Auto merge of #73265 - mark-i-m:mv-std, r=<try>tmp-nightly

mv std libs to library/

This is the first step in refactoring the directory layout of this repository, with further followup steps planned (but not done yet).

Background: currently, all crates are under src/, without nested src directories and with the unconventional `lib*` prefixes (e.g., `src/libcore/lib.rs`). This directory structures is not idiomatic and makes the `src/` directory rather overwhelming. To improve contributor experience and make things a bit more approachable, we are reorganizing the repo a bit.

In this PR, we move the standard libs (basically anything that is "runtime", as opposed to part of the compiler, build system, or one of the tools, etc). The new layout moves these libraries to a new `library/` directory in the root of the repo. Additionally, we remove the `lib*` prefixes and add nested `src/` directories.  The other crates/tools in this repo are not touched. So in summary:

```
library/<crate>/src/*.rs
src/<all the rest>     // unchanged
```

where `<crate>` is:
- core
- alloc
- std
- test
- proc_macro
- panic_abort
- panic_unwind
- profiler_builtins
- term
- unwind
- rtstartup
- backtrace
- rustc-std-workspace-*

There was a lot of discussion about this and a few rounds of compiler team approvals, FCPs, MCPs, and nominations. The original MCP is https://github.com/rust-lang/compiler-team/issues/298. The final approval of the compiler team was given here: https://github.com/rust-lang/rust/pull/73265#issuecomment-659498446.

The name `library` was chosen to complement a later move of the compiler crates to a `compiler/` directory. There was a lot of discussion around adding the nested `src/` directories. Note that this does increase the nesting depth (plausibly important for manual traversal of the tree, e.g., through GitHub's UI or `cd`), but this is deemed to be better as it fits the standard layout of Rust crates throughout most of the ecosystem, though there is some debate about how much this should apply to multi-crate projects. Overall, there seem to be more people in favor of nested `src/` than against.

After this PR, there are no dependencies out of the `library/` directory except on the `build_helper` (or crates.io crates).

