tcwg-llvm-build.sh: Use --revision argument

The new argument will move the tree to a specific SVN revision on all
repos by finding the nearest Git commit and checking out to it.

This will be merged with https://review.linaro.org/#/c/18783/ for the
flock issue before commit.

The test-suite doesn't need a specific commit, since it doesn't change
much and the only place it really matters is the release, which will be
dealt with separately.

Change-Id: I469c6cfd83e0b1f0c9038b767bf8e07b522df1cd

1 files changed, 36 insertions, 1 deletions

diff --git a/tcwg-llvm-build.sh b/tcwg-llvm-build.sh
index fc69b987..420d271e 100755
--- a/tcwg-llvm-build.sh
+++ b/tcwg-llvm-build.sh
@@ -9,16 +9,19 @@ set -o pipefail
 
 # Syntax
 SYN_WORKSPACE="--workspace=/path/to/workspace"
+SYN_REVISION="--revision=rNNNNN (SVN revision, def. tip)"
 SYN_BUILDTYPE="--buildtype={Release|Debug} (def. Release)"
 SYN_ASSERTS="--asserts={True|False} (def. True)"
 SYN_BUILDJOBS="--buildjobs=N (def. CPUS)"
 SYN_LINKJOBS="--linkjobs=N (def. RAM+1)"
 SYN_TOOLCHAIN="--toolchain=http://url/for/tarball"
 SYN_BUILDID="--buildid=<text-to-add-to-tarball>"
-SYNTAX="$0 $SYN_WORKSPACE $SYN_ASSERTS $SYN_LINKJOBS $SYN_BUILDJOBS $SYN_TOOLCHAIN $SYN_BUILDID"
+SYNTAX="$0 $SYN_WORKSPACE $SYN_REVISION $SYN_ASSERTS $SYN_LINKJOBS $SYN_BUILDJOBS $SYN_TOOLCHAIN $SYN_BUILDID"
 
 # Environment Variables and default values
+BASEDIR=$(dirname "$(readlink -f $0)")
 WORKSPACE=$(pwd)
+REVISION=
 BUILDTYPE="Release"
 ASSERTS="True"
 CPUS=$(nproc --all)
@@ -53,6 +56,17 @@ while [ "$#" -gt 0 ]; do
           exit 1
         fi
         shift ;;
+      --revision)
+        if [ ! -z "$VAL" ]; then
+          if echo "$VAL" | grep -q "r[0-9]\+"; then
+            REVISION="$VAL"
+          else
+            echo "ERROR: $1"
+            echo "Syntax: $SYN_REVISION"
+            exit 1
+          fi
+        fi
+        shift ;;
       --buildid)
         if [ "$VAL" != "" ]; then
           BUILDID="$VAL"
@@ -162,6 +176,7 @@ INSTDIR="$WORKSPACE/install"
 REFDIR="$HOME/llvm-reference"
 
 # Dump
+echo "REVISION = $REVISION"
 echo "BUILDTYPE = $BUILDTYPE"
 echo "ASSERTS = $ASSERTS"
 echo "SRCDIR = $SRCDIR"
@@ -189,6 +204,26 @@ LOGEXT="txt"
             "$SRCDIR/tools/clang" |& tee -a "$LOGBASE-clone.$LOGEXT"
 ) 9>$REFDIR.lock
 
+update_git() {
+  base=$1
+  rev=$2
+
+  # Find the closest git hash for the SVN revision
+  pushd "$base"
+  hash=$("$BASEDIR/svn-git-hash.pl" "$rev" | awk '{print $2}')
+
+  # We don't need to create a branch with the commit, as the clones are new
+  # Should be ok to stay in a detached head state for this purpose
+  git checkout "$hash"
+  popd
+}
+
+# Move down to the right revision
+if [ ! -z "$REVISION" ]; then
+  update_git "$SRCDIR" "$REVISION"
+  update_git "$SRCDIR/tools/clang" "$REVISION"
+fi
+
 # CMake
 OPTIONS="-DLLVM_BUILD_TESTS=True "
 OPTIONS+="-DCMAKE_BUILD_TYPE='$BUILDTYPE' "