From 12642f9a4216443027bd772efebc82c93d131cf9 Mon Sep 17 00:00:00 2001
From: Dimitar Dobrev <dpldobrev@protonmail.com>
Date: Tue, 5 Feb 2019 04:09:39 +0200
Subject: [PATCH] Fixed the generated C# when an unsigned enum is assigned a
 negative value.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>
---
 build/InstallMono.sh                          |  2 +-
 .../Passes/HandleDefaultParamValuesPass.cs    | 34 ++++++++++++++++---
 tests/CSharp/CSharp.Tests.cs                  |  1 +
 tests/CSharp/CSharp.cpp                       |  4 +++
 tests/CSharp/CSharp.h                         |  5 +++
 5 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/build/InstallMono.sh b/build/InstallMono.sh
index 37998da3..5e85fabf 100755
--- a/build/InstallMono.sh
+++ b/build/InstallMono.sh
@@ -1,6 +1,6 @@
 OS=$(uname -s)
 if [ "$OS" == "Darwin" ]; then
-	wget -O mono.pkg https://download.mono-project.com/archive/5.2.0/macos-10-universal/MonoFramework-MDK-5.2.0.215.macos10.xamarin.universal.pkg
+	wget -O mono.pkg https://download.mono-project.com/archive/5.18.0/macos-10-universal/MonoFramework-MDK-5.18.0.240.macos10.xamarin.universal.pkg
 	sudo installer -pkg mono.pkg -target /
 	export PATH=$PATH:/Library/Frameworks/Mono.framework/Versions/Current/bin
 elif [ "$OS" == "Linux" ]; then
diff --git a/src/Generator/Passes/HandleDefaultParamValuesPass.cs b/src/Generator/Passes/HandleDefaultParamValuesPass.cs
index 86922160..ee299f8c 100644
--- a/src/Generator/Passes/HandleDefaultParamValuesPass.cs
+++ b/src/Generator/Passes/HandleDefaultParamValuesPass.cs
@@ -129,8 +129,7 @@ namespace CppSharp.Passes
             Class @class;
             if (desugared.GetFinalPointee().TryGetClass(out @class) && @class.IsValueType)
             {
-                result = string.Format("new {0}()",
-                    new CSharpTypePrinter(Context).VisitClassDecl(@class));
+                result = $"new {@class.Visit(new CSharpTypePrinter(Context))}()";
                 return true;
             }
 
@@ -253,15 +252,40 @@ namespace CppSharp.Passes
             if (call != null && statement.String != "0")
             {
                 var @params = regexFunctionParams.Match(statement.String).Groups[1].Value;
-                result = TranslateEnumExpression(call, desugared, @params);
+                result = TranslateEnumExpression(desugared, @params);
+                return true;
+            }
+
+            if (desugared.TryGetEnum(out Enumeration @enum) &&
+                int.TryParse(statement.String, out int value))
+            {
+                var typePrinter = new CSharpTypePrinter(Context);
+                var printedEnum = @enum.Visit(typePrinter);
+                if (value < 0)
+                    switch (@enum.BuiltinType.Type)
+                    {
+                        case PrimitiveType.UShort:
+                        case PrimitiveType.UInt:
+                        case PrimitiveType.ULong:
+                        case PrimitiveType.ULongLong:
+                        case PrimitiveType.UInt128:
+                            result = $@"({printedEnum}) unchecked(({
+                                @enum.BuiltinType.Visit(typePrinter)}) {
+                                statement.String})";
+                            break;
+                        default:
+                            result = $"({printedEnum}) ({statement.String})";
+                            break;
+                    }
+                else
+                    result = $"({printedEnum}) {statement.String}";
                 return true;
             }
 
             return false;
         }
 
-        private string TranslateEnumExpression(Function function,
-            Type desugared, string @params)
+        private string TranslateEnumExpression(Type desugared, string @params)
         {
             if (@params.Contains("::"))
                 return regexDoubleColon.Replace(@params, desugared + ".");
diff --git a/tests/CSharp/CSharp.Tests.cs b/tests/CSharp/CSharp.Tests.cs
index 41411a1d..6d5829e2 100644
--- a/tests/CSharp/CSharp.Tests.cs
+++ b/tests/CSharp/CSharp.Tests.cs
@@ -229,6 +229,7 @@ public unsafe class CSharpTests : GeneratorTestFixture
             methodsWithDefaultValues.DefaultValueType();
             methodsWithDefaultValues.DefaultChar();
             methodsWithDefaultValues.DefaultEmptyChar();
+            methodsWithDefaultValues.DefaultEmptyEnum();
             methodsWithDefaultValues.DefaultRefTypeBeforeOthers();
             methodsWithDefaultValues.DefaultRefTypeAfterOthers();
             methodsWithDefaultValues.DefaultRefTypeBeforeAndAfterOthers(0, null);
diff --git a/tests/CSharp/CSharp.cpp b/tests/CSharp/CSharp.cpp
index bafd2d8b..26955ff1 100644
--- a/tests/CSharp/CSharp.cpp
+++ b/tests/CSharp/CSharp.cpp
@@ -584,6 +584,10 @@ void MethodsWithDefaultValues::defaultEmptyChar(char c)
 {
 }
 
+void MethodsWithDefaultValues::defaultEmptyEnum(Empty e)
+{
+}
+
 void MethodsWithDefaultValues::defaultRefTypeBeforeOthers(Foo foo, int i, Bar::Items item)
 {
 }
diff --git a/tests/CSharp/CSharp.h b/tests/CSharp/CSharp.h
index 326a55c2..5dd81f57 100644
--- a/tests/CSharp/CSharp.h
+++ b/tests/CSharp/CSharp.h
@@ -379,6 +379,10 @@ public:
     DefaultZeroMappedToEnum(int* = 0);
 };
 
+enum class Empty : unsigned long long int
+{
+};
+
 class DLL_API MethodsWithDefaultValues : public Quux
 {
 public:
@@ -404,6 +408,7 @@ public:
     void defaultValueType(QGenericArgument valueType = QGenericArgument());
     void defaultChar(char c = 'a');
     void defaultEmptyChar(char c = 0);
+    void defaultEmptyEnum(Empty e = Empty(-1));
     void defaultRefTypeBeforeOthers(Foo foo = Foo(), int i = 5, Bar::Items item = Bar::Item2);
     void defaultRefTypeAfterOthers(int i = 5, Bar::Items item = Bar::Item2, Foo foo = Foo());
     void defaultRefTypeBeforeAndAfterOthers(int i = 5, Foo foo = Foo(), Bar::Items item = Bar::Item2, Baz baz = Baz());