CMake build system

cmake/utils/add_git_dependency.cmake

@@ -0,0 +1,27 @@
+include_guard(GLOBAL)
+
+function(add_git_dependency SOURCE_FILE)
+    set(GIT_DIR ${CMAKE_SOURCE_DIR}/.git)
+    if(NOT EXISTS ${GIT_DIR})
+        return()
+    endif()
+
+    set(GIT_FILES)
+    list(APPEND GIT_FILES ${GIT_DIR}/HEAD)
+    list(APPEND GIT_FILES ${GIT_DIR}/packed-refs)
+
+    file(READ ${GIT_DIR}/HEAD GIT_HEAD)
+    string(REGEX MATCH "^ref: (.+)$" HAVE_REF ${GIT_HEAD})
+    if(HAVE_REF)
+        set(GIT_REF_PATH ${CMAKE_MATCH_1})
+        string(STRIP ${GIT_REF_PATH} GIT_REF_PATH)
+        list(APPEND GIT_FILES ${GIT_DIR}/${GIT_REF_PATH})
+    endif()
+
+    foreach(GIT_FILE IN LISTS GIT_FILES)
+        if(EXISTS ${GIT_FILE})
+            set_source_files_properties(${SOURCE_FILE}
+                PROPERTIES OBJECT_DEPENDS ${GIT_FILE})
+        endif()
+    endforeach()
+endfunction()