cef/tools/make_cpptoc_impl.py

# Copyright (c) 2011 The Chromium Embedded Framework Authors. All rights
# reserved. Use of this source code is governed by a BSD-style license that
# can be found in the LICENSE file.

from __future__ import absolute_import
from cef_parser import *


def make_cpptoc_impl_proto(name, func, parts):
  if isinstance(func, obj_function_virtual):
    proto = parts['retval'] + ' CEF_CALLBACK'
  else:
    proto = 'CEF_EXPORT ' + parts['retval']

  proto += ' ' + name + '(' + ', '.join(parts['args']) + ')'
  return proto


def make_cpptoc_function_impl_existing(cls, name, func, impl, defined_names):
  notify(name + ' has manual edits')

  # retrieve the C API prototype parts
  parts = func.get_capi_parts(defined_names, True)

  changes = format_translation_changes(impl, parts)
  if len(changes) > 0:
    notify(name + ' prototype changed')

  return make_cpptoc_impl_proto(
      name, func, parts) + '{' + changes + impl['body'] + '\n}\n\n'


def make_cpptoc_function_impl_new(cls, name, func, defined_names, base_scoped):
  # Special handling for the cef_shutdown global function.
  is_cef_shutdown = name == 'cef_shutdown' and isinstance(
      func.parent, obj_header)

  # retrieve the C API prototype parts
  parts = func.get_capi_parts(defined_names, True)
  result = make_cpptoc_impl_proto(name, func, parts) + ' {'

  if isinstance(func.parent, obj_class) and \
      not func.parent.has_attrib('no_debugct_check') and \
      not base_scoped:
    result += '\n  shutdown_checker::AssertNotShutdown();\n'

  invalid = []

  # retrieve the function arguments
  args = func.get_arguments()

  # determine the argument types
  for arg in args:
    if arg.get_arg_type() == 'invalid':
      invalid.append(arg.get_name())

  # retrieve the function return value
  retval = func.get_retval()
  retval_type = retval.get_retval_type()
  if retval_type == 'invalid':
    invalid.append('(return value)')
    retval_default = ''
  else:
    retval_default = retval.get_retval_default(True)
    if len(retval_default) > 0:
      retval_default = ' ' + retval_default

  if len(invalid) > 0:
    notify(name + ' could not be autogenerated')
    # code could not be auto-generated
    result += '\n  // BEGIN DELETE BEFORE MODIFYING'
    result += '\n  // AUTO-GENERATED CONTENT'
    result += '\n  // COULD NOT IMPLEMENT DUE TO: ' + ', '.join(invalid)
    result += '\n  #pragma message("Warning: "__FILE__": ' + name + ' is not implemented")'
    result += '\n  // END DELETE BEFORE MODIFYING'
    result += '\n}\n\n'
    return result

  result += '\n  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING\n'

  result_len = len(result)

  optional = []

  # parameter verification
  if isinstance(func, obj_function_virtual):
    result += '\n  DCHECK(self);'\
              '\n  if (!self)'\
              '\n    return'+retval_default+';'

  for arg in args:
    arg_type = arg.get_arg_type()
    arg_name = arg.get_type().get_name()

    # skip optional params
    optional_params = arg.parent.get_attrib_list('optional_param')
    if not optional_params is None and arg_name in optional_params:
      optional.append(arg_name)
      continue

