/* 
 * 
 * Copyright (c) 2009 Monty Taylor
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 *     * The names of its contributors may not be used to endorse or
 * promote products derived from this software without specific prior
 * written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/* GL_LINK_WARNING("literal string") arranges to emit the literal string as
   a linker warning on most glibc systems.
   We use a linker warning rather than a preprocessor warning, because
   #warning cannot be used inside macros.  */

#ifndef GL_LINK_WARNING
  /* This works on platforms with GNU ld and ELF object format.
     Testing __GLIBC__ is sufficient for asserting that GNU ld is in use.
     Testing __ELF__ guarantees the ELF object format.
     Testing __GNUC__ is necessary for the compound expression syntax.  */
# if defined __GLIBC__ && defined __ELF__ && defined __GNUC__
#  define GL_LINK_WARNING(message) \
     GL_LINK_WARNING1 (__FILE__, __LINE__, message)
#  define GL_LINK_WARNING1(file, line, message) \
     GL_LINK_WARNING2 (file, line, message)  /* macroexpand file and line */
#  define GL_LINK_WARNING2(file, line, message) \
     GL_LINK_WARNING3 (file ":" #line ": warning: " message)
#  define GL_LINK_WARNING3(message) \
     ({ static const char warning[sizeof (message)]		\
          __attribute__ ((__unused__,				\
                          __section__ (".gnu.warning"),		\
                          __aligned__ (1)))			\
          = message "\n";					\
        (void)0;						\
     })
# else
#  define GL_LINK_WARNING(message) ((void) 0)
# endif
#endif