Auto merge of #80550 - bugadani:markdown-refactor, r=jyn514

Cleanup markdown span handling, take 2

This PR includes the cleanups made in #80244 except for the removal of `locate()`.

While the biggest conceptual part in #80244 was the removal of `locate()`, it introduced a diagnostic regression.

Additional cleanup:
 - Use `RefCell` to avoid building two separate vectors for the links

Work to do:
- [ ] Decide if `locate()` can be simplified by assuming `s` is always in `md`
- [ ] Should probably add some tests that still provide the undesired diagnostics causing #80381

cc `@jyn514` This is the best I can do without patching Pulldown to provide multiple ranges for reference-style links. Also, since `locate` is probably more efficient than `rfind` (at least it's constant time), I decided to not check the link type and just cover every &str as it was before.
This commit is contained in:
bors 2021-01-02 15:31:53 +00:00
commit fd85ca02f6
2 changed files with 107 additions and 99 deletions

View File

@ -25,6 +25,7 @@ use rustc_session::lint;
use rustc_span::edition::Edition;
use rustc_span::Span;
use std::borrow::Cow;
use std::cell::RefCell;
use std::collections::VecDeque;
use std::default::Default;
use std::fmt::Write;
@ -414,11 +415,13 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for LinkReplacer<'a, I> {
}
}
type SpannedEvent<'a> = (Event<'a>, Range<usize>);
/// Make headings links with anchor IDs and build up TOC.
struct HeadingLinks<'a, 'b, 'ids, I> {
inner: I,
toc: Option<&'b mut TocBuilder>,
buf: VecDeque<Event<'a>>,
buf: VecDeque<SpannedEvent<'a>>,
id_map: &'ids mut IdMap,
}
@ -428,8 +431,10 @@ impl<'a, 'b, 'ids, I> HeadingLinks<'a, 'b, 'ids, I> {
}
}
impl<'a, 'b, 'ids, I: Iterator<Item = Event<'a>>> Iterator for HeadingLinks<'a, 'b, 'ids, I> {
type Item = Event<'a>;
impl<'a, 'b, 'ids, I: Iterator<Item = SpannedEvent<'a>>> Iterator
for HeadingLinks<'a, 'b, 'ids, I>
{
type Item = SpannedEvent<'a>;
fn next(&mut self) -> Option<Self::Item> {
if let Some(e) = self.buf.pop_front() {
@ -437,31 +442,29 @@ impl<'a, 'b, 'ids, I: Iterator<Item = Event<'a>>> Iterator for HeadingLinks<'a,
}
let event = self.inner.next();
if let Some(Event::Start(Tag::Heading(level))) = event {
if let Some((Event::Start(Tag::Heading(level)), _)) = event {
let mut id = String::new();
for event in &mut self.inner {
match &event {
match &event.0 {
Event::End(Tag::Heading(..)) => break,
Event::Start(Tag::Link(_, _, _)) | Event::End(Tag::Link(..)) => {}
Event::Text(text) | Event::Code(text) => {
id.extend(text.chars().filter_map(slugify));
self.buf.push_back(event);
}
_ => {}
}
match event {
Event::Start(Tag::Link(_, _, _)) | Event::End(Tag::Link(..)) => {}
event => self.buf.push_back(event),
_ => self.buf.push_back(event),
}
}
let id = self.id_map.derive(id);
if let Some(ref mut builder) = self.toc {
let mut html_header = String::new();
html::push_html(&mut html_header, self.buf.iter().cloned());
html::push_html(&mut html_header, self.buf.iter().map(|(ev, _)| ev.clone()));
let sec = builder.push(level as u32, html_header, id.clone());
self.buf.push_front(Event::Html(format!("{} ", sec).into()));
self.buf.push_front((Event::Html(format!("{} ", sec).into()), 0..0));
}
self.buf.push_back(Event::Html(format!("</a></h{}>", level).into()));
self.buf.push_back((Event::Html(format!("</a></h{}>", level).into()), 0..0));
