Remove #![feature(let_chains)] from libcore

[est31]

PR #132833 has stabilized the let_chains feature. This PR removes the last occurrence from the library.

Split out of #140966 as it caused breakage. Now we have a patch to the linux tree that fixes the build, so we update the linux tree to it.

cc Rust-for-Linux/linux#1163
cc #140722

[rustbot]

r? @Mark-Simulacrum

rustbot has assigned @Mark-Simulacrum.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[est31]

cc @nbdd0121

[est31]

r? @tgross35 as you also reviewed #140966

[tgross35]

@bors r+

[bors]

📌 Commit 6d71674 has been approved by tgross35

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6d71674 with merge 5af801b...

[bors]

☀️ Test successful - checks-actions
Approved by: tgross35
Pushing 5af801b to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 105354d (parent) -> 5af801b (this PR)

Test differences

Show 33262 test diffs

Stage 1

• error::verify_middle_const_eval_non_int_5: [missing] -> pass (J0)
• errors::verify_ast_passes_obsolete_auto_37: [missing] -> pass (J0)
• errors::verify_builtin_macros_trace_macros_23: [missing] -> pass (J0)
• errors::verify_codegen_ssa_unable_to_exe_linker_50: [missing] -> pass (J0)
• errors::verify_const_eval_long_running_25: [missing] -> pass (J0)
• errors::verify_mir_build_non_const_path_2: [missing] -> pass (J0)
• errors::verify_parse_assignment_else_not_allowed_45: [missing] -> pass (J0)
• errors::verify_parse_frontmatter_invalid_close_preceding_whitespace_36: [missing] -> pass (J0)
• errors::verify_parse_maybe_fn_typo_with_impl_61: [missing] -> pass (J0)
• errors::verify_parse_missing_expression_in_for_loop_21: [missing] -> pass (J0)
• errors::verify_parse_nested_adt_156: [missing] -> pass (J0)
• errors::verify_passes_no_mangle_72: [missing] -> pass (J0)
• lints::verify_lint_uses_power_alignment_86: [missing] -> pass (J0)
• spec::tests::arm_unknown_linux_musleabi: [missing] -> pass (J0)
• tests::format_raw: [missing] -> pass (J0)
• net::udp::tests::ttl: [missing] -> pass (J1)
• num::int_sqrt::u64_sqrt_random_small: [missing] -> pass (J1)
• path::bench_hash_path_long: [missing] -> pass (J1)
• sort::tests::unstable::correct_f128_ascending: [missing] -> pass (J1)
• term::terminfo::parm::tests::test_format: [missing] -> pass (J1)
• term::terminfo::parm::tests::test_param_stack_failure_conditions: [missing] -> pass (J1)
• tests::run_include_ignored_option: [missing] -> pass (J1)
• vec::bench_clone_from_01_0100_1000: [missing] -> pass (J1)
• vec::bench_extend_1000_1000: [missing] -> pass (J1)
• clone::test_clone_to_uninit_slice_drops_on_panic: [missing] -> pass (J2)
• collections::btree::map::tests::test_extract_if::height_0_keeping_half: [missing] -> pass (J2)
• collections::hash::map::tests::test_into_keys: [missing] -> pass (J2)
• collections::linked_list::tests::test_rev_iter: [missing] -> pass (J2)
• iter::adapters::filter::test_iterator_filter_count: [missing] -> pass (J2)
• iter::adapters::fuse::test_fuse_fold: [missing] -> pass (J2)
• mpsc_sync::oneshot_single_thread_try_recv_closed: [missing] -> pass (J2)
• num::bignum::test_sub_underflow_1: [missing] -> pass (J2)
• num::i16::test_borrowing_sub: [missing] -> pass (J2)
• num::u16::test_carrying_add: [missing] -> pass (J2)
• num::u16::test_count_zeros: [missing] -> pass (J2)
• num::u8::test_next_multiple_of: [missing] -> pass (J2)
• result::test_expect_err: [missing] -> pass (J2)
• slice::memchr::no_match: [missing] -> pass (J2)
• str::pattern::char_searcher_ascii_haystack::bwd: [missing] -> pass (J2)
• sys_common::wtf8::tests::wtf8_slice_to: [missing] -> pass (J2)
• sys_common::wtf8::tests::wtf8buf_from_string: [missing] -> pass (J2)
• test_set_var: [missing] -> pass (J2)
• vec::test_retain_drop_panic: [missing] -> pass (J2)
• sort::tests::stable::correct_u64_saw_mixed: [missing] -> ignore (J3)

