Re: [Libunwind-devel] Testing time

[Arun Sharma]

On Tue, Mar 29, 2011 at 6:03 AM, Lassi Tuura <address@hidden> wrote:
> I have some reports of crashes on RHEL6 + GCC 4.6 + gold linker. LTO may be 
> involved, I am not sure.
>

I did some gcc-4.6 testing today. Two new failures: Ltest-exc and
Gtest-exc. I think the root cause is that gcc-4.6 is optimizing the
recursive call to a() somehow.

gcc-4.4.5:

(gdb) bt
#0  0x00000000004008c0 in raise_exception ()
#1  0x0000000000400999 in b ()
#2  0x0000000000400a79 in a ()
#3  0x00000000004009fd in a ()
#4  0x00000000004009fd in a ()
#5  0x00000000004009fd in a ()
#6  0x00000000004009fd in a ()
#7  0x00000000004009fd in a ()
#8  0x00000000004009fd in a ()
#9  0x00000000004009fd in a ()
#10 0x00000000004009fd in a ()
#11 0x00000000004009fd in a ()
#12 0x00000000004009fd in a ()
#13 0x00000000004009fd in a ()
#14 0x00000000004009fd in a ()
#15 0x00000000004009fd in a ()
#16 0x0000000000400ab0 in main ()

gcc-4.6:

(gdb) bt
#0  0x00000000004009b0 in raise_exception ()
#1  0x0000000000401045 in a ()
#2  0x0000000000400b91 in a ()
#3  0x00000000004013f1 in main ()

My inclination is to change the test so gcc-4.6 can't do this optimization.

 -Arun