1/*
2 *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11// This file is a supermacro
12// (see http://wanderinghorse.net/computing/papers/supermacros_cpp.html) to
13// expand a declaration of a late-binding symbol table class.
14//
15// Arguments:
16// LATE_BINDING_SYMBOL_TABLE_CLASS_NAME: Name of the class to generate.
17// LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST: List of symbols to load from the DLL,
18//     as an X-Macro list (see http://www.drdobbs.com/blogs/cpp/228700289).
19//
20// From a .h file, include the header(s) for the DLL to late-bind and the
21// latebindingsymboltable.h header, and then call this supermacro (optionally
22// from inside the namespace for the class to generate, if any). Example:
23//
24// #include <headerfordll.h>
25//
26// #include "webrtc/base/latebindingsymboltable.h"
27//
28// namespace foo {
29//
30// #define MY_CLASS_NAME DesiredClassName
31// #define MY_SYMBOLS_LIST X(acos) X(sin) X(tan)
32//
33// #define LATE_BINDING_SYMBOL_TABLE_CLASS_NAME MY_CLASS_NAME
34// #define LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST MY_SYMBOLS_LIST
35// #include "webrtc/base/latebindingsymboltable.h.def"
36//
37// }
38
39#ifndef WEBRTC_BASE_LATEBINDINGSYMBOLTABLE_H_
40#error You must first include latebindingsymboltable.h
41#endif
42
43#ifndef LATE_BINDING_SYMBOL_TABLE_CLASS_NAME
44#error You must define LATE_BINDING_SYMBOL_TABLE_CLASS_NAME
45#endif
46
47#ifndef LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST
48#error You must define LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST
49#endif
50
51class LATE_BINDING_SYMBOL_TABLE_CLASS_NAME :
52    public ::rtc::LateBindingSymbolTable {
53 public:
54  LATE_BINDING_SYMBOL_TABLE_CLASS_NAME();
55  ~LATE_BINDING_SYMBOL_TABLE_CLASS_NAME();
56
57#define X(sym) \
58  typeof(&::sym) sym() const { \
59    ASSERT(::rtc::LateBindingSymbolTable::IsLoaded()); \
60    return reinterpret_cast<typeof(&::sym)>(table_[SYMBOL_TABLE_INDEX_##sym]); \
61  }
62LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST
63#undef X
64
65 private:
66  enum {
67#define X(sym) \
68    SYMBOL_TABLE_INDEX_##sym,
69LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST
70#undef X
71    SYMBOL_TABLE_SIZE
72  };
73
74  static const ::rtc::LateBindingSymbolTable::TableInfo kTableInfo;
75  static const char *const kSymbolNames[];
76
77  void *table_[SYMBOL_TABLE_SIZE];
78
79  DISALLOW_COPY_AND_ASSIGN(LATE_BINDING_SYMBOL_TABLE_CLASS_NAME);
80};
81
82#undef LATE_BINDING_SYMBOL_TABLE_CLASS_NAME
83#undef LATE_BINDING_SYMBOL_TABLE_SYMBOLS_LIST
84