Auto merge of rust-lang#90151 - Mark-Simulacrum:beta-next, r=Mark-Simulacrum

[beta] backports

*  Don't emit a warning for empty rmeta files. rust-lang#90072
*  Erase late-bound regions before computing vtable debuginfo name. rust-lang#90050
*  Fix wrong niche calculation when 2+ niches are placed at the start rust-lang#90040
*  Revert rust-lang#86011 to fix an incorrect bound check rust-lang#90025
*  Fix macro_rules! duplication when reexported in the same module rust-lang#89867
* Bump cargo to include rust-lang/cargo#9979 - Fix fetching git repos after a force push.

r? `@Mark-Simulacrum`

Author: bors

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -480,14 +480,11 @@ pub fn compute_debuginfo_vtable_name<'tcx>(
     }
 
     if let Some(trait_ref) = trait_ref {
-        push_item_name(tcx, trait_ref.skip_binder().def_id, true, &mut vtable_name);
+        let trait_ref =
+            tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), trait_ref);
+        push_item_name(tcx, trait_ref.def_id, true, &mut vtable_name);
         visited.clear();
-        push_generic_params_internal(
-            tcx,
-            trait_ref.skip_binder().substs,
-            &mut vtable_name,
-            &mut visited,
-        );
+        push_generic_params_internal(tcx, trait_ref.substs, &mut vtable_name, &mut visited);
     } else {
         vtable_name.push_str("_");
     }

compiler/rustc_metadata/src/locator.rs

@@ -529,6 +529,15 @@ impl<'a> CrateLocator<'a> {
         let mut err_data: Option<Vec<PathBuf>> = None;
         for (lib, kind) in m {
             info!("{} reading metadata from: {}", flavor, lib.display());
+            if flavor == CrateFlavor::Rmeta && lib.metadata().map_or(false, |m| m.len() == 0) {
+                // Empty files will cause get_metadata_section to fail. Rmeta
+                // files can be empty, for example with binaries (which can
+                // often appear with `cargo check` when checking a library as
+                // a unittest). We don't want to emit a user-visible warning
+                // in this case as it is not a real problem.
+                debug!("skipping empty file");
+                continue;
+            }
             let (hash, metadata) =
                 match get_metadata_section(self.target, flavor, &lib, self.metadata_loader) {
                     Ok(blob) => {

compiler/rustc_target/src/abi/mod.rs

@@ -1117,7 +1117,7 @@ impl Niche {
         // In practice this means that enums with `count > 1` are unlikely to claim niche zero, since they have to fit perfectly.
         // If niche zero is already reserved, the selection of bounds are of little interest.
         let move_start = |v: WrappingRange| {
-            let start = v.start.wrapping_sub(1) & max_value;
+            let start = v.start.wrapping_sub(count) & max_value;
             Some((start, Scalar { value, valid_range: v.with_start(start) }))
         };
         let move_end = |v: WrappingRange| {

compiler/rustc_typeck/src/bounds.rs

@@ -64,16 +64,16 @@ impl<'tcx> Bounds<'tcx> {
             })
         });
 
-        self.region_bounds
-            .iter()
-            .map(|&(region_bound, span)| {
+        sized_predicate
+            .into_iter()
+            .chain(self.region_bounds.iter().map(|&(region_bound, span)| {
                 (
                     region_bound
                         .map_bound(|region_bound| ty::OutlivesPredicate(param_ty, region_bound))
                         .to_predicate(tcx),
                     span,
                 )
-            })
+            }))
             .chain(self.trait_bounds.iter().map(|&(bound_trait_ref, span, constness)| {
                 let predicate = bound_trait_ref.with_constness(constness).to_predicate(tcx);
                 (predicate, span)
@@ -83,7 +83,6 @@ impl<'tcx> Bounds<'tcx> {
                     .iter()
                     .map(|&(projection, span)| (projection.to_predicate(tcx), span)),
             )
-            .chain(sized_predicate.into_iter())
             .collect()
     }
 }

