tor/scripts/git/git-merge-forward.sh
2019-10-11 17:26:34 -04:00

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#!/usr/bin/env bash
SCRIPT_NAME=`basename $0`
function usage()
{
echo "$SCRIPT_NAME [-h] [-n] [-t <test-branch-prefix> [-u]]"
echo
echo " arguments:"
echo " -h: show this help text"
echo " -n: dry run mode"
echo " (default: run commands)"
echo " -t: test branch mode: create new branches from the commits checked"
echo " out in each maint directory. Call these branches prefix_029,"
echo " prefix_035, ... , prefix_master."
echo " (default: merge forward maint-*, release-*, and master)"
echo " -u: in test branch mode, if a prefix_* branch already exists,"
echo " skip creating that branch. Use after a merge error, to"
echo " restart the merge forward at the first unmerged branch."
echo " (default: if a prefix_* branch already exists, fail and exit)"
echo
echo " env vars:"
echo " required:"
echo " TOR_FULL_GIT_PATH: where the git repository directories reside."
echo " You must set this env var, we recommend \$HOME/git/"
echo " (default: fail if this env var is not set;"
echo " current: $GIT_PATH)"
echo
echo " optional:"
echo " TOR_MASTER: the name of the directory containing the tor.git clone"
echo " The tor master git directory is \$GIT_PATH/\$TOR_MASTER"
echo " (default: tor; current: $TOR_MASTER_NAME)"
echo " TOR_WKT_NAME: the name of the directory containing the tor"
echo " worktrees. The tor worktrees are:"
echo " \$GIT_PATH/\$TOR_WKT_NAME/{maint-*,release-*}"
echo " (default: tor-wkt; current: $TOR_WKT_NAME)"
echo " we recommend that you set these env vars in your ~/.profile"
}
#################
# Configuration #
#################
# Don't change this configuration - set the env vars in your .profile
# Where are all those git repositories?
GIT_PATH=${TOR_FULL_GIT_PATH:-"FULL_PATH_TO_GIT_REPOSITORY_DIRECTORY"}
# The tor master git repository directory from which all the worktree have
# been created.
TOR_MASTER_NAME=${TOR_MASTER_NAME:-"tor"}
# The worktrees location (directory).
TOR_WKT_NAME=${TOR_WKT_NAME:-"tor-wkt"}
##########################
# Git branches to manage #
##########################
# The branches and worktrees need to be modified when there is a new branch,
# and when an old branch is no longer supported.
# Configuration of the branches that needs merging. The values are in order:
# (0) current maint/release branch name
# (1) previous maint/release name to merge into (0)
# (only used in merge forward mode)
# (2) Full path of the git worktree
# (3) current branch suffix
# (maint branches only, only used in test branch mode)
# (4) previous test branch suffix to merge into (3)
# (maint branches only, only used in test branch mode)
#
# Merge forward example:
# $ cd <PATH/TO/WORKTREE> (2)
# $ git checkout maint-0.3.5 (0)
# $ git pull
# $ git merge maint-0.3.4 (1)
#
# Test branch example:
# $ cd <PATH/TO/WORKTREE> (2)
# $ git checkout -b ticket99999_035 (3)
# $ git checkout maint-0.3.5 (0)
# $ git pull
# $ git checkout ticket99999_035
# $ git merge maint-0.3.5
# $ git merge ticket99999_034 (4)
#
# First set of arrays are the maint-* branch and then the release-* branch.
# New arrays need to be in the WORKTREE= array else they aren't considered.
#
# Only used in test branch mode
# There is no previous branch to merge forward, so the second and fifth items
# must be blank ("")
MAINT_029_TB=( "maint-0.2.9" "" "$GIT_PATH/$TOR_WKT_NAME/maint-0.2.9" \
"_029" "")
# Used in maint/release merge and test branch modes
MAINT_035=( "maint-0.3.5" "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/maint-0.3.5" \
"_035" "_029")
MAINT_040=( "maint-0.4.0" "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.0" \
"_040" "_035")
MAINT_041=( "maint-0.4.1" "maint-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.1" \
"_041" "_040")
MAINT_042=( "maint-0.4.2" "maint-0.4.1" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.2" \
"_042" "_041")
MAINT_MASTER=( "master" "maint-0.4.2" "$GIT_PATH/$TOR_MASTER_NAME" \
"_master" "_041")
RELEASE_029=( "release-0.2.9" "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/release-0.2.9" )
RELEASE_035=( "release-0.3.5" "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/release-0.3.5" )
RELEASE_040=( "release-0.4.0" "maint-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.0" )
RELEASE_041=( "release-0.4.1" "maint-0.4.1" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.1" )
RELEASE_042=( "release-0.4.2" "maint-0.4.2" "$GIT_PATH/$TOR_WKT_NAME/release-0.4.2" )
