diff options
| -rw-r--r-- | ops/pipelines/static-pipeline.yaml | 5 | ||||
| -rw-r--r-- | tools/depot-deps.nix | 1 | ||||
| -rw-r--r-- | tools/git-r.nix | 138 |
3 files changed, 144 insertions, 0 deletions
diff --git a/ops/pipelines/static-pipeline.yaml b/ops/pipelines/static-pipeline.yaml index 46b41480ed58..af4f9d784e60 100644 --- a/ops/pipelines/static-pipeline.yaml +++ b/ops/pipelines/static-pipeline.yaml @@ -35,6 +35,11 @@ steps: # # Revision numbers are defined as the number of commits in the # lineage of HEAD, following only the first parent of merges. + # + # Note that git does not fetch these refs by default, instead + # you'll have to modify your git config using + # `git config --add remote.origin.fetch '+refs/r/*:refs/r/*'`. + # The refs are available after the next `git fetch`. - label: ":git:" branches: "refs/heads/canon" command: | diff --git a/tools/depot-deps.nix b/tools/depot-deps.nix index 60af9f1378c5..480b8c2f7c34 100644 --- a/tools/depot-deps.nix +++ b/tools/depot-deps.nix @@ -7,6 +7,7 @@ depot.nix.lazy-deps { age.attr = "third_party.nixpkgs.age"; depotfmt.attr = "tools.depotfmt"; fetch-depot-inbox.attr = "tools.fetch-depot-inbox"; + git-r.attr = "tools.git-r"; gerrit-update.attr = "tools.gerrit-update"; gerrit.attr = "tools.gerrit-cli"; hash-password.attr = "tools.hash-password"; diff --git a/tools/git-r.nix b/tools/git-r.nix new file mode 100644 index 000000000000..dbda330082a3 --- /dev/null +++ b/tools/git-r.nix @@ -0,0 +1,138 @@ +# Git subcommand loaded into the depot direnv via //tools/depot-deps that can +# display the r/number for (a) given commit(s) in depot. The r/number is a +# monotonically increasing number assigned to each commit which correspond to +# refs/r/* as created by `//ops/pipelines/static-pipeline.yaml`. They can also +# be used as TVL shortlinks and are supported by //web/atward. +{ pkgs, lib, ... }: + +pkgs.writeTextFile { + name = "git-r"; + destination = "/bin/git-r"; + executable = true; + text = '' + set -euo pipefail + + PROG_NAME="$0" + + CANON_BRANCH="canon" + CANON_REMOTE="$(git config "branch.$CANON_BRANCH.remote" || echo "origin")" + CANON_HEAD="$CANON_REMOTE/$CANON_BRANCH" + + usage() { + cat <<EOF + Usage: git r [-h | --usage] [<git commit> ...] + + Display the r/number for the given git commit(s). If none is given, + HEAD is used as a default. The r/number is a monotonically increasing + number assigned to each commit on the $CANON_BRANCH branch in depot + equivalent to the revcount ignoring merged in branches (using + git-rev-list(1) internally). + + The r/numbers displayed by \`git r\` correspond to refs created by CI + in depot, so they can be used as monotonically increasing commit + identifiers that can be used instead of a commit hash. To have + \`refs/r/*\` available locally (which is not necessary for the operation + of \`git r\`), you may have to enable fetching them like this: + + git config --add remote.origin.fetch '+refs/r/*:refs/r/*' + + They are created the next time you run `git fetch origin`. + + EOF + exit "''${1:-0}" + } + + eprintf() { + printf "$@" 1>&2 + } + + revs=() + + if [[ $# -le 0 ]]; then + revs+=("HEAD") + fi + + for arg in "$@"; do + # No flags supported at the moment + case "$arg" in + # --help is mapped to `man git-r` by git(1) + # TODO(sterni): git-r man page + -h | --usage) + usage + ;; + -*) + eprintf 'error: unknown flag %s\n' "$PROG_NAME" "$arg" + usage 100 1>&2 + ;; + *) + revs+=("$arg") + ;; + esac + done + + for rev in "''${revs[@]}"; do + # Make sure $rev is well formed + git rev-parse "$rev" -- > /dev/null + + if git merge-base --is-ancestor "$rev" "$CANON_HEAD"; then + printf 'r/' + git rev-list --count --first-parent "$rev" + else + eprintf 'error: refusing to calculate r/number: %s is not an ancestor of %s\n' \ + "$rev" "$CANON_HEAD" 1>&2 + exit 100 + fi + done + ''; + + # Test case, assumes that it is executed in a checkout of depot + meta.ci.extraSteps.matches-refs = { + needsOutput = true; + label = "Verify `git r` output matches refs/r/*"; + command = pkgs.writeShellScript "git-r-matches-refs" '' + set -euo pipefail + + export PATH="${lib.makeBinPath [ pkgs.git pkgs.findutils ]}" + revs=("origin/canon" "origin/canon~1" "93a746aaaa092ffc3e7eb37e1df30bfd3a28435f") + + failed=false + + # assert_eq DESCRIPTION EXPECTED GIVEN + assert_eq() { + desc="$1" + exp="$2" + given="$3" + + if [[ "$exp" != "$given" ]]; then + failed=true + printf 'error: case "%s" failed\n\texp:\t%s\n\tgot:\t%s\n' "$desc" "$exp" "$given" 1>&2 + fi + } + + git fetch origin '+refs/r/*:refs/r/*' + + for rev in "''${revs[@]}"; do + assert_eq \ + "r/number ref for $rev points at that rev" \ + "$(git rev-parse "$rev")" \ + "$(git rev-parse "$(./result/bin/git-r "$rev")")" + done + + for rev in "''${revs[@]}"; do + assert_eq \ + "r/number for matches ref pointing at $rev" \ + "$(git for-each-ref --points-at="$rev" --format="%(refname:short)" 'refs/r/*')" \ + "$(./result/bin/git-r "$rev")" + done + + assert_eq \ + "Passing multiple revs to git r works as expected" \ + "$(git rev-parse "''${revs[@]}")" \ + "$(./result/bin/git-r "''${revs[@]}" | xargs git rev-parse)" + + if $failed; then + exit 1 + fi + ''; + }; +} |