    comment = '\n  // Verify param: ' + arg_name + '; type: ' + arg_type

    if arg_type == 'simple_byref' or arg_type == 'simple_byref_const' or \
       arg_type == 'simple_byaddr' or arg_type == 'bool_byref' or arg_type == 'bool_byaddr' or \
       arg_type == 'struct_byref_const' or arg_type == 'struct_byref' or \
       arg_type == 'string_byref_const' or arg_type == 'string_byref' or \
       arg_type == 'refptr_same' or arg_type == 'refptr_same_byref' or \
       arg_type == 'refptr_diff' or arg_type == 'refptr_diff_byref' or \
       arg_type == 'ownptr_same' or arg_type == 'ownptr_same_byref' or \
       arg_type == 'ownptr_diff' or arg_type == 'ownptr_diff_byref' or \
       arg_type == 'rawptr_same' or arg_type == 'rawptr_same_byref' or \
       arg_type == 'rawptr_diff' or arg_type == 'rawptr_diff_byref' or \
       arg_type == 'string_vec_byref' or arg_type == 'string_vec_byref_const' or \
       arg_type == 'string_map_single_byref' or arg_type == 'string_map_single_byref_const' or \
       arg_type == 'string_map_multi_byref' or arg_type == 'string_map_multi_byref_const':
      result += comment+\
                '\n  DCHECK('+arg_name+');'\
                '\n  if (!'+arg_name+')'\
                '\n    return'+retval_default+';'
      if arg_type == 'struct_byref_const' or arg_type == 'struct_byref':
        result +=\
                '\n  if (!template_util::has_valid_size('+arg_name+')) {'\
                '\n    NOTREACHED() << "invalid '+arg_name+'->[base.]size";'\
                '\n    return'+retval_default+';'\
                '\n  }'
    elif arg_type == 'simple_vec_byref' or arg_type == 'bool_vec_byref' or \
        arg_type == 'refptr_vec_same_byref' or arg_type == 'refptr_vec_diff_byref' or \
        arg_type == 'ownptr_vec_same_byref' or arg_type == 'ownptr_vec_diff_byref' or \
        arg_type == 'rawptr_vec_same_byref' or arg_type == 'rawptr_vec_diff_byref':
      result += comment+\
                '\n  DCHECK('+arg_name+'Count && (*'+arg_name+'Count == 0 || '+arg_name+'));'\
                '\n  if (!'+arg_name+'Count || (*'+arg_name+'Count > 0 && !'+arg_name+'))'\
                '\n    return'+retval_default+';'
    elif arg_type == 'simple_vec_byref_const' or arg_type == 'bool_vec_byref_const' or \
        arg_type == 'refptr_vec_same_byref_const' or arg_type == 'refptr_vec_diff_byref_const' or \
        arg_type == 'ownptr_vec_same_byref_const' or arg_type == 'ownptr_vec_diff_byref_const' or \
        arg_type == 'rawptr_vec_same_byref_const' or arg_type == 'rawptr_vec_diff_byref_const':
      result += comment+\
                '\n  DCHECK('+arg_name+'Count == 0 || '+arg_name+');'\
                '\n  if ('+arg_name+'Count > 0 && !'+arg_name+')'\
                '\n    return'+retval_default+';'

    # check index params
    index_params = arg.parent.get_attrib_list('index_param')
    if not index_params is None and arg_name in index_params:
      result += comment+\
                '\n  DCHECK_GE('+arg_name+', 0);'\
                '\n  if ('+arg_name+' < 0)'\
                '\n    return'+retval_default+';'

  if len(optional) > 0:
    # Wrap the comment at 80 characters.
    str = '\n  // Unverified params: ' + optional[0]
    for name in optional[1:]:
      str += ','
      if len(str) + len(name) + 1 > 80:
        result += str
        str = '\n  //'
      str += ' ' + name
    result += str

  if len(result) != result_len:
    result += '\n'
  result_len = len(result)

  # parameter translation
  params = []

  for arg in args:
    arg_type = arg.get_arg_type()
    arg_name = arg.get_type().get_name()

