linux-yocto/scripts/check-sysctl-docs

#!/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:

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)

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 entries curtable = "" curentry = "" delete vars if (debug) print "Processing file " FILENAME }

/^static( const)? struct ctl_table/ { match($0, /static( const)? struct ctl_table ([^][]+)/, tables) curtable = tables[2] if (debug) print "Processing table " curtable }

/^};$/ { curtable = "" curentry = "" delete vars }

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 }

/register_sysctl.*/ { match($0, /register_sysctl(|_init|_sz)("([^"]+)" *, *([^,)]+)/, tables) if (debug) print "Registering table " tables[3] " at " tables[2] if (tables[2] == table) { for (entry in entries[tables[3]]) { printentry(entry) } } }

/kmemdup.*/ { match($0, /([^ \t]+) *= *kmemdup(([^,]+) *,/, names) if (debug) print "Found variable " names[1] " for table " names[2] if (names[2] in entries) { vars[names[1]] = names[2] } }

/__register_sysctl_table.*/ { match($0, /__register_sysctl_table([^,]+, *"([^"]+)" *, *([^,]+)/, tables) if (debug) print "Registering variable table " tables[2] " at " tables[1] if (tables[1] == table && tables[2] in vars) { for (entry in entries[vars[tables[2]]]) { printentry(entry) } } }

END { for (entry in documented) { if (!seen[entry]) { print "No implementation for " entry } } }