Handle git program or .git folder absence (#5878)

Assume version is 0.0.0.0 in such cases.

Author: dvolosnykh

CMake/Version.cmake

@@ -1,11 +1,28 @@
+set(VERSION_MAJOR 1)
+set(VERSION_MINOR 12)
+set(VERSION_PATCH 0)
+set(VERSION_COMMIT 0)
+
 find_program(GIT git)
-execute_process(
-    COMMAND ${GIT} describe
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-    OUTPUT_VARIABLE GIT_DESCRIBE_DIRTY
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-)
-string(REGEX REPLACE "^v([0-9]+)\\..*" "\\1" VERSION_MAJOR "${GIT_DESCRIBE_DIRTY}")
-string(REGEX REPLACE "^v[0-9]+\\.([0-9]+).*" "\\1" VERSION_MINOR "${GIT_DESCRIBE_DIRTY}")
-string(REGEX REPLACE "^v[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" VERSION_PATCH "${GIT_DESCRIBE_DIRTY}")
-string(REGEX REPLACE "^v[0-9]+\\.[0-9]+\\.[0-9]+\\-([0-9]+).*" "\\1" VERSION_COMMIT "${GIT_DESCRIBE_DIRTY}")
+if(GIT)
+  execute_process(
+      COMMAND ${GIT} describe
+      WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+      OUTPUT_VARIABLE GIT_DESCRIBE_DIRTY
+      OUTPUT_STRIP_TRAILING_WHITESPACE
+      RESULT_VARIABLE GIT_DESCRIBE_RESULT
+  )
+
+  if(GIT_DESCRIBE_RESULT EQUAL 0)
+    string(REGEX REPLACE "^v([0-9]+)\\..*" "\\1" VERSION_MAJOR "${GIT_DESCRIBE_DIRTY}")
+    string(REGEX REPLACE "^v[0-9]+\\.([0-9]+).*" "\\1" VERSION_MINOR "${GIT_DESCRIBE_DIRTY}")
+    string(REGEX REPLACE "^v[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" VERSION_PATCH "${GIT_DESCRIBE_DIRTY}")
+    string(REGEX REPLACE "^v[0-9]+\\.[0-9]+\\.[0-9]+\\-([0-9]+).*" "\\1" VERSION_COMMIT "${GIT_DESCRIBE_DIRTY}")
+  else()
+    message(WARNING "git describe failed with exit code: ${GIT_DESCRIBE_RESULT}")
+  endif()
+else()
+  message(WARNING "git is not found")
+endif()
+
+message("Proceeding with version: ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}.${VERSION_COMMIT}")