1 files changed, 46 insertions, 1 deletions
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 0e87131cfbe..53e8ae76e6f 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -2,7 +2,6 @@
 
 import sys
 
-
 class Error(Exception):
     """Base class for regression test exceptions."""
 
@@ -22,6 +21,26 @@ class TestSkipped(Error):
 verbose = 1              # Flag set to 0 by regrtest.py
 use_resources = None       # Flag set to [] by regrtest.py
 
+# _output_comparison controls whether regrtest will try to compare stdout
+# with an expected-output file.  For straight regrtests, it should.
+# The doctest driver should set_output_comparison(0) for the duration, and
+# restore the old value when it's done.
+# Note that this control is in addition to verbose mode:  output will be
+# compared if and only if _output_comparison is true and verbose mode is
+# not in effect.
+_output_comparison = 1
+
+def set_output_comparison(newvalue):
+    global _output_comparison
+    oldvalue = _output_comparison
+    _output_comparison = newvalue
+    return oldvalue
+
+# regrtest's interface to _output_comparison.
+def suppress_output_comparison():
+    return not _output_comparison
+
+
 def unload(name):
     try:
         del sys.modules[name]
@@ -156,3 +175,29 @@ def run_unittest(testclass):
             raise TestFailed("errors occurred in %s.%s"
                              % (testclass.__module__, testclass.__name__))
         raise TestFailed(err)
+
+#=======================================================================
+# doctest driver.
+
+def run_doctest(module, verbosity=None):
+    """Run doctest on the given module.
+
+    If optional argument verbosity is not specified (or is None), pass
+    test_support's belief about verbosity on to doctest.  Else doctest
+    sys.argv for -v.
+    """
+
+    import doctest
+
+    if verbosity is None:
+        verbosity = verbose
+    else:
+        verbosity = None
+
+    oldvalue = set_output_comparison(0)
+    try:
+        f, t = doctest.testmod(module, verbose=verbosity)
+        if f:
+            raise TestFailed("%d of %d doctests failed" % (f, t))
+    finally:
+        set_output_comparison(oldvalue)