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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_66
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_66
28
29 #pragma GCC diagnostic push
30 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
31
32 #include <glib.h>
33 #include <glib/gstdio.h>
34 #if defined(G_OS_UNIX)
35 #include <glib-unix.h>
36 #include <sys/types.h>
37 #include <pwd.h>
38 #endif
39
40 /*
41 * These functions perform function pointer casts which can cause function call
42 * failure on Emscripten. Use g_slist_sort_with_data and g_list_sort_with_data
43 * instead of these functions.
44 */
45 #pragma GCC poison g_slist_sort g_list_sort
46
47 /*
48 * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
49 * use of functions from newer GLib via this compat header needs a little
50 * trickery to prevent warnings being emitted.
51 *
52 * Consider a function from newer glib-X.Y that we want to use
53 *
54 * int g_foo(const char *wibble)
55 *
56 * We must define a static inline function with the same signature that does
57 * what we need, but with a "_compat" suffix e.g.
58 *
59 * static inline void g_foo_compat(const char *wibble)
60 * {
61 * #if GLIB_CHECK_VERSION(X, Y, 0)
62 * g_foo(wibble)
63 * #else
64 * g_something_equivalent_in_older_glib(wibble);
65 * #endif
66 * }
67 *
68 * The #pragma at the top of this file turns off -Wdeprecated-declarations,
69 * ensuring this wrapper function impl doesn't trigger the compiler warning
70 * about using too new glib APIs. Finally we can do
71 *
72 * #define g_foo(a) g_foo_compat(a)
73 *
74 * So now the code elsewhere in QEMU, which *does* have the
75 * -Wdeprecated-declarations warning active, can call g_foo(...) as normal,
76 * without generating warnings.
77 */
78
79 /*
80 * g_memdup2_qemu:
81 * @mem: (nullable): the memory to copy.
82 * @byte_size: the number of bytes to copy.
83 *
84 * Allocates @byte_size bytes of memory, and copies @byte_size bytes into it
85 * from @mem. If @mem is %NULL it returns %NULL.
86 *
87 * This replaces g_memdup(), which was prone to integer overflows when
88 * converting the argument from a #gsize to a #guint.
89 *
90 * This static inline version is a backport of the new public API from
91 * GLib 2.68, kept internal to GLib for backport to older stable releases.
92 * See https://gitlab.gnome.org/GNOME/glib/-/issues/2319.
93 *
94 * Returns: (nullable): a pointer to the newly-allocated copy of the memory,
95 * or %NULL if @mem is %NULL.
96 */
97 static inline gpointer g_memdup2_qemu(gconstpointer mem, gsize byte_size)
98 {
99 #if GLIB_CHECK_VERSION(2, 68, 0)
100 return g_memdup2(mem, byte_size);
101 #else
102 gpointer new_mem;
103
104 if (mem && byte_size != 0) {
105 new_mem = g_malloc(byte_size);
106 memcpy(new_mem, mem, byte_size);
107 } else {
108 new_mem = NULL;
109 }
110
111 return new_mem;
112 #endif
113 }
114 #define g_memdup2(m, s) g_memdup2_qemu(m, s)
115
116 static inline bool
117 qemu_g_test_slow(void)
118 {
119 static int cached = -1;
120 if (cached == -1) {
121 cached = g_test_slow() || getenv("G_TEST_SLOW") != NULL;
122 }
123 return cached;
124 }
125
126 #undef g_test_slow
127 #undef g_test_thorough
128 #undef g_test_quick
129 #define g_test_slow() qemu_g_test_slow()
130 #define g_test_thorough() qemu_g_test_slow()
131 #define g_test_quick() (!qemu_g_test_slow())
132
133 static inline gboolean g_clear_fd_qemu(int *fd_ptr, GError **error)
134 {
135 #if GLIB_CHECK_VERSION(2, 76, 0)
136 return g_clear_fd(fd_ptr, error);
137 #else
138 int fd = *fd_ptr;
139
140 *fd_ptr = -1;
141
142 if (fd < 0) {
143 return TRUE;
144 }
145
146 return g_close(fd, error);
147 #endif
148 }
149 #define g_clear_fd(fd, err) g_clear_fd_qemu(fd, err)
150
151 #if !GLIB_CHECK_VERSION(2, 76, 0)
152 static inline void _g_clear_fd_ignore_error(int *fd_ptr)
153 {
154 int errsv = errno;
155 g_clear_fd(fd_ptr, NULL);
156 errno = errsv;
157 }
158 #define g_autofd __attribute__((cleanup(_g_clear_fd_ignore_error)))
159 #endif
160
161 #pragma GCC diagnostic pop
162
163 #ifndef G_NORETURN
164 #define G_NORETURN G_GNUC_NORETURN
165 #endif
166
167 #endif