scripts/git/git-merge-forward.sh

   1 #!/usr/bin/env bash
   2
   3 SCRIPT_NAME=$(basename "$0")
   4
   5 function usage()
   6 {
   7   echo "$SCRIPT_NAME [-h] [-n] [-t <test-branch-prefix> [-u]]"
   8   echo
   9   echo "  arguments:"
  10   echo "   -h: show this help text"
  11   echo "   -n: dry run mode"
  12   echo "       (default: run commands)"
  13   echo "   -t: test branch mode: create new branches from the commits checked"
  14   echo "       out in each maint directory. Call these branches prefix_035,"
  15   echo "       prefix_040, ... , prefix_master."
  16   echo "       (default: merge forward maint-*, release-*, and master)"
  17   echo "   -u: in test branch mode, if a prefix_* branch already exists,"
  18   echo "       skip creating that branch. Use after a merge error, to"
  19   echo "       restart the merge forward at the first unmerged branch."
  20   echo "       (default: if a prefix_* branch already exists, fail and exit)"
  21   echo
  22   echo " env vars:"
  23   echo "   required:"
  24   echo "   TOR_FULL_GIT_PATH: where the git repository directories reside."
  25   echo "       You must set this env var, we recommend \$HOME/git/"
  26   echo "       (default: fail if this env var is not set;"
  27   echo "       current: $GIT_PATH)"
  28   echo
  29   echo "   optional:"
  30   echo "   TOR_MASTER: the name of the directory containing the tor.git clone"
  31   echo "       The tor master git directory is \$GIT_PATH/\$TOR_MASTER"
  32   echo "       (default: tor; current: $TOR_MASTER_NAME)"
  33   echo "   TOR_WKT_NAME: the name of the directory containing the tor"
  34   echo "       worktrees. The tor worktrees are:"
  35   echo "       \$GIT_PATH/\$TOR_WKT_NAME/{maint-*,release-*}"
  36   echo "       (default: tor-wkt; current: $TOR_WKT_NAME)"
  37   echo "   we recommend that you set these env vars in your ~/.profile"
  38 }
  39
  40 #################
  41 # Configuration #
  42 #################
  43
  44 # Don't change this configuration - set the env vars in your .profile
  45
  46 # Where are all those git repositories?
  47 GIT_PATH=${TOR_FULL_GIT_PATH:-"FULL_PATH_TO_GIT_REPOSITORY_DIRECTORY"}
  48 # The tor master git repository directory from which all the worktree have
  49 # been created.
  50 TOR_MASTER_NAME=${TOR_MASTER_NAME:-"tor"}
  51 # The worktrees location (directory).
  52 TOR_WKT_NAME=${TOR_WKT_NAME:-"tor-wkt"}
  53
  54 ##########################
  55 # Git branches to manage #
  56 ##########################
  57
  58 # The branches and worktrees need to be modified when there is a new branch,
  59 # and when an old branch is no longer supported.
  60
  61 # Configuration of the branches that needs merging. The values are in order:
  62 #   (0) current maint/release branch name
  63 #   (1) previous maint/release name to merge into (0)
  64 #         (only used in merge forward mode)
  65 #   (2) Full path of the git worktree
  66 #   (3) current branch suffix
  67 #         (maint branches only, only used in test branch mode)
  68 #   (4) previous test branch suffix to merge into (3)
  69 #         (maint branches only, only used in test branch mode)
  70 #
  71 # Merge forward example:
  72 #   $ cd <PATH/TO/WORKTREE> (2)
  73 #   $ git checkout maint-0.3.5 (0)
  74 #   $ git pull
  75 #   $ git merge maint-0.3.4 (1)
  76 #
  77 # Test branch example:
  78 #   $ cd <PATH/TO/WORKTREE> (2)
  79 #   $ git checkout -b ticket99999_035 (3)
  80 #   $ git checkout maint-0.3.5 (0)
  81 #   $ git pull
  82 #   $ git checkout ticket99999_035
  83 #   $ git merge maint-0.3.5
  84 #   $ git merge ticket99999_034 (4)
  85 #
  86 # First set of arrays are the maint-* branch and then the release-* branch.
  87 # New arrays need to be in the WORKTREE= array else they aren't considered.
  88 #
  89 # Only used in test branch mode
  90 # We create a test branch for the earliest maint branch.
  91 # But it's the earliest maint branch, so we don't merge forward into it.
  92 # Since we don't merge forward into it, the second and fifth items must be
  93 # blank ("").
  94
  95 # origin that will be used to fetch the updates. All the worktrees are created
  96 # from that repository.
  97 ORIGIN_PATH="$GIT_PATH/$TOR_MASTER_NAME"
  98
  99 #######################
 100 # Argument processing #
 101 #######################
 102
 103 # Controlled by the -n option. The dry run option will just output the command
 104 # that would have been executed for each worktree.
