[Bug backtrace/33256] New: incorrect prototype in backtrace when using GCC's cleanup attribute (GCC 8)

[vincent-srcware at vinc17 dot net]

https://sourceware.org/bugzilla/show_bug.cgi?id=33256

            Bug ID: 33256
           Summary: incorrect prototype in backtrace when using GCC's
                    cleanup attribute (GCC 8)
           Product: gdb
           Version: 16.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: backtrace
          Assignee: unassigned at sourceware dot org
          Reporter: vincent-srcware at vinc17 dot net
  Target Milestone: ---

Created attachment 16232
  --> https://sourceware.org/bugzilla/attachment.cgi?id=16232&action=edit
executable generated by gcc-8

gdb shows an incorrect prototype in backtrace when using GCC's cleanup
attribute, visible when the testcase below is compiled with GCC 8. It is not
clear whether this was actually a bug in GCC 8 fixed in GCC 9 and later or this
is a bug in gdb that is not longer visible when the testcase below is compiled
with GCC 9 and later but which may still appear with other C codes.

I had initially reported this bug in 2011 at

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=624465

(hence the use of GCC 8 at that time).

The testcase:

#include <stdio.h>
#include <stdlib.h>

int fct (int *x, int y, int z)
{
  void log_cleanup (int *time)
  {
    fprintf (stderr, "x=%d\n", *x);
  }
  int log_time __attribute__ ((cleanup (log_cleanup)));

  *x = y;
  abort ();
  return 0;
}

int main (void)
{
  int x;

  fct (&x, 17, 1);
  return 0;
}

compiled with "gcc-8 -Wall -g tst.c -o tst" under Debian/unstable (this is an
old machine where I have kept various GCC versions).

cventin% gdb tst
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Reading symbols from tst...
(gdb) run
Starting program: /home/vlefevre/tst
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGABRT, Aborted.
__pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6,
    no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44
warning: 44     ./nptl/pthread_kill.c: No such file or directory
(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>,
    signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44
#1  0x00007ffff7e309ff in __pthread_kill_internal (threadid=<optimized out>,
    signo=6) at ./nptl/pthread_kill.c:89
#2  0x00007ffff7ddbcc2 in __GI_raise (sig=sig@entry=6)
    at ../sysdeps/posix/raise.c:26
#3  0x00007ffff7dc44ac in __GI_abort () at ./stdlib/abort.c:73
#4  0x0000555555555140 in fct (y=y@entry=17, z=z@entry=1) at tst.c:13
#5  0x0000555555555158 in main () at tst.c:21
(gdb)

One can see that the x is absent from fct in #4.

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