cmd/mandoc/html.c

/*  $Id: html.c,v 1.192 2016/01/04 12:45:29 schwarze Exp $ */
/*
 * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2011-2015 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.
 */
#include "config.h"

#include <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mandoc.h"
#include "mandoc_aux.h"
#include "out.h"
#include "html.h"
#include "manconf.h"
#include "main.h"

struct  htmldata {
    const char   *name;
    int       flags;
#define HTML_CLRLINE     (1 << 0)
#define HTML_NOSTACK     (1 << 1)
#define HTML_AUTOCLOSE   (1 << 2) /* Tag has auto-closure. */
};

static  const struct htmldata htmltags[TAG_MAX] = {
    {"html",    HTML_CLRLINE}, /* TAG_HTML */
    {"head",    HTML_CLRLINE}, /* TAG_HEAD */
    {"body",    HTML_CLRLINE}, /* TAG_BODY */
    {"meta",    HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_META */
    {"title",   HTML_CLRLINE}, /* TAG_TITLE */
    {"div",     HTML_CLRLINE}, /* TAG_DIV */
    {"h1",      0}, /* TAG_H1 */
    {"h2",      0}, /* TAG_H2 */
    {"span",    0}, /* TAG_SPAN */
    {"link",    HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_LINK */
    {"br",      HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_BR */
    {"a",       0}, /* TAG_A */
    {"table",   HTML_CLRLINE}, /* TAG_TABLE */
    {"tbody",   HTML_CLRLINE}, /* TAG_TBODY */
    {"col",     HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_COL */
    {"tr",      HTML_CLRLINE}, /* TAG_TR */
    {"td",      HTML_CLRLINE}, /* TAG_TD */
    {"li",      HTML_CLRLINE}, /* TAG_LI */
    {"ul",      HTML_CLRLINE}, /* TAG_UL */
    {"ol",      HTML_CLRLINE}, /* TAG_OL */
    {"dl",      HTML_CLRLINE}, /* TAG_DL */
    {"dt",      HTML_CLRLINE}, /* TAG_DT */
    {"dd",      HTML_CLRLINE}, /* TAG_DD */
    {"blockquote",  HTML_CLRLINE}, /* TAG_BLOCKQUOTE */
    {"pre",     HTML_CLRLINE }, /* TAG_PRE */
    {"b",       0 }, /* TAG_B */
    {"i",       0 }, /* TAG_I */
    {"code",    0 }, /* TAG_CODE */
    {"small",   0 }, /* TAG_SMALL */
    {"style",   HTML_CLRLINE}, /* TAG_STYLE */
    {"math",    HTML_CLRLINE}, /* TAG_MATH */
    {"mrow",    0}, /* TAG_MROW */
    {"mi",      0}, /* TAG_MI */
    {"mo",      0}, /* TAG_MO */
    {"msup",    0}, /* TAG_MSUP */
    {"msub",    0}, /* TAG_MSUB */
    {"msubsup", 0}, /* TAG_MSUBSUP */
    {"mfrac",   0}, /* TAG_MFRAC */
    {"msqrt",   0}, /* TAG_MSQRT */
    {"mfenced", 0}, /* TAG_MFENCED */
    {"mtable",  0}, /* TAG_MTABLE */
    {"mtr",     0}, /* TAG_MTR */
    {"mtd",     0}, /* TAG_MTD */
    {"munderover",  0}, /* TAG_MUNDEROVER */
    {"munder",  0}, /* TAG_MUNDER*/
    {"mover",   0}, /* TAG_MOVER*/
};

static  const char  *const htmlattrs[ATTR_MAX] = {
    "name", /* ATTR_NAME */
    "rel", /* ATTR_REL */
    "href", /* ATTR_HREF */
    "type", /* ATTR_TYPE */
    "media", /* ATTR_MEDIA */
    "class", /* ATTR_CLASS */
    "style", /* ATTR_STYLE */
    "id", /* ATTR_ID */
    "colspan", /* ATTR_COLSPAN */
    "charset", /* ATTR_CHARSET */
    "open", /* ATTR_OPEN */
    "close", /* ATTR_CLOSE */
    "mathvariant", /* ATTR_MATHVARIANT */
};

static  const char  *const roffscales[SCALE_MAX] = {
    "cm", /* SCALE_CM */
    "in", /* SCALE_IN */
    "pc", /* SCALE_PC */
    "pt", /* SCALE_PT */
    "em", /* SCALE_EM */
    "em", /* SCALE_MM */
    "ex", /* SCALE_EN */
    "ex", /* SCALE_BU */
    "em", /* SCALE_VS */
    "ex", /* SCALE_FS */
};

