Auto merge of #108934 - matthiaskrgr:rollup-vm414p5, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #106915 (Only load one CSS theme by default)
 - #108294 (Place binder correctly for arbitrary trait bound suggestion)
 - #108778 (x fmt: Don't print all modified files if there's more than 10)
 - #108854 (feat/refactor: improve errors in case of ident with number at start)
 - #108870 (Fix invalid inlining of reexport of reexport of private item)
 - #108917 (Consider target_family as pal)
 - #108922 (Add auto notification for changes to stable mir)
 - #108929 (Fix typo in span_map.rs)

Failed merges:

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

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -117,7 +117,7 @@ pub fn suggest_arbitrary_trait_bound<'tcx>(
     }
 
     let param_name = trait_pred.skip_binder().self_ty().to_string();
-    let mut constraint = trait_pred.print_modifiers_and_trait_path().to_string();
+    let mut constraint = trait_pred.to_string();
 
     if let Some((name, term)) = associated_ty {
         // FIXME: this case overlaps with code in TyCtxt::note_and_explain_type_err.
@@ -144,7 +144,7 @@ pub fn suggest_arbitrary_trait_bound<'tcx>(
              this requirement",
             if generics.where_clause_span.is_empty() { "introducing a" } else { "extending the" },
         ),
-        format!("{} {}: {}", generics.add_where_or_trailing_comma(), param_name, constraint),
+        format!("{} {constraint}", generics.add_where_or_trailing_comma()),
         Applicability::MaybeIncorrect,
     );
     true

compiler/rustc_parse/locales/en-US.ftl

@@ -412,8 +412,7 @@ parse_fn_ptr_with_generics = function pointer types may not have generic paramet
         *[false] a
     } `for` parameter list
 
-parse_invalid_identifier_with_leading_number = expected identifier, found number literal
-    .label = identifiers cannot start with a number
+parse_invalid_identifier_with_leading_number = identifiers cannot start with a number
 
 parse_maybe_fn_typo_with_impl = you might have meant to write `impl` instead of `fn`
     .suggestion = replace `fn` with `impl` here

compiler/rustc_parse/src/errors.rs

@@ -939,6 +939,7 @@ pub(crate) struct ExpectedIdentifier {
     pub token: Token,
     pub suggest_raw: Option<SuggEscapeToUseAsIdentifier>,
     pub suggest_remove_comma: Option<SuggRemoveComma>,
+    pub help_cannot_start_number: Option<HelpIdentifierStartsWithNumber>,
 }
 
 impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedIdentifier {
@@ -975,10 +976,18 @@ impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedIdentifier {
             sugg.add_to_diagnostic(&mut diag);
         }
 
+        if let Some(help) = self.help_cannot_start_number {
+            help.add_to_diagnostic(&mut diag);
+        }
+
         diag
     }
 }
 
+#[derive(Subdiagnostic)]
+#[help(parse_invalid_identifier_with_leading_number)]
+pub(crate) struct HelpIdentifierStartsWithNumber;
+
 pub(crate) struct ExpectedSemi {
     pub span: Span,
     pub token: Token,
@@ -1207,14 +1216,6 @@ pub(crate) struct SelfParamNotFirst {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(parse_invalid_identifier_with_leading_number)]
-pub(crate) struct InvalidIdentiferStartsWithNumber {
-    #[primary_span]
-    #[label]
-    pub span: Span,
-}
-
 #[derive(Diagnostic)]
 #[diag(parse_const_generic_without_braces)]
 pub(crate) struct ConstGenericWithoutBraces {

