From 27e7b634d31498783ea6d24b72f02f3f1287851d Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 12 Mar 2021 23:58:14 +0200
Subject: [PATCH] Handle redeclaration of variables in VariableResolver

---
 source/glsl/compiler.cpp |  1 -
 source/glsl/generate.cpp | 89 +++++++++++++++++-----------------------
 source/glsl/generate.h   | 19 +--------
 3 files changed, 39 insertions(+), 70 deletions(-)

diff --git a/source/glsl/compiler.cpp b/source/glsl/compiler.cpp
index 3516048c..b4b63e27 100644
--- a/source/glsl/compiler.cpp
+++ b/source/glsl/compiler.cpp
@@ -214,7 +214,6 @@ void Compiler::append_stage(Stage &stage)
 		target->required_features.glsl_version = stage.required_features.glsl_version;
 	for(NodeList<Statement>::iterator i=stage.content.body.begin(); i!=stage.content.body.end(); ++i)
 		target->content.body.push_back(*i);
-	DeclarationCombiner().apply(*target);
 }
 
 void Compiler::import(DataFile::Collection *resources, const string &name)
diff --git a/source/glsl/generate.cpp b/source/glsl/generate.cpp
index e5855e94..a2fd3608 100644
--- a/source/glsl/generate.cpp
+++ b/source/glsl/generate.cpp
@@ -12,57 +12,6 @@ namespace Msp {
 namespace GL {
 namespace SL {
 
-void DeclarationCombiner::apply(Stage &stage)
-{
-	stage.content.visit(*this);
-	NodeRemover().apply(stage, nodes_to_remove);
-}
-
-void DeclarationCombiner::visit(Block &block)
-{
-	if(current_block)
-		return;
-
-	TraversingVisitor::visit(block);
-}
-
-void DeclarationCombiner::visit(VariableDeclaration &var)
-{
-	VariableDeclaration *&ptr = variables[var.name];
-	if(ptr)
-	{
-		ptr->type = var.type;
-		if(var.init_expression)
-			ptr->init_expression = var.init_expression;
-		if(var.layout)
-		{
-			if(ptr->layout)
-			{
-				for(vector<Layout::Qualifier>::iterator i=var.layout->qualifiers.begin(); i!=var.layout->qualifiers.end(); ++i)
-				{
-					bool found = false;
-					for(vector<Layout::Qualifier>::iterator j=ptr->layout->qualifiers.begin(); (!found && j!=ptr->layout->qualifiers.end()); ++j)
-						if(j->name==i->name)
-						{
-							j->has_value = i->value;
-							j->value = i->value;
-							found = true;
-						}
-
-					if(!found)
-						ptr->layout->qualifiers.push_back(*i);
-				}
-			}
-			else
-				ptr->layout = var.layout;
-		}
-		nodes_to_remove.insert(&var);
-	}
-	else
-		ptr = &var;
-}
-
-
 ConstantSpecializer::ConstantSpecializer():
 	values(0)
 { }
@@ -270,6 +219,7 @@ bool VariableResolver::apply(Stage &s)
 	s.interface_blocks.clear();
 	r_any_resolved = false;
 	s.content.visit(*this);
+	NodeRemover().apply(s, nodes_to_remove);
 	return r_any_resolved;
 }
 
@@ -485,10 +435,45 @@ void VariableResolver::visit(Assignment &assign)
 	assign.self_referencing = (r_self_referencing || assign.oper->token[0]!='=');
 }
 
+void VariableResolver::merge_layouts(Layout &to_layout, const Layout &from_layout)
+{
+	for(vector<Layout::Qualifier>::const_iterator i=from_layout.qualifiers.begin(); i!=from_layout.qualifiers.end(); ++i)
+	{
+		bool found = false;
+		for(vector<Layout::Qualifier>::iterator j=to_layout.qualifiers.begin(); (!found && j!=to_layout.qualifiers.end()); ++j)
+			if(j->name==i->name)
+			{
+				j->has_value = i->value;
+				j->value = i->value;
+				found = true;
+			}
+
+		if(!found)
+			to_layout.qualifiers.push_back(*i);
+	}
+}
+
 void VariableResolver::visit(VariableDeclaration &var)
 {
 	TraversingVisitor::visit(var);
-	current_block->variables.insert(make_pair(var.name, &var));
+	VariableDeclaration *&ptr = current_block->variables[var.name];
+	if(!ptr)
+		ptr = &var;
+	else if(!current_block->parent && ptr->interface==var.interface && ptr->type==var.type)
+	{
+		if(var.init_expression)
+			ptr->init_expression = var.init_expression;
+		if(var.layout)
+		{
+			if(ptr->layout)
+				merge_layouts(*ptr->layout, *var.layout);
+			else
+				ptr->layout = var.layout;
+		}
+		nodes_to_remove.insert(&var);
+
+		r_any_resolved = true;
+	}
 }
 
 void VariableResolver::visit(InterfaceBlock &iface)
diff --git a/source/glsl/generate.h b/source/glsl/generate.h
index 0a940cea..402f07f4 100644
--- a/source/glsl/generate.h
+++ b/source/glsl/generate.h
@@ -11,23 +11,6 @@ namespace Msp {
 namespace GL {
 namespace SL {
 
-/** Combines multiple declarations of the same identifier into one. */
-class DeclarationCombiner: private TraversingVisitor
-{
-private:
-	std::map<std::string, std::vector<FunctionDeclaration *> > functions;
-	std::map<std::string, VariableDeclaration *> variables;
-	std::set<Node *> nodes_to_remove;
-
-public:
-	void apply(Stage &);
-
-private:
-	virtual void visit(Block &);
-	virtual void visit(VariableDeclaration &);
-	virtual void visit(FunctionDeclaration &) { }
-};
-
 /** Manipulates specialization constants.  If values are specified, turns
 specialization constants into normal constants.  Without values assigns
 automatic constant_ids to specialization constants. */
@@ -99,6 +82,7 @@ private:
 	bool record_target;
 	bool r_self_referencing;
 	Assignment::Target r_assignment_target;
+	std::set<Node *> nodes_to_remove;
 
 public:
 	VariableResolver();
@@ -116,6 +100,7 @@ private:
 	virtual void visit(Swizzle &);
 	virtual void visit(BinaryExpression &);
 	virtual void visit(Assignment &);
+	void merge_layouts(Layout &, const Layout &);
 	virtual void visit(VariableDeclaration &);
 	virtual void visit(InterfaceBlock &);
 };
-- 
2.43.0