project tests: Verify that UWP cross binaries use the right arch

This is a test for https://github.com/mesonbuild/meson/pull/7021, to
verify that `link.exe` uses the correct architecture when targeting
ARM64. Can be extended to other cross targets later.

test cases/common/233 link depends indexed custom target/check_arch.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+import re
+import sys
+import shutil
+import subprocess
+
+exepath = sys.argv[1]
+want_arch = sys.argv[2]
+dummy_output = sys.argv[3]
+
+with open(dummy_output, 'w') as f:
+    f.write('')
+
+if not shutil.which('dumpbin'):
+    print('dumpbin not found, skipping')
+    sys.exit(0)
+
+out = subprocess.check_output(['dumpbin', '/HEADERS', exepath],
+                              universal_newlines=True)
+for line in out.split('\n'):
+    m = re.match(r'.* machine \(([A-Za-z0-9]+)\)$', line)
+    if m:
+        arch = m.groups()[0].lower()
+
+if arch == 'arm64':
+    arch = 'aarch64'
+elif arch == 'x64':
+    arch = 'x86_64'
+
+if arch != want_arch:
+    raise RuntimeError('Wanted arch {} but exe uses {}'.format(want_arch, arch))

test cases/common/233 link depends indexed custom target/meson.build

@@ -15,5 +15,11 @@ exe = executable('foo', 'foo.c',
         link_depends: dep_files[1],
         c_args: ['-DDEPFILE="' + dep_files[0].full_path()+ '"'])
 
+check_arch = find_program('check_arch.py')
+custom_target('check-arch',
+        command: [check_arch, exe, host_machine.cpu_family(), '@OUTPUT@'],
+        build_by_default: true,
+        output: 'dummy.txt')
+
 # check that dep_file1 exists, which means that link_depends target ran
 test('runtest', exe)