Auto merge of rust-lang#90422 - GuillaumeGomez:rollup-s1mdag0, r=GuillaumeGomez

Rollup of 5 pull requests

Successful merges:

 - rust-lang#90156 (Remove underlines from non-top docblocks.)
 - rust-lang#90183 (Show all Deref implementations recursively)
 - rust-lang#90202 (Improve and test cross-crate hygiene)
 - rust-lang#90375 (Use `is_global` in `candidate_should_be_dropped_in_favor_of`)
 - rust-lang#90399 (Skipping verbose diagnostic suggestions when calling .as_ref() on type not implementing AsRef)

Failed merges:

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

Author: bors

Diff for: compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -1198,8 +1198,8 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             }
         }
 
-        if let EntryKind::Mod(data) = kind {
-            for exp in data.decode((self, sess)).reexports.decode((self, sess)) {
+        if let EntryKind::Mod(exports) = kind {
+            for exp in exports.decode((self, sess)) {
                 match exp.res {
                     Res::Def(DefKind::Macro(..), _) => {}
                     _ if macros_only => continue,
@@ -1219,10 +1219,11 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
     }
 
     fn module_expansion(&self, id: DefIndex, sess: &Session) -> ExpnId {
-        if let EntryKind::Mod(m) = self.kind(id) {
-            m.decode((self, sess)).expansion
-        } else {
-            panic!("Expected module, found {:?}", self.local_def_id(id))
+        match self.kind(id) {
+            EntryKind::Mod(_) | EntryKind::Enum(_) | EntryKind::Trait(_) => {
+                self.get_expn_that_defined(id, sess)
+            }
+            _ => panic!("Expected module, found {:?}", self.local_def_id(id)),
         }
     }
 

Diff for: compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1086,11 +1086,11 @@ impl EncodeContext<'a, 'tcx> {
             Lazy::empty()
         };
 
-        let data = ModData { reexports, expansion: tcx.expn_that_defined(local_def_id) };
-
-        record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
+        record!(self.tables.kind[def_id] <- EntryKind::Mod(reexports));
         if self.is_proc_macro {
             record!(self.tables.children[def_id] <- &[]);
+            // Encode this here because we don't do it in encode_def_ids.
+            record!(self.tables.expn_that_defined[def_id] <- tcx.expn_that_defined(local_def_id));
         } else {
             record!(self.tables.children[def_id] <- md.item_ids.iter().map(|item_id| {
                 item_id.def_id.local_def_index

Diff for: compiler/rustc_metadata/src/rmeta/mod.rs

@@ -346,7 +346,7 @@ enum EntryKind {
     Union(Lazy<VariantData>, ReprOptions),
     Fn(Lazy<FnData>),
     ForeignFn(Lazy<FnData>),
-    Mod(Lazy<ModData>),
+    Mod(Lazy<[Export]>),
     MacroDef(Lazy<MacroDef>),
     ProcMacro(MacroKind),
     Closure,
@@ -364,12 +364,6 @@ enum EntryKind {
 #[derive(Encodable, Decodable)]
 struct RenderedConst(String);
 
-#[derive(MetadataEncodable, MetadataDecodable)]
-struct ModData {
-    reexports: Lazy<[Export]>,
-    expansion: ExpnId,
-}
-
 #[derive(MetadataEncodable, MetadataDecodable)]
 struct FnData {
     asyncness: hir::IsAsync,

Diff for: compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -145,17 +145,11 @@ impl<'a> Resolver<'a> {
                     } else {
                         def_key.disambiguated_data.data.get_opt_name().expect("module without name")
                     };
-                    let expn_id = if def_kind == DefKind::Mod {
-                        self.cstore().module_expansion_untracked(def_id, &self.session)
-                    } else {
-                        // FIXME: Parent expansions for enums and traits are not kept in metadata.
-                        ExpnId::root()
-                    };
 
                     Some(self.new_module(
                         parent,
                         ModuleKind::Def(def_kind, def_id, name),
-                        expn_id,
+                        self.cstore().module_expansion_untracked(def_id, &self.session),
                         self.cstore().get_span_untracked(def_id, &self.session),
                         // FIXME: Account for `#[no_implicit_prelude]` attributes.
                         parent.map_or(false, |module| module.no_implicit_prelude),

