Remove all unused feature gates from the compiler

compiler/rustc_ast_lowering/src/lib.rs

@@ -33,9 +33,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![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_builtin_macros/src/lib.rs

@@ -15,7 +15,6 @@
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustdoc_internals)]
-#![feature(string_from_utf8_lossy_owned)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end

compiler/rustc_codegen_gcc/src/lib.rs

@@ -16,7 +16,7 @@
 #![allow(internal_features)]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![feature(rustc_private, decl_macro, never_type, trusted_len)]
+#![feature(rustc_private)]
 #![allow(broken_intra_doc_links)]
 #![recursion_limit = "256"]
 #![warn(rust_2018_idioms)]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -9,7 +9,6 @@
 #![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)]

compiler/rustc_data_structures/src/lib.rs

@@ -25,7 +25,6 @@
 #![feature(dropck_eyepatch)]
 #![feature(extend_one)]
 #![feature(file_buffered)]
-#![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(negative_impls)]

compiler/rustc_errors/src/lib.rs

@@ -15,12 +15,10 @@
 #![feature(box_patterns)]
 #![feature(default_field_values)]
 #![feature(error_reporter)]
-#![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
-#![feature(trait_alias)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
 // tidy-alphabetical-end

compiler/rustc_expand/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
 #![feature(macro_metavar_expr)]
-#![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_internals)]
 #![feature(rustdoc_internals)]

compiler/rustc_fluent_macro/src/lib.rs

@@ -4,7 +4,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(proc_macro_diagnostic)]
-#![feature(proc_macro_span)]
 #![feature(rustdoc_internals)]
 #![feature(track_path)]
 // tidy-alphabetical-end

compiler/rustc_hir/src/lib.rs

@@ -5,7 +5,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![feature(associated_type_defaults)]
-#![feature(box_patterns)]
 #![feature(closure_track_caller)]
 #![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,13 +1,11 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(never_type)]
-#![feature(try_blocks)]
 // tidy-alphabetical-end
 
 mod _match;

compiler/rustc_infer/src/lib.rs

@@ -20,7 +20,6 @@
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(extend_one)]
-#![feature(iterator_try_collect)]
 #![feature(rustdoc_internals)]
 #![recursion_limit = "512"] // For rustdoc
 // tidy-alphabetical-end

compiler/rustc_macros/src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(if_let_guard)]
 #![feature(never_type)]
 #![feature(proc_macro_diagnostic)]
-#![feature(proc_macro_span)]
 #![feature(proc_macro_tracked_env)]
 // tidy-alphabetical-end
 

compiler/rustc_middle/src/lib.rs

@@ -54,7 +54,6 @@
 #![feature(round_char_boundary)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
-#![feature(trusted_len)]
 #![feature(try_blocks)]
 #![feature(try_trait_v2)]
 #![feature(try_trait_v2_yeet)]

compiler/rustc_mir_transform/src/lib.rs

@@ -7,10 +7,7 @@
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
-#![feature(map_try_insert)]
-#![feature(never_type)]
 #![feature(try_blocks)]
-#![feature(vec_deque_pop_if)]
 #![feature(yeet_expr)]
 // tidy-alphabetical-end
 

compiler/rustc_parse/src/lib.rs

@@ -9,7 +9,6 @@
 #![feature(debug_closure_helpers)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
-#![feature(string_from_utf8_lossy_owned)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
 

compiler/rustc_passes/src/lib.rs

@@ -8,10 +8,8 @@
 #![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(box_patterns)]
 #![feature(map_try_insert)]
 #![feature(rustdoc_internals)]
-#![feature(try_blocks)]
 // tidy-alphabetical-end
 
 use rustc_middle::util::Providers;

compiler/rustc_query_system/src/lib.rs

@@ -2,7 +2,6 @@
 #![allow(internal_features)]
 #![feature(assert_matches)]
 #![feature(core_intrinsics)]
-#![feature(dropck_eyepatch)]
 #![feature(min_specialization)]
 // tidy-alphabetical-end
 

compiler/rustc_span/src/lib.rs

@@ -23,7 +23,6 @@
 #![doc(rust_logo)]
 #![feature(array_windows)]
 #![feature(core_io_borrowed_buf)]
-#![feature(hash_set_entry)]
 #![feature(if_let_guard)]
 #![feature(map_try_insert)]
 #![feature(negative_impls)]

compiler/rustc_target/src/lib.rs

@@ -11,10 +11,8 @@
 #![allow(internal_features)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(assert_matches)]
 #![feature(debug_closure_helpers)]
 #![feature(iter_intersperse)]
-#![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_trait_selection/src/lib.rs

@@ -19,14 +19,12 @@
 #![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)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]
-#![feature(type_alias_impl_trait)]
 #![feature(unwrap_infallible)]
 #![feature(yeet_expr)]
 #![recursion_limit = "512"] // For rustdoc