https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89093
--- Comment #53 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Bernd Edlinger from comment #52)
> I digged a bit, and found a D syntax for the target attribute,
> it is a bit of a complication since D does not have a pre-processor,
> but an empty target attribute does seem to be ignored without warnings.
>
>
> --- libphobos/libdruntime/gcc/deh.d 2019-01-01 13:31:55.000000000 +0100
> +++ libphobos/libdruntime/gcc/deh.d 2019-04-17 11:24:24.171579381 +0200
> @@ -28,6 +28,7 @@ import gcc.unwind;
> import gcc.unwind.pe;
> import gcc.builtins;
> import gcc.config;
> +import gcc.attribute;
>
> extern(C)
> {
> @@ -519,10 +520,19 @@ extern(C) void _d_throw(Throwable object
> terminate("unwind error", __LINE__);
> }
>
> +static if (GNU_ARM_EABI_Unwinder)
> +{
> + enum TARGET_ATTRIBUTE = "general-regs-only";
> +}
> +else
> +{
> + enum TARGET_ATTRIBUTE = "";
> +}
>
> /**
> * Read and extract information from the LSDA (.gcc_except_table section).
> */
> +@attribute("target", (TARGET_ATTRIBUTE))
> _Unwind_Reason_Code scanLSDA(const(ubyte)* lsda, _Unwind_Exception_Class
> exceptionClass,
> _Unwind_Action actions, _Unwind_Exception*
> unwindHeader,
> _Unwind_Context* context, _Unwind_Word cfa,
> @@ -772,6 +782,7 @@ int actionTableLookup(_Unwind_Action act
> * Called when the personality function has found neither a cleanup or
> handler.
> * To support ARM EABI personality routines, that must also unwind the
> stack.
> */
> +@attribute("target", (TARGET_ATTRIBUTE))
> _Unwind_Reason_Code CONTINUE_UNWINDING(_Unwind_Exception* unwindHeader,
> _Unwind_Context* context)
> {
> static if (GNU_ARM_EABI_Unwinder)
> @@ -814,6 +825,7 @@ else
> static if (GNU_ARM_EABI_Unwinder)
> {
> pragma(mangle, PERSONALITY_FUNCTION)
> + @attribute("target", (TARGET_ATTRIBUTE))
> extern(C) _Unwind_Reason_Code gdc_personality(_Unwind_State state,
> _Unwind_Exception*
> unwindHeader,
> _Unwind_Context* context)
> @@ -873,6 +885,7 @@ else
> }
> }
>
> +@attribute("target", (TARGET_ATTRIBUTE))
> private _Unwind_Reason_Code __gdc_personality(_Unwind_Action actions,
> _Unwind_Exception_Class
> exceptionClass,
> _Unwind_Exception*
> unwindHeader,
That is not going to work I'm afraid, many targets don't support target
attribute at all.
default_target_option_valid_attribute_p
will then just complain.
Only i386, rs6000, s390, arm, aarch64 and nios2 backends do support those.
On the other side, given the above, I thought all you want to ensure is that
the attribute is on the personality routine, not on the other ones, and the
gdc_personality definition is in
static if (GNU_ARM_EABI_Unwinder)
{
pragma(mangle, PERSONALITY_FUNCTION)
extern(C) _Unwind_Reason_Code gdc_personality(_Unwind_State state,
so can't you just stick @attribute("target", "general-regs-only") to there?
