[pushed][PATCH v2] LoongArch: Adjust C++ multilib header layout.

[chenglulu]

PUshed to r14-3803.

在 2023/9/7 下午2:50, Yang Yujie 写道:
> For LoongArch, the toplevel library build is always aliased to
> one of the multilib variants.  This patch installs it with the
> actual MULTISUBDIR (instead of ".") so that the headers can be
> reached by the compiler.
>
> This patch is an update of
> https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629435.html
>
> libstdc++-v3/ChangeLog:
>
> 	* configure.host: Register t-loongarch in tmake_file.
> 	* config/cpu/loongarch/t-loongarch: New file.  Manually refresh
> 	MULTISUBDIR with $(shell $(CXX) --print-multi-directory).
> ---
>   libstdc++-v3/config/cpu/loongarch/t-loongarch | 1 +
>   libstdc++-v3/configure.host                   | 5 ++++-
>   2 files changed, 5 insertions(+), 1 deletion(-)
>   create mode 100644 libstdc++-v3/config/cpu/loongarch/t-loongarch
>
> diff --git a/libstdc++-v3/config/cpu/loongarch/t-loongarch b/libstdc++-v3/config/cpu/loongarch/t-loongarch
> new file mode 100644
> index 00000000000..adfc8ebb93e
> --- /dev/null
> +++ b/libstdc++-v3/config/cpu/loongarch/t-loongarch
> @@ -0,0 +1 @@
> +AM_MAKEFLAGS += " MULTISUBDIR=/$(shell $(CXX) --print-multi-directory)"
> diff --git a/libstdc++-v3/configure.host b/libstdc++-v3/configure.host
> index 9e7c7f02dfd..9dc42ad3edb 100644
> --- a/libstdc++-v3/configure.host
> +++ b/libstdc++-v3/configure.host
> @@ -315,7 +315,10 @@ esac
>   # Set any OS-dependent and CPU-dependent bits.
>   # THIS TABLE IS SORTED.  KEEP IT THAT WAY.
>   case "${host}" in
> -  *-*-linux* | *-*-uclinux*)
> + loongarch*)
> +    tmake_file="cpu/loongarch/t-loongarch"
> +    ;;
> + *-*-linux* | *-*-uclinux*)
>       case "${host_cpu}" in
>         i[567]86)
>           abi_baseline_pair=i486-linux-gnu