rust/src/librustdoc/html/markdown.rs
2014-11-06 12:26:08 -05:00

488 lines
18 KiB
Rust

// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Markdown formatting for rustdoc
//!
//! This module implements markdown formatting through the hoedown C-library
//! (bundled into the rust runtime). This module self-contains the C bindings
//! and necessary legwork to render markdown, and exposes all of the
//! functionality through a unit-struct, `Markdown`, which has an implementation
//! of `fmt::Show`. Example usage:
//!
//! ```rust,ignore
//! use rustdoc::html::markdown::Markdown;
//!
//! let s = "My *markdown* _text_";
//! let html = format!("{}", Markdown(s));
//! // ... something using html
//! ```
#![allow(dead_code)]
#![allow(non_camel_case_types)]
use libc;
use std::cell::{RefCell, Cell};
use std::fmt;
use std::slice;
use std::str;
use std::string;
use std::collections::HashMap;
use html::toc::TocBuilder;
use html::highlight;
use html::escape::Escape;
use test;
/// A unit struct which has the `fmt::Show` trait implemented. When
/// formatted, this struct will emit the HTML corresponding to the rendered
/// version of the contained markdown string.
pub struct Markdown<'a>(pub &'a str);
/// A unit struct like `Markdown`, that renders the markdown with a
/// table of contents.
pub struct MarkdownWithToc<'a>(pub &'a str);
const DEF_OUNIT: libc::size_t = 64;
const HOEDOWN_EXT_NO_INTRA_EMPHASIS: libc::c_uint = 1 << 10;
const HOEDOWN_EXT_TABLES: libc::c_uint = 1 << 0;
const HOEDOWN_EXT_FENCED_CODE: libc::c_uint = 1 << 1;
const HOEDOWN_EXT_AUTOLINK: libc::c_uint = 1 << 3;
const HOEDOWN_EXT_STRIKETHROUGH: libc::c_uint = 1 << 4;
const HOEDOWN_EXT_SUPERSCRIPT: libc::c_uint = 1 << 8;
const HOEDOWN_EXT_FOOTNOTES: libc::c_uint = 1 << 2;
const HOEDOWN_EXTENSIONS: libc::c_uint =
HOEDOWN_EXT_NO_INTRA_EMPHASIS | HOEDOWN_EXT_TABLES |
HOEDOWN_EXT_FENCED_CODE | HOEDOWN_EXT_AUTOLINK |
HOEDOWN_EXT_STRIKETHROUGH | HOEDOWN_EXT_SUPERSCRIPT |
HOEDOWN_EXT_FOOTNOTES;
type hoedown_document = libc::c_void; // this is opaque to us
#[repr(C)]
struct hoedown_renderer {
opaque: *mut hoedown_html_renderer_state,
blockcode: Option<extern "C" fn(*mut hoedown_buffer, *const hoedown_buffer,
*const hoedown_buffer, *mut libc::c_void)>,
blockquote: Option<extern "C" fn(*mut hoedown_buffer, *const hoedown_buffer,
*mut libc::c_void)>,
blockhtml: Option<extern "C" fn(*mut hoedown_buffer, *const hoedown_buffer,
*mut libc::c_void)>,
header: Option<extern "C" fn(*mut hoedown_buffer, *const hoedown_buffer,
libc::c_int, *mut libc::c_void)>,
other: [libc::size_t, ..28],
}
#[repr(C)]
struct hoedown_html_renderer_state {
opaque: *mut libc::c_void,
toc_data: html_toc_data,
flags: libc::c_uint,
link_attributes: Option<extern "C" fn(*mut hoedown_buffer,
*const hoedown_buffer,
*mut libc::c_void)>,
}
#[repr(C)]
struct html_toc_data {
header_count: libc::c_int,
current_level: libc::c_int,
level_offset: libc::c_int,
nesting_level: libc::c_int,
}
struct MyOpaque {
dfltblk: extern "C" fn(*mut hoedown_buffer, *const hoedown_buffer,
*const hoedown_buffer, *mut libc::c_void),
toc_builder: Option<TocBuilder>,
}
#[repr(C)]
struct hoedown_buffer {
data: *const u8,
size: libc::size_t,
asize: libc::size_t,
unit: libc::size_t,
}
// hoedown FFI
#[link(name = "hoedown", kind = "static")]
extern {
fn hoedown_html_renderer_new(render_flags: libc::c_uint,
nesting_level: libc::c_int)
-> *mut hoedown_renderer;
fn hoedown_html_renderer_free(renderer: *mut hoedown_renderer);
fn hoedown_document_new(rndr: *mut hoedown_renderer,
extensions: libc::c_uint,
max_nesting: libc::size_t) -> *mut hoedown_document;
fn hoedown_document_render(doc: *mut hoedown_document,
ob: *mut hoedown_buffer,
document: *const u8,
doc_size: libc::size_t);
fn hoedown_document_free(md: *mut hoedown_document);
fn hoedown_buffer_new(unit: libc::size_t) -> *mut hoedown_buffer;
fn hoedown_buffer_puts(b: *mut hoedown_buffer, c: *const libc::c_char);
fn hoedown_buffer_free(b: *mut hoedown_buffer);
}
/// Returns Some(code) if `s` is a line that should be stripped from
/// documentation but used in example code. `code` is the portion of
/// `s` that should be used in tests. (None for lines that should be
/// left as-is.)
