C trace function now roundtrips properly. Fixes #123 and #125.

--HG--
branch : bug_123

3 files changed, 26 insertions, 5 deletions

diff --git a/test/farm/run/run_timid.py b/test/farm/run/run_timid.py
index 3810e6db..19651a1c 100644
--- a/test/farm/run/run_timid.py
+++ b/test/farm/run/run_timid.py
@@ -20,9 +20,8 @@ contains("out/showtraceout.txt", "timid PyTracer")
 
 if os.environ.get('COVERAGE_TEST_TRACER', 'c') == 'c':
     # If the C trace function is being tested, then regular running should have
-    # the C function (shown as None in f_trace since it isn't a Python
-    # function).
-    contains("out/showtraceout.txt", "regular None")
+    # the C function, which registers itself as f_trace.
+    contains("out/showtraceout.txt", "regular Tracer")
 else:
     # If the Python trace function is being tested, then regular running will
     # also show the Python function.
diff --git a/test/farm/run/src/showtrace.py b/test/farm/run/src/showtrace.py
index c3b4356c..e97412e0 100644
--- a/test/farm/run/src/showtrace.py
+++ b/test/farm/run/src/showtrace.py
@@ -4,7 +4,7 @@
 import sys
 
 # Show what the trace function is.  If a C-based function is used, then f_trace
-# is None.
+# may be None.
 trace_fn = sys._getframe(0).f_trace
 if trace_fn is None:
     trace_name = "None"
@@ -13,6 +13,11 @@ else:
     try:
         trace_name = trace_fn.im_class.__name__
     except AttributeError:
-        trace_name = trace_fn.__self__.__class__.__name__
+        try:
+            trace_name = trace_fn.__self__.__class__.__name__
+        except AttributeError:
+            # A C-based function could also manifest as an f_trace value
+            # which doesn't have im_class or __self__.
+            trace_name = trace_fn.__class__.__name__
 
 print("%s %s" % (sys.argv[1], trace_name))
diff --git a/test/test_oddball.py b/test/test_oddball.py
index 9b65a986..859648fa 100644
--- a/test/test_oddball.py
+++ b/test/test_oddball.py
@@ -365,3 +365,20 @@ if hasattr(sys, 'gettrace'):
                 a = bar(8)
                 ''',
                 [1,2,3,4,5,6,7,8], "")
+
+        def test_multi_layers(self):
+            self.check_coverage('''\
+                import sys
+                def level1():
+                    a = 3
+                    level2()
+                    b = 5
+                def level2():
+                    c = 7
+                    sys.settrace(sys.gettrace())
+                    d = 9
+                e = 10
+                level1()
+                f = 12
+                ''',
+                [1,2,3,4,5,6,7,8,9,10,11,12], "")