Auto merge of rust-lang#74569 - Manishearth:rollup-hkn5ex9, r=Manishe…

…arth

Rollup of 13 pull requests

Successful merges:

 - rust-lang#72714 (Fix debug assertion in typeck)
 - rust-lang#73197 (Impl Default for ranges)
 - rust-lang#73323 (wf: check foreign fn decls for well-formedness)
 - rust-lang#74051 (disallow non-static lifetimes in const generics)
 - rust-lang#74376 (test caching opt_const_param_of on disc)
 - rust-lang#74501 (Ayu theme: Use different background color for Run button)
 - rust-lang#74505 (Fix search input focus in ayu theme)
 - rust-lang#74522 (Update sanitizer docs)
 - rust-lang#74546 (Fix duplicate maybe_uninit_extra attribute)
 - rust-lang#74552 (Stabilize TAU constant.)
 - rust-lang#74555 (Improve "important traits" popup display on mobile)
 - rust-lang#74557 (Fix an ICE on an invalid `binding @ ...` in a tuple struct pattern)
 - rust-lang#74561 (update backtrace-rs)

Failed merges:

r? @ghost

src/doc/unstable-book/src/compiler-flags/sanitizer.md

@@ -26,6 +26,9 @@ of bugs:
 * Double-free, invalid free
 * Memory leaks
 
+The memory leak detection is enabled by default on Linux, and can be enabled
+with runtime flag `ASAN_OPTIONS=detect_leaks=1` on macOS.
+
 AddressSanitizer is supported on the following targets:
 
