Auto merge of #104573 - matthiaskrgr:rollup-k36ybtp, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #101162 (Migrate rustc_resolve to use SessionDiagnostic, part # 1)
 - #103386 (Don't allow `CoerceUnsized` into `dyn*` (except for trait upcasting))
 - #103405 (Detect incorrect chaining of if and if let conditions and recover)
 - #103594 (Fix non-associativity of `Instant` math on `aarch64-apple-darwin` targets)
 - #104006 (Add variant_name function to `LangItem`)
 - #104494 (Migrate GUI test to use functions)
 - #104516 (rustdoc: clean up sidebar width CSS)
 - #104550 (fix a typo)

Failed merges:

 - #104554 (Use `ErrorGuaranteed::unchecked_claim_error_was_emitted` less)

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

Cargo.lock

@@ -4047,6 +4047,7 @@ dependencies = [
  "rustc_feature",
  "rustc_hir",
  "rustc_index",
+ "rustc_macros",
  "rustc_metadata",
  "rustc_middle",
  "rustc_query_system",

compiler/rustc_error_messages/locales/en-US/parser.ftl

@@ -54,6 +54,9 @@ parser_invalid_logical_operator = `{$incorrect}` is not a logical operator
 parser_tilde_is_not_unary_operator = `~` cannot be used as a unary operator
     .suggestion = use `!` to perform bitwise not
 
+parser_unexpected_if_with_if = unexpected `if` in the condition expression
+    .suggestion = remove the `if`
+
 parser_unexpected_token_after_not = unexpected {$negated_desc} after identifier
 parser_unexpected_token_after_not_bitwise = use `!` to perform bitwise not
 parser_unexpected_token_after_not_logical = use `!` to perform logical negation

compiler/rustc_error_messages/locales/en-US/resolve.ftl

@@ -0,0 +1,211 @@
+resolve_parent_module_reset_for_binding =
+    parent module is reset for binding
+
+resolve_ampersand_used_without_explicit_lifetime_name =
+    `&` without an explicit lifetime name cannot be used here
+    .note = explicit lifetime name needed here
+
+resolve_underscore_lifetime_name_cannot_be_used_here =
+    `'_` cannot be used here
+    .note = `'_` is a reserved lifetime name
+
+resolve_crate_may_not_be_imported =
+    `$crate` may not be imported
+
+resolve_crate_root_imports_must_be_named_explicitly =
+    crate root imports need to be explicitly named: `use crate as name;`
+
+resolve_generic_params_from_outer_function =
+    can't use generic parameters from outer function
+    .label = use of generic parameter from outer function
+    .suggestion = try using a local generic parameter instead
+
+resolve_self_type_implicitly_declared_by_impl =
+    `Self` type implicitly declared here, by this `impl`
+
+resolve_cannot_use_self_type_here =
+    can't use `Self` here
+
+resolve_use_a_type_here_instead =
+    use a type here instead
+
+resolve_type_param_from_outer_fn =
+    type parameter from outer function
+
+resolve_const_param_from_outer_fn =
+    const parameter from outer function
+
+resolve_try_using_local_generic_parameter =
+    try using a local generic parameter instead
+
+resolve_try_adding_local_generic_param_on_method =
+    try adding a local generic parameter in this method instead
+
+resolve_help_try_using_local_generic_param =
+    try using a local generic paramter instead
+
+resolve_name_is_already_used_as_generic_parameter =
+    the name `{$name}` is already used for a generic parameter in this item's generic parameters
+    .label = already used
+    .first_use_of_name = first use of `{$name}`
+
+resolve_method_not_member_of_trait =
+    method `{$method}` is not a member of trait `{$trait_}`
+    .label = not a member of trait `{$trait_}`
+
+resolve_associated_fn_with_similar_name_exists =
+    there is an associated function with a similar name
+
+resolve_type_not_member_of_trait =
+    type `{$type_}` is not a member of trait `{$trait_}`
+    .label = not a member of trait `{$trait_}`
+
+resolve_associated_type_with_similar_name_exists =
+    there is an associated type with a similar name
+
+resolve_const_not_member_of_trait =
+    const `{$const_}` is not a member of trait `{$trait_}`
+    .label = not a member of trait `{$trait_}`
+
+resolve_associated_const_with_similar_name_exists =
+    there is an associated constant with a similar name
+
+resolve_variable_bound_with_different_mode =
+    variable `{$variable_name}` is bound inconsistently across alternatives separated by `|`
+    .label = bound in different ways
+    .first_binding_span = first binding
+
+resolve_ident_bound_more_than_once_in_parameter_list =
+    identifier `{$identifier}` is bound more than once in this parameter list
+    .label = used as parameter more than once
+
+resolve_ident_bound_more_than_once_in_same_pattern =
+    identifier `{$identifier}` is bound more than once in the same pattern
+    .label = used in a pattern more than once
+
+resolve_undeclared_label =
+    use of undeclared label `{$name}`
+    .label = undeclared label `{$name}`
+
+resolve_label_with_similar_name_reachable =
+    a label with a similar name is reachable
+
+resolve_try_using_similarly_named_label =
+    try using similarly named label
+
+resolve_unreachable_label_with_similar_name_exists =
+    a label with a similar name exists but is unreachable
+
+resolve_self_import_can_only_appear_once_in_the_list =
+    `self` import can only appear once in an import list
+    .label = can only appear once in an import list
+
+resolve_self_import_only_in_import_list_with_non_empty_prefix =
+    `self` import can only appear in an import list with a non-empty prefix
+    .label = can only appear in an import list with a non-empty prefix
+
+resolve_cannot_capture_dynamic_environment_in_fn_item =
+    can't capture dynamic environment in a fn item
+    .help = use the `|| {"{"} ... {"}"}` closure form instead
+
+resolve_attempt_to_use_non_constant_value_in_constant =
+    attempt to use a non-constant value in a constant
+
+resolve_attempt_to_use_non_constant_value_in_constant_with_suggestion =
+    consider using `{$suggestion}` instead of `{$current}`
+
+resolve_attempt_to_use_non_constant_value_in_constant_label_with_suggestion =
+    non-constant value
+
+resolve_attempt_to_use_non_constant_value_in_constant_without_suggestion =
+    this would need to be a `{$suggestion}`
+
+resolve_self_imports_only_allowed_within =
+    `self` imports are only allowed within a {"{"} {"}"} list
+
+resolve_self_imports_only_allowed_within_suggestion =
+    consider importing the module directly
+
+resolve_self_imports_only_allowed_within_multipart_suggestion =
+    alternatively, use the multi-path `use` syntax to import `self`
+
+resolve_binding_shadows_something_unacceptable =
+    {$shadowing_binding}s cannot shadow {$shadowed_binding}s
+    .label = cannot be named the same as {$article} {$shadowed_binding}
+    .label_shadowed_binding = the {$shadowed_binding} `{$name}` is {$participle} here
+
+resolve_binding_shadows_something_unacceptable_suggestion =
+    try specify the pattern arguments
+
+resolve_forward_declared_generic_param =
+    generic parameters with a default cannot use forward declared identifiers
+    .label = defaulted generic parameters cannot be forward declared
+
+resolve_param_in_ty_of_const_param =
+    the type of const parameters must not depend on other generic parameters
+    .label = the type must not depend on the parameter `{$name}`
+
+resolve_self_in_generic_param_default =
+    generic parameters cannot use `Self` in their defaults
+    .label = `Self` in generic parameter default
+
+resolve_param_in_non_trivial_anon_const =
+    generic parameters may not be used in const operations
+    .label = cannot perform const operation using `{$name}`
+
+resolve_param_in_non_trivial_anon_const_help =
+    use `#![feature(generic_const_exprs)]` to allow generic const expressions
+
+resolve_param_in_non_trivial_anon_const_sub_type =
+    type parameters may not be used in const expressions
+
+resolve_param_in_non_trivial_anon_const_sub_non_type =
+    const parameters may only be used as standalone arguments, i.e. `{$name}`
+
+resolve_unreachable_label =
+    use of unreachable label `{$name}`
+    .label = unreachable label `{$name}`
+    .label_definition_span = unreachable label defined here
+    .note = labels are unreachable through functions, closures, async blocks and modules
+
+resolve_unreachable_label_suggestion_use_similarly_named =
+    try using similarly named label
+
+resolve_unreachable_label_similar_name_reachable =
+    a label with a similar name is reachable
+
+resolve_unreachable_label_similar_name_unreachable =
+    a label with a similar name exists but is also unreachable
+
+resolve_trait_impl_mismatch =
+    item `{$name}` is an associated {$kind}, which doesn't match its trait `{$trait_path}`
+    .label = does not match trait
+    .label_trait_item = item in trait
+
+resolve_invalid_asm_sym =
+    invalid `sym` operand
+    .label = is a local variable
+    .help = `sym` operands must refer to either a function or a static
+
+resolve_trait_impl_duplicate =
+    duplicate definitions with name `{$name}`:
+    .label = duplicate definition
+    .old_span_label = previous definition here
+    .trait_item_span = item in trait
+
+resolve_relative_2018 =
+    relative paths are not supported in visibilities in 2018 edition or later
+    .suggestion = try
+
+resolve_ancestor_only =
+    visibilities can only be restricted to ancestor modules
+
+resolve_expected_found =
+    expected module, found {$res} `{$path_str}`
+    .label = not a module
+
+resolve_indeterminate =
+    cannot determine resolution for the visibility
+
+resolve_module_only =
+    visibility must resolve to a module

compiler/rustc_error_messages/src/lib.rs

@@ -63,6 +63,7 @@ fluent_messages! {
     plugin_impl => "../locales/en-US/plugin_impl.ftl",
     privacy => "../locales/en-US/privacy.ftl",
     query_system => "../locales/en-US/query_system.ftl",
+    resolve => "../locales/en-US/resolve.ftl",
     save_analysis => "../locales/en-US/save_analysis.ftl",
     session => "../locales/en-US/session.ftl",
     symbol_mangling => "../locales/en-US/symbol_mangling.ftl",

