[mandoc.git] / read.c

/*      $Id: read.c,v 1.172 2017/06/07 23:29:48 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2010, 2012 Joerg Sonnenberger <joerg@netbsd.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.
 */
#include "config.h"

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>

#include <assert.h>
#include <ctype.h>
#if HAVE_ERR
#include <err.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zlib.h>

#include "mandoc_aux.h"
#include "mandoc.h"
#include "roff.h"
#include "mdoc.h"
#include "man.h"
#include "libmandoc.h"
#include "roff_int.h"

#define REPARSE_LIMIT   1000

struct  mparse {
        struct roff      *roff; /* roff parser (!NULL) */
        struct roff_man  *man; /* man parser */
        char             *sodest; /* filename pointed to by .so */
        const char       *file; /* filename of current input file */
        struct buf       *primary; /* buffer currently being parsed */
        struct buf       *secondary; /* preprocessed copy of input */
        const char       *defos; /* default operating system */
        mandocmsg         mmsg; /* warning/error message handler */
        enum mandoclevel  file_status; /* status of current parse */
        enum mandoclevel  wlevel; /* ignore messages below this */
        int               options; /* parser options */
        int               gzip; /* current input file is gzipped */
        int               filenc; /* encoding of the current file */
        int               reparse_count; /* finite interp. stack */
        int               line; /* line number in the file */
};

static  void      choose_parser(struct mparse *);
static  void      resize_buf(struct buf *, size_t);
static  int       mparse_buf_r(struct mparse *, struct buf, size_t, int);
static  int       read_whole_file(struct mparse *, const char *, int,
                                struct buf *, int *);
static  void      mparse_end(struct mparse *);
static  void      mparse_parse_buffer(struct mparse *, struct buf,
                        const char *);

static  const enum mandocerr    mandoclimits[MANDOCLEVEL_MAX] = {
        MANDOCERR_OK,
        MANDOCERR_STYLE,
        MANDOCERR_WARNING,
        MANDOCERR_ERROR,
        MANDOCERR_UNSUPP,
        MANDOCERR_MAX,
        MANDOCERR_MAX
};

static  const char * const      mandocerrs[MANDOCERR_MAX] = {
        "ok",

        "generic style suggestion",

        "useless macro",
        "consider using OS macro",
        "errnos out of order",
        "duplicate errno",
        "description line ends with a full stop",

        "generic warning",

        /* related to the prologue */
        "missing manual title, using UNTITLED",
        "missing manual title, using \"\"",
        "lower case character in document title",
        "missing manual section, using \"\"",
        "unknown manual section",
        "missing date, using today's date",
        "cannot parse date, using it verbatim",
        "missing Os macro, using \"\"",
        "duplicate prologue macro",
        "late prologue macro",
        "skipping late title macro",
        "prologue macros out of order",

        /* related to document structure */
        ".so is fragile, better use ln(1)",
        "no document body",
        "content before first section header",
        "first section is not \"NAME\"",
        "NAME section without Nm before Nd",
        "NAME section without description",
        "description not at the end of NAME",
        "bad NAME section content",
        "missing comma before name",
        "missing description line, using \"\"",
        "description line outside NAME section",
        "sections out of conventional order",
        "duplicate section title",
        "unexpected section",
        "unusual Xr order",
        "unusual Xr punctuation",
        "AUTHORS section without An macro",

        /* related to macros and nesting */
        "obsolete macro",
        "macro neither callable nor escaped",
        "skipping paragraph macro",
        "moving paragraph macro out of list",
        "skipping no-space macro",
        "blocks badly nested",
        "nested displays are not portable",
        "moving content out of list",
        "fill mode already enabled, skipping",
        "fill mode already disabled, skipping",
        "line scope broken",
        "skipping blank line in line scope",

        /* related to missing macro arguments */
        "skipping empty request",
        "conditional request controls empty scope",
        "skipping empty macro",
        "empty block",
        "empty argument, using 0n",
        "missing display type, using -ragged",
        "list type is not the first argument",
        "missing -width in -tag list, using 6n",
        "missing utility name, using \"\"",
        "missing function name, using \"\"",
        "empty head in list item",
        "empty list item",
        "missing font type, using \\fR",
        "unknown font type, using \\fR",
        "nothing follows prefix",
        "empty reference block",
        "missing section argument",
        "missing -std argument, adding it",
        "missing option string, using \"\"",
        "missing resource identifier, using \"\"",
        "missing eqn box, using \"\"",

