diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index c9786328565ba..63ef821279397 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -470,7 +470,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
ty: &Ty,
span: Span,
body: Option<&Expr>,
- impl_trait_position: ImplTraitPosition,
+ impl_trait_position: ImplTraitPosition<'_>,
) -> (&'hir hir::Ty<'hir>, hir::BodyId) {
let ty = self.lower_ty(ty, ImplTraitContext::Disallowed(impl_trait_position));
(ty, self.lower_const_body(span, body))
@@ -1418,7 +1418,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
generics: &Generics,
constness: Const,
parent_node_id: NodeId,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
f: impl FnOnce(&mut Self) -> T,
) -> (&'hir hir::Generics<'hir>, T) {
debug_assert!(self.impl_trait_defs.is_empty());
@@ -1624,7 +1624,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
bounds: &[GenericBound],
colon_span: Option<Span>,
parent_span: Span,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
origin: PredicateOrigin,
) -> Option<hir::WherePredicate<'hir>> {
// Do not create a clause if we do not have anything inside it.
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 833b0e9b5679e..9e5f669630891 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -255,7 +255,7 @@ impl ResolverAstLowering {
/// Context of `impl Trait` in code, which determines whether it is allowed in an HIR subtree,
/// and if so, what meaning it has.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-enum ImplTraitContext {
+enum ImplTraitContext<'a> {
/// Treat `impl Trait` as shorthand for a new universal generic parameter.
/// Example: `fn foo(x: impl Debug)`, where `impl Debug` is conceptually
/// equivalent to a fresh universal parameter like `fn foo<T: Debug>(x: T)`.
@@ -274,14 +274,14 @@ enum ImplTraitContext {
fn_kind: Option<FnDeclKind>,
},
/// `impl Trait` is unstably accepted in this position.
- FeatureGated(ImplTraitPosition, Symbol),
+ FeatureGated(ImplTraitPosition<'a>, Symbol),
/// `impl Trait` is not accepted in this position.
- Disallowed(ImplTraitPosition),
+ Disallowed(ImplTraitPosition<'a>),
}
/// Position in which `impl Trait` is disallowed.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-enum ImplTraitPosition {
+enum ImplTraitPosition<'a> {
Path,
Variable,
Trait,
@@ -303,9 +303,10 @@ enum ImplTraitPosition {
Cast,
ImplSelf,
OffsetOf,
+ ImplTrait { outer: &'a ImplTraitContext<'a> },
}
-impl std::fmt::Display for ImplTraitPosition {
+impl std::fmt::Display for ImplTraitPosition<'_> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let name = match self {
ImplTraitPosition::Path => "paths",
@@ -329,6 +330,7 @@ impl std::fmt::Display for ImplTraitPosition {
ImplTraitPosition::Cast => "cast expression types",
ImplTraitPosition::ImplSelf => "impl headers",
ImplTraitPosition::OffsetOf => "`offset_of!` parameters",
+ ImplTraitPosition::ImplTrait { .. } => "`impl Trait`",
};
write!(f, "{name}")
@@ -979,7 +981,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_assoc_ty_constraint(
&mut self,
constraint: &AssocConstraint,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::TypeBinding<'hir> {
debug!("lower_assoc_ty_constraint(constraint={:?}, itctx={:?})", constraint, itctx);
// lower generic arguments of identifier in constraint
@@ -1129,7 +1131,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_generic_arg(
&mut self,
arg: &ast::GenericArg,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::GenericArg<'hir> {
match arg {
ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(lt)),
@@ -1208,7 +1210,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
}
#[instrument(level = "debug", skip(self))]
- fn lower_ty(&mut self, t: &Ty, itctx: ImplTraitContext) -> &'hir hir::Ty<'hir> {
+ fn lower_ty(&mut self, t: &Ty, itctx: ImplTraitContext<'_>) -> &'hir hir::Ty<'hir> {
self.arena.alloc(self.lower_ty_direct(t, itctx))
}
@@ -1218,7 +1220,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
qself: &Option<ptr::P<QSelf>>,
path: &Path,
param_mode: ParamMode,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::Ty<'hir> {
// Check whether we should interpret this as a bare trait object.
// This check mirrors the one in late resolution. We only introduce this special case in
@@ -1260,7 +1262,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
self.ty(span, hir::TyKind::Tup(tys))
}
- fn lower_ty_direct(&mut self, t: &Ty, itctx: ImplTraitContext) -> hir::Ty<'hir> {
+ fn lower_ty_direct(&mut self, t: &Ty, itctx: ImplTraitContext<'_>) -> hir::Ty<'hir> {
let kind = match &t.kind {
TyKind::Infer => hir::TyKind::Infer,
TyKind::Err(guar) => hir::TyKind::Err(*guar),
@@ -1407,7 +1409,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
*def_node_id,
bounds,
fn_kind,
- itctx,
+ ImplTraitContext::Disallowed(ImplTraitPosition::ImplTrait {
+ outer: &itctx,
+ }),
),
ImplTraitContext::Universal => {
let span = t.span;
@@ -1516,7 +1520,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
opaque_ty_node_id: NodeId,
bounds: &GenericBounds,
fn_kind: Option<FnDeclKind>,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::TyKind<'hir> {
// Make sure we know that some funky desugaring has been going on here.
