--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.7/site-packages/setuptools/command/build_clib.py	Sat May 02 07:14:21 2020 -0400
@@ -0,0 +1,98 @@
+import distutils.command.build_clib as orig
+from distutils.errors import DistutilsSetupError
+from distutils import log
+from setuptools.dep_util import newer_pairwise_group
+
+
+class build_clib(orig.build_clib):
+    """
+    Override the default build_clib behaviour to do the following:
+
+    1. Implement a rudimentary timestamp-based dependency system
+       so 'compile()' doesn't run every time.
+    2. Add more keys to the 'build_info' dictionary:
+        * obj_deps - specify dependencies for each object compiled.
+                     this should be a dictionary mapping a key
+                     with the source filename to a list of
+                     dependencies. Use an empty string for global
+                     dependencies.
+        * cflags   - specify a list of additional flags to pass to
+                     the compiler.
+    """
+
+    def build_libraries(self, libraries):
+        for (lib_name, build_info) in libraries:
+            sources = build_info.get('sources')
+            if sources is None or not isinstance(sources, (list, tuple)):
+                raise DistutilsSetupError(
+                       "in 'libraries' option (library '%s'), "
+                       "'sources' must be present and must be "
+                       "a list of source filenames" % lib_name)
+            sources = list(sources)
+
+            log.info("building '%s' library", lib_name)
+
+            # Make sure everything is the correct type.
+            # obj_deps should be a dictionary of keys as sources
+            # and a list/tuple of files that are its dependencies.
+            obj_deps = build_info.get('obj_deps', dict())
+            if not isinstance(obj_deps, dict):
+                raise DistutilsSetupError(
+                       "in 'libraries' option (library '%s'), "
+                       "'obj_deps' must be a dictionary of "
+                       "type 'source: list'" % lib_name)
+            dependencies = []
+
+            # Get the global dependencies that are specified by the '' key.
+            # These will go into every source's dependency list.
+            global_deps = obj_deps.get('', list())
+            if not isinstance(global_deps, (list, tuple)):
+                raise DistutilsSetupError(
+                       "in 'libraries' option (library '%s'), "
+                       "'obj_deps' must be a dictionary of "
+                       "type 'source: list'" % lib_name)
+
+            # Build the list to be used by newer_pairwise_group
+            # each source will be auto-added to its dependencies.
+            for source in sources:
+                src_deps = [source]
+                src_deps.extend(global_deps)
+                extra_deps = obj_deps.get(source, list())
+                if not isinstance(extra_deps, (list, tuple)):
+                    raise DistutilsSetupError(
+                           "in 'libraries' option (library '%s'), "
+                           "'obj_deps' must be a dictionary of "
+                           "type 'source: list'" % lib_name)
+                src_deps.extend(extra_deps)
+                dependencies.append(src_deps)
+
+            expected_objects = self.compiler.object_filenames(
+                    sources,
+                    output_dir=self.build_temp
+                    )
+
+            if newer_pairwise_group(dependencies, expected_objects) != ([], []):
+                # First, compile the source code to object files in the library
+                # directory.  (This should probably change to putting object
+                # files in a temporary build directory.)
+                macros = build_info.get('macros')
+                include_dirs = build_info.get('include_dirs')
+                cflags = build_info.get('cflags')
+                objects = self.compiler.compile(
+                        sources,
+                        output_dir=self.build_temp,
+                        macros=macros,
+                        include_dirs=include_dirs,
+                        extra_postargs=cflags,
+                        debug=self.debug
+                        )
+
+            # Now "link" the object files together into a static library.
+            # (On Unix at least, this isn't really linking -- it just
+            # builds an archive.  Whatever.)
+            self.compiler.create_static_lib(
+                    expected_objects,
+                    lib_name,
+                    output_dir=self.build_clib,
+                    debug=self.debug
+                    )