Implement OS detection in Emscripten.

tdutils/td/utils/port/uname.cpp

@@ -20,6 +20,10 @@
 
 #if TD_ANDROID
 #include <sys/system_properties.h>
+#elif TD_EMSCRIPTEN
+#include <cstdlib>
+
+#include <emscripten.h>
 #else
 #if TD_DARWIN
 #include <sys/sysctl.h>
@@ -90,6 +94,98 @@ Slice get_operating_system_version() {
     if (length > 0) {
       return "Android " + string(version, length);
     }
+#elif TD_EMSCRIPTEN
+    // clang-format off
+    char *os_name_js = (char*)EM_ASM_INT(({
+      function detectOsName() {
+        if (typeof process === 'object' && typeof process.platform === 'string') { // Node.js
+           switch (process.platform) {
+             case 'aix':
+               return 'IBM AIX';
+             case 'android':
+               return 'Android';
+             case 'darwin':
+               return 'macOS';
+             case 'freebsd':
+               return 'FreeBSD';
+             case 'linux':
+               return 'Linux';
+             case 'openbsd':
+               return 'OpenBSD';
+             case 'sunos':
+               return 'SunOS';
+             case 'win32':
+               return 'Windows';
+             case 'darwin':
+               return 'macOS';
+             default:
+               return 'Node.js';
+          }
+        }
+
+        var userAgent = 'Unknown';
+        if (typeof window === 'object') { // Web
+          userAgent = window.navigator.userAgent;
+        } else if (typeof importScripts === 'function') { // Web Worker
+          userAgent = navigator.userAgent;
+        }
+
+        var match = /(Mac OS|Mac OS X|MacPPC|MacIntel|Mac_PowerPC|Macintosh) ([._0-9]+)/.exec(userAgent);
+        if (match !== null) {
+          return 'macOS ' + match[2].replace('_', '.');
+        }
+
+        match = /Android [._0-9]+/.exec(userAgent);
+        if (match !== null) {
+          return match[0].replace('_', '.');
+        }
+
+        if (/(iPhone|iPad|iPod)/.test(userAgent)) {
+          match = /OS ([._0-9]+)/.exec(userAgent);
+          if (match !== null) {
+            return 'iOS ' + match[1].replace('_', '.');
+          }
+          return 'iOS';
+        }
+
+        var clientStrings = [
+          {s:'Windows 10', r:/(Windows 10.0|Windows NT 10.0)/},
+          {s:'Windows 8.1', r:/(Windows 8.1|Windows NT 6.3)/},
+          {s:'Windows 8', r:/(Windows 8|Windows NT 6.2)/},
+          {s:'Windows 7', r:/(Windows 7|Windows NT 6.1)/},
+          {s:'Windows Vista', r:/Windows NT 6.0/},
+          {s:'Windows Server 2003', r:/Windows NT 5.2/},
+          {s:'Windows XP', r:/(Windows XP|Windows NT 5.1)/},
+          {s:'Windows', r:/Windows/},
+          {s:'Android', r:/Android/},
+          {s:'FreeBSD', r:/FreeBSD/},
+          {s:'OpenBSD', r:/OpenBSD/},
+          {s:'Chrome OS', r:/CrOS/},
+          {s:'Linux', r:/(Linux|X11)/},
+          {s:'macOS', r:/(Mac OS|MacPPC|MacIntel|Mac_PowerPC|Macintosh)/},
+          {s:'QNX', r:/QNX/},
+          {s:'BeOS', r:/BeOS/}
+        ];
+        for (var id in clientStrings) {
+          var cs = clientStrings[id];
+          if (cs.r.test(userAgent)) {
+            return cs.s;
+          }
+        }
+        return 'Emscripten';
+      }
+
+      var os_name = detectOsName();
+      var length = lengthBytesUTF8(os_name) + 1;
+      var result = _malloc(length);
+      stringToUTF8(os_name, result, length);
+      return result;
+    }));
+    // clang-format on
+    string os_name(os_name_js);
+    std::free(os_name_js);
+
+    return os_name;
 #else
 #if TD_LINUX
     auto os_name = read_os_name("/etc/os-release", "PRETTY_NAME=\"", "\"\n");
@@ -124,8 +220,6 @@ Slice get_operating_system_version() {
     return "NetBSD";
 #elif TD_CYGWIN
     return "Cygwin";
-#elif TD_EMSCRIPTEN
-    return "Emscripten";
 #else
     return "Unix";
 #endif