[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #13 from ebotcazou at gcc dot gnu dot org 2008-11-19 18:51
---
I'm a bit unsure how to test this right now: what I find is that C objects
have read-only .eh_frame sections and use .cfi* directives, while C++, Java
and Ada objects have read-write .eh_frame sections and still use .eh_frame
sections directly emitted by the compiler.
The decision is made in dwarf2out_do_cfi_asm:
/* Decide whether to emit frame unwind via assembler directives. */
int
dwarf2out_do_cfi_asm (void)
{
int enc;
#ifdef MIPS_DEBUGGING_INFO
return false;
#endif
if (!flag_dwarf2_cfi_asm || !dwarf2out_do_frame ())
return false;
if (!eh_personality_libfunc)
return true;
if (!HAVE_GAS_CFI_PERSONALITY_DIRECTIVE)
return false;
/* Make sure the personality encoding is one the assembler can support.
In particular, aligned addresses can't be handled. */
enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/2,/*global=*/1);
if ((enc 0x70) != 0 (enc 0x70) != DW_EH_PE_pcrel)
return false;
enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0,/*global=*/0);
if ((enc 0x70) != 0 (enc 0x70) != DW_EH_PE_pcrel)
return false;
return true;
}
On Solaris with Sun ld, ASM_PREFERRED_EH_DATA_FORMAT is defined so that at
least one of the 2 tests will always return false. Therefore the only way
to have dwarf2out_do_cfi_asm return true is
if (!eh_personality_libfunc)
return true;
The C++, Java and Ada compilers unconditionally register their personality
routine, whereas the C compiler doesn't, even with -fexceptions: if there
is no EH action in the code, it doesn't register it. Hence the discrepancy.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #10 from jakub at gcc dot gnu dot org 2008-11-03 16:46 --- Patch preapproved by Alex: http://gcc.gnu.org/ml/gcc-patches/2008-10/msg01378.html -- jakub at gcc dot gnu dot org changed: What|Removed |Added AssignedTo|unassigned at gcc dot gnu |ro at gcc dot gnu dot org |dot org | Status|NEW |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #11 from ro at gcc dot gnu dot org 2008-11-03 19:04 --- Subject: Bug 37463 Author: ro Date: Mon Nov 3 19:03:28 2008 New Revision: 141555 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=141555 Log: PR other/37463 * configure.ac (gcc_cv_ld_ro_rw_mix): Move before gcc_cv_as_cfi_directive. (gcc_cv_as_cfi_directive) [*-*-solaris*]: Check if linker supports merging read-only and read-write sections or assembler emits read-write .eh_frame sections. * configure: Regenerate. Modified: trunk/gcc/ChangeLog trunk/gcc/configure trunk/gcc/configure.ac -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #12 from jakub at gcc dot gnu dot org 2008-11-03 19:23 --- Fixed. -- jakub at gcc dot gnu dot org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
-- mmitchel at gcc dot gnu dot org changed: What|Removed |Added Priority|P3 |P1 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #9 from jakub at gcc dot gnu dot org 2008-10-13 10:00 --- If you have prehistoric assembler which doesn't support .cfi_personality directive, then .cfi_* directives can't be used for C++. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #8 from ro at techfak dot uni-bielefeld dot de 2008-10-07 16:04 --- Subject: Re: [4.4 regression] All Solaris/x86 eh tests fail ebotcazou at gcc dot gnu dot org writes: I think that we should assemble some C code with CFI directives and see whether the resulting .eh_frame is read-only; if so, HAVE_GAS_CFI_DIRECTIVE must be set to 0 instead of 1. This should discriminate between 2.18 and upcoming 2.19. That's what I did in my patch at http://gcc.gnu.org/ml/gcc-patches/2008-10/msg00249.html I could just take the current test code for gcc_cv_as_cfi_directive as is and inspect the object file with objdump on Solaris. Using C code directly with gcc -fexceptions -fdwarf2-cfi-asm didn't work since it relies upon the bootstrap compiler being gcc and sufficiently recent to support -fdwarf2-cfi-asm, leading to comparions failures