[PATCH v4 2/2] devtools: add tracepoint check in checkpatch

[Ankur Dwivedi <adwivedi@marvell.com>]

This patch adds a validation in checkpatch tool, to check if a
tracepoint is present in any new function added in ethdev library.

It uses the existing build_map_changes function to create a map
of functions. In the map, the newly added functions, added in the
experimental section are identified and their definition are checked for
the presence of tracepoint. The checkpatch return error if the tracepoint
is not present.

For functions for which trace is not needed, they can be added to
devtools/trace-skiplist.txt file. The above tracepoint check will be
skipped for them.

Signed-off-by: Ankur Dwivedi <adwivedi@marvell.com>
---
 devtools/check-tracepoint.sh | 146 +++++++++++++++++++++++++++++++++++
 devtools/checkpatches.sh     |   9 +++
 devtools/trace-skiplist.txt  |   0
 3 files changed, 155 insertions(+)
 create mode 100755 devtools/check-tracepoint.sh
 create mode 100644 devtools/trace-skiplist.txt

diff --git a/devtools/check-tracepoint.sh b/devtools/check-tracepoint.sh
new file mode 100755
index 0000000000..591d5cd397
--- /dev/null
+++ b/devtools/check-tracepoint.sh
@@ -0,0 +1,146 @@
+#!/bin/sh
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (C) 2023 Marvell.
+
+selfdir=$(dirname $(readlink -f $0))
+. $selfdir/build-symbol-map.sh
+
+# Library for trace check
+libdir="ethdev"
+
+# Functions for which the trace check can be skipped
+skiplist="$selfdir/trace-skiplist.txt"
+
+find_trace_fn()
+{
+	local fname="$1"
+
+	cat "$fname" | awk -v symname="$2 *\\\(" '
+		# Initialize the variables.
+		# The variable symname provides a pattern to match
+		# "function_name(", zero or more spaces can be present
+		# between function_name and (.
+		BEGIN {found=0}
+
+		# Matches the function name, set found=1.
+		$0 ~ symname {found=1}
+
+		# If closing parentheses with semicolon ");" is found, then it
+		# is not the function definition.
+		/) *;/ {
+			if (found == 1) {
+				found=0
+			}
+		}
+
+		/)/ {
+			if (found == 1) {
+				ln_pth = NR
+			}
+		}
+
+		# If closing parentheses and then opening braces is found in
+		# adjacent line, then this is the start of function
+		# definition. Check for tracepoint in the function definition.
+		# The tracepoint has _trace_ in its name.
+		/{/ {
+			if (found == 1) {
+				if (ln_pth != NR - 1) {
+					found = 0
+					next
+				}
+				while (index($0, "}") != 2) {
+					if (index($0, "_trace_") != 0) {
+						exit 0
+					}
+					if (getline <= 0) {
+						break
+					}
+				}
+				exit 1
+			}
+		}
+	'
+}
+
+check_for_tracepoint()
+{
+	local patch="$1"
+	local mapdb="$2"
+	local skip_sym
+	local libname
+	local secname
+	local mname
+	local ret=0
+	local pdir
+	local libp
+	local libn
+	local sym
+	local ar
+
+	while read -r mname symname secname ar; do
+		pdir=$(echo $mname | awk 'BEGIN {FS="/"};{print $2}')
+		libname=$(echo $mname | awk 'BEGIN {FS="/"};{print $3}')
+		skip_sym=0
+		libp=0
+
+		if [ "$pdir" != "lib" ]; then
+			continue
+		fi
+
+		for libn in $libdir; do
+			if [ $libn = $libname ]; then
+				libp=1
+				break
+			fi
+		done
+
+		if [ $libp -eq 0 ]; then
+			continue
+		fi
+
+		for sym in $(cat $skiplist); do
+			if [ $sym = $symname ]; then
+				skip_sym=1
+				break
+			fi
+		done
+
+		if [ $skip_sym -eq 1 ]; then
+			continue
+		fi
+
+		if [ "$ar" = "add" ] && [ "$secname" = "EXPERIMENTAL" ]; then
+			# Check if new API is added with tracepoint
+			find_trace_fn $patch $symname
+			if [ $? -eq 1 ]; then
+				ret=1
+				echo -n "ERROR: New function $symname is added "
+				echo -n "without a tracepoint. Please add a tracepoint "
+				echo -n "or add the function $symname in "
+				echo "devtools/trace-skiplist.txt to skip this error."
+			fi
+		fi
+	done < "$mapdb"
+
+	return $ret
+}
+
+trap clean_and_exit_on_sig EXIT
+
+mapfile=`mktemp -t dpdk.mapdb.XXXXXX`
+patch=$1
+exit_code=1
+
+clean_and_exit_on_sig()
+{
+	rm -f "$mapfile"
+	exit $exit_code
+}
+
+build_map_changes "$patch" "$mapfile"
+check_for_tracepoint "$patch" "$mapfile"
+exit_code=$?
+rm -f "$mapfile"
+
+exit $exit_code
diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
index 1dee094c7a..471db1d21b 100755
--- a/devtools/checkpatches.sh
+++ b/devtools/checkpatches.sh
@@ -10,6 +10,7 @@
 . $(dirname $(readlink -f $0))/load-devel-config
 
 VALIDATE_NEW_API=$(dirname $(readlink -f $0))/check-symbol-change.sh
+VALIDATE_TRACEPOINT=$(dirname $(readlink -f $0))/check-tracepoint.sh
 
 # Enable codespell by default. This can be overwritten from a config file.
 # Codespell can also be enabled by setting DPDK_CHECKPATCH_CODESPELL to a valid path
@@ -386,6 +387,14 @@ check () { # <patch-file> <commit>
 		ret=1
 	fi
 
+	! $verbose || printf '\nChecking API additions with tracepoint :\n'
+	report=$($VALIDATE_TRACEPOINT "$tmpinput")
+	if [ $? -ne 0 ] ; then
+		$headline_printed || print_headline "$subject"
+		printf '%s\n' "$report"
+		ret=1
+	fi
+
 	if [ "$tmpinput" != "$1" ]; then
 		rm -f "$tmpinput"
 		trap - INT
diff --git a/devtools/trace-skiplist.txt b/devtools/trace-skiplist.txt
new file mode 100644
index 0000000000..e69de29bb2
-- 
2.25.1