/*************************************************************************/
/*  gd_compiler.cpp                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "gd_compiler.h"
#include "gd_script.h"


void GDCompiler::_set_error(const String& p_error,const GDParser::Node *p_node) {

	if (error!="")
		return;

	error=p_error;
	if (p_node) {
		err_line=p_node->line;
		err_column=p_node->column;
	} else {
		err_line=0;
		err_column=0;
	}
}

bool GDCompiler::_create_unary_operator(CodeGen& codegen,const GDParser::OperatorNode *on,Variant::Operator op, int p_stack_level) {

	ERR_FAIL_COND_V(on->arguments.size()!=1,false);

	int src_address_a = _parse_expression(codegen,on->arguments[0],p_stack_level);
	if (src_address_a<0)
		return false;

	codegen.opcodes.push_back(GDFunction::OPCODE_OPERATOR); // perform operator
	codegen.opcodes.push_back(op); //which operator
	codegen.opcodes.push_back(src_address_a); // argument 1
	codegen.opcodes.push_back(src_address_a); // argument 2 (repeated)
	//codegen.opcodes.push_back(GDFunction::ADDR_TYPE_NIL); // argument 2 (unary only takes one parameter)
	return true;
}

bool GDCompiler::_create_binary_operator(CodeGen& codegen,const GDParser::OperatorNode *on,Variant::Operator op, int p_stack_level,bool p_initializer) {

	ERR_FAIL_COND_V(on->arguments.size()!=2,false);


	int src_address_a = _parse_expression(codegen,on->arguments[0],p_stack_level,false,p_initializer);
	if (src_address_a<0)
		return false;
	if (src_address_a&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)
		p_stack_level++; //uses stack for return, increase stack

	int src_address_b = _parse_expression(codegen,on->arguments[1],p_stack_level,false,p_initializer);
	if (src_address_b<0)
		return false;


	codegen.opcodes.push_back(GDFunction::OPCODE_OPERATOR); // perform operator
	codegen.opcodes.push_back(op); //which operator
	codegen.opcodes.push_back(src_address_a); // argument 1
	codegen.opcodes.push_back(src_address_b); // argument 2 (unary only takes one parameter)
	return true;
}


/*
int GDCompiler::_parse_subexpression(CodeGen& codegen,const GDParser::Node *p_expression) {


	int ret = _parse_expression(codegen,p_expression);
	if (ret<0)
		return ret;

	if (ret&(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)) {
		codegen.stack_level++;
		codegen.check_max_stack_level();
		//stack was used, keep value
	}

	return ret;
}
*/

int GDCompiler::_parse_assign_right_expression(CodeGen& codegen,const GDParser::OperatorNode *p_expression, int p_stack_level) {

	Variant::Operator var_op=Variant::OP_MAX;


	switch(p_expression->op) {

		case GDParser::OperatorNode::OP_ASSIGN_ADD: var_op=Variant::OP_ADD; break;
		case GDParser::OperatorNode::OP_ASSIGN_SUB: var_op=Variant::OP_SUBSTRACT; break;
		case GDParser::OperatorNode::OP_ASSIGN_MUL: var_op=Variant::OP_MULTIPLY; break;
		case GDParser::OperatorNode::OP_ASSIGN_DIV: var_op=Variant::OP_DIVIDE; break;
		case GDParser::OperatorNode::OP_ASSIGN_MOD: var_op=Variant::OP_MODULE; break;
		case GDParser::OperatorNode::OP_ASSIGN_SHIFT_LEFT: var_op=Variant::OP_SHIFT_LEFT; break;
		case GDParser::OperatorNode::OP_ASSIGN_SHIFT_RIGHT: var_op=Variant::OP_SHIFT_RIGHT; break;
		case GDParser::OperatorNode::OP_ASSIGN_BIT_AND: var_op=Variant::OP_BIT_AND; break;
		case GDParser::OperatorNode::OP_ASSIGN_BIT_OR: var_op=Variant::OP_BIT_OR; break;
		case GDParser::OperatorNode::OP_ASSIGN_BIT_XOR: var_op=Variant::OP_BIT_XOR; break;
		case GDParser::OperatorNode::OP_INIT_ASSIGN:
		case GDParser::OperatorNode::OP_ASSIGN: {

			//none
		} break;
	default: {

			ERR_FAIL_V(-1);
		}
	}

	bool initializer = p_expression->op==GDParser::OperatorNode::OP_INIT_ASSIGN;

	if (var_op==Variant::OP_MAX) {

		return _parse_expression(codegen,p_expression->arguments[1],p_stack_level,false,initializer);
	}

	if (!_create_binary_operator(codegen,p_expression,var_op,p_stack_level,initializer))
		return -1;

	int dst_addr=(p_stack_level)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
	codegen.opcodes.push_back(dst_addr); // append the stack level as destination address of the opcode
	codegen.alloc_stack(p_stack_level);
	return dst_addr;

}

int GDCompiler::_parse_expression(CodeGen& codegen,const GDParser::Node *p_expression, int p_stack_level,bool p_root,bool p_initializer) {


	switch(p_expression->type) {
		//should parse variable declaration and adjust stack accordingly...
		case GDParser::Node::TYPE_IDENTIFIER: {
			//return identifier
			//wait, identifier could be a local variable or something else... careful here, must reference properly
			//as stack may be more interesting to work with

			//This could be made much simpler by just indexing "self", but done this way (with custom self-addressing modes) increases peformance a lot.

			const GDParser::IdentifierNode *in = static_cast<const GDParser::IdentifierNode*>(p_expression);

			StringName identifier = in->name;

			// TRY STACK!
			if (!p_initializer && codegen.stack_identifiers.has(identifier)) {

				int pos = codegen.stack_identifiers[identifier];
				return pos|(GDFunction::ADDR_TYPE_STACK_VARIABLE<<GDFunction::ADDR_BITS);

			}
			//TRY MEMBERS!
			if (!codegen.function_node || !codegen.function_node->_static) {

				// TRY MEMBER VARIABLES!
				//static function
				if (codegen.script->member_indices.has(identifier)) {

					int idx = codegen.script->member_indices[identifier].index;
					return idx|(GDFunction::ADDR_TYPE_MEMBER<<GDFunction::ADDR_BITS); //argument (stack root)
				}
			}

			//TRY CLASS CONSTANTS

			GDScript *owner = codegen.script;
			while (owner) {

				GDScript *scr = owner;
				GDNativeClass *nc=NULL;
				while(scr) {

					if (scr->constants.has(identifier)) {

						//int idx=scr->constants[identifier];
						int idx = codegen.get_name_map_pos(identifier);
						return idx|(GDFunction::ADDR_TYPE_CLASS_CONSTANT<<GDFunction::ADDR_BITS); //argument (stack root)
					}
					if (scr->native.is_valid())
						nc=scr->native.ptr();
					scr=scr->_base;
				}

				// CLASS C++ Integer Constant

				if (nc) {

					bool success=false;
					int constant = ObjectTypeDB::get_integer_constant(nc->get_name(),identifier,&success);
					if (success) {
						Variant key=constant;
						int idx;

						if (!codegen.constant_map.has(key)) {

							idx=codegen.constant_map.size();
							codegen.constant_map[key]=idx;

						} else {
							idx=codegen.constant_map[key];
						}

						return idx|(GDFunction::ADDR_TYPE_LOCAL_CONSTANT<<GDFunction::ADDR_BITS); //make it a local constant (faster access)
					}

				}

				owner=owner->_owner;
			}

			/*
			 handled in constants now
			 if (codegen.script->subclasses.has(identifier)) {
				//same with a subclass, make it a local constant.
				int idx = codegen.get_constant_pos(codegen.script->subclasses[identifier]);
				return idx|(GDFunction::ADDR_TYPE_LOCAL_CONSTANT<<GDFunction::ADDR_BITS); //make it a local constant (faster access)

