[PATCH] D54222: [clang-tidy] Add a check to detect returning static locals in public headers

[Joe Ranieri via Phabricator via cfe-commits]

jranieri-grammatech added a comment.

In D54222#1290789 <https://reviews.llvm.org/D54222#1290789>, @JonasToth wrote:

> I agree with @Eugene.Zelenko that this check should rather live in `bugprone-` as the issue its diagnosing is not LLVM specific. It is ok to add an alias into the llvm module.

Here are the warnings it issues with the patch's matcher:

  clang/include/clang/StaticAnalyzer/Core/CheckerManager.h:625:43: warning: address of static local variable 'tag' may not be identical across library boundaries [llvm-problematic-statics]
  clang/include/clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h:219:1: warning: address of static local variable 'Index' may not be identical across library boundaries [llvm-problematic-statics]
  clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h:25:1: warning: address of static local variable 'Index' may not be identical across library boundaries [llvm-problematic-statics]

And here are the additional warnings it issues when relaxing the matcher (to be `unless(isExpansionInMainFile())`):

  clang/lib/StaticAnalyzer/Checkers/Iterator.h:130:47: warning: address of static local variable 'Index' may not be identical across library boundaries [llvm-problematic-statics]
  clang/lib/StaticAnalyzer/Checkers/Iterator.h:136:47: warning: address of static local variable 'Index' may not be identical across library boundaries [llvm-problematic-statics]
  clang/lib/StaticAnalyzer/Checkers/Iterator.h:142:47: warning: address of static local variable 'Index' may not be identical across library boundaries [llvm-problematic-statics]
  clang/lib/StaticAnalyzer/Checkers/MPI-Checker/MPITypes.h:60:5: warning: address of static local variable 'index' may not be identical across library boundaries [llvm-problematic-statics]
  llvm/utils/unittest/googletest/src/gtest.cc:3989:3: warning: address of static local variable 'instance' may not be identical across library boundaries [llvm-problematic-statics]

And also this one, which was hidden by default but made running tidy noisier by always saying there was a hidden warning:

  /usr/bin/../include/c++/v1/functional:1960:9: warning: address of static local variable '__policy_' may not be identical across library boundaries [llvm-problematic-statics]

All of the first set of warnings might be actual problems, but the second set definitely aren't problems because they aren't going to be used across shared library boundaries. By making this be a LLVM-specific check, we can avoid the noise of these false positives. Also, I looked through the C++ Core Guidelines for any rules that might address this but didn't see anything relevant.

Thoughts?


Repository:
  rCTE Clang Tools Extra

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  https://reviews.llvm.org/D54222/new/

https://reviews.llvm.org/D54222