Added option to build only tests and link to an external rocshmem library (#43)

* Rearrange CMakefile

* Enable linking to external rocshmem library

* Minor fix for the functional test driver

* ROCSHMEM_HOME detection fixed

tests/unit_tests/CMakeLists.txt

@@ -102,19 +102,56 @@ target_sources(
 ###############################################################################
 find_package(hip REQUIRED)
 
-target_include_directories(
-  ${PROJECT_NAME}
-  PRIVATE
-    roc::rocshmem
-)
+if (BUILD_TESTS_ONLY)
+  find_package(MPI REQUIRED)
 
-target_link_libraries(
-  ${PROJECT_NAME}
-  PRIVATE
-    roc::rocshmem
-    hip::host
-    -fgpu-rdc
-)
+  target_include_directories(
+    ${PROJECT_NAME}
+    PRIVATE
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/..>
+      $<BUILD_INTERFACE:${CMAKE_BINARY_DIR}>
+      $<BUILD_INTERFACE:${ROCSHMEM_HOME}/include>
+      $<BUILD_INTERFACE:${MPI_CXX_HEADER_DIR}>
+  )
+
+  foreach (target ${DEFAULT_GPUS})
+    list(APPEND static_link_flags --offload-arch=${target})
+  endforeach()
+  list(JOIN static_link_flags " " flags_str)
+
+  target_compile_options(
+    ${PROJECT_NAME}
+    PRIVATE
+      ${flags_str}
+       -fgpu-rdc
+  )
+
+  target_link_libraries(
+    ${PROJECT_NAME}
+    PRIVATE
+      ${MPI_mpi_LIBRARY}
+      ${MPI_mpicxx_LIBRARY}
+      -L${ROCSHMEM_HOME}/lib
+      -lamdhip64
+      -lhsa-runtime64
+      -lrocshmem
+      -fgpu-rdc
+  )
+else()
+  target_include_directories(
+    ${PROJECT_NAME}
+    PRIVATE
+      roc::rocshmem
+  )
+
+  target_link_libraries(
+    ${PROJECT_NAME}
+    PRIVATE
+      roc::rocshmem
+      hip::host
+      -fgpu-rdc
+  )
+endif()
 
 ###############################################################################
 # GTEST DEPENDENCY