Add patch-merging script

tools/merge-to-branch.sh

Index: tools/merge-to-branch.sh
diff --git a/tools/merge-to-branch.sh b/tools/merge-to-branch.sh
new file mode 100755
index 0000000000000000000000000000000000000000..c0d5a502357b32e15e536e8bf93efb031845665c
--- /dev/null
+++ b/tools/merge-to-branch.sh
@@ -0,0 +1,356 @@
+#!/bin/bash
+# Copyright 2012 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+########## Global variable definitions
+
+BRANCHNAME=prepare-merge
+VERSION_FILE="src/version.cc"
+PERSISTFILE_BASENAME=/tmp/v8-merge-to-branch-tempfile
+ALREADY_MERGING_SENTINEL_FILE="$PERSISTFILE_BASENAME-already-merging"
+CHANGELOG_ENTRY_FILE="$PERSISTFILE_BASENAME-changelog-entry"
+PATCH_FILE="$PERSISTFILE_BASENAME-patch"
+COMMITMSG_FILE="$PERSISTFILE_BASENAME-commitmsg"
+COMMITMSG_FILE_COPY="$PERSISTFILE_BASENAME-commitmsg-copy"
+TOUCHED_FILES_FILE="$PERSISTFILE_BASENAME-touched-files"
+TRUNK_REVISION_FILE="$PERSISTFILE_BASENAME-trunkrevision"
+START_STEP=0
+CURRENT_STEP=0
+
+usage() {
+cat << EOF
+usage: $0 [OPTIONS]... [BRANCH] [REVISION]...
+
+Performs the necessary steps to merge revisions from bleeding_edge
+to other branches, including trunk.
+
+OPTIONS:
+  -h    Show this message
+  -s    Specify the step where to start work. Default: 0.
+EOF
+}
+
+########## Function definitions
+
+die() {
+  [[ -n "$1" ]] && echo "Error: $1"
+  echo "Exiting."
+  exit 1
+}
+
+confirm() {
+  echo -n "$1 [Y/n] "
+  read ANSWER
+  if [[ -z "$ANSWER" || "$ANSWER" == "Y" || "$ANSWER" == "y" ]] ; then
+    return 0
+  else
+    return 1
+  fi
+}
+
+delete_branch() {
+  local MATCH=$(git branch | grep $1 | awk '{print $NF}' )
+  if [ "$MATCH" == "$1" ] ; then
+    confirm "Branch $1 exists, do you want to delete it?"
+    if [ $? -eq 0 ] ; then
+      git branch -D $1 || die "Deleting branch '$1' failed."
+      echo "Branch $1 deleted."
+    else
+      die "Can't continue. Please delete branch $1 and try again."
+    fi
+  fi
+}
+
+# Persist and restore variables to support canceling/resuming execution
+# of this script.
+persist() {
+  local VARNAME=$1
+  local FILE="$PERSISTFILE_BASENAME-$VARNAME"
+  echo "${!VARNAME}" > $FILE
+}
+
+restore() {
+  local VARNAME=$1
+  local FILE="$PERSISTFILE_BASENAME-$VARNAME"
+  local VALUE="$(cat $FILE)"
+  eval "$VARNAME=\"$VALUE\""
+}
+
+restore_if_unset() {
+  local VARNAME=$1
+  [[ -z "${!VARNAME}" ]] && restore "$VARNAME"
+  [[ -z "${!VARNAME}" ]] && die "Variable '$VARNAME' could not be restored."
+}
+
+persist_patch_commit_hashes() {
+  local FILE="$PERSISTFILE_BASENAME-PATCH_COMMIT_HASHES"
+  echo "PATCH_COMMIT_HASHES=( ${PATCH_COMMIT_HASHES[@]} )" > $FILE
+}
+
+restore_patch_commit_hashes() {
+  local FILE="$PERSISTFILE_BASENAME-PATCH_COMMIT_HASHES"
+  source $FILE
+}
+
+restore_patch_commit_hashes_if_unset() {
+  [[ "${#PATCH_COMMIT_HASHES[@]}" == 0 ]] && restore_patch_commit_hashes
+  [[ "${#PATCH_COMMIT_HASHES[@]}" == 0 ]] && \
+      die "Variable PATCH_COMMIT_HASHES could not be restored."
+}
+
+########## Option parsing
+
+while getopts ":hs:f" OPTION ; do
+  case $OPTION in
+    h)  usage
+        exit 0
+        ;;
+    f)  rm "$ALREADY_MERGING_SENTINEL_FILE"
+        ;;
+    s)  START_STEP=$OPTARG
+        ;;
+    ?)  echo "Illegal option: -$OPTARG"
+        usage
+        exit 1
+        ;;
+  esac
+done
+let OPTION_COUNT=$OPTIND-1
+shift $OPTION_COUNT
+
+########## Regular workflow
+
+# If there is a merge in progress, abort.
+[[ -e "$ALREADY_MERGING_SENTINEL_FILE" ]] && [[ -z "$START_STEP" ]] \
+   && die "A merge is already in progress"
+touch "$ALREADY_MERGING_SENTINEL_FILE"
+
+# Cancel if this is not a git checkout.
+[[ -d .git ]] \
+  || die "This is not a git checkout, this script won't work for you."
+
+# Cancel if EDITOR is unset or not executable.
+[[ -n "$EDITOR" && -x "$(which $EDITOR)" ]] \
+  || die "Please set your EDITOR environment variable, you'll need it."
+
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  MERGE_TO_BRANCH=$1
+  [[ -n "$MERGE_TO_BRANCH" ]] \
+    || die "Please specify a branch to merge to"
+  shift
+  persist "MERGE_TO_BRANCH"
+
+  echo ">>> Step $CURRENT_STEP: Preparation"
+  # Check for a clean workdir.
+  [[ -z "$(git status -s -uno)" ]] \
+    || die "Workspace is not clean. Please commit or undo your changes."
+
+  # Persist current branch.
+  CURRENT_BRANCH=$(git status -s -b -uno | grep "^##" | awk '{print $2}')
+  persist "CURRENT_BRANCH"
+  delete_branch $BRANCHNAME
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Fetch unfetched revisions."
+  git svn fetch || die "'git svn fetch' failed."
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  restore_if_unset "MERGE_TO_BRANCH"
+  echo ">>> Step $CURRENT_STEP: Create a fresh branch for the patch."
+  git checkout -b $BRANCHNAME svn/$MERGE_TO_BRANCH \
+    || die "Creating branch $BRANCHNAME failed."
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Find the git \
+revisions associated with the patches."
+  current=0
+  for REVISION in "$@" ; do
+    NEXT_HASH=$(git svn find-rev "r$REVISION" svn/bleeding_edge)
+    [[ -n "$NEXT_HASH" ]] \
+      || die "Cannot determine git hash for r$REVISION"
+    PATCH_COMMIT_HASHES[$current]="$NEXT_HASH"
+    [[ -n "$NEW_COMMIT_MSG" ]] && NEW_COMMIT_MSG="$NEW_COMMIT_MSG,"
+    NEW_COMMIT_MSG="$NEW_COMMIT_MSG r$REVISION"
+    let current+=1
+  done
+  NEW_COMMIT_MSG="Merged$NEW_COMMIT_MSG into \