1 files changed, 0 insertions, 503 deletions

diff --git a/src/libcore/tests/pattern.rs b/src/libcore/tests/pattern.rs
deleted file mode 100644
index d4bec996d89..00000000000
--- a/src/libcore/tests/pattern.rs
+++ /dev/null
@@ -1,503 +0,0 @@
-use std::str::pattern::*;
-
-// This macro makes it easier to write
-// tests that do a series of iterations
-macro_rules! search_asserts {
-    ($haystack:expr, $needle:expr, $testname:expr, [$($func:ident),*], $result:expr) => {
-        let mut searcher = $needle.into_searcher($haystack);
-        let arr = [$( Step::from(searcher.$func()) ),*];
-        assert_eq!(&arr[..], &$result, $testname);
-    }
-}
-
-/// Combined enum for the results of next() and next_match()/next_reject()
-#[derive(Debug, PartialEq, Eq)]
-enum Step {
-    // variant names purposely chosen to
-    // be the same length for easy alignment
-    Matches(usize, usize),
-    Rejects(usize, usize),
-    InRange(usize, usize),
-    Done,
-}
-
-use self::Step::*;
-
-impl From<SearchStep> for Step {
-    fn from(x: SearchStep) -> Self {
-        match x {
-            SearchStep::Match(a, b) => Matches(a, b),
-            SearchStep::Reject(a, b) => Rejects(a, b),
-            SearchStep::Done => Done,
-        }
-    }
-}
-
-impl From<Option<(usize, usize)>> for Step {
-    fn from(x: Option<(usize, usize)>) -> Self {
-        match x {
-            Some((a, b)) => InRange(a, b),
-            None => Done,
-        }
-    }
-}
-
-// FIXME(Manishearth) these tests focus on single-character searching  (CharSearcher)
-// and on next()/next_match(), not next_reject(). This is because
-// the memchr changes make next_match() for single chars complex, but next_reject()
-// continues to use next() under the hood. We should add more test cases for all
-// of these, as well as tests for StrSearcher and higher level tests for str::find() (etc)
-
-#[test]
-fn test_simple_iteration() {
-    search_asserts!(
-        "abcdeabcd",
-        'a',
-        "forward iteration for ASCII string",
-        // a            b              c              d              e              a              b              c              d              EOF
-        [next, next, next, next, next, next, next, next, next, next],
-        [
-            Matches(0, 1),
-            Rejects(1, 2),
-            Rejects(2, 3),
-            Rejects(3, 4),
-            Rejects(4, 5),
-            Matches(5, 6),
-            Rejects(6, 7),
-            Rejects(7, 8),
-            Rejects(8, 9),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        "abcdeabcd",
-        'a',
-        "reverse iteration for ASCII string",
-        // d            c              b              a            e                d              c              b              a             EOF
-        [
-            next_back, next_back, next_back, next_back, next_back, next_back, next_back, next_back,
-            next_back, next_back
-        ],
-        [
-            Rejects(8, 9),
-            Rejects(7, 8),
-            Rejects(6, 7),
-            Matches(5, 6),
-            Rejects(4, 5),
-            Rejects(3, 4),
-            Rejects(2, 3),
-            Rejects(1, 2),
-            Matches(0, 1),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        "我爱我的猫",
-        '我',
-        "forward iteration for Chinese string",
-        // 我           愛             我             的              貓               EOF
-        [next, next, next, next, next, next],
-        [Matches(0, 3), Rejects(3, 6), Matches(6, 9), Rejects(9, 12), Rejects(12, 15), Done]
-    );
-
-    search_asserts!(
-        "我的猫说meow",
-        'm',
-        "forward iteration for mixed string",
-        // 我           的             猫             说              m                e                o                w                EOF
-        [next, next, next, next, next, next, next, next, next],
-        [
-            Rejects(0, 3),
-            Rejects(3, 6),
-            Rejects(6, 9),
-            Rejects(9, 12),
-            Matches(12, 13),
-            Rejects(13, 14),
-            Rejects(14, 15),
-            Rejects(15, 16),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        "我的猫说meow",
-        '猫',
-        "reverse iteration for mixed string",
-        // w             o                 e                m                说              猫             的             我             EOF
-        [
-            next_back, next_back, next_back, next_back, next_back, next_back, next_back, next_back,
-            next_back
-        ],
-        [
-            Rejects(15, 16),
-            Rejects(14, 15),
-            Rejects(13, 14),
-            Rejects(12, 13),
-            Rejects(9, 12),
-            Matches(6, 9),
-            Rejects(3, 6),
-            Rejects(0, 3),
-            Done
-        ]
-    );
-}
-
-#[test]
-fn test_simple_search() {
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'a',
-        "next_match for ASCII string",
-        [next_match, next_match, next_match, next_match],
-        [InRange(0, 1), InRange(5, 6), InRange(10, 11), Done]
-    );
-
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'a',
-        "next_match_back for ASCII string",
-        [next_match_back, next_match_back, next_match_back, next_match_back],
-        [InRange(10, 11), InRange(5, 6), InRange(0, 1), Done]
-    );
-
-    search_asserts!(