 105 DRY_RUN=0
 106
 107 # Controlled by the -t <test-branch-prefix> option. The test branch base
 108 # name option makes git-merge-forward.sh create new test branches:
 109 # <tbbn>_035, <tbbn>_040, ... , <tbbn>_master, and merge forward.
 110 TEST_BRANCH_PREFIX=
 111
 112 # Controlled by the -u option. The use existing option checks for existing
 113 # branches with the <test-branch-prefix>, and checks them out, rather than
 114 # creating a new branch.
 115 USE_EXISTING=0
 116
 117 while getopts "hnt:u" opt; do
 118   case "$opt" in
 119     h) usage
 120        exit 0
 121        ;;
 122     n) DRY_RUN=1
 123        echo "    *** DRY RUN MODE ***"
 124        ;;
 125     t) TEST_BRANCH_PREFIX="$OPTARG"
 126        echo "    *** CREATING TEST BRANCHES: ${TEST_BRANCH_PREFIX}_nnn ***"
 127        ;;
 128     u) USE_EXISTING=1
 129        echo "    *** USE EXISTING TEST BRANCHES MODE ***"
 130        ;;
 131     *)
 132        echo
 133        usage
 134        exit 1
 135        ;;
 136   esac
 137 done
 138
 139 ###########################
 140 # Git worktrees to manage #
 141 ###########################
 142
 143 set -e
 144 if [ -z "$TEST_BRANCH_PREFIX" ]; then
 145   # maint/release merge mode
 146   eval "$(git-list-tor-branches.sh -m)"
 147   # Remove first element: we don't merge forward into it.
 148   WORKTREE=( "${WORKTREE[@]:1}" )
 149 else
 150   eval "$(git-list-tor-branches.sh -m -R)"
 151 fi
 152 set +e
 153
 154 COUNT=${#WORKTREE[@]}
 155
 156 #############
 157 # Constants #
 158 #############
 159
 160 # Control characters
 161 CNRM=$'\x1b[0;0m'   # Clear color
 162
 163 # Bright color
 164 BGRN=$'\x1b[1;32m'
 165 BBLU=$'\x1b[1;34m'
 166 BRED=$'\x1b[1;31m'
 167 BYEL=$'\x1b[1;33m'
 168 IWTH=$'\x1b[3;37m'
 169
 170 # Strings for the pretty print.
 171 MARKER="${BBLU}[${BGRN}+${BBLU}]${CNRM}"
 172 SUCCESS="${BGRN}success${CNRM}"
 173 FAILED="${BRED}failed${CNRM}"
 174
 175 ####################
 176 # Helper functions #
 177 ####################
 178
 179 # Validate the given returned value (error code), print success or failed. The
 180 # second argument is the error output in case of failure, it is printed out.
 181 # On failure, this function exits.
 182 function validate_ret
 183 {
 184   if [ "$1" -eq 0 ]; then
 185     printf "%s\\n" "$SUCCESS"
 186   else
 187     printf "%s\\n" "$FAILED"
 188     printf "    %s" "$2"
 189     exit 1
 190   fi
 191 }
 192
 193 # Switch to the given branch name.
 194 function switch_branch
 195 {
 196   local cmd="git checkout '$1'"
 197   printf "  %s Switching branch to %s..." "$MARKER" "$1"
 198   if [ $DRY_RUN -eq 0 ]; then
 199     msg=$( eval "$cmd" 2>&1 )
 200     validate_ret $? "$msg"
 201   else
 202     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 203   fi
 204 }
 205
 206 # Checkout a new branch with the given branch name.
 207 function new_branch
 208 {
 209   local cmd="git checkout -b '$1'"
 210   printf "  %s Creating new branch %s..." "$MARKER" "$1"
 211   if [ $DRY_RUN -eq 0 ]; then
 212     msg=$( eval "$cmd" 2>&1 )
 213     validate_ret $? "$msg"
 214   else
 215     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 216   fi
 217 }
 218
 219 # Switch to an existing branch, or checkout a new branch with the given
 220 # branch name.
 221 function switch_or_new_branch
 222 {
 223   local cmd="git rev-parse --verify '$1'"
 224   if [ $DRY_RUN -eq 0 ]; then
 225     # Call switch_branch if there is a branch, or new_branch if there is not
 226     msg=$( eval "$cmd" 2>&1 )
 227     RET=$?
 228     if [ $RET -eq 0 ]; then
 229       # Branch: (commit id)
 230       switch_branch "$1"
 231     elif [ $RET -eq 128 ]; then
 232       # Not a branch: "fatal: Needed a single revision"
 233       new_branch "$1"
 234     else
 235       # Unexpected return value
 236       validate_ret $RET "$msg"
 237     fi
 238   else
 239     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}, then depending on the result:"
 240     switch_branch "$1"
 241     new_branch "$1"
 242   fi
 243 }
 244
 245 # Pull the given branch name.