 * `x86_64-apple-darwin`
@@ -196,10 +199,6 @@ fn main() {
 
 ```shell
 $ export \
-  CC=clang \
-  CXX=clang++ \
-  CFLAGS='-fsanitize=memory -fsanitize-memory-track-origins' \
-  CXXFLAGS='-fsanitize=memory -fsanitize-memory-track-origins' \
   RUSTFLAGS='-Zsanitizer=memory -Zsanitizer-memory-track-origins' \
   RUSTDOCFLAGS='-Zsanitizer=memory -Zsanitizer-memory-track-origins'
 $ cargo clean

src/libcore/num/f32.rs

@@ -242,7 +242,7 @@ pub mod consts {
     /// The full circle constant (τ)
     ///
     /// Equal to 2π.
-    #[unstable(feature = "tau_constant", issue = "66770")]
+    #[stable(feature = "tau_constant", since = "1.47.0")]
     pub const TAU: f32 = 6.28318530717958647692528676655900577_f32;
 
     /// π/2

src/libcore/num/f64.rs

@@ -242,7 +242,7 @@ pub mod consts {
     /// The full circle constant (τ)
     ///
     /// Equal to 2π.
-    #[unstable(feature = "tau_constant", issue = "66770")]
+    #[stable(feature = "tau_constant", since = "1.47.0")]
     pub const TAU: f64 = 6.28318530717958647692528676655900577_f64;
 
     /// π/2

src/libcore/ops/range.rs

@@ -39,7 +39,7 @@ use crate::hash::Hash;
 /// [`Iterator`]: ../iter/trait.IntoIterator.html
 /// [slicing index]: ../slice/trait.SliceIndex.html
 #[doc(alias = "..")]
-#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, Default, PartialEq, Eq, Hash)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RangeFull;
 
@@ -71,7 +71,7 @@ impl fmt::Debug for RangeFull {
 /// assert_eq!(arr[1..=3], [  1,2,3  ]);
 /// ```
 #[doc(alias = "..")]
-#[derive(Clone, PartialEq, Eq, Hash)] // not Copy -- see #27186
+#[derive(Clone, Default, PartialEq, Eq, Hash)] // not Copy -- see #27186
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Range<Idx> {
     /// The lower bound of the range (inclusive).

src/librustc_error_codes/error_codes.rs

@@ -453,6 +453,7 @@ E0767: include_str!("./error_codes/E0767.md"),
 E0768: include_str!("./error_codes/E0768.md"),
 E0769: include_str!("./error_codes/E0769.md"),
 E0770: include_str!("./error_codes/E0770.md"),
+E0771: include_str!("./error_codes/E0771.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard

src/librustc_error_codes/error_codes/E0771.md

@@ -0,0 +1,23 @@
+A non-`'static` lifetime was used in a const generic. This is currently not
+allowed.
+
+Erroneous code example:
+
+```compile_fail,E0771
+#![feature(const_generics)]
+
+fn function_with_str<'a, const STRING: &'a str>() {} // error!
+```
+
+To fix this issue, the lifetime in the const generic need to be changed to
+`'static`:
+
+```
+#![feature(const_generics)]
+
+fn function_with_str<const STRING: &'static str>() {} // ok!
+```
+
+For more information, see [GitHub issue #74052].
+
+[GitHub issue #74052]: https://github.com/rust-lang/rust/issues/74052

src/librustc_middle/query/mod.rs

@@ -103,9 +103,13 @@ rustc_queries! {
         /// // ^ While calling `opt_const_param_of` for other bodies returns `None`.
         /// }
         /// ```
+        // It looks like caching this query on disk actually slightly
+        // worsened performance in #74376.
+        //
+        // Once const generics are more prevalently used, we might want to
+        // consider only caching calls returning `Some`.
         query opt_const_param_of(key: LocalDefId) -> Option<DefId> {
             desc { |tcx| "computing the optional const parameter of `{}`", tcx.def_path_str(key.to_def_id()) }
-            // FIXME(#74113): consider storing this query on disk.
         }
 
         /// Records the type of every item.

src/librustc_resolve/late.rs

@@ -1500,11 +1500,17 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         pat_src: PatternSource,
         bindings: &mut SmallVec<[(PatBoundCtx, FxHashSet<Ident>); 1]>,
     ) {
+        let is_tuple_struct_pat = matches!(pat.kind, PatKind::TupleStruct(_, _));
+
         // Visit all direct subpatterns of this pattern.
         pat.walk(&mut |pat| {
             debug!("resolve_pattern pat={:?} node={:?}", pat, pat.kind);
             match pat.kind {
-                PatKind::Ident(bmode, ident, ref sub) => {
+                // In tuple struct patterns ignore the invalid `ident @ ...`.
+                // It will be handled as an error by the AST lowering.
+                PatKind::Ident(bmode, ident, ref sub)
+                    if !(is_tuple_struct_pat && sub.as_ref().filter(|p| p.is_rest()).is_some()) =>
+                {
                     // First try to resolve the identifier as some existing entity,
                     // then fall back to a fresh binding.
                     let has_sub = sub.is_some();

src/librustc_resolve/late/diagnostics.rs

@@ -1141,6 +1141,24 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
         err.emit();
     }
 
+    // FIXME(const_generics): This patches over a ICE caused by non-'static lifetimes in const
+    // generics. We are disallowing this until we can decide on how we want to handle non-'static
