Change #259212

Comments

GHA/linux: replace scan-build with clang-tidy
`scan-build` is a (Perl) wrapper around clang's built-in `--analyze`
option. Which look similar or identical to clang-tidy checkers under
the `clang-analyzer-*` namespace:
https://clang.llvm.org/docs/ClangStaticAnalyzer.html

Unless somebody has other information, it appears redundant to run
scan-build in parallel with clang-tidy in CI, now that the latter is
working reliably and with good performance for all curl components.

Another scan-build issue is the lack of a markup to suppress false
positives. It ignores `NOLINT`, yet finds the same false positives as
clang-tidy. This happens with scan-build v20+. v18 is silent, but it's
a blocker to upgrade to a newer version.

scan-build may still be a useful when combined with autotools, where
clang-tidy support is incomplete, slow (no parallelism), and uses
a distinct make target, which does not build binaries in the same pass.
But, scan-build also lacks extra checkers that are now enabled for
clang-tidy.

The clang-tidy job is also 30-40s faster than the one it replaced.

Also:
- drop scan-build job configured the same way as a clang-tidy one.
  CI time saved: 6m30s
- bump to clang-20 (from 18) in the replacement job.
- build tests in the replacement job.
  To verify a cmake command-line reconstruction issue only hit in this
  job in CI.
  CI time cost: 1m40s
- replacement job caught a minor, new, issue.
  Ref: b2076d3c2f5386068d9b0199f25a81147784d8ac #20752
- drop unused scan-build logic.

Bug: https://github.com/curl/curl/pull/20732#issuecomment-3963873838
Ref: https://github.com/curl/curl/pull/20732#issuecomment-3967479228

Closes #20751

Changed files

• .github/workflows/linux.yml