Rollup of 7 pull requests

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -20,7 +20,6 @@ use rustc_span::{ErrorGuaranteed, Span, Symbol, sym};
 use thin_vec::ThinVec;
 
 use crate::attributes::AttributeSafety;
-use crate::attributes::diagnostic::check_cfg;
 use crate::context::{AcceptContext, ShouldEmit};
 use crate::parser::{
     AllowExprMetavar, ArgParser, MetaItemListParser, MetaItemOrLitParser, NameValueParser,
@@ -29,7 +28,7 @@ use crate::session_diagnostics::{
     AttributeParseError, AttributeParseErrorReason, CfgAttrBadDelim, MetaBadDelimSugg,
     ParsedDescription,
 };
-use crate::{AttributeParser, parse_version, session_diagnostics};
+use crate::{AttributeParser, check_cfg, parse_version, session_diagnostics};
 
 pub const CFG_TEMPLATE: AttributeTemplate = template!(
     List: &["predicate"],

compiler/rustc_attr_parsing/src/attributes/diagnostic/mod.rs

@@ -23,7 +23,6 @@ use crate::errors::{
 };
 use crate::parser::{ArgParser, MetaItemListParser, MetaItemOrLitParser, MetaItemParser};
 
-pub(crate) mod check_cfg;
 pub(crate) mod do_not_recommend;
 pub(crate) mod on_const;
 pub(crate) mod on_move;

compiler/rustc_attr_parsing/src/lib.rs

@@ -106,6 +106,7 @@ mod interface;
 /// like lists or name-value pairs.
 pub mod parser;
 
+mod check_cfg;
 mod early_parsed;
 mod errors;
 mod safety;

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -274,11 +274,7 @@ pub(crate) enum IncorrectReprFormatGenericCause {
     Int {
         #[primary_span]
         span: Span,
-
-        #[skip_arg]
         name: Symbol,
-
-        #[skip_arg]
         value: u128,
     },
 
@@ -290,11 +286,7 @@ pub(crate) enum IncorrectReprFormatGenericCause {
     Symbol {
         #[primary_span]
         span: Span,
-
-        #[skip_arg]
         name: Symbol,
-
-        #[skip_arg]
         value: Symbol,
     },
 }

compiler/rustc_hir_typeck/src/pat.rs

@@ -1007,7 +1007,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         //
         // then that's equivalent to there existing a LUB.
         let cause = self.pattern_cause(ti, span);
-        if let Err(err) = self.demand_suptype_with_origin(&cause, expected, pat_ty) {
+        if let Err(mut err) = self.demand_suptype_with_origin(&cause, expected, pat_ty) {
+            // If scrutinee is String and pattern is &str, suggest .as_str()
+            let expected = self.resolve_vars_with_obligations(expected);
+            if let ty::Adt(adt, _) = expected.kind()
+                && self.tcx.is_lang_item(adt.did(), LangItem::String)
+                && pat_ty.is_ref()
+                && pat_ty.peel_refs().is_str()
+                && let Some(origin_expr) = ti.origin_expr
+            {
+                err.span_suggestion_verbose(
+                    origin_expr.span.shrink_to_hi(),
+                    "consider converting the `String` to a `&str` using `.as_str()`",
+                    ".as_str()",
+                    Applicability::MachineApplicable,
+                );
+            }
             err.emit();
         }
 

compiler/rustc_next_trait_solver/src/solve/trait_goals.rs

@@ -898,6 +898,8 @@ where
                         predicate: TraitRef::new(ecx.cx(), sized_trait, [ty]).upcast(ecx.cx()),
                     },
                 );
+                // FIXME(field_projections): This function does some questionable incomplete stuff by
+                // returning `Err(NoSolution)` on ambiguity.
                 ecx.try_evaluate_added_goals()? == Certainty::Yes
             }
             && match base.kind() {

compiler/rustc_parse/src/errors.rs

@@ -4639,3 +4639,28 @@ pub(crate) struct ReservedMultihashLint {
     )]
     pub suggestion: Span,
 }
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    "if you meant to write a path, use a double colon:",
+    code = "::",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct UseDoubleColonSuggestion {
+    #[primary_span]
+    pub colon: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+    "if you meant to create a regular struct, use curly braces:",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct UseRegularStructSuggestion {
+    #[suggestion_part(code = "{{")]
+    pub open: Span,
+    #[suggestion_part(code = "}}")]
+    pub close: Span,
+    #[suggestion_part(code = "")]
+    pub semicolon: Option<Span>,
+}

