send-emails.yml

name: Send emails for merged PR

on:
  push:
    branches:
      - "master"

jobs:
  send_patches:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repo with full history
        uses: actions/checkout@v5
        with:
          fetch-depth: 100

      - name: Install deps (git send-email and jq)
        run: |
          sudo apt-get update
          sudo apt-get install -y jq

          ## GHA images have a special git package that conflicts with
          ## git-send-email So this is a workaround to force the installation of
          ## the conflicting package.
          sudo apt-get install -y libauthen-sasl-perl \
            libemail-valid-perl \
            libio-socket-ssl-perl \
            libmailtools-perl perl \
            libnet-smtp-ssl-perl

          apt-get download git-email
          sudo dpkg -i --force-all git-email*deb

      - name: Configure git identity
        run: |
          git config user.name "gccrs gerris bot"
          git config user.email "${{ vars.SMTP_FROM }}"

      - name: Export env
        env:
          GH_EVENT: ${{ toJson(github.event) }}
        run: |
          # GH_EVENT can be very big as it contains the full commit log and
          # overflow the shell's maximum length.
          echo '$GH_EVENT' | envsubst '$GH_EVENT' > /tmp/gh_event.json

          BEFORE_REF=$(jq -r '.before' /tmp/gh_event.json)
          echo "BEFORE_REF=$BEFORE_REF" >> $GITHUB_ENV

          AFTER_REF=$(jq -r '.after' /tmp/gh_event.json)
          echo "AFTER_REF=$AFTER_REF" >> $GITHUB_ENV

          # PR_NUMBER=$(jq -r '.pull_request.number' /tmp/gh_event.json)
          # echo "PR_NUMBER=$PR_NUMBER" >> $GITHUB_ENV

          # PR_TITLE=$(jq -r '.pull_request.title' /tmp/gh_event.json)
          # echo "PR_TITLE=$PR_TITLE" >> $GITHUB_ENV

          # PR_URL=$(jq -r '.pull_request.html_url' /tmp/gh_event.json)
          # echo "PR_URL=$PR_URL" >> $GITHUB_ENV

          # PR_MERGE_COMMIT=$(jq -r '.pull_request.merge_commit_sha' /tmp/gh_event.json)
          # echo "PR_MERGE_COMMIT=$PR_MERGE_COMMIT" >> $GITHUB_ENV

          # PR_TARGET_BRANCH=$(jq -r '.pull_request.base.ref' /tmp/gh_event.json)
          # echo "PR_TARGET_BRANCH=$PR_TARGET_BRANCH" >> $GITHUB_ENV

          # PR_LABELS=$(jq -r '[.pull_request.labels[].name] | join(",")' /tmp/gh_event.json)
          # echo "PR_LABELS=$PR_LABELS" >> $GITHUB_ENV

          # REPO_SSH=$(jq -r '.repository.ssh_url' /tmp/gh_event.json)
          # echo "REPO_SSH=$REPO_SSH" >> $GITHUB_ENV

          echo "GH_TOKEN=${{ github.token }}" >> $GITHUB_ENV

          # echo "SERIES_DIR=/tmp/series" >> $GITHUB_ENV

      - name: Get commit list and skip the internal ones
        id: commits
        env:
          MAX_NUM_COMMITS: 30
          BEFORE_REF: ${{ github.event.before }}
          AFTER_REF: ${{ github.event.after }}
        run: |
          # Skip commits that touches any of these
          patterns=(".github/"
            "CODE_OF_CONDUCT.md"
            "CONTRIBUTING.md"
            "Dockerfile"
            "README.md"
            "logo.png"
            "gcc/rust/gource-gccrs.sh"
            "gcc/rust/monthly-diff.py"
          )
          regex=$(printf '%s\n' "${patterns[@]}" | sed -e 's/[.[\*^$+?(){|\/\\]/\\&/g' | paste -sd'|' -)

          rm -f /tmp/commits.txt

          if [ "$BEFORE_REF" = "0000000000000000000000000000000000000000" ] ; then
             echo "New branch created, not sending anything" | tee $GITHUB_STEP_SUMMARY
             echo "has_commits=false" >> $GITHUB_OUTPUT
             exit 0
          fi

          if [ "$AFTER_REF" = "0000000000000000000000000000000000000000" ] ; then
             echo "Branch is being deleted, not sending anything" | tee $GITHUB_STEP_SUMMARY
             echo "has_commits=false" >> $GITHUB_OUTPUT
             exit 0
          fi

          if git merge-base --is-ancestor "$BEFORE_REF" "$AFTER_REF"; then
            echo "fast-forward push (not forced)"
          else
            echo "non-fast-forward push (force push or history rewrite), not sending anything" | tee $GITHUB_STEP_SUMMARY
            echo "has_commits=false" >> $GITHUB_OUTPUT
            exit 0
          fi

