Read git sha1 when building Paddle, and add it to PADDLE_VERSION macro

* save the model file including git sha1

CMakeLists.txt

@@ -65,6 +65,19 @@ else()
             Subversion_WC_INFO(${PROJ_ROOT} Project)
             add_definitions(-DPADDLE_VERSION=${Project_WC_REVISION})
         endif()
+    elseif(EXISTS ${PROJ_ROOT}/.git/)
+        find_package(Git REQUIRED)
+        execute_process(
+            COMMAND ${GIT_EXECUTABLE} log -1 --format=%H
+            WORKING_DIRECTORY ${PROJ_ROOT}
+            OUTPUT_VARIABLE GIT_SHA1
+            RESULT_VARIABLE GIT_RESULT
+            ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+        if(NOT ${GIT_RESULT})
+            add_definitions(-DPADDLE_VERSION=\"${GIT_SHA1}\")
+        else()
+            message(WARNING "Cannot add paddle version from git tag")
+        endif()
     endif()
 endif()