Diff for: compiler/rustc_resolve/src/diagnostics.rs

@@ -842,9 +842,11 @@ impl<'a> Resolver<'a> {
 
                 // collect results based on the filter function
                 // avoid suggesting anything from the same module in which we are resolving
+                // avoid suggesting anything with a hygienic name
                 if ident.name == lookup_ident.name
                     && ns == namespace
                     && !ptr::eq(in_module, parent_scope.module)
+                    && !ident.span.normalize_to_macros_2_0().from_expansion()
                 {
                     let res = name_binding.res();
                     if filter_fn(res) {

Diff for: compiler/rustc_span/src/hygiene.rs

@@ -709,7 +709,7 @@ impl SyntaxContext {
     ///         pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`.
     ///         pub fn $i() {} // `$i`'s `SyntaxContext` is empty.
     ///     }
-    ///     n(f);
+    ///     n!(f);
     ///     macro n($j:ident) {
     ///         use foo::*;
     ///         f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n`

Diff for: compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -1547,8 +1547,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // Check if a bound would previously have been removed when normalizing
         // the param_env so that it can be given the lowest priority. See
         // #50825 for the motivation for this.
-        let is_global =
-            |cand: &ty::PolyTraitRef<'_>| cand.is_known_global() && !cand.has_late_bound_regions();
+        let is_global = |cand: &ty::PolyTraitRef<'tcx>| {
+            cand.is_global(self.infcx.tcx) && !cand.has_late_bound_regions()
+        };
 
         // (*) Prefer `BuiltinCandidate { has_nested: false }`, `PointeeCandidate`,
         // and `DiscriminantKindCandidate` to anything else.

Diff for: compiler/rustc_typeck/src/check/method/suggest.rs

@@ -15,7 +15,7 @@ use rustc_middle::ty::print::with_crate_prefix;
 use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness};
 use rustc_span::lev_distance;
 use rustc_span::symbol::{kw, sym, Ident};
-use rustc_span::{source_map, FileName, MultiSpan, Span};
+use rustc_span::{source_map, FileName, MultiSpan, Span, Symbol};
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
 use rustc_trait_selection::traits::{FulfillmentError, Obligation};
 
@@ -1251,6 +1251,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.tcx.lang_items().deref_trait(),
                 self.tcx.lang_items().deref_mut_trait(),
                 self.tcx.lang_items().drop_trait(),
+                self.tcx.get_diagnostic_item(sym::AsRef),
             ];
             // Try alternative arbitrary self types that could fulfill this call.
             // FIXME: probe for all types that *could* be arbitrary self-types, not
@@ -1300,7 +1301,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             // We don't want to suggest a container type when the missing
                             // method is `.clone()` or `.deref()` otherwise we'd suggest
                             // `Arc::new(foo).clone()`, which is far from what the user wants.
-                            let skip = skippable.contains(&did);
+                            // Explicitly ignore the `Pin::as_ref()` method as `Pin` does not
+                            // implement the `AsRef` trait.
+                            let skip = skippable.contains(&did)
+                                || (("Pin::new" == *pre)
+                                    && (Symbol::intern("as_ref") == item_name.name));
                             // Make sure the method is defined for the *actual* receiver: we don't
                             // want to treat `Box<Self>` as a receiver if it only works because of
                             // an autoderef to `&self`

Diff for: src/librustdoc/html/render/context.rs

@@ -6,7 +6,7 @@ use std::rc::Rc;
 use std::sync::mpsc::{channel, Receiver};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_hir::def_id::LOCAL_CRATE;
+use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::edition::Edition;
@@ -54,6 +54,9 @@ crate struct Context<'tcx> {
     /// real location of an item. This is used to allow external links to
     /// publicly reused items to redirect to the right location.
     pub(super) render_redirect_pages: bool,
+    /// Tracks section IDs for `Deref` targets so they match in both the main
+    /// body and the sidebar.
+    pub(super) deref_id_map: RefCell<FxHashMap<DefId, String>>,
     /// The map used to ensure all generated 'id=' attributes are unique.
     pub(super) id_map: RefCell<IdMap>,
     /// Shared mutable state.
@@ -70,7 +73,7 @@ crate struct Context<'tcx> {
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Context<'_>, 104);
+rustc_data_structures::static_assert_size!(Context<'_>, 144);
 
