[Buildroot] [PATCH] package/mesa3d: dri: link statically libmegadriver_stub after libdricommon

[Buildroot] [PATCH] package/mesa3d: dri: link statically libmegadriver_stub after libdricommon

[Romain Naour]

Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
due to this the megadriver_stub build can fail with some toolchain:

/home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
  -o src/mesa/drivers/dri/libmesa_dri_drivers.so
  -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
  -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
  src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
  -Wl,--no-whole-archive
  src/mesa/drivers/dri/common/libmegadriver_stub.a
  src/mesa/drivers/dri/common/libdricommon.a
  src/mapi/shared-glapi/libglapi.so.0.0.0
  src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
  src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
  src/util/libmesa_util.a src/util/format/libmesa_format.a
  src/compiler/nir/libnir.a src/compiler/libcompiler.a
  src/util/libxmlconfig.a
  [...]
src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
collect2: error: ld returned 1 exit status

This is because the static librairies needs to be correcly sorted by dependency.
libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
dlsym and dladdr definition.

[1] https://mesonbuild.com/Builtin-options.html

Fixes:
http://autobuild.buildroot.net/results/eec39a4fbfbfaa58980fab36f2fd902a16eecf0f/build-end.log

Signed-off-by: Romain Naour <romain.naour@gmail.com>
---
 ...lly-libmegadriver_stub-after-libdric.patch | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch

diff --git a/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
new file mode 100644
index 0000000000..47909ed5e5
--- /dev/null
+++ b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
@@ -0,0 +1,58 @@
+From b4f68629937eac22f122b9b069e4e5acbcc51a75 Mon Sep 17 00:00:00 2001
+From: Romain Naour <romain.naour@gmail.com>
+Date: Tue, 9 Jun 2020 16:49:32 +0200
+Subject: [PATCH] dri: link statically libmegadriver_stub after libdricommon
+
+Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
+due to this the megadriver_stub build can fail with some toolchain:
+
+/home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
+  -o src/mesa/drivers/dri/libmesa_dri_drivers.so
+  -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
+  -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
+  src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
+  -Wl,--no-whole-archive
+  src/mesa/drivers/dri/common/libmegadriver_stub.a
+  src/mesa/drivers/dri/common/libdricommon.a
+  src/mapi/shared-glapi/libglapi.so.0.0.0
+  src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
+  src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
+  src/util/libmesa_util.a src/util/format/libmesa_format.a
+  src/compiler/nir/libnir.a src/compiler/libcompiler.a
+  src/util/libxmlconfig.a
+  [...]
+src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
+megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
+megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
+collect2: error: ld returned 1 exit status
+
+This is because the static librairies needs to be correcly sorted by dependency.
+libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
+dlsym and dladdr definition.
+
+[1] https://mesonbuild.com/Builtin-options.html
+
+Fixes:
+http://autobuild.buildroot.net/results/eec39a4fbfbfaa58980fab36f2fd902a16eecf0f/build-end.log
+
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ src/mesa/drivers/dri/meson.build | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/mesa/drivers/dri/meson.build b/src/mesa/drivers/dri/meson.build
+index b09ca16e38a..9ac6731c522 100644
+--- a/src/mesa/drivers/dri/meson.build
++++ b/src/mesa/drivers/dri/meson.build
+@@ -59,7 +59,7 @@ if _dri_drivers != []
+     [],
+     link_whole : _dri_drivers,
+     link_with : [
+-      libmegadriver_stub, libdricommon, libglapi,
++      libdricommon, libmegadriver_stub, libglapi,
+       libmesa_classic,
+     ],
+     dependencies : [
+-- 
+2.25.4
+
-- 
2.25.4

[Buildroot] [PATCH] package/mesa3d: dri: link statically libmegadriver_stub after libdricommon

[Thomas Petazzoni]

On Tue,  9 Jun 2020 17:20:07 +0200
Romain Naour <romain.naour@gmail.com> wrote:

> Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
> due to this the megadriver_stub build can fail with some toolchain:
> 
> /home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
>   -o src/mesa/drivers/dri/libmesa_dri_drivers.so
>   -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
>   -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
>   src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
>   -Wl,--no-whole-archive
>   src/mesa/drivers/dri/common/libmegadriver_stub.a
>   src/mesa/drivers/dri/common/libdricommon.a
>   src/mapi/shared-glapi/libglapi.so.0.0.0
>   src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
>   src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
>   src/util/libmesa_util.a src/util/format/libmesa_format.a
>   src/compiler/nir/libnir.a src/compiler/libcompiler.a
>   src/util/libxmlconfig.a
>   [...]
> src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
> megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
> megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
> collect2: error: ld returned 1 exit status
> 
> This is because the static librairies needs to be correcly sorted by dependency.
> libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
> dlsym and dladdr definition.
> 
> [1] https://mesonbuild.com/Builtin-options.html
> 
> Fixes:
> http://autobuild.buildroot.net/results/eec39a4fbfbfaa58980fab36f2fd902a16eecf0f/build-end.log
> 
> Signed-off-by: Romain Naour <romain.naour@gmail.com>
> ---
>  ...lly-libmegadriver_stub-after-libdric.patch | 58 +++++++++++++++++++
>  1 file changed, 58 insertions(+)
>  create mode 100644 package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
> 
> diff --git a/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
> new file mode 100644
> index 0000000000..47909ed5e5
> --- /dev/null
> +++ b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
> @@ -0,0 +1,58 @@
> +From b4f68629937eac22f122b9b069e4e5acbcc51a75 Mon Sep 17 00:00:00 2001
> +From: Romain Naour <romain.naour@gmail.com>
> +Date: Tue, 9 Jun 2020 16:49:32 +0200
> +Subject: [PATCH] dri: link statically libmegadriver_stub after libdricommon
> +
> +Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
> +due to this the megadriver_stub build can fail with some toolchain:
> +
> +/home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
> +  -o src/mesa/drivers/dri/libmesa_dri_drivers.so
> +  -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
> +  -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
> +  src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
> +  -Wl,--no-whole-archive
> +  src/mesa/drivers/dri/common/libmegadriver_stub.a
> +  src/mesa/drivers/dri/common/libdricommon.a
> +  src/mapi/shared-glapi/libglapi.so.0.0.0
> +  src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
> +  src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
> +  src/util/libmesa_util.a src/util/format/libmesa_format.a
> +  src/compiler/nir/libnir.a src/compiler/libcompiler.a
> +  src/util/libxmlconfig.a
> +  [...]
> +src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
> +megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
> +megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
> +collect2: error: ld returned 1 exit status
> +
> +This is because the static librairies needs to be correcly sorted by dependency.
> +libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
> +dlsym and dladdr definition.

Why do .h files matter here? This sort of linking issue really should
have nothing to do with header files inclusion/ordering, but just about
object file/library ordering at link time.

Could you clarify what is happening here? dladdr and dlsym are provided
by the C library, so I'm not sure why the ordering between libdricommon
and libmegadriver_stub can matter here.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[Buildroot] [PATCH] package/mesa3d: dri: link statically libmegadriver_stub after libdricommon

[Romain Naour]

