X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fprogramcompiler.cpp;h=63939409fc4c7d28c6f38cc031925cacb919257f;hb=7434b80c452eb8f7ac8200a6f693a9eb668421f0;hp=6bf5ba66a83ed851075e48fda66f33a3a17b5d6e;hpb=961715848c111907b5f443c5b545a429b40583e6;p=libs%2Fgl.git

diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 6bf5ba66..63939409 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -8,6 +8,26 @@
 
 using namespace std;
 
+namespace {
+
+const char builtins_src[] =
+	"////// vertex\n"
+	"out gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"};"
+	"////// geometry\n"
+	"in gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"} gl_in[];\n"
+	"out gl_PerVertex {\n"
+	"  vec4 gl_Position;\n"
+	"  float gl_ClipDistance[];\n"
+	"};\n";
+
+}
+
 namespace Msp {
 namespace GL {
 
@@ -35,12 +55,15 @@ void ProgramCompiler::add_shaders(Program &program)
 		throw invalid_operation("ProgramCompiler::add_shaders");
 
 	string head = "#version 150\n";
-	if(module->vertex_context.present)
-		program.attach_shader_owned(new VertexShader(head+format_context(module->vertex_context)));
-	if(module->geometry_context.present)
-		program.attach_shader_owned(new GeometryShader(head+format_context(module->geometry_context)));
-	if(module->fragment_context.present)
-		program.attach_shader_owned(new FragmentShader(head+format_context(module->fragment_context)));
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+	{
+		if(i->type==VERTEX)
+			program.attach_shader_owned(new VertexShader(head+apply<Formatter>(*i)));
+		else if(i->type==GEOMETRY)
+			program.attach_shader_owned(new GeometryShader(head+apply<Formatter>(*i)));
+		else if(i->type==FRAGMENT)
+			program.attach_shader_owned(new FragmentShader(head+apply<Formatter>(*i)));
+	}
 
 	program.bind_attribute(VERTEX4, "vertex");
 	program.bind_attribute(NORMAL3, "normal");
@@ -48,42 +71,64 @@ void ProgramCompiler::add_shaders(Program &program)
 	program.bind_attribute(TEXCOORD4, "texcoord");
 }
 
-void ProgramCompiler::process()
+Module *ProgramCompiler::create_builtins_module()
 {
-	if(module->vertex_context.present)
-		process(module->vertex_context);
-	if(module->geometry_context.present)
-		process(module->geometry_context);
-	if(module->fragment_context.present)
-		process(module->fragment_context);
+	ProgramParser parser;
+	Module *module = new Module(parser.parse(builtins_src));
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+	{
+		VariableResolver resolver;
+		i->content.visit(resolver);
+		for(map<string, VariableDeclaration *>::iterator j=i->content.variables.begin(); j!=i->content.variables.end(); ++j)
+			j->second->linked_declaration = j->second;
+	}
+	return module;
 }
 
-void ProgramCompiler::process(Context &context)
+Module &ProgramCompiler::get_builtins_module()
 {
-	inject_block(context.content, module->global_context.content);
-
-	resolve_variables(context);
+	static RefPtr<Module> builtins_module = create_builtins_module();
+	return *builtins_module;
+}
 
-	InterfaceGenerator generator;
-	generator.visit(context);
+Stage *ProgramCompiler::get_builtins(StageType type)
+{
+	Module &module = get_builtins_module();
+	for(list<Stage>::iterator i=module.stages.begin(); i!=module.stages.end(); ++i)
+		if(i->type==type)
+			return &*i;
+	return 0;
+}
 
-	resolve_variables(context);
+void ProgramCompiler::process()
+{
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); ++i)
+		generate(*i);
+	for(list<Stage>::iterator i=module->stages.begin(); i!=module->stages.end(); )
+	{
+		if(optimize(*i))
+			i = module->stages.begin();
+		else
+			++i;
+	}
+}
 
