[PATCH] D143768: [Clang] Add options to disable direct linking of arch tools

[Aaron Siddhartha Mondal via Phabricator via cfe-commits]

aaronmondal added a comment.

Fun fact I now know that libxml2 also struggles with this 😆

The following would roughly be how zlib and others handle it:

  if (CLANG_ENABLE_HSA)
  
    if (CLANG_ENABLE_HSA STREQUAL FORCE_ON)
      find_package(hsa-runtime... REQUIRED)
    else()
      find_package (hsa-runtime...)
    endif()
  
    if (hsa-runtime_FOUND)
      # TODO: Some hsa sanity check, executed during configuration.
      # If check passes, `HAVE_HSA` is set.
      if (CLANG_ENABLE_HSA STREQUAL FORCE_ON AND NOT HAVE_HSA)
        message(FATAL_ERROR "Failed to configure HSA.")
      endif()
    endif()
  
    set(CLANG_ENABLE_HSA "${HAVE_HSA}")
  
  else()
    set(CLANG_ENABLE_HSA 0)
  endif()

Then we could remove `__have_include` and could directly check for `CLANG_ENABLE_HSA` during compile time.

  #ifdef CLANG_HAVE_HSA
  #include "hsa/hsa.h"
  #endif

Since HSA is used by both OpenMP and the amdgpu-arch plugin, I think it would make sense to not call it `CLANG_ENABLE_HSA` but instead use `LLVM_ENABLE_HSA` and just put it `llvm/cmake/config-ix.cmake` (where I took the above code from).

@jhuber6 This doesn't consider the "DYNAMIC_..." macros. Do you think an approach like this, if worked out a bit more, could work?


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D143768