path: root/tools/check-typo

#!/bin/sh

#**************************************************************************
#*                                                                        *
#*                                 OCaml                                  *
#*                                                                        *
#*           Damien Doligez, projet Gallium, INRIA Rocquencourt           *
#*                                                                        *
#*   Copyright 2012 Institut National de Recherche en Informatique et     *
#*     en Automatique.                                                    *
#*                                                                        *
#*   All rights reserved.  This file is distributed under the terms of    *
#*   the GNU Lesser General Public License version 2.1, with the          *
#*   special exception on linking described in the file LICENSE.          *
#*                                                                        *
#**************************************************************************

# check-typo - Check typographic conventions on OCaml sources.

# This program will check files for the following rules:

# - absence of TAB characters (tab)
# - absence of non-ASCII characters (non-ascii)
# - absence of non-printing ASCII characters (non-printing)
# - absence of white space at end of line (white-at-eol)
# - absence of empty lines at end of file (white-at-eof)
# - presence of a LF character at the end of the file (missing-lf)
# - maximum line length of 80 characters (long-line)
# - maximum line length of 132 characters (very-long-line)
# - presence of a copyright header (missing-header)
# - absence of a leftover "$Id" string (svn-keyword)

# Exceptions are handled with a git attribute: "ocaml-typo".
# Its value for a given file is a comma-separated list of rule names,
# which lists the rules that should be disabled for this file.
# The rule names are the ones shown above in parentheses.

# Built-in exceptions:
# - Any file git identifies as binary
#   is automatically exempt from all the rules.
# - Any file whose name matches one of the following patterns is
#   automatically exempt from all rules
#     *.reference
#     *.opt_reference
#     */reference
#     */.depend*
# - Any file whose name begins with "Makefile" is automatically exempt
#   from the "tabs" rule.
# - Any file whose name matches one of the following patterns is
#   automatically exempt from the "missing-header" rule.
#     *.mlpack
#     *.mllib
#     *.mltop
#     *.odocl
#     *.clib
# - Any file whose name matches the following pattern is automatically
#   exempt from the "long-line" rule (but not from "very-long-line").
#   */ocamldoc/*

# ASCII characters are bytes from 0 to 127.  Any other byte is
# flagged as a non-ASCII character.

# For the purpose of this tool, printing ASCII characters are:
# - the non-white printable ASCII characters (33 to 126)
# - TAB (09)
# - LF (10)
# - SPC (32)
# Anything else is flagged as a non-printing ASCII character.

# This program will recursively explore the files and directories given
# on the command line (or by default the current directory), and check
# every file therein for compliance to the rules.

# Directories named .git (and their contents) are always ignored.
# This program ignores any file that is not under git control, unless
# explicitly given on the command line.

# If a directory has the git attribute "ocaml-typo" set to "prune",
# then it and its contents are ignored.

# You can ignore a rule by giving the option -<rule> on the command
# line (before any file names).

# First prevent i18n from messing up everything.
export LC_ALL=C

# Special case for recursive call from the find command (see IGNORE_DIRS).
case "$1" in
  --check-prune)
    case `git check-attr ocaml-typo "$2" 2>/dev/null` in
      *prune*) echo "INFO: pruned directory $2 (ocaml-typo=prune)" >&2; exit 0;;
      *) exit 3;;
    esac;;
esac

usage () {
  echo "usage: check-typo {-<rule>} [--] {<file-or-dir>}" >&2
  exit 2
}

userrules=''

while : ; do
  case "$1" in
    -help|--help) usage;;
    -*) userrules="${1#-},$userrules"; shift;;
    --) shift; break;;
    *) break;;
  esac
done

IGNORE_DIRS="
  -name .git -prune -o
  -type d -exec $0 --check-prune {} ; -prune -o
"

( case $# in
    0) find . $IGNORE_DIRS -type f -print;;
    *) for i in "$@"; do find "$i" $IGNORE_DIRS -type f -print; done;;
  esac
) | (
  while read f; do
    case `git ls-files "$f" 2>&1` in
      "") is_svn=false;;
      *) is_svn=true;;
    esac
    case "$*" in
      *$f*) is_cmd_line=true;;
      *) is_cmd_line=false;;
    esac
    if $is_svn || $is_cmd_line; then :; else continue; fi
    svnrules=''
    if $is_svn; then
      # Below is a git plumbing command to detect whether git regards a
      # particular file as binary. This takes into account .gitattributes, but
      # also works if the file has been automatically detected as binary by git.
      # EMPTY is the hash of the empty tree (which is specially known to git -
      # it is automatically included in every repository) as a way to get
      # `diff-tree` to print the whole tree state; its `--numstat` output then
      # prints a summary where two dashes in the first two columns indicates a
      # binary file.
      #   (See https://git-scm.com/docs/git-diff-tree#_other_diff_formats and
      #    the documentation for the --numstat option. Commands designated as
      #    "plumbing" commands in git have stable output intended for parsing)
      EMPTY=`git hash-object -t tree /dev/null`
      git diff-tree --numstat $EMPTY HEAD -- "$f" | grep -q "^-[[:blank:]]-" \
        && continue
      svnrules=`git check-attr ocaml-typo "$f" | sed -e 's/.*: //'`
      case $svnrules in unspecified) svnrules= ;; esac
    fi
    rules="$userrules"
    add_hd(){ rules="missing-header,$rules"; }
    case "$f" in
      Makefile*|*/Makefile*) rules="tab,$rules";;
      *.mlpack|*.mllib|*.mltop|*.odocl|*.itarget|*.clib) add_hd;;
      *.reference|*.opt_reference|*/reference|*/.depend*) continue;;
    esac
    case "$f" in
      ocamldoc/*|*/ocamldoc/*) rules="long-line,$rules";;
    esac