-	VariableRenamer renamer;
-	context.content.visit(renamer);
+void ProgramCompiler::generate(Stage &stage)
+{
+	inject_block(stage.content, module->shared.content);
 
-	while(1)
-	{
-		UnusedVariableLocator unused_locator;
-		context.content.visit(unused_locator);
+	apply<VariableResolver>(stage);
+	apply<InterfaceGenerator>(stage);
+	apply<VariableResolver>(stage);
+	apply<VariableRenamer>(stage);
+}
 
-		NodeRemover remover;
-		remover.to_remove.insert(unused_locator.unused_variables.begin(), unused_locator.unused_variables.end());
-		context.content.visit(remover);
+bool ProgramCompiler::optimize(Stage &stage)
+{
+	set<Node *> unused = apply<UnusedVariableLocator>(stage);
+	apply<NodeRemover>(stage, unused);
 
-		if(!remover.n_removed)
-			break;
-	}
+	return !unused.empty();
 }
 
 void ProgramCompiler::inject_block(Block &target, const Block &source)
@@ -93,24 +138,38 @@ void ProgramCompiler::inject_block(Block &target, const Block &source)
 		target.body.insert(insert_point, (*i)->clone());
 }
 
-void ProgramCompiler::resolve_variables(Context &context)
+template<typename T>
+typename T::ResultType ProgramCompiler::apply(Stage &stage)
 {
-	VariableResolver resolver;
-	context.content.visit(resolver);
+	T visitor;
+	visitor.apply(stage);
+	return visitor.get_result();
 }
 
-string ProgramCompiler::format_context(Context &context)
+template<typename T, typename A>
+typename T::ResultType ProgramCompiler::apply(Stage &stage, const A &arg)
 {
-	Formatter formatter;
-	context.content.visit(formatter);
-	return formatter.formatted;
+	T visitor(arg);
+	visitor.apply(stage);
+	return visitor.get_result();
+}
+
+
+ProgramCompiler::Visitor::Visitor():
+	stage(0)
+{ }
+
+void ProgramCompiler::Visitor::apply(Stage &s)
+{
+	SetForScope<Stage *> set(stage, &s);
+	stage->content.visit(*this);
 }
 
 
 ProgramCompiler::Formatter::Formatter():
 	indent(0),
 	parameter_list(false),
-	else_if(false)
+	else_if(0)
 { }
 
 void ProgramCompiler::Formatter::visit(Literal &literal)
@@ -148,14 +207,18 @@ void ProgramCompiler::Formatter::visit(UnaryExpression &unary)
 void ProgramCompiler::Formatter::visit(BinaryExpression &binary)
 {
 	binary.left->visit(*this);
-	if(binary.assignment)
-		formatted += format(" %s ", binary.oper);
-	else
-		formatted += binary.oper;
+	formatted += binary.oper;
 	binary.right->visit(*this);
 	formatted += binary.after;
 }
 
+void ProgramCompiler::Formatter::visit(Assignment &assign)
+{
+	assign.left->visit(*this);
+	formatted += format(" %s ", assign.oper);
+	assign.right->visit(*this);
+}
+
 void ProgramCompiler::Formatter::visit(FunctionCall &call)
 {
 	formatted += format("%s(", call.name);
@@ -176,31 +239,27 @@ void ProgramCompiler::Formatter::visit(ExpressionStatement &expr)
 
 void ProgramCompiler::Formatter::visit(Block &block)
 {
-	if(block.use_braces)
-	{
-		if(else_if)
-		{
-			formatted += '\n';
-			else_if = false;
-		}
-		formatted += format("%s{\n", string(indent*2, ' '));
-	}
+	if(else_if)
+		--else_if;
+
+	unsigned brace_indent = indent;
+	bool use_braces = (block.use_braces || (indent && block.body.size()!=1));
+	if(use_braces)
+		formatted += format("%s{\n", string(brace_indent*2, ' '));
 
