Auto merge of rust-lang#134795 - GuillaumeGomez:rollup-9x8n7pi, r=GuillaumeGomez

Rollup of 4 pull requests

Successful merges:

 - rust-lang#134656 (Migrate `incr-add-rust-src-component` to rmake)
 - rust-lang#134664 (Account for removal of multiline span in suggestion)
 - rust-lang#134772 (Improve/cleanup rustdoc code)
 - rust-lang#134781 (Add more `begin_panic` normalizations to panic backtrace tests)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_errors/src/emitter.rs

@@ -2216,6 +2216,11 @@ impl HumanEmitter {
                 show_code_change
             {
                 for part in parts {
+                    let snippet = if let Ok(snippet) = sm.span_to_snippet(part.span) {
+                        snippet
+                    } else {
+                        String::new()
+                    };
                     let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
                     let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
 
@@ -2263,13 +2268,80 @@ impl HumanEmitter {
                     }
                     if let DisplaySuggestion::Diff = show_code_change {
                         // Colorize removal with red in diff format.
-                        buffer.set_style_range(
-                            row_num - 2,
-                            (padding as isize + span_start_pos as isize) as usize,
-                            (padding as isize + span_end_pos as isize) as usize,
-                            Style::Removal,
-                            true,
-                        );
+
+                        // Below, there's some tricky buffer indexing going on. `row_num` at this
+                        // point corresponds to:
+                        //
+                        //    |
+                        // LL | CODE
+                        //    | ++++  <- `row_num`
+                        //
+                        // in the buffer. When we have a diff format output, we end up with
+                        //
+                        //    |
+                        // LL - OLDER   <- row_num - 2
+                        // LL + NEWER
+                        //    |         <- row_num
+                        //
+                        // The `row_num - 2` is to select the buffer line that has the "old version
+                        // of the diff" at that point. When the removal is a single line, `i` is
+                        // `0`, `newlines` is `1` so `(newlines - i - 1)` ends up being `0`, so row
+                        // points at `LL - OLDER`. When the removal corresponds to multiple lines,
+                        // we end up with `newlines > 1` and `i` being `0..newlines - 1`.
+                        //
+                        //    |
+                        // LL - OLDER   <- row_num - 2 - (newlines - last_i - 1)
+                        // LL - CODE
+                        // LL - BEING
+                        // LL - REMOVED <- row_num - 2 - (newlines - first_i - 1)
+                        // LL + NEWER
+                        //    |         <- row_num
+
+                        let newlines = snippet.lines().count();
+                        if newlines > 0 && row_num > newlines {
+                            // Account for removals where the part being removed spans multiple
+                            // lines.
+                            // FIXME: We check the number of rows because in some cases, like in
+                            // `tests/ui/lint/invalid-nan-comparison-suggestion.rs`, the rendered
+                            // suggestion will only show the first line of code being replaced. The
+                            // proper way of doing this would be to change the suggestion rendering
+                            // logic to show the whole prior snippet, but the current output is not
+                            // too bad to begin with, so we side-step that issue here.
+                            for (i, line) in snippet.lines().enumerate() {
+                                let line = normalize_whitespace(line);
+                                let row = row_num - 2 - (newlines - i - 1);
+                                // On the first line, we highlight between the start of the part
+                                // span, and the end of that line.
+                                // On the last line, we highlight between the start of the line, and
+                                // the column of the part span end.
+                                // On all others, we highlight the whole line.
+                                let start = if i == 0 {
+                                    (padding as isize + span_start_pos as isize) as usize
+                                } else {
+                                    padding
+                                };
+                                let end = if i == 0 {
+                                    (padding as isize
+                                        + span_start_pos as isize
+                                        + line.len() as isize)
+                                        as usize
+                                } else if i == newlines - 1 {
+                                    (padding as isize + span_end_pos as isize) as usize
+                                } else {
+                                    (padding as isize + line.len() as isize) as usize
+                                };
+                                buffer.set_style_range(row, start, end, Style::Removal, true);
+                            }
+                        } else {
+                            // The removed code fits all in one line.
+                            buffer.set_style_range(
+                                row_num - 2,
+                                (padding as isize + span_start_pos as isize) as usize,
+                                (padding as isize + span_end_pos as isize) as usize,
+                                Style::Removal,
+                                true,
+                            );
+                        }
                     }
 
                     // length of the code after substitution

src/librustdoc/clean/mod.rs

@@ -894,7 +894,7 @@ fn clean_ty_generics<'tcx>(
 
         // Add back a `Sized` bound if there are no *trait* bounds remaining (incl. `?Sized`).
         // Since all potential trait bounds are at the front we can just check the first bound.
-        if bounds.first().map_or(true, |b| !b.is_trait_bound()) {
+        if bounds.first().is_none_or(|b| !b.is_trait_bound()) {
             bounds.insert(0, GenericBound::sized(cx));
         }
 
@@ -1811,7 +1811,7 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
         }
         TyKind::Slice(ty) => Slice(Box::new(clean_ty(ty, cx))),
         TyKind::Pat(ty, pat) => Type::Pat(Box::new(clean_ty(ty, cx)), format!("{pat:?}").into()),
-        TyKind::Array(ty, ref const_arg) => {
+        TyKind::Array(ty, const_arg) => {
             // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
             // as we currently do not supply the parent generics to anonymous constants
             // but do allow `ConstKind::Param`.
@@ -2337,7 +2337,7 @@ fn clean_middle_opaque_bounds<'tcx>(
 
