#!/usr/bin/gawk -f
# SPDX-License-Identifier: GPL-2.0
# Script to check sysctl documentation against source files
#
# Copyright (c) 2020 Stephen Kitt
# Example invocation:
# scripts/check-sysctl-docs -vtable="kernel" \
# Documentation/admin-guide/sysctl/kernel.rst \
# $(git grep -l register_sysctl_)
#
# Specify -vdebug=1 to see debugging information
BEGIN {
if (!table) {
print "Please specify the table to look for using the table variable" > "/dev/stderr"
exit 1
}
}
# The following globals are used:
# children: maps ctl_table names and procnames to child ctl_table names
# documented: maps documented entries (each key is an entry)
# entries: maps ctl_table names and procnames to counts (so
# enumerating the subkeys for a given ctl_table lists its
# procnames)
# files: maps procnames to source file names
# paths: maps ctl_path names to paths
# curpath: the name of the current ctl_path struct
# curtable: the name of the current ctl_table struct
# curentry: the name of the current proc entry (procname when parsing
# a ctl_table, constructed path when parsing a ctl_path)
# Remove punctuation from the given value
function trimpunct(value) {
while (value ~ /^["&]/) {
value = substr(value, 2)
}
while (value ~ /[]["&,}]$/) {
value = substr(value, 1, length(value) - 1)
}
return value
}
# Print the information for the given entry
function printentry(entry) {
seen[entry]++
printf "* %s from %s", entry, file[entry]
if (documented[entry]) {
printf " (documented)"
}
print ""
}
# Stage 1: build the list of documented entries
FNR == NR && /^=+$/ {
if (prevline ~ /Documentation for/) {
# This is the main title
next
}
# The previous line is a section title, parse it
$0 = prevline
if (debug) print "Parsing " $0
inbrackets = 0
for (i = 1; i <= NF; i++) {
if (length($i) == 0) {
continue
}
if (!inbrackets && substr($i, 1, 1) == "(") {
inbrackets = 1
}
if (!inbrackets) {
token = trimpunct($i)
if (length(token) > 0 && token != "and") {
if (debug) print trimpunct($i)
documented[trimpunct($i)]++
}
}
if (inbrackets && substr($i, length($i), 1) == ")") {
inbrackets = 0
}
}
}
FNR == NR {
prevline = $0
next
}
# Stage 2: process each file and find all sysctl tables
BEGINFILE {
delete children
delete entries
delete paths
curpath = ""
curtable = ""
curentry = ""
if (debug) print "Processing file " FILENAME
}
/^static struct ctl_path/ {
match($0, /static struct ctl_path ([^][]+)/, tables)
curpath = tables[1]
if (debug) print "Processing path " curpath
}
/^static struct ctl_table/ {
match($0, /static struct ctl_table ([^][]+)/, tables)
curtable = tables[1]
if (debug) print "Processing table " curtable
}
/^};$/ {
curpath = ""
curtable = ""
curentry = ""
}
curpath && /\.procname[\t ]*=[\t ]*".+"/ {
match($0, /.procname[\t ]*=[\t ]*"([^"]+)"/, names)
if (curentry) {
curentry = curentry "/" names[1]
} else {
curentry = names[1]
}
if (debug) print "Setting path " curpath " to " curentry
paths[curpath] = curentry
}
curtable && /\.procname[\t ]*=[\t ]*".+"/ {
match($0, /.procname[\t ]*=[\t ]*"([^"]+)"/, names)
curentry = names[1]
if (debug) print "Adding entry " curentry " to table " curtable
entries[curtable][curentry]++
file[curentry] = FILENAME
}
/\.child[\t ]*=/ {
child = trimpunct($NF)
if (debug) print "Linking child " child " to table " curtable " entry " curentry
children[curtable][curentry] = child
}
/register_sysctl_table\(.*\)/ {
match($0, /register_sysctl_table\(([^)]+)\)/, tables)
if (debug) print "Registering table " tables[1]
if (children[tables[1]][table]) {
for (entry in entries[children[tables[1]][table]]) {
printentry(entry)
}
}
}
/register_sysctl_paths\(.*\)/ {
match($0, /register_sysctl_paths\(([^)]+), ([^)]+)\)/, tables)
if (debug) print "Attaching table " tables[2] " to path " tables[1]
if (paths[tables[1]] == table) {
for (entry in entries[tables[2]]) {
printentry(entry)
}
}
split(paths[tables[1]], components, "/")
if (length(components) > 1 && components[1] == table) {
# Count the first subdirectory as seen
seen[components[2]]++
}
}
END {
for (entry in documented) {
if (!seen[entry]) {
print "No implementation for " entry
}
}
}
