core: Preparation for handling backend-specific options

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

libusb/core.c

@@ -2065,6 +2065,19 @@ int API_EXPORTED libusb_set_option(libusb_context *ctx,
 			ctx->debug = (enum libusb_log_level)arg;
 #endif
 		break;
+	/* Handle all backend-specific options here */
+#if 0
+	/* This code is compiled out until the first backend-specific option is
+	 * added to the library. When this time comes, remove the #if/#endif
+	 * lines and this comment, then replace the case statement with the
+	 * valid option name. */
+	case LIBUSB_OPTION_<...>:
+		if (usbi_backend.set_option)
+			r = usbi_backend.set_option(ctx, option, ap);
+		else
+			r = LIBUSB_ERROR_NOT_SUPPORTED;
+		break;
+#endif
 	default:
 		r = LIBUSB_ERROR_INVALID_PARAM;
 	}

libusb/libusbi.h

@@ -616,6 +616,16 @@ struct usbi_os_backend {
 	 */
 	void (*exit)(struct libusb_contex *ctx);
 
+	/* Set a backend-specific option. Optional.
+	 *
+	 * This function is called when the user calls libusb_set_option() and
+	 * the option is not handled by the core library.
+	 *
+	 * Return 0 on success, or a LIBUSB_ERROR code on failure.
+	 */
+	int (*set_option)(struct libusb_context *ctx, enum libusb_option option,
+		va_list args);
+
 	/* Enumerate all the USB devices on the system, returning them in a list
 	 * of discovered devices.
 	 *

libusb/os/haiku_usb_raw.cpp

@@ -201,6 +201,7 @@ const struct usbi_os_backend usbi_backend = {
 	/*.caps =*/ 0,
 	/*.init =*/ haiku_init,
 	/*.exit =*/ haiku_exit,
+	/*.set_option =*/ NULL,
 	/*.get_device_list =*/ NULL,
 	/*.hotplug_poll =*/ NULL,
 	/*.open =*/ haiku_open,

libusb/os/netbsd_usb.c

@@ -91,6 +91,7 @@ const struct usbi_os_backend usbi_backend = {
 	0,
 	NULL,				/* init() */
 	NULL,				/* exit() */
+	NULL,				/* set_option() */
 	netbsd_get_device_list,
 	NULL,				/* hotplug_poll */
 	netbsd_open,

libusb/os/openbsd_usb.c

@@ -94,6 +94,7 @@ const struct usbi_os_backend usbi_backend = {
 	0,
 	NULL,				/* init() */
 	NULL,				/* exit() */
+	NULL,				/* set_option() */
 	obsd_get_device_list,
 	NULL,				/* hotplug_poll */
 	obsd_open,

libusb/os/wince_usb.c

@@ -854,6 +854,7 @@ const struct usbi_os_backend usbi_backend = {
 	0,
 	wince_init,
 	wince_exit,
+	NULL,				/* set_option() */
 
 	wince_get_device_list,
 	NULL,				/* hotplug_poll */

libusb/os/windows_usbdk.c

@@ -851,6 +851,7 @@ const struct usbi_os_backend usbi_backend = {
 	USBI_CAP_HAS_HID_ACCESS,
 	usbdk_init,
 	usbdk_exit,
+	NULL,	// set_option()
 
 	usbdk_get_device_list,
 	NULL,

libusb/os/windows_winusb.c

@@ -2047,6 +2047,7 @@ const struct usbi_os_backend usbi_backend = {
 	USBI_CAP_HAS_HID_ACCESS,
 	windows_init,
 	windows_exit,
+	NULL,				/* set_option */
 
 	windows_get_device_list,
 	NULL,				/* hotplug_poll */

libusb/version_nano.h

@@ -1 +1 @@
-#define LIBUSB_NANO 11212
+#define LIBUSB_NANO 11213