Skip writing reflection_generated.h if not changed (#5776)

diff --git a/reflection/generate_code.sh b/reflection/generate_code.sh
index 0c1157d..f0405d5 100755 (executable)
--- a/reflection/generate_code.sh
+++ b/reflection/generate_code.sh
@@ -15,4 +15,16 @@
 # limitations under the License.
 set -e
 
-../flatc -c --cpp-std c++0x --no-prefix -o ../include/flatbuffers reflection.fbs
+tempDir="../include/flatbuffers/.tmp"
+originalFile="../include/flatbuffers/reflection_generated.h"
+newFile="$tempDir/reflection_generated.h"
+
+../flatc -c --cpp-std c++0x --no-prefix -o $tempDir reflection.fbs
+
+if [ -f "$newFile" ]; then
+  if ! cmp -s "$originalFile" "$newFile"; then
+    mv $newFile $original
+  fi
+  rm $newFile
+  rmdir $tempDir
+fi
\ No newline at end of file