// This is a first: there is code in other places like for loop
@@ -1924,7 +1928,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
output: &FnRetTy,
coro: CoroutineKind,
opaque_ty_span: Span,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::GenericBound<'hir> {
// Compute the `T` in `Future<Output = T>` from the return type.
let output_ty = match output {
@@ -1972,7 +1976,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_param_bound(
&mut self,
tpb: &GenericBound,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::GenericBound<'hir> {
match tpb {
GenericBound::Trait(p, modifiers) => hir::GenericBound::Trait(
@@ -2151,7 +2155,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
&mut self,
modifiers: ast::TraitBoundModifiers,
p: &TraitRef,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::TraitRef<'hir> {
let path = match self.lower_qpath(
p.ref_id,
@@ -2171,7 +2175,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_poly_trait_ref(
&mut self,
p: &PolyTraitRef,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
modifiers: ast::TraitBoundModifiers,
) -> hir::PolyTraitRef<'hir> {
let bound_generic_params =
@@ -2180,7 +2184,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
hir::PolyTraitRef { bound_generic_params, trait_ref, span: self.lower_span(p.span) }
}
- fn lower_mt(&mut self, mt: &MutTy, itctx: ImplTraitContext) -> hir::MutTy<'hir> {
+ fn lower_mt(&mut self, mt: &MutTy, itctx: ImplTraitContext<'_>) -> hir::MutTy<'hir> {
hir::MutTy { ty: self.lower_ty(&mt.ty, itctx), mutbl: mt.mutbl }
}
@@ -2188,16 +2192,17 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_param_bounds(
&mut self,
bounds: &[GenericBound],
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> hir::GenericBounds<'hir> {
self.arena.alloc_from_iter(self.lower_param_bounds_mut(bounds, itctx))
}
- fn lower_param_bounds_mut<'s>(
+ fn lower_param_bounds_mut<'s, 'c>(
&'s mut self,
bounds: &'s [GenericBound],
- itctx: ImplTraitContext,
- ) -> impl Iterator<Item = hir::GenericBound<'hir>> + Captures<'s> + Captures<'a> {
+ itctx: ImplTraitContext<'c>,
+ ) -> impl Iterator<Item = hir::GenericBound<'hir>> + Captures<'s> + Captures<'c> + Captures<'a>
+ {
bounds.iter().map(move |bound| self.lower_param_bound(bound, itctx))
}
@@ -2232,7 +2237,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
bounds,
/* colon_span */ None,
span,
- ImplTraitContext::Universal,
+ ImplTraitContext::Disallowed(ImplTraitPosition::ImplTrait {
+ outer: &ImplTraitContext::Universal,
+ }),
hir::PredicateOrigin::ImplTrait,
);
diff --git a/compiler/rustc_ast_lowering/src/path.rs b/compiler/rustc_ast_lowering/src/path.rs
index aeeb4bf9e763a..d22e88be1e4e2 100644
--- a/compiler/rustc_ast_lowering/src/path.rs
+++ b/compiler/rustc_ast_lowering/src/path.rs
@@ -27,12 +27,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
qself: &Option<ptr::P<QSelf>>,
p: &Path,
param_mode: ParamMode,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
// modifiers of the impl/bound if this is a trait path
modifiers: Option<ast::TraitBoundModifiers>,
) -> hir::QPath<'hir> {
let qself_position = qself.as_ref().map(|q| q.position);
- let qself = qself.as_ref().map(|q| self.lower_ty(&q.ty, itctx));
+ let qself = qself
+ .as_ref()
+ .map(|q| self.lower_ty(&q.ty, ImplTraitContext::Disallowed(ImplTraitPosition::Path)));
let partial_res =
self.resolver.get_partial_res(id).unwrap_or_else(|| PartialRes::new(Res::Err));
@@ -71,14 +73,17 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
res,
segments: self.arena.alloc_from_iter(p.segments[..proj_start].iter().enumerate().map(
|(i, segment)| {
- let param_mode = match (qself_position, param_mode) {
+ let (param_mode, itctx) = match (qself_position, param_mode) {
(Some(j), ParamMode::Optional) if i < j => {
- // This segment is part of the trait path in a
- // qualified path - one of `a`, `b` or `Trait`
- // in `<X as a::b::Trait>::T::U::method`.
- ParamMode::Explicit
+ // This segment is part of the trait path in a qualified path:
+ // One of `a`, `b` or `Trait` in `<X as a::b::Trait>::T::U::method`.
+ // `impl Trait` is unconditionally disallowed here.
