/**

  * $Id$

  *

  * gendec instruction definitions parser

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * 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.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  */

 #include <stdlib.h>

 #include <stdio.h>

 #include <string.h>

 #include <ctype.h>

 #include "tools/gendec.h"

 #define CONSUME_CHAR(x) if( **str != x ) { fprintf( stderr, "Unexpected input character '%c', expected '%c' at line %d\n", **str, x, yyline ); return -1; } else { (*str)++; }

 static int yyline;

 struct rule *new_rule() {

     struct rule *rule = malloc( sizeof( struct rule ) );

     memset( rule, 0, sizeof( struct rule ) );

     return rule;

 }

 int parse_registers_block( char *buf, int buflen, FILE *f );

 int parse_rule( char **str, struct rule *rule );

 int parse_bitstring( char **str, struct rule *rule );

 int parse_bitoperand( char **str, struct rule *rule );

 int parse_integer( char **str );

 int parse_rule_format( char **str, struct rule *rule );

 int parse_operand_uses( char **str, struct rule *rule );

 struct ruleset *parse_ruleset_file( FILE *f ) 

 {

     struct ruleset *rules = malloc( sizeof(struct ruleset ) );

     char buf[512];

     rules->rule_count = 0;

     yyline = 0;

     while( fgets( buf, sizeof(buf), f ) != NULL ) {

 	yyline++;

 	if( strncasecmp(buf, "registers", 9) == 0 ) {

 	    parse_registers_block(buf, sizeof(buf), f);

 	} else if( buf[0] != '\0' && buf[0] != '#' && buf[0] != '\n' ) {

 	    struct rule *rule;

 	    char *p = buf;

 	    rule = new_rule();

 	    if( parse_rule( &p, rule ) != 0 ) {

 		free( rule );

 	    } else {

 		rules->rules[rules->rule_count++] = rule;

 	    }

 	}

     }

     return rules;

 }

 int parse_registers_block( char *buf, int buflen, FILE *f ) {

     do {

 	if( strchr(buf, '}') != NULL ) {

 	    break;

 	}

     } while( fgets( buf, buflen, f ) != NULL );

     return 0;

 }

 /**

  * Parse a single complete rule

  * @return 0 on success, non-zero on failure

  */

 int parse_rule( char **str, struct rule *rule ) 

 {

     if( parse_bitstring( str, rule ) != 0 ) {

 	return -1;

     }

     /* consume whitespace in between */

     while( isspace(**str) ) (*str)++;

     if( **str == '\0' ) {

 	fprintf( stderr, "Unexpected end of file in rule on line %d\n", yyline );

 	return -1;

     }

     int result = parse_rule_format( str, rule );

     if( result == 0 ) {

 	/* Reverse operand bit shifts */

 	int j;

 	for( j=0; j<rule->operand_count; j++ ) {

 	    rule->operands[j].bit_shift = 

 		rule->bit_count - rule->operands[j].bit_shift - rule->operands[j].bit_count;

 	}

 	if( **str == '!' ) {

 	    (*str)++;

 	    result = parse_operand_uses( str, rule );

 	}

     }

     return 0;

 }

 int parse_bitstring( char **str, struct rule *rule )

 {

     while( !isspace(**str) ) {

 	int ch = **str;

 	(*str)++;

 	switch( ch ) {

 	case '0':

 	    rule->bits = rule->bits << 1;

 	    rule->mask = (rule->mask << 1) | 1;

 	    rule->bit_count++;

 	    break;

 	case '1':

 	    rule->bits = (rule->bits << 1) | 1;

 	    rule->mask = (rule->mask << 1) | 1;

 	    rule->bit_count++;

 	    break;

 	case '(':

 	    if( parse_bitoperand( str, rule ) != 0 ) {

 		return -1 ;

 	    }

 	    break;

 	default:

 	    (*str)--;

 	    fprintf( stderr, "Unexpected character '%c' in bitstring at line %d\n", ch, yyline );

 	    return -1;

