Issue 4125 - [emscripten] Convert filter classes to C++

compile

 #!/usr/bin/env python
 
 import json
 import os
 import re
 import subprocess
 import warnings
 
 EMSCRIPTEN_PATH = '../emscripten'
 SOURCE_DIR = './compiled'
 SOURCE_FILES = [
   os.path.join(SOURCE_DIR, f)
   for f in os.listdir(SOURCE_DIR)
   if f.endswith('.cpp')
 ]
-API_FILE = os.path.join(SOURCE_DIR, 'api.cpp')
-API_OUTPUT = os.path.join(SOURCE_DIR, 'api.js')
+BINDINGS_FILE = os.path.join(SOURCE_DIR, 'bindings.cpp')
+BINDINGS_GENERATOR = os.path.join(SOURCE_DIR, 'bindings.cpp.js')
+BINDINGS_OUTPUT = os.path.join(SOURCE_DIR, 'bindings.js')
 COMPILER_OUTPUT = './lib/compiled.js'
 GENERATION_PARAMS = {
   'SHELL_FILE': "'%s'" % os.path.abspath(os.path.join(SOURCE_DIR, 'shell.js')),
+  'ASM_JS': 2,  # "almost asm"
   'TOTAL_MEMORY': 16*1024*1024,
   'TOTAL_STACK': 1*1024*1024,
   'ALLOW_MEMORY_GROWTH': 1,
   'NO_EXIT_RUNTIME': 1,
-  'DISABLE_EXCEPTION_CATCHING': 0,
   'NO_DYNAMIC_EXECUTION': 1,
   'NO_BROWSER': 1,
   'NO_FILESYSTEM': 1,
   'INVOKE_RUN': 0,
   'NODE_STDOUT_FLUSH_WORKAROUND': 0,
 }
-DEFINES = ['DEBUG']
-ADDITIONAL_PARAMS = ['-O3', '-m32', '-std=gnu++11', '--memory-init-file', '0',
+DEFINES = []
+ADDITIONAL_PARAMS = ['-O3', '-m32', '-std=gnu++14', '--memory-init-file', '0',
     '--emit-symbol-map']
 
 def getenv():
   path = []
   env = {}
   output = subprocess.check_output([
-      '/bin/sh', '-c', os.path.join(EMSCRIPTEN_PATH, 'emsdk_env.sh')])
+      '/bin/bash', '-c', os.path.join(EMSCRIPTEN_PATH, 'emsdk_env.sh')])
   for line in output.splitlines():
     match = re.search(r'^\s*PATH\s*\+=\s*(.*)', line)
     if match:
       path.append(match.group(1))
     match = re.search(r'^\s*(\w+)\s*=\s*(.*)', line)
     if match:
       env[match.group(1)] = match.group(2)
-  env['PATH'] = ':'.join([os.environ['PATH']] + path)
+  env['PATH'] = os.pathsep.join([os.environ['PATH']] + path)
   return env
 
-def generate_api(env):
-  params = [os.path.join(env['EMSCRIPTEN'], 'emcc'), '-E', API_FILE]
-  params.extend(ADDITIONAL_PARAMS)
-  output = subprocess.check_output(params, env=env)
+def generate_bindings(env):
+  params = [os.path.join(env['EMSCRIPTEN'], 'emcc'), BINDINGS_FILE,
+    '-o', BINDINGS_GENERATOR, '-std=gnu++14', '-DPRINT_BINDINGS',
+    '-s', 'WARN_ON_UNDEFINED_SYMBOLS=0',
+  ]
+  subprocess.check_call(params, env=env)
 