+    // lifetimes in const generics. See issue #74052 for discussion.
+    crate fn emit_non_static_lt_in_const_generic_error(&self, lifetime_ref: &hir::Lifetime) {
+        let mut err = struct_span_err!(
+            self.tcx.sess,
+            lifetime_ref.span,
+            E0771,
+            "use of non-static lifetime `{}` in const generic",
+            lifetime_ref
+        );
+        err.note(
+            "for more information, see issue #74052 \
+            <https://github.com/rust-lang/rust/issues/74052>",
+        );
+        err.emit();
+    }
+
     crate fn is_trait_ref_fn_scope(&mut self, trait_ref: &'tcx hir::PolyTraitRef<'tcx>) -> bool {
         if let def::Res::Def(_, did) = trait_ref.trait_ref.path.res {
             if [

src/librustc_resolve/late/lifetimes.rs

@@ -173,6 +173,8 @@ crate struct LifetimeContext<'a, 'tcx> {
     /// Used to disallow the use of in-band lifetimes in `fn` or `Fn` syntax.
     is_in_fn_syntax: bool,
 
+    is_in_const_generic: bool,
+
     /// List of labels in the function/method currently under analysis.
     labels_in_fn: Vec<Ident>,
 
@@ -333,6 +335,7 @@ fn krate(tcx: TyCtxt<'_>) -> NamedRegionMap {
             scope: ROOT_SCOPE,
             trait_ref_hack: false,
             is_in_fn_syntax: false,
+            is_in_const_generic: false,
             labels_in_fn: vec![],
             xcrate_object_lifetime_defaults: Default::default(),
             lifetime_uses: &mut Default::default(),
@@ -828,6 +831,10 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
             self.insert_lifetime(lifetime_ref, Region::Static);
             return;
         }
+        if self.is_in_const_generic && lifetime_ref.name != LifetimeName::Error {
+            self.emit_non_static_lt_in_const_generic_error(lifetime_ref);
+            return;
+        }
         self.resolve_lifetime_ref(lifetime_ref);
     }
 
@@ -860,8 +867,11 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                     }
                 }
                 GenericParamKind::Const { ref ty, .. } => {
+                    let was_in_const_generic = self.is_in_const_generic;
+                    self.is_in_const_generic = true;
                     walk_list!(self, visit_param_bound, param.bounds);
                     self.visit_ty(&ty);
+                    self.is_in_const_generic = was_in_const_generic;
                 }
             }
         }
@@ -1317,6 +1327,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             scope: &wrap_scope,
             trait_ref_hack: self.trait_ref_hack,
             is_in_fn_syntax: self.is_in_fn_syntax,
+            is_in_const_generic: self.is_in_const_generic,
             labels_in_fn,
             xcrate_object_lifetime_defaults,
             lifetime_uses,

src/librustc_typeck/check/wfcheck.rs

@@ -15,7 +15,7 @@ use rustc_middle::ty::{
     self, AdtKind, GenericParamDefKind, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness,
 };
 use rustc_session::parse::feature_err;
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
 use rustc_trait_selection::opaque_types::may_define_opaque_type;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
@@ -142,8 +142,8 @@ pub fn check_item_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                 _ => unreachable!(),
             }
         }
-        hir::ItemKind::Fn(..) => {
-            check_item_fn(tcx, item);
+        hir::ItemKind::Fn(ref sig, ..) => {
+            check_item_fn(tcx, item.hir_id, item.ident, item.span, sig.decl);
         }
         hir::ItemKind::Static(ref ty, ..) => {
             check_item_type(tcx, item.hir_id, ty.span, false);
@@ -153,8 +153,14 @@ pub fn check_item_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         }
         hir::ItemKind::ForeignMod(ref module) => {
             for it in module.items.iter() {
-                if let hir::ForeignItemKind::Static(ref ty, ..) = it.kind {
-                    check_item_type(tcx, it.hir_id, ty.span, true);
+                match it.kind {
+                    hir::ForeignItemKind::Fn(ref decl, ..) => {
+                        check_item_fn(tcx, it.hir_id, it.ident, it.span, decl)
+                    }
+                    hir::ForeignItemKind::Static(ref ty, ..) => {
+                        check_item_type(tcx, it.hir_id, ty.span, true)
+                    }
+                    hir::ForeignItemKind::Type => (),
                 }
             }
         }
@@ -303,7 +309,7 @@ fn check_associated_item(
                     fcx,
                     item.ident.span,
                     sig,
-                    hir_sig,
+                    hir_sig.decl,
                     item.def_id,
                     &mut implied_bounds,
                 );
@@ -564,22 +570,24 @@ fn check_associated_type_defaults(fcx: &FnCtxt<'_, '_>, trait_def_id: DefId) {
     }
 }
 
-fn check_item_fn(tcx: TyCtxt<'_>, item: &hir::Item<'_>) {