fn stripped_filtered_line<'a>(s: &'a str) -> Option<&'a str> {
let trimmed = s.trim();
if trimmed.starts_with("# ") {
Some(trimmed.slice_from(2))
} else {
None
}
}
local_data_key!(used_header_map: RefCell<HashMap<String, uint>>)
local_data_key!(test_idx: Cell<uint>)
// None == render an example, but there's no crate name
local_data_key!(pub playground_krate: Option<String>)
pub fn render(w: &mut fmt::Formatter, s: &str, print_toc: bool) -> fmt::Result {
extern fn block(ob: *mut hoedown_buffer, orig_text: *const hoedown_buffer,
lang: *const hoedown_buffer, opaque: *mut libc::c_void) {
unsafe {
if orig_text.is_null() { return }
let opaque = opaque as *mut hoedown_html_renderer_state;
let my_opaque: &MyOpaque = &*((*opaque).opaque as *const MyOpaque);
slice::raw::buf_as_slice((*orig_text).data, (*orig_text).size as uint,
|text| {
let origtext = str::from_utf8(text).unwrap();
debug!("docblock: ==============\n{}\n=======", text);
let rendered = if lang.is_null() {
false
} else {
slice::raw::buf_as_slice((*lang).data,
(*lang).size as uint, |rlang| {
let rlang = str::from_utf8(rlang).unwrap();
if LangString::parse(rlang).notrust {
(my_opaque.dfltblk)(ob, orig_text, lang,
opaque as *mut libc::c_void);
true
} else {
false
}
})
};
let mut lines = origtext.lines().filter(|l| {
stripped_filtered_line(*l).is_none()
});
let text = lines.collect::<Vec<&str>>().connect("\n");
if !rendered {
let mut s = String::new();
let id = playground_krate.get().map(|krate| {
let idx = test_idx.get().unwrap();
let i = idx.get();
idx.set(i + 1);
let test = origtext.lines().map(|l| {
stripped_filtered_line(l).unwrap_or(l)
}).collect::<Vec<&str>>().connect("\n");
let krate = krate.as_ref().map(|s| s.as_slice());
let test = test::maketest(test.as_slice(), krate, false, false);
s.push_str(format!("<span id='rust-example-raw-{}' \
class='rusttest'>{}</span>",
i, Escape(test.as_slice())).as_slice());
format!("rust-example-rendered-{}", i)
});
let id = id.as_ref().map(|a| a.as_slice());
s.push_str(highlight::highlight(text.as_slice(), None, id)
.as_slice());
let output = s.to_c_str();
hoedown_buffer_puts(ob, output.as_ptr());
}
})
}
}
extern fn header(ob: *mut hoedown_buffer, text: *const hoedown_buffer,
level: libc::c_int, opaque: *mut libc::c_void) {
// hoedown does this, we may as well too
"\n".with_c_str(|p| unsafe { hoedown_buffer_puts(ob, p) });
// Extract the text provided
let s = if text.is_null() {
"".to_string()
} else {
unsafe {
string::raw::from_buf_len((*text).data, (*text).size as uint)
}
};
// Transform the contents of the header into a hyphenated string
let id = s.as_slice().words().map(|s| {
match s.to_ascii_opt() {
Some(s) => s.to_lowercase().into_string(),
None => s.to_string()
}
}).collect::<Vec<String>>().connect("-");
// This is a terrible hack working around how hoedown gives us rendered
// html for text rather than the raw text.
