configure.py should support "-DLLVM_USE_LINKER=gold"

[erichkeane]

On my RHEL7 machine the default LD linker is both super slow and crashes routinely. I also don't have access to LLD on the machine, so I'm stuck with having to either use cmake directly, or just doing my build calls multiple times until the link succeeds.

I would like to be able to use 'gold' via configure.py instead.

[bader]

This cmake option can be passed via --cmake-opt.
Do you mean we should add a dedicated option to configure the linker?

[erichkeane]

That --cmake-opt actually doesn't work it seems, since it either has an equal-sign in it, or it is a 2-part option.

[erichkeane]

Here is my attempts to use --cmake-opt

bash-4.2$ python ../buildbot/configure.py --cmake-gen "Ninja" --cmake-opt -DLLVM_USE_LINKER=gold
usage: configure.py [-h] [-n BUILD_NUM] [-b BRANCH] [-d BASE_BRANCH]
                    [-r PR_NUM] [-w BUILDER_DIR] [-s SRC_DIR] [-o OBJ_DIR]
                    [--l0-headers L0_HEADER_DIR] [--l0-loader L0_LOADER]
                    [-t BUILD_TYPE] [--cuda] [--arm] [--disable-esimd-cpu]
                    [--no-assertions] [--docs] [--no-werror] [--shared-libs]
                    [--cmake-opt CMAKE_OPT] [--cmake-gen CMAKE_GEN]
                    [--use-libcxx] [--libcxx-include LIBCXX_INCLUDE_PATH]
                    [--libcxx-library LIBCXX_LIBRARY_PATH] [--use-lld]
configure.py: error: argument --cmake-opt: expected one argument
bash-4.2$ python ../buildbot/configure.py --cmake-gen "Ninja" --cmake-opt "-DLLVM_USE_LINKER=gold"
usage: configure.py [-h] [-n BUILD_NUM] [-b BRANCH] [-d BASE_BRANCH]
                    [-r PR_NUM] [-w BUILDER_DIR] [-s SRC_DIR] [-o OBJ_DIR]
                    [--l0-headers L0_HEADER_DIR] [--l0-loader L0_LOADER]
                    [-t BUILD_TYPE] [--cuda] [--arm] [--disable-esimd-cpu]
                    [--no-assertions] [--docs] [--no-werror] [--shared-libs]
                    [--cmake-opt CMAKE_OPT] [--cmake-gen CMAKE_GEN]
                    [--use-libcxx] [--libcxx-include LIBCXX_INCLUDE_PATH]
                    [--libcxx-library LIBCXX_LIBRARY_PATH] [--use-lld]
configure.py: error: argument --cmake-opt: expected one argument

[bader]

It might be confusing, but this seems to work for me.

python ./buildbot/configure.py --cmake-opt=-DLLVM_USE_LINKER=gold
args:Namespace(arm=False, base_branch=None, branch=None, build_number=None, build_type='Release', builder_dir=None, cmake_gen='Ninja', cmake_opt=['-DLLVM_USE_LINKER=gold'], cuda=False, disable_esimd_cpu=False, docs=False, l0_headers=None, l0_loader=None, libcxx_include=None, libcxx_library=None, no_assertions=False, no_werror=False, obj_dir=None, pr_number=None, rocm=False, shared_libs=False, src_dir=None, use_libcxx=False, use_lld=False)
[Cmake Command]: cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_TARGETS_TO_BUILD=X86 ...skip... -DLLVM_USE_LINKER=gold /export/users/bader/intel/test-cmake-opt/llvm

[erichkeane]

Ah, that does it! It wasn't at all clear to me from the 'usage' output that it requires an 'equal' sign to do so, when none of the others do.