Merge remote-tracking branch 'remotes/alistair23/tags/pull-riscv-to-apply-20211022...
[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_56
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_56
28
29 #pragma GCC diagnostic push
30 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
31
32 #include <glib.h>
33 #if defined(G_OS_UNIX)
34 #include <glib-unix.h>
35 #include <sys/types.h>
36 #include <pwd.h>
37 #endif
38
39 /*
40 * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
41 * use of functions from newer GLib via this compat header needs a little
42 * trickery to prevent warnings being emitted.
43 *
44 * Consider a function from newer glib-X.Y that we want to use
45 *
46 * int g_foo(const char *wibble)
47 *
48 * We must define a static inline function with the same signature that does
49 * what we need, but with a "_qemu" suffix e.g.
50 *
51 * static inline void g_foo_qemu(const char *wibble)
52 * {
53 * #if GLIB_CHECK_VERSION(X, Y, 0)
54 * g_foo(wibble)
55 * #else
56 * g_something_equivalent_in_older_glib(wibble);
57 * #endif
58 * }
59 *
60 * The #pragma at the top of this file turns off -Wdeprecated-declarations,
61 * ensuring this wrapper function impl doesn't trigger the compiler warning
62 * about using too new glib APIs. Finally we can do
63 *
64 * #define g_foo(a) g_foo_qemu(a)
65 *
66 * So now the code elsewhere in QEMU, which *does* have the
67 * -Wdeprecated-declarations warning active, can call g_foo(...) as normal,
68 * without generating warnings.
69 */
70
71 #if defined(G_OS_UNIX)
72 /*
73 * Note: The fallback implementation is not MT-safe, and it returns a copy of
74 * the libc passwd (must be g_free() after use) but not the content. Because of
75 * these important differences the caller must be aware of, it's not #define for
76 * GLib API substitution.
77 */
78 static inline struct passwd *
79 g_unix_get_passwd_entry_qemu(const gchar *user_name, GError **error)
80 {
81 #if GLIB_CHECK_VERSION(2, 64, 0)
82 return g_unix_get_passwd_entry(user_name, error);
83 #else
84 struct passwd *p = getpwnam(user_name);
85 if (!p) {
86 g_set_error_literal(error, G_UNIX_ERROR, 0, g_strerror(errno));
87 return NULL;
88 }
89 return (struct passwd *)g_memdup(p, sizeof(*p));
90 #endif
91 }
92 #endif /* G_OS_UNIX */
93
94 static inline bool
95 qemu_g_test_slow(void)
96 {
97 static int cached = -1;
98 if (cached == -1) {
99 cached = g_test_slow() || getenv("G_TEST_SLOW") != NULL;
100 }
101 return cached;
102 }
103
104 #undef g_test_slow
105 #undef g_test_thorough
106 #undef g_test_quick
107 #define g_test_slow() qemu_g_test_slow()
108 #define g_test_thorough() qemu_g_test_slow()
109 #define g_test_quick() (!qemu_g_test_slow())
110
111 #pragma GCC diagnostic pop
112
113 #endif