 /// Shared mutable state used in [`Context`] and elsewhere.
 crate struct SharedContext<'tcx> {
@@ -513,6 +516,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             dst,
             render_redirect_pages: false,
             id_map: RefCell::new(id_map),
+            deref_id_map: RefCell::new(FxHashMap::default()),
             shared: Rc::new(scx),
             include_sources,
         };
@@ -536,6 +540,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             current: self.current.clone(),
             dst: self.dst.clone(),
             render_redirect_pages: self.render_redirect_pages,
+            deref_id_map: RefCell::new(FxHashMap::default()),
             id_map: RefCell::new(IdMap::new()),
             shared: Rc::clone(&self.shared),
             include_sources: self.include_sources,

Diff for: src/librustdoc/html/render/mod.rs

@@ -1054,6 +1054,19 @@ fn render_assoc_items(
     containing_item: &clean::Item,
     it: DefId,
     what: AssocItemRender<'_>,
+) {
+    let mut derefs = FxHashSet::default();
+    derefs.insert(it);
+    render_assoc_items_inner(w, cx, containing_item, it, what, &mut derefs)
+}
+
+fn render_assoc_items_inner(
+    w: &mut Buffer,
+    cx: &Context<'_>,
+    containing_item: &clean::Item,
+    it: DefId,
+    what: AssocItemRender<'_>,
+    derefs: &mut FxHashSet<DefId>,
 ) {
     info!("Documenting associated items of {:?}", containing_item.name);
     let cache = cx.cache();
@@ -1063,31 +1076,39 @@ fn render_assoc_items(
     };
     let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
     if !non_trait.is_empty() {
+        let mut tmp_buf = Buffer::empty_from(w);
         let render_mode = match what {
             AssocItemRender::All => {
-                w.write_str(
+                tmp_buf.write_str(
                     "<h2 id=\"implementations\" class=\"small-section-header\">\
                          Implementations<a href=\"#implementations\" class=\"anchor\"></a>\
                     </h2>",
                 );
                 RenderMode::Normal
             }
             AssocItemRender::DerefFor { trait_, type_, deref_mut_ } => {
+                let id =
+                    cx.derive_id(small_url_encode(format!("deref-methods-{:#}", type_.print(cx))));
+                if let Some(def_id) = type_.def_id(cx.cache()) {
+                    cx.deref_id_map.borrow_mut().insert(def_id, id.clone());
+                }
                 write!(
-                    w,
-                    "<h2 id=\"deref-methods\" class=\"small-section-header\">\
+                    tmp_buf,
+                    "<h2 id=\"{id}\" class=\"small-section-header\">\
                          <span>Methods from {trait_}&lt;Target = {type_}&gt;</span>\
-                         <a href=\"#deref-methods\" class=\"anchor\"></a>\
+                         <a href=\"#{id}\" class=\"anchor\"></a>\
                      </h2>",
+                    id = id,
                     trait_ = trait_.print(cx),
                     type_ = type_.print(cx),
                 );
                 RenderMode::ForDeref { mut_: deref_mut_ }
             }
         };
+        let mut impls_buf = Buffer::empty_from(w);
         for i in &non_trait {
             render_impl(
-                w,
+                &mut impls_buf,
                 cx,
                 i,
                 containing_item,
@@ -1104,18 +1125,27 @@ fn render_assoc_items(
                 },
             );
         }
+        if !impls_buf.is_empty() {
+            w.push_buffer(tmp_buf);
+            w.push_buffer(impls_buf);
+        }
     }
-    if let AssocItemRender::DerefFor { .. } = what {
-        return;
-    }
+
     if !traits.is_empty() {
         let deref_impl =
             traits.iter().find(|t| t.trait_did() == cx.tcx().lang_items().deref_trait());
         if let Some(impl_) = deref_impl {
             let has_deref_mut =
                 traits.iter().any(|t| t.trait_did() == cx.tcx().lang_items().deref_mut_trait());
-            render_deref_methods(w, cx, impl_, containing_item, has_deref_mut);
+            render_deref_methods(w, cx, impl_, containing_item, has_deref_mut, derefs);
+        }
+
+        // If we were already one level into rendering deref methods, we don't want to render
+        // anything after recursing into any further deref methods above.
+        if let AssocItemRender::DerefFor { .. } = what {
+            return;
         }
+
         let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) =
             traits.iter().partition(|t| t.inner_impl().synthetic);
         let (blanket_impl, concrete): (Vec<&&Impl>, _) =
@@ -1167,6 +1197,7 @@ fn render_deref_methods(
     impl_: &Impl,
     container_item: &clean::Item,
     deref_mut: bool,
+    derefs: &mut FxHashSet<DefId>,
 ) {
     let cache = cx.cache();
     let deref_type = impl_.inner_impl().trait_.as_ref().unwrap();
@@ -1188,16 +1219,16 @@ fn render_deref_methods(
     if let Some(did) = target.def_id(cache) {
         if let Some(type_did) = impl_.inner_impl().for_.def_id(cache) {
             // `impl Deref<Target = S> for S`
-            if did == type_did {
+            if did == type_did || !derefs.insert(did) {
                 // Avoid infinite cycles
                 return;
             }
         }
-        render_assoc_items(w, cx, container_item, did, what);
+        render_assoc_items_inner(w, cx, container_item, did, what, derefs);
     } else {
         if let Some(prim) = target.primitive_type() {
             if let Some(&did) = cache.primitive_locations.get(&prim) {
-                render_assoc_items(w, cx, container_item, did, what);
+                render_assoc_items_inner(w, cx, container_item, did, what, derefs);
             }
         }
     }
@@ -1987,7 +2018,9 @@ fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
             if let Some(impl_) =
                 v.iter().find(|i| i.trait_did() == cx.tcx().lang_items().deref_trait())
             {
-                sidebar_deref_methods(cx, out, impl_, v);
+                let mut derefs = FxHashSet::default();
+                derefs.insert(did);
+                sidebar_deref_methods(cx, out, impl_, v, &mut derefs);
             }
 
