/*	$OpenBSD: main.c,v 1.18 1999/11/17 15:34:13 espie Exp $	*/
/*	$NetBSD: main.c,v 1.12 1997/02/08 23:54:49 cgd Exp $	*/

/*-
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit at York University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)main.c	8.1 (Berkeley) 6/6/93";
#else
static char rcsid[] = "$OpenBSD: main.c,v 1.18 1999/11/17 15:34:13 espie Exp $";
#endif
#endif /* not lint */

/*
 * main.c
 * Facility: m4 macro processor
 * by: oz
 */

#include <sys/types.h>
#include <signal.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stddef.h>
#include <err.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
#include "pathnames.h"

ndptr hashtab[HASHSIZE];	/* hash table for macros etc.  */
stae mstack[STACKMAX+1]; 	/* stack of m4 machine         */
int sp; 			/* current m4  stack pointer   */
int fp; 			/* m4 call frame pointer       */
FILE *infile[MAXINP];		/* input file stack (0=stdin)  */
FILE *outfile[MAXOUT];		/* diversion array(0=bitbucket)*/
FILE *active;			/* active output file pointer  */
int ilevel = 0; 		/* input file stack pointer    */
int oindex = 0; 		/* diversion index..	       */
char *null = "";                /* as it says.. just a null..  */
char *m4wraps = "";             /* m4wrap string default..     */
char lquote[MAXCCHARS+1] = {LQUOTE};	/* left quote character  (`)   */
char rquote[MAXCCHARS+1] = {RQUOTE};	/* right quote character (')   */
char scommt[MAXCCHARS+1] = {SCOMMT};	/* start character for comment */
char ecommt[MAXCCHARS+1] = {ECOMMT};	/* end character for comment   */

struct keyblk keywrds[] = {	/* m4 keywords to be installed */
	{ "include",      INCLTYPE },
	{ "sinclude",     SINCTYPE },
	{ "define",       DEFITYPE },
	{ "defn",         DEFNTYPE },
	{ "divert",       DIVRTYPE },
	{ "expr",         EXPRTYPE },
	{ "eval",         EXPRTYPE },
	{ "substr",       SUBSTYPE },
	{ "ifelse",       IFELTYPE },
	{ "ifdef",        IFDFTYPE },
	{ "len",          LENGTYPE },
	{ "incr",         INCRTYPE },
	{ "decr",         DECRTYPE },
	{ "dnl",          DNLNTYPE },
	{ "changequote",  CHNQTYPE },
	{ "changecom",    CHNCTYPE },
	{ "index",        INDXTYPE },
#ifdef EXTENDED
	{ "paste",        PASTTYPE },
	{ "spaste",       SPASTYPE },
#endif
	{ "popdef",       POPDTYPE },
	{ "pushdef",      PUSDTYPE },
	{ "dumpdef",      DUMPTYPE },
	{ "shift",        SHIFTYPE },
	{ "translit",     TRNLTYPE },
	{ "undefine",     UNDFTYPE },
	{ "undivert",     UNDVTYPE },
	{ "divnum",       DIVNTYPE },
	{ "maketemp",     MKTMTYPE },
	{ "errprint",     ERRPTYPE },
	{ "m4wrap",       M4WRTYPE },
	{ "m4exit",       EXITTYPE },
	{ "syscmd",       SYSCTYPE },
	{ "sysval",       SYSVTYPE },

#if defined(unix) || defined(__NetBSD__) || defined(__OpenBSD__)
	{ "unix",         MACRTYPE },
#else
#ifdef vms
	{ "vms",          MACRTYPE },
#endif
#endif
};

#define MAXKEYS	(sizeof(keywrds)/sizeof(struct keyblk))

extern int optind;
extern char *optarg;

static void macro __P((void));
static void initkwds __P((void));
static ndptr inspect __P((char *));
static int do_look_ahead __P((int, const char *));

int main __P((int, char *[]));

int
main(argc,argv)
	int argc;
	char *argv[];
{
	int c;
	int n;
	char *p;
	FILE *ifp;

