llvm/utils/git/sync-release-repo.sh

   1 #!/bin/bash
   2
   3 # This script will sync github.com/llvm/llvm-project with
   4 # github.com/llvm/llvm-project-release-prs and try to merge
   5 # the changes in the release branch.
   6
   7 set -e
   8 set -x
   9
  10 # We should always get the branch from the environment.
  11 # But otherwise just default to something. We can probably
  12 # have a better default here?
  13 RELEASE_BRANCH="${RELEASE_BRANCH:-release/16.x}"
  14
  15 # We will add two remotes here:
  16 #  main - which will point to the main llvm-project repo
  17 #  release - which will point to the release-prs repo
  18 # The remotes will use random strings to avoid
  19 # collisions
  20 MAIN_REMOTE=$(uuidgen)
  21 RELEASE_REMOTE=$(uuidgen)
  22 CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
  23 # depth here must make sure to fetch enough history to make a merge,
  24 # it's an arbritary value at this point. Consider using --shallow-since=
  25 FETCH_OPTIONS="--prune --no-tags --progress --depth=100"
  26
  27 git remote add $MAIN_REMOTE "https://github.com/llvm/llvm-project"
  28 git remote add $RELEASE_REMOTE "https://token:$GH_TOKEN@github.com/llvm/llvm-project-release-prs"
  29
  30 # Make sure we are up to date on all our repos first
  31 git fetch $FETCH_OPTIONS $MAIN_REMOTE $RELEASE_BRANCH
  32 git fetch $FETCH_OPTIONS $RELEASE_REMOTE $RELEASE_BRANCH
  33
  34 # Create our sync branch. Starting with the main
  35 # repo first since it's important to get those
  36 # changes
  37 MERGE_BRANCH=$(uuidgen)
  38 git switch -c $MERGE_BRANCH $MAIN_REMOTE/$RELEASE_BRANCH
  39
  40 # Merge changes from the release repo
  41 git merge --ff-only $RELEASE_REMOTE/$RELEASE_BRANCH
  42
  43 if ! git diff-index --quiet $MAIN_REMOTE/$RELEASE_BRANCH; then
  44   echo "Changes in the release remote - pushing to main remote"
  45   git push $MAIN_REMOTE $MERGE_BRANCH:$RELEASE_BRANCH
  46 fi
  47
  48 # Before we merge back into the release repo
  49 # let's update to make sure nothing has been
  50 # pushed to either repo while we do this work.
  51 # Most of the time this won't do anything, and
  52 # the real solution would instead be to fetch
  53 # in a loop if pushing fails. But that's a very
  54 # tiny edge-case, so let's not complicate this.
  55 git fetch $FETCH_OPTIONS $MAIN_REMOTE $RELEASE_BRANCH
  56 git fetch $FETCH_OPTIONS $RELEASE_REMOTE $RELEASE_BRANCH
  57
  58 # And merge all the new data to the current branch
  59 git merge --ff-only $MAIN_REMOTE/$RELEASE_BRANCH
  60
  61 # If anything changed let's merge it
  62 if ! git diff-index --quiet $RELEASE_REMOTE/$RELEASE_BRANCH; then
  63   echo "Changes in main - pushing to release"
  64   # Remove the token stored by GH Actions, otherwise it
  65   # won't use our own token in $GH_TOKEN
  66   git config --unset-all http.https://github.com/.extraheader
  67   git push $RELEASE_REMOTE $MERGE_BRANCH:$RELEASE_BRANCH
  68 fi
  69
  70 # Cleanup - enable for debug
  71 if false; then
  72   git remote remove $RELEASE_REMOTE
  73   git remote remove $MAIN_REMOTE
  74
  75   git switch $CURRENT_BRANCH
  76   git branch -D $MERGE_BRANCH
  77 fi