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -211,6 +211,12 @@ impl IntoDiagnosticArg for DiagnosticSymbolList {
     }
 }
 
+impl<Id> IntoDiagnosticArg for hir::def::Res<Id> {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Borrowed(self.descr()))
+    }
+}
+
 impl IntoDiagnostic<'_, !> for TargetDataLayoutErrors<'_> {
     fn into_diagnostic(self, handler: &Handler) -> DiagnosticBuilder<'_, !> {
         let mut diag;

compiler/rustc_hir/src/lang_items.rs

@@ -95,6 +95,14 @@ macro_rules! language_item_table {
                 }
             }
 
+            /// Returns the name of the `LangItem` enum variant.
+            // This method is used by Clippy for internal lints.
+            pub fn variant_name(self) -> &'static str {
+                match self {
+                    $( LangItem::$variant => stringify!($variant), )*
+                }
+            }
+
             pub fn target(self) -> Target {
                 match self {
                     $( LangItem::$variant => $target, )*

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -144,7 +144,7 @@ impl fmt::Display for InvalidProgramInfo<'_> {
             AlreadyReported(ErrorGuaranteed { .. }) => {
                 write!(
                     f,
-                    "an error has already been reported elsewhere (this sould not usually be printed)"
+                    "an error has already been reported elsewhere (this should not usually be printed)"
                 )
             }
             Layout(ref err) => write!(f, "{err}"),

compiler/rustc_parse/src/errors.rs

@@ -1219,3 +1219,11 @@ pub(crate) struct FnPtrWithGenericsSugg {
     pub arity: usize,
     pub for_param_list_exists: bool,
 }
+
+#[derive(Diagnostic)]
+#[diag(parser_unexpected_if_with_if)]
+pub(crate) struct UnexpectedIfWithIf(
+    #[primary_span]
+    #[suggestion(applicability = "machine-applicable", code = " ", style = "verbose")]
+    pub Span,
+);

compiler/rustc_parse/src/parser/expr.rs

@@ -21,8 +21,8 @@ use crate::errors::{
     NoFieldsForFnCall, NotAsNegationOperator, NotAsNegationOperatorSub,
     OuterAttributeNotAllowedOnIfElse, ParenthesesWithStructFields,
     RequireColonAfterLabeledExpression, ShiftInterpretedAsGeneric, StructLiteralNotAllowedHere,
-    StructLiteralNotAllowedHereSugg, TildeAsUnaryOperator, UnexpectedTokenAfterLabel,
-    UnexpectedTokenAfterLabelSugg, WrapExpressionInParentheses,
+    StructLiteralNotAllowedHereSugg, TildeAsUnaryOperator, UnexpectedIfWithIf,
+    UnexpectedTokenAfterLabel, UnexpectedTokenAfterLabelSugg, WrapExpressionInParentheses,
 };
 use crate::maybe_recover_from_interpolated_ty_qpath;
 use core::mem;
@@ -2239,6 +2239,7 @@ impl<'a> Parser<'a> {
                 if let Some(block) = recover_block_from_condition(self) {
                     block
                 } else {
+                    self.error_on_extra_if(&cond)?;
                     // Parse block, which will always fail, but we can add a nice note to the error
                     self.parse_block().map_err(|mut err| {
                         err.span_note(
@@ -2375,6 +2376,16 @@ impl<'a> Parser<'a> {
         });
     }
 
+    fn error_on_extra_if(&mut self, cond: &P<Expr>) -> PResult<'a, ()> {
+        if let ExprKind::Binary(Spanned { span: binop_span, node: binop}, _, right) = &cond.kind &&
+            let BinOpKind::And = binop &&
+            let ExprKind::If(cond, ..) = &right.kind {
+                    Err(self.sess.create_err(UnexpectedIfWithIf(binop_span.shrink_to_hi().to(cond.span.shrink_to_lo()))))
+            } else {
+                Ok(())
+            }
+    }
+
     /// Parses `for <src_pat> in <src_expr> <src_loop_block>` (`for` token already eaten).
     fn parse_for_expr(&mut self, opt_label: Option<Label>, lo: Span) -> PResult<'a, P<Expr>> {
         // Record whether we are about to parse `for (`.

compiler/rustc_resolve/Cargo.toml

@@ -17,6 +17,7 @@ rustc_expand = { path = "../rustc_expand" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_metadata = { path = "../rustc_metadata" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_query_system = { path = "../rustc_query_system" }

compiler/rustc_resolve/src/diagnostics.rs

@@ -27,6 +27,7 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, Span, SyntaxContext};
 use thin_vec::ThinVec;
 
+use crate::errors as errs;
 use crate::imports::{Import, ImportKind, ImportResolver};
 use crate::late::{PatternSource, Rib};
 use crate::path_names_to_string;
@@ -598,78 +599,41 @@ impl<'a> Resolver<'a> {
 
                 err
             }
-            ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0403,
-                    "the name `{}` is already used for a generic \
-                     parameter in this item's generic parameters",
-                    name,
-                );
-                err.span_label(span, "already used");
-                err.span_label(first_use_span, format!("first use of `{}`", name));
-                err
-            }
+            ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => self
+                .session
+                .create_err(errs::NameAlreadyUsedInParameterList { span, first_use_span, name }),
             ResolutionError::MethodNotMemberOfTrait(method, trait_, candidate) => {
-                let mut err = struct_span_err!(
-                    self.session,
+                self.session.create_err(errs::MethodNotMemberOfTrait {
                     span,
-                    E0407,
-                    "method `{}` is not a member of trait `{}`",
                     method,
-                    trait_
-                );
-                err.span_label(span, format!("not a member of trait `{}`", trait_));
-                if let Some(candidate) = candidate {
-                    err.span_suggestion(
-                        method.span,
-                        "there is an associated function with a similar name",
-                        candidate.to_ident_string(),
-                        Applicability::MaybeIncorrect,
-                    );
-                }
-                err
+                    trait_,
+                    sub: candidate.map(|c| errs::AssociatedFnWithSimilarNameExists {
+                        span: method.span,
+                        candidate: c,
+                    }),
+                })
             }
             ResolutionError::TypeNotMemberOfTrait(type_, trait_, candidate) => {
-                let mut err = struct_span_err!(
-                    self.session,
+                self.session.create_err(errs::TypeNotMemberOfTrait {
                     span,
-                    E0437,
-                    "type `{}` is not a member of trait `{}`",
                     type_,
-                    trait_
-                );
-                err.span_label(span, format!("not a member of trait `{}`", trait_));
-                if let Some(candidate) = candidate {
-                    err.span_suggestion(
-                        type_.span,
-                        "there is an associated type with a similar name",
-                        candidate.to_ident_string(),
-                        Applicability::MaybeIncorrect,
-                    );
-                }
-                err
+                    trait_,
+                    sub: candidate.map(|c| errs::AssociatedTypeWithSimilarNameExists {
+                        span: type_.span,
+                        candidate: c,
+                    }),
+                })
             }
             ResolutionError::ConstNotMemberOfTrait(const_, trait_, candidate) => {
-                let mut err = struct_span_err!(
-                    self.session,
+                self.session.create_err(errs::ConstNotMemberOfTrait {
                     span,
-                    E0438,
-                    "const `{}` is not a member of trait `{}`",
                     const_,
-                    trait_
-                );
-                err.span_label(span, format!("not a member of trait `{}`", trait_));
-                if let Some(candidate) = candidate {
-                    err.span_suggestion(
-                        const_.span,
-                        "there is an associated constant with a similar name",
-                        candidate.to_ident_string(),
-                        Applicability::MaybeIncorrect,
-                    );
-                }
-                err
+                    trait_,
+                    sub: candidate.map(|c| errs::AssociatedConstWithSimilarNameExists {
+                        span: const_.span,
+                        candidate: c,
+                    }),
+                })
             }
             ResolutionError::VariableNotBoundInPattern(binding_error, parent_scope) => {
                 let BindingError { name, target, origin, could_be_path } = binding_error;
@@ -731,128 +695,78 @@ impl<'a> Resolver<'a> {
                 err
             }
             ResolutionError::VariableBoundWithDifferentMode(variable_name, first_binding_span) => {
-                let mut err = struct_span_err!(
-                    self.session,
+                self.session.create_err(errs::VariableBoundWithDifferentMode {
                     span,
-                    E0409,
-                    "variable `{}` is bound inconsistently across alternatives separated by `|`",
-                    variable_name
-                );
-                err.span_label(span, "bound in different ways");
-                err.span_label(first_binding_span, "first binding");
-                err
-            }
-            ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0415,
-                    "identifier `{}` is bound more than once in this parameter list",
-                    identifier
-                );
-                err.span_label(span, "used as parameter more than once");
-                err
-            }
-            ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0416,
-                    "identifier `{}` is bound more than once in the same pattern",
-                    identifier
-                );
-                err.span_label(span, "used in a pattern more than once");
-                err
+                    first_binding_span,
+                    variable_name,
+                })
             }
+            ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => self
+                .session
+                .create_err(errs::IdentifierBoundMoreThanOnceInParameterList { span, identifier }),
+            ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => self
+                .session
+                .create_err(errs::IdentifierBoundMoreThanOnceInSamePattern { span, identifier }),
             ResolutionError::UndeclaredLabel { name, suggestion } => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0426,
-                    "use of undeclared label `{}`",
-                    name
-                );
-
-                err.span_label(span, format!("undeclared label `{}`", name));
-
-                match suggestion {
+                let ((sub_reachable, sub_reachable_suggestion), sub_unreachable) = match suggestion
+                {
                     // A reachable label with a similar name exists.
-                    Some((ident, true)) => {
-                        err.span_label(ident.span, "a label with a similar name is reachable");
-                        err.span_suggestion(
-                            span,
-                            "try using similarly named label",
-                            ident.name,
-                            Applicability::MaybeIncorrect,
-                        );
-                    }
+                    Some((ident, true)) => (
+                        (
+                            Some(errs::LabelWithSimilarNameReachable(ident.span)),
+                            Some(errs::TryUsingSimilarlyNamedLabel {
+                                span,
+                                ident_name: ident.name,
+                            }),
+                        ),
+                        None,
+                    ),
                     // An unreachable label with a similar name exists.
-                    Some((ident, false)) => {
-                        err.span_label(
-                            ident.span,
-                            "a label with a similar name exists but is unreachable",
-                        );
-                    }
+                    Some((ident, false)) => (
+                        (None, None),
+                        Some(errs::UnreachableLabelWithSimilarNameExists {
+                            ident_span: ident.span,
+                        }),
+                    ),
                     // No similarly-named labels exist.
-                    None => (),
-                }
-
-                err
+                    None => ((None, None), None),
+                };
+                self.session.create_err(errs::UndeclaredLabel {
+                    span,
+                    name,
+                    sub_reachable,
+                    sub_reachable_suggestion,
+                    sub_unreachable,
+                })
             }
             ResolutionError::SelfImportsOnlyAllowedWithin { root, span_with_rename } => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0429,
-                    "{}",
-                    "`self` imports are only allowed within a { } list"
-                );
-
                 // None of the suggestions below would help with a case like `use self`.
-                if !root {
+                let (suggestion, mpart_suggestion) = if root {
+                    (None, None)
+                } else {
                     // use foo::bar::self        -> foo::bar
                     // use foo::bar::self as abc -> foo::bar as abc
-                    err.span_suggestion(
-                        span,
-                        "consider importing the module directly",
-                        "",
-                        Applicability::MachineApplicable,
-                    );
+                    let suggestion = errs::SelfImportsOnlyAllowedWithinSuggestion { span };
 
