如何在 gdb 断点的命令中单步执行更多命令答案

【问题标题】：How to step and execute more commands inside a gdb breakpoint's command如何在 gdb 断点的命令中单步执行更多命令
【发布时间】：2017-03-23 05:34:27
【问题描述】：

每当为断点定义命令时，它都无法执行，例如：步骤，否则以下命令不会执行。

代码示例：

[/tmp]$ cat a.c
void increment(int* x) {
  *x = (*x) + 1;
}

int main() {
  int a = 1;
  for (int i = 0; i < 10; i++)
    increment(&a);
  return 0;
}

[/tmp]$ gcc --std=c99 a.c -O0 -g
[/tmp]$ gdb a.out

gdb：

(gdb) b increment
Breakpoint 1 at 0x10000600: file a.c, line 2.
(gdb) command 1
Type commands for breakpoint(s) 1, one per line.
End with a line saying just "end".
>p *x
>n
>p *x
>end
(gdb) r
Starting program: /tmp/a.out

Breakpoint 1, increment (x=0x3ffffffff670) at a.c:2
2         *x = (*x) + 1;
$1 = 1
3       }
(gdb) p *x
$2 = 2

它执行了p *x 和n，但没有执行n 之后的命令，即p *x。

c、fin、s 也会发生这种情况...

【问题讨论】：

来自the user manual:Any other commands in the command list, after a command that resumes execution, are ignored. This is because any time you resume execution (even with a simple next or step), you may encounter another breakpoint—which could have its own command list, leading to ambiguities about which list to execute.tldr;你不能！

标签： gdb

【解决方案1】：

我找到了出路，但这是一种解决方法....

让我们重新考虑一下我正在编写的 gdb 脚本：

(gdb) b increment
Breakpoint 1 at 0x10000600: file a.c, line 2.
(gdb) command 1
Type commands for breakpoint(s) 1, one per line.
End with a line saying just "end".
>p *x
>n
>end
(gdb) r
Starting program: /tmp/a.out

Breakpoint 1, increment (x=0x3ffffffff670) at a.c:2
2         *x = (*x) + 1;
$1 = 1
3       }
(gdb) b
Breakpoint 2 at 0x1000061c: file a.c, line 3.
(gdb) command 2
Type commands for breakpoint(s) 2, one per line.
End with a line saying just "end".
>p *x
>end
(gdb) p *x
$2 = 2
(gdb) c
Continuing.

Breakpoint 1, increment (x=0x3ffffffff670) at a.c:2
2         *x = (*x) + 1;
$3 = 2

Breakpoint 2, increment (x=0x3ffffffff670) at a.c:3
3       }
$4 = 3
(gdb)

所以基本上如果我需要在n、s、fin... .

【讨论】：