Auto merge of #106892 - matthiaskrgr:rollup-ohneu8o, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #106072 (fix: misleading "add dyn keyword before derive macro" suggestion)
 - #106859 (Suggestion for type mismatch when we need a u8 but the programmer wrote a char literal)
 - #106863 (Remove various double spaces in compiler source comments.)
 - #106865 (Add explanation comment for GUI test)
 - #106867 (Fix the stability attributes for `std::os::fd`.)
 - #106878 (Add regression test for #92157)
 - #106879 (Add regression test for #42114)
 - #106880 (doc: fix typo)

Failed merges:

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

Author: bors

compiler/rustc_abi/src/lib.rs

@@ -1100,7 +1100,7 @@ pub enum FieldsShape {
         /// named `inverse_memory_index`.
         ///
         // FIXME(eddyb) build a better abstraction for permutations, if possible.
-        // FIXME(camlorn) also consider small vector  optimization here.
+        // FIXME(camlorn) also consider small vector optimization here.
         memory_index: Vec<u32>,
     },
 }

compiler/rustc_borrowck/src/places_conflict.rs

@@ -209,7 +209,7 @@ fn place_components_conflict<'tcx>(
             match (elem, &base_ty.kind(), access) {
                 (_, _, Shallow(Some(ArtificialField::ArrayLength)))
                 | (_, _, Shallow(Some(ArtificialField::ShallowBorrow))) => {
-                    // The array length is like  additional fields on the
+                    // The array length is like additional fields on the
                     // type; it does not overlap any existing data there.
                     // Furthermore, if cannot actually be a prefix of any
                     // borrowed place (at least in MIR as it is currently.)

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -235,7 +235,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
     /// # Parameters
     ///
     /// - `def_id`, the `impl Trait` type
-    /// - `substs`, the substs  used to instantiate this opaque type
+    /// - `substs`, the substs used to instantiate this opaque type
     /// - `instantiated_ty`, the inferred type C1 -- fully resolved, lifted version of
     ///   `opaque_defn.concrete_ty`
     #[instrument(level = "debug", skip(self))]

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -3305,7 +3305,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 let label = "add `dyn` keyword before this trait";
                 let mut diag =
                     rustc_errors::struct_span_err!(tcx.sess, self_ty.span, E0782, "{}", msg);
-                diag.multipart_suggestion_verbose(label, sugg, Applicability::MachineApplicable);
+                if self_ty.span.can_be_used_for_suggestions() {
+                    diag.multipart_suggestion_verbose(
+                        label,
+                        sugg,
+                        Applicability::MachineApplicable,
+                    );
+                }
                 // check if the impl trait that we are considering is a impl of a local trait
                 self.maybe_lint_blanket_trait_impl(&self_ty, &mut diag);
                 diag.emit();

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -417,7 +417,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                                 // Named constants have to be equated with the value
                                 // being matched, so that's a read of the value being matched.
                                 //
-                                // FIXME: We don't actually  reads for ZSTs.
+                                // FIXME: We don't actually reads for ZSTs.
                                 needs_to_be_read = true;
                             }
                             _ => {

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -232,7 +232,7 @@ pub type PickResult<'tcx> = Result<Pick<'tcx>, MethodError<'tcx>>;
 pub enum Mode {
     // An expression of the form `receiver.method_name(...)`.
     // Autoderefs are performed on `receiver`, lookup is done based on the
-    // `self` argument  of the method, and static methods aren't considered.
+    // `self` argument of the method, and static methods aren't considered.
     MethodCall,
     // An expression of the form `Type::item` or `<T>::item`.
     // No autoderefs are performed, lookup is done based on the type each

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1923,6 +1923,22 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                         (ty::Tuple(fields), _) => {
                             self.emit_tuple_wrap_err(&mut err, span, found, fields)
                         }
+                        // If a byte was expected and the found expression is a char literal
+                        // containing a single ASCII character, perhaps the user meant to write `b'c'` to
+                        // specify a byte literal
+                        (ty::Uint(ty::UintTy::U8), ty::Char) => {
+                            if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span)
+                                && let Some(code) = code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
+                                && code.chars().next().map_or(false, |c| c.is_ascii())
+                            {
+                                err.span_suggestion(
+                                    span,
+                                    "if you meant to write a byte literal, prefix with `b`",
+                                    format!("b'{}'", escape_literal(code)),
+                                    Applicability::MachineApplicable,
+                                );
+                            }
+                        }
                         // If a character was expected and the found expression is a string literal
                         // containing a single character, perhaps the user meant to write `'c'` to
                         // specify a character literal (issue #92479)

compiler/rustc_middle/src/ty/typeck_results.rs

@@ -193,7 +193,7 @@ pub struct TypeckResults<'tcx> {
     pub generator_interior_types: ty::Binder<'tcx, Vec<GeneratorInteriorTypeCause<'tcx>>>,
 
