spice-protocol/spice/macros.h
Alexander Larsson cac2bc7984 Add a bunch of generically useful macros
This is largely based on gmacros.h from glib with a few
custom macros that were repeated in the spice codebase.
2010-03-09 11:53:59 +01:00

187 lines
6.3 KiB
C

/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
Copyright (C) 2010 Red Hat, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* This file is to a large extent based on gmacros.h from glib
* Which is LGPL and copyright:
*
* 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/.
*/
#ifndef _H_SPICE_MACROS
#define _H_SPICE_MACROS
/* We include stddef.h to get the system's definition of NULL */
#include <stddef.h>
#include <spice/types.h>
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
#define SPICE_GNUC_PURE __attribute__((__pure__))
#define SPICE_GNUC_MALLOC __attribute__((__malloc__))
#else
#define SPICE_GNUC_PURE
#define SPICE_GNUC_MALLOC
#endif
#if __GNUC__ >= 4
#define SPICE_GNUC_NULL_TERMINATED __attribute__((__sentinel__))
#else
#define SPICE_GNUC_NULL_TERMINATED
#endif
#if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
#define SPICE_GNUC_ALLOC_SIZE(x) __attribute__((__alloc_size__(x)))
#define SPICE_GNUC_ALLOC_SIZE2(x,y) __attribute__((__alloc_size__(x,y)))
#else
#define SPICE_GNUC_ALLOC_SIZE(x)
#define SPICE_GNUC_ALLOC_SIZE2(x,y)
#endif
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
#define SPICE_GNUC_PRINTF( format_idx, arg_idx ) __attribute__((__format__ (__printf__, format_idx, arg_idx)))
#define SPICE_GNUC_SCANF( format_idx, arg_idx ) __attribute__((__format__ (__scanf__, format_idx, arg_idx)))
#define SPICE_GNUC_FORMAT( arg_idx ) __attribute__((__format_arg__ (arg_idx)))
#define SPICE_GNUC_NORETURN __attribute__((__noreturn__))
#define SPICE_GNUC_CONST __attribute__((__const__))
#define SPICE_GNUC_UNUSED __attribute__((__unused__))
#define SPICE_GNUC_NO_INSTRUMENT __attribute__((__no_instrument_function__))
#else /* !__GNUC__ */
#define SPICE_GNUC_PRINTF( format_idx, arg_idx )
#define SPICE_GNUC_SCANF( format_idx, arg_idx )
#define SPICE_GNUC_FORMAT( arg_idx )
#define SPICE_GNUC_NORETURN
#define SPICE_GNUC_CONST
#define SPICE_GNUC_UNUSED
#define SPICE_GNUC_NO_INSTRUMENT
#endif /* !__GNUC__ */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
#define SPICE_GNUC_DEPRECATED __attribute__((__deprecated__))
#else
#define SPICE_GNUC_DEPRECATED
#endif /* __GNUC__ */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
# define SPICE_GNUC_MAY_ALIAS __attribute__((may_alias))
#else
# define SPICE_GNUC_MAY_ALIAS
#endif
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
#define SPICE_GNUC_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
#else
#define SPICE_GNUC_WARN_UNUSED_RESULT
#endif /* __GNUC__ */
/* Guard C code in headers, while including them from C++ */
#ifdef __cplusplus
# define SPICE_BEGIN_DECLS extern "C" {
# define SPICE_END_DECLS }
#else
# define SPICE_BEGIN_DECLS
# define SPICE_END_DECLS
#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))
/* 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 SPICE_N_ELEMENTS(arr) (sizeof (arr) / sizeof ((arr)[0]))
#define SPICE_ALIGN(a, size) (((a) + ((size) - 1)) & ~((size) - 1))
/* Provide convenience macros for handling structure
* fields through their offsets.
*/
#if defined(__GNUC__) && __GNUC__ >= 4
# define SPICE_OFFSETOF(struct_type, member) \
((long) offsetof (struct_type, member))
#else
# define SPICE_OFFSETOF(struct_type, member) \
((long) ((uint8_t*) &((struct_type*) 0)->member))
#endif
#define SPICE_CONTAINEROF(ptr, struct_type, member) \
((struct_type *)((uint8_t *)(ptr) - SPICE_OFFSETOF(struct_type, member)))
#define SPICE_MEMBER_P(struct_p, struct_offset) \
((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
#define SPICE_MEMBER(member_type, struct_p, struct_offset) \
(*(member_type*) SPICE_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
/* Provide simple macro statement wrappers:
* SPICE_STMT_START { statements; } SPICE_STMT_END;
* This can be used as a single statement, like:
* if (x) SPICE_STMT_START { ... } SPICE_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 (SPICE_STMT_START) && defined (SPICE_STMT_END))
# define SPICE_STMT_START do
# define SPICE_STMT_END while (0)
#endif
/*
* The SPICE_LIKELY and SPICE_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 _SPICE_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 _SPICE_BOOLEAN_EXPR(expr) \
__extension__ ({ \
int _g_boolean_var_; \
if (expr) \
_g_boolean_var_ = 1; \
else \
_g_boolean_var_ = 0; \
_g_boolean_var_; \
})
#define SPICE_LIKELY(expr) (__builtin_expect (_SPICE_BOOLEAN_EXPR(expr), 1))
#define SPICE_UNLIKELY(expr) (__builtin_expect (_SPICE_BOOLEAN_EXPR(expr), 0))
#else
#define SPICE_LIKELY(expr) (expr)
#define SPICE_UNLIKELY(expr) (expr)
#endif
#endif /* _H_SPICE_MACROS */