[Buildroot] [PATCH] Sets LD_LIBRARY_PATH inside toolchain-wrapper.

[Buildroot] [PATCH] Sets LD_LIBRARY_PATH inside toolchain-wrapper.

[Daniel Serpell]

Setting the host library path in the toolchain wrapper allows moving the
host toolchain folder to a new path, as some of the tools depends on
buildroot provided libraries.

Signed-off-by: Daniel Serpell <daniel.serpell@gmail.com>
---
 toolchain/toolchain-wrapper.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c
index 2928ea42d0..53ea73fdf1 100644
--- a/toolchain/toolchain-wrapper.c
+++ b/toolchain/toolchain-wrapper.c
@@ -231,6 +231,7 @@ int main(int argc, char **argv)
 	char *progpath = argv[0];
 	char *basename;
 	char *env_debug;
+        char *ld_path, *new_ld_path;
 	char *paranoid_wrapper;
 	int paranoid;
 	int ret, i, count = 0, debug;
@@ -442,6 +443,19 @@ int main(int argc, char **argv)
 	}
 #endif
 
+        /* Adds library path to our host libraries */
+	if ((ld_path = getenv("LD_LIBRARY_PATH")) && ld_path[0]) {
+		new_ld_path = malloc(strlen(ld_path) + strlen(absbasedir) + 6);
+		sprintf(new_ld_path, "%s:%s/lib", ld_path, absbasedir);
+	} else {
+		new_ld_path = malloc(strlen(absbasedir) + 5);
+		sprintf(new_ld_path, "%s/lib", absbasedir);
+	}
+	if (setenv("LD_LIBRARY_PATH", new_ld_path, 1)) {
+		perror(__FILE__ ": Failed to set LD_LIBRARY_PATH");
+		return 3;
+	}
+
 	if (execv(exec_args[0], exec_args))
 		perror(path);
 
-- 
2.16.1

[Buildroot] [PATCH] Sets LD_LIBRARY_PATH inside toolchain-wrapper.

[Thomas Petazzoni]

Hello,

On Fri, 16 Feb 2018 19:18:45 -0300, Daniel Serpell wrote:
> Setting the host library path in the toolchain wrapper allows moving the
> host toolchain folder to a new path, as some of the tools depends on
> buildroot provided libraries.
> 
> Signed-off-by: Daniel Serpell <daniel.serpell@gmail.com>

This is not needed. If you want to move around the host toolchain
folder, run "make sdk", which prepares the host toolchain to be a
relocatable SDK.

See slide 280 of
https://bootlin.com/doc/training/buildroot/buildroot-slides.pdf for
more details.

And yes, we should mention this in the Buildroot manual. Patches
welcome :-)

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com

[Buildroot] [PATCH] Sets LD_LIBRARY_PATH inside toolchain-wrapper.

[Daniel Serpell]

Hi Thomas,

On Fri, Feb 16, 2018 at 7:46 PM, Thomas Petazzoni
<thomas.petazzoni@bootlin.com> wrote:
> Hello,
>
> On Fri, 16 Feb 2018 19:18:45 -0300, Daniel Serpell wrote:
>> Setting the host library path in the toolchain wrapper allows moving the
>> host toolchain folder to a new path, as some of the tools depends on
>> buildroot provided libraries.
>>
>> Signed-off-by: Daniel Serpell <daniel.serpell@gmail.com>
>
> This is not needed. If you want to move around the host toolchain
> folder, run "make sdk", which prepares the host toolchain to be a
> relocatable SDK.
>
> See slide 280 of
> https://bootlin.com/doc/training/buildroot/buildroot-slides.pdf for
> more details.

Yes, I missed that.

I see that you are using patchelf to make RPATH relative inside host binaries,
is there any reason to not run that always, or at least in the "make toolchain"
target?

>
> And yes, we should mention this in the Buildroot manual. Patches
> welcome :-)
>

I'm not very good at writing documentation, perhaps the attached patch
is enough.

Regards,

    Daniel.

PD: Sorry, I first emailed this off-list on error.
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[Buildroot] [PATCH] Sets LD_LIBRARY_PATH inside toolchain-wrapper.

[Thomas Petazzoni]

Hello,

On Fri, 16 Feb 2018 21:43:36 -0300, Daniel Serpell wrote:

> I see that you are using patchelf to make RPATH relative inside host binaries,
> is there any reason to not run that always, or at least in the "make toolchain"
> target?

Because there's no real reason to do that. During the build, the
toolchain and other host tools are not moving, so keeping the absolute
RPATH is fine. It's only when you want to move the toolchain/SDK around
that the rpath needs to be adjusted to be relative RPATH.

> I'm not very good at writing documentation, perhaps the attached patch
> is enough.

Patch looks good. Could you send it with "git send-email", and change
the commit title to something like:

 docs/manual: add documentation for the "make sdk" target

Thanks!

Thoas
-- 
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com