[Mesa-dev] [PATCH] mesa: don't touch git_sha1.h if sha1 didn't change

[Marcin Slusarz]

Less recompiles...
---
 bin/extract_git_sha1 |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/bin/extract_git_sha1 b/bin/extract_git_sha1
index e6e6731..fc7bf85 100755
--- a/bin/extract_git_sha1
+++ b/bin/extract_git_sha1
@@ -1,10 +1,14 @@
 #!/bin/sh
-touch src/mesa/main/git_sha1.h
 if which git > /dev/null; then
     # Extract the 7-digit "short" SHA1 for the current HEAD, convert
     # it to a string, and wrap it in a #define.  This is used in
     # src/mesa/main/version.c to put the GIT SHA1 in the GL_VERSION string.
     git log -n 1 --oneline |\
 	sed 's/^\([^ ]*\) .*/#define MESA_GIT_SHA1 "git-\1"/' \
-	> src/mesa/main/git_sha1.h
+	> src/mesa/main/git_sha1.h.tmp
+    if ! diff src/mesa/main/git_sha1.h.tmp src/mesa/main/git_sha1.h >/dev/null; then
+    	mv src/mesa/main/git_sha1.h.tmp src/mesa/main/git_sha1.h
+    fi
+else
+    touch src/mesa/main/git_sha1.h
 fi
-- 
1.7.4.1