let start_tags = format!(
"<h{level} id=\"{id}\" class=\"section-header\">\
@ -469,7 +472,7 @@ impl<'a, 'b, 'ids, I: Iterator<Item = Event<'a>>> Iterator for HeadingLinks<'a,
id = id,
level = level
);
return Some(Event::Html(start_tags.into()));
return Some((Event::Html(start_tags.into()), 0..0));
}
event
}
@ -555,23 +558,23 @@ impl<'a, I> Footnotes<'a, I> {
}
}
impl<'a, I: Iterator<Item = Event<'a>>> Iterator for Footnotes<'a, I> {
type Item = Event<'a>;
impl<'a, I: Iterator<Item = SpannedEvent<'a>>> Iterator for Footnotes<'a, I> {
type Item = SpannedEvent<'a>;
fn next(&mut self) -> Option<Self::Item> {
loop {
match self.inner.next() {
Some(Event::FootnoteReference(ref reference)) => {
Some((Event::FootnoteReference(ref reference), range)) => {
let entry = self.get_entry(&reference);
let reference = format!(
"<sup id=\"fnref{0}\"><a href=\"#fn{0}\">{0}</a></sup>",
(*entry).1
);
return Some(Event::Html(reference.into()));
return Some((Event::Html(reference.into()), range));
}
Some(Event::Start(Tag::FootnoteDefinition(def))) => {
Some((Event::Start(Tag::FootnoteDefinition(def)), _)) => {
let mut content = Vec::new();
for event in &mut self.inner {
for (event, _) in &mut self.inner {
if let Event::End(Tag::FootnoteDefinition(..)) = event {
break;
}
@ -602,7 +605,7 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for Footnotes<'a, I> {
ret.push_str("</li>");
}
ret.push_str("</ol></div>");
return Some(Event::Html(ret.into()));
return Some((Event::Html(ret.into()), 0..0));
} else {
return None;
}
@ -912,13 +915,14 @@ impl Markdown<'_> {
};
let p = Parser::new_with_broken_link_callback(md, opts(), Some(&mut replacer));
let p = p.into_offset_iter();
let mut s = String::with_capacity(md.len() * 3 / 2);
let p = HeadingLinks::new(p, None, &mut ids);
let p = LinkReplacer::new(p, links);
let p = CodeBlocks::new(p, codes, edition, playground);
let p = Footnotes::new(p);
let p = LinkReplacer::new(p.map(|(ev, _)| ev), links);
let p = CodeBlocks::new(p, codes, edition, playground);
html::push_html(&mut s, p);
s
@ -929,7 +933,7 @@ impl MarkdownWithToc<'_> {
crate fn into_string(self) -> String {
let MarkdownWithToc(md, mut ids, codes, edition, playground) = self;
let p = Parser::new_ext(md, opts());
let p = Parser::new_ext(md, opts()).into_offset_iter();
let mut s = String::with_capacity(md.len() * 3 / 2);
@ -937,8 +941,8 @@ impl MarkdownWithToc<'_> {
{
let p = HeadingLinks::new(p, Some(&mut toc), &mut ids);
let p = CodeBlocks::new(p, codes, edition, playground);
let p = Footnotes::new(p);
let p = CodeBlocks::new(p.map(|(ev, _)| ev), codes, edition, playground);
html::push_html(&mut s, p);
}
@ -954,19 +958,19 @@ impl MarkdownHtml<'_> {
if md.is_empty() {
return String::new();
}
let p = Parser::new_ext(md, opts());
let p = Parser::new_ext(md, opts()).into_offset_iter();
// Treat inline HTML as plain text.
let p = p.map(|event| match event {
Event::Html(text) => Event::Text(text),
let p = p.map(|event| match event.0 {
Event::Html(text) => (Event::Text(text), event.1),
_ => event,
});
let mut s = String::with_capacity(md.len() * 3 / 2);
let p = HeadingLinks::new(p, None, &mut ids);
let p = CodeBlocks::new(p, codes, edition, playground);
let p = Footnotes::new(p);
let p = CodeBlocks::new(p.map(|(ev, _)| ev), codes, edition, playground);
html::push_html(&mut s, p);
s