        /* related to bad macro arguments */
        "unterminated quoted argument",
        "duplicate argument",
        "skipping duplicate argument",
        "skipping duplicate display type",
        "skipping duplicate list type",
        "skipping -width argument",
        "wrong number of cells",
        "unknown AT&T UNIX version",
        "comma in function argument",
        "parenthesis in function name",
        "invalid content in Rs block",
        "invalid Boolean argument",
        "unknown font, skipping request",
        "odd number of characters in request",

        /* related to plain text */
        "blank line in fill mode, using .sp",
        "tab in filled text",
        "whitespace at end of input line",
        "new sentence, new line",
        "bad comment style",
        "invalid escape sequence",
        "undefined string, using \"\"",

        /* related to tables */
        "tbl line starts with span",
        "tbl column starts with span",
        "skipping vertical bar in tbl layout",

        "generic error",

        /* related to tables */
        "non-alphabetic character in tbl options",
        "skipping unknown tbl option",
        "missing tbl option argument",
        "wrong tbl option argument size",
        "empty tbl layout",
        "invalid character in tbl layout",
        "unmatched parenthesis in tbl layout",
        "tbl without any data cells",
        "ignoring data in spanned tbl cell",
        "ignoring extra tbl data cells",
        "data block open at end of tbl",

        /* related to document structure and macros */
        NULL,
        "input stack limit exceeded, infinite loop?",
        "skipping bad character",
        "skipping unknown macro",
        "skipping insecure request",
        "skipping item outside list",
        "skipping column outside column list",
        "skipping end of block that is not open",
        "fewer RS blocks open, skipping",
        "inserting missing end of block",
        "appending missing end of block",

        /* related to request and macro arguments */
        "escaped character not allowed in a name",
        "NOT IMPLEMENTED: Bd -file",
        "skipping display without arguments",
        "missing list type, using -item",
        "argument is not numeric, using 1",
        "missing manual name, using \"\"",
        "uname(3) system call failed, using UNKNOWN",
        "unknown standard specifier",
        "skipping request without numeric argument",
        "NOT IMPLEMENTED: .so with absolute path or \"..\"",
        ".so request failed",
        "skipping all arguments",
        "skipping excess arguments",
        "divide by zero",

        "unsupported feature",
        "input too large",
        "unsupported control character",
        "unsupported roff request",
        "eqn delim option in tbl",
        "unsupported tbl layout modifier",
        "ignoring macro in table",
};

static  const char * const      mandoclevels[MANDOCLEVEL_MAX] = {
        "SUCCESS",
        "STYLE",
        "WARNING",
        "ERROR",
        "UNSUPP",
        "BADARG",
        "SYSERR"
};


static void
resize_buf(struct buf *buf, size_t initial)
{

        buf->sz = buf->sz > initial/2 ? 2 * buf->sz : initial;
        buf->buf = mandoc_realloc(buf->buf, buf->sz);
}

static void
choose_parser(struct mparse *curp)
{
        char            *cp, *ep;
        int              format;

        /*
         * If neither command line arguments -mdoc or -man select
         * a parser nor the roff parser found a .Dd or .TH macro
         * yet, look ahead in the main input buffer.
         */

        if ((format = roff_getformat(curp->roff)) == 0) {
                cp = curp->primary->buf;
                ep = cp + curp->primary->sz;
                while (cp < ep) {
                        if (*cp == '.' || *cp == '\'') {
                                cp++;
                                if (cp[0] == 'D' && cp[1] == 'd') {
                                        format = MPARSE_MDOC;
                                        break;
                                }
                                if (cp[0] == 'T' && cp[1] == 'H') {
                                        format = MPARSE_MAN;
                                        break;
                                }
                        }
                        cp = memchr(cp, '\n', ep - cp);
                        if (cp == NULL)
                                break;
                        cp++;
                }
        }

        if (format == MPARSE_MDOC) {
                curp->man->macroset = MACROSET_MDOC;
                if (curp->man->mdocmac == NULL)
                        curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
        } else {
                curp->man->macroset = MACROSET_MAN;
                if (curp->man->manmac == NULL)
                        curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
        }
        curp->man->first->tok = TOKEN_NONE;
}

