For building a upb amalgamator.

amalgamate.py

#!/usr/bin/python

import sys
import re

INCLUDE_RE = re.compile('^#include "([^"]*)"$')

def parse_include(line):
  match = INCLUDE_RE.match(line)
  return match.groups()[0] if match else None

class Amalgamator:
  def __init__(self):
    self.included = set()
    self.output_h = open("upb.h", "w")
    self.output_c = open("upb.c", "w")

    self.output_c.write("// Amalgamated source file\n")
    self.output_c.write('#include "upb.h"\n')

    self.output_h.write("// Amalgamated source file\n")

  def _process_file(self, infile_name, outfile):
    for line in open(infile_name):
      include = parse_include(line)
      if include is not None and include.startswith("upb"):
        if include not in self.included:
          self.included.add(include)
          self._add_header(include)
      else:
        outfile.write(line)

  def _add_header(self, filename):
    self._process_file(filename, self.output_h)

  def add_src(self, filename):
    self._process_file(filename, self.output_c)

amalgamator = Amalgamator()

for filename in sys.argv[1:]:
  amalgamator.add_src(filename.strip())