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else/SnudownTest/markdown.c
unknown 80966b7fb8 else
2015-11-20 04:08:53 -08:00

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/* markdown.c - generic markdown parser */
/*
* Copyright (c) 2009, Natacha Porté
* Copyright (c) 2011, Vicent Marti
*
* 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 AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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 "markdown.h"
#include "stack.h"
#include <assert.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#if defined(_WIN32)
#define strncasecmp _strnicmp
#endif
#define REF_TABLE_SIZE 8
#define BUFFER_BLOCK 0
#define BUFFER_SPAN 1
#define MKD_LI_END 8 /* internal list flag */
#define gperf_case_strncmp(s1, s2, n) strncasecmp(s1, s2, n)
#define GPERF_DOWNCASE 1
#define GPERF_CASE_STRNCMP 1
#include "html_blocks.h"
#include "html_entities.h"
/***************
* LOCAL TYPES *
***************/
/* link_ref: reference to a link */
struct link_ref {
unsigned int id;
struct buf *link;
struct buf *title;
struct link_ref *next;
};
/* char_trigger: function pointer to render active chars */
/* returns the number of chars taken care of */
/* data is the pointer of the beginning of the span */
/* offset is the number of valid chars before data */
struct sd_markdown;
typedef size_t
(*char_trigger)(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_emphasis(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_linebreak(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_codespan(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_escape(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_entity(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_langle_tag(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_autolink_url(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_autolink_email(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_autolink_www(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_autolink_subreddit_or_username(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_link(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
static size_t char_superscript(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size);
enum markdown_char_t {
MD_CHAR_NONE = 0,
MD_CHAR_EMPHASIS,
MD_CHAR_CODESPAN,
MD_CHAR_LINEBREAK,
MD_CHAR_LINK,
MD_CHAR_LANGLE,
MD_CHAR_ESCAPE,
MD_CHAR_ENTITITY,
MD_CHAR_AUTOLINK_URL,
MD_CHAR_AUTOLINK_EMAIL,
MD_CHAR_AUTOLINK_WWW,
MD_CHAR_AUTOLINK_SUBREDDIT_OR_USERNAME,
MD_CHAR_SUPERSCRIPT,
};
static char_trigger markdown_char_ptrs[] = {
NULL,
&char_emphasis,
&char_codespan,
&char_linebreak,
&char_link,
&char_langle_tag,
&char_escape,
&char_entity,
&char_autolink_url,
&char_autolink_email,
&char_autolink_www,
&char_autolink_subreddit_or_username,
&char_superscript,
};
/* render • structure containing one particular render */
struct sd_markdown {
struct sd_callbacks cb;
void *opaque;
struct link_ref *refs[REF_TABLE_SIZE];
uint8_t active_char[256];
struct stack work_bufs[2];
unsigned int ext_flags;
size_t max_nesting;
size_t max_table_cols;
int in_link_body;
};
/***************************
* HELPER FUNCTIONS *
***************************/
static inline struct buf *
rndr_newbuf(struct sd_markdown *rndr, int type)
{
static const size_t buf_size[2] = {256, 64};
struct buf *work = NULL;
struct stack *pool = &rndr->work_bufs[type];
if (pool->size < pool->asize &&
pool->item[pool->size] != NULL) {
work = pool->item[pool->size++];
work->size = 0;
} else {
work = bufnew(buf_size[type]);
stack_push(pool, work);
}
return work;
}
static inline void
rndr_popbuf(struct sd_markdown *rndr, int type)
{
rndr->work_bufs[type].size--;
}
static void
unscape_text(struct buf *ob, struct buf *src)
{
size_t i = 0, org;
while (i < src->size) {
org = i;
while (i < src->size && src->data[i] != '\\')
i++;
if (i > org)
bufput(ob, src->data + org, i - org);
if (i + 1 >= src->size)
break;
bufputc(ob, src->data[i + 1]);
i += 2;
}
}
static unsigned int
hash_link_ref(const uint8_t *link_ref, size_t length)
{
size_t i;
unsigned int hash = 0;
for (i = 0; i < length; ++i)
hash = tolower(link_ref[i]) + (hash << 6) + (hash << 16) - hash;
return hash;
}
static struct link_ref *
add_link_ref(
struct link_ref **references,
const uint8_t *name, size_t name_size)
{
struct link_ref *ref = calloc(1, sizeof(struct link_ref));
if (!ref)
return NULL;
ref->id = hash_link_ref(name, name_size);
ref->next = references[ref->id % REF_TABLE_SIZE];
references[ref->id % REF_TABLE_SIZE] = ref;
return ref;
}
static struct link_ref *
find_link_ref(struct link_ref **references, uint8_t *name, size_t length)
{
unsigned int hash = hash_link_ref(name, length);
struct link_ref *ref = NULL;
ref = references[hash % REF_TABLE_SIZE];
while (ref != NULL) {
if (ref->id == hash)
return ref;
ref = ref->next;
}
return NULL;
}
static void
free_link_refs(struct link_ref **references)
{
size_t i;
for (i = 0; i < REF_TABLE_SIZE; ++i) {
struct link_ref *r = references[i];
struct link_ref *next;
while (r) {
next = r->next;
bufrelease(r->link);
bufrelease(r->title);
free(r);
r = next;
}
}
}
/*
* Check whether a char is a Markdown space.
* Right now we only consider spaces the actual
* space and a newline: tabs and carriage returns
* are filtered out during the preprocessing phase.
*
* If we wanted to actually be UTF-8 compliant, we
* should instead extract an Unicode codepoint from
* this character and check for space properties.
*/
static inline int
_isspace(int c)
{
return c == ' ' || c == '\n';
}
/****************************
* INLINE PARSING FUNCTIONS *
****************************/
/* is_mail_autolink • looks for the address part of a mail autolink and '>' */
/* this is less strict than the original markdown e-mail address matching */
static size_t
is_mail_autolink(uint8_t *data, size_t size)
{
size_t i = 0, nb = 0;
/* address is assumed to be: [-@._a-zA-Z0-9]+ with exactly one '@' */
for (i = 0; i < size; ++i) {
if (isalnum(data[i]))
continue;
switch (data[i]) {
case '@':
nb++;
case '-':
case '.':
case '_':
break;
case '>':
return (nb == 1) ? i + 1 : 0;
default:
return 0;
}
}
return 0;
}
/* tag_length • returns the length of the given tag, or 0 is it's not valid */
static size_t
tag_length(uint8_t *data, size_t size, enum mkd_autolink *autolink)
{
size_t i, j;
/* a valid tag can't be shorter than 3 chars */
if (size < 3) return 0;
/* begins with a '<' optionally followed by '/', followed by letter or number */
if (data[0] != '<') return 0;
i = (data[1] == '/') ? 2 : 1;
if (!isalnum(data[i]))
return 0;
/* scheme test */
*autolink = MKDA_NOT_AUTOLINK;
/* try to find the beginning of an URI */
while (i < size && (isalnum(data[i]) || data[i] == '.' || data[i] == '+' || data[i] == '-'))
i++;
if (i > 1 && data[i] == '@') {
if ((j = is_mail_autolink(data + i, size - i)) != 0) {
*autolink = MKDA_EMAIL;
return i + j;
}
}
if (i > 2 && data[i] == ':') {
*autolink = MKDA_NORMAL;
i++;
}
