Auto merge of #116376 - matthiaskrgr:rollup-b3d14gq, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #115863 (Add check_unused_messages in tidy)
 - #116210 (Ensure that `~const` trait bounds on associated functions are in const traits or impls)
 - #116358 (Rename both of the `Match` relations)
 - #116371 (Remove unused features from `rustc_llvm`.)
 - #116374 (Print normalized ty)

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

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -52,7 +52,8 @@ struct AstValidator<'a> {
     /// Are we inside a trait impl?
     in_trait_impl: bool,
 
-    in_const_trait_impl: bool,
+    /// Are we inside a const trait defn or impl?
+    in_const_trait_or_impl: bool,
 
     has_proc_macro_decls: bool,
 
@@ -78,11 +79,19 @@ impl<'a> AstValidator<'a> {
         f: impl FnOnce(&mut Self),
     ) {
         let old = mem::replace(&mut self.in_trait_impl, is_in);
-        let old_const =
+        let old_const = mem::replace(
-            mem::replace(&mut self.in_const_trait_impl, matches!(constness, Some(Const::Yes(_))));
+            &mut self.in_const_trait_or_impl,
+            matches!(constness, Some(Const::Yes(_))),
+        );
         f(self);
         self.in_trait_impl = old;
-        self.in_const_trait_impl = old_const;
+        self.in_const_trait_or_impl = old_const;
+    }
+
+    fn with_in_trait(&mut self, is_const: bool, f: impl FnOnce(&mut Self)) {
+        let old = mem::replace(&mut self.in_const_trait_or_impl, is_const);
+        f(self);
+        self.in_const_trait_or_impl = old;
     }
 
     fn with_banned_impl_trait(&mut self, f: impl FnOnce(&mut Self)) {
@@ -933,23 +942,26 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 }
             }
             ItemKind::Trait(box Trait { is_auto, generics, bounds, items, .. }) => {
-                if *is_auto == IsAuto::Yes {
+                let is_const_trait = attr::contains_name(&item.attrs, sym::const_trait);
-                    // Auto traits cannot have generics, super traits nor contain items.
+                self.with_in_trait(is_const_trait, |this| {
-                    self.deny_generic_params(generics, item.ident.span);
+                    if *is_auto == IsAuto::Yes {
-                    self.deny_super_traits(bounds, item.ident.span);
+                        // Auto traits cannot have generics, super traits nor contain items.
-                    self.deny_where_clause(&generics.where_clause, item.ident.span);
+                        this.deny_generic_params(generics, item.ident.span);
-                    self.deny_items(items, item.ident.span);
+                        this.deny_super_traits(bounds, item.ident.span);
-                }
+                        this.deny_where_clause(&generics.where_clause, item.ident.span);
+                        this.deny_items(items, item.ident.span);
+                    }
 
-                // Equivalent of `visit::walk_item` for `ItemKind::Trait` that inserts a bound
+                    // Equivalent of `visit::walk_item` for `ItemKind::Trait` that inserts a bound
-                // context for the supertraits.
+                    // context for the supertraits.
-                self.visit_vis(&item.vis);
+                    this.visit_vis(&item.vis);
-                self.visit_ident(item.ident);
+                    this.visit_ident(item.ident);
-                self.visit_generics(generics);
+                    this.visit_generics(generics);
-                self.with_tilde_const_allowed(|this| {
+                    this.with_tilde_const_allowed(|this| {
-                    walk_list!(this, visit_param_bound, bounds, BoundKind::SuperTraits)
+                        walk_list!(this, visit_param_bound, bounds, BoundKind::SuperTraits)
+                    });
+                    walk_list!(this, visit_assoc_item, items, AssocCtxt::Trait);
                 });
-                walk_list!(self, visit_assoc_item, items, AssocCtxt::Trait);
                 walk_list!(self, visit_attribute, &item.attrs);
                 return; // Avoid visiting again
             }
@@ -1278,7 +1290,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
 
         let tilde_const_allowed =
             matches!(fk.header(), Some(FnHeader { constness: ast::Const::Yes(_), .. }))
-                || matches!(fk.ctxt(), Some(FnCtxt::Assoc(_)));
+                || matches!(fk.ctxt(), Some(FnCtxt::Assoc(_)) if self.in_const_trait_or_impl);
 
         let disallowed = (!tilde_const_allowed).then(|| DisallowTildeConstContext::Fn(fk));
 