			}*/

			if (GDScriptLanguage::get_singleton()->get_global_map().has(identifier)) {

				int idx = GDScriptLanguage::get_singleton()->get_global_map()[identifier];
				return idx|(GDFunction::ADDR_TYPE_GLOBAL<<GDFunction::ADDR_BITS); //argument (stack root)
			}

			//not found, error

			_set_error("Identifier not found: "+String(identifier),p_expression);

			return -1;


		} break;
		case GDParser::Node::TYPE_CONSTANT: {
			//return constant
			const GDParser::ConstantNode *cn = static_cast<const GDParser::ConstantNode*>(p_expression);


			int idx;

			if (!codegen.constant_map.has(cn->value)) {

				idx=codegen.constant_map.size();
				codegen.constant_map[cn->value]=idx;

			} else {
				idx=codegen.constant_map[cn->value];
			}


			return idx|(GDFunction::ADDR_TYPE_LOCAL_CONSTANT<<GDFunction::ADDR_BITS); //argument (stack root)

		} break;
		case GDParser::Node::TYPE_SELF: {
			//return constant
			if (codegen.function_node && codegen.function_node->_static) {
				_set_error("'self' not present in static function!",p_expression);
				return -1;
			}
			return (GDFunction::ADDR_TYPE_SELF<<GDFunction::ADDR_BITS);
		} break;
		case GDParser::Node::TYPE_ARRAY: {

			const GDParser::ArrayNode *an = static_cast<const GDParser::ArrayNode*>(p_expression);
			Vector<int> values;

			int slevel=p_stack_level;

			for(int i=0;i<an->elements.size();i++) {

				int ret = _parse_expression(codegen,an->elements[i],slevel);
				if (ret<0)
					return ret;
				if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
					slevel++;
					codegen.alloc_stack(slevel);
				}

				values.push_back(ret);
			}

			codegen.opcodes.push_back(GDFunction::OPCODE_CONSTRUCT_ARRAY);
			codegen.opcodes.push_back(values.size());
			for(int i=0;i<values.size();i++)
				codegen.opcodes.push_back(values[i]);

			int dst_addr=(p_stack_level)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
			codegen.opcodes.push_back(dst_addr); // append the stack level as destination address of the opcode
			codegen.alloc_stack(p_stack_level);
			return dst_addr;

		} break;
		case GDParser::Node::TYPE_DICTIONARY: {

			const GDParser::DictionaryNode *dn = static_cast<const GDParser::DictionaryNode*>(p_expression);
			Vector<int> values;

			int slevel=p_stack_level;

			for(int i=0;i<dn->elements.size();i++) {

				int ret = _parse_expression(codegen,dn->elements[i].key,slevel);
				if (ret<0)
					return ret;
				if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
					slevel++;
					codegen.alloc_stack(slevel);
				}

				values.push_back(ret);

				ret = _parse_expression(codegen,dn->elements[i].value,slevel);
				if (ret<0)
					return ret;
				if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
					slevel++;
					codegen.alloc_stack(slevel);
				}

				values.push_back(ret);
			}

			codegen.opcodes.push_back(GDFunction::OPCODE_CONSTRUCT_DICTIONARY);
			codegen.opcodes.push_back(dn->elements.size());
			for(int i=0;i<values.size();i++)
				codegen.opcodes.push_back(values[i]);

			int dst_addr=(p_stack_level)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
			codegen.opcodes.push_back(dst_addr); // append the stack level as destination address of the opcode
			codegen.alloc_stack(p_stack_level);
			return dst_addr;

		} break;
		case GDParser::Node::TYPE_OPERATOR: {
			//hell breaks loose

			const GDParser::OperatorNode *on = static_cast<const GDParser::OperatorNode*>(p_expression);
			switch(on->op) {


				//call/constructor operator
				case GDParser::OperatorNode::OP_PARENT_CALL: {


					ERR_FAIL_COND_V(on->arguments.size()<1,-1);

					const GDParser::IdentifierNode *in = (const GDParser::IdentifierNode *)on->arguments[0];


					Vector<int> arguments;
					int slevel = p_stack_level;
					for(int i=1;i<on->arguments.size();i++) {

						int ret = _parse_expression(codegen,on->arguments[i],slevel);
						if (ret<0)
							return ret;
						if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
							slevel++;
							codegen.alloc_stack(slevel);
						}
						arguments.push_back(ret);
					}

					//push call bytecode
					codegen.opcodes.push_back(GDFunction::OPCODE_CALL_SELF_BASE); // basic type constructor

					codegen.opcodes.push_back(codegen.get_name_map_pos(in->name)); //instance
					codegen.opcodes.push_back(arguments.size()); //argument count
					codegen.alloc_call(arguments.size());
					for(int i=0;i<arguments.size();i++)
						codegen.opcodes.push_back(arguments[i]); //arguments

				} break;
				case GDParser::OperatorNode::OP_CALL: {

					if (on->arguments[0]->type==GDParser::Node::TYPE_TYPE) {
						//construct a basic type
						ERR_FAIL_COND_V(on->arguments.size()<1,-1);

						const GDParser::TypeNode *tn = (const GDParser::TypeNode *)on->arguments[0];
						int vtype = tn->vtype;

						Vector<int> arguments;
						int slevel = p_stack_level;
						for(int i=1;i<on->arguments.size();i++) {

							int ret = _parse_expression(codegen,on->arguments[i],slevel);
							if (ret<0)
								return ret;
							if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
								slevel++;
								codegen.alloc_stack(slevel);
							}
							arguments.push_back(ret);
						}

						//push call bytecode
						codegen.opcodes.push_back(GDFunction::OPCODE_CONSTRUCT); // basic type constructor
						codegen.opcodes.push_back(vtype); //instance
						codegen.opcodes.push_back(arguments.size()); //argument count
						codegen.alloc_call(arguments.size());
						for(int i=0;i<arguments.size();i++)
							codegen.opcodes.push_back(arguments[i]); //arguments

					} else if (on->arguments[0]->type==GDParser::Node::TYPE_BUILT_IN_FUNCTION) {
						//built in function

						ERR_FAIL_COND_V(on->arguments.size()<1,-1);


						Vector<int> arguments;
						int slevel = p_stack_level;
						for(int i=1;i<on->arguments.size();i++) {

							int ret = _parse_expression(codegen,on->arguments[i],slevel);
							if (ret<0)
								return ret;

							if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
								slevel++;
								codegen.alloc_stack(slevel);
							}

							arguments.push_back(ret);
						}


						codegen.opcodes.push_back(GDFunction::OPCODE_CALL_BUILT_IN);
						codegen.opcodes.push_back(static_cast<const GDParser::BuiltInFunctionNode*>(on->arguments[0])->function);
						codegen.opcodes.push_back(on->arguments.size()-1);
						codegen.alloc_call(on->arguments.size()-1);
						for(int i=0;i<arguments.size();i++)
							codegen.opcodes.push_back(arguments[i]);

					} else {
						//regular function
						ERR_FAIL_COND_V(on->arguments.size()<2,-1);

						const GDParser::Node *instance = on->arguments[0];

						if (instance->type==GDParser::Node::TYPE_SELF) {
							//room for optimization

						}


						Vector<int> arguments;
						int slevel = p_stack_level;

						for(int i=0;i<on->arguments.size();i++) {

							int ret;

							if (i==0 && on->arguments[i]->type==GDParser::Node::TYPE_SELF && codegen.function_node && codegen.function_node->_static) {
								//static call to self
								ret=(GDFunction::ADDR_TYPE_CLASS<<GDFunction::ADDR_BITS);
							} else if (i==1) {

								if (on->arguments[i]->type!=GDParser::Node::TYPE_IDENTIFIER) {
									_set_error("Attempt to call a non-identifier.",on);
									return -1;
								}
								GDParser::IdentifierNode *id = static_cast<GDParser::IdentifierNode*>(on->arguments[i]);
								ret=codegen.get_name_map_pos(id->name);

