attributes.h

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// Copyright (C) 2012,2013,2014,2015,2017 Olly Betts
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, see
// <https://www.gnu.org/licenses/>.
 
#ifndef XAPIAN_INCLUDED_ATTRIBUTES_H
#define XAPIAN_INCLUDED_ATTRIBUTES_H
 
#ifdef __GNUC__
 
// __attribute__((__const__)) is available at least as far back as GCC 2.95.
# define XAPIAN_CONST_FUNCTION __attribute__((__const__))
// __attribute__((__pure__)) is available from GCC 2.96 onwards.
# define XAPIAN_PURE_FUNCTION __attribute__((__pure__))
 
// We don't enable XAPIAN_NONNULL when building the library because that
// results in warnings when we check the parameter really isn't NULL, and we
// ought to still do that as (a) not all compilers support such annotations,
// and (b) even those that do don't actually prevent you from passing NULL.
# ifndef XAPIAN_LIB_BUILD
// __attribute__((__nonnull__(a,b,c))) is available from GCC 3.3 onwards, but
// seems to be buggy in GCC 4.8 so only enable it for versions after that.
// It's also supported by clang, which we have to check for separately as
// current versions pretend to be GCC 4.2.
#  if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 8) || \
      defined __clang__
#   define XAPIAN_NONNULL(LIST) __attribute__((__nonnull__ LIST))
#  endif
# endif
 
#else
 
# define XAPIAN_CONST_FUNCTION
 
# define XAPIAN_PURE_FUNCTION
 
#endif
 
#ifndef XAPIAN_NONNULL
# define XAPIAN_NONNULL(LIST)
#endif
 
#endif // XAPIAN_INCLUDED_ATTRIBUTES_H