/*
 * Main parse routine for a buffer.
 * It assumes encoding and line numbering are already set up.
 * It can recurse directly (for invocations of user-defined
 * macros, inline equations, and input line traps)
 * and indirectly (for .so file inclusion).
 */
static int
mparse_buf_r(struct mparse *curp, struct buf blk, size_t i, int start)
{
        const struct tbl_span   *span;
        struct buf       ln;
        const char      *save_file;
        char            *cp;
        size_t           pos; /* byte number in the ln buffer */
        enum rofferr     rr;
        int              of;
        int              lnn; /* line number in the real file */
        int              fd;
        unsigned char    c;

        memset(&ln, 0, sizeof(ln));

        lnn = curp->line;
        pos = 0;

        while (i < blk.sz) {
                if (0 == pos && '\0' == blk.buf[i])
                        break;

                if (start) {
                        curp->line = lnn;
                        curp->reparse_count = 0;

                        if (lnn < 3 &&
                            curp->filenc & MPARSE_UTF8 &&
                            curp->filenc & MPARSE_LATIN1)
                                curp->filenc = preconv_cue(&blk, i);
                }

                while (i < blk.sz && (start || blk.buf[i] != '\0')) {

                        /*
                         * When finding an unescaped newline character,
                         * leave the character loop to process the line.
                         * Skip a preceding carriage return, if any.
                         */

                        if ('\r' == blk.buf[i] && i + 1 < blk.sz &&
                            '\n' == blk.buf[i + 1])
                                ++i;
                        if ('\n' == blk.buf[i]) {
                                ++i;
                                ++lnn;
                                break;
                        }

                        /*
                         * Make sure we have space for the worst
                         * case of 11 bytes: "\\[u10ffff]\0"
                         */

                        if (pos + 11 > ln.sz)
                                resize_buf(&ln, 256);

                        /*
                         * Encode 8-bit input.
                         */

                        c = blk.buf[i];
                        if (c & 0x80) {
                                if ( ! (curp->filenc && preconv_encode(
                                    &blk, &i, &ln, &pos, &curp->filenc))) {
                                        mandoc_vmsg(MANDOCERR_CHAR_BAD, curp,
                                            curp->line, pos, "0x%x", c);
                                        ln.buf[pos++] = '?';
                                        i++;
                                }
                                continue;
                        }

                        /*
                         * Exclude control characters.
                         */

                        if (c == 0x7f || (c < 0x20 && c != 0x09)) {
                                mandoc_vmsg(c == 0x00 || c == 0x04 ||
                                    c > 0x0a ? MANDOCERR_CHAR_BAD :
                                    MANDOCERR_CHAR_UNSUPP,
                                    curp, curp->line, pos, "0x%x", c);
                                i++;
                                if (c != '\r')
                                        ln.buf[pos++] = '?';
                                continue;
                        }

                        ln.buf[pos++] = blk.buf[i++];
                }

                if (pos + 1 >= ln.sz)
                        resize_buf(&ln, 256);

                if (i == blk.sz || blk.buf[i] == '\0')
                        ln.buf[pos++] = '\n';
                ln.buf[pos] = '\0';

                /*
                 * A significant amount of complexity is contained by
                 * the roff preprocessor.  It's line-oriented but can be
                 * expressed on one line, so we need at times to
                 * readjust our starting point and re-run it.  The roff
                 * preprocessor can also readjust the buffers with new
                 * data, so we pass them in wholesale.
                 */

                of = 0;

