Auto merge of rust-lang#89530 - workingjubilee:rollup-ua14iq6, r=workingjubilee

Rollup of 13 pull requests

Successful merges:

 - rust-lang#83655 ([aarch64] add target feature outline-atomics)
 - rust-lang#87091 (implement advance_(back_)_by on more iterators)
 - rust-lang#88451 (Fix an ICE caused by type mismatch errors being ignored)
 - rust-lang#88452 (VecDeque: improve performance for From<[T; N]>)
 - rust-lang#89400 (Improve wording of `map_or_else` docs)
 - rust-lang#89407 (Recommend running `cargo clean` in E0514 output)
 - rust-lang#89443 (Include the length in BTree hashes)
 - rust-lang#89444 (rustdoc: use slice::contains instead of open-coding it)
 - rust-lang#89447 (Improve error message for missing angle brackets in `[_]::method`)
 - rust-lang#89453 (Consistently use 'supertrait'.)
 - rust-lang#89483 (Practice diagnostic message convention)
 - rust-lang#89500 (Fix ICE with buffered lint referring to AST node deleted by everybody_loops)
 - rust-lang#89508 (Stabilize `const_panic`)

Failed merges:

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

Author: bors

compiler/rustc_ast/src/ast.rs

@@ -1211,6 +1211,8 @@ impl Expr {
                 }
             }
 
+            ExprKind::Underscore => TyKind::Infer,
+
             // This expression doesn't look like a type syntactically.
             _ => return None,
         };

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -590,7 +590,7 @@ impl<'a> AstValidator<'a> {
                 )
                 .span_label(self.current_extern_span(), "in this `extern` block")
                 .note(&format!(
-                    "This limitation may be lifted in the future; see issue #{} <https://github.com/rust-lang/rust/issues/{}> for more information",
+                    "this limitation may be lifted in the future; see issue #{} <https://github.com/rust-lang/rust/issues/{}> for more information",
                     n, n,
                 ))
                 .emit();

compiler/rustc_borrowck/src/lib.rs

@@ -2,7 +2,7 @@
 
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
-#![feature(const_panic)]
+#![cfg_attr(bootstrap, feature(const_panic))]
 #![feature(crate_visibility_modifier)]
 #![feature(format_args_capture)]
 #![feature(in_band_lifetimes)]

compiler/rustc_builtin_macros/src/concat_idents.rs

@@ -12,7 +12,7 @@ pub fn expand_concat_idents<'cx>(
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'cx> {
     if tts.is_empty() {
-        cx.span_err(sp, "concat_idents! takes 1 or more arguments.");
+        cx.span_err(sp, "concat_idents! takes 1 or more arguments");
         return DummyResult::any(sp);
     }
 
@@ -22,7 +22,7 @@ pub fn expand_concat_idents<'cx>(
             match e {
                 TokenTree::Token(Token { kind: token::Comma, .. }) => {}
                 _ => {
-                    cx.span_err(sp, "concat_idents! expecting comma.");
+                    cx.span_err(sp, "concat_idents! expecting comma");
                     return DummyResult::any(sp);
                 }
             }
@@ -34,7 +34,7 @@ pub fn expand_concat_idents<'cx>(
                 }
             }
 
-            cx.span_err(sp, "concat_idents! requires ident args.");
+            cx.span_err(sp, "concat_idents! requires ident args");
             return DummyResult::any(sp);
         }
     }

compiler/rustc_builtin_macros/src/test.rs

@@ -382,7 +382,7 @@ fn should_panic(cx: &ExtCtxt<'_>, i: &ast::Item) -> ShouldPanic {
                         .note(
                             "errors in this attribute were erroneously \
                                 allowed and will become a hard error in a \
-                                future release.",
+                                future release",
                         )
                         .emit();
                         ShouldPanic::Yes(None)

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -416,6 +416,11 @@ pub fn llvm_global_features(sess: &Session) -> Vec<String> {
     // -Ctarget-features
     features.extend(sess.opts.cg.target_feature.split(',').flat_map(&filter));
 
+    // FIXME: Move outline-atomics to target definition when earliest supported LLVM is 12.
+    if get_version() >= (12, 0, 0) && sess.target.llvm_target.contains("aarch64-unknown-linux") {
+        features.push("+outline-atomics".to_string());
+    }
+
     features
 }
 

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -887,8 +887,6 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
 
                 // At this point, we are calling a function, `callee`, whose `DefId` is known...
                 if is_lang_panic_fn(tcx, callee) {
-                    self.check_op(ops::Panic);
-
                     // `begin_panic` and `panic_display` are generic functions that accept
                     // types other than str. Check to enforce that only str can be used in
                     // const-eval.

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -368,23 +368,6 @@ impl NonConstOp for MutDeref {
     }
 }
 
-#[derive(Debug)]
-pub struct Panic;
-impl NonConstOp for Panic {
-    fn status_in_item(&self, _: &ConstCx<'_, '_>) -> Status {
-        Status::Unstable(sym::const_panic)
-    }
-
-    fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
-        feature_err(
-            &ccx.tcx.sess.parse_sess,
-            sym::const_panic,
-            span,
-            &format!("panicking in {}s is unstable", ccx.const_kind()),
-        )
-    }
-}
-
 /// A call to a `panic()` lang item where the first argument is _not_ a `&str`.
 #[derive(Debug)]
 pub struct PanicNonStr;
@@ -407,7 +390,7 @@ impl NonConstOp for RawPtrComparison {
         let mut err = ccx
             .tcx
             .sess
-            .struct_span_err(span, "pointers cannot be reliably compared during const eval.");
+            .struct_span_err(span, "pointers cannot be reliably compared during const eval");
         err.note(
             "see issue #53020 <https://github.com/rust-lang/rust/issues/53020> \
             for more information",
@@ -443,7 +426,7 @@ impl NonConstOp for RawPtrToIntCast {
         let mut err = ccx
             .tcx
             .sess
-            .struct_span_err(span, "pointers cannot be cast to integers during const eval.");
+            .struct_span_err(span, "pointers cannot be cast to integers during const eval");
         err.note("at compile-time, pointers do not have an integer value");
         err.note(
             "avoiding this restriction via `transmute`, `union`, or raw pointers leads to compile-time undefined behavior",

compiler/rustc_data_structures/src/lib.rs

@@ -11,7 +11,7 @@
 #![feature(associated_type_bounds)]
 #![feature(auto_traits)]
 #![feature(bool_to_option)]
-#![feature(const_panic)]
+#![cfg_attr(bootstrap, feature(const_panic))]
 #![feature(control_flow_enum)]
 #![feature(core_intrinsics)]
 #![feature(extend_one)]

compiler/rustc_driver/src/pretty.rs

@@ -88,7 +88,7 @@ trait PrinterSupport: pprust::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust::PpAnn;
 }
 
@@ -104,7 +104,7 @@ trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
 }