-        "abcdeab",
-        'a',
-        "next_reject for ASCII string",
-        [next_reject, next_reject, next_match, next_reject, next_reject],
-        [InRange(1, 2), InRange(2, 3), InRange(5, 6), InRange(6, 7), Done]
-    );
-
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'a',
-        "next_reject_back for ASCII string",
-        [
-            next_reject_back,
-            next_reject_back,
-            next_match_back,
-            next_reject_back,
-            next_reject_back,
-            next_reject_back
-        ],
-        [
-            InRange(14, 15),
-            InRange(13, 14),
-            InRange(10, 11),
-            InRange(9, 10),
-            InRange(8, 9),
-            InRange(7, 8)
-        ]
-    );
-}
-
-// Á, 각, ก, 😀 all end in 0x81
-// 🁀, ᘀ do not end in 0x81 but contain the byte
-// ꁁ has 0x81 as its second and third bytes.
-//
-// The memchr-using implementation of next_match
-// and next_match_back temporarily violate
-// the property that the search is always on a unicode boundary,
-// which is fine as long as this never reaches next() or next_back().
-// So we test if next() is correct after each next_match() as well.
-const STRESS: &str = "Áa🁀bÁꁁfg😁각กᘀ각aÁ각ꁁก😁a";
-
-#[test]
-fn test_stress_indices() {
-    // this isn't really a test, more of documentation on the indices of each character in the stresstest string
-
-    search_asserts!(
-        STRESS,
-        'x',
-        "Indices of characters in stress test",
-        [
-            next, next, next, next, next, next, next, next, next, next, next, next, next, next,
-            next, next, next, next, next, next, next
-        ],
-        [
-            Rejects(0, 2),   // Á
-            Rejects(2, 3),   // a
-            Rejects(3, 7),   // 🁀
-            Rejects(7, 8),   // b
-            Rejects(8, 10),  // Á
-            Rejects(10, 13), // ꁁ
-            Rejects(13, 14), // f
-            Rejects(14, 15), // g
-            Rejects(15, 19), // 😀
-            Rejects(19, 22), // 각
-            Rejects(22, 25), // ก
-            Rejects(25, 28), // ᘀ
-            Rejects(28, 31), // 각
-            Rejects(31, 32), // a
-            Rejects(32, 34), // Á
-            Rejects(34, 37), // 각
-            Rejects(37, 40), // ꁁ
-            Rejects(40, 43), // ก
-            Rejects(43, 47), // 😀
-            Rejects(47, 48), // a
-            Done
-        ]
-    );
-}
-
-#[test]
-fn test_forward_search_shared_bytes() {
-    search_asserts!(
-        STRESS,
-        'Á',
-        "Forward search for two-byte Latin character",
-        [next_match, next_match, next_match, next_match],
-        [InRange(0, 2), InRange(8, 10), InRange(32, 34), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'Á',
-        "Forward search for two-byte Latin character; check if next() still works",
-        [next_match, next, next_match, next, next_match, next, next_match],
-        [
-            InRange(0, 2),
-            Rejects(2, 3),
-            InRange(8, 10),
-            Rejects(10, 13),
-            InRange(32, 34),
-            Rejects(34, 37),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        STRESS,
-        '각',
-        "Forward search for three-byte Hangul character",
-        [next_match, next, next_match, next_match, next_match],
-        [InRange(19, 22), Rejects(22, 25), InRange(28, 31), InRange(34, 37), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '각',
-        "Forward search for three-byte Hangul character; check if next() still works",
-        [next_match, next, next_match, next, next_match, next, next_match],
-        [
-            InRange(19, 22),
-            Rejects(22, 25),
-            InRange(28, 31),
-            Rejects(31, 32),
-            InRange(34, 37),
-            Rejects(37, 40),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ก',
-        "Forward search for three-byte Thai character",
-        [next_match, next, next_match, next, next_match],
-        [InRange(22, 25), Rejects(25, 28), InRange(40, 43), Rejects(43, 47), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ก',
-        "Forward search for three-byte Thai character; check if next() still works",
-        [next_match, next, next_match, next, next_match],
-        [InRange(22, 25), Rejects(25, 28), InRange(40, 43), Rejects(43, 47), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '😁',
-        "Forward search for four-byte emoji",
-        [next_match, next, next_match, next, next_match],
-        [InRange(15, 19), Rejects(19, 22), InRange(43, 47), Rejects(47, 48), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '😁',
-        "Forward search for four-byte emoji; check if next() still works",
-        [next_match, next, next_match, next, next_match],
-        [InRange(15, 19), Rejects(19, 22), InRange(43, 47), Rejects(47, 48), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ꁁ',
-        "Forward search for three-byte Yi character with repeated bytes",
-        [next_match, next, next_match, next, next_match],
-        [InRange(10, 13), Rejects(13, 14), InRange(37, 40), Rejects(40, 43), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ꁁ',
-        "Forward search for three-byte Yi character with repeated bytes; check if next() still works",
-        [next_match, next, next_match, next, next_match],
-        [InRange(10, 13), Rejects(13, 14), InRange(37, 40), Rejects(40, 43), Done]