                /*
                 * Maintain a lookaside buffer of all parsed lines.  We
                 * only do this if mparse_keep() has been invoked (the
                 * buffer may be accessed with mparse_getkeep()).
                 */

                if (curp->secondary) {
                        curp->secondary->buf = mandoc_realloc(
                            curp->secondary->buf,
                            curp->secondary->sz + pos + 2);
                        memcpy(curp->secondary->buf +
                            curp->secondary->sz,
                            ln.buf, pos);
                        curp->secondary->sz += pos;
                        curp->secondary->buf
                                [curp->secondary->sz] = '\n';
                        curp->secondary->sz++;
                        curp->secondary->buf
                                [curp->secondary->sz] = '\0';
                }
rerun:
                rr = roff_parseln(curp->roff, curp->line, &ln, &of);

                switch (rr) {
                case ROFF_REPARSE:
                        if (++curp->reparse_count > REPARSE_LIMIT)
                                mandoc_msg(MANDOCERR_ROFFLOOP, curp,
                                    curp->line, pos, NULL);
                        else if (mparse_buf_r(curp, ln, of, 0) == 1 ||
                            start == 1) {
                                pos = 0;
                                continue;
                        }
                        free(ln.buf);
                        return 0;
                case ROFF_APPEND:
                        pos = strlen(ln.buf);
                        continue;
                case ROFF_RERUN:
                        goto rerun;
                case ROFF_IGN:
                        pos = 0;
                        continue;
                case ROFF_SO:
                        if ( ! (curp->options & MPARSE_SO) &&
                            (i >= blk.sz || blk.buf[i] == '\0')) {
                                curp->sodest = mandoc_strdup(ln.buf + of);
                                free(ln.buf);
                                return 1;
                        }
                        /*
                         * We remove `so' clauses from our lookaside
                         * buffer because we're going to descend into
                         * the file recursively.
                         */
                        if (curp->secondary)
                                curp->secondary->sz -= pos + 1;
                        save_file = curp->file;
                        if ((fd = mparse_open(curp, ln.buf + of)) != -1) {
                                mparse_readfd(curp, fd, ln.buf + of);
                                close(fd);
                                curp->file = save_file;
                        } else {
                                curp->file = save_file;
                                mandoc_vmsg(MANDOCERR_SO_FAIL,
                                    curp, curp->line, pos,
                                    ".so %s", ln.buf + of);
                                ln.sz = mandoc_asprintf(&cp,
                                    ".sp\nSee the file %s.\n.sp",
                                    ln.buf + of);
                                free(ln.buf);
                                ln.buf = cp;
                                of = 0;
                                mparse_buf_r(curp, ln, of, 0);
                        }
                        pos = 0;
                        continue;
                default:
                        break;
                }

                if (curp->man->macroset == MACROSET_NONE)
                        choose_parser(curp);

                /*
                 * Lastly, push down into the parsers themselves.
                 * If libroff returns ROFF_TBL, then add it to the
                 * currently open parse.  Since we only get here if
                 * there does exist data (see tbl_data.c), we're
                 * guaranteed that something's been allocated.
                 * Do the same for ROFF_EQN.
                 */

                if (rr == ROFF_TBL)
                        while ((span = roff_span(curp->roff)) != NULL)
                                roff_addtbl(curp->man, span);
                else if (rr == ROFF_EQN)
                        roff_addeqn(curp->man, roff_eqn(curp->roff));
                else if ((curp->man->macroset == MACROSET_MDOC ?
                    mdoc_parseln(curp->man, curp->line, ln.buf, of) :
                    man_parseln(curp->man, curp->line, ln.buf, of)) == 2)
                                break;

                /* Temporary buffers typically are not full. */

                if (0 == start && '\0' == blk.buf[i])
                        break;

                /* Start the next input line. */

                pos = 0;
        }

        free(ln.buf);
        return 1;
}

static int
read_whole_file(struct mparse *curp, const char *file, int fd,
                struct buf *fb, int *with_mmap)
{
        struct stat      st;
        gzFile           gz;
        size_t           off;
        ssize_t          ssz;

        if (fstat(fd, &st) == -1)
                err((int)MANDOCLEVEL_SYSERR, "%s", file);

