From 35505d905a7b13ab38d25d03d97fa83f5966394d Mon Sep 17 00:00:00 2001
From: Brian Fiete <bfiete@gmail.com>
Date: Mon, 10 Aug 2020 17:02:48 -0700
Subject: [PATCH] More extern constraints work

---
 BeefLibs/corlib/src/Math.bf                |  4 ++--
 IDEHelper/Compiler/BfExprEvaluator.cpp     | 17 +++++++++++------
 IDEHelper/Compiler/BfModule.cpp            |  4 +++-
 IDEHelper/Compiler/BfResolvedTypeUtils.cpp |  5 +++++
 IDEHelper/Compiler/BfResolvedTypeUtils.h   |  1 +
 IDEHelper/Tests/src/ExtensionMethods.bf    |  2 +-
 IDEHelper/Tests/src/Generics.bf            | 11 +++++++++++
 7 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/BeefLibs/corlib/src/Math.bf b/BeefLibs/corlib/src/Math.bf
index 0dda54c2..415c7564 100644
--- a/BeefLibs/corlib/src/Math.bf
+++ b/BeefLibs/corlib/src/Math.bf
@@ -443,7 +443,7 @@ namespace System
 		        return 0;
 		}
 
-		/*public static int Sign<T>(T value) where int : operator T <=> T, ICanBeNaN
+		public static int Sign<T>(T value) where int : operator T <=> T where T : ICanBeNaN
 		{
 		    if (value < default)
 		        return -1;
@@ -453,7 +453,7 @@ namespace System
 		        return 0;
 
 			Runtime.FatalError("Cannot be used on NaN");
-		}*/
+		}
 		
 		public static int32 DivRem(int32 a, int32 b, out int32 result)
         {
diff --git a/IDEHelper/Compiler/BfExprEvaluator.cpp b/IDEHelper/Compiler/BfExprEvaluator.cpp
index c0bd1c7d..84611fc8 100644
--- a/IDEHelper/Compiler/BfExprEvaluator.cpp
+++ b/IDEHelper/Compiler/BfExprEvaluator.cpp
@@ -209,15 +209,15 @@ void BfMethodMatcher::Init(/*SizedArrayImpl<BfResolvedArg>& arguments, */BfSized
 }
 
 bool BfMethodMatcher::IsMemberAccessible(BfTypeInstance* typeInst, BfTypeDef* declaringType)
-{
+{	
 	if (mActiveTypeDef == NULL)
 		mActiveTypeDef = mModule->GetActiveTypeDef();
-	if (!typeInst->IsTypeMemberIncluded(declaringType, mActiveTypeDef, mModule))
-		return false;
 
 	// This may not be completely correct - BUT if we don't have this then even Dictionary TKey's operator == won't be considered accessible
 	if ((!mModule->IsInSpecializedSection()) && (mActiveTypeDef->mTypeDeclaration != NULL))
-	{
+	{		
+		if (!typeInst->IsTypeMemberIncluded(declaringType, mActiveTypeDef, mModule))
+			return false;
 		if (!typeInst->IsTypeMemberAccessible(declaringType, mActiveTypeDef))
 			return false;
 	}
@@ -931,8 +931,13 @@ void BfMethodMatcher::CompareMethods(BfMethodInstance* prevMethodInstance, BfTyp
 			auto prevMethodGenericParam = prevMethodInstance->mMethodInfoEx->mGenericParams[genericParamIdx];
 			SET_BETTER_OR_WORSE(mModule->AreConstraintsSubset(prevMethodGenericParam, newMethodGenericParam), mModule->AreConstraintsSubset(newMethodGenericParam, prevMethodGenericParam));
 		}
-	}
-	
+
+		if ((!isBetter) && (!isWorse))
+		{
+			SET_BETTER_OR_WORSE(newMethodInstance->HasExternConstraints(), prevMethodInstance->HasExternConstraints());
+		}
+	}		
+
 	if ((isBetter) || (isWorse))
 	{
 		RETURN_RESULTS;
diff --git a/IDEHelper/Compiler/BfModule.cpp b/IDEHelper/Compiler/BfModule.cpp
index 90ea91a3..e6763abe 100644
--- a/IDEHelper/Compiler/BfModule.cpp
+++ b/IDEHelper/Compiler/BfModule.cpp
@@ -12788,9 +12788,11 @@ bool BfModule::InDefinitionSection()
 
