Make #![feature(let_chains)] bootstrap conditional in compiler/

compiler/rustc_ast/src/lib.rs

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

compiler/rustc_ast_lowering/src/lib.rs

@@ -32,12 +32,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_ast_passes/src/lib.rs

@@ -4,11 +4,11 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_is_partitioned)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_attr_data_structures/src/lib.rs

@@ -1,7 +1,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_attr_parsing/src/lib.rs

@@ -77,8 +77,8 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_borrowck/src/lib.rs

@@ -2,12 +2,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

compiler/rustc_builtin_macros/src/lib.rs

@@ -5,6 +5,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
@@ -12,7 +13,6 @@
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustdoc_internals)]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -6,6 +6,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
@@ -15,7 +16,6 @@
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![feature(slice_as_array)]
 #![feature(try_blocks)]

compiler/rustc_codegen_ssa/src/lib.rs

@@ -2,13 +2,13 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![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(let_chains)]
 #![feature(negative_impls)]
 #![feature(rustdoc_internals)]
 #![feature(string_from_utf8_lossy_owned)]

compiler/rustc_const_eval/src/lib.rs

@@ -1,12 +1,12 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 #![feature(slice_ptr_get)]

compiler/rustc_driver_impl/src/lib.rs

@@ -7,10 +7,10 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(decl_macro)]
-#![feature(let_chains)]
 #![feature(panic_backtrace_config)]
 #![feature(panic_update_hook)]
 #![feature(result_flattening)]

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(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -17,7 +18,6 @@
 #![feature(default_field_values)]
 #![feature(error_reporter)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

compiler/rustc_expand/src/lib.rs

@@ -1,11 +1,11 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(rust_logo)]
 #![feature(array_windows)]
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]

compiler/rustc_hir/src/lib.rs

@@ -4,12 +4,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(closure_track_caller)]
 #![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]
-#![feature(let_chains)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -59,6 +59,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
@@ -67,7 +68,6 @@
 #![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 #![feature(slice_partition_dedup)]

compiler/rustc_hir_pretty/src/lib.rs

@@ -2,7 +2,7 @@
 //! the definitions in this file have equivalents in `rustc_ast_pretty`.
 
 // tidy-alphabetical-start
-#![feature(let_chains)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
 

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,11 +1,11 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(array_windows)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end

compiler/rustc_infer/src/lib.rs

@@ -16,12 +16,12 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(extend_one)]
 #![feature(iterator_try_collect)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![recursion_limit = "512"] // For rustdoc
 // tidy-alphabetical-end

compiler/rustc_interface/src/lib.rs

@@ -1,8 +1,8 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(decl_macro)]
 #![feature(file_buffered)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end
 

compiler/rustc_lint/src/lib.rs

@@ -21,6 +21,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -28,7 +29,6 @@
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_order_by)]
-#![feature(let_chains)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]

compiler/rustc_macros/src/lib.rs

@@ -1,7 +1,7 @@
 // tidy-alphabetical-start
 #![allow(rustc::default_hash_types)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]

compiler/rustc_metadata/src/lib.rs

@@ -1,5 +1,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(coroutines)]
@@ -8,7 +9,6 @@
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(iter_from_coroutine)]
-#![feature(let_chains)]
 #![feature(macro_metavar_expr)]
 #![feature(min_specialization)]
 #![feature(never_type)]

compiler/rustc_middle/src/lib.rs

@@ -29,6 +29,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::potential_query_instability)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(allocator_api)]
@@ -48,7 +49,6 @@
 #![feature(if_let_guard)]
 #![feature(intra_doc_pointers)]
 #![feature(iter_from_coroutine)]
-#![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(negative_impls)]
 #![feature(never_type)]

compiler/rustc_mir_build/src/lib.rs

@@ -3,10 +3,10 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end
 

compiler/rustc_mir_dataflow/src/lib.rs

@@ -1,10 +1,10 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
 #![feature(exact_size_is_empty)]
 #![feature(file_buffered)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end

compiler/rustc_mir_transform/src/lib.rs

@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
@@ -7,7 +8,6 @@
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
-#![feature(let_chains)]
 #![feature(map_try_insert)]
 #![feature(never_type)]
 #![feature(try_blocks)]

compiler/rustc_monomorphize/src/lib.rs

@@ -1,9 +1,9 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(array_windows)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
-#![feature(let_chains)]
 // tidy-alphabetical-end
 
 use rustc_hir::lang_items::LangItem;

compiler/rustc_parse/src/lib.rs

@@ -4,13 +4,13 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(string_from_utf8_lossy_owned)]
 // tidy-alphabetical-end
 

compiler/rustc_passes/src/lib.rs

@@ -6,9 +6,9 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(let_chains)]
 #![feature(map_try_insert)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]

compiler/rustc_pattern_analysis/src/lib.rs

@@ -6,7 +6,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![allow(unused_crate_dependencies)]
-#![cfg_attr(feature = "rustc", feature(let_chains))]
+#![cfg_attr(all(feature = "rustc", bootstrap), feature(let_chains))]
 // tidy-alphabetical-end
 
 pub mod constructor;

compiler/rustc_privacy/src/lib.rs

@@ -1,9 +1,9 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(associated_type_defaults)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end

compiler/rustc_query_system/src/lib.rs

@@ -1,9 +1,9 @@
 // tidy-alphabetical-start
 #![allow(rustc::potential_query_instability, internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(assert_matches)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
-#![feature(let_chains)]
 #![feature(min_specialization)]
 // tidy-alphabetical-end
 

compiler/rustc_resolve/src/lib.rs

@@ -10,13 +10,13 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![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(let_chains)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end

compiler/rustc_sanitizers/src/lib.rs

@@ -4,7 +4,7 @@
 //! compiler.
 
 // tidy-alphabetical-start
-#![feature(let_chains)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 // tidy-alphabetical-end
 
 pub mod cfi;

compiler/rustc_session/src/lib.rs

@@ -1,8 +1,8 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![feature(default_field_values)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(rustc_attrs)]
 // To generate CodegenOptionsTargetModifiers and UnstableOptionsTargetModifiers enums
 // with macro_rules, it is necessary to use recursive mechanic ("Incremental TT Munchers").

compiler/rustc_span/src/lib.rs

@@ -17,6 +17,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -24,7 +25,6 @@
 #![feature(core_io_borrowed_buf)]
 #![feature(hash_set_entry)]
 #![feature(if_let_guard)]
-#![feature(let_chains)]
 #![feature(map_try_insert)]
 #![feature(negative_impls)]
 #![feature(read_buf)]

compiler/rustc_symbol_mangling/src/lib.rs

@@ -89,9 +89,9 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(let_chains)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 

compiler/rustc_target/src/lib.rs

@@ -9,12 +9,12 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![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(let_chains)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end

compiler/rustc_trait_selection/src/lib.rs

@@ -14,6 +14,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
@@ -23,7 +24,6 @@
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(iterator_try_reduce)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 #![feature(try_blocks)]

compiler/rustc_ty_utils/src/lib.rs

@@ -6,6 +6,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(let_chains))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
@@ -13,7 +14,6 @@
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iterator_try_collect)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end