%{
/* 
 * lang.y - BOOM grammar
 *
 *  Copyright 2012 by Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <stdlib.h>
#include <assert.h>

#include "util.h"
#include "param.h"
#include "chr.h"
#include "db.h"
#include "lang.h"

#include "y.tab.h"


static const struct field *hierarchy;

static struct field_stack {
	const struct field *field;
	struct field_stack *next;
} *field_stack = NULL;


static void push_field(const struct field *field)
{
	struct field_stack *entry;

	entry = alloc_type(struct field_stack);
	entry->field = field;
	entry->next = field_stack;
	field_stack = entry;
}


static void pop_field(void)
{
	struct field_stack *entry;

	assert(field_stack);
	entry = field_stack;
	field_stack = entry->next;
	free(entry);
}


static const struct field *top_field(void)
{
	return field_stack ? field_stack->field : NULL;
}


%}


%union {
	const char *s;
	struct equiv *equiv;
	struct names *names;
	struct format *format;
	enum relop relop;
	struct field *field;
	struct selector *sel;
	struct condition *cond;
	struct action act;
	struct part *part;
	struct param *param;
};


%token			START_HIERARCHY START_CHAR
%token			TOK_LE TOK_GE TOK_NL
%token	<s>		WORD

%type	<equiv>		nameqs
%type	<names>		names nameq
%type	<format>	format
%type	<relop>		relop opt_relop
%type	<field>		/*rules*/ opt_rule rule opt_fields fields field
%type	<sel>		selectors
%type	<cond>		conditions condition
%type	<act>		opt_wildcard action
%type	<part>		part
%type	<param>		param params

%%

all:
	START_HIERARCHY hierarchy
	| START_CHAR characteristics
	;

hierarchy:
	nameset hierarchy
	| rule
		{
			hierarchy = $1;
			field_dump(stderr, $1);
		}
	;

nameset:
	'<' WORD '>' '=' names ';'
		{
			register_nameset($2, $5);
		}
	;

names:
	nameq
		{
			$$ = $1;
		}
	| nameq '<' names
		{
			$$ = $1;
			$$->next = $3;
		}
	;

nameq:
	nameqs
		{
			$$ = alloc_type(struct names);
			$$->equiv = $1;
			$$->next = NULL;
		}
	;

nameqs:
	WORD
		{
			$$ = alloc_type(struct equiv);
			$$->name = $1;
			$$->next = NULL;
		}
	| WORD '=' nameqs
		{
			$$ = alloc_type(struct equiv);
			$$->name = $1;
			$$->next = $3;
		}
	;

/*
 * @@@ for now, we can't select on a collective of fields. maybe later, with
 * a syntax change.
 *
rules:
		{
			$$ = NULL;
		}
	| rule rules
		{
			$$ = $1;
			$$->next = $2;
		}
	;
*/

opt_rule:
		{
			$$ = NULL;
		}
	| rule
		{
			$$ = $1;
		}
	;

rule:
	field
		{
			$1->prev = top_field();
			push_field($1);
		}
	    '{' selectors opt_wildcard '}'
		{
			$$ = $1;
			$$->sel = $4;
			$$->any = $5;
			$$->next = NULL;
			field_finalize($$);
			pop_field();
		}
	;

selectors:
		{
			$$ = NULL;
		}
	| conditions ':' action selectors
		{
			$$ = new_selector();
			$$->cond = $1;
			$$->act = $3;
			$$->next = $4;
		}
	;

conditions:
	condition
		{
			$$ = $1;
		}
	| condition '|' conditions
		{
			$$ = $1;
			$$->next = $3;
		}
	;

condition:
	opt_relop WORD
		{
			$$ = new_condition($1, $2);
		}
	;

opt_wildcard:
		{
			$$.fields = NULL;
			$$.rules = NULL;
		}
	| '*' ':' action
		{
			$$ = $3;
		}
	;

action:
		{
			push_field(top_field());
		}
	opt_fields opt_rule ';'
		{
			$$.fields = $2;
			$$.rules = $3;
			pop_field();
		}
	;

opt_relop:
		{
			$$ = rel_eq;
		}
	| relop
		{
			$$ = $1;
		}
	;

relop:
	'='
		{
			$$ = rel_eq;
		}
	| '<'
		{
			$$ = rel_le;
		}
	| '>'
		{
			$$ = rel_gt;
		}
	| TOK_LE
		{
			$$ = rel_le;
		}
	| TOK_GE
		{
			$$ = rel_ge;
		}
	;

opt_fields:
		{
			$$ = NULL;
		}
	| '{' fields '}'
		{
			$$ = $2;
		}
	;

fields:
		{
			$$ = NULL;
		}
	| field
		{
			push_field($1);
		}
	    fields
		{
			$$ = $1;
			$$->next = $3;
			pop_field();
			$$->prev = top_field();
			if ($3)
				$3->prev = $1;
		}
	;

field:
	WORD '=' format
		{
			$$ = new_field($1, $3, top_field());
		}
	;

format:
	'*'
		{
			$$ = alloc_type(struct format);
			$$->ops = &param_ops_name;
		}
	| '<' WORD '>'
		{
			$$ = alloc_type(struct format);
			$$->ops = &param_ops_set;
			$$->u.set = find_nameset($2);
			if (!$$->u.set)
				yyerrorf("unknown name set \"%s\"", $2);
		}
	| '#' WORD
		{
			$$ = alloc_type(struct format);
			$$->ops = &param_ops_abs;
			$$->u.abs = $2;
		}
	| '%' WORD
		{
			$$ = alloc_type(struct format);
			$$->ops = &param_ops_rel;
			$$->u.rel = field_find($2, top_field());
			if (!$$->u.rel)
				yyerrorf("unknown field \"%s\"", $2);
		}
	;

characteristics:
	| TOK_NL
	| part characteristics
		{
			part_finalize($1, hierarchy);
		}
	;

part:
	WORD WORD params TOK_NL
		{
			$$ = part_lookup($1, $2);
			if (!$$)
				$$ = part_add($1, $2);
			if ($$->param)
				yyerror("parameters already defined");
			$$->param = $3;
		}
	;

params:
		{
			$$ = NULL;
		}
	| param params
		{
			$$ = $1;
			$$->next = $2;
		}
	;

param:
	WORD '=' WORD
		{
			$$ = alloc_type(struct param);
			$$->u.name = $1;
			$$->value.u.name = $3;
		}
	;