	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
		signal(SIGINT, onintr);

	initkwds();
	initspaces();

	while ((c = getopt(argc, argv, "tD:U:o:I:")) != -1)
		switch(c) {

		case 'D':               /* define something..*/
			for (p = optarg; *p; p++)
				if (*p == '=')
					break;
			if (*p)
				*p++ = EOS;
			dodefine(optarg, p);
			break;
		case 'I':
			addtoincludepath(optarg);
			break;
		case 'U':               /* undefine...       */
			remhash(optarg, TOP);
			break;
		case 'o':		/* specific output   */
		case '?':
			usage();
		}

        argc -= optind;
        argv += optind;

	active = stdout;		/* default active output     */
	bbase[0] = bufbase;
        if (!argc) {
 		sp = -1;		/* stack pointer initialized */
		fp = 0; 		/* frame pointer initialized */
		infile[0] = stdin;	/* default input (naturally) */
		macro();
	} else
		for (; argc--; ++argv) {
			p = *argv;
			if (p[0] == '-' && p[1] == EOS)
				ifp = stdin;
			else if ((ifp = fopen_trypath(p)) == NULL)
				err(1, "%s", p);
			sp = -1;
			fp = 0; 
			infile[0] = ifp;
			macro();
			if (ifp != stdin)
				(void)fclose(ifp);
		}

	if (*m4wraps) { 		/* anything for rundown ??   */
		ilevel = 0;		/* in case m4wrap includes.. */
		bufbase = bp = buf;	/* use the entire buffer   */
		putback(EOF);		/* eof is a must !!	     */
		pbstr(m4wraps); 	/* user-defined wrapup act   */
		macro();		/* last will and testament   */
	}

	if (active != stdout)
		active = stdout;	/* reset output just in case */
	for (n = 1; n < MAXOUT; n++)	/* default wrap-up: undivert */
		if (outfile[n] != NULL)
			getdiv(n);
					/* remove bitbucket if used  */
	if (outfile[0] != NULL) {
		(void) fclose(outfile[0]);
	}

	return 0;
}

/*
 * Look ahead (at most MAXCCHARS characters) for `token'.
 * (on input `t == token[0]')
 * Used for comment and quoting delimiters.
 * Returns 1 if `token' present; copied to output.
 *         0 if `token' not found; all characters pushed back
 */
static int
do_look_ahead(t, token)
	int	t;
	const char	*token;
{
	int i;

	if (t != token[0])
		errx(1, "internal error");

	for (i = 1; *++token; i++) {
		t = gpbc();
		if (t == EOF || t != *token) {
			if (t != EOF)
				putback(t);
			while (--i)
				putback(*--token);
			return 0;
		}
	}
	return 1;
}

#define LOOK_AHEAD(t, token) ((t)==(token)[0] && do_look_ahead(t,token))

/*
 * macro - the work horse..
 */
static void
macro()
{
	char token[MAXTOK], chars[2];
	char *s;
	int t, l;
	ndptr p;
	int  nlpar;

	cycle {
		t = gpbc();
		if (t == '_' || isalpha(t)) {
			putback(t);
			s = token;
			if ((p = inspect(s)) == nil) {
				if (sp < 0)
					while (*s)
						putc(*s++, active);
				else
					while (*s)
						chrsave(*s++);
			}
			else {
		/*
		 * real thing.. First build a call frame:
		 */
				pushf(fp);	/* previous call frm */
				pushf(p->type); /* type of the call  */
				pushf(0);	/* parenthesis level */
				fp = sp;	/* new frame pointer */
		/*
		 * now push the string arguments:
		 */
				pushs(p->defn);	      /* defn string */
				pushs(p->name);	      /* macro name  */
				pushs(ep);	      /* start next..*/

				putback(l = gpbc());
				if (l != LPAREN)  {   /* add bracks  */
					putback(RPAREN);
					putback(LPAREN);
				}
			}
		}
		else if (t == EOF) {
			if (sp > -1)
				errx(1, "unexpected end of input");
			if (ilevel <= 0)
				break;			/* all done thanks.. */
			--ilevel;
			(void) fclose(infile[ilevel+1]);
			bufbase = bbase[ilevel];
			continue;
		}
	/*
	 * non-alpha token possibly seen..
	 * [the order of else if .. stmts is important.]
	 */
		else if (LOOK_AHEAD(t,lquote)) {	/* strip quotes */
			nlpar = 1;
			do {