    comment = '\n  // Translate param: ' + arg_name + '; type: ' + arg_type

    if arg_type == 'simple_byval' or arg_type == 'simple_byaddr':
      params.append(arg_name)
    elif arg_type == 'simple_byref' or arg_type == 'simple_byref_const':
      data_type = arg.get_type().get_type()
      default = arg.get_type().get_result_simple_default()
      result += comment+\
                '\n  '+data_type+' '+arg_name+'Val = '+arg_name+'?*'+arg_name+':'+default+';'
      params.append(arg_name + 'Val')
    elif arg_type == 'bool_byval':
      params.append(arg_name + '?true:false')
    elif arg_type == 'bool_byref' or arg_type == 'bool_byaddr':
      result += comment+\
                '\n  bool '+arg_name+'Bool = ('+arg_name+' && *'+arg_name+')?true:false;'
      if arg_type == 'bool_byref':
        params.append(arg_name + 'Bool')
      else:
        params.append('&' + arg_name + 'Bool')
    elif arg_type == 'struct_byref_const':
      struct_type = arg.get_type().get_type()
      result += comment+\
                '\n  '+struct_type+' '+arg_name+'Obj;'\
                '\n  if ('+arg_name+')'\
                '\n    '+arg_name+'Obj.Set(*'+arg_name+', false);'
      params.append(arg_name + 'Obj')
    elif arg_type == 'struct_byref':
      struct_type = arg.get_type().get_type()
      result += comment+\
                '\n  '+struct_type+' '+arg_name+'Obj;'\
                '\n  if ('+arg_name+')'\
                '\n    '+arg_name+'Obj.AttachTo(*'+arg_name+');'
      params.append(arg_name + 'Obj')
    elif arg_type == 'string_byref_const':
      params.append('CefString(' + arg_name + ')')
    elif arg_type == 'string_byref':
      result += comment+\
                '\n  CefString '+arg_name+'Str('+arg_name+');'
      params.append(arg_name + 'Str')
    elif arg_type == 'refptr_same' or arg_type == 'refptr_diff':
      ptr_class = arg.get_type().get_ptr_type()
      if arg_type == 'refptr_same':
        params.append(ptr_class + 'CppToC::Unwrap(' + arg_name + ')')
      else:
        params.append(ptr_class + 'CToCpp::Wrap(' + arg_name + ')')
    elif arg_type == 'ownptr_same' or arg_type == 'rawptr_same':
      ptr_class = arg.get_type().get_ptr_type()
      if arg_type == 'ownptr_same':
        params.append(ptr_class + 'CppToC::UnwrapOwn(' + arg_name + ')')
      else:
        params.append(ptr_class + 'CppToC::UnwrapRaw(' + arg_name + ')')
    elif arg_type == 'ownptr_diff' or arg_type == 'rawptr_diff':
      ptr_class = arg.get_type().get_ptr_type()
      result += comment+\
                '\n  CefOwnPtr<'+ptr_class+'> '+arg_name+'Ptr('+ptr_class+'CToCpp::Wrap('+arg_name+'));'
      if arg_type == 'ownptr_diff':
        params.append('std::move(' + arg_name + 'Ptr)')
      else:
        params.append(arg_name + 'Ptr.get()')
    elif arg_type == 'refptr_same_byref' or arg_type == 'refptr_diff_byref':
      ptr_class = arg.get_type().get_ptr_type()
      if arg_type == 'refptr_same_byref':
        assign = ptr_class + 'CppToC::Unwrap(*' + arg_name + ')'
      else:
        assign = ptr_class + 'CToCpp::Wrap(*' + arg_name + ')'
      result += comment+\
                '\n  CefRefPtr<'+ptr_class+'> '+arg_name+'Ptr;'\
                '\n  if ('+arg_name+' && *'+arg_name+')'\
                '\n    '+arg_name+'Ptr = '+assign+';'\
                '\n  '+ptr_class+'* '+arg_name+'Orig = '+arg_name+'Ptr.get();'
      params.append(arg_name + 'Ptr')
    elif arg_type == 'string_vec_byref' or arg_type == 'string_vec_byref_const':
      result += comment+\
                '\n  std::vector<CefString> '+arg_name+'List;'\
