Rollup merge of #119616 - rylev:wasm32-wasi-preview2, r=petrochenkov,m-ou-se

Add a new `wasm32-wasi-preview2` target

This is the initial implementation of the MCP https://github.com/rust-lang/compiler-team/issues/694 creating a new tier 3 target `wasm32-wasi-preview2`. That MCP has been seconded and will most likely be approved in a little over a week from now. For more information on the need for this target, please read the [MCP](https://github.com/rust-lang/compiler-team/issues/694).

There is one aspect of this PR that will become insta-stable once these changes reach a stable compiler:
* A new `target_family` named `wasi` is introduced. This target family incorporates all wasi targets including `wasm32-wasi` and its derivative `wasm32-wasi-preview1-threads`. The difference between `target_family = wasi` and `target_os = wasi` will become much clearer when `wasm32-wasi` is renamed to `wasm32-wasi-preview1` and the `target_os` becomes `wasm32-wasi-preview1`. You can read about this target rename in [this MCP](https://github.com/rust-lang/compiler-team/issues/695) which has also been seconded and will hopefully be officially approved soon.

Additional technical details include:
* Both `std::sys::wasi_preview2` and `std::os::wasi_preview2` have been created and mostly use `#[path]` annotations on their submodules to reach into the existing `wasi` (soon to be `wasi_preview1`) modules. Over time the differences between `wasi_preview1` and `wasi_preview2` will grow and most like all `#[path]` based module aliases will fall away.
* Building `wasi-preview2` relies on a [`wasi-sdk`](https://github.com/WebAssembly/wasi-sdk) in the same way that `wasi-preview1` does (one must include a `wasi-root` path in the `Config.toml` pointing to sysroot included in the wasi-sdk). The target should build against [wasi-sdk v21](https://github.com/WebAssembly/wasi-sdk/releases/tag/wasi-sdk-21) without modifications. However, the wasi-sdk itself is growing [preview2 support](https://github.com/WebAssembly/wasi-sdk/pull/370) so this might shift rapidly. We will be following along quickly to make sure that building the target remains possible as the wasi-sdk changes.
* This requires a [patch to libc](https://github.com/rylev/rust-libc/tree/wasm32-wasi-preview2) that we'll need to land in conjunction with this change. Until that patch lands the target won't actually build.

