Revert "[cmake] Pass LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN to NATIVE configure"

[jfb]

Summary

We’re about to migrate to C++14, which means that we’ll bump the minimum
compiler version to the “soft” one. This option therefore won’t do anything
anymore.

This was originally committed in r353463.

[jfb]

Latest discussion: http://lists.llvm.org/pipermail/llvm-dev/2019-August/134360.html

[smeenai]

I take it LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN will be going away entirely? If so, LGTM.

[jfb]

In D65924#1620379, @smeenai wrote:

I take it LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN will be going away entirely? If so, LGTM.

I intend to leave it there so it's easy to do the same dance for the next compiler bump. It won't be active for a bit, but we also won't have to re-agree on how to bump the version next time around :)

[smeenai]

In D65924#1620382, @jfb wrote:

In D65924#1620379, @smeenai wrote:

I take it LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN will be going away entirely? If so, LGTM.

I intend to leave it there so it's easy to do the same dance for the next compiler bump. It won't be active for a bit, but we also won't have to re-agree on how to bump the version next time around :)

In that case, is there any harm to leaving this one around? It'll be a no-op for now, but we'd need this next time around too.

[jfb]

In D65924#1620383, @smeenai wrote:

In D65924#1620382, @jfb wrote:

In D65924#1620379, @smeenai wrote:

I take it LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN will be going away entirely? If so, LGTM.

I intend to leave it there so it's easy to do the same dance for the next compiler bump. It won't be active for a bit, but we also won't have to re-agree on how to bump the version next time around :)

In that case, is there any harm to leaving this one around? It'll be a no-op for now, but we'd need this next time around too.

Hmm, I think you're right! Let's leave it as-is then!

llvm/cmake/modules/CrossCompile.cmake

COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
         ${CROSS_TOOLCHAIN_FLAGS_${project_name}_${target_name}}
         -DLLVM_TARGET_IS_CROSSCOMPILE_HOST=TRUE
         -DLLVM_TARGETS_TO_BUILD="${targets_to_build_arg}"
         -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="${experimental_targets_to_build_arg}"
         -DLLVM_DEFAULT_TARGET_TRIPLE="${TARGET_TRIPLE}"
         -DLLVM_TARGET_ARCH="${LLVM_TARGET_ARCH}"
         -DLLVM_ENABLE_PROJECTS="${llvm_enable_projects_arg}"
         -DLLVM_EXTERNAL_PROJECTS="${llvm_external_projects_arg}"
-        -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN="${LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN}"
         ${build_type_flags} ${linker_flag} ${external_clang_dir}
         ${ARGN}
     WORKING_DIRECTORY ${${project_name}_${target_name}_BUILD}
     DEPENDS CREATE_${project_name}_${target_name}
     COMMENT "Configuring ${target_name} ${project_name}...")
 
   add_custom_target(CONFIGURE_${project_name}_${target_name}
     DEPENDS ${${project_name}_${target_name}_BUILD}/CMakeCache.txt)