Linux: Dynamically load libudev.

third_party/libusb/linux-udev.patch

Index: third_party/libusb/linux-udev.patch
diff --git a/third_party/libusb/linux-udev.patch b/third_party/libusb/linux-udev.patch
new file mode 100644
index 0000000000000000000000000000000000000000..93249c04d12723a584f7792c1231c709474d7a00
--- /dev/null
+++ b/third_party/libusb/linux-udev.patch
@@ -0,0 +1,209 @@
+Index: third_party/libusb/src/libusb/os/linux_udev.cc
+diff --git a/third_party/libusb/src/libusb/os/linux_udev.c b/third_party/libusb/src/libusb/os/linux_udev.cc
+similarity index 83%
+rename from third_party/libusb/src/libusb/os/linux_udev.c
+rename to third_party/libusb/src/libusb/os/linux_udev.cc
+index 99ac943410557de1a5cdd54082932db972040c2c..1b51ce44f4973c39b906d472b2a0cab51f987d3c 100644
+--- a/third_party/libusb/src/libusb/os/linux_udev.c
++++ b/third_party/libusb/src/libusb/os/linux_udev.cc
+@@ -37,11 +37,14 @@
+ #include <sys/utsname.h>
+ #include <sys/socket.h>
+ #include <unistd.h>
+-#include <libudev.h>
+ 
++extern "C" {
+ #include "libusb.h"
+ #include "libusbi.h"
+ #include "linux_usbfs.h"
++}
++
++#include "device/udev_linux/udev.h"
+ 
+ /* udev context */
+ static struct udev *udev_ctx = NULL;
+@@ -58,30 +61,30 @@ int linux_udev_start_event_monitor(void)
+ 	int r;
+ 
+ 	assert(udev_ctx == NULL);
+-	udev_ctx = udev_new();
++	udev_ctx = device::udev_new();
+ 	if (!udev_ctx) {
+ 		usbi_err(NULL, "could not create udev context");
+ 		return LIBUSB_ERROR_OTHER;
+ 	}
+ 
+-	udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
++	udev_monitor = device::udev_monitor_new_from_netlink(udev_ctx, "udev");
+ 	if (!udev_monitor) {
+ 		usbi_err(NULL, "could not initialize udev monitor");
+ 		goto err_free_ctx;
+ 	}
+ 
+-	r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", 0);
++	r = device::udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", 0);
+ 	if (r) {
+ 		usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
+ 		goto err_free_monitor;
+ 	}
+ 
+-	if (udev_monitor_enable_receiving(udev_monitor)) {
++	if (device::udev_monitor_enable_receiving(udev_monitor)) {
+ 		usbi_err(NULL, "failed to enable the udev monitor");
+ 		goto err_free_monitor;
+ 	}
+ 
+-	udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
++	udev_monitor_fd = device::udev_monitor_get_fd(udev_monitor);
+ 
+ 	/* Some older versions of udev are not non-blocking by default,
+ 	 * so make sure this is set */
+@@ -114,11 +117,11 @@ err_close_pipe:
+ 	close(udev_control_pipe[0]);
+ 	close(udev_control_pipe[1]);
+ err_free_monitor:
+-	udev_monitor_unref(udev_monitor);
++	device::udev_monitor_unref(udev_monitor);
+ 	udev_monitor = NULL;
+ 	udev_monitor_fd = -1;
+ err_free_ctx:
+-	udev_unref(udev_ctx);
++	device::udev_unref(udev_ctx);
+ 	udev_ctx = NULL;
+ 	return LIBUSB_ERROR_OTHER;
+ }
+@@ -141,12 +144,12 @@ int linux_udev_stop_event_monitor(void)
+ 	pthread_join(linux_event_thread, NULL);
+ 
+ 	/* Release the udev monitor */
+-	udev_monitor_unref(udev_monitor);
++	device::udev_monitor_unref(udev_monitor);
+ 	udev_monitor = NULL;
+ 	udev_monitor_fd = -1;
+ 
+ 	/* Clean up the udev context */
+-	udev_unref(udev_ctx);
++	device::udev_unref(udev_ctx);
+ 	udev_ctx = NULL;
+ 
+ 	/* close and reset control pipe */
+@@ -183,7 +186,7 @@ static void *linux_udev_event_thread_main(void *arg)
+ 		}
+ 		if (fds[1].revents & POLLIN) {
+ 			usbi_mutex_static_lock(&linux_hotplug_lock);
+-			udev_dev = udev_monitor_receive_device(udev_monitor);
++			udev_dev = device::udev_monitor_receive_device(udev_monitor);
+ 			if (udev_dev)
+ 				udev_hotplug_event(udev_dev);
+ 			usbi_mutex_static_unlock(&linux_hotplug_lock);