							} else {

								ret = _parse_expression(codegen,on->arguments[i],slevel);
								if (ret<0)
									return ret;
								if (ret&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
									slevel++;
									codegen.alloc_stack(slevel);
								}
							}
							arguments.push_back(ret);

						}

						codegen.opcodes.push_back(p_root?GDFunction::OPCODE_CALL:GDFunction::OPCODE_CALL_RETURN); // perform operator
						codegen.opcodes.push_back(on->arguments.size()-2);
						codegen.alloc_call(on->arguments.size()-2);
						for(int i=0;i<arguments.size();i++)
							codegen.opcodes.push_back(arguments[i]);
					}
				} break;
				case GDParser::OperatorNode::OP_YIELD: {


					ERR_FAIL_COND_V(on->arguments.size() && on->arguments.size()!=2,-1);

					Vector<int> arguments;
					int slevel = p_stack_level;
					for(int i=0;i<on->arguments.size();i++) {

						int ret = _parse_expression(codegen,on->arguments[i],slevel);
						if (ret<0)
							return ret;
						if (ret&(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)) {
							slevel++;
							codegen.alloc_stack(slevel);
						}
						arguments.push_back(ret);
					}

					//push call bytecode
					codegen.opcodes.push_back(arguments.size()==0?GDFunction::OPCODE_YIELD:GDFunction::OPCODE_YIELD_SIGNAL); // basic type constructor
					for(int i=0;i<arguments.size();i++)
						codegen.opcodes.push_back(arguments[i]); //arguments
					codegen.opcodes.push_back(GDFunction::OPCODE_YIELD_RESUME);
					//next will be where to place the result :)

				} break;

				//indexing operator
				case GDParser::OperatorNode::OP_INDEX:
				case GDParser::OperatorNode::OP_INDEX_NAMED: {

					ERR_FAIL_COND_V(on->arguments.size()!=2,-1);

					int slevel = p_stack_level;
					bool named=(on->op==GDParser::OperatorNode::OP_INDEX_NAMED);

					int from = _parse_expression(codegen,on->arguments[0],slevel);
					if (from<0)
						return from;

					int index;
					if (named) {
						if (on->arguments[0]->type==GDParser::Node::TYPE_SELF && codegen.script && codegen.function_node && !codegen.function_node->_static) {

							GDParser::IdentifierNode* identifier = static_cast<GDParser::IdentifierNode*>(on->arguments[1]);
							const Map<StringName,GDScript::MemberInfo>::Element *MI = codegen.script->member_indices.find(identifier->name);

#ifdef DEBUG_ENABLED
							if (MI && MI->get().getter==codegen.function_node->name) {
								String n = static_cast<GDParser::IdentifierNode*>(on->arguments[1])->name;
								_set_error("Must use '"+n+"' instead of 'self."+n+"' in getter.",on);
								return -1;
							}
#endif

							if (MI && MI->get().getter=="") {
								// Faster than indexing self (as if no self. had been used)
								return (MI->get().index)|(GDFunction::ADDR_TYPE_MEMBER<<GDFunction::ADDR_BITS);
							}
						}

						index=codegen.get_name_map_pos(static_cast<GDParser::IdentifierNode*>(on->arguments[1])->name);

					} else {

						if (on->arguments[1]->type==GDParser::Node::TYPE_CONSTANT && static_cast<const GDParser::ConstantNode*>(on->arguments[1])->value.get_type()==Variant::STRING) {
							//also, somehow, named (speed up anyway)
							StringName name = static_cast<const GDParser::ConstantNode*>(on->arguments[1])->value;
							index=codegen.get_name_map_pos(name);
							named=true;

						} else {
							//regular indexing
							if (from&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
								slevel++;
								codegen.alloc_stack(slevel);
							}

							index = _parse_expression(codegen,on->arguments[1],slevel);
							if (index<0)
								return index;
						}
					}

					codegen.opcodes.push_back(named?GDFunction::OPCODE_GET_NAMED:GDFunction::OPCODE_GET); // perform operator
					codegen.opcodes.push_back(from); // argument 1
					codegen.opcodes.push_back(index); // argument 2 (unary only takes one parameter)

				} break;
				case GDParser::OperatorNode::OP_AND: {

					// AND operator with early out on failure

					int res = _parse_expression(codegen,on->arguments[0],p_stack_level);
					if (res<0)
						return res;
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
					codegen.opcodes.push_back(res);
					int jump_fail_pos=codegen.opcodes.size();
					codegen.opcodes.push_back(0);

					res = _parse_expression(codegen,on->arguments[1],p_stack_level);
					if (res<0)
						return res;

					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
					codegen.opcodes.push_back(res);
					int jump_fail_pos2=codegen.opcodes.size();
					codegen.opcodes.push_back(0);

					codegen.alloc_stack(p_stack_level); //it will be used..
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN_TRUE);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
					codegen.opcodes.push_back(codegen.opcodes.size()+3);
					codegen.opcodes[jump_fail_pos]=codegen.opcodes.size();
					codegen.opcodes[jump_fail_pos2]=codegen.opcodes.size();
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN_FALSE);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					return p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS;

				} break;
				case GDParser::OperatorNode::OP_OR: {

					// OR operator with early out on success

					int res = _parse_expression(codegen,on->arguments[0],p_stack_level);
					if (res<0)
						return res;
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF);
					codegen.opcodes.push_back(res);
					int jump_success_pos=codegen.opcodes.size();
					codegen.opcodes.push_back(0);

					res = _parse_expression(codegen,on->arguments[1],p_stack_level);
					if (res<0)
						return res;

					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF);
					codegen.opcodes.push_back(res);
					int jump_success_pos2=codegen.opcodes.size();
					codegen.opcodes.push_back(0);

					codegen.alloc_stack(p_stack_level); //it will be used..
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN_FALSE);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
					codegen.opcodes.push_back(codegen.opcodes.size()+3);
					codegen.opcodes[jump_success_pos]=codegen.opcodes.size();
					codegen.opcodes[jump_success_pos2]=codegen.opcodes.size();
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN_TRUE);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					return p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS;

				} break;
				// ternary operators
				case GDParser::OperatorNode::OP_TERNARY_IF: {

					// x IF a ELSE y operator with early out on failure

					int res = _parse_expression(codegen,on->arguments[0],p_stack_level);
					if (res<0)
						return res;
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
					codegen.opcodes.push_back(res);
					int jump_fail_pos=codegen.opcodes.size();
					codegen.opcodes.push_back(0);


					res = _parse_expression(codegen,on->arguments[1],p_stack_level);
					if (res<0)
						return res;
					
					codegen.alloc_stack(p_stack_level); //it will be used..
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					codegen.opcodes.push_back(res);
					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
					int jump_past_pos=codegen.opcodes.size();
					codegen.opcodes.push_back(0);
					
					codegen.opcodes[jump_fail_pos]=codegen.opcodes.size();
					res = _parse_expression(codegen,on->arguments[2],p_stack_level);
					if (res<0)
						return res;
					
					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN);
					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
					codegen.opcodes.push_back(res);
					
					codegen.opcodes[jump_past_pos]=codegen.opcodes.size();
					
					return p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS;

