[WIP] Restore usage of macOS @rpath

Author: jimporter

bfg9000/tools/cc/linker.py

@@ -119,33 +119,44 @@ def _always_flags(self):
         return []
 
     def _local_rpath(self, library, output):
-        if ( not isinstance(library, Library) or
-             self.builder.object_format != 'elf' ):
+        if not isinstance(library, Library):
             return None, []
-
-        rpath = patchelf.local_rpath(self.env, library, output)
-        if rpath is None:
+        elif self.builder.object_format == 'elf':
+            rpath = patchelf.local_rpath(self.env, library, output)
+            if rpath is None:
+                return None, []
+
+            # Prior to binutils 2.28, GNU's BFD-based ld doesn't correctly
+            # respect $ORIGIN in a shared library's DT_RPATH/DT_RUNPATH field.
+            # This results in ld being unable to find other shared libraries
+            # needed by the directly-linked library. For more information, see:
+            # <https://sourceware.org/bugzilla/show_bug.cgi?id=20535>.
+            try:
+                ld = self.builder.linker('raw')
+                fix_rpath = (ld.brand == 'bfd' and ld.version in
+                             SpecifierSet('<2.28'))
+            except KeyError:
+                fix_rpath = False
+
+            rpath_link = []
+            if output and fix_rpath:
+                rpath_link = [
+                    i.path.parent() for i in
+                    recursive_walk(library.runtime_file, 'runtime_deps')
+                ]
+
+            return rpath, rpath_link
+        elif self.builder.object_format == 'mach-o':
+            if not library.runtime_file:
+                return None, []
+            rpath = Path('.', library.runtime_file.path.root).cross(self.env)
+            if rpath.root == output.path.root:
+                rpath = rpath.relpath(output.path.parent(),
+                                      prefix='@loader_path')
+            return rpath, []
+        else:
             return None, []
 
-        # Prior to binutils 2.28, GNU's BFD-based ld doesn't correctly respect
-        # $ORIGIN in a shared library's DT_RPATH/DT_RUNPATH field. This results
-        # in ld being unable to find other shared libraries needed by the
-        # directly-linked library. For more information, see:
-        # <https://sourceware.org/bugzilla/show_bug.cgi?id=20535>.
-        try:
-            ld = self.builder.linker('raw')
-            fix_rpath = (ld.brand == 'bfd' and ld.version in
-                         SpecifierSet('<2.28'))
-        except KeyError:
-            fix_rpath = False
-
-        rpath_link = []
-        if output and fix_rpath:
-            rpath_link = [i.path.parent() for i in
-                          recursive_walk(library.runtime_file, 'runtime_deps')]
-
-        return rpath, rpath_link
-
     def always_libs(self, primary):
         # XXX: Don't just asssume that these are the right libraries to use.
         # For instance, clang users might want to use libc++ instead.

bfg9000/tools/install_name_tool.py

@@ -1,3 +1,5 @@
+import os
+
 from . import tool
 from .. import file_types, options as opts
 from .common import SimpleCommand
@@ -25,18 +27,13 @@ def _call(self, cmd, file, *, id=None, changes=[]):
 
 
 def darwin_install_name(library, env, strict=True):
-    while isinstance(library, file_types.LinkLibrary):
-        library = library.library
-
-    if isinstance(library, file_types.VersionedSharedLibrary):
-        return library.soname.path.string(env.base_dirs)
-    elif isinstance(library, file_types.SharedLibrary):
-        return library.path.string(env.base_dirs)
-    elif strict:  # pragma: no cover
-        raise TypeError('unable to create darwin install_name')
-    else:
+    if isinstance(library, file_types.SharedLibrary):
+        return os.path.join('@rpath', library.runtime_file.path.suffix)
+    elif not strict:
         return None
 
+    raise TypeError('unable to create darwin install_name')  # pragma: no cover
+
 
 def post_install(env, options, output, install_db, *, is_library=False):
     change_opts = options.filter(opts.install_name_change)