ci: add a CI job for compiling with clang

.github/workflows/ci.yml

@@ -8,6 +8,13 @@ jobs:
             matrix:
                 arch: [x86_64, riscv64, aarch64, x86]
                 builds: [mlibc, mlibc-static, mlibc-shared, mlibc-ansi-only, mlibc-headers-only]
+                compiler: [gcc, clang]
+                exclude:
+                  - compiler: clang
+                include:
+                  - arch: x86_64
+                    builds: mlibc
+                    compiler: clang
         name: Build mlibc
         runs-on: ubuntu-20.04
         container:
@@ -18,7 +25,7 @@ jobs:
                 apt-get update
                 apt-get install -y ninja-build qemu-user \
                                 python3-setuptools python3-jsonschema \
-                                python3-pexpect python3-pip netbase
+                                python3-pexpect python3-pip netbase clang lld
                 pip install --break-system-packages -U xbstrap pyexpect meson
           - name: Prepare directories
             run: |
@@ -39,6 +46,7 @@ jobs:
               cat > bootstrap-site.yml << EOF
               define_options:
                 arch: ${{matrix.arch}}
+                compiler: ${{matrix.compiler}}
               EOF
               xbstrap init ../src
             working-directory: build/

ci/bootstrap.yml

@@ -1,6 +1,8 @@
 declare_options:
   - name: arch
     default: x86_64
+  - name: compiler
+    default: gcc
 
 sources:
   - name: mlibc
@@ -13,7 +15,7 @@ sources:
     format: 'tar.xz'
     version: '6.1.8'
 
-tools:
+tools: []
 
 packages:
   - name: mlibc
@@ -28,14 +30,14 @@ packages:
         - '--prefix=/usr'
         - '--libdir=lib'
         - '--buildtype=debugoptimized'
-        - "-Dc_args=['-Wno-error=maybe-uninitialized']"
-        - "-Dcpp_args=['-Wno-error=maybe-uninitialized']"
+        - "-Dc_args=['-Wno-error=maybe-uninitialized', '-Wno-unknown-warning-option']"
+        - "-Dcpp_args=['-Wno-error=maybe-uninitialized', '-Wno-unknown-warning-option']"
         - "-Dbuild_tests=true"
         - "-Db_sanitize=undefined"
         - "-Ddefault_library=both"
         - "-Dwerror=true"
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
-        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:[email protected]"
+        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:arch@-@OPTION:compiler@.cross-file"
         - '@THIS_SOURCE_DIR@'
         environ:
           CFLAGS: '-Wno-error=maybe-uninitialized'
@@ -66,7 +68,7 @@ packages:
         - "-Ddefault_library=static"
         - "-Dwerror=true"
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
-        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:[email protected]"
+        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:arch@-@OPTION:compiler@.cross-file"
         - '@THIS_SOURCE_DIR@'
     build:
       - args: ['ninja']
@@ -93,7 +95,7 @@ packages:
         - "-Ddefault_library=shared"
         - "-Dwerror=true"
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
-        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:[email protected]"
+        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:arch@-@OPTION:compiler@.cross-file"
         - '@THIS_SOURCE_DIR@'
     build:
       - args: ['ninja']
@@ -125,7 +127,7 @@ packages:
         - "-Ddisable_glibc_option=true"
         - "-Ddisable_bsd_option=true"
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
-        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:[email protected]"
+        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:arch@-@OPTION:compiler@.cross-file"
         - '@THIS_SOURCE_DIR@'
     build:
       - args: ['ninja']
@@ -152,7 +154,7 @@ packages:
         - "-Dwerror=true"
         - "-Dheaders_only=true"
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
-        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:[email protected]"
+        - "--cross-file=@THIS_SOURCE_DIR@/ci/linux-@OPTION:arch@-@OPTION:compiler@.cross-file"
         - '@THIS_SOURCE_DIR@'
     build:
       - args: ['ninja']

ci/linux-x86_64-clang.cross-file

@@ -0,0 +1,11 @@
+[binaries]
+c = 'clang'
+c_ld = 'lld'
+cpp = 'clang++'
+cpp_ld = 'lld'
+
+[host_machine]
+system = 'linux'
+cpu_family = 'x86_64'
+cpu = 'x86_64'
+endian = 'little'