				} break;
				//unary operators
				case GDParser::OperatorNode::OP_NEG: { if (!_create_unary_operator(codegen,on,Variant::OP_NEGATE,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_NOT: { if (!_create_unary_operator(codegen,on,Variant::OP_NOT,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_BIT_INVERT: { if (!_create_unary_operator(codegen,on,Variant::OP_BIT_NEGATE,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_PREINC: { } break; //?
				case GDParser::OperatorNode::OP_PREDEC: { } break;
				case GDParser::OperatorNode::OP_INC: { } break;
				case GDParser::OperatorNode::OP_DEC: { } break;
				//binary operators (in precedence order)
				case GDParser::OperatorNode::OP_IN: { if (!_create_binary_operator(codegen,on,Variant::OP_IN,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_EQUAL: { if (!_create_binary_operator(codegen,on,Variant::OP_EQUAL,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_NOT_EQUAL: { if (!_create_binary_operator(codegen,on,Variant::OP_NOT_EQUAL,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_LESS: { if (!_create_binary_operator(codegen,on,Variant::OP_LESS,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_LESS_EQUAL: { if (!_create_binary_operator(codegen,on,Variant::OP_LESS_EQUAL,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_GREATER: { if (!_create_binary_operator(codegen,on,Variant::OP_GREATER,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_GREATER_EQUAL: { if (!_create_binary_operator(codegen,on,Variant::OP_GREATER_EQUAL,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_ADD: { if (!_create_binary_operator(codegen,on,Variant::OP_ADD,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_SUB: { if (!_create_binary_operator(codegen,on,Variant::OP_SUBSTRACT,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_MUL: { if (!_create_binary_operator(codegen,on,Variant::OP_MULTIPLY,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_DIV: { if (!_create_binary_operator(codegen,on,Variant::OP_DIVIDE,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_MOD: { if (!_create_binary_operator(codegen,on,Variant::OP_MODULE,p_stack_level)) return -1;} break;
				//case GDParser::OperatorNode::OP_SHIFT_LEFT: { if (!_create_binary_operator(codegen,on,Variant::OP_SHIFT_LEFT,p_stack_level)) return -1;} break;
				//case GDParser::OperatorNode::OP_SHIFT_RIGHT: { if (!_create_binary_operator(codegen,on,Variant::OP_SHIFT_RIGHT,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_BIT_AND: { if (!_create_binary_operator(codegen,on,Variant::OP_BIT_AND,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_BIT_OR: { if (!_create_binary_operator(codegen,on,Variant::OP_BIT_OR,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_BIT_XOR: { if (!_create_binary_operator(codegen,on,Variant::OP_BIT_XOR,p_stack_level)) return -1;} break;
                //shift
				case GDParser::OperatorNode::OP_SHIFT_LEFT: { if (!_create_binary_operator(codegen,on,Variant::OP_SHIFT_LEFT,p_stack_level)) return -1;} break;
				case GDParser::OperatorNode::OP_SHIFT_RIGHT: { if (!_create_binary_operator(codegen,on,Variant::OP_SHIFT_RIGHT,p_stack_level)) return -1;} break;
				//assignment operators
				case GDParser::OperatorNode::OP_ASSIGN_ADD:
				case GDParser::OperatorNode::OP_ASSIGN_SUB:
				case GDParser::OperatorNode::OP_ASSIGN_MUL:
				case GDParser::OperatorNode::OP_ASSIGN_DIV:
				case GDParser::OperatorNode::OP_ASSIGN_MOD:
				case GDParser::OperatorNode::OP_ASSIGN_SHIFT_LEFT:
				case GDParser::OperatorNode::OP_ASSIGN_SHIFT_RIGHT:
				case GDParser::OperatorNode::OP_ASSIGN_BIT_AND:
				case GDParser::OperatorNode::OP_ASSIGN_BIT_OR:
				case GDParser::OperatorNode::OP_ASSIGN_BIT_XOR:
				case GDParser::OperatorNode::OP_INIT_ASSIGN:
				case GDParser::OperatorNode::OP_ASSIGN: {

					ERR_FAIL_COND_V(on->arguments.size()!=2,-1);


					if (on->arguments[0]->type==GDParser::Node::TYPE_OPERATOR && (static_cast<GDParser::OperatorNode*>(on->arguments[0])->op==GDParser::OperatorNode::OP_INDEX || static_cast<GDParser::OperatorNode*>(on->arguments[0])->op==GDParser::OperatorNode::OP_INDEX_NAMED)) {
						//SET (chained) MODE!!


#ifdef DEBUG_ENABLED
						if (static_cast<GDParser::OperatorNode*>(on->arguments[0])->op==GDParser::OperatorNode::OP_INDEX_NAMED) {
							const GDParser::OperatorNode* inon = static_cast<GDParser::OperatorNode*>(on->arguments[0]);


							if (inon->arguments[0]->type==GDParser::Node::TYPE_SELF && codegen.script && codegen.function_node && !codegen.function_node->_static) {

								const Map<StringName,GDScript::MemberInfo>::Element *MI = codegen.script->member_indices.find(static_cast<GDParser::IdentifierNode*>(inon->arguments[1])->name);
								if (MI && MI->get().setter==codegen.function_node->name) {
									String n = static_cast<GDParser::IdentifierNode*>(inon->arguments[1])->name;
									_set_error("Must use '"+n+"' instead of 'self."+n+"' in setter.",inon);
									return -1;
								}
							}
						}
#endif


						int slevel=p_stack_level;

						GDParser::OperatorNode* op = static_cast<GDParser::OperatorNode*>(on->arguments[0]);

						/* Find chain of sets */

						List<GDParser::OperatorNode*> chain;

						{
							//create get/set chain
							GDParser::OperatorNode* n=op;
							while(true) {

								chain.push_back(n);
								if (n->arguments[0]->type!=GDParser::Node::TYPE_OPERATOR)
									break;
								n = static_cast<GDParser::OperatorNode*>(n->arguments[0]);
								if (n->op!=GDParser::OperatorNode::OP_INDEX && n->op!=GDParser::OperatorNode::OP_INDEX_NAMED)
									break;
							}
						}

						/* Chain of gets */

						//get at (potential) root stack pos, so it can be returned
						int prev_pos = _parse_expression(codegen,chain.back()->get()->arguments[0],slevel);
						if (prev_pos<0)
							return prev_pos;
						int retval=prev_pos;

						//print_line("retval: "+itos(retval));

						if (retval&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
							slevel++;
							codegen.alloc_stack(slevel);
						}


						Vector<int> setchain;

						for(List<GDParser::OperatorNode*>::Element *E=chain.back();E;E=E->prev()) {


							if (E==chain.front()) //ignore first
								break;

							bool named = E->get()->op==GDParser::OperatorNode::OP_INDEX_NAMED;
							int key_idx;

							if (named) {

								key_idx = codegen.get_name_map_pos(static_cast<const GDParser::IdentifierNode*>(E->get()->arguments[1])->name);
								//printf("named key %x\n",key_idx);

							} else {

								if (prev_pos&(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)) {
									slevel++;
									codegen.alloc_stack(slevel);
								}

								GDParser::Node *key = E->get()->arguments[1];
								key_idx = _parse_expression(codegen,key,slevel);
								//printf("expr key %x\n",key_idx);


								//stack was raised here if retval was stack but..

