+bool is_scalar(const BasicTypeDeclaration &type)
+{
+ return (type.kind==BasicTypeDeclaration::INT || type.kind==BasicTypeDeclaration::FLOAT);
+}
+
+bool is_vector_or_matrix(const BasicTypeDeclaration &type)
+{
+ return (type.kind==BasicTypeDeclaration::VECTOR || type.kind==BasicTypeDeclaration::MATRIX);
+}
+
+BasicTypeDeclaration *get_element_type(BasicTypeDeclaration &type)
+{
+ if(is_vector_or_matrix(type) || type.kind==BasicTypeDeclaration::ARRAY)
+ {
+ BasicTypeDeclaration *basic_base = dynamic_cast<BasicTypeDeclaration *>(type.base_type);
+ return (basic_base ? get_element_type(*basic_base) : 0);
+ }
+ else
+ return &type;
+}
+
+bool can_convert(const BasicTypeDeclaration &from, const BasicTypeDeclaration &to)
+{
+ if(from.kind==BasicTypeDeclaration::INT && to.kind==BasicTypeDeclaration::FLOAT)
+ return from.size<=to.size;
+ else if(from.kind!=to.kind)
+ return false;
+ else if(from.kind==BasicTypeDeclaration::INT && from.sign!=to.sign)
+ return from.sign && from.size<=to.size;
+ else if(is_vector_or_matrix(from) && from.size==to.size)
+ {
+ BasicTypeDeclaration *from_base = dynamic_cast<BasicTypeDeclaration *>(from.base_type);
+ BasicTypeDeclaration *to_base = dynamic_cast<BasicTypeDeclaration *>(to.base_type);
+ return (from_base && to_base && can_convert(*from_base, *to_base));
+ }
+ else
+ return false;
+}
+
+
+unsigned TypeComparer::next_tag = 1;
+
+void TypeComparer::compare(Node &node1, Node &node2)
+{
+ if(&node1==&node2)
+ r_result = true;
+ else
+ {
+ second = &node2;
+ node1.visit(*this);
+ }
+}
+
+template<typename T>
+T *TypeComparer::multi_visit(T &node)
+{
+ static unsigned tag = next_tag++;
+
+ if(second)
+ {
+ Node *s = second;
+ first = &node;
+ first_tag = tag;
+ second = 0;
+ s->visit(*this);
+ }
+ else if(!first || tag!=first_tag)
+ r_result = false;
+ else
+ {
+ T *f = static_cast<T *>(first);
+ first = 0;
+ return f;
+ }
+
+ return 0;
+}
+
+void TypeComparer::visit(Literal &literal)
+{
+ if(Literal *lit1 = multi_visit(literal))
+ {
+ if(!lit1->type || !literal.type)
+ r_result = false;
+ else
+ {
+ compare(*lit1->type, *literal.type);
+ if(r_result)
+ r_result = (literal.value.check_type<int>() && lit1->value.value<int>()==literal.value.value<int>());
+ }
+ }
+}
+
+void TypeComparer::visit(VariableReference &var)
+{
+ if(VariableReference *var1 = multi_visit(var))
+ {
+ if(!var1->declaration || !var.declaration)
+ r_result = false;
+ else if(!var1->declaration->constant || !var.declaration->constant)
+ r_result = false;
+ else if(!var1->declaration->init_expression || !var.declaration->init_expression)
+ r_result = false;
+ else
+ compare(*var1->declaration->init_expression, *var.declaration->init_expression);
+ }
+}
+
+void TypeComparer::visit(UnaryExpression &unary)
+{
+ if(UnaryExpression *unary1 = multi_visit(unary))
+ {
+ if(unary1->oper!=unary.oper)
+ r_result = false;
+ else
+ compare(*unary1->expression, *unary.expression);
+ }
+}
+
+void TypeComparer::visit(BinaryExpression &binary)
+{
+ if(BinaryExpression *binary1 = multi_visit(binary))
+ {
+ if(binary1->oper!=binary.oper)
+ r_result = false;
+ else
+ {
+ compare(*binary1->left, *binary.left);
+ if(r_result)
+ compare(*binary1->right, *binary.right);
+ }
+ }
+}
+
+void TypeComparer::visit(TernaryExpression &ternary)
+{
+ if(TernaryExpression *ternary1 = multi_visit(ternary))
+ {
+ if(ternary1->oper!=ternary.oper)
+ r_result = false;
+ else
+ {
+ compare(*ternary1->condition, *ternary.condition);
+ if(r_result)
+ compare(*ternary1->true_expr, *ternary.true_expr);
+ if(r_result)
+ compare(*ternary1->false_expr, *ternary.false_expr);
+ }
+ }
+}
+
+void TypeComparer::visit(BasicTypeDeclaration &basic)
+{
+ if(BasicTypeDeclaration *basic1 = multi_visit(basic))
+ {
+ if(basic1->kind!=basic.kind || basic1->size!=basic.size || basic1->sign!=basic.sign)
+ r_result = false;
+ else if(basic1->base_type && basic.base_type)
+ compare(*basic1->base_type, *basic.base_type);
+ else
+ r_result = (!basic1->base_type && !basic.base_type);
+ }
+}
+
+void TypeComparer::visit(ImageTypeDeclaration &image)
+{
+ if(ImageTypeDeclaration *image1 = multi_visit(image))
+ {
+ if(image1->dimensions!=image.dimensions || image1->array!=image.array)
+ r_result = false;
+ else if(image1->sampled!=image.sampled || image1->shadow!=image.shadow)
+ r_result = false;
+ else if(image1->base_type && image.base_type)
+ compare(*image1->base_type, *image.base_type);
+ else
+ r_result = (!image1->base_type && !image.base_type);
+ }
+}
+
+void TypeComparer::visit(StructDeclaration &strct)
+{
+ if(StructDeclaration *strct1 = multi_visit(strct))
+ {
+ if(strct1->members.body.size()!=strct.members.body.size())
+ r_result = false;
+ else
+ {
+ r_result = true;
+ auto i = strct1->members.body.begin();
+ auto j = strct.members.body.begin();
+ for(; (r_result && i!=strct1->members.body.end()); ++i, ++j)
+ compare(**i, **j);
+ }
+ }
+}
+
+void TypeComparer::visit(VariableDeclaration &var)
+{
+ if(VariableDeclaration *var1 = multi_visit(var))
+ {
+ if(var1->name!=var.name || var1->array!=var.array)
+ r_result = false;
+ else if(!var1->type_declaration || !var.type_declaration)
+ r_result = false;
+ else
+ {
+ if(var1->array)
+ {
+ r_result = false;
+ if(var1->array_size && var.array_size)
+ compare(*var1->array_size, *var.array_size);
+ }
+ if(r_result && var1->type_declaration!=var.type_declaration)
+ compare(*var1->type_declaration, *var.type_declaration);
+ // TODO Compare layout qualifiers for interface block members
+ }
+ }
+}
+