/*      $OpenBSD: main.c,v 1.80 2011/09/27 07:24:02 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. 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.
 *
 * $FreeBSD: src/usr.bin/m4/main.c,v 1.33 2012/11/17 01:54:24 svnexp Exp $
 */

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

#include <assert.h>
#include <signal.h>
#include <err.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <ohash.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
#include "pathnames.h"

stae *mstack;                   /* stack of m4 machine */
char *sstack;                   /* shadow stack, for string space extension */
static size_t STACKMAX;         /* current maximum size of stack */
int sp;                         /* current m4 stack pointer */
int fp;                         /* m4 call frame pointer */
struct input_file infile[MAXINP];/* input file stack (0=stdin) */
FILE **outfile;                 /* diversion array(0=bitbucket) */
int maxout;
FILE *active;                   /* active output file pointer */
int ilevel = 0;                 /* input file stack pointer */
int oindex = 0;                 /* diversion index.. */
const char *null = "";          /* as it says.. just a null.. */
char **m4wraps = NULL;          /* m4wraps array. */
int maxwraps = 0;               /* size of m4wraps array */
int wrapindex = 0;              /* current offset in m4wraps */
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 */
int synch_lines = 0;            /* line synchronisation for C preprocessor */
int prefix_builtins = 0;        /* -P option to prefix builtin keywords */

struct keyblk {
        const char      *knam;  /* keyword name */
        int             ktyp;   /* keyword type */
};

static struct keyblk keywrds[] = {      /* m4 keywords to be installed */
        { "include",    INCLTYPE },
        { "sinclude",   SINCTYPE },
        { "define",     DEFITYPE },
        { "defn",       DEFNTYPE },
        { "divert",     DIVRTYPE | NOARGS },
        { "expr",       EXPRTYPE },
        { "eval",       EXPRTYPE },
        { "substr",     SUBSTYPE },
        { "ifelse",     IFELTYPE },
        { "ifdef",      IFDFTYPE },
        { "len",        LENGTYPE },
        { "incr",       INCRTYPE },
        { "decr",       DECRTYPE },
        { "dnl",        DNLNTYPE | NOARGS },
        { "changequote",CHNQTYPE | NOARGS },
        { "changecom",  CHNCTYPE | NOARGS },
        { "index",      INDXTYPE },
#ifdef EXTENDED
        { "paste",      PASTTYPE },
        { "spaste",     SPASTYPE },
        /* Newer extensions, needed to handle gnu-m4 scripts */
        { "indir",      INDIRTYPE},
        { "builtin",    BUILTINTYPE},
        { "patsubst",   PATSTYPE},
        { "regexp",     REGEXPTYPE},
        { "esyscmd",    ESYSCMDTYPE},
        { "__file__",   FILENAMETYPE | NOARGS},
        { "__line__",   LINETYPE | NOARGS},
#endif
        { "popdef",     POPDTYPE },
        { "pushdef",    PUSDTYPE },
        { "dumpdef",    DUMPTYPE | NOARGS },
        { "shift",      SHIFTYPE | NOARGS },
        { "translit",   TRNLTYPE },
        { "undefine",   UNDFTYPE },
        { "undivert",   UNDVTYPE | NOARGS },
        { "divnum",     DIVNTYPE | NOARGS },
        { "maketemp",   MKTMTYPE },
        { "mkstemp",    MKTMTYPE },
        { "errprint",   ERRPTYPE | NOARGS },
        { "m4wrap",     M4WRTYPE | NOARGS },
        { "m4exit",     EXITTYPE | NOARGS },
        { "syscmd",     SYSCTYPE },
        { "sysval",     SYSVTYPE | NOARGS },
        { "traceon",    TRACEONTYPE | NOARGS },
        { "traceoff",   TRACEOFFTYPE | NOARGS },
        { "unix",       SELFTYPE | NOARGS },
};

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

#define MAXRECORD 50
static struct position {
        char *name;
        unsigned long line;
} quotes[MAXRECORD], paren[MAXRECORD];

static void record(struct position *, int);
static void dump_stack(struct position *, int);

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

static void enlarge_stack(void);

int exit_code = 0;

