1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
21 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GLib Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GLib at ftp://ftp.gtk.org/pub/gtk/.
27 /* This file must not include any other glib header file and must thus
28 * not refer to variables from glibconfig.h
31 #ifndef __G_MACROS_H__
32 #define __G_MACROS_H__
34 /* We include stddef.h to get the system's definition of NULL
38 /* Here we provide G_GNUC_EXTENSION as an alias for __extension__,
39 * where this is valid. This allows for warningless compilation of
40 * "long long" types even in the presence of '-ansi -pedantic'.
42 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
43 # define G_GNUC_EXTENSION __extension__
45 # define G_GNUC_EXTENSION
48 /* Provide macros to feature the GCC function attribute.
50 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
52 __attribute__((__pure__))
58 * Provide G_GNUC_INTERNAL that is used for marking library
59 * functions as being used internally to the lib only, to not
60 * create inefficient PLT entries.
62 #if defined (__GNUC__)
63 #define G_GNUC_INTERNAL __attribute__((visibility("hidden")))
65 #define G_GNUC_INTERNAL
68 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
69 #define G_GNUC_PRINTF( format_idx, arg_idx ) \
70 __attribute__((__format__ (__printf__, format_idx, arg_idx)))
71 #define G_GNUC_SCANF( format_idx, arg_idx ) \
72 __attribute__((__format__ (__scanf__, format_idx, arg_idx)))
73 #define G_GNUC_FORMAT( arg_idx ) \
74 __attribute__((__format_arg__ (arg_idx)))
75 #define G_GNUC_NORETURN \
76 __attribute__((__noreturn__))
77 #define G_GNUC_CONST \
78 __attribute__((__const__))
79 #define G_GNUC_UNUSED \
80 __attribute__((__unused__))
81 #define G_GNUC_NO_INSTRUMENT \
82 __attribute__((__no_instrument_function__))
84 #define G_GNUC_PRINTF( format_idx, arg_idx )
85 #define G_GNUC_SCANF( format_idx, arg_idx )
86 #define G_GNUC_FORMAT( arg_idx )
87 #define G_GNUC_NORETURN
90 #define G_GNUC_NO_INSTRUMENT
91 #endif /* !__GNUC__ */
93 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
94 #define G_GNUC_DEPRECATED \
95 __attribute__((__deprecated__))
97 #define G_GNUC_DEPRECATED
100 /* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
101 * macros, so we can refer to them as strings unconditionally.
102 * usage not-recommended since gcc-3.0
104 #if defined (__GNUC__) && (__GNUC__ < 3)
105 #define G_GNUC_FUNCTION __FUNCTION__
106 #define G_GNUC_PRETTY_FUNCTION __PRETTY_FUNCTION__
107 #else /* !__GNUC__ */
108 #define G_GNUC_FUNCTION ""
109 #define G_GNUC_PRETTY_FUNCTION ""
110 #endif /* !__GNUC__ */
112 #define G_STRINGIFY(macro_or_string) G_STRINGIFY_ARG (macro_or_string)
113 #define G_STRINGIFY_ARG(contents) #contents
115 /* Provide a string identifying the current code position */
116 #if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)
117 # define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
119 # define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__)
122 /* Provide a string identifying the current function, non-concatenatable */
123 #if defined (__GNUC__)
124 # define G_STRFUNC ((const char*) (__PRETTY_FUNCTION__))
125 #elif defined (G_HAVE_ISO_VARARGS)
126 # define G_STRFUNC ((const char*) (__func__))
128 # define G_STRFUNC ((const char*) ("???"))
131 /* Guard C code in headers, while including them from C++ */
133 # define G_BEGIN_DECLS extern "C" {
134 # define G_END_DECLS }
136 # define G_BEGIN_DECLS
140 /* Provide definitions for some commonly used macros.
141 * Some of them are only provided if they haven't already
142 * been defined. It is assumed that if they are already
143 * defined then the current definition is correct.
148 # else /* !__cplusplus */
149 # define NULL ((void*) 0)
150 # endif /* !__cplusplus */
158 #define TRUE (!FALSE)
162 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
165 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
168 #define ABS(a) (((a) < 0) ? -(a) : (a))
171 #define CLAMP(x, low, high) (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
173 /* Count the number of elements in an array. The array must be defined
174 * as such; using this with a dynamically allocated array will give
177 #define G_N_ELEMENTS(arr) (sizeof (arr) / sizeof ((arr)[0]))
179 /* Macros by analogy to GINT_TO_POINTER, GPOINTER_TO_INT
181 #define GPOINTER_TO_SIZE(p) ((gsize) (p))
182 #define GSIZE_TO_POINTER(s) ((gpointer) (gsize) (s))
184 /* Provide convenience macros for handling structure
185 * fields through their offsets.
187 #define G_STRUCT_OFFSET(struct_type, member) \
188 ((glong) ((guint8*) &((struct_type*) 0)->member))
189 #define G_STRUCT_MEMBER_P(struct_p, struct_offset) \
190 ((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
191 #define G_STRUCT_MEMBER(member_type, struct_p, struct_offset) \
192 (*(member_type*) G_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
194 /* Provide simple macro statement wrappers (adapted from Perl):
195 * G_STMT_START { statements; } G_STMT_END;
196 * can be used as a single statement, as in
197 * if (x) G_STMT_START { ... } G_STMT_END; else ...
199 * For gcc we will wrap the statements within `({' and `})' braces.
200 * For SunOS they will be wrapped within `if (1)' and `else (void) 0',
201 * and otherwise within `do' and `while (0)'.
203 #if !(defined (G_STMT_START) && defined (G_STMT_END))
204 # if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
205 # define G_STMT_START (void) __extension__ (
206 # define G_STMT_END )
208 # if (defined (sun) || defined (__sun__))
209 # define G_STMT_START if (1)
210 # define G_STMT_END else (void)0
212 # define G_STMT_START do
213 # define G_STMT_END while (0)
218 /* Allow the app programmer to select whether or not return values
219 * (usually char*) are const or not. Don't try using this feature for
220 * functions with C++ linkage.
222 #ifdef G_DISABLE_CONST_RETURNS
223 #define G_CONST_RETURN
225 #define G_CONST_RETURN const
229 * The G_LIKELY and G_UNLIKELY macros let the programmer give hints to
230 * the compiler about the expected result of an expression. Some compilers
231 * can use this information for optimizations.
233 * The _G_BOOLEAN_EXPR macro is intended to trigger a gcc warning when
234 * putting assignments in g_return_if_fail ().
236 #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
237 #define _G_BOOLEAN_EXPR(expr) \
239 int _g_boolean_var_; \
241 _g_boolean_var_ = 1; \
243 _g_boolean_var_ = 0; \
246 #define G_LIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 1))
247 #define G_UNLIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 0))
249 #define G_LIKELY(expr) (expr)
250 #define G_UNLIKELY(expr) (expr)
253 #endif /* __G_MACROS_H__ */