Impl progress on c++ name mangling on Clang for proper P/Invokes binding

Source/Tools/Flax.Build/Bindings/BindingsGenerator.CSharp.cs

@@ -18,6 +18,7 @@ namespace Flax.Build.Bindings
         private static readonly List<string> CSharpAdditionalCode = new List<string>();
         private static readonly Dictionary<string, string> CSharpAdditionalCodeCache = new Dictionary<string, string>();
 #if USE_NETCORE
+        private static readonly TypeInfo CSharpEventBindReturn = new TypeInfo("void");
         private static readonly List<FunctionInfo.ParameterInfo> CSharpEventBindParams = new List<FunctionInfo.ParameterInfo>() { new FunctionInfo.ParameterInfo() { Name = "bind", Type = new TypeInfo("bool") } };
 #endif
 
@@ -1009,7 +1010,7 @@ namespace Flax.Build.Bindings
                 if (buildData.Toolchain.Compiler == TargetCompiler.MSVC)
                     libraryEntryPoint = $"{classInfo.FullNameManaged}::Internal_{eventInfo.Name}_Bind"; // MSVC allows to override exported symbol name
                 else
-                    libraryEntryPoint = CppNameMangling.MangleFunctionName(buildData, eventInfo.Name + "_ManagedBind", classInfo.FullNameNativeInternal + "Internal", CSharpEventBindParams);
+                    libraryEntryPoint = CppNameMangling.MangleFunctionName(buildData, eventInfo.Name + "_ManagedBind", classInfo.FullNameNativeInternal + "Internal", CSharpEventBindReturn, CSharpEventBindParams);
                 contents.Append(indent).Append($"[LibraryImport(\"{classInfo.ParentModule.Module.BinaryModuleName}\", EntryPoint = \"{libraryEntryPoint}\", StringMarshalling = StringMarshalling.Custom, StringMarshallingCustomType = typeof(FlaxEngine.StringMarshaller))]").AppendLine();
                 contents.Append(indent).Append($"internal static partial void Internal_{eventInfo.Name}_Bind(");
                 if (!eventInfo.IsStatic)

Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cpp.cs

@@ -947,10 +947,7 @@ namespace Flax.Build.Bindings
                 {
                     Name = "__returnCount",
                     DefaultValue = "var __returnCount",
-                    Type = new TypeInfo
+                    Type = new TypeInfo("int"),
-                    {
-                        Type = "int"
-                    },
                     IsOut = true,
                 });
             }
@@ -969,7 +966,7 @@ namespace Flax.Build.Bindings
             }
             else
             {
-                libraryEntryPoint = CppNameMangling.MangleFunctionName(buildData, functionInfo.Name, callerName, functionInfo.Parameters, functionInfo.Glue.CustomParameters);
+                libraryEntryPoint = CppNameMangling.MangleFunctionName(buildData, functionInfo.Name, callerName, functionInfo.ReturnType, functionInfo.IsStatic ? null : new TypeInfo(caller.Name) { IsPtr = true }, functionInfo.Parameters, functionInfo.Glue.CustomParameters);
                 useSeparateImpl = true; // DLLEXPORT doesn't properly export function thus separate implementation from declaration
             }
             functionInfo.Glue.LibraryEntryPoint = libraryEntryPoint;

Source/Tools/Flax.Build/Utilities/CppNameMangling.cs

@@ -1,6 +1,7 @@
 // Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.
 
 using System;
+using System.Text;
 using System.Collections.Generic;
 using Flax.Build.Bindings;
 
