Stabilize if let guards (feature(if_let_guard))

compiler/rustc_ast/src/lib.rs

@@ -6,6 +6,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(attr(deny(warnings)))
@@ -14,7 +15,6 @@
 #![feature(array_windows)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(macro_metavar_expr)]
 #![feature(negative_impls)]
 #![feature(never_type)]

compiler/rustc_ast_lowering/src/lib.rs

@@ -32,11 +32,11 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
-#![feature(if_let_guard)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -454,11 +454,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
             }
         };
     }
-    gate_all!(
-        if_let_guard,
-        "`if let` guards are experimental",
-        "you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`"
-    );
     gate_all!(let_chains, "`let` expressions in this position are unstable");
     gate_all!(
         async_trait_bounds,

compiler/rustc_ast_passes/src/lib.rs

@@ -4,9 +4,9 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(rust_logo)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(iter_is_partitioned)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end

compiler/rustc_borrowck/src/lib.rs

@@ -2,11 +2,11 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

compiler/rustc_builtin_macros/src/lib.rs

@@ -5,13 +5,13 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(autodiff)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
-#![feature(if_let_guard)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustdoc_internals)]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -6,13 +6,13 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]
 #![feature(rustdoc_internals)]

compiler/rustc_codegen_ssa/src/lib.rs

@@ -2,12 +2,12 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(rustdoc_internals)]
 #![feature(string_from_utf8_lossy_owned)]

compiler/rustc_const_eval/src/lib.rs

@@ -1,11 +1,11 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
-#![feature(if_let_guard)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 #![feature(slice_ptr_get)]

compiler/rustc_errors/src/lib.rs

@@ -7,6 +7,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -16,7 +17,6 @@
 #![feature(box_patterns)]
 #![feature(default_field_values)]
 #![feature(error_reporter)]
-#![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

compiler/rustc_expand/src/lib.rs

@@ -1,10 +1,10 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(rust_logo)]
 #![feature(array_windows)]
 #![feature(associated_type_defaults)]
-#![feature(if_let_guard)]
 #![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]

compiler/rustc_feature/src/accepted.rs

@@ -234,6 +234,8 @@ declare_features! (
     (accepted, i128_type, "1.26.0", Some(35118)),
     /// Allows the use of `if let` expressions.
     (accepted, if_let, "1.0.0", None),
+    /// Allows `if let` guard in match arms.
+    (accepted, if_let_guard, "CURRENT_RUSTC_VERSION", Some(51114)),
     /// Rescoping temporaries in `if let` to align with Rust 2024.
     (accepted, if_let_rescope, "1.84.0", Some(124085)),
     /// Allows top level or-patterns (`p | q`) in `if let` and `while let`.

compiler/rustc_feature/src/unstable.rs

@@ -530,8 +530,6 @@ declare_features! (
     (incomplete, guard_patterns, "1.85.0", Some(129967)),
     /// Allows using `..=X` as a patterns in slices.
     (unstable, half_open_range_patterns_in_slices, "1.66.0", Some(67264)),
-    /// Allows `if let` guard in match arms.
-    (unstable, if_let_guard, "1.47.0", Some(51114)),
     /// Allows `impl Trait` to be used inside associated types (RFC 2515).
     (unstable, impl_trait_in_assoc_type, "1.70.0", Some(63063)),
     /// Allows `impl Trait` in bindings (`let`).

compiler/rustc_hir_analysis/src/lib.rs

@@ -59,12 +59,12 @@ This API is completely unstable and subject to change.
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(coroutines)]
 #![feature(debug_closure_helpers)]
-#![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
 #![feature(iter_intersperse)]
 #![feature(never_type)]

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,9 +1,9 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(array_windows)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(never_type)]
 #![feature(try_blocks)]

compiler/rustc_lint/src/lib.rs

@@ -21,12 +21,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(iter_order_by)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]

compiler/rustc_macros/src/lib.rs

@@ -1,6 +1,6 @@
 // tidy-alphabetical-start
 #![allow(rustc::default_hash_types)]
-#![feature(if_let_guard)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(never_type)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]

compiler/rustc_metadata/src/lib.rs

@@ -1,12 +1,12 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(coroutines)]
 #![feature(decl_macro)]
 #![feature(error_iter)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
 #![feature(macro_metavar_expr)]
 #![feature(min_specialization)]

compiler/rustc_middle/src/lib.rs

@@ -28,6 +28,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(allocator_api)]
@@ -44,7 +45,6 @@
 #![feature(discriminant_kind)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(intra_doc_pointers)]
 #![feature(iter_from_coroutine)]
 #![feature(min_specialization)]

compiler/rustc_mir_build/src/lib.rs

@@ -3,9 +3,9 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end
 

compiler/rustc_mir_transform/src/lib.rs

@@ -1,11 +1,11 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(const_type_name)]
 #![feature(cow_is_borrowed)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(map_try_insert)]
 #![feature(never_type)]

compiler/rustc_monomorphize/src/lib.rs

@@ -1,7 +1,7 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(array_windows)]
 #![feature(file_buffered)]
-#![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(once_cell_get_mut)]
 // tidy-alphabetical-end

compiler/rustc_parse/src/lib.rs

@@ -4,10 +4,10 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
-#![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(string_from_utf8_lossy_owned)]
 #![recursion_limit = "256"]

compiler/rustc_parse/src/parser/expr.rs

@@ -3405,33 +3405,15 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_match_arm_guard(&mut self) -> PResult<'a, Option<P<Expr>>> {
-        // Used to check the `if_let_guard` feature mostly by scanning
-        // `&&` tokens.
-        fn has_let_expr(expr: &Expr) -> bool {
-            match &expr.kind {
-                ExprKind::Binary(BinOp { node: BinOpKind::And, .. }, lhs, rhs) => {
-                    let lhs_rslt = has_let_expr(lhs);
-                    let rhs_rslt = has_let_expr(rhs);
-                    lhs_rslt || rhs_rslt
-                }
-                ExprKind::Let(..) => true,
-                _ => false,
-            }
-        }
         if !self.eat_keyword(exp!(If)) {
             // No match arm guard present.
             return Ok(None);
         }
 
-        let if_span = self.prev_token.span;
         let mut cond = self.parse_match_guard_condition()?;
 
         CondChecker::new(self, LetChainsPolicy::AlwaysAllowed).visit_expr(&mut cond);
 
-        if has_let_expr(&cond) {
-            let span = if_span.to(cond.span);
-            self.psess.gated_spans.gate(sym::if_let_guard, span);
-        }
         Ok(Some(cond))
     }
 

compiler/rustc_resolve/src/lib.rs

@@ -10,11 +10,11 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]

compiler/rustc_span/src/lib.rs

@@ -17,13 +17,13 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
 #![feature(cfg_match)]
 #![feature(core_io_borrowed_buf)]
 #![feature(hash_set_entry)]
-#![feature(if_let_guard)]
 #![feature(map_try_insert)]
 #![feature(negative_impls)]
 #![feature(read_buf)]

compiler/rustc_trait_selection/src/lib.rs

@@ -14,13 +14,13 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(cfg_version)]
-#![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(iterator_try_reduce)]
 #![feature(never_type)]

compiler/rustc_ty_utils/src/lib.rs

@@ -6,12 +6,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(if_let_guard))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
-#![feature(if_let_guard)]
 #![feature(iterator_try_collect)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]