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

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

        init_macros();
        initspaces();
        STACKMAX = INITSTACKMAX;

        mstack = (stae *)xalloc(sizeof(stae) * STACKMAX, NULL);
        sstack = (char *)xalloc(STACKMAX, NULL);

        maxout = 0;
        outfile = NULL;
        resizedivs(MAXOUT);

        while ((c = getopt(argc, argv, "gst:d:D:U:o:I:P")) != -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 'P':
                        prefix_builtins = 1;
                        break;
                case 'U':       /* undefine... */
                        macro_popdef(optarg);
                        break;
                case 'g':
                        mimic_gnu = 1;
                        break;
                case 'd':
                        set_trace_flags(optarg);
                        break;
                case 's':
                        synch_lines = 1;
                        break;
                case 't':
                        mark_traced(optarg, 1);
                        break;
                case 'o':
                        trace_file(optarg);
                        break;
                case '?':
                        usage();
                }

        argc -= optind;
        argv += optind;

        initkwds();
        if (mimic_gnu)
                setup_builtin("format", FORMATTYPE);

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

        if (wrapindex) {
                int i;

                ilevel = 0;             /* in case m4wrap includes.. */
                bufbase = bp = buf;     /* use the entire buffer   */
                if (mimic_gnu) {
                        while (wrapindex != 0) {
                                for (i = 0; i < wrapindex; i++)
                                        pbstr(m4wraps[i]);
                                wrapindex =0;
                                macro();
                        }
                } else {
                        for (i = 0; i < wrapindex; i++) {
                                pbstr(m4wraps[i]);
                                macro();
                        }
                }
        }

        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)
                fclose(outfile[0]);

        return exit_code;
}

/*
 * Look ahead 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(int t, const char *token)
{
        int i;

        assert((unsigned char)t == (unsigned char)token[0]);

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

#define LOOK_AHEAD(t, token) (t != EOF &&               \
    (unsigned char)(t) == (unsigned char)(token)[0] &&  \
    do_look_ahead(t, token))

/*
 * macro - the work horse..
 */
static void
macro(void)
{
        char token[MAXTOK + 1];
        int t, l;
        ndptr p;
        int nlpar;

        for (;;) {
                t = gpbc();

                if (LOOK_AHEAD(t, lquote)) {    /* strip quotes */
                        nlpar = 0;
                        record(quotes, nlpar++);
                        /*
                         * Opening quote: scan forward until matching
                         * closing quote has been found.
                         */
                        do {
                                l = gpbc();
                                if (LOOK_AHEAD(l,rquote)) {
                                        if (--nlpar > 0)
                                                outputstr(rquote);
                                } else if (LOOK_AHEAD(l,lquote)) {
                                        record(quotes, nlpar++);
                                        outputstr(lquote);
                                } else if (l == EOF) {
                                        if (nlpar == 1)
                                                warnx("unclosed quote:");
                                        else
                                                warnx("%d unclosed quotes:", nlpar);
                                        dump_stack(quotes, nlpar);
                                        exit(1);
                                } else {
                                        if (nlpar > 0) {
                                                if (sp < 0)
                                                        reallyputchar(l);
                                                else
                                                        CHRSAVE(l);
                                        }
                                }
                        }
                        while (nlpar != 0);
                } else if (sp < 0 && LOOK_AHEAD(t, scommt)) {
                        reallyoutputstr(scommt);

                        for(;;) {
                                t = gpbc();
                                if (LOOK_AHEAD(t, ecommt)) {
                                        reallyoutputstr(ecommt);
                                        break;
                                }
                                if (t == EOF)
                                        break;
                                reallyputchar(t);
                        }
                } else if (t == '_' || isalpha(t)) {
                        p = inspect(t, token);
                        if (p != NULL)
                                pushback(l = gpbc());
                        if (p == NULL || (l != LPAREN &&
                            (macro_getdef(p)->type & NEEDARGS) != 0))
                                outputstr(token);
                        else {
                                /*
                                 * real thing.. First build a call frame:
                                 */
                                pushf(fp);      /* previous call frm */
                                /* type of the call */
                                pushf(macro_getdef(p)->type);
                                pushf(is_traced(p));
                                pushf(0);       /* parenthesis level */
                                fp = sp;        /* new frame pointer */
                                /*
                                 * now push the string arguments:
                                 */
                                pushs1(macro_getdef(p)->defn);  /* defn string */
                                pushs1((char *)macro_name(p));  /* macro name  */
                                pushs(ep);                      /* start next..*/

                                if (l != LPAREN && PARLEV == 0) {
                                        /* no bracks  */
                                        chrsave(EOS);

                                        if (sp == (int)STACKMAX) {
                                                errx(1,
                                                    "internal stack overflow");
                                        }
                                        eval((const char **) mstack + fp + 1, 2,
                                            CALTYP, TRACESTATUS);

