Auto merge of rust-lang#129994 - matthiaskrgr:rollup-zkj4ekl, r=matth…

…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#128820 (fix: get llvm type of global val)
 - rust-lang#129028 (`impl_trait_overcaptures`: Don't worry about uncaptured contravariant lifetimes if they outlive a captured lifetime)
 - rust-lang#129471 ([rustdoc] Sort impl associated items by kinds and then by appearance)
 - rust-lang#129706 (Rename dump of coroutine by-move-body to be more consistent, fix ICE in dump_mir)
 - rust-lang#129720 (Simplify DestProp memory management)
 - rust-lang#129796 (Unify scraped examples with other code examples)
 - rust-lang#129938 (Elaborate on deriving vs implementing `Copy`)
 - rust-lang#129973 (run_make_support: rename `Command::stdin` to `stdin_buf` and add `std{in,out,err}` config helpers)

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

compiler/rustc_codegen_llvm/src/consts.rs

@@ -390,7 +390,7 @@ impl<'ll> CodegenCx<'ll, '_> {
             let val_llty = self.val_ty(v);
 
             let g = self.get_static_inner(def_id, val_llty);
-            let llty = self.val_ty(g);
+            let llty = llvm::LLVMGlobalGetValueType(g);
 
             let g = if val_llty == llty {
                 g

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -974,6 +974,7 @@ unsafe extern "C" {
     pub fn LLVMGetAlignment(Global: &Value) -> c_uint;
     pub fn LLVMSetAlignment(Global: &Value, Bytes: c_uint);
     pub fn LLVMSetDLLStorageClass(V: &Value, C: DLLStorageClass);
+    pub fn LLVMGlobalGetValueType(Global: &Value) -> &Type;
 
     // Operations on global variables
     pub fn LLVMIsAGlobalVariable(GlobalVar: &Value) -> Option<&Value>;

compiler/rustc_lint/src/lib.rs

@@ -30,6 +30,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(extract_if)]

compiler/rustc_middle/src/mir/pretty.rs

@@ -612,7 +612,9 @@ fn write_mir_sig(tcx: TyCtxt<'_>, body: &Body<'_>, w: &mut dyn io::Write) -> io:
     let def_id = body.source.def_id();
     let kind = tcx.def_kind(def_id);
     let is_function = match kind {
-        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) => true,
+        DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(..) | DefKind::SyntheticCoroutineBody => {
+            true
+        }
         _ => tcx.is_closure_like(def_id),
     };
     match (kind, body.source.promoted) {

compiler/rustc_mir_transform/src/coroutine/by_move_body.rs

@@ -207,11 +207,12 @@ pub fn coroutine_by_move_body_def_id<'tcx>(
 
     let mut by_move_body = body.clone();
     MakeByMoveBody { tcx, field_remapping, by_move_coroutine_ty }.visit_body(&mut by_move_body);
-    dump_mir(tcx, false, "coroutine_by_move", &0, &by_move_body, |_, _| Ok(()));
 
-    let body_def = tcx.create_def(coroutine_def_id, kw::Empty, DefKind::SyntheticCoroutineBody);
+    // This will always be `{closure#1}`, since the original coroutine is `{closure#0}`.
+    let body_def = tcx.create_def(parent_def_id, kw::Empty, DefKind::SyntheticCoroutineBody);
     by_move_body.source =
         mir::MirSource::from_instance(InstanceKind::Item(body_def.def_id().to_def_id()));
+    dump_mir(tcx, false, "built", &"after", &by_move_body, |_, _| Ok(()));
 
     // Inherited from the by-ref coroutine.
     body_def.codegen_fn_attrs(tcx.codegen_fn_attrs(coroutine_def_id).clone());

compiler/rustc_mir_transform/src/dest_prop.rs

@@ -163,7 +163,8 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation {
 
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let def_id = body.source.def_id();
-        let mut allocations = Allocations::default();
+        let mut candidates = Candidates::default();
+        let mut write_info = WriteInfo::default();
         trace!(func = ?tcx.def_path_str(def_id));
 
         let borrowed = rustc_mir_dataflow::impls::borrowed_locals(body);
@@ -191,20 +192,15 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation {
         loop {
             // PERF: Can we do something smarter than recalculating the candidates and liveness
             // results?
-            let mut candidates = find_candidates(
-                body,
-                &borrowed,
-                &mut allocations.candidates,
-                &mut allocations.candidates_reverse,
-            );
+            candidates.reset_and_find(body, &borrowed);
             trace!(?candidates);
             dest_prop_mir_dump(tcx, body, &points, &live, round_count);
 
