[PATCH v11] devtools: alert on new instances of rte_panic and rte_exit

[Arnon Warshavsky <arnon@qwilt.com>]

This patch adds a new function that is called
per every checked patch,
and alerts for new instances of rte_panic/rte_exit.
The check excludes comments, and alerts in the case
of a positive balance between additions and removals.

Signed-off-by: Arnon Warshavsky <arnon@qwilt.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
---

v11 
- Use Neils tmpfile infrastructure to consume the patches
- Allow different calls to the awk script decide if they want
  to fail the check or just warn

 devtools/checkpatches.sh | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index 1439bce..22832ef 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh
@@ -43,6 +43,94 @@ print_usage () {
 	END_OF_HELP
 }
 
+
+check_forbidden_additions() { # <file>
+    # ---------------------------------
+    #This awk script receives a list of expressions to monitor
+    #and a list of folders to search these expressions in
+    # - No search is done inside comments
+    # - Both additions and removals of the expressions are checked
+    #   A positive balance of additions fails the check
+	read -d '' awk_script << 'EOF'
+	BEGIN{
+		split(FOLDERS,deny_folders," ");
+		split(EXPRESSIONS,deny_expr," ");
+		in_file=0;
+		in_comment=0;
+		count=0;
+		comment_start="/*"
+		comment_end="*/"
+	}
+	# search for add/remove instances in current file
+	# state machine assumes the comments structure is enforced by
+	# checkpatches.pl
+	(in_file) {
+		# comment start
+		if (index($0,comment_start) > 0){
+			in_comment = 1
+		}
+		# non comment code
+		if (in_comment == 0) {
+			for (i in deny_expr) {
+				forbidden_added = "^\+.*" deny_expr[i];
+				forbidden_removed="^-.*" deny_expr[i];
+				current = expressions[deny_expr[i]]
+				if ($0 ~ forbidden_added) {
+					count = count + 1;
+					expressions[deny_expr[i]] = current + 1
+				}
+				if ($0 ~ forbidden_removed) {
+					count = count - 1;
+					expressions[deny_expr[i]] = current - 1
+				}
+			}
+		}
+
+		# comment end
+		if (index($0,comment_end) > 0)  {
+			in_comment = 0
+		}
+	}
+	# switch to next file , check if the balance of add/remove
+	# of previous filehad new additions
+	($0 ~ "^\+\+\+ b/") {
+		in_file = 0;
+		if (count > 0){
+			exit;
+		}
+		for (i in deny_folders){
+			re = "^\+\+\+ b/" deny_folders[i];
+			if ($0 ~ deny_folders[i]) {
+				in_file = 1
+				last_file = $0
+			}
+		}
+	}
+	END{
+		if (count > 0){
+			warnText = "\\033[1;31m" "Warning:" "\\033[0m"
+			print warnText " in " substr(last_file,6) ":"
+			print "are you sure you want to add the following:"
+			for (key in expressions) {
+				if (expressions[key] > 0) {
+					print key
+				}
+			}
+			exit RET_ON_FAIL
+		}
+	}
+EOF
+	# ---------------------------------
+
+	# refrain from new additions of rte_panic() and rte_exit()
+	# under lib and net
+	# multiple folders and expressions are separated by spaces
+	awk -v FOLDERS="lib net" \
+		-v EXPRESSIONS="rte_panic\\\( rte_exit\\\(" \
+		-v RET_ON_FAIL=0 \
+		"$awk_script" -
+}
+
 number=0
 quiet=false
 verbose=false
@@ -97,6 +185,13 @@ check () { # <patch> <commit> <title>
 		ret=1
 	fi
 
+	! $verbose || printf '\nChecking forbidden tokens additions/removals:\n'
+	report=$(cat $tmpinput | check_forbidden_additions)
+	if [ $? -ne 0 ] ; then
+		ret=1
+	fi
+	printf '%s\n' "$report"
+
 	clean_tmp_files
 	[ $ret -eq 0 ] && return 0
 
-- 
1.8.3.1