@ -1119,56 +1123,65 @@ crate fn plain_text_summary(md: &str) -> String {
s
}
crate fn markdown_links(md: &str) -> Vec<(String, Option<Range<usize>>)> {
crate fn markdown_links(md: &str) -> Vec<(String, Range<usize>)> {
if md.is_empty() {
return vec![];
}
let mut links = vec![];
let mut shortcut_links = vec![];
let links = RefCell::new(vec![]);
{
let locate = |s: &str| unsafe {
let s_start = s.as_ptr();
let s_end = s_start.add(s.len());
let md_start = md.as_ptr();
let md_end = md_start.add(md.len());
if md_start <= s_start && s_end <= md_end {
let start = s_start.offset_from(md_start) as usize;
let end = s_end.offset_from(md_start) as usize;
Some(start..end)
} else {
None
}
};
// FIXME: remove this function once pulldown_cmark can provide spans for link definitions.
let locate = |s: &str, fallback: Range<usize>| unsafe {
let s_start = s.as_ptr();
let s_end = s_start.add(s.len());
let md_start = md.as_ptr();
let md_end = md_start.add(md.len());
if md_start <= s_start && s_end <= md_end {
let start = s_start.offset_from(md_start) as usize;
let end = s_end.offset_from(md_start) as usize;
start..end
} else {
fallback
}
};
let mut push = |link: BrokenLink<'_>| {
// FIXME: use `link.span` instead of `locate`
// (doing it now includes the `[]` as well as the text)
shortcut_links.push((link.reference.to_owned(), locate(link.reference)));
None
};
let p = Parser::new_with_broken_link_callback(md, opts(), Some(&mut push));
let span_for_link = |link: &CowStr<'_>, span: Range<usize>| {
// For diagnostics, we want to underline the link's definition but `span` will point at
// where the link is used. This is a problem for reference-style links, where the definition
// is separate from the usage.
match link {
// `Borrowed` variant means the string (the link's destination) may come directly from
// the markdown text and we can locate the original link destination.
// NOTE: LinkReplacer also provides `Borrowed` but possibly from other sources,
// so `locate()` can fall back to use `span`.
CowStr::Borrowed(s) => locate(s, span),
// There's no need to thread an IdMap through to here because
// the IDs generated aren't going to be emitted anywhere.
let mut ids = IdMap::new();
let iter = Footnotes::new(HeadingLinks::new(p, None, &mut ids));
// For anything else, we can only use the provided range.
CowStr::Boxed(_) | CowStr::Inlined(_) => span,
}
};
for ev in iter {
if let Event::Start(Tag::Link(_, dest, _)) = ev {
debug!("found link: {}", dest);
links.push(match dest {
CowStr::Borrowed(s) => (s.to_owned(), locate(s)),
s @ (CowStr::Boxed(..) | CowStr::Inlined(..)) => (s.into_string(), None),
});
}
let mut push = |link: BrokenLink<'_>| {
let span = span_for_link(&CowStr::Borrowed(link.reference), link.span);
links.borrow_mut().push((link.reference.to_owned(), span));
None
};
let p = Parser::new_with_broken_link_callback(md, opts(), Some(&mut push)).into_offset_iter();
// There's no need to thread an IdMap through to here because
// the IDs generated aren't going to be emitted anywhere.
let mut ids = IdMap::new();
let iter = Footnotes::new(HeadingLinks::new(p, None, &mut ids));
for ev in iter {
if let Event::Start(Tag::Link(_, dest, _)) = ev.0 {
debug!("found link: {}", dest);
let span = span_for_link(&dest, ev.1);
links.borrow_mut().push((dest.into_string(), span));
}
}
links.append(&mut shortcut_links);
links
links.into_inner()
}
#[derive(Debug)]

