[PATCH RFC] binutils: allow distro to select gold as default cross-linker

[PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

This is not particularly pretty but I couldn't think of any obviously
better way of doing it.  Any suggestions?

Signed-off-by: Phil Blundell <philb@gnu.org>
---
 meta/recipes-devtools/binutils/binutils-cross.inc |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/meta/recipes-devtools/binutils/binutils-cross.inc b/meta/recipes-devtools/binutils/binutils-cross.inc
index 4b90972..5a41970 100644
--- a/meta/recipes-devtools/binutils/binutils-cross.inc
+++ b/meta/recipes-devtools/binutils/binutils-cross.inc
@@ -5,7 +5,8 @@ EXTRA_OECONF = "--with-sysroot=${STAGING_DIR_TARGET} \
                 --program-prefix=${TARGET_PREFIX} \
                 --disable-install-libbfd \
                 --disable-werror \
-                --enable-poison-system-directories"
+                --enable-poison-system-directories \
+		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--enable-gold=default', '', d)}"
 
 do_install () {
 	oe_runmake 'DESTDIR=${D}' install
-- 
1.7.2.5

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Koen Kooi]

Op 14 jun 2011, om 17:30 heeft Phil Blundell het volgende geschreven:

> This is not particularly pretty but I couldn't think of any obviously
> better way of doing it.  Any suggestions?
> 
> Signed-off-by: Phil Blundell <philb@gnu.org>
> ---
> meta/recipes-devtools/binutils/binutils-cross.inc |    3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/meta/recipes-devtools/binutils/binutils-cross.inc b/meta/recipes-devtools/binutils/binutils-cross.inc
> index 4b90972..5a41970 100644
> --- a/meta/recipes-devtools/binutils/binutils-cross.inc
> +++ b/meta/recipes-devtools/binutils/binutils-cross.inc
> @@ -5,7 +5,8 @@ EXTRA_OECONF = "--with-sysroot=${STAGING_DIR_TARGET} \
>                 --program-prefix=${TARGET_PREFIX} \
>                 --disable-install-libbfd \
>                 --disable-werror \
> -                --enable-poison-system-directories"
> +                --enable-poison-system-directories \
> +		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--enable-gold=default', '', d)}"

Out of curiousity, how well does gold work nowadays? Last I remember hearing of it was in its x86-only days.

regards,

Koen

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Khem Raj]

On 06/14/2011 08:38 AM, Koen Kooi wrote:
>
> Op 14 jun 2011, om 17:30 heeft Phil Blundell het volgende geschreven:
>
>> This is not particularly pretty but I couldn't think of any obviously
>> better way of doing it.  Any suggestions?
>>
>> Signed-off-by: Phil Blundell<philb@gnu.org>
>> ---
>> meta/recipes-devtools/binutils/binutils-cross.inc |    3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/meta/recipes-devtools/binutils/binutils-cross.inc b/meta/recipes-devtools/binutils/binutils-cross.inc
>> index 4b90972..5a41970 100644
>> --- a/meta/recipes-devtools/binutils/binutils-cross.inc
>> +++ b/meta/recipes-devtools/binutils/binutils-cross.inc
>> @@ -5,7 +5,8 @@ EXTRA_OECONF = "--with-sysroot=${STAGING_DIR_TARGET} \
>>                  --program-prefix=${TARGET_PREFIX} \
>>                  --disable-install-libbfd \
>>                  --disable-werror \
>> -                --enable-poison-system-directories"
>> +                --enable-poison-system-directories \
>> +		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--enable-gold=default', '', d)}"
>
> Out of curiousity, how well does gold work nowadays? Last I remember hearing of it was in its x86-only days.
>

it works well on arm in fact link times are way better on some 
(especially C++) applications using gold. We can try to use gold for 
x86, x86_64 and arm to start with.

> regards,
>
> Koen
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Tue, 2011-06-14 at 17:38 +0200, Koen Kooi wrote:
> Out of curiousity, how well does gold work nowadays? Last I remember hearing of it was in its x86-only days.

It works for arm, x86 and amd64 which are the only targets that I've
tried for myself.  I suspect it doesn't support some of the more obscure
architectures.  Obviously it doesn't (and isn't intended to) support non
ELF targets, though I can't think of any such in OE.

One slightly annoying thing is that (e)glibc isn't buildable with gold
because the linker scripts don't work.  So a little bit of patching is
going to be needed to have it use ld.bfd there.  There might be some
other packages with similar issues but I haven't come across any yet.

p.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Wed, 2011-06-15 at 09:04 +0100, Phil Blundell wrote:
> One slightly annoying thing is that (e)glibc isn't buildable with gold
> because the linker scripts don't work.  So a little bit of patching is
> going to be needed to have it use ld.bfd there.  There might be some
> other packages with similar issues but I haven't come across any yet.

I think something like this is probably what's required for that.