Hi Thomas,

Le 10/06/2020 ? 22:59, Thomas Petazzoni a ?crit?:
> On Tue,  9 Jun 2020 17:20:07 +0200
> Romain Naour <romain.naour@gmail.com> wrote:
> 
>> Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
>> due to this the megadriver_stub build can fail with some toolchain:
>>
>> /home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
>>   -o src/mesa/drivers/dri/libmesa_dri_drivers.so
>>   -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
>>   -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
>>   src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
>>   -Wl,--no-whole-archive
>>   src/mesa/drivers/dri/common/libmegadriver_stub.a
>>   src/mesa/drivers/dri/common/libdricommon.a
>>   src/mapi/shared-glapi/libglapi.so.0.0.0
>>   src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
>>   src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
>>   src/util/libmesa_util.a src/util/format/libmesa_format.a
>>   src/compiler/nir/libnir.a src/compiler/libcompiler.a
>>   src/util/libxmlconfig.a
>>   [...]
>> src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
>> megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
>> megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
>> collect2: error: ld returned 1 exit status
>>
>> This is because the static librairies needs to be correcly sorted by dependency.
>> libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
>> dlsym and dladdr definition.
>>
>> [1] https://mesonbuild.com/Builtin-options.html
>>
>> Fixes:
>> http://autobuild.buildroot.net/results/eec39a4fbfbfaa58980fab36f2fd902a16eecf0f/build-end.log
>>
>> Signed-off-by: Romain Naour <romain.naour@gmail.com>
>> ---
>>  ...lly-libmegadriver_stub-after-libdric.patch | 58 +++++++++++++++++++
>>  1 file changed, 58 insertions(+)
>>  create mode 100644 package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
>>
>> diff --git a/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
>> new file mode 100644
>> index 0000000000..47909ed5e5
>> --- /dev/null
>> +++ b/package/mesa3d/0009-dri-link-statically-libmegadriver_stub-after-libdric.patch
>> @@ -0,0 +1,58 @@
>> +From b4f68629937eac22f122b9b069e4e5acbcc51a75 Mon Sep 17 00:00:00 2001
>> +From: Romain Naour <romain.naour@gmail.com>
>> +Date: Tue, 9 Jun 2020 16:49:32 +0200
>> +Subject: [PATCH] dri: link statically libmegadriver_stub after libdricommon
>> +
>> +Meson build system enable by default -Wl,--as-needed in the linker command line [1] and
>> +due to this the megadriver_stub build can fail with some toolchain:
>> +
>> +/home/buildroot/autobuild/run/instance-1/output-1/host/bin/arm-none-linux-gnueabi-g++
>> +  -o src/mesa/drivers/dri/libmesa_dri_drivers.so
>> +  -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared -fPIC -Wl,--start-group
>> +  -Wl,-soname,libmesa_dri_drivers.so -Wl,--whole-archive
>> +  src/mesa/drivers/dri/radeon/libr100.a src/mesa/drivers/dri/nouveau/libnouveau_vieux.a
>> +  -Wl,--no-whole-archive
>> +  src/mesa/drivers/dri/common/libmegadriver_stub.a
>> +  src/mesa/drivers/dri/common/libdricommon.a
>> +  src/mapi/shared-glapi/libglapi.so.0.0.0
>> +  src/mesa/libmesa_classic.a src/mesa/libmesa_common.a
>> +  src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
>> +  src/util/libmesa_util.a src/util/format/libmesa_format.a
>> +  src/compiler/nir/libnir.a src/compiler/libcompiler.a
>> +  src/util/libxmlconfig.a
>> +  [...]
>> +src/mesa/drivers/dri/common/libmegadriver_stub.a(megadriver_stub.c.o): In function `megadriver_stub_init':
>> +megadriver_stub.c:(.text.startup+0x20): undefined reference to `dladdr'
>> +megadriver_stub.c:(.text.startup+0xbc): undefined reference to `dlsym'
>> +collect2: error: ld returned 1 exit status
>> +
>> +This is because the static librairies needs to be correcly sorted by dependency.
>> +libmegadriver_stub include dri_util.h that internally include dri_interface.h needed for
>> +dlsym and dladdr definition.
> 
> Why do .h files matter here? This sort of linking issue really should
> have nothing to do with header files inclusion/ordering, but just about
> object file/library ordering at link time.

I noticed that linker flag --as-needed is important to trigger the issue, I
disabled it by using -Db_asneeded=false in MESA3D_CONF_OPTS. The .h was here to
try to "explain" why we have a dependency between static libraries when
--as-needed is used.

> 
> Could you clarify what is happening here? dladdr and dlsym are provided
> by the C library, so I'm not sure why the ordering between libdricommon
> and libmegadriver_stub can matter here.

I tried with more recent toolchain and there is no issue.

The toolchain used to reproduce the issue is the old ARM codesourcery 2014.05.

I discover an interesting commit and bug report in binutils about --as-needed
option before version 2.25.

https://sourceware.org/bugzilla/show_bug.cgi?id=17287

I can reproduce the issue issue with the codesourcery toolchain and Linaro
4.9-4.9-2014.11 but not with 5.2-2015.11-2 toolchain:

Linaro 4.9-4.9-2014.11: OK (binutils linaro_binutils-2_24-branch)
Linaro 5.2-2015.11-2: OK (binutils 2.25)

But for both Linaro toolchain mesa3d build correctly, I gess it's because Linaro
binutils 2.24 is patched with another patch related to --as-needed:

http://git.linaro.org/toolchain/binutils-gdb.git/commit/?id=72f758d066732d56d50851a97dd67a31f331e2b3

So either we reorder the libraries in the meson build system (like the patch
does) or we can disable --as-needed for this toolchain by using -Db_asneeded=false.

Best regards,
Romain


> 
> Thomas
>