libraries/source/spidermonkey/include-win32-debug/js/experimental/CTypes.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef js_experimental_CTypes_h
   8 #define js_experimental_CTypes_h
   9
  10 #include "mozilla/Attributes.h"  // MOZ_RAII
  11
  12 #include <stddef.h>  // size_t
  13
  14 #include "jstypes.h"  // JS_PUBLIC_API
  15
  16 #include "js/TypeDecls.h"
  17
  18 namespace JS {
  19
  20 #ifdef JS_HAS_CTYPES
  21
  22 /**
  23  * Initialize the 'ctypes' object on a global variable 'obj'. The 'ctypes'
  24  * object will be sealed.
  25  */
  26 extern JS_PUBLIC_API bool InitCTypesClass(JSContext* cx,
  27                                           Handle<JSObject*> global);
  28
  29 #endif  // JS_HAS_CTYPES
  30
  31 /**
  32  * The type of ctypes activity that is occurring.
  33  */
  34 enum class CTypesActivityType {
  35   BeginCall,
  36   EndCall,
  37   BeginCallback,
  38   EndCallback,
  39 };
  40
  41 /**
  42  * The signature of a function invoked at the leading or trailing edge of ctypes
  43  * activity.
  44  */
  45 using CTypesActivityCallback = void (*)(JSContext*, CTypesActivityType);
  46
  47 /**
  48  * Sets a callback that is run whenever js-ctypes is about to be used when
  49  * calling into C.
  50  */
  51 extern JS_PUBLIC_API void SetCTypesActivityCallback(JSContext* cx,
  52                                                     CTypesActivityCallback cb);
  53
  54 class MOZ_RAII JS_PUBLIC_API AutoCTypesActivityCallback {
  55  private:
  56   JSContext* cx;
  57   CTypesActivityCallback callback;
  58   CTypesActivityType endType;
  59
  60  public:
  61   AutoCTypesActivityCallback(JSContext* cx, CTypesActivityType beginType,
  62                              CTypesActivityType endType);
  63
  64   ~AutoCTypesActivityCallback() { DoEndCallback(); }
  65
  66   void DoEndCallback() {
  67     if (callback) {
  68       callback(cx, endType);
  69       callback = nullptr;
  70     }
  71   }
  72 };
  73
  74 #ifdef JS_HAS_CTYPES
  75
  76 /**
  77  * Convert a unicode string 'source' of length 'slen' to the platform native
  78  * charset, returning a null-terminated string allocated with JS_malloc. On
  79  * failure, this function should report an error.
  80  */
  81 using CTypesUnicodeToNativeFun = char* (*)(JSContext*, const char16_t*, size_t);
  82
  83 /**
  84  * Set of function pointers that ctypes can use for various internal functions.
  85  * See JS::SetCTypesCallbacks below. Providing nullptr for a function is safe
  86  * and will result in the applicable ctypes functionality not being available.
  87  */
  88 struct CTypesCallbacks {
  89   CTypesUnicodeToNativeFun unicodeToNative;
  90 };
  91
  92 /**
  93  * Set the callbacks on the provided 'ctypesObj' object. 'callbacks' should be a
  94  * pointer to static data that exists for the lifetime of 'ctypesObj', but it
  95  * may safely be altered after calling this function and without having
  96  * to call this function again.
  97  */
  98 extern JS_PUBLIC_API void SetCTypesCallbacks(JSObject* ctypesObj,
  99                                              const CTypesCallbacks* callbacks);
 100
 101 #endif  // JS_HAS_CTYPES
 102
 103 }  // namespace JS
 104
 105 #endif  // js_experimental_CTypes_h