[PATCH] gcc_update: use gcc-descr git alias for revision string in gcc/REVISION

[Serge Belyshev]

This is to make development version string more readable, and
to simplify navigation through gcc-testresults.

Currently gcc_update uses git log --pretty=tformat:%p:%t:%H to
generate version string, which is somewhat excessive since conversion
to git because commit hashes are now stable.

Even better, gcc-git-customization.sh script provides gcc-descr alias
which makes prettier version string, and thus use it instead (or just
abbreviated commit hash when the alias is not available).

Before: [master revision 
b25edf6e6fe:e035f180ebf:7094a69bd62a14dfa311eaa2fea468f221c7c9f3]
After: [master r12-2331]

OK for mainline?

contrib/Changelog:

        * gcc_update: Use gcc-descr alias for revision string if it exists, or
        abbreviated commit hash instead. Drop "revision" from gcc/REVISION.
---
 contrib/gcc_update | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contrib/gcc_update b/contrib/gcc_update
index 80fac9fc995..8f712e37616 100755
--- a/contrib/gcc_update
+++ b/contrib/gcc_update
@@ -332,7 +332,7 @@ case $vcs_type in
             exit 1
        fi
 
-       revision=`$GCC_GIT log -n1 --pretty=tformat:%p:%t:%H`
+       revision=`$GCC_GIT gcc-descr || $GCC_GIT log -n1 --pretty=tformat:%h`
        branch=`$GCC_GIT name-rev --name-only HEAD || :`
        ;;    
 
@@ -414,6 +414,6 @@ rm -f LAST_UPDATED gcc/REVISION
     date
     echo "`TZ=UTC date` (revision $revision)"
 } > LAST_UPDATED
-echo "[$branch revision $revision]" > gcc/REVISION
+echo "[$branch $revision]" > gcc/REVISION
 
 touch_files_reexec