%{
/*      $OpenBSD: scan.l,v 1.23 2009/10/27 23:59:36 deraadt Exp $	*/

/*
 * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <err.h>
#include <errno.h>
#include <histedit.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"
#include "bc.h"
#include "pathnames.h"

int		 lineno;

bool		 interactive;
HistEvent	 he;
EditLine	*el;
History		*hist;

static char	*strbuf = NULL;
static size_t	 strbuf_sz = 1;
static bool	 dot_seen;

static void	 init_strbuf(void);
static void	 add_str(const char *);
static int	 bc_yyinput(char *, int);

#define YY_NO_INPUT
#undef YY_INPUT
#define YY_INPUT(buf,retval,max) \
	(retval = bc_yyinput(buf, max))
%}

%option always-interactive

DIGIT		[0-9A-F]
ALPHA		[a-z_]
ALPHANUM	[a-z_0-9]

%x		comment string number

%%

"/*"		BEGIN(comment);
<comment>{
	"*/"	BEGIN(INITIAL);
	\n	lineno++;
	\*	;
	[^*\n]+	;
	<<EOF>>	fatal("end of file in comment");
}

\"		BEGIN(string); init_strbuf();
<string>{
	[^"\n\\\[\]]+	add_str(yytext);
	\[	add_str("\\[");
	\]	add_str("\\]");
	\\	add_str("\\\\");
	\n	add_str("\n"); lineno++;
	\"	BEGIN(INITIAL); yylval.str = strbuf; return STRING;
	<<EOF>>	fatal("end of file in string");
}

{DIGIT}+	{
			BEGIN(number);
			dot_seen = false;
			init_strbuf();
			add_str(yytext);
		}
\.		{
			BEGIN(number);
			dot_seen = true;
			init_strbuf();
			add_str(".");
		}
<number>{
	{DIGIT}+	add_str(yytext);
	\.	{
			if (dot_seen) {
				BEGIN(INITIAL);
				yylval.str = strbuf;
				unput('.');
				return (NUMBER);
			} else {
				dot_seen = true;
				add_str(".");
			}
		}
	\\\n[ \t]*	lineno++;
	[^0-9A-F\.]	{
			BEGIN(INITIAL);
			unput(yytext[0]);
			if (strcmp(strbuf, ".") == 0)
				return (DOT);
			else {
				yylval.str = strbuf;
				return (NUMBER);
			}
		}
}

"auto"		return (AUTO);
"break"		return (BREAK);
"continue"	return (CONTINUE);
"define"	return (DEFINE);
"else"		return (ELSE);
"ibase"		return (IBASE);
"if"		return (IF);
"last"		return (DOT);
"for"		return (FOR);
"length"	return (LENGTH);
"obase"		return (OBASE);
"print"		return (PRINT);
"quit"		return (QUIT);
"return"	return (RETURN);
"scale"		return (SCALE);
"sqrt"		return (SQRT);
"while"		return (WHILE);

"^"		return (EXPONENT);
"*"		return (MULTIPLY);
"/"		return (DIVIDE);
"%"		return (REMAINDER);

"!"		return (BOOL_NOT);
"&&"		return (BOOL_AND);
"||"		return (BOOL_OR);

"+"		return (PLUS);
"-"		return (MINUS);

"++"		return (INCR);
"--"		return (DECR);

"="		yylval.str = ""; return (ASSIGN_OP);
"+="		yylval.str = "+"; return (ASSIGN_OP);
"-="		yylval.str = "-"; return (ASSIGN_OP);
"*="		yylval.str = "*"; return (ASSIGN_OP);
"/="		yylval.str = "/"; return (ASSIGN_OP);
"%="		yylval.str = "%"; return (ASSIGN_OP);
"^="		yylval.str = "^"; return (ASSIGN_OP);

"=="		return (EQUALS);
"<="		return (LESS_EQ);
">="		return (GREATER_EQ);
"!="		return (UNEQUALS);
"<"		return (LESS);
">"		return (GREATER);

","		return (COMMA);
";"		return (SEMICOLON);

"("		return (LPAR);
")"		return (RPAR);

"["		return (LBRACKET);
"]"		return (RBRACKET);

"{"		return (LBRACE);
"}"		return (RBRACE);

{ALPHA}{ALPHANUM}* {
			/* alloc an extra byte for the type marker */
			char *p = malloc(yyleng + 2);
			if (p == NULL)
				err(1, NULL);
			strlcpy(p, yytext, yyleng + 1);
			yylval.astr = p;
			return (LETTER);
		}

\\\n		lineno++;
\n		lineno++; return (NEWLINE);

#[^\n]*		;
[ \t]		;
<<EOF>>		return (QUIT);
.		yyerror("illegal character");

%%

static void
init_strbuf(void)
{

	if (strbuf == NULL) {
		strbuf = malloc(strbuf_sz);
		if (strbuf == NULL)
			err(1, NULL);
	}
	strbuf[0] = '\0';
}

static void
add_str(const char *str)
{
	size_t arglen;

	arglen = strlen(str);

	if (strlen(strbuf) + arglen + 1 > strbuf_sz) {
		size_t	 newsize;
		char	*p;

		newsize = strbuf_sz + arglen + 1;
		p = realloc(strbuf, newsize);
		if (p == NULL) {
			free(strbuf);
			err(1, NULL);
		}
		strbuf_sz = newsize;
		strbuf = p;
	}
	strlcat(strbuf, str, strbuf_sz);
}

int
yywrap(void)
{
	static YY_BUFFER_STATE buf;
	static int state;

	if (fileindex == 0 && sargc > 0 && strcmp(sargv[0], _PATH_LIBB) == 0) {
		filename = sargv[fileindex++];
		yyin = fopen(filename, "r");
		lineno = 1;
		if (yyin == NULL)
			err(1, "cannot open %s", filename);
		return (0);
	}
	if (state == 0 && cmdexpr[0] != '\0') {
		buf = yy_scan_string(cmdexpr);
		state++;
		lineno = 1;
		filename = "command line";
		return (0);
	} else if (state == 1) {
		yy_delete_buffer(buf);
		free(cmdexpr);
		state++;
	}
	if (yyin != NULL && yyin != stdin)
		fclose(yyin);
	if (fileindex < sargc) {
		filename = sargv[fileindex++];
		yyin = fopen(filename, "r");
		lineno = 1;
		if (yyin == NULL)
			err(1, "cannot open %s", filename);
		return (0);
	} else if (fileindex == sargc) {
		fileindex++;
		yyin = stdin;
		lineno = 1;
		filename = "stdin";
		return (0);
	}
	return (1);
}

static int
bc_yyinput(char *buf, int maxlen)
{
	int num;
	if (yyin == stdin && interactive) {
		const char *bp;

		if ((bp = el_gets(el, &num)) == NULL || num == 0)
			return (0);
		if (num > maxlen) {
			el_push(el, (char *)(uintptr_t)(bp) + maxlen);
			num = maxlen;
		}
		memcpy(buf, bp, num);
		history(hist, &he, H_ENTER, bp);
	} else {
		int c = '*';
		for (num = 0; num < maxlen &&
		    (c = getc(yyin)) != EOF && c != '\n'; ++num)
			buf[num] = (char) c;
		if (c == '\n')
			buf[num++] = (char) c;
		if (c == EOF && ferror(yyin))
			YY_FATAL_ERROR( "input in flex scanner failed" );
	}
	return (num);
}