[Openmp-commits] [PATCH] D89426: [libomptarget] Require LLVM source tree to build libomptarget

Fri Oct 16 07:30:20 PDT 2020

JonChesterfield added a comment.

I'm unclear on what that cmake is doing. Copied here:

  set(ENABLE_LIBOMPTARGET ON)
  # Currently libomptarget cannot be compiled on Windows or MacOS X.                                                                                                                                                 
  # Since the device plugins are only supported on Linux anyway,                                                                                                                                                     
  # there is no point in trying to compile libomptarget on other OSes.                                                                                                                                               
  if (APPLE OR WIN32 OR NOT OPENMP_HAVE_STD_CPP14_FLAG)
    set(ENABLE_LIBOMPTARGET OFF)
  endif()

  option(OPENMP_ENABLE_LIBOMPTARGET "Enable building libomptarget for offloading."
         ${ENABLE_LIBOMPTARGET})
  if (OPENMP_ENABLE_LIBOMPTARGET)
    # Check that the library can actually be built.                                                                                                                                                                  
    if (APPLE OR WIN32)
      message(FATAL_ERROR "libomptarget cannot be built on Windows and MacOS X!")
    elseif (NOT OPENMP_HAVE_STD_CPP14_FLAG)
      message(FATAL_ERROR "Host compiler must support C++14 to build libomptarget!")
    endif()

    add_subdirectory(libomptarget)
  endif()

Is this using ENABLE_LIBOMPTARGET as the default value for OPENMP_ENABLE_LIBOMPTARGET? If so, does setting OPENMP_ENABLE_LIBOMPTARGET win out?

A reasonable guess seems to be:

  if (NOT LLVM_MAIN_INCLUDE_DIR)
  message(...) #not fatal
  set(ENABLE_LIBOMPTARGET OFF)
  endif()

Probably combined with the above for anyone who builds libomptarget without the containing libomp.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89426/new/

https://reviews.llvm.org/D89426