+ (
+ ParamMode::Explicit,
+ ImplTraitContext::Disallowed(ImplTraitPosition::Path),
+ )
}
- _ => param_mode,
+ _ => (param_mode, itctx),
};
let parenthesized_generic_args = match base_res {
@@ -162,6 +167,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
segment,
param_mode,
ParenthesizedGenericArgs::Err,
+ // Whether `impl Trait` is allowed here depends on the context contrary to
+ // the self type and trait segment paths in qualified paths (see above).
itctx,
None,
None,
@@ -220,7 +227,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
segment: &PathSegment,
param_mode: ParamMode,
parenthesized_generic_args: ParenthesizedGenericArgs,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
constness: Option<ast::BoundConstness>,
// Additional features ungated with a bound modifier like `async`.
// This is passed down to the implicit associated type binding in
@@ -374,7 +381,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
&mut self,
data: &AngleBracketedArgs,
param_mode: ParamMode,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
) -> (GenericArgsCtor<'hir>, bool) {
let has_non_lt_args = data.args.iter().any(|arg| match arg {
AngleBracketedArg::Arg(ast::GenericArg::Lifetime(_))
@@ -389,10 +396,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
AngleBracketedArg::Constraint(_) => None,
})
.collect();
- let bindings = self.arena.alloc_from_iter(data.args.iter().filter_map(|arg| match arg {
- AngleBracketedArg::Constraint(c) => Some(self.lower_assoc_ty_constraint(c, itctx)),
- AngleBracketedArg::Arg(_) => None,
- }));
+ let bindings = {
+ // FIXME(fmease): explainer
+ let itctx = match itctx {
+ ImplTraitContext::Disallowed(ImplTraitPosition::ImplTrait { outer }) => *outer,
+ itctx => itctx,
+ };
+
+ self.arena.alloc_from_iter(data.args.iter().filter_map(|arg| match arg {
+ AngleBracketedArg::Constraint(c) => Some(self.lower_assoc_ty_constraint(c, itctx)),
+ AngleBracketedArg::Arg(_) => None,
+ }))
+ };
let ctor = GenericArgsCtor {
args,
bindings,
@@ -405,7 +420,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
fn lower_parenthesized_parameter_data(
&mut self,
data: &ParenthesizedArgs,
- itctx: ImplTraitContext,
+ itctx: ImplTraitContext<'_>,
bound_modifier_allowed_features: Option<Lrc<[Symbol]>>,
) -> (GenericArgsCtor<'hir>, bool) {
// Switch to `PassThrough` mode for anonymous lifetimes; this
diff --git a/compiler/rustc_ast_passes/messages.ftl b/compiler/rustc_ast_passes/messages.ftl
index 28a13d275a559..a6a0d80e45895 100644
--- a/compiler/rustc_ast_passes/messages.ftl
+++ b/compiler/rustc_ast_passes/messages.ftl
@@ -149,8 +149,6 @@ ast_passes_generic_before_constraints = generic arguments must come before the f
ast_passes_generic_default_trailing = generic parameters with a default must be trailing
-ast_passes_impl_trait_path = `impl Trait` is not allowed in path parameters
-
ast_passes_incompatible_features = `{$f1}` and `{$f2}` are incompatible, using them at the same time is not allowed
.help = remove one of these features
@@ -191,10 +189,6 @@ ast_passes_negative_bound_not_supported =
ast_passes_negative_bound_with_parenthetical_notation =
parenthetical notation may not be used for negative bounds
-ast_passes_nested_impl_trait = nested `impl Trait` is not allowed
- .outer = outer `impl Trait`
- .inner = nested `impl Trait` here
-
ast_passes_nested_lifetimes = nested quantification of lifetimes
ast_passes_nomangle_ascii = `#[no_mangle]` requires ASCII identifier
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index 80c62d3fecf49..7c91b664c9c92 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -76,17 +76,8 @@ struct AstValidator<'a> {
has_proc_macro_decls: bool,
- /// Used to ban nested `impl Trait`, e.g., `impl Into<impl Debug>`.
- /// Nested `impl Trait` _is_ allowed in associated type position,
- /// e.g., `impl Iterator<Item = impl Debug>`.
- outer_impl_trait: Option<Span>,
-
disallow_tilde_const: Option<DisallowTildeConstContext<'a>>,
- /// Used to ban `impl Trait` in path projections like `<impl Iterator>::Item`
- /// or `Foo::Bar<impl Trait>`
- is_impl_trait_banned: bool,
-
lint_buffer: &'a mut LintBuffer,
}
@@ -117,12 +108,6 @@ impl<'a> AstValidator<'a> {
self.outer_trait_or_trait_impl = old;
}
- fn with_banned_impl_trait(&mut self, f: impl FnOnce(&mut Self)) {
- let old = mem::replace(&mut self.is_impl_trait_banned, true);
- f(self);
- self.is_impl_trait_banned = old;
- }
-
fn with_tilde_const(
&mut self,
disallowed: Option<DisallowTildeConstContext<'a>>,
@@ -175,53 +160,13 @@ impl<'a> AstValidator<'a> {
Err(errors::WhereClauseBeforeTypeAlias { span, sugg })
}
- fn with_impl_trait(&mut self, outer: Option<Span>, f: impl FnOnce(&mut Self)) {
- let old = mem::replace(&mut self.outer_impl_trait, outer);
- f(self);
- self.outer_impl_trait = old;
- }
-
// Mirrors `visit::walk_ty`, but tracks relevant state.
