/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozjemalloc_h
#define mozjemalloc_h

#include "mozjemalloc_types.h"
#include "mozilla/MacroArgs.h"

// Macro helpers

#define MACRO_CALL(a, b) a b
// Can't use macros recursively, so we need another one doing the same as above.
#define MACRO_CALL2(a, b) a b

#define ARGS_HELPER(name, ...)                                     \
  MACRO_CALL2(MOZ_PASTE_PREFIX_AND_ARG_COUNT(name, ##__VA_ARGS__), \
              (__VA_ARGS__))
#define TYPED_ARGS0()
#define TYPED_ARGS1(t1) t1 arg1
#define TYPED_ARGS2(t1, t2) TYPED_ARGS1(t1), t2 arg2
#define TYPED_ARGS3(t1, t2, t3) TYPED_ARGS2(t1, t2), t3 arg3

#define ARGS0()
#define ARGS1(t1) arg1
#define ARGS2(t1, t2) ARGS1(t1), arg2
#define ARGS3(t1, t2, t3) ARGS2(t1, t2), arg3

#ifdef MOZ_MEMORY

// Generic interface exposing the whole public allocator API
// This facilitates the implementation of things like replace-malloc.
// Note: compilers are expected to be able to optimize out `this`.
template <typename T>
struct Allocator : public T {
#  define MALLOC_DECL(name, return_type, ...) \
    static return_type name(__VA_ARGS__);
#  include "malloc_decls.h"
};

// The MozJemalloc allocator
struct MozJemallocBase {};
typedef Allocator<MozJemallocBase> MozJemalloc;

#  ifdef MOZ_REPLACE_MALLOC
// The replace-malloc allocator
struct ReplaceMallocBase {};
typedef Allocator<ReplaceMallocBase> ReplaceMalloc;

typedef ReplaceMalloc DefaultMalloc;
#  else
typedef MozJemalloc DefaultMalloc;
#  endif

#endif  // MOZ_MEMORY

// Dummy implementation of the moz_arena_* API, falling back to a given
// implementation of the base allocator.
template <typename T>
struct DummyArenaAllocator {
  static arena_id_t moz_create_arena_with_params(arena_params_t*) { return 0; }

  static void moz_dispose_arena(arena_id_t) {}

  static void moz_set_max_dirty_page_modifier(int32_t) {}

#define MALLOC_DECL(name, return_type, ...)                 \
  static return_type moz_arena_##name(                      \
      arena_id_t, ARGS_HELPER(TYPED_ARGS, ##__VA_ARGS__)) { \
    return T::name(ARGS_HELPER(ARGS, ##__VA_ARGS__));       \
  }
#define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
#include "malloc_decls.h"
};

#endif
