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_40
  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_40
  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 static inline gboolean g_strv_contains_qemu(const gchar *const *strv,
  67                                             const gchar *str)
  68 {
  69 #if GLIB_CHECK_VERSION(2, 44, 0)
  70     return g_strv_contains(strv, str);
  71 #else
  72     g_return_val_if_fail(strv != NULL, FALSE);
  73     g_return_val_if_fail(str != NULL, FALSE);
  74
  75     for (; *strv != NULL; strv++) {
  76         if (g_str_equal(str, *strv)) {
  77             return TRUE;
  78         }
  79     }
  80
  81     return FALSE;
  82 #endif
  83 }
  84 #define g_strv_contains(a, b) g_strv_contains_qemu(a, b)
  85
  86 #if !GLIB_CHECK_VERSION(2, 58, 0)
  87 typedef struct QemuGSpawnFds {
  88     GSpawnChildSetupFunc child_setup;
  89     gpointer user_data;
  90     gint stdin_fd;
  91     gint stdout_fd;
  92     gint stderr_fd;
  93 } QemuGSpawnFds;
  94
  95 static inline void
  96 qemu_gspawn_fds_setup(gpointer user_data)
  97 {
  98     QemuGSpawnFds *q = (QemuGSpawnFds *)user_data;
  99
 100     dup2(q->stdin_fd, 0);
 101     dup2(q->stdout_fd, 1);
 102     dup2(q->stderr_fd, 2);
 103     q->child_setup(q->user_data);
 104 }
 105 #endif
 106
 107 static inline gboolean
 108 g_spawn_async_with_fds_qemu(const gchar *working_directory,
 109                             gchar **argv,
 110                             gchar **envp,
 111                             GSpawnFlags flags,
 112                             GSpawnChildSetupFunc child_setup,
 113                             gpointer user_data,
 114                             GPid *child_pid,
 115                             gint stdin_fd,
 116                             gint stdout_fd,
 117                             gint stderr_fd,
 118                             GError **error)
 119 {
 120 #if GLIB_CHECK_VERSION(2, 58, 0)
 121     return g_spawn_async_with_fds(working_directory, argv, envp, flags,
 122                                   child_setup, user_data,
 123                                   child_pid, stdin_fd, stdout_fd, stderr_fd,
 124                                   error);
 125 #else
 126     QemuGSpawnFds setup = {
 127         .child_setup = child_setup,
 128         .user_data = user_data,
 129         .stdin_fd = stdin_fd,
 130         .stdout_fd = stdout_fd,
 131         .stderr_fd = stderr_fd,
 132     };
 133
 134     return g_spawn_async(working_directory, argv, envp, flags,
 135                          qemu_gspawn_fds_setup, &setup,
 136                          child_pid, error);
 137 #endif
 138 }
 139
 140 #define g_spawn_async_with_fds(wd, argv, env, f, c, d, p, ifd, ofd, efd, err) \
 141     g_spawn_async_with_fds_qemu(wd, argv, env, f, c, d, p, ifd, ofd, efd, err)
 142
 143 #if defined(_WIN32) && !GLIB_CHECK_VERSION(2, 50, 0)
 144 /*
 145  * g_poll has a problem on Windows when using
 146  * timeouts < 10ms, so use wrapper.
 147  */
 148 #define g_poll(fds, nfds, timeout) g_poll_fixed(fds, nfds, timeout)
 149 gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
 150 #endif
 151
 152
 153 #ifndef g_assert_cmpmem
 154 #define g_assert_cmpmem(m1, l1, m2, l2)                                        \
 155     do {                                                                       \
 156         gconstpointer __m1 = m1, __m2 = m2;                                    \
 157         int __l1 = l1, __l2 = l2;                                              \
 158         if (__l1 != __l2) {                                                    \
 159             g_assertion_message_cmpnum(                                        \
 160                 G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,                   \
 161                 #l1 " (len(" #m1 ")) == " #l2 " (len(" #m2 "))", __l1, "==",   \
 162                 __l2, 'i');                                                    \
 163         } else if (memcmp(__m1, __m2, __l1) != 0) {                            \
 164             g_assertion_message(G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC,   \
 165                                 "assertion failed (" #m1 " == " #m2 ")");      \
 166         }                                                                      \
 167     } while (0)
 168 #endif
 169
 170 #pragma GCC diagnostic pop
 171
 172 #endif