Re: [PATCH] LoongArch: Fix multiarch tuple canonization

[Lulu Cheng <chenglulu@loongson.cn>]

Hi,

在 2023/2/15 下午6:42, WANG Xuerui 写道:
> Hi,
>
> On 2023/2/13 18:38, Xi Ruoyao wrote:
>> Multiarch tuple will be coded in file or directory names in
>> multiarch-aware distros, so one ABI should have only one multiarch
>> tuple.  For example, "--target=loongarch64-linux-gnu --with-abi=lp64s"
>> and "--target=loongarch64-linux-gnusf" should both set multiarch tuple
>> to "loongarch64-linux-gnusf".  Before this commit,
>> "--target=loongarch64-linux-gnu --with-abi=lp64s --disable-multilib"
>> will produce wrong result (loongarch64-linux-gnu).
>>
>> A recent LoongArch psABI revision mandates "loongarch64-linux-gnu" to be
>> used for -mabi=lp64d (instead of "loongarch64-linux-gnuf64") for some
>> non-technical reason [1].  Note that we cannot make
>> "loongarch64-linux-gnuf64" an alias for "loongarch64-linux-gnu" because
>> to implement such an alias, we must create thousands of symlinks in the
>> distro and doing so would be completely unpractical.  This commit also
>> aligns GCC with the revision.
>>
>> Tested by building cross compilers with --enable-multiarch and multiple
>> combinations of --target=loongarch64-linux-gnu*, --with-abi=lp64{s,f,d},
>> and --{enable,disable}-multilib; and run "xgcc --print-multiarch" then
>> manually verify the result with eyesight.
>>
>> Ok for trunk and backport to releases/gcc-12?
>>
>> [1]: https://github.com/loongson/LoongArch-Documentation/pull/80
>>
>> gcc/ChangeLog:
>>
>>     * config.gcc (triplet_abi): Set its value based on $with_abi,
>>     instead of $target.
>>     (la_canonical_triplet): Set it after $triplet_abi is set
>>     correctly.
>>     * config/loongarch/t-linux (MULTILIB_OSDIRNAMES): Make the
>>     multiarch tuple for lp64d "loongarch64-linux-gnu" (without
>>     "f64" suffix).
>> ---
>>   gcc/config.gcc               | 14 +++++++-------
>>   gcc/config/loongarch/t-linux |  2 +-
>>   2 files changed, 8 insertions(+), 8 deletions(-)
>>
>> diff --git a/gcc/config.gcc b/gcc/config.gcc
>> index 067720ac795..c070e6ecd2e 100644
>> --- a/gcc/config.gcc
>> +++ b/gcc/config.gcc
>> @@ -4889,20 +4889,16 @@ case "${target}" in
>>           case ${target} in
>>           loongarch64-*-*-*f64)
>>               abi_pattern="lp64d"
>> -            triplet_abi="f64"
>>               ;;
>>           loongarch64-*-*-*f32)
>>               abi_pattern="lp64f"
>> -            triplet_abi="f32"
>>               ;;
>>           loongarch64-*-*-*sf)
>>               abi_pattern="lp64s"
>> -            triplet_abi="sf"
>>               ;;
>>           loongarch64-*-*-*)
>>               abi_pattern="lp64[dfs]"
>>               abi_default="lp64d"
>> -            triplet_abi=""
>>               ;;
>>           *)
>>               echo "Unsupported target ${target}." 1>&2
>> @@ -4923,9 +4919,6 @@ case "${target}" in
>>                 ;;
>>           esac
>>   - la_canonical_triplet="loongarch64-${triplet_os}${triplet_abi}"
>> -
>> -
>>           # Perform initial sanity checks on --with-* options.
>>           case ${with_arch} in
>>           "" | loongarch64 | la464) ;; # OK, append here.
>> @@ -4996,6 +4989,13 @@ case "${target}" in
>>               ;;
>>           esac
>>   +        case ${with_abi} in
>> +          "lp64d") triplet_abi="";;
>> +          "lp64f") triplet_abi="f32";;
>> +          "lp64s") triplet_abi="sf";;
>> +        esac
>> + la_canonical_triplet="loongarch64-${triplet_os}${triplet_abi}"
>> +
>>           # Set default value for with_abiext (internal)
>>           case ${with_abiext} in
>>           "")
>> diff --git a/gcc/config/loongarch/t-linux b/gcc/config/loongarch/t-linux
>> index 131c45fdced..e40da179203 100644
>> --- a/gcc/config/loongarch/t-linux
>> +++ b/gcc/config/loongarch/t-linux
>> @@ -40,7 +40,7 @@ ifeq ($(filter LA_DISABLE_MULTILIB,$(tm_defines)),)
>>         MULTILIB_OSDIRNAMES = \
>>         mabi.lp64d=../lib64$\
>> -      $(call if_multiarch,:loongarch64-linux-gnuf64)
>> +      $(call if_multiarch,:loongarch64-linux-gnu)
>>         MULTILIB_OSDIRNAMES += \
>>         mabi.lp64f=../lib64/f32$\
>
> Thanks for the quick patch; however Revy told me offline yesterday 
> that this might conflict with things Debian side once this gets 
> merged. He may have more details to share.
>
> Adding him to CC -- you could keep him CC-ed on future changes that 
> may impact distro packaging.

Thank you for your feedback.

This modification plan is determined by the operating system group. If 
there is any problem, you can describe it clearly.

If there is no problem, we will combine this patch.

Thanks!