@@ -1363,7 +1375,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 walk_list!(self, visit_ty, ty);
             }
             AssocItemKind::Fn(box Fn { sig, generics, body, .. })
-                if self.in_const_trait_impl
+                if self.in_const_trait_or_impl
                     || ctxt == AssocCtxt::Trait
                     || matches!(sig.header.constness, Const::Yes(_)) =>
             {
@@ -1510,7 +1522,7 @@ pub fn check_crate(
         features,
         extern_mod: None,
         in_trait_impl: false,
-        in_const_trait_impl: false,
+        in_const_trait_or_impl: false,
         has_proc_macro_decls: false,
         outer_impl_trait: None,
         disallow_tilde_const: None,

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -670,19 +670,24 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
         trace!("eval_place_to_op: got {:?}", op);
         // Sanity-check the type we ended up with.
-        debug_assert!(
+        if cfg!(debug_assertions) {
-            mir_assign_valid_types(
+            let normalized_place_ty = self.subst_from_current_frame_and_normalize_erasing_regions(
+                mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty,
+            )?;
+            if !mir_assign_valid_types(
                 *self.tcx,
                 self.param_env,
-                self.layout_of(self.subst_from_current_frame_and_normalize_erasing_regions(
+                self.layout_of(normalized_place_ty)?,
-                    mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty
-                )?)?,
                 op.layout,
-            ),
+            ) {
-            "eval_place of a MIR place with type {:?} produced an interpreter operand with type {}",
+                span_bug!(
-            mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty,
+                    self.cur_span(),
-            op.layout.ty,
+                    "eval_place of a MIR place with type {} produced an interpreter operand with type {}",
-        );
+                    normalized_place_ty,
+                    op.layout.ty,
+                )
+            }
+        }
         Ok(op)
     }
 

compiler/rustc_const_eval/src/interpret/place.rs

@@ -573,19 +573,24 @@ where
 
         trace!("{:?}", self.dump_place(&place));
         // Sanity-check the type we ended up with.
-        debug_assert!(
+        if cfg!(debug_assertions) {
-            mir_assign_valid_types(
+            let normalized_place_ty = self.subst_from_current_frame_and_normalize_erasing_regions(
+                mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty,
+            )?;
+            if !mir_assign_valid_types(
                 *self.tcx,
                 self.param_env,
-                self.layout_of(self.subst_from_current_frame_and_normalize_erasing_regions(
+                self.layout_of(normalized_place_ty)?,
-                    mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty
-                )?)?,
                 place.layout,
-            ),
+            ) {
-            "eval_place of a MIR place with type {:?} produced an interpreter place with type {}",
+                span_bug!(
-            mir_place.ty(&self.frame().body.local_decls, *self.tcx).ty,
+                    self.cur_span(),
-            place.layout.ty,
+                    "eval_place of a MIR place with type {} produced an interpreter place with type {}",
-        );
+                    normalized_place_ty,
+                    place.layout.ty,
+                )
+            }
+        }
         Ok(place)
     }
 

compiler/rustc_hir_analysis/messages.ftl

@@ -96,8 +96,6 @@ hir_analysis_enum_discriminant_overflowed = enum discriminant overflowed
     .label = overflowed on value after {$discr}
     .note = explicitly set `{$item_name} = {$wrapped_discr}` if that is desired outcome
 
-hir_analysis_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)`
-
 hir_analysis_field_already_declared =
     field `{$field_name}` is already declared
     .label = field already declared

compiler/rustc_infer/messages.ftl

@@ -66,7 +66,6 @@ infer_await_both_futures = consider `await`ing on both `Future`s
 infer_await_future = consider `await`ing on the `Future`
 infer_await_note = calling an async function returns a future
 
