From: Fangrui Song <maskray@google.com>
To: "Richard Earnshaw (lists)" <Richard.Earnshaw@arm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
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, 5 Jun 2024 14:50:04 -0700 [thread overview]
Message-ID: <CAFP8O3JirEoog8M9vYE_22=0SZsTaicKnxwnSqUvD4Ue17Hvsg@mail.gmail.com> (raw)
In-Reply-To: <CAFP8O3JkFift-qkVR-UKVgkFGpmWkJWqUMbmBtuZiZyhNDLKOQ@mail.gmail.com>
On Mon, May 6, 2024 at 4:09 PM Fangrui Song <maskray@google.com> wrote:
>
> On Wed, Mar 6, 2024 at 1:54 AM Richard Earnshaw (lists)
> <Richard.Earnshaw@arm.com> wrote:
> >
> > 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.
>
> refs/heads/releases/gcc-14 has been cut :)
>
>
>
> --
> 宋方睿
Ping this patch and
https://gcc.gnu.org/pipermail/gcc-patches/2024-March/647097.html
("arm: Force flag_pic for FDPIC") :)
prev parent reply other threads:[~2024-06-05 21:50 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)
2024-05-06 23:09 ` Fangrui Song
2024-06-05 21:50 ` Fangrui Song [this message]
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