fn walk_ty(&mut self, t: &'a Ty) {
match &t.kind {
- TyKind::ImplTrait(..) => {
- self.with_impl_trait(Some(t.span), |this| visit::walk_ty(this, t))
- }
TyKind::TraitObject(..) => self
.with_tilde_const(Some(DisallowTildeConstContext::TraitObject), |this| {
visit::walk_ty(this, t)
}),
- TyKind::Path(qself, path) => {
- // We allow these:
- // - `Option<impl Trait>`
- // - `option::Option<impl Trait>`
- // - `option::Option<T>::Foo<impl Trait>`
- //
- // But not these:
- // - `<impl Trait>::Foo`
- // - `option::Option<impl Trait>::Foo`.
- //
- // To implement this, we disallow `impl Trait` from `qself`
- // (for cases like `<impl Trait>::Foo>`)
- // but we allow `impl Trait` in `GenericArgs`
- // iff there are no more PathSegments.
- if let Some(qself) = qself {
- // `impl Trait` in `qself` is always illegal
- self.with_banned_impl_trait(|this| this.visit_ty(&qself.ty));
- }
-
- // Note that there should be a call to visit_path here,
- // so if any logic is added to process `Path`s a call to it should be
- // added both in visit_path and here. This code mirrors visit::walk_path.
- for (i, segment) in path.segments.iter().enumerate() {
- // Allow `impl Trait` iff we're on the final path segment
- if i == path.segments.len() - 1 {
- self.visit_path_segment(segment);
- } else {
- self.with_banned_impl_trait(|this| this.visit_path_segment(segment));
- }
- }
- }
TyKind::AnonStruct(_, ref fields) | TyKind::AnonUnion(_, ref fields) => {
walk_list!(self, visit_struct_field_def, fields)
}
@@ -715,18 +660,6 @@ impl<'a> AstValidator<'a> {
}
}
TyKind::ImplTrait(_, bounds) => {
- if self.is_impl_trait_banned {
- self.dcx().emit_err(errors::ImplTraitPath { span: ty.span });
- }
-
- if let Some(outer_impl_trait_sp) = self.outer_impl_trait {
- self.dcx().emit_err(errors::NestedImplTrait {
- span: ty.span,
- outer: outer_impl_trait_sp,
- inner: ty.span,
- });
- }
-
if !bounds.iter().any(|b| matches!(b, GenericBound::Trait(..))) {
self.dcx().emit_err(errors::AtLeastOneTrait { span: ty.span });
}
@@ -1178,25 +1111,21 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
GenericArgs::AngleBracketed(data) => {
self.check_generic_args_before_constraints(data);
+ // FIXME: use walk method if available
for arg in &data.args {
match arg {
AngleBracketedArg::Arg(arg) => self.visit_generic_arg(arg),
- // Type bindings such as `Item = impl Debug` in `Iterator<Item = Debug>`
- // are allowed to contain nested `impl Trait`.
AngleBracketedArg::Constraint(constraint) => {
- self.with_impl_trait(None, |this| {
- this.visit_assoc_constraint(constraint);
- });
+ self.visit_assoc_constraint(constraint);
}
}
}
}
+ // FIXME: use walk method if available
GenericArgs::Parenthesized(data) => {
walk_list!(self, visit_ty, &data.inputs);
if let FnRetTy::Ty(ty) = &data.output {
- // `-> Foo` syntax is essentially an associated type binding,
- // so it is also allowed to contain nested `impl Trait`.
