williamr@2: /* GLIB - Library of useful routines for C programming
williamr@2:  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
williamr@2:  *
williamr@2:  * This library is free software; you can redistribute it and/or
williamr@2:  * modify it under the terms of the GNU Lesser General Public
williamr@2:  * License as published by the Free Software Foundation; either
williamr@2:  * version 2 of the License, or (at your option) any later version.
williamr@2:  *
williamr@2:  * This library is distributed in the hope that it will be useful,
williamr@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
williamr@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
williamr@2:  * Lesser General Public License for more details.
williamr@2:  *
williamr@2:  * You should have received a copy of the GNU Lesser General Public
williamr@2:  * License along with this library; if not, write to the
williamr@2:  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
williamr@2:  * Boston, MA 02111-1307, USA.
williamr@2:  */
williamr@2: 
williamr@2: /*
williamr@2:  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
williamr@2:  * file for a list of people on the GLib Team.  See the ChangeLog
williamr@2:  * files for a list of changes.  These files are distributed with
williamr@2:  * GLib at ftp://ftp.gtk.org/pub/gtk/. 
williamr@2:  */
williamr@2: 
williamr@2: /* This file must not include any other glib header file and must thus
williamr@2:  * not refer to variables from glibconfig.h 
williamr@2:  */
williamr@2: 
williamr@2: #ifndef __G_MACROS_H__
williamr@2: #define __G_MACROS_H__
williamr@2: 
williamr@2: /* We include stddef.h to get the system's definition of NULL
williamr@2:  */
williamr@2: #include <stddef.h>
williamr@2: 
williamr@2: /* Here we provide G_GNUC_EXTENSION as an alias for __extension__,
williamr@2:  * where this is valid. This allows for warningless compilation of
williamr@2:  * "long long" types even in the presence of '-ansi -pedantic'. 
williamr@2:  */
williamr@2: #if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
williamr@2: #  define G_GNUC_EXTENSION __extension__
williamr@2: #else
williamr@2: #  define G_GNUC_EXTENSION
williamr@2: #endif
williamr@2: 
williamr@2: /* Provide macros to feature the GCC function attribute.
williamr@2:  */
williamr@2: #if    __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
williamr@2: #define G_GNUC_PURE                            \
williamr@2:   __attribute__((__pure__))
williamr@2: #define G_GNUC_MALLOC    			\
williamr@2:   __attribute__((__malloc__))
williamr@2: #else
williamr@2: #define G_GNUC_PURE
williamr@2: #define G_GNUC_MALLOC
williamr@2: #endif
williamr@2: 
williamr@2: #if     __GNUC__ >= 4
williamr@2: #define G_GNUC_NULL_TERMINATED __attribute__((__sentinel__))
williamr@2: #else
williamr@2: #define G_GNUC_NULL_TERMINATED
williamr@2: #endif
williamr@2: 
williamr@2: #if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
williamr@2: #define G_GNUC_PRINTF( format_idx, arg_idx )    \
williamr@2:   __attribute__((__format__ (__printf__, format_idx, arg_idx)))
williamr@2: #define G_GNUC_SCANF( format_idx, arg_idx )     \
williamr@2:   __attribute__((__format__ (__scanf__, format_idx, arg_idx)))
williamr@2: #define G_GNUC_FORMAT( arg_idx )                \
williamr@2:   __attribute__((__format_arg__ (arg_idx)))
williamr@2: #define G_GNUC_NORETURN                         \
williamr@2:   __attribute__((__noreturn__))
williamr@2: #define G_GNUC_CONST                            \
williamr@2:   __attribute__((__const__))
williamr@2: #define G_GNUC_UNUSED                           \
williamr@2:   __attribute__((__unused__))
williamr@2: #define G_GNUC_NO_INSTRUMENT			\
williamr@2:   __attribute__((__no_instrument_function__))
williamr@2: #else   /* !__GNUC__ */
williamr@2: #define G_GNUC_PRINTF( format_idx, arg_idx )
williamr@2: #define G_GNUC_SCANF( format_idx, arg_idx )
williamr@2: #define G_GNUC_FORMAT( arg_idx )
williamr@2: #define G_GNUC_NORETURN
williamr@2: #define G_GNUC_CONST
williamr@2: #define G_GNUC_UNUSED
williamr@2: #define G_GNUC_NO_INSTRUMENT
williamr@2: #endif  /* !__GNUC__ */
williamr@2: 
williamr@2: #if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
williamr@2: #define G_GNUC_DEPRECATED                            \
williamr@2:   __attribute__((__deprecated__))
williamr@2: #else
williamr@2: #define G_GNUC_DEPRECATED
williamr@2: #endif /* __GNUC__ */
williamr@2: 
williamr@2: #if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
williamr@2: #define G_GNUC_WARN_UNUSED_RESULT 		\
williamr@2:   __attribute__((warn_unused_result))
williamr@2: #else
williamr@2: #define G_GNUC_WARN_UNUSED_RESULT
williamr@2: #endif /* __GNUC__ */
williamr@2: 
williamr@2: /* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
williamr@2:  * macros, so we can refer to them as strings unconditionally.
