平台Ubuntu20.04 + ROS noetic

程序算法：VINS-mono

如何用gdb调试ROS程序？首先看官方的办法，

How to Roslaunch Nodes in Valgrind or GDB

Description: When debugging roscpp nodes that you are launching with roslaunch, you may wish to launch the node in a debugging program like gdb or valgrind instead. Doing this is very simple.
Keywords: roslaunch, valgrind, gdb, pdb
Tutorial Level: INTERMEDIATE
Next Tutorial: Profiling roslaunch nodes

The launch-prefix attribute of the <node> tag that, among other things, makes it easy to debug a ROS node process. Here are some example launch-prefixes you might find useful:

• launch-prefix="xterm -e gdb --args" : run your node in a gdb in a separate xterm window, manually type run to start it

• launch-prefix="gdb -ex run --args" : run your node in gdb in the same xterm as your launch without having to type run to start it

• launch-prefix="stterm -g 200x60 -e gdb -ex run --args" : run your node in gdb in a new stterm window without having to type run to start it

• launch-prefix="valgrind" : run your node in valgrind

• launch-prefix="xterm -e" : run your node in a separate xterm window

• launch-prefix="nice" : nice your process to lower its CPU usage

• launch-prefix="screen -d -m gdb --args" : useful if the node is being run on another machine; you can then ssh to that machine and do screen -D -R to see the gdb session

• launch-prefix="xterm -e python -m pdb" : run your python node a separate xterm window in pdb for debugging; manually type run to start it

• launch-prefix="yappi -b -f pstat -o <filename>": run your rospy node in a multi-thread profiler such as yappi.

• launch-prefix="/path/to/run_tmux": run your node in a new tmux window; you'll need to create /path/to/run_tmux with the contents:

  • #!/bin/shtmux new-window "gdb --args $*"

Obtaining core dumps

To obtain core dumps when processes crash, first set the core file size limit. To check the limits, run:

$ ulimit -a
core file size          (blocks, -c) 0           #  <-- Prevents core dumps
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 20
file size               (blocks, -f) unlimited
pending signals                 (-i) 16382
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) unlimited
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Set the core size to unlimited:

ulimit -c unlimited

Now crashing processes will attempt to create core files. Currently (2010-07-02) they will fail to create the file because the default roslaunch working directory, $ROS_HOME, contains a directory named "core". This directory prevents the core dump from being created.

To allow core dumps to be created, set the core filename to use the process pid by default. Run the following as root:

echo 1 > /proc/sys/kernel/core_uses_pid

Now core dumps will show up as $ROS_HOME/core.PID

Error shooting

• If you get error like below one, you should try to launch node in another windows with gdb.link

• launch-prefix="xterm -e gdb --args"

[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]

怎么操作？

实际上看了官方这段还是云里雾里，我大致以VINS-mono这个工程，比如euro.launch为例说明一下，

（1）编译debug版本的vins-mono

catkin_make -DCMAKE_BUILD_TYPE=Debug

有的说可以去直接修改CMakelist.txt，添加以下代码,

SET(CMAKE_BUILD_TYPE "Debug")
SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")

不过VINS-mono有多个CMakelist.txt文件要修改，有点麻烦。

（2）修改euroc.launch

在estimator节点里，我添加了一句：launch-prefix="xterm -e gdb -ex run --args"，当然你可以选择自己需要调试的其他节点添加，加完后整个文件是这样的，

<launch><arg name="config_path" default = "$(find feature_tracker)/../config/euroc/euroc_config.yaml" /><arg name="vins_path" default = "$(find feature_tracker)/../config/../" /><node name="feature_tracker" pkg="feature_tracker" type="feature_tracker" output="log"><param name="config_file" type="string" value="$(arg config_path)" /><param name="vins_folder" type="string" value="$(arg vins_path)" /></node><node name="vins_estimator" pkg="vins_estimator" type="vins_estimator" output="screen" launch-prefix="xterm -e gdb -ex run --args"><param name="config_file" type="string" value="$(arg config_path)" /><param name="vins_folder" type="string" value="$(arg vins_path)" /></node><node name="pose_graph" pkg="pose_graph" type="pose_graph" output="screen"><param name="config_file" type="string" value="$(arg config_path)" /><param name="visualization_shift_x" type="int" value="0" /><param name="visualization_shift_y" type="int" value="0" /><param name="skip_cnt" type="int" value="0" /><param name="skip_dis" type="double" value="0" /></node></launch>

指令的介绍参考前面提到的官方解释。

（3）启动调试

因为viz不需要调试，所以我们直接打开一个终端开始运行，euroc.launch打开后会弹出调试窗口，play打开后会有动作，xterm gdb窗口可以看到信息迅速滚动，

roslaunch vins_estimator vins_rviz.launch

roslaunch vins_estimator euroc.launch

rosbag play YOUR_PATH_TO_DATASET/MH_01_easy.bag

然后就可以启动euroc.launch了，

暂时先写到这里吧。

附：GDB 最常用的命令:

• b main - Puts a breakpoint at the beginning of the program

• b - Puts a breakpoint at the current line

• b N - Puts a breakpoint at line N

• b +N - Puts a breakpoint N lines down from the current line

• b fn - Puts a breakpoint at the beginning of function "fn"

• d N - Deletes breakpoint number N

• info break - list breakpoints

• r - Runs the program until a breakpoint or error

• c - Continues running the program until the next breakpoint or error

• f - Runs until the current function is finished

• s - Runs the next line of the program

• s N - Runs the next N lines of the program

• n - Like s, but it does not step into functions

• u N - Runs until you get N lines in front of the current line

• p var - Prints the current value of the variable "var"

• bt - Prints a stack trace

• u - Goes up a level in the stack

• d - Goes down a level in the stack

• q - Quits gdb

参考资料：

ros项目调试:ROS项目使用GDB调试_Coulson的博客-CSDN博客_ros程序调试

GDB常用命令大全 GDB 命令详细解释_Linlei的专栏-CSDN博客_gdb 命令