Bug 1816164 - pt2 - add new build_no_op_commits.sh r=ng DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D170266

dom/media/webrtc/third_party_build/build_no_op_commits.sh

+#!/bin/bash
+
+function show_error_msg()
+{
+  echo "*** ERROR *** $? line $1 $0 did not complete successfully!"
+  echo "$ERROR_HELP"
+}
+ERROR_HELP=""
+
+# Print an Error message if `set -eE` causes the script to exit due to a failed command
+trap 'show_error_msg $LINENO' ERR
+
+source dom/media/webrtc/third_party_build/use_config_env.sh
+
+echo "MOZ_LIBWEBRTC_SRC: $MOZ_LIBWEBRTC_SRC"
+echo "MOZ_PRIOR_LIBWEBRTC_BRANCH: $MOZ_PRIOR_LIBWEBRTC_BRANCH"
+
+# After this point:
+# * eE: All commands should succeed.
+# * u: All variables should be defined before use.
+# * o pipefail: All stages of all pipes should succeed.
+set -eEuo pipefail
+
+# wipe no-op commit tracking files for new run
+rm -f $STATE_DIR/*.no-op-cherry-pick-msg
+
+CURRENT_DIR=`pwd`
+cd $MOZ_LIBWEBRTC_SRC
+
+MANUAL_INTERVENTION_COMMIT_FILE="$TMP_DIR/manual_commits.txt"
+rm -f $MANUAL_INTERVENTION_COMMIT_FILE
+
+# Find the common commit between our previous work branch and trunk
+CURRENT_RELEASE_BASE=`git merge-base $MOZ_PRIOR_LIBWEBRTC_BRANCH master`
+
+# Write no-op files for the cherry-picked release branch commits.  For more
+# details on what this is doing, see make_upstream_revert_noop.sh.
+COMMITS=`git log -r $CURRENT_RELEASE_BASE..branch-heads/$MOZ_PRIOR_UPSTREAM_BRANCH_HEAD_NUM --format='%h'`
+for commit in $COMMITS; do
+
+  echo "Processing release branch commit $commit for no-op handling"
+
+  # Don't process the commit if the commit message is missing the customary
+  # line that shows which upstream commit is being cherry-picked.
+  CNT=`git show $commit | grep "cherry picked from commit" | wc -l | tr -d " " || true`
+  if [ $CNT != 1 ]; then
+    # record the commit to list at the end of this script as
+    # 'needing intervention'
+    echo "    no cherry-pick info found, skipping commit $commit"
+    echo "$commit" >> $MANUAL_INTERVENTION_COMMIT_FILE
+    continue
+  fi
+
+  CHERRY_PICK_COMMIT=`git show $commit | grep "cherry picked from commit" | tr -d "()" | awk '{ print $5; }'`
+  SHORT_SHA=`git show --name-only $CHERRY_PICK_COMMIT --format='%h' | head -1`
+  echo "    commit $commit cherry-picks $SHORT_SHA"
+
+  echo "We already cherry-picked this when we vendored $commit." \
+  > $STATE_DIR/$SHORT_SHA.no-op-cherry-pick-msg
+
+done
+
+# This section checks for commits that may have been cherry-picked in more
+# than one release branch.
+TARGET_RELEASE_BASE=`git merge-base $MOZ_TARGET_UPSTREAM_BRANCH_HEAD master`
+NEW_COMMITS=`git log -r $TARGET_RELEASE_BASE..$MOZ_TARGET_UPSTREAM_BRANCH_HEAD --format='%h'`
+
+# Convert the files that we've already generated for no-op detection into
+# something that we can use as a regular expression for searching.
+KNOWN_NO_OP_COMMITS=`cd $STATE_DIR ; \
+  ls *.no-op-cherry-pick-msg \
+  | sed 's/\.no-op-cherry-pick-msg//' \
+  | paste -sd '|' /dev/stdin`
+
+for commit in $NEW_COMMITS; do
+
+  echo "Processing next release branch commit $commit for no-op handling"
+
+  # Don't process the commit if the commit message is missing the customary
+  # line that shows which upstream commit is being cherry-picked.
+  CNT=`git show $commit | grep "cherry picked from commit" | wc -l | tr -d " " || true`
+  if [ $CNT != 1 ]; then
+    # record the commit to list at the end of this script as
+    # 'needing intervention'
+    echo "    no cherry-pick info found, skipping commit $commit"
+    echo "$commit" >> $MANUAL_INTERVENTION_COMMIT_FILE
+    continue
+  fi
+
+  CHERRY_PICK_COMMIT=`git show $commit | grep "cherry picked from commit" | tr -d "()" | awk '{ print $5; }'`
+  SHORT_SHA=`git show --name-only $CHERRY_PICK_COMMIT --format='%h' | head -1`
+  echo "    commit $commit cherry-picks $SHORT_SHA"
+
+  # The trick here is that we only want to include no-op processing for the
+  # commits that appear both here _and_ in the previous release's cherry-pick
+  # commits.  We check the known list of no-op commits to see if it was
+  # cherry picked in the previous release branch and then create another
+  # file for the new release branch commit that will ultimately be a no-op.
+  if [[ "$SHORT_SHA" =~ ^($KNOWN_NO_OP_COMMITS)$ ]]; then
+    cp $STATE_DIR/$SHORT_SHA.no-op-cherry-pick-msg $STATE_DIR/$commit.no-op-cherry-pick-msg
+  fi
+
+done
+
+if [ ! -f $MANUAL_INTERVENTION_COMMIT_FILE ]; then
+  echo "we have no commits needing manual intervention"
+  exit
+fi
+
+echo $"
+Each of the following commits requires manual intervention to
+verify the source of the cherry-pick or there may be errors
+reported during the fast-forward processing.  Without this
+intervention, the common symptom is that the vendored commit
+file count (0) will not match the upstream commit file count.
+"
+
+for commit in `cat $MANUAL_INTERVENTION_COMMIT_FILE`; do
+  SUMMARY=`git show --oneline --name-only $commit | head -1`
+  echo "  '$SUMMARY'"
+done
+
+echo $"
+To manually create the no-op tracking files needed,
+run the following command for each commit in question:
+  ( export UPSTREAM_COMMIT=\"{sha-of-upstream-commit}\" ; \\
+    export PICKED_COMMIT=\"{sha-of-already-used-commit}\" ; \\
+    echo \"We already cherry-picked this when we vendored \$PICKED_COMMIT.\" \\
+    > $STATE_DIR/\$UPSTREAM_COMMIT.no-op-cherry-pick-msg )
+"