macos: Rewrite install_name for dependent built libraries on install

On macOS, we set the install_name for built libraries to
@rpath/libfoo.dylib, and when linking to the library, we set the RPATH
to its path in the build directory. This allows all built binaries to
be run as-is from the build directory (uninstalled).

However, on install, we have to strip all the RPATHs because they
point to the build directory, and we change the install_name of all
built libraries to the absolute path to the library. This causes the
install name in binaries to be out of date.

We now change that install name to point to the absolute path to each
built library after installation.

Fixes https://github.com/mesonbuild/meson/issues/3038
Fixes https://github.com/mesonbuild/meson/issues/3077

With this, the default workflow on macOS matches what everyone seems
to do, including Autotools and CMake. The next step is providing a way
for build files to override the install_name that is used after
installation for use with, f.ex., private libraries when combined with
the install_rpath: kwarg on targets.

1 files changed, 20 insertions, 7 deletions

diff --git a/run_unittests.py b/run_unittests.py
index c4d9547..1c722c1 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -2759,7 +2759,8 @@ class LinuxlikeTests(BasePlatformTests):
         self._test_soname_impl(self.builddir, False)
 
     def test_installed_soname(self):
-        self._test_soname_impl(self.installdir + self.libdir, True)
+        libdir = self.installdir + os.path.join(self.prefix, self.libdir)
+        self._test_soname_impl(libdir, True)
 
     def test_compiler_check_flags_order(self):
         '''
@@ -3333,33 +3334,45 @@ endian = 'little'
         self.run_tests()
 
     @skipIfNoPkgconfig
-    def test_uninstalled_usage_external_library(self):
+    def test_usage_external_library(self):
         '''
         Test that uninstalled usage of an external library (from the system or
-        PkgConfigDependency) works. On Linux/BSD/macOS it tests if RPATHs are
-        set correctly.
-
-        TODO: On Windows, this can test whether PATH is set properly
+        PkgConfigDependency) works. On macOS, this workflow works out of the
+        box. On Linux, BSDs, Windows, etc, you need to set extra arguments such
+        as LD_LIBRARY_PATH, etc, so this test is skipped.
 
         The system library is found with cc.find_library() and pkg-config deps.
         '''
+        if not is_osx():
+            raise unittest.SkipTest('workflow currently only works on macOS')
         oldprefix = self.prefix
         # Install external library so we can find it
         testdir = os.path.join(self.unit_test_dir, '33 external, internal library rpath', 'external library')
+        # install into installdir without using DESTDIR
         installdir = self.installdir
         self.prefix = installdir
         self.init(testdir)
+        self.prefix = oldprefix
         self.build()
         self.install(use_destdir=False)
-        self.prefix = oldprefix
         # New builddir for the consumer
         self.new_builddir()
         os.environ['LIBRARY_PATH'] = os.path.join(installdir, self.libdir)
         os.environ['PKG_CONFIG_PATH'] = os.path.join(installdir, self.libdir, 'pkgconfig')
         testdir = os.path.join(self.unit_test_dir, '33 external, internal library rpath', 'built library')
+        # install into installdir without using DESTDIR
+        self.prefix = self.installdir
         self.init(testdir)
+        self.prefix = oldprefix
         self.build()
+        # test uninstalled
         self.run_tests()
+        # test running after installation
+        self.install(use_destdir=False)
+        prog = os.path.join(self.installdir, 'bin', 'prog')
+        self._run([prog])
+        out = self._run(['otool', '-L', prog])
+        self.assertNotIn('@rpath', out)
 
 
 class LinuxArmCrossCompileTests(BasePlatformTests):