- self.with_impl_trait(None, |this| this.visit_ty(ty));
+ self.visit_ty(ty);
}
}
}
@@ -1716,9 +1645,7 @@ pub fn check_crate(
extern_mod: None,
outer_trait_or_trait_impl: None,
has_proc_macro_decls: false,
- outer_impl_trait: None,
disallow_tilde_const: Some(DisallowTildeConstContext::Item),
- is_impl_trait_banned: false,
lint_buffer: lints,
};
visit::walk_crate(&mut validator, krate);
diff --git a/compiler/rustc_ast_passes/src/errors.rs b/compiler/rustc_ast_passes/src/errors.rs
index 9e8c1d7f5fd19..2cb5162853640 100644
--- a/compiler/rustc_ast_passes/src/errors.rs
+++ b/compiler/rustc_ast_passes/src/errors.rs
@@ -397,24 +397,6 @@ pub struct TraitObjectBound {
pub span: Span,
}
-#[derive(Diagnostic)]
-#[diag(ast_passes_impl_trait_path, code = E0667)]
-pub struct ImplTraitPath {
- #[primary_span]
- pub span: Span,
-}
-
-#[derive(Diagnostic)]
-#[diag(ast_passes_nested_impl_trait, code = E0666)]
-pub struct NestedImplTrait {
- #[primary_span]
- pub span: Span,
- #[label(ast_passes_outer)]
- pub outer: Span,
- #[label(ast_passes_inner)]
- pub inner: Span,
-}
-
#[derive(Diagnostic)]
#[diag(ast_passes_at_least_one_trait)]
pub struct AtLeastOneTrait {
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index 8886a78c6ecdc..08ddd2bb0502b 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -1212,7 +1212,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
err.emit()
} else if let Err(reported) = qself_ty.error_reported() {
reported
- } else if let ty::Alias(ty::Opaque, alias_ty) = qself_ty.kind() {
+ } else if let ty::Alias(ty::Opaque, alias_ty) = qself_ty.kind() { // FIXME: bug!
// `<impl Trait as OtherTrait>::Assoc` makes no sense.
struct_span_code_err!(
tcx.dcx(),
diff --git a/tests/rustdoc/rrustdoc/auxiliary/dep.rs b/tests/rustdoc/rrustdoc/auxiliary/dep.rs
new file mode 100644
index 0000000000000..ddd7ee5579374
--- /dev/null
+++ b/tests/rustdoc/rrustdoc/auxiliary/dep.rs
@@ -0,0 +1,2 @@
+pub struct X;
+
diff --git a/tests/rustdoc/rrustdoc/crazy.rs b/tests/rustdoc/rrustdoc/crazy.rs
new file mode 100644
index 0000000000000..4f6662026a14d
--- /dev/null
+++ b/tests/rustdoc/rrustdoc/crazy.rs
@@ -0,0 +1,9 @@
+//(@) aux-crate:dep=dep.rs
+//@ aux-crate:dep
+//(@) aux-build:../dep.rs
+
+extern crate dep;
+
+use dep::X;
+
+
diff --git a/tests/rustdoc/rrustdoc/dep.rs b/tests/rustdoc/rrustdoc/dep.rs
new file mode 100644
index 0000000000000..10ff0bd960d06
--- /dev/null
+++ b/tests/rustdoc/rrustdoc/dep.rs
@@ -0,0 +1 @@
+pub struct X;
diff --git a/tests/ui/impl-trait/impl_trait_projections.rs b/tests/ui/impl-trait/impl_trait_projections.rs
index 365ac85e2f665..2c277aee06dad 100644
--- a/tests/ui/impl-trait/impl_trait_projections.rs
+++ b/tests/ui/impl-trait/impl_trait_projections.rs
@@ -10,30 +10,27 @@ fn path_parametrized_type_is_allowed() -> option::Option<impl Debug> {
}
fn projection_is_disallowed(x: impl Iterator) -> <impl Iterator>::Item {
-//~^ ERROR `impl Trait` is not allowed in path parameters
-//~| ERROR `impl Trait` is not allowed in path parameters
+//~^ ERROR `impl Trait` is not allowed in paths
x.next().unwrap()
}
fn projection_with_named_trait_is_disallowed(mut x: impl Iterator)
-> <impl Iterator as Iterator>::Item
-//~^ ERROR `impl Trait` is not allowed in path parameters
+//~^ ERROR `impl Trait` is not allowed in paths
{
x.next().unwrap()
}
fn projection_with_named_trait_inside_path_is_disallowed()
-> <::std::ops::Range<impl Debug> as Iterator>::Item
-//~^ ERROR `impl Trait` is not allowed in path parameters
-//~| ERROR `impl Debug: Step` is not satisfied
+//~^ ERROR `impl Trait` is not allowed in paths
{
- //~^ ERROR `impl Debug: Step` is not satisfied
(1i32..100).next().unwrap()
}
fn projection_from_impl_trait_inside_dyn_trait_is_disallowed()
-> <dyn Iterator<Item = impl Debug> as Iterator>::Item
-//~^ ERROR `impl Trait` is not allowed in path parameters
+//~^ ERROR `impl Trait` is not allowed in paths
{
panic!()
}
diff --git a/tests/ui/impl-trait/impl_trait_projections.stderr b/tests/ui/impl-trait/impl_trait_projections.stderr
index d62e3ac4183f5..5e0b80fcd5922 100644
--- a/tests/ui/impl-trait/impl_trait_projections.stderr
+++ b/tests/ui/impl-trait/impl_trait_projections.stderr
@@ -1,73 +1,35 @@
-error[E0667]: `impl Trait` is not allowed in path parameters
+error[E0562]: `impl Trait` is not allowed in paths
--> $DIR/impl_trait_projections.rs:12:51
|
LL | fn projection_is_disallowed(x: impl Iterator) -> <impl Iterator>::Item {
