cmd/mandoc/mandoc.c

	mandoc.c revision 95c635efb7c3b86efc493e0447eaec7aecca3f0f
/*  $Id: mandoc.c,v 1.62 2011/12/03 16:08:51 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
 *
 * 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 AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include "mandoc.h"
#include "libmandoc.h"

#define DATESIZE 32

static  int  a2time(time_t *, const char *, const char *);
static  char    *time2a(time_t);
static  int  numescape(const char *);

/*
 * Pass over recursive numerical expressions.  This context of this
 * function is important: it's only called within character-terminating
 * escapes (e.g., \s[xxxyyy]), so all we need to do is handle initial
 * recursion: we don't care about what's in these blocks.
 * This returns the number of characters skipped or -1 if an error
 * occurs (the caller should bail).
 */
static int
numescape(const char *start)
{
    int      i;
    size_t       sz;
    const char  *cp;

    i = 0;

    /* The expression consists of a subexpression. */

    if ('\\' == start[i]) {
        cp = &start[++i];
        /*
         * Read past the end of the subexpression.
         * Bail immediately on errors.
         */
        if (ESCAPE_ERROR == mandoc_escape(&cp, NULL, NULL))
            return(-1);
        return(i + cp - &start[i]);
    }

    if ('(' != start[i++])
        return(0);

    /*
     * A parenthesised subexpression.  Read until the closing
     * parenthesis, making sure to handle any nested subexpressions
     * that might ruin our parse.
     */

    while (')' != start[i]) {
        sz = strcspn(&start[i], ")\\");
        i += (int)sz;

        if ('\0' == start[i])
            return(-1);
        else if ('\\' != start[i])
            continue;

        cp = &start[++i];
        if (ESCAPE_ERROR == mandoc_escape(&cp, NULL, NULL))
            return(-1);
        i += cp - &start[i];
    }

    /* Read past the terminating ')'. */
    return(++i);
}

enum mandoc_esc
mandoc_escape(const char **end, const char **start, int *sz)
{
    char         c, term, numeric;
    int      i, lim, ssz, rlim;
    const char  *cp, *rstart;
    enum mandoc_esc  gly;

    cp = *end;
    rstart = cp;
    if (start)
        *start = rstart;
    i = lim = 0;
    gly = ESCAPE_ERROR;
    term = numeric = '\0';

    switch ((c = cp[i++])) {
    /*
     * First the glyphs.  There are several different forms of
     * these, but each eventually returns a substring of the glyph
     * name.
     */
    case ('('):
        gly = ESCAPE_SPECIAL;
        lim = 2;
        break;
    case ('['):
        gly = ESCAPE_SPECIAL;
        /*
         * Unicode escapes are defined in groff as \[uXXXX] to
         * \[u10FFFF], where the contained value must be a valid
         * Unicode codepoint.  Here, however, only check whether
         * it's not a zero-width escape.
         */
        if ('u' == cp[i] && ']' != cp[i + 1])
            gly = ESCAPE_UNICODE;
        term = ']';
        break;
    case ('C'):
        if ('\'' != cp[i])
            return(ESCAPE_ERROR);
        gly = ESCAPE_SPECIAL;
        term = '\'';
        break;

    /*
     * Handle all triggers matching \X(xy, \Xx, and \X[xxxx], where
     * 'X' is the trigger.  These have opaque sub-strings.
     */
    case ('F'):
        /* FALLTHROUGH */
    case ('g'):
        /* FALLTHROUGH */
    case ('k'):
        /* FALLTHROUGH */
    case ('M'):
        /* FALLTHROUGH */
    case ('m'):
        /* FALLTHROUGH */
    case ('n'):
        /* FALLTHROUGH */
    case ('V'):
        /* FALLTHROUGH */
    case ('Y'):
        gly = ESCAPE_IGNORE;
        /* FALLTHROUGH */
    case ('f'):
        if (ESCAPE_ERROR == gly)
            gly = ESCAPE_FONT;

        rstart= &cp[i];
        if (start)
            *start = rstart;

        switch (cp[i++]) {
        case ('('):
            lim = 2;
            break;
        case ('['):
            term = ']';
            break;
        default:
            lim = 1;
            i--;
            break;
        }
        break;

