Output shader errors to console when uber shader has error

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Graphs/MaterialGraphAsset.cs

+using System;
-using UnityEditor;
+
-using UnityEditor.Graphing;
-    public class MaterialGraphAsset
+    static class MaterialGraphAsset
     {
         public static bool ShaderHasError(Shader shader)
         {
+        }
+
+        public struct ShaderError
+        {
+            public string message;
+            public string messageDetails;
+            public string platform;
+            public string file;
+            public int line;
+            public int warning;
+        }
+
+        static MethodInfo s_GetErrorsCall = typeof(ShaderUtil).GetMethod("GetShaderErrors", BindingFlags.Static | BindingFlags.NonPublic);
+        static Type s_ShaderErrorType = typeof(ShaderUtil).Assembly.GetType("UnityEditor.ShaderError");
+        static FieldInfo s_ShaderErrorMessageField = s_ShaderErrorType.GetField("message", BindingFlags.Instance | BindingFlags.Public);
+        static FieldInfo s_ShaderErrorMessageDetailsField = s_ShaderErrorType.GetField("messageDetails", BindingFlags.Instance | BindingFlags.Public);
+        static FieldInfo s_ShaderErrorPlatformField = s_ShaderErrorType.GetField("platform", BindingFlags.Instance | BindingFlags.Public);
+        static FieldInfo s_ShaderErrorFileField = s_ShaderErrorType.GetField("file", BindingFlags.Instance | BindingFlags.Public);
+        static FieldInfo s_ShaderErrorLineField = s_ShaderErrorType.GetField("line", BindingFlags.Instance | BindingFlags.Public);
+        static FieldInfo s_ShaderErrorWarningField = s_ShaderErrorType.GetField("warning", BindingFlags.Instance | BindingFlags.Public);
+
+        public static ShaderError[] GetShaderErrors(Shader shader)
+        {
+            var invoke = s_GetErrorsCall.Invoke(null, new object[] { shader });
+            var objects = (Array)invoke;
+            var errors = new ShaderError[objects.Length];
+            for (var i = 0; i < objects.Length; i++)
+            {
+                var obj = objects.GetValue(i);
+                errors[i] = new ShaderError
+                {
+                    message = (string)s_ShaderErrorMessageField.GetValue(obj),
+                    messageDetails = (string)s_ShaderErrorMessageDetailsField.GetValue(obj),
+                    platform = (string)s_ShaderErrorPlatformField.GetValue(obj),
+                    file = (string)s_ShaderErrorFileField.GetValue(obj),
+                    line = (int)s_ShaderErrorLineField.GetValue(obj),
+                    warning = (int)s_ShaderErrorWarningField.GetValue(obj),
+                };
+            }
+            return errors;
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/PreviewManager.cs

 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
+using System.Text;
 using System.Threading;
 using UnityEditor.Graphing.Util;
 using UnityEngine;
                         m_UberShaderString = m_Graph.GetUberPreviewShader(m_UberShaderIds, out m_OutputIdProperty);
                         ShaderUtil.UpdateShaderAsset(m_UberShader, m_UberShaderString);
                         File.WriteAllText(Application.dataPath + "/../UberShader.shader", (m_UberShaderString ?? "null").Replace("UnityEngine.MaterialGraph", "Generated"));
-                        var message = "RecreateUberShader: " + Environment.NewLine + m_UberShaderString;
-                            Debug.LogWarning(message);
+                            var errors = MaterialGraphAsset.GetShaderErrors(m_UberShader);
+                            var message = new ShaderStringBuilder();
+                            message.AppendLine("Uber shader has {0} error{1}:", errors.Length, errors.Length != 1 ? "s" : "");
+                            foreach (var error in errors)
+                            {
+                                message.AppendLine("{0} at line {1} (on {2})", error.message, error.line, error.platform);
+                                message.AppendLine(error.messageDetails);
+                            }
+                            Debug.LogWarning(message.ToString());
                             ShaderUtil.ClearShaderErrors(m_UberShader);
                             ShaderUtil.UpdateShaderAsset(m_UberShader, k_EmptyShader);
                             uberShaderHasError = true;