     // Add back a `Sized` bound if there are no *trait* bounds remaining (incl. `?Sized`).
     // Since all potential trait bounds are at the front we can just check the first bound.
-    if bounds.first().map_or(true, |b| !b.is_trait_bound()) {
+    if bounds.first().is_none_or(|b| !b.is_trait_bound()) {
         bounds.insert(0, GenericBound::sized(cx));
     }
 

src/librustdoc/doctest.rs

@@ -220,7 +220,7 @@ pub(crate) fn run(dcx: DiagCtxtHandle<'_>, input: Input, options: RustdocOptions
     } = interface::run_compiler(config, |compiler| {
         let krate = rustc_interface::passes::parse(&compiler.sess);
 
-        let collector = rustc_interface::create_and_enter_global_ctxt(&compiler, krate, |tcx| {
+        let collector = rustc_interface::create_and_enter_global_ctxt(compiler, krate, |tcx| {
             let crate_name = tcx.crate_name(LOCAL_CRATE).to_string();
             let crate_attrs = tcx.hir().attrs(CRATE_HIR_ID);
             let opts = scrape_test_config(crate_name, crate_attrs, args_path);

src/librustdoc/doctest/make.rs

@@ -538,7 +538,7 @@ fn handle_attr(mod_attr_pending: &mut String, source_info: &mut SourceInfo, edit
         // If it's complete, then we can clear the pending content.
         mod_attr_pending.clear();
     } else {
-        mod_attr_pending.push_str("\n");
+        mod_attr_pending.push('\n');
     }
 }
 

src/librustdoc/formats/cache.rs

@@ -413,7 +413,7 @@ impl DocFolder for CacheBuilder<'_, '_> {
             let impl_item = Impl { impl_item: item };
             let impl_did = impl_item.def_id();
             let trait_did = impl_item.trait_did();
-            if trait_did.map_or(true, |d| self.cache.traits.contains_key(&d)) {
+            if trait_did.is_none_or(|d| self.cache.traits.contains_key(&d)) {
                 for did in dids {
                     if self.impl_ids.entry(did).or_default().insert(impl_did) {
                         self.cache.impls.entry(did).or_default().push(impl_item.clone());

src/librustdoc/html/escape.rs

@@ -104,10 +104,9 @@ impl fmt::Display for EscapeBodyTextWithWbr<'_> {
                 continue;
             }
             let is_uppercase = || s.chars().any(|c| c.is_uppercase());
-            let next_is_uppercase =
-                || pk.map_or(true, |(_, t)| t.chars().any(|c| c.is_uppercase()));
-            let next_is_underscore = || pk.map_or(true, |(_, t)| t.contains('_'));
-            let next_is_colon = || pk.map_or(true, |(_, t)| t.contains(':'));
+            let next_is_uppercase = || pk.is_none_or(|(_, t)| t.chars().any(|c| c.is_uppercase()));
+            let next_is_underscore = || pk.is_none_or(|(_, t)| t.contains('_'));
+            let next_is_colon = || pk.is_none_or(|(_, t)| t.contains(':'));
             // Check for CamelCase.
             //
             // `i - last > 3` avoids turning FmRadio into Fm<wbr>Radio, which is technically

src/librustdoc/html/markdown.rs

@@ -480,7 +480,7 @@ impl<'a, I: Iterator<Item = SpannedEvent<'a>>> Iterator for SpannedLinkReplacer<
     type Item = SpannedEvent<'a>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        let Some((mut event, range)) = self.iter.next() else { return None };
+        let (mut event, range) = self.iter.next()?;
         self.inner.handle_event(&mut event);
         // Yield the modified event
         Some((event, range))
@@ -2039,7 +2039,7 @@ impl IdMap {
                 let candidate = candidate.to_string();
                 if is_default_id(&candidate) {
                     let id = format!("{}-{}", candidate, 1);
-                    self.map.insert(candidate.into(), 2);
+                    self.map.insert(candidate, 2);
                     id
                 } else {
                     candidate
@@ -2052,7 +2052,7 @@ impl IdMap {
             }
         };
 
-        self.map.insert(id.clone().into(), 1);
+        self.map.insert(id.clone(), 1);
         id
     }
 

src/librustdoc/html/render/context.rs

@@ -748,7 +748,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
                 &shared.layout,
                 &page,
                 "",
-                scrape_examples_help(&shared),
+                scrape_examples_help(shared),
                 &shared.style_files,
             );
             shared.fs.write(scrape_examples_help_file, v)?;

src/librustdoc/html/render/mod.rs

@@ -1974,7 +1974,7 @@ fn render_impl(
             .opt_doc_value()
             .map(|dox| {
                 Markdown {
-                    content: &*dox,
+                    content: &dox,
                     links: &i.impl_item.links(cx),
                     ids: &mut cx.id_map.borrow_mut(),
                     error_codes: cx.shared.codes,

src/librustdoc/html/render/print_item.rs

@@ -1420,7 +1420,7 @@ fn item_union(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, s: &clean::Uni
             ty: &'a clean::Type,
         ) -> impl fmt::Display + Captures<'a> + 'b + Captures<'cx> {
             display_fn(move |f| {
-                let v = ty.print(&self.cx);
+                let v = ty.print(self.cx);
                 write!(f, "{v}")
             })
         }