Pdb does not stop at a breakpoint

[xdegaye]

BPO	14751
Nosy	@xdegaye
Files	pdb_default.patch pdb_default_2.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2012-05-08.13:00:17.907>
labels = ['type-bug', 'library']
title = 'Pdb does not stop at a breakpoint'
updated_at = <Date 2012-05-13.15:48:49.831>
user = 'https://github.com/xdegaye'

bugs.python.org fields:

activity = <Date 2012-05-13.15:48:49.831>
actor = 'xdegaye'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2012-05-08.13:00:17.907>
creator = 'xdegaye'
dependencies = []
files = ['25494', '25561']
hgrepos = []
issue_num = 14751
keywords = ['patch']
message_count = 2.0
messages = ['160202', '160518']
nosy_count = 1.0
nosy_names = ['xdegaye']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue14751'
versions = ['Python 2.7', 'Python 3.2', 'Python 3.3']

Linked PRs

• gh-58956: Set f_trace on frames with breakpoints after setting a new breakpoint #124454
• [3.13] gh-58956: Set f_trace on frames with breakpoints after setting a new breakpoint (GH-124454) #125548
• [3.12] gh-58956: Set f_trace on frames with breakpoints after setting a new breakpoint (GH-124454) #125549
• gh-58956: Fix a frame refleak in bdb #128190
• [3.13] gh-58956: Fix a frame refleak in bdb (GH-128190) #128947
• [3.12] gh-58956: Fix a frame refleak in bdb (GH-128190) #128953

[xdegaye]

When a breakpoint is set in one of the frames of the frame stack, Pdb
may not stop at that breakpoint when the frame does not have a trace
function. This problem is closely related to bpo-13183 and issue
14728. The following scenario demonstrates this problem.

==== main.py ================================

import bar

def foo():
    bar.bar()
    x = 1

foo()
====   bar.py  ==================================
def bar():
    pass

=================================================

$ python3 -m pdb main.py 
> /path_to/main.py(1)<module>()
-> import bar
(Pdb) import sys; print(sys.version)
3.2.2 (default, Dec 27 2011, 17:35:55) 
[GCC 4.3.2]
(Pdb) break bar.bar
Breakpoint 1 at /path_to/bar.py:1
(Pdb) continue
> /path_to/bar.py(2)bar()
-> pass
(Pdb) break main.py:5
Breakpoint 2 at /path_to/main.py:5
(Pdb) continue
The program finished and will be restarted
> /path_to/main.py(1)<module>()
-> import bar
(Pdb) quit

=================================================

The attached patch fixes this problem. A test case is included in the
patch. The patch is made against the proposed fix of bpo-14728 (i.e.
assumes this patch is applied), the reason being that self._curframe
must be correctly set. Actually this issue and bpo-14728 should
probably be merged.

Note that the trace function does not need anymore to be set in all
the frames of the frame stack in set_trace(), so setting the trace
function has been removed from the while loop.

[xdegaye]

Uploaded pdb_default_2.patch that corrects the initial patch: the
trace function must be set in all frames whose co_filename is the
breakpoint file name and not just the first frame of this set.

[gaogaotiantian]

Fixed in #124454