/*

   attrs.h - wrapper macros for the gcc __attribute__(()) directive

   Copyright (C) 2007, 2008, 2012 Arthur de Jong

   This library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with this library; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

   02110-1301 USA

*/

#ifndef COMPAT__ATTRS_H

#define COMPAT__ATTRS_H 1

/* macro for testing the version of GCC */

#define GCC_VERSION(major, minor)                                           \

  ((__GNUC__ > (major)) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))

/* These are macros to use some gcc-specific flags in case the're available

   and otherwise define them to empty strings. This allows us to give

   the compiler some extra information.

   See http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html

   for a list of attributes supported by gcc */

/* this is used to flag function parameters that are not used in the function

   body. */

#if GCC_VERSION(3, 0)

#define UNUSED(x)   x __attribute__((__unused__))

#else

#define UNUSED(x)   x

#endif

/* this is used to add extra format checking to the function calls as if this

   was a printf()-like function */

#if GCC_VERSION(3, 0)

#define LIKE_PRINTF(format_idx, arg_idx)                                    \

                    __attribute__((__format__(__printf__, format_idx, arg_idx)))

#else

#define LIKE_PRINTF(format_idx, arg_idx) /* no attribute */

#endif

/* indicates that the function is "pure": its result is purely based on

   the parameters and has no side effects or used static data */

#if GCC_VERSION(3, 0)

#define PURE        __attribute__((__pure__))

#else

#define PURE        /* no attribute */

#endif

/* the function returns a new data structure that has been freshly

   allocated */

#if GCC_VERSION(3, 0)

#define LIKE_MALLOC __attribute__((__malloc__))

#else

#define LIKE_MALLOC /* no attribute */

#endif

/* the function's return value should be used by the caller */

#if GCC_VERSION(3, 4)

#define MUST_USE    __attribute__((__warn_unused_result__))

#else

#define MUST_USE    /* no attribute */

#endif

/* the function's return value should be used by the caller */

#if GCC_VERSION(2, 5)

#define NORETURN    __attribute__((__noreturn__))

#else

#define NORETURN    /* no attribute */

#endif

/* we don't need an explicit break statement in this case block */

#if GCC_VERSION(7, 0)

#define FALLTHROUGH __attribute__((fallthrough))

#else

#define FALLTHROUGH /* no attribute */

#endif

/* define __STRING if it's not yet defined */

#ifndef __STRING

#ifdef __STDC__

#define __STRING(x) #x

#else /* __STDC__ */

#define __STRING(x) "x"

#endif /* not __STDC__ */

#endif /* not __STRING */

#endif /* not COMPAT__ATTRS_H */