a state change (eg., assignment operators in case of `NoStore`) but we only check if the region was explicitly made accessible. This makes things a lot easier (we don't have to build an auxiliary AST-based analysis) and I'm not sure if this other heuristic that I thought we have would actually make things significantly better. I guess it makes sense to keep in mind that we might want to ultimately plug it in but I don't immediately see what'd stop us.



================
Comment at: clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h:629
+
+/// Put a diagnostic on return statement of all inlined functions for which some
+/// property remained unchanged.
----------------
Or on the `}` if there's no return statement.


================
Comment at: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp:399
+/// to get the correct parameter name.
+static ArrayRef<ParmVarDecl *> getCallParameters(const CallEvent &Call) {
+  // Use runtime definition, if available.
----------------
While we're at it, can you take a look if the recently introduced `CallEvent::parameters()` is good enough for this?


================
Comment at: clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp:532-533
 
-  /// Check and lazily calculate whether the region of interest is
-  /// modified in the stack frame to which \p N belongs.
-  /// The calculation is cached in FramesModifyingRegion.
-  bool isRegionOfInterestModifiedInFrame(const ExplodedNode *N) {
-    const LocationContext *Ctx = N->getLocationContext();
-    const StackFrameContext *SCtx = Ctx->getStackFrame();
-    if (!FramesModifyingCalculated.count(SCtx))
-      findModifyingFrames(N);
-    return FramesModifyingRegion.count(SCtx);
-  }
+  // Region of interest corresponds to an IVar, exiting a method
+  // which could have written into that IVar, but did not.
+  virtual PathDiagnosticPieceRef
----------------
I guess this comment could be copied to the other two virtual methods?


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