                     // use foo::bar::self        -> foo::bar::{self}
                     // use foo::bar::self as abc -> foo::bar::{self as abc}
-                    let braces = vec![
-                        (span_with_rename.shrink_to_lo(), "{".to_string()),
-                        (span_with_rename.shrink_to_hi(), "}".to_string()),
-                    ];
-                    err.multipart_suggestion(
-                        "alternatively, use the multi-path `use` syntax to import `self`",
-                        braces,
-                        Applicability::MachineApplicable,
-                    );
-                }
-                err
+                    let mpart_suggestion = errs::SelfImportsOnlyAllowedWithinMultipartSuggestion {
+                        multipart_start: span_with_rename.shrink_to_lo(),
+                        multipart_end: span_with_rename.shrink_to_hi(),
+                    };
+                    (Some(suggestion), Some(mpart_suggestion))
+                };
+                self.session.create_err(errs::SelfImportsOnlyAllowedWithin {
+                    span,
+                    suggestion,
+                    mpart_suggestion,
+                })
             }
             ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0430,
-                    "`self` import can only appear once in an import list"
-                );
-                err.span_label(span, "can only appear once in an import list");
-                err
+                self.session.create_err(errs::SelfImportCanOnlyAppearOnceInTheList { span })
             }
             ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0431,
-                    "`self` import can only appear in an import list with \
-                                                a non-empty prefix"
-                );
-                err.span_label(span, "can only appear in an import list with a non-empty prefix");
-                err
+                self.session.create_err(errs::SelfImportOnlyInImportListWithNonEmptyPrefix { span })
             }
             ResolutionError::FailedToResolve { label, suggestion } => {
                 let mut err =
@@ -870,23 +784,9 @@ impl<'a> Resolver<'a> {
                 err
             }
             ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0434,
-                    "{}",
-                    "can't capture dynamic environment in a fn item"
-                );
-                err.help("use the `|| { ... }` closure form instead");
-                err
+                self.session.create_err(errs::CannotCaptureDynamicEnvironmentInFnItem { span })
             }
-            ResolutionError::AttemptToUseNonConstantValueInConstant(ident, sugg, current) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0435,
-                    "attempt to use a non-constant value in a constant"
-                );
+            ResolutionError::AttemptToUseNonConstantValueInConstant(ident, suggestion, current) => {
                 // let foo =...
                 //     ^^^ given this Span
                 // ------- get this Span to have an applicable suggestion
@@ -900,23 +800,34 @@ impl<'a> Resolver<'a> {
                     .source_map()
                     .span_extend_to_prev_str(ident.span, current, true, false);
 
-                match sp {
+                let ((with, with_label), without) = match sp {
                     Some(sp) if !self.session.source_map().is_multiline(sp) => {
                         let sp = sp.with_lo(BytePos(sp.lo().0 - (current.len() as u32)));
-                        err.span_suggestion(
-                            sp,
-                            &format!("consider using `{}` instead of `{}`", sugg, current),
-                            format!("{} {}", sugg, ident),
-                            Applicability::MaybeIncorrect,
-                        );
-                        err.span_label(span, "non-constant value");
+                        (
+                        (Some(errs::AttemptToUseNonConstantValueInConstantWithSuggestion {
+                                span: sp,
+                                ident,
+                                suggestion,
+                                current,
+                            }), Some(errs::AttemptToUseNonConstantValueInConstantLabelWithSuggestion {span})),
+                            None,
+                        )
                     }
-                    _ => {
-                        err.span_label(ident.span, &format!("this would need to be a `{}`", sugg));
-                    }
-                }
+                    _ => (
+                        (None, None),
+                        Some(errs::AttemptToUseNonConstantValueInConstantWithoutSuggestion {
+                            ident_span: ident.span,
+                            suggestion,
+                        }),
+                    ),
+                };
 
