Get Different Result for the same core file with different versions of gdb.

[Andy Fan]

On Mon, Feb 1, 2021 at 11:57 AM Andy Fan <zhihui.fan1213@gmail.com> wrote:

> Hi:
>
> You can pay attention to $2 and $3.They check the same addr in the same
> core file.
> I'm sure I am debugging the same file in the same machine.
>
> GDB 7.6:
>
> (gdb) up 3
> #3  ResetPlanCache () at plancache.c:1922
> 1922 plancache.c: No such file or directory.
> (gdb) p ((AllocSet)plansource->query_context)->freelist
> $1 = {0x0, *0x5bdd3b8*, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
> (gdb) p *((AllocSet)plansource->query_context)->freelist[1]
> *$2 = {size = 10649824, aset = 0xa283c0 <AllocSetFree>}*
> (gdb) p plansource->query_context->name
> *$3 = 0xbfd929 "unnamed prepared statement"*
> (gdb) x /10c plansource->query_context->name
> 0xbfd929: 117 'u' 110 'n' 110 'n' 97 'a' 109 'm' 101 'e' 100 'd' 32 ' '
> 0xbfd931: 112 'p' 114 'r'
> (gdb) quit
>
>
> GDB  9.2:
> (gdb) up 3
> #3  ResetPlanCache () at plancache.c:1922
> 1922 plancache.c: No such file or directory.
> (gdb) p ((AllocSet)plansource->query_context)->freelist
> $1 = {0x0, *0x5bdd3b8*, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
> (gdb) p *((AllocSet)plansource->query_context)->freelist[1]
> *$2 = {size = 16, aset = 0x0}*
> (gdb) p plansource->query_context->name
> *$3 = 0xbfd929 ""*
> (gdb) x /10c plansource->query_context->name
> 0xbfd929: 0 '\000' 0 '\000' 0 '\000' 0 '\000' 0 '\000' 0 '\000' 0 '\000' 0
> '\000'
> 0xbfd931: 0 '\000' 0 '\000'
>
>
> Any ideas? Thanks!
>
> --
> Best Regards
> Andy Fan
>

Will it have something with compiler?  The compiler I used
to build the software (which generated the core file) is LLVM 6.0.0.



-- 
Best Regards
Andy Fan (https://www.aliyun.com/)