Debugging c++ code behind python

Question

I am trying to debug C++ code behind python for this library (faster rcnn).

I followed the instruction here.

Say I like to stop a break point at solver.cpp and line 188.

gdb -ex r --args python ./tools/train_faster_rcnn_alt_opt.py --gpu 0 --net_name headhand --weights data/imagenet_models/VGG_CNN_M_1024.v2.caffemodel --imdb headhand_train --cfg experiments/cfgs/config.yml

I press Ctrl + c

then

gdb python 8504

break solver.cpp:188

then type c and enter

But never break at solver.cpp. How can I debug?

n. m. could be an AI · Accepted Answer · 2017-12-12 07:32:18Z

2

If you are not debugging the python interpreter itself, you don't need any python debugging stuff described in the linked article. You can use the regular interpreter and no extensions. You also don't want to run gdb twice. You only need to make sure you set your breakpoint early enough.

$ gdb python --args <your-args> # no -x r 
(gdb) break <your-breakpoint>
No symbol table is loaded. Use the "file" comand.
Make breakpoint pending on future shared library load? (y or [n])

Answer "y".

(gdb) run

That's it.

answered Dec 12, 2017 at 7:32

n. m. could be an AI

122k14 gold badges141 silver badges267 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

batuman Over a year ago

I did as what you mentioned and I have (gdb) run Starting program: --gpu 0 --net_name headhand --weights data/imagenet_models/VGG_CNN_M_1024.v2.caffemodel --imdb headhand_train --cfg experiments/cfgs/config.yml No executable file specified. Use the "file" or "exec-file" command.

Basile Starynkevitch · Accepted Answer · 2017-12-12 06:25:17Z

0

You probably has passed your breakpoint (before GDB got started). You should, per the instructions mentioned:

run python under gdb from the start

Try to run your python under GDB.

Read about Debugging with GDB.

You might want to use a python interpreter built with DWARF debug info, so compiled with -g (and of course your solver.cpp should also be compiled with -g). Since Python is free software recompiling it with -g should be pretty simple.

BTW, are you sure of the line position 188 of your breakpoint? Did you try to add more breakpoints in solver.cpp at other positions, or to break at function names?

edited Dec 12, 2017 at 6:25

answered Dec 12, 2017 at 6:20

Basile Starynkevitch

231k18 gold badges322 silver badges578 bronze badges

Collectives™ on Stack Overflow

Debugging c++ code behind python

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related