clang-tidy error (on not-linux): use nullptr instead of NULL #261

issue pinheadmz opened this issue on March 19, 2026

pinheadmz commented at 9:02 PM on March 19, 2026: none
Running clang-tidy on macos I get this error:
```
/Users/matthewzipkin/Desktop/work/bitcoin/src/ipc/libmultiprocess/src/mp/util.cpp:84:25: error: use nullptr [modernize-use-nullptr,-warnings-as-errors]
   84 |     pthread_threadid_np(NULL, &tid);
      |                         ^~~~
      |                         nullptr
```
I suspect the reason this hasn't triggered failures on our CI is that this code block is not compiled on linux:

https://github.com/bitcoin-core/libmultiprocess/blob/22bec918c97d32660c4694c3a8b5af4cdbb88481/src/mp/util.cpp#L80-L90
Sjors commented at 1:04 PM on March 20, 2026: member

One does not simply ... run clang-tidy on macOS. Anything special needed to reproduce this?

pinheadmz commented at 1:26 PM on March 20, 2026: none

Simple!

brew install llvm:

--> which clang-tidy
/opt/homebrew/Cellar/llvm/22.1.1/bin/clang-tidy
--> clang-tidy --version
Homebrew LLVM version 22.1.1
  Optimized build.

Modified some code from bitcoin core ci/test/03_test_script.sh and added to .bash_profile:

bctidy(){
  cd /Users/matthewzipkin/Desktop/work/bitcoin
  cmake -B build_tidy -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
  cmake --build build_tidy -j 8

  set -eo pipefail
  (
    cd ./src/ &&
    if ! ( PYTHONUNBUFFERED=1  run-clang-tidy -p ../build_tidy -quiet -config-file=.clang-tidy -j 8 | tee  ../build_tidy/tidy-out.txt ); then
      echo
      echo "Failure generated from clang-tidy:"
      grep -C5 "error: " ../build_tidy/tidy-out.txt
    fi
  )
}

Sjors commented at 2:30 PM on March 20, 2026: member

Thanks, managed to reproduce. I also made a utility out of your script: https://github.com/Sjors/dev-utils/tree/master?tab=readme-ov-file#tidy-btc-maczsh
Sjors commented at 2:54 PM on March 20, 2026: member

Fixed in #262.

Contributors

pinheadmz

Sjors

Linked (view graph)

#262 ci: enable clang-tidy in macOS job, use nullptr