             FilterInformation::filter_liveness(
                 &mut candidates,
                 &points,
                 &live,
-                &mut allocations.write_info,
+                &mut write_info,
                 body,
             );
 
@@ -253,20 +249,8 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation {
     }
 }
 
-/// Container for the various allocations that we need.
-///
-/// We store these here and hand out `&mut` access to them, instead of dropping and recreating them
-/// frequently. Everything with a `&'alloc` lifetime points into here.
-#[derive(Default)]
-struct Allocations {
-    candidates: FxIndexMap<Local, Vec<Local>>,
-    candidates_reverse: FxIndexMap<Local, Vec<Local>>,
-    write_info: WriteInfo,
-    // PERF: Do this for `MaybeLiveLocals` allocations too.
-}
-
-#[derive(Debug)]
-struct Candidates<'alloc> {
+#[derive(Debug, Default)]
+struct Candidates {
     /// The set of candidates we are considering in this optimization.
     ///
     /// We will always merge the key into at most one of its values.
@@ -281,11 +265,12 @@ struct Candidates<'alloc> {
     ///
     /// We will still report that we would like to merge `_1` and `_2` in an attempt to allow us to
     /// remove that assignment.
-    c: &'alloc mut FxIndexMap<Local, Vec<Local>>,
+    c: FxIndexMap<Local, Vec<Local>>,
+
     /// A reverse index of the `c` set; if the `c` set contains `a => Place { local: b, proj }`,
     /// then this contains `b => a`.
     // PERF: Possibly these should be `SmallVec`s?
-    reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>,
+    reverse: FxIndexMap<Local, Vec<Local>>,
 }
 
 //////////////////////////////////////////////////////////
@@ -358,19 +343,40 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Merger<'a, 'tcx> {
 //
 // This section enforces bullet point 2
 
-struct FilterInformation<'a, 'body, 'alloc, 'tcx> {
-    body: &'body Body<'tcx>,
+struct FilterInformation<'a, 'tcx> {
+    body: &'a Body<'tcx>,
     points: &'a DenseLocationMap,
     live: &'a SparseIntervalMatrix<Local, PointIndex>,
-    candidates: &'a mut Candidates<'alloc>,
-    write_info: &'alloc mut WriteInfo,
+    candidates: &'a mut Candidates,
+    write_info: &'a mut WriteInfo,
     at: Location,
 }
 
 // We first implement some utility functions which we will expose removing candidates according to
 // different needs. Throughout the liveness filtering, the `candidates` are only ever accessed
 // through these methods, and not directly.
-impl<'alloc> Candidates<'alloc> {
+impl Candidates {
+    /// Collects the candidates for merging.
+    ///
+    /// This is responsible for enforcing the first and third bullet point.
+    fn reset_and_find<'tcx>(&mut self, body: &Body<'tcx>, borrowed: &BitSet<Local>) {
+        self.c.clear();
+        self.reverse.clear();
+        let mut visitor = FindAssignments { body, candidates: &mut self.c, borrowed };
+        visitor.visit_body(body);
+        // Deduplicate candidates.
+        for (_, cands) in self.c.iter_mut() {
+            cands.sort();
+            cands.dedup();
+        }
+        // Generate the reverse map.
+        for (src, cands) in self.c.iter() {
+            for dest in cands.iter().copied() {
+                self.reverse.entry(dest).or_default().push(*src);
+            }
+        }
+    }
+
     /// Just `Vec::retain`, but the condition is inverted and we add debugging output
     fn vec_filter_candidates(
         src: Local,
@@ -445,7 +451,7 @@ enum CandidateFilter {
     Remove,
 }
 
-impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> {
+impl<'a, 'tcx> FilterInformation<'a, 'tcx> {
     /// Filters the set of candidates to remove those that conflict.
     ///
     /// The steps we take are exactly those that are outlined at the top of the file. For each
@@ -463,12 +469,12 @@ impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> {
     /// before the statement/terminator will correctly report locals that are read in the
     /// statement/terminator to be live. We are additionally conservative by treating all written to
     /// locals as also being read from.
-    fn filter_liveness<'b>(
-        candidates: &mut Candidates<'alloc>,
+    fn filter_liveness(
+        candidates: &mut Candidates,
         points: &DenseLocationMap,
         live: &SparseIntervalMatrix<Local, PointIndex>,
-        write_info_alloc: &'alloc mut WriteInfo,
-        body: &'b Body<'tcx>,
+        write_info: &mut WriteInfo,
+        body: &Body<'tcx>,
     ) {
         let mut this = FilterInformation {
             body,
@@ -477,7 +483,7 @@ impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> {
             candidates,
             // We don't actually store anything at this scope, we just keep things here to be able
             // to reuse the allocation.
-            write_info: write_info_alloc,
+            write_info,
             // Doesn't matter what we put here, will be overwritten before being used
             at: Location::START,
         };
@@ -734,40 +740,13 @@ fn places_to_candidate_pair<'tcx>(
     Some((a, b))
 }
 
-/// Collects the candidates for merging
-///
-/// This is responsible for enforcing the first and third bullet point.
-fn find_candidates<'alloc, 'tcx>(
-    body: &Body<'tcx>,
-    borrowed: &BitSet<Local>,
-    candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>,
-    candidates_reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>,
-) -> Candidates<'alloc> {
-    candidates.clear();
-    candidates_reverse.clear();
-    let mut visitor = FindAssignments { body, candidates, borrowed };
-    visitor.visit_body(body);
-    // Deduplicate candidates
-    for (_, cands) in candidates.iter_mut() {
-        cands.sort();
-        cands.dedup();
-    }
-    // Generate the reverse map
-    for (src, cands) in candidates.iter() {
-        for dest in cands.iter().copied() {
-            candidates_reverse.entry(dest).or_default().push(*src);
-        }
-    }
-    Candidates { c: candidates, reverse: candidates_reverse }
-}
-
-struct FindAssignments<'a, 'alloc, 'tcx> {
+struct FindAssignments<'a, 'tcx> {
     body: &'a Body<'tcx>,
-    candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>,
+    candidates: &'a mut FxIndexMap<Local, Vec<Local>>,
     borrowed: &'a BitSet<Local>,
 }
 
-impl<'tcx> Visitor<'tcx> for FindAssignments<'_, '_, 'tcx> {
+impl<'tcx> Visitor<'tcx> for FindAssignments<'_, 'tcx> {
     fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) {
         if let StatementKind::Assign(box (
             lhs,
@@ -819,9 +798,9 @@ fn is_local_required(local: Local, body: &Body<'_>) -> bool {
 /////////////////////////////////////////////////////////
 // MIR Dump
 
-fn dest_prop_mir_dump<'body, 'tcx>(
+fn dest_prop_mir_dump<'tcx>(
     tcx: TyCtxt<'tcx>,
-    body: &'body Body<'tcx>,
+    body: &Body<'tcx>,
     points: &DenseLocationMap,
     live: &SparseIntervalMatrix<Local, PointIndex>,
     round: usize,

library/core/src/marker.rs

@@ -288,8 +288,19 @@ marker_impls! {
 /// }
 /// ```
 ///
-/// There is a small difference between the two: the `derive` strategy will also place a `Copy`
-/// bound on type parameters, which isn't always desired.
+/// There is a small difference between the two. The `derive` strategy will also place a `Copy`
+/// bound on type parameters:
+///
+/// ```
+/// #[derive(Clone)]
+/// struct MyStruct<T>(T);
+///
+/// impl<T: Copy> Copy for MyStruct<T> { }
+/// ```
+///
+/// This isn't always desired. For example, shared references (`&T`) can be copied regardless of
+/// whether `T` is `Copy`. Likewise, a generic struct containing markers such as [`PhantomData`]
+/// could potentially be duplicated with a bit-wise copy.
 ///
 /// ## What's the difference between `Copy` and `Clone`?
 ///

src/librustdoc/html/render/mod.rs

@@ -1794,13 +1794,64 @@ fn render_impl(
     let mut default_impl_items = Buffer::empty_from(w);
     let impl_ = i.inner_impl();
 
