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 #if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__G_LIB_H__) && !defined (GLIB_COMPILATION)
32 #error "Only <glib.h> can be included directly."
35 #ifndef __G_MACROS_H__
36 #define __G_MACROS_H__
38 /* We include stddef.h to get the system's definition of NULL
42 /* Here we provide G_GNUC_EXTENSION as an alias for __extension__,
43 * where this is valid. This allows for warningless compilation of
44 * "long long" types even in the presence of '-ansi -pedantic'.
46 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
47 # define G_GNUC_EXTENSION __extension__
49 # define G_GNUC_EXTENSION
52 /* Provide macros to feature the GCC function attribute.
54 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
56 __attribute__((__pure__))
57 #define G_GNUC_MALLOC \
58 __attribute__((__malloc__))
65 #define G_GNUC_NULL_TERMINATED __attribute__((__sentinel__))
67 #define G_GNUC_NULL_TERMINATED
70 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
71 #define G_GNUC_PRINTF( format_idx, arg_idx ) \
72 __attribute__((__format__ (__printf__, format_idx, arg_idx)))
73 #define G_GNUC_SCANF( format_idx, arg_idx ) \
74 __attribute__((__format__ (__scanf__, format_idx, arg_idx)))
75 #define G_GNUC_FORMAT( arg_idx ) \
76 __attribute__((__format_arg__ (arg_idx)))
77 #define G_GNUC_NORETURN \
78 __attribute__((__noreturn__))
79 #define G_GNUC_CONST \
80 __attribute__((__const__))
81 #define G_GNUC_UNUSED \
82 __attribute__((__unused__))
83 #define G_GNUC_NO_INSTRUMENT \
84 __attribute__((__no_instrument_function__))
86 #define G_GNUC_PRINTF( format_idx, arg_idx )
87 #define G_GNUC_SCANF( format_idx, arg_idx )
88 #define G_GNUC_FORMAT( arg_idx )
89 #define G_GNUC_NORETURN
92 #define G_GNUC_NO_INSTRUMENT
93 #endif /* !__GNUC__ */
95 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
96 #define G_GNUC_DEPRECATED \
97 __attribute__((__deprecated__))
99 #define G_GNUC_DEPRECATED
100 #endif /* __GNUC__ */
102 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
103 # define G_GNUC_MAY_ALIAS __attribute__((may_alias))
105 # define G_GNUC_MAY_ALIAS
108 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
109 #define G_GNUC_WARN_UNUSED_RESULT \
110 __attribute__((warn_unused_result))
112 #define G_GNUC_WARN_UNUSED_RESULT
113 #endif /* __GNUC__ */
115 #ifndef G_DISABLE_DEPRECATED
116 /* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
117 * macros, so we can refer to them as strings unconditionally.
118 * usage not-recommended since gcc-3.0
120 #if defined (__GNUC__) && (__GNUC__ < 3)
121 #define G_GNUC_FUNCTION __FUNCTION__
122 #define G_GNUC_PRETTY_FUNCTION __PRETTY_FUNCTION__
123 #else /* !__GNUC__ */
124 #define G_GNUC_FUNCTION ""
125 #define G_GNUC_PRETTY_FUNCTION ""
126 #endif /* !__GNUC__ */
127 #endif /* !G_DISABLE_DEPRECATED */
129 #define G_STRINGIFY(macro_or_string) G_STRINGIFY_ARG (macro_or_string)
130 #define G_STRINGIFY_ARG(contents) #contents
132 /* Provide a string identifying the current code position */
133 #if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)
134 # define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
136 # define G_STRLOC __FILE__ ":" G_STRINGIFY (__LINE__)
139 /* Provide a string identifying the current function, non-concatenatable */
140 #if defined (__GNUC__)
141 # define G_STRFUNC ((const char*) (__PRETTY_FUNCTION__))
142 #elif defined (G_HAVE_ISO_VARARGS)
143 # define G_STRFUNC ((const char*) (__func__))
145 # define G_STRFUNC ((const char*) ("???"))
