Rework cmakery: (#136)

* Rework cmakery:
  * detect rocm/hip/rocshmem better, make sure that ROCM_PATH and
    ROCM_ROOT don't conflict and are taken by default
  * add /opt/rocm as a fallback when nothing else found
  * obtain hipcc in a sanitized way (ensure we use the same logic we
    use to later find_package hip)
  * factorize redundancies
  * export GPU_TARGETS as part of the cmake target for librocshmem,
    this helps with a clean error when an application tries to link
    with the wrong offload-target flag (rather than a cryptic link error)
  * phased out ROCSHMEM_HOME, in favor of rocshmem_ROOT (the cmake
    blessed way)

* Remove references to ROCSHMEM_HOME, we prefer ROCSHMEM_ROOT

* Pick CMAKE_PREFIX_PATH method for consistent finding hip/rocm

* Undo this pr using LANGUAGE HIP, maybe later

* Use only rocmcmakebuildtools as recommended from 6.4 onward

examples/CMakeLists.txt

@@ -21,6 +21,13 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 # IN THE SOFTWARE.
 ###############################################################################
+cmake_minimum_required(VERSION 3.16.3 FATAL_ERROR)
+
+###############################################################################
+# PROJECT
+###############################################################################
+include(${CMAKE_SOURCE_DIR}/cmake/setup_project.cmake)
+project(rocshmem_examples VERSION 1.0.0 LANGUAGES CXX)
 
 ###############################################################################
 # SOURCES
@@ -34,56 +41,21 @@ set(EXAMPLE_SOURCES
   rocshmem_init_attr_test.cc
 )
 
+find_package(MPI REQUIRED)
+find_package(hip REQUIRED PATHS /opt/rocm)
+if(NOT TARGET roc::rocshmem)
+  find_package(rocshmem REQUIRED PATHS /opt/rocm)
+endif()
+
 foreach(SOURCE_FILE IN LISTS EXAMPLE_SOURCES)
   get_filename_component(EXECUTABLE_NAME ${SOURCE_FILE} NAME_WE)
 
   add_executable(${EXECUTABLE_NAME} ${SOURCE_FILE})
 
-  if (BUILD_TESTS_ONLY)
-    find_package(MPI REQUIRED)
-
-    target_include_directories(
-      ${EXECUTABLE_NAME}
-      PRIVATE
-        $<BUILD_INTERFACE:${ROCSHMEM_HOME}/include>
-        $<BUILD_INTERFACE:${MPI_CXX_HEADER_DIR}>
-    )
-
-    foreach (target ${DEFAULT_GPUS})
-      list(APPEND offload_flags --offload-arch=${target})
-    endforeach()
-
-    target_compile_options(
-      ${EXECUTABLE_NAME}
-      PRIVATE
-        ${offload_flags}
-        -fgpu-rdc
-    )
-
-    target_link_libraries(
-      ${EXECUTABLE_NAME}
-      PRIVATE
-        ${MPI_mpi_LIBRARY}
-        ${MPI_mpicxx_LIBRARY}
-        ${offload_flags}
-        -L${ROCSHMEM_HOME}/lib
-        -lamdhip64
-        -lhsa-runtime64
-        -lrocshmem
-        -fgpu-rdc
-    )
-  else()
-    target_include_directories(
-      ${EXECUTABLE_NAME}
-      PRIVATE
-        roc::rocshmem
-    )
-
-    target_link_libraries(
-      ${EXECUTABLE_NAME}
-      PRIVATE
-        roc::rocshmem
-        -fgpu-rdc
-    )
-  endif()
+  target_link_libraries(
+    ${EXECUTABLE_NAME}
+    PRIVATE
+      MPI::MPI_CXX
+      roc::rocshmem
+  )
 endforeach()