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 except AttributeError:
  31         # No uname. Probably Windows.
  32         import sys
  33         p = sys.platform
  34         import platform
  35         bits, linkage = platform.architecture()
  36         if p == 'win32' and (bits == '' or bits == '32bit'):
  37                 _uname = ('Windows', 'i486')
  38         elif p == 'win64' or (p == 'win32' and bits == '64bit'):
  39                 _uname = ('Windows', 'x86_64')
  40         else:
  41                 _uname = (p, 'i486')
  42
  43 def canonicalize_os(os_):
  44         if os_.startswith('CYGWIN_NT'):
  45                 os_ = 'Cygwin'
  46         elif os_ == 'SunOS':
  47                 os_ = 'Solaris'
  48         return os_
  49
  50 def _get_os_ranks(target_os):
  51         target_os = canonicalize_os(target_os)
  52
  53         if target_os == 'Darwin':
  54                 # Special case Mac OS X, to separate it from Darwin/X
  55                 # (Mac OS X also includes the closed Apple frameworks)
  56                 if os.path.exists('/System/Library/Frameworks/Carbon.framework'):
  57                         target_os = 'MacOSX'
  58
  59         # Binaries compiled for _this_ OS are best...
  60         os_ranks = {target_os : 1}
  61
  62         # If target_os appears in the first column of this table, all
  63         # following OS types on the line will also run on this one
  64         # (earlier ones preferred):
  65         _os_matrix = {
  66                 'Cygwin': ['Windows'],
  67                 'MacOSX': ['Darwin'],
  68         }
  69
  70         for supported in _os_matrix.get(target_os, []):
  71                 os_ranks[supported] = len(os_ranks) + 1
  72
  73         # At the lowest priority, try an OS-independent implementation
  74         os_ranks[None] = len(os_ranks) + 1
  75         return os_ranks
  76
  77 os_ranks = _get_os_ranks(_uname[0])
  78
  79 # All chosen machine-specific implementations must come from the same group
  80 # Unlisted archs are in group 0
  81 machine_groups = {
  82         'x86_64': 64,
  83         'ppc64': 64,
  84 }
  85
  86 def canonicalize_machine(machine):
  87         if machine == 'x86':
  88                 machine = 'i386'
  89         elif machine == 'amd64':
  90                 machine = 'x86_64'
  91         elif machine == 'Power Macintosh':
  92                 machine = 'ppc'
  93         elif machine == 'i86pc':
  94                 machine = 'i686'
  95         return machine
  96
  97 def _get_machine_ranks(target_machine):
  98         target_machine = canonicalize_machine(target_machine)
  99
 100         # Binaries compiled for _this_machine are best...
 101         machine_ranks = {target_machine : 0}
 102
 103         # If target_machine appears in the first column of this table, all
 104         # following machine types on the line will also run on this one
 105         # (earlier ones preferred):
 106         _machine_matrix = {
 107                 'i486': ['i386'],
 108                 'i586': ['i486', 'i386'],
 109                 'i686': ['i586', 'i486', 'i386'],
 110                 'x86_64': ['i686', 'i586', 'i486', 'i386'],
 111                 'ppc': ['ppc32'],
 112                 'ppc64': ['ppc'],
 113         }
 114         for supported in _machine_matrix.get(target_machine, []):
 115                 machine_ranks[supported] = len(machine_ranks)
 116
 117         # At the lowest priority, try a machine-independant implementation
 118         machine_ranks[None] = len(machine_ranks)
 119         return machine_ranks
 120
 121 machine_ranks = _get_machine_ranks(_uname[-1])
 122
 123 class Architecture:
 124         """A description of an architecture. Use by L{solver} to make sure it chooses
 125         compatible versions.
 126         @ivar os_ranks: supported operating systems and their desirability
 127         @type os_ranks: {str: int}
 128         @ivar machine_ranks: supported CPU types and their desirability
 129         @type machine_ranks: {str: int}
 130         @ivar child_arch: architecture for dependencies (usually C{self})
 131         @type child_arch: L{Architecture}
 132         @ivar use: matching values for <requires use='...'>; otherwise the dependency is ignored
 133         @type use: set(str)
 134         """
 135
 136         use = frozenset([None])
 137
 138         def __init__(self, os_ranks, machine_ranks):
 139                 self.os_ranks = os_ranks
 140                 self.machine_ranks = machine_ranks
 141                 self.child_arch = self
 142
 143         def __str__(self):
 144                 return _("<Arch: %(os_ranks)s %(machine_ranks)s>") % {'os_ranks': self.os_ranks, 'machine_ranks': self.machine_ranks}
 145
 146 class SourceArchitecture(Architecture):
 147         """Matches source code that creates binaries for a particular architecture.
 148         Note that the L{child_arch} here is the binary; source code depends on binary tools,
 149         not on other source packages.
 150         """
 151         def __init__(self, binary_arch):
 152                 Architecture.__init__(self, binary_arch.os_ranks, {'src': 1})
 153                 self.child_arch = binary_arch
 154
 155 def get_host_architecture():
 156         """Get an Architecture that matches implementations that will run on the host machine.
 157         @rtype: L{Architecture}"""
 158         return Architecture(os_ranks, machine_ranks)
 159
 160 def get_architecture(os, machine):
 161         """Get an Architecture that matches binaries that will work on the given system.
 162         @param os: OS type, or None for host's type
 163         @param machine: CPU type, or None for host's type
 164         @return: an Architecture object
 165         @rtype: L{Architecture}"""
 166
 167         if os is None:
 168                 target_os_ranks = os_ranks
 169         else:
 170                 target_os_ranks = _get_os_ranks(os)
 171         if machine is None:
 172                 target_machine_ranks = machine_ranks
 173         else:
 174                 target_machine_ranks = _get_machine_ranks(machine)
 175
 176         return Architecture(target_os_ranks, target_machine_ranks)