     /// We sometimes treat byte string literals (which are of type `&[u8; N]`)
-    /// as `&[u8]`, depending on the pattern  in which they are used.
+    /// as `&[u8]`, depending on the pattern in which they are used.
     /// This hashset records all instances where we behave
     /// like this to allow `const_to_pat` to reliably handle this situation.
     pub treat_byte_string_as_slice: ItemLocalSet,

compiler/rustc_parse/src/parser/pat.rs

@@ -469,7 +469,7 @@ impl<'a> Parser<'a> {
     /// Try to recover the more general form `intersect ::= $pat_lhs @ $pat_rhs`.
     ///
     /// Allowed binding patterns generated by `binding ::= ref? mut? $ident @ $pat_rhs`
-    /// should already have been parsed by now  at this point,
+    /// should already have been parsed by now at this point,
     /// if the next token is `@` then we can try to parse the more general form.
     ///
     /// Consult `parse_pat_ident` for the `binding` grammar.

compiler/rustc_session/src/config.rs

@@ -2091,7 +2091,7 @@ fn parse_libs(matches: &getopts::Matches, error_format: ErrorOutputType) -> Vec<
         .map(|s| {
             // Parse string of the form "[KIND[:MODIFIERS]=]lib[:new_name]",
             // where KIND is one of "dylib", "framework", "static", "link-arg" and
-            // where MODIFIERS are  a comma separated list of supported modifiers
+            // where MODIFIERS are a comma separated list of supported modifiers
             // (bundle, verbatim, whole-archive, as-needed). Each modifier is prefixed
             // with either + or - to indicate whether it is enabled or disabled.
             // The last value specified for a given modifier wins.

compiler/rustc_target/src/asm/mod.rs

@@ -462,7 +462,7 @@ impl InlineAsmRegClass {
     }
 
     /// Returns a suggested template modifier to use for this type and an
-    /// example of a  register named formatted with it.
+    /// example of a register named formatted with it.
     ///
     /// Such suggestions are useful if a type smaller than the full register
     /// size is used and a modifier can be used to point to the subregister of

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -308,7 +308,7 @@ pub fn normalize_param_env_or_error<'tcx>(
     // the `TypeOutlives` predicates first inside the unnormalized parameter environment, and
     // then we normalize the `TypeOutlives` bounds inside the normalized parameter environment.
     //
-    // This works fairly well because trait matching  does not actually care about param-env
+    // This works fairly well because trait matching does not actually care about param-env
     // TypeOutlives predicates - these are normally used by regionck.
     let outlives_predicates: Vec<_> = predicates
         .drain_filter(|predicate| {

library/core/src/num/int_macros.rs

@@ -1625,7 +1625,7 @@ macro_rules! int_impl {
         /// overflow.
         ///
         /// Performs "ternary subtraction" by subtracting both an integer
-        /// operandand a borrow-in bit from `self`, and returns a tuple of the
+        /// operand and a borrow-in bit from `self`, and returns a tuple of the
         /// difference along with a boolean indicating whether an arithmetic
         /// overflow would occur. On overflow, the wrapped value is returned.
         ///

library/std/src/os/fd/mod.rs

@@ -3,7 +3,7 @@
 //! This module is supported on Unix platforms and WASI, which both use a
 //! similar file descriptor system for referencing OS resources.
 
-#![stable(feature = "io_safety", since = "1.63.0")]
+#![stable(feature = "os_fd", since = "1.66.0")]
 #![deny(unsafe_op_in_unsafe_fn)]
 
 // `RawFd`, `AsRawFd`, etc.
@@ -19,7 +19,7 @@ mod net;
 mod tests;
 
 // Export the types and traits for the public API.
-#[unstable(feature = "os_fd", issue = "98699")]
+#[stable(feature = "os_fd", since = "1.66.0")]
 pub use owned::*;
-#[unstable(feature = "os_fd", issue = "98699")]
+#[stable(feature = "os_fd", since = "1.66.0")]
 pub use raw::*;

tests/rustdoc-gui/scrape-examples-button-focus.goml

@@ -1,3 +1,5 @@
+// This test ensures that the scraped examples buttons are working as expecting
+// when 'Enter' key is pressed when they're focused.
 goto: "file://" + |DOC_PATH| + "/scrape_examples/fn.test.html"
 