                '\n  transfer_string_list_contents('+arg_name+', '+arg_name+'List);'
      params.append(arg_name + 'List')
    elif arg_type == 'string_map_single_byref' or arg_type == 'string_map_single_byref_const':
      result += comment+\
                '\n  std::map<CefString, CefString> '+arg_name+'Map;'\
                '\n  transfer_string_map_contents('+arg_name+', '+arg_name+'Map);'
      params.append(arg_name + 'Map')
    elif arg_type == 'string_map_multi_byref' or arg_type == 'string_map_multi_byref_const':
      result += comment+\
                '\n  std::multimap<CefString, CefString> '+arg_name+'Multimap;'\
                '\n  transfer_string_multimap_contents('+arg_name+', '+arg_name+'Multimap);'
      params.append(arg_name + 'Multimap')
    elif arg_type == 'simple_vec_byref' or arg_type == 'bool_vec_byref' or \
        arg_type == 'refptr_vec_same_byref' or arg_type == 'refptr_vec_diff_byref':
      vec_type = arg.get_type().get_vector_type()
      if arg_type == 'simple_vec_byref':
        assign = arg_name + '[i]'
      elif arg_type == 'bool_vec_byref':
        assign = arg_name + '[i]?true:false'
      elif arg_type == 'refptr_vec_same_byref':
        ptr_class = arg.get_type().get_ptr_type()
        assign = ptr_class + 'CppToC::Unwrap(' + arg_name + '[i])'
      elif arg_type == 'refptr_vec_diff_byref':
        ptr_class = arg.get_type().get_ptr_type()
        assign = ptr_class + 'CToCpp::Wrap(' + arg_name + '[i])'
      result += comment+\
                '\n  std::vector<'+vec_type+' > '+arg_name+'List;'\
                '\n  if ('+arg_name+'Count && *'+arg_name+'Count > 0 && '+arg_name+') {'\
                '\n    for (size_t i = 0; i < *'+arg_name+'Count; ++i) {'\
                '\n      '+arg_name+'List.push_back('+assign+');'\
                '\n    }'\
                '\n  }'
      params.append(arg_name + 'List')
    elif arg_type == 'simple_vec_byref_const' or arg_type == 'bool_vec_byref_const' or \
        arg_type == 'refptr_vec_same_byref_const' or arg_type == 'refptr_vec_diff_byref_const' or \
        arg_type == 'rawptr_vec_same_byref_const' or arg_type == 'rawptr_vec_diff_byref_const':
      vec_type = arg.get_type().get_vector_type()
      if arg_type == 'simple_vec_byref_const':
        assign = arg_name + '[i]'
      elif arg_type == 'bool_vec_byref_const':
        assign = arg_name + '[i]?true:false'
      else:
        ptr_class = arg.get_type().get_ptr_type()
        if arg_type == 'refptr_vec_same_byref_const':
          assign = ptr_class + 'CppToC::Unwrap(' + arg_name + '[i])'
        elif arg_type == 'refptr_vec_diff_byref_const':
          assign = ptr_class + 'CToCpp::Wrap(' + arg_name + '[i])'
        elif arg_type == 'rawptr_vec_same_byref_const':
          assign = ptr_class + 'CppToC::UnwrapRaw(' + arg_name + '[i])'
        elif arg_type == 'rawptr_vec_diff_byref_const':
          assign = ptr_class + 'CToCpp::Wrap(' + arg_name + '[i]).release()'
      result += comment+\
                '\n  std::vector<'+vec_type+' > '+arg_name+'List;'\
                '\n  if ('+arg_name+'Count > 0) {'\
                '\n    for (size_t i = 0; i < '+arg_name+'Count; ++i) {'\
                '\n      '+vec_type+' '+arg_name+'Val = '+assign+';'\
                '\n      '+arg_name+'List.push_back('+arg_name+'Val);'\
                '\n    }'\
                '\n  }'
      params.append(arg_name + 'List')
    else:
      raise Exception('Unsupported argument type %s for parameter %s in %s' %
                      (arg_type, arg_name, name))

