[PATCH v2] scripts: check headline of drivers commits

[Thomas Monjalon <thomas.monjalon@6wind.com>]

From: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

A driver patch under net should start with "net/<driver name>" or if
a patch touch multiple drivers, it should only start with "net:".
The same apply for crypto.
A patch touching all drivers (net + crypto) should start with "drivers:".

Longer prefixes like "net/mlx:" (for mlx4/mlx5) or "net/e1000/base:" are
handled by not checking the colon.

The directories doc/ and config/ are ignored because a driver patch
can modify them.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
v2:
- fix capture in bad variable
- ignore doc/ and config/
---
 scripts/check-git-log.sh | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/scripts/check-git-log.sh b/scripts/check-git-log.sh
index 833aa39..21f1055 100755
--- a/scripts/check-git-log.sh
+++ b/scripts/check-git-log.sh
@@ -70,6 +70,24 @@ bad=$(echo "$headlines" | grep --color=always \
 	| sed 's,^,\t,')
 [ -z "$bad" ] || printf "Wrong headline format:\n$bad\n"
 
+# check headline prefix when touching only drivers, e.g. net/<driver name>
+bad=$(for commit in $commits ; do
+	headline=$(git log --format='%s' -1 $commit)
+	files=$(git diff-tree --no-commit-id --name-only -r $commit)
+	[ -z "$(echo "$files" | grep -v '^\(drivers\|doc\|config\)/')" ] ||
+		continue
+	drv=$(echo "$files" | grep '^drivers/' | cut -d "/" -f 2,3 | sort -u)
+	drvgrp=$(echo "$drv" | cut -d "/" -f 1 | uniq)
+	if [ $(echo "$drvgrp" | wc -l) -gt 1 ] ; then
+		echo "$headline" | grep -v '^drivers:'
+	elif [ $(echo "$drv" | wc -l) -gt 1 ] ; then
+		echo "$headline" | grep -v "^$drvgrp"
+	else
+		echo "$headline" | grep -v "^$drv"
+	fi
+done | sed 's,^,\t,')
+[ -z "$bad" ] || printf "Wrong headline prefix:\n$bad\n"
+
 # check headline label for common typos
 bad=$(echo "$headlines" | grep --color=always \
 	-e '^example[:/]' \
-- 
2.7.0