static  void     bufncat(struct html *, const char *, size_t);
static  void     print_ctag(struct html *, struct tag *);
static  int  print_escape(char);
static  int  print_encode(struct html *, const char *, int);
static  void     print_metaf(struct html *, enum mandoc_esc);
static  void     print_attr(struct html *, const char *, const char *);


void *
html_alloc(const struct manoutput *outopts)
{
    struct html *h;

    h = mandoc_calloc(1, sizeof(struct html));

    h->tags.head = NULL;
    h->style = outopts->style;
    h->base_man = outopts->man;
    h->base_includes = outopts->includes;
    if (outopts->fragment)
        h->oflags |= HTML_FRAGMENT;

    return h;
}

void
html_free(void *p)
{
    struct tag  *tag;
    struct html *h;

    h = (struct html *)p;

    while ((tag = h->tags.head) != NULL) {
        h->tags.head = tag->next;
        free(tag);
    }

    free(h);
}

void
print_gen_head(struct html *h)
{
    struct htmlpair  tag[4];
    struct tag  *t;

    tag[0].key = ATTR_CHARSET;
    tag[0].val = "utf-8";
    print_otag(h, TAG_META, 1, tag);

    /*
     * Print a default style-sheet.
     */
    t = print_otag(h, TAG_STYLE, 0, NULL);
    print_text(h, "table.head, table.foot { width: 100%; }\n"
          "td.head-rtitle, td.foot-os { text-align: right; }\n"
          "td.head-vol { text-align: center; }\n"
          "table.foot td { width: 50%; }\n"
          "table.head td { width: 33%; }\n"
          "div.spacer { margin: 1em 0; }\n");
    print_tagq(h, t);

    if (h->style) {
        tag[0].key = ATTR_REL;
        tag[0].val = "stylesheet";
        tag[1].key = ATTR_HREF;
        tag[1].val = h->style;
        tag[2].key = ATTR_TYPE;
        tag[2].val = "text/css";
        tag[3].key = ATTR_MEDIA;
        tag[3].val = "all";
        print_otag(h, TAG_LINK, 4, tag);
    }
}

static void
print_metaf(struct html *h, enum mandoc_esc deco)
{
    enum htmlfont    font;

    switch (deco) {
    case ESCAPE_FONTPREV:
        font = h->metal;
        break;
    case ESCAPE_FONTITALIC:
        font = HTMLFONT_ITALIC;
        break;
    case ESCAPE_FONTBOLD:
        font = HTMLFONT_BOLD;
        break;
    case ESCAPE_FONTBI:
        font = HTMLFONT_BI;
        break;
    case ESCAPE_FONT:
    case ESCAPE_FONTROMAN:
        font = HTMLFONT_NONE;
        break;
    default:
        abort();
    }

    if (h->metaf) {
        print_tagq(h, h->metaf);
        h->metaf = NULL;
    }

    h->metal = h->metac;
    h->metac = font;

    switch (font) {
    case HTMLFONT_ITALIC:
        h->metaf = print_otag(h, TAG_I, 0, NULL);
        break;
    case HTMLFONT_BOLD:
        h->metaf = print_otag(h, TAG_B, 0, NULL);
        break;
    case HTMLFONT_BI:
        h->metaf = print_otag(h, TAG_B, 0, NULL);
        print_otag(h, TAG_I, 0, NULL);
        break;
    default:
        break;
    }
}

int
html_strlen(const char *cp)
{
    size_t       rsz;
    int      skip, sz;

    /*
     * Account for escaped sequences within string length
     * calculations.  This follows the logic in term_strlen() as we
     * must calculate the width of produced strings.
     * Assume that characters are always width of "1".  This is
     * hacky, but it gets the job done for approximation of widths.
     */

    sz = 0;
    skip = 0;
    while (1) {
        rsz = strcspn(cp, "\\");
        if (rsz) {
            cp += rsz;
            if (skip) {
                skip = 0;
                rsz--;
            }
            sz += rsz;
        }
        if ('\0' == *cp)
            break;
        cp++;
        switch (mandoc_escape(&cp, NULL, NULL)) {
        case ESCAPE_ERROR:
            return sz;
        case ESCAPE_UNICODE:
        case ESCAPE_NUMBERED:
        case ESCAPE_SPECIAL:
        case ESCAPE_OVERSTRIKE:
            if (skip)
                skip = 0;
            else
                sz++;
            break;
        case ESCAPE_SKIPCHAR:
            skip = 1;
            break;
        default:
            break;
        }
    }
    return sz;
}

static int
print_escape(char c)
{

    switch (c) {
    case '<':
        printf("&lt;");
        break;
    case '>':
        printf("&gt;");
        break;
    case '&':
        printf("&amp;");
        break;
    case '"':
        printf("&quot;");
        break;
    case ASCII_NBRSP:
        printf("&nbsp;");
        break;
    case ASCII_HYPH:
        putchar('-');
        break;
    case ASCII_BREAK:
        break;
    default:
        return 0;
    }
    return 1;
}