  if len(result) != result_len:
    result += '\n'
  result_len = len(result)

  if is_cef_shutdown:
    result += '\n\n#if DCHECK_IS_ON()'\
              '\n  shutdown_checker::SetIsShutdown();'\
              '\n#endif\n'

  # execution
  result += '\n  // Execute\n  '

  if retval_type != 'none':
    # has a return value
    if retval_type == 'simple':
      result += retval.get_type().get_result_simple_type()
    else:
      result += retval.get_type().get_type()
    result += ' _retval = '

  if isinstance(func.parent, obj_class):
    # virtual and static class methods
    if isinstance(func, obj_function_virtual):
      if cls.get_name() == func.parent.get_name():
        # virtual method for the current class
        result += func.parent.get_name() + 'CppToC::Get(self)->'
      else:
        # virtual method for a parent class
        result += cls.get_name(
        ) + 'CppToC::Get(reinterpret_cast<' + cls.get_capi_name() + '*>(self))->'
    else:
      result += func.parent.get_name() + '::'
  result += func.get_name() + '('

  if len(params) > 0:
    result += '\n      ' + ',\n      '.join(params)

  result += ');\n'

  result_len = len(result)

  # parameter restoration
  for arg in args:
    arg_type = arg.get_arg_type()
    arg_name = arg.get_type().get_name()

    comment = '\n  // Restore param: ' + arg_name + '; type: ' + arg_type

    if arg_type == 'simple_byref':
      result += comment+\
                '\n  if ('+arg_name+')'\
                '\n    *'+arg_name+' = '+arg_name+'Val;'
    elif arg_type == 'bool_byref' or arg_type == 'bool_byaddr':
      result += comment+\
                '\n  if ('+arg_name+')'\
                '\n    *'+arg_name+' = '+arg_name+'Bool?true:false;'
    elif arg_type == 'struct_byref':
      result += comment+\
                '\n  if ('+arg_name+')'\
                '\n    '+arg_name+'Obj.DetachTo(*'+arg_name+');'
    elif arg_type == 'refptr_same_byref' or arg_type == 'refptr_diff_byref':
      ptr_class = arg.get_type().get_ptr_type()
      if arg_type == 'refptr_same_byref':
        assign = ptr_class + 'CppToC::Wrap(' + arg_name + 'Ptr)'
      else:
        assign = ptr_class + 'CToCpp::Unwrap(' + arg_name + 'Ptr)'
      result += comment+\
                '\n  if ('+arg_name+') {'\
                '\n    if ('+arg_name+'Ptr.get()) {'\
                '\n      if ('+arg_name+'Ptr.get() != '+arg_name+'Orig) {'\
                '\n        *'+arg_name+' = '+assign+';'\
                '\n      }'\
                '\n    } else {'\
                '\n      *'+arg_name+' = nullptr;'\
                '\n    }'\
                '\n  }'
    elif arg_type == 'string_vec_byref':
      result += comment+\
                '\n  cef_string_list_clear('+arg_name+');'\
                '\n  transfer_string_list_contents('+arg_name+'List, '+arg_name+');'
    elif arg_type == 'string_map_single_byref':
      result += comment+\
                '\n  cef_string_map_clear('+arg_name+');'\
                '\n  transfer_string_map_contents('+arg_name+'Map, '+arg_name+');'
    elif arg_type == 'string_map_multi_byref':
      result += comment+\
                '\n  cef_string_multimap_clear('+arg_name+');'\
                '\n  transfer_string_multimap_contents('+arg_name+'Multimap, '+arg_name+');'
    elif arg_type == 'simple_vec_byref' or arg_type == 'bool_vec_byref' or \
        arg_type == 'refptr_vec_same_byref' or arg_type == 'refptr_vec_diff_byref':
      if arg_type == 'simple_vec_byref' or arg_type == 'bool_vec_byref':
        assign = arg_name + 'List[i]'
      elif arg_type == 'refptr_vec_same_byref':
        ptr_class = arg.get_type().get_ptr_type()
        assign = ptr_class + 'CppToC::Wrap(' + arg_name + 'List[i])'
      elif arg_type == 'refptr_vec_diff_byref':
        ptr_class = arg.get_type().get_ptr_type()
        assign = ptr_class + 'CToCpp::Unwrap(' + arg_name + 'List[i])'
      result += comment+\
                '\n  if ('+arg_name+'Count && '+arg_name+') {'\
                '\n    *'+arg_name+'Count = std::min('+arg_name+'List.size(), *'+arg_name+'Count);'\
                '\n    if (*'+arg_name+'Count > 0) {'\
                '\n      for (size_t i = 0; i < *'+arg_name+'Count; ++i) {'\
                '\n        '+arg_name+'[i] = '+assign+';'\
                '\n      }'\
                '\n    }'\
                '\n  }'
    elif arg_type == 'rawptr_vec_diff_byref_const':
      result += comment+\
                '\n  if ('+arg_name+'Count > 0) {'\
                '\n    for (size_t i = 0; i < '+arg_name+'Count; ++i) {'\
                '\n      delete '+arg_name+'List[i];'\
                '\n    }'\
                '\n  }'

  if len(result) != result_len:
    result += '\n'
  result_len = len(result)

  if len(result) != result_len:
    result += '\n'
  result_len = len(result)