             let format_impls = |impls: Vec<&Impl>| {
@@ -2061,7 +2094,13 @@ fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
     }
 }
 
-fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &[Impl]) {
+fn sidebar_deref_methods(
+    cx: &Context<'_>,
+    out: &mut Buffer,
+    impl_: &Impl,
+    v: &[Impl],
+    derefs: &mut FxHashSet<DefId>,
+) {
     let c = cx.cache();
 
     debug!("found Deref: {:?}", impl_);
@@ -2078,7 +2117,7 @@ fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &[
         if let Some(did) = target.def_id(c) {
             if let Some(type_did) = impl_.inner_impl().for_.def_id(c) {
                 // `impl Deref<Target = S> for S`
-                if did == type_did {
+                if did == type_did || !derefs.insert(did) {
                     // Avoid infinite cycles
                     return;
                 }
@@ -2102,9 +2141,17 @@ fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &[
                 })
                 .collect::<Vec<_>>();
             if !ret.is_empty() {
+                let map;
+                let id = if let Some(target_def_id) = real_target.def_id(c) {
+                    map = cx.deref_id_map.borrow();
+                    map.get(&target_def_id).expect("Deref section without derived id")
+                } else {
+                    "deref-methods"
+                };
                 write!(
                     out,
-                    "<h3 class=\"sidebar-title\"><a href=\"#deref-methods\">Methods from {}&lt;Target={}&gt;</a></h3>",
+                    "<h3 class=\"sidebar-title\"><a href=\"#{}\">Methods from {}&lt;Target={}&gt;</a></h3>",
+                    id,
                     Escape(&format!("{:#}", impl_.inner_impl().trait_.as_ref().unwrap().print(cx))),
                     Escape(&format!("{:#}", real_target.print(cx))),
                 );
@@ -2117,6 +2164,21 @@ fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &[
                 out.push_str("</div>");
             }
         }
+
+        // Recurse into any further impls that might exist for `target`
+        if let Some(target_did) = target.def_id_no_primitives() {
+            if let Some(target_impls) = c.impls.get(&target_did) {
+                if let Some(target_deref_impl) = target_impls.iter().find(|i| {
+                    i.inner_impl()
+                        .trait_
+                        .as_ref()
+                        .map(|t| Some(t.def_id()) == cx.tcx().lang_items().deref_trait())
+                        .unwrap_or(false)
+                }) {
+                    sidebar_deref_methods(cx, out, target_deref_impl, target_impls, derefs);
+                }
+            }
+        }
     }
 }