Merge pull request #1441 from Unity-Technologies/handle-missing-libc-better

Handle platforms that don't have libc (case 1340695)

Author: Joshua Peterson

mcs/class/System/System.Net.NetworkInformation/UnixIPGlobalProperties.cs

@@ -57,8 +57,17 @@ public override string DhcpScopeName {
 		public override string DomainName {
 			get {
 				byte [] bytes = new byte [256];
-				if (getdomainname (bytes, 256) != 0)
-					throw new NetworkInformationException ();
+#if UNITY
+				try
+				{
+#endif
+					if (getdomainname (bytes, 256) != 0)
+						throw new NetworkInformationException ();
+#if UNITY
+				} catch (EntryPointNotFoundException) {
+					return String.Empty;
+				}
+#endif
 				int len = Array.IndexOf<byte> (bytes, 0);
 				return Encoding.ASCII.GetString (bytes, 0, len < 0 ? 256 : len);
 			}
@@ -152,6 +161,17 @@ public override string DomainName {
 	}
 #endif
 
+#if UNITY
+	sealed class UnixNoLibCIPGlobalProperties : UnixIPGlobalProperties
+	{
+		public override string DomainName {
+			get {
+				return String.Empty;
+			}
+		}
+	}
+#endif
+
 	// It expects /proc/net/snmp (or /usr/compat/linux/proc/net/snmp),
 	// formatted like:
 	// http://www.linuxdevcenter.com/linux/2000/11/16/example5.html
@@ -389,6 +409,11 @@ public override UdpStatistics GetUdpIPv6Statistics ()
 	}
 
 	internal static class UnixIPGlobalPropertiesFactoryPal {
+#if UNITY
+        // defaults to false, but may be replaced by intrinsic in runtime
+        static bool PlatformNeedsLibCWorkaround { get; }
+#endif
+
 		public static IPGlobalProperties Create ()
 		{
 #if MONODROID
@@ -398,6 +423,10 @@ public static IPGlobalProperties Create ()
 #elif MONO
 			switch (Environment.OSVersion.Platform) {
 			case PlatformID.Unix:
+#if UNITY
+                if (PlatformNeedsLibCWorkaround)
+                    return new UnixNoLibCIPGlobalProperties();
+#endif
 				MibIPGlobalProperties impl = null;
 				if (Directory.Exists (MibIPGlobalProperties.ProcDir)) {
 					impl = new MibIPGlobalProperties (MibIPGlobalProperties.ProcDir);

mcs/class/System/System/Platform.cs

@@ -89,14 +89,26 @@ private static void CheckOS() {
 		}
 #endif
 
+		// UNITY: runtime replaces this with intrinsic
 		public static bool IsMacOS {
 			get {
 				if (!checkedOS)
+#if UNITY
+					try {
+						CheckOS();
+					}
+					catch (DllNotFoundException) {
+						// libc does not exist, so this is not MacOS
+						isMacOS = false;
+					}
+#else
 					CheckOS();
+#endif
 				return isMacOS;
 			}
 		}
 
+		// UNITY: runtime replaces this with intrinsic
 		public static bool IsFreeBSD {
 			get {
 				if (!checkedOS)

mono/mini/intrinsics.c

@@ -1898,6 +1898,34 @@ mini_emit_inst_for_method (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSign
 				return ins;
 			}
 		}
+	} else if (!strcmp (cmethod->klass->image->assembly->aname.name, "System") &&
+			   !strcmp (cmethod->klass->name_space, "System") &&
+			   !strcmp (cmethod->klass->name, "Platform") &&
+			   !strcmp (cmethod->name, "get_IsMacOS")) {
+#if defined(TARGET_OSX)
+		EMIT_NEW_ICONST (cfg, ins, 1);
+#else
+		EMIT_NEW_ICONST (cfg, ins, 0);
+#endif
+		return ins;
+	} else if (!strcmp (cmethod->klass->image->assembly->aname.name, "System") &&
+			   !strcmp (cmethod->klass->name_space, "System") &&
+			   !strcmp (cmethod->klass->name, "Platform") &&
+			   !strcmp (cmethod->name, "get_IsFreeBSD")) {
+#if defined(__FreeBSD__)
+		EMIT_NEW_ICONST (cfg, ins, 1);
+#else
+		EMIT_NEW_ICONST (cfg, ins, 0);
+#endif
+		return ins;
+	} else if (!strcmp (cmethod->klass->image->assembly->aname.name, "System") &&
+			   !strcmp (cmethod->klass->name_space, "System.Net.NetworkInformation") &&
+			   !strcmp (cmethod->klass->name, "UnixIPGlobalPropertiesFactoryPal") &&
+			   !strcmp (cmethod->name, "get_PlatformNeedsLibCWorkaround")) {
+#if defined(HOST_ANDROID)
+		EMIT_NEW_ICONST (cfg, ins, 1);
+		return ins;
+#endif
 	}
 
 #ifdef MONO_ARCH_SIMD_INTRINSICS