williamr@2:  * usage not-recommended since gcc-3.0
williamr@2:  */
williamr@2: #if defined (__GNUC__) && (__GNUC__ < 3)
williamr@2: #define G_GNUC_FUNCTION         __FUNCTION__
williamr@2: #define G_GNUC_PRETTY_FUNCTION  __PRETTY_FUNCTION__
williamr@2: #else   /* !__GNUC__ */
williamr@2: #define G_GNUC_FUNCTION         ""
williamr@2: #define G_GNUC_PRETTY_FUNCTION  ""
williamr@2: #endif  /* !__GNUC__ */
williamr@2: 
williamr@2: #define G_STRINGIFY(macro_or_string)	G_STRINGIFY_ARG (macro_or_string)
williamr@2: #define	G_STRINGIFY_ARG(contents)	#contents
williamr@2: 
williamr@2: /* Provide a string identifying the current code position */
williamr@2: #if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)
williamr@2: #  define G_STRLOC	__FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
williamr@2: #else
williamr@2: #  define G_STRLOC	__FILE__ ":" G_STRINGIFY (__LINE__)
williamr@2: #endif
williamr@2: 
williamr@2: /* Provide a string identifying the current function, non-concatenatable */
williamr@2: #if defined (__GNUC__)
williamr@2: #  define G_STRFUNC     ((const char*) (__PRETTY_FUNCTION__))
williamr@2: #elif defined (G_HAVE_ISO_VARARGS)
williamr@2: #  define G_STRFUNC     ((const char*) (__func__))
williamr@2: #else
williamr@2: #  define G_STRFUNC     ((const char*) ("???"))
williamr@2: #endif
williamr@2: 
williamr@2: /* Guard C code in headers, while including them from C++ */
williamr@2: #ifdef  __cplusplus
williamr@2: # define G_BEGIN_DECLS  extern "C" {
williamr@2: # define G_END_DECLS    }
williamr@2: #else
williamr@2: # define G_BEGIN_DECLS
williamr@2: # define G_END_DECLS
williamr@2: #endif
williamr@2: 
williamr@2: /* Provide definitions for some commonly used macros.
williamr@2:  *  Some of them are only provided if they haven't already
williamr@2:  *  been defined. It is assumed that if they are already
williamr@2:  *  defined then the current definition is correct.
williamr@2:  */
williamr@2: #ifndef NULL
williamr@2: #  ifdef __cplusplus
williamr@2: #    define NULL        (0L)
williamr@2: #  else /* !__cplusplus */
williamr@2: #    define NULL        ((void*) 0)
williamr@2: #  endif /* !__cplusplus */
williamr@2: #endif
williamr@2: 
williamr@2: #ifndef	FALSE
williamr@2: #define	FALSE	(0)
williamr@2: #endif
williamr@2: 
williamr@2: #ifndef	TRUE
williamr@2: #define	TRUE	(!FALSE)
williamr@2: #endif
williamr@2: 
williamr@2: #undef	MAX
williamr@2: #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
williamr@2: 
williamr@2: #undef	MIN
williamr@2: #define MIN(a, b)  (((a) < (b)) ? (a) : (b))
williamr@2: 
williamr@2: #undef	ABS
williamr@2: #define ABS(a)	   (((a) < 0) ? -(a) : (a))
williamr@2: 
williamr@2: #undef	CLAMP
williamr@2: #define CLAMP(x, low, high)  (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
williamr@2: 
williamr@2: /* Count the number of elements in an array. The array must be defined
williamr@2:  * as such; using this with a dynamically allocated array will give
williamr@2:  * incorrect results.
