remote core file analysis with eclipse - c++

Question

I want to use eclipse IDE as front-end GUI to debug a core file of another OS that is docker'ed in my host. With 'gdbserver' in the docker i can only debug a running process. But i need post-mortem debugging of core files.
I tried some /home/me/bin/remote_gdb wrapper that uses
docker exec -it $DOCKER_CONTAINER bash -c "gdb /usr/bin/executable /opt/crash/executable.core
This works using in a shell. But it fails using in 'eclipse' because of
Could not determine GDB version using command: remote_gdb --version
even though 'remote_gdb --version' prints out exactly the same as the original 'gdb --version'.
I could make something work with 'ddd' as a front-end - let me exercise:
> cd $HOME/SRC
> ls -l
total 4
-rw-rw-r-- 1 frank frank 96 Aug 24 18:04 test.c
> cat test.c
#include <stdio.h>
int main(int argc, char** argv)
{
printf("hello, world!\n");
return 0;
}
> docker run -v $HOME/SRC:/SRC -t fedora /bin/bash
// IN DOCKER NOW:
>> yum install gcc
[...]
>> yum install gdb
[...]
>> cd /SRC
>> gcc -g3 -O0 -o test test.c
>> ls -l
total 40
-rwxr-xr-x 1 root root 34864 Aug 24 16:26 test
-rw-rw-r-- 1 1000 1000 96 Aug 24 16:04 test.c
Back in Host:
> docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e501d8384060 fedora "/bin/bash" 4 minutes ago Up 4 minutes stupefied_murdock
> cat $HOME/bin/remote_gdb
#!/bin/bash
docker exec -it e501d8384060 gdb /SRC/test
> remote_gdb # $HOME/bin/ is in $PATH
GNU gdb (GDB) Fedora 8.0-20.fc26
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /SRC/test...done.
(gdb) list
1 #include <stdio.h>
2
3 int main(int argc, char** argv)
4 {
5 printf("hello, world!\n");
6 return 0;
7 }
8
(gdb)
Switching back to the shell, where i am in the docker - see 'gdb' is running:
>> yum install procps-ng
[...]
>> ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 16:22 ? 00:00:00 /bin/bash
root 16 0 0 16:23 ? 00:00:00 bash
root 116 0 0 16:28 ? 00:00:00 gdb /SRC/test
root 131 16 0 16:30 ? 00:00:00 ps -ef
Back again on the host shell (after quit gdb session in docker):
> ddd --debugger remote_gdb
The 'ddd' plays nicely with gdb started in docker.
And it also works with core-files (add a "sleep(100);" and kill the process).
But 'ddd' doesn't have a really good GUI.
So what's the way to make such work with 'eclipse'?
I also couldn't make it work with other options: 'qtcreator', 'kdevelop', 'nemiver', 'kdbg', etc
Addendum:
It also doesn't work with 'ssh' into container.
But when i execute the same 'remote_gdb' wrapper script as 'External Tool' it can be executed(?!)

Answer 1

I partially could solve the issue.
The main problem was: my docker command does not provide a tty to eclipse.
As a workaround i switched over to 'ssh' into the docker image.
Moreover i had to align the file locations (executable, core-file and source-files) between host and docker image. Because using a 'gdb' wrapper script, 'eclipse' is not aware that i am debugging remotely and verifies all files for local availability.
This works for post-mortem debugging (core file analysis) and attaching a running process in docker (in general on the remote system).
However, it does not work for starting up a process in gdb via eclipse.
So used 'strace' to check for the activities between 'eclipse' and 'gdb' and found out, that for starting up a new process in 'gdb', 'eclipse' tries to apply some '--interpreter mi2 -nx' command:
inferior-tty-set --thread-group i1 /dev/pts/27
Does it mean it tries to bind a local tty to gdb?
That of course does not work remotely.
What is the reason to use "inferior-tty-set" by 'eclipse'?
It doesn't use this command for doing post-mortem debugging or attaching a running process - while for both i even have a gdb console operable in 'eclipse'
?