src/librustdoc/visit_ast.rs

@@ -87,13 +87,21 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         // the rexport defines the path that a user will actually see. Accordingly,
         // we add the rexport as an item here, and then skip over the original
         // definition in `visit_item()` below.
+        //
+        // We also skip `#[macro_export] macro_rules!` that have already been inserted,
+        // it can happen if within the same module a `#[macro_export] macro_rules!`
+        // is declared but also a reexport of itself producing two exports of the same
+        // macro in the same module.
+        let mut inserted = FxHashSet::default();
         for export in self.cx.tcx.module_exports(CRATE_DEF_ID).unwrap_or(&[]) {
             if let Res::Def(DefKind::Macro(_), def_id) = export.res {
                 if let Some(local_def_id) = def_id.as_local() {
                     if self.cx.tcx.has_attr(def_id, sym::macro_export) {
-                        let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
-                        let item = self.cx.tcx.hir().expect_item(hir_id);
-                        top_level_module.items.push((item, None));
+                        if inserted.insert(def_id) {
+                            let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_def_id);
+                            let item = self.cx.tcx.hir().expect_item(hir_id);
+                            top_level_module.items.push((item, None));
+                        }
                     }
                 }
             }

src/test/codegen/debug-vtable.rs

@@ -18,6 +18,9 @@
 // MSVC-LABEL: !DIGlobalVariable(name: "impl$<debug_vtable::Foo, _>::vtable$"
 // CHECK: !DISubrange(count: 3
 
+// NONMSVC-LABEL: !DIGlobalVariable(name: "<debug_vtable::bar::{closure#0} as core::ops::function::FnOnce<(core::option::Option<&dyn core::ops::function::Fn<(), Output=()>>)>>::{vtable}"
+// MSVC-LABEL: !DIGlobalVariable(name: "impl$<debug_vtable::bar::closure$0, core::ops::function::FnOnce<tuple$<enum$<core::option::Option<ref$<dyn$<core::ops::function::Fn<tuple$<>,assoc$<Output,tuple$<> > > > > >, {{.*}}, {{.*}}, Some> > > >::vtable$"
+
 #![crate_type = "lib"]
 
 pub struct Foo;
@@ -45,3 +48,10 @@ pub fn foo(x: &Foo) -> (u32, (u64, i8), &dyn Send) {
     let z: &dyn SomeTraitWithGenerics<u64, i8> = x;
     (y.method1(), z.method1(), x as &dyn Send)
 }
+
+// Constructing the debuginfo name for the FnOnce vtable below initially caused an ICE on MSVC
+// because the trait type contains a late bound region that needed to be erased before the type
+// layout for the niche enum `Option<&dyn Fn()>` could be computed.
+pub fn bar() -> Box<dyn FnOnce(Option<&dyn Fn()>)> {
+    Box::new(|_x: Option<&dyn Fn()>| {})
+}

src/test/rustdoc-json/reexport/macro.rs

@@ -0,0 +1,17 @@
+// edition:2018
+
+#![no_core]
+#![feature(no_core)]
+
+// @count macro.json "$.index[*][?(@.name=='macro')].inner.items[*]" 2
+
+// @set repro_id = macro.json "$.index[*][?(@.name=='repro')].id"
+// @has - "$.index[*][?(@.name=='macro')].inner.items[*]" $repro_id
+#[macro_export]
+macro_rules! repro {
+    () => {};
+}
+
+// @set repro2_id = macro.json "$.index[*][?(@.inner.name=='repro2')].id"
+// @has - "$.index[*][?(@.name=='macro')].inner.items[*]" $repro2_id
+pub use crate::repro as repro2;

src/test/rustdoc/issue-89852.rs

@@ -0,0 +1,14 @@
+// edition:2018
+
+#![no_core]
+#![feature(no_core)]
+
+// @matches 'issue_89852/sidebar-items.js' '"repro"'
+// @!matches 'issue_89852/sidebar-items.js' '"repro".*"repro"'
+
+#[macro_export]
+macro_rules! repro {
+    () => {};
+}
+
+pub use crate::repro as repro2;

src/test/ui/derives/derives-span-Hash-enum-struct-variant.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
+   |             ^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/derives/derives-span-Hash-enum.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
+   |             ^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error