+    // Impl items are grouped by kinds:
+    //
+    // 1. Constants
+    // 2. Types
+    // 3. Functions
+    //
+    // This order is because you can have associated constants used in associated types (like array
+    // length), and both in associcated functions. So with this order, when reading from top to
+    // bottom, you should see items definitions before they're actually used most of the time.
+    let mut assoc_types = Vec::new();
+    let mut methods = Vec::new();
+
     if !impl_.is_negative_trait_impl() {
         for trait_item in &impl_.items {
+            match *trait_item.kind {
+                clean::MethodItem(..) | clean::TyMethodItem(_) => methods.push(trait_item),
+                clean::TyAssocTypeItem(..) | clean::AssocTypeItem(..) => {
+                    assoc_types.push(trait_item)
+                }
+                clean::TyAssocConstItem(..) | clean::AssocConstItem(_) => {
+                    // We render it directly since they're supposed to come first.
+                    doc_impl_item(
+                        &mut default_impl_items,
+                        &mut impl_items,
+                        cx,
+                        trait_item,
+                        if trait_.is_some() { &i.impl_item } else { parent },
+                        link,
+                        render_mode,
+                        false,
+                        trait_,
+                        rendering_params,
+                    );
+                }
+                _ => {}
+            }
+        }
+
+        for assoc_type in assoc_types {
             doc_impl_item(
                 &mut default_impl_items,
                 &mut impl_items,
                 cx,
-                trait_item,
+                assoc_type,
+                if trait_.is_some() { &i.impl_item } else { parent },
+                link,
+                render_mode,
+                false,
+                trait_,
+                rendering_params,
+            );
+        }
+        for method in methods {
+            doc_impl_item(
+                &mut default_impl_items,
+                &mut impl_items,
+                cx,
+                method,
                 if trait_.is_some() { &i.impl_item } else { parent },
                 link,
                 render_mode,
@@ -2455,28 +2506,6 @@ fn render_call_locations<W: fmt::Write>(mut w: W, cx: &mut Context<'_>, item: &c
         let needs_expansion = line_max - line_min > NUM_VISIBLE_LINES;
         let locations_encoded = serde_json::to_string(&line_ranges).unwrap();
 
-        write!(
-            &mut w,
-            "<div class=\"scraped-example {expanded_cls}\" data-locs=\"{locations}\">\
-                <div class=\"scraped-example-title\">\
-                   {name} (<a href=\"{url}\">{title}</a>)\
-                </div>\
-                <div class=\"code-wrapper\">",
-            expanded_cls = if needs_expansion { "" } else { "expanded" },
-            name = call_data.display_name,
-            url = init_url,
-            title = init_title,
-            // The locations are encoded as a data attribute, so they can be read
-            // later by the JS for interactions.
-            locations = Escape(&locations_encoded)
-        )
-        .unwrap();
-
-        if line_ranges.len() > 1 {
-            w.write_str(r#"<button class="prev">&pr;</button> <button class="next">&sc;</button>"#)
-                .unwrap();
-        }
-
         // Look for the example file in the source map if it exists, otherwise return a dummy span
         let file_span = (|| {
             let source_map = tcx.sess.source_map();
@@ -2507,9 +2536,16 @@ fn render_call_locations<W: fmt::Write>(mut w: W, cx: &mut Context<'_>, item: &c
             cx,
             &cx.root_path(),
             highlight::DecorationInfo(decoration_info),
-            sources::SourceContext::Embedded { offset: line_min, needs_expansion },
+            sources::SourceContext::Embedded(sources::ScrapedInfo {
+                needs_prev_next_buttons: line_ranges.len() > 1,
+                needs_expansion,
+                offset: line_min,
+                name: &call_data.display_name,
+                url: init_url,
+                title: init_title,
+                locations: locations_encoded,
+            }),
         );
-        w.write_str("</div></div>").unwrap();
 
         true
     };