[Jakob Kummerow, 2012/01/31 11:11:10]

nit: fits on one line

[danno, 2012/01/31 11:13:11]

Done.

+$MERGE_TO_BRANCH branch."
+  
+  echo "$NEW_COMMIT_MSG" > $COMMITMSG_FILE
+  echo >> $COMMITMSG_FILE
+  for HASH in ${PATCH_COMMIT_HASHES[@]} ;  do

[Jakob Kummerow, 2012/01/31 11:11:10]

nit: double space before "do"

[danno, 2012/01/31 11:13:11]

Done.

+    PATCH_MERGE_DESCRIPTION=$(git log -1 --format=%s $HASH)
+    echo "$PATCH_MERGE_DESCRIPTION" >> $COMMITMSG_FILE
+    echo >> $COMMITMSG_FILE
+  done
+  for HASH in ${PATCH_COMMIT_HASHES[@]} ; do
+    BUG=$(git log -1 $HASH | grep "BUG=" | awk -F '=' '{print $NF}')
+    if [ $BUG ] ; then
+      if [ "$BUG_AGGREGATE" ] ; then
+        BUG_AGGREGATE="$BUG_AGGREGATE,"
+      fi
+      BUG_AGGREGATE="$BUG_AGGREGATE$BUG"
+    fi
+  done
+  if [ "$BUG_AGGREGATE" ] ; then
+    echo "BUG=$BUG_AGGREGATE" >> $COMMITMSG_FILE
+  else
+    echo "BUG=none" >> $COMMITMSG_FILE

[Jakob Kummerow, 2012/01/31 11:11:10]

I'd just remove this. "BUG=none" adds no useful information.

[danno, 2012/01/31 11:13:11]

Done.

+  fi
+  echo -n "TEST=none" >> $COMMITMSG_FILE

[Jakob Kummerow, 2012/01/31 11:11:10]

Same here.

[danno, 2012/01/31 11:13:11]

Done.

+  persist "NEW_COMMIT_MSG"
+  persist_patch_commit_hashes
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  restore_if_unset "MERGE_TO_BRANCH"
+  restore_patch_commit_hashes_if_unset "PATCH_COMMIT_HASHES"
+  echo "${PATCH_COMMIT_HASHES[@]}"
+  echo ">>> Step $CURRENT_STEP: Apply the revision patch and create commit message."
+  for HASH in ${PATCH_COMMIT_HASHES[@]} ; do
+    git log -1 -p $HASH | patch -p1 \
+      || die "Cannot apply the patch for $HASH to $MERGE_TO_BRANCH"
+  done
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Prepare version.cc"
+# These version numbers are used again for creating the tag
+  MAJOR=$(grep "#define MAJOR_VERSION" "$VERSION_FILE" | awk '{print $NF}')

[Jakob Kummerow, 2012/01/31 11:11:10]

AFAICS the tag is created using NEWMAJOR, NEWMINOR, NEWBUILD, which are created
and persisted in the next step. So you really don't need these.

