xfa.h

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/*
 * Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#pragma once
 
#include <inttypes.h>
#include "compiler_hints.h"
 
/*
 * Unfortunately, current gcc trips over accessing XFA's because of their
 * zero-size start/end array that are used of symbol markers, with an "array
 * index out of bounds" warning.  So until a solution for that is found, we
 * need to disable array bounds checks for files using XFAs.
 */
#ifndef DOXYGEN
_Pragma("GCC diagnostic ignored \"-Warray-bounds\"")
#endif
 
#define _XFA(type, name, prio) \
    NO_SANITIZE_ARRAY \
    __attribute__((used, section(".xfa." #name "." #prio))) _Alignas(type) type
 
#define _XFA_CONST(type, name, prio) \
    NO_SANITIZE_ARRAY \
    __attribute__((used, section(".roxfa." #name "." #prio))) _Alignas(type) type
 
#define XFA_INIT_CONST(type, name) \
    _Pragma("GCC diagnostic push") \
    _Pragma("GCC diagnostic ignored \"-Wpedantic\"") \
    _XFA_CONST(type, name, 0_) name [0] = {}; \
    _XFA_CONST(type, name, 9_) name ## _end [0] = {}; \
    _Pragma("GCC diagnostic pop") \
    extern const unsigned __xfa_dummy
 
#define XFA_INIT(type, name) \
    _Pragma("GCC diagnostic push") \
    _Pragma("GCC diagnostic ignored \"-Wpedantic\"") \
    _XFA(type, name, 0_) name [0] = {}; \
    _XFA(type, name, 9_) name ## _end [0] = {}; \
    _Pragma("GCC diagnostic pop") \
    extern const unsigned __xfa_dummy
 
#define XFA_USE_CONST(type, name) \
    XFA_USE(type, name)
 
#define XFA_USE(type, name) \
    extern type name []; \
    extern type name ## _end []
 
#define XFA(type, xfa_name, prio) _XFA(type, xfa_name, 5_ ## prio)
 
#define XFA_CONST(type, xfa_name, prio) _XFA_CONST(type, xfa_name, 5_ ## prio)
 
#define XFA_ADD_PTR(xfa_name, prio, name, entry) \
    _XFA_CONST(__typeof__(entry), xfa_name, 5_ ## prio) \
    xfa_name ## _ ## prio ## _ ## name = entry
 
#define XFA_LEN(type, \
                name) (((uintptr_t)name ## _end - (uintptr_t)name) / \
                       sizeof(type))
 
#ifdef __cplusplus
extern "C" {
#endif
/* making externc happy */
#ifdef __cplusplus
}
#endif