							}

							if (key_idx<0)
								return key_idx;

							codegen.opcodes.push_back(named ? GDFunction::OPCODE_GET_NAMED : GDFunction::OPCODE_GET);
							codegen.opcodes.push_back(prev_pos);
							codegen.opcodes.push_back(key_idx);
							slevel++;
							codegen.alloc_stack(slevel);
							int dst_pos = (GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)|slevel;

							codegen.opcodes.push_back(dst_pos);

							//add in reverse order, since it will be reverted
							setchain.push_back(dst_pos);
							setchain.push_back(key_idx);
							setchain.push_back(prev_pos);
							setchain.push_back(named ? GDFunction::OPCODE_SET_NAMED : GDFunction::OPCODE_SET);

							prev_pos=dst_pos;

						}

						setchain.invert();


						int set_index;
						bool named=false;


						if (static_cast<const GDParser::OperatorNode*>(op)->op==GDParser::OperatorNode::OP_INDEX_NAMED) {


							set_index=codegen.get_name_map_pos(static_cast<const GDParser::IdentifierNode*>(op->arguments[1])->name);
							named=true;
						} else {

							set_index = _parse_expression(codegen,op->arguments[1],slevel+1);
							named=false;
						}


						if (set_index<0)
							return set_index;

						if (set_index&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
							slevel++;
							codegen.alloc_stack(slevel);
						}


						int set_value = _parse_assign_right_expression(codegen,on,slevel+1);
						if (set_value<0)
							return set_value;

						codegen.opcodes.push_back(named?GDFunction::OPCODE_SET_NAMED:GDFunction::OPCODE_SET);
						codegen.opcodes.push_back(prev_pos);
						codegen.opcodes.push_back(set_index);
						codegen.opcodes.push_back(set_value);

						for(int i=0;i<setchain.size();i+=4) {


							codegen.opcodes.push_back(setchain[i+0]);
							codegen.opcodes.push_back(setchain[i+1]);
							codegen.opcodes.push_back(setchain[i+2]);
							codegen.opcodes.push_back(setchain[i+3]);
						}

						return retval;


					} else {
						//ASSIGNMENT MODE!!

						int slevel = p_stack_level;

						int dst_address_a = _parse_expression(codegen,on->arguments[0],slevel,false,on->op==GDParser::OperatorNode::OP_INIT_ASSIGN);
						if (dst_address_a<0)
							return -1;

						if (dst_address_a&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS) {
							slevel++;
							codegen.alloc_stack(slevel);
						}

						int src_address_b = _parse_assign_right_expression(codegen,on,slevel);
						if (src_address_b<0)
							return -1;




						codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN); // perform operator
						codegen.opcodes.push_back(dst_address_a); // argument 1
						codegen.opcodes.push_back(src_address_b); // argument 2 (unary only takes one parameter)
						return dst_address_a; //if anything, returns wathever was assigned or correct stack position

					}


				} break;
				case GDParser::OperatorNode::OP_EXTENDS: {

					ERR_FAIL_COND_V(on->arguments.size()!=2,false);


					int slevel = p_stack_level;

					int src_address_a = _parse_expression(codegen,on->arguments[0],slevel);
					if (src_address_a<0)
						return -1;

					if (src_address_a&GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)
						slevel++; //uses stack for return, increase stack

					int src_address_b = _parse_expression(codegen,on->arguments[1],slevel);
					if (src_address_b<0)
						return -1;

					codegen.opcodes.push_back(GDFunction::OPCODE_EXTENDS_TEST); // perform operator
					codegen.opcodes.push_back(src_address_a); // argument 1
					codegen.opcodes.push_back(src_address_b); // argument 2 (unary only takes one parameter)

				} break;
				default: {


					ERR_EXPLAIN("Bug in bytecode compiler, unexpected operator #"+itos(on->op)+" in parse tree while parsing expression.");
					ERR_FAIL_V(0); //unreachable code

				} break;
			}

			int dst_addr=(p_stack_level)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
			codegen.opcodes.push_back(dst_addr); // append the stack level as destination address of the opcode
			codegen.alloc_stack(p_stack_level);
			return dst_addr;
		} break;
		//TYPE_TYPE,
		default: {

			ERR_EXPLAIN("Bug in bytecode compiler, unexpected node in parse tree while parsing expression.");
			ERR_FAIL_V(-1); //unreachable code
		} break;


	}

	ERR_FAIL_V(-1); //unreachable code
}


Error GDCompiler::_parse_block(CodeGen& codegen,const GDParser::BlockNode *p_block,int p_stack_level,int p_break_addr,int p_continue_addr) {

	codegen.push_stack_identifiers();
	int new_identifiers=0;
	codegen.current_line=p_block->line;

	for(int i=0;i<p_block->statements.size();i++) {

		const GDParser::Node *s = p_block->statements[i];


		switch(s->type) {
			case GDParser::Node::TYPE_NEWLINE: {

				const GDParser::NewLineNode *nl = static_cast<const GDParser::NewLineNode*>(s);
				codegen.opcodes.push_back(GDFunction::OPCODE_LINE);
				codegen.opcodes.push_back(nl->line);
				codegen.current_line=nl->line;

			} break;
			case GDParser::Node::TYPE_CONTROL_FLOW: {
				// try subblocks

				const GDParser::ControlFlowNode *cf = static_cast<const GDParser::ControlFlowNode*>(s);

				switch(cf->cf_type) {


					case GDParser::ControlFlowNode::CF_IF: {

#ifdef DEBUG_ENABLED
						codegen.opcodes.push_back(GDFunction::OPCODE_LINE);
						codegen.opcodes.push_back(cf->line);
						codegen.current_line=cf->line;
#endif
						int ret = _parse_expression(codegen,cf->arguments[0],p_stack_level,false);
						if (ret<0)
							return ERR_PARSE_ERROR;

						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
						codegen.opcodes.push_back(ret);
						int else_addr=codegen.opcodes.size();
						codegen.opcodes.push_back(0); //temporary

						Error err = _parse_block(codegen,cf->body,p_stack_level,p_break_addr,p_continue_addr);
						if (err)
							return err;

						if (cf->body_else) {

							codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
							int end_addr=codegen.opcodes.size();
							codegen.opcodes.push_back(0);
							codegen.opcodes[else_addr]=codegen.opcodes.size();

							Error err = _parse_block(codegen,cf->body_else,p_stack_level,p_break_addr,p_continue_addr);
							if (err)
								return err;

							codegen.opcodes[end_addr]=codegen.opcodes.size();
						} else {
							//end without else
							codegen.opcodes[else_addr]=codegen.opcodes.size();

						}

					} break;
					case GDParser::ControlFlowNode::CF_FOR: {



						int slevel=p_stack_level;
						int iter_stack_pos=slevel;
						int iterator_pos = (slevel++)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
						int counter_pos = (slevel++)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
						int container_pos = (slevel++)|(GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
						codegen.alloc_stack(slevel);

						    codegen.push_stack_identifiers();
						      codegen.add_stack_identifier(static_cast<const GDParser::IdentifierNode*>(cf->arguments[0])->name,iter_stack_pos);

						int ret = _parse_expression(codegen,cf->arguments[1],slevel,false);
						if (ret<0)
							return ERR_COMPILATION_FAILED;

						//assign container
						codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN);
						codegen.opcodes.push_back(container_pos);
						codegen.opcodes.push_back(ret);

						//begin loop
						codegen.opcodes.push_back(GDFunction::OPCODE_ITERATE_BEGIN);
						codegen.opcodes.push_back(counter_pos);
						codegen.opcodes.push_back(container_pos);
						codegen.opcodes.push_back(codegen.opcodes.size()+4);
						codegen.opcodes.push_back(iterator_pos);
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); //skip code for next
						codegen.opcodes.push_back(codegen.opcodes.size()+8);
						//break loop
						int break_pos=codegen.opcodes.size();
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP); //skip code for next
						codegen.opcodes.push_back(0); //skip code for next
						//next loop
						int continue_pos=codegen.opcodes.size();
						codegen.opcodes.push_back(GDFunction::OPCODE_ITERATE);
						codegen.opcodes.push_back(counter_pos);
						codegen.opcodes.push_back(container_pos);
						codegen.opcodes.push_back(break_pos);
						codegen.opcodes.push_back(iterator_pos);


