Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
269 views
in Technique[技术] by (71.8m points)

c - How to execute finish and then another command from inside commands?

This is a reduced example of the structure of my code:

void increment(int j);

int main()
{
  int i = 0;

  while(1) {
    i = increment(i);
  }

  return 0;
}

int increment(int j)
{
  return j + 1;
}

And here is the corresponding GDB script:

b increment
command 1
finish
print i
continue
end

The problem is that the finish command prevents the commands that come after it (namely print i and continue) to not be called.

Is there a way to tell GDB to print i right after any increment call?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can apparently work around this bug by wrapping all the commands in a single python invocation e.g.

(gdb) break doSomething
Breakpoint 1 at 0x400478: file iter.c, line 5.
(gdb) commands
Type commands for breakpoint(s) 1, one per line.
End with a line saying just "end".
>python gdb.execute("print i"); gdb.execute("finish"); gdb.execute("print i");
>end

Breakpoint 1, doSomething () at iter.c:5
5     while (i < 5)
$1 = 0
main (argc=1, argv=0x7fffffffe178) at iter.c:13
13    return 0;
$2 = 5

edit: a 2nd work around that doesn't require python appears to be defining a new gdb command and running that in commands:

define foo
print *i
set $addrOfI = i
finish
print *$addrOfI
end

break doSomething
commands
foo
end

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...