-	bool change_indent = (!formatted.empty() && !else_if);
-	indent += change_indent;
+	SetForScope<unsigned> set(indent, indent+!formatted.empty());
 	string spaces(indent*2, ' ');
 	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); ++i)
 	{
 		if(i!=block.body.begin())
 			formatted += '\n';
-		if(!else_if)
-			formatted += spaces;
+		formatted += spaces;
 		(*i)->visit(*this);
+		else_if = 0;
 	}
-	indent -= change_indent;
 
-	if(block.use_braces)
-		formatted += format("\n%s}", string(indent*2, ' '));
+	if(use_braces)
+		formatted += format("\n%s}", string(brace_indent*2, ' '));
 }
 
 void ProgramCompiler::Formatter::visit(Layout &layout)
@@ -230,7 +289,7 @@ void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 		formatted += "const ";
 	if(!var.sampling.empty())
 		formatted += format("%s ", var.sampling);
-	if(!var.interface.empty())
+	if(!var.interface.empty() && var.interface!=block_interface)
 		formatted += format("%s ", var.interface);
 	formatted += format("%s %s", var.type, var.name);
 	if(var.array)
@@ -251,6 +310,7 @@ void ProgramCompiler::Formatter::visit(VariableDeclaration &var)
 
 void ProgramCompiler::Formatter::visit(InterfaceBlock &iface)
 {
+	SetForScope<string> set(block_interface, iface.interface);
 	formatted += format("%s %s\n", iface.interface, iface.name);
 	iface.members.visit(*this);
 	formatted += ';';
@@ -279,10 +339,9 @@ void ProgramCompiler::Formatter::visit(FunctionDeclaration &func)
 void ProgramCompiler::Formatter::visit(Conditional &cond)
 {
 	if(else_if)
-	{
-		formatted += ' ';
-		else_if = false;
-	}
+		formatted.replace(formatted.rfind('\n'), string::npos, 1, ' ');
+
+	indent -= else_if;
 
 	formatted += "if(";
 	cond.condition->visit(*this);
@@ -291,8 +350,8 @@ void ProgramCompiler::Formatter::visit(Conditional &cond)
 	cond.body.visit(*this);
 	if(!cond.else_body.body.empty())
 	{
-		formatted += format("\n%selse", string(indent*2, ' '));
-		SetFlag set(else_if);
+		formatted += format("\n%selse\n", string(indent*2, ' '));
+		SetForScope<unsigned> set(else_if, 2);
 		cond.else_body.visit(*this);
 	}
 }
@@ -318,9 +377,23 @@ void ProgramCompiler::Formatter::visit(Return &ret)
 
 
 ProgramCompiler::VariableResolver::VariableResolver():
-	anonymous(false)
+	anonymous(false),
+	record_target(false),
+	assignment_target(0),
+	self_referencing(false)
 { }
 
+void ProgramCompiler::VariableResolver::apply(Stage &s)
+{
+	SetForScope<Stage *> set(stage, &s);
+	Stage *builtins = get_builtins(stage->type);
+	if(builtins)
+		blocks.push_back(&builtins->content);
+	stage->content.visit(*this);
+	if(builtins)
+		blocks.pop_back();
+}
+
 void ProgramCompiler::VariableResolver::visit(Block &block)
 {
 	blocks.push_back(&block);
@@ -344,6 +417,19 @@ void ProgramCompiler::VariableResolver::visit(VariableReference &var)
 			break;
 		}
 	}
+
+	if(record_target)
+	{
+		if(assignment_target)
+		{
+			record_target = false;
+			assignment_target = 0;
+		}
+		else
+			assignment_target = var.declaration;
+	}
+	else if(var.declaration && var.declaration==assignment_target)
+		self_referencing = true;
 }
 
 void ProgramCompiler::VariableResolver::visit(MemberAccess &memacc)
@@ -368,7 +454,10 @@ void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 {
 	if(binary.oper=="[")
 	{
-		binary.right->visit(*this);
+		{
+			SetForScope<bool> set(record_target, false);
+			binary.right->visit(*this);
+		}
 		type = 0;
 		binary.left->visit(*this);
 	}
@@ -379,6 +468,21 @@ void ProgramCompiler::VariableResolver::visit(BinaryExpression &binary)
 	}
 }
 
