/// Reports a resolution failure diagnostic.
///
-/// Ideally we can report the diagnostic with the actual span in the source where the link failure
-/// occurred. However, there's a mismatch between the span in the source code and the span in the
-/// markdown, so we have to do a bit of work to figure out the correspondence.
-///
-/// It's not too hard to find the span for sugared doc comments (`///` and `/**`), because the
-/// source will match the markdown exactly, excluding the comment markers. However, it's much more
-/// difficult to calculate the spans for unsugared docs, because we have to deal with escaping and
-/// other source features. So, we attempt to find the exact source span of the resolution failure
-/// in sugared docs, but use the span of the documentation attributes themselves for unsugared
-/// docs. Because this span might be overly large, we display the markdown line containing the
-/// failure as a note.
+/// If we cannot find the exact source span of the resolution failure, we use the span of the
+/// documentation attributes themselves. This is a little heavy-handed, so we display the markdown
+/// line containing the failure as a note as well.
fn resolution_failure(
cx: &DocContext,
attrs: &Attributes,
let msg = format!("`[{}]` cannot be resolved, ignoring it...", path_str);
let mut diag = if let Some(link_range) = link_range {
- let src = cx.sess().source_map().span_to_snippet(sp);
- let is_all_sugared_doc = attrs.doc_strings.iter().all(|frag| match frag {
- DocFragment::SugaredDoc(..) => true,
- _ => false,
- });
-
- if let (Ok(src), true) = (src, is_all_sugared_doc) {
- // The number of markdown lines up to and including the resolution failure.
- let num_lines = dox[..link_range.start].lines().count();
-
- // We use `split_terminator('\n')` instead of `lines()` when counting bytes to ensure
- // that DOS-style line endings do not cause the spans to be calculated incorrectly.
- let mut src_lines = src.split_terminator('\n');
- let mut md_lines = dox.split_terminator('\n').take(num_lines).peekable();
-
- // The number of bytes from the start of the source span to the resolution failure that
- // are *not* part of the markdown, like comment markers.
- let mut extra_src_bytes = 0;
-
- while let Some(md_line) = md_lines.next() {
- loop {
- let source_line = src_lines
- .next()
- .expect("could not find markdown line in source");
-
- match source_line.find(md_line) {
- Some(offset) => {
- extra_src_bytes += if md_lines.peek().is_some() {
- source_line.len() - md_line.len()
- } else {
- offset
- };
- break;
- }
- None => {
- // Since this is a source line that doesn't include a markdown line,
- // we have to count the newline that we split from earlier.
- extra_src_bytes += source_line.len() + 1;
- }
- }
- }
- }
-
- let sp = sp.from_inner_byte_pos(
- link_range.start + extra_src_bytes,
- link_range.end + extra_src_bytes,
- );
-
+ if let Some(sp) = super::source_span_for_markdown_range(cx, dox, &link_range, attrs) {
let mut diag = cx.tcx.struct_span_lint_node(
lint::builtin::INTRA_DOC_LINK_RESOLUTION_FAILURE,
NodeId::from_u32(0),
use std::mem;
use std::fmt;
use syntax::ast::NodeId;
+use syntax_pos::Span;
+use std::ops::Range;
use clean::{self, GetDefId, Item};
use core::{DocContext, DocAccessLevels};
}
}
}
+
+/// Attempts to match a range of bytes from parsed markdown to a `Span` in the source code.
+///
+/// This method will return `None` if we cannot construct a span from the source map or if the
+/// attributes are not all sugared doc comments. It's difficult to calculate the correct span in
+/// that case due to escaping and other source features.
+crate fn source_span_for_markdown_range(
+ cx: &DocContext,
+ markdown: &str,
+ md_range: &Range<usize>,
+ attrs: &clean::Attributes,
+) -> Option<Span> {
+ let is_all_sugared_doc = attrs.doc_strings.iter().all(|frag| match frag {
+ clean::DocFragment::SugaredDoc(..) => true,
+ _ => false,
+ });
+
+ if !is_all_sugared_doc {
+ return None;
+ }
+
+ let snippet = cx
+ .sess()
+ .source_map()
+ .span_to_snippet(span_of_attrs(attrs))
+ .ok()?;
+
+ let starting_line = markdown[..md_range.start].lines().count() - 1;
+ let ending_line = markdown[..md_range.end].lines().count() - 1;
+
+ // We use `split_terminator('\n')` instead of `lines()` when counting bytes so that we only
+ // we can treat CRLF and LF line endings the same way.
+ let mut src_lines = snippet.split_terminator('\n');
+ let md_lines = markdown.split_terminator('\n');
+
+ // The number of bytes from the source span to the markdown span that are not part
+ // of the markdown, like comment markers.
+ let mut start_bytes = 0;
+ let mut end_bytes = 0;
+
+ 'outer: for (line_no, md_line) in md_lines.enumerate() {
+ loop {
+ let source_line = src_lines.next().expect("could not find markdown in source");
+ match source_line.find(md_line) {
+ Some(offset) => {
+ if line_no == starting_line {
+ start_bytes += offset;
+
+ if starting_line == ending_line {
+ break 'outer;
+ }
+ } else if line_no == ending_line {
+ end_bytes += offset;
+ break 'outer;
+ } else if line_no < starting_line {
+ start_bytes += source_line.len() - md_line.len();
+ } else {
+ end_bytes += source_line.len() - md_line.len();
+ }
+ break;
+ }
+ None => {
+ // Since this is a source line that doesn't include a markdown line,
+ // we have to count the newline that we split from earlier.
+ if line_no <= starting_line {
+ start_bytes += source_line.len() + 1;
+ } else {
+ end_bytes += source_line.len() + 1;
+ }
+ }
+ }
+ }
+ }
+
+ let sp = span_of_attrs(attrs).from_inner_byte_pos(
+ md_range.start + start_bytes,
+ md_range.end + start_bytes + end_bytes,
+ );
+
+ Some(sp)
+}
projects / rust.git / commitdiff