compiler/rustc_parse/src/parser/item.rs

@@ -23,7 +23,10 @@ use super::{
     AllowConstBlockItems, AttrWrapper, ExpKeywordPair, ExpTokenPair, FollowedByType, ForceCollect,
     Parser, PathStyle, Recovered, Trailing, UsePreAttrPos,
 };
-use crate::errors::{self, FnPointerCannotBeAsync, FnPointerCannotBeConst, MacroExpandsToAdtField};
+use crate::errors::{
+    self, FnPointerCannotBeAsync, FnPointerCannotBeConst, MacroExpandsToAdtField,
+    UseDoubleColonSuggestion, UseRegularStructSuggestion,
+};
 use crate::exp;
 
 impl<'a> Parser<'a> {
@@ -2084,10 +2087,11 @@ impl<'a> Parser<'a> {
             Safety::Default
         }
     }
-
+    /// This is the case where we find `struct Foo<T>(T) where T: Copy;`
+    /// Unit like structs are handled in parse_item_struct function
     pub(super) fn parse_tuple_struct_body(&mut self) -> PResult<'a, ThinVec<FieldDef>> {
-        // This is the case where we find `struct Foo<T>(T) where T: Copy;`
-        // Unit like structs are handled in parse_item_struct function
+        let openparen_span = self.token.span;
+        let mut encountered_colon = false;
         self.parse_paren_comma_seq(|p| {
             let attrs = p.parse_outer_attributes()?;
             p.collect_tokens(None, attrs, ForceCollect::No, |p, attrs| {
@@ -2109,6 +2113,8 @@ impl<'a> Parser<'a> {
                     }
                 };
                 let mut_restriction = p.parse_mut_restriction()?;
+                encountered_colon |=
+                    p.token.is_ident() && p.look_ahead(1, |tok| tok == &token::Colon);
                 // Unsafe fields are not supported in tuple structs, as doing so would result in a
                 // parsing ambiguity for `struct X(unsafe fn())`.
                 let ty = match p.parse_ty() {
@@ -2156,6 +2162,19 @@ impl<'a> Parser<'a> {
             })
         })
         .map(|(r, _)| r)
+        .map_err(|mut error| {
+            if encountered_colon {
+                error.subdiagnostic(UseDoubleColonSuggestion { colon: self.token.span });
+                self.eat_to_tokens(&[exp!(CloseParen)]);
+                self.bump();
+                error.subdiagnostic(UseRegularStructSuggestion {
+                    open: openparen_span,
+                    close: self.prev_token.span,
+                    semicolon: if self.token == token::Semi { Some(self.token.span) } else { None },
+                });
+            }
+            error
+        })
     }
 
     /// Parses an element of a struct declaration.

compiler/rustc_parse_format/src/lib.rs

@@ -491,6 +491,7 @@ impl<'input> Parser<'input> {
                 ('<' | '^' | '>', _) => self.suggest_format_align(c),
                 (',', _) => self.suggest_unsupported_python_numeric_grouping(),
                 ('=', '}') => self.suggest_rust_debug_printing_macro(),
+                ('+', _) => self.suggest_format_missing_colon_for_sign(),
                 _ => self.suggest_positional_arg_instead_of_captured_arg(arg),
             }
         }
@@ -939,6 +940,23 @@ impl<'input> Parser<'input> {
         }
     }
 