/* completing autolink test: no whitespace or ' or " */
if (i >= size)
*autolink = MKDA_NOT_AUTOLINK;
else if (*autolink) {
j = i;
while (i < size) {
if (data[i] == '\\') i += 2;
else if (data[i] == '>' || data[i] == '\'' ||
data[i] == '"' || data[i] == ' ' || data[i] == '\n')
break;
else i++;
}
if (i >= size) return 0;
if (i > j && data[i] == '>') return i + 1;
/* one of the forbidden chars has been found */
*autolink = MKDA_NOT_AUTOLINK;
}
/* looking for sometinhg looking like a tag end */
while (i < size && data[i] != '>') i++;
if (i >= size) return 0;
return i + 1;
}
/* parse_inline • parses inline markdown elements */
static void
parse_inline(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t i = 0, end = 0, last_special = 0;
uint8_t action = 0;
struct buf work = { 0, 0, 0, 0 };
if (rndr->work_bufs[BUFFER_SPAN].size +
rndr->work_bufs[BUFFER_BLOCK].size > rndr->max_nesting)
return;
while (i < size) {
/* copying inactive chars into the output */
while (end < size && (action = rndr->active_char[data[end]]) == 0) {
end++;
}
if (rndr->cb.normal_text) {
work.data = data + i;
work.size = end - i;
rndr->cb.normal_text(ob, &work, rndr->opaque);
}
else
bufput(ob, data + i, end - i);
if (end >= size) break;
i = end;
end = markdown_char_ptrs[(int)action](ob, rndr, data + i, i - last_special, i, size - i);
if (!end) /* no action from the callback */
end = i + 1;
else {
i += end;
last_special = end = i;
}
}
}
/* find_emph_char • looks for the next emph uint8_t, skipping other constructs */
static size_t
find_emph_char(uint8_t *data, size_t size, uint8_t c)
{
size_t i = 1;
while (i < size) {
while (i < size && data[i] != c && data[i] != '`' && data[i] != '[')
i++;
if (i == size)
return 0;
if (data[i] == c)
return i;
/* not counting escaped chars */
if (i && data[i - 1] == '\\') {
i++; continue;
}
if (data[i] == '`') {
size_t span_nb = 0, bt;
size_t tmp_i = 0;
/* counting the number of opening backticks */
while (i < size && data[i] == '`') {
i++; span_nb++;
}
if (i >= size) return 0;
/* finding the matching closing sequence */
bt = 0;
while (i < size && bt < span_nb) {
if (!tmp_i && data[i] == c) tmp_i = i;
if (data[i] == '`') bt++;
else bt = 0;
i++;
}
if (i >= size) return tmp_i;
}
/* skipping a link */
else if (data[i] == '[') {
size_t tmp_i = 0;
uint8_t cc;
i++;
while (i < size && data[i] != ']') {
if (!tmp_i && data[i] == c) tmp_i = i;
i++;
}
i++;
while (i < size && (data[i] == ' ' || data[i] == '\n'))
i++;
if (i >= size)
return tmp_i;
switch (data[i]) {
case '[':
cc = ']'; break;
case '(':
cc = ')'; break;
default:
if (tmp_i)
return tmp_i;
else
continue;
}
i++;
while (i < size && data[i] != cc) {
if (!tmp_i && data[i] == c) tmp_i = i;
i++;
}
if (i >= size)
return tmp_i;
i++;
}
}
return 0;
}
/* parse_emph1 • parsing single emphase */
/* closed by a symbol not preceded by whitespace and not followed by symbol */
static size_t
parse_emph1(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, uint8_t c)
{
size_t i = 0, len;
struct buf *work = 0;
int r;
if (!rndr->cb.emphasis) return 0;
/* skipping one symbol if coming from emph3 */
if (size > 1 && data[0] == c && data[1] == c) i = 1;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
if (i >= size) return 0;
if (data[i] == c && !_isspace(data[i - 1])) {
if ((rndr->ext_flags & MKDEXT_NO_INTRA_EMPHASIS) && (c == '_')) {
if (!(i + 1 == size || _isspace(data[i + 1]) || ispunct(data[i + 1])))
continue;
}
work = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(work, rndr, data, i);
r = rndr->cb.emphasis(ob, work, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
return r ? i + 1 : 0;
}
}
return 0;
}
/* parse_emph2 • parsing single emphase */
static size_t
parse_emph2(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, uint8_t c)
{
int (*render_method)(struct buf *ob, const struct buf *text, void *opaque);
size_t i = 0, len;
struct buf *work = 0;
int r;
render_method = (c == '~') ? rndr->cb.strikethrough : rndr->cb.double_emphasis;
if (!render_method)
return 0;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
if (i + 1 < size && data[i] == c && data[i + 1] == c && i && !_isspace(data[i - 1])) {
work = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(work, rndr, data, i);
r = render_method(ob, work, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
return r ? i + 2 : 0;
}
i++;
}
return 0;
}
/* parse_emph3 • parsing single emphase */
/* finds the first closing tag, and delegates to the other emph */
static size_t
parse_emph3(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, uint8_t c)
{
size_t i = 0, len;
int r;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
/* skip whitespace preceded symbols */
if (data[i] != c || _isspace(data[i - 1]))
continue;
if (i + 2 < size && data[i + 1] == c && data[i + 2] == c && rndr->cb.triple_emphasis) {
/* triple symbol found */
struct buf *work = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(work, rndr, data, i);
r = rndr->cb.triple_emphasis(ob, work, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
return r ? i + 3 : 0;
} else if (i + 1 < size && data[i + 1] == c) {
/* double symbol found, handing over to emph1 */
len = parse_emph1(ob, rndr, data - 2, size + 2, c);
if (!len) return 0;
else return len - 2;
} else {
/* single symbol found, handing over to emph2 */
len = parse_emph2(ob, rndr, data - 1, size + 1, c);
if (!len) return 0;
else return len - 1;
}
}
return 0;
}
/* char_emphasis • single and double emphasis parsing */
static size_t
char_emphasis(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
uint8_t c = data[0];
size_t ret;
if (size > 2 && data[1] != c) {
/* whitespace cannot follow an opening emphasis;
* strikethrough only takes two characters '~~' */
if (c == '~' || _isspace(data[1]) || (ret = parse_emph1(ob, rndr, data + 1, size - 1, c)) == 0)
return 0;
return ret + 1;
}
if (size > 3 && data[1] == c && data[2] != c) {
if (_isspace(data[2]) || (ret = parse_emph2(ob, rndr, data + 2, size - 2, c)) == 0)
return 0;
return ret + 2;
}
if (size > 4 && data[1] == c && data[2] == c && data[3] != c) {
if (c == '~' || _isspace(data[3]) || (ret = parse_emph3(ob, rndr, data + 3, size - 3, c)) == 0)
return 0;
return ret + 3;
}
return 0;
}
/* char_linebreak • '\n' preceded by two spaces (assuming linebreak != 0) */
static size_t
char_linebreak(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
if (max_rewind < 2 || data[-1] != ' ' || data[-2] != ' ')
return 0;
/* removing the last space from ob and rendering */
while (ob->size && ob->data[ob->size - 1] == ' ')
ob->size--;
return rndr->cb.linebreak(ob, rndr->opaque) ? 1 : 0;
}
/* char_codespan • '`' parsing a code span (assuming codespan != 0) */
static size_t
char_codespan(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
size_t end, nb = 0, i, f_begin, f_end;
/* counting the number of backticks in the delimiter */
while (nb < size && data[nb] == '`')
nb++;
/* finding the next delimiter */
i = 0;
for (end = nb; end < size && i < nb; end++) {