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -8,14 +8,14 @@ use crate::errors::{
     ComparisonOperatorsCannotBeChained, ComparisonOperatorsCannotBeChainedSugg,
     ConstGenericWithoutBraces, ConstGenericWithoutBracesSugg, DocCommentOnParamType,
     DoubleColonInBound, ExpectedIdentifier, ExpectedSemi, ExpectedSemiSugg,
-    GenericParamsWithoutAngleBrackets, GenericParamsWithoutAngleBracketsSugg, InInTypo,
-    IncorrectAwait, IncorrectSemicolon, IncorrectUseOfAwait, ParenthesesInForHead,
-    ParenthesesInForHeadSugg, PatternMethodParamWithoutBody, QuestionMarkInType,
-    QuestionMarkInTypeSugg, SelfParamNotFirst, StructLiteralBodyWithoutPath,
-    StructLiteralBodyWithoutPathSugg, StructLiteralNeedingParens, StructLiteralNeedingParensSugg,
-    SuggEscapeToUseAsIdentifier, SuggRemoveComma, UnexpectedConstInGenericParam,
-    UnexpectedConstParamDeclaration, UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets,
-    UseEqInstead,
+    GenericParamsWithoutAngleBrackets, GenericParamsWithoutAngleBracketsSugg,
+    HelpIdentifierStartsWithNumber, InInTypo, IncorrectAwait, IncorrectSemicolon,
+    IncorrectUseOfAwait, ParenthesesInForHead, ParenthesesInForHeadSugg,
+    PatternMethodParamWithoutBody, QuestionMarkInType, QuestionMarkInTypeSugg, SelfParamNotFirst,
+    StructLiteralBodyWithoutPath, StructLiteralBodyWithoutPathSugg, StructLiteralNeedingParens,
+    StructLiteralNeedingParensSugg, SuggEscapeToUseAsIdentifier, SuggRemoveComma,
+    UnexpectedConstInGenericParam, UnexpectedConstParamDeclaration,
+    UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, UseEqInstead,
 };
 
 use crate::fluent_generated as fluent;
@@ -280,6 +280,7 @@ impl<'a> Parser<'a> {
             TokenKind::CloseDelim(Delimiter::Brace),
             TokenKind::CloseDelim(Delimiter::Parenthesis),
         ];
+
         let suggest_raw = match self.token.ident() {
             Some((ident, false))
                 if ident.is_raw_guess()
@@ -295,18 +296,19 @@ impl<'a> Parser<'a> {
             _ => None,
         };
 
-        let suggest_remove_comma =
-            if self.token == token::Comma && self.look_ahead(1, |t| t.is_ident()) {
-                Some(SuggRemoveComma { span: self.token.span })
-            } else {
-                None
-            };
+        let suggest_remove_comma = (self.token == token::Comma
+            && self.look_ahead(1, |t| t.is_ident()))
+        .then_some(SuggRemoveComma { span: self.token.span });
+
+        let help_cannot_start_number =
+            self.is_lit_bad_ident().then_some(HelpIdentifierStartsWithNumber);
 
         let err = ExpectedIdentifier {
             span: self.token.span,
             token: self.token.clone(),
             suggest_raw,
             suggest_remove_comma,
+            help_cannot_start_number,
         };
         let mut err = err.into_diagnostic(&self.sess.span_diagnostic);
 
@@ -365,6 +367,17 @@ impl<'a> Parser<'a> {
         err
     }
 
+    /// Checks if the current token is a integer or float literal and looks like
+    /// it could be a invalid identifier with digits at the start.
+    pub(super) fn is_lit_bad_ident(&mut self) -> bool {
+        matches!(self.token.uninterpolate().kind, token::Literal(Lit { kind: token::LitKind::Integer | token::LitKind::Float, .. })
+            // ensure that the integer literal is followed by a *invalid*
+            // suffix: this is how we know that it is a identifier with an
+            // invalid beginning.
+            if rustc_ast::MetaItemLit::from_token(&self.token).is_none()
+        )
+    }
+
     pub(super) fn expected_one_of_not_found(
         &mut self,
         edible: &[TokenKind],

compiler/rustc_parse/src/parser/pat.rs

@@ -348,6 +348,10 @@ impl<'a> Parser<'a> {
             lo = self.token.span;
         }
 
+        if self.is_lit_bad_ident() {
+            return Err(self.expected_ident_found());
+        }
+
         let pat = if self.check(&token::BinOp(token::And)) || self.token.kind == token::AndAnd {
             self.parse_pat_deref(expected)?
         } else if self.check(&token::OpenDelim(Delimiter::Parenthesis)) {

compiler/rustc_parse/src/parser/stmt.rs

@@ -273,7 +273,6 @@ impl<'a> Parser<'a> {
             self.bump();
         }
 
-        self.report_invalid_identifier_error()?;
         let (pat, colon) =
             self.parse_pat_before_ty(None, RecoverComma::Yes, PatternLocation::LetBinding)?;
 
@@ -366,17 +365,6 @@ impl<'a> Parser<'a> {
         Ok(P(ast::Local { ty, pat, kind, id: DUMMY_NODE_ID, span: lo.to(hi), attrs, tokens: None }))
     }
 
