glib/gmacros.h

189 lines
6.0 KiB
C
Raw Normal View History

/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* 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 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/* This file must not include any other glib header file and must thus
* not refer to variables from glibconfig.h
*/
#ifndef __G_MACROS_H__
#define __G_MACROS_H__
/* Here we provide G_GNUC_EXTENSION as an alias for __extension__,
* where this is valid. This allows for warningless compilation of
* "long long" types even in the presence of '-ansi -pedantic'.
*/
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
# define G_GNUC_EXTENSION __extension__
#else
# define G_GNUC_EXTENSION
#endif
/* Provide macros to feature the GCC function attribute.
*/
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
#define G_GNUC_PURE \
__attribute__((pure))
#else
#define G_GNUC_PURE
#endif
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
#define G_GNUC_PRINTF( format_idx, arg_idx ) \
__attribute__((format (printf, format_idx, arg_idx)))
#define G_GNUC_SCANF( format_idx, arg_idx ) \
__attribute__((format (scanf, format_idx, arg_idx)))
#define G_GNUC_FORMAT( arg_idx ) \
__attribute__((format_arg (arg_idx)))
#define G_GNUC_NORETURN \
__attribute__((noreturn))
#define G_GNUC_CONST \
__attribute__((const))
#define G_GNUC_UNUSED \
__attribute__((unused))
#else /* !__GNUC__ */
#define G_GNUC_PRINTF( format_idx, arg_idx )
#define G_GNUC_SCANF( format_idx, arg_idx )
#define G_GNUC_FORMAT( arg_idx )
#define G_GNUC_NORETURN
#define G_GNUC_CONST
#define G_GNUC_UNUSED
#endif /* !__GNUC__ */
/* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
* macros, so we can refer to them as strings unconditionally.
*/
#ifdef __GNUC__
#define G_GNUC_FUNCTION __FUNCTION__
#define G_GNUC_PRETTY_FUNCTION __PRETTY_FUNCTION__
#else /* !__GNUC__ */
#define G_GNUC_FUNCTION ""
#define G_GNUC_PRETTY_FUNCTION ""
#endif /* !__GNUC__ */
#define G_STRINGIFY(macro_or_string) G_STRINGIFY_ARG (macro_or_string)
#define G_STRINGIFY_ARG(contents) #contents
/* Provide a string identifying the current code position */
#ifdef __GNUC__
# define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
#else
# define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__)
#endif
/* Guard C code in headers, while including them from C++ */
#ifdef __cplusplus
# define G_BEGIN_DECLS extern "C" {
# define G_END_DECLS }
#else
# define G_BEGIN_DECLS
# define G_END_DECLS
#endif
/* Provide definitions for some commonly used macros.
* Some of them are only provided if they haven't already
* been defined. It is assumed that if they are already
* defined then the current definition is correct.
*/
#ifndef NULL
# ifdef __cplusplus
# define NULL (0L)
# else /* !__cplusplus */
# define NULL ((void*) 0)
# endif /* !__cplusplus */
#endif
#ifndef FALSE
#define FALSE (0)
#endif
#ifndef TRUE
#define TRUE (!FALSE)
#endif
#undef MAX
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#undef MIN
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#undef ABS
#define ABS(a) (((a) < 0) ? -(a) : (a))
#undef CLAMP
#define CLAMP(x, low, high) (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
/* Count the number of elements in an array. The array must be defined
* as such; using this with a dynamically allocated array will give
* incorrect results.
*/
#define G_N_ELEMENTS(arr) (sizeof (arr) / sizeof ((arr)[0]))
/* Provide convenience macros for handling structure
* fields through their offsets.
*/
#define G_STRUCT_OFFSET(struct_type, member) \
((glong) ((guint8*) &((struct_type*) 0)->member))
#define G_STRUCT_MEMBER_P(struct_p, struct_offset) \
((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
#define G_STRUCT_MEMBER(member_type, struct_p, struct_offset) \
(*(member_type*) G_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
/* Provide simple macro statement wrappers (adapted from Perl):
* G_STMT_START { statements; } G_STMT_END;
* can be used as a single statement, as in
* if (x) G_STMT_START { ... } G_STMT_END; else ...
*
* For gcc we will wrap the statements within `({' and `})' braces.
* For SunOS they will be wrapped within `if (1)' and `else (void) 0',
* and otherwise within `do' and `while (0)'.
*/
#if !(defined (G_STMT_START) && defined (G_STMT_END))
# if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
# define G_STMT_START (void)(
# define G_STMT_END )
# else
# if (defined (sun) || defined (__sun__))
# define G_STMT_START if (1)
# define G_STMT_END else (void)0
# else
# define G_STMT_START do
# define G_STMT_END while (0)
# endif
# endif
#endif
/* Allow the app programmer to select whether or not return values
* (usually char*) are const or not. Don't try using this feature for
* functions with C++ linkage.
*/
#ifdef G_DISABLE_CONST_RETURNS
#define G_CONST_RETURN
#else
#define G_CONST_RETURN const
#endif
#endif /* __G_MACROS_H__ */