| ^^^^^^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error[E0667]: `impl Trait` is not allowed in path parameters
- --> $DIR/impl_trait_projections.rs:19:9
+error[E0562]: `impl Trait` is not allowed in paths
+ --> $DIR/impl_trait_projections.rs:18:9
|
LL | -> <impl Iterator as Iterator>::Item
| ^^^^^^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error[E0667]: `impl Trait` is not allowed in path parameters
- --> $DIR/impl_trait_projections.rs:26:27
+error[E0562]: `impl Trait` is not allowed in paths
+ --> $DIR/impl_trait_projections.rs:25:27
|
LL | -> <::std::ops::Range<impl Debug> as Iterator>::Item
| ^^^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error[E0667]: `impl Trait` is not allowed in path parameters
- --> $DIR/impl_trait_projections.rs:35:29
+error[E0562]: `impl Trait` is not allowed in paths
+ --> $DIR/impl_trait_projections.rs:32:29
|
LL | -> <dyn Iterator<Item = impl Debug> as Iterator>::Item
| ^^^^^^^^^^
-
-error[E0667]: `impl Trait` is not allowed in path parameters
- --> $DIR/impl_trait_projections.rs:12:51
- |
-LL | fn projection_is_disallowed(x: impl Iterator) -> <impl Iterator>::Item {
- | ^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `impl Debug: Step` is not satisfied
- --> $DIR/impl_trait_projections.rs:26:8
- |
-LL | -> <::std::ops::Range<impl Debug> as Iterator>::Item
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Step` is not implemented for `impl Debug`, which is required by `std::ops::Range<impl Debug>: Iterator`
- |
- = help: the following other types implement trait `Step`:
- Char
- Ipv4Addr
- Ipv6Addr
- char
- i128
- i16
- i32
- i64
- and 8 others
- = note: required for `std::ops::Range<impl Debug>` to implement `Iterator`
-
-error[E0277]: the trait bound `impl Debug: Step` is not satisfied
- --> $DIR/impl_trait_projections.rs:29:1
- |
-LL | / {
-LL | |
-LL | | (1i32..100).next().unwrap()
-LL | | }
- | |_^ the trait `Step` is not implemented for `impl Debug`, which is required by `std::ops::Range<impl Debug>: Iterator`
|
- = help: the following other types implement trait `Step`:
- Char
- Ipv4Addr
- Ipv6Addr
- char
- i128
- i16
- i32
- i64
- and 8 others
- = note: required for `std::ops::Range<impl Debug>` to implement `Iterator`
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error: aborting due to 7 previous errors
+error: aborting due to 4 previous errors
-Some errors have detailed explanations: E0277, E0667.
-For more information about an error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0562`.
diff --git a/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.rs b/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.rs
index 0daec3305c0ae..dd8f7453aa127 100644
--- a/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.rs
+++ b/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.rs
@@ -12,6 +12,6 @@ pub trait Foo<T> { }
pub trait Bar { }
pub trait Quux { type Assoc; }
pub fn demo(_: impl Quux<Assoc=Deeper<impl Foo<impl Bar>>>) { }
-//~^ ERROR nested `impl Trait` is not allowed
+//~^ ERROR `impl Trait` is not allowed in `impl Trait`
fn main() { }
diff --git a/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.stderr b/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.stderr
index 83d0d77657247..8145d4ab5e3de 100644
--- a/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.stderr
+++ b/tests/ui/impl-trait/issues/issue-57979-deeply-nested-impl-trait-in-assoc-proj.stderr
@@ -1,12 +1,11 @@
-error[E0666]: nested `impl Trait` is not allowed
+error[E0562]: `impl Trait` is not allowed in `impl Trait`
--> $DIR/issue-57979-deeply-nested-impl-trait-in-assoc-proj.rs:14:48
|
LL | pub fn demo(_: impl Quux<Assoc=Deeper<impl Foo<impl Bar>>>) { }
- | ---------^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
+ | ^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
error: aborting due to 1 previous error
-For more information about this error, try `rustc --explain E0666`.
+For more information about this error, try `rustc --explain E0562`.
diff --git a/tests/ui/impl-trait/issues/issue-57979-impl-trait-in-path.rs b/tests/ui/impl-trait/issues/issue-57979-impl-trait-in-path.rs
index c5ecd1caae1f9..718830589af6a 100644
--- a/tests/ui/impl-trait/issues/issue-57979-impl-trait-in-path.rs
+++ b/tests/ui/impl-trait/issues/issue-57979-impl-trait-in-path.rs
@@ -3,10 +3,12 @@
// Here we test behavior of occurrences of `impl Trait` within a path
// component in that context.
