Bridgesupport

This module takes care of loading the BridgeSupport XML files for a given framework, and parsing the data into the given framework object.

References:

bridgesupport()

Attempts to retrieve the BridgeSupport files for the given framework. It synchronously reads the contents of the bridgesupport files and parses them in order to add the symbols that the Obj-C runtime functions cannot determine.

function bridgesupport (fw) {

  var bridgeSupportDir = join(fw.basePath, 'Resources', 'BridgeSupport')
    , bridgeSupportXML = join(bridgeSupportDir, fw.name + BS_SUFFIX)
    , bridgeSupportDylib = join(bridgeSupportDir, fw.name + DY_SUFFIX)

  // If there's no BridgeSupport file, then bail...
  if (!exists(bridgeSupportXML)) {
    debug('no BridgeSupport files found for framework "%s" at:', fw.name, bridgeSupportXML)
    return
  }

  // Load the "inline" dylib if it exists
  if (exists(bridgeSupportDylib)) {
    debug('importing "inline" dylib for framework "%s" at:', fw.name, bridgeSupportDylib)
    fw.inline = core.dlopen(bridgeSupportDylib)
  }

  var contents = read(bridgeSupportXML, 'utf8')
    , doc = libxmljs.parseXmlString(contents)
    , nodes = doc.childNodes()

  nodes.forEach(function (node) {
    var name = node.name()
    node._name = name
    //console.error(0, name, node)
    switch (name) {
      case 'text':
        // ignore; just '\n' whitespace
        break;
      case 'depends_on':
        Import(node.attr('path').value(), true)
        break;
      case 'class':
        node.name = node.attr('name').value()
        exports.classes[node.name] = node
        break;
      case 'string_constant':
        _global[node.attr('name').value()] = getValue(node)
        break;
      case 'enum':
        _global[node.attr('name').value()] = Number(getValue(node))
        break;
      case 'struct':
        // TODO: Remove the try/catch when all the Struct formats are supported
        //       Still need Array and Union support.
        try {
          _global[node.attr('name').value()] = struct.getStruct(getType(node))
        } catch (e) {
          //console.error('FAILED:\n', a)
          //console.error(e.stack)
        }
        break;
      case 'field':
        break;
      case 'cftype':
        break;
      case 'constant':
        node.name = node.attr('name').value()
        defineConstant(node, fw)
        break;
      case 'function':
        node.name = node.attr('name').value()
        defineFunction(node, fw)
        break;
      case 'opaque':
        break;
      case 'informal_protocol':
        node.name = node.attr('name').value()
        exports.informal_protocols[node.name] = node
        break;
      case 'function_alias':
        break;
      default:
        throw new Error('unkown tag: '+ node.name)
        break;
    }
  })

}

defineConstant()

Sets up a tag onto the global exports. These start out as simple JS getters, so that the underlying symbol pointer can be lazy-loaded on-demand.

function defineConstant (node, fw) {
  var name = node.name
    , type = getType(node)
  _global.__defineGetter__(name, function () {
    var ptr = fw.lib.get(name) // TODO: Cache the pointer after the 1st call
    ptr._type = '^' + type
    var val = ptr.deref()
    return val
  })
}

defineFunction()

Sets up a tag onto the global exports. These start out as simple JS getters, so that the underlying function pointer can be lazy-loaded on-demand.

function defineFunction (node, fw) {
  var name = node.name
  _global.__defineGetter__(name, function () {
    //console.error(require('util').inspect(a, true, 10))
    // TODO: Handle 'variadic' arg functions (NSLog), will require
    //       a "function generator" to get a Function from the passed
    //       in args (and guess at the types that were passed in...)
    debug('loading function pointer for:', name)
    var isInline = node.attr('inline')
    if (isInline && isInline.value() === 'true') {
      debug('function "%s" is declared as an inline function pointer:', name)
      assert.ok(fw.inline, name+', '+fw.name+': declared inline but could not find inline dylib!')
    }
    node.args = []
    node.childNodes().forEach(function (n, i) {
      var type = n.name()
      //console.error(i, type, n.toString())
      switch (type) {
        case 'arg':
          node.args.push(flattenNode(n))
          break;
        case 'retval':
          node.retval = flattenNode(n)
          break;
        default:
          break;
      }
    })
    //console.error(node)
    var ptr = (isInline ? fw.inline : fw.lib).get(name)
      , unwrapper = IMP.createUnwrapperFunction(ptr, node)
    unwrapper.info = node
    delete _global[name]
    return _global[name] = unwrapper
  })
}

function flattenNode (node) {
  node.type = getType(node)
  var functionPointer = node.attr('function_pointer')
  if (functionPointer && functionPointer.value() === 'true') {
    node.function_pointer = 'true' // XXX: Remove? Used by the function_pointer test case
    node.args = []
    node.childNodes().forEach(function (n, i) {
      var type = n.name()
      switch (type) {
        case 'arg':
          node.args.push(flattenNode(n))
          break;
        case 'retval':
          node.retval = flattenNode(n)
          break;
        default:
          break;
      }
    })
  }
  return node
}

NodObjC

The NodeJS ⇆ Objective-C Bridge

Bridgesupport

References:

bridgesupport()

defineConstant()

defineFunction()