 // The next/prev buttons vertically scroll the code viewport between examples

tests/ui/borrowck/issue-92157.rs

@@ -0,0 +1,40 @@
+#![feature(no_core)]
+#![feature(lang_items)]
+
+#![no_core]
+
+#[cfg(target_os = "linux")]
+#[link(name = "c")]
+extern {}
+
+#[lang = "start"]
+fn start<T>(_main: fn() -> T, _argc: isize, _argv: *const *const u8) -> isize {
+    //~^ ERROR: incorrect number of parameters for the `start` lang item
+    40+2
+}
+
+#[lang = "sized"]
+pub trait Sized {}
+#[lang = "copy"]
+pub trait Copy {}
+
+#[lang = "drop_in_place"]
+#[allow(unconditional_recursion)]
+pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
+    drop_in_place(to_drop)
+}
+
+#[lang = "add"]
+trait Add<RHS> {
+    type Output;
+    fn add(self, other: RHS) -> Self::Output;
+}
+
+impl Add<isize> for isize {
+    type Output = isize;
+    fn add(self, other: isize) -> isize {
+        self + other
+    }
+}
+
+fn main() {}

tests/ui/borrowck/issue-92157.stderr

@@ -0,0 +1,11 @@
+error: incorrect number of parameters for the `start` lang item
+  --> $DIR/issue-92157.rs:11:1
+   |
+LL | fn start<T>(_main: fn() -> T, _argc: isize, _argv: *const *const u8) -> isize {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `start` lang item should have four parameters, but found 3
+   = note: the `start` lang item should have the signature `fn(fn() -> T, isize, *const *const u8, u8) -> isize`
+
+error: aborting due to previous error
+

tests/ui/higher-rank-trait-bounds/issue-42114.rs

@@ -0,0 +1,20 @@
+// check-pass
+
+fn lifetime<'a>()
+where
+    &'a (): 'a,
+{
+    /* do nothing */
+}
+
+fn doesnt_work()
+where
+    for<'a> &'a (): 'a,
+{
+    /* do nothing */
+}
+
+fn main() {
+    lifetime();
+    doesnt_work();
+}

tests/ui/suggestions/type-mismatch-byte-literal.rs

@@ -0,0 +1,18 @@
+// Tests that a suggestion is issued for type mismatch errors when a
+// u8 is expected and a char literal which is ASCII is supplied.
+
+fn foo(_t: u8) {}
+
+fn main() {
+    let _x: u8 = 'X';
+    //~^ ERROR: mismatched types [E0308]
+    //~| HELP: if you meant to write a byte literal, prefix with `b`
+
+    foo('#');
+    //~^ ERROR: mismatched types [E0308]
+    //~| HELP: if you meant to write a byte literal, prefix with `b`
+
+    // Do not issue the suggestion if the char literal isn't ASCII
+    let _t: u8 = '€';
+    //~^ ERROR: mismatched types [E0308]
+}

tests/ui/suggestions/type-mismatch-byte-literal.stderr

@@ -0,0 +1,42 @@
+error[E0308]: mismatched types
+  --> $DIR/type-mismatch-byte-literal.rs:7:18
+   |
+LL |     let _x: u8 = 'X';
+   |             --   ^^^ expected `u8`, found `char`
+   |             |
+   |             expected due to this
+   |
+help: if you meant to write a byte literal, prefix with `b`
+   |
+LL |     let _x: u8 = b'X';
+   |                  ~~~~
+
+error[E0308]: mismatched types
+  --> $DIR/type-mismatch-byte-literal.rs:11:9
+   |
+LL |     foo('#');
+   |     --- ^^^ expected `u8`, found `char`
+   |     |
+   |     arguments to this function are incorrect
+   |
+note: function defined here
+  --> $DIR/type-mismatch-byte-literal.rs:4:4
+   |
+LL | fn foo(_t: u8) {}
+   |    ^^^ ------
+help: if you meant to write a byte literal, prefix with `b`
+   |
+LL |     foo(b'#');
+   |         ~~~~
+
+error[E0308]: mismatched types
+  --> $DIR/type-mismatch-byte-literal.rs:16:18
+   |
+LL |     let _t: u8 = '€';
+   |             --   ^^^ expected `u8`, found `char`
+   |             |
+   |             expected due to this
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

tests/ui/traits/issue-106072.rs

@@ -0,0 +1,5 @@
+#[derive(Clone)] //~  trait objects must include the `dyn` keyword
+                 //~| trait objects must include the `dyn` keyword
+struct Foo;
+trait Foo {} //~ the name `Foo` is defined multiple times
+fn main() {}

tests/ui/traits/issue-106072.stderr

@@ -0,0 +1,30 @@
+error[E0428]: the name `Foo` is defined multiple times
+  --> $DIR/issue-106072.rs:4:1
+   |
+LL | struct Foo;
+   | ----------- previous definition of the type `Foo` here
+LL | trait Foo {}
+   | ^^^^^^^^^ `Foo` redefined here
+   |
+   = note: `Foo` must be defined only once in the type namespace of this module
+
+error[E0782]: trait objects must include the `dyn` keyword
+  --> $DIR/issue-106072.rs:1:10
+   |
+LL | #[derive(Clone)]
+   |          ^^^^^
+   |
+   = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0782]: trait objects must include the `dyn` keyword
+  --> $DIR/issue-106072.rs:1:10
+   |
+LL | #[derive(Clone)]
+   |          ^^^^^
+   |
+   = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0428, E0782.
+For more information about an error, try `rustc --explain E0428`.