4 files changed, 213 insertions, 123 deletions

diff --git a/library/std/src/sys/pal/mod.rs b/library/std/src/sys/pal/mod.rs
index 041b7c35582..f927d88d46c 100644
--- a/library/std/src/sys/pal/mod.rs
+++ b/library/std/src/sys/pal/mod.rs
@@ -40,6 +40,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "wasi")] {
         mod wasi;
         pub use self::wasi::*;
+    } else if #[cfg(all(target_os = "wasi", target_env = "preview2"))] {
+        mod wasi_preview2;
+        pub use self::wasi_preview2::*;
     } else if #[cfg(target_family = "wasm")] {
         mod wasm;
         pub use self::wasm::*;
diff --git a/library/std/src/sys/pal/wasi/helpers.rs b/library/std/src/sys/pal/wasi/helpers.rs
new file mode 100644
index 00000000000..82149cef8fa
--- /dev/null
+++ b/library/std/src/sys/pal/wasi/helpers.rs
@@ -0,0 +1,123 @@
+use crate::io as std_io;
+use crate::mem;
+
+#[inline]
+pub fn is_interrupted(errno: i32) -> bool {
+    errno == wasi::ERRNO_INTR.raw().into()
+}
+
+pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
+    use std_io::ErrorKind;
+
+    let Ok(errno) = u16::try_from(errno) else {
+        return ErrorKind::Uncategorized;
+    };
+
+    macro_rules! match_errno {
+        ($($($errno:ident)|+ => $errkind:ident),*, _ => $wildcard:ident $(,)?) => {
+            match errno {
+                $(e if $(e == ::wasi::$errno.raw())||+ => ErrorKind::$errkind),*,
+                _ => ErrorKind::$wildcard,
+            }
+        };
+    }
+
+    match_errno! {
+        ERRNO_2BIG           => ArgumentListTooLong,
+        ERRNO_ACCES          => PermissionDenied,
+        ERRNO_ADDRINUSE      => AddrInUse,
+        ERRNO_ADDRNOTAVAIL   => AddrNotAvailable,
+        ERRNO_AFNOSUPPORT    => Unsupported,
+        ERRNO_AGAIN          => WouldBlock,
+        //    ALREADY        => "connection already in progress",
+        //    BADF           => "bad file descriptor",
+        //    BADMSG         => "bad message",
+        ERRNO_BUSY           => ResourceBusy,
+        //    CANCELED       => "operation canceled",
+        //    CHILD          => "no child processes",
+        ERRNO_CONNABORTED    => ConnectionAborted,
+        ERRNO_CONNREFUSED    => ConnectionRefused,
+        ERRNO_CONNRESET      => ConnectionReset,
+        ERRNO_DEADLK         => Deadlock,
+        //    DESTADDRREQ    => "destination address required",
+        ERRNO_DOM            => InvalidInput,
+        //    DQUOT          => /* reserved */,
+        ERRNO_EXIST          => AlreadyExists,
+        //    FAULT          => "bad address",
+        ERRNO_FBIG           => FileTooLarge,
+        ERRNO_HOSTUNREACH    => HostUnreachable,
+        //    IDRM           => "identifier removed",
+        //    ILSEQ          => "illegal byte sequence",
+        //    INPROGRESS     => "operation in progress",
+        ERRNO_INTR           => Interrupted,
+        ERRNO_INVAL          => InvalidInput,
+        ERRNO_IO             => Uncategorized,
+        //    ISCONN         => "socket is connected",
+        ERRNO_ISDIR          => IsADirectory,
+        ERRNO_LOOP           => FilesystemLoop,
+        //    MFILE          => "file descriptor value too large",
