Build failed due to implicit declaration

[Vineyo]

/home/usrname/.cache/paru/clone/scalapack/src/scalapack-2.2.0/BLACS/SRC/igsum2d_.c: In function ‘igsum2d_’:
/home/usrname/.cache/paru/clone/scalapack/src/scalapack-2.2.0/BLACS/SRC/igsum2d_.c:154:7: error: implicit declaration of function ‘BI_imvcopy’; did you mean ‘BI_zmvcopy’? [-Wimplicit-function-declaration]
  154 |       BI_imvcopy(Mpval(m), Mpval(n), A, tlda, bp->Buff);
      |       ^~~~~~~~~~
      |       BI_zmvcopy
/home/usrname/.cache/paru/clone/scalapack/src/scalapack-2.2.0/BLACS/SRC/igsum2d_.c:169:13: error: implicit declaration of function ‘BI_ivmcopy’; did you mean ‘BI_cvmcopy’? [-Wimplicit-function-declaration]
  169 |             BI_ivmcopy(Mpval(m), Mpval(n), A, tlda, bp2->Buff);
      |             ^~~~~~~~~~
      |             BI_cvmcopy
make[2]: *** [CMakeFiles/scalapack.dir/build.make:636: CMakeFiles/scalapack.dir/BLACS/SRC/igsum2d_.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:1039: CMakeFiles/scalapack.dir/all] Error 2
make: *** [Makefile:166: all] Error 2

I've found similar issues, but I don't know what to do.

[carlosal1015]

Changes in compiler, use gcc 13 or older. https://gcc.gnu.org/gcc-14/changes.html

[eeickmeyer]

I'm having the same problem in Ubuntu, and Debian is having the same problem as well despite their package bug being closed (it looks like an erroneous merge/diagnostic). See https://launchpadlibrarian.net/741773910/buildlog_ubuntu-oracular-amd64.scalapack_2.2.1-3.1ubuntu2_BUILDING.txt.gz. We cannot use an older compiler, so the above option is not an option for us.

[robert-mijakovic]

Any plans or guidelines on how to solve this but still compile with GCC 14?

[davidedelvento]

This can be actually worked around by adding the -Wno-error=implicit-function-declaration flag to the compilers.

[fsidoli]

Hi @davidedelvento,

How did you implement this? I naively added -DCMAKE_C_FLAGS="-Wno-error=implicit-function-declaration" to the cmake command line but this hasn't worked.

Fab

[davidedelvento]

I don't recall the details, but I did get it to work. My shell history has invocation of make (not cmake) with that flag added to both CFLAGS and FFLAGS, with something like:

FC=mpif90 CFLAGS="...." FFLAGS="...." make -j 32

However these were only "throw away" experiments, which I do to explore what works and what doesn't, but I don't carefully document.

---

In fact I use SPACK for all my installs.

SPACK: https://github.com/spack/spack/

Once it did get it to work, I implemented it by patching spack's netlib-scalapack/package.py. Important: this is with spack v0.23.1 (at this time in history, before they sort several important things, I recommend against using any other version, besides possible v0.23.2 if they released that). I simply added

if self.spec.satisfies("%cce"):
  flags.append("-Wno-error=implicit-function-declaration")

under the if name == "cflags": section of the flag_handler method (sorry I'd give you a diff, but I'm on a different computer at the moment and I can't).

Note that if you didn't ever use spack before, it has a steep learning curve. It's very well worth, but only if you install lots of things from source with intention to keep several versions of the same software and/or same version compiled with different options and/or with different compilers. If you do that, spack makes your life much easier. If you don't (i.e. if you just casually install one piece of software occasionally because your distro does not provide what you need), then spack is overkill and adds lots of complexity which you would hate.

---

If you don't want to use spack, I recommend asking cmake to be verbose (by default it's not) and trying to track all compiler invocations. I suspect the relevant ones aren't getting that flag for whatever reason.

[fsidoli]

Thanks @davidedelvento. I'll have a dig around and will report back if I get it working.

[fsidoli]

Update: I found that using -DCMAKE_C_FLAGS="-Wno-error=implicit-function-declaration" with cmake resulted in some parts being ignored. Using -fpermissive (which downgrades the error to warnings) allows me to build ScaLAPACK.