 bool BfModule::IsInSpecializedGeneric()
 {	
+	if (mCurTypeInstance->IsSpecializedType())
+		return true;
 	if ((mCurMethodInstance == NULL) || (mCurMethodInstance->mIsUnspecialized))
 		return false;
-	return (mCurMethodInstance->GetNumGenericArguments() != 0) || (mCurTypeInstance->IsGenericTypeInstance());
+	return (mCurMethodInstance->GetNumGenericArguments() != 0);
 }
 
 bool BfModule::IsInSpecializedSection()
diff --git a/IDEHelper/Compiler/BfResolvedTypeUtils.cpp b/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
index 9d0a78e1..7c07743b 100644
--- a/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
+++ b/IDEHelper/Compiler/BfResolvedTypeUtils.cpp
@@ -645,6 +645,11 @@ bool BfMethodInstance::IsSpecializedByAutoCompleteMethod()
 	return false;
 }
 
+bool BfMethodInstance::HasExternConstraints()
+{
+	return (mMethodInfoEx != NULL) && (mMethodInfoEx->mGenericParams.size() > mMethodInfoEx->mMethodGenericArguments.size());
+}
+
 bool BfMethodInstance::HasParamsArray()
 {
 	if (mParams.size() == 0)
diff --git a/IDEHelper/Compiler/BfResolvedTypeUtils.h b/IDEHelper/Compiler/BfResolvedTypeUtils.h
index 263d3bde..c2ab7da6 100644
--- a/IDEHelper/Compiler/BfResolvedTypeUtils.h
+++ b/IDEHelper/Compiler/BfResolvedTypeUtils.h
@@ -865,6 +865,7 @@ public:
 	bool IsSpecializedGenericMethod();
 	bool IsSpecializedGenericMethodOrType();
 	bool IsSpecializedByAutoCompleteMethod();
+	bool HasExternConstraints();
 	bool HasThis();	
 	bool HasExplicitThis();
 	bool HasParamsArray();
diff --git a/IDEHelper/Tests/src/ExtensionMethods.bf b/IDEHelper/Tests/src/ExtensionMethods.bf
index 8d37e89c..3c12484e 100644
--- a/IDEHelper/Tests/src/ExtensionMethods.bf
+++ b/IDEHelper/Tests/src/ExtensionMethods.bf
@@ -47,7 +47,7 @@ namespace Tests
 
 	static
 	{
-		public static T Total<T>(this List<T> list) where T : IOpAddable
+		public static T Total<T>(this List<T> list) where T : operator T + T
 		{
 			T total = default;
 			for (let val in list)
diff --git a/IDEHelper/Tests/src/Generics.bf b/IDEHelper/Tests/src/Generics.bf
index e009e2b7..7a54a555 100644
--- a/IDEHelper/Tests/src/Generics.bf
+++ b/IDEHelper/Tests/src/Generics.bf
@@ -116,9 +116,20 @@ namespace Tests
 			return 3;
 		}
 
+		public struct Entry
+		{
+			public static int operator<=>(Entry lhs, Entry rhs)
+			{
+				return 0;
+			}
+		}
+
 		[Test]
 		public static void TestBasics()
 		{
+			List<Entry> list = scope .();
+			list.Sort();
+
 			ClassA ca = scope .();
 			ClassB cb = scope .();
 			Test.Assert(LibA.LibA0.GetVal(ca) == 123);