+@@ -200,12 +203,12 @@ static int udev_device_info(struct libusb_context *ctx, int detached,
+ 			    uint8_t *devaddr, const char **sys_name) {
+ 	const char *dev_node;
+ 
+-	dev_node = udev_device_get_devnode(udev_dev);
++	dev_node = device::udev_device_get_devnode(udev_dev);
+ 	if (!dev_node) {
+ 		return LIBUSB_ERROR_OTHER;
+ 	}
+ 
+-	*sys_name = udev_device_get_sysname(udev_dev);
++	*sys_name = device::udev_device_get_sysname(udev_dev);
+ 	if (!*sys_name) {
+ 		return LIBUSB_ERROR_OTHER;
+ 	}
+@@ -223,7 +226,7 @@ static void udev_hotplug_event(struct udev_device* udev_dev)
+ 	int r;
+ 
+ 	do {
+-		udev_action = udev_device_get_action(udev_dev);
++		udev_action = device::udev_device_get_action(udev_dev);
+ 		if (!udev_action) {
+ 			break;
+ 		}
+@@ -246,7 +249,7 @@ static void udev_hotplug_event(struct udev_device* udev_dev)
+ 		}
+ 	} while (0);
+ 
+-	udev_device_unref(udev_dev);
++	device::udev_device_unref(udev_dev);
+ }
+ 
+ int linux_udev_scan_devices(struct libusb_context *ctx)
+@@ -259,33 +262,33 @@ int linux_udev_scan_devices(struct libusb_context *ctx)
+ 
+ 	assert(udev_ctx != NULL);
+ 
+-	enumerator = udev_enumerate_new(udev_ctx);
++	enumerator = device::udev_enumerate_new(udev_ctx);
+ 	if (NULL == enumerator) {
+ 		usbi_err(ctx, "error creating udev enumerator");
+ 		return LIBUSB_ERROR_OTHER;
+ 	}
+ 
+-	udev_enumerate_add_match_subsystem(enumerator, "usb");
+-	udev_enumerate_scan_devices(enumerator);
+-	devices = udev_enumerate_get_list_entry(enumerator);
++	device::udev_enumerate_add_match_subsystem(enumerator, "usb");
++	device::udev_enumerate_scan_devices(enumerator);
++	devices = device::udev_enumerate_get_list_entry(enumerator);
+ 
+ 	udev_list_entry_foreach(entry, devices) {
+-		const char *path = udev_list_entry_get_name(entry);
++		const char *path = device::udev_list_entry_get_name(entry);
+ 		uint8_t busnum = 0, devaddr = 0;
+ 
+-		udev_dev = udev_device_new_from_syspath(udev_ctx, path);
++		udev_dev = device::udev_device_new_from_syspath(udev_ctx, path);
+ 
+ 		r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
+ 		if (r) {
+-			udev_device_unref(udev_dev);
++			device::udev_device_unref(udev_dev);
+ 			continue;
+ 		}
+ 
+ 		linux_enumerate_device(ctx, busnum, devaddr, sys_name);
+-		udev_device_unref(udev_dev);
++		device::udev_device_unref(udev_dev);
+ 	}
+ 
+-	udev_enumerate_unref(enumerator);
++	device::udev_enumerate_unref(enumerator);
+ 
+ 	return LIBUSB_SUCCESS;
+ }
+@@ -296,7 +299,7 @@ void linux_udev_hotplug_poll(void)
+ 
+ 	usbi_mutex_static_lock(&linux_hotplug_lock);
+ 	do {
+-		udev_dev = udev_monitor_receive_device(udev_monitor);
++		udev_dev = device::udev_monitor_receive_device(udev_monitor);
+ 		if (udev_dev) {
+ 			usbi_dbg("Handling hotplug event from hotplug_poll");
+ 			udev_hotplug_event(udev_dev);
+Index: third_party/libusb/src/libusb/os/linux_usbfs.h
+diff --git a/third_party/libusb/src/libusb/os/linux_usbfs.h b/third_party/libusb/src/libusb/os/linux_usbfs.h
+index 1f5b191f4a745937efe52695d7dbaa949a15df08..eedeaaf3654f22ecaac9fd1332d32b2855450bce 100644
+--- a/third_party/libusb/src/libusb/os/linux_usbfs.h
++++ b/third_party/libusb/src/libusb/os/linux_usbfs.h
+@@ -159,10 +159,20 @@ struct usbfs_disconnect_claim {
+ extern usbi_mutex_static_t linux_hotplug_lock;
+ 
+ #if defined(HAVE_LIBUDEV)
++
++#ifdef __cplusplus
++extern "C" {
++#endif
++
+ int linux_udev_start_event_monitor(void);
+ int linux_udev_stop_event_monitor(void);
+ int linux_udev_scan_devices(struct libusb_context *ctx);
+ void linux_udev_hotplug_poll(void);
++
++#ifdef __cplusplus
++}
++#endif
++
+ #else
+ int linux_netlink_start_event_monitor(void);
+ int linux_netlink_stop_event_monitor(void);