Added long doubles to the marshalling structures in the C# generator. (#842)

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -637,15 +637,14 @@ namespace CppSharp.Generators.CSharp
             if (arrayType != null && arrayType.SizeType == ArrayType.ArraySize.Constant)
                 coreType = arrayType.Type.Desugar();
             // we do not support the primitives below yet because their representation in C# is problematic
-            if (coreType.IsPrimitiveType(PrimitiveType.LongDouble) ||
-                coreType.IsPrimitiveType(PrimitiveType.Int128) ||
+            if (coreType.IsPrimitiveType(PrimitiveType.Int128) ||
                 coreType.IsPrimitiveType(PrimitiveType.UInt128) ||
                 coreType.IsPrimitiveType(PrimitiveType.Half))
                 return;
 
             TypePrinterResult retType = TypePrinter.VisitFieldDecl(
                 new Field { Name = field.Name, QualifiedType = field.QualifiedType });
-           
+
             PushBlock(BlockKind.Field);
 
             if (!Options.GenerateSequentialLayout || @class.IsUnion)

src/Generator/Generators/CSharp/CSharpTypePrinter.cs

@@ -517,8 +517,8 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.Half: return "__fp16";
                 case PrimitiveType.Float: return "float";
                 case PrimitiveType.Double: return "double";
-                // not really supported yet but it's closest, and we don't want crashes when parsing long doubles
-                case PrimitiveType.LongDouble: return "decimal";
+                case PrimitiveType.LongDouble: return new TypePrinterResult { Type = "fixed byte",
+                    NameSuffix = $"[{Context.TargetInfo.LongDoubleWidth}]"};
                 case PrimitiveType.IntPtr: return IntPtrType;
                 case PrimitiveType.UIntPtr: return "global::System.UIntPtr";
                 case PrimitiveType.Null: return "void*";

tests/Common/Common.h

@@ -7,6 +7,12 @@
 #include <string>
 #include <vector>
 
+class TestPrimitiveTypes
+{
+public:
+    long double longDouble;
+};
+
 class DLL_API IgnoredType
 {
     class IgnoredNested
@@ -1180,12 +1186,6 @@ class HasSystemBase : public std::string
 
 typedef SpecialisesVoid<std::vector<std::string>> SpecialisesWithNestedSystemTypes;
 
-struct HasLongDoubles
-{
-    long double simple;
-    long double array[4];
-};
-
 enum
 {
     EmptyEnumsWithSameMemberPrefix1,