-    /// report error for `let 1x = 123`
-    pub fn report_invalid_identifier_error(&mut self) -> PResult<'a, ()> {
-        if let token::Literal(lit) = self.token.uninterpolate().kind &&
-            rustc_ast::MetaItemLit::from_token(&self.token).is_none() &&
-            (lit.kind == token::LitKind::Integer || lit.kind == token::LitKind::Float) &&
-            self.look_ahead(1, |t| matches!(t.kind, token::Eq) || matches!(t.kind, token::Colon ) ) {
-                return Err(self.sess.create_err(errors::InvalidIdentiferStartsWithNumber { span: self.token.span }));
-        }
-        Ok(())
-    }
-
     fn check_let_else_init_bool_expr(&self, init: &ast::Expr) {
         if let ast::ExprKind::Binary(op, ..) = init.kind {
             if op.node.lazy() {

src/bootstrap/format.rs

@@ -165,8 +165,14 @@ pub fn format(build: &Builder<'_>, check: bool, paths: &[PathBuf]) {
             if !CiEnv::is_ci() && paths.is_empty() {
                 match get_modified_rs_files(build) {
                     Ok(Some(files)) => {
+                        if files.len() <= 10 {
+                            for file in &files {
+                                println!("formatting modified file {file}");
+                            }
+                        } else {
+                            println!("formatting {} modified files", files.len());
+                        }
                         for file in files {
-                            println!("formatting modified file {file}");
                             ignore_fmt.add(&format!("/{file}")).expect(&file);
                         }
                     }

src/librustdoc/clean/mod.rs

@@ -2065,23 +2065,81 @@ fn clean_bare_fn_ty<'tcx>(
     BareFunctionDecl { unsafety: bare_fn.unsafety, abi: bare_fn.abi, decl, generic_params }
 }
 
-/// This visitor is used to go through only the "top level" of a item and not enter any sub
-/// item while looking for a given `Ident` which is stored into `item` if found.
-struct OneLevelVisitor<'hir> {
+/// Get DefId of of an item's user-visible parent.
+///
+/// "User-visible" should account for re-exporting and inlining, which is why this function isn't
+/// just `tcx.parent(def_id)`. If the provided `path` has more than one path element, the `DefId`
+/// of the second-to-last will be given.
+///
+/// ```text
+/// use crate::foo::Bar;
+///            ^^^ DefId of this item will be returned
+/// ```
+///
+/// If the provided path has only one item, `tcx.parent(def_id)` will be returned instead.
+fn get_path_parent_def_id(
+    tcx: TyCtxt<'_>,
+    def_id: DefId,
+    path: &hir::UsePath<'_>,
+) -> Option<DefId> {
+    if let [.., parent_segment, _] = &path.segments {
+        match parent_segment.res {
+            hir::def::Res::Def(_, parent_def_id) => Some(parent_def_id),
+            _ if parent_segment.ident.name == kw::Crate => {
+                // In case the "parent" is the crate, it'll give `Res::Err` so we need to
+                // circumvent it this way.
+                Some(tcx.parent(def_id))
+            }
+            _ => None,
+        }
+    } else {
+        // If the path doesn't have a parent, then the parent is the current module.
+        Some(tcx.parent(def_id))
+    }
+}
+
+/// This visitor is used to find an HIR Item based on its `use` path. This doesn't use the ordinary
+/// name resolver because it does not walk all the way through a chain of re-exports.
+pub(crate) struct OneLevelVisitor<'hir> {
     map: rustc_middle::hir::map::Map<'hir>,
-    item: Option<&'hir hir::Item<'hir>>,
+    pub(crate) item: Option<&'hir hir::Item<'hir>>,
     looking_for: Ident,
     target_def_id: LocalDefId,
 }
 
 impl<'hir> OneLevelVisitor<'hir> {
-    fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
+    pub(crate) fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
         Self { map, item: None, looking_for: Ident::empty(), target_def_id }
     }
 
-    fn reset(&mut self, looking_for: Ident) {
-        self.looking_for = looking_for;
+    pub(crate) fn find_target(
+        &mut self,
+        tcx: TyCtxt<'_>,
+        def_id: DefId,
+        path: &hir::UsePath<'_>,
+    ) -> Option<&'hir hir::Item<'hir>> {
+        let parent_def_id = get_path_parent_def_id(tcx, def_id, path)?;
+        let parent = self.map.get_if_local(parent_def_id)?;
+
+        // We get the `Ident` we will be looking for into `item`.
+        self.looking_for = path.segments[path.segments.len() - 1].ident;
+        // We reset the `item`.
         self.item = None;
+
+        match parent {
+            hir::Node::Item(parent_item) => {
+                hir::intravisit::walk_item(self, parent_item);
+            }
+            hir::Node::Crate(m) => {
+                hir::intravisit::walk_mod(
+                    self,
+                    m,
+                    tcx.local_def_id_to_hir_id(parent_def_id.as_local().unwrap()),
+                );
+            }
+            _ => return None,
+        }
+        self.item
     }
 }
 
