[PATCH] bitbake.conf: add --enable-new-dtags to linker

[PATCH] bitbake.conf: add --enable-new-dtags to linker

[Alexander Kanavin]

Various versions of ld have different defaults for this
(even between e.g. Ubuntu 16.04 and 18.04). This has the
consequence of putting either RPATH or RUNPATH into the binary,
depending on the linker, which have different priorities
vs LD_LIBRARY_PATH env var. Also, I think, the original
executable binary is looked up for the tags when resolving
a dependency of a shared library when using RPATH, but not
RUNPATH.

Let's make this deterministic.

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
---
 meta/conf/bitbake.conf | 1 +
 1 file changed, 1 insertion(+)

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 64800623545..732e4f93328 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -573,6 +573,7 @@ export TARGET_CXXFLAGS = "${TARGET_CFLAGS}"
 
 export BUILD_LDFLAGS = "-L${STAGING_LIBDIR_NATIVE} \
                         -L${STAGING_BASE_LIBDIR_NATIVE} \
+                        -Wl,--enable-new-dtags \
                         -Wl,-rpath-link,${STAGING_LIBDIR_NATIVE} \
                         -Wl,-rpath-link,${STAGING_BASE_LIBDIR_NATIVE} \
                         -Wl,-rpath,${STAGING_LIBDIR_NATIVE} \
-- 
2.17.1

Re: [PATCH] bitbake.conf: add --enable-new-dtags to linker

[Khem Raj]

On Fri, Dec 21, 2018 at 6:24 AM Alexander Kanavin
<alex.kanavin@gmail.com> wrote:
>
> Various versions of ld have different defaults for this
> (even between e.g. Ubuntu 16.04 and 18.04). This has the
> consequence of putting either RPATH or RUNPATH into the binary,
> depending on the linker, which have different priorities
> vs LD_LIBRARY_PATH env var. Also, I think, the original
> executable binary is looked up for the tags when resolving
> a dependency of a shared library when using RPATH, but not
> RUNPATH.
>
> Let's make this deterministic.
>

this change is fine in general. What we have to understand is that
--enable-new-dtags actually sets DT_RUNPATH instead of DT_RPATH.
DT_RPATH has higher precedence than LD_LIBRARY_PATH; DT_RUNPATH has
lower precedence.

with this change we will let LD_LIBRARY_PATH override our
settings. So look for case where we might have assumed that
we are setting DT_RPATH so no environment can affect us

> Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
> ---
>  meta/conf/bitbake.conf | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
> index 64800623545..732e4f93328 100644
> --- a/meta/conf/bitbake.conf
> +++ b/meta/conf/bitbake.conf
> @@ -573,6 +573,7 @@ export TARGET_CXXFLAGS = "${TARGET_CFLAGS}"
>
>  export BUILD_LDFLAGS = "-L${STAGING_LIBDIR_NATIVE} \
>                          -L${STAGING_BASE_LIBDIR_NATIVE} \
> +                        -Wl,--enable-new-dtags \
>                          -Wl,-rpath-link,${STAGING_LIBDIR_NATIVE} \
>                          -Wl,-rpath-link,${STAGING_BASE_LIBDIR_NATIVE} \
>                          -Wl,-rpath,${STAGING_LIBDIR_NATIVE} \
> --
> 2.17.1
>
> --
> _______________________________________________
> Openembedded-core mailing list
> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core