-                err
+                self.session.create_err(errs::AttemptToUseNonConstantValueInConstant {
+                    span,
+                    with,
+                    with_label,
+                    without,
+                })
             }
             ResolutionError::BindingShadowsSomethingUnacceptable {
                 shadowing_binding,
@@ -925,135 +836,80 @@ impl<'a> Resolver<'a> {
                 article,
                 shadowed_binding,
                 shadowed_binding_span,
-            } => {
-                let shadowed_binding_descr = shadowed_binding.descr();
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0530,
-                    "{}s cannot shadow {}s",
-                    shadowing_binding.descr(),
-                    shadowed_binding_descr,
-                );
-                err.span_label(
-                    span,
-                    format!("cannot be named the same as {} {}", article, shadowed_binding_descr),
-                );
-                match (shadowing_binding, shadowed_binding) {
+            } => self.session.create_err(errs::BindingShadowsSomethingUnacceptable {
+                span,
+                shadowing_binding,
+                shadowed_binding,
+                article,
+                sub_suggestion: match (shadowing_binding, shadowed_binding) {
                     (
                         PatternSource::Match,
                         Res::Def(DefKind::Ctor(CtorOf::Variant | CtorOf::Struct, CtorKind::Fn), _),
-                    ) => {
-                        err.span_suggestion(
-                            span,
-                            "try specify the pattern arguments",
-                            format!("{}(..)", name),
-                            Applicability::Unspecified,
-                        );
-                    }
-                    _ => (),
-                }
-                let msg =
-                    format!("the {} `{}` is {} here", shadowed_binding_descr, name, participle);
-                err.span_label(shadowed_binding_span, msg);
-                err
-            }
+                    ) => Some(errs::BindingShadowsSomethingUnacceptableSuggestion { span, name }),
+                    _ => None,
+                },
+                shadowed_binding_span,
+                participle,
+                name,
+            }),
             ResolutionError::ForwardDeclaredGenericParam => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0128,
-                    "generic parameters with a default cannot use \
-                                                forward declared identifiers"
-                );
-                err.span_label(span, "defaulted generic parameters cannot be forward declared");
-                err
+                self.session.create_err(errs::ForwardDeclaredGenericParam { span })
             }
             ResolutionError::ParamInTyOfConstParam(name) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0770,
-                    "the type of const parameters must not depend on other generic parameters"
-                );
-                err.span_label(
-                    span,
-                    format!("the type must not depend on the parameter `{}`", name),
-                );
-                err
+                self.session.create_err(errs::ParamInTyOfConstParam { span, name })
             }
             ResolutionError::ParamInNonTrivialAnonConst { name, is_type } => {
-                let mut err = self.session.struct_span_err(
+                self.session.create_err(errs::ParamInNonTrivialAnonConst {
                     span,
-                    "generic parameters may not be used in const operations",
-                );
-                err.span_label(span, &format!("cannot perform const operation using `{}`", name));
-
-                if is_type {
-                    err.note("type parameters may not be used in const expressions");
-                } else {
-                    err.help(&format!(
-                        "const parameters may only be used as standalone arguments, i.e. `{}`",
-                        name
-                    ));
-                }
-
-                if self.session.is_nightly_build() {
-                    err.help(
-                        "use `#![feature(generic_const_exprs)]` to allow generic const expressions",
-                    );
-                }
-
-                err
+                    name,
+                    sub_is_type: if is_type {
+                        errs::ParamInNonTrivialAnonConstIsType::AType
+                    } else {
+                        errs::ParamInNonTrivialAnonConstIsType::NotAType { name }
+                    },
+                    help: self
+                        .session
+                        .is_nightly_build()
+                        .then_some(errs::ParamInNonTrivialAnonConstHelp),
+                })
             }
             ResolutionError::SelfInGenericParamDefault => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0735,
-                    "generic parameters cannot use `Self` in their defaults"
-                );
-                err.span_label(span, "`Self` in generic parameter default");
-                err
+                self.session.create_err(errs::SelfInGenericParamDefault { span })
             }
             ResolutionError::UnreachableLabel { name, definition_span, suggestion } => {
-                let mut err = struct_span_err!(
-                    self.session,
+                let ((sub_suggestion_label, sub_suggestion), sub_unreachable_label) =
+                    match suggestion {
+                        // A reachable label with a similar name exists.
+                        Some((ident, true)) => (
+                            (
+                                Some(errs::UnreachableLabelSubLabel { ident_span: ident.span }),
+                                Some(errs::UnreachableLabelSubSuggestion {
+                                    span,
+                                    // intentionally taking 'ident.name' instead of 'ident' itself, as this
+                                    // could be used in suggestion context
+                                    ident_name: ident.name,
+                                }),
+                            ),
+                            None,
+                        ),
+                        // An unreachable label with a similar name exists.
+                        Some((ident, false)) => (
+                            (None, None),
+                            Some(errs::UnreachableLabelSubLabelUnreachable {
+                                ident_span: ident.span,
+                            }),
+                        ),
+                        // No similarly-named labels exist.
+                        None => ((None, None), None),
+                    };
+                self.session.create_err(errs::UnreachableLabel {
                     span,
-                    E0767,
-                    "use of unreachable label `{}`",
                     name,
-                );
-
-                err.span_label(definition_span, "unreachable label defined here");
-                err.span_label(span, format!("unreachable label `{}`", name));
-                err.note(
-                    "labels are unreachable through functions, closures, async blocks and modules",
-                );
-
-                match suggestion {
-                    // A reachable label with a similar name exists.
-                    Some((ident, true)) => {
-                        err.span_label(ident.span, "a label with a similar name is reachable");
-                        err.span_suggestion(
-                            span,
-                            "try using similarly named label",
-                            ident.name,
-                            Applicability::MaybeIncorrect,
-                        );
-                    }
-                    // An unreachable label with a similar name exists.
-                    Some((ident, false)) => {
-                        err.span_label(
-                            ident.span,
-                            "a label with a similar name exists but is also unreachable",
-                        );
-                    }
-                    // No similarly-named labels exist.
-                    None => (),
-                }
-
-                err
+                    definition_span,
+                    sub_suggestion,
+                    sub_suggestion_label,
+                    sub_unreachable_label,
+                })
             }
             ResolutionError::TraitImplMismatch {
                 name,
@@ -1074,25 +930,10 @@ impl<'a> Resolver<'a> {
                 err.span_label(trait_item_span, "item in trait");
                 err
             }
-            ResolutionError::TraitImplDuplicate { name, trait_item_span, old_span } => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0201,
-                    "duplicate definitions with name `{}`:",
-                    name,
-                );
-                err.span_label(old_span, "previous definition here");
-                err.span_label(trait_item_span, "item in trait");
-                err.span_label(span, "duplicate definition");
-                err
-            }
-            ResolutionError::InvalidAsmSym => {
-                let mut err = self.session.struct_span_err(span, "invalid `sym` operand");
-                err.span_label(span, "is a local variable");
-                err.help("`sym` operands must refer to either a function or a static");
-                err
-            }
+            ResolutionError::TraitImplDuplicate { name, trait_item_span, old_span } => self
+                .session
+                .create_err(errs::TraitImplDuplicate { span, name, trait_item_span, old_span }),
+            ResolutionError::InvalidAsmSym => self.session.create_err(errs::InvalidAsmSym { span }),
         }
     }
 
@@ -1102,48 +943,27 @@ impl<'a> Resolver<'a> {
     ) -> ErrorGuaranteed {
         match vis_resolution_error {
             VisResolutionError::Relative2018(span, path) => {
-                let mut err = self.session.struct_span_err(
+                self.session.create_err(errs::Relative2018 {
                     span,
-                    "relative paths are not supported in visibilities in 2018 edition or later",
-                );
-                err.span_suggestion(
-                    path.span,
-                    "try",
-                    format!("crate::{}", pprust::path_to_string(&path)),
-                    Applicability::MaybeIncorrect,
-                );
-                err
+                    path_span: path.span,
+                    // intentionally converting to String, as the text would also be used as
+                    // in suggestion context
+                    path_str: pprust::path_to_string(&path),
+                })
+            }
+            VisResolutionError::AncestorOnly(span) => {
+                self.session.create_err(errs::AncestorOnly(span))
             }
-            VisResolutionError::AncestorOnly(span) => struct_span_err!(
-                self.session,
-                span,
-                E0742,
-                "visibilities can only be restricted to ancestor modules"
-            ),
             VisResolutionError::FailedToResolve(span, label, suggestion) => {
                 self.into_struct_error(span, ResolutionError::FailedToResolve { label, suggestion })
             }
             VisResolutionError::ExpectedFound(span, path_str, res) => {
-                let mut err = struct_span_err!(
-                    self.session,
-                    span,
-                    E0577,
-                    "expected module, found {} `{}`",
-                    res.descr(),
-                    path_str
-                );
-                err.span_label(span, "not a module");
-                err
+                self.session.create_err(errs::ExpectedFound { span, res, path_str })
             }
-            VisResolutionError::Indeterminate(span) => struct_span_err!(
-                self.session,
-                span,
-                E0578,
-                "cannot determine resolution for the visibility"
-            ),
-            VisResolutionError::ModuleOnly(span) => {
-                self.session.struct_span_err(span, "visibility must resolve to a module")
+            VisResolutionError::Indeterminate(span) => {
+                self.session.create_err(errs::Indeterminate(span))
             }
+            VisResolutionError::ModuleOnly(span) => self.session.create_err(errs::ModuleOnly(span)),
         }
         .emit()
     }

