mercurial/ignore.py

ignore: remove .hgignore from ignore list if nonexistent

Previously we would always pass the root .hgignore path to the ignore parser.
The parser then had to be aware that the first path was special, and not warn if
it didn't exist.

In preparation for making the ignore file parser more generically usable, let's
make the parse logic not aware of this special case, and instead just not pass
the root .hgignore in if it doesn't exist.

# ignore.py - ignored file handling for mercurial
#
# Copyright 2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import util, match
import re

_commentre = None

def ignorepats(lines):
    '''parse lines (iterable) of .hgignore text, returning a tuple of
    (patterns, parse errors). These patterns should be given to compile()
    to be validated and converted into a match function.'''
    syntaxes = {'re': 'relre:', 'regexp': 'relre:', 'glob': 'relglob:'}
    syntax = 'relre:'
    patterns = []
    warnings = []

    for line in lines:
        if "#" in line:
            global _commentre
            if not _commentre:
                _commentre = re.compile(r'((^|[^\\])(\\\\)*)#.*')
            # remove comments prefixed by an even number of escapes
            line = _commentre.sub(r'\1', line)
            # fixup properly escaped comments that survived the above
            line = line.replace("\\#", "#")
        line = line.rstrip()
        if not line:
            continue

        if line.startswith('syntax:'):
            s = line[7:].strip()
            try:
                syntax = syntaxes[s]
            except KeyError:
                warnings.append(_("ignoring invalid syntax '%s'") % s)
            continue

        linesyntax = syntax
        for s, rels in syntaxes.iteritems():
            if line.startswith(rels):
                linesyntax = rels
                line = line[len(rels):]
                break
            elif line.startswith(s+':'):
                linesyntax = rels
                line = line[len(s) + 1:]
                break
        patterns.append(linesyntax + line)

    return patterns, warnings

def readignorefile(filepath, warn):
    try:
        pats = []
        fp = open(filepath)
        pats, warnings = ignorepats(fp)
        fp.close()
        for warning in warnings:
            warn("%s: %s\n" % (filepath, warning))
    except IOError, inst:
        warn(_("skipping unreadable ignore file '%s': %s\n") %
             (filepath, inst.strerror))
    return pats

def readpats(root, files, warn):
    '''return a dict mapping ignore-file-name to list-of-patterns'''

    pats = {}
    for f in files:
        if f in pats:
            continue
        pats[f] = readignorefile(f, warn)

    return [(f, pats[f]) for f in files if f in pats]

def ignore(root, files, warn):
    '''return matcher covering patterns in 'files'.

    the files parsed for patterns include:
    .hgignore in the repository root
    any additional files specified in the [ui] section of ~/.hgrc

    trailing white space is dropped.
    the escape character is backslash.
    comments start with #.
    empty lines are skipped.

    lines can be of the following formats:

    syntax: regexp # defaults following lines to non-rooted regexps
    syntax: glob   # defaults following lines to non-rooted globs
    re:pattern     # non-rooted regular expression
    glob:pattern   # non-rooted glob
    pattern        # pattern of the current default type'''

    pats = readpats(root, files, warn)

    allpats = []
    for f, patlist in pats:
        allpats.extend(patlist)
    if not allpats:
        return util.never

    try:
        ignorefunc = match.match(root, '', [], allpats)
    except util.Abort:
        # Re-raise an exception where the src is the right file
        for f, patlist in pats:
            try:
                match.match(root, '', [], patlist)
            except util.Abort, inst:
                raise util.Abort('%s: %s' % (f, inst[0]))

    return ignorefunc