Hi,
the patch
2017-07-06 Jan Hubicka <hubi...@ucw.cz>
* lto-wrapper.c (merge_and_complain): Do not merge
fexceptions, fnon_call_exceptions, ftrapv, ffp_contract_, fmath_errno,
fsigned_zeros, ftrapping_math, fwrapv.
(append_compiler_options): Do not track these options.
(append_linker_options): Likewie
has broken exception handling in LTO mode for targets which don't force either
-funwind-tables or -fasynchronous-unwind-tables (i.e not x86) and do not
default to -fdwarf2-cfi-asm (i.e. not Linux), for example SPARC/Solaris.
The problem is that the eh_frame section is no longer generated because it is
emitted from compile_file:
#if defined DWARF2_DEBUGGING_INFO || defined DWARF2_UNWIND_INFO
if (dwarf2out_do_frame ())
dwarf2out_frame_finish ();
#endif
and this requires that either flag_unwind_tables or flag_exceptions be set.
But both -funwind-tables and -fexceptions are optimization options defaulting
to 0 and they are reset to 0 through optimization_default_node after the last
function is processed by the cgraph machinery.
Note that flag_exceptions is generally set to 1 in lto_init_eh very early, but
the above mechanism overrides it. However, flag_exceptions may *never* be set
to 1 for a specific partition if it contains only EH-neutral functions; that's
why I think that there is no other way than restoring the build-wide handling
of -fexceptions before Jan's patch (hopefully it's the only affected switch).
Tested (lightly for now) on x86-64/Linux and SPARC/Solaris, OK for mainline?
2017-11-09 Eric Botcazou <ebotca...@adacore.com>
* lto-opts.c (lto_write_options): Do not save -fnon-call-exceptions,
-ffp-contract, -fmath-errno, -fsigned-zeros, -ftrapping-math, -ftrapv
and -fwrapv.
* lto-wrapper.c (merge_and_complain): Merge again -fexceptions.
(append_compiler_options): Pass again -fexceptions.
--
Eric BotcazouIndex: lto-opts.c
===================================================================
--- lto-opts.c (revision 254560)
+++ lto-opts.c (working copy)
@@ -82,61 +82,10 @@ lto_write_options (void)
&& global_options.x_flag_exceptions)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
"-fexceptions");
- /* -fnon-call-exceptions changes the generation of exception
- regions. It is enabled implicitly by the Go frontend. */
- if (!global_options_set.x_flag_non_call_exceptions
- && global_options.x_flag_non_call_exceptions)
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- "-fnon-call-exceptions");
- /* The default -ffp-contract changes depending on the language
- standard. Pass thru conservative standard settings. */
- if (!global_options_set.x_flag_fp_contract_mode)
- switch (global_options.x_flag_fp_contract_mode)
- {
- case FP_CONTRACT_OFF:
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- "-ffp-contract=off");
- break;
- case FP_CONTRACT_ON:
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- "-ffp-contract=on");
- break;
- case FP_CONTRACT_FAST:
- /* Nothing. That merges conservatively and is the default for LTO. */
- break;
- default:
- gcc_unreachable ();
- }
- /* The default -fmath-errno, -fsigned-zeros and -ftrapping-math change
- depending on the language (they can be disabled by the Ada front-end).
- Pass thru conservative standard settings. */
- if (!global_options_set.x_flag_errno_math)
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- global_options.x_flag_errno_math
- ? "-fmath-errno"
- : "-fno-math-errno");
- if (!global_options_set.x_flag_signed_zeros)
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- global_options.x_flag_signed_zeros
- ? "-fsigned-zeros"
- : "-fno-signed-zeros");
- if (!global_options_set.x_flag_trapping_math)
- append_to_collect_gcc_options (&temporary_obstack, &first_p,
- global_options.x_flag_trapping_math
- ? "-ftrapping-math"
- : "-fno-trapping-math");
- /* We need to merge -f[no-]strict-overflow, -f[no-]wrapv and -f[no-]trapv
- conservatively, so stream out their defaults. */
- if (!global_options_set.x_flag_wrapv
- && global_options.x_flag_wrapv)
- append_to_collect_gcc_options (&temporary_obstack, &first_p, "-fwrapv");
- if (!global_options_set.x_flag_trapv
- && !global_options.x_flag_trapv)
- append_to_collect_gcc_options (&temporary_obstack, &first_p, "-fno-trapv");
-
if (!global_options_set.x_flag_openmp
&& !global_options.x_flag_openmp)
- append_to_collect_gcc_options (&temporary_obstack, &first_p, "-fno-openmp");
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ "-fno-openmp");
if (!global_options_set.x_flag_openacc
&& !global_options.x_flag_openacc)
append_to_collect_gcc_options (&temporary_obstack, &first_p,
Index: lto-wrapper.c
===================================================================
--- lto-wrapper.c (revision 254560)
+++ lto-wrapper.c (working copy)
@@ -280,6 +280,7 @@ merge_and_complain (struct cl_decoded_op
pie_option = foption;
break;
+ case OPT_fexceptions:
case OPT_fopenmp:
case OPT_fopenacc:
case OPT_fcilkplus:
@@ -290,10 +291,11 @@ merge_and_complain (struct cl_decoded_op
break;
if (j == *decoded_options_count)
append_option (decoded_options, decoded_options_count, foption);
- /* -fopenmp > -fno-openmp,
+ /* -fexceptions -> -fno-exceptions
+ -fopenmp > -fno-openmp,
-fopenacc > -fno-openacc,
-fcilkplus > -fno-cilkplus,
- -fcheck_pointer_bounds > -fcheck_pointer_bounds */
+ -fcheck-pointer-bounds > -fno-check-pointer-bounds */
else if (foption->value > (*decoded_options)[j].value)
(*decoded_options)[j] = *foption;
break;
@@ -546,6 +548,7 @@ append_compiler_options (obstack *argv_o
case OPT_fpie:
case OPT_fcommon:
case OPT_fgnu_tm:
+ case OPT_fexceptions:
case OPT_fopenmp:
case OPT_fopenacc:
case OPT_fopenacc_dim_:
