sim: stabilize camera enumeration ordering for macOS and Linux V4L2

Add macOS AVFoundation camera enumeration.
Filter Linux V4L2 nodes that do not support CAP_VIDEO_CAPTURE to
fix Linux/macOS camera device node mount ordering and exclude Linux
metadata nodes.

Signed-off-by: Peter Bee <bijunda@bytedance.com>

Author: bijunda

arch/sim/src/sim/macos/sim_host_avfoundation_backend.m

@@ -151,6 +151,8 @@ static int avf_report_open_error(int err, const char *message)
 {
   AVCaptureDeviceDiscoverySession *discovery;
   NSArray<AVCaptureDevice *> *devices;
+  NSMutableArray<AVCaptureDevice *> *ordered;
+  AVCaptureDevice *device;
 
   discovery = [AVCaptureDeviceDiscoverySession
     discoverySessionWithDeviceTypes:@[
@@ -171,7 +173,36 @@ static int avf_report_open_error(int err, const char *message)
       devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
     }
 
-  return devices;
+  if (devices == nil || [devices count] == 0)
+    {
+      return devices;
+    }
+
+  ordered = [NSMutableArray arrayWithCapacity:[devices count]];
+  if (ordered == nil)
+    {
+      return devices;
+    }
+
+  for (device in devices)
+    {
+      if ([device.deviceType isEqualToString:
+          AVCaptureDeviceTypeBuiltInWideAngleCamera])
+        {
+          [ordered addObject:device];
+        }
+    }
+
+  for (device in devices)
+    {
+      if (![device.deviceType isEqualToString:
+           AVCaptureDeviceTypeBuiltInWideAngleCamera])
+        {
+          [ordered addObject:device];
+        }
+    }
+
+  return ordered;
 }
 
 static bool avf_parse_device_index(const char *dev_path, unsigned long *index_out)

arch/sim/src/sim/posix/sim_host_v4l2.c

@@ -31,7 +31,6 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
-#include <dirent.h>
 #include <limits.h>
 #include <sys/stat.h>
 #include <syslog.h>
@@ -47,6 +46,7 @@
  ****************************************************************************/
 
 #define MAX_REQBUFS 3
+#define HOST_MAX_VIDEO_DEVICES 64
 
 #define WARN(fmt, ...) \
         syslog(LOG_WARNING, "sim_host_video: " fmt "\n", ##__VA_ARGS__)
@@ -120,37 +120,24 @@ static bool host_video_is_capture_device(const char *host_video_dev_path)
   return available;
 }
 
-static int host_video_get_device_path_by_index(const char *dirpath,
-                                               int index,
+static int host_video_get_device_path_by_index(int index,
                                                char *devpath,
                                                size_t devpathlen)
 {
-  DIR *dir;
-  struct dirent *entry;
   int count = 0;
+  int i;
 
-  dir = opendir(dirpath);
-  if (dir == NULL)
-    {
-      return -errno;
-    }
-
-  while ((entry = readdir(dir)) != NULL)
+  for (i = 0; i < HOST_MAX_VIDEO_DEVICES; i++)
     {
-      char path[PATH_MAX];
-
-      if (strncmp(entry->d_name, "video", 5) != 0)
-        {
-          continue;
-        }
+      char path[32];
 
-      if (snprintf(path, sizeof(path), "/dev/%s", entry->d_name) >=
+      if (snprintf(path, sizeof(path), "/dev/video%d", i) >=
           (int)sizeof(path))
         {
           continue;
         }
 
-      if (!host_video_is_capture_device(path))
+      if (access(path, F_OK) != 0 || !host_video_is_capture_device(path))
         {
           continue;
         }
@@ -159,55 +146,40 @@ static int host_video_get_device_path_by_index(const char *dirpath,
         {
           if (snprintf(devpath, devpathlen, "%s", path) >= devpathlen)
             {
-              closedir(dir);
               return -ENAMETOOLONG;
             }
 
-          closedir(dir);
           return 0;
         }
 
       count++;
     }
 
-  closedir(dir);
   return -ENODEV;
 }
 
-static int host_video_count_devices_in_dir(const char *dirpath)
+static int host_video_count_devices(void)
 {
-  DIR *dir;
-  struct dirent *entry;
   int count = 0;
+  int i;
 
-  dir = opendir(dirpath);
-  if (dir == NULL)
-    {
-      return -errno;
-    }
-
-  while ((entry = readdir(dir)) != NULL)
+  for (i = 0; i < HOST_MAX_VIDEO_DEVICES; i++)
     {
-      char devpath[PATH_MAX];
+      char devpath[32];
 
-      if (strncmp(entry->d_name, "video", 5) != 0)
-        {
-          continue;
-        }
-
-      if (snprintf(devpath, sizeof(devpath), "/dev/%s", entry->d_name) >=
+      if (snprintf(devpath, sizeof(devpath), "/dev/video%d", i) >=
           (int)sizeof(devpath))
         {
           continue;
         }
 
-      if (host_video_is_capture_device(devpath))
+      if (access(devpath, F_OK) == 0 &&
+          host_video_is_capture_device(devpath))
         {
           count++;
         }
     }
 
-  closedir(dir);
   return count;
 }
 
@@ -241,15 +213,8 @@ static int host_video_resolve_device_path(const char *host_video_dev_path,
       return -EINVAL;
     }
 
-  ret = host_video_get_device_path_by_index("/sys/class/video4linux", index,
-                                            resolved_path,
+  ret = host_video_get_device_path_by_index(index, resolved_path,
                                             resolved_path_len);
-  if (ret == -ENOENT || ret == -ENODEV || ret == -EINVAL)
-    {
-      ret = host_video_get_device_path_by_index("/dev", index,
-                                                resolved_path,
-                                                resolved_path_len);
-    }
 
   if (ret < 0)
     {
@@ -266,21 +231,7 @@ static int host_video_resolve_device_path(const char *host_video_dev_path,
 
 int host_video_get_device_count(void)
 {
-  int count;
-
-  count = host_video_count_devices_in_dir("/sys/class/video4linux");
-  if (count >= 0)
-    {
-      return count;
-    }
-
-  count = host_video_count_devices_in_dir("/dev");
-  if (count >= 0)
-    {
-      return count;
-    }
-
-  return 0;
+  return host_video_count_devices();
 }
 
 bool host_video_is_available(const char *host_video_dev_path)

tools/mkallsyms.sh

@@ -64,7 +64,8 @@ if [ -f "${1}" ];then
   ${nm} -n ${1} | grep -E " [T|t] "  | uniq | \
   while read addr type name
   do
-    echo "  { \"$(${filt} $name | sed -e "s/(.*)$//")\", (FAR ${CONST} void *)0x$addr },"
+    demangled=$(printf '%s\n' "$name" | ${filt} | sed -e "s/(.*)$//")
+    echo "  { \"${demangled}\", (FAR ${CONST} void *)0x$addr },"
   done
 fi