+void ProgramCompiler::VariableResolver::visit(Assignment &assign)
+{
+	{
+		SetFlag set(record_target);
+		assignment_target = 0;
+		assign.left->visit(*this);
+	}
+
+	self_referencing = false;
+	assign.right->visit(*this);
+
+	assign.self_referencing = (self_referencing || assign.oper!="=");
+	assign.target_declaration = assignment_target;
+}
+
 void ProgramCompiler::VariableResolver::visit(StructDeclaration &strct)
 {
 	TraversingVisitor::visit(strct);
@@ -395,6 +499,9 @@ void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 			var.type_declaration = j->second;
 	}
 
+	if(!block_interface.empty() && var.interface.empty())
+		var.interface = block_interface;
+
 	TraversingVisitor::visit(var);
 	blocks.back()->variables[var.name] = &var;
 	if(anonymous && blocks.size()>1)
@@ -404,17 +511,17 @@ void ProgramCompiler::VariableResolver::visit(VariableDeclaration &var)
 void ProgramCompiler::VariableResolver::visit(InterfaceBlock &iface)
 {
 	SetFlag set(anonymous);
+	SetForScope<string> set2(block_interface, iface.interface);
 	TraversingVisitor::visit(iface);
 }
 
 
 ProgramCompiler::InterfaceGenerator::InterfaceGenerator():
-	context(0),
 	scope_level(0),
 	remove_node(false)
 { }
 
-string ProgramCompiler::InterfaceGenerator::get_out_prefix(ContextType type)
+string ProgramCompiler::InterfaceGenerator::get_out_prefix(StageType type)
 {
 	if(type==VERTEX)
 		return "_vs_out_";
@@ -424,13 +531,13 @@ string ProgramCompiler::InterfaceGenerator::get_out_prefix(ContextType type)
 		return string();
 }
 
-void ProgramCompiler::InterfaceGenerator::visit(Context &ctx)
+void ProgramCompiler::InterfaceGenerator::apply(Stage &s)
 {
-	SetForScope<Context *> set(context, &ctx);
-	if(context->previous)
-		in_prefix = get_out_prefix(context->previous->type);
-	out_prefix = get_out_prefix(context->type);
-	ctx.content.visit(*this);
+	SetForScope<Stage *> set(stage, &s);
+	if(stage->previous)
+		in_prefix = get_out_prefix(stage->previous->type);
+	out_prefix = get_out_prefix(stage->type);
+	stage->content.visit(*this);
 }
 
 void ProgramCompiler::InterfaceGenerator::visit(Block &block)
@@ -442,7 +549,7 @@ void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 
 		if(scope_level==1)
 		{
-			for(map<string, NodePtr<Node> >::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
+			for(map<string, VariableDeclaration *>::iterator j=iface_declarations.begin(); j!=iface_declarations.end(); ++j)
 			{
 				list<NodePtr<Node> >::iterator k = block.body.insert(i, j->second);
 				(*k)->visit(*this);
@@ -450,7 +557,7 @@ void ProgramCompiler::InterfaceGenerator::visit(Block &block)
 			iface_declarations.clear();
 		}
 
-		for(list<NodePtr<Node> >::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
+		for(list<Node *>::iterator j=insert_nodes.begin(); j!=insert_nodes.end(); ++j)
 			block.body.insert(i, *j);
 		insert_nodes.clear();
 
@@ -468,36 +575,39 @@ string ProgramCompiler::InterfaceGenerator::change_prefix(const string &name, co
 	return prefix+name.substr(offset);
 }
 
-bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &out, const string &iface, const string &name)
+bool ProgramCompiler::InterfaceGenerator::generate_interface(VariableDeclaration &var, const string &iface, const string &name)
 {
-	const map<string, VariableDeclaration *> &context_vars = (iface=="in" ? context->in_variables : context->out_variables);
-	if(context_vars.count(name) || iface_declarations.count(name))
+	const map<string, VariableDeclaration *> &stage_vars = (iface=="in" ? stage->in_variables : stage->out_variables);
+	if(stage_vars.count(name) || iface_declarations.count(name))
 		return false;
 
 	VariableDeclaration* iface_var = new VariableDeclaration;
-	iface_var->sampling = out.sampling;
+	iface_var->sampling = var.sampling;
 	iface_var->interface = iface;
-	iface_var->type = out.type;
-	iface_var->type_declaration = out.type_declaration;
+	iface_var->type = var.type;
+	iface_var->type_declaration = var.type_declaration;
 	iface_var->name = name;
-	iface_var->array = (out.array || (context->type==GEOMETRY && iface=="in"));
-	iface_var->array_size = out.array_size;
+	if(stage->type==GEOMETRY)
+		iface_var->array = ((var.array && var.interface!="in") || iface=="in");
+	else
+		iface_var->array = var.array;
+	if(iface_var->array)
+		iface_var->array_size = var.array_size;
 	if(iface=="in")
-		iface_var->linked_declaration = &out;
-	iface_declarations[iface_var->name] = iface_var;
+		iface_var->linked_declaration = &var;
+	iface_declarations[name] = iface_var;
 
 	return true;
 }
 
 void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left, ProgramSyntax::Expression *right)
 {
-	BinaryExpression *assign = new BinaryExpression;
+	Assignment *assign = new Assignment;
 	VariableReference *ref = new VariableReference;
 	ref->name = left;
 	assign->left = ref;
 	assign->oper = "=";
 	assign->right = right;
-	assign->assignment = true;
 
 	ExpressionStatement *stmt = new ExpressionStatement;
 	stmt->expression = assign;
@@ -506,12 +616,12 @@ void ProgramCompiler::InterfaceGenerator::insert_assignment(const string &left,
 
 void ProgramCompiler::InterfaceGenerator::visit(VariableReference &var)
 {
-	if(var.declaration || !context->previous)
+	if(var.declaration || !stage->previous)
 		return;
 	if(iface_declarations.count(var.name))
 		return;
 
-	const map<string, VariableDeclaration *> &prev_out = context->previous->out_variables;
+	const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 	map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 	if(i==prev_out.end())
 		i = prev_out.find(in_prefix+var.name);
@@ -524,7 +634,7 @@ void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 	if(var.interface=="out")
 	{
 		if(scope_level==1)
-			context->out_variables[var.name] = &var;
+			stage->out_variables[var.name] = &var;
 		else if(generate_interface(var, "out", change_prefix(var.name, string())))
 		{
 			remove_node = true;
@@ -534,10 +644,12 @@ void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 	}
 	else if(var.interface=="in")
 	{
-		context->in_variables[var.name] = &var;
-		if(context->previous)
+		stage->in_variables[var.name] = &var;
+		if(var.linked_declaration)
+			var.linked_declaration->linked_declaration = &var;
+		else if(stage->previous)
 		{
-			const map<string, VariableDeclaration *> &prev_out = context->previous->out_variables;
+			const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 			map<string, VariableDeclaration *>::const_iterator i = prev_out.find(var.name);
 			if(i!=prev_out.end())
 			{
@@ -552,29 +664,64 @@ void ProgramCompiler::InterfaceGenerator::visit(VariableDeclaration &var)
 
