1"""
2   class for handling configuration data files
3
4   Reads a .conf file and obtains its metadata
5
6"""
7
8# Copyright (C) 2003, 2004  Chris Larson
9# Copyright (C) 2003, 2004  Phil Blundell
10#
11# SPDX-License-Identifier: GPL-2.0-only
12#
13
14import errno
15import re
16import os
17import bb.utils
18from bb.parse import ParseError, resolve_file, ast, logger, handle
19
20__config_regexp__  = re.compile( r"""
21    ^
22    (?P<exp>export\s+)?
23    (?P<var>[a-zA-Z0-9\-_+.${}/~:]+?)
24    (\[(?P<flag>[a-zA-Z0-9\-_+.]+)\])?
25
26    \s* (
27        (?P<colon>:=) |
28        (?P<lazyques>\?\?=) |
29        (?P<ques>\?=) |
30        (?P<append>\+=) |
31        (?P<prepend>=\+) |
32        (?P<predot>=\.) |
33        (?P<postdot>\.=) |
34        =
35    ) \s*
36
37    (?!'[^']*'[^']*'$)
38    (?!\"[^\"]*\"[^\"]*\"$)
39    (?P<apo>['\"])
40    (?P<value>.*)
41    (?P=apo)
42    $
43    """, re.X)
44__include_regexp__ = re.compile( r"include\s+(.+)" )
45__require_regexp__ = re.compile( r"require\s+(.+)" )
46__export_regexp__ = re.compile( r"export\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
47__unset_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)$" )
48__unset_flag_regexp__ = re.compile( r"unset\s+([a-zA-Z0-9\-_+.${}/~]+)\[([a-zA-Z0-9\-_+.]+)\]$" )
49__addpylib_regexp__      = re.compile(r"addpylib\s+(.+)\s+(.+)" )
50
51def init(data):
52    return
53
54def supports(fn, d):
55    return fn[-5:] == ".conf"
56
57def include(parentfn, fns, lineno, data, error_out):
58    """
59    error_out: A string indicating the verb (e.g. "include", "inherit") to be
60    used in a ParseError that will be raised if the file to be included could
61    not be included. Specify False to avoid raising an error in this case.
62    """
63    fns = data.expand(fns)
64    parentfn = data.expand(parentfn)
65
66    # "include" or "require" accept zero to n space-separated file names to include.
67    for fn in fns.split():
68        include_single_file(parentfn, fn, lineno, data, error_out)
69
70def include_single_file(parentfn, fn, lineno, data, error_out):
71    """
72    Helper function for include() which does not expand or split its parameters.
73    """
74    if parentfn == fn: # prevent infinite recursion
75        return None
76
77    if not os.path.isabs(fn):
78        dname = os.path.dirname(parentfn)
79        bbpath = "%s:%s" % (dname, data.getVar("BBPATH"))
80        abs_fn, attempts = bb.utils.which(bbpath, fn, history=True)
81        if abs_fn and bb.parse.check_dependency(data, abs_fn):
82            logger.warning("Duplicate inclusion for %s in %s" % (abs_fn, data.getVar('FILE')))
83        for af in attempts:
84            bb.parse.mark_dependency(data, af)
85        if abs_fn:
86            fn = abs_fn
87    elif bb.parse.check_dependency(data, fn):
88        logger.warning("Duplicate inclusion for %s in %s" % (fn, data.getVar('FILE')))
89
90    try:
91        bb.parse.handle(fn, data, True)
92    except (IOError, OSError) as exc:
93        if exc.errno == errno.ENOENT:
94            if error_out:
95                raise ParseError("Could not %s file %s" % (error_out, fn), parentfn, lineno)
96            logger.debug2("CONF file '%s' not found", fn)
97        else:
98            if error_out:
99                raise ParseError("Could not %s file %s: %s" % (error_out, fn, exc.strerror), parentfn, lineno)
100            else:
101                raise ParseError("Error parsing %s: %s" % (fn, exc.strerror), parentfn, lineno)
102
103# We have an issue where a UI might want to enforce particular settings such as
104# an empty DISTRO variable. If configuration files do something like assigning
105# a weak default, it turns out to be very difficult to filter out these changes,
106# particularly when the weak default might appear half way though parsing a chain
107# of configuration files. We therefore let the UIs hook into configuration file
108# parsing. This turns out to be a hard problem to solve any other way.
109confFilters = []
110
111def handle(fn, data, include, baseconfig=False):
112    init(data)
113
114    if include == 0:
115        oldfile = None
116    else:
117        oldfile = data.getVar('FILE', False)
118
119    abs_fn = resolve_file(fn, data)
120    with open(abs_fn, 'r') as f:
121
122        statements = ast.StatementGroup()
123        lineno = 0
124        while True:
125            lineno = lineno + 1
126            s = f.readline()
127            if not s:
128                break
129            origlineno = lineno
130            origline = s
131            w = s.strip()
132            # skip empty lines
133            if not w:
134                continue
135            s = s.rstrip()
136            while s[-1] == '\\':
137                line = f.readline()
138                origline += line
139                s2 = line.rstrip()
140                lineno = lineno + 1
141                if (not s2 or s2 and s2[0] != "#") and s[0] == "#" :
142                    bb.fatal("There is a confusing multiline, partially commented expression starting on line %s of file %s:\n%s\nPlease clarify whether this is all a comment or should be parsed." % (origlineno, fn, origline))
143
144                s = s[:-1] + s2
145            # skip comments
146            if s[0] == '#':
147                continue
148            feeder(lineno, s, abs_fn, statements, baseconfig=baseconfig)
149
150    # DONE WITH PARSING... time to evaluate
151    data.setVar('FILE', abs_fn)
152    statements.eval(data)
153    if oldfile:
154        data.setVar('FILE', oldfile)
155
156    for f in confFilters:
157        f(fn, data)
158
159    return data
160
161# baseconfig is set for the bblayers/layer.conf cookerdata config parsing
162# The function is also used by BBHandler, conffile would be False
163def feeder(lineno, s, fn, statements, baseconfig=False, conffile=True):
164    m = __config_regexp__.match(s)
165    if m:
166        groupd = m.groupdict()
167        ast.handleData(statements, fn, lineno, groupd)
168        return
169
170    m = __include_regexp__.match(s)
171    if m:
172        ast.handleInclude(statements, fn, lineno, m, False)
173        return
174
175    m = __require_regexp__.match(s)
176    if m:
177        ast.handleInclude(statements, fn, lineno, m, True)
178        return
179
180    m = __export_regexp__.match(s)
181    if m:
182        ast.handleExport(statements, fn, lineno, m)
183        return
184
185    m = __unset_regexp__.match(s)
186    if m:
187        ast.handleUnset(statements, fn, lineno, m)
188        return
189
190    m = __unset_flag_regexp__.match(s)
191    if m:
192        ast.handleUnsetFlag(statements, fn, lineno, m)
193        return
194
195    m = __addpylib_regexp__.match(s)
196    if baseconfig and conffile and m:
197        ast.handlePyLib(statements, fn, lineno, m)
198        return
199
200    raise ParseError("unparsed line: '%s'" % s, fn, lineno);
201
202# Add us to the handlers list
203from bb.parse import handlers
204handlers.append({'supports': supports, 'handle': handle, 'init': init})
205del handlers
206