1#!/usr/bin/python3
2# Processing of symbols and abilist files.
3# Copyright (C) 2020-2022 Free Software Foundation, Inc.
4# This file is part of the GNU C Library.
5#
6# The GNU C Library is free software; you can redistribute it and/or
7# modify it under the terms of the GNU Lesser General Public
8# License as published by the Free Software Foundation; either
9# version 2.1 of the License, or (at your option) any later version.
10#
11# The GNU C Library is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14# Lesser General Public License for more details.
15#
16# You should have received a copy of the GNU Lesser General Public
17# License along with the GNU C Library; if not, see
18# <https://www.gnu.org/licenses/>.
19
20"""Symbol processing for glibc."""
21
22import os
23
24def replace_file(path, new_contents):
25    """Atomically replace PATH with lines from NEW_CONTENTS.
26
27    NEW_CONTENTS must be a sequence of strings.
28
29    """
30    temppath = path + 'T'
31    with open(temppath, 'w') as out:
32        for line in new_contents:
33            out.write(line)
34    os.rename(temppath, path)
35
36class VersionedSymbol:
37    """A combination of a symbol and its version."""
38
39    def __init__(self, symbol, version):
40        """Construct a new versioned symbol."""
41        assert symbol
42        assert version
43        self.symbol = symbol
44        self.version = version
45
46    def __str__(self):
47        return self.symbol + '@' + self.version
48
49    def __eq__(self, other):
50        return self.symbol == other.symbol and self.version == other.version
51
52    def __hash__(self):
53        return hash(self.symbol) ^ hash(self.version)
54
55def read_abilist(path):
56    """Read the abilist file at PATH.
57
58    Return a dictionary from VersionedSymbols to their flags (as
59    strings).
60
61    """
62    result = {}
63    with open(path) as inp:
64        for line in inp:
65            version, symbol, flags = line.strip().split(' ', 2)
66            versym = VersionedSymbol(symbol, version)
67            if versym in result:
68                raise IOError("{}: duplicate symbol {}".format(path, versym))
69            result[versym] = flags
70    return result
71
72def abilist_lines(symbols):
73    """Build the abilist file contents (as a list of lines).
74
75    SYMBOLS is a dictionary from VersionedSymbols to their flags.
76
77    """
78    result = []
79    for versym, flags in symbols.items():
80        result.append('{} {} {}\n'.format(
81            versym.version, versym.symbol, flags))
82    result.sort()
83    return result
84