let id = id.replace("<code>", "").replace("</code>", "").to_string();
let opaque = opaque as *mut hoedown_html_renderer_state;
let opaque = unsafe { &mut *((*opaque).opaque as *mut MyOpaque) };
// Make sure our hyphenated ID is unique for this page
let map = used_header_map.get().unwrap();
let id = match map.borrow_mut().get_mut(&id) {
None => id,
Some(a) => { *a += 1; format!("{}-{}", id, *a - 1) }
};
map.borrow_mut().insert(id.clone(), 1);
let sec = match opaque.toc_builder {
Some(ref mut builder) => {
builder.push(level as u32, s.clone(), id.clone())
}
None => {""}
};
// Render the HTML
let text = format!(r##"<h{lvl} id="{id}" class='section-header'><a
href="#{id}">{sec}{}</a></h{lvl}>"##,
s, lvl = level, id = id,
sec = if sec.len() == 0 {
sec.to_string()
} else {
format!("{} ", sec)
});
text.with_c_str(|p| unsafe { hoedown_buffer_puts(ob, p) });
}
if used_header_map.get().is_none() {
reset_headers();
}
unsafe {
let ob = hoedown_buffer_new(DEF_OUNIT);
let renderer = hoedown_html_renderer_new(0, 0);
let mut opaque = MyOpaque {
dfltblk: (*renderer).blockcode.unwrap(),
toc_builder: if print_toc {Some(TocBuilder::new())} else {None}
};
(*(*renderer).opaque).opaque = &mut opaque as *mut _ as *mut libc::c_void;
(*renderer).blockcode = Some(block);
(*renderer).header = Some(header);
let document = hoedown_document_new(renderer, HOEDOWN_EXTENSIONS, 16);
hoedown_document_render(document, ob, s.as_ptr(),
s.len() as libc::size_t);
hoedown_document_free(document);
hoedown_html_renderer_free(renderer);
let mut ret = match opaque.toc_builder {
Some(b) => write!(w, "<nav id=\"TOC\">{}</nav>", b.into_toc()),
None => Ok(())
};
if ret.is_ok() {
ret = slice::raw::buf_as_slice((*ob).data, (*ob).size as uint, |buf| {
w.write(buf)
});
}
hoedown_buffer_free(ob);
ret
}
}
pub fn find_testable_code(doc: &str, tests: &mut ::test::Collector) {
extern fn block(_ob: *mut hoedown_buffer,
text: *const hoedown_buffer,
lang: *const hoedown_buffer,
opaque: *mut libc::c_void) {
unsafe {
if text.is_null() { return }
let block_info = if lang.is_null() {
LangString::all_false()
} else {
slice::raw::buf_as_slice((*lang).data,
(*lang).size as uint, |lang| {
let s = str::from_utf8(lang).unwrap();
LangString::parse(s)
})
};
if block_info.notrust { return }
slice::raw::buf_as_slice((*text).data, (*text).size as uint, |text| {
let opaque = opaque as *mut hoedown_html_renderer_state;
let tests = &mut *((*opaque).opaque as *mut ::test::Collector);
let text = str::from_utf8(text).unwrap();
let mut lines = text.lines().map(|l| {
stripped_filtered_line(l).unwrap_or(l)
});
let text = lines.collect::<Vec<&str>>().connect("\n");
tests.add_test(text.to_string(),
block_info.should_fail, block_info.no_run,
block_info.ignore, block_info.test_harness);
})
}
}
extern fn header(_ob: *mut hoedown_buffer,
text: *const hoedown_buffer,
level: libc::c_int, opaque: *mut libc::c_void) {
unsafe {
let opaque = opaque as *mut hoedown_html_renderer_state;
let tests = &mut *((*opaque).opaque as *mut ::test::Collector);
if text.is_null() {
tests.register_header("", level as u32);
} else {
slice::raw::buf_as_slice((*text).data, (*text).size as uint, |text| {
let text = str::from_utf8(text).unwrap();
tests.register_header(text, level as u32);
})
}
}
}
unsafe {
let ob = hoedown_buffer_new(DEF_OUNIT);
let renderer = hoedown_html_renderer_new(0, 0);
(*renderer).blockcode = Some(block);
(*renderer).header = Some(header);