if (data[end] == '`') i++;
else i = 0;
}
if (i < nb && end >= size)
return 0; /* no matching delimiter */
/* trimming outside whitespaces */
f_begin = nb;
while (f_begin < end && data[f_begin] == ' ')
f_begin++;
f_end = end - nb;
while (f_end > nb && data[f_end-1] == ' ')
f_end--;
/* real code span */
if (f_begin < f_end) {
struct buf work = { data + f_begin, f_end - f_begin, 0, 0 };
if (!rndr->cb.codespan(ob, &work, rndr->opaque))
end = 0;
} else {
if (!rndr->cb.codespan(ob, 0, rndr->opaque))
end = 0;
}
return end;
}
/* char_escape • '\\' backslash escape */
static size_t
char_escape(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
static const char *escape_chars = "\\`*_{}[]()#+-.!:|&<>/^~";
struct buf work = { 0, 0, 0, 0 };
if (size > 1) {
if (strchr(escape_chars, data[1]) == NULL)
return 0;
if (rndr->cb.normal_text) {
work.data = data + 1;
work.size = 1;
rndr->cb.normal_text(ob, &work, rndr->opaque);
}
else bufputc(ob, data[1]);
} else if (size == 1) {
bufputc(ob, data[0]);
}
return 2;
}
/* char_entity • '&' escaped when it doesn't belong to an entity */
static size_t
char_entity(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
size_t end = 1;
size_t content_start;
size_t content_end;
struct buf work = { 0, 0, 0, 0 };
int numeric = 0;
int hex = 0;
int entity_base;
uint32_t entity_val;
if (end < size && data[end] == '#') {
numeric = 1;
end++;
}
if (end < size && numeric && tolower(data[end]) == 'x') {
hex = 1;
end++;
}
content_start = end;
while (end < size) {
const char c = data[end];
if (hex) {
if (!isxdigit(c)) break;
} else if (numeric) {
if (!isdigit(c)) break;
} else if (!isalnum(c)) {
break;
}
end++;
}
content_end = end;
if (end > content_start && end < size && data[end] == ';')
end++; /* well-formed entity */
else
return 0; /* not an entity */
/* way too long to be a valid numeric entity */
if (numeric && content_end - content_start > MAX_NUM_ENTITY_LEN)
return 0;
/* Validate the entity's contents */
if (numeric) {
if (hex)
entity_base = 16;
else
entity_base = 10;
// This is ok because it'll stop once it hits the ';'
entity_val = strtol((char*)data + content_start, NULL, entity_base);
if (!is_valid_numeric_entity(entity_val))
return 0;
} else {
if (!is_allowed_named_entity((const char *)data, end))
return 0;
}
if (rndr->cb.entity) {
work.data = data;
work.size = end;
rndr->cb.entity(ob, &work, rndr->opaque);
} else {
/* Necessary so we can normalize `&#X3E;` to `&#x3E;` */
bufputc(ob, '&');
if (numeric)
bufputc(ob, '#');
if (hex)
bufputc(ob, 'x');
bufput(ob, data + content_start, end - content_start);
}
return end;
}
/* char_langle_tag • '<' when tags or autolinks are allowed */
static size_t
char_langle_tag(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
enum mkd_autolink altype = MKDA_NOT_AUTOLINK;
size_t end = tag_length(data, size, &altype);
struct buf work = { data, end, 0, 0 };
int ret = 0;
if (end > 2) {
if (rndr->cb.autolink && altype != MKDA_NOT_AUTOLINK) {
struct buf *u_link = rndr_newbuf(rndr, BUFFER_SPAN);
work.data = data + 1;
work.size = end - 2;
unscape_text(u_link, &work);
ret = rndr->cb.autolink(ob, u_link, altype, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
}
else if (rndr->cb.raw_html_tag)
ret = rndr->cb.raw_html_tag(ob, &work, rndr->opaque);
}
if (!ret) return 0;
else return end;
}
static size_t
char_autolink_www(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
struct buf *link, *link_url, *link_text;
size_t link_len, rewind;
if (!rndr->cb.link || rndr->in_link_body)
return 0;
link = rndr_newbuf(rndr, BUFFER_SPAN);
if ((link_len = sd_autolink__www(&rewind, link, data, max_rewind, size, 0)) > 0) {
link_url = rndr_newbuf(rndr, BUFFER_SPAN);
BUFPUTSL(link_url, "http://");
bufput(link_url, link->data, link->size);
buftruncate(ob, ob->size - rewind);
if (rndr->cb.normal_text) {
link_text = rndr_newbuf(rndr, BUFFER_SPAN);
rndr->cb.normal_text(link_text, link, rndr->opaque);
rndr->cb.link(ob, link_url, NULL, link_text, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
} else {
rndr->cb.link(ob, link_url, NULL, link, rndr->opaque);
}
rndr_popbuf(rndr, BUFFER_SPAN);
}
rndr_popbuf(rndr, BUFFER_SPAN);
return link_len;
}
static size_t
char_autolink_subreddit_or_username(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
struct buf *link, *link_text, *link_url;
size_t link_len, rewind;
int no_slash;
if (!rndr->cb.autolink || rndr->in_link_body)
return 0;
link = rndr_newbuf(rndr, BUFFER_SPAN);
link_len = sd_autolink__subreddit(&rewind, link, data, max_rewind, max_lookbehind, size, &no_slash);
if (link_len == 0)
link_len = sd_autolink__username(&rewind, link, data, max_rewind, max_lookbehind, size, &no_slash);
/* Found either a user or subreddit link */
if (link_len > 0) {
link_url = rndr_newbuf(rndr, BUFFER_SPAN);
if (no_slash)
bufputc(link_url, '/');
bufput(link_url, link->data, link->size);
buftruncate(ob, ob->size - rewind);
if (rndr->cb.normal_text) {
link_text = rndr_newbuf(rndr, BUFFER_SPAN);
rndr->cb.normal_text(link_text, link, rndr->opaque);
rndr->cb.link(ob, link_url, NULL, link_text, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
} else {
rndr->cb.link(ob, link_url, NULL, link, rndr->opaque);
}
rndr_popbuf(rndr, BUFFER_SPAN);
}
rndr_popbuf(rndr, BUFFER_SPAN);
return link_len;
}
static size_t
char_autolink_email(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
struct buf *link;
size_t link_len, rewind;
if (!rndr->cb.autolink || rndr->in_link_body)
return 0;
link = rndr_newbuf(rndr, BUFFER_SPAN);
if ((link_len = sd_autolink__email(&rewind, link, data, max_rewind, size, 0)) > 0) {
buftruncate(ob, ob->size - rewind);
rndr->cb.autolink(ob, link, MKDA_EMAIL, rndr->opaque);
}
rndr_popbuf(rndr, BUFFER_SPAN);
return link_len;
}
static size_t
char_autolink_url(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
struct buf *link;
size_t link_len, rewind;
if (!rndr->cb.autolink || rndr->in_link_body)
return 0;
link = rndr_newbuf(rndr, BUFFER_SPAN);
if ((link_len = sd_autolink__url(&rewind, link, data, max_rewind, size, 0)) > 0) {
buftruncate(ob, ob->size - rewind);
rndr->cb.autolink(ob, link, MKDA_NORMAL, rndr->opaque);
}
rndr_popbuf(rndr, BUFFER_SPAN);
return link_len;
}
/* char_link • '[': parsing a link or an image */
static size_t
char_link(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
int is_img = (max_rewind && data[-1] == '!'), level;
size_t i = 1, txt_e, link_b = 0, link_e = 0, title_b = 0, title_e = 0;
struct buf *content = 0;
struct buf *link = 0;
struct buf *title = 0;
struct buf *u_link = 0;
size_t org_work_size = rndr->work_bufs[BUFFER_SPAN].size;
int text_has_nl = 0, ret = 0;
int in_title = 0, qtype = 0;
/* checking whether the correct renderer exists */
if ((is_img && !rndr->cb.image) || (!is_img && !rndr->cb.link))
goto cleanup;
/* looking for the matching closing bracket */
for (level = 1; i < size; i++) {
if (data[i] == '\n')
text_has_nl = 1;
else if (data[i - 1] == '\\')
continue;
else if (data[i] == '[')
level++;