From 48eaba1da89086b8edccaa03c27075d78635ab01 Mon Sep 17 00:00:00 2001
From: Phil Blundell <philb@gnu.org>
Date: Wed, 15 Jun 2011 15:22:47 +0100
Subject: [PATCH] gcc-cross-intermediate: use ld.bfd if distro prefers gold


Signed-off-by: Phil Blundell <philb@gnu.org>
---
 .../gcc/gcc-cross-intermediate.inc                 |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc b/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
index 92c3ce2..05b5dbc 100644
--- a/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
+++ b/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
@@ -7,6 +7,10 @@ CROSS_TARGET_SYS_DIR_append = ".${PN}"
 
 # This is intended to be a -very- basic config
 # sysroot is needed in case we use libc-initial
+#
+# Glibc won't compile with gold, and building glibc is the whole point of
+# this recipe.   So we select ld.bfd explicitly here if gold is the distro's 
+# preferred linker.
 EXTRA_OECONF = "--with-local-prefix=${STAGING_DIR_TARGET}${target_prefix} \
 		--enable-shared \
 		--disable-multilib \
@@ -17,7 +21,8 @@ EXTRA_OECONF = "--with-local-prefix=${STAGING_DIR_TARGET}${target_prefix} \
 		--with-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
 		--with-build-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
 		${EXTRA_OECONF_INTERMEDIATE} \
-		${@get_gcc_fpu_setting(bb, d)}"
+		${@get_gcc_fpu_setting(bb, d)} \
+		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--with-ld=${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.bfd', '', d)}"
 
 do_populate_sysroot[sstate-inputdirs] = "${SYSROOT_DESTDIR}/${STAGING_DIR_HOST} ${SYSROOT_DESTDIR}/${STAGING_DIR_TARGET}/${target_base_libdir}"
 do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_HOST} ${STAGING_DIR_TCBOOTSTRAP}/${target_base_libdir}"
-- 
1.7.2.5

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Khem Raj]

On 06/15/2011 07:32 AM, Phil Blundell wrote:
> On Wed, 2011-06-15 at 09:04 +0100, Phil Blundell wrote:
>> One slightly annoying thing is that (e)glibc isn't buildable with gold
>> because the linker scripts don't work.  So a little bit of patching is
>> going to be needed to have it use ld.bfd there.  There might be some
>> other packages with similar issues but I haven't come across any yet.
>
> I think something like this is probably what's required for that.
>
>  From 48eaba1da89086b8edccaa03c27075d78635ab01 Mon Sep 17 00:00:00 2001
> From: Phil Blundell<philb@gnu.org>
> Date: Wed, 15 Jun 2011 15:22:47 +0100
> Subject: [PATCH] gcc-cross-intermediate: use ld.bfd if distro prefers gold
>
>
> Signed-off-by: Phil Blundell<philb@gnu.org>
> ---
>   .../gcc/gcc-cross-intermediate.inc                 |    7 ++++++-
>   1 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc b/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
> index 92c3ce2..05b5dbc 100644
> --- a/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
> +++ b/meta/recipes-devtools/gcc/gcc-cross-intermediate.inc
> @@ -7,6 +7,10 @@ CROSS_TARGET_SYS_DIR_append = ".${PN}"
>
>   # This is intended to be a -very- basic config
>   # sysroot is needed in case we use libc-initial
> +#
> +# Glibc won't compile with gold, and building glibc is the whole point of
> +# this recipe.   So we select ld.bfd explicitly here if gold is the distro's
> +# preferred linker.
>   EXTRA_OECONF = "--with-local-prefix=${STAGING_DIR_TARGET}${target_prefix} \
>   		--enable-shared \
>   		--disable-multilib \
> @@ -17,7 +21,8 @@ EXTRA_OECONF = "--with-local-prefix=${STAGING_DIR_TARGET}${target_prefix} \
>   		--with-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
>   		--with-build-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
>   		${EXTRA_OECONF_INTERMEDIATE} \
> -		${@get_gcc_fpu_setting(bb, d)}"
> +		${@get_gcc_fpu_setting(bb, d)} \
> +		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--with-ld=${STAGING_BINDIR_TOOLCHAIN}/${TARGET_PREFIX}ld.bfd', '', d)}"
>
>   do_populate_sysroot[sstate-inputdirs] = "${SYSROOT_DESTDIR}/${STAGING_DIR_HOST} ${SYSROOT_DESTDIR}/${STAGING_DIR_TARGET}/${target_base_libdir}"
>   do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_HOST} ${STAGING_DIR_TCBOOTSTRAP}/${target_base_libdir}"

this might not work second time around when gcc-cross has been staged.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Wed, 2011-06-15 at 09:26 -0700, Khem Raj wrote:
> this might not work second time around when gcc-cross has been staged.

Oh, I thought that mess was fixed nowadays.  Doesn't eglibc always use
the -intermediate compiler from the special tcbootstrap place?  

