Ping: [RFA configure parts] aarch64: Make cc1 &co handle --with options

[Richard Sandiford <richard.sandiford@arm.com>]

Ping for the configure bits

Richard Sandiford via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> On aarch64, --with-arch, --with-cpu and --with-tune only have an
> effect on the driver, so “./xgcc -B./ -O3” can give significantly
> different results from “./cc1 -O3”.  --with-arch did have a limited
> effect on ./cc1 in previous releases, although it didn't work
> entirely correctly.
>
> Being of a lazy persuasion, I've got used to ./cc1 selecting SVE for
> --with-arch=armv8.2-a+sve without having to supply an explicit -march,
> so this patch makes ./cc1 emulate the relevant OPTION_DEFAULT_SPECS.
> It relies on Wilco's earlier clean-ups.
>
> The patch makes config.gcc define WITH_FOO_STRING macros for each
> supported --with-foo option.  This could be done only in aarch64-
> specific code, but I thought it could be useful on other targets
> too (and can be safely ignored otherwise).  There didn't seem to
> be any existing and potentially clashing uses of macros with this
> style of name.
>
> Tested on aarch64-linux-gnu & x86_64-linux-gnu.  OK for the configure
> bits?
>
> Richard
>
>
> gcc/
> 	* config.gcc: Define WITH_FOO_STRING macros for each supported
> 	--with-foo option.
> 	* config/aarch64/aarch64.cc (aarch64_override_options): Emulate
> 	OPTION_DEFAULT_SPECS.
> 	* config/aarch64/aarch64.h (OPTION_DEFAULT_SPECS): Reference the above.
> ---
>  gcc/config.gcc                | 14 ++++++++++++++
>  gcc/config/aarch64/aarch64.cc |  8 ++++++++
>  gcc/config/aarch64/aarch64.h  |  5 ++++-
>  3 files changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index cdbefb5b4f5..e039230431c 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -5865,6 +5865,20 @@ else
>  	configure_default_options="{ ${t} }"
>  fi
>  
> +for option in $supported_defaults
> +do
> +	lc_option=`echo $option | sed s/-/_/g`
> +	uc_option=`echo $lc_option | tr a-z A-Z`
> +	eval "val=\$with_$lc_option"
> +	if test -n "$val"
> +	then
> +		val="\\\"$val\\\""
> +	else
> +		val=nullptr
> +	fi
> +	tm_defines="$tm_defines WITH_${uc_option}_STRING=$val"
> +done
> +
>  if test "$target_cpu_default2" != ""
>  then
>  	if test "$target_cpu_default" != ""
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index d21e041eccb..0bc700b81ad 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -18109,6 +18109,14 @@ aarch64_override_options (void)
>    if (aarch64_branch_protection_string)
>      aarch64_validate_mbranch_protection (aarch64_branch_protection_string);
>  
> +  /* Emulate OPTION_DEFAULT_SPECS.  */
> +  if (!aarch64_arch_string && !aarch64_cpu_string)
> +    aarch64_arch_string = WITH_ARCH_STRING;
> +  if (!aarch64_arch_string && !aarch64_cpu_string)
> +    aarch64_cpu_string = WITH_CPU_STRING;
> +  if (!aarch64_cpu_string && !aarch64_tune_string)
> +    aarch64_tune_string = WITH_TUNE_STRING;
> +
>    /* -mcpu=CPU is shorthand for -march=ARCH_FOR_CPU, -mtune=CPU.
>       If either of -march or -mtune is given, they override their
>       respective component of -mcpu.  */
> diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
> index 80cfe4b7407..3122dbd7098 100644
> --- a/gcc/config/aarch64/aarch64.h
> +++ b/gcc/config/aarch64/aarch64.h
> @@ -1267,7 +1267,10 @@ extern enum aarch64_code_model aarch64_cmodel;
>  /* Support for configure-time --with-arch, --with-cpu and --with-tune.
>     --with-arch and --with-cpu are ignored if either -mcpu or -march is used.
>     --with-tune is ignored if either -mtune or -mcpu is used (but is not
> -   affected by -march).  */
> +   affected by -march).
> +
> +   There is corresponding code in aarch64_override_options that emulates
> +   this behavior when cc1 &co are invoked directly.  */
>  #define OPTION_DEFAULT_SPECS				\
>    {"arch", "%{!march=*:%{!mcpu=*:-march=%(VALUE)}}" },	\
>    {"cpu",  "%{!march=*:%{!mcpu=*:-mcpu=%(VALUE)}}" },   \