GDB调试常用命令 #
设置gdbinit初始环境 #
GDB reads commands from $HOME/.gdbinit, then from .gdbinit in the current directory, and then from files specified on the command line with the -x parameter.
https://wizardforcel.gitbooks.io/100-gdb-tips/content/config-gdbinit.html
创建~/.gdbinit文件，添加如下内容，避免每次重复设置
set sysroot /home/ubuntu/test_ti_sdk_debug/linux-devkit/sysroots/armv7at2hf-neon-linux-gnueabi/
#设置源码搜索目录
directory /home/ubuntu/targetNFS/test
set environment LD_LIBRARY_PATH /usr/local/lib/
define bsave
save breakpoints ~/.breakpoints
end
define brestore
source ~/.breakpoints
end
# 保存历史命令
set history filename ~/.gdb_history
set history save on
# 退出时不显示提示信息
set confirm off
# 按照派生类型打印对象
set print object on
# 打印数组的索引下标
set print array-indexes on
# 每行打印一个结构体成员
set print pretty on
运行时指定gdbinit文件,推荐使用
[linux-devkit]:~> arm-none-linux-gnueabihf-gdb test_main -x ../.gdbinit
设置断点 #
#filename:linenum
(gdb) break /Full/path/to/service.cpp:45
#function
(gdb) b NamespaceA::ClassA::foo
#filename:function
(gdb) b object5.cpp:test
保存断点 #
https://stackoverflow.com/questions/501486/getting-gdb-to-save-a-list-of-breakpoints
As of GDB 7.2 (2011-08-23) you can now use the save breakpoints command.
(gdb) save breakpoints <filename>
Save all current breakpoint definitions to a file suitable for use
in a later debugging session. To read the saved breakpoint
definitions, use the `source' command.
Use source command to restore the saved breakpoints from the file.
(gdb) source <filename>
测试
(gdb) save breakpoints br_file
Saved to file 'br_file'.
(gdb) source br_file
Breakpoint 1 at 0x43ccea: file /home/ubuntu/targetNFS/test/TestMain.cpp, line 219.
Breakpoint 2 at 0x43ccf6: file /home/ubuntu/targetNFS/test/TestMain.cpp, line 220.
删除断点 #
clear
clear function
clear filename:function
clear linenum
clear filename:linenum
delete [breakpoints] [range...]
d #清空所有
查看断点 #
设置记录日志
(gdb) b main
Breakpoint 1 at 0x8049329
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x08049329 <main+16>
(gdb) set logging file breaks.txt
(gdb) set logging on
Copying output to breaks.txt.
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x08049329 <main+16>
(gdb) q
(gdb) i b
Num Type Disp Enb Address What
1 breakpoint keep y 0x000000000043ccea in main() at /home/ubuntu/targetNFS/test/TestMain.cpp:219
2 breakpoint keep y 0x000000000043ccf6 in main() at /home/ubuntu/targetNFS/test/TestMain.cpp:220
查看变量值 #
1、每次停在断点时，自动打印变量值
Use the display command:
(gdb> display decoder.m_msg
2、打印所有变量
This will cause decoder.m_msg to be printed every time that the prompt is shown (not only after a breakpoint).
Type
info variables to list “All global and static variable names”.
Type
info locals to list “Local variables of current stack frame” (names and values), including static variables in that function.
Type
info args to list “Arguments of the current stack frame” (names and values).
传入运行参数 #
gdb --args executablename arg1 arg2 arg3
(gdb) set args a b c
(gdb) show args
Argument list to give program being debugged when it is started is "a b c".
(gdb) r a b
Starting program: /home/xmj/tmp/a.out a b
Beej’s Quick Guide to GDB #
| command | Note |
|---|---|
| help command | Get help on a certain command |
| apropos keyword | Search help for a particular keyword |
| Starting and Quitting | |
| gdb [-tui] [-c core] [exename] | (Unix Command) Start gdb on an executable or standalone; specify “-tui” to start the TUI GUI; specify “-c” with a corefile name to see where a crash occurred |
| run [arg1] [arg2] […] | Run the currently loaded program with the given command line arguments |
| quit | Exit the debugger |
| file exename | Load an executable file by name |
| Breakpoints and Watchpoints | |
| break location | Set a breakpoint at a location, line number, or file (e.g. “main”, “5”, or “hello.c:23”) |
| watch expression | Break when a variable is written to |
| rwatch expression | Break when a variable is read from |
| awatch expression | Break when a variable is written to or read from |
| info break | Display breakpoint and watchpoint information and numbers |
| info watch | Same as info break |
| clear location | Clear a breakpoint from a location |
| delete num | Delete a breakpoint or watchpoint by number |
| Stepping and Running | |
| next | Run to the next line of this function |
| step | Step into the function on this line, if possible |
| stepi | Step a single assembly instruction |
| continue | Keep running from here |
| CTRL-C | Stop running, wherever you are |
| finish | Run until the end of the current function |
| advance location | Advance to a location, line number, or file (e.g. “somefunction”, “5”, or “hello.c:23”) |
| jump location | Just like continue, except jump to a particular location first. |
| Examining and Modifying Variables | |
| display expression | Display the value of a variable or expression every step of the program—the expression must make sense in the current scope |
| info display | Show a list of expressions currently being displayed and their numbers |
| undisplay num | Stop showing an expression identified by its number (see info display) |
| print expression | Print the value of a variable or expression |
| printf formatstr expressionlist | Do some formatted output with printf() e.g. printf "i = %d, p = %s\n", i, p |
| set variable expression | Set a variable to value, e.g. set variable x=20 |
| set (expression) | Works like set variable |
| Window Commands | |
| info win | Shows current window info |
| focus winname | Set focus to a particular window bby name (“SRC”, “CMD”, “ASM”, or “REG”) or by position (“next” or “prev”) |
| fs | Alias for focus |
| layout type | Set the window layout (“src”, “asm”, “split”, or “reg”) |
| tui reg type | Set the register window layout (“general”, “float”, “system”, or “next”) |
| winheight val | Set the window height (either an absolute value, or a relative value prefaced with “+” or “-”) |
| wh | Alias for winheight |
| set disassembly-flavor flavor | Set the look-and-feel of the disassembly. On Intel machines, valid flavors are intel and att |
| Misc Commands | |
| RETURN | Hit RETURN to repeat the last command |
| backtrace | Show the current stack |
| bt | Alias for backtrace |
| attach pid | Attach to an already-running process by its PID |
| info registers | Dump integer registers to screen |
| info all-registers | Dump all registers to screen |
参考链接 #
https://visualgdb.com/gdbreference/commands/