+        ERRNO_MLINK          => TooManyLinks,
+        //    MSGSIZE        => "message too large",
+        //    MULTIHOP       => /* reserved */,
+        ERRNO_NAMETOOLONG    => InvalidFilename,
+        ERRNO_NETDOWN        => NetworkDown,
+        //    NETRESET       => "connection aborted by network",
+        ERRNO_NETUNREACH     => NetworkUnreachable,
+        //    NFILE          => "too many files open in system",
+        //    NOBUFS         => "no buffer space available",
+        ERRNO_NODEV          => NotFound,
+        ERRNO_NOENT          => NotFound,
+        //    NOEXEC         => "executable file format error",
+        //    NOLCK          => "no locks available",
+        //    NOLINK         => /* reserved */,
+        ERRNO_NOMEM          => OutOfMemory,
+        //    NOMSG          => "no message of the desired type",
+        //    NOPROTOOPT     => "protocol not available",
+        ERRNO_NOSPC          => StorageFull,
+        ERRNO_NOSYS          => Unsupported,
+        ERRNO_NOTCONN        => NotConnected,
+        ERRNO_NOTDIR         => NotADirectory,
+        ERRNO_NOTEMPTY       => DirectoryNotEmpty,
+        //    NOTRECOVERABLE => "state not recoverable",
+        //    NOTSOCK        => "not a socket",
+        ERRNO_NOTSUP         => Unsupported,
+        //    NOTTY          => "inappropriate I/O control operation",
+        ERRNO_NXIO           => NotFound,
+        //    OVERFLOW       => "value too large to be stored in data type",
+        //    OWNERDEAD      => "previous owner died",
+        ERRNO_PERM           => PermissionDenied,
+        ERRNO_PIPE           => BrokenPipe,
+        //    PROTO          => "protocol error",
+        ERRNO_PROTONOSUPPORT => Unsupported,
+        //    PROTOTYPE      => "protocol wrong type for socket",
+        //    RANGE          => "result too large",
+        ERRNO_ROFS           => ReadOnlyFilesystem,
+        ERRNO_SPIPE          => NotSeekable,
+        ERRNO_SRCH           => NotFound,
+        //    STALE          => /* reserved */,
+        ERRNO_TIMEDOUT       => TimedOut,
+        ERRNO_TXTBSY         => ResourceBusy,
+        ERRNO_XDEV           => CrossesDevices,
+        ERRNO_NOTCAPABLE     => PermissionDenied,
+        _                    => Uncategorized,
+    }
+}
+
+pub fn abort_internal() -> ! {
+    unsafe { libc::abort() }
+}
+
+pub fn hashmap_random_keys() -> (u64, u64) {
+    let mut ret = (0u64, 0u64);
+    unsafe {
+        let base = &mut ret as *mut (u64, u64) as *mut u8;
+        let len = mem::size_of_val(&ret);
+        wasi::random_get(base, len).expect("random_get failure");
+    }
+    return ret;
+}
+
+#[inline]
+pub(crate) fn err2io(err: wasi::Errno) -> std_io::Error {
+    std_io::Error::from_raw_os_error(err.raw().into())
+}
diff --git a/library/std/src/sys/pal/wasi/mod.rs b/library/std/src/sys/pal/wasi/mod.rs
index 4ffc8ecdd67..a4b55093bf4 100644
--- a/library/std/src/sys/pal/wasi/mod.rs
+++ b/library/std/src/sys/pal/wasi/mod.rs
@@ -14,9 +14,6 @@
 //! compiling for wasm. That way it's a compile time error for something that's
 //! guaranteed to be a runtime error!
 