else if (data[i] == ']') {
level--;
if (level <= 0)
break;
}
}
if (i >= size)
goto cleanup;
txt_e = i;
i++;
/* skip any amount of whitespace or newline */
/* (this is much more laxist than original markdown syntax) */
while (i < size && _isspace(data[i]))
i++;
/* inline style link */
if (i < size && data[i] == '(') {
/* skipping initial whitespace */
i++;
while (i < size && _isspace(data[i]))
i++;
link_b = i;
/* looking for link end: ' " ) */
while (i < size) {
if (data[i] == '\\') i += 2;
else if (data[i] == ')') break;
else if (i >= 1 && _isspace(data[i-1]) && (data[i] == '\'' || data[i] == '"')) break;
else i++;
}
if (i >= size) goto cleanup;
link_e = i;
/* looking for title end if present */
if (data[i] == '\'' || data[i] == '"') {
qtype = data[i];
in_title = 1;
i++;
title_b = i;
while (i < size) {
if (data[i] == '\\') i += 2;
else if (data[i] == qtype) {in_title = 0; i++;}
else if ((data[i] == ')') && !in_title) break;
else i++;
}
if (i >= size) goto cleanup;
/* skipping whitespaces after title */
title_e = i - 1;
while (title_e > title_b && _isspace(data[title_e]))
title_e--;
/* checking for closing quote presence */
if (data[title_e] != '\'' && data[title_e] != '"') {
title_b = title_e = 0;
link_e = i;
}
}
/* remove whitespace at the end of the link */
while (link_e > link_b && _isspace(data[link_e - 1]))
link_e--;
/* remove optional angle brackets around the link */
if (data[link_b] == '<') link_b++;
if (data[link_e - 1] == '>') link_e--;
/* building escaped link and title */
if (link_e > link_b) {
link = rndr_newbuf(rndr, BUFFER_SPAN);
bufput(link, data + link_b, link_e - link_b);
}
if (title_e > title_b) {
title = rndr_newbuf(rndr, BUFFER_SPAN);
bufput(title, data + title_b, title_e - title_b);
}
i++;
}
/* reference style link */
else if (i < size && data[i] == '[') {
struct buf id = { 0, 0, 0, 0 };
struct link_ref *lr;
/* looking for the id */
i++;
link_b = i;
while (i < size && data[i] != ']') i++;
if (i >= size) goto cleanup;
link_e = i;
/* finding the link_ref */
if (link_b == link_e) {
if (text_has_nl) {
struct buf *b = rndr_newbuf(rndr, BUFFER_SPAN);
size_t j;
for (j = 1; j < txt_e; j++) {
if (data[j] != '\n')
bufputc(b, data[j]);
else if (data[j - 1] != ' ')
bufputc(b, ' ');
}
id.data = b->data;
id.size = b->size;
} else {
id.data = data + 1;
id.size = txt_e - 1;
}
} else {
id.data = data + link_b;
id.size = link_e - link_b;
}
lr = find_link_ref(rndr->refs, id.data, id.size);
if (!lr)
goto cleanup;
/* keeping link and title from link_ref */
link = lr->link;
title = lr->title;
i++;
}
/* shortcut reference style link */
else {
struct buf id = { 0, 0, 0, 0 };
struct link_ref *lr;
/* crafting the id */
if (text_has_nl) {
struct buf *b = rndr_newbuf(rndr, BUFFER_SPAN);
size_t j;
for (j = 1; j < txt_e; j++) {
if (data[j] != '\n')
bufputc(b, data[j]);
else if (data[j - 1] != ' ')
bufputc(b, ' ');
}
id.data = b->data;
id.size = b->size;
} else {
id.data = data + 1;
id.size = txt_e - 1;
}
/* finding the link_ref */
lr = find_link_ref(rndr->refs, id.data, id.size);
if (!lr)
goto cleanup;
/* keeping link and title from link_ref */
link = lr->link;
title = lr->title;
/* rewinding the whitespace */
i = txt_e + 1;
}
/* building content: img alt is escaped, link content is parsed */
if (txt_e > 1) {
content = rndr_newbuf(rndr, BUFFER_SPAN);
if (is_img) {
bufput(content, data + 1, txt_e - 1);
} else {
/* disable autolinking when parsing inline the
* content of a link */
rndr->in_link_body = 1;
parse_inline(content, rndr, data + 1, txt_e - 1);
rndr->in_link_body = 0;
}
}
if (link) {
u_link = rndr_newbuf(rndr, BUFFER_SPAN);
unscape_text(u_link, link);
} else {
goto cleanup;
}
/* calling the relevant rendering function */
if (is_img) {
if (ob->size && ob->data[ob->size - 1] == '!')
ob->size -= 1;
ret = rndr->cb.image(ob, u_link, title, content, rndr->opaque);
} else {
ret = rndr->cb.link(ob, u_link, title, content, rndr->opaque);
}
/* cleanup */
cleanup:
rndr->work_bufs[BUFFER_SPAN].size = (int)org_work_size;
return ret ? i : 0;
}
static size_t
char_superscript(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t max_rewind, size_t max_lookbehind, size_t size)
{
size_t sup_start, sup_len;
struct buf *sup;
if (!rndr->cb.superscript)
return 0;
if (size < 2)
return 0;
if (data[1] == '(') {
sup_start = sup_len = 2;
while (sup_len < size && data[sup_len] != ')' && data[sup_len - 1] != '\\')
sup_len++;
if (sup_len == size)
return 0;
} else {
sup_start = sup_len = 1;
while (sup_len < size && !_isspace(data[sup_len]))
sup_len++;
}
if (sup_len - sup_start == 0)
return (sup_start == 2) ? 3 : 0;
sup = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(sup, rndr, data + sup_start, sup_len - sup_start);
rndr->cb.superscript(ob, sup, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
return (sup_start == 2) ? sup_len + 1 : sup_len;
}
/*********************************
* BLOCK-LEVEL PARSING FUNCTIONS *
*********************************/
/* is_empty • returns the line length when it is empty, 0 otherwise */
static size_t
is_empty(uint8_t *data, size_t size)
{
size_t i;
for (i = 0; i < size && data[i] != '\n'; i++)
if (data[i] != ' ')
return 0;
return i + 1;
}
/* is_hrule • returns whether a line is a horizontal rule */
static int
is_hrule(uint8_t *data, size_t size)
{
size_t i = 0, n = 0;
uint8_t c;
/* skipping initial spaces */
if (size < 3) return 0;
if (data[0] == ' ') { i++;
if (data[1] == ' ') { i++;
if (data[2] == ' ') { i++; } } }
/* looking at the hrule uint8_t */
if (i + 2 >= size
|| (data[i] != '*' && data[i] != '-' && data[i] != '_'))
return 0;
c = data[i];
/* the whole line must be the char or whitespace */
while (i < size && data[i] != '\n') {
if (data[i] == c) n++;
else if (data[i] != ' ')
return 0;
i++;
}
return n >= 3;
}
/* check if a line begins with a code fence; return the
* width of the code fence */
static size_t
prefix_codefence(uint8_t *data, size_t size)
{
size_t i = 0, n = 0;
uint8_t c;
/* skipping initial spaces */
if (size < 3) return 0;
if (data[0] == ' ') { i++;
if (data[1] == ' ') { i++;
if (data[2] == ' ') { i++; } } }
/* looking at the hrule uint8_t */
if (i + 2 >= size || !(data[i] == '~' || data[i] == '`'))
return 0;
c = data[i];
/* the whole line must be the uint8_t or whitespace */
while (i < size && data[i] == c) {
n++; i++;
}
if (n < 3)
return 0;
return i;
}
/* check if a line is a code fence; return its size if it is */
static size_t
is_codefence(uint8_t *data, size_t size, struct buf *syntax)
{
size_t i = 0, syn_len = 0;
uint8_t *syn_start;
i = prefix_codefence(data, size);
if (i == 0)
return 0;
while (i < size && data[i] == ' ')
i++;
syn_start = data + i;
if (i < size && data[i] == '{') {
i++; syn_start++;
while (i < size && data[i] != '}' && data[i] != '\n') {
syn_len++; i++;
}
if (i == size || data[i] != '}')
return 0;
/* strip all whitespace at the beginning and the end
* of the {} block */
while (syn_len > 0 && _isspace(syn_start[0])) {
syn_start++; syn_len--;
}