  # return translation
  if retval_type != 'none':
    # has a return value
    result += '\n  // Return type: ' + retval_type
    if retval_type == 'simple' or retval_type == 'bool':
      result += '\n  return _retval;'
    elif retval_type == 'string':
      result += '\n  return _retval.DetachToUserFree();'
    elif retval_type == 'refptr_same':
      ptr_class = retval.get_type().get_ptr_type()
      result += '\n  return ' + ptr_class + 'CppToC::Wrap(_retval);'
    elif retval_type == 'refptr_diff':
      ptr_class = retval.get_type().get_ptr_type()
      result += '\n  return ' + ptr_class + 'CToCpp::Unwrap(_retval);'
    elif retval_type == 'ownptr_same':
      ptr_class = retval.get_type().get_ptr_type()
      result += '\n  return ' + ptr_class + 'CppToC::WrapOwn(std::move(_retval));'
    elif retval_type == 'ownptr_diff':
      ptr_class = retval.get_type().get_ptr_type()
      result += '\n  return ' + ptr_class + 'CToCpp::UnwrapOwn(std::move(_retval));'
    else:
      raise Exception('Unsupported return type %s in %s' % (retval_type, name))

  if len(result) != result_len:
    result += '\n'

  result += '}\n\n'
  return result


def make_cpptoc_function_impl(cls, funcs, existing, prefixname, defined_names,
                              base_scoped):
  impl = ''

  for func in funcs:
    if not prefixname is None:
      name = prefixname + '_' + func.get_capi_name()
    else:
      name = func.get_capi_name()
    value = get_next_function_impl(existing, name)
    if not value is None \
        and value['body'].find('// AUTO-GENERATED CONTENT') < 0:
      # an implementation exists that was not auto-generated
      impl += make_cpptoc_function_impl_existing(cls, name, func, value,
                                                 defined_names)
    else:
      impl += make_cpptoc_function_impl_new(cls, name, func, defined_names,
                                            base_scoped)

  return impl


def make_cpptoc_virtual_function_impl(header, cls, existing, prefixname,
                                      defined_names, base_scoped):
  funcs = []
  funcs.extend(cls.get_virtual_funcs())
  cur_cls = cls
  while True:
    parent_name = cur_cls.get_parent_name()
    if is_base_class(parent_name):
      break
    else:
      parent_cls = header.get_class(parent_name, defined_names)
      if parent_cls is None:
        raise Exception('Class does not exist: ' + parent_name)
      funcs.extend(parent_cls.get_virtual_funcs())
    cur_cls = header.get_class(parent_name, defined_names)

  return make_cpptoc_function_impl(cls, funcs, existing, prefixname,
                                   defined_names, base_scoped)


def make_cpptoc_virtual_function_assignment_block(funcs, offset, prefixname):
  impl = ''
  for func in funcs:
    name = func.get_capi_name()
    impl += '  GetStruct()->' + offset + name + ' = ' + prefixname + '_' + name + ';\n'
  return impl


def make_cpptoc_virtual_function_assignment(header, cls, prefixname,
                                            defined_names):
  impl = make_cpptoc_virtual_function_assignment_block(cls.get_virtual_funcs(),
                                                       '', prefixname)

  cur_cls = cls
  offset = ''
  while True:
    parent_name = cur_cls.get_parent_name()
    offset += 'base.'
    if is_base_class(parent_name):
      break
    else:
      parent_cls = header.get_class(parent_name, defined_names)
      if parent_cls is None:
        raise Exception('Class does not exist: ' + parent_name)
      impl += make_cpptoc_virtual_function_assignment_block(
          parent_cls.get_virtual_funcs(), offset, prefixname)
    cur_cls = header.get_class(parent_name, defined_names)

