/*
 * Copyright (c) 1988 by Sozobon, Limited.  Author: Joseph M Treat
 *
 * Permission is granted to anyone to use this software for any purpose
 * on any computer system, and to redistribute it freely, with the
 * following restrictions:
 * 1) No charge may be made other than reasonable charges for reproduction.
 * 2) Modified versions must be clearly marked as such.
 * 3) The authors are not responsible for any harmful consequences
 *    of using this software, even if they result from defects in it.
 */

#include "jas.h"
#include "scan.h"
#include "parse.h"

FILE *yyin;
int lastc = 0;
int ateof = 0;
int do_star = 1;

getnext()
{
	static char buf[80];
	static int cnt = 0, size = 0;
	static last = '\n';
	int sawstar = 0;
	extern char *fgets();

	do {
		while ( cnt >= size ) {
			if ( fgets( buf, 80, yyin ) == (char *) NULL ) {
				return EOF;
			}
			size = strlen( buf );
			cnt = 0;
			if ( do_star && last == '\n' ) {
				while ( buf[cnt] &&
						(buf[cnt]==' '||buf[cnt]=='\t'))
					cnt++;
				if ( sawstar || buf[cnt] == '*' ) {
					sawstar = 1;
					while ( buf[cnt] && buf[cnt] != '\n' )
						cnt++;
				}
			}
		}
		if (sawstar || (do_star && buf[cnt]=='\t' && buf[cnt+1]=='*')) {
			sawstar = 1;
			while ( buf[cnt] && buf[cnt] != '\n' )
				cnt++;
		}
	} while ( ! buf[cnt] );
	return last = buf[cnt++];
}

yygetc()
{
	register int c;

	if ( ateof )
		return 0;
	if ( lastc ) {
		c = lastc;
		lastc = 0;
	} else
		c = getnext();
	if ( c && c != EOF ) {
		return c;
	}
	ateof = 1;
	return 0;
}

yyungetc( c )
	int c;
{
	if ( lastc ) {
		char buf[32];
		extern int line;

		sprintf( buf, "%c & %c pushed back!!", lastc, c );
		error( line, buf );
	}
	lastc = c;
}

yylex()
{
	register i;
	int c;
	struct lexacts *lp;
	char buf[256];
	extern YYSTYPE yylval;
	extern int nwords;
	extern struct lexacts actions[];
	extern struct reserved words[];
	extern INST *ifind();
	extern SYM *lookup();

	for ( c = yygetc(); c; c = yygetc() ) {
		lp = &actions[c];
		if ( lp->acts & L_EXTRA ) {
			i = yyprocess( c );
			if ( i == COMMENT )
				continue;
			else if ( i )
				return i;
		}
		if ( lp->acts & L_TOKEN ) {
			return lp->retval;
		}
		if ( lp->acts & L_BEGID ) {
			int tsz;
			char *tbuf;
			extern yywidth;

			for (i = 0; c && (actions[c].acts & L_MIDID); i++) {
				buf[i] = c;
				c = yygetc();
			}
			buf[i] = '\0';
			if ( c )
				yyungetc( c );
			tbuf = STRCPY( buf );
			yymodify( tbuf );
			yywidth = 0;

			tsz = strlen( tbuf );
			if ( tsz >= 2 && tbuf[tsz-2] == '.' ) {
				switch ( tbuf[tsz-1] ) {
				case 'b':
					yywidth = 8;
					buf[tsz-2] = tbuf[tsz-2] = '\0';
					break;
				case 'w':
					yywidth = 16;
					buf[tsz-2] = tbuf[tsz-2] = '\0';
					break;
				case 'l':
					yywidth = 32;
					buf[tsz-2] = tbuf[tsz-2] = '\0';
					break;
				}
			}
			
			{
				register int lo = 0;
				register int hi = nwords-2;
				register int d;
				register struct reserved *rp;

				while ( lo <= hi ) {
					i = (lo + hi) / 2;
					rp = &words[i];
					d = strcmp( tbuf, rp->name );
					if (! strcmp( tbuf, rp->name ) ) {
						yylval.val = rp->value;
						free( tbuf );
						return rp->token;
					} else if ( d < 0 ) {
						hi = i-1;
					} else if ( d > 0 ) {
						lo = i+1;
					} else { /* wrong scope */
						break;
					}
				}
			}
			
			/*
			 * if it's not a reserved word, put the length back
			 */
			if ( yywidth != 0 )
				buf[tsz-2] = tbuf[tsz-2] = '.';

			{
				register STMT *sp;
				register INST *ip;
				short misc;

				ip = ifind( tbuf, &misc );
				if ( ip != (INST *) NULL ) {
					sp = ALLO(STMT);
					sp->inst = ip;
					sp->misc = misc;
					free( tbuf );
					yylval.stmt = sp; 
					return INSTR;
				}
			}

			free( tbuf );

			yylval.sym = lookup( buf );
			return lp->retval;
		}
		if ( lp->acts & L_DIGIT ) {
			extern long getnum();

			for (i = 0; c && (actions[c].acts & L_DIGIT); i++) {
				buf[i] = c;
				c = yygetc();
			}
			buf[i] = '\0';
			if ( c )
				yyungetc( c );
			yylval.val = getnum( buf );
			return lp->retval;
		}
		/* L_SKIP */
	}
	return 0;
}

long
getnum( s )
	register char *s;
{
	register long val;
	register int base;

	switch ( *s ) {
	case '$':
		base = 16;
		s++;
		break;
	case '0':
	case '@':
		base = 8;
		s++;
		break;
	default:
		base = 10;
		break;
	}

	for ( val = 0L; *s; s++ ) {
		if ( *s >= '0' && *s <= '7' ) {
			val = val * base + ( *s - '0' );
		} else if ( *s >= '8' && *s <= '9' ) {
			if ( base == 8 )
				Yerror( "invalid octal constant" );
			val = val * base + ( *s - '0' );
		} else if ( *s >= 'a' && *s <= 'f' ) {
			if ( base == 8 )
				Yerror( "invalid octal constant" );
			if ( base == 10 )
				Yerror( "invalid decimal constant" );
			val = val * base + ( *s - 'a' + 10 );
		} else /* if ( *s >= 'A' && *s <= 'F' ) */ {
			if ( base == 8 )
				Yerror( "invalid octal constant" );
			if ( base == 10 )
				Yerror( "invalid decimal constant" );
			val = val * base + ( *s - 'A' + 10 );
		}

	}
	return val;
}