+// FIXME(fmease): this is now check-pass :(
+
pub trait Bar { }
pub trait Quux<T> { type Assoc; }
pub fn demo(_: impl Quux<(), Assoc=<() as Quux<impl Bar>>::Assoc>) { }
-//~^ ERROR `impl Trait` is not allowed in path parameters
+//~^ ERROR `impl Trait` is not allowed in paths
impl<T> Quux<T> for () { type Assoc = u32; }
fn main() { }
diff --git a/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.rs b/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.rs
index 5a444d3dfddfa..0c1ef2088963d 100644
--- a/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.rs
+++ b/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.rs
@@ -7,6 +7,6 @@ pub trait Foo<T> { }
pub trait Bar { }
pub trait Quux { type Assoc; }
pub fn demo(_: impl Quux<Assoc=impl Foo<impl Bar>>) { }
-//~^ ERROR nested `impl Trait` is not allowed
+//~^ ERROR `impl Trait` is not allowed in `impl Trait`
fn main() { }
diff --git a/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.stderr b/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.stderr
index 0e105817b18af..f03bc62608341 100644
--- a/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.stderr
+++ b/tests/ui/impl-trait/issues/issue-57979-nested-impl-trait-in-assoc-proj.stderr
@@ -1,12 +1,11 @@
-error[E0666]: nested `impl Trait` is not allowed
+error[E0562]: `impl Trait` is not allowed in `impl Trait`
--> $DIR/issue-57979-nested-impl-trait-in-assoc-proj.rs:9:41
|
LL | pub fn demo(_: impl Quux<Assoc=impl Foo<impl Bar>>) { }
- | ---------^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
+ | ^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
error: aborting due to 1 previous error
-For more information about this error, try `rustc --explain E0666`.
+For more information about this error, try `rustc --explain E0562`.
diff --git a/tests/ui/impl-trait/nested_impl_trait.rs b/tests/ui/impl-trait/nested_impl_trait.rs
index 760102794c34e..610159d0b4773 100644
--- a/tests/ui/impl-trait/nested_impl_trait.rs
+++ b/tests/ui/impl-trait/nested_impl_trait.rs
@@ -4,20 +4,20 @@ use std::fmt::Debug;
fn fine(x: impl Into<u32>) -> impl Into<u32> { x }
fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x }
-//~^ ERROR nested `impl Trait` is not allowed
+//~^ ERROR `impl Trait` is not allowed in `impl Trait`
//~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
fn bad_in_fn_syntax(x: fn() -> impl Into<impl Debug>) {}
-//~^ ERROR nested `impl Trait` is not allowed
+//~^ ERROR `impl Trait` is not allowed in `impl Trait`
//~| `impl Trait` is not allowed in `fn` pointer
fn bad_in_arg_position(_: impl Into<impl Debug>) { }
-//~^ ERROR nested `impl Trait` is not allowed
+//~^ ERROR `impl Trait` is not allowed in `impl Trait`
struct X;
impl X {
fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x }
- //~^ ERROR nested `impl Trait` is not allowed
+ //~^ ERROR `impl Trait` is not allowed in `impl Trait`
//~| ERROR the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
}
diff --git a/tests/ui/impl-trait/nested_impl_trait.stderr b/tests/ui/impl-trait/nested_impl_trait.stderr
index 83d1347aff431..b2c66dd5f3981 100644
--- a/tests/ui/impl-trait/nested_impl_trait.stderr
+++ b/tests/ui/impl-trait/nested_impl_trait.stderr
@@ -1,38 +1,10 @@
-error[E0666]: nested `impl Trait` is not allowed
+error[E0562]: `impl Trait` is not allowed in `impl Trait`
--> $DIR/nested_impl_trait.rs:6:56
|
LL | fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x }
- | ----------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
-
-error[E0666]: nested `impl Trait` is not allowed
- --> $DIR/nested_impl_trait.rs:10:42
- |
-LL | fn bad_in_fn_syntax(x: fn() -> impl Into<impl Debug>) {}
- | ----------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
-
-error[E0666]: nested `impl Trait` is not allowed
- --> $DIR/nested_impl_trait.rs:14:37
+ | ^^^^^^^^^^
|
-LL | fn bad_in_arg_position(_: impl Into<impl Debug>) { }
- | ----------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
-
-error[E0666]: nested `impl Trait` is not allowed
- --> $DIR/nested_impl_trait.rs:19:44
- |
-LL | fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x }
- | ----------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
error[E0562]: `impl Trait` is not allowed in `fn` pointer return types
--> $DIR/nested_impl_trait.rs:10:32
@@ -42,25 +14,30 @@ LL | fn bad_in_fn_syntax(x: fn() -> impl Into<impl Debug>) {}
|
= note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error[E0277]: the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
- --> $DIR/nested_impl_trait.rs:6:46
+error[E0562]: `impl Trait` is not allowed in `impl Trait`
+ --> $DIR/nested_impl_trait.rs:14:37
|
-LL | fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x }
- | ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`, which is required by `impl Into<u32>: Into<impl Debug>`
+LL | fn bad_in_arg_position(_: impl Into<impl Debug>) { }
+ | ^^^^^^^^^^
|
- = help: the trait `Into<U>` is implemented for `T`
- = note: required for `impl Into<u32>` to implement `Into<impl Debug>`
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error[E0277]: the trait bound `impl Debug: From<impl Into<u32>>` is not satisfied
- --> $DIR/nested_impl_trait.rs:19:34
+error[E0562]: `impl Trait` is not allowed in `impl Trait`
+ --> $DIR/nested_impl_trait.rs:19:44
|
LL | fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x }
- | ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`, which is required by `impl Into<u32>: Into<impl Debug>`
+ | ^^^^^^^^^^
|
- = help: the trait `Into<U>` is implemented for `T`
- = note: required for `impl Into<u32>` to implement `Into<impl Debug>`
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
+
+error[E0562]: `impl Trait` is not allowed in the return type of `Fn` trait bounds
+ --> $DIR/nested_impl_trait.rs:28:42
+ |
+LL | fn allowed_in_ret_type() -> impl Fn() -> impl Into<u32> {
+ | ^^^^^^^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
-error: aborting due to 7 previous errors
+error: aborting due to 5 previous errors
-Some errors have detailed explanations: E0277, E0562, E0666.