[danno, 2012/01/31 11:13:11]

Done.

+  persist "MAJOR"
+  MINOR=$(grep "#define MINOR_VERSION" "$VERSION_FILE" | awk '{print $NF}')
+  persist "MINOR"
+  BUILD=$(grep "#define BUILD_NUMBER" "$VERSION_FILE" | awk '{print $NF}')
+  persist "BUILD"
+  PATCH=$(grep "#define PATCH_LEVEL" "$VERSION_FILE" | awk '{print $NF}')
+  persist "PATCH"
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Increment version number."
+  restore_if_unset "PATCH"
+  NEWPATCH=$(($PATCH + 1))
+  confirm "Automatically increment PATCH_LEVEL? (Saying 'n' will fire up \
+your EDITOR on $VERSION_FILE so you can make arbitrary changes. When \
+you're done, save the file and exit your EDITOR.)"
+  if [ $? -eq 0 ] ; then
+    sed -e "/#define PATCH_LEVEL/s/[0-9]*$/$NEWPATCH/" \
+        -i "$VERSION_FILE"
+  else
+    $EDITOR "$VERSION_FILE"
+  fi
+  NEWMAJOR=$(grep "#define MAJOR_VERSION" "$VERSION_FILE" | awk '{print $NF}')
+  persist "NEWMAJOR"
+  NEWMINOR=$(grep "#define MINOR_VERSION" "$VERSION_FILE" | awk '{print $NF}')
+  persist "NEWMINOR"
+  NEWBUILD=$(grep "#define BUILD_NUMBER" "$VERSION_FILE" | awk '{print $NF}')
+  persist "NEWBUILD"
+  NEWPATCH=$(grep "#define PATCH_LEVEL" "$VERSION_FILE" | awk '{print $NF}')
+  persist "NEWPATCH"
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Commit to local branch."
+  git commit -a -F "$COMMITMSG_FILE" \
+    || die "'git commit -a' failed."
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Upload for code review."
+  echo -n "Please enter the email address of a V8 reviewer for your patch: "
+  read REVIEWER
+  git cl upload -r "$REVIEWER" --send-mail \
+    || die "'git cl upload' failed, please try again."
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  restore_if_unset "MERGE_TO_BRANCH"
+  git checkout $BRANCHNAME \
+    || die "cannot ensure that the current branch is $BRANCHNAME" 
+  echo ">>> Step $CURRENT_STEP: Commit to the repository."
+  echo "Please wait for an LGTM, then type \"LGTM<Return>\" to commit your \
+change. (If you need to iterate on the patch or double check that it's \
+sane, do so in another shell, but remember to not change the headline of \
+the uploaded CL."
+  unset ANSWER
+  while [ "$ANSWER" != "LGTM" ] ; do
+    [[ -n "$ANSWER" ]] && echo "That was not 'LGTM'."
+    echo -n "> "
+    read ANSWER
+  done
+  git cl dcommit || die "failed to commit to $MERGE_TO_BRANCH"
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  restore_if_unset "NEW_COMMIT_MSG"
+  restore_if_unset "MERGE_TO_BRANCH"
+  echo ">>> Step $CURRENT_STEP: Determine svn commit revision"
+  git svn fetch || die "'git svn fetch' failed."
+  COMMIT_HASH=$(git log -1 --format=%H --grep="$NEW_COMMIT_MSG" \
+svn/$MERGE_TO_BRANCH)
+  [[ -z "$COMMIT_HASH" ]] && die "Unable to map git commit to svn revision"
+  SVN_REVISION=$(git svn find-rev $COMMIT_HASH)
+  echo "subversion revision number is r$SVN_REVISION"
+  persist "SVN_REVISION"
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  restore_if_unset "SVN_REVISION"
+  restore_if_unset "NEWMAJOR"
+  restore_if_unset "NEWMINOR"
+  restore_if_unset "NEWBUILD"
+  restore_if_unset "NEWPATCH"
+  echo ">>> Step $CURRENT_STEP: Create the tag."
+  echo "Creating tag svn/tags/$NEWMAJOR.$NEWMINOR.$NEWBUILD.$NEWPATCH"
+  svn copy -r $SVN_REVISION \
+https://v8.googlecode.com/svn/branches/$MERGE_TO_BRANCH \
+https://v8.googlecode.com/svn/tags/$NEWMAJOR.$NEWMINOR.$NEWBUILD.$NEWPATCH \
+-m "Tagging version $NEWMAJOR.$NEWMINOR.$NEWBUILD.$NEWPATCH"
+fi
+
+let CURRENT_STEP+=1
+if [ $START_STEP -le $CURRENT_STEP ] ; then
+  echo ">>> Step $CURRENT_STEP: Cleanup."
+  restore_if_unset "CURRENT_BRANCH"
+  git checkout -f $CURRENT_BRANCH
+  [[ "$BRANCHNAME" != "$CURRENT_BRANCH" ]] && git branch -D $BRANCHNAME
+  rm -f "$ALREADY_MERGING_SENTINEL_FILE"
+fi