while (syn_len > 0 && _isspace(syn_start[syn_len - 1]))
syn_len--;
i++;
} else {
while (i < size && !_isspace(data[i])) {
syn_len++; i++;
}
}
if (syntax) {
syntax->data = syn_start;
syntax->size = syn_len;
}
while (i < size && data[i] != '\n') {
if (!_isspace(data[i]))
return 0;
i++;
}
return i + 1;
}
/* is_atxheader • returns whether the line is a hash-prefixed header */
static int
is_atxheader(struct sd_markdown *rndr, uint8_t *data, size_t size)
{
if (data[0] != '#')
return 0;
if (rndr->ext_flags & MKDEXT_SPACE_HEADERS) {
size_t level = 0;
while (level < size && level < 6 && data[level] == '#')
level++;
if (level < size && data[level] != ' ')
return 0;
}
return 1;
}
/* is_headerline • returns whether the line is a setext-style hdr underline */
static int
is_headerline(uint8_t *data, size_t size)
{
size_t i = 0;
/* test of level 1 header */
if (data[i] == '=') {
for (i = 1; i < size && data[i] == '='; i++);
while (i < size && data[i] == ' ') i++;
return (i >= size || data[i] == '\n') ? 1 : 0; }
/* test of level 2 header */
if (data[i] == '-') {
for (i = 1; i < size && data[i] == '-'; i++);
while (i < size && data[i] == ' ') i++;
return (i >= size || data[i] == '\n') ? 2 : 0; }
return 0;
}
static int
is_next_headerline(uint8_t *data, size_t size)
{
size_t i = 0;
while (i < size && data[i] != '\n')
i++;
if (++i >= size)
return 0;
return is_headerline(data + i, size - i);
}
/* prefix_quote • returns blockquote prefix length */
static size_t
prefix_quote(uint8_t *data, size_t size)
{
size_t i = 0;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == '>') {
if (i + 1 < size && data[i + 1] == ' ')
return i + 2;
return i + 1;
}
return 0;
}
/* prefix_code • returns prefix length for block code*/
static size_t
prefix_code(uint8_t *data, size_t size)
{
if (size > 3 && data[0] == ' ' && data[1] == ' '
&& data[2] == ' ' && data[3] == ' ') return 4;
return 0;
}
/* prefix_oli • returns ordered list item prefix */
static size_t
prefix_oli(uint8_t *data, size_t size)
{
size_t i = 0;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i >= size || data[i] < '0' || data[i] > '9')
return 0;
while (i < size && data[i] >= '0' && data[i] <= '9')
i++;
if (i + 1 >= size || data[i] != '.' || data[i + 1] != ' ')
return 0;
if (is_next_headerline(data + i, size - i))
return 0;
return i + 2;
}
/* prefix_uli • returns ordered list item prefix */
static size_t
prefix_uli(uint8_t *data, size_t size)
{
size_t i = 0;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i < size && data[i] == ' ') i++;
if (i + 1 >= size ||
(data[i] != '*' && data[i] != '+' && data[i] != '-') ||
data[i + 1] != ' ')
return 0;
if (is_next_headerline(data + i, size - i))
return 0;
return i + 2;
}
/* parse_block • parsing of one block, returning next uint8_t to parse */
static void parse_block(struct buf *ob, struct sd_markdown *rndr,
uint8_t *data, size_t size);
/* parse_blockquote • handles parsing of a blockquote fragment */
static size_t
parse_blockquote(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t beg, end = 0, pre, work_size = 0;
uint8_t *work_data = 0;
struct buf *out = 0;
out = rndr_newbuf(rndr, BUFFER_BLOCK);
beg = 0;
while (beg < size) {
for (end = beg + 1; end < size && data[end - 1] != '\n'; end++);
pre = prefix_quote(data + beg, end - beg);
if (pre)
beg += pre; /* skipping prefix */
/* empty line followed by non-quote line */
else if (is_empty(data + beg, end - beg) &&
(end >= size || (prefix_quote(data + end, size - end) == 0 &&
!is_empty(data + end, size - end))))
break;
if (beg < end) { /* copy into the in-place working buffer */
/* bufput(work, data + beg, end - beg); */
if (!work_data)
work_data = data + beg;
else if (data + beg != work_data + work_size)
memmove(work_data + work_size, data + beg, end - beg);
work_size += end - beg;
}
beg = end;
}
parse_block(out, rndr, work_data, work_size);
if (rndr->cb.blockquote)
rndr->cb.blockquote(ob, out, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
return end;
}
static size_t
parse_htmlblock(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, int do_render);
/* parse_blockquote • handles parsing of a regular paragraph */
static size_t
parse_paragraph(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t i = 0, end = 0;
int level = 0;
struct buf work = { data, 0, 0, 0 };
while (i < size) {
for (end = i + 1; end < size && data[end - 1] != '\n'; end++) /* empty */;
if (prefix_quote(data + i, end - i) != 0) {
end = i;
break;
}
if (is_empty(data + i, size - i))
break;
if ((level = is_headerline(data + i, size - i)) != 0)
break;
if (is_atxheader(rndr, data + i, size - i) ||
is_hrule(data + i, size - i) ||
prefix_quote(data + i, size - i)) {
end = i;
break;
}
/*
* Early termination of a paragraph with the same logic
* as Markdown 1.0.0. If this logic is applied, the
* Markdown 1.0.3 test suite won't pass cleanly
*
* :: If the first character in a new line is not a letter,
* let's check to see if there's some kind of block starting
* here
*/
if ((rndr->ext_flags & MKDEXT_LAX_SPACING) && !isalnum(data[i])) {
if (prefix_oli(data + i, size - i) ||
prefix_uli(data + i, size - i)) {
end = i;
break;
}
/* see if an html block starts here */
if (data[i] == '<' && rndr->cb.blockhtml &&
parse_htmlblock(ob, rndr, data + i, size - i, 0)) {
end = i;
break;
}
/* see if a code fence starts here */
if ((rndr->ext_flags & MKDEXT_FENCED_CODE) != 0 &&
is_codefence(data + i, size - i, NULL) != 0) {
end = i;
break;
}
}
i = end;
}
work.size = i;
while (work.size && data[work.size - 1] == '\n')
work.size--;
if (!level) {
struct buf *tmp = rndr_newbuf(rndr, BUFFER_BLOCK);
parse_inline(tmp, rndr, work.data, work.size);
if (rndr->cb.paragraph)
rndr->cb.paragraph(ob, tmp, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
} else {
struct buf *header_work;
if (work.size) {
size_t beg;
i = work.size;
work.size -= 1;
while (work.size && data[work.size] != '\n')
work.size -= 1;
beg = work.size + 1;
while (work.size && data[work.size - 1] == '\n')
work.size -= 1;
if (work.size > 0) {
struct buf *tmp = rndr_newbuf(rndr, BUFFER_BLOCK);
parse_inline(tmp, rndr, work.data, work.size);
if (rndr->cb.paragraph)
rndr->cb.paragraph(ob, tmp, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
work.data += beg;
work.size = i - beg;
}
else work.size = i;
}
header_work = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(header_work, rndr, work.data, work.size);
if (rndr->cb.header)
rndr->cb.header(ob, header_work, (int)level, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
}
return end;
}
/* parse_fencedcode • handles parsing of a block-level code fragment */
static size_t
parse_fencedcode(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t beg, end;
struct buf *work = 0;
struct buf lang = { 0, 0, 0, 0 };
beg = is_codefence(data, size, &lang);
if (beg == 0) return 0;
work = rndr_newbuf(rndr, BUFFER_BLOCK);
while (beg < size) {
size_t fence_end;
struct buf fence_trail = { 0, 0, 0, 0 };
fence_end = is_codefence(data + beg, size - beg, &fence_trail);
