From d502c4a58c3ac4e49f2412e13f26fe69432c6ffb Mon Sep 17 00:00:00 2001
From: Merlin <36685500+Merlin-san@users.noreply.github.com>
Date: Thu, 9 Apr 2020 17:05:23 -0700
Subject: [PATCH] More improvements to the binary expression handling

- Avoid extra copy in binary expressions when the lhs is a constant expression since it can't be modified.
---
 Assets/UdonSharp/Editor/UdonSharpASTVisitor.cs        | 2 +-
 Assets/UdonSharp/Editor/UdonSharpExpressionCapture.cs | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Assets/UdonSharp/Editor/UdonSharpASTVisitor.cs b/Assets/UdonSharp/Editor/UdonSharpASTVisitor.cs
index 022ad86c..fdfb7f3d 100644
--- a/Assets/UdonSharp/Editor/UdonSharpASTVisitor.cs
+++ b/Assets/UdonSharp/Editor/UdonSharpASTVisitor.cs
@@ -1574,7 +1574,7 @@ public override void VisitBinaryExpression(BinaryExpressionSyntax node)
             {
                 Visit(node.Left);
 
-                if (lhsCapture.DoesReturnIntermediateSymbol())
+                if (lhsCapture.DoesReturnIntermediateSymbol() || lhsCapture.IsConstExpression())
                 {
                     lhsValue = lhsCapture.ExecuteGet();
                 }
diff --git a/Assets/UdonSharp/Editor/UdonSharpExpressionCapture.cs b/Assets/UdonSharp/Editor/UdonSharpExpressionCapture.cs
index 0b4b1b6c..68594186 100644
--- a/Assets/UdonSharp/Editor/UdonSharpExpressionCapture.cs
+++ b/Assets/UdonSharp/Editor/UdonSharpExpressionCapture.cs
@@ -1419,6 +1419,15 @@ public bool DoesReturnIntermediateSymbol()
             return !IsLocalSymbol();
         }
 
+        public bool IsConstExpression()
+        {
+            // Only basic handling for local symbols for now since we can directly reference them
+            if (IsLocalSymbol() && ExecuteGet().declarationType.HasFlag(SymbolDeclTypeFlags.Constant))
+                return true;
+
+            return false;
+        }
+
         public bool ResolveAccessToken(string accessToken)
         {
             bool resolvedToken = false;