[Python-checkins] devguide: Give an example backtrace

[antoine.pitrou]

antoine.pitrou pushed b3be5d9849cc to devguide:

http://hg.python.org/devguide/rev/b3be5d9849cc
changeset:   163:b3be5d9849cc
tag:         tip
user:        Antoine Pitrou <solipsis at pitrou.net>
date:        Thu Jan 20 21:17:49 2011 +0100
summary:
  Give an example backtrace

files:
  gdb.rst

diff --git a/gdb.rst b/gdb.rst
--- a/gdb.rst
+++ b/gdb.rst
@@ -22,6 +22,29 @@
 root directory of your checkout. Read the module docstring for details on how
 to use the file to enhance gdb for easier debugging of a CPython process.
 
+This is what a backtrace looks like (truncated) when this extension is
+enabled::
+
+   #0  0x000000000041a6b1 in PyObject_Malloc (nbytes=Cannot access memory at address 0x7fffff7fefe8
+   ) at Objects/obmalloc.c:748
+   #1  0x000000000041b7c0 in _PyObject_DebugMallocApi (id=111 'o', nbytes=24) at Objects/obmalloc.c:1445
+   #2  0x000000000041b717 in _PyObject_DebugMalloc (nbytes=24) at Objects/obmalloc.c:1412
+   #3  0x000000000044060a in _PyUnicode_New (length=11) at Objects/unicodeobject.c:346
+   #4  0x00000000004466aa in PyUnicodeUCS2_DecodeUTF8Stateful (s=0x5c2b8d "__lltrace__", size=11, errors=0x0, consumed=
+       0x0) at Objects/unicodeobject.c:2531
+   #5  0x0000000000446647 in PyUnicodeUCS2_DecodeUTF8 (s=0x5c2b8d "__lltrace__", size=11, errors=0x0)
+       at Objects/unicodeobject.c:2495
+   #6  0x0000000000440d1b in PyUnicodeUCS2_FromStringAndSize (u=0x5c2b8d "__lltrace__", size=11)
+       at Objects/unicodeobject.c:551
+   #7  0x0000000000440d94 in PyUnicodeUCS2_FromString (u=0x5c2b8d "__lltrace__") at Objects/unicodeobject.c:569
+   #8  0x0000000000584abd in PyDict_GetItemString (v=
+       {'Yuck': <type at remote 0xad4730>, '__builtins__': <module at remote 0x7ffff7fd5ee8>, '__file__': 'Lib/test/crashers/nasty_eq_vs_dict.py', '__package__': None, 'y': <Yuck(i=0) at remote 0xaacd80>, 'dict': {0: 0, 1: 1, 2: 2, 3: 3}, '__cached__': None, '__name__': '__main__', 'z': <Yuck(i=0) at remote 0xaace60>, '__doc__': None}, key=
+       0x5c2b8d "__lltrace__") at Objects/dictobject.c:2171
+
+(notice how the dictionary argument to ``PyDict_GetItemString`` is displayed
+as its ``repr()``, rather than an opaque ``PyObject *`` pointer)
+
+
 .. note: This is only available for Python 2.7, 3.2 and higher.
 
 gdb 6 and earlier

--
Repository URL: http://hg.python.org/devguide