if (fence_end != 0 && fence_trail.size == 0) {
beg += fence_end;
break;
}
for (end = beg + 1; end < size && data[end - 1] != '\n'; end++);
if (beg < end) {
/* verbatim copy to the working buffer,
escaping entities */
if (is_empty(data + beg, end - beg))
bufputc(work, '\n');
else bufput(work, data + beg, end - beg);
}
beg = end;
}
if (work->size && work->data[work->size - 1] != '\n')
bufputc(work, '\n');
if (rndr->cb.blockcode)
rndr->cb.blockcode(ob, work, lang.size ? &lang : NULL, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
return beg;
}
static size_t
parse_blockcode(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t beg, end, pre;
struct buf *work = 0;
work = rndr_newbuf(rndr, BUFFER_BLOCK);
beg = 0;
while (beg < size) {
for (end = beg + 1; end < size && data[end - 1] != '\n'; end++) {};
pre = prefix_code(data + beg, end - beg);
if (pre)
beg += pre; /* skipping prefix */
else if (!is_empty(data + beg, end - beg))
/* non-empty non-prefixed line breaks the pre */
break;
if (beg < end) {
/* verbatim copy to the working buffer,
escaping entities */
if (is_empty(data + beg, end - beg))
bufputc(work, '\n');
else bufput(work, data + beg, end - beg);
}
beg = end;
}
while (work->size && work->data[work->size - 1] == '\n')
work->size -= 1;
bufputc(work, '\n');
if (rndr->cb.blockcode)
rndr->cb.blockcode(ob, work, NULL, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
return beg;
}
/* parse_listitem • parsing of a single list item */
/* assuming initial prefix is already removed */
static size_t
parse_listitem(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, int *flags)
{
struct buf *work = 0, *inter = 0;
size_t beg = 0, end, pre, sublist = 0, orgpre = 0, i;
int in_empty = 0, has_inside_empty = 0, in_fence = 0;
/* keeping track of the first indentation prefix */
while (orgpre < 3 && orgpre < size && data[orgpre] == ' ')
orgpre++;
beg = prefix_uli(data, size);
if (!beg)
beg = prefix_oli(data, size);
if (!beg)
return 0;
/* skipping to the beginning of the following line */
end = beg;
while (end < size && data[end - 1] != '\n')
end++;
/* getting working buffers */
work = rndr_newbuf(rndr, BUFFER_SPAN);
inter = rndr_newbuf(rndr, BUFFER_SPAN);
/* putting the first line into the working buffer */
bufput(work, data + beg, end - beg);
beg = end;
/* process the following lines */
while (beg < size) {
size_t has_next_uli = 0, has_next_oli = 0;
end++;
while (end < size && data[end - 1] != '\n')
end++;
/* process an empty line */
if (is_empty(data + beg, end - beg)) {
in_empty = 1;
beg = end;
continue;
}
/* calculating the indentation */
i = 0;
while (i < 4 && beg + i < end && data[beg + i] == ' ')
i++;
pre = i;
if (rndr->ext_flags & MKDEXT_FENCED_CODE) {
if (is_codefence(data + beg + i, end - beg - i, NULL) != 0)
in_fence = !in_fence;
}
/* Only check for new list items if we are **not** inside
* a fenced code block */
if (!in_fence) {
has_next_uli = prefix_uli(data + beg + i, end - beg - i);
has_next_oli = prefix_oli(data + beg + i, end - beg - i);
}
/* checking for ul/ol switch */
if (in_empty && (
((*flags & MKD_LIST_ORDERED) && has_next_uli) ||
(!(*flags & MKD_LIST_ORDERED) && has_next_oli))){
*flags |= MKD_LI_END;
break; /* the following item must have same list type */
}
/* checking for a new item */
if ((has_next_uli && !is_hrule(data + beg + i, end - beg - i)) || has_next_oli) {
if (in_empty)
has_inside_empty = 1;
if (pre == orgpre) /* the following item must have */
break; /* the same indentation */
if (!sublist)
sublist = work->size;
}
/* joining only indented stuff after empty lines;
* note that now we only require 1 space of indentation
* to continue a list */
else if (in_empty && pre == 0) {
*flags |= MKD_LI_END;
break;
}
else if (in_empty) {
bufputc(work, '\n');
has_inside_empty = 1;
}
in_empty = 0;
/* adding the line without prefix into the working buffer */
bufput(work, data + beg + i, end - beg - i);
beg = end;
}
/* render of li contents */
if (has_inside_empty)
*flags |= MKD_LI_BLOCK;
if (*flags & MKD_LI_BLOCK) {
/* intermediate render of block li */
if (sublist && sublist < work->size) {
parse_block(inter, rndr, work->data, sublist);
parse_block(inter, rndr, work->data + sublist, work->size - sublist);
}
else
parse_block(inter, rndr, work->data, work->size);
} else {
/* intermediate render of inline li */
if (sublist && sublist < work->size) {
parse_inline(inter, rndr, work->data, sublist);
parse_block(inter, rndr, work->data + sublist, work->size - sublist);
}
else
parse_inline(inter, rndr, work->data, work->size);
}
/* render of li itself */
if (rndr->cb.listitem)
rndr->cb.listitem(ob, inter, *flags, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
rndr_popbuf(rndr, BUFFER_SPAN);
return beg;
}
/* parse_list • parsing ordered or unordered list block */
static size_t
parse_list(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, int flags)
{
struct buf *work = 0;
size_t i = 0, j;
work = rndr_newbuf(rndr, BUFFER_BLOCK);
while (i < size) {
j = parse_listitem(work, rndr, data + i, size - i, &flags);
i += j;
if (!j || (flags & MKD_LI_END))
break;
}
if (rndr->cb.list)
rndr->cb.list(ob, work, flags, rndr->opaque);
rndr_popbuf(rndr, BUFFER_BLOCK);
return i;
}
/* parse_atxheader • parsing of atx-style headers */
static size_t
parse_atxheader(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t level = 0;
size_t i, end, skip;
while (level < size && level < 6 && data[level] == '#')
level++;
for (i = level; i < size && data[i] == ' '; i++);
for (end = i; end < size && data[end] != '\n'; end++);
skip = end;
while (end && data[end - 1] == '#')
end--;
while (end && data[end - 1] == ' ')
end--;
if (end > i) {
struct buf *work = rndr_newbuf(rndr, BUFFER_SPAN);
parse_inline(work, rndr, data + i, end - i);
if (rndr->cb.header)
rndr->cb.header(ob, work, (int)level, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
}
return skip;
}
/* htmlblock_end • checking end of HTML block : </tag>[ \t]*\n[ \t*]\n */
/* returns the length on match, 0 otherwise */
static size_t
htmlblock_end_tag(
const char *tag,
size_t tag_len,
struct sd_markdown *rndr,
uint8_t *data,
size_t size)
{
size_t i, w;
/* checking if tag is a match */
if (tag_len + 3 >= size ||
strncasecmp((char *)data + 2, tag, tag_len) != 0 ||
data[tag_len + 2] != '>')
return 0;
/* checking white lines */
i = tag_len + 3;
w = 0;
if (i < size && (w = is_empty(data + i, size - i)) == 0)
return 0; /* non-blank after tag */
i += w;
w = 0;
if (i < size)
w = is_empty(data + i, size - i);
return i + w;
}
static size_t
htmlblock_end(const char *curtag,
struct sd_markdown *rndr,
uint8_t *data,
size_t size,
int start_of_line)
{
size_t tag_size = strlen(curtag);
size_t i = 1, end_tag;
int block_lines = 0;
while (i < size) {
i++;
while (i < size && !(data[i - 1] == '<' && data[i] == '/')) {
if (data[i] == '\n')
block_lines++;
i++;
}
/* If we are only looking for unindented tags, skip the tag
* if it doesn't follow a newline.
