# 一個gdb會話中同時調試多個程序 ## 例子 a.c: #include <stdio.h> int func(int a, int b) { int c = a * b; printf("c is %d\n", c); } int main(void) { func(1, 2); return 0; } b.c: #include <stdio.h> int func1(int a) { return 2 * a; } int func2(int a) { int c = 0; c = 2 * func1(a); return c; } int func3(int a) { int c = 0; c = 2 * func2(a); return c; } int main(void) { printf("%d\n", func3(10)); return 0; } ## 技巧 gdb支持在一個會話中同時調試多個程序。以上面程序為例，首先調試`a`程序： root@bash:~$ gdb a GNU gdb (Ubuntu 7.7-0ubuntu3) 7.7 Copyright (C) 2014 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-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 a...done. (gdb) start Temporary breakpoint 1 at 0x400568: file a.c, line 10. Starting program: /home/nanxiao/a 接著使用“`add-inferior [ -copies n ] [ -exec executable ]`”命令加載可執行文件`b`。其中`n`默認為1： (gdb) add-inferior -copies 2 -exec b Added inferior 2 Reading symbols from b...done. Added inferior 3 Reading symbols from b...done. (gdb) i inferiors Num Description Executable 3 <null> /home/nanxiao/b 2 <null> /home/nanxiao/b * 1 process 1586 /home/nanxiao/a (gdb) inferior 2 [Switching to inferior 2 [<null>] (/home/nanxiao/b)] (gdb) start Temporary breakpoint 2 at 0x400568: main. (3 locations) Starting program: /home/nanxiao/b Temporary breakpoint 2, main () at b.c:24 24 printf("%d\n", func3(10)); (gdb) i inferiors Num Description Executable 3 <null> /home/nanxiao/b * 2 process 1590 /home/nanxiao/b 1 process 1586 /home/nanxiao/a 可以看到可以調試`b`程序了。 另外也可用“`clone-inferior [ -copies n ] [ infno ]`”克隆現有的`inferior`，其中`n`默認為1，`infno`默認為當前的`inferior`： (gdb) i inferiors Num Description Executable 3 <null> /home/nanxiao/b * 2 process 1590 /home/nanxiao/b 1 process 1586 /home/nanxiao/a (gdb) clone-inferior -copies 1 Added inferior 4. (gdb) i inferiors Num Description Executable 4 <null> /home/nanxiao/b 3 <null> /home/nanxiao/b * 2 process 1590 /home/nanxiao/b 1 process 1586 /home/nanxiao/a 可以看到又多了一個`b`程序。 參見[gdb手冊](https://sourceware.org/gdb/onlinedocs/gdb/Inferiors-and-Programs.html). ## 貢獻者 nanxiao