compiler/rustc_resolve/src/errors.rs

@@ -0,0 +1,474 @@
+use rustc_macros::{Diagnostic, Subdiagnostic};
+use rustc_span::{
+    symbol::{Ident, Symbol},
+    Span,
+};
+
+use crate::{late::PatternSource, Res};
+
+#[derive(Diagnostic)]
+#[diag(resolve_parent_module_reset_for_binding, code = "E0637")]
+pub(crate) struct ParentModuleResetForBinding;
+
+#[derive(Diagnostic)]
+#[diag(resolve_ampersand_used_without_explicit_lifetime_name, code = "E0637")]
+#[note]
+pub(crate) struct AmpersandUsedWithoutExplicitLifetimeName(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_underscore_lifetime_name_cannot_be_used_here, code = "E0637")]
+#[note]
+pub(crate) struct UnderscoreLifetimeNameCannotBeUsedHere(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_crate_may_not_be_imported)]
+pub(crate) struct CrateMayNotBeImprted(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_crate_root_imports_must_be_named_explicitly)]
+pub(crate) struct CrateRootNamesMustBeNamedExplicitly(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_crate_root_imports_must_be_named_explicitly)]
+pub(crate) struct ResolutionError(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_name_is_already_used_as_generic_parameter, code = "E0403")]
+pub(crate) struct NameAlreadyUsedInParameterList {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    #[label(first_use_of_name)]
+    pub(crate) first_use_span: Span,
+    pub(crate) name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_method_not_member_of_trait, code = "E0407")]
+pub(crate) struct MethodNotMemberOfTrait {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) method: Ident,
+    pub(crate) trait_: String,
+    #[subdiagnostic]
+    pub(crate) sub: Option<AssociatedFnWithSimilarNameExists>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_associated_fn_with_similar_name_exists,
+    code = "{candidate}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AssociatedFnWithSimilarNameExists {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) candidate: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_type_not_member_of_trait, code = "E0437")]
+pub(crate) struct TypeNotMemberOfTrait {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) type_: Ident,
+    pub(crate) trait_: String,
+    #[subdiagnostic]
+    pub(crate) sub: Option<AssociatedTypeWithSimilarNameExists>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_associated_type_with_similar_name_exists,
+    code = "{candidate}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AssociatedTypeWithSimilarNameExists {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) candidate: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_const_not_member_of_trait, code = "E0438")]
+pub(crate) struct ConstNotMemberOfTrait {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) const_: Ident,
+    pub(crate) trait_: String,
+    #[subdiagnostic]
+    pub(crate) sub: Option<AssociatedConstWithSimilarNameExists>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_associated_const_with_similar_name_exists,
+    code = "{candidate}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AssociatedConstWithSimilarNameExists {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) candidate: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_variable_bound_with_different_mode, code = "E0409")]
+pub(crate) struct VariableBoundWithDifferentMode {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    #[label(first_binding_span)]
+    pub(crate) first_binding_span: Span,
+    pub(crate) variable_name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_ident_bound_more_than_once_in_parameter_list, code = "E0415")]
+pub(crate) struct IdentifierBoundMoreThanOnceInParameterList {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) identifier: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_ident_bound_more_than_once_in_same_pattern, code = "E0416")]
+pub(crate) struct IdentifierBoundMoreThanOnceInSamePattern {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) identifier: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_undeclared_label, code = "E0426")]
+pub(crate) struct UndeclaredLabel {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+    #[subdiagnostic]
+    pub(crate) sub_reachable: Option<LabelWithSimilarNameReachable>,
+    #[subdiagnostic]
+    pub(crate) sub_reachable_suggestion: Option<TryUsingSimilarlyNamedLabel>,
+    #[subdiagnostic]
+    pub(crate) sub_unreachable: Option<UnreachableLabelWithSimilarNameExists>,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_label_with_similar_name_reachable)]
+pub(crate) struct LabelWithSimilarNameReachable(#[primary_span] pub(crate) Span);
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_try_using_similarly_named_label,
+    code = "{ident_name}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct TryUsingSimilarlyNamedLabel {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) ident_name: Symbol,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_unreachable_label_with_similar_name_exists)]
+pub(crate) struct UnreachableLabelWithSimilarNameExists {
+    #[primary_span]
+    pub(crate) ident_span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_self_import_can_only_appear_once_in_the_list, code = "E0430")]
+pub(crate) struct SelfImportCanOnlyAppearOnceInTheList {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_self_import_only_in_import_list_with_non_empty_prefix, code = "E0431")]
+pub(crate) struct SelfImportOnlyInImportListWithNonEmptyPrefix {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_cannot_capture_dynamic_environment_in_fn_item, code = "E0434")]
+#[help]
+pub(crate) struct CannotCaptureDynamicEnvironmentInFnItem {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_attempt_to_use_non_constant_value_in_constant, code = "E0435")]
+pub(crate) struct AttemptToUseNonConstantValueInConstant<'a> {
+    #[primary_span]
+    pub(crate) span: Span,
+    #[subdiagnostic]
+    pub(crate) with: Option<AttemptToUseNonConstantValueInConstantWithSuggestion<'a>>,
+    #[subdiagnostic]
+    pub(crate) with_label: Option<AttemptToUseNonConstantValueInConstantLabelWithSuggestion>,
+    #[subdiagnostic]
+    pub(crate) without: Option<AttemptToUseNonConstantValueInConstantWithoutSuggestion<'a>>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_attempt_to_use_non_constant_value_in_constant_with_suggestion,
+    code = "{suggestion} {ident}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct AttemptToUseNonConstantValueInConstantWithSuggestion<'a> {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) ident: Ident,
+    pub(crate) suggestion: &'a str,
+    pub(crate) current: &'a str,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_attempt_to_use_non_constant_value_in_constant_label_with_suggestion)]
+pub(crate) struct AttemptToUseNonConstantValueInConstantLabelWithSuggestion {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_attempt_to_use_non_constant_value_in_constant_without_suggestion)]
+pub(crate) struct AttemptToUseNonConstantValueInConstantWithoutSuggestion<'a> {
+    #[primary_span]
+    pub(crate) ident_span: Span,
+    pub(crate) suggestion: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_self_imports_only_allowed_within, code = "E0429")]
+pub(crate) struct SelfImportsOnlyAllowedWithin {
+    #[primary_span]
+    pub(crate) span: Span,
+    #[subdiagnostic]
+    pub(crate) suggestion: Option<SelfImportsOnlyAllowedWithinSuggestion>,
+    #[subdiagnostic]
+    pub(crate) mpart_suggestion: Option<SelfImportsOnlyAllowedWithinMultipartSuggestion>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_self_imports_only_allowed_within_suggestion,
+    code = "",
+    applicability = "machine-applicable"
+)]
+pub(crate) struct SelfImportsOnlyAllowedWithinSuggestion {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+    resolve_self_imports_only_allowed_within_multipart_suggestion,
+    applicability = "machine-applicable"
+)]
+pub(crate) struct SelfImportsOnlyAllowedWithinMultipartSuggestion {
+    #[suggestion_part(code = "{{")]
+    pub(crate) multipart_start: Span,
+    #[suggestion_part(code = "}}")]
+    pub(crate) multipart_end: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_binding_shadows_something_unacceptable, code = "E0530")]
+pub(crate) struct BindingShadowsSomethingUnacceptable<'a> {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) shadowing_binding: PatternSource,
+    pub(crate) shadowed_binding: Res,
+    pub(crate) article: &'a str,
+    #[subdiagnostic]
+    pub(crate) sub_suggestion: Option<BindingShadowsSomethingUnacceptableSuggestion>,
+    #[label(label_shadowed_binding)]
+    pub(crate) shadowed_binding_span: Span,
+    pub(crate) participle: &'a str,
+    pub(crate) name: Symbol,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_binding_shadows_something_unacceptable_suggestion,
+    code = "{name}(..)",
+    applicability = "unspecified"
+)]
+pub(crate) struct BindingShadowsSomethingUnacceptableSuggestion {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_forward_declared_generic_param, code = "E0128")]
+pub(crate) struct ForwardDeclaredGenericParam {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_param_in_ty_of_const_param, code = "E0770")]
+pub(crate) struct ParamInTyOfConstParam {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_self_in_generic_param_default, code = "E0735")]
+pub(crate) struct SelfInGenericParamDefault {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_param_in_non_trivial_anon_const)]
+pub(crate) struct ParamInNonTrivialAnonConst {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+    #[subdiagnostic]
+    pub(crate) sub_is_type: ParamInNonTrivialAnonConstIsType,
+    #[subdiagnostic]
+    pub(crate) help: Option<ParamInNonTrivialAnonConstHelp>,
+}
+
+#[derive(Subdiagnostic)]
+#[help(resolve_param_in_non_trivial_anon_const_help)]
+pub(crate) struct ParamInNonTrivialAnonConstHelp;
+
+#[derive(Subdiagnostic)]
+pub(crate) enum ParamInNonTrivialAnonConstIsType {
+    #[note(resolve_param_in_non_trivial_anon_const_sub_type)]
+    AType,
+    #[help(resolve_param_in_non_trivial_anon_const_sub_non_type)]
+    NotAType { name: Symbol },
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_unreachable_label, code = "E0767")]
+#[note]
+pub(crate) struct UnreachableLabel {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+    #[label(label_definition_span)]
+    pub(crate) definition_span: Span,
+    #[subdiagnostic]
+    pub(crate) sub_suggestion: Option<UnreachableLabelSubSuggestion>,
+    #[subdiagnostic]
+    pub(crate) sub_suggestion_label: Option<UnreachableLabelSubLabel>,
+    #[subdiagnostic]
+    pub(crate) sub_unreachable_label: Option<UnreachableLabelSubLabelUnreachable>,
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+    resolve_unreachable_label_suggestion_use_similarly_named,
+    code = "{ident_name}",
+    applicability = "maybe-incorrect"
+)]
+pub(crate) struct UnreachableLabelSubSuggestion {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) ident_name: Symbol,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_unreachable_label_similar_name_reachable)]
+pub(crate) struct UnreachableLabelSubLabel {
+    #[primary_span]
+    pub(crate) ident_span: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[label(resolve_unreachable_label_similar_name_unreachable)]
+pub(crate) struct UnreachableLabelSubLabelUnreachable {
+    #[primary_span]
+    pub(crate) ident_span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_trait_impl_mismatch, code = "{code}")]
+pub(crate) struct TraitImplMismatch {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) name: Symbol,
+    pub(crate) kind: String,
+    #[label(label_trait_item)]
+    pub(crate) trait_item_span: Span,
+    pub(crate) trait_path: String,
+    pub(crate) code: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_invalid_asm_sym)]
+#[help]
+pub(crate) struct InvalidAsmSym {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_trait_impl_duplicate, code = "E0201")]
+pub(crate) struct TraitImplDuplicate {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    #[label(old_span_label)]
+    pub(crate) old_span: Span,
+    #[label(trait_item_span)]
+    pub(crate) trait_item_span: Span,
+    pub(crate) name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_relative_2018)]
+pub(crate) struct Relative2018 {
+    #[primary_span]
+    pub(crate) span: Span,
+    #[suggestion(code = "crate::{path_str}", applicability = "maybe-incorrect")]
+    pub(crate) path_span: Span,
+    pub(crate) path_str: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_ancestor_only, code = "E0742")]
+pub(crate) struct AncestorOnly(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_expected_found, code = "E0577")]
+pub(crate) struct ExpectedFound {
+    #[primary_span]
+    #[label]
+    pub(crate) span: Span,
+    pub(crate) res: Res,
+    pub(crate) path_str: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(resolve_indeterminate, code = "E0578")]
+pub(crate) struct Indeterminate(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic)]
+#[diag(resolve_module_only)]
+pub(crate) struct ModuleOnly(#[primary_span] pub(crate) Span);

compiler/rustc_resolve/src/late.rs

@@ -16,7 +16,7 @@ use rustc_ast::ptr::P;
 use rustc_ast::visit::{self, AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
 use rustc_ast::*;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
-use rustc_errors::DiagnosticId;
+use rustc_errors::{DiagnosticArgValue, DiagnosticId, IntoDiagnosticArg};
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, PartialRes, PerNS};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
@@ -31,6 +31,7 @@ use smallvec::{smallvec, SmallVec};
 
 use rustc_span::source_map::{respan, Spanned};
 use std::assert_matches::debug_assert_matches;
+use std::borrow::Cow;
 use std::collections::{hash_map::Entry, BTreeSet};
 use std::mem::{replace, swap, take};
 
