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..5d3f07dc0d56bb449eda8afbe775196f7d72413d
--- /dev/null
+++ b/tools/merge-to-branch.sh
@@ -0,0 +1,338 @@
+#!/bin/bash
+# Copyright 2011 the V8 project authors. All rights reserved.

[Jakob Kummerow, 2012/01/27 16:28:12]

nit: 2012

[danno, 2012/01/31 10:37:57]

Done.

+# 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
+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"
+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."
+}
+
+
+########## Option parsing
+
+while getopts ":hs:" OPTION ; do
+  case $OPTION in
+    h)  usage
+        exit 0
+        ;;
+    s)  STEP=$OPTARG
+        ;;
+    ?)  echo "Illegal option: -$OPTARG"
+        usage
+        exit 1
+        ;;
+  esac
+done
+
+MERGE_TO_BRANCH=$1
+[[ -n "$MERGE_TO_BRANCH" ]] \
+  || die "Please specify a branch to merge to"
+shift
+
+MERGE_REVISION=$1
+[[ -n "$MERGE_REVISION" ]] \
+  || die "Please specify a svn revision to merge"
+
+########## Regular workflow
+
+# 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 [ $STEP -le 0 ] ; then
+  echo ">>> Step 0: Preparation"
+  # Check for a clean workdir.
+  [[ -z "$(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
+
+if [ $STEP -le 1 ] ; then
+  echo ">>> Step 1: Fetch unfetched revisions."
+  git svn fetch || die "'git svn fetch' failed."
+fi
+
+if [ $STEP -le 2 ] ; then
+  echo ">>> Step 2: Create a fresh branch for the patch."
+  git checkout -b $BRANCHNAME svn/$MERGE_TO_BRANCH \
+    || die "Creating branch $BRANCHNAME failed."
+fi
+
+if [ $STEP -le 3 ] ; then
+  echo ">>> Step 3: Find the git revsions associated with the patches."

[Jakob Kummerow, 2012/01/27 16:28:12]

nit: "revisions"

[danno, 2012/01/31 10:37:57]

Done.

+  current=0
+  for REVISION in "$@" 

[Jakob Kummerow, 2012/01/27 16:28:12]

nit: You can get closer to our C++ style by putting the "do" on the same line,
separated by a semicolon:

for REVISION in "$@" ; do

[danno, 2012/01/31 10:37:57]

Done.

+  do
+    NEXT_HASH=$(git svn find-rev "r$REVISION" bleeding_edge)

[Jakob Kummerow, 2012/01/27 16:28:12]

"bleeding_edge" is one of your local git branches. Please use
"svn/bleeding_edge" instead.

[danno, 2012/01/31 10:37:57]

Done.

+    [[ -n "$NEXT_HASH" ]] \
+      || die "Cannot determine git hash for r$REVISION"
+    PATCH_COMMIT_HASHES[$current]="$NEXT_HASH"
+    if [ "$NEW_COMMIT_MSG" ] ; then

[Jakob Kummerow, 2012/01/27 16:28:12]

for consistency:

[[ -n "$NEW_COMMIT_MSG" ]] && NEW_COMMIT_MSG="$NEW_COMMIT_MSG,"

[danno, 2012/01/31 10:37:57]

Done.

+      NEW_COMMIT_MSG="$NEW_COMMIT_MSG,"
+    fi
+    NEW_COMMIT_MSG="$NEW_COMMIT_MSG r$REVISION"
+    let current+=1
+  done
+  NEW_COMMIT_MSG="Merged$NEW_COMMIT_MSG into \
+$MERGE_TO_BRANCH branch."
+  persist PATCH_COMMIT_HASHES

[Jakob Kummerow, 2012/01/27 16:28:12]

Have you tested whether persist() can handle arrays correctly?

[danno, 2012/01/31 10:37:57]

Done.

+  persist NEW_COMMIT_MSG
+fi
+
+if [ $STEP -le 4 ] ; then
+  restore_if_unset "PATCH_COMMIT_HASHES"
+  restore_if_unset "NEW_COMMIT_MSG"
+  echo ">>> Step 4: Aggregate patch description and bugs numbers."
+  
+  echo "$NEW_COMMIT_MSG" > $COMMITMSG_FILE

[Jakob Kummerow, 2012/01/27 16:28:12]

If you move this to the end of step 3, you don't need the
persist()/restore_if_unset() cycle.

