Re: [PATCH] Objective-C: don't require redundant -fno-objc-sjlj-exceptions for the NeXT v2 ABI

[Eric Gallager <egall@gwmail.gwu.edu>]

On Wed, Jul 28, 2021 at 11:36 PM Matt Jacobson via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> As is, an invocation of GCC with -fnext-runtime -fobjc-abi-version=2 crashes,
> unless target-specific code adds an implicit -fno-objc-sjlj-exceptions (which
> Darwin does).
>
> This patch makes the general case not crash.
>
> I don't have commit access, so if this patch is suitable, I'd need someone else
> to commit it for me.  Thanks.

Is there a bug open for the issue that this fixes? Just wondering for
cross-referencing purposes...

>
> gcc/objc/ChangeLog:
>
> 2021-07-28  Matt Jacobson  <mhjacobson@me.com>
>
>         * objc-next-runtime-abi-02.c (objc_next_runtime_abi_02_init): Warn
>         about and reset flag_objc_sjlj_exceptions regardless of
>         flag_objc_exceptions.
>
>
> gcc/c-family/ChangeLog:
>
> 2021-07-28  Matt Jacobson  <mhjacobson@me.com>
>
>         * c-opts.c (c_common_post_options): Default to
>         flag_objc_sjlj_exceptions = 1 only when flag_objc_abi < 2.
>
> diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
> index c51d6d34726..2568df67972 100644
> --- a/gcc/c-family/c-opts.c
> +++ b/gcc/c-family/c-opts.c
> @@ -840,9 +840,9 @@ c_common_post_options (const char **pfilename)
>    else if (!flag_gnu89_inline && !flag_isoc99)
>      error ("%<-fno-gnu89-inline%> is only supported in GNU99 or C99 mode");
>
> -  /* Default to ObjC sjlj exception handling if NeXT runtime.  */
> +  /* Default to ObjC sjlj exception handling if NeXT <v2 runtime.  */
>    if (flag_objc_sjlj_exceptions < 0)
> -    flag_objc_sjlj_exceptions = flag_next_runtime;
> +    flag_objc_sjlj_exceptions = (flag_next_runtime && flag_objc_abi < 2);
>    if (flag_objc_exceptions && !flag_objc_sjlj_exceptions)
>      flag_exceptions = 1;
>
> diff --git a/gcc/objc/objc-next-runtime-abi-02.c b/gcc/objc/objc-next-runtime-abi-02.c
> index 66c13ad0db2..9a0868410a8 100644
> --- a/gcc/objc/objc-next-runtime-abi-02.c
> +++ b/gcc/objc/objc-next-runtime-abi-02.c
> @@ -245,7 +245,7 @@ objc_next_runtime_abi_02_init (objc_runtime_hooks *rthooks)
>  {
>    extern_names = ggc_cleared_vec_alloc<hash> (SIZEHASHTABLE);
>
> -  if (flag_objc_exceptions && flag_objc_sjlj_exceptions)
> +  if (flag_objc_sjlj_exceptions)
>      {
>        inform (UNKNOWN_LOCATION,
>               "%<-fobjc-sjlj-exceptions%> is ignored for "
>