From 455fbb0b9c7d7c4b66cc969ad0e9915fe95e420f Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 3 Mar 2021 18:48:34 +0200
Subject: [PATCH] Fix an issue where member assignments were incorrectly
 optimized away

They are now treated as subfield assignments, same as array subscripts.
---
 source/glsl/optimize.cpp | 9 +++++----
 source/glsl/optimize.h   | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/source/glsl/optimize.cpp b/source/glsl/optimize.cpp
index 8a9992a2..afa6394e 100644
--- a/source/glsl/optimize.cpp
+++ b/source/glsl/optimize.cpp
@@ -408,7 +408,7 @@ UnusedVariableRemover::UnusedVariableRemover():
 	aggregate(0),
 	r_assignment(0),
 	assignment_target(false),
-	r_assign_to_subscript(false),
+	r_assign_to_subfield(false),
 	r_side_effects(false)
 { }
 
@@ -455,6 +455,7 @@ void UnusedVariableRemover::visit(InterfaceBlockReference &iface)
 
 void UnusedVariableRemover::visit(MemberAccess &memacc)
 {
+	r_assign_to_subfield = true;
 	TraversingVisitor::visit(memacc);
 	unused_nodes.erase(memacc.declaration);
 }
@@ -471,7 +472,7 @@ void UnusedVariableRemover::visit(BinaryExpression &binary)
 	if(binary.oper->token[0]=='[')
 	{
 		if(assignment_target)
-			r_assign_to_subscript = true;
+			r_assign_to_subfield = true;
 		binary.left->visit(*this);
 		SetForScope<bool> set(assignment_target, false);
 		binary.right->visit(*this);
@@ -483,7 +484,6 @@ void UnusedVariableRemover::visit(BinaryExpression &binary)
 void UnusedVariableRemover::visit(Assignment &assign)
 {
 	{
-		r_assign_to_subscript = false;
 		SetForScope<bool> set(assignment_target, !assign.self_referencing);
 		assign.left->visit(*this);
 	}
@@ -520,10 +520,11 @@ void UnusedVariableRemover::clear_assignments(VariableInfo &var_info, bool mark_
 void UnusedVariableRemover::visit(ExpressionStatement &expr)
 {
 	r_assignment = 0;
+	r_assign_to_subfield = false;
 	r_side_effects = false;
 	TraversingVisitor::visit(expr);
 	if(r_assignment && r_assignment->target_declaration)
-		record_assignment(*r_assignment->target_declaration, expr, (r_assignment->self_referencing || r_assign_to_subscript));
+		record_assignment(*r_assignment->target_declaration, expr, (r_assignment->self_referencing || r_assign_to_subfield));
 	if(!r_side_effects)
 		unused_nodes.insert(&expr);
 }
diff --git a/source/glsl/optimize.h b/source/glsl/optimize.h
index 373e0199..28f5e876 100644
--- a/source/glsl/optimize.h
+++ b/source/glsl/optimize.h
@@ -145,7 +145,7 @@ private:
 	std::vector<BlockVariableMap> variables;
 	Assignment *r_assignment;
 	bool assignment_target;
-	bool r_assign_to_subscript;
+	bool r_assign_to_subfield;
 	bool r_side_effects;
 
 public:
-- 
2.43.0