Auto merge of #73265 - mark-i-m:mv-std, r=Mark-Simulacrum,mark-i-m

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, 168 deletions

diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
deleted file mode 100644
index eddf00d3979..00000000000
--- a/src/libstd/sys/unix/mod.rs
+++ /dev/null
@@ -1,168 +0,0 @@
-#![allow(missing_docs, nonstandard_style)]
-
-use crate::io::ErrorKind;
-
-#[cfg(any(doc, target_os = "linux"))]
-pub use crate::os::linux as platform;
-
-#[cfg(all(not(doc), target_os = "android"))]
-pub use crate::os::android as platform;
-#[cfg(all(not(doc), target_os = "dragonfly"))]
-pub use crate::os::dragonfly as platform;
-#[cfg(all(not(doc), target_os = "emscripten"))]
-pub use crate::os::emscripten as platform;
-#[cfg(all(not(doc), target_os = "freebsd"))]
-pub use crate::os::freebsd as platform;
-#[cfg(all(not(doc), target_os = "fuchsia"))]
-pub use crate::os::fuchsia as platform;
-#[cfg(all(not(doc), target_os = "haiku"))]
-pub use crate::os::haiku as platform;
-#[cfg(all(not(doc), target_os = "illumos"))]
-pub use crate::os::illumos as platform;
-#[cfg(all(not(doc), target_os = "ios"))]
-pub use crate::os::ios as platform;
-#[cfg(all(not(doc), target_os = "l4re"))]
-pub use crate::os::linux as platform;
-#[cfg(all(not(doc), target_os = "macos"))]
-pub use crate::os::macos as platform;
-#[cfg(all(not(doc), target_os = "netbsd"))]
-pub use crate::os::netbsd as platform;
-#[cfg(all(not(doc), target_os = "openbsd"))]
-pub use crate::os::openbsd as platform;
-#[cfg(all(not(doc), target_os = "redox"))]
-pub use crate::os::redox as platform;
-#[cfg(all(not(doc), target_os = "solaris"))]
-pub use crate::os::solaris as platform;
-
-pub use self::rand::hashmap_random_keys;
-pub use libc::strlen;
-
-#[macro_use]
-pub mod weak;
-
-pub mod alloc;
-pub mod android;
-pub mod args;
-pub mod cmath;
-pub mod condvar;
-pub mod env;
-pub mod ext;
-pub mod fd;
-pub mod fs;
-pub mod io;
-#[cfg(target_os = "l4re")]
-mod l4re;
-pub mod memchr;
-pub mod mutex;
-#[cfg(not(target_os = "l4re"))]
-pub mod net;
-#[cfg(target_os = "l4re")]
-pub use self::l4re::net;
-pub mod os;
-pub mod path;
-pub mod pipe;
-pub mod process;
-pub mod rand;
-pub mod rwlock;
-pub mod stack_overflow;
-pub mod stdio;
-pub mod thread;
-pub mod thread_local_dtor;
-pub mod thread_local_key;
-pub mod time;
-
-pub use crate::sys_common::os_str_bytes as os_str;
-
-#[cfg(not(test))]
-pub fn init() {
-    // By default, some platforms will send a *signal* when an EPIPE error
-    // would otherwise be delivered. This runtime doesn't install a SIGPIPE
-    // handler, causing it to kill the program, which isn't exactly what we
-    // want!
-    //
-    // Hence, we set SIGPIPE to ignore when the program starts up in order
-    // to prevent this problem.
-    unsafe {
-        reset_sigpipe();
-    }
-
-    #[cfg(not(any(target_os = "emscripten", target_os = "fuchsia")))]
-    unsafe fn reset_sigpipe() {
-        assert!(signal(libc::SIGPIPE, libc::SIG_IGN) != libc::SIG_ERR);
-    }
-    #[cfg(any(target_os = "emscripten", target_os = "fuchsia"))]
-    unsafe fn reset_sigpipe() {}
-}
-
-#[cfg(target_os = "android")]
-pub use crate::sys::android::signal;
-#[cfg(not(target_os = "android"))]
-pub use libc::signal;
-
-pub fn decode_error_kind(errno: i32) -> ErrorKind {
-    match errno as libc::c_int {
-        libc::ECONNREFUSED => ErrorKind::ConnectionRefused,
-        libc::ECONNRESET => ErrorKind::ConnectionReset,
-        libc::EPERM | libc::EACCES => ErrorKind::PermissionDenied,
-        libc::EPIPE => ErrorKind::BrokenPipe,
-        libc::ENOTCONN => ErrorKind::NotConnected,
-        libc::ECONNABORTED => ErrorKind::ConnectionAborted,
-        libc::EADDRNOTAVAIL => ErrorKind::AddrNotAvailable,
-        libc::EADDRINUSE => ErrorKind::AddrInUse,
-        libc::ENOENT => ErrorKind::NotFound,
-        libc::EINTR => ErrorKind::Interrupted,
-        libc::EINVAL => ErrorKind::InvalidInput,
-        libc::ETIMEDOUT => ErrorKind::TimedOut,
-        libc::EEXIST => ErrorKind::AlreadyExists,
-
-        // These two constants can have the same value on some systems,
-        // but different values on others, so we can't use a match
-        // clause
-        x if x == libc::EAGAIN || x == libc::EWOULDBLOCK => ErrorKind::WouldBlock,
-
-        _ => ErrorKind::Other,
-    }
-}
-
-#[doc(hidden)]
-pub trait IsMinusOne {
-    fn is_minus_one(&self) -> bool;
-}
-
-macro_rules! impl_is_minus_one {
-    ($($t:ident)*) => ($(impl IsMinusOne for $t {
-        fn is_minus_one(&self) -> bool {
-            *self == -1
-        }
-    })*)
-}
-
-impl_is_minus_one! { i8 i16 i32 i64 isize }
-
-pub fn cvt<T: IsMinusOne>(t: T) -> crate::io::Result<T> {
-    if t.is_minus_one() { Err(crate::io::Error::last_os_error()) } else { Ok(t) }
-}
-
-pub fn cvt_r<T, F>(mut f: F) -> crate::io::Result<T>
-where
-    T: IsMinusOne,
-    F: FnMut() -> T,
-{
-    loop {
-        match cvt(f()) {
-            Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
-            other => return other,
-        }
-    }
-}
-
-// On Unix-like platforms, libc::abort will unregister signal handlers
-// including the SIGABRT handler, preventing the abort from being blocked, and
-// fclose streams, with the side effect of flushing them so libc buffered
-// output will be printed.  Additionally the shell will generally print a more
-// understandable error message like "Abort trap" rather than "Illegal
-// instruction" that intrinsics::abort would cause, as intrinsics::abort is
-// implemented as an illegal instruction.
-pub fn abort_internal() -> ! {
-    unsafe { libc::abort() }
-}