On 04/06/2016 05:12 AM, Rainer Orth wrote:
I've finally gotten around to analyzing this testsuite failure on 32-bit
Solaris/x86:
FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -O1 -fcilkplus execution test
FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -O3 -fcilkplus execution test
FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -g -O2 -fcilkplus execution test
FAIL: g++.dg/cilk-plus/CK/catch_exc.cc -g -fcilkplus execution test
The testcase aborts like this:
Thread 2 received signal SIGABRT, Aborted.
[Switching to Thread 1 (LWP 1)]
0xfe3ba3c5 in __lwp_sigqueue () from /lib/libc.so.1
(gdb) where
#0 0xfe3ba3c5 in __lwp_sigqueue () from /lib/libc.so.1
#1 0xfe3b2d4f in thr_kill () from /lib/libc.so.1
#2 0xfe2f64da in raise () from /lib/libc.so.1
#3 0xfe2c93ee in abort () from /lib/libc.so.1
#4 0xfe525b37 in _Unwind_Resume (exc=0x80a75a0)
at /vol/gcc/src/hg/trunk/local/libgcc/unwind.inc:234
#5 0xfe783b85 in __cilkrts_gcc_rethrow (sf=0xfeffdb00)
at /vol/gcc/src/hg/trunk/local/libcilkrts/runtime/except-gcc.cpp:589
#6 0xfe77f0ea in __cilkrts_rethrow (sf=0xfeffdb00)
at /vol/gcc/src/hg/trunk/local/libcilkrts/runtime/cilk-abi.c:548
#7 0x080513a3 in my_test ()
at
/vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/cilk-plus/CK/catch_exc.cc:38
#8 0x080515bd in main ()
at
/vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/cilk-plus/CK/catch_exc.cc:62
The gcc_assert in _Unwind_Resume triggers since
_Unwind_RaiseException_Phase2 returned _URC_FATAL_PHASE2_ERROR. I found
that x86_fallback_frame_state had been invoked for this pc:
0xfe77218e <__cilkrts_rethrow+30>: add $0x10,%esp
and returned _URC_END_OF_STACK, which is totally unexpected since
_Unwind_Find_FDE should have found it. __cilkrts_rethrow is defined in
libcilkrts/cilk-abi.o, but in the 32-bit case EH info is missing:
32-bit:
ro@fuego 339 > elfdump -u .libs/libcilkrts.so|grep rethrow
0x18def 0x3558c __cilkrts_gcc_rethrow
[0x11fc] initloc: 0x18def [ sdata4 pcrel ] __cilkrts_gcc_rethrow
64-bit:
ro@fuego 341 > elfdump -u amd64/libcilkrts/.libs/libcilkrts.so|grep rethrow
0x1c639 0x2010 __cilkrts_rethrow
0x2388b 0x5510 __cilkrts_gcc_rethrow
[0x488] initloc: 0x1c639 [ sdata4 pcrel ] __cilkrts_rethrow
[0x3988] initloc: 0x2388b [ sdata4 pcrel ] __cilkrts_gcc_rethrow
I traced this to -funwind-tables bein set on 32-bit Linux/x86, while it
is unset on 32-bit Solaris/x86 due to
i386/i386.c (ix86_option_override_internal):
if (opts->x_flag_asynchronous_unwind_tables == 2)
opts->x_flag_asynchronous_unwind_tables = !USE_IX86_FRAME_POINTER;
where i386/sol2.h has
#define USE_IX86_FRAME_POINTER 1
while the default is 0.
As expected, compiling libcilkrts with -funwind-tables (which is a no-op
on Linux/x86, Linux/x86_64, and Solaris/amd64) makes the failure go
away.
I'm uncertain if this is ok for mainline at this stage or has to wait
for gcc-7. Once it goes into mainline, it's probably worth a backport
to all active release branches.
Thoughts?
Rainer
2016-04-04 Rainer Orth <r...@cebitec.uni-bielefeld.de>
PR target/60290
* Makefile.am (GENERAL_FLAGS): Add -funwind-tables.
* Makefile.in: Regenerate.
OK. Thanks for tracking this down, including verification that the
difference between Solaris and Linux is the latter having
-funwind-tables on by default.
jeff
