Improving lit test targets

1) Adding tests to projects as source files to simplify the access to them
2) Dividing custom_target into custom_command and custom_target for lit test targets

Author: krystian-andrzejewski

IGC/Compiler/tests/CMakeLists.txt

@@ -38,20 +38,39 @@ set(IGC_LIT_TEST_DEPENDS
   "${IGC_BUILD__PROJ__igc_opt}"
   )
 
+
+# Note:
+# This command must be consistent with lit.cfg.py in the following points:
+# 1) the path to tests must be consistent with config.test_source_root
+# 2) the suffix must be consistent with config.suffixes
+# The consistency can be achived by calling a process which returns the list of tests.
+file(GLOB_RECURSE _tests "${IGC_TEST_SOURCE_DIR}/*.ll")
+if(MSVC)
+  source_group(TREE "${IGC_TEST_SOURCE_DIR}" PREFIX "tests" FILES ${_tests})
+endif()
+
 # This will create a target called `check-igc`, which will run all tests from
 # IGC/Compiler/tests directory. The tests will be run on files in the source
 # directory, since they are not modified, there doesn't seem to be any reason
 # for copying them.
-add_lit_testsuite(check-igc "Running the IGC LIT tests"
-  ${IGC_TEST_BINARY_DIR}
-  DEPENDS ${IGC_LIT_TEST_DEPENDS}
-  )
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17")
+  igc_add_lit_target(check-igc "${IGC_TEST_BINARY_DIR}" "Running the IGC LIT tests"
+    DEPENDS ${IGC_LIT_TEST_DEPENDS} ${_tests}
+    SOURCES ${_tests} ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
+    )
+else()
+  add_lit_testsuite(check-igc "Running the IGC LIT tests"
+    ${IGC_TEST_BINARY_DIR}
+    DEPENDS ${IGC_LIT_TEST_DEPENDS}
+    )
+endif()
 
 # Tests should not be excluded from "Build Solution" in VS.
 set_target_properties(check-igc
-    PROPERTIES
-        EXCLUDE_FROM_DEFAULT_BUILD OFF
-        EXCLUDE_FROM_ALL OFF)
+  PROPERTIES
+    EXCLUDE_FROM_DEFAULT_BUILD OFF
+    EXCLUDE_FROM_ALL OFF
+  )
 
 # Line below is just used to group LIT reated targets in single directory
 # in IDE. This is completely optional.

IGC/cmake/igc_llvm_utils.cmake

@@ -93,6 +93,41 @@ function(igc_configure_lit_site_cfg in out)
     )
 endfunction()
 
+function(igc_add_lit_target target binary_dir comment)
+  cmake_parse_arguments(ARG "" "" "DEPENDS;SOURCES" ${ARGN})
+  set(LIT_ARGS "${LLVM_LIT_ARGS}")
+  separate_arguments(LIT_ARGS)
+  if (NOT CMAKE_CFG_INTDIR STREQUAL ".")
+    list(APPEND LIT_ARGS --param build_mode=${CMAKE_CFG_INTDIR})
+  endif ()
+
+  # Get the path to the lit to *run* tests with.  This can be overriden by
+  # the user by specifying -DLLVM_EXTERNAL_LIT=<path-to-lit.py>
+  get_llvm_lit_path(
+    lit_base_dir
+    lit_file_name
+    ALLOW_EXTERNAL
+    )
+
+  set(LIT_COMMAND "${PYTHON_EXECUTABLE};${lit_base_dir}/${lit_file_name}")
+  list(APPEND LIT_COMMAND ${LIT_ARGS})
+  set(run_tests_stamp_file "${binary_dir}/run_${target}.stamp")
+  add_custom_command(
+    OUTPUT "${run_tests_stamp_file}"
+    COMMAND ${LIT_COMMAND} "${binary_dir}"
+    COMMAND ${CMAKE_COMMAND} -E touch "${run_tests_stamp_file}"
+    DEPENDS ${ARG_DEPENDS}
+    COMMENT "${comment}"
+    USES_TERMINAL
+    )
+  add_custom_target(${target}
+    DEPENDS "${run_tests_stamp_file}"
+    SOURCES ${ARG_SOURCES}
+    )
+  # Tests should be excluded from "Build Solution".
+  set_target_properties(${target} PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD ON)
+endfunction()
+
 # Helper macro to set LLVM_EXTERNAL_LIT variable for LLVM lit tests.
 # Variable can be overridden from command line to set custom lit tool.
 macro(igc_find_external_lit)