[PATCH] D41815: [clang-tidy] implement check for goto

[Jonas Toth via Phabricator via cfe-commits]

JonasToth added inline comments.


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Comment at: clang-tidy/cppcoreguidelines/AvoidGotoCheck.cpp:22
+  if (getLangOpts().CPlusPlus)
+    Finder->addMatcher(gotoStmt().bind("goto"), this);
+}
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aaron.ballman wrote:
> aaron.ballman wrote:
> > Are you planning to add the exception listed in the C++ Core Guideline? It makes an explicit exception allowing you to jump forward out of a loop construct.
> What should this check do with indirect goto statements (it's a GCC extension we support where you can jump to an expression)?
> 
> Regardless, there should be a test for indirect gotos and jump forward out of loop constructs.
> Are you planning to add the exception listed in the C++ Core Guideline? It makes an explicit exception allowing you to jump forward out of a loop construct.

I do plan for this. Because I dont have any experience with gotos I wanted to do it in small steps.

> What should this check do with indirect goto statements (it's a GCC extension we support where you can jump to an expression)?
Iam not aware of these :) 


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Comment at: clang-tidy/cppcoreguidelines/AvoidGotoCheck.cpp:27-28
+  const auto *Match = Result.Nodes.getNodeAs<GotoStmt>("goto");
+  diag(Match->getGotoLoc(), "'goto' is considered harmful; use high level "
+                            "programming constructs instead")
+      << Match->getSourceRange();
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aaron.ballman wrote:
> I don't think this diagnostic really helps the user all that much. It doesn't say what's harmful about the goto, nor what high level programming construct to use to make it not harmful.
I dont like the diagnostic too. But i dont know how to give a sensefull short message.

Here Andrei Alexandrescu introduced some high level rules, maybe i the Rule of Minimum Power could be a starting point?
https://github.com/isocpp/CppCoreGuidelines/issues/19

> Good example for Rule of Minimum Power: goto is the most powerful looping construct (it can do everything while does, and a lot more such as jumping in the middle of a loop etc.) and the most unrecommended.


Repository:
  rCTE Clang Tools Extra

https://reviews.llvm.org/D41815