1  # Check for a module in a set of extension directories.
       2  # An extension directory should contain a Setup file
       3  # and one or more .o files or a lib.a file.
       4  
       5  import os
       6  import parsesetup
       7  
       8  def checkextensions(unknown, extensions):
       9      files = []
      10      modules = []
      11      edict = {}
      12      for e in extensions:
      13          setup = os.path.join(e, 'Setup')
      14          liba = os.path.join(e, 'lib.a')
      15          if not os.path.isfile(liba):
      16              liba = None
      17          edict[e] = parsesetup.getsetupinfo(setup), liba
      18      for mod in unknown:
      19          for e in extensions:
      20              (mods, vars), liba = edict[e]
      21              if mod not in mods:
      22                  continue
      23              modules.append(mod)
      24              if liba:
      25                  # If we find a lib.a, use it, ignore the
      26                  # .o files, and use *all* libraries for
      27                  # *all* modules in the Setup file
      28                  if liba in files:
      29                      break
      30                  files.append(liba)
      31                  for m in list(mods.keys()):
      32                      files = files + select(e, mods, vars,
      33                                             m, 1)
      34                  break
      35              files = files + select(e, mods, vars, mod, 0)
      36              break
      37      return files, modules
      38  
      39  def select(e, mods, vars, mod, skipofiles):
      40      files = []
      41      for w in mods[mod]:
      42          w = treatword(w)
      43          if not w:
      44              continue
      45          w = expandvars(w, vars)
      46          for w in w.split():
      47              if skipofiles and w[-2:] == '.o':
      48                  continue
      49              # Assume $var expands to absolute pathname
      50              if w[0] not in ('-', '$') and w[-2:] in ('.o', '.a'):
      51                  w = os.path.join(e, w)
      52              if w[:2] in ('-L', '-R') and w[2:3] != '$':
      53                  w = w[:2] + os.path.join(e, w[2:])
      54              files.append(w)
      55      return files
      56  
      57  cc_flags = ['-I', '-D', '-U']
      58  cc_exts = ['.c', '.C', '.cc', '.c++']
      59  
      60  def treatword(w):
      61      if w[:2] in cc_flags:
      62          return None
      63      if w[:1] == '-':
      64          return w # Assume loader flag
      65      head, tail = os.path.split(w)
      66      base, ext = os.path.splitext(tail)
      67      if ext in cc_exts:
      68          tail = base + '.o'
      69          w = os.path.join(head, tail)
      70      return w
      71  
      72  def expandvars(str, vars):
      73      i = 0
      74      while i < len(str):
      75          i = k = str.find('$', i)
      76          if i < 0:
      77              break
      78          i = i+1
      79          var = str[i:i+1]
      80          i = i+1
      81          if var == '(':
      82              j = str.find(')', i)
      83              if j < 0:
      84                  break
      85              var = str[i:j]
      86              i = j+1
      87          if var in vars:
      88              str = str[:k] + vars[var] + str[i:]
      89              i = k
      90      return str