gecko/js/ctypes/ctypes.jsm

118 lines
5.0 KiB
JavaScript

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is js-ctypes.
*
* The Initial Developer of the Original Code is
* The Mozilla Foundation <http://www.mozilla.org/>.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Dan Witte <dwitte@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
let EXPORTED_SYMBOLS = [ "ctypes" ];
/**
* This is the js module for ctypes. Import it like so:
* Components.utils.import("resource://gre/modules/ctypes.jsm");
*
* This will create a 'ctypes' object, which provides an interface to describe
* C types and call C functions from a dynamic library. It has the following
* properties and functions:
*
* ABI constants that specify the calling convention to use.
* ctypes.default_abi corresponds to the cdecl convention, and in almost all
* cases is the correct choice. ctypes.stdcall is provided for calling
* functions in the Microsoft Win32 API.
*
* ctypes.default_abi // corresponds to cdecl
* ctypes.stdcall_abi // for calling Win32 API functions
*
* Types available for arguments and return values, representing
* their C counterparts.
*
* ctypes.void_t // Only allowed for return types.
* ctypes.bool // _Bool type (assumed 8 bits wide).
* ctypes.int8_t // int8_t (signed char) type.
* ctypes.int16_t // int16_t (short) type.
* ctypes.int32_t // int32_t (int) type.
* ctypes.int64_t // int64_t (long long) type.
* ctypes.uint8_t // uint8_t (unsigned char) type.
* ctypes.uint16_t // uint16_t (unsigned short) type.
* ctypes.uint32_t // uint32_t (unsigned int) type.
* ctypes.uint64_t // uint64_t (unsigned long long) type.
* ctypes.float // float type.
* ctypes.double // double type.
* ctypes.string // C string (char *).
* ctypes.ustring // 16-bit string (char16_t *).
*
* Library ctypes.open(name)
*
* Attempts to dynamically load the specified library. Returns a Library
* object on success.
* @name A string or nsILocalFile representing the name and path of
* the library to open.
* @returns A Library object.
*
* Library.close()
*
* Unloads the currently loaded library. Any subsequent attempts to call
* functions on this interface will fail.
*
* function Library.declare(name, abi, returnType, argType1, argType2, ...)
*
* Declares a C function in a library.
* @name Function name. This must be a valid symbol in the library.
* @abi The calling convention to use. Must be an ABI constant
* from ctypes.
* @returnType The return type of the function. Must be a type constant
* from ctypes.
* @argTypes Argument types. Must be a type constant (other than void_t)
* from ctypes.
* @returns A function object.
*
* A function object can then be used to call the C function it represents
* like so:
*
* const myFunction = myLibrary.declare("myFunction", ctypes.default_abi,
* ctypes.double, ctypes.int32_t, ctypes.int32_t, ...);
*
* var result = myFunction(5, 10, ...);
*
* Arguments will be checked against the types supplied at declaration, and
* some attempt to convert values (e.g. boolean true/false to integer 0/1)
* will be made. Otherwise, if types do not match, or conversion fails,
* an exception will be thrown.
*/
// Initialize the ctypes object. You do not need to do this yourself.
const init = Components.classes["@mozilla.org/jsctypes;1"].createInstance();
init();