block/export: Add query-block-exports
[qemu.git] / include / glib-compat.h
1 /*
2 * GLIB Compatibility Functions
3 *
4 * Copyright IBM, Corp. 2013
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 * Michael Tokarev <mjt@tls.msk.ru>
9 * Paolo Bonzini <pbonzini@redhat.com>
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
12 * See the COPYING file in the top-level directory.
13 *
14 */
15
16 #ifndef QEMU_GLIB_COMPAT_H
17 #define QEMU_GLIB_COMPAT_H
18
19 /* Ask for warnings for anything that was marked deprecated in
20 * the defined version, or before. It is a candidate for rewrite.
21 */
22 #define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_48
23
24 /* Ask for warnings if code tries to use function that did not
25 * exist in the defined version. These risk breaking builds
26 */
27 #define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_48
28
29 #pragma GCC diagnostic push
30 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
31
32 #include <glib.h>
33
34 /*
35 * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
36 * use of functions from newer GLib via this compat header needs a little
37 * trickery to prevent warnings being emitted.
38 *
39 * Consider a function from newer glib-X.Y that we want to use
40 *
41 * int g_foo(const char *wibble)
42 *
43 * We must define a static inline function with the same signature that does
44 * what we need, but with a "_qemu" suffix e.g.
45 *
46 * static inline void g_foo_qemu(const char *wibble)
47 * {
48 * #if GLIB_CHECK_VERSION(X, Y, 0)
49 * g_foo(wibble)
50 * #else
51 * g_something_equivalent_in_older_glib(wibble);
52 * #endif
53 * }
54 *
55 * The #pragma at the top of this file turns off -Wdeprecated-declarations,
56 * ensuring this wrapper function impl doesn't trigger the compiler warning
57 * about using too new glib APIs. Finally we can do
58 *
59 * #define g_foo(a) g_foo_qemu(a)
60 *
61 * So now the code elsewhere in QEMU, which *does* have the
62 * -Wdeprecated-declarations warning active, can call g_foo(...) as normal,
63 * without generating warnings.
64 */
65
66 #if defined(_WIN32) && !GLIB_CHECK_VERSION(2, 50, 0)
67 /*
68 * g_poll has a problem on Windows when using
69 * timeouts < 10ms, so use wrapper.
70 */
71 #define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
72 gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
73 #endif
74
75 #pragma GCC diagnostic pop
76
77 #endif