    /*
     * These escapes are of the form \X'Y', where 'X' is the trigger
     * and 'Y' is any string.  These have opaque sub-strings.
     */
    case ('A'):
        /* FALLTHROUGH */
    case ('b'):
        /* FALLTHROUGH */
    case ('D'):
        /* FALLTHROUGH */
    case ('o'):
        /* FALLTHROUGH */
    case ('R'):
        /* FALLTHROUGH */
    case ('X'):
        /* FALLTHROUGH */
    case ('Z'):
        if ('\'' != cp[i++])
            return(ESCAPE_ERROR);
        gly = ESCAPE_IGNORE;
        term = '\'';
        break;

    /*
     * These escapes are of the form \X'N', where 'X' is the trigger
     * and 'N' resolves to a numerical expression.
     */
    case ('B'):
        /* FALLTHROUGH */
    case ('h'):
        /* FALLTHROUGH */
    case ('H'):
        /* FALLTHROUGH */
    case ('L'):
        /* FALLTHROUGH */
    case ('l'):
        gly = ESCAPE_NUMBERED;
        /* FALLTHROUGH */
    case ('S'):
        /* FALLTHROUGH */
    case ('v'):
        /* FALLTHROUGH */
    case ('w'):
        /* FALLTHROUGH */
    case ('x'):
        if (ESCAPE_ERROR == gly)
            gly = ESCAPE_IGNORE;
        if ('\'' != cp[i++])
            return(ESCAPE_ERROR);
        term = numeric = '\'';
        break;

    /*
     * Special handling for the numbered character escape.
     * XXX Do any other escapes need similar handling?
     */
    case ('N'):
        if ('\0' == cp[i])
            return(ESCAPE_ERROR);
        *end = &cp[++i];
        if (isdigit((unsigned char)cp[i-1]))
            return(ESCAPE_IGNORE);
        while (isdigit((unsigned char)**end))
            (*end)++;
        if (start)
            *start = &cp[i];
        if (sz)
            *sz = *end - &cp[i];
        if ('\0' != **end)
            (*end)++;
        return(ESCAPE_NUMBERED);

    /*
     * Sizes get a special category of their own.
     */
    case ('s'):
        gly = ESCAPE_IGNORE;

        rstart = &cp[i];
        if (start)
            *start = rstart;

        /* See +/- counts as a sign. */
        c = cp[i];
        if ('+' == c || '-' == c || ASCII_HYPH == c)
            ++i;

        switch (cp[i++]) {
        case ('('):
            lim = 2;
            break;
        case ('['):
            term = numeric = ']';
            break;
        case ('\''):
            term = numeric = '\'';
            break;
        default:
            lim = 1;
            i--;
            break;
        }

        /* See +/- counts as a sign. */
        c = cp[i];
        if ('+' == c || '-' == c || ASCII_HYPH == c)
            ++i;

        break;

    /*
     * Anything else is assumed to be a glyph.
     */
    default:
        gly = ESCAPE_SPECIAL;
        lim = 1;
        i--;
        break;
    }

    assert(ESCAPE_ERROR != gly);

    rstart = &cp[i];
    if (start)
        *start = rstart;

    /*
     * If a terminating block has been specified, we need to
     * handle the case of recursion, which could have their
     * own terminating blocks that mess up our parse.  This, by the
     * way, means that the "start" and "size" values will be
     * effectively meaningless.
     */

    ssz = 0;
    if (numeric && -1 == (ssz = numescape(&cp[i])))
        return(ESCAPE_ERROR);

    i += ssz;
    rlim = -1;

    /*
     * We have a character terminator.  Try to read up to that
     * character.  If we can't (i.e., we hit the nil), then return
     * an error; if we can, calculate our length, read past the
     * terminating character, and exit.
     */

    if ('\0' != term) {
        *end = strchr(&cp[i], term);
        if ('\0' == *end)
            return(ESCAPE_ERROR);

        rlim = *end - &cp[i];
        if (sz)
            *sz = rlim;
        (*end)++;
        goto out;
    }

    assert(lim > 0);

    /*
     * We have a numeric limit.  If the string is shorter than that,
     * stop and return an error.  Else adjust our endpoint, length,
     * and return the current glyph.
     */

    if ((size_t)lim > strlen(&cp[i]))
        return(ESCAPE_ERROR);

    rlim = lim;
    if (sz)
        *sz = rlim;

    *end = &cp[i] + lim;

out:
    assert(rlim >= 0 && rstart);