    (cat "$f"; echo) \
    | awk -v rules="$rules" -v svnrules="$svnrules" -v file="$f" \
      '
        function err(name, msg) {
          ++ counts[name];
          if (("," rules svnrules ",") !~ ("[, ]" name "[, ]") \
              && counts[name] <= 10){
            printf ("%s:%d.%d:", file, NR, RSTART + RLENGTH);
            printf (" [%s] %s\n", name, msg);
            got_errors = 1;
            if (counts[name] == 10){
              printf ("WARNING: too many [%s] in this file.", name);
              printf ("  Others will not be reported.\n");
            }
          }
        }

        function more_columns(str, limit,       c){
          c = 0;
          for (i = 1; i <= length(str); i++){
            if (substr(str, i, 1) == "\t"){
              c = int((c + 8) / 8) * 8;
            }else{
              ++ c;
            }
          }
          return c > limit;
        }

        BEGIN { state = "(first line)"; }

        match($0, /\t/) {
          err("tab", "TAB character(s)");
          if (more_columns($0, 80)){
            RSTART=81;
            RLENGTH = 0;
            err("long-line", "line is over 80 columns");
          }
          if (more_columns($0, 132)){
            RSTART=133;
            RLENGTH = 0;
            err("very-long-line", "line is over 132 columns");
          }
        }

        match($0, /[\200-\377]/) {
          err("non-ascii", "non-ASCII character(s)");
        }

        match($0, /[^\t\200-\377 -~]/) {
          err("non-printing", "non-printing ASCII character(s)");
        }

        match($0, /[ \t]+$/) {
          err("white-at-eol", "whitespace at end of line");
        }

        match($0, /\$Id(: .*)?\$/) {
          err("svn-keyword", "SVN keyword marker");
        }

        $0 !~ /\t/ && length($0) > 80 {
          RSTART = 81;
          RLENGTH = 0;
          err("long-line", "line is over 80 columns");
        }

        $0 !~ /\t/ && length($0) > 132 {
          RSTART = 133;
          RLENGTH = 0;
          err("very-long-line", "line is over 132 columns");
        }

        # Header-recognition automaton. Read this from bottom to top.

        state == "close" && $0 ~ /\*{74}/ { state = "OK"; }
        state == "close" { state = "(last line)"; }
        state == "blurb" && $0 ~ /\* {72}\*/ { state = "close"; }
        state == "blurb" && $0 ~ /\/LICENSE/ { state = "(license path)" }
        state == "blurb1" && $0 ~ /\*   All rights reserved. .{47} \*/ \
                                                 { state = "blurb"; }
        state == "blurb1" { state = "(blurb line 1)"; }
        state == "copyright" && $0 ~ /\* {72}\*/ { state = "blurb1"; }
        state == "copyright" && $0 !~ /\*   Copyright [0-9]{4}.{54} \*/ \
                             && $0 !~ /\*     .{66} \*/ \
                      { state = "(copyright lines)"; }
        state == "authors" && $0 ~ /\* {72}\*/ { state = "copyright"; }
        state == "authors" && $0 !~ /\* .{70} \*/ { state = "(authors)"; }
        state == "blank2" && $0 ~ /\* {72}\*/ { state = "authors"; }
        state == "blank2" { state = "(blank line 2)"; }
        state == "title" && $0 ~ /\* {33}OCaml {34}\*/ { state = "blank2"; }
        state == "title" { state = "(title line)"; }
        state == "blank1" && $0 ~ /\* {72}\*/ { state = "title"; }
        state == "blank1" { state = "(blank line 1)"; }
        state == "(first line)" && NR < 4 && $0 ~ /\*{74}/ { state = "blank1"; }

        {
          prev_line = last_line;
          last_line = $0;
        }

        END {
          if (match(last_line, /.+/)){
            err("missing-lf", "missing linefeed at EOF");
            prev_line = last_line;
            ++ NR;
            empty_file = 0;
          }else{
            empty_file = NR == 1;
          }
          if (!empty_file && match(prev_line, /^$/)){
            err("white-at-eof", "empty line(s) at EOF");
          }
          if (state != "OK"){
            if (NR >= 10){
              NR = 1;
              RSTART = 1;
              RLENGTH = 0;
              err("missing-header", sprintf("bad copyright header %s", state));
            }else{
              counts["missing-header"] = 1;
            }
          }
          split(svnrules, r, "[, ]");
          for (i in r){
            name = r[i];
            if (name != "" && !counts[name]){
              NR = 1;
              RSTART = 1;
              RLENGTH = 0;
              err("unused-prop", sprintf("unused [%s] in ocaml-typo", name));
            }
          }
          exit got_errors;
        }
      '
  done
)