+    fn suggest_format_missing_colon_for_sign(&mut self) {
+        if let Some((range, _)) = self.consume_pos('+') {
+            self.errors.insert(
+                0,
+                ParseError {
+                    description: "the `+` sign flag must appear after `:` in a format string"
+                        .to_owned(),
+                    note: Some("`+` comes after `:`, try `{:+}` instead of `{+}`".to_owned()),
+                    label: "expected `:` before `+` sign flag".to_owned(),
+                    span: range,
+                    secondary_label: None,
+                    suggestion: Suggestion::None,
+                },
+            );
+        }
+    }
+
     fn suggest_positional_arg_instead_of_captured_arg(&mut self, arg: &Argument<'_>) {
         // If the argument is not an identifier, it is not a field access.
         if !arg.is_identifier() {

compiler/rustc_parse_format/src/tests.rs

@@ -595,3 +595,13 @@ fn diagnostic_format_mod() {
     assert_eq!(parser.line_spans, &[]);
     assert!(parser.errors.is_empty());
 }
+#[test]
+fn format_plus_sign_missing_colon_error() {
+    // `{+}` should produce an error suggesting `:` before `+`
+    let mut p = Parser::new("{+}", None, None, false, ParseMode::Format);
+    let _ = p.by_ref().collect::<Vec<Piece<'static>>>();
+    assert!(!p.errors.is_empty());
+    assert!(p.errors[0].description.contains("`+` sign flag must appear after `:`"));
+    assert!(p.errors[0].label.contains("expected `:` before `+` sign flag"));
+    assert_eq!(p.errors[0].span, 2..3);
+}

compiler/rustc_trait_selection/src/errors.rs

@@ -869,7 +869,6 @@ pub(crate) enum ExplicitLifetimeRequired<'a> {
             style = "verbose"
         )]
         new_ty_span: Span,
-        #[skip_arg]
         new_ty: Ty<'a>,
     },
     #[diag("explicit lifetime required in parameter type", code = E0621)]
@@ -885,7 +884,6 @@ pub(crate) enum ExplicitLifetimeRequired<'a> {
             style = "verbose"
         )]
         new_ty_span: Span,
-        #[skip_arg]
         new_ty: Ty<'a>,
     },
 }
@@ -1519,7 +1517,6 @@ pub(crate) enum FunctionPointerSuggestion<'a> {
     RemoveRef {
         #[primary_span]
         span: Span,
-        #[skip_arg]
         fn_name: String,
     },
     #[suggestion(
@@ -1531,9 +1528,7 @@ pub(crate) enum FunctionPointerSuggestion<'a> {
     CastRef {
         #[primary_span]
         span: Span,
-        #[skip_arg]
         fn_name: String,
-        #[skip_arg]
         sig: Binder<'a, FnSig<'a>>,
     },
     #[suggestion(
@@ -1545,7 +1540,6 @@ pub(crate) enum FunctionPointerSuggestion<'a> {
     Cast {
         #[primary_span]
         span: Span,
-        #[skip_arg]
         sig: Binder<'a, FnSig<'a>>,
     },
     #[suggestion(
@@ -1557,7 +1551,6 @@ pub(crate) enum FunctionPointerSuggestion<'a> {
     CastBoth {
         #[primary_span]
         span: Span,
-        #[skip_arg]
         found_sig: Binder<'a, FnSig<'a>>,
         expected_sig: Binder<'a, FnSig<'a>>,
     },
@@ -1570,9 +1563,7 @@ pub(crate) enum FunctionPointerSuggestion<'a> {
     CastBothRef {
         #[primary_span]
         span: Span,
-        #[skip_arg]
         fn_name: String,
-        #[skip_arg]
         found_sig: Binder<'a, FnSig<'a>>,
         expected_sig: Binder<'a, FnSig<'a>>,
     },

src/librustdoc/clean/utils.rs

@@ -351,8 +351,10 @@ pub(crate) fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
 pub(crate) fn print_const(tcx: TyCtxt<'_>, n: ty::Const<'_>) -> String {
     match n.kind() {
         ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args: _ }) => {
-            if let Some(def) = def.as_local() {
-                rendered_const(tcx, tcx.hir_body_owned_by(def), def)
+            if let Some(def) = def.as_local()
+                && let Some(body_id) = tcx.hir_maybe_body_owned_by(def)
+            {
+                rendered_const(tcx, body_id, def)
             } else {
                 inline::print_inlined_const(tcx, def)
             }

tests/rustdoc-ui/type-const-associated-const-no-body.rs

@@ -0,0 +1,16 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/149287>
+//! Ensure that rustdoc does not ICE when a body-less type const is used
+//! as an associated const.
+//@ check-pass
+
+#![feature(min_generic_const_args)]
+
+pub trait Tr {
+    type const SIZE: usize;
+}
+
+fn mk_array<T: Tr>() -> [(); <T as Tr>::SIZE] {
+    [(); T::SIZE]
+}
+
+fn main() {}

