config/expandlibs.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 '''Expandlibs is a system that allows to replace some libraries with a
   6 descriptor file containing some linking information about them.
   7
   8 The descriptor file format is as follows:
   9 ---8<-----
  10 OBJS = a.o b.o ...
  11 LIBS = libfoo.a libbar.a ...
  12 --->8-----
  13
  14 (In the example above, OBJ_SUFFIX is o and LIB_SUFFIX is a).
  15
  16 Expandlibs also canonicalizes how to pass libraries to the linker, such
  17 that only the ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} form needs to be used:
  18 given a list of files, expandlibs will replace items with the form
  19 ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} following these rules:
  20
  21 - If a ${DLL_PREFIX}${ROOT}.${DLL_SUFFIX} or
  22   ${DLL_PREFIX}${ROOT}.${IMPORT_LIB_SUFFIX} file exists, use that instead
  23 - If the ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} file exists, use it
  24 - If a ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX}.${LIB_DESC_SUFFIX} file exists,
  25   replace ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} with the OBJS and LIBS the
  26   descriptor contains. And for each of these LIBS, also apply the same
  27   rules.
  28 '''
  29 from __future__ import with_statement
  30 import sys, os, errno
  31 import expandlibs_config as conf
  32
  33 def ensureParentDir(file):
  34     '''Ensures the directory parent to the given file exists'''
  35     dir = os.path.dirname(file)
  36     if dir and not os.path.exists(dir):
  37         try:
  38             os.makedirs(dir)
  39         except OSError, error:
  40             if error.errno != errno.EEXIST:
  41                 raise
  42
  43 def relativize(path):
  44     '''Returns a path relative to the current working directory, if it is
  45     shorter than the given path'''
  46     def splitpath(path):
  47         dir, file = os.path.split(path)
  48         if os.path.splitdrive(dir)[1] == os.sep:
  49             return [file]
  50         return splitpath(dir) + [file]
  51
  52     if not os.path.exists(path):
  53         return path
  54     curdir = splitpath(os.path.abspath(os.curdir))
  55     abspath = splitpath(os.path.abspath(path))
  56     while curdir and abspath and curdir[0] == abspath[0]:
  57         del curdir[0]
  58         del abspath[0]
  59     if not curdir and not abspath:
  60         return '.'
  61     relpath = os.path.join(*[os.pardir for i in curdir] + abspath)
  62     if len(path) > len(relpath):
  63         return relpath
  64     return path
  65
  66 def isObject(path):
  67     '''Returns whether the given path points to an object file, that is,
  68     ends with OBJ_SUFFIX or .i_o'''
  69     return os.path.splitext(path)[1] in [conf.OBJ_SUFFIX, '.i_o']
  70
  71 def isDynamicLib(path):
  72     '''Returns whether the given path points to a dynamic library, that is,
  73     ends with DLL_SUFFIX.'''
  74     # On mac, the xul library is named XUL, instead of libxul.dylib. Assume any
  75     # file by that name is a dynamic library.
  76     return os.path.splitext(path)[1] == conf.DLL_SUFFIX or os.path.basename(path) == 'XUL'
  77
  78 class LibDescriptor(dict):
  79     KEYS = ['OBJS', 'LIBS']
  80
  81     def __init__(self, content=None):
  82         '''Creates an instance of a lib descriptor, initialized with contents
  83         from a list of strings when given. This is intended for use with
  84         file.readlines()'''
  85         if isinstance(content, list) and all([isinstance(item, str) for item in content]):
  86             pass
  87         elif content is not None:
  88             raise TypeError("LibDescriptor() arg 1 must be None or a list of strings")
  89         super(LibDescriptor, self).__init__()
  90         for key in self.KEYS:
  91             self[key] = []
  92         if not content:
  93             return
  94         for key, value in [(s.strip() for s in item.split('=', 2)) for item in content if item.find('=') >= 0]:
  95             if key in self.KEYS:
  96                 self[key] = value.split()
  97
  98     def __str__(self):
  99         '''Serializes the lib descriptor'''
 100         return '\n'.join('%s = %s' % (k, ' '.join(self[k])) for k in self.KEYS if len(self[k]))
 101
 102 class ExpandArgs(list):
 103     def __init__(self, args):
 104         '''Creates a clone of the |args| list and performs file expansion on
 105         each item it contains'''
 106         super(ExpandArgs, self).__init__()
 107         self._descs = set()
 108         for arg in args:
 109             self += self._expand(arg)
 110
 111     def _expand(self, arg):
 112         '''Internal function doing the actual work'''
 113         (root, ext) = os.path.splitext(arg)
 114         if ext != conf.LIB_SUFFIX or not os.path.basename(root).startswith(conf.LIB_PREFIX):
 115             return [relativize(arg)]
 116         if len(conf.IMPORT_LIB_SUFFIX):
 117             dll = root + conf.IMPORT_LIB_SUFFIX
 118         else:
 119             dll = root.replace(conf.LIB_PREFIX, conf.DLL_PREFIX, 1) + conf.DLL_SUFFIX
 120         if os.path.exists(dll):
 121             return [relativize(dll)]
 122         if os.path.exists(arg):
 123             return [relativize(arg)]
 124         return self._expand_desc(arg)
 125
 126     def _expand_desc(self, arg):
 127         '''Internal function taking care of lib descriptor expansion only'''
 128         desc = os.path.abspath(arg + conf.LIBS_DESC_SUFFIX)
 129         if os.path.exists(desc):
 130             if desc in self._descs:
 131                 return []
 132             self._descs.add(desc)
 133             with open(desc, 'r') as f:
 134                 desc = LibDescriptor(f.readlines())
 135             objs = [relativize(o) for o in desc['OBJS']]
 136             for lib in desc['LIBS']:
 137                 objs += self._expand(lib)
 138             return objs
 139         return [arg]
 140
 141 if __name__ == '__main__':
 142     print " ".join(ExpandArgs(sys.argv[1:]))