update.sh: add MV-like function preserving file timestamps

Add a do_mv()/$MV wrappers to be called instead of just mv. This
function will preserve the target file if it does not differ from the
source file. This helps to remove unnecessary compilator calls after
calling update.sh w/o source changes.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/update.sh b/update.sh
index f7c38c9..9c49ad5 100755
--- a/update.sh
+++ b/update.sh
@@ -44,7 +44,16 @@ libtls_version=$major:$minor:0
 echo "libtls version $libtls_version"
 echo $libtls_version > tls/VERSION
 
+do_mv() {
+        if ! cmp -s "$1" "$2"
+        then
+                mv "$1" "$2"
+        else
+                rm -f "$1"
+        fi
+}
 CP='cp -p'
+MV='do_mv'
 
 $CP $libssl_src/src/LICENSE COPYING
 
@@ -68,8 +77,8 @@ $CP $libcrypto_src/crypto/arc4random_*.h crypto/compat
         perl objects.pl objects.txt obj_mac.num obj_mac.h;
         perl obj_dat.pl obj_mac.h obj_dat.h )
 mkdir -p include/openssl crypto/objects
-mv $libssl_src/src/crypto/objects/obj_mac.h ./include/openssl/obj_mac.h
-mv $libssl_src/src/crypto/objects/obj_dat.h ./crypto/objects/obj_dat.h
+$MV $libssl_src/src/crypto/objects/obj_mac.h ./include/openssl/obj_mac.h
+$MV $libssl_src/src/crypto/objects/obj_dat.h ./crypto/objects/obj_dat.h
 
 copy_hdrs() {
         for file in $2; do