round-robin.sh: Always generate email reports, not just for regressions

... and gracefully handle builds with multiple updated components and
multiple new commits.

Change-Id: I6c0126fe6403a7f6ea34072cb3e84582634a3463

2 files changed, 96 insertions, 45 deletions

diff --git a/round-robin-bisect.sh b/round-robin-bisect.sh
index 31119420..e762f86d 100755
--- a/round-robin-bisect.sh
+++ b/round-robin-bisect.sh
@@ -792,8 +792,9 @@ $(git -C $current_project show --stat --patch $first_bad | head -n 1000)
 </cut>
 EOF
 
-    cp $artifacts/build-$first_bad/mail/mail-subject.txt \
-       $artifacts/jenkins/mail-subject.draft
+    cat > $artifacts/jenkins/mail-subject.draft <<EOF
+[TCWG CI] $(cat $artifacts/build-$first_bad/mail/mail-subject.txt)
+EOF
 
     # Set mail recipients last to preserve catch-error value from .yaml file.
     # Email developers.
diff --git a/round-robin.sh b/round-robin.sh
index a769abc6..705aeb23 100644
--- a/round-robin.sh
+++ b/round-robin.sh
@@ -737,9 +737,102 @@ check_regression ()
 	rm -rf $run_step_artifacts/top-artifacts
     fi
 
+    # Generate default notification templates
+    if ! [ -f $run_step_artifacts/mail-subject.txt ]; then
+	if [ $res != 0 ]; then
+	cat <<EOF
+Regression after \$COMMIT_COMPONENT: \$COMMIT_SUBJECT
+EOF
+	else
+	cat <<EOF
+Successful build after \$COMMIT_COMPONENT: \$COMMIT_SUBJECT
+EOF
+	fi > $run_step_artifacts/mail-subject.txt
+    fi
+
+    if ! [ -f $run_step_artifacts/jira-body.txt ]; then
+	cat > $run_step_artifacts/jira-body.txt <<EOF
+$(cat $run_step_artifacts/mail-subject.txt):
+\$COMMIT_LOG
+EOF
+    fi
+
+    if ! [ -f $run_step_artifacts/mail-body.txt ]; then
+	cat > $run_step_artifacts/mail-body.txt <<EOF
+$(cat $run_step_artifacts/jira-body.txt)
+
+Results changed to
+$(cat ${rr[top_artifacts]}/results)
+
+from
+$(cat base-artifacts/results)
+EOF
+    fi
+
     local -a changed_components
     IFS=" " read -r -a changed_components <<< "$(print_changed_components)"
 
+    local single_commit_p=false
+    if [ ${#changed_components[@]} = 1 ]; then
+	local c base_rev cur_rev sha1
+	c=${changed_components[0]}
+	base_rev=$(get_baseline_git ${c}_rev)
+	cur_rev=$(get_current_git ${c}_rev)
+	for sha1 in $(git -C $c rev-parse $cur_rev^@); do
+	    if [ x"$sha1" = x"$base_rev" ]; then
+		# We have a single-commit build
+		single_commit_p=true
+		break
+	    fi
+	done
+    fi
+
+    # Generate text for COMMIT_* variables._
+    (
+	local new_commits=0 c base_rev cur_rev c_commits
+
+	if [ ${#changed_components[@]} = 0 ]; then
+	    COMMIT_COMPONENT="baseline build"
+	    COMMIT_SUBJECT="no new commits"
+	    COMMIT_LOG=""
+	elif $single_commit_p; then
+	    c=${changed_components[0]}
+	    base_rev=$(get_baseline_git ${c}_rev)
+	    cur_rev=$(get_current_git ${c}_rev)
+	    COMMIT_COMPONENT=$c
+	    COMMIT_SUBJECT=$(git -C $c log --pretty=%s -n1 $cur_rev)
+	    COMMIT_LOG=$(git -C $c log --pretty=short -n1 $cur_rev)
+	else
+	    COMMIT_COMPONENT=$(print_changed_components "/")
+	    COMMIT_LOG=""
+	    for c in "${changed_components[@]}"; do
+		base_rev=$(get_baseline_git ${c}_rev)
+		cur_rev=$(get_current_git ${c}_rev)
+		c_commits=$(git -C $c rev-list --count $base_rev..$cur_rev)
+		new_commits=$(($new_commits + $c_commits))
+
+		COMMIT_LOG="$COMMIT_LOG
+$(git -C $c log --pretty=oneline $base_rev..$cur_rev | head -n5 || true)"
+		if [ $c_commits -gt 5 ]; then
+		    COMMIT_LOG="$COMMIT_LOG
+... and $(($c_commits - 5)) more $c commits"
+		fi
+	    done
+
+	    COMMIT_SUBJECT="$new_commits commits"
+	fi
+
+	export COMMIT_COMPONENT COMMIT_SUBJECT COMMIT_LOG
+
+	local mail_dir=${rr[top_artifacts]}/mail
+	mkdir -p $mail_dir
+
+	for i in mail-subject.txt jira-body.txt mail-body.txt; do
+	    envsubst '$COMMIT_COMPONENT $COMMIT_SUBJECT $COMMIT_LOG' \
+		     < $run_step_artifacts/$i > $mail_dir/$i
+	done
+    )
+
     if [ $res = 0 ]; then
 	# All good, no regression
 	return
@@ -818,49 +911,6 @@ EOF
 	fi
     fi
 
-    if [ x"$single_component" != x"" ] && ! [ $score -lt 0 ] 2>/dev/null; then
-	local mail_dir=${rr[top_artifacts]}/mail
-	mkdir -p $mail_dir
-
-	if ! [ -f $run_step_artifacts/mail-subject.txt ]; then
-	    cat > $run_step_artifacts/mail-subject.txt <<EOF
-[TCWG CI] Regression caused by \$COMMIT_COMPONENT: \$COMMIT_SUBJECT
-EOF
-	fi
-
-	if ! [ -f $run_step_artifacts/jira-body.txt ]; then
-	    cat > $run_step_artifacts/jira-body.txt <<EOF
-$(cat $run_step_artifacts/mail-subject.txt):
-\$COMMIT_LOG
-EOF
-	fi
-
-	if ! [ -f $run_step_artifacts/mail-body.txt ]; then
-	    cat > $run_step_artifacts/mail-body.txt <<EOF
-$(cat $run_step_artifacts/jira-body.txt)
-
-Results regressed to
-$(cat ${rr[top_artifacts]}/results)
-
-from
-$(cat base-artifacts/results)
-EOF
-	fi
-
-	(
-	    COMMIT_COMPONENT=$single_component
-	    export COMMIT_COMPONENT
-	    COMMIT_SUBJECT=$(git -C $single_component log --pretty=%s -n 1 HEAD)
-	    export COMMIT_SUBJECT
-	    COMMIT_LOG=$(git -C $single_component log --pretty=short -n 1 HEAD)
-	    export COMMIT_LOG
-	    for i in mail-subject.txt jira-body.txt mail-body.txt; do
-		envsubst '$COMMIT_COMPONENT $COMMIT_SUBJECT $COMMIT_LOG' \
-			 < $run_step_artifacts/$i > $mail_dir/$i
-	    done
-	)
-    fi
-
     if [ x"${rr[update_baseline]}" != x"force" ]; then
 	echo "Detected a regression!"
 	false