				l = gpbc();
				if (LOOK_AHEAD(l,rquote)) {
					nlpar--;
					s = rquote;
				} else if (LOOK_AHEAD(l,lquote)) {
					nlpar++;
					s = lquote;
				} else if (l == EOF) {
					if (nlpar == 1)
						errx(1, "missing right quote.");
					else
						errx(1, "missing %d right quotes.", nlpar);
				} else {
					chars[0] = l;
					chars[1] = EOS;
					s = chars;
				}
				if (nlpar > 0) {
					if (sp < 0)
						while (*s)
							putc(*s++, active);
					else
						while (*s)
							chrsave(*s++);
				}
			}
			while (nlpar != 0);
		}

		else if (sp < 0 && LOOK_AHEAD(t, scommt)) {
			int i;
			for (i = 0; i < MAXCCHARS && scommt[i]; i++)
				putc(scommt[i], active);

			for(;;) {
				t = gpbc();
				if (LOOK_AHEAD(t, ecommt)) {
					for (i = 0; i < MAXCCHARS && ecommt[i];
					     i++)
						putc(ecommt[i], active);
					break;
				}
				if (t == EOF)
					break;
				putc(t, active);
			}
		}

		else if (sp < 0) {		/* not in a macro at all */
			putc(t, active);	/* output directly..	 */
		}

		else switch(t) {

		case LPAREN:
			if (PARLEV > 0)
				chrsave(t);
			while (isspace(l = gpbc()))
				;		/* skip blank, tab, nl.. */
			putback(l);
			PARLEV++;
			break;

		case RPAREN:
			if (--PARLEV > 0)
				chrsave(t);
			else {			/* end of argument list */
				chrsave(EOS);

				if (sp == STACKMAX)
					errx(1, "internal stack overflow");

				if (CALTYP == MACRTYPE)
					expand((const char **) mstack+fp+1, sp-fp);
				else
					eval((const char **) mstack+fp+1, sp-fp, CALTYP);

				ep = PREVEP;	/* flush strspace */
				sp = PREVSP;	/* previous sp..  */
				fp = PREVFP;	/* rewind stack...*/
			}
			break;

		case COMMA:
			if (PARLEV == 1) {
				chrsave(EOS);		/* new argument   */
				while (isspace(l = gpbc()))
					;
				putback(l);
				pushs(ep);
			} else
				chrsave(t);
			break;

		default:
			chrsave(t);			/* stack the char */
			break;
		}
	}
}

/*
 * build an input token..
 * consider only those starting with _ or A-Za-z. This is a
 * combo with lookup to speed things up.
 */
static ndptr
inspect(tp) 
	char *tp;
{
	char c;
	char *name = tp;
	char *etp = tp+MAXTOK;
	ndptr p;
	unsigned long h = 0;

	while ((isalnum(c = gpbc()) || c == '_') && tp < etp)
		h = (h << 5) + h + (*tp++ = c);
	putback(c);
	if (tp == etp)
		errx(1, "token too long");

	*tp = EOS;

	for (p = hashtab[h%HASHSIZE]; p != nil; p = p->nxtptr)
		if (STREQ(name, p->name))
			break;
	return p;
}

/*
 * initkwds - initialise m4 keywords as fast as possible. 
 * This very similar to install, but without certain overheads,
 * such as calling lookup. Malloc is not used for storing the 
 * keyword strings, since we simply use the static pointers
 * within keywrds block.
 */
static void
initkwds()
{
	size_t i;
	int h;
	ndptr p;

	for (i = 0; i < MAXKEYS; i++) {
		h = hash(keywrds[i].knam);
		p = (ndptr) xalloc(sizeof(struct ndblock));
		p->nxtptr = hashtab[h];
		hashtab[h] = p;
		p->name = keywrds[i].knam;
		p->defn = null;
		p->type = keywrds[i].ktyp | STATIC;
	}
}