    /* Run post-processors. */

    switch (gly) {
    case (ESCAPE_FONT):
        /*
         * Pretend that the constant-width font modes are the
         * same as the regular font modes.
         */
        if (2 == rlim && 'C' == *rstart)
            rstart++;
        else if (1 != rlim)
            break;

        switch (*rstart) {
        case ('3'):
            /* FALLTHROUGH */
        case ('B'):
            gly = ESCAPE_FONTBOLD;
            break;
        case ('2'):
            /* FALLTHROUGH */
        case ('I'):
            gly = ESCAPE_FONTITALIC;
            break;
        case ('P'):
            gly = ESCAPE_FONTPREV;
            break;
        case ('1'):
            /* FALLTHROUGH */
        case ('R'):
            gly = ESCAPE_FONTROMAN;
            break;
        }
        break;
    case (ESCAPE_SPECIAL):
        if (1 != rlim)
            break;
        if ('c' == *rstart)
            gly = ESCAPE_NOSPACE;
        break;
    default:
        break;
    }

    return(gly);
}

void *
mandoc_calloc(size_t num, size_t size)
{
    void        *ptr;

    ptr = calloc(num, size);
    if (NULL == ptr) {
        perror(NULL);
        exit((int)MANDOCLEVEL_SYSERR);
    }

    return(ptr);
}


void *
mandoc_malloc(size_t size)
{
    void        *ptr;

    ptr = malloc(size);
    if (NULL == ptr) {
        perror(NULL);
        exit((int)MANDOCLEVEL_SYSERR);
    }

    return(ptr);
}


void *
mandoc_realloc(void *ptr, size_t size)
{

    ptr = realloc(ptr, size);
    if (NULL == ptr) {
        perror(NULL);
        exit((int)MANDOCLEVEL_SYSERR);
    }

    return(ptr);
}

char *
mandoc_strndup(const char *ptr, size_t sz)
{
    char        *p;

    p = mandoc_malloc(sz + 1);
    memcpy(p, ptr, sz);
    p[(int)sz] = '\0';
    return(p);
}

char *
mandoc_strdup(const char *ptr)
{
    char        *p;

    p = strdup(ptr);
    if (NULL == p) {
        perror(NULL);
        exit((int)MANDOCLEVEL_SYSERR);
    }

    return(p);
}

/*
 * Parse a quoted or unquoted roff-style request or macro argument.
 * Return a pointer to the parsed argument, which is either the original
 * pointer or advanced by one byte in case the argument is quoted.
 * Null-terminate the argument in place.
 * Collapse pairs of quotes inside quoted arguments.
 * Advance the argument pointer to the next argument,
 * or to the null byte terminating the argument line.
 */
char *
mandoc_getarg(struct mparse *parse, char **cpp, int ln, int *pos)
{
    char     *start, *cp;
    int   quoted, pairs, white;

    /* Quoting can only start with a new word. */
    start = *cpp;
    quoted = 0;
    if ('"' == *start) {
        quoted = 1;
        start++;
    }

    pairs = 0;
    white = 0;
    for (cp = start; '\0' != *cp; cp++) {
        /* Move left after quoted quotes and escaped backslashes. */
        if (pairs)
            cp[-pairs] = cp[0];
        if ('\\' == cp[0]) {
            if ('\\' == cp[1]) {
                /* Poor man's copy mode. */
                pairs++;
                cp++;
            } else if (0 == quoted && ' ' == cp[1])
                /* Skip escaped blanks. */
                cp++;
        } else if (0 == quoted) {
            if (' ' == cp[0]) {
                /* Unescaped blanks end unquoted args. */
                white = 1;
                break;
            }
        } else if ('"' == cp[0]) {
            if ('"' == cp[1]) {
                /* Quoted quotes collapse. */
                pairs++;
                cp++;
            } else {
                /* Unquoted quotes end quoted args. */
                quoted = 2;
                break;
            }
        }
    }

    /* Quoted argument without a closing quote. */
    if (1 == quoted)
        mandoc_msg(MANDOCERR_BADQUOTE, parse, ln, *pos, NULL);