@@ -78,6 +79,12 @@ impl PatternSource {
     }
 }
 
+impl IntoDiagnosticArg for PatternSource {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Borrowed(self.descr()))
+    }
+}
+
 /// Denotes whether the context for the set of already bound bindings is a `Product`
 /// or `Or` context. This is used in e.g., `fresh_binding` and `resolve_pattern_inner`.
 /// See those functions for more information.

compiler/rustc_resolve/src/lib.rs

@@ -73,6 +73,7 @@ mod check_unused;
 mod def_collector;
 mod diagnostics;
 mod effective_visibilities;
+mod errors;
 mod ident;
 mod imports;
 mod late;

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -780,7 +780,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
         match (source.kind(), target.kind()) {
             // Trait+Kx+'a -> Trait+Ky+'b (upcasts).
-            (&ty::Dynamic(ref data_a, ..), &ty::Dynamic(ref data_b, ..)) => {
+            (&ty::Dynamic(ref data_a, _, dyn_a), &ty::Dynamic(ref data_b, _, dyn_b))
+                if dyn_a == dyn_b =>
+            {
                 // Upcast coercions permit several things:
                 //
                 // 1. Dropping auto traits, e.g., `Foo + Send` to `Foo`
@@ -841,7 +843,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             }
 
             // `T` -> `Trait`
-            (_, &ty::Dynamic(..)) => {
+            (_, &ty::Dynamic(_, _, ty::Dyn)) => {
                 candidates.vec.push(BuiltinUnsizeCandidate);
             }
 

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -912,7 +912,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let mut nested = vec![];
         match (source.kind(), target.kind()) {
             // Trait+Kx+'a -> Trait+Ky+'b (auto traits and lifetime subtyping).
-            (&ty::Dynamic(ref data_a, r_a, ty::Dyn), &ty::Dynamic(ref data_b, r_b, ty::Dyn)) => {
+            (&ty::Dynamic(ref data_a, r_a, dyn_a), &ty::Dynamic(ref data_b, r_b, dyn_b))
+                if dyn_a == dyn_b =>
+            {
                 // See `assemble_candidates_for_unsizing` for more info.
                 // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`.
                 let iter = data_a
@@ -931,7 +933,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             .map(ty::Binder::dummy),
                     );
                 let existential_predicates = tcx.mk_poly_existential_predicates(iter);
-                let source_trait = tcx.mk_dynamic(existential_predicates, r_b, ty::Dyn);
+                let source_trait = tcx.mk_dynamic(existential_predicates, r_b, dyn_a);
 
                 // Require that the traits involved in this upcast are **equal**;
                 // only the **lifetime bound** is changed.
@@ -1140,7 +1142,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 }));
             }
 
-            _ => bug!(),
+            _ => bug!("source: {source}, target: {target}"),
         };
 
         Ok(ImplSourceBuiltinData { nested })

library/std/src/sys/unix/time.rs

@@ -149,7 +149,11 @@ impl From<libc::timespec> for Timespec {
     }
 }
 
-#[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))]
+#[cfg(any(
+    all(target_os = "macos", any(not(target_arch = "aarch64"), miri)),
+    target_os = "ios",
+    target_os = "watchos"
+))]
 mod inner {
     use crate::sync::atomic::{AtomicU64, Ordering};
     use crate::sys::cvt;
@@ -265,7 +269,11 @@ mod inner {
     }
 }
 
-#[cfg(not(any(target_os = "macos", target_os = "ios", target_os = "watchos")))]
+#[cfg(not(any(
+    all(target_os = "macos", any(not(target_arch = "aarch64"), miri)),
+    target_os = "ios",
+    target_os = "watchos"
+)))]
 mod inner {
     use crate::fmt;
     use crate::mem::MaybeUninit;
@@ -281,7 +289,11 @@ mod inner {
 
     impl Instant {
         pub fn now() -> Instant {
-            Instant { t: Timespec::now(libc::CLOCK_MONOTONIC) }
+            #[cfg(target_os = "macos")]
+            const clock_id: libc::clockid_t = libc::CLOCK_UPTIME_RAW;
+            #[cfg(not(target_os = "macos"))]
+            const clock_id: libc::clockid_t = libc::CLOCK_MONOTONIC;
+            Instant { t: Timespec::now(clock_id) }
         }
 
         pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> {
@@ -312,13 +324,8 @@ mod inner {
         }
     }
 
-    #[cfg(not(any(target_os = "dragonfly", target_os = "espidf", target_os = "horizon")))]
-    pub type clock_t = libc::c_int;
-    #[cfg(any(target_os = "dragonfly", target_os = "espidf", target_os = "horizon"))]
-    pub type clock_t = libc::c_ulong;
-
     impl Timespec {
-        pub fn now(clock: clock_t) -> Timespec {
+        pub fn now(clock: libc::clockid_t) -> Timespec {
             // Try to use 64-bit time in preparation for Y2038.
             #[cfg(all(target_os = "linux", target_env = "gnu", target_pointer_width = "32"))]
             {

library/std/src/time/tests.rs

@@ -88,6 +88,14 @@ fn instant_math_is_associative() {
     // Changing the order of instant math shouldn't change the results,
     // especially when the expression reduces to X + identity.
     assert_eq!((now + offset) - now, (now - now) + offset);
+
+    // On any platform, `Instant` should have the same resolution as `Duration` (e.g. 1 nanosecond)
+    // or better. Otherwise, math will be non-associative (see #91417).
+    let now = Instant::now();
+    let provided_offset = Duration::from_nanos(1);
+    let later = now + provided_offset;
+    let measured_offset = later - now;
+    assert_eq!(measured_offset, provided_offset);
 }
 
 #[test]

src/librustdoc/html/static/css/rustdoc.css

@@ -384,8 +384,7 @@ img {
 
 .sidebar {
 	font-size: 0.875rem;
-	width: 200px;
-	min-width: 200px;
+	flex: 0 0 200px;
 	overflow-y: scroll;
 	position: sticky;
 	height: 100vh;
@@ -394,12 +393,7 @@ img {
 }
 
 .rustdoc.source .sidebar {
-	width: 50px;
-	min-width: 0px;
-	max-width: 300px;
-	flex-grow: 0;
-	flex-shrink: 0;
-	flex-basis: auto;
+	flex-basis: 50px;
 	border-right: 1px solid;
 	overflow-x: hidden;
 	/* The sidebar is by default hidden  */
@@ -420,7 +414,7 @@ img {
 
 .source-sidebar-expanded .source .sidebar {
 	overflow-y: auto;
-	width: 300px;
+	flex-basis: 300px;
 }
 
 .source-sidebar-expanded .source .sidebar > *:not(#sidebar-toggle) {
@@ -1701,6 +1695,7 @@ in storage.js
 		z-index: 11;
 		/* Reduce height slightly to account for mobile topbar. */
 		height: calc(100vh - 45px);
+		width: 200px;
 	}
 
 	/* The source view uses a different design for the sidebar toggle, and doesn't have a topbar,

src/test/rustdoc-gui/sidebar-source-code-display.goml

@@ -29,170 +29,95 @@ assert-local-storage: {"rustdoc-source-sidebar-show": "true"}
 // Now we check the display of the sidebar items.
 show-text: true
 
