From: "Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com>
To: Fangrui Song <maskray@google.com>, GCC Patches <gcc-patches@gcc.gnu.org>
Cc: Christophe Lyon <christophe.lyon@linaro.org>,
Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
Fangrui Song <maskray@gcc.gnu.org>
Subject: Re: [PATCH] arm: Support -mfdpic for more targets
Date: Wed, 6 Mar 2024 09:54:45 +0000 [thread overview]
Message-ID: <30f1b722-7227-4bee-80e5-c8b790c3d1bd@arm.com> (raw)
In-Reply-To: <CAFP8O3J5F5w0t=R+RnDaZVz3nBQgyuQUAz6S3DVhhz=tgq1eyg@mail.gmail.com>
On 06/03/2024 05:07, Fangrui Song wrote:
> On Fri, Feb 23, 2024 at 7:33 PM Fangrui Song <maskray@google.com> wrote:
>>
>> From: Fangrui Song <maskray@gcc.gnu.org>
>>
>> Targets that are not arm*-*-uclinuxfdpiceabi can use -S -mfdpic, but -c
>> -mfdpic does not pass --fdpic to gas. This is an unnecessary
>> restriction. Just define the ASM_SPEC in bpabi.h.
>>
>> Additionally, use armelf[b]_linux_fdpiceabi emulations for -mfdpic in
>> linux-eabi.h. This will allow a future musl fdpic port to use the
>> desired BFD emulation.
>>
>> gcc/ChangeLog:
>>
>> * config/arm/bpabi.h (TARGET_FDPIC_ASM_SPEC): Transform -mfdpic.
>> * config/arm/linux-eabi.h (TARGET_FDPIC_LINKER_EMULATION): Define.
>> (SUBTARGET_EXTRA_LINK_SPEC): Use TARGET_FDPIC_LINKER_EMULATION
>> if -mfdpic.
>> ---
>> gcc/config/arm/bpabi.h | 2 +-
>> gcc/config/arm/linux-eabi.h | 5 ++++-
>> 2 files changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/gcc/config/arm/bpabi.h b/gcc/config/arm/bpabi.h
>> index 7a279f3ed3c..6778be1a8bf 100644
>> --- a/gcc/config/arm/bpabi.h
>> +++ b/gcc/config/arm/bpabi.h
>> @@ -55,7 +55,7 @@
>> #define TARGET_FIX_V4BX_SPEC " %{mcpu=arm8|mcpu=arm810|mcpu=strongarm*"\
>> "|march=armv4|mcpu=fa526|mcpu=fa626:--fix-v4bx}"
>>
>> -#define TARGET_FDPIC_ASM_SPEC ""
>> +#define TARGET_FDPIC_ASM_SPEC "%{mfdpic: --fdpic}"
>>
>> #define BE8_LINK_SPEC \
>> "%{!r:%{!mbe32:%:be8_linkopt(%{mlittle-endian:little}" \
>> diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h
>> index eef791f6a02..0c5c58e4928 100644
>> --- a/gcc/config/arm/linux-eabi.h
>> +++ b/gcc/config/arm/linux-eabi.h
>> @@ -46,12 +46,15 @@
>> #undef TARGET_LINKER_EMULATION
>> #if TARGET_BIG_ENDIAN_DEFAULT
>> #define TARGET_LINKER_EMULATION "armelfb_linux_eabi"
>> +#define TARGET_FDPIC_LINKER_EMULATION "armelfb_linux_fdpiceabi"
>> #else
>> #define TARGET_LINKER_EMULATION "armelf_linux_eabi"
>> +#define TARGET_FDPIC_LINKER_EMULATION "armelf_linux_fdpiceabi"
>> #endif
>>
>> #undef SUBTARGET_EXTRA_LINK_SPEC
>> -#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
>> +#define SUBTARGET_EXTRA_LINK_SPEC " -m %{mfdpic: " \
>> + TARGET_FDPIC_LINKER_EMULATION ";:" TARGET_LINKER_EMULATION "}"
>>
>> /* GNU/Linux on ARM currently supports three dynamic linkers:
>> - ld-linux.so.2 - for the legacy ABI
>> --
>> 2.44.0.rc1.240.g4c46232300-goog
>>
>
> Ping:)
>
We're in stage4 at present and this is new material. I'll look at it after the branch has been cut.
R.
>
> --
> 宋方睿
next prev parent reply other threads:[~2024-03-06 9:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-24 3:33 Fangrui Song
2024-03-06 5:07 ` Fangrui Song
2024-03-06 9:54 ` Richard Earnshaw (lists) [this message]
2024-05-06 23:09 ` Fangrui Song
2024-06-05 21:50 ` Fangrui Song
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