*
* The only exception to this is if the tag is still on the
* initial line; in that case it still counts as a closing
* tag
*/
if (start_of_line && block_lines > 0 && data[i - 2] != '\n')
continue;
if (i + 2 + tag_size >= size)
break;
end_tag = htmlblock_end_tag(curtag, tag_size, rndr, data + i - 1, size - i + 1);
if (end_tag)
return i + end_tag - 1;
}
return 0;
}
/* parse_htmlblock • parsing of inline HTML block */
static size_t
parse_htmlblock(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size, int do_render)
{
size_t i, j = 0, tag_end;
const char *curtag = NULL;
struct buf work = { data, 0, 0, 0 };
/* identification of the opening tag */
if (size < 2 || data[0] != '<')
return 0;
i = 1;
while (i < size && data[i] != '>' && data[i] != ' ')
i++;
if (i < size)
curtag = find_block_tag((char *)data + 1, (int)i - 1);
/* handling of special cases */
if (!curtag) {
/* HTML comment, laxist form */
if (size > 5 && data[1] == '!' && data[2] == '-' && data[3] == '-') {
i = 5;
while (i < size && !(data[i - 2] == '-' && data[i - 1] == '-' && data[i] == '>'))
i++;
i++;
if (i < size)
j = is_empty(data + i, size - i);
if (j) {
work.size = i + j;
if (do_render && rndr->cb.blockhtml)
rndr->cb.blockhtml(ob, &work, rndr->opaque);
return work.size;
}
}
/* HR, which is the only self-closing block tag considered */
if (size > 4 && (data[1] == 'h' || data[1] == 'H') && (data[2] == 'r' || data[2] == 'R')) {
i = 3;
while (i < size && data[i] != '>')
i++;
if (i + 1 < size) {
i++;
j = is_empty(data + i, size - i);
if (j) {
work.size = i + j;
if (do_render && rndr->cb.blockhtml)
rndr->cb.blockhtml(ob, &work, rndr->opaque);
return work.size;
}
}
}
/* no special case recognised */
return 0;
}
/* looking for an unindented matching closing tag */
/* followed by a blank line */
tag_end = htmlblock_end(curtag, rndr, data, size, 1);
/* if not found, trying a second pass looking for indented match */
/* but not if tag is "ins" or "del" (following original Markdown.pl) */
if (!tag_end && strcmp(curtag, "ins") != 0 && strcmp(curtag, "del") != 0) {
tag_end = htmlblock_end(curtag, rndr, data, size, 0);
}
if (!tag_end)
return 0;
/* the end of the block has been found */
work.size = tag_end;
if (do_render && rndr->cb.blockhtml)
rndr->cb.blockhtml(ob, &work, rndr->opaque);
return tag_end;
}
static void
parse_table_row(
struct buf *ob,
struct sd_markdown *rndr,
uint8_t *data,
size_t size,
size_t columns,
int *col_data,
int header_flag)
{
size_t i = 0, col, cols_left;
struct buf *row_work = 0;
if (!rndr->cb.table_cell || !rndr->cb.table_row)
return;
row_work = rndr_newbuf(rndr, BUFFER_SPAN);
if (i < size && data[i] == '|')
i++;
for (col = 0; col < columns && i < size; ++col) {
size_t cell_start, cell_end;
struct buf *cell_work;
cell_work = rndr_newbuf(rndr, BUFFER_SPAN);
while (i < size && _isspace(data[i]))
i++;
cell_start = i;
while (i < size && data[i] != '|')
i++;
cell_end = i - 1;
while (cell_end > cell_start && _isspace(data[cell_end]))
cell_end--;
parse_inline(cell_work, rndr, data + cell_start, 1 + cell_end - cell_start);
rndr->cb.table_cell(row_work, cell_work, col_data[col] | header_flag, rndr->opaque, 0);
rndr_popbuf(rndr, BUFFER_SPAN);
i++;
}
cols_left = columns - col;
if (cols_left > 0) {
struct buf empty_cell = { 0, 0, 0, 0 };
rndr->cb.table_cell(row_work, &empty_cell, col_data[col] | header_flag, rndr->opaque, cols_left);
}
rndr->cb.table_row(ob, row_work, rndr->opaque);
rndr_popbuf(rndr, BUFFER_SPAN);
}
static size_t
parse_table_header(
struct buf *ob,
struct sd_markdown *rndr,
uint8_t *data,
size_t size,
size_t *columns,
int **column_data)
{
int pipes;
size_t i = 0, col, header_end, under_end;
pipes = 0;
while (i < size && data[i] != '\n')
if (data[i++] == '|')
pipes++;
if (i == size || pipes == 0)
return 0;
header_end = i;
while (header_end > 0 && _isspace(data[header_end - 1]))
header_end--;
if (data[0] == '|')
pipes--;
if (header_end && data[header_end - 1] == '|')
pipes--;
if (pipes + 1 > rndr->max_table_cols)
return 0;
*columns = pipes + 1;
*column_data = calloc(*columns, sizeof(int));
/* Parse the header underline */
i++;
if (i < size && data[i] == '|')
i++;
under_end = i;
while (under_end < size && data[under_end] != '\n')
under_end++;
for (col = 0; col < *columns && i < under_end; ++col) {
size_t dashes = 0;
while (i < under_end && data[i] == ' ')
i++;
if (data[i] == ':') {
i++; (*column_data)[col] |= MKD_TABLE_ALIGN_L;
dashes++;
}
while (i < under_end && data[i] == '-') {
i++; dashes++;
}
if (i < under_end && data[i] == ':') {
i++; (*column_data)[col] |= MKD_TABLE_ALIGN_R;
dashes++;
}
while (i < under_end && data[i] == ' ')
i++;
if (i < under_end && data[i] != '|')
break;
if (dashes < 1)
break;
i++;
}
if (col < *columns)
return 0;
parse_table_row(
ob, rndr, data,
header_end,
*columns,
*column_data,
MKD_TABLE_HEADER
);
return under_end + 1;
}
static size_t
parse_table(
struct buf *ob,
struct sd_markdown *rndr,
uint8_t *data,
size_t size)
{
size_t i;
struct buf *header_work = 0;
struct buf *body_work = 0;
size_t columns;
int *col_data = NULL;
header_work = rndr_newbuf(rndr, BUFFER_SPAN);
body_work = rndr_newbuf(rndr, BUFFER_BLOCK);
i = parse_table_header(header_work, rndr, data, size, &columns, &col_data);
if (i > 0) {
while (i < size) {
size_t row_start;
int pipes = 0;
row_start = i;
while (i < size && data[i] != '\n')
if (data[i++] == '|')
pipes++;
if (pipes == 0 || i == size) {
i = row_start;
break;
}
parse_table_row(
body_work,
rndr,
data + row_start,
i - row_start,
columns,
col_data, 0
);
i++;
}
if (rndr->cb.table)
rndr->cb.table(ob, header_work, body_work, rndr->opaque);
}
free(col_data);
rndr_popbuf(rndr, BUFFER_SPAN);
rndr_popbuf(rndr, BUFFER_BLOCK);
return i;
}
/* parse_block • parsing of one block, returning next uint8_t to parse */
static void
parse_block(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t size)
{
size_t beg, end, i;
uint8_t *txt_data;
beg = 0;
if (rndr->work_bufs[BUFFER_SPAN].size +
rndr->work_bufs[BUFFER_BLOCK].size > rndr->max_nesting)
return;
while (beg < size) {
txt_data = data + beg;
end = size - beg;
if (is_atxheader(rndr, txt_data, end))
beg += parse_atxheader(ob, rndr, txt_data, end);
else if (data[beg] == '<' && rndr->cb.blockhtml &&
(i = parse_htmlblock(ob, rndr, txt_data, end, 1)) != 0)
beg += i;
else if ((i = is_empty(txt_data, end)) != 0)
beg += i;
else if (is_hrule(txt_data, end)) {
if (rndr->cb.hrule)
rndr->cb.hrule(ob, rndr->opaque);
while (beg < size && data[beg] != '\n')
beg++;
beg++;
}
else if ((rndr->ext_flags & MKDEXT_FENCED_CODE) != 0 &&
(i = parse_fencedcode(ob, rndr, txt_data, end)) != 0)
beg += i;
else if ((rndr->ext_flags & MKDEXT_TABLES) != 0 &&
(i = parse_table(ob, rndr, txt_data, end)) != 0)
beg += i;
else if (prefix_quote(txt_data, end))
beg += parse_blockquote(ob, rndr, txt_data, end);
else if (prefix_code(txt_data, end))
beg += parse_blockcode(ob, rndr, txt_data, end);
else if (prefix_uli(txt_data, end))
beg += parse_list(ob, rndr, txt_data, end, 0);
else if (prefix_oli(txt_data, end))
beg += parse_list(ob, rndr, txt_data, end, MKD_LIST_ORDERED);
else
beg += parse_paragraph(ob, rndr, txt_data, end);
}
}
/*********************
* REFERENCE PARSING *
*********************/
/* is_ref • returns whether a line is a reference or not */
static int
is_ref(const uint8_t *data, size_t beg, size_t end, size_t *last, struct link_ref **refs)
{
/* int n; */
size_t i = 0;