-infer_borrowed_too_long = a value of type `{$ty}` is borrowed for too long
 infer_but_calling_introduces = {$has_param_name ->
     [true] `{$param_name}`
     *[false] `fn` parameter
@@ -181,8 +180,6 @@ infer_more_targeted = {$has_param_name ->
 } but calling `{$ident}` introduces an implicit `'static` lifetime requirement
 
 infer_msl_introduces_static = introduces a `'static` lifetime requirement
-infer_msl_trait_note = this has an implicit `'static` lifetime requirement
-infer_msl_trait_sugg = consider relaxing the implicit `'static` requirement
 infer_msl_unmet_req = because this has an unmet lifetime requirement
 infer_need_type_info_in_generator =
     type inside {$generator_kind ->
@@ -233,7 +230,6 @@ infer_prlf_known_limitation = this is a known limitation that will be removed in
 infer_prlf_must_outlive_with_sup = ...must outlive the lifetime `{$sup_symbol}` defined here
 infer_prlf_must_outlive_without_sup = ...must outlive the lifetime defined here
 infer_reborrow = ...so that reference does not outlive borrowed content
-infer_reborrow_upvar = ...so that closure can access `{$name}`
 infer_ref_longer_than_data = in type `{$ty}`, reference has a longer lifetime than the data it references
 
 infer_reference_outlives_referent = ...so that the reference type `{$name}` does not outlive the data it points at

compiler/rustc_infer/src/infer/outlives/test_type_match.rs

@@ -44,7 +44,7 @@ pub fn extract_verify_if_eq<'tcx>(
     test_ty: Ty<'tcx>,
 ) -> Option<ty::Region<'tcx>> {
     assert!(!verify_if_eq_b.has_escaping_bound_vars());
-    let mut m = Match::new(tcx, param_env);
+    let mut m = MatchAgainstHigherRankedOutlives::new(tcx, param_env);
     let verify_if_eq = verify_if_eq_b.skip_binder();
     m.relate(verify_if_eq.ty, test_ty).ok()?;
 
@@ -87,24 +87,32 @@ pub(super) fn can_match_erased_ty<'tcx>(
         // pointless micro-optimization
         true
     } else {
-        Match::new(tcx, param_env).relate(outlives_ty, erased_ty).is_ok()
+        MatchAgainstHigherRankedOutlives::new(tcx, param_env).relate(outlives_ty, erased_ty).is_ok()
     }
 }
 
-struct Match<'tcx> {
+struct MatchAgainstHigherRankedOutlives<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     pattern_depth: ty::DebruijnIndex,
     map: FxHashMap<ty::BoundRegion, ty::Region<'tcx>>,
 }
 
-impl<'tcx> Match<'tcx> {
+impl<'tcx> MatchAgainstHigherRankedOutlives<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Match<'tcx> {
+    fn new(
-        Match { tcx, param_env, pattern_depth: ty::INNERMOST, map: FxHashMap::default() }
+        tcx: TyCtxt<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+    ) -> MatchAgainstHigherRankedOutlives<'tcx> {
+        MatchAgainstHigherRankedOutlives {
+            tcx,
+            param_env,
+            pattern_depth: ty::INNERMOST,
+            map: FxHashMap::default(),
+        }
     }
 }
 
-impl<'tcx> Match<'tcx> {
+impl<'tcx> MatchAgainstHigherRankedOutlives<'tcx> {
     /// Creates the "Error" variant that signals "no match".
     fn no_match<T>(&self) -> RelateResult<'tcx, T> {
         Err(TypeError::Mismatch)
@@ -134,7 +142,7 @@ impl<'tcx> Match<'tcx> {
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for Match<'tcx> {
+impl<'tcx> TypeRelation<'tcx> for MatchAgainstHigherRankedOutlives<'tcx> {
     fn tag(&self) -> &'static str {
         "Match"
     }

compiler/rustc_llvm/Cargo.toml

@@ -3,10 +3,6 @@ name = "rustc_llvm"
 version = "0.0.0"
 edition = "2021"
 