upon a mismatch. That the non-C compilers still emit .eh_frame directly is unexpected I'd think. I think I'll raise a separate PR for that and add rth to the Cc:. Rainer -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #3 from ro at techfak dot uni-bielefeld dot de 2008-09-30 18:09 --- Subject: Re: [4.4 regression] All Solaris/x86 eh tests fail I've done some further debugging: contrary to what gdb suggested, the reason for the abort is the gcc_assert call in unwind-dw2.c (uw_init_context_1): code = uw_frame_state_for (context, fs); gcc_assert (code == _URC_NO_REASON); Single-stepping at the assembler level, I find that code is _URC_END_OF_STACK, i.e. _Unwind_Find_FDE () in uw_frame_state_for () returned NULL. Since this code is such a maze, I'm hard pressed to further debug this, so any guidance is appreciated. Rainer -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #4 from ebotcazou at gcc dot gnu dot org 2008-09-30 18:18 --- Yep, same on SPARC. -- ebotcazou at gcc dot gnu dot org changed: What|Removed |Added CC||ebotcazou at gcc dot gnu dot ||org Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|-00-00 00:00:00 |2008-09-30 18:18:17 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #5 from ebotcazou at gcc dot gnu dot org 2008-09-30 18:19 --- See http://sourceware.org/ml/binutils/2008-09/msg00195.html Now someone needs to write a configure test for the compiler. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #6 from ro at techfak dot uni-bielefeld dot de 2008-09-30 19:22 --- Subject: Re: [4.4 regression] All Solaris/x86 eh tests fail ebotcazou at gcc dot gnu dot org writes: See http://sourceware.org/ml/binutils/2008-09/msg00195.html Thanks for the info. Now someone needs to write a configure test for the compiler. I'm a bit unsure how to test this right now: what I find is that C objects have read-only .eh_frame sections and use .cfi* directives, while C++, Java and Ada objects have read-write .eh_frame sections and still use .eh_frame sections directly emitted by the compiler. Rainer -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #7 from ebotcazou at gcc dot gnu dot org 2008-09-30 19:41 --- I'm a bit unsure how to test this right now: what I find is that C objects have read-only .eh_frame sections and use .cfi* directives, while C++, Java and Ada objects have read-write .eh_frame sections and still use .eh_frame sections directly emitted by the compiler. I think that we should assemble some C code with CFI directives and see whether the resulting .eh_frame is read-only; if so, HAVE_GAS_CFI_DIRECTIVE must be set to 0 instead of 1. This should discriminate between 2.18 and upcoming 2.19. That the non-C compilers still emit .eh_frame directly is unexpected I'd think. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
--- Comment #2 from ro at techfak dot uni-bielefeld dot de 2008-09-16 15:02 --- Subject: Re: [4.4 regression] All Solaris/x86 eh tests fail jakub at gcc dot gnu dot org writes: gas 2.15 is helplessly outdated and buggy. Can you retry with -fno-dwarf2-cfi-asm ? Unfortunately, passing in BOOT_CFLAGS='-g -O2 -fno-dwarf2-cfi-asm' didn't help (the value wasn't picked up from the environment). Even if I manually set BOOT_CFLAGS like that in the toplevel Makefile, it isn't passed down to the libgcc and libstdc++-v3 builds, and manually compiling an individual testcase with -fno-... isn't enough. If I add -fno-... to i386-pc-solaris2.10/libgcc/Makefile, rebuild libgcc and a testcase with -fno-..., the test passes. On the other hand, I tried bootstrapping with the current binutils 2.18 release, which makes no difference, so this doesn't seem to be a gas problem. Rainer -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
[Bug other/37463] [4.4 regression] All Solaris/x86 eh tests fail
-- pinskia at gcc dot gnu dot org changed: What|Removed |Added CC||pinskia at gcc dot gnu dot ||org Target Milestone|--- |4.4.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37463