-For more information about an error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0562`.
diff --git a/tests/ui/impl-trait/where-allowed.rs b/tests/ui/impl-trait/where-allowed.rs
index 72ce617693e40..60fa3e5f95183 100644
--- a/tests/ui/impl-trait/where-allowed.rs
+++ b/tests/ui/impl-trait/where-allowed.rs
@@ -49,7 +49,7 @@ fn in_dyn_Fn_return_in_return() -> &'static dyn Fn() -> impl Debug { panic!() }
// Disallowed
fn in_impl_Fn_parameter_in_parameters(_: &impl Fn(impl Debug)) { panic!() }
//~^ ERROR `impl Trait` is not allowed in the parameters of `Fn` trait bounds
-//~^^ ERROR nested `impl Trait` is not allowed
+//~| ERROR `impl Trait` is not allowed in `impl Trait`
// Disallowed
fn in_impl_Fn_return_in_parameters(_: &impl Fn() -> impl Debug) { panic!() }
@@ -58,7 +58,7 @@ fn in_impl_Fn_return_in_parameters(_: &impl Fn() -> impl Debug) { panic!() }
// Disallowed
fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic!() }
//~^ ERROR `impl Trait` is not allowed in the parameters of `Fn` trait bounds
-//~| ERROR nested `impl Trait` is not allowed
+//~| ERROR `impl Trait` is not allowed in `impl Trait`
// Allowed
fn in_impl_Fn_return_in_return() -> &'static impl Fn() -> impl Debug { panic!() }
diff --git a/tests/ui/impl-trait/where-allowed.stderr b/tests/ui/impl-trait/where-allowed.stderr
index bffe0447f8bb4..ec7898a1d11bf 100644
--- a/tests/ui/impl-trait/where-allowed.stderr
+++ b/tests/ui/impl-trait/where-allowed.stderr
@@ -1,21 +1,3 @@
-error[E0666]: nested `impl Trait` is not allowed
- --> $DIR/where-allowed.rs:50:51
- |
-LL | fn in_impl_Fn_parameter_in_parameters(_: &impl Fn(impl Debug)) { panic!() }
- | --------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
-
-error[E0666]: nested `impl Trait` is not allowed
- --> $DIR/where-allowed.rs:59:57
- |
-LL | fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic!() }
- | --------^^^^^^^^^^-
- | | |
- | | nested `impl Trait` here
- | outer `impl Trait`
-
error[E0658]: `impl Trait` in associated types is unstable
--> $DIR/where-allowed.rs:122:16
|
@@ -126,6 +108,14 @@ LL | fn in_impl_Fn_parameter_in_return() -> &'static impl Fn(impl Debug) { panic
|
= note: `impl Trait` is only allowed in arguments and return types of functions and methods
+error[E0562]: `impl Trait` is not allowed in the return type of `Fn` trait bounds
+ --> $DIR/where-allowed.rs:64:59
+ |
+LL | fn in_impl_Fn_return_in_return() -> &'static impl Fn() -> impl Debug { panic!() }
+ | ^^^^^^^^^^
+ |
+ = note: `impl Trait` is only allowed in arguments and return types of functions and methods
+
error[E0562]: `impl Trait` is not allowed in the parameters of `Fn` trait bounds
--> $DIR/where-allowed.rs:68:38
|
@@ -428,7 +418,7 @@ LL | fn in_method_generic_param_default<T = impl Debug>(_: T) {}
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #36887 <https://github.com/rust-lang/rust/issues/36887>
-error: aborting due to 50 previous errors
+error: aborting due to 49 previous errors
-Some errors have detailed explanations: E0053, E0118, E0283, E0562, E0599, E0658, E0666.
+Some errors have detailed explanations: E0053, E0118, E0283, E0562, E0599, E0658.
For more information about an error, try `rustc --explain E0053`.