CI: Update for meson build

We now include a Meson build that uses Clang + lld as
the build system to catch bugs and warningsthat our traditional
autotools + GCC builds might miss.

This commit changes the autotools build to be more like the
meson build path: We no longer build a docker image, rather
directly executing the fvwm3-build container as a github
action.

Factor out the GH Actions steps into a common set, and use them
as a matrix set to apply to Ubuntu (glibc) and Alpine (musl).

The Go version in fvwm3-build has been updated to enable use
with meson and eliminate the need for a complex envvar setup
and invocation, however older golang is still supported (>=1.14);
we're just relying on users to tell us if something is broken.

While the issue with LTO builds has been resolved in this PR, it was
incidental and the introduced changes will catch LTO errors before
they make it into a release.

Closes: fvwmorg#1056
Co-authored-by: Thomas Adam <thomas@fvwm.org>
Signed-off-by: Matt Jolly <Kangie@gentoo.org>

.github/workflows/ccpp.yml

@@ -10,13 +10,44 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    container:
+      image: ${{ matrix.os == 'alpine' && 'fvwmorg/fvwm3-build-alpine:latest' || 'fvwmorg/fvwm3-build:latest' }}
+    env:
+      GO111MODULE: "on"
+
+    strategy:
+      matrix:
+        os: [ubuntu-latest, alpine]
+        build-system: [autotools, meson]
+        compiler: [gcc, clang]
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Pulling docker image
-      run: docker pull fvwmorg/fvwm3-build:latest
-    - name: Build Package
-      run: 'docker build -t fvwm3 .'
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set git safe directory
+        run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
+
+      - name: Configure and Build
+        run: |
+          if [ "${{ matrix.build-system }}" = "autotools" ]; then
+            if [ "${{ matrix.compiler }}" = "gcc" ]; then
+              export CFLAGS="-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing"
+            else
+              export CC_LD=lld
+            fi
+            export CC=${{ matrix.compiler }}
+            ./autogen.sh && ./configure --enable-mandoc --enable-golang && make -j
+          fi
+          if [ "${{ matrix.build-system }}" = "meson" ]; then
+            if [ "${{ matrix.compiler }}" = "gcc" ]; then
+              export CFLAGS="-flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing"
+            else
+              export CC_LD=lld
+            fi
+            export CC=${{ matrix.compiler }}
+            meson setup builddir -Dhtmldoc=true -Dmandoc=true && ninja -C builddir
+          fi
 
   notification:
     runs-on: ubuntu-20.04
@@ -26,7 +57,7 @@ jobs:
         uses: Gottox/irc-message-action@v2.1.3
         if: github.event_name == 'pull_request'
         with:
-          server: "irc.libera.chat"
+          server: irc.libera.chat
           notice: false
           channel: "#fvwm"
           nickname: fvwm3-gh-pr
@@ -35,7 +66,7 @@ jobs:
         uses: Gottox/irc-message-action@v2.1.3
         if: github.event_name == 'create' && github.event.ref_type == 'tag'
         with:
-          server: "irc.libera.chat"
+          server: irc.libera.chat
           notice: false
           channel: "#fvwm"
           nickname: fvwm-gh