Linux: Dynamically load libudev.

third_party/libusb/linux-udev.patch

+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);