@@ -2129,41 +2187,7 @@ fn get_all_import_attributes<'hir>(
             add_without_unwanted_attributes(attributes, hir_map.attrs(item.hir_id()), is_inline);
         }
 
-        let def_id = if let [.., parent_segment, _] = &path.segments {
-            match parent_segment.res {
-                hir::def::Res::Def(_, def_id) => def_id,
-                _ if parent_segment.ident.name == kw::Crate => {
-                    // In case the "parent" is the crate, it'll give `Res::Err` so we need to
-                    // circumvent it this way.
-                    tcx.parent(item.owner_id.def_id.to_def_id())
-                }
-                _ => break,
-            }
-        } else {
-            // If the path doesn't have a parent, then the parent is the current module.
-            tcx.parent(item.owner_id.def_id.to_def_id())
-        };
-
-        let Some(parent) = hir_map.get_if_local(def_id) else { break };
-
-        // We get the `Ident` we will be looking for into `item`.
-        let looking_for = path.segments[path.segments.len() - 1].ident;
-        visitor.reset(looking_for);
-
-        match parent {
-            hir::Node::Item(parent_item) => {
-                hir::intravisit::walk_item(&mut visitor, parent_item);
-            }
-            hir::Node::Crate(m) => {
-                hir::intravisit::walk_mod(
-                    &mut visitor,
-                    m,
-                    tcx.local_def_id_to_hir_id(def_id.as_local().unwrap()),
-                );
-            }
-            _ => break,
-        }
-        if let Some(i) = visitor.item {
+        if let Some(i) = visitor.find_target(tcx, item.owner_id.def_id.to_def_id(), path) {
             item = i;
         } else {
             break;

src/librustdoc/html/render/context.rs

@@ -647,11 +647,35 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
                      </noscript>\
                      <link rel=\"stylesheet\" \
                          href=\"{static_root_path}{settings_css}\">\
-                     <script defer src=\"{static_root_path}{settings_js}\"></script>",
+                     <script defer src=\"{static_root_path}{settings_js}\"></script>\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_light_css}\" \
+                         as=\"style\">\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_dark_css}\" \
+                         as=\"style\">\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_ayu_css}\" \
+                         as=\"style\">",
                     static_root_path = page.get_static_root_path(),
                     settings_css = static_files::STATIC_FILES.settings_css,
                     settings_js = static_files::STATIC_FILES.settings_js,
-                )
+                    theme_light_css = static_files::STATIC_FILES.theme_light_css,
+                    theme_dark_css = static_files::STATIC_FILES.theme_dark_css,
+                    theme_ayu_css = static_files::STATIC_FILES.theme_ayu_css,
+                );
+                // Pre-load all theme CSS files, so that switching feels seamless.
+                //
+                // When loading settings.html as a popover, the equivalent HTML is
+                // generated in main.js.
+                for file in &shared.style_files {
+                    if let Ok(theme) = file.basename() {
+                        write!(
+                            buf,
+                            "<link rel=\"preload\" href=\"{root_path}{theme}{suffix}.css\" \
+                                as=\"style\">",
+                            root_path = page.static_root_path.unwrap_or(""),
+                            suffix = page.resource_suffix,
+                        );
+                    }
+                }
             },
             &shared.style_files,
         );

src/librustdoc/html/render/span_map.rs

@@ -29,12 +29,12 @@ pub(crate) enum LinkFromSrc {
 
 /// This function will do at most two things:
 ///
-/// 1. Generate a `span` correspondance map which links an item `span` to its definition `span`.
+/// 1. Generate a `span` correspondence map which links an item `span` to its definition `span`.
 /// 2. Collect the source code files.
 ///
-/// It returns the `krate`, the source code files and the `span` correspondance map.
+/// It returns the `krate`, the source code files and the `span` correspondence map.
 ///
-/// Note about the `span` correspondance map: the keys are actually `(lo, hi)` of `span`s. We don't
+/// Note about the `span` correspondence map: the keys are actually `(lo, hi)` of `span`s. We don't
 /// need the `span` context later on, only their position, so instead of keep a whole `Span`, we
 /// only keep the `lo` and `hi`.
 pub(crate) fn collect_spans_and_sources(