View File

@ -245,7 +245,7 @@ struct DiagnosticInfo<'a> {
item: &'a Item,
dox: &'a str,
ori_link: &'a str,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
}
#[derive(Clone, Debug, Hash)]
@ -960,7 +960,7 @@ impl LinkCollector<'_, '_> {
parent_node: Option<DefId>,
krate: CrateNum,
ori_link: String,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
) -> Option<ItemLink> {
trace!("considering link '{}'", ori_link);
@ -1606,7 +1606,7 @@ fn report_diagnostic(
msg: &str,
item: &Item,
dox: &str,
link_range: &Option<Range<usize>>,
link_range: &Range<usize>,
decorate: impl FnOnce(&mut DiagnosticBuilder<'_>, Option<rustc_span::Span>),
) {
let hir_id = match cx.as_local_hir_id(item.def_id) {
@ -1624,31 +1624,27 @@ fn report_diagnostic(
cx.tcx.struct_span_lint_hir(lint, hir_id, sp, |lint| {
let mut diag = lint.build(msg);
let span = link_range
.as_ref()
.and_then(|range| super::source_span_for_markdown_range(cx, dox, range, attrs));
let span = super::source_span_for_markdown_range(cx, dox, link_range, attrs);
if let Some(link_range) = link_range {
if let Some(sp) = span {
diag.set_span(sp);
} else {
// blah blah blah\nblah\nblah [blah] blah blah\nblah blah
// ^ ~~~~
// | link_range
// last_new_line_offset
let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
if let Some(sp) = span {
diag.set_span(sp);
} else {
// blah blah blah\nblah\nblah [blah] blah blah\nblah blah
// ^ ~~~~
// | link_range
// last_new_line_offset
let last_new_line_offset = dox[..link_range.start].rfind('\n').map_or(0, |n| n + 1);
let line = dox[last_new_line_offset..].lines().next().unwrap_or("");
// Print the line containing the `link_range` and manually mark it with '^'s.
diag.note(&format!(
"the link appears in this line:\n\n{line}\n\
// Print the line containing the `link_range` and manually mark it with '^'s.
diag.note(&format!(
"the link appears in this line:\n\n{line}\n\
{indicator: <before$}{indicator:^<found$}",
line = line,
indicator = "",
before = link_range.start - last_new_line_offset,
found = link_range.len(),
));
}
line = line,
indicator = "",
before = link_range.start - last_new_line_offset,
found = link_range.len(),
));
}
decorate(&mut diag, span);
@ -1668,7 +1664,7 @@ fn resolution_failure(
path_str: &str,
disambiguator: Option<Disambiguator>,
dox: &str,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
kinds: SmallVec<[ResolutionFailure<'_>; 3]>,
) {
let tcx = collector.cx.tcx;
@ -1892,7 +1888,7 @@ fn anchor_failure(
item: &Item,
path_str: &str,
dox: &str,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
failure: AnchorFailure,
) {
let msg = match failure {
@ -1917,7 +1913,7 @@ fn ambiguity_error(
item: &Item,
path_str: &str,
dox: &str,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
candidates: Vec<Res>,
) {
let mut msg = format!("`{}` is ", path_str);
@ -1966,13 +1962,12 @@ fn suggest_disambiguator(
path_str: &str,
dox: &str,
sp: Option<rustc_span::Span>,
link_range: &Option<Range<usize>>,
link_range: &Range<usize>,
) {
let suggestion = disambiguator.suggestion();
let help = format!("to link to the {}, {}", disambiguator.descr(), suggestion.descr());
if let Some(sp) = sp {
let link_range = link_range.as_ref().expect("must have a link range if we have a span");
let msg = if dox.bytes().nth(link_range.start) == Some(b'`') {
format!("`{}`", suggestion.as_help(path_str))
} else {
@ -1991,7 +1986,7 @@ fn privacy_error(
item: &Item,
path_str: &str,
dox: &str,
link_range: Option<Range<usize>>,
link_range: Range<usize>,
) {
let sym;
let item_name = match item.name {