Rename _mangle_base to _make_relative and add documentation about its purpose. Ref pypa/distutils#169.

2 files changed, 6 insertions, 4 deletions

diff --git a/conftest.py b/conftest.py
index feac1b60..018e1075 100644
--- a/conftest.py
+++ b/conftest.py
@@ -154,5 +154,5 @@ def suppress_path_mangle(monkeysession):
     from distutils import ccompiler
 
     monkeysession.setattr(
-        ccompiler.CCompiler, '_mangle_base', staticmethod(lambda x: x)
+        ccompiler.CCompiler, '_make_relative', staticmethod(lambda x: x)
     )
diff --git a/distutils/ccompiler.py b/distutils/ccompiler.py
index c8d3b24b..6b168792 100644
--- a/distutils/ccompiler.py
+++ b/distutils/ccompiler.py
@@ -927,7 +927,7 @@ int main (int argc, char **argv) {
         obj_names = []
         for src_name in source_filenames:
             base, ext = os.path.splitext(src_name)
-            base = self._mangle_base(base)
+            base = self._make_relative(base)
             if ext not in self.src_extensions:
                 raise UnknownFileError(
                     "unknown file type '{}' (from '{}')".format(ext, src_name)
@@ -938,9 +938,11 @@ int main (int argc, char **argv) {
         return obj_names
 
     @staticmethod
-    def _mangle_base(base):
+    def _make_relative(base):
         """
-        For unknown reasons, absolute paths are mangled.
+        In order to ensure that a filename always honors the
+        indicated output_dir, make sure it's relative.
+        Ref python/cpython#37775.
         """
         # Chop off the drive
         no_drive = os.path.splitdrive(base)[1]