  return impl


def make_cpptoc_unwrap_derived(header, cls, base_scoped):
  # identify all classes that derive from cls
  derived_classes = []
  cur_clsname = cls.get_name()
  allclasses = header.get_classes()
  for cur_cls in allclasses:
    if cur_cls.get_name() == cur_clsname:
      continue
    if cur_cls.has_parent(cur_clsname):
      derived_classes.append(cur_cls.get_name())

  derived_classes = sorted(derived_classes)

  if base_scoped:
    impl = ['', '']
    for clsname in derived_classes:
      impl[0] += '  if (type == '+get_wrapper_type_enum(clsname)+') {\n'+\
                 '    return '+clsname+'CppToC::UnwrapOwn(reinterpret_cast<'+\
                 get_capi_name(clsname, True)+'*>(s));\n'+\
                 '  }\n'
      impl[1] += '  if (type == '+get_wrapper_type_enum(clsname)+') {\n'+\
                 '    return '+clsname+'CppToC::UnwrapRaw(reinterpret_cast<'+\
                 get_capi_name(clsname, True)+'*>(s));\n'+\
                 '  }\n'
  else:
    impl = ''
    for clsname in derived_classes:
      impl += '  if (type == '+get_wrapper_type_enum(clsname)+') {\n'+\
              '    return '+clsname+'CppToC::Unwrap(reinterpret_cast<'+\
              get_capi_name(clsname, True)+'*>(s));\n'+\
              '  }\n'
  return impl


def make_cpptoc_class_impl(header, clsname, impl):
  # structure names that have already been defined
  defined_names = header.get_defined_structs()

  # retrieve the class and populate the defined names
  cls = header.get_class(clsname, defined_names)
  if cls is None:
    raise Exception('Class does not exist: ' + clsname)

  capiname = cls.get_capi_name()
  prefixname = get_capi_name(clsname[3:], False)

  # retrieve the existing virtual function implementations
  existing = get_function_impls(impl, 'CEF_CALLBACK')

  base_class_name = header.get_base_class_name(clsname)
  base_scoped = True if base_class_name == 'CefBaseScoped' else False
  if base_scoped:
    template_class = 'CefCppToCScoped'
  else:
    template_class = 'CefCppToCRefCounted'

  # generate virtual functions
  virtualimpl = make_cpptoc_virtual_function_impl(
      header, cls, existing, prefixname, defined_names, base_scoped)
  if len(virtualimpl) > 0:
    virtualimpl = '\nnamespace {\n\n// MEMBER FUNCTIONS - Body may be edited by hand.\n\n' + virtualimpl + '}  // namespace'

  # the current class is already defined for static functions
  defined_names.append(cls.get_capi_name())

  # retrieve the existing static function implementations
  existing = get_function_impls(impl, 'CEF_EXPORT')

  # generate static functions
  staticimpl = make_cpptoc_function_impl(cls,
                                         cls.get_static_funcs(), existing, None,
                                         defined_names, base_scoped)
  if len(staticimpl) > 0:
    staticimpl = '\n// GLOBAL FUNCTIONS - Body may be edited by hand.\n\n' + staticimpl

  resultingimpl = staticimpl + virtualimpl

  # any derived classes can be unwrapped
  unwrapderived = make_cpptoc_unwrap_derived(header, cls, base_scoped)

  const =  '// CONSTRUCTOR - Do not edit by hand.\n\n'+ \
           clsname+'CppToC::'+clsname+'CppToC() {\n'
  const += make_cpptoc_virtual_function_assignment(header, cls, prefixname,
                                                   defined_names)
  const += '}\n\n'+ \
           '// DESTRUCTOR - Do not edit by hand.\n\n'+ \
           clsname+'CppToC::~'+clsname+'CppToC() {\n'

  if not cls.has_attrib('no_debugct_check') and not base_scoped:
    const += '  shutdown_checker::AssertNotShutdown();\n'

  const += '}\n\n'

  # determine what includes are required by identifying what translation
  # classes are being used
  includes = format_translation_includes(header, const + resultingimpl +
                                         (unwrapderived[0]
                                          if base_scoped else unwrapderived))