@@ -11,19 +12,30 @@ namespace Flax.Build
     /// </summary>
     internal static class CppNameMangling
     {
-        public static string MangleFunctionName(Builder.BuildData buildData, string name, string outerName, List<FunctionInfo.ParameterInfo> parameters1, List<FunctionInfo.ParameterInfo> parameters2)
+        public static string MangleFunctionName(Builder.BuildData buildData, string name, string outerName, TypeInfo returnType, TypeInfo parameter0, List<FunctionInfo.ParameterInfo> parameters1, List<FunctionInfo.ParameterInfo> parameters2)
         {
-            if (parameters1 == null || parameters1.Count == 0)
+            List<FunctionInfo.ParameterInfo> parameters = null;
-                return MangleFunctionName(buildData, name, outerName, parameters2);
+            if (parameter0 == null)
-            if (parameters2 == null || parameters2.Count == 0)
+            {
-                return MangleFunctionName(buildData, name, outerName, parameters1);
+                if (parameters1 == null || parameters1.Count == 0)
-            var parameters = new List<FunctionInfo.ParameterInfo>();
+                    parameters = parameters2;
-            parameters.AddRange(parameters1);
+                else if (parameters2 == null || parameters2.Count == 0)
-            parameters.AddRange(parameters2);
+                    parameters = parameters1;
-            return MangleFunctionName(buildData, name, outerName, parameters);
+            }
+            if (parameters == null)
+            {
+                parameters = new List<FunctionInfo.ParameterInfo>();
+                if (parameter0 != null)
+                    parameters.Add(new FunctionInfo.ParameterInfo() { Type = parameter0 });
+                if (parameters1 != null)
+                    parameters.AddRange(parameters1);
+                if (parameters2 != null)
+                    parameters.AddRange(parameters2);
+            }
+            return MangleFunctionName(buildData, name, outerName, returnType, parameters);
         }
 
-        public static string MangleFunctionName(Builder.BuildData buildData, string name, string outerName, List<FunctionInfo.ParameterInfo> parameters)
+        public static string MangleFunctionName(Builder.BuildData buildData, string name, string outerName, TypeInfo returnType, List<FunctionInfo.ParameterInfo> parameters)
         {
             if (name.Contains(":"))
                 throw new NotImplementedException("No nested types mangling support.");
@@ -42,7 +54,28 @@ namespace Flax.Build
                 // TODO: mangle parameters
                 break;
             case TargetCompiler.Clang:
-                sb.Append("todo");
+                // References:
+                // http://web.mit.edu/tibbetts/Public/inside-c/www/mangling.html
+                // https://en.wikipedia.org/wiki/Name_mangling
+                sb.Append("_ZN");
+                //if (!returnType.IsVoid)
+                //    MangleTypeClang(sb, returnType);
+                sb.Append(outerName.Length);
+                sb.Append(outerName);
+                sb.Append(name.Length);
+                sb.Append(name);
+                sb.Append('E');
+                if (parameters == null || parameters.Count == 0)
+                {
+                    sb.Append('v');
+                }
+                else
+                {
+                    foreach (var e in parameters)
+                    {
+                        MangleTypeClang(sb, e.Type);
+                    }
+                }
                 break;
             default:
                 throw new InvalidPlatformException(buildData.Platform.Target);
@@ -51,5 +84,54 @@ namespace Flax.Build
             BindingsGenerator.PutStringBuilder(sb);
             return result;
         }
+
+        private static void MangleTypeClang(StringBuilder sb, TypeInfo type)
+        {
+            if (type.IsPtr)
+                sb.Append('P');
+            if (type.IsRef)
+                sb.Append('R');
+            if (type.IsConst)
+                sb.Append('K');
+            switch (type.Type)
+            {
+            // TODO: use proper typedef extraction from TypedefInfo
+            case "Float2":
+                sb.Append("11Vector2BaseIfE");
+                break;
+            case "Float3":
+                sb.Append("11Vector3BaseIfE");
+                break;
+            case "Float4":
+                sb.Append("11Vector4BaseIfE");
+                break;
+
+            case "bool":
+                sb.Append('b');
+                break;
+            case "char":
+            case "int8":
+                sb.Append('c');
+                break;
+            case "int":
+            case "int32":
+                sb.Append('i');
+                break;
+            case "float":
+                sb.Append('f');
+                break;
+            default:
+                sb.Append(type.Type.Length);
+                sb.Append(type.Type);
+                if (type.GenericArgs != null)
+                {
+                    sb.Append('I');
+                    foreach (var e in type.GenericArgs)
+                        MangleTypeClang(sb, e);
+                    sb.Append('E');
+                }
+                break;
+            }
+        }
     }
 }