 void ProgramCompiler::InterfaceGenerator::visit(Passthrough &pass)
 {
-	if(context->previous)
+	vector<VariableDeclaration *> pass_vars;
+
+	for(map<string, VariableDeclaration *>::const_iterator i=stage->in_variables.begin(); i!=stage->in_variables.end(); ++i)
+		pass_vars.push_back(i->second);
+	for(map<string, VariableDeclaration *>::const_iterator i=iface_declarations.begin(); i!=iface_declarations.end(); ++i)
+		if(i->second->interface=="in")
+			pass_vars.push_back(i->second);
+
+	if(stage->previous)
 	{
-		const map<string, VariableDeclaration *> &prev_out = context->previous->out_variables;
+		const map<string, VariableDeclaration *> &prev_out = stage->previous->out_variables;
 		for(map<string, VariableDeclaration *>::const_iterator i=prev_out.begin(); i!=prev_out.end(); ++i)
 		{
-			string out_name = change_prefix(i->second->name, out_prefix);
-			generate_interface(*i->second, "in", i->second->name);
-			generate_interface(*i->second, "out", out_name);
+			bool linked = false;
+			for(vector<VariableDeclaration *>::const_iterator j=pass_vars.begin(); (!linked && j!=pass_vars.end()); ++j)
+				linked = ((*j)->linked_declaration==i->second);
 
-			VariableReference *ref = new VariableReference;
-			ref->name = i->first;
-			if(pass.subscript)
-			{
-				BinaryExpression *subscript = new BinaryExpression;
-				subscript->left = ref;
-				subscript->oper = "[";
-				subscript->right = pass.subscript;
-				subscript->after = "]";
-				insert_assignment(out_name, subscript);
-			}
-			else
-				insert_assignment(out_name, ref);
+			if(!linked && generate_interface(*i->second, "in", i->second->name))
+				pass_vars.push_back(i->second);
+		}
+	}
+
+	if(stage->type==GEOMETRY)
+	{
+		VariableReference *ref = new VariableReference;
+		ref->name = "gl_in";
+
+		BinaryExpression *subscript = new BinaryExpression;
+		subscript->left = ref;
+		subscript->oper = "[";
+		subscript->right = pass.subscript;
+		subscript->after = "]";
+
+		MemberAccess *memacc = new MemberAccess;
+		memacc->left = subscript;
+		memacc->member = "gl_Position";
+
+		insert_assignment("gl_Position", memacc);
+	}
+
+	for(vector<VariableDeclaration *>::const_iterator i=pass_vars.begin(); i!=pass_vars.end(); ++i)
+	{
+		string out_name = change_prefix((*i)->name, out_prefix);
+		generate_interface(**i, "out", out_name);
+
+		VariableReference *ref = new VariableReference;
+		ref->name = (*i)->name;
+		if(pass.subscript)
+		{
+			BinaryExpression *subscript = new BinaryExpression;
+			subscript->left = ref;
+			subscript->oper = "[";
+			subscript->right = pass.subscript;
+			subscript->after = "]";
+			insert_assignment(out_name, subscript);
 		}
+		else
+			insert_assignment(out_name, ref);
 	}
 
 	remove_node = true;
@@ -595,64 +742,233 @@ void ProgramCompiler::VariableRenamer::visit(VariableDeclaration &var)
 }
 
 
+ProgramCompiler::UnusedVariableLocator::UnusedVariableLocator():
+	aggregate(0),
+	assignment(0),
+	assignment_target(false)
+{ }
+
+void ProgramCompiler::UnusedVariableLocator::apply(Stage &s)
+{
+	assignments.push_back(BlockAssignmentMap());
+	Visitor::apply(s);
+	assignments.pop_back();
+}
+
 void ProgramCompiler::UnusedVariableLocator::visit(VariableReference &var)
 {
-	unused_variables.erase(var.declaration);
+	unused_nodes.erase(var.declaration);
+
+	map<VariableDeclaration *, Node *>::iterator i = aggregates.find(var.declaration);
+	if(i!=aggregates.end())
+		unused_nodes.erase(i->second);
+
+	if(assignment_target)
+		return;
+
+	for(vector<BlockAssignmentMap>::iterator j=assignments.end(); j!=assignments.begin(); )
+	{
+		--j;
+		BlockAssignmentMap::iterator k = j->find(var.declaration);
+		if(k!=j->end())
+		{
+			for(vector<Node *>::iterator l=k->second.nodes.begin(); l!=k->second.nodes.end(); ++l)
+				unused_nodes.erase(*l);
+			j->erase(k);
+			break;
+		}
+	}
 }
 
