1#!/usr/bin/env python
2# ex:ts=4:sw=4:sts=4:et
3# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
4"""
5   class for handling configuration data files
6
7   Reads a .conf file and obtains its metadata
8
9"""
10
11# Copyright (C) 2003, 2004  Chris Larson
12# Copyright (C) 2003, 2004  Phil Blundell
13#
14# This program is free software; you can redistribute it and/or modify
15# it under the terms of the GNU General Public License version 2 as
16# published by the Free Software Foundation.
17#
18# This program is distributed in the hope that it will be useful,
19# but WITHOUT ANY WARRANTY; without even the implied warranty of
20# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21# GNU General Public License for more details.
22#
23# You should have received a copy of the GNU General Public License along
24# with this program; if not, write to the Free Software Foundation, Inc.,
25# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26
27import errno
28import re
29import os
30import bb.utils
31from bb.parse import ParseError, resolve_file, ast, logger, handle
32
33__config_regexp__  = re.compile( r"""
34    ^
35    (?P<exp>export\s+)?
36    (?P<var>[a-zA-Z0-9\-_+.${}/~]+?)
37    (\[(?P<flag>[a-zA-Z0-9\-_+.]+)\])?
38
39    \s* (
40        (?P<colon>:=) |
41        (?P<lazyques>\?\?=) |
42        (?P<ques>\?=) |
43        (?P<append>\+=) |
44        (?P<prepend>=\+) |
45        (?P<predot>=\.) |
46        (?P<postdot>\.=) |
47        =
48    ) \s*
49
50    (?!'[^']*'[^']*'$)
51    (?!\"[^\"]*\"[^\"]*\"$)
52    (?P<apo>['\"])
53    (?P<value>.*)
54    (?P=apo)
55    $
56    """, re.X)
57__include_regexp__ = re.compile( r"include\s+(.+)" )
58__require_regexp__ = re.compile( r"require\s+(.+)" )
59__export_regexp__ = re.compile( r"export\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
60__unset_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
61__unset_flag_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)\[([a-zA-Z0-9\-_+.]+)\]$" )
62
63def init(data):
64    topdir = data.getVar('TOPDIR', False)
65    if not topdir:
66        data.setVar('TOPDIR', os.getcwd())
67
68
69def supports(fn, d):
70    return fn[-5:] == ".conf"
71
72def include(parentfn, fns, lineno, data, error_out):
73    """
74    error_out: A string indicating the verb (e.g. "include", "inherit") to be
75    used in a ParseError that will be raised if the file to be included could
76    not be included. Specify False to avoid raising an error in this case.
77    """
78    fns = data.expand(fns)
79    parentfn = data.expand(parentfn)
80
81    # "include" or "require" accept zero to n space-separated file names to include.
82    for fn in fns.split():
83        include_single_file(parentfn, fn, lineno, data, error_out)
84
85def include_single_file(parentfn, fn, lineno, data, error_out):
86    """
87    Helper function for include() which does not expand or split its parameters.
88    """
89    if parentfn == fn: # prevent infinite recursion
90        return None
91
92    if not os.path.isabs(fn):
93        dname = os.path.dirname(parentfn)
94        bbpath = "%s:%s" % (dname, data.getVar("BBPATH"))
95        abs_fn, attempts = bb.utils.which(bbpath, fn, history=True)
96        if abs_fn and bb.parse.check_dependency(data, abs_fn):
97            logger.warning("Duplicate inclusion for %s in %s" % (abs_fn, data.getVar('FILE')))
98        for af in attempts:
99            bb.parse.mark_dependency(data, af)
100        if abs_fn:
101            fn = abs_fn
102    elif bb.parse.check_dependency(data, fn):
103        logger.warning("Duplicate inclusion for %s in %s" % (fn, data.getVar('FILE')))
104
105    try:
106        bb.parse.handle(fn, data, True)
107    except (IOError, OSError) as exc:
108        if exc.errno == errno.ENOENT:
109            if error_out:
110                raise ParseError("Could not %s file %s" % (error_out, fn), parentfn, lineno)
111            logger.debug(2, "CONF file '%s' not found", fn)
112        else:
113            if error_out:
114                raise ParseError("Could not %s file %s: %s" % (error_out, fn, exc.strerror), parentfn, lineno)
115            else:
116                raise ParseError("Error parsing %s: %s" % (fn, exc.strerror), parentfn, lineno)
117
118# We have an issue where a UI might want to enforce particular settings such as
119# an empty DISTRO variable. If configuration files do something like assigning
120# a weak default, it turns out to be very difficult to filter out these changes,
121# particularly when the weak default might appear half way though parsing a chain
122# of configuration files. We therefore let the UIs hook into configuration file
123# parsing. This turns out to be a hard problem to solve any other way.
124confFilters = []
125
126def handle(fn, data, include):
127    init(data)
128
129    if include == 0:
130        oldfile = None
131    else:
132        oldfile = data.getVar('FILE', False)
133
134    abs_fn = resolve_file(fn, data)
135    f = open(abs_fn, 'r')
136
137    statements = ast.StatementGroup()
138    lineno = 0
139    while True:
140        lineno = lineno + 1
141        s = f.readline()
142        if not s:
143            break
144        w = s.strip()
145        # skip empty lines
146        if not w:
147            continue
148        s = s.rstrip()
149        while s[-1] == '\\':
150            s2 = f.readline().strip()
151            lineno = lineno + 1
152            if (not s2 or s2 and s2[0] != "#") and s[0] == "#" :
153                bb.fatal("There is a confusing multiline, partially commented expression on line %s of file %s (%s).\nPlease clarify whether this is all a comment or should be parsed." % (lineno, fn, s))
154            s = s[:-1] + s2
155        # skip comments
156        if s[0] == '#':
157            continue
158        feeder(lineno, s, abs_fn, statements)
159
160    # DONE WITH PARSING... time to evaluate
161    data.setVar('FILE', abs_fn)
162    statements.eval(data)
163    if oldfile:
164        data.setVar('FILE', oldfile)
165
166    f.close()
167
168    for f in confFilters:
169        f(fn, data)
170
171    return data
172
173def feeder(lineno, s, fn, statements):
174    m = __config_regexp__.match(s)
175    if m:
176        groupd = m.groupdict()
177        ast.handleData(statements, fn, lineno, groupd)
178        return
179
180    m = __include_regexp__.match(s)
181    if m:
182        ast.handleInclude(statements, fn, lineno, m, False)
183        return
184
185    m = __require_regexp__.match(s)
186    if m:
187        ast.handleInclude(statements, fn, lineno, m, True)
188        return
189
190    m = __export_regexp__.match(s)
191    if m:
192        ast.handleExport(statements, fn, lineno, m)
193        return
194
195    m = __unset_regexp__.match(s)
196    if m:
197        ast.handleUnset(statements, fn, lineno, m)
198        return
199
200    m = __unset_flag_regexp__.match(s)
201    if m:
202        ast.handleUnsetFlag(statements, fn, lineno, m)
203        return
204
205    raise ParseError("unparsed line: '%s'" % s, fn, lineno);
206
207# Add us to the handlers list
208from bb.parse import handlers
209handlers.append({'supports': supports, 'handle': handle, 'init': init})
210del handlers
211