minstall: make do_strip run with -Sx for macOS targets

This commit also adds some extra symbol noise to lib.c, in order to aid
detection of the debug information with nm.

Fixes #10943

mesonbuild/minstall.py

@@ -27,7 +27,7 @@ import typing as T
 from . import build
 from . import environment
 from .backend.backends import InstallData
-from .mesonlib import MesonException, Popen_safe, RealPathAction, is_windows, setup_vsenv, pickle_load
+from .mesonlib import MesonException, Popen_safe, RealPathAction, is_windows, setup_vsenv, pickle_load, is_osx
 from .scripts import depfixer, destdir_join
 from .scripts.meson_exe import run_exe
 try:
@@ -566,7 +566,13 @@ class Installer:
 
     def do_strip(self, strip_bin: T.List[str], fname: str, outname: str) -> None:
         self.log(f'Stripping target {fname!r}.')
-        returncode, stdo, stde = self.Popen_safe(strip_bin + [outname])
+        if is_osx():
+            # macOS expects dynamic objects to be stripped with -x maximum.
+            # To also strip the debug info, -S must be added.
+            # See: https://www.unix.com/man-page/osx/1/strip/
+            returncode, stdo, stde = self.Popen_safe(strip_bin + ['-S', '-x', outname])
+        else:
+            returncode, stdo, stde = self.Popen_safe(strip_bin + [outname])
         if returncode != 0:
             print('Could not strip file.\n')
             print(f'Stdout:\n{stdo}\n')

test cases/unit/103 strip/lib.c

@@ -1 +1,3 @@
-void func(void){}
+#include <stdio.h>
+
+void func(void){ fprintf(stderr, "Test 1 2 3\n"); }

unittests/linuxliketests.py

@@ -1773,25 +1773,41 @@ class LinuxlikeTests(BasePlatformTests):
         # If so, we can test that cmake works with "gcc -m32"
         self.do_one_test_with_nativefile('../cmake/1 basic', "['gcc', '-m32']")
 
-    @skipUnless(is_linux(), 'Test only applicable to Linux')
+    @skipUnless(is_linux() or is_osx(), 'Test only applicable to Linux and macOS')
     def test_install_strip(self):
         testdir = os.path.join(self.unit_test_dir, '103 strip')
         self.init(testdir)
         self.build()
 
         destdir = self.installdir + self.prefix
-        lib = os.path.join(destdir, self.libdir, 'liba.so')
+        if is_linux():
+            lib = os.path.join(destdir, self.libdir, 'liba.so')
+        else:
+            lib = os.path.join(destdir, self.libdir, 'liba.dylib')
         install_cmd = self.meson_command + ['install', '--destdir', self.installdir]
 
         # Check we have debug symbols by default
         self._run(install_cmd, workdir=self.builddir)
-        stdout = self._run(['file', '-b', lib])
-        self.assertIn('not stripped', stdout)
+        if is_linux():
+            # file can detect stripped libraries on linux
+            stdout = self._run(['file', '-b', lib])
+            self.assertIn('not stripped', stdout)
+        else:
+            # on macOS we need to query dsymutil instead.
+            # Alternatively, check if __dyld_private is defined
+            # in the output of nm liba.dylib, but that is not
+            # 100% reliable, it needs linking to an external library
+            stdout = self._run(['dsymutil', '--dump-debug-map', lib])
+            self.assertIn('symbols:', stdout)
 
         # Check debug symbols got removed with --strip
         self._run(install_cmd + ['--strip'], workdir=self.builddir)
-        stdout = self._run(['file', '-b', lib])
-        self.assertNotIn('not stripped', stdout)
+        if is_linux():
+            stdout = self._run(['file', '-b', lib])
+            self.assertNotIn('not stripped', stdout)
+        else:
+            stdout = self._run(['dsymutil', '--dump-debug-map', lib])
+            self.assertNotIn('symbols:', stdout)
 
     def test_isystem_default_removal_with_symlink(self):
         env = get_fake_env()