-  differentiators = {}
-  differentiator = None
-
-  cls = None
-  method = None
-
-  def wrap_call(func, is_instance, result_type, string_args):
-    prefix = '''\
-function()
-{
-  var params = Array.prototype.slice.apply(arguments);
-'''
-    suffix = '''\
-  return result;
-}'''
-
-    if result_type == 'string' or len(string_args):
-      prefix += '  var sp = Runtime.stackSave();\n'
-      suffix = '  Runtime.stackRestore(sp);\n' + suffix
-
-    for pos in string_args:
-      prefix += '  params[%i] = createString(params[%i]);\n' % (pos, pos)
-
-    if is_instance:
-      prefix += '  params.unshift(this._pointer);\n'
-
-    if result_type == 'primitive':
-      prefix += '  var result = _%s.apply(null, params);\n' % func
-    elif result_type == 'string':
-      prefix += '  params.unshift(createString());\n'
-      prefix += '  _%s.apply(null, params);\n' % func
-      prefix += '  var result = getStringData(params[0]);\n'
-    else:
-      prefix += '  var pointer = _%s.apply(null, params);\n' % func
-      if result_type in differentiators:
-        prefix += '  var type = _%s(pointer);\n' % differentiator['func']
-        prefix += '  if (type in %s_mapping)\n' % result_type
-        prefix += '    var result = new (exports[%s_mapping[type]])(pointer);\n' % result_type
-        prefix += '  else\n'
-        prefix += '    throw new Error("Unexpected %s type: " + type);\n' % result_type
-      else:
-        prefix += '  var result = %s(pointer);\n' % result_type
-
-    return prefix + suffix
-
-  def property_descriptor(property):
-    if property['type'] == 'static':
-      return 'value: %s' % property['getter']
-
-    result = 'get: %s' % wrap_call(property['getter'], True, property['type'], [])
-    if property['setter'] is not None:
-      string_args = [0] if property['type'] == 'string' else []
-      result += ', set: %s' % wrap_call(property['setter'], True, 'primitive', string_args)
-    return result
-
-  def method_descriptor(method):
-    return wrap_call(method['func'], method['type'] == 'instance',
-        method['result'], method['string_args'])
-
-  def write_class(file, cls):
-    name = cls['name']
-    if name in differentiators:
-      print >>file, 'var %s_mapping = %s;' % (
-          name, json.dumps(differentiators[name]['mapping'], sort_keys=True))
-
-    print >>file, 'exports.%s = createClass(%s);' % (
-        name, 'exports.' + cls['superclass'] if cls['superclass'] else '')
-    for property in cls['properties']:
-      print >>file, 'Object.defineProperty(exports.%s.prototype, "%s", {%s});' % (
-          name, property['name'], property_descriptor(property))
-    for method in cls['methods']:
-      obj = ('exports.%s' if method['type'] == 'class' else 'exports.%s.prototype') % name
-      print >>file, '%s.%s = %s;' % (
-          obj, method['name'], method_descriptor(method))
-    for initializer in cls['class_initializers']:
-      print >>file, '_%s();' % initializer
-
-  def handle_class(name):
-    if cls is not None:
-      write_class(file, cls)
-    differentiator = None
-    return {
-      'name': command[1],
-      'superclass': None,
-      'properties': [],
-      'methods': [],
-      'class_initializers': [],
-    }
-
-  def handle_superclass(name):
-    if cls is None:
-      warnings.warn('Superclass declared outside a class: ' + name)
-      return
-    differentiator = None
-    cls['superclass'] = name
-
-  def handle_class_init(func):
-    if cls is None:
-      warnings.warn('Class initializer declared outside a class: ' + func)
-      return
-    differentiator = None
-    method = None
-    cls['class_initializers'].append(func)
-
-  def handle_differentiator(cls, func):
-    differentiator = {'func': func, 'mapping': {}}
-    differentiators[cls] = differentiator
-    return differentiator
-
-  def handle_differentiator_mapping(value, subclass):
-    if differentiator is None:
-      warnings.warn('Differentiator mapping declared without a differentiator: ' + subclass)
-      return
-    differentiator['mapping'][value] = subclass
-
-  def handle_property(type, name, getter, setter):
-    if cls is None:
-      warnings.warn('Property declared outside a class: ' + name)
-      return
-    method = None
-    differentiator = None
-    cls['properties'].append({
-      'type': type,
-      'name': name,
-      'getter': getter,
-      'setter': setter,
-    })
-
-  def handle_method(type, name, func):
-    if cls is None:
-      warnings.warn('Method declared outside a class: ' + name)
-      return
-    differentiator = None
-    method = {
-      'type': type,
-      'name': name,
-      'func': func,
-      'result': 'primitive',
-      'string_args': [],
-    }
-    cls['methods'].append(method)
-    return method
-
-  def handle_method_result(type):
-    if method is None:
-      warnings.warn('Method result declared without a method definition')
-      return
-    method['result'] = type
-
-  def handle_string_arg(pos):
-    if method is None:
-      warnings.warn('Argument type declared without a method definition')
-      return
-    method['string_args'].append(int(pos))
-
-  with open(API_OUTPUT, 'w') as file:
-    for line in output.splitlines():
-      match = re.search(r'#pragma\s+comment\((.+?)\)', line)
-      if match:
-        command = match.group(1).strip().split()
-        if command[0] == 'class':
-          cls = handle_class(command[1])
-        elif command[0] == 'augments':
-          handle_superclass(command[1])
-        elif command[0] == 'class_init':
-          handle_class_init(command[1])
-        elif command[0] == 'differentiator':
-          differentiator = handle_differentiator(command[1], command[2])
-        elif command[0] == 'differentiator_mapping':
-          handle_differentiator_mapping(command[1], command[2])
-        elif command[0] == 'property':
-          handle_property('primitive', command[1], command[2], command[3] if len(command) > 3 else None)
-        elif command[0] == 'string_property':
-          handle_property('string', command[1], command[2], command[3] if len(command) > 3 else None)
-        elif command[0] == 'static_property':
-          handle_property('static', command[1], command[2], None)
-        elif command[0] == 'method':
-          method = handle_method('instance', command[1], command[2])
-        elif command[0] == 'class_method':
-          method = handle_method('class', command[1], command[2])
-        elif command[0] == 'string_result':
-          handle_method_result('string')
-        elif command[0] == 'pointer_result':
-          handle_method_result(command[1])
-        elif command[0] == 'string_arg':
-          handle_string_arg(command[1])
-        else:
-          warnings.warn('Unknown declaration: ' + str(command))
-
-    if cls is not None:
-      write_class(file, cls)
+  node = subprocess.check_output('which node', env=env, shell=True).strip();
+  with open(BINDINGS_OUTPUT, 'w') as file:
+    subprocess.check_call([node, BINDINGS_GENERATOR], env=env, stdout=file)
 
 def run_compiler(env):
   params = [
     os.path.join(env['EMSCRIPTEN'], 'emcc'),
     '-o', COMPILER_OUTPUT,
-    '--post-js', API_OUTPUT,
+    '--post-js', BINDINGS_OUTPUT,
   ]
   params.extend(SOURCE_FILES)
   params.extend('-D' + flag for flag in DEFINES)
   for key, value in GENERATION_PARAMS.iteritems():
     params.extend(['-s', '%s=%s' % (key, str(value))])
   params.extend(ADDITIONAL_PARAMS)
   subprocess.check_call(params, env=env)
 
 if __name__ == '__main__':
   env = getenv()
-  generate_api(env)
+  generate_bindings(env)
   run_compiler(env)