static int
print_encode(struct html *h, const char *p, int norecurse)
{
    size_t       sz;
    int      c, len, nospace;
    const char  *seq;
    enum mandoc_esc  esc;
    static const char rejs[9] = { '\\', '<', '>', '&', '"',
        ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };

    nospace = 0;

    while ('\0' != *p) {
        if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
            h->flags &= ~HTML_SKIPCHAR;
            p++;
            continue;
        }

        sz = strcspn(p, rejs);

        fwrite(p, 1, sz, stdout);
        p += (int)sz;

        if ('\0' == *p)
            break;

        if (print_escape(*p++))
            continue;

        esc = mandoc_escape(&p, &seq, &len);
        if (ESCAPE_ERROR == esc)
            break;

        switch (esc) {
        case ESCAPE_FONT:
        case ESCAPE_FONTPREV:
        case ESCAPE_FONTBOLD:
        case ESCAPE_FONTITALIC:
        case ESCAPE_FONTBI:
        case ESCAPE_FONTROMAN:
            if (0 == norecurse)
                print_metaf(h, esc);
            continue;
        case ESCAPE_SKIPCHAR:
            h->flags |= HTML_SKIPCHAR;
            continue;
        default:
            break;
        }

        if (h->flags & HTML_SKIPCHAR) {
            h->flags &= ~HTML_SKIPCHAR;
            continue;
        }

        switch (esc) {
        case ESCAPE_UNICODE:
            /* Skip past "u" header. */
            c = mchars_num2uc(seq + 1, len - 1);
            break;
        case ESCAPE_NUMBERED:
            c = mchars_num2char(seq, len);
            if (c < 0)
                continue;
            break;
        case ESCAPE_SPECIAL:
            c = mchars_spec2cp(seq, len);
            if (c <= 0)
                continue;
            break;
        case ESCAPE_NOSPACE:
            if ('\0' == *p)
                nospace = 1;
            continue;
        case ESCAPE_OVERSTRIKE:
            if (len == 0)
                continue;
            c = seq[len - 1];
            break;
        default:
            continue;
        }
        if ((c < 0x20 && c != 0x09) ||
            (c > 0x7E && c < 0xA0))
            c = 0xFFFD;
        if (c > 0x7E)
            printf("&#%d;", c);
        else if ( ! print_escape(c))
            putchar(c);
    }

    return nospace;
}

static void
print_attr(struct html *h, const char *key, const char *val)
{
    printf(" %s=\"", key);
    (void)print_encode(h, val, 1);
    putchar('\"');
}

struct tag *
print_otag(struct html *h, enum htmltag tag,
        int sz, const struct htmlpair *p)
{
    int      i;
    struct tag  *t;

    /* Push this tags onto the stack of open scopes. */

    if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
        t = mandoc_malloc(sizeof(struct tag));
        t->tag = tag;
        t->next = h->tags.head;
        h->tags.head = t;
    } else
        t = NULL;

    if ( ! (HTML_NOSPACE & h->flags))
        if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
            /* Manage keeps! */
            if ( ! (HTML_KEEP & h->flags)) {
                if (HTML_PREKEEP & h->flags)
                    h->flags |= HTML_KEEP;
                putchar(' ');
            } else
                printf("&#160;");
        }

    if ( ! (h->flags & HTML_NONOSPACE))
        h->flags &= ~HTML_NOSPACE;
    else
        h->flags |= HTML_NOSPACE;

    /* Print out the tag name and attributes. */

    printf("<%s", htmltags[tag].name);
    for (i = 0; i < sz; i++)
        print_attr(h, htmlattrs[p[i].key], p[i].val);

    /* Accommodate for "well-formed" singleton escaping. */

    if (HTML_AUTOCLOSE & htmltags[tag].flags)
        putchar('/');

    putchar('>');

    h->flags |= HTML_NOSPACE;

    if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
        putchar('\n');

    return t;
}

static void
print_ctag(struct html *h, struct tag *tag)
{

    /*
     * Remember to close out and nullify the current
     * meta-font and table, if applicable.
     */
    if (tag == h->metaf)
        h->metaf = NULL;
    if (tag == h->tblt)
        h->tblt = NULL;

    printf("</%s>", htmltags[tag->tag].name);
    if (HTML_CLRLINE & htmltags[tag->tag].flags) {
        h->flags |= HTML_NOSPACE;
        putchar('\n');
    }

    h->tags.head = tag->next;
    free(tag);
}

void
print_gen_decls(struct html *h)
{

    puts("<!DOCTYPE html>");
}

void
print_text(struct html *h, const char *word)
{

    if ( ! (HTML_NOSPACE & h->flags)) {
        /* Manage keeps! */
        if ( ! (HTML_KEEP & h->flags)) {
            if (HTML_PREKEEP & h->flags)
                h->flags |= HTML_KEEP;
            putchar(' ');
        } else
            printf("&#160;");
    }

