zeroinstall/injector/arch.py

   1 """
   2 Information about the current system's architecture.
   3
   4 This module provides information about the current system. It is used to determine
   5 whether an implementation is suitable for this machine, and to compare different implementations.
   6
   7 For example, it will indicate that:
   8
   9  - An i486 machine cannot run an i686 binary.
  10  - An i686 machine can run an i486 binary, but would prefer an i586 one.
  11  - A Windows binary cannot run on a Linux machine.
  12
  13 Each dictionary maps from a supported architecture type to a preference level. Lower numbers are
  14 better, Unsupported architectures are not listed at all.
  15 """
  16
  17 # Copyright (C) 2009, Thomas Leonard
  18 # See the README file for details, or visit http://0install.net.
  19
  20 from zeroinstall import _
  21 import os
  22
  23 # TODO: "import platform"?
  24
  25 # os_ranks and mapping are mappings from names to how good they are.
  26 # 1 => Native (best)
  27 # Higher numbers are worse but usable.
  28 try:
  29         _uname = os.uname()
  30         # On Darwin, machine is wrong.
  31         if _uname[0] == 'Darwin' and _uname[-1] == 'i386':
  32                 _cpu64 = os.popen('sysctl -n hw.cpu64bit_capable 2>&1').next().strip()
  33                 if _cpu64 == '1':
  34                         _uname = tuple(list(_uname[:-1])+['x86_64'])
  35 except AttributeError:
  36         # No uname. Probably Windows.
  37         import sys
  38         p = sys.platform
  39         if p == 'win64':
  40                 _uname = ('Windows', 'x86_64')
  41         elif p == 'win32':
  42                 from win32process import IsWow64Process
  43                 if IsWow64Process():
  44                         _uname = ('Windows', 'x86_64')
  45                 else:
  46                         _uname = ('Windows', 'i486')
  47         else:
  48                 _uname = (p, 'i486')
  49
  50 def canonicalize_os(os_):
  51         if os_.startswith('CYGWIN_NT'):
  52                 os_ = 'Cygwin'
  53         elif os_ == 'SunOS':
  54                 os_ = 'Solaris'
  55         return os_
  56
  57 def _get_os_ranks(target_os):
  58         target_os = canonicalize_os(target_os)
  59
  60         if target_os == 'Darwin':
  61                 # Special case Mac OS X, to separate it from Darwin/X
  62                 # (Mac OS X also includes the closed Apple frameworks)
  63                 if os.path.exists('/System/Library/Frameworks/Carbon.framework'):
  64                         target_os = 'MacOSX'
  65
  66         # Binaries compiled for _this_ OS are best...
  67         os_ranks = {target_os : 1}
  68
  69         # If target_os appears in the first column of this table, all
  70         # following OS types on the line will also run on this one
  71         # (earlier ones preferred):
  72         _os_matrix = {
  73                 'Cygwin': ['Windows'],
  74                 'MacOSX': ['Darwin'],
  75         }
  76
  77         for supported in _os_matrix.get(target_os, []):
  78                 os_ranks[supported] = len(os_ranks) + 1
  79
  80         # At the lowest priority, try an OS-independent implementation
  81         os_ranks[None] = len(os_ranks) + 1
  82         return os_ranks
  83
  84 os_ranks = _get_os_ranks(_uname[0])
  85
  86 # All chosen machine-specific implementations must come from the same group
  87 # Unlisted archs are in group 0
  88 machine_groups = {
  89         'x86_64': 64,
  90         'ppc64': 64,
  91 }
  92
  93 def canonicalize_machine(machine):
  94         if machine == 'x86':
  95                 machine = 'i386'
  96         elif machine == 'amd64':
  97                 machine = 'x86_64'
  98         elif machine == 'Power Macintosh':
  99                 machine = 'ppc'
 100         elif machine == 'i86pc':
 101                 machine = 'i686'
 102         return machine
 103
 104 def _get_machine_ranks(target_machine):
 105         target_machine = canonicalize_machine(target_machine)
 106
 107         # Binaries compiled for _this_machine are best...
 108         machine_ranks = {target_machine : 0}
 109
 110         # If target_machine appears in the first column of this table, all
 111         # following machine types on the line will also run on this one
 112         # (earlier ones preferred):
 113         _machine_matrix = {
 114                 'i486': ['i386'],
 115                 'i586': ['i486', 'i386'],
 116                 'i686': ['i586', 'i486', 'i386'],
 117                 'x86_64': ['i686', 'i586', 'i486', 'i386'],
 118                 'ppc': ['ppc32'],
 119                 'ppc64': ['ppc'],
 120         }
 121         for supported in _machine_matrix.get(target_machine, []):
 122                 machine_ranks[supported] = len(machine_ranks)
 123
 124         # At the lowest priority, try a machine-independant implementation
 125         machine_ranks[None] = len(machine_ranks)
 126         return machine_ranks
 127
 128 machine_ranks = _get_machine_ranks(_uname[-1])
 129
 130 class Architecture:
 131         """A description of an architecture. Use by L{solver} to make sure it chooses
 132         compatible versions.
 133         @ivar os_ranks: supported operating systems and their desirability
 134         @type os_ranks: {str: int}
 135         @ivar machine_ranks: supported CPU types and their desirability
 136         @type machine_ranks: {str: int}
 137         @ivar child_arch: architecture for dependencies (usually C{self})
 138         @type child_arch: L{Architecture}
 139         @ivar use: matching values for <requires use='...'>; otherwise the dependency is ignored
 140         @type use: set(str)
 141         """
 142
 143         use = frozenset([None])
 144
 145         def __init__(self, os_ranks, machine_ranks):
 146                 self.os_ranks = os_ranks
 147                 self.machine_ranks = machine_ranks
 148                 self.child_arch = self
 149
 150         def __str__(self):
 151                 return _("<Arch: %(os_ranks)s %(machine_ranks)s>") % {'os_ranks': self.os_ranks, 'machine_ranks': self.machine_ranks}
 152
 153 class SourceArchitecture(Architecture):
 154         """Matches source code that creates binaries for a particular architecture.
 155         Note that the L{child_arch} here is the binary; source code depends on binary tools,
 156         not on other source packages.
 157         """
 158         def __init__(self, binary_arch):
 159                 Architecture.__init__(self, binary_arch.os_ranks, {'src': 1})
 160                 self.child_arch = binary_arch
 161
 162 def get_host_architecture():
 163         """Get an Architecture that matches implementations that will run on the host machine.
 164         @rtype: L{Architecture}"""
 165         return Architecture(os_ranks, machine_ranks)
 166
 167 def get_architecture(os, machine):
 168         """Get an Architecture that matches binaries that will work on the given system.
 169         @param os: OS type, or None for host's type
 170         @param machine: CPU type, or None for host's type
 171         @return: an Architecture object
 172         @rtype: L{Architecture}"""
 173
 174         if os is None:
 175                 target_os_ranks = os_ranks
 176         else:
 177                 target_os_ranks = _get_os_ranks(os)
 178         if machine is None:
 179                 target_machine_ranks = machine_ranks
 180         else:
 181                 target_machine_ranks = _get_machine_ranks(machine)
 182
 183         return Architecture(target_os_ranks, target_machine_ranks)