OpenMP/cmake: Use TARGET instead of looking for amdgpu-arch

[arsenm]

Summary

Not sure if the standalone build case is supposed to be a supported
path. Should probably rely on find_package and imported targets
anyway.

[tianshilei1992]

LG

[arsenm]

I do not understand the contexts where generator expressions work. Also make execution a fatal error. If it's found it should work

[tianshilei1992]

$<TARGET_FILE:amdgpu-arch> should work. We have similar code in openmp/libomptarget/DeviceRTL/CMakeLists.txt.

[arsenm]

In D153628#4445094, @tianshilei1992 wrote:

$<TARGET_FILE:amdgpu-arch> should work. We have similar code in openmp/libomptarget/DeviceRTL/CMakeLists.txt.

But those are to add_custom_command with an output that targets depend on, which is at build time. It seems to not work with execute_process which is configure time?

[tianshilei1992]

In D153628#4445131, @arsenm wrote:

In D153628#4445094, @tianshilei1992 wrote:

$<TARGET_FILE:amdgpu-arch> should work. We have similar code in openmp/libomptarget/DeviceRTL/CMakeLists.txt.

But those are to add_custom_command with an output that targets depend on, which is at build time. It seems to not work with execute_process which is configure time?

Hmm, that's odd as TARGET_FILE is supposed to give the full path of the target binary file (https://cmake.org/cmake/help/latest/manual/cmake-generator-expressions.7.html#genex:TARGET_FILE), and using that in execute_process should be fine. Not sure what error you encountered.

[arsenm]

In D153628#4445163, @tianshilei1992 wrote:

In D153628#4445131, @arsenm wrote:

In D153628#4445094, @tianshilei1992 wrote:

$<TARGET_FILE:amdgpu-arch> should work. We have similar code in openmp/libomptarget/DeviceRTL/CMakeLists.txt.

But those are to add_custom_command with an output that targets depend on, which is at build time. It seems to not work with execute_process which is configure time?

Hmm, that's odd as TARGET_FILE is supposed to give the full path of the target binary file (https://cmake.org/cmake/help/latest/manual/cmake-generator-expressions.7.html#genex:TARGET_FILE), and using that in execute_process should be fine. Not sure what error you encountered.

It tries to execute the literal string '$<TARGET_FILE:amdgpu-arch>' and produces no such file or directory error

[tianshilei1992]

In D153628#4445178, @arsenm wrote:

In D153628#4445163, @tianshilei1992 wrote:

In D153628#4445131, @arsenm wrote:

In D153628#4445094, @tianshilei1992 wrote:

$<TARGET_FILE:amdgpu-arch> should work. We have similar code in openmp/libomptarget/DeviceRTL/CMakeLists.txt.

But those are to add_custom_command with an output that targets depend on, which is at build time. It seems to not work with execute_process which is configure time?

Hmm, that's odd as TARGET_FILE is supposed to give the full path of the target binary file (https://cmake.org/cmake/help/latest/manual/cmake-generator-expressions.7.html#genex:TARGET_FILE), and using that in execute_process should be fine. Not sure what error you encountered.

It tries to execute the literal string '$<TARGET_FILE:amdgpu-arch>' and produces no such file or directory error

Oh you are right. The generator expression will not be evaluated at configure time.

[arsenm]

7c3fa755f1ee87d8984ec4bcf57ffdb136fea862

openmp/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake

if(LIBOMPTARGET_NVPTX_ARCH)
   endif()
 endif()
 
 
 ################################################################################
 # Looking for AMD GPUs...
 ################################################################################
 
+if(TARGET amdgpu-arch)
+  get_property(LIBOMPTARGET_AMDGPU_ARCH TARGET amdgpu-arch PROPERTY LOCATION)
+ else()
    find_program(LIBOMPTARGET_AMDGPU_ARCH NAMES amdgpu-arch PATHS ${LLVM_BINARY_DIR}/bin)
+endif()
+
 if(LIBOMPTARGET_AMDGPU_ARCH)
   execute_process(COMMAND ${LIBOMPTARGET_AMDGPU_ARCH}
                   OUTPUT_VARIABLE LIBOMPTARGET_AMDGPU_ARCH_OUTPUT
-                  OUTPUT_STRIP_TRAILING_WHITESPACE)
+                  OUTPUT_STRIP_TRAILING_WHITESPACE
+                  COMMAND_ERROR_IS_FATAL ANY)
   string(REPLACE "\n" ";" amdgpu_arch_list "${LIBOMPTARGET_AMDGPU_ARCH_OUTPUT}")
   if(amdgpu_arch_list)
     set(LIBOMPTARGET_FOUND_AMDGPU_GPU TRUE)
     set(LIBOMPTARGET_AMDGPU_DETECTED_ARCH_LIST "${amdgpu_arch_list}")
   endif()
 endif()