size_t id_offset, id_end;
size_t link_offset, link_end;
size_t title_offset, title_end;
size_t line_end;
/* up to 3 optional leading spaces */
if (beg + 3 >= end) return 0;
if (data[beg] == ' ') { i = 1;
if (data[beg + 1] == ' ') { i = 2;
if (data[beg + 2] == ' ') { i = 3;
if (data[beg + 3] == ' ') return 0; } } }
i += beg;
/* id part: anything but a newline between brackets */
if (data[i] != '[') return 0;
i++;
id_offset = i;
while (i < end && data[i] != '\n' && data[i] != '\r' && data[i] != ']')
i++;
if (i >= end || data[i] != ']') return 0;
id_end = i;
/* spacer: colon (space | tab)* newline? (space | tab)* */
i++;
if (i >= end || data[i] != ':') return 0;
i++;
while (i < end && data[i] == ' ') i++;
if (i < end && (data[i] == '\n' || data[i] == '\r')) {
i++;
if (i < end && data[i] == '\r' && data[i - 1] == '\n') i++; }
while (i < end && data[i] == ' ') i++;
if (i >= end) return 0;
/* link: whitespace-free sequence, optionally between angle brackets */
if (data[i] == '<')
i++;
link_offset = i;
while (i < end && data[i] != ' ' && data[i] != '\n' && data[i] != '\r')
i++;
if (data[i - 1] == '>') link_end = i - 1;
else link_end = i;
/* optional spacer: (space | tab)* (newline | '\'' | '"' | '(' ) */
while (i < end && data[i] == ' ') i++;
if (i < end && data[i] != '\n' && data[i] != '\r'
&& data[i] != '\'' && data[i] != '"' && data[i] != '(')
return 0;
line_end = 0;
/* computing end-of-line */
if (i >= end || data[i] == '\r' || data[i] == '\n') line_end = i;
if (i + 1 < end && data[i] == '\n' && data[i + 1] == '\r')
line_end = i + 1;
/* optional (space|tab)* spacer after a newline */
if (line_end) {
i = line_end + 1;
while (i < end && data[i] == ' ') i++; }
/* optional title: any non-newline sequence enclosed in '"()
alone on its line */
title_offset = title_end = 0;
if (i + 1 < end
&& (data[i] == '\'' || data[i] == '"' || data[i] == '(')) {
i++;
title_offset = i;
/* looking for EOL */
while (i < end && data[i] != '\n' && data[i] != '\r') i++;
if (i + 1 < end && data[i] == '\n' && data[i + 1] == '\r')
title_end = i + 1;
else title_end = i;
/* stepping back */
i -= 1;
while (i > title_offset && data[i] == ' ')
i -= 1;
if (i > title_offset
&& (data[i] == '\'' || data[i] == '"' || data[i] == ')')) {
line_end = title_end;
title_end = i; } }
if (!line_end || link_end == link_offset)
return 0; /* garbage after the link empty link */
/* a valid ref has been found, filling-in return structures */
if (last)
*last = line_end;
if (refs) {
struct link_ref *ref;
ref = add_link_ref(refs, data + id_offset, id_end - id_offset);
if (!ref)
return 0;
ref->link = bufnew(link_end - link_offset);
bufput(ref->link, data + link_offset, link_end - link_offset);
if (title_end > title_offset) {
ref->title = bufnew(title_end - title_offset);
bufput(ref->title, data + title_offset, title_end - title_offset);
}
}
return 1;
}
static void expand_tabs(struct buf *ob, const uint8_t *line, size_t size)
{
size_t i = 0, tab = 0;
while (i < size) {
size_t org = i;
while (i < size && line[i] != '\t') {
i++; tab++;
}
if (i > org)
bufput(ob, line + org, i - org);
if (i >= size)
break;
do {
bufputc(ob, ' '); tab++;
} while (tab % 4);
i++;
}
}
/**********************
* EXPORTED FUNCTIONS *
**********************/
struct sd_markdown *
sd_markdown_new(
unsigned int extensions,
size_t max_nesting,
size_t max_table_cols,
const struct sd_callbacks *callbacks,
void *opaque)
{
struct sd_markdown *md = NULL;
assert(max_nesting > 0 && max_table_cols > 0 && callbacks);
md = malloc(sizeof(struct sd_markdown));
if (!md)
return NULL;
memcpy(&md->cb, callbacks, sizeof(struct sd_callbacks));
stack_init(&md->work_bufs[BUFFER_BLOCK], 4);
stack_init(&md->work_bufs[BUFFER_SPAN], 8);
memset(md->active_char, 0x0, 256);
if (md->cb.emphasis || md->cb.double_emphasis || md->cb.triple_emphasis) {
md->active_char['*'] = MD_CHAR_EMPHASIS;
md->active_char['_'] = MD_CHAR_EMPHASIS;
if (extensions & MKDEXT_STRIKETHROUGH)
md->active_char['~'] = MD_CHAR_EMPHASIS;
}
if (md->cb.codespan)
md->active_char['`'] = MD_CHAR_CODESPAN;
if (md->cb.linebreak)
md->active_char['\n'] = MD_CHAR_LINEBREAK;
if (md->cb.image || md->cb.link)
md->active_char['['] = MD_CHAR_LINK;
md->active_char['<'] = MD_CHAR_LANGLE;
md->active_char['\\'] = MD_CHAR_ESCAPE;
md->active_char['&'] = MD_CHAR_ENTITITY;
if (extensions & MKDEXT_AUTOLINK) {
if (!(extensions & MKDEXT_NO_EMAIL_AUTOLINK))
md->active_char['@'] = MD_CHAR_AUTOLINK_EMAIL;
md->active_char[':'] = MD_CHAR_AUTOLINK_URL;
md->active_char['w'] = MD_CHAR_AUTOLINK_WWW;
md->active_char['/'] = MD_CHAR_AUTOLINK_SUBREDDIT_OR_USERNAME;
}
if (extensions & MKDEXT_SUPERSCRIPT)
md->active_char['^'] = MD_CHAR_SUPERSCRIPT;
/* Extension data */
md->ext_flags = extensions;
md->opaque = opaque;
md->max_nesting = max_nesting;
md->max_table_cols = max_table_cols;
md->in_link_body = 0;
return md;
}
void
sd_markdown_render(struct buf *ob, const uint8_t *document, size_t doc_size, struct sd_markdown *md)
{
#define MARKDOWN_GROW(x) ((x) + ((x) >> 1))
static const char UTF8_BOM[] = {0xEF, 0xBB, 0xBF};
struct buf *text;
size_t beg, end;
text = bufnew(64);
if (!text)
return;
/* Preallocate enough space for our buffer to avoid expanding while copying */
bufgrow(text, doc_size);
/* reset the references table */
memset(&md->refs, 0x0, REF_TABLE_SIZE * sizeof(void *));
/* first pass: looking for references, copying everything else */
beg = 0;
/* Skip a possible UTF-8 BOM, even though the Unicode standard
* discourages having these in UTF-8 documents */
if (doc_size >= 3 && memcmp(document, UTF8_BOM, 3) == 0)
beg += 3;
while (beg < doc_size) /* iterating over lines */
if (is_ref(document, beg, doc_size, &end, md->refs))
beg = end;
else { /* skipping to the next line */
end = beg;
while (end < doc_size && document[end] != '\n' && document[end] != '\r')
end++;
/* adding the line body if present */
if (end > beg)
expand_tabs(text, document + beg, end - beg);
while (end < doc_size && (document[end] == '\n' || document[end] == '\r')) {
/* add one \n per newline */
if (document[end] == '\n' || (end + 1 < doc_size && document[end + 1] != '\n'))
bufputc(text, '\n');
end++;
}
beg = end;
}
/* pre-grow the output buffer to minimize allocations */
bufgrow(ob, MARKDOWN_GROW(text->size));
/* second pass: actual rendering */
if (md->cb.doc_header)
md->cb.doc_header(ob, md->opaque);
if (text->size) {
/* adding a final newline if not already present */
if (text->data[text->size - 1] != '\n' && text->data[text->size - 1] != '\r')
bufputc(text, '\n');
parse_block(ob, md, text->data, text->size);
}
if (md->cb.doc_footer)
md->cb.doc_footer(ob, md->opaque);
/* clean-up */
bufrelease(text);
free_link_refs(md->refs);
assert(md->work_bufs[BUFFER_SPAN].size == 0);
assert(md->work_bufs[BUFFER_BLOCK].size == 0);
}
void
sd_markdown_free(struct sd_markdown *md)
{
size_t i;
for (i = 0; i < (size_t)md->work_bufs[BUFFER_SPAN].asize; ++i)
bufrelease(md->work_bufs[BUFFER_SPAN].item[i]);
for (i = 0; i < (size_t)md->work_bufs[BUFFER_BLOCK].asize; ++i)
bufrelease(md->work_bufs[BUFFER_BLOCK].item[i]);
stack_free(&md->work_bufs[BUFFER_SPAN]);
stack_free(&md->work_bufs[BUFFER_BLOCK]);
free(md);
}
void
sd_version(int *ver_major, int *ver_minor, int *ver_revision)
{
*ver_major = SUNDOWN_VER_MAJOR;
*ver_minor = SUNDOWN_VER_MINOR;
*ver_revision = SUNDOWN_VER_REVISION;
}
/* vim: set filetype=c: */
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