diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs index 1bc41e68cf372..5dc49ea51d1dc 100644 --- a/compiler/rustc_parse/src/parser/attr_wrapper.rs +++ b/compiler/rustc_parse/src/parser/attr_wrapper.rs @@ -110,17 +110,15 @@ impl ToAttrTokenStream for LazyAttrTokenStreamImpl { replace_ranges.sort_by_key(|(range, _)| range.start); #[cfg(debug_assertions)] - { - for [(range, tokens), (next_range, next_tokens)] in replace_ranges.array_windows() { - assert!( - range.end <= next_range.start || range.end >= next_range.end, - "Replace ranges should either be disjoint or nested: ({:?}, {:?}) ({:?}, {:?})", - range, - tokens, - next_range, - next_tokens, - ); - } + for [(range, tokens), (next_range, next_tokens)] in replace_ranges.array_windows() { + assert!( + range.end <= next_range.start || range.end >= next_range.end, + "Replace ranges should either be disjoint or nested: ({:?}, {:?}) ({:?}, {:?})", + range, + tokens, + next_range, + next_tokens, + ); } // Process the replace ranges, starting from the highest start @@ -133,9 +131,9 @@ impl ToAttrTokenStream for LazyAttrTokenStreamImpl { // `#[cfg(FALSE)] struct Foo { #[cfg(FALSE)] field: bool }` // // By starting processing from the replace range with the greatest - // start position, we ensure that any replace range which encloses - // another replace range will capture the *replaced* tokens for the inner - // range, not the original tokens. + // start position, we ensure that any (outer) replace range which + // encloses another (inner) replace range will fully overwrite the + // inner range's replacement. for (range, target) in replace_ranges.into_iter().rev() { assert!(!range.is_empty(), "Cannot replace an empty range: {range:?}"); @@ -293,11 +291,13 @@ impl<'a> Parser<'a> { // with `None`, which means the relevant tokens will be removed. (More // details below.) let mut inner_attr_replace_ranges = Vec::new(); - for inner_attr in ret.attrs().iter().filter(|a| a.style == ast::AttrStyle::Inner) { - if let Some(attr_range) = self.capture_state.inner_attr_ranges.remove(&inner_attr.id) { - inner_attr_replace_ranges.push((attr_range, None)); - } else { - self.dcx().span_delayed_bug(inner_attr.span, "Missing token range for attribute"); + for attr in ret.attrs() { + if attr.style == ast::AttrStyle::Inner { + if let Some(attr_range) = self.capture_state.inner_attr_ranges.remove(&attr.id) { + inner_attr_replace_ranges.push((attr_range, None)); + } else { + self.dcx().span_delayed_bug(attr.span, "Missing token range for attribute"); + } } } @@ -333,8 +333,7 @@ impl<'a> Parser<'a> { // When parsing `m`: // - `start_pos..end_pos` is `0..34` (`mod m`, excluding the `#[cfg_eval]` attribute). // - `inner_attr_replace_ranges` is empty. - // - `replace_range_start..replace_ranges_end` has two entries. - // - One to delete the inner attribute (`17..27`), obtained when parsing `g` (see above). + // - `replace_range_start..replace_ranges_end` has one entry. // - One `AttrsTarget` (added below when parsing `g`) to replace all of `g` (`3..33`, // including its outer attribute), with: // - `attrs`: includes the outer and the inner attr. @@ -365,12 +364,10 @@ impl<'a> Parser<'a> { // What is the status here when parsing the example code at the top of this method? // - // When parsing `g`, we add two entries: + // When parsing `g`, we add one entry: // - The `start_pos..end_pos` (`3..33`) entry has a new `AttrsTarget` with: // - `attrs`: includes the outer and the inner attr. // - `tokens`: lazy tokens for `g` (with its inner attr deleted). - // - `inner_attr_replace_ranges` contains the one entry to delete the inner attr's - // tokens (`17..27`). // // When parsing `m`, we do nothing here. @@ -380,7 +377,6 @@ impl<'a> Parser<'a> { let start_pos = if has_outer_attrs { attrs.start_pos } else { start_pos }; let target = AttrsTarget { attrs: ret.attrs().iter().cloned().collect(), tokens }; self.capture_state.replace_ranges.push((start_pos..end_pos, Some(target))); - self.capture_state.replace_ranges.extend(inner_attr_replace_ranges); } else if matches!(self.capture_state.capturing, Capturing::No) { // Only clear the ranges once we've finished capturing entirely, i.e. we've finished // the outermost call to this method.