[dpdk-dev] [PATCH] checkpatches.sh: Add checks for ABI symbol addition

[Neil Horman <nhorman@tuxdriver.com>]

Recently, some additional patches were added to allow for programmatic
marking of C symbols as experimental.  The addition of these markers is
dependent on the manual addition of exported symbols to the EXPERIMENTAL
section of the corresponding libraries version map file.  The consensus
on review is that, in addition to mandating the addition of symbols to
the EXPERIMENTAL version in the map, we need a mechanism to enforce our
documented process of mandating that addition when they are introduced.
To that end, I am proposing this change.  It is an addition to the
checkpatches script, which scan incoming patches for additions and
removals of symbols to the map file, and warns the user appropriately

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: thomas@monjalon.net
CC: john.mcnamara@intel.com
CC: bruce.richardson@intel.com
CC: Ferruh Yigit <ferruh.yigit@intel.com>
---
 devtools/checkpatches.sh | 89 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index 7676a6b50..d0e2120fe 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh
@@ -61,6 +61,77 @@ print_usage () {
 	END_OF_HELP
 }
 
+build_map_changes()
+{
+	local fname=$1
+	local mapdb=$2
+
+	cat $fname | filterdiff -i *.map | awk '
+		BEGIN {map="";sym="";ar="";sec=""; in_sec=0}
+		/[-+] a\/.*\.map/ {map=$2}
+		/+.*{/ {gsub("+","");sec=$1; in_sec=1}
+		/.*}/ {in_sec=0}
+		/^+.*[^:*];/ {gsub(";","");sym=$2;
+			if (in_sec == 1) {
+				print map " " sym " " sec " add"
+			}
+		}
+		/^-.*[^:*];/ {gsub(";","");sym=$2;
+			if (in_sec == 1) {
+				print map " " sym " " sec " del"
+			}
+		}' > ./$mapdb
+
+		sort $mapdb | uniq > ./$mapdb.2
+		mv -f $mapdb.2 $mapdb
+
+}
+
+check_for_rule_violations()
+{
+	local mapdb=$1
+	local mname
+	local symname
+	local secname
+	local ar
+
+	cat $mapdb | while read mname symname secname ar
+	do
+		if [ "$ar" == "add" -a "$secname" != "EXPERIMENTAL" ]
+		then
+			# Symbols that are getting added in a section other
+			# Than the experimental section need to be moving
+			# from an already supported section or its a violation
+			grep -q "$mname $symname [^EXPERIMENTAL] del" $mapdb
+			if [ $? -ne 0 ]
+			then
+				echo "ERROR: symbol $symname is added in a section other than the EXPERIMENTAL section of the version map"
+			fi
+		fi
+
+		if [ "$ar" == "del" -a "$secname" != "EXPERIMENTAL" ]
+		then
+			# Just inform users that non-experimenal symbols need
+			# to go through a deprecation process
+			echo "INFO: symbol $symname is being removed, ensure that it has gone through the deprecation process"
+		fi
+
+	done
+}
+
+validate_api_changes()
+{
+	mapfile=`mktemp mapdb.XXXXXX`
+	patch=$1
+
+	build_map_changes $patch $mapfile
+	result=$(check_for_rule_violations $mapfile)
+
+	rm -f $mapfile
+
+	echo $result
+}
+
 number=0
 quiet=false
 verbose=false
@@ -96,9 +167,25 @@ check () { # <patch> <commit> <title>
 	else
 		report=$($DPDK_CHECKPATCH_PATH $options - 2>/dev/null)
 	fi
-	[ $? -ne 0 ] || return 0
+	reta=$?
+
 	$verbose || printf '\n### %s\n\n' "$3"
 	printf '%s\n' "$report" | sed -n '1,/^total:.*lines checked$/p'
+
+	echo
+	echo "Checking API additions/removals:"
+	if [ -n "$1" ] ; then
+		report=$(validate_api_changes $1)
+	elif [ -n "$2" ] ; then
+		report=$(git format-patch \
+			 --find-renames --no-stat --stdout -1 $commit |
+			validate_api_changes /dev/stdin)
+	else
+		report=$(validate_api_changes /dev/stdin)
+	fi
+	[ $? -ne 0 -o $reta -ne 0 ] || return 0
+	printf '%s\n' "$report" | sed -n '1,/^total:.*lines checked$/p'
+
 	status=$(($status + 1))
 }
 
-- 
2.14.3