 246 function pull_branch
 247 {
 248   local cmd="git pull"
 249   printf "  %s Pulling branch %s..." "$MARKER" "$1"
 250   if [ $DRY_RUN -eq 0 ]; then
 251     msg=$( eval "$cmd" 2>&1 )
 252     validate_ret $? "$msg"
 253   else
 254     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 255   fi
 256 }
 257
 258 # Merge the given branch name ($1) into the current branch ($2).
 259 function merge_branch
 260 {
 261   local cmd="git merge --no-edit '$1'"
 262   printf "  %s Merging branch %s into %s..." "$MARKER" "$1" "$2"
 263   if [ $DRY_RUN -eq 0 ]; then
 264     msg=$( eval "$cmd" 2>&1 )
 265     validate_ret $? "$msg"
 266   else
 267     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 268   fi
 269 }
 270
 271 # Merge origin/(branch name) into the current branch.
 272 function merge_branch_origin
 273 {
 274   local cmd="git merge --ff-only 'origin/$1'"
 275   printf "  %s Merging branch origin/%s..." "$MARKER" "$1"
 276   if [ $DRY_RUN -eq 0 ]; then
 277     msg=$( eval "$cmd" 2>&1 )
 278     validate_ret $? "$msg"
 279   else
 280     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 281   fi
 282 }
 283
 284 # Go into the worktree repository.
 285 function goto_repo
 286 {
 287   if [ ! -d "$1" ]; then
 288     echo "  $1: Not found. Stopping."
 289     exit 1
 290   fi
 291   cd "$1" || exit
 292 }
 293
 294 # Fetch the origin. No arguments.
 295 function fetch_origin
 296 {
 297   local cmd="git fetch origin"
 298   printf "  %s Fetching origin..." "$MARKER"
 299   if [ $DRY_RUN -eq 0 ]; then
 300     msg=$( eval "$cmd" 2>&1 )
 301     validate_ret $? "$msg"
 302   else
 303     printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
 304   fi
 305 }
 306
 307 ###############
 308 # Entry point #
 309 ###############
 310
 311 # First, fetch the origin.
 312 goto_repo "$ORIGIN_PATH"
 313 fetch_origin
 314
 315 # Go over all configured worktree.
 316 for ((i=0; i<COUNT; i++)); do
 317   current=${!WORKTREE[$i]:0:1}
 318   previous=${!WORKTREE[$i]:1:1}
 319   repo_path=${!WORKTREE[$i]:2:1}
 320   # default to merge forward mode
 321   test_current=
 322   test_previous=
 323   target_current="$current"
 324   target_previous="$previous"
 325   if [ "$TEST_BRANCH_PREFIX" ]; then
 326     test_current_suffix=${!WORKTREE[$i]:3:1}
 327     test_current=${TEST_BRANCH_PREFIX}${test_current_suffix}
 328     # the current test branch, if present, or maint/release branch, if not
 329     target_current="$test_current"
 330     test_previous_suffix=${!WORKTREE[$i]:4:1}
 331     if [ "$test_previous_suffix" ]; then
 332       test_previous=${TEST_BRANCH_PREFIX}${test_previous_suffix}
 333       # the previous test branch, if present, or maint/release branch, if not
 334       target_previous="$test_previous"
 335     fi
 336   fi
 337
 338   printf "%s Handling branch \\n" "$MARKER" "${BYEL}$target_current${CNRM}"
 339
 340   # Go into the worktree to start merging.
 341   goto_repo "$repo_path"
 342   if [ "$test_current" ]; then
 343     if [ $USE_EXISTING -eq 0 ]; then
 344       # Create a test branch from the currently checked-out branch/commit
 345       # Fail if it already exists
 346       new_branch "$test_current"
 347     else
 348       # Switch if it exists, or create if it does not
 349       switch_or_new_branch "$test_current"
 350     fi
 351   fi
 352   # Checkout the current maint/release branch
 353   switch_branch "$current"
 354   # Update the current maint/release branch with an origin merge to get the
 355   # latest updates
 356   merge_branch_origin "$current"
 357   if [ "$test_current" ]; then
 358     # Checkout the test branch
 359     switch_branch "$test_current"
 360     # Merge the updated maint branch into the test branch
 361     merge_branch "$current" "$test_current"
 362   fi
 363   # Merge the previous branch into the target branch
 364   # Merge Forward Example:
 365   #   merge maint-0.3.5 into maint-0.4.0.
 366   # Test Branch Example:
 367   #   merge bug99999_035 into bug99999_040.
 368   # Skip the merge if the previous branch does not exist
 369   # (there's nothing to merge forward into the oldest test branch)
 370   if [ "$target_previous" ]; then
 371     merge_branch "$target_previous" "$target_current"
 372   fi
 373 done