[danno, 2012/01/31 10:37:57]

Done.

+  echo >> $COMMITMSG_FILE
+  for HASH in ${PATCH_COMMIT_HASHES[@]}
+  do
+    PATCH_MERGE_DESCRIPTION=$(git show --notes $HASH \

[Jakob Kummerow, 2012/01/27 16:28:12]

I think what you mean here is just:

PATCH_MERGE_DESCRIPTION=$(git log -1 --format=%s $HASH)

no awk/sed necessary.

[danno, 2012/01/31 10:37:57]

Done.

+      | awk '{
+        if (line_number == 4) {
+          printf($0);
+        };
+        line_number++
+      }' \
+      | sed 's/    //')
+    echo "DESC: $PATCH_MERGE_DESCRIPTION"
+    echo "$PATCH_MERGE_DESCRIPTION" >> $COMMITMSG_FILE
+    echo >> $COMMITMSG_FILE
+  done
+  for HASH in ${PATCH_COMMIT_HASHES[@]}
+  do
+    BUG=$(git show --notes $HASH | grep "BUG=" | awk -F '=' '{print $NF}')

[Jakob Kummerow, 2012/01/27 16:28:12]

I guess it doesn't really matter, but "git log -1" emits only the log message
(and not the entire diff).

[danno, 2012/01/31 10:37:57]

Done.

+    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
+  fi
+fi
+
+if [ $STEP -le 5 ] ; then
+  echo ">>> Step 5: Apply the revision patch and create commit message."
+  for HASH in ${PATCH_COMMIT_HASHES[@]}

[Jakob Kummerow, 2012/01/27 16:28:12]

missing restore_if_unset for PATCH_COMMIT_HASHES

[danno, 2012/01/31 10:37:57]

Done.

+  do
+    git log -1 -p $HASH | patch -p1 \
+      || die "Cannot apply the patch for r$MERGE_REVISION on $MERGE_TO_BRANCH"

[Jakob Kummerow, 2012/01/27 16:28:12]

Talking about a single MERGE_REVISION here is inconsistent with the for-loops
elsewhere...

[danno, 2012/01/31 10:37:57]

Done.

+  done
+fi
+
+if [ $STEP -le 6 ] ; then
+  echo ">>> Step 6: Prepare version.cc"
+# These version numbers are used again later for the trunk commit.

[Jakob Kummerow, 2012/01/27 16:28:12]

outdated comment?

[danno, 2012/01/31 10:37:57]

Done.

+  MAJOR=$(grep "#define MAJOR_VERSION" "$VERSION_FILE" | awk '{print $NF}')

[Jakob Kummerow, 2012/01/27 16:28:12]

do we need MAJOR, MINOR and BUILD at all?

[danno, 2012/01/31 10:37:57]

Yes. For building the tag.
On 2012/01/27 16:28:12, Jakob wrote:

+  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
+
+if [ $STEP -le 7 ] ; then
+  echo ">>> Step 7: Increment version number."
+  restore_if_unset "PATCH"
+  NEWPATCH=$(($PATCH + 1))
+  confirm "Automatically increment BUILD_NUMBER? (Saying 'n' will fire up \

[Jakob Kummerow, 2012/01/27 16:28:12]

s/BUILD_NUMBER/PATCH_LEVEL/

[danno, 2012/01/31 10:37:57]

Done.

+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
+
+if [ $STEP -le 8 ] ; then
+  echo ">>> Step 8: Commit to local branch."
+  restore_if_unset "NEW_COMMIT_MSG"
+  git commit -a -m "$NEW_COMMIT_MSG" \
+    || die "'git commit -a' failed."
+fi
+
+if [ $STEP -le 9 ] ; then
+  echo ">>> Step 9: Confirm merge commit."
+  echo "This is the message that will be used for the commit:"
+  echo "--------------------"
+  cat "$COMMITMSG_FILE"
+  echo -e "--------------------"

[Jakob Kummerow, 2012/01/27 16:28:12]

nit: "-e" is unnecessary (since you don't have any escaped characters such as \n
in the echoed string)

[danno, 2012/01/31 10:37:57]

Done.

