Add a test run in an environment which only has a cross compiler

Add '--cross-only' option to run_tests.py, so we can arrange not to run
tests in the 'native' suite when only a cross-compiler is available, as
they can't succeed.

.github/workflows/nonative.yml

@@ -0,0 +1,19 @@
+name: Cross-only compilation environment
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  cross-only-armhf:
+    runs-on: ubuntu-latest
+    container: mesonbuild/eoan:latest
+    steps:
+    - run: |
+        apt-get -y purge clang gcc gdc
+        apt-get -y autoremove
+    - uses: actions/checkout@v2
+    - name: Run tests
+      run: bash -c 'source /ci/env_vars.sh; cd $GITHUB_WORKSPACE; ./run_tests.py $CI_ARGS --cross ubuntu-armhf.txt --cross-only'

run_cross_test.py

@@ -25,17 +25,20 @@ from mesonbuild import mesonlib
 from mesonbuild.coredata import version as meson_version
 
 
-def runtests(cross_file, failfast):
-    tests = ['--only', 'common', 'native']
+def runtests(cross_file, failfast, cross_only):
+    tests = ['--only', 'common']
+    if not cross_only:
+        tests.append('native')
     cmd = mesonlib.python_command + ['run_project_tests.py', '--backend', 'ninja'] + (['--failfast'] if failfast else []) + tests + ['--cross-file', cross_file]
     return subprocess.call(cmd)
 
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--failfast', action='store_true')
+    parser.add_argument('--cross-only', action='store_true')
     parser.add_argument('cross_file')
     options = parser.parse_args()
-    return runtests(options.cross_file, options.failfast)
+    return runtests(options.cross_file, options.failfast, options.cross_only)
 
 if __name__ == '__main__':
     print('Meson build system', meson_version, 'Cross Tests')

run_tests.py

@@ -319,6 +319,7 @@ def main():
     parser.add_argument('--backend', default=None, dest='backend',
                         choices=backendlist)
     parser.add_argument('--cross', default=[], dest='cross', action='append')
+    parser.add_argument('--cross-only', action='store_true')
     parser.add_argument('--failfast', action='store_true')
     parser.add_argument('--no-unittests', action='store_true', default=False)
     (options, _) = parser.parse_known_args()
@@ -330,7 +331,6 @@ def main():
         import coverage
         coverage.process_startup()
     returncode = 0
-    cross = options.cross
     backend, _ = guess_backend(options.backend, shutil.which('msbuild'))
     no_unittests = options.no_unittests
     # Running on a developer machine? Be nice!
@@ -365,7 +365,7 @@ def main():
                 env['PYTHONPATH'] = os.pathsep.join([temp_dir, env.get('PYTHONPATH')])
             else:
                 env['PYTHONPATH'] = temp_dir
-        if not cross:
+        if not options.cross:
             cmd = mesonlib.python_command + ['run_meson_command_tests.py', '-v']
             if options.failfast:
                 cmd += ['--failfast']
@@ -395,6 +395,8 @@ def main():
                 cmd = cross_test_args + ['cross/' + cf]
                 if options.failfast:
                     cmd += ['--failfast']
+                if options.cross_only:
+                    cmd += ['--cross-only']
                 returncode += subprocess.call(cmd, env=env)
                 if options.failfast and returncode != 0:
                     return returncode