Chosing a specific CLANG version out of multiple installations

Software darktable
1

Hi, trying to build on a Gentoo based system, GCC fails due to missing the graphite flag.
I try to build it with LLVM/CLANG 15, still fails.
Now, I have two LLVM/CLANG versions, 14 & 15.
How would I make DT build with LLVM/CLANG 14 instead of the latest detected version (15)?

Thanks.

2

Hi @msdobrescu,

I am on a bit of thin ice here, but…

a) What “gentoo based” system are you using?
b) What version of gcc?
c) I presume you have tried to add USE flag “graphite”?

Have fun!
Claes in Lund, Sweden

3

MocaccinoOS (https://www.mocaccino.org/).
We avoided graphite, as this brings some complications and DT is the only one needing that flag.
Anyway, now we moved to LLVM/CLANG 15, but we try to use 14 along with it, as a test.
Under CLANG 15 DT build fails with clang-15: error: linker command failed with exit code 1.

I think the relevant part is:

       `fast_surface_blur.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.fast_surface_blur.resolver[fast_surface_blur.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `interpolate_bilinear.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.interpolate_bilinear.resolver[interpolate_bilinear.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `quantize.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.quantize.resolver[quantize.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `variance_analyse.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.variance_analyse.resolver[variance_analyse.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `apply_linear_blending.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.apply_linear_blending.resolver[apply_linear_blending.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `apply_linear_blending_w_geomean.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.apply_linear_blending_w_geomean.resolver[apply_linear_blending_w_geomean.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       `fast_clamp.ifunc' referenced in section `.text' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o: defined in discarded section `.text.fast_clamp.resolver[fast_clamp.resolver]' of bin/CMakeFiles/lib_darktable.dir/views/view.c.o
       clang-15: error: linker command failed with exit code 1 (use -v to see invocation)
       ninja: build stopped: subcommand failed.
4

@LebedevRI is probably the correct person to comment on this.

5

JFYI openSUSE Tumbleweed builds with clang 15.0.7. which is kinda in the same boat as the other rolling release distributions.

6

Thanks! it would be interesting to see the package source code that does the build.

7
1 Like
8

Never seen that kind of issue.
Which linker is being used, LLD?

9

In Portage a profile is created and assigned to the package.
The profile looks like this:

COMMON_FLAGS="-march=x86-64 -O2 -pipe"
CFLAGS="${COMMON_FLAGS}"
CXXFLAGS="${COMMON_FLAGS}"

CC="clang"
CXX="clang++"
AR="llvm-ar"
NM="llvm-nm"
RANLIB="llvm-ranlib"

LDFLAGS="${LDFLAGS} -Wl,-O2 -Wl,--as-needed"```
10

I see, LLD + -DBINARY_PACKAGE_BUILD=ON is all it takes.
Same with ld.gold, so it’s LLVM bug that someone should report.

At the same time, it might be good to have a cmake option
to better control Unset target_clones attribute for -march=native build · darktable-org/darktable@4ba6413 · GitHub

11

Any other packages that use this profile build successfully. What makes DT not to?

But, to go to the original question, if there are both installed at a time, 14 & 15, is there a way to select only one? I see DT detects the latest all the time, which is 15, while I’d like to try 14.

12

Do any of them use __attribute__((target_clones(...))) feature?

The same way you’d normally switch compilers, via CC/CXX.
But it doesn’t work with LLVM14 either.

13

Not sure about that macro, but why does it build for Suse above?

14

Because it doesn’t:
https://build.opensuse.org/public/build/graphics:darktable/openSUSE_Tumbleweed/x86_64/darktable/_log

[   49s] -- The CXX compiler identification is GNU 12.2.1
[   49s] -- The C compiler identification is GNU 12.2.1
15

OK, thanks for clarifying this!

16

I’ve filed CI coverage issues · Issue #13583 · darktable-org/darktable · GitHub
This really should be fixed on darktable’s side (point 2.).

17

On top of this, would be there a graphite flag equivalent for clang? If not, would be there a way to disable it for gcc too?

18

https://polly.llvm.org/docs/UsingPollyWithClang.html i guess,
though i have absolutely no idea about the either of the two.

19

openSUSE does not build with march=native.

20

That would be not so generic.

I’ve found this: ports - FreeBSD ports tree

It claims it’s possible to disable/remove the graphite optimizations. I could not build with that either or I missed something.

Would be truly nice to have the possibility to disable all these to be able to build it without graphite.