1 files changed, 113 insertions, 0 deletions
diff --git a/include/glib-compat.h b/include/glib-compat.h
new file mode 100644
index 000000000..9e95c888f
--- /dev/null
+++ b/include/glib-compat.h
@@ -0,0 +1,113 @@
+/*
+ * GLIB Compatibility Functions
+ *
+ * Copyright IBM, Corp. 2013
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Michael Tokarev   <mjt@tls.msk.ru>
+ *  Paolo Bonzini     <pbonzini@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_GLIB_COMPAT_H
+#define QEMU_GLIB_COMPAT_H
+
+/* Ask for warnings for anything that was marked deprecated in
+ * the defined version, or before. It is a candidate for rewrite.
+ */
+#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_56
+
+/* Ask for warnings if code tries to use function that did not
+ * exist in the defined version. These risk breaking builds
+ */
+#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_56
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+
+#include <glib.h>
+#if defined(G_OS_UNIX)
+#include <glib-unix.h>
+#include <sys/types.h>
+#include <pwd.h>
+#endif
+
+/*
+ * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
+ * use of functions from newer GLib via this compat header needs a little
+ * trickery to prevent warnings being emitted.
+ *
+ * Consider a function from newer glib-X.Y that we want to use
+ *
+ *    int g_foo(const char *wibble)
+ *
+ * We must define a static inline function with the same signature that does
+ * what we need, but with a "_qemu" suffix e.g.
+ *
+ * static inline void g_foo_qemu(const char *wibble)
+ * {
+ *     #if GLIB_CHECK_VERSION(X, Y, 0)
+ *        g_foo(wibble)
+ *     #else
+ *        g_something_equivalent_in_older_glib(wibble);
+ *     #endif
+ * }
+ *
+ * The #pragma at the top of this file turns off -Wdeprecated-declarations,
+ * ensuring this wrapper function impl doesn't trigger the compiler warning
+ * about using too new glib APIs. Finally we can do
+ *
+ *   #define g_foo(a) g_foo_qemu(a)
+ *
+ * So now the code elsewhere in QEMU, which *does* have the
+ * -Wdeprecated-declarations warning active, can call g_foo(...) as normal,
+ * without generating warnings.
+ */
+
+#if defined(G_OS_UNIX)
+/*
+ * Note: The fallback implementation is not MT-safe, and it returns a copy of
+ * the libc passwd (must be g_free() after use) but not the content. Because of
+ * these important differences the caller must be aware of, it's not #define for
+ * GLib API substitution.
+ */
+static inline struct passwd *
+g_unix_get_passwd_entry_qemu(const gchar *user_name, GError **error)
+{
+#if GLIB_CHECK_VERSION(2, 64, 0)
+    return g_unix_get_passwd_entry(user_name, error);
+#else
+    struct passwd *p = getpwnam(user_name);
+    if (!p) {
+        g_set_error_literal(error, G_UNIX_ERROR, 0, g_strerror(errno));
+        return NULL;
+    }
+    return (struct passwd *)g_memdup(p, sizeof(*p));
+#endif
+}
+#endif /* G_OS_UNIX */
+
+static inline bool
+qemu_g_test_slow(void)
+{
+    static int cached = -1;
+    if (cached == -1) {
+        cached = g_test_slow() || getenv("G_TEST_SLOW") != NULL;
+    }
+    return cached;
+}
+
+#undef g_test_slow
+#undef g_test_thorough
+#undef g_test_quick
+#define g_test_slow() qemu_g_test_slow()
+#define g_test_thorough() qemu_g_test_slow()
+#define g_test_quick() (!qemu_g_test_slow())
+
+#pragma GCC diagnostic pop
+
+#endif