  # build the final output
  result = get_copyright()

  result += includes + '\n' + resultingimpl + '\n'

  parent_sig = template_class + '<' + clsname + 'CppToC, ' + clsname + ', ' + capiname + '>'

  if base_scoped:
    const += 'template<> CefOwnPtr<'+clsname+'> '+parent_sig+'::UnwrapDerivedOwn(CefWrapperType type, '+capiname+'* s) {\n' + \
             unwrapderived[0] + \
             '  NOTREACHED() << "Unexpected class type: " << type;\n'+ \
             '  return CefOwnPtr<'+clsname+'>();\n'+ \
             '}\n\n' + \
             'template<> CefRawPtr<'+clsname+'> '+parent_sig+'::UnwrapDerivedRaw(CefWrapperType type, '+capiname+'* s) {\n' + \
             unwrapderived[1] + \
             '  NOTREACHED() << "Unexpected class type: " << type;\n'+ \
             '  return nullptr;\n'+ \
             '}\n\n'
  else:
    const += 'template<> CefRefPtr<'+clsname+'> '+parent_sig+'::UnwrapDerived(CefWrapperType type, '+capiname+'* s) {\n' + \
             unwrapderived + \
             '  NOTREACHED() << "Unexpected class type: " << type;\n'+ \
             '  return nullptr;\n'+ \
             '}\n\n'

  const += 'template<> CefWrapperType ' + parent_sig + '::kWrapperType = ' + get_wrapper_type_enum(
      clsname) + ';'

  result += '\n\n' + const

  return result


def make_cpptoc_global_impl(header, impl):
  # structure names that have already been defined
  defined_names = header.get_defined_structs()

  # retrieve the existing global function implementations
  existing = get_function_impls(impl, 'CEF_EXPORT')

  # generate global functions
  impl = make_cpptoc_function_impl(None,
                                   header.get_funcs(), existing, None,
                                   defined_names, False)
  if len(impl) > 0:
    impl = '\n// GLOBAL FUNCTIONS - Body may be edited by hand.\n\n' + impl

  includes = ''

  # include required headers for global functions
  filenames = []
  for func in header.get_funcs():
    filename = func.get_file_name()
    if not filename in filenames:
      includes += '#include "include/'+func.get_file_name()+'"\n' \
                  '#include "include/capi/'+func.get_capi_file_name()+'"\n'
      filenames.append(filename)

  # determine what includes are required by identifying what translation
  # classes are being used
  includes += format_translation_includes(header, impl)

  # build the final output
  result = get_copyright()

  result += includes + '\n' + impl

  return result


def write_cpptoc_impl(header, clsname, dir):
  if clsname is None:
    # global file
    file = dir
  else:
    # class file
    # give the output file the same directory offset as the input file
    cls = header.get_class(clsname)
    dir = os.path.dirname(os.path.join(dir, cls.get_file_name()))
    file = os.path.join(dir, get_capi_name(clsname[3:], False) + '_cpptoc.cc')

  if path_exists(file):
    oldcontents = read_file(file)
  else:
    oldcontents = ''

  if clsname is None:
    newcontents = make_cpptoc_global_impl(header, oldcontents)
  else:
    newcontents = make_cpptoc_class_impl(header, clsname, oldcontents)
  return (file, newcontents)


# test the module
if __name__ == "__main__":
  import sys

  # verify that the correct number of command-line arguments are provided
  if len(sys.argv) < 4:
    sys.stderr.write('Usage: ' + sys.argv[0] +
                     ' <infile> <classname> <existing_impl>')
    sys.exit()

  # create the header object
  header = obj_header()
  header.add_file(sys.argv[1])

  # read the existing implementation file into memory
  try:
    with open(sys.argv[3], 'r') as f:
      data = f.read()
  except IOError as e:
    (errno, strerror) = e.args
    raise Exception('Failed to read file ' + sys.argv[3] + ': ' + strerror)
  else:
    f.close()

  # dump the result to stdout
  sys.stdout.write(make_cpptoc_class_impl(header, sys.argv[2], data))