Stabilize RTN

Author: compiler-errors

compiler/rustc_ast_lowering/src/lib.rs

@@ -954,17 +954,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                 }
                             }
                         };
-                        let mut err = self.dcx().create_err(err);
-                        if !self.tcx.features().return_type_notation()
-                            && self.tcx.sess.is_nightly_build()
-                        {
-                            add_feature_diagnostics(
-                                &mut err,
-                                &self.tcx.sess,
-                                sym::return_type_notation,
-                            );
-                        }
-                        err.emit();
+                        self.dcx().emit_err(err);
                         GenericArgsCtor {
                             args: Default::default(),
                             constraints: &[],

compiler/rustc_ast_lowering/src/path.rs

@@ -6,7 +6,6 @@ use rustc_hir::GenericArg;
 use rustc_hir::def::{DefKind, PartialRes, Res};
 use rustc_hir::def_id::DefId;
 use rustc_middle::span_bug;
-use rustc_session::parse::add_feature_diagnostics;
 use rustc_span::{BytePos, DUMMY_SP, DesugaringKind, Ident, Span, Symbol, kw, sym};
 use smallvec::{SmallVec, smallvec};
 use tracing::{debug, instrument};
@@ -287,17 +286,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                 }
                             }
                         };
-                        let mut err = self.dcx().create_err(err);
-                        if !self.tcx.features().return_type_notation()
-                            && self.tcx.sess.is_nightly_build()
-                        {
-                            add_feature_diagnostics(
-                                &mut err,
-                                &self.tcx.sess,
-                                sym::return_type_notation,
-                            );
-                        }
-                        err.emit();
+                        self.dcx().emit_err(err);
                         (
                             GenericArgsCtor {
                                 args: Default::default(),

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -498,7 +498,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
     gate_all!(postfix_match, "postfix match is experimental");
     gate_all!(mut_ref, "mutable by-reference bindings are experimental");
     gate_all!(global_registration, "global registration is experimental");
-    gate_all!(return_type_notation, "return type notation is experimental");
     gate_all!(pin_ergonomics, "pinned reference syntax is experimental");
     gate_all!(unsafe_fields, "`unsafe` fields are experimental");
     gate_all!(unsafe_binders, "unsafe binder types are experimental");

compiler/rustc_feature/src/accepted.rs

@@ -364,6 +364,8 @@ declare_features! (
     (accepted, result_ffi_guarantees, "1.84.0", Some(110503)),
     /// Allows return-position `impl Trait` in traits.
     (accepted, return_position_impl_trait_in_trait, "1.75.0", Some(91611)),
+    /// Allows bounding the return type of AFIT/RPITIT.
+    (accepted, return_type_notation, "CURRENT_RUSTC_VERSION", Some(109417)),
     /// Allows code like `let x: &'static u32 = &42` to work (RFC 1414).
     (accepted, rvalue_static_promotion, "1.21.0", Some(38865)),
     /// Allows `Self` in type definitions (RFC 2300).

compiler/rustc_feature/src/unstable.rs

@@ -616,8 +616,6 @@ declare_features! (
     (incomplete, repr128, "1.16.0", Some(56071)),
     /// Allows `repr(simd)` and importing the various simd intrinsics.
     (unstable, repr_simd, "1.4.0", Some(27731)),
-    /// Allows bounding the return type of AFIT/RPITIT.
-    (unstable, return_type_notation, "1.70.0", Some(109417)),
     /// Allows `extern "rust-cold"`.
     (unstable, rust_cold_cc, "1.63.0", Some(97544)),
     /// Allows use of x86 SHA512, SM3 and SM4 target-features and intrinsics

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -475,7 +475,11 @@ fn fn_sig_suggestion<'tcx>(
         ""
     };
 
-    let output = if !output.is_unit() { format!(" -> {output}") } else { String::new() };
+    let output = if !output.is_unit() {
+        with_types_for_signature!(format!(" -> {output}"))
+    } else {
+        String::new()
+    };
 
     let safety = sig.safety.prefix_str();
     let (generics, where_clauses) = bounds_from_generic_predicates(tcx, predicates);

compiler/rustc_lint/src/async_fn_in_trait.rs

@@ -95,7 +95,8 @@ impl<'tcx> LateLintPass<'tcx> for AsyncFnInTrait {
             && let hir::IsAsync::Async(async_span) = sig.header.asyncness
         {
             // RTN can be used to bound `async fn` in traits in a better way than "always"
-            if cx.tcx.features().return_type_notation() {
+            // TODO:
+            if true {
                 return;
             }
 

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1339,15 +1339,17 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
         def_id: DefId,
         args: ty::GenericArgsRef<'tcx>,
     ) -> Result<(), PrintError> {
-        let fn_args = if self.tcx().features().return_type_notation()
-            && let Some(ty::ImplTraitInTraitData::Trait { fn_def_id, .. }) =
-                self.tcx().opt_rpitit_info(def_id)
+        let fn_args = if let Some(ty::ImplTraitInTraitData::Trait { fn_def_id, .. }) =
+            self.tcx().opt_rpitit_info(def_id)
             && let ty::Alias(_, alias_ty) =
                 self.tcx().fn_sig(fn_def_id).skip_binder().output().skip_binder().kind()
             && alias_ty.def_id == def_id
             && let generics = self.tcx().generics_of(fn_def_id)
             // FIXME(return_type_notation): We only support lifetime params for now.
-            && generics.own_params.iter().all(|param| matches!(param.kind, ty::GenericParamDefKind::Lifetime))
+            && generics
+                .own_params
+                .iter()
+                .all(|param| matches!(param.kind, ty::GenericParamDefKind::Lifetime))
         {
             let num_args = generics.count();
             Some((fn_def_id, &args[..num_args]))

compiler/rustc_parse/src/parser/path.rs

@@ -377,8 +377,6 @@ impl<'a> Parser<'a> {
                     self.expect(exp!(CloseParen))?;
                     let span = lo.to(self.prev_token.span);
 
-                    self.psess.gated_spans.gate(sym::return_type_notation, span);
-
                     let prev_lo = self.prev_token.span.shrink_to_hi();
                     if self.eat_noexpect(&token::RArrow) {
                         let lo = self.prev_token.span;

compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

@@ -524,7 +524,6 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                         }
 
                         self.explain_hrtb_projection(&mut err, leaf_trait_predicate, obligation.param_env, &obligation.cause);
-                        self.suggest_desugaring_async_fn_in_trait(&mut err, main_trait_predicate);
 
                         // Return early if the trait is Debug or Display and the invocation
                         // originates within a standard library macro, because the output