        /*
         * If we're a regular file, try just reading in the whole entry
         * via mmap().  This is faster than reading it into blocks, and
         * since each file is only a few bytes to begin with, I'm not
         * concerned that this is going to tank any machines.
         */

        if (curp->gzip == 0 && S_ISREG(st.st_mode)) {
                if (st.st_size > 0x7fffffff) {
                        mandoc_msg(MANDOCERR_TOOLARGE, curp, 0, 0, NULL);
                        return 0;
                }
                *with_mmap = 1;
                fb->sz = (size_t)st.st_size;
                fb->buf = mmap(NULL, fb->sz, PROT_READ, MAP_SHARED, fd, 0);
                if (fb->buf != MAP_FAILED)
                        return 1;
        }

        if (curp->gzip) {
                if ((gz = gzdopen(fd, "rb")) == NULL)
                        err((int)MANDOCLEVEL_SYSERR, "%s", file);
        } else
                gz = NULL;

        /*
         * If this isn't a regular file (like, say, stdin), then we must
         * go the old way and just read things in bit by bit.
         */

        *with_mmap = 0;
        off = 0;
        fb->sz = 0;
        fb->buf = NULL;
        for (;;) {
                if (off == fb->sz) {
                        if (fb->sz == (1U << 31)) {
                                mandoc_msg(MANDOCERR_TOOLARGE, curp,
                                    0, 0, NULL);
                                break;
                        }
                        resize_buf(fb, 65536);
                }
                ssz = curp->gzip ?
                    gzread(gz, fb->buf + (int)off, fb->sz - off) :
                    read(fd, fb->buf + (int)off, fb->sz - off);
                if (ssz == 0) {
                        fb->sz = off;
                        return 1;
                }
                if (ssz == -1)
                        err((int)MANDOCLEVEL_SYSERR, "%s", file);
                off += (size_t)ssz;
        }

        free(fb->buf);
        fb->buf = NULL;
        return 0;
}

static void
mparse_end(struct mparse *curp)
{
        if (curp->man->macroset == MACROSET_NONE)
                curp->man->macroset = MACROSET_MAN;
        if (curp->man->macroset == MACROSET_MDOC)
                mdoc_endparse(curp->man);
        else
                man_endparse(curp->man);
        roff_endparse(curp->roff);
}

static void
mparse_parse_buffer(struct mparse *curp, struct buf blk, const char *file)
{
        struct buf      *svprimary;
        const char      *svfile;
        size_t           offset;
        static int       recursion_depth;

        if (64 < recursion_depth) {
                mandoc_msg(MANDOCERR_ROFFLOOP, curp, curp->line, 0, NULL);
                return;
        }

        /* Line number is per-file. */
        svfile = curp->file;
        curp->file = file;
        svprimary = curp->primary;
        curp->primary = &blk;
        curp->line = 1;
        recursion_depth++;

        /* Skip an UTF-8 byte order mark. */
        if (curp->filenc & MPARSE_UTF8 && blk.sz > 2 &&
            (unsigned char)blk.buf[0] == 0xef &&
            (unsigned char)blk.buf[1] == 0xbb &&
            (unsigned char)blk.buf[2] == 0xbf) {
                offset = 3;
                curp->filenc &= ~MPARSE_LATIN1;
        } else
                offset = 0;

        mparse_buf_r(curp, blk, offset, 1);

        if (--recursion_depth == 0)
                mparse_end(curp);

        curp->primary = svprimary;
        curp->file = svfile;
}

enum mandoclevel
mparse_readmem(struct mparse *curp, void *buf, size_t len,
                const char *file)
{
        struct buf blk;

        blk.buf = buf;
        blk.sz = len;

        mparse_parse_buffer(curp, blk, file);
        return curp->file_status;
}

/*
 * Read the whole file into memory and call the parsers.
 * Called recursively when an .so request is encountered.
 */
enum mandoclevel
mparse_readfd(struct mparse *curp, int fd, const char *file)
{
        struct buf       blk;
        int              with_mmap;
        int              save_filenc;

        if (read_whole_file(curp, file, fd, &blk, &with_mmap)) {
                save_filenc = curp->filenc;
                curp->filenc = curp->options &
                    (MPARSE_UTF8 | MPARSE_LATIN1);
                mparse_parse_buffer(curp, blk, file);
                curp->filenc = save_filenc;
                if (with_mmap)
                        munmap(blk.buf, blk.sz);
                else
                        free(blk.buf);
        }
        return curp->file_status;
}

int
mparse_open(struct mparse *curp, const char *file)
{
        char             *cp;
        int               fd;

        curp->file = file;
        cp = strrchr(file, '.');
        curp->gzip = (cp != NULL && ! strcmp(cp + 1, "gz"));

