scripts: Add a script to find unused documentation

Add a script that finds files with kernel-doc comments for imported functions
that are not included anywhere in documentation.
Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/find-unused-docs.sh

+#!/bin/bash
+# (c) 2017, Jonathan Corbet <corbet@lwn.net>
+#           sayli karnik <karniksayli1995@gmail.com>
+#
+# This script detects files with kernel-doc comments for exported functions
+# that are not included in documentation.
+#
+# usage: Run 'scripts/find-unused-docs.sh directory' from top level of kernel
+# 	 tree.
+#
+# example: $scripts/find-unused-docs.sh drivers/scsi
+#
+# Licensed under the terms of the GNU GPL License
+
+if ! [ -d "Documentation" ]; then
+	echo "Run from top level of kernel tree"
+	exit 1
+fi
+
+if [ "$#" -ne 1 ]; then
+	echo "Usage: scripts/find-unused-docs.sh directory"
+	exit 1
+fi
+
+if ! [ -d "$1" ]; then
+	echo "Directory $1 doesn't exist"
+	exit 1
+fi
+
+cd "$( dirname "${BASH_SOURCE[0]}" )"
+cd ..
+
+cd Documentation/
+
+echo "The following files contain kerneldoc comments for exported functions \
+that are not used in the formatted documentation"
+
+# FILES INCLUDED
+
+files_included=($(grep -rHR ".. kernel-doc" --include \*.rst | cut -d " " -f 3))
+
+declare -A FILES_INCLUDED
+
+for each in "${files_included[@]}"; do
+	FILES_INCLUDED[$each]="$each"
+	done
+
+cd ..
+
+# FILES NOT INCLUDED
+
+for file in `find $1 -name '*.c'`; do
+
+	if [[ ${FILES_INCLUDED[$file]+_} ]]; then
+	continue;
+	fi
+	str=$(scripts/kernel-doc -text -export "$file" 2>/dev/null)
+	if [[ -n "$str" ]]; then
+	echo "$file"
+	fi
+	done
+