GHA/linux: switch clang-tidy job to cmake for 2x speed, bump to v20, enable for tests

Checking lib and src under 3m15s versus 7m15s.

Downside: autotools clang-tidy support is no longer CI-tested.

The reason for the slowness is invoking a single clang-tidy command with
all source files, and clang-tidy checking them in a single thread,
sequentially. clang-tidy offers a `run-clang-tidy` Python script for
parallel  processing, which may help with this. However at this point
it's more practical to use cmake, which also supports verifying the
whole codebase, not only lib and src.

Also:
- bump clang-tidy to the latest available, v20 (from v18).
- enable running clang-tidy on tests. Takes under 2 minutes.

Also tried `_CURL_TESTS_CONCAT=ON`, it brings down the build tests step
from 1m47s to 54s, saving 1 minute. Skipped using it for now.

Closes #20725

diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index d3cbc8038f1ad6aee5cf56a2566da9cc0ee78fa6..32f9382cb97e3443f367926d9c24560dcba9a426 100644 (file)
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -276,18 +276,18 @@ jobs:
               -DCURL_DISABLE_LDAP=ON -DUSE_LIBIDN2=OFF -DCURL_USE_LIBSSH2=OFF
 
           - name: 'clang-tidy'
-            install_packages: clang-19 clang-tidy-19 libssl-dev libidn2-dev libssh2-1-dev libnghttp2-dev libldap-dev libkrb5-dev librtmp-dev libgnutls28-dev
-            install_steps: skipall mbedtls-latest-intel rustls wolfssl-opensslextra-intel
+            install_packages: clang-20 clang-tidy-20 libssl-dev libidn2-dev libssh2-1-dev libnghttp2-dev libldap-dev libkrb5-dev librtmp-dev libgnutls28-dev
+            install_steps: skiprun mbedtls-latest-intel rustls wolfssl-opensslextra-intel
             install_steps_brew: gsasl
             make-custom-target: tidy
-            LDFLAGS: -Wl,-rpath,/home/runner/wolfssl-opensslextra/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/gsasl/lib
-            PKG_CONFIG_PATH: /home/linuxbrew/.linuxbrew/opt/gsasl/lib/pkgconfig
-            CC: clang-19
-            configure: >-
-              CLANG_TIDY=clang-tidy-19
-              --with-wolfssl=/home/runner/wolfssl-opensslextra --with-openssl --with-rustls --with-mbedtls=/home/runner/mbedtls --with-gnutls --with-libgsasl
-              --with-librtmp --with-libssh2 --with-libidn2
-              --enable-ech --with-gssapi --enable-ssls-export --disable-typecheck
+            CC: clang-20
+            LDFLAGS: -Wl,-rpath,/home/runner/wolfssl-opensslextra/lib -Wl,-rpath,/home/runner/mbedtls/lib -Wl,-rpath,/home/runner/rustls/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/gsasl/lib
+            PKG_CONFIG_PATH: /home/runner/wolfssl-opensslextra/lib/pkgconfig:/home/runner/mbedtls/lib/pkgconfig:/home/runner/rustls/lib/pkgconfig:/home/linuxbrew/.linuxbrew/opt/gsasl/lib/pkgconfig
+            generate: >-
+              -DCURL_USE_OPENSSL=ON -DCURL_USE_WOLFSSL=ON -DCURL_USE_GNUTLS=ON -DCURL_USE_MBEDTLS=ON -DCURL_USE_RUSTLS=ON
+              -DCURL_USE_GSASL=ON -DUSE_LIBRTMP=ON
+              -DUSE_ECH=ON -DCURL_USE_GSSAPI=ON -DUSE_SSLS_EXPORT=ON
+              -DCURL_CLANG_TIDY=ON -DCLANG_TIDY=/usr/bin/clang-tidy-20
 
           - name: 'scan-build'
             install_packages: clang-tools clang libssl-dev libidn2-dev libssh2-1-dev libnghttp2-dev libldap-dev libgss-dev librtmp-dev libgnutls28-dev