arm: Support -mfdpic for more targets

Message ID 20240224033354.3767291-1-maskray@google.com
State New
Headers
Series arm: Support -mfdpic for more targets |

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Commit Message

Fangrui Song Feb. 24, 2024, 3:33 a.m. UTC
  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(-)
  

Comments

Fangrui Song March 6, 2024, 5:07 a.m. UTC | #1
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:)
  
Richard Earnshaw (lists) March 6, 2024, 9:54 a.m. UTC | #2
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
  
Fangrui Song May 6, 2024, 11:09 p.m. UTC | #3
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 :)
  

Patch

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