Stage 2

• errors::verify_const_eval_nullary_intrinsic_fail_34: pass -> [missing] (J0)
• errors::verify_const_eval_unallowed_inline_asm_22: pass -> [missing] (J0)
• errors::verify_const_eval_unmarked_const_item_exposed_13: pass -> [missing] (J0)
• errors::verify_incremental_delete_lock_24: pass -> [missing] (J0)
• errors::verify_parse_lifetime_in_borrow_expression_7: pass -> [missing] (J0)
• errors::verify_passes_unknown_lang_item_113: pass -> [missing] (J0)
• errors::verify_passes_unreachable_due_to_uninhabited_165: pass -> [missing] (J0)
• lints::verify_lint_byte_slice_in_packed_struct_with_derive_140: pass -> [missing] (J0)
• lints::verify_lint_dangling_pointers_from_temporaries_71: pass -> [missing] (J0)
• markdown::parse::tests::test_parse_heading: pass -> [missing] (J0)
• pprust::tests::test_variant_to_string: pass -> [missing] (J0)
• session_diagnostics::verify_attr_parsing_expects_features_24: pass -> [missing] (J0)
• spec::tests::m68k_unknown_none_elf: pass -> [missing] (J0)
• spec::tests::riscv32im_risc0_zkvm_elf: pass -> [missing] (J0)
• ascii::medium::case03_branch_and_subtract: pass -> [missing] (J1)
• btree::set::difference_random_100_vs_100: pass -> [missing] (J1)
• num::bench_i32_from_str_radix_16: pass -> [missing] (J1)
• num::bench_i8_from_str_radix_2: pass -> [missing] (J1)
• num::int_log::u64_log_random: pass -> [missing] (J1)
• slice::rotate_huge_by1: pass -> [missing] (J1)
• sort::tests::unstable::correct_1k_random: pass -> [missing] (J1)
• str::char_count::ru_large::case02_iter_increment: pass -> [missing] (J1)
• str::find_zzz_str::long_lorem_ipsum: pass -> [missing] (J1)
• str::rfind_underscore_char::short_ascii: pass -> [missing] (J1)
• vec::test_try_reserve_exact: pass -> [missing] (J1)
• collections::binary_heap::test_drain_forget: pass -> [missing] (J2)
• collections::hash::set::tests::test_difference: pass -> [missing] (J2)
• fmt::builders::debug_map::test_multiple_and_non_exhaustive: pass -> [missing] (J2)
• iter::adapters::filter_map::test_filter_map: pass -> [missing] (J2)
• join_paths_unix: pass -> [missing] (J2)
• mem::test_transmute_copy_unaligned: pass -> [missing] (J2)
• mpsc::try_recv_states: pass -> [missing] (J2)
• mutex::test_arc_condvar_poison: pass -> [missing] (J2)
• nonzero::test_create_nonzero_instance: pass -> [missing] (J2)
• num::bignum::test_fmt: pass -> [missing] (J2)
• num::dec2flt::zero: pass -> [missing] (J2)
• num::i16::test_unbounded_shr: pass -> [missing] (J2)
• num::test_i16i64: pass -> [missing] (J2)
• num::test_try_i32i128: pass -> [missing] (J2)
• num::u128::test_div_floor: pass -> [missing] (J2)
• num::u32::test_overflows: pass -> [missing] (J2)
• num::u8::test_pow: pass -> [missing] (J2)
• ops::range_structural_match: pass -> [missing] (J2)
• simd::testing: pass -> [missing] (J2)
• slice::slice_index::rangefrom_len::index_fail: pass -> [missing] (J2)
• slice::test_splitn_iterator_mut: pass -> [missing] (J2)
• str::slice_index::boundary::rangeinclusive_1::index_fail: pass -> [missing] (J2)
• str::slice_index::test_slice_fail_truncated_2: pass -> [missing] (J2)
• sys_common::wtf8::tests::wtf8_clone_into: pass -> [missing] (J2)
• sys_common::wtf8::tests::wtf8_to_ascii_uppercase: pass -> [missing] (J2)
• vec::extract_if_complex: pass -> [missing] (J2)
• vec::test_pop_if_empty: pass -> [missing] (J2)
• sort::tests::unstable::deterministic_i32_random_d2: ignore -> [missing] (J3)
• sort::tests::unstable::deterministic_string_saw_mixed: ignore -> [missing] (J3)
• sort::tests::unstable::violate_ord_retain_orig_set_i32_random_s95: ignore -> [missing] (J3)
• backtrace_rs::symbolize::gimli::parse_running_mmaps::check_maps_entry_parsing_32bit: pass -> [missing] (J4)

(and 16556 additional test diffs)

Additionally, 16606 doctest diffs were found. These are ignored, as they are noisy.

Job group index

• J0: aarch64-apple, x86_64-apple-1
• J1: aarch64-apple, test-various, x86_64-apple-1
• J2: aarch64-apple, test-various, x86_64-apple-1, x86_64-gnu-aux
• J3: x86_64-gnu-aux
• J4: test-various

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 5af801b687e6e8b860ae970e725c8b9a3820d0ce --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. x86_64-apple-2: 1395.0s -> 4366.8s (213.0%)
2. test-various: 2313.7s -> 4207.8s (81.9%)
3. x86_64-gnu-aux: 4282.1s -> 6103.3s (42.5%)
4. dist-apple-various: 8706.1s -> 6059.4s (-30.4%)
5. aarch64-apple: 3171.5s -> 3975.6s (25.4%)
6. x86_64-apple-1: 7847.0s -> 6502.1s (-17.1%)
7. dist-armv7-linux: 6092.2s -> 5327.8s (-12.5%)
8. dist-s390x-linux: 5154.9s -> 5485.9s (6.4%)
9. dist-ohos-aarch64: 4510.9s -> 4774.2s (5.8%)
10. x86_64-rust-for-linux: 2557.4s -> 2692.8s (5.3%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (5af801b): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 4.2%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	4.2%	[4.2%, 4.2%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	4.2%	[4.2%, 4.2%]	1

Cycles

Results (secondary 7.5%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	7.5%	[7.2%, 7.9%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 777.008s -> 776.203s (-0.10%)
Artifact size: 366.29 MiB -> 366.33 MiB (0.01%)