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.

2 files changed, 187 insertions, 0 deletions

diff --git a/spice/Makefile.am b/spice/Makefile.am
index 5867653..d5dea6a 100644
--- a/spice/Makefile.am
+++ b/spice/Makefile.am
@@ -9,6 +9,7 @@ spice_protocol_include_HEADERS=		\
 	error_codes.h	\
 	ipc_ring.h	\
 	protocol.h	\
+	macros.h	\
 	qxl_dev.h	\
 	start-packed.h	\
 	stats.h		\
diff --git a/spice/macros.h b/spice/macros.h
new file mode 100644
index 0000000..72186dd
--- /dev/null
+++ b/spice/macros.h
@@ -0,0 +1,186 @@
+/* -*- 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 */