+  confirm "Does this look good to you? (Saying 'n' will fire up your \
+EDITOR so you can change the commit message. When you're done, save the \
+file and exit your EDITOR.)"
+  if [ $? -ne 0 ] ; then
+    $EDITOR "$COMMITMSG_FILE"
+  fi
+fi
+
+if [ $STEP -le 10 ] ; then
+  echo ">>> Step 10: Upload for code review."
+  echo -n "Please enter the email address of a V8 reviewer for your patch: "
+  read REVIEWER
+  cat $COMMITMSG_FILE > $COMMITMSG_FILE_COPY
+  echo "R=$REVIEWER" >> $COMMITMSG_FILE_COPY

[Jakob Kummerow, 2012/01/27 16:28:12]

You don't need this. "git cl upload --review" automatically inserts the R= line.

+  export EDITOR="cat $COMMITMSG_FILE_COPY >"

[Jakob Kummerow, 2012/01/27 16:28:12]

I'm not sure I like messing with my EDITOR variable... but it's up to you.

[danno, 2012/01/31 10:37:57]

Done.

+  git cl upload --review "$REVIEWER" --send-mail \
+    || die "'git cl upload' failed, please try again."
+fi
+
+if [ $STEP -le 11 ] ; then
+  echo ">>> Step 11: Sanity check."
+  confirm "Please check if your local checkout is sane: Inspect $VERSION_FILE, \
+compile, run tests. Do you want to commit this new trunk revision to the \

[Jakob Kummerow, 2012/01/27 16:28:12]

nit: s/new trunk//

Also, we don't really need step 11 at all, since step 12 is asking for
confirmation yet again. I'd integrate the message that's printed here into step
12's message ("Now is also the right time to run sanity checks in your working
directory"), and get rid of step 11.

[danno, 2012/01/31 10:37:57]

Done.

+repository?"
+  [[ $? -eq 0 ]] || die "Execution canceled."
+fi
+
+if [ $STEP -le 12 ] ; then
+  echo ">>> Step 12: 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, do so in another shell. Do not \

[Jakob Kummerow, 2012/01/27 16:28:12]

You can remove the "Do not modify..." part, as it doesn't apply here.

[danno, 2012/01/31 10:37:57]

Done.

+modify the existing local commit's commit message.)"
+  unset ANSWER
+  while [ "$ANSWER" != "LGTM" ] ; do
+    [[ -n "$ANSWER" ]] && echo "That was not 'LGTM'."
+    echo -n "> "
+    read ANSWER
+  done
+  echo "git-cl dcommit"

[Jakob Kummerow, 2012/01/27 16:28:12]

Forgot to remove the "echo".

[danno, 2012/01/31 10:37:57]

Done.

+fi
+
+if [ $STEP -le 13 ] ; then
+  restore_if_unset "NEWMAJOR"
+  restore_if_unset "NEWMINOR"
+  restore_if_unset "NEWBUILD"
+  restore_if_unset "NEWPATCH"
+  echo ">>> Step 13: Create the tag."
+  echo "svn copy -r ? https://v8.googlecode.com/svn/branches/$MERGE_TO_BRANCH https://v8.googlecode.com/svn/tags/$NEWMAJOR.$NEWMINOR.$NEWBUILD.$NEWPATCH -m \"Tagging version $NEWMAJOR.$NEWMINOR.$NEWBUILD.$NEWPATCH\""

[Jakob Kummerow, 2012/01/27 16:28:12]

another "echo" that needs to go.

[danno, 2012/01/31 10:37:57]

Done.

+fi
+
+if [ $STEP -le 14 ] ; then
+  echo ">>> Step 14: Cleanup."
+  restore_if_unset "CURRENT_BRANCH"
+  git checkout -f $CURRENT_BRANCH
+  [[ "$BRANCHNAME" != "$CURRENT_BRANCH" ]] && echo "git branch -D $BRANCHNAME"

[Jakob Kummerow, 2012/01/27 16:28:12]

another "echo" that needs to go.

[danno, 2012/01/31 10:37:57]

Done.

+fi