If it's just picking whatever was staged most recently then yeah, this
will lose. 

p.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Khem Raj]

On 06/15/2011 09:31 AM, Phil Blundell wrote:
> On Wed, 2011-06-15 at 09:26 -0700, Khem Raj wrote:
>> this might not work second time around when gcc-cross has been staged.
>
> Oh, I thought that mess was fixed nowadays.  Doesn't eglibc always use
> the -intermediate compiler from the special tcbootstrap place?
>
> If it's just picking whatever was staged most recently then yeah, this
> will lose.
>

ah I stand corrected.

STAGINGCC = "gcc-cross-intermediate"
PATH_prepend = "${STAGING_BINDIR_TOOLCHAIN}.${STAGINGCC}:"

so yes it uses gcc-cross-intermediate all the time.

This will work. Do you know what problems eglibc has linking with gold ?
may be we can fix it

> p.
>
>
>
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Wed, 2011-06-15 at 09:35 -0700, Khem Raj wrote:
> This will work. Do you know what problems eglibc has linking with gold ?
> may be we can fix it

If I remember right, it relies on linker script functionality which gold
just doesn't have.  I suspect this would be hard to fix and, unless
there is a pressing need to fight that particular battle, I would be
inclined not to bother.

That said, though, I haven't checked recently and it's possible that
recent versions of gold will "just work".  If you wanted to give it a
try then I think it'd just be a question of h4x0ring eglibc's configure
script slightly to get it to accept gold as a valid linker version.

p.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Khem Raj]

On 06/15/2011 09:42 AM, Phil Blundell wrote:
> On Wed, 2011-06-15 at 09:35 -0700, Khem Raj wrote:
>> This will work. Do you know what problems eglibc has linking with gold ?
>> may be we can fix it
>
> If I remember right, it relies on linker script functionality which gold
> just doesn't have.  I suspect this would be hard to fix and, unless
> there is a pressing need to fight that particular battle, I would be
> inclined not to bother.
>
> That said, though, I haven't checked recently and it's possible that
> recent versions of gold will "just work".  If you wanted to give it a
> try then I think it'd just be a question of h4x0ring eglibc's configure
> script slightly to get it to accept gold as a valid linker version.
>

I remember now. Accepting gold would be easier but changing how ld.so is 
built where it asks ld to spit out default linker script and then munge 
it before reusing it is harder part. I think status is still same. It 
reminds me that we probably need ld.bfd for kernel too.


> p.
>
>
>
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Wed, 2011-06-15 at 09:47 -0700, Khem Raj wrote:
> we probably need ld.bfd for kernel too.

Yeah.  That's easy though, because the kernel invokes ld directly rather
than going through the compiler driver.  Just need to set ${KERNEL_LD}
appropriately and it should all be fine.

p.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Khem Raj]

On 06/14/2011 08:30 AM, Phil Blundell wrote:
> This is not particularly pretty but I couldn't think of any obviously
> better way of doing it.  Any suggestions?
>
> Signed-off-by: Phil Blundell<philb@gnu.org>
> ---
>   meta/recipes-devtools/binutils/binutils-cross.inc |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/meta/recipes-devtools/binutils/binutils-cross.inc b/meta/recipes-devtools/binutils/binutils-cross.inc
> index 4b90972..5a41970 100644
> --- a/meta/recipes-devtools/binutils/binutils-cross.inc
> +++ b/meta/recipes-devtools/binutils/binutils-cross.inc
> @@ -5,7 +5,8 @@ EXTRA_OECONF = "--with-sysroot=${STAGING_DIR_TARGET} \
>                   --program-prefix=${TARGET_PREFIX} \
>                   --disable-install-libbfd \
>                   --disable-werror \
> -                --enable-poison-system-directories"
> +                --enable-poison-system-directories \
> +		${@base_contains('DISTRO_FEATURES', 'ld-is-gold', '--enable-gold=default', '', d)}"
>
>   do_install () {
>   	oe_runmake 'DESTDIR=${D}' install

I think we need to document this distro feature somewhere as well. We 
need the same for target binutils too.

Re: [PATCH RFC] binutils: allow distro to select gold as default cross-linker

[Phil Blundell]

On Tue, 2011-06-14 at 19:42 -0700, Khem Raj wrote:
> I think we need to document this distro feature somewhere as well.

Yeah, agreed.  Any suggestions for "somewhere"?  Traditionally this kind
of thing has been sort-of-documented in local.conf.sample{.extended} but
that doesn't seem like a terribly good model for the future.  

If the wiki were ever to become editable then I guess a page there might
be a good place, perhaps.

>We need the same for target binutils too.

Yeah, though it wants slightly different handling in the target case.  I
was planning to leave that for someone who actually uses on-target
binutils to sort out :-)

There's also the sdk case which I haven't looked at either.  I'm not
sure to what extent that needs special handling.

p.