                                        ep = PREVEP;    /* flush strspace */
                                        sp = PREVSP;    /* previous sp..  */
                                        fp = PREVFP;    /* rewind stack...*/
                                }
                        }
                } else if (t == EOF) {
                        if (sp > -1 && ilevel <= 0) {
                                warnx( "unexpected end of input, unclosed parenthesis:");
                                dump_stack(paren, PARLEV);
                                exit(1);
                        }
                        if (ilevel <= 0)
                                break;                  /* all done thanks.. */
                        release_input(infile+ilevel--);
                        emit_synchline();
                        bufbase = bbase[ilevel];
                        continue;
                } else if (sp < 0) {            /* not in a macro at all */
                        reallyputchar(t);       /* output directly..     */
                }

                else switch(t) {

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

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

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

                                eval((const char **) mstack + fp + 1, sp-fp,
                                    CALTYP, TRACESTATUS);

                                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()))
                                        ;
                                pushback(l);
                                pushs(ep);
                        } else
                                chrsave(t);
                        break;

                default:
                        if (LOOK_AHEAD(t, scommt)) {
                                char *cp;
                                for (cp = scommt; *cp; cp++)
                                        chrsave(*cp);
                                for(;;) {
                                        t = gpbc();
                                        if (LOOK_AHEAD(t, ecommt)) {
                                                for (cp = ecommt; *cp; cp++)
                                                        chrsave(*cp);
                                                break;
                                        }
                                        if (t == EOF)
                                                break;
                                        CHRSAVE(t);
                                }
                        } else
                                CHRSAVE(t);             /* stack the char */
                        break;
                }
        }
}

/*
 * output string directly, without pushing it for reparses.
 */
void
outputstr(const char *s)
{
        if (sp < 0)
                reallyoutputstr(s);
        else
                while (*s)
                        CHRSAVE(*s++);
}

void
reallyoutputstr(const char *s)
{
        if (synch_lines) {
                while (*s) {
                        fputc(*s, active);
                        if (*s++ == '\n') {
                                infile[ilevel].synch_lineno++;
                                if (infile[ilevel].synch_lineno !=
                                    infile[ilevel].lineno)
                                        do_emit_synchline();
                        }
                }
        } else
                fputs(s, active);
}

void
reallyputchar(int c)
{
        putc(c, active);
        if (synch_lines && c == '\n') {
                infile[ilevel].synch_lineno++;
                if (infile[ilevel].synch_lineno != infile[ilevel].lineno)
                        do_emit_synchline();
        }
}

/*
 * build an input token..
 * consider only those starting with _ or A-Za-z.
 */
static ndptr
inspect(int c, char *tp)
{
        char *name = tp;
        char *etp = tp + MAXTOK;
        ndptr p;

        *tp++ = c;

        while ((isalnum(c = gpbc()) || c == '_') && tp < etp)
                *tp++ = c;
        if (c != EOF)
                PUSHBACK(c);
        *tp = EOS;
        /* token is too long, it won't match anything, but it can still
         * be output. */
        if (tp == ep) {
                outputstr(name);
                while (isalnum(c = gpbc()) || c == '_') {
                        if (sp < 0)
                                reallyputchar(c);
                        else
                                CHRSAVE(c);
                }
                *name = EOS;
                return NULL;
        }

        p = ohash_find(&macros, ohash_qlookupi(&macros, name, (const char **)(void *)&tp));
        if (p == NULL)
                return NULL;
        if (macro_getdef(p) == NULL)
                return NULL;
        return p;
}

/*
 * initkwds - initialize 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(void)
{
        unsigned int type;
        int i;

        for (i = 0; i < (int)MAXKEYS; i++) {
                type = keywrds[i].ktyp & TYPEMASK;
                if ((keywrds[i].ktyp & NOARGS) == 0)
                        type |= NEEDARGS;
                setup_builtin(keywrds[i].knam, type);
        }
}

static void
record(struct position *t, int lev)
{
        if (lev < MAXRECORD) {
                t[lev].name = CURRENT_NAME;
                t[lev].line = CURRENT_LINE;
        }
}

static void
dump_stack(struct position *t, int lev)
{
        int i;

        for (i = 0; i < lev; i++) {
                if (i == MAXRECORD) {
                        fprintf(stderr, "   ...\n");
                        break;
                }
                fprintf(stderr, "   %s at line %lu\n",
                        t[i].name, t[i].line);
        }
}


static void
enlarge_stack(void)
{
        STACKMAX += STACKMAX/2;
        mstack = xrealloc(mstack, sizeof(stae) * STACKMAX,
            "Evaluation stack overflow (%lu)",
            (unsigned long)STACKMAX);
        sstack = xrealloc(sstack, STACKMAX,
            "Evaluation stack overflow (%lu)",
            (unsigned long)STACKMAX);
}