-[features]
-static-libstdcpp = []
-emscripten = []
-
 [dependencies]
 libc = "0.2.73"
 

compiler/rustc_middle/src/ty/_match.rs

@@ -18,20 +18,20 @@ use crate::ty::{self, InferConst, Ty, TyCtxt};
 /// Like subtyping, matching is really a binary relation, so the only
 /// important thing about the result is Ok/Err. Also, matching never
 /// affects any type variables or unification state.
-pub struct Match<'tcx> {
+pub struct MatchAgainstFreshVars<'tcx> {
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
 }
 
-impl<'tcx> Match<'tcx> {
+impl<'tcx> MatchAgainstFreshVars<'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Match<'tcx> {
+    pub fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> MatchAgainstFreshVars<'tcx> {
-        Match { tcx, param_env }
+        MatchAgainstFreshVars { tcx, param_env }
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for Match<'tcx> {
+impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
     fn tag(&self) -> &'static str {
-        "Match"
+        "MatchAgainstFreshVars"
     }
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx

compiler/rustc_monomorphize/messages.ftl

@@ -7,8 +7,6 @@ monomorphize_couldnt_dump_mono_stats =
 monomorphize_encountered_error_while_instantiating =
     the above error was encountered while instantiating `{$formatted_item}`
 
-monomorphize_fatal_error = {$error_message}
-
 monomorphize_large_assignments =
     moving {$size} bytes
     .label = value moved from here

compiler/rustc_parse/messages.ftl

@@ -59,7 +59,6 @@ parse_bare_cr = {$double_quotes ->
 
 parse_bare_cr_in_raw_string = bare CR not allowed in raw string
 
-parse_binary_float_literal_not_supported = binary float literal is not supported
 parse_bounds_not_allowed_on_trait_aliases = bounds are not allowed on trait aliases
 
 parse_box_not_pat = expected pattern, found {$descr}
@@ -284,7 +283,6 @@ parse_generics_in_path = unexpected generic arguments in path
 
 parse_help_set_edition_cargo = set `edition = "{$edition}"` in `Cargo.toml`
 parse_help_set_edition_standalone = pass `--edition {$edition}` to `rustc`
-parse_hexadecimal_float_literal_not_supported = hexadecimal float literal is not supported
 parse_if_expression_missing_condition = missing condition for `if` expression
     .condition_label = expected condition here
     .block_label = if this block is the condition of the `if` expression, then it must be followed by another block
@@ -356,8 +354,6 @@ parse_inner_doc_comment_not_permitted = expected outer doc comment
     .label_does_not_annotate_this = the inner doc comment doesn't annotate this {$item}
     .sugg_change_inner_to_outer = to annotate the {$item}, change the doc comment from inner to outer style
 
-parse_int_literal_too_large = integer literal is too large
-
 parse_invalid_block_macro_segment = cannot use a `block` macro fragment here
     .label = the `block` fragment is within this context
     .suggestion = wrap this in another block
@@ -382,18 +378,8 @@ parse_invalid_dyn_keyword = invalid `dyn` keyword
     .suggestion = remove this keyword
 
 parse_invalid_expression_in_let_else = a `{$operator}` expression cannot be directly assigned in `let...else`
-parse_invalid_float_literal_suffix = invalid suffix `{$suffix}` for float literal
-    .label = invalid suffix `{$suffix}`
-    .help = valid suffixes are `f32` and `f64`
-
-parse_invalid_float_literal_width = invalid width `{$width}` for float literal
-    .help = valid widths are 32 and 64
-
 parse_invalid_identifier_with_leading_number = identifiers cannot start with a number
 
-parse_invalid_int_literal_width = invalid width `{$width}` for integer literal
-    .help = valid widths are 8, 16, 32, 64 and 128
-
 parse_invalid_interpolated_expression = invalid interpolated expression
 
 parse_invalid_literal_suffix = suffixes on {$kind} literals are invalid
@@ -412,14 +398,6 @@ parse_invalid_logical_operator = `{$incorrect}` is not a logical operator
 
 parse_invalid_meta_item = expected unsuffixed literal or identifier, found `{$token}`
 