williamr@2:  */
williamr@2: #define G_N_ELEMENTS(arr)		(sizeof (arr) / sizeof ((arr)[0]))
williamr@2: 
williamr@2: /* Macros by analogy to GINT_TO_POINTER, GPOINTER_TO_INT
williamr@2:  */
williamr@2: #define GPOINTER_TO_SIZE(p)	((gsize) (p))
williamr@2: #define GSIZE_TO_POINTER(s)	((gpointer) (gsize) (s))
williamr@2: 
williamr@2: /* Provide convenience macros for handling structure
williamr@2:  * fields through their offsets.
williamr@2:  */
williamr@2: #define G_STRUCT_OFFSET(struct_type, member)	\
williamr@2:     ((glong) ((guint8*) &((struct_type*) 0)->member))
williamr@2: #define G_STRUCT_MEMBER_P(struct_p, struct_offset)   \
williamr@2:     ((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
williamr@2: #define G_STRUCT_MEMBER(member_type, struct_p, struct_offset)   \
williamr@2:     (*(member_type*) G_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
williamr@2: 
williamr@2: /* Provide simple macro statement wrappers (adapted from Perl):
williamr@2:  *  G_STMT_START { statements; } G_STMT_END;
williamr@2:  *  can be used as a single statement, as in
williamr@2:  *  if (x) G_STMT_START { ... } G_STMT_END; else ...
williamr@2:  *
williamr@2:  *  When GCC is compiling C code in non-ANSI mode, it will use the
williamr@2:  *  compiler __extension__ to wrap the statements wihin `({' and '})' braces.
williamr@2:  *  When compiling on platforms where configure has defined
williamr@2:  *  HAVE_DOWHILE_MACROS, statements will be wrapped with `do' and `while (0)'.
williamr@2:  *  For any other platforms (SunOS4 is known to have this issue), wrap the
williamr@2:  *  statements with `if (1)' and `else (void) 0'.
williamr@2:  */
williamr@2: #if !(defined (G_STMT_START) && defined (G_STMT_END))
williamr@2: # if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
williamr@2: #  define G_STMT_START (void) __extension__ (
williamr@2: #  define G_STMT_END )
williamr@2: # else /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
williamr@2: #  if defined (HAVE_DOWHILE_MACROS)
williamr@2: #   define G_STMT_START do
williamr@2: #   define G_STMT_END while (0)
williamr@2: #  else /* !HAVE_DOWHILE_MACROS */
williamr@2: #   define G_STMT_START if (1)
williamr@2: #   define G_STMT_END else (void) 0
williamr@2: #  endif /* !HAVE_DOWHILE_MACROS */
williamr@2: # endif /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
williamr@2: #endif
williamr@2: 
williamr@2: /* Allow the app programmer to select whether or not return values
williamr@2:  * (usually char*) are const or not.  Don't try using this feature for
williamr@2:  * functions with C++ linkage.
williamr@2:  */
williamr@2: #ifdef G_DISABLE_CONST_RETURNS
williamr@2: #define G_CONST_RETURN
williamr@2: #else
williamr@2: #define G_CONST_RETURN const
williamr@2: #endif
williamr@2: 
williamr@2: /*
williamr@2:  * The G_LIKELY and G_UNLIKELY macros let the programmer give hints to 
williamr@2:  * the compiler about the expected result of an expression. Some compilers
williamr@2:  * can use this information for optimizations.
williamr@2:  *
williamr@2:  * The _G_BOOLEAN_EXPR macro is intended to trigger a gcc warning when
williamr@2:  * putting assignments in g_return_if_fail ().  
williamr@2:  */
williamr@2: #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
williamr@2: #define _G_BOOLEAN_EXPR(expr)                   \
williamr@2:  __extension__ ({                               \
williamr@2:    int _g_boolean_var_;                         \
williamr@2:    if (expr)                                    \
williamr@2:       _g_boolean_var_ = 1;                      \
williamr@2:    else                                         \
williamr@2:       _g_boolean_var_ = 0;                      \
williamr@2:    _g_boolean_var_;                             \
williamr@2: })
williamr@2: #define G_LIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 1))
williamr@2: #define G_UNLIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 0))
williamr@2: #else
williamr@2: #define G_LIKELY(expr) (expr)
williamr@2: #define G_UNLIKELY(expr) (expr)
williamr@2: #endif
williamr@2: 
williamr@2: #endif /* __G_MACROS_H__ */