build:
- autotools: fix to build generated sources for the `tidy` target.
- autotools: allow passing custom clang-tidy options via
`CURL_CLANG_TIDYFLAGS` env.
- cmake: add `CURL_CLANG_TIDY` option to configure for `clang-tidy`.
Also add:
- `CLANG_TIDY` variable to customize the `clang-tidy` tool.
- `CURL_CLANG_TIDYFLAGS` to pass custom options to `clang-tidy`.
- apply `--enable-werror` and `-DCURL_WERROR=ON` to `clang-tidy`.
CI/GHA:
- add clang-tidy job for Linux, using autotools and clang-tidy v18.
This one needs to disable `clang-analyzer-valist.Uninitialized`
to avoid false positives:
https://github.com/llvm/llvm-project/issues/40656
Duration: 5.5 minutes
- add clang-tidy job for macOS, using cmake and clang-tidy v19.
This one also covers tests and examples, and doesn't hit the false
positives seen with llvm v18 and earlier.
Duration: 4.5 minutes
- Linux/macOS: skip installing test dependencies when not building or
running tests.
fix fallouts reported by `clang-tidy`:
- lib:
- cf-h2-proxy: unused assignment in non-debug builds.
- cf-socket: silence warning.
FIXME: https://github.com/curl/curl/pull/15825#issuecomment-2561867769
- ftp: NULL passed to `strncmp()`.
- http2: NULL-ptr deref.
- mprintf: silence warning.
- src/tool_writeout: NULL passed to `fputs()`.
- examples:
- invalid file pointers.
- missing `fclose()`.
- tests:
- http/clients/hx-download: memory leaks on error.
- http/clients/hx-download: memory leak on repeat `-r` option.
- server: double `fclose()`.
https://www.man7.org/linux/man-pages/man3/fclose.3.html
- server: invalid file pointer/handle.
- server/getpart: unused assignments.
- server/mqttd: leak on failed `realloc()`.
- server/tftpd: NULL passed to `strcmp()`.
Closes#15825