-// First we start with the light theme.
-local-storage: {"rustdoc-theme": "light", "rustdoc-use-system-theme": "false"}
-reload:
-// Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
-assert-css: (
-    "#source-sidebar details[open] > .files a.selected",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgb(255, 255, 255)"},
-)
-// Without hover or focus.
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgba(0, 0, 0, 0)"})
-// With focus.
-focus: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgb(224, 224, 224)"})
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgb(224, 224, 224)"})
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .files a:not(.selected)"
-wait-for-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgb(224, 224, 224)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .files a:not(.selected)"
-assert-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgb(224, 224, 224)"},
-)
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .folders > details > summary"
-wait-for-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgb(224, 224, 224)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .folders > details > summary"
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(0, 0, 0)", "background-color": "rgb(224, 224, 224)"},
+define-function: (
+    "check-colors",
+    (
+        theme, color, color_hover, background, background_hover, background_toggle,
+        background_toggle_hover,
+    ),
+    [
+        ("local-storage", {"rustdoc-theme": |theme|, "rustdoc-use-system-theme": "false"}),
+        ("reload"),
+        ("wait-for-css", ("#sidebar-toggle", {"visibility": "visible"})),
+        ("assert-css", (
+            "#source-sidebar details[open] > .files a.selected",
+            {"color": |color_hover|, "background-color": |background|},
+        )),
+        // Without hover or focus.
+        ("assert-css", ("#sidebar-toggle > button", {"background-color": |background_toggle|})),
+        // With focus.
+        ("focus", "#sidebar-toggle > button"),
+        ("assert-css", ("#sidebar-toggle > button", {"background-color": |background_toggle_hover|})),
+        ("focus", ".search-input"),
+        // With hover.
+        ("move-cursor-to", "#sidebar-toggle > button"),
+        ("assert-css", ("#sidebar-toggle > button", {"background-color": |background_toggle_hover|})),
+        // Without hover.
+        ("assert-css", (
+            "#source-sidebar details[open] > .files a:not(.selected)",
+            {"color": |color|, "background-color": |background_toggle|},
+        )),
+        // With focus.
+        ("focus", "#source-sidebar details[open] > .files a:not(.selected)"),
+        ("wait-for-css", (
+            "#source-sidebar details[open] > .files a:not(.selected)",
+            {"color": |color_hover|, "background-color": |background_hover|},
+        )),
+        ("focus", ".search-input"),
+        // With hover.
+        ("move-cursor-to", "#source-sidebar details[open] > .files a:not(.selected)"),
+        ("assert-css", (
+            "#source-sidebar details[open] > .files a:not(.selected)",
+            {"color": |color_hover|, "background-color": |background_hover|},
+        )),
+        // Without hover.
+        ("assert-css", (
+            "#source-sidebar details[open] > .folders > details > summary",
+            {"color": |color|, "background-color": |background_toggle|},
+        )),
+        // With focus.
+        ("focus", "#source-sidebar details[open] > .folders > details > summary"),
+        ("wait-for-css", (
+            "#source-sidebar details[open] > .folders > details > summary",
+            {"color": |color_hover|, "background-color": |background_hover|},
+        )),
+        ("focus", ".search-input"),
+        // With hover.
+        ("move-cursor-to", "#source-sidebar details[open] > .folders > details > summary"),
+        ("assert-css", (
+            "#source-sidebar details[open] > .folders > details > summary",
+            {"color": |color_hover|, "background-color": |background_hover|},
+        )),
+    ],
 )
 
-// Now with the dark theme.
-local-storage: {"rustdoc-theme": "dark", "rustdoc-use-system-theme": "false"}
-reload:
-// Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
-assert-css: (
-    "#source-sidebar details[open] > .files > a.selected",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgb(51, 51, 51)"},
-)
-// Without hover or focus.
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgba(0, 0, 0, 0)"})
-// With focus.
-focus: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgb(103, 103, 103)"})
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgb(103, 103, 103)"})
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .files > a:not(.selected)",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .files a:not(.selected)"
-wait-for-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgb(68, 68, 68)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .files a:not(.selected)"
-assert-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgb(68, 68, 68)"},
-)
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .folders > details > summary"
-wait-for-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgb(68, 68, 68)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .folders > details > summary"
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(221, 221, 221)", "background-color": "rgb(68, 68, 68)"},
-)
-
-// And finally with the ayu theme.
-local-storage: {"rustdoc-theme": "ayu", "rustdoc-use-system-theme": "false"}
-reload:
-// Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
-assert-css: (
-    "#source-sidebar details[open] > .files a.selected",
-    {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
-)
-// Without hover or focus.
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgba(0, 0, 0, 0)"})
-// With focus.
-focus: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgba(70, 70, 70, 0.33)"})
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#sidebar-toggle > button"
-assert-css: ("#sidebar-toggle > button", {"background-color": "rgba(70, 70, 70, 0.33)"})
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(197, 197, 197)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .files a:not(.selected)"
-wait-for-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .files a:not(.selected)"
-assert-css: (
-    "#source-sidebar details[open] > .files a:not(.selected)",
-    {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
-)
-// Without hover.
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(197, 197, 197)", "background-color": "rgba(0, 0, 0, 0)"},
-)
-// With focus.
-focus: "#source-sidebar details[open] > .folders > details > summary"
-wait-for-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
-)
-focus: ".search-input"
-// With hover.
-move-cursor-to: "#source-sidebar details[open] > .folders > details > summary"
-assert-css: (
-    "#source-sidebar details[open] > .folders > details > summary",
-    {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
-)
+call-function: ("check-colors", {
+    "theme": "light",
+    "color": "rgb(0, 0, 0)",
+    "color_hover": "rgb(0, 0, 0)",
+    "background": "rgb(255, 255, 255)",
+    "background_hover": "rgb(224, 224, 224)",
+    "background_toggle": "rgba(0, 0, 0, 0)",
+    "background_toggle_hover": "rgb(224, 224, 224)",
+})
+call-function: ("check-colors", {
+    "theme": "dark",
+    "color": "rgb(221, 221, 221)",
+    "color_hover": "rgb(221, 221, 221)",
+    "background": "rgb(51, 51, 51)",
+    "background_hover": "rgb(68, 68, 68)",
+    "background_toggle": "rgba(0, 0, 0, 0)",
+    "background_toggle_hover": "rgb(103, 103, 103)",
+})
+call-function: ("check-colors", {
+    "theme": "ayu",
+    "color": "rgb(197, 197, 197)",
+    "color_hover": "rgb(255, 180, 76)",
+    "background": "rgb(20, 25, 31)",
+    "background_hover": "rgb(20, 25, 31)",
+    "background_toggle": "rgba(0, 0, 0, 0)",
+    "background_toggle_hover": "rgba(70, 70, 70, 0.33)",
+})
 
 // Now checking on mobile devices.
 size: (500, 700)

src/test/ui/dyn-star/dont-unsize-coerce-dyn-star.rs

@@ -0,0 +1,26 @@
+// check-pass
+
+#![feature(dyn_star)]
+#![allow(incomplete_features)]
+
+trait AddOne {
+    fn add1(&mut self) -> usize;
+}
+
+impl AddOne for usize {
+    fn add1(&mut self) -> usize {
+        *self += 1;
+        *self
+    }
+}
+
+fn add_one(i: &mut (dyn* AddOne + '_)) -> usize {
+    i.add1()
+}
+
+fn main() {
+    let mut x = 42usize as dyn* AddOne;
+
+    println!("{}", add_one(&mut x));
+    println!("{}", add_one(&mut x));
+}

src/test/ui/dyn-star/unsize-into-ref-dyn-star.rs

@@ -0,0 +1,9 @@
+#![feature(dyn_star)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
+
+fn main() {
+    let i = 42 as &dyn* Debug;
+    //~^ ERROR non-primitive cast: `i32` as `&dyn* Debug`
+}

src/test/ui/dyn-star/unsize-into-ref-dyn-star.stderr

@@ -0,0 +1,9 @@
+error[E0605]: non-primitive cast: `i32` as `&dyn* Debug`
+  --> $DIR/unsize-into-ref-dyn-star.rs:7:13
+   |
+LL |     let i = 42 as &dyn* Debug;
+   |             ^^^^^^^^^^^^^^^^^ an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0605`.

src/test/ui/parser/issue-103381.fixed

@@ -0,0 +1,59 @@
+// run-rustfix
+
+#![feature(let_chains)]
+#![allow(unused_variables)]
+#![allow(dead_code)]
+#![allow(irrefutable_let_patterns)]
+
+fn err_some(b: bool, x: Option<u32>) {
+    if b && let Some(x) = x {}
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_none(b: bool, x: Option<u32>) {
+    if b && let None = x {}
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_bool_1() {
+    if true && true { true } else { false };
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_bool_2() {
+    if true && false { true } else { false };
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn should_ok_1() {
+    if true && if let x = 1 { true } else { true } {}
+}
+
+fn should_ok_2() {
+    if true && if let 1 = 1 { true } else { true } {}
+}
+
+fn should_ok_3() {
+    if true && if true { true } else { false } {}
+}
+
+fn shoule_match_ok() {
+    #[cfg(feature = "full")]
+    {
+        let a = 1;
+        let b = 2;
+        if match a {
+            1 if b == 1 => true,
+            _ => false,
+        } && if a > 1 { true } else { false }
+        {
+            true
+        }
+    }
+}
+
+fn should_ok_in_nested() {
+    if true && if true { true } else { false } { true } else { false };
+}
+
+fn main() {}

src/test/ui/parser/issue-103381.rs

@@ -0,0 +1,59 @@
+// run-rustfix
+
+#![feature(let_chains)]
+#![allow(unused_variables)]
+#![allow(dead_code)]
+#![allow(irrefutable_let_patterns)]
+
+fn err_some(b: bool, x: Option<u32>) {
+    if b && if let Some(x) = x {}
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_none(b: bool, x: Option<u32>) {
+    if b && if let None = x {}
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_bool_1() {
+    if true && if true { true } else { false };
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn err_bool_2() {
+    if true && if false { true } else { false };
+    //~^ ERROR unexpected `if` in the condition expression
+}
+
+fn should_ok_1() {
+    if true && if let x = 1 { true } else { true } {}
+}
+
+fn should_ok_2() {
+    if true && if let 1 = 1 { true } else { true } {}
+}
+
+fn should_ok_3() {
+    if true && if true { true } else { false } {}
+}
+
+fn shoule_match_ok() {
+    #[cfg(feature = "full")]
+    {
+        let a = 1;
+        let b = 2;
+        if match a {
+            1 if b == 1 => true,
+            _ => false,
+        } && if a > 1 { true } else { false }
+        {
+            true
+        }
+    }
+}
+
+fn should_ok_in_nested() {
+    if true && if true { true } else { false } { true } else { false };
+}
+
+fn main() {}