# The master branch path has to be the main repository thus contains the
# origin that will be used to fetch the updates. All the worktrees are created
# from that repository.
ORIGIN_PATH="$GIT_PATH/$TOR_MASTER_NAME"
# SC2034 -- shellcheck thinks that these are unused. We know better.
ACTUALLY_THESE_ARE_USED=<<EOF
${MAINT_029_TB[0]}
${MAINT_035[0]}
${MAINT_040[0]}
${MAINT_041[0]}
${MAINT_042[0]}
${MAINT_MASTER[0]}
${RELEASE_029[0]}
${RELEASE_035[0]}
${RELEASE_040[0]}
${RELEASE_041[0]}
${RELEASE_042[0]}
EOF
#######################
# Argument processing #
#######################
# Controlled by the -n option. The dry run option will just output the command
# that would have been executed for each worktree.
DRY_RUN=0
# Controlled by the -t <test-branch-prefix> option. The test branch base
# name option makes git-merge-forward.sh create new test branches:
# <tbbn>_029, <tbbn>_035, ... , <tbbn>_master, and merge forward.
TEST_BRANCH_PREFIX=
# Controlled by the -u option. The use existing option checks for existing
# branches with the <test-branch-prefix>, and checks them out, rather than
# creating a new branch.
USE_EXISTING=0
while getopts "hnt:u" opt; do
case "$opt" in
h) usage
exit 0
;;
n) DRY_RUN=1
echo " *** DRY RUN MODE ***"
;;
t) TEST_BRANCH_PREFIX="$OPTARG"
echo " *** CREATING TEST BRANCHES: ${TEST_BRANCH_PREFIX}_nnn ***"
;;
u) USE_EXISTING=1
echo " *** USE EXISTING TEST BRANCHES MODE ***"
;;
*)
echo
usage
exit 1
;;
esac
done
###########################
# Git worktrees to manage #
###########################
if [ -z "$TEST_BRANCH_PREFIX" ]; then
# maint/release merge mode
#
# List of all worktrees to work on. All defined above. Ordering is important.
# Always the maint-* branch BEFORE then the release-*.
WORKTREE=(
RELEASE_029[@]
MAINT_035[@]
RELEASE_035[@]
MAINT_040[@]
RELEASE_040[@]
MAINT_041[@]
RELEASE_041[@]
MAINT_042[@]
RELEASE_042[@]
MAINT_MASTER[@]
)
else
# Test branch mode: merge to maint only, and create a new branch for 0.2.9
WORKTREE=(
MAINT_029_TB[@]
MAINT_035[@]
MAINT_040[@]
MAINT_041[@]
MAINT_042[@]
MAINT_MASTER[@]
)
fi
COUNT=${#WORKTREE[@]}
#############
# Constants #
#############
# Control characters
CNRM=$'\x1b[0;0m' # Clear color
# Bright color
BGRN=$'\x1b[1;32m'
BBLU=$'\x1b[1;34m'
BRED=$'\x1b[1;31m'
BYEL=$'\x1b[1;33m'
IWTH=$'\x1b[3;37m'
# Strings for the pretty print.
MARKER="${BBLU}[${BGRN}+${BBLU}]${CNRM}"
SUCCESS="${BGRN}success${CNRM}"
FAILED="${BRED}failed${CNRM}"
####################
# Helper functions #
####################
# Validate the given returned value (error code), print success or failed. The
# second argument is the error output in case of failure, it is printed out.
# On failure, this function exits.
function validate_ret
{
if [ "$1" -eq 0 ]; then
printf "%s\\n" "$SUCCESS"
else
printf "%s\\n" "$FAILED"
printf " %s" "$2"
exit 1
fi
}
# Switch to the given branch name.
function switch_branch
{
local cmd="git checkout '$1'"
printf " %s Switching branch to %s..." "$MARKER" "$1"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
# Checkout a new branch with the given branch name.
function new_branch
{
local cmd="git checkout -b '$1'"
printf " %s Creating new branch %s..." "$MARKER" "$1"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
# Switch to an existing branch, or checkout a new branch with the given
# branch name.
function switch_or_new_branch
{
local cmd="git rev-parse --verify '$1'"
if [ $DRY_RUN -eq 0 ]; then
# Call switch_branch if there is a branch, or new_branch if there is not
msg=$( eval "$cmd" 2>&1 )
RET=$?
