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 class LibDescriptor(dict):
  72     KEYS = ['OBJS', 'LIBS']
  73
  74     def __init__(self, content=None):
  75         '''Creates an instance of a lib descriptor, initialized with contents
  76         from a list of strings when given. This is intended for use with
  77         file.readlines()'''
  78         if isinstance(content, list) and all([isinstance(item, str) for item in content]):
  79             pass
  80         elif content is not None:
  81             raise TypeError("LibDescriptor() arg 1 must be None or a list of strings")
  82         super(LibDescriptor, self).__init__()
  83         for key in self.KEYS:
  84             self[key] = []
  85         if not content:
  86             return
  87         for key, value in [(s.strip() for s in item.split('=', 2)) for item in content if item.find('=') >= 0]:
  88             if key in self.KEYS:
  89                 self[key] = value.split()
  90
  91     def __str__(self):
  92         '''Serializes the lib descriptor'''
  93         return '\n'.join('%s = %s' % (k, ' '.join(self[k])) for k in self.KEYS if len(self[k]))
  94
  95 class ExpandArgs(list):
  96     def __init__(self, args):
  97         '''Creates a clone of the |args| list and performs file expansion on
  98         each item it contains'''
  99         super(ExpandArgs, self).__init__()
 100         for arg in args:
 101             self += self._expand(arg)
 102
 103     def _expand(self, arg):
 104         '''Internal function doing the actual work'''
 105         (root, ext) = os.path.splitext(arg)
 106         if ext != conf.LIB_SUFFIX or not os.path.basename(root).startswith(conf.LIB_PREFIX):
 107             return [relativize(arg)]
 108         if len(conf.IMPORT_LIB_SUFFIX):
 109             dll = root + conf.IMPORT_LIB_SUFFIX
 110         else:
 111             dll = root.replace(conf.LIB_PREFIX, conf.DLL_PREFIX, 1) + conf.DLL_SUFFIX
 112         if os.path.exists(dll):
 113             return [relativize(dll)]
 114         if os.path.exists(arg):
 115             return [relativize(arg)]
 116         return self._expand_desc(arg)
 117
 118     def _expand_desc(self, arg):
 119         '''Internal function taking care of lib descriptor expansion only'''
 120         if os.path.exists(arg + conf.LIBS_DESC_SUFFIX):
 121             with open(arg + conf.LIBS_DESC_SUFFIX, 'r') as f:
 122                 desc = LibDescriptor(f.readlines())
 123             objs = [relativize(o) for o in desc['OBJS']]
 124             for lib in desc['LIBS']:
 125                 objs += self._expand(lib)
 126             return objs
 127         return [arg]
 128
 129 class ExpandLibsDeps(ExpandArgs):
 130     '''Same as ExpandArgs, but also adds the library descriptor to the list'''
 131     def _expand_desc(self, arg):
 132         objs = super(ExpandLibsDeps, self)._expand_desc(arg)
 133         if os.path.exists(arg + conf.LIBS_DESC_SUFFIX):
 134             objs += [relativize(arg + conf.LIBS_DESC_SUFFIX)]
 135         return objs
 136
 137 if __name__ == '__main__':
 138     print " ".join(ExpandArgs(sys.argv[1:]))