Add automatic build of libcapnp if it's not detected

buildutils/patch.py

@@ -0,0 +1,61 @@
+"""utils for patching libraries"""
+
+# Copyright (c) PyZMQ Developers.
+# Distributed under the terms of the Modified BSD License.
+
+
+import re
+import sys
+import os
+import logging
+
+from .misc import get_output_error
+
+pjoin = os.path.join
+
+# LIB_PAT from delocate
+LIB_PAT = re.compile(r"\s*(.*) \(compatibility version (\d+\.\d+\.\d+), "
+                   r"current version (\d+\.\d+\.\d+)\)")
+
+def _get_libs(fname):
+    rc, so, se = get_output_error(['otool', '-L', fname])
+    if rc:
+        logging.error("otool -L %s failed: %r" % (fname, se))
+        return
+    for line in so.splitlines()[1:]:
+        m = LIB_PAT.match(line)
+        if m:
+            yield m.group(1)
+
+def _find_library(lib, path):
+    """Find a library"""
+    for d in path[::-1]:
+        real_lib = os.path.join(d, lib)
+        if os.path.exists(real_lib):
+            return real_lib
+
+def _install_name_change(fname, lib, real_lib):
+    rc, so, se = get_output_error(['install_name_tool', '-change', lib, real_lib, fname])
+    if rc:
+        logging.error("Couldn't update load path: %s", se)
+
+def patch_lib_paths(fname, library_dirs):
+    """Load any weakly-defined libraries from their real location
+    
+    (only on OS X)
+    
+    - Find libraries with `otool -L`
+    - Update with `install_name_tool -change`
+    """
+    if sys.platform != 'darwin':
+        return
+    
+    libs = _get_libs(fname)
+    for lib in libs:
+        if not lib.startswith(('@', '/')):
+            real_lib = _find_library(lib, library_dirs)
+            if real_lib:
+                _install_name_change(fname, lib, real_lib)
+
+
+__all__ = ['patch_lib_paths']