scripts/check-sysctl-docs

   1 #!/usr/bin/gawk -f
   2 # SPDX-License-Identifier: GPL-2.0
   3
   4 # Script to check sysctl documentation against source files
   5 #
   6 # Copyright (c) 2020 Stephen Kitt
   7
   8 # Example invocation:
   9 #       scripts/check-sysctl-docs -vtable="kernel" \
  10 #               Documentation/admin-guide/sysctl/kernel.rst \
  11 #               $(git grep -l register_sysctl)
  12 #
  13 # Specify -vdebug=1 to see debugging information
  14
  15 BEGIN {
  16     if (!table) {
  17         print "Please specify the table to look for using the table variable" > "/dev/stderr"
  18         exit 1
  19     }
  20 }
  21
  22 # The following globals are used:
  23 # documented: maps documented entries (each key is an entry)
  24 # entries: maps ctl_table names and procnames to counts (so
  25 #          enumerating the subkeys for a given ctl_table lists its
  26 #          procnames)
  27 # curtable: the name of the current ctl_table struct
  28 # curentry: the name of the current proc entry (procname when parsing
  29 #           a ctl_table, constructed path when parsing a ctl_path)
  30
  31
  32 # Remove punctuation from the given value
  33 function trimpunct(value) {
  34     while (value ~ /^["&]/) {
  35         value = substr(value, 2)
  36     }
  37     while (value ~ /[]["&,}]$/) {
  38         value = substr(value, 1, length(value) - 1)
  39     }
  40     return value
  41 }
  42
  43 # Print the information for the given entry
  44 function printentry(entry) {
  45     seen[entry]++
  46     printf "* %s from %s", entry, file[entry]
  47     if (documented[entry]) {
  48         printf " (documented)"
  49     }
  50     print ""
  51 }
  52
  53
  54 # Stage 1: build the list of documented entries
  55 FNR == NR && /^=+$/ {
  56     if (prevline ~ /Documentation for/) {
  57         # This is the main title
  58         next
  59     }
  60
  61     # The previous line is a section title, parse it
  62     $0 = prevline
  63     if (debug) print "Parsing " $0
  64     inbrackets = 0
  65     for (i = 1; i <= NF; i++) {
  66         if (length($i) == 0) {
  67             continue
  68         }
  69         if (!inbrackets && substr($i, 1, 1) == "(") {
  70             inbrackets = 1
  71         }
  72         if (!inbrackets) {
  73             token = trimpunct($i)
  74             if (length(token) > 0 && token != "and") {
  75                 if (debug) print trimpunct($i)
  76                 documented[trimpunct($i)]++
  77             }
  78         }
  79         if (inbrackets && substr($i, length($i), 1) == ")") {
  80             inbrackets = 0
  81         }
  82     }
  83 }
  84
  85 FNR == NR {
  86     prevline = $0
  87     next
  88 }
  89
  90
  91 # Stage 2: process each file and find all sysctl tables
  92 BEGINFILE {
  93     delete entries
  94     curtable = ""
  95     curentry = ""
  96     delete vars
  97     if (debug) print "Processing file " FILENAME
  98 }
  99
 100 /^static( const)? struct ctl_table/ {
 101     match($0, /static( const)? struct ctl_table ([^][]+)/, tables)
 102     curtable = tables[2]
 103     if (debug) print "Processing table " curtable
 104 }
 105
 106 /^};$/ {
 107     curtable = ""
 108     curentry = ""
 109     delete vars
 110 }
 111
 112 curtable && /\.procname[\t ]*=[\t ]*".+"/ {
 113     match($0, /.procname[\t ]*=[\t ]*"([^"]+)"/, names)
 114     curentry = names[1]
 115     if (debug) print "Adding entry " curentry " to table " curtable
 116     entries[curtable][curentry]++
 117     file[curentry] = FILENAME
 118 }
 119
 120 /register_sysctl.*/ {
 121     match($0, /register_sysctl(|_init|_sz)\("([^"]+)" *, *([^,)]+)/, tables)
 122     if (debug) print "Registering table " tables[3] " at " tables[2]
 123     if (tables[2] == table) {
 124         for (entry in entries[tables[3]]) {
 125             printentry(entry)
 126         }
 127     }
 128 }
 129
 130 /kmemdup.*/ {
 131     match($0, /([^ \t]+) *= *kmemdup\(([^,]+) *,/, names)
 132     if (debug) print "Found variable " names[1] " for table " names[2]
 133     if (names[2] in entries) {
 134         vars[names[1]] = names[2]
 135     }
 136 }
 137
 138 /__register_sysctl_table.*/ {
 139     match($0, /__register_sysctl_table\([^,]+, *"([^"]+)" *, *([^,]+)/, tables)
 140     if (debug) print "Registering variable table " tables[2] " at " tables[1]
 141     if (tables[1] == table && tables[2] in vars) {
 142         for (entry in entries[vars[tables[2]]]) {
 143             printentry(entry)
 144         }
 145     }
 146 }
 147
 148 END {
 149     for (entry in documented) {
 150         if (!seen[entry]) {
 151             print "No implementation for " entry
 152         }
 153     }
 154 }