glib/glib/gmacros.h
2011-06-13 09:27:41 -04:00

285 lines
9.4 KiB
C

/* 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
*/
#if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif
#ifndef __G_MACROS_H__
#define __G_MACROS_H__
/* We include stddef.h to get the system's definition of NULL
*/
#include <stddef.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__))
#define G_GNUC_MALLOC \
__attribute__((__malloc__))
#else
#define G_GNUC_PURE
#define G_GNUC_MALLOC
#endif
#if __GNUC__ >= 4
#define G_GNUC_NULL_TERMINATED __attribute__((__sentinel__))
#else
#define G_GNUC_NULL_TERMINATED
#endif
#if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
#define G_GNUC_ALLOC_SIZE(x) __attribute__((__alloc_size__(x)))
#define G_GNUC_ALLOC_SIZE2(x,y) __attribute__((__alloc_size__(x,y)))
#else
#define G_GNUC_ALLOC_SIZE(x)
#define G_GNUC_ALLOC_SIZE2(x,y)
#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__))
#define G_GNUC_NO_INSTRUMENT \
__attribute__((__no_instrument_function__))
#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
#define G_GNUC_NO_INSTRUMENT
#endif /* !__GNUC__ */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
#define G_GNUC_DEPRECATED \
__attribute__((__deprecated__))
#else
#define G_GNUC_DEPRECATED
#endif /* __GNUC__ */
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
#define G_GNUC_DEPRECATED_FOR(f) \
__attribute__((deprecated("Use " #f " instead")))
#else
#define G_GNUC_DEPRECATED_FOR(f) G_GNUC_DEPRECATED
#endif /* __GNUC__ */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
# define G_GNUC_MAY_ALIAS __attribute__((may_alias))
#else
# define G_GNUC_MAY_ALIAS
#endif
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
#define G_GNUC_WARN_UNUSED_RESULT \
__attribute__((warn_unused_result))
#else
#define G_GNUC_WARN_UNUSED_RESULT
#endif /* __GNUC__ */
#ifndef G_DISABLE_DEPRECATED
/* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
* macros, so we can refer to them as strings unconditionally.
* usage not-recommended since gcc-3.0
*/
#if defined (__GNUC__) && (__GNUC__ < 3)
#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__ */
#endif /* !G_DISABLE_DEPRECATED */
#define G_STRINGIFY(macro_or_string) G_STRINGIFY_ARG (macro_or_string)
#define G_STRINGIFY_ARG(contents) #contents
#define G_PASTE_ARGS(identifier1,identifier2) identifier1 ## identifier2
#define G_PASTE(identifier1,identifier2) G_PASTE_ARGS (identifier1, identifier2)
#define G_STATIC_ASSERT(expr) typedef struct { char Compile_Time_Assertion[(expr) ? 1 : -1]; } G_PASTE (_GStaticAssert_, __LINE__)
#define G_STATIC_ASSERT_EXPR(expr) ((void) sizeof (char[(expr) ? 1 : -1]))
/* Provide a string identifying the current code position */
#if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)
# define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
#else
# define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__)
#endif
/* Provide a string identifying the current function, non-concatenatable */
#if defined (__GNUC__)
# define G_STRFUNC ((const char*) (__PRETTY_FUNCTION__))
#elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 19901L
# define G_STRFUNC ((const char*) (__func__))
#else
# define G_STRFUNC ((const char*) ("???"))
#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]))
/* Macros by analogy to GINT_TO_POINTER, GPOINTER_TO_INT
*/
#define GPOINTER_TO_SIZE(p) ((gsize) (p))
#define GSIZE_TO_POINTER(s) ((gpointer) (gsize) (s))
/* Provide convenience macros for handling structure
* fields through their offsets.
*/
#if defined(__GNUC__) && __GNUC__ >= 4
# define G_STRUCT_OFFSET(struct_type, member) \
((glong) offsetof (struct_type, member))
#else
# define G_STRUCT_OFFSET(struct_type, member) \
((glong) ((guint8*) &((struct_type*) 0)->member))
#endif
#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:
* G_STMT_START { statements; } G_STMT_END;
* This can be used as a single statement, like:
* if (x) G_STMT_START { ... } G_STMT_END; else ...
* This intentionally does not use compiler extensions like GCC's '({...})' to
* avoid portability issue or side effects when compiled with different compilers.
*/
#if !(defined (G_STMT_START) && defined (G_STMT_END))
# define G_STMT_START do
# define G_STMT_END while (0)
#endif
/* Deprecated -- do not use. */
#ifndef G_DISABLE_DEPRECATED
#ifdef G_DISABLE_CONST_RETURNS
#define G_CONST_RETURN
#else
#define G_CONST_RETURN const
#endif
#endif
/*
* The G_LIKELY and G_UNLIKELY macros let the programmer give hints to
* the compiler about the expected result of an expression. Some compilers
* can use this information for optimizations.
*
* The _G_BOOLEAN_EXPR macro is intended to trigger a gcc warning when
* putting assignments in g_return_if_fail ().
*/
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
#define _G_BOOLEAN_EXPR(expr) \
G_GNUC_EXTENSION ({ \
int _g_boolean_var_; \
if (expr) \
_g_boolean_var_ = 1; \
else \
_g_boolean_var_ = 0; \
_g_boolean_var_; \
})
#define G_LIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 1))
#define G_UNLIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 0))
#else
#define G_LIKELY(expr) (expr)
#define G_UNLIKELY(expr) (expr)
#endif
#endif /* __G_MACROS_H__ */