 void ProgramCompiler::UnusedVariableLocator::visit(MemberAccess &memacc)
 {
 	TraversingVisitor::visit(memacc);
-	unused_variables.erase(memacc.declaration);
+	unused_nodes.erase(memacc.declaration);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(BinaryExpression &binary)
+{
+	if(binary.oper=="[")
+	{
+		binary.left->visit(*this);
+		SetForScope<bool> set(assignment_target, false);
+		binary.right->visit(*this);
+	}
+	else
+		TraversingVisitor::visit(binary);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(Assignment &assign)
+{
+	{
+		SetForScope<bool> set(assignment_target, !assign.self_referencing);
+		assign.left->visit(*this);
+	}
+	assign.right->visit(*this);
+	assignment = &assign;
+}
+
+void ProgramCompiler::UnusedVariableLocator::record_assignment(VariableDeclaration &var, Node &node, bool self_ref)
+{
+	unused_nodes.insert(&node);
+	BlockAssignmentMap &block_assignments = assignments.back();
+	AssignmentList &var_assignments = block_assignments[&var];
+	if(!self_ref)
+		var_assignments.nodes.clear();
+	var_assignments.nodes.push_back(&node);
+	var_assignments.conditional = false;
+	var_assignments.self_referencing = self_ref;
+}
+
+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);
+}
+
+void ProgramCompiler::UnusedVariableLocator::visit(StructDeclaration &strct)
+{
+	SetForScope<Node *> set(aggregate, &strct);
+	unused_nodes.insert(&strct);
+	TraversingVisitor::visit(strct);
 }
 
 void ProgramCompiler::UnusedVariableLocator::visit(VariableDeclaration &var)
 {
-	unused_variables.insert(&var);
+	if(aggregate)
+		aggregates[&var] = aggregate;
+	else
+	{
+		unused_nodes.insert(&var);
+		if(var.init_expression)
+			record_assignment(var, *var.init_expression, false);
+	}
+	unused_nodes.erase(var.type_declaration);
 	TraversingVisitor::visit(var);
 }
 
+void ProgramCompiler::UnusedVariableLocator::visit(InterfaceBlock &iface)
+{
+	SetForScope<Node *> set(aggregate, &iface);
+	unused_nodes.insert(&iface);
+	TraversingVisitor::visit(iface);
+}
 
-ProgramCompiler::NodeRemover::NodeRemover():
-	n_removed(0),
-	immutable_block(false),
-	remove_block(false)
-{ }
+void ProgramCompiler::UnusedVariableLocator::visit(FunctionDeclaration &func)
+{
+	assignments.push_back(BlockAssignmentMap());
 
