Re: [PATCH] Merge from LTO: eh_personality changes

[Richard Henderson <rth@redhat.com>]

On 09/10/2009 07:52 AM, Richard Guenther wrote:
>> Doesn't seem to work.  Instead I tried to fall back to
>> the gcc personality for detecting empty type lists, again setting
>> a cfi personality for all functions we emit.  But that doesn't work
>> either (it seems catch (...) doesn't work with the gcc personality,
>> g++.dg/eh/loop1.C fails).

Interesting.  I wouldn't have expected that.  Though your patch
doesn't seem to indicate that:

> + 	case ERT_CATCH:
> + 	  /* An empty type list is ok with the default C EH personality.  */
> + 	  if (i->u.eh_catch.type_list)
> + 	    return true;
> + 	  break;

> 	* langhooks-def.h (LANG_HOOKS_INIT_EH): Define.
> 	(LANG_HOOKS_EH_RUNTIME_TYPE): Likewise.
> 	(LANG_HOOKS_INITIALIZER): Adjust.
> 	(lhd_pass_through_t): Declare.
> 	* langhooks.h (struct lang_hooks): Add init_eh and eh_runtime_type.
> 	* langhooks.c (lhd_pass_through_t): New function.
...
>          * toplev.c (eh_personality_decl): New.

I'm surprised you're not taking the opportunity to make
the eh_personality_thingy a proper lang hook.

> + 	case ERT_MUST_NOT_THROW:
> + 	case ERT_CLEANUP:
> + 	  /* Ok with the default C EH personality.  */
> + 	  break;

MUST_NOT_THROW is not ok with default personality.
You'll wind up invoking abort instead of std::terminate.

> *** gcc/fortran/f95-lang.c.orig	2009-09-10 13:40:45.000000000 +0200
> --- gcc/fortran/f95-lang.c	2009-09-10 14:18:42.000000000 +0200
> *************** gfc_maybe_initialize_eh (void)
> *** 1155,1164 ****
>        return;
>
>      gfc_eh_initialized_p = true;
> !   eh_personality_libfunc
> !     = init_one_libfunc (USING_SJLJ_EXCEPTIONS
> !                        ? "__gcc_personality_sj0"
> !                        : "__gcc_personality_v0");
>      default_init_unwind_resume_libfunc ();
>      using_eh_for_cleanups ();
>    }
> --- 1155,1164 ----
>        return;
>
>      gfc_eh_initialized_p = true;
> !   eh_personality_decl
> !     = build_personality_function (USING_SJLJ_EXCEPTIONS
> ! 				  ? "__gcc_personality_sj0"
> ! 				  : "__gcc_personality_v0");

Surely Fortran can simply avoid setting this up at all?

> + rtx
> + get_personality_function (tree decl)
> + {
> +   tree personality = DECL_FUNCTION_PERSONALITY (decl);
> +   tree name;
> +
> +   if (!personality&&  !eh_personality_decl)
> +     return NULL;
> +
> +   if (!personality)
> +     return init_one_libfunc (USING_SJLJ_EXCEPTIONS
> + 			     ? "__gcc_personality_sj0"
> + 			     : "__gcc_personality_v0");
> +
> +   name = DECL_ASSEMBLER_NAME (personality);
> +
> +   return init_one_libfunc (IDENTIFIER_POINTER (name));
> + }

Why in the world are you extracting the name and invoking 
init_one_libfunc instead of using the DECL_RTL of the function_decl? And 
what's with the eh_personality_decl check at this point?


r~