    /* Null-terminate this argument and move to the next one. */
    if (pairs)
        cp[-pairs] = '\0';
    if ('\0' != *cp) {
        *cp++ = '\0';
        while (' ' == *cp)
            cp++;
    }
    *pos += (int)(cp - start) + (quoted ? 1 : 0);
    *cpp = cp;

    if ('\0' == *cp && (white || ' ' == cp[-1]))
        mandoc_msg(MANDOCERR_EOLNSPACE, parse, ln, *pos, NULL);

    return(start);
}

static int
a2time(time_t *t, const char *fmt, const char *p)
{
    struct tm    tm;
    char        *pp;

    memset(&tm, 0, sizeof(struct tm));

    pp = NULL;
#ifdef  HAVE_STRPTIME
    pp = strptime(p, fmt, &tm);
#endif
    if (NULL != pp && '\0' == *pp) {
        *t = mktime(&tm);
        return(1);
    }

    return(0);
}

static char *
time2a(time_t t)
{
    struct tm   *tm;
    char        *buf, *p;
    size_t       ssz;
    int      isz;

    tm = localtime(&t);

    /*
     * Reserve space:
     * up to 9 characters for the month (September) + blank
     * up to 2 characters for the day + comma + blank
     * 4 characters for the year and a terminating '\0'
     */
    p = buf = mandoc_malloc(10 + 4 + 4 + 1);

    if (0 == (ssz = strftime(p, 10 + 1, "%B ", tm)))
        goto fail;
    p += (int)ssz;

    if (-1 == (isz = snprintf(p, 4 + 1, "%d, ", tm->tm_mday)))
        goto fail;
    p += isz;

    if (0 == strftime(p, 4 + 1, "%Y", tm))
        goto fail;
    return(buf);

fail:
    free(buf);
    return(NULL);
}

char *
mandoc_normdate(struct mparse *parse, char *in, int ln, int pos)
{
    char        *out;
    time_t       t;

    if (NULL == in || '\0' == *in ||
        0 == strcmp(in, "$" "Mdocdate$")) {
        mandoc_msg(MANDOCERR_NODATE, parse, ln, pos, NULL);
        time(&t);
    }
    else if (a2time(&t, "%Y-%m-%d", in))
        t = 0;
    else if (!a2time(&t, "$" "Mdocdate: %b %d %Y $", in) &&
        !a2time(&t, "%b %d, %Y", in)) {
        mandoc_msg(MANDOCERR_BADDATE, parse, ln, pos, NULL);
        t = 0;
    }
    out = t ? time2a(t) : NULL;
    return(out ? out : mandoc_strdup(in));
}

int
mandoc_eos(const char *p, size_t sz, int enclosed)
{
    const char *q;
    int found;

    if (0 == sz)
        return(0);

    /*
     * End-of-sentence recognition must include situations where
     * some symbols, such as `)', allow prior EOS punctuation to
     * propagate outward.
     */

    found = 0;
    for (q = p + (int)sz - 1; q >= p; q--) {
        switch (*q) {
        case ('\"'):
            /* FALLTHROUGH */
        case ('\''):
            /* FALLTHROUGH */
        case (']'):
            /* FALLTHROUGH */
        case (')'):
            if (0 == found)
                enclosed = 1;
            break;
        case ('.'):
            /* FALLTHROUGH */
        case ('!'):
            /* FALLTHROUGH */
        case ('?'):
            found = 1;
            break;
        default:
            return(found && (!enclosed || isalnum((unsigned char)*q)));
        }
    }

    return(found && !enclosed);
}

/*
 * Find out whether a line is a macro line or not.  If it is, adjust the
 * current position and return one; if it isn't, return zero and don't
 * change the current position.
 */
int
mandoc_getcontrol(const char *cp, int *ppos)
{
    int     pos;

    pos = *ppos;

    if ('\\' == cp[pos] && '.' == cp[pos + 1])
        pos += 2;
    else if ('.' == cp[pos] || '\'' == cp[pos])
        pos++;
    else
        return(0);

    while (' ' == cp[pos] || '\t' == cp[pos])
        pos++;

    *ppos = pos;
    return(1);
}

/*
 * Convert a string to a long that may not be <0.
 * If the string is invalid, or is less than 0, return -1.
 */
int
mandoc_strntoi(const char *p, size_t sz, int base)
{
    char         buf[32];
    char        *ep;
    long         v;

    if (sz > 31)
        return(-1);

    memcpy(buf, p, sz);
    buf[(int)sz] = '\0';

    errno = 0;
    v = strtol(buf, &ep, base);

    if (buf[0] == '\0' || *ep != '\0')
        return(-1);

    if (v > INT_MAX)
        v = INT_MAX;
    if (v < INT_MIN)
        v = INT_MIN;

    return((int)v);
}