						Error err = _parse_block(codegen,cf->body,slevel,break_pos,continue_pos);
						if (err)
							return err;


						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(continue_pos);
						codegen.opcodes[break_pos+1]=codegen.opcodes.size();


						codegen.pop_stack_identifiers();

					} break;
					case GDParser::ControlFlowNode::CF_WHILE: {

						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(codegen.opcodes.size()+3);
						int break_addr=codegen.opcodes.size();
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(0);
						int continue_addr=codegen.opcodes.size();

						int ret = _parse_expression(codegen,cf->arguments[0],p_stack_level,false);
						if (ret<0)
							return ERR_PARSE_ERROR;
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
						codegen.opcodes.push_back(ret);
						codegen.opcodes.push_back(break_addr);
						Error err = _parse_block(codegen,cf->body,p_stack_level,break_addr,continue_addr);
						if (err)
							return err;
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(continue_addr);

						codegen.opcodes[break_addr+1]=codegen.opcodes.size();

					} break;
					case GDParser::ControlFlowNode::CF_SWITCH: {

					} break;
					case GDParser::ControlFlowNode::CF_BREAK: {

						if (p_break_addr<0) {

							_set_error("'break'' not within loop",cf);
							return ERR_COMPILATION_FAILED;
						}
						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(p_break_addr);

					} break;
					case GDParser::ControlFlowNode::CF_CONTINUE: {

						if (p_continue_addr<0) {

							_set_error("'continue' not within loop",cf);
							return ERR_COMPILATION_FAILED;
						}

						codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
						codegen.opcodes.push_back(p_continue_addr);

					} break;
					case GDParser::ControlFlowNode::CF_RETURN: {

						int ret;

						if (cf->arguments.size()) {

							ret = _parse_expression(codegen,cf->arguments[0],p_stack_level,false);
							if (ret<0)
								return ERR_PARSE_ERROR;

						} else {

							ret=GDFunction::ADDR_TYPE_NIL << GDFunction::ADDR_BITS;
						}

						codegen.opcodes.push_back(GDFunction::OPCODE_RETURN);
						codegen.opcodes.push_back(ret);

					} break;

				}
			} break;
			case GDParser::Node::TYPE_ASSERT: {
				// try subblocks

				const GDParser::AssertNode *as = static_cast<const GDParser::AssertNode*>(s);

				int ret = _parse_expression(codegen,as->condition,p_stack_level,false);
				if (ret<0)
					return ERR_PARSE_ERROR;

				codegen.opcodes.push_back(GDFunction::OPCODE_ASSERT);
				codegen.opcodes.push_back(ret);
			} break;
			case GDParser::Node::TYPE_BREAKPOINT: {
				// try subblocks
				codegen.opcodes.push_back(GDFunction::OPCODE_BREAKPOINT);
			} break;
			case GDParser::Node::TYPE_LOCAL_VAR: {


				const GDParser::LocalVarNode *lv = static_cast<const GDParser::LocalVarNode*>(s);

				codegen.add_stack_identifier(lv->name,p_stack_level++);
				codegen.alloc_stack(p_stack_level);
				new_identifiers++;

			} break;
			default: {
				//expression
				int ret = _parse_expression(codegen,s,p_stack_level,true);
				if (ret<0)
					return ERR_PARSE_ERROR;
			} break;

		}

	}
	codegen.pop_stack_identifiers();
	return OK;
}


Error GDCompiler::_parse_function(GDScript *p_script,const GDParser::ClassNode *p_class,const GDParser::FunctionNode *p_func,bool p_for_ready) {

	Vector<int> bytecode;
	CodeGen codegen;

	codegen.class_node=p_class;
	codegen.script=p_script;
	codegen.function_node=p_func;
	codegen.stack_max=0;
	codegen.current_line=0;
	codegen.call_max=0;
	codegen.debug_stack=ScriptDebugger::get_singleton()!=NULL;
	Vector<StringName> argnames;

	int stack_level=0;

	if (p_func) {
		for(int i=0;i<p_func->arguments.size();i++) {
			codegen.add_stack_identifier(p_func->arguments[i],i);
#ifdef TOOLS_ENABLED
			argnames.push_back(p_func->arguments[i]);
#endif
		}
		stack_level=p_func->arguments.size();
	}

	codegen.alloc_stack(stack_level);

	/* Parse initializer -if applies- */

	bool is_initializer=!p_for_ready && !p_func;

	if (is_initializer || (p_func && String(p_func->name)=="_init")) {
		//parse initializer for class members
		if (!p_func && p_class->extends_used && p_script->native.is_null()){

			//call implicit parent constructor
			codegen.opcodes.push_back(GDFunction::OPCODE_CALL_SELF_BASE);
			codegen.opcodes.push_back(codegen.get_name_map_pos("_init"));
			codegen.opcodes.push_back(0);
			codegen.opcodes.push_back((GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS)|0);

		}
		Error err = _parse_block(codegen,p_class->initializer,stack_level);
		if (err)
			return err;
		is_initializer=true;

	}

	if (p_for_ready || (p_func && String(p_func->name)=="_ready")) {
		//parse initializer for class members
		if (p_class->ready->statements.size()) {
			Error err = _parse_block(codegen,p_class->ready,stack_level);
			if (err)
				return err;
		}

	}


	/* Parse default argument code -if applies- */

	Vector<int> defarg_addr;
	StringName func_name;

	if (p_func) {

		if (p_func->default_values.size()) {

			codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_TO_DEF_ARGUMENT);
			defarg_addr.push_back(codegen.opcodes.size());
			for(int i=0;i<p_func->default_values.size();i++) {

				_parse_expression(codegen,p_func->default_values[i],stack_level,true);
				defarg_addr.push_back(codegen.opcodes.size());
			}


			defarg_addr.invert();
		}



		Error err = _parse_block(codegen,p_func->body,stack_level);
		if (err)
			return err;

		func_name=p_func->name;
	} else {
		if (p_for_ready)
			func_name="_ready";
		else
			func_name="_init";
	}

	codegen.opcodes.push_back(GDFunction::OPCODE_END);

	GDFunction *gdfunc=NULL;

	//if (String(p_func->name)=="") { //initializer func
	//	gdfunc = &p_script->initializer;

	//} else { //regular func
		p_script->member_functions[func_name]=memnew(GDFunction);
		gdfunc = p_script->member_functions[func_name];
	//}

	if (p_func) {
		gdfunc->_static=p_func->_static;
		gdfunc->rpc_mode=p_func->rpc_mode;
	}

#ifdef TOOLS_ENABLED
	gdfunc->arg_names=argnames;
#endif
	//constants
	if (codegen.constant_map.size()) {
		gdfunc->_constant_count=codegen.constant_map.size();
		gdfunc->constants.resize(codegen.constant_map.size());
		gdfunc->_constants_ptr=&gdfunc->constants[0];
		const Variant *K=NULL;
		while((K=codegen.constant_map.next(K))) {
			int idx = codegen.constant_map[*K];
			gdfunc->constants[idx]=*K;
		}
	} else {

		gdfunc->_constants_ptr=NULL;
		gdfunc->_constant_count=0;
	}
	//global names
	if (codegen.name_map.size()) {

		gdfunc->global_names.resize(codegen.name_map.size());
		gdfunc->_global_names_ptr = &gdfunc->global_names[0];
		for(Map<StringName,int>::Element *E=codegen.name_map.front();E;E=E->next()) {

			gdfunc->global_names[E->get()]=E->key();
		}
		gdfunc->_global_names_count=gdfunc->global_names.size();