 	}

     }

     return 0;

 }

 int parse_bitoperand( char **str, struct rule *rule )

 {

     char *p = rule->operands[rule->operand_count].name;

     if( rule->operand_count == MAX_OPERANDS ) {

 	fprintf( stderr, "Maximum operands/rule exceeded (%d) at line %d\n", MAX_OPERANDS, yyline );

 	return -1;

     }

     while( isalnum(**str) || **str == '_' ) {

 	*p++ = *(*str)++;

     }

     *p = '\0';

     CONSUME_CHAR(':');

     int size = parse_integer( str );

     if( size == -1 ) {

 	return -1; 

     }

     rule->operands[rule->operand_count].bit_count = size;

     if( **str == 's' || **str == 'S' ) {

 	(*str)++;

 	rule->operands[rule->operand_count].is_signed = 1;

     } else if( **str == 'u' || **str == 'U' ) {

 	(*str)++;

 	rule->operands[rule->operand_count].is_signed = 0;

     }

     if( **str == '<' ) {

 	(*str)++;

 	CONSUME_CHAR('<');

 	int lsl = parse_integer(str);

 	if( lsl == -1 ) {

 	    return -1;

 	}

 	rule->operands[rule->operand_count].left_shift = lsl;

     }

     CONSUME_CHAR(')');

     rule->operands[rule->operand_count].bit_shift = rule->bit_count;

     rule->bit_count += size;

     rule->bits = rule->bits << size;

     rule->mask = rule->mask << size;

     rule->operand_count++;

     return 0;

 }

 int parse_integer( char **str )

 {

     uint32_t val = 0;

     if( !isdigit(**str) ) {

 	fprintf(stderr, "Expected digit (0-9) but was '%c' at line %d\n", **str, yyline );

 	return -1;

     }

     do {

 	val = val * 10 + (**str - '0');

 	(*str)++;

     } while( isdigit(**str) );

     return val;

 }

 int parse_rule_format( char **str, struct rule *rule )

 {

     char tmp[64];

     char *p = tmp;

     while( **str != '\n' && **str != '\0' && **str != '!' ) {

 	*p++ = *(*str)++;

     }

     *p = '\0';

     strcpy( rule->format, tmp );

     return 0;

 }

 int parse_operand_uses( char **str, struct rule *rule )

 {

     return 0;

 }

 void dump_ruleset( struct ruleset *rules, FILE *f ) 

 {

     int i, j;

     fprintf( f, "Rulset: %d rules\n", rules->rule_count );

     for( i=0; i<rules->rule_count; i++ ) {

 	struct rule *rule = rules->rules[i];

 	fprintf( f, "Match: %08X/%08X %s: ", rule->bits, rule->mask, rule->format );

 	for( j=0; j<rule->operand_count; j++ ) {

 	    fprintf( f, "%s = (%s)(ir>>%d)&0x%X ", rule->operands[j].name,

 		     rule->operands[j].is_signed ? "signed" : "unsigned", 

 		     rule->operands[j].bit_shift,

 		     (1<<rule->operands[j].bit_count)-1 );

 	}

 	fprintf( f, "\n" );

     }

 }

 void dump_rulesubset( struct ruleset *rules, int ruleidx[], int rule_count, FILE *f )

 {

     int i,j;

     for( i=0; i<rule_count; i++ ) {

 	struct rule *rule = rules->rules[ruleidx[i]];

 	fprintf( f, "Match: %08X/%08X %s: ", rule->bits, rule->mask, rule->format );

 	for( j=0; j<rule->operand_count; j++ ) {

 	    fprintf( f, "%s = (%s)(ir>>%d)&0x%X ", rule->operands[j].name,

 		     rule->operands[j].is_signed ? "signed" : "unsigned", 

 		     rule->operands[j].bit_shift,

 		     (1<<rule->operands[j].bit_count)-1 );

 	}

 	fprintf( f, "\n" );

     }

 }