Issue #25136: Support Apple Xcode 7's new textual SDK stub libraries.
As of Xcode 7, SDKs for Apple platforms now include textual-format stub
libraries whose file names have a .tbd extension rather than the
standard OS X .dylib extension. The Apple compiler tool chain handles
these stub libraries transparently and the installed system shared libraries
are still .dylibs. However, the new stub libraries cause problems for
third-party programs that support building with Apple SDKs and make
build-time decisions based on the presence or paths of system-supplied
shared libraries in the SDK. In particular, building Python itself with
an SDK fails to find system-supplied libraries during setup.py's build of
standard library extension modules. The solution is to have
find_library_file() in Distutils search for .tbd files, along with
the existing types (.a, .so, and .dylib). Patch by Tim Smith.
diff --git a/Lib/distutils/unixccompiler.py b/Lib/distutils/unixccompiler.py
index 2aa1cb1..4c35676 100644
--- a/Lib/distutils/unixccompiler.py
+++ b/Lib/distutils/unixccompiler.py
@@ -79,7 +79,9 @@
static_lib_extension = ".a"
shared_lib_extension = ".so"
dylib_lib_extension = ".dylib"
+ xcode_stub_lib_extension = ".tbd"
static_lib_format = shared_lib_format = dylib_lib_format = "lib%s%s"
+ xcode_stub_lib_format = dylib_lib_format
if sys.platform == "cygwin":
exe_extension = ".exe"
@@ -245,12 +247,28 @@
def find_library_file(self, dirs, lib, debug=0):
shared_f = self.library_filename(lib, lib_type='shared')
dylib_f = self.library_filename(lib, lib_type='dylib')
+ xcode_stub_f = self.library_filename(lib, lib_type='xcode_stub')
static_f = self.library_filename(lib, lib_type='static')
if sys.platform == 'darwin':
# On OSX users can specify an alternate SDK using
# '-isysroot', calculate the SDK root if it is specified
# (and use it further on)
+ #
+ # Note that, as of Xcode 7, Apple SDKs may contain textual stub
+ # libraries with .tbd extensions rather than the normal .dylib
+ # shared libraries installed in /. The Apple compiler tool
+ # chain handles this transparently but it can cause problems
+ # for programs that are being built with an SDK and searching
+ # for specific libraries. Callers of find_library_file need to
+ # keep in mind that the base filename of the returned SDK library
+ # file might have a different extension from that of the library
+ # file installed on the running system, for example:
+ # /Applications/Xcode.app/Contents/Developer/Platforms/
+ # MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/
+ # usr/lib/libedit.tbd
+ # vs
+ # /usr/lib/libedit.dylib
cflags = sysconfig.get_config_var('CFLAGS')
m = re.search(r'-isysroot\s+(\S+)', cflags)
if m is None:
@@ -264,6 +282,7 @@
shared = os.path.join(dir, shared_f)
dylib = os.path.join(dir, dylib_f)
static = os.path.join(dir, static_f)
+ xcode_stub = os.path.join(dir, xcode_stub_f)
if sys.platform == 'darwin' and (
dir.startswith('/System/') or (
@@ -272,6 +291,7 @@
shared = os.path.join(sysroot, dir[1:], shared_f)
dylib = os.path.join(sysroot, dir[1:], dylib_f)
static = os.path.join(sysroot, dir[1:], static_f)
+ xcode_stub = os.path.join(sysroot, dir[1:], xcode_stub_f)
# We're second-guessing the linker here, with not much hard
# data to go on: GCC seems to prefer the shared library, so I'm
@@ -279,6 +299,8 @@
# ignoring even GCC's "-static" option. So sue me.
if os.path.exists(dylib):
return dylib
+ elif os.path.exists(xcode_stub):
+ return xcode_stub
elif os.path.exists(shared):
return shared
elif os.path.exists(static):