        /* First try to use the filename as it is. */

        if ((fd = open(file, O_RDONLY)) != -1)
                return fd;

        /*
         * If that doesn't work and the filename doesn't
         * already  end in .gz, try appending .gz.
         */

        if ( ! curp->gzip) {
                mandoc_asprintf(&cp, "%s.gz", file);
                fd = open(cp, O_RDONLY);
                free(cp);
                if (fd != -1) {
                        curp->gzip = 1;
                        return fd;
                }
        }

        /* Neither worked, give up. */

        mandoc_msg(MANDOCERR_FILE, curp, 0, 0, strerror(errno));
        return -1;
}

struct mparse *
mparse_alloc(int options, enum mandoclevel wlevel, mandocmsg mmsg,
    const char *defos)
{
        struct mparse   *curp;

        curp = mandoc_calloc(1, sizeof(struct mparse));

        curp->options = options;
        curp->wlevel = wlevel;
        curp->mmsg = mmsg;
        curp->defos = defos;

        curp->roff = roff_alloc(curp, options);
        curp->man = roff_man_alloc( curp->roff, curp, curp->defos,
                curp->options & MPARSE_QUICK ? 1 : 0);
        if (curp->options & MPARSE_MDOC) {
                curp->man->macroset = MACROSET_MDOC;
                if (curp->man->mdocmac == NULL)
                        curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
        } else if (curp->options & MPARSE_MAN) {
                curp->man->macroset = MACROSET_MAN;
                if (curp->man->manmac == NULL)
                        curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
        }
        curp->man->first->tok = TOKEN_NONE;
        return curp;
}

void
mparse_reset(struct mparse *curp)
{
        roff_reset(curp->roff);
        roff_man_reset(curp->man);

        free(curp->sodest);
        curp->sodest = NULL;

        if (curp->secondary)
                curp->secondary->sz = 0;

        curp->file_status = MANDOCLEVEL_OK;
        curp->gzip = 0;
}

void
mparse_free(struct mparse *curp)
{

        roffhash_free(curp->man->mdocmac);
        roffhash_free(curp->man->manmac);
        roff_man_free(curp->man);
        roff_free(curp->roff);
        if (curp->secondary)
                free(curp->secondary->buf);

        free(curp->secondary);
        free(curp->sodest);
        free(curp);
}

void
mparse_result(struct mparse *curp, struct roff_man **man,
        char **sodest)
{

        if (sodest && NULL != (*sodest = curp->sodest)) {
                *man = NULL;
                return;
        }
        if (man)
                *man = curp->man;
}

void
mparse_updaterc(struct mparse *curp, enum mandoclevel *rc)
{
        if (curp->file_status > *rc)
                *rc = curp->file_status;
}

void
mandoc_vmsg(enum mandocerr t, struct mparse *m,
                int ln, int pos, const char *fmt, ...)
{
        char             buf[256];
        va_list          ap;

        va_start(ap, fmt);
        (void)vsnprintf(buf, sizeof(buf), fmt, ap);
        va_end(ap);

        mandoc_msg(t, m, ln, pos, buf);
}

void
mandoc_msg(enum mandocerr er, struct mparse *m,
                int ln, int col, const char *msg)
{
        enum mandoclevel level;

        level = MANDOCLEVEL_UNSUPP;
        while (er < mandoclimits[level])
                level--;

        if (level < m->wlevel && er != MANDOCERR_FILE)
                return;

        if (m->mmsg)
                (*m->mmsg)(er, level, m->file, ln, col, msg);

        if (m->file_status < level)
                m->file_status = level;
}

const char *
mparse_strerror(enum mandocerr er)
{

        return mandocerrs[er];
}

const char *
mparse_strlevel(enum mandoclevel lvl)
{
        return mandoclevels[lvl];
}

void
mparse_keep(struct mparse *p)
{

        assert(NULL == p->secondary);
        p->secondary = mandoc_calloc(1, sizeof(struct buf));
}

const char *
mparse_getkeep(const struct mparse *p)
{

        assert(p->secondary);
        return p->secondary->sz ? p->secondary->buf : NULL;
}