Bug 10347 - gdb crashes with MI commands in hook-stop
Summary: gdb crashes with MI commands in hook-stop
Alias: None
Product: gdb
Classification: Unclassified
Component: mi (show other bugs)
Version: 6.8
: P2 normal
Target Milestone: 13.1
Assignee: Tom Tromey
Depends on:
Reported: 2009-06-30 11:02 UTC by Andre'
Modified: 2022-08-31 17:15 UTC (History)
2 users (show)

See Also:
Last reconfirmed: 2022-08-12 00:00:00


Note You need to log in before you can comment on or make changes to this bug.
Description Andre' 2009-06-30 11:02:43 UTC

echo 'int main() {}' | gcc -x c -
echo -e 'define hook-stop\ninterpreter mi "-stack-list-locals 2"\nend\nb
main\nrun' > x  
gdb -x x ./a.out
Comment 1 Marc Khouzam 2009-07-22 17:06:48 UTC
This crash actually happens when using "interpreter mi" inside a define.
It is not only with hook-stop.  Below is an analysis from Paul P that comes from

-----Original Message-----

From: Paul Pluzhnikov [mailto:ppluzhnikov@google.com] 

Sent: Tuesday, July 21, 2009 1:44 AM

The problem is that in cli/cli-script.c, execute_user_command(),

instream is set to NULL:

312	  /* Set the instream to 0, indicating execution of a

313	     user-defined function.  */

314	  make_cleanup (do_restore_instream_cleanup, instream);

315	  instream = (FILE *) 0;

and later used for fileno():

#0  0x00007ffff6ea19f0 in fileno_unlocked () from /lib/libc.so.6

#1  0x000000000051d2ff in gdb_setup_readline () at


#2  0x00000000004aaa09 in mi_interpreter_resume (data=0x0) at


#3  0x00000000005180d7 in interp_set (interp=0xa7a850, top_level=0) at


#4  0x000000000051834e in interpreter_exec_cmd (args=<value optimized

out>, from_tty=<value optimized out>) at ../../src/gdb/interps.c:398

#5  0x0000000000459984 in execute_command (p=0xb295fd "t", from_tty=0)

at ../../src/gdb/top.c:442

#6  0x00000000004a2c04 in execute_control_command (cmd=0xb23c40) at


#7  0x00000000004a31ad in execute_user_command (c=0xb3fd60, args=0x0)

at ../../src/gdb/cli/cli-script.c:324

Comment 2 Tom Tromey 2022-08-12 19:16:26 UTC
Fixing the crash is easy enough but then this trips over
bug #21388.

Also the test hits the double-prompt issue pointed out in
Comment 3 Tom Tromey 2022-08-12 19:51:58 UTC
I have a patch.
Comment 4 cvs-commit@gcc.gnu.org 2022-08-31 17:15:17 UTC
The master branch has been updated by Tom Tromey <tromey@sourceware.org>:


commit 058dc2c95935d54caa8891613a1080d57665fc43
Author: Tom Tromey <tromey@adacore.com>
Date:   Fri Aug 12 13:15:01 2022 -0600

    Fix interpreter-exec crash
    PR mi/10347 points out that using interpreter-exec inside of a
    "define" command will crash gdb.  The bug here is that
    gdb_setup_readline doesn't check for the case where instream==nullptr.
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=10347
Comment 5 Tom Tromey 2022-08-31 17:15:53 UTC