-void ProgramCompiler::NodeRemover::visit(Block &block)
+	for(vector<NodePtr<VariableDeclaration> >::iterator i=func.parameters.begin(); i!=func.parameters.end(); ++i)
+		(*i)->visit(*this);
+	func.body.visit(*this);
+
+	BlockAssignmentMap &block_assignments = assignments.back();
+	for(map<string, VariableDeclaration *>::iterator i=func.body.variables.begin(); i!=func.body.variables.end(); ++i)
+		block_assignments.erase(i->second);
+	for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
+	{
+		if(i->first->interface=="out" && stage->type!=FRAGMENT && !i->first->linked_declaration)
+			continue;
+
+		for(vector<Node *>::iterator j=i->second.nodes.begin(); j!=i->second.nodes.end(); ++j)
+			unused_nodes.erase(*j);
+	}
+
+	assignments.pop_back();
+}
+
+void ProgramCompiler::UnusedVariableLocator::merge_down_assignments()
 {
-	remove_block = immutable_block;
-	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
+	BlockAssignmentMap &parent_assignments = assignments[assignments.size()-2];
+	BlockAssignmentMap &block_assignments = assignments.back();
+	for(BlockAssignmentMap::iterator i=block_assignments.begin(); i!=block_assignments.end(); ++i)
 	{
-		bool remove = false;
-		if(to_remove.count(&**i))
-			remove = !immutable_block;
-		else
+		BlockAssignmentMap::iterator j = parent_assignments.find(i->first);
+		if(j==parent_assignments.end())
+			parent_assignments.insert(*i);
+		else if(i->second.self_referencing || i->second.conditional)
 		{
-			remove_block = false;
-			(*i)->visit(*this);
-			remove = remove_block;
+			j->second.nodes.insert(j->second.nodes.end(), i->second.nodes.begin(), i->second.nodes.end());
+			j->second.conditional |= i->second.conditional;
+			j->second.self_referencing |= i->second.self_referencing;
 		}
+		else
+			j->second = i->second;
+	}
+	assignments.pop_back();
+}
 
-		if(remove)
-			block.body.erase(i++);
+void ProgramCompiler::UnusedVariableLocator::visit(Conditional &cond)
+{
+	cond.condition->visit(*this);
+	assignments.push_back(BlockAssignmentMap());
+	cond.body.visit(*this);
+
+	BlockAssignmentMap if_assignments;
+	swap(assignments.back(), if_assignments);
+	cond.else_body.visit(*this);
+
+	BlockAssignmentMap &else_assignments = assignments.back();
+	for(BlockAssignmentMap::iterator i=else_assignments.begin(); i!=else_assignments.end(); ++i)
+	{
+		BlockAssignmentMap::iterator j = if_assignments.find(i->first);
+		if(j!=if_assignments.end())
+		{
+			i->second.nodes.insert(i->second.nodes.end(), j->second.nodes.begin(), j->second.nodes.end());
+			i->second.conditional |= j->second.conditional;
+			i->second.self_referencing |= j->second.self_referencing;
+			if_assignments.erase(j);
+		}
 		else
-			++i;
+			i->second.conditional = true;
+	}
 
-		n_removed += remove;
+	for(BlockAssignmentMap::iterator i=if_assignments.begin(); i!=if_assignments.end(); ++i)
+	{
+		i->second.conditional = true;
+		else_assignments.insert(*i);
 	}
+
+	merge_down_assignments();
 }
 
-void ProgramCompiler::NodeRemover::visit(StructDeclaration &strct)
+void ProgramCompiler::UnusedVariableLocator::visit(Iteration &iter)
 {
-	SetFlag set(immutable_block);
-	TraversingVisitor::visit(strct);
+	assignments.push_back(BlockAssignmentMap());
+	TraversingVisitor::visit(iter);
+	merge_down_assignments();
 }
 
-void ProgramCompiler::NodeRemover::visit(InterfaceBlock &iface)
+
+ProgramCompiler::NodeRemover::NodeRemover(const set<Node *> &r):
+	to_remove(r)
+{ }
+
+void ProgramCompiler::NodeRemover::visit(Block &block)
 {
-	SetFlag set(immutable_block);
-	TraversingVisitor::visit(iface);
+	for(list<NodePtr<Node> >::iterator i=block.body.begin(); i!=block.body.end(); )
+	{
+		(*i)->visit(*this);
+		if(to_remove.count(&**i))
+			block.body.erase(i++);
+		else
+			++i;
+	}
+}
+
+void ProgramCompiler::NodeRemover::visit(VariableDeclaration &var)
+{
+	if(to_remove.count(&var))
+	{
+		stage->in_variables.erase(var.name);
+		stage->out_variables.erase(var.name);
+		if(var.linked_declaration)
+			var.linked_declaration->linked_declaration = 0;
+	}
+	else if(var.init_expression && to_remove.count(&*var.init_expression))
+		var.init_expression = 0;
 }
 
 } // namespace GL