-    );
-}
-
-#[test]
-fn test_reverse_search_shared_bytes() {
-    search_asserts!(
-        STRESS,
-        'Á',
-        "Reverse search for two-byte Latin character",
-        [next_match_back, next_match_back, next_match_back, next_match_back],
-        [InRange(32, 34), InRange(8, 10), InRange(0, 2), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'Á',
-        "Reverse search for two-byte Latin character; check if next_back() still works",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back, next_back],
-        [InRange(32, 34), Rejects(31, 32), InRange(8, 10), Rejects(7, 8), InRange(0, 2), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '각',
-        "Reverse search for three-byte Hangul character",
-        [next_match_back, next_back, next_match_back, next_match_back, next_match_back],
-        [InRange(34, 37), Rejects(32, 34), InRange(28, 31), InRange(19, 22), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '각',
-        "Reverse search for three-byte Hangul character; check if next_back() still works",
-        [
-            next_match_back,
-            next_back,
-            next_match_back,
-            next_back,
-            next_match_back,
-            next_back,
-            next_match_back
-        ],
-        [
-            InRange(34, 37),
-            Rejects(32, 34),
-            InRange(28, 31),
-            Rejects(25, 28),
-            InRange(19, 22),
-            Rejects(15, 19),
-            Done
-        ]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ก',
-        "Reverse search for three-byte Thai character",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(40, 43), Rejects(37, 40), InRange(22, 25), Rejects(19, 22), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ก',
-        "Reverse search for three-byte Thai character; check if next_back() still works",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(40, 43), Rejects(37, 40), InRange(22, 25), Rejects(19, 22), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '😁',
-        "Reverse search for four-byte emoji",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(43, 47), Rejects(40, 43), InRange(15, 19), Rejects(14, 15), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        '😁',
-        "Reverse search for four-byte emoji; check if next_back() still works",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(43, 47), Rejects(40, 43), InRange(15, 19), Rejects(14, 15), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ꁁ',
-        "Reverse search for three-byte Yi character with repeated bytes",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(37, 40), Rejects(34, 37), InRange(10, 13), Rejects(8, 10), Done]
-    );
-
-    search_asserts!(
-        STRESS,
-        'ꁁ',
-        "Reverse search for three-byte Yi character with repeated bytes; check if next_back() still works",
-        [next_match_back, next_back, next_match_back, next_back, next_match_back],
-        [InRange(37, 40), Rejects(34, 37), InRange(10, 13), Rejects(8, 10), Done]
-    );
-}
-
-#[test]
-fn double_ended_regression_test() {
-    // https://github.com/rust-lang/rust/issues/47175
-    // Ensures that double ended searching comes to a convergence
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'a',
-        "alternating double ended search",
-        [next_match, next_match_back, next_match, next_match_back],
-        [InRange(0, 1), InRange(10, 11), InRange(5, 6), Done]
-    );
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'a',
-        "triple double ended search for a",
-        [next_match, next_match_back, next_match_back, next_match_back],
-        [InRange(0, 1), InRange(10, 11), InRange(5, 6), Done]
-    );
-    search_asserts!(
-        "abcdeabcdeabcde",
-        'd',
-        "triple double ended search for d",
-        [next_match, next_match_back, next_match_back, next_match_back],
-        [InRange(3, 4), InRange(13, 14), InRange(8, 9), Done]
-    );
-    search_asserts!(
-        STRESS,
-        'Á',
-        "Double ended search for two-byte Latin character",
-        [next_match, next_match_back, next_match, next_match_back],
-        [InRange(0, 2), InRange(32, 34), InRange(8, 10), Done]
-    );
-    search_asserts!(
-        STRESS,
-        '각',
-        "Reverse double ended search for three-byte Hangul character",
-        [next_match_back, next_back, next_match, next, next_match_back, next_match],
-        [InRange(34, 37), Rejects(32, 34), InRange(19, 22), Rejects(22, 25), InRange(28, 31), Done]
-    );
-    search_asserts!(
-        STRESS,
-        'ก',
-        "Double ended search for three-byte Thai character",
-        [next_match, next_back, next, next_match_back, next_match],
-        [InRange(22, 25), Rejects(47, 48), Rejects(25, 28), InRange(40, 43), Done]
-    );
-    search_asserts!(
-        STRESS,
-        '😁',
-        "Double ended search for four-byte emoji",
-        [next_match_back, next, next_match, next_back, next_match],
-        [InRange(43, 47), Rejects(0, 2), InRange(15, 19), Rejects(40, 43), Done]
-    );
-    search_asserts!(
-        STRESS,
-        'ꁁ',
-        "Double ended search for three-byte Yi character with repeated bytes",
-        [next_match, next, next_match_back, next_back, next_match],
-        [InRange(10, 13), Rejects(13, 14), InRange(37, 40), Rejects(34, 37), Done]
-    );
-}