Quoting Ned Batchelder (2013-11-09 14:24:34)
Hi all,
I have an .py file with a simple assignment in it:
foo = 'bar'
Now, I want to set a conditional breakpoint in gdb, breaking on that
assignment (I'm guessing the top of the stack would be breaking on the
LOAD_CONST with a value or 'bar'). How would I go about doing that?
b ceval.c:1368 if [?]
Thanks,
I don't know how to use gdb the way you want, but it sounds like you are on a fascinating journey of discovery. What are you trying to learn? Perhaps we can talk about how the interpreter works.
--Ned.
Hi all,
In the purpose of debugging C/C++ Python extensions, I've been also lookingfor
a way to put a gdb breakpoint on a Python line file, like this:
(gdb) b foo.py:47
But I have no idea how this could be implemented.
To break in a C/C++ extension with gdb, on can declare a function, for
example 'Py_DebugTrap' [1], and call it call in the C/C++ code where he/she
want to break, then in gdb:
(gdb) b Py_DebugTrap
So a altenative to break into Python could be to do the same: wrap the
Py_DebugTrap in a Python module, then in the Python file, call the trap
function, for example:
import gdbbreak
gdbbreak.breakpoint_here()
foo = 'bar'
The function gdbbreak.breakpoint_here() would just call the 'Py_DebugTrap'
function, and then in gdb:
(gdb) b Py_DebugTrap
(gdb) next # until foo = 'bar' assignement is reach
(I never try this, be it should work.)
[1]
http://joyrex.spc.uchicago.edu/bookshelves/python/cookbook/pythoncook-CHP-16-SECT-8.html