-use crate::io as std_io;
-use crate::mem;
-
 #[path = "../unix/alloc.rs"]
 pub mod alloc;
 pub mod args;
@@ -72,123 +69,12 @@ cfg_if::cfg_if! {
 mod common;
 pub use common::*;
 
-#[inline]
-pub fn is_interrupted(errno: i32) -> bool {
-    errno == wasi::ERRNO_INTR.raw().into()
-}
-
-pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
-    use std_io::ErrorKind;
-
-    let Ok(errno) = u16::try_from(errno) else {
-        return ErrorKind::Uncategorized;
-    };
-
-    macro_rules! match_errno {
-        ($($($errno:ident)|+ => $errkind:ident),*, _ => $wildcard:ident $(,)?) => {
-            match errno {
-                $(e if $(e == ::wasi::$errno.raw())||+ => ErrorKind::$errkind),*,
-                _ => ErrorKind::$wildcard,
-            }
-        };
-    }
-
-    match_errno! {
-        ERRNO_2BIG           => ArgumentListTooLong,
-        ERRNO_ACCES          => PermissionDenied,
-        ERRNO_ADDRINUSE      => AddrInUse,
-        ERRNO_ADDRNOTAVAIL   => AddrNotAvailable,
-        ERRNO_AFNOSUPPORT    => Unsupported,
-        ERRNO_AGAIN          => WouldBlock,
-        //    ALREADY        => "connection already in progress",
-        //    BADF           => "bad file descriptor",
-        //    BADMSG         => "bad message",
-        ERRNO_BUSY           => ResourceBusy,
-        //    CANCELED       => "operation canceled",
-        //    CHILD          => "no child processes",
-        ERRNO_CONNABORTED    => ConnectionAborted,
-        ERRNO_CONNREFUSED    => ConnectionRefused,
-        ERRNO_CONNRESET      => ConnectionReset,
-        ERRNO_DEADLK         => Deadlock,
-        //    DESTADDRREQ    => "destination address required",
-        ERRNO_DOM            => InvalidInput,
-        //    DQUOT          => /* reserved */,
-        ERRNO_EXIST          => AlreadyExists,
-        //    FAULT          => "bad address",
-        ERRNO_FBIG           => FileTooLarge,
-        ERRNO_HOSTUNREACH    => HostUnreachable,
-        //    IDRM           => "identifier removed",
-        //    ILSEQ          => "illegal byte sequence",
-        //    INPROGRESS     => "operation in progress",
-        ERRNO_INTR           => Interrupted,
-        ERRNO_INVAL          => InvalidInput,
-        ERRNO_IO             => Uncategorized,
-        //    ISCONN         => "socket is connected",
-        ERRNO_ISDIR          => IsADirectory,
-        ERRNO_LOOP           => FilesystemLoop,
-        //    MFILE          => "file descriptor value too large",
-        ERRNO_MLINK          => TooManyLinks,
-        //    MSGSIZE        => "message too large",
-        //    MULTIHOP       => /* reserved */,
-        ERRNO_NAMETOOLONG    => InvalidFilename,
-        ERRNO_NETDOWN        => NetworkDown,
-        //    NETRESET       => "connection aborted by network",
-        ERRNO_NETUNREACH     => NetworkUnreachable,
-        //    NFILE          => "too many files open in system",
-        //    NOBUFS         => "no buffer space available",
-        ERRNO_NODEV          => NotFound,
-        ERRNO_NOENT          => NotFound,
-        //    NOEXEC         => "executable file format error",
-        //    NOLCK          => "no locks available",
-        //    NOLINK         => /* reserved */,
-        ERRNO_NOMEM          => OutOfMemory,
-        //    NOMSG          => "no message of the desired type",
-        //    NOPROTOOPT     => "protocol not available",
-        ERRNO_NOSPC          => StorageFull,
-        ERRNO_NOSYS          => Unsupported,
-        ERRNO_NOTCONN        => NotConnected,
-        ERRNO_NOTDIR         => NotADirectory,
-        ERRNO_NOTEMPTY       => DirectoryNotEmpty,
-        //    NOTRECOVERABLE => "state not recoverable",
-        //    NOTSOCK        => "not a socket",
-        ERRNO_NOTSUP         => Unsupported,
-        //    NOTTY          => "inappropriate I/O control operation",
-        ERRNO_NXIO           => NotFound,
-        //    OVERFLOW       => "value too large to be stored in data type",
-        //    OWNERDEAD      => "previous owner died",
-        ERRNO_PERM           => PermissionDenied,
-        ERRNO_PIPE           => BrokenPipe,
-        //    PROTO          => "protocol error",
-        ERRNO_PROTONOSUPPORT => Unsupported,
-        //    PROTOTYPE      => "protocol wrong type for socket",
-        //    RANGE          => "result too large",
-        ERRNO_ROFS           => ReadOnlyFilesystem,
-        ERRNO_SPIPE          => NotSeekable,
-        ERRNO_SRCH           => NotFound,
-        //    STALE          => /* reserved */,
-        ERRNO_TIMEDOUT       => TimedOut,
-        ERRNO_TXTBSY         => ResourceBusy,
-        ERRNO_XDEV           => CrossesDevices,
-        ERRNO_NOTCAPABLE     => PermissionDenied,
-        _                    => Uncategorized,
-    }
-}
-
-pub fn abort_internal() -> ! {
-    unsafe { libc::abort() }
-}
-
-pub fn hashmap_random_keys() -> (u64, u64) {
-    let mut ret = (0u64, 0u64);
-    unsafe {
-        let base = &mut ret as *mut (u64, u64) as *mut u8;
-        let len = mem::size_of_val(&ret);
-        wasi::random_get(base, len).expect("random_get failure");
-    }
-    return ret;
-}
-
-#[inline]
-fn err2io(err: wasi::Errno) -> std_io::Error {
-    std_io::Error::from_raw_os_error(err.raw().into