glib gmacros.h
/* 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__) /* 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 /* 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 /* * 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) \ __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__ */