148 /* Guard C code in headers, while including them from C++ */
150 # define G_BEGIN_DECLS extern "C" {
151 # define G_END_DECLS }
153 # define G_BEGIN_DECLS
157 /* Provide definitions for some commonly used macros.
158 * Some of them are only provided if they haven't already
159 * been defined. It is assumed that if they are already
160 * defined then the current definition is correct.
165 # else /* !__cplusplus */
166 # define NULL ((void*) 0)
167 # endif /* !__cplusplus */
175 #define TRUE (!FALSE)
179 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
182 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
185 #define ABS(a) (((a) < 0) ? -(a) : (a))
188 #define CLAMP(x, low, high) (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
190 /* Count the number of elements in an array. The array must be defined
191 * as such; using this with a dynamically allocated array will give
194 #define G_N_ELEMENTS(arr) (sizeof (arr) / sizeof ((arr)[0]))
196 /* Macros by analogy to GINT_TO_POINTER, GPOINTER_TO_INT
198 #define GPOINTER_TO_SIZE(p) ((gsize) (p))
199 #define GSIZE_TO_POINTER(s) ((gpointer) (gsize) (s))
201 /* Provide convenience macros for handling structure
202 * fields through their offsets.
204 #define G_STRUCT_OFFSET(struct_type, member) \
205 ((glong) ((guint8*) &((struct_type*) 0)->member))
206 #define G_STRUCT_MEMBER_P(struct_p, struct_offset) \
207 ((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
208 #define G_STRUCT_MEMBER(member_type, struct_p, struct_offset) \
209 (*(member_type*) G_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
211 /* Provide simple macro statement wrappers (adapted from Perl):
212 * G_STMT_START { statements; } G_STMT_END;
213 * can be used as a single statement, as in
214 * if (x) G_STMT_START { ... } G_STMT_END; else ...
216 * When GCC is compiling C code in non-ANSI mode, it will use the
217 * compiler __extension__ to wrap the statements wihin `({' and '})' braces.
218 * When compiling on platforms where configure has defined
219 * HAVE_DOWHILE_MACROS, statements will be wrapped with `do' and `while (0)'.
220 * For any other platforms (SunOS4 is known to have this issue), wrap the
221 * statements with `if (1)' and `else (void) 0'.
223 #if !(defined (G_STMT_START) && defined (G_STMT_END))
224 # if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
225 # define G_STMT_START (void) __extension__ (
226 # define G_STMT_END )
227 # else /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
228 # if defined (HAVE_DOWHILE_MACROS)
229 # define G_STMT_START do
230 # define G_STMT_END while (0)
231 # else /* !HAVE_DOWHILE_MACROS */
232 # define G_STMT_START if (1)
233 # define G_STMT_END else (void) 0
234 # endif /* !HAVE_DOWHILE_MACROS */
235 # endif /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
238 /* Allow the app programmer to select whether or not return values
239 * (usually char*) are const or not. Don't try using this feature for
240 * functions with C++ linkage.
242 #ifdef G_DISABLE_CONST_RETURNS
243 #define G_CONST_RETURN
245 #define G_CONST_RETURN const
249 * The G_LIKELY and G_UNLIKELY macros let the programmer give hints to
250 * the compiler about the expected result of an expression. Some compilers
251 * can use this information for optimizations.
253 * The _G_BOOLEAN_EXPR macro is intended to trigger a gcc warning when
254 * putting assignments in g_return_if_fail ().
256 #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
257 #define _G_BOOLEAN_EXPR(expr) \
259 int _g_boolean_var_; \
261 _g_boolean_var_ = 1; \
263 _g_boolean_var_ = 0; \
266 #define G_LIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 1))
267 #define G_UNLIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 0))
269 #define G_LIKELY(expr) (expr)
270 #define G_UNLIKELY(expr) (expr)
273 #endif /* __G_MACROS_H__ */