#!/usr/bin/python
#
# ### docco. prefix all external symbols, write a new .o file
#

import sys

import coff_file


def apply_prefix(prefix, src_fname, dst_fname, rename_one=None):
  tm, fileflags, symbols, sections = coff_file.read_file(src_fname)

  for i in range(len(symbols)):
    # Symbol exists (not a placeholder):
    #   1) the specific symbol we're looking for
    #   2) otherwise, is externally visible, and is within a SECTION
    #      (meaning: defined, rather than just declared). The section
    #      number specifies definition, rather than external reference.
    if symbols[i] \
        and (rename_one == symbols[i][0]
             or (rename_one is None
                 and symbols[i][4] == coff_file.C_EXT
                 and symbols[i][2] > 0)):
      name = symbols[i][0]
      print 'Renaming: %s  ==>  %s' % (name, prefix + name)
      symbols[i] = (prefix + name,) + symbols[i][1:]

  coff_file.write_file(dst_fname, tm, fileflags, symbols, sections)


if __name__ == '__main__':
  if len(sys.argv) != 4 and len(sys.argv) != 5:
    print 'USAGE: %s PREFIX [SYMBOL] SOURCE DEST' \
        % (os.path.basename(sys.argv[0]),)
    sys.exit(1)

  if len(sys.argv) == 5:
    apply_prefix(sys.argv[1], sys.argv[3], sys.argv[4], sys.argv[2])
  else:
    apply_prefix(*sys.argv[1:])