-parse_invalid_num_literal_base_prefix = invalid base prefix for number literal
-    .note = base prefixes (`0xff`, `0b1010`, `0o755`) are lowercase
-    .suggestion = try making the prefix lowercase
-
-parse_invalid_num_literal_suffix = invalid suffix `{$suffix}` for number literal
-    .label = invalid suffix `{$suffix}`
-    .help = the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
-
 parse_invalid_unicode_escape = invalid unicode character escape
     .label = invalid escape
     .help = unicode escape must {$surrogate ->
@@ -603,13 +581,6 @@ parse_no_brace_unicode_escape = incorrect unicode escape sequence
 
 parse_no_digits_literal = no valid digits found for number
 
-parse_non_item_in_item_list = non-item in item list
-    .suggestion_use_const_not_let = consider using `const` instead of `let` for associated const
-    .label_list_start = item list starts here
-    .label_non_item = non-item starts here
-    .label_list_end = item list ends here
-    .suggestion_remove_semicolon = consider removing this semicolon
-
 parse_non_string_abi_literal = non-string ABI literal
     .suggestion = specify the ABI with a string literal
 
@@ -626,7 +597,6 @@ parse_note_mut_pattern_usage = `mut` may be followed by `variable` and `variable
 
 parse_note_pattern_alternatives_use_single_vert = alternatives in or-patterns are separated with `|`, not `||`
 
-parse_octal_float_literal_not_supported = octal float literal is not supported
 parse_or_pattern_not_allowed_in_fn_parameters = top-level or-patterns are not allowed in function parameters
 parse_or_pattern_not_allowed_in_let_binding = top-level or-patterns are not allowed in `let` bindings
 parse_out_of_range_hex_escape = out of range hex escape

compiler/rustc_query_system/messages.ftl

@@ -15,8 +15,6 @@ query_system_cycle_stack_single = ...which immediately requires {$stack_bottom}
 
 query_system_cycle_usage = cycle used when {$usage}
 
-query_system_cycle_which_requires = ...which requires {$desc}...
-
 query_system_increment_compilation = internal compiler error: encountered incremental compilation error with {$dep_node}
     .help = This is a known issue with the compiler. Run {$run_cmd} to allow your project to compile
 

compiler/rustc_resolve/messages.ftl

@@ -130,9 +130,6 @@ resolve_generic_params_from_outer_item_ty_param = type parameter from outer item
 resolve_glob_import_doesnt_reexport =
     glob import doesn't reexport anything because no candidate is public enough
 
-resolve_help_try_using_local_generic_param =
-    try using a local generic parameter instead
-
 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
@@ -249,9 +246,6 @@ resolve_self_in_generic_param_default =
     generic parameters cannot use `Self` in their defaults
     .label = `Self` in generic parameter default
 
-resolve_self_type_implicitly_declared_by_impl =
-    `Self` type implicitly declared here, by this `impl`
-
 resolve_tool_module_imported =
     cannot use a tool module through an import
     .note = the tool module imported here
@@ -267,12 +261,6 @@ resolve_trait_impl_mismatch =
     .label = does not match trait
     .label_trait_item = item in trait
 
-resolve_try_adding_local_generic_param_on_method =
-    try adding a local generic parameter in this method instead
-
-resolve_try_using_local_generic_parameter =
-    try using a local generic parameter instead
-
 resolve_try_using_similarly_named_label =
     try using similarly named label
 

compiler/rustc_session/messages.ftl

@@ -25,8 +25,6 @@ session_feature_diagnostic_for_issue =
 session_feature_diagnostic_help =
     add `#![feature({$feature})]` to the crate attributes to enable
 