tests/ui/fmt/format-string-wrong-order.rs

@@ -20,4 +20,8 @@ fn main() {
     //~^ ERROR invalid format string: expected alignment specifier after `:` in format string; example: `{:>?}`
     println!("{0:#X>18}", 12345);
     //~^ ERROR invalid format string: expected alignment specifier after `:` in format string; example: `{:>?}`
+    format!("{+:}");
+    //~^ ERROR invalid format string: the `+` sign flag must appear after `:` in a format string
+    format!("{bar+:}");
+    //~^ ERROR invalid format string: the `+` sign flag must appear after `:` in a format string
 }

tests/ui/fmt/format-string-wrong-order.stderr

@@ -74,5 +74,21 @@ error: invalid format string: expected alignment specifier after `:` in format s
 LL |     println!("{0:#X>18}", 12345);
    |                    ^ expected `>` to occur after `:` in format string
 
-error: aborting due to 10 previous errors
+error: invalid format string: the `+` sign flag must appear after `:` in a format string
+  --> $DIR/format-string-wrong-order.rs:23:15
+   |
+LL |     format!("{+:}");
+   |               ^ expected `:` before `+` sign flag in format string
+   |
+   = note: `+` comes after `:`, try `{:+}` instead of `{+}`
+
+error: invalid format string: the `+` sign flag must appear after `:` in a format string
+  --> $DIR/format-string-wrong-order.rs:25:18
+   |
+LL |     format!("{bar+:}");
+   |                  ^ expected `:` before `+` sign flag in format string
+   |
+   = note: `+` comes after `:`, try `{:+}` instead of `{+}`
+
+error: aborting due to 12 previous errors
 

tests/ui/parser/field-name-in-tuple-struct.rs

@@ -0,0 +1,6 @@
+// Provide diagnostics when the user writes field names in tuple struct.(issue#144595)
+
+struct Foo(a:u8,b:u8);
+//~^ ERROR expected one of `!`, `(`, `)`, `+`, `,`, `::`, or `<`, found `:`
+//~| HELP if you meant to write a path, use a double colon:
+//~| HELP if you meant to create a regular struct, use curly braces:

tests/ui/parser/field-name-in-tuple-struct.stderr

@@ -0,0 +1,18 @@
+error: expected one of `!`, `(`, `)`, `+`, `,`, `::`, or `<`, found `:`
+  --> $DIR/field-name-in-tuple-struct.rs:3:13
+   |
+LL | struct Foo(a:u8,b:u8);
+   |             ^ expected one of 7 possible tokens
+   |
+help: if you meant to write a path, use a double colon:
+   |
+LL | struct Foo(a::u8,b:u8);
+   |              +
+help: if you meant to create a regular struct, use curly braces:
+   |
+LL - struct Foo(a:u8,b:u8);
+LL + struct Foo{a:u8,b:u8}
+   |
+
+error: aborting due to 1 previous error
+

tests/ui/pattern/deref-patterns/needs-gate.stderr

@@ -76,6 +76,11 @@ LL |     match "str".to_owned() {
    |           ---------------- this expression has type `String`
 LL |         "str" => {}
    |         ^^^^^ expected `String`, found `&str`
+   |
+help: consider converting the `String` to a `&str` using `.as_str()`
+   |
+LL |     match "str".to_owned().as_str() {
+   |                           +++++++++
 
 error[E0308]: mismatched types
   --> $DIR/needs-gate.rs:52:12

tests/ui/pattern/string-match-as-str-suggestion.fixed

@@ -0,0 +1,18 @@
+//@ run-rustfix
+
+fn main() {
+    let s = "yes".to_owned();
+
+    let _ = match s.as_str() {
+        "yes" => Some(true),
+        //~^ ERROR mismatched types
+        "no" => Some(false),
+        //~^ ERROR mismatched types
+        _ => None,
+    };
+
+    let s2 = String::from("hello");
+    if let "hello" = s2.as_str() {
+        //~^ ERROR mismatched types
+    }
+}