(*(*renderer).opaque).opaque = tests as *mut _ as *mut libc::c_void;
let document = hoedown_document_new(renderer, HOEDOWN_EXTENSIONS, 16);
hoedown_document_render(document, ob, doc.as_ptr(),
doc.len() as libc::size_t);
hoedown_document_free(document);
hoedown_html_renderer_free(renderer);
hoedown_buffer_free(ob);
}
}
#[deriving(Eq, PartialEq, Clone, Show)]
struct LangString {
should_fail: bool,
no_run: bool,
ignore: bool,
notrust: bool,
test_harness: bool,
}
impl LangString {
fn all_false() -> LangString {
LangString {
should_fail: false,
no_run: false,
ignore: false,
notrust: false,
test_harness: false,
}
}
fn parse(string: &str) -> LangString {
let mut seen_rust_tags = false;
let mut seen_other_tags = false;
let mut data = LangString::all_false();
let mut tokens = string.as_slice().split(|c: char|
!(c == '_' || c == '-' || c.is_alphanumeric())
);
for token in tokens {
match token {
"" => {},
"should_fail" => { data.should_fail = true; seen_rust_tags = true; },
"no_run" => { data.no_run = true; seen_rust_tags = true; },
"ignore" => { data.ignore = true; seen_rust_tags = true; },
"notrust" => { data.notrust = true; seen_rust_tags = true; },
"rust" => { data.notrust = false; seen_rust_tags = true; },
"test_harness" => { data.test_harness = true; seen_rust_tags = true; }
_ => { seen_other_tags = true }
}
}
data.notrust |= seen_other_tags && !seen_rust_tags;
data
}
}
/// By default this markdown renderer generates anchors for each header in the
/// rendered document. The anchor name is the contents of the header separated
/// by hyphens, and a task-local map is used to disambiguate among duplicate
/// headers (numbers are appended).
///
/// This method will reset the local table for these headers. This is typically
/// used at the beginning of rendering an entire HTML page to reset from the
/// previous state (if any).
pub fn reset_headers() {
used_header_map.replace(Some(RefCell::new(HashMap::new())));
test_idx.replace(Some(Cell::new(0)));
}
impl<'a> fmt::Show for Markdown<'a> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
let Markdown(md) = *self;
// This is actually common enough to special-case
if md.len() == 0 { return Ok(()) }
render(fmt, md.as_slice(), false)
}
}
impl<'a> fmt::Show for MarkdownWithToc<'a> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
let MarkdownWithToc(md) = *self;
render(fmt, md.as_slice(), true)
}
}
#[cfg(test)]
mod tests {
use super::{LangString, Markdown};
#[test]
fn test_lang_string_parse() {
fn t(s: &str,
should_fail: bool, no_run: bool, ignore: bool, notrust: bool, test_harness: bool) {
assert_eq!(LangString::parse(s), LangString {
should_fail: should_fail,
no_run: no_run,
ignore: ignore,
notrust: notrust,
test_harness: test_harness,
})
}
t("", false,false,false,false,false);
t("rust", false,false,false,false,false);
t("sh", false,false,false,true,false);
t("notrust", false,false,false,true,false);
t("ignore", false,false,true,false,false);
t("should_fail", true,false,false,false,false);
t("no_run", false,true,false,false,false);
t("test_harness", false,false,false,false,true);
t("{.no_run .example}", false,true,false,false,false);
t("{.sh .should_fail}", true,false,false,false,false);
t("{.example .rust}", false,false,false,false,false);
t("{.test_harness .rust}", false,false,false,false,true);
}
#[test]
fn issue_17736() {
let markdown = "# title";
format!("{}", Markdown(markdown.as_slice()));
}
}