-session_feature_gate_error = {$explain}
-
 session_file_is_not_writeable = output file {$file} is not writeable -- check its permissions
 
 session_file_write_fail = failed to write `{$path}` due to error `{$err}`

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

@@ -39,6 +39,7 @@ use rustc_middle::dep_graph::dep_kinds;
 use rustc_middle::dep_graph::DepNodeIndex;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::traits::DefiningAnchor;
+use rustc_middle::ty::_match::MatchAgainstFreshVars;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::relate::TypeRelation;
@@ -2642,7 +2643,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
         current: ty::PolyTraitPredicate<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> bool {
-        let mut matcher = ty::_match::Match::new(self.tcx(), param_env);
+        let mut matcher = MatchAgainstFreshVars::new(self.tcx(), param_env);
         matcher.relate(previous, current).is_ok()
     }
 

tests/ui/rfcs/rfc-2632-const-trait-impl/effects/const-bound-on-not-const-associated-fn.rs

@@ -0,0 +1,28 @@
+#![feature(const_trait_impl, effects)]
+
+#[const_trait]
+trait MyTrait {
+    fn do_something(&self);
+}
+
+trait OtherTrait {
+    fn do_something_else() where Self: ~const MyTrait;
+    //~^ ERROR `~const` is not allowed here
+}
+
+struct MyStruct<T>(T);
+
+impl const MyTrait for u32 {
+    fn do_something(&self) {}
+}
+
+impl<T> MyStruct<T> {
+    pub fn foo(&self) where T: ~const MyTrait {
+        //~^ ERROR `~const` is not allowed here
+        self.0.do_something();
+    }
+}
+
+fn main() {
+    MyStruct(0u32).foo();
+}

tests/ui/rfcs/rfc-2632-const-trait-impl/effects/const-bound-on-not-const-associated-fn.stderr

@@ -0,0 +1,26 @@
+error: `~const` is not allowed here
+  --> $DIR/const-bound-on-not-const-associated-fn.rs:9:40
+   |
+LL |     fn do_something_else() where Self: ~const MyTrait;
+   |                                        ^^^^^^^^^^^^^^
+   |
+note: this function is not `const`, so it cannot have `~const` trait bounds
+  --> $DIR/const-bound-on-not-const-associated-fn.rs:9:8
+   |
+LL |     fn do_something_else() where Self: ~const MyTrait;
+   |        ^^^^^^^^^^^^^^^^^
+
+error: `~const` is not allowed here
+  --> $DIR/const-bound-on-not-const-associated-fn.rs:20:32
+   |
+LL |     pub fn foo(&self) where T: ~const MyTrait {
+   |                                ^^^^^^^^^^^^^^
+   |
+note: this function is not `const`, so it cannot have `~const` trait bounds
+  --> $DIR/const-bound-on-not-const-associated-fn.rs:20:12
+   |
+LL |     pub fn foo(&self) where T: ~const MyTrait {
+   |            ^^^
+
+error: aborting due to 2 previous errors
+

tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-and-const-params.rs

@@ -7,7 +7,8 @@ struct Foo<const N: usize>;
 
 impl<const N: usize> Foo<N> {
     fn add<A: ~const Add42>(self) -> Foo<{ A::add(N) }> {
-        //~^ ERROR mismatched types
+        //~^ ERROR `~const` is not allowed here
+        //~| ERROR mismatched types
         Foo
     }
 }
@@ -30,7 +31,7 @@ fn bar<A: ~const Add42, const N: usize>(_: Foo<N>) -> Foo<{ A::add(N) }> {
 }
 
 fn main() {
-   let foo = Foo::<0>;
+    let foo = Foo::<0>;
-   let foo = bar::<(), _>(foo);
+    let foo = bar::<(), _>(foo);
-   let _foo = bar::<(), _>(foo);
+    let _foo = bar::<(), _>(foo);
 }

tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-and-const-params.stderr

@@ -1,17 +1,29 @@
 error: `~const` is not allowed here
-  --> $DIR/tilde-const-and-const-params.rs:26:11
+  --> $DIR/tilde-const-and-const-params.rs:9:15
+   |
+LL |     fn add<A: ~const Add42>(self) -> Foo<{ A::add(N) }> {
+   |               ^^^^^^^^^^^^
+   |
+note: this function is not `const`, so it cannot have `~const` trait bounds
+  --> $DIR/tilde-const-and-const-params.rs:9:8
+   |
+LL |     fn add<A: ~const Add42>(self) -> Foo<{ A::add(N) }> {
+   |        ^^^
+
+error: `~const` is not allowed here
+  --> $DIR/tilde-const-and-const-params.rs:27:11
    |
 LL | fn bar<A: ~const Add42, const N: usize>(_: Foo<N>) -> Foo<{ A::add(N) }> {
    |           ^^^^^^^^^^^^
    |
 note: this function is not `const`, so it cannot have `~const` trait bounds
-  --> $DIR/tilde-const-and-const-params.rs:26:4
+  --> $DIR/tilde-const-and-const-params.rs:27:4
    |
 LL | fn bar<A: ~const Add42, const N: usize>(_: Foo<N>) -> Foo<{ A::add(N) }> {
    |    ^^^
 
 error[E0308]: mismatched types
-  --> $DIR/tilde-const-and-const-params.rs:26:61
+  --> $DIR/tilde-const-and-const-params.rs:27:61
    |
 LL | fn bar<A: ~const Add42, const N: usize>(_: Foo<N>) -> Foo<{ A::add(N) }> {
    |                                                             ^^^^^^^^^ expected `false`, found `true`
@@ -28,6 +40,6 @@ LL |     fn add<A: ~const Add42>(self) -> Foo<{ A::add(N) }> {
    = note: expected constant `false`
               found constant `true`
 
-error: aborting due to 3 previous errors
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0308`.

tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause.rs

@@ -6,7 +6,9 @@ trait Bar {}
 trait Foo {
     fn a();
     fn b() where Self: ~const Bar;
+    //~^ ERROR `~const` is not allowed here
     fn c<T: ~const Bar>();
+    //~^ ERROR `~const` is not allowed here
 }
 
 fn test1<T: Foo>() {

tests/ui/rfcs/rfc-2632-const-trait-impl/trait-where-clause.stderr

@@ -1,5 +1,29 @@
+error: `~const` is not allowed here
+  --> $DIR/trait-where-clause.rs:8:24
+   |
+LL |     fn b() where Self: ~const Bar;
+   |                        ^^^^^^^^^^
+   |
+note: this function is not `const`, so it cannot have `~const` trait bounds
+  --> $DIR/trait-where-clause.rs:8:8
+   |
+LL |     fn b() where Self: ~const Bar;
+   |        ^
+
+error: `~const` is not allowed here
+  --> $DIR/trait-where-clause.rs:10:13
+   |
+LL |     fn c<T: ~const Bar>();
+   |             ^^^^^^^^^^
+   |
+note: this function is not `const`, so it cannot have `~const` trait bounds
+  --> $DIR/trait-where-clause.rs:10:8
+   |
+LL |     fn c<T: ~const Bar>();
+   |        ^
+
 error[E0277]: the trait bound `T: Bar` is not satisfied
-  --> $DIR/trait-where-clause.rs:14:5
+  --> $DIR/trait-where-clause.rs:16:5
    |
 LL |     T::b();
    |     ^ the trait `Bar` is not implemented for `T`
@@ -15,13 +39,13 @@ LL | fn test1<T: Foo + Bar>() {
    |                 +++++
 
 error[E0277]: the trait bound `T: Bar` is not satisfied
-  --> $DIR/trait-where-clause.rs:16:12
+  --> $DIR/trait-where-clause.rs:18:12
    |
 LL |     T::c::<T>();
    |            ^ the trait `Bar` is not implemented for `T`
    |
 note: required by a bound in `Foo::c`
-  --> $DIR/trait-where-clause.rs:9:13
+  --> $DIR/trait-where-clause.rs:10:13
    |
 LL |     fn c<T: ~const Bar>();
    |             ^^^^^^^^^^ required by this bound in `Foo::c`
@@ -30,6 +54,6 @@ help: consider further restricting this bound
 LL | fn test1<T: Foo + Bar>() {
    |                 +++++
 
-error: aborting due to 2 previous errors
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0277`.