	} else {
		gdfunc->_global_names_ptr = NULL;
		gdfunc->_global_names_count =0;
	}


	if (codegen.opcodes.size()) {

		gdfunc->code=codegen.opcodes;
		gdfunc->_code_ptr=&gdfunc->code[0];
		gdfunc->_code_size=codegen.opcodes.size();

	} else {

		gdfunc->_code_ptr=NULL;
		gdfunc->_code_size=0;
	}

	if (defarg_addr.size()) {

		gdfunc->default_arguments=defarg_addr;
		gdfunc->_default_arg_count=defarg_addr.size()-1;
		gdfunc->_default_arg_ptr=&gdfunc->default_arguments[0];
	} else {
		gdfunc->_default_arg_count=0;
		gdfunc->_default_arg_ptr=NULL;
	}

	gdfunc->_argument_count=p_func ? p_func->arguments.size() : 0;
	gdfunc->_stack_size=codegen.stack_max;
	gdfunc->_call_size=codegen.call_max;
	gdfunc->name=func_name;
#ifdef DEBUG_ENABLED
	if (ScriptDebugger::get_singleton()){
		String signature;
		//path
		if (p_script->get_path()!=String())
			signature+=p_script->get_path();
		//loc
		if (p_func) {
			signature+="::"+itos(p_func->body->line);
		} else {
			signature+="::0";
		}

		//funciton and class

		if (p_class->name) {
			signature+="::"+String(p_class->name)+"."+String(func_name);;
		} else {
			signature+="::"+String(func_name);
		}



		gdfunc->profile.signature=signature;
	}
#endif
	gdfunc->_script=p_script;
	gdfunc->source=source;

#ifdef DEBUG_ENABLED

	{
		gdfunc->func_cname=(String(source)+" - "+String(func_name)).utf8();
		gdfunc->_func_cname=gdfunc->func_cname.get_data();

	}

#endif
	if (p_func) {
		gdfunc->_initial_line=p_func->line;
#ifdef TOOLS_ENABLED

		p_script->member_lines[func_name]=p_func->line;
#endif
	} else {
		gdfunc->_initial_line=0;
	}

	if (codegen.debug_stack)
		gdfunc->stack_debug=codegen.stack_debug;

	if (is_initializer)
		p_script->initializer=gdfunc;


	return OK;
}



Error GDCompiler::_parse_class(GDScript *p_script, GDScript *p_owner, const GDParser::ClassNode *p_class, bool p_keep_state) {

	Map<StringName,Ref<GDScript> > old_subclasses;

	if (p_keep_state) {
		old_subclasses=p_script->subclasses;
	}

	p_script->native=Ref<GDNativeClass>();
	p_script->base=Ref<GDScript>();
	p_script->_base=NULL;
	p_script->members.clear();
	p_script->constants.clear();
	for (Map<StringName,GDFunction*>::Element *E=p_script->member_functions.front();E;E=E->next()) {
		memdelete(E->get());
	}
	p_script->member_functions.clear();
	p_script->member_indices.clear();
	p_script->member_info.clear();
	p_script->_signals.clear();
	p_script->initializer=NULL;

	p_script->subclasses.clear();
	p_script->_owner=p_owner;
	p_script->tool=p_class->tool;
	p_script->name=p_class->name;


	Ref<GDNativeClass> native;

	if (p_class->extends_used) {
		//do inheritance
		String path = p_class->extends_file;

		Ref<GDScript> script;


		if (path!="") {
			//path (and optionally subclasses)

			if (path.is_rel_path()) {

				String base;

				if (p_owner) {
					GDScript *current_class = p_owner;
					while (current_class != NULL) {
						base=current_class->get_path();
						if (base=="")
							current_class = current_class->_owner;
						else
							break;
					}
				}
				else {
					base = p_script->get_path();
				}

				if (base=="" || base.is_rel_path()) {
					_set_error("Could not resolve relative path for parent class: "+path,p_class);
					return ERR_FILE_NOT_FOUND;
				}
				path=base.get_base_dir().plus_file(path).simplify_path();
			}
			script = ResourceLoader::load(path);
			if (script.is_null()) {
				_set_error("Could not load base class: "+path,p_class);
				return ERR_FILE_NOT_FOUND;
			}
			if (!script->valid) {

				_set_error("Script not fully loaded (cyclic preload?): "+path,p_class);
				return ERR_BUSY;
			}
			//print_line("EXTENDS PATH: "+path+" script is "+itos(script.is_valid())+" indices is "+itos(script->member_indices.size())+" valid? "+itos(script->valid));

			if (p_class->extends_class.size()) {

				for(int i=0;i<p_class->extends_class.size();i++) {

					String sub = p_class->extends_class[i];
					if (script->subclasses.has(sub)) {

						Ref<Script> subclass = script->subclasses[sub]; //avoid reference from dissapearing
						script=subclass;
					} else {

						_set_error("Could not find subclass: "+sub,p_class);
						return ERR_FILE_NOT_FOUND;
					}
				}
			}

		} else {

			ERR_FAIL_COND_V(p_class->extends_class.size()==0,ERR_BUG);
			//look around for the subclasses

			String base=p_class->extends_class[0];
			GDScript *p = p_owner;
			Ref<GDScript> base_class;

			while(p) {

				if (p->subclasses.has(base)) {

					base_class=p->subclasses[base];
					break;
				}
				p=p->_owner;
			}

			if (base_class.is_valid()) {

				for(int i=1;i<p_class->extends_class.size();i++) {

					String subclass=p_class->extends_class[i];

					if (base_class->subclasses.has(subclass)) {

						base_class=base_class->subclasses[subclass];
					} else {

						_set_error("Could not find subclass: "+subclass,p_class);
						return ERR_FILE_NOT_FOUND;
					}
				}

				script=base_class;


			} else {

				if (p_class->extends_class.size()>1) {

					_set_error("Invalid inheritance (unknown class+subclasses)",p_class);
					return ERR_FILE_NOT_FOUND;

				}
				//if not found, try engine classes
				if (!GDScriptLanguage::get_singleton()->get_global_map().has(base)) {

					_set_error("Unknown class: '"+base+"'",p_class);
					return ERR_FILE_NOT_FOUND;
				}

				int base_idx = GDScriptLanguage::get_singleton()->get_global_map()[base];
				native = GDScriptLanguage::get_singleton()->get_global_array()[base_idx];
				if (!native.is_valid()) {

					_set_error("Global not a class: '"+base+"'",p_class);

					return ERR_FILE_NOT_FOUND;
				}
			}


		}

		if (script.is_valid()) {

			p_script->base=script;
			p_script->_base=p_script->base.ptr();
			p_script->member_indices=script->member_indices;

		} else if (native.is_valid()) {

			p_script->native=native;
		} else {

			_set_error("Could not determine inheritance",p_class);
			return ERR_FILE_NOT_FOUND;
		}


	}


	//print_line("Script: "+p_script->get_path()+" indices: "+itos(p_script->member_indices.size()));


	for(int i=0;i<p_class->variables.size();i++) {

		StringName name = p_class->variables[i].identifier;
		if (p_script->member_indices.has(name)) {
			_set_error("Member '"+name+"' already exists (in current or parent class)",p_class);
			return ERR_ALREADY_EXISTS;
		}

		if (p_class->variables[i]._export.type!=Variant::NIL) {

			p_script->member_info[name]=p_class->variables[i]._export;
#ifdef TOOLS_ENABLED
			if (p_class->variables[i].default_value.get_type()!=Variant::NIL) {

				p_script->member_default_values[name]=p_class->variables[i].default_value;
			}
#endif
		} else {

			p_script->member_info[name]=PropertyInfo(Variant::NIL,name,PROPERTY_HINT_NONE,"",PROPERTY_USAGE_SCRIPT_VARIABLE);
		}

