From 8c02d17bea5def5b7006a7290a9f111433d0ab19 Mon Sep 17 00:00:00 2001
From: Derek Bailey <derekbailey@google.com>
Date: Mon, 24 Feb 2020 14:46:24 -0800
Subject: [PATCH] Skip writing reflection_generated.h if not changed (#5776)

---
 reflection/generate_code.sh | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/reflection/generate_code.sh b/reflection/generate_code.sh
index 0c1157d3f..f0405d5ca 100755
--- 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