DebugWipeFinder fixes for 3.12

Summary:
X-link: facebookincubator/zstrong#662

find_module has been deprecated for some time. Instead use find_spec

Reviewed By: itamaro

Differential Revision: D52495680

fbshipit-source-id: 9b827a783af2d858816a8d197530874f680502f3

build/fbcode_builder/CMake/fb_py_test_main.py

@@ -22,11 +22,8 @@
 import traceback
 import unittest
 import warnings
+from importlib.machinery import PathFinder
 
-# Hide warning about importing "imp"; remove once python2 is gone.
-with warnings.catch_warnings():
-    warnings.filterwarnings("ignore", category=DeprecationWarning)
-    import imp
 
 try:
     from StringIO import StringIO
@@ -82,7 +79,7 @@ def include(self, path):
         return not self.omit(path)
 
 
-class DebugWipeFinder(object):
+class DebugWipeFinder(PathFinder):
     """
     PEP 302 finder that uses a DebugWipeLoader for all files which do not need
     coverage
@@ -91,28 +88,15 @@ class DebugWipeFinder(object):
     def __init__(self, matcher):
         self.matcher = matcher
 
-    def find_module(self, fullname, path=None):
-        _, _, basename = fullname.rpartition(".")
-        try:
-            fd, pypath, (_, _, kind) = imp.find_module(basename, path)
-        except Exception:
-            # Finding without hooks using the imp module failed. One reason
-            # could be that there is a zip file on sys.path. The imp module
-            # does not support loading from there. Leave finding this module to
-            # the others finders in sys.meta_path.
+    def find_spec(self, fullname, path=None, target=None):
+        spec = super().find_spec(fullname, path=path, target=target)
+        if spec is None or spec.origin is None:
             return None
-
-        if hasattr(fd, "close"):
-            fd.close()
-        if kind != imp.PY_SOURCE:
+        if not spec.origin.endswith(".py"):
             return None
-        if self.matcher.include(pypath):
+        if self.matcher.include(spec.origin):
             return None
 
-        """
-        This is defined to match CPython's PyVarObject struct
-        """
-
         class PyVarObject(ctypes.Structure):
             _fields_ = [
                 ("ob_refcnt", ctypes.c_long),
@@ -126,7 +110,7 @@ class DebugWipeLoader(SourceFileLoader):
             """
 
             def get_code(self, fullname):
-                code = super(DebugWipeLoader, self).get_code(fullname)
+                code = super().get_code(fullname)
                 if code:
                     # Ideally we'd do
                     # code.co_lnotab = b''
@@ -136,7 +120,8 @@ def get_code(self, fullname):
                     code_impl.ob_size = 0
                 return code
 
-        return DebugWipeLoader(fullname, pypath)
+        spec.loader = DebugWipeLoader(fullname, spec.origin)
+        return spec
 
 
 def optimize_for_coverage(cov, include_patterns, omit_patterns):