if [ $RET -eq 0 ]; then
# Branch: (commit id)
switch_branch "$1"
elif [ $RET -eq 128 ]; then
# Not a branch: "fatal: Needed a single revision"
new_branch "$1"
else
# Unexpected return value
validate_ret $RET "$msg"
fi
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}, then depending on the result:"
switch_branch "$1"
new_branch "$1"
fi
}
# Pull the given branch name.
function pull_branch
{
local cmd="git pull"
printf " %s Pulling branch %s..." "$MARKER" "$1"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
# Merge the given branch name ($1) into the current branch ($2).
function merge_branch
{
local cmd="git merge --no-edit '$1'"
printf " %s Merging branch %s into %s..." "$MARKER" "$1" "$2"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
# Pull the given branch name.
function merge_branch_origin
{
local cmd="git merge --ff-only 'origin/$1'"
printf " %s Merging branch origin/%s..." "$MARKER" "$1"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
# Go into the worktree repository.
function goto_repo
{
if [ ! -d "$1" ]; then
echo " $1: Not found. Stopping."
exit 1
fi
cd "$1" || exit
}
# Fetch the origin. No arguments.
function fetch_origin
{
local cmd="git fetch origin"
printf " %s Fetching origin..." "$MARKER"
if [ $DRY_RUN -eq 0 ]; then
msg=$( eval "$cmd" 2>&1 )
validate_ret $? "$msg"
else
printf "\\n %s\\n" "${IWTH}$cmd${CNRM}"
fi
}
###############
# Entry point #
###############
# First, fetch the origin.
goto_repo "$ORIGIN_PATH"
fetch_origin
# Go over all configured worktree.
for ((i=0; i<COUNT; i++)); do
current=${!WORKTREE[$i]:0:1}
previous=${!WORKTREE[$i]:1:1}
repo_path=${!WORKTREE[$i]:2:1}
# default to merge forward mode
test_current=
test_previous=
target_current="$current"
target_previous="$previous"
if [ "$TEST_BRANCH_PREFIX" ]; then
test_current_suffix=${!WORKTREE[$i]:3:1}
test_current=${TEST_BRANCH_PREFIX}${test_current_suffix}
# the current test branch, if present, or maint/release branch, if not
target_current="$test_current"
test_previous_suffix=${!WORKTREE[$i]:4:1}
if [ "$test_previous_suffix" ]; then
test_previous=${TEST_BRANCH_PREFIX}${test_previous_suffix}
# the previous test branch, if present, or maint/release branch, if not
target_previous="$test_previous"
fi
fi
printf "%s Handling branch \\n" "$MARKER" "${BYEL}$target_current${CNRM}"
# Go into the worktree to start merging.
goto_repo "$repo_path"
if [ "$test_current" ]; then
if [ $USE_EXISTING -eq 0 ]; then
# Create a test branch from the currently checked-out branch/commit
# Fail if it already exists
new_branch "$test_current"
else
# Switch if it exists, or create if it does not
switch_or_new_branch "$test_current"
fi
fi
# Checkout the current maint/release branch
switch_branch "$current"
# Update the current maint/release branch with an origin merge to get the
# latest updates
merge_branch_origin "$current"
if [ "$test_current" ]; then
# Checkout the test branch
switch_branch "$test_current"
# Merge the updated maint branch into the test branch
merge_branch "$current" "$test_current"
fi
# Merge the previous branch into the target branch
# Merge Forward Example:
# merge maint-0.2.9 into maint-0.3.5.
# Test Branch Example:
# merge bug99999_029 into bug99999_035.
# Skip the merge if the previous branch does not exist
# (there's nothing to merge forward into the oldest test branch)
if [ "$target_previous" ]; then
merge_branch "$target_previous" "$target_current"
fi
done