#
# ldd.py
# library dependencies
#
# Copyright (C) 2009  Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Red Hat Author(s):  Martin Gracik <mgracik@redhat.com>
#

import os
import re
import commands


class LDD(object):

    def __init__(self, libroots=["/lib", "/usr/lib"]):
        f = open("/usr/bin/ldd", "r")
        for line in f.readlines():
            line = line.strip()
            if line.startswith("RTLDLIST="):
                rtldlist, sep, ld_linux = line.partition("=")
                break
        f.close()

        self._lddcmd = "LD_LIBRARY_PATH=%s %s --list" % (":".join(libroots),
                ld_linux)
        
        pattern = r"^([a-zA-Z0-9.]*\s=>\s)(?P<lib>[a-zA-Z0-9./-]*)\s\(0x[0-9a-f]*\)$"
        self.pattern = re.compile(pattern)

        self._deps = set()

        self._errors = []

    def is_elf(self, filename):
        cmd = "file --brief %s" % (filename)
        err, out = commands.getstatusoutput(cmd)
        if err:
            return False

        if not out.split()[0] == "ELF":
            return False

        return True

    def getDeps(self, filename):
        # skip no elf files
        if not self.is_elf(filename):
            return

        cmd = "%s %s" % (self._lddcmd, filename)
        err, out = commands.getstatusoutput(cmd)
        if err:
            self._errors.append((filename, out))
            return

        lines = out.splitlines()
        for line in lines:
            line = line.strip()

            m = self.pattern.match(line)
            if m:
                lib = m.group("lib")
                if lib not in self._deps:
                    self._deps.add(lib)
                    self.getDeps(lib)

    @property
    def deps(self):
        return self._deps

    @property
    def errors(self):
        return self._errors