-    for_item(tcx, item).with_fcx(|fcx, tcx| {
-        let def_id = fcx.tcx.hir().local_def_id(item.hir_id);
+fn check_item_fn(
+    tcx: TyCtxt<'_>,
+    item_id: hir::HirId,
+    ident: Ident,
+    span: Span,
+    decl: &hir::FnDecl<'_>,
+) {
+    for_id(tcx, item_id, span).with_fcx(|fcx, tcx| {
+        let def_id = fcx.tcx.hir().local_def_id(item_id);
         let sig = fcx.tcx.fn_sig(def_id);
-        let sig = fcx.normalize_associated_types_in(item.span, &sig);
+        let sig = fcx.normalize_associated_types_in(span, &sig);
         let mut implied_bounds = vec![];
-        let hir_sig = match &item.kind {
-            ItemKind::Fn(sig, ..) => sig,
-            _ => bug!("expected `ItemKind::Fn`, found `{:?}`", item.kind),
-        };
         check_fn_or_method(
             tcx,
             fcx,
-            item.ident.span,
+            ident.span,
             sig,
-            hir_sig,
+            decl,
             def_id.to_def_id(),
             &mut implied_bounds,
         );
@@ -835,28 +843,28 @@ fn check_fn_or_method<'fcx, 'tcx>(
     fcx: &FnCtxt<'fcx, 'tcx>,
     span: Span,
     sig: ty::PolyFnSig<'tcx>,
-    hir_sig: &hir::FnSig<'_>,
+    hir_decl: &hir::FnDecl<'_>,
     def_id: DefId,
     implied_bounds: &mut Vec<Ty<'tcx>>,
 ) {
     let sig = fcx.normalize_associated_types_in(span, &sig);
     let sig = fcx.tcx.liberate_late_bound_regions(def_id, &sig);
 
-    for (&input_ty, span) in sig.inputs().iter().zip(hir_sig.decl.inputs.iter().map(|t| t.span)) {
+    for (&input_ty, span) in sig.inputs().iter().zip(hir_decl.inputs.iter().map(|t| t.span)) {
         fcx.register_wf_obligation(input_ty.into(), span, ObligationCauseCode::MiscObligation);
     }
     implied_bounds.extend(sig.inputs());
 
     fcx.register_wf_obligation(
         sig.output().into(),
-        hir_sig.decl.output.span(),
+        hir_decl.output.span(),
         ObligationCauseCode::ReturnType,
     );
 
     // FIXME(#25759) return types should not be implied bounds
     implied_bounds.push(sig.output());
 
-    check_where_clauses(tcx, fcx, span, def_id, Some((sig.output(), hir_sig.decl.output.span())));
+    check_where_clauses(tcx, fcx, span, def_id, Some((sig.output(), hir_decl.output.span())));
 }
 
 /// Checks "defining uses" of opaque `impl Trait` types to ensure that they meet the restrictions

src/librustc_typeck/collect.rs

@@ -1927,7 +1927,7 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
                         let re_root_empty = tcx.lifetimes.re_root_empty;
                         let predicate = ty::OutlivesPredicate(ty, re_root_empty);
                         predicates.push((
-                            ty::PredicateKind::TypeOutlives(ty::Binder::dummy(predicate))
+                            ty::PredicateKind::TypeOutlives(ty::Binder::bind(predicate))
                                 .to_predicate(tcx),
                             span,
                         ));

src/librustdoc/html/static/rustdoc.css

@@ -1511,6 +1511,11 @@ h4 > .important-traits {
 	#main > .line-numbers {
 		margin-top: 0;
 	}
+
+	.important-traits .important-traits-tooltiptext {
+		left: 0;
+		top: 100%;
+	}
 }
 
 @media print {

src/librustdoc/html/static/themes/ayu.css

@@ -237,16 +237,6 @@ a {
 
 #crate-search+.search-input:focus {
 	box-shadow: 0 0 0 1px #148099,0 0 0 2px transparent;
-	color: #ffffff;
-	background-color: #141920;
-	box-shadow: none;
-	transition: box-shadow 150ms ease-in-out;
-	border-radius: 4px;
-	margin-left: 8px;
-}
-
-#crate-search+.search-input:focus {
-	box-shadow: 0px 6px 20px 0px black;
 }
 
 .search-focus:disabled {
@@ -318,12 +308,12 @@ a.test-arrow {
 	font-size: 100%;
 	color: #788797;
 	border-radius: 4px;
-	background-color: rgba(255, 255, 255, 0);
+	background-color: rgba(57, 175, 215, 0.09);
 }
 
 a.test-arrow:hover {
-	background-color: rgba(242, 151, 24, 0.05);
-	color: #ffb44c;
+	background-color: rgba(57, 175, 215, 0.368);
+	color: #c5c5c5;
 }
 
 .toggle-label {

src/libstd/lib.rs

@@ -224,10 +224,7 @@
     all(target_vendor = "fortanix", target_env = "sgx"),
     feature(slice_index_methods, coerce_unsized, sgx_platform, ptr_wrapping_offset_from)
 )]
-#![cfg_attr(
-    all(test, target_vendor = "fortanix", target_env = "sgx"),
-    feature(fixed_size_array, maybe_uninit_extra)
-)]
+#![cfg_attr(all(test, target_vendor = "fortanix", target_env = "sgx"), feature(fixed_size_array))]
 // std is implemented with unstable features, many of which are internal
 // compiler details that will never be stable
 // NB: the following list is sorted to minimize merge conflicts.

src/test/ui/const-generics/const-argument-non-static-lifetime.rs

@@ -0,0 +1,17 @@
+// run-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete
+#![allow(dead_code)]
+
+fn test<const N: usize>() {}
+
+fn wow<'a>() -> &'a () {
+    test::<{
+        let _: &'a ();
+        3
+    }>();
+    &()
+}
+
+fn main() {}