1// Copyright (C) 2013 The Android Open Source Project
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions
6// are met:
7// 1. Redistributions of source code must retain the above copyright
8//    notice, this list of conditions and the following disclaimer.
9// 2. Redistributions in binary form must reproduce the above copyright
10//    notice, this list of conditions and the following disclaimer in the
11//    documentation and/or other materials provided with the distribution.
12// 3. Neither the name of the project nor the names of its contributors
13//    may be used to endorse or promote products derived from this software
14//    without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19// ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26// SUCH DAMAGE.
27
28#ifndef __GABIXX_CONFIG_H__
29#define __GABIXX_CONFIG_H__
30
31// Used to tag functions that never return.
32// IMPORTANT: This must appear at the left of function definitions,
33// as in:
34//  _GABIXX_NORETURN <return-type> <name>(....) { ... }
35#define _GABIXX_NORETURN  __attribute__((__noreturn__))
36
37// Use _GABIXX_NOEXCEPT to use the equivalent of the C++11 noexcept
38// qualifier at the end of function declarations.
39//
40// _GABIXX_NOEXCEPT_() only in C++11 mode to use the noexcept() operator.
41// _GABIXX_NOEXCEPT_CXX11_ONLY uses noexcept in C++11, nothing otherwise.
42#if __cplusplus >= 201103L
43#  define _GABIXX_NOEXCEPT noexcept
44#  define _GABIXX_NOEXCEPT_(x) noexcept(x)
45#  define _GABIXX_NOEXCEPT_CXX11_ONLY noexcept
46#else
47#  define _GABIXX_NOEXCEPT throw()
48#  define _GABIXX_NOEXCEPT_(x) /* nothing */
49#  define _GABIXX_NOEXCEPT_CXX11_ONLY /* nothing */
50#endif
51
52// Use _GABIXX_HIDDEN to declare internal functions of GAbi++ that should
53// never be exposed to client code.
54#define _GABIXX_HIDDEN  __attribute__((__visibility__("hidden")))
55
56// Use _GABIXX_DEFAULT to prevent user command -fvisibility=hidden
57#define _GABIXX_DEFAULT __attribute__((__visibility__("default")))
58
59// Use _GABIXX_WEAK to define a symbol with weak linkage.
60#define _GABIXX_WEAK  __attribute__((__weak__))
61
62// Use _GABIXX_ALWAYS_INLINE to declare a function that shall always be
63// inlined. Note that the always_inline doesn't make a function inline
64// per se.
65#define _GABIXX_ALWAYS_INLINE \
66  inline __attribute__((__always_inline__))
67
68// _GABIXX_HAS_EXCEPTIONS will be 1 if the current source file is compiled
69// with exceptions support, or 0 otherwise.
70#if !defined(__clang__) && !defined(__has_feature)
71#define __has_feature(x) 0
72#endif
73
74#if (defined(__clang__) && __has_feature(cxx_exceptions)) || \
75    (defined(__GNUC__) && defined(__EXCEPTIONS))
76#define _GABIXX_HAS_EXCEPTIONS 1
77#else
78#define _GABIXX_HAS_EXCEPTIONS 0
79#endif
80
81// TODO(digit): Use __atomic_load_acq_rel when available.
82#define __gabixx_sync_load(address)  \
83    __sync_fetch_and_add((address), (__typeof__(*(address)))0)
84
85// Clang provides __sync_swap(), but GCC does not.
86// IMPORTANT: For GCC, __sync_lock_test_and_set has acquire semantics only
87// so an explicit __sync_synchronize is needed to ensure a full barrier.
88// TODO(digit): Use __atomic_swap_acq_rel when available.
89#if defined(__clang__)
90#  define __gabixx_sync_swap(address,value)  __sync_swap((address),(value))
91#else
92#  define __gabixx_sync_swap(address, value)  \
93  __extension__ ({ \
94    __typeof__(*(address)) __ret = __sync_lock_test_and_set((address),(value)); \
95    __sync_synchronize(); \
96    __ret; \
97  })
98#endif
99
100#endif  // __GABIXX_CONFIG_H__
101