		//int new_idx = p_script->member_indices.size();
		GDScript::MemberInfo minfo;
		minfo.index = p_script->member_indices.size();
		minfo.setter = p_class->variables[i].setter;
		minfo.getter = p_class->variables[i].getter;
		minfo.rpc_mode=p_class->variables[i].rpc_mode;

		p_script->member_indices[name]=minfo;
		p_script->members.insert(name);

#ifdef TOOLS_ENABLED

		p_script->member_lines[name]=p_class->variables[i].line;
#endif


	}

	for(int i=0;i<p_class->constant_expressions.size();i++) {

		StringName name = p_class->constant_expressions[i].identifier;
		ERR_CONTINUE( p_class->constant_expressions[i].expression->type!=GDParser::Node::TYPE_CONSTANT );

		GDParser::ConstantNode *constant = static_cast<GDParser::ConstantNode*>(p_class->constant_expressions[i].expression);

		p_script->constants.insert(name,constant->value);
		//p_script->constants[constant->value].make_const();
#ifdef TOOLS_ENABLED

		p_script->member_lines[name]=p_class->constant_expressions[i].expression->line;
#endif

	}

	for(int i=0;i<p_class->_signals.size();i++) {

		StringName name = p_class->_signals[i].name;

		GDScript *c = p_script;

		while(c) {

			if (c->_signals.has(name)) {
				_set_error("Signal '"+name+"' redefined (in current or parent class)",p_class);
				return ERR_ALREADY_EXISTS;
			}

			if (c->base.is_valid()) {
				c=c->base.ptr();
			} else {
				c=NULL;
			}
		}

		if (native.is_valid()) {
			if (ObjectTypeDB::has_signal(native->get_name(),name)) {
				_set_error("Signal '"+name+"' redefined (original in native class '"+String(native->get_name())+"')",p_class);
				return ERR_ALREADY_EXISTS;
			}
		}

		p_script->_signals[name]=p_class->_signals[i].arguments;
	}
	//parse sub-classes

	for(int i=0;i<p_class->subclasses.size();i++) {
		StringName name = p_class->subclasses[i]->name;

		Ref<GDScript> subclass;

		if (old_subclasses.has(name)) {
			subclass=old_subclasses[name];
		} else {
			subclass.instance();
		}

		Error err = _parse_class(subclass.ptr(),p_script,p_class->subclasses[i],p_keep_state);
		if (err)
			return err;

#ifdef TOOLS_ENABLED

		p_script->member_lines[name]=p_class->subclasses[i]->line;
#endif

		p_script->constants.insert(name,subclass); //once parsed, goes to the list of constants
		p_script->subclasses.insert(name,subclass);

	}


	//parse methods

	bool has_initializer=false;
	bool has_ready=false;

	for(int i=0;i<p_class->functions.size();i++) {

		if (!has_initializer && p_class->functions[i]->name=="_init")
			has_initializer=true;
		if (!has_ready && p_class->functions[i]->name=="_ready")
			has_ready=true;
		Error err = _parse_function(p_script,p_class,p_class->functions[i]);
		if (err)
			return err;
	}

	//parse static methods

	for(int i=0;i<p_class->static_functions.size();i++) {

		Error err = _parse_function(p_script,p_class,p_class->static_functions[i]);
		if (err)
			return err;
	}


	if (!has_initializer) {
		//create a constructor
		Error err = _parse_function(p_script,p_class,NULL);
		if (err)
			return err;
	}

	if (!has_ready && p_class->ready->statements.size()) {
		//create a constructor
		Error err = _parse_function(p_script,p_class,NULL,true);
		if (err)
			return err;
	}

#ifdef DEBUG_ENABLED
	//validate setters/getters if debug is enabled
	for(int i=0;i<p_class->variables.size();i++) {

		if (p_class->variables[i].setter) {
			const Map<StringName,GDFunction*>::Element *E=p_script->get_member_functions().find(p_class->variables[i].setter);
			if (!E) {
				_set_error("Setter function '"+String(p_class->variables[i].setter)+"' not found in class.",NULL);
				err_line=p_class->variables[i].line;
				err_column=0;
				return ERR_PARSE_ERROR;
			}

			if (E->get()->is_static()) {

				_set_error("Setter function '"+String(p_class->variables[i].setter)+"' is static.",NULL);
				err_line=p_class->variables[i].line;
				err_column=0;
				return ERR_PARSE_ERROR;
			}

		}
		if (p_class->variables[i].getter) {
			const Map<StringName,GDFunction*>::Element *E=p_script->get_member_functions().find(p_class->variables[i].getter);
			if (!E) {
				_set_error("Getter function '"+String(p_class->variables[i].getter)+"' not found in class.",NULL);
				err_line=p_class->variables[i].line;
				err_column=0;
				return ERR_PARSE_ERROR;
			}

			if (E->get()->is_static()) {

				_set_error("Getter function '"+String(p_class->variables[i].getter)+"' is static.",NULL);
				err_line=p_class->variables[i].line;
				err_column=0;
				return ERR_PARSE_ERROR;
			}

		}
	}

	//validate instances if keeping state

	if (p_keep_state) {

		print_line("RELOAD KEEP "+p_script->path);
		for (Set<Object*>::Element *E=p_script->instances.front();E;) {

			Set<Object*>::Element *N = E->next();

			ScriptInstance *si = E->get()->get_script_instance();
			if (si->is_placeholder()) {
#ifdef TOOLS_ENABLED
				PlaceHolderScriptInstance *psi = static_cast<PlaceHolderScriptInstance*>(si);

				if (p_script->is_tool()) {
					//re-create as an instance
					p_script->placeholders.erase(psi); //remove placeholder

					GDInstance* instance = memnew( GDInstance );
					instance->base_ref=E->get()->cast_to<Reference>();
					instance->members.resize(p_script->member_indices.size());
					instance->script=Ref<GDScript>(p_script);
					instance->owner=E->get();

					//needed for hot reloading
					for(Map<StringName,GDScript::MemberInfo>::Element *E=p_script->member_indices.front();E;E=E->next()) {
						instance->member_indices_cache[E->key()]=E->get().index;
					}
					instance->owner->set_script_instance(instance);


					/* STEP 2, INITIALIZE AND CONSRTUCT */

					Variant::CallError ce;
					p_script->initializer->call(instance,NULL,0,ce);

					if (ce.error!=Variant::CallError::CALL_OK) {
						//well, tough luck, not goinna do anything here
					}
				}
#endif
			} else {

				GDInstance *gi = static_cast<GDInstance*>(si);
				gi->reload_members();
			}

			E=N;

		}


	}
#endif

	p_script->valid=true;
	return OK;
}

Error GDCompiler::compile(const GDParser *p_parser,GDScript *p_script,bool p_keep_state) {

	err_line=-1;
	err_column=-1;
	error="";
	parser=p_parser;
	const GDParser::Node* root = parser->get_parse_tree();
	ERR_FAIL_COND_V(root->type!=GDParser::Node::TYPE_CLASS,ERR_INVALID_DATA);

	source=p_script->get_path();

	Error err = _parse_class(p_script,NULL,static_cast<const GDParser::ClassNode*>(root),p_keep_state);

	if (err)
		return err;

	return OK;

}

String GDCompiler::get_error() const {

	return error;
}
int GDCompiler::get_error_line() const{

	return err_line;
}
int GDCompiler::get_error_column() const{

	return err_column;
}

GDCompiler::GDCompiler()
{
}