[Flang][LLVM] Remove leftover CMake for old flang handling

[jhuber6]

Summary:
I'm pretty sure this LLVM variable is unused and flang is now a
first-class target. This can likely be replaced with the other
support for the OpenMP module files that we have.

[Meinersbur]

Without trying out, I think it is still needed. LLVM_TOOL_<project>_BUILD is set whenever LLVM_ENABLE_PROJECTS=<project>. extra_deps ensures that flang and the Fortran built modules are built before OpenMP tries to build omp_lib.mod using flang and the builtin modules. I don't know what you mean by "old flang handling"

[jhuber6]

Without trying out, I think it is still needed. LLVM_TOOL_<project>_BUILD is set whenever LLVM_ENABLE_PROJECTS=<project>. extra_deps ensures that flang and the Fortran built modules are built before OpenMP tries to build omp_lib.mod using flang and the builtin modules. I don't know what you mean by "old flang handling"

I thought that handling was moved into the runtimes job itself as in #137035.

[Meinersbur]

Do you mean #130975?

LLVM_ENABLE_RUNTIMES=openmp and LLVM_ENABLE_PROJECTS=openmp are both still supposed to work. It just fixed a dependency problem with LLVM_ENABLE_RUNTIMES=openmp (and updates some CMake messages to clarify that there are two ways to build it.

[jhuber6]

Do you mean #130975?

LLVM_ENABLE_RUNTIMES=openmp and LLVM_ENABLE_PROJECTS=openmp are both still supposed to work. It just fixed a dependency problem with LLVM_ENABLE_RUNTIMES=openmp (and updates some CMake messages to clarify that there are two ways to build it.

Yeah, I figured that the only part we still needed was the dependency.

[Meinersbur]

• [Flang] Add omp_lib dependency to check-flang #130975 is for the dependencies for the LLVM_ENABLE_RUNTIMES=openmp build
• This code deleted in this PR is for ensuring dependencies in the LLVM_ENABLE_PROJECTS=openmp build

Unless you entirely remove support for LLVM_ENABLE_PROJECTS=openmp, this code in this PR is still needed.

[jhuber6]

• [Flang] Add omp_lib dependency to check-flang #130975 is for the dependencies for the LLVM_ENABLE_RUNTIMES=openmp build

  • This code deleted in this PR is for ensuring dependencies in the LLVM_ENABLE_PROJECTS=openmp build

Unless you entirely remove support for LLVM_ENABLE_PROJECTS=openmp, this code in this PR is still needeed.

Well, it's been made a warning and will probably be an error by the time the release rolls out. But I guess we can delay this if needed.

[Meinersbur]

When that happens, the entire code for omp_lib.mod generation in LLVM_ENABLE_PROJECTS=openmp builds should be removed.