          IS_MERGE=$(git show --pretty=%P -s HEAD | wc -w)
          if [ "$IS_MERGE" -gt 1 ] ; then
             echo "Last commit is a merge, don't send anything" | tee $GITHUB_STEP_SUMMARY
             echo "has_commits=false" >> $GITHUB_OUTPUT
             exit 0
          fi

          # Fetch commits from the pull request (maybe they're from another repository)
          #git fetch origin "pull/$PR_NUMBER/head"

          TOTAL=$(git log --oneline "$BEFORE_REF..$AFTER_REF" | wc -l)
          if [ "${TOTAL}" -gt "$MAX_NUM_COMMITS" ]; then
             echo "Push has too many commits" | tee $GITHUB_STEP_SUMMARY
             echo "has_commits=false" >> $GITHUB_OUTPUT
             exit 0
          fi

          git log --reverse --format=%H "$BEFORE_REF..$AFTER_REF" | while read SHA1; do
             echo "Looking at $SHA1"
             if grep -q -E "$regex" <(git diff-tree --no-commit-id --name-only -r "$SHA1"); then
                echo "Touching something not to be upstreamed, skipping commit $SHA1"
             else
                echo "Adding one commit to the send list"
                echo "$SHA1" >> /tmp/commits.txt
             fi
          done

          if [ ! -f /tmp/commits.txt ]; then
            echo "No commits to send email for" | tee $GITHUB_STEP_SUMMARY
            echo "has_commits=false" >> $GITHUB_OUTPUT
            exit 0
          fi

          COUNT=$(wc -l < /tmp/commits.txt)
          echo "Has $COUNT commits in the series"

          echo "has_commits=true" >> $GITHUB_OUTPUT

      - name: Check for label 'no-ml' to skip sending emails
        id: checklabel
        run: |
          # not sure how to do that with "push".
          echo "skip=false" >> $GITHUB_OUTPUT
          exit 0

          # Skip if PR has label "no-ml"
          # if echo "$PR_LABELS" | grep -qiE "(^|,)no-ml(,|$)"; then
          #   echo "Opt-out label present: skipping mailing list." | tee $GITHUB_STEP_SUMMARY
          #   echo "skip=true" >> $GITHUB_OUTPUT
          # else
          #   echo "No opt-out label found"
          #   echo "skip=false" >> $GITHUB_OUTPUT
          # fi

      - name: Decide if we're sending something or not
        id: send_emails
        if: ( steps.commits.outputs.has_commits == 'true' &&
          steps.checklabel.outputs.skip == 'false' )
        run: |
          echo "enabled=true" >> $GITHUB_OUTPUT

      - name: Prepare patch series
        if: steps.send_emails.outputs.enabled == 'true'
        run: |
          set -euo pipefail

          # Create a temporary branch that linearizes the PR commits
          git checkout -B ci-mail-patches "$BEFORE_REF"
          # Cherry-pick commits in the exact PR order (no-commit to batch, then commit)
          while read sha; do
            git cherry-pick "$sha"
          done < /tmp/commits.txt

          echo "This change was merged into the gccrs repository and is posted here for" >> /tmp/description.txt
          echo "upstream visibility and potential drive-by review, as requested by GCC" >>  /tmp/description.txt
          echo "release managers." >> /tmp/description.txt
          echo "Each commit email contains a link to its details on github from where you can"  >>  /tmp/description.txt
          echo "find the Pull-Request and associated discussions." >> /tmp/description.txt
          echo "" >> /tmp/description.txt

          mkdir /tmp/series

          # Generate series + cover letter
          git format-patch \
              --subject-prefix="gccrs COMMIT" \
              --no-cover-letter \
              --base="$BEFORE_REF" \
              --output-directory /tmp/series \
              "$BEFORE_REF"..HEAD

          echo "" >> /tmp/description.txt

          cp /tmp/commits.txt /tmp/commits_stack.txt
          while IFS= read -r -d '' f;do
             # Read next SHA1...
             SHA1=$(head -n1 /tmp/commits_stack.txt)

