add qemu_add_data_dir()

Add helper function to add a directory to the qemu search path, so we
don't duplicate the checks.  Add a check for duplicate entries, so we
stop trying to open files twice.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20170914114236.25343-2-kraxel@redhat.com

vl.c

@@ -2348,6 +2348,24 @@ char *qemu_find_file(int type, const char *name)
     return NULL;
 }
 
+static void qemu_add_data_dir(const char *path)
+{
+    int i;
+
+    if (path == NULL) {
+        return;
+    }
+    if (data_dir_idx == ARRAY_SIZE(data_dir)) {
+        return;
+    }
+    for (i = 0; i < data_dir_idx; i++) {
+        if (strcmp(data_dir[i], path) == 0) {
+            return; /* duplicate */
+        }
+    }
+    data_dir[data_dir_idx++] = path;
+}
+
 static inline bool nonempty_str(const char *str)
 {
     return str && *str;
@@ -3527,8 +3545,8 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_L:
                 if (is_help_option(optarg)) {
                     list_data_dirs = true;
-                } else if (data_dir_idx < ARRAY_SIZE(data_dir)) {
-                    data_dir[data_dir_idx++] = optarg;
+                } else {
+                    qemu_add_data_dir(optarg);
                 }
                 break;
             case QEMU_OPTION_bios:
@@ -4293,16 +4311,10 @@ int main(int argc, char **argv, char **envp)
 
     /* If no data_dir is specified then try to find it relative to the
        executable path.  */
-    if (data_dir_idx < ARRAY_SIZE(data_dir)) {
-        data_dir[data_dir_idx] = os_find_datadir();
-        if (data_dir[data_dir_idx] != NULL) {
-            data_dir_idx++;
-        }
-    }
+    qemu_add_data_dir(os_find_datadir());
+
     /* If all else fails use the install path specified when building. */
-    if (data_dir_idx < ARRAY_SIZE(data_dir)) {
-        data_dir[data_dir_idx++] = CONFIG_QEMU_DATADIR;
-    }
+    qemu_add_data_dir(CONFIG_QEMU_DATADIR);
 
     /* -L help lists the data directories and exits. */
     if (list_data_dirs) {