src/test/ui/parser/issue-103381.stderr

@@ -0,0 +1,50 @@
+error: unexpected `if` in the condition expression
+  --> $DIR/issue-103381.rs:9:12
+   |
+LL |     if b && if let Some(x) = x {}
+   |            ^^^^
+   |
+help: remove the `if`
+   |
+LL -     if b && if let Some(x) = x {}
+LL +     if b && let Some(x) = x {}
+   |
+
+error: unexpected `if` in the condition expression
+  --> $DIR/issue-103381.rs:14:12
+   |
+LL |     if b && if let None = x {}
+   |            ^^^^
+   |
+help: remove the `if`
+   |
+LL -     if b && if let None = x {}
+LL +     if b && let None = x {}
+   |
+
+error: unexpected `if` in the condition expression
+  --> $DIR/issue-103381.rs:19:15
+   |
+LL |     if true && if true { true } else { false };
+   |               ^^^^
+   |
+help: remove the `if`
+   |
+LL -     if true && if true { true } else { false };
+LL +     if true && true { true } else { false };
+   |
+
+error: unexpected `if` in the condition expression
+  --> $DIR/issue-103381.rs:24:15
+   |
+LL |     if true && if false { true } else { false };
+   |               ^^^^
+   |
+help: remove the `if`
+   |
+LL -     if true && if false { true } else { false };
+LL +     if true && false { true } else { false };
+   |
+
+error: aborting due to 4 previous errors
+

src/tools/clippy/clippy_lints/src/utils/internal_lints/invalid_paths.rs

@@ -79,22 +79,22 @@ pub fn check_path(cx: &LateContext<'_>, path: &[&str]) -> bool {
         SimplifiedTypeGen::StrSimplifiedType,
     ]
     .iter()
-    .flat_map(|&ty| cx.tcx.incoherent_impls(ty));
-    for item_def_id in lang_items.items().iter().flatten().chain(incoherent_impls) {
-        let lang_item_path = cx.get_def_path(*item_def_id);
+    .flat_map(|&ty| cx.tcx.incoherent_impls(ty).iter().copied());
+    for item_def_id in lang_items.iter().map(|(_, def_id)| def_id).chain(incoherent_impls) {
+        let lang_item_path = cx.get_def_path(item_def_id);
         if path_syms.starts_with(&lang_item_path) {
             if let [item] = &path_syms[lang_item_path.len()..] {
                 if matches!(
-                    cx.tcx.def_kind(*item_def_id),
+                    cx.tcx.def_kind(item_def_id),
                     DefKind::Mod | DefKind::Enum | DefKind::Trait
                 ) {
-                    for child in cx.tcx.module_children(*item_def_id) {
+                    for child in cx.tcx.module_children(item_def_id) {
                         if child.ident.name == *item {
                             return true;
                         }
                     }
                 } else {
-                    for child in cx.tcx.associated_item_def_ids(*item_def_id) {
+                    for child in cx.tcx.associated_item_def_ids(item_def_id) {
                         if cx.tcx.item_name(*child) == *item {
                             return true;
                         }

src/tools/clippy/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs

@@ -6,7 +6,7 @@ use rustc_ast::ast::LitKind;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
-use rustc_hir::def::{DefKind, Namespace, Res};
+use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{Expr, ExprKind, Local, Mutability, Node};
 use rustc_lint::{LateContext, LateLintPass};
@@ -91,7 +91,7 @@ impl UnnecessaryDefPath {
     #[allow(clippy::too_many_lines)]
     fn check_call(&mut self, cx: &LateContext<'_>, func: &Expr<'_>, args: &[Expr<'_>], span: Span) {
         enum Item {
-            LangItem(Symbol),
+            LangItem(&'static str),
             DiagnosticItem(Symbol),
         }
         static PATHS: &[&[&str]] = &[
@@ -325,18 +325,9 @@ fn inherent_def_path_res(cx: &LateContext<'_>, segments: &[&str]) -> Option<DefI
     })
 }
 
-fn get_lang_item_name(cx: &LateContext<'_>, def_id: DefId) -> Option<Symbol> {
-    if let Some(lang_item) = cx.tcx.lang_items().items().iter().position(|id| *id == Some(def_id)) {
-        let lang_items = def_path_res(cx, &["rustc_hir", "lang_items", "LangItem"], Some(Namespace::TypeNS)).def_id();
-        let item_name = cx
-            .tcx
-            .adt_def(lang_items)
-            .variants()
-            .iter()
-            .nth(lang_item)
-            .unwrap()
-            .name;
-        Some(item_name)
+fn get_lang_item_name(cx: &LateContext<'_>, def_id: DefId) -> Option<&'static str> {
+    if let Some((lang_item, _)) = cx.tcx.lang_items().iter().find(|(_, id)| *id == def_id) {
+        Some(lang_item.variant_name())
     } else {
         None
     }

src/tools/clippy/tests/ui-internal/unnecessary_def_path.fixed

@@ -48,14 +48,14 @@ fn _f<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, did: DefId, expr: &Expr<'_>) {
     let _ = is_type_lang_item(cx, ty, LangItem::OwnedBox);
     let _ = is_type_diagnostic_item(cx, ty, sym::maybe_uninit_uninit);
 
-    let _ = cx.tcx.lang_items().require(LangItem::OwnedBox).ok() == Some(did);
+    let _ = cx.tcx.lang_items().get(LangItem::OwnedBox) == Some(did);
     let _ = cx.tcx.is_diagnostic_item(sym::Option, did);
-    let _ = cx.tcx.lang_items().require(LangItem::OptionSome).ok() == Some(did);
+    let _ = cx.tcx.lang_items().get(LangItem::OptionSome) == Some(did);
 
     let _ = is_trait_method(cx, expr, sym::AsRef);
 
     let _ = is_path_diagnostic_item(cx, expr, sym::Option);
-    let _ = path_res(cx, expr).opt_def_id().map_or(false, |id| cx.tcx.lang_items().require(LangItem::IteratorNext).ok() == Some(id));
+    let _ = path_res(cx, expr).opt_def_id().map_or(false, |id| cx.tcx.lang_items().get(LangItem::IteratorNext) == Some(id));
     let _ = is_res_lang_ctor(cx, path_res(cx, expr), LangItem::OptionSome);
 }
 

src/tools/clippy/tests/ui-internal/unnecessary_def_path.stderr

@@ -57,7 +57,7 @@ error: use of a def path to a `LangItem`
   --> $DIR/unnecessary_def_path.rs:51:13
    |
 LL |     let _ = match_def_path(cx, did, &["alloc", "boxed", "Box"]);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `cx.tcx.lang_items().require(LangItem::OwnedBox).ok() == Some(did)`
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `cx.tcx.lang_items().get(LangItem::OwnedBox) == Some(did)`
 
 error: use of a def path to a diagnostic item
   --> $DIR/unnecessary_def_path.rs:52:13
@@ -69,7 +69,7 @@ error: use of a def path to a `LangItem`
   --> $DIR/unnecessary_def_path.rs:53:13
    |
 LL |     let _ = match_def_path(cx, did, &["core", "option", "Option", "Some"]);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `cx.tcx.lang_items().require(LangItem::OptionSome).ok() == Some(did)`
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `cx.tcx.lang_items().get(LangItem::OptionSome) == Some(did)`
    |
    = help: if this `DefId` came from a constructor expression or pattern then the parent `DefId` should be used instead
 
@@ -89,7 +89,7 @@ error: use of a def path to a `LangItem`
   --> $DIR/unnecessary_def_path.rs:58:13
    |
 LL |     let _ = is_expr_path_def_path(cx, expr, &["core", "iter", "traits", "Iterator", "next"]);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `path_res(cx, expr).opt_def_id().map_or(false, |id| cx.tcx.lang_items().require(LangItem::IteratorNext).ok() == Some(id))`
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `path_res(cx, expr).opt_def_id().map_or(false, |id| cx.tcx.lang_items().get(LangItem::IteratorNext) == Some(id))`
 
 error: use of a def path to a `LangItem`
   --> $DIR/unnecessary_def_path.rs:59:13

src/tools/clippy/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr

@@ -1,10 +1,10 @@
-error: hardcoded path to a language item
-  --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40
+error: hardcoded path to a diagnostic item
+  --> $DIR/unnecessary_def_path_hardcoded_path.rs:10:36
    |
-LL |     const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"];
-   |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"];
+   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: convert all references to use `LangItem::DerefMut`
+   = help: convert all references to use `sym::Deref`
    = note: `-D clippy::unnecessary-def-path` implied by `-D warnings`
 
 error: hardcoded path to a diagnostic item
@@ -15,13 +15,13 @@ LL |     const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref",
    |
    = help: convert all references to use `sym::deref_method`
 
-error: hardcoded path to a diagnostic item
-  --> $DIR/unnecessary_def_path_hardcoded_path.rs:10:36
+error: hardcoded path to a language item
+  --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40
    |
-LL |     const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"];
-   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"];
+   |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = help: convert all references to use `sym::Deref`
+   = help: convert all references to use `LangItem::DerefMut`
 
 error: aborting due to 3 previous errors