             # ... and pop it from the stack
             sed -i '1d' /tmp/commits_stack.txt

             echo "SHA1: $SHA1"
             echo "patch file: $f"
             echo ""

             cp /tmp/description.txt "/tmp/tmp_descr.txt"
             echo "Commit on github: https://github.com/${{ github.repository }}/commit/$SHA1" >> /tmp/tmp_descr.txt

             LINKED_ISSUES_LIST_FILE=/tmp/commit_linked_issues.txt

             ## find issue(s) referenced in commit message
             gccrs_ref_regex='Rust-GCC/gccrs#[0-9]+'
             git show -s --format=%B "$SHA1" | \
                grep -Eo "$gccrs_ref_regex" | \
                sort -u > "$LINKED_ISSUES_LIST_FILE"

             echo "Issues list: >>>"
             cat "$LINKED_ISSUES_LIST_FILE"
             echo "<<<"
             echo

             if [ -s "$LINKED_ISSUES_LIST_FILE" ]; then
               echo -e "\nThe commit has been mentioned in the following issue(s):" >> /tmp/tmp_descr.txt
               while read -r i; do
                 ISSUE_NUM=${i##*#}    # 1234
                 echo " - $i: https://github.com/Rust-GCC/gccrs/issues/${ISSUE_NUM}" >> /tmp/tmp_descr.txt
               done < "$LINKED_ISSUES_LIST_FILE"
             fi

             ## find corresponding pull-request(s)
             if gh api "repos/${{ github.repository }}/commits/$SHA1/pulls" | \
                  jq '.[].html_url' > /tmp/tmp_pr_links.txt;
             then
               if [ -s /tmp/tmp_pr_links.txt ]; then
                 echo -e "\nThe commit has been mentioned in the following pull-request(s):" >> /tmp/tmp_descr.txt

                 tr -d '"' < /tmp/tmp_pr_links.txt | \
                   sed 's/^/ - /'  >> /tmp/tmp_descr.txt
               else
                 echo "The commit is not linked to any pull-request" >> /tmp/tmp_descr.txt
               fi
             else
               echo "There was an error fetching data from github API for getting PR for commit" | tee -a "$GITHUB_STEP_SUMMARY"
             fi

             echo >> /tmp/tmp_descr.txt

             # insert the github header right after the '---'.
             sed '/^---$/ r /tmp/tmp_descr.txt' -i "$f"

             # loop over the patches and make sure to do that in numerical order
             # 0001-..., 0002-...., ...
          done < <(find /tmp/series/ -maxdepth 1 -type f -print0|sort -z -n)

      - name: Send series via git send-email
        if: steps.send_emails.outputs.enabled == 'true'
        env:
          GIT_SMTP_SERVER: ${{ vars.SMTP_SERVER }}
          GIT_SMTP_ENCRYPTION: tls
          GIT_SMTP_SERVER_PORT: ${{ vars.SMTP_PORT }}
          GIT_SMTP_AUTH: "true"
          GIT_SMTP_USER: ${{ vars.SMTP_USERNAME }}
          GIT_SMTP_PASSWORD: ${{ secrets.SMTP_PASSWORD }}
          FROM: ${{ vars.SMTP_FROM }}
          TO: ${{ vars.PATCH_TO }}
          CC: ${{ vars.PATCH_CC }}
        run: |
          set -euo pipefail

          git config sendemail.smtpserver "$GIT_SMTP_SERVER"
          git config sendemail.smtpserverport "$GIT_SMTP_SERVER_PORT"
          git config sendemail.smtpencryption "$GIT_SMTP_ENCRYPTION"
          git config sendemail.smtpuser "$GIT_SMTP_USER"
          git config sendemail.smtppass "$GIT_SMTP_PASSWORD"
          git config sendemail.from "$FROM"
          git config sendemail.to "$TO"
          if [ -n "${CC:-}" ]; then git config sendemail.cc "$CC"; fi
          git config sendemail.thread "true"
          git config sendemail.confirm "never"
          git config sendemail.annotate "false"

          git send-email /tmp/series/*