%{
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include "symbol_table.h"
%}

%start		Input
%token		FUNC END STRUCT VAR IF THEN ELSE WHILE DO RETURN OR NOT
%token		ID NUM ASSIGN GREATER

@autoinh symbols

@attributes	{ char *name; } ID
@attributes	{ struct symbol_t *fields; struct symbol_t *symbols; } Program
@attributes	{ struct symbol_t *fields; } Ids Structdef
@attributes	{ struct symbol_t *pars; } Pars
@attributes	{ struct symbol_t *symbols; } Funcdef Stats Bool Expr Call Lexpr Field Term Plusterm Malterm Bterm Orterm Exprs
@attributes	{ struct symbol_t *in_symbols; struct symbol_t *out_symbols; } Stat

@traversal @postorder t

%%

Input:		  Program
     		@{ @i @Program.symbols@ = @Program.fields@; @}

		;

Program:	  Funcdef ';' Program
		@{
		   @i @Program.fields@ = @Program.1.fields@;
		@}

		| Structdef ';' Program
		@{
		   @i @Program.fields@ = table_merge(@Structdef.fields@, @Program.1.fields@, 1);
		   @i @Program.1.symbols@ = @Program.0.symbols@;
		@}

		|
		@{ @i @Program.fields@ = new_table(); @}

		;
 
Funcdef:	  FUNC ID '(' Pars ')' Stats END
       		@{ @i @Stats.symbols@ = table_merge(@Funcdef.symbols@, @Pars.pars@, 0); @}

		|
		  FUNC ID '(' ')' Stats END
       		@{ @i @Stats.symbols@ = table_merge(@Funcdef.symbols@, new_table(), 0); @}

		;  
 
Structdef: 	  STRUCT Ids END
	 	@{ @i @Structdef.fields@ = @Ids.fields@; @}

		;  

Ids:		  ID Ids
		@{ @i @Ids.fields@ = table_add_symbol(@Ids.1.fields@, @ID.name@, SYMBOL_TYPE_FIELD, 1); @}

		|
		@{ @i @Ids.fields@ = new_table(); @}

		;

Pars: 		  Pars ',' ID
		@{ @i @Pars.pars@ = table_add_symbol(@Pars.1.pars@, @ID.name@, SYMBOL_TYPE_VAR, 0); @}

  		| ID
		@{ @i @Pars.pars@ = table_add_symbol(new_table(), @ID.name@, SYMBOL_TYPE_VAR, 0); @}

		; 
 
Stats:		  Stat ';' Stats
     		@{
		   @i @Stat.in_symbols@ = @Stats.symbols@;
		   @i @Stats.1.symbols@ = @Stat.out_symbols@;
		@}

		|
		;  
 
Stat:		  VAR ID ASSIGN Expr
    		@{
		   @i @Stat.out_symbols@ = table_add_symbol(clone_table(@Stat.in_symbols@), @ID.name@, SYMBOL_TYPE_VAR, 0);
		   @i @Expr.symbols@ = @Stat.in_symbols@;
		@}

		| Lexpr ASSIGN Expr
		@{
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		   @i @Lexpr.symbols@ = @Stat.in_symbols@;
		   @i @Expr.symbols@ = @Stat.in_symbols@;
		@}

		| IF Bool THEN Stats END
		@{
		   @i @Bool.symbols@ = @Stat.in_symbols@;
		   @i @Stats.symbols@ = @Stat.in_symbols@;
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		@}

		| IF Bool THEN Stats ELSE Stats END
		@{
		   @i @Bool.symbols@ = @Stat.in_symbols@;
		   @i @Stats.symbols@ = @Stat.in_symbols@;
		   @i @Stats.1.symbols@ = @Stat.in_symbols@;
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		@}

		| WHILE Bool DO Stats END
		@{
		   @i @Bool.symbols@ = @Stat.in_symbols@;
		   @i @Stats.symbols@ = @Stat.in_symbols@;
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		@}

		| Call
		@{
		   @i @Call.symbols@ = @Stat.in_symbols@;
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		@}

		| RETURN Expr
		@{
		   @i @Expr.symbols@ = @Stat.in_symbols@;
		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
		@}

		;
 
Lexpr:		  ID
		@{ @t check_variable(@Lexpr.symbols@, @ID.name@); @}

		| Field
		;
 
Expr: 		  '-' Term
    		| Term
		| Term Plusterm
		| Term Malterm
		;

Plusterm:	  '+' Term Plusterm
		| '+' Term
		;

Malterm:	  '*' Term Malterm
       		| '*' Term
		;
 
Term:		  '(' Expr ')'
    		| ID
		@{ @t check_variable(@Term.symbols@, @ID.name@); @}

		| NUM
		| Call
		| Field
		;

Bool:		  Bterm
		| Bterm Orterm
		| NOT Bterm
		;

Orterm:		  OR Bterm Orterm
      		| OR Bterm
		;

Bterm:		  Term GREATER Term
     		| Term '=' Term
		| '(' Bool ')'
		;

Field:		  Term '.' ID
		@{ @t check_field(@Field.symbols@, @ID.name@); @}

     		;

Call:		  ID '(' Exprs ')'
		| ID '(' ')'
    		;

Exprs:		  Expr
		| Exprs ',' Expr
		;

%%

extern int yylex();
extern int yylineno;

int yyerror(char *error_text) {
	fprintf(stderr,"Line %i: %s\n",yylineno, error_text);
	exit(2);
}

int main(int argc, char **argv) {
	yyparse();
	return 0;
}