Re-implement the 'warnings' module in C. This allows for usage of the

'warnings' code in places where it was previously not possible (e.g., the
parser). It could also potentially lead to a speed-up in interpreter start-up
if the C version of the code (_warnings) is imported over the use of the
Python version in key places.

Closes issue #1631171.

1 files changed, 21 insertions, 9 deletions

diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 2a9474e..d2d530f 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -363,14 +363,26 @@ class WarningMessage(object):
         self.filename = None
         self.lineno = None
 
-    def _showwarning(self, message, category, filename, lineno, file=None):
+    def _showwarning(self, message, category, filename, lineno, file=None,
+                        line=None):
         self.message = message
         self.category = category
         self.filename = filename
         self.lineno = lineno
+        self.line = line
+
+    def reset(self):
+        self._showwarning(*((None,)*6))
+
+    def __str__(self):
+        return ("{message : %r, category : %r, filename : %r, lineno : %s, "
+                    "line : %r}" % (self.message,
+                            self.category.__name__ if self.category else None,
+                            self.filename, self.lineno, self.line))
+
 
 @contextlib.contextmanager
-def catch_warning():
+def catch_warning(module=warnings):
     """
     Guard the warnings filter from being permanently changed and record the
     data of the last warning that has been issued.
@@ -381,15 +393,15 @@ def catch_warning():
             warnings.warn("foo")
             assert str(w.message) == "foo"
     """
-    warning = WarningMessage()
-    original_filters = warnings.filters[:]
-    original_showwarning = warnings.showwarning
-    warnings.showwarning = warning._showwarning
+    warning_obj = WarningMessage()
+    original_filters = module.filters[:]
+    original_showwarning = module.showwarning
+    module.showwarning = warning_obj._showwarning
     try:
-        yield warning
+        yield warning_obj
     finally:
-        warnings.showwarning = original_showwarning
-        warnings.filters = original_filters
+        module.showwarning = original_showwarning
+        module.filters = original_filters
 
 class EnvironmentVarGuard(object):