From c5f011ef508d580f332e4bd6065a013b24de8840 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 7 Jun 2019 22:18:05 +0300
Subject: [PATCH] Do not clear previous assignments on assignment to array
 subscript

It makes manual array impossible if the previous elements are thrown
away.
---
 source/programcompiler.cpp | 10 +++++++---
 source/programcompiler.h   |  1 +
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 0559d41e..3dc07d80 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -1415,6 +1415,7 @@ ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
 	aggregate(0),
 	assignment(0),
 	assignment_target(false),
+	assign_to_subscript(false),
 	global_scope(true)
 { }
 
@@ -1460,6 +1461,8 @@ void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
 {
 	if(binary.oper=="[")
 	{
+		if(assignment_target)
+			assign_to_subscript = true;
 		binary.left->visit(*this);
 		SetForScope<bool> set(assignment_target, false);
 		binary.right->visit(*this);
@@ -1471,6 +1474,7 @@ void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
 void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
 {
 	{
+		assign_to_subscript = false;
 		SetForScope<bool> set(assignment_target, !assign.self_referencing);
 		assign.left->visit(*this);
 	}
@@ -1478,10 +1482,10 @@ void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
 	assignment = &assign;
 }
 
-void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool self_ref)
+void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool chained)
 {
 	VariableInfo &var_info = variables.back()[&var];
-	if(!self_ref)
+	if(!chained)
 		clear_assignments(var_info, true);
 	var_info.assignments.push_back(&node);
 	var_info.conditionally_assigned = false;
@@ -1502,7 +1506,7 @@ void ProgramCompiler::UnusedVariableLocator::visit(ExpressionStatement &expr)
 	assignment = 0;
 	TraversingVisitor::visit(expr);
 	if(assignment && assignment->target_declaration)
-		record_assignment(*assignment->target_declaration, expr, assignment->self_referencing);
+		record_assignment(*assignment->target_declaration, expr, (assignment->self_referencing || assign_to_subscript));
 }
 
 void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
diff --git a/source/programcompiler.h b/source/programcompiler.h
index 06306743..1f0601b5 100644
--- a/source/programcompiler.h
+++ b/source/programcompiler.h
@@ -279,6 +279,7 @@ private:
 		std::vector<BlockVariableMap> variables;
 		ProgramSyntax::Assignment *assignment;
 		bool assignment_target;
+		bool assign_to_subscript;
 		bool global_scope;
 
 		UnusedVariableLocator();
-- 
2.45.2