    assert(NULL == h->metaf);
    switch (h->metac) {
    case HTMLFONT_ITALIC:
        h->metaf = print_otag(h, TAG_I, 0, NULL);
        break;
    case HTMLFONT_BOLD:
        h->metaf = print_otag(h, TAG_B, 0, NULL);
        break;
    case HTMLFONT_BI:
        h->metaf = print_otag(h, TAG_B, 0, NULL);
        print_otag(h, TAG_I, 0, NULL);
        break;
    default:
        break;
    }

    assert(word);
    if ( ! print_encode(h, word, 0)) {
        if ( ! (h->flags & HTML_NONOSPACE))
            h->flags &= ~HTML_NOSPACE;
        h->flags &= ~HTML_NONEWLINE;
    } else
        h->flags |= HTML_NOSPACE | HTML_NONEWLINE;

    if (h->metaf) {
        print_tagq(h, h->metaf);
        h->metaf = NULL;
    }

    h->flags &= ~HTML_IGNDELIM;
}

void
print_tagq(struct html *h, const struct tag *until)
{
    struct tag  *tag;

    while ((tag = h->tags.head) != NULL) {
        print_ctag(h, tag);
        if (until && tag == until)
            return;
    }
}

void
print_stagq(struct html *h, const struct tag *suntil)
{
    struct tag  *tag;

    while ((tag = h->tags.head) != NULL) {
        if (suntil && tag == suntil)
            return;
        print_ctag(h, tag);
    }
}

void
print_paragraph(struct html *h)
{
    struct tag  *t;
    struct htmlpair  tag;

    PAIR_CLASS_INIT(&tag, "spacer");
    t = print_otag(h, TAG_DIV, 1, &tag);
    print_tagq(h, t);
}


void
bufinit(struct html *h)
{

    h->buf[0] = '\0';
    h->buflen = 0;
}

void
bufcat_style(struct html *h, const char *key, const char *val)
{

    bufcat(h, key);
    bufcat(h, ":");
    bufcat(h, val);
    bufcat(h, ";");
}

void
bufcat(struct html *h, const char *p)
{

    /*
     * XXX This is broken and not easy to fix.
     * When using the -Oincludes option, buffmt_includes()
     * may pass in strings overrunning BUFSIZ, causing a crash.
     */

    h->buflen = strlcat(h->buf, p, BUFSIZ);
    assert(h->buflen < BUFSIZ);
}

void
bufcat_fmt(struct html *h, const char *fmt, ...)
{
    va_list      ap;

    va_start(ap, fmt);
    (void)vsnprintf(h->buf + (int)h->buflen,
        BUFSIZ - h->buflen - 1, fmt, ap);
    va_end(ap);
    h->buflen = strlen(h->buf);
}

static void
bufncat(struct html *h, const char *p, size_t sz)
{

    assert(h->buflen + sz + 1 < BUFSIZ);
    strncat(h->buf, p, sz);
    h->buflen += sz;
}

void
buffmt_includes(struct html *h, const char *name)
{
    const char  *p, *pp;

    pp = h->base_includes;

    bufinit(h);
    while (NULL != (p = strchr(pp, '%'))) {
        bufncat(h, pp, (size_t)(p - pp));
        switch (*(p + 1)) {
        case'I':
            bufcat(h, name);
            break;
        default:
            bufncat(h, p, 2);
            break;
        }
        pp = p + 2;
    }
    if (pp)
        bufcat(h, pp);
}

void
buffmt_man(struct html *h, const char *name, const char *sec)
{
    const char  *p, *pp;

    pp = h->base_man;

    bufinit(h);
    while (NULL != (p = strchr(pp, '%'))) {
        bufncat(h, pp, (size_t)(p - pp));
        switch (*(p + 1)) {
        case 'S':
            bufcat(h, sec ? sec : "1");
            break;
        case 'N':
            bufcat_fmt(h, "%s", name);
            break;
        default:
            bufncat(h, p, 2);
            break;
        }
        pp = p + 2;
    }
    if (pp)
        bufcat(h, pp);
}

void
bufcat_su(struct html *h, const char *p, const struct roffsu *su)
{
    double       v;

    v = su->scale;
    if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
        v = 1.0;
    else if (SCALE_BU == su->unit)
        v /= 24.0;

    bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
}

void
bufcat_id(struct html *h, const char *src)
{

    /* Cf. <http://www.w3.org/TR/html5/dom.html#the-id-attribute>. */

    for (; '\0' != *src; src++)
        bufncat(h, *src == ' ' ? "_" : src, 1);
}