[PATCH] D118224: [clang-tidy] bugprone-signal-handler improvements: display call chain

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


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Comment at: clang-tools-extra/clang-tidy/bugprone/SignalHandlerCheck.cpp:199-200
+    const FunctionDecl *HandlerDecl, const Expr *HandlerRef) {
+  int CallLevel = Itr.getPathLength() - 2;
+  const CallGraphNode *Caller = Itr.getPath(CallLevel + 1), *Callee = nullptr;
+  while (CallLevel >= 0) {
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balazske wrote:
> aaron.ballman wrote:
> > Do we have to worry about `CallLevel + 1` being negative here? (Is there a need for an assert?)
> Really yes, but here is no assert because it is on line 161 and the function is called only there. A `df_iterator` path contains the start and end node, and there should be at least one function if we have any report do show, the path length should be at least 1 (make assert for that?). (Later there could be cases when the function is called with path length 1.)
Thanks for the explanation -- an assert that the path has at least 1 element wouldn't be awful, but also doesn't seem like something we'd get a lot of value from here. It's up to you if you want to add an assert or not.


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Comment at: clang-tools-extra/clang-tidy/bugprone/SignalHandlerCheck.cpp:207-208
+         DiagnosticIDs::Note)
+        << cast<FunctionDecl>(Callee->getDecl())
+        << cast<FunctionDecl>(Caller->getDecl());
+    --CallLevel;
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balazske wrote:
> aaron.ballman wrote:
> > Do we have to worry about call expressions for which we cannot find the declaration (like a call through a function pointer)? (Should we add some test coverage involving a call stack with a call through a function pointer?)
> A declaration should always be there in the `CallGraphNode`, probably not a definition. The call graph does not insert nodes for function pointer calls.
Oh! I didn't know the CallGraph didn't model calls through function pointers (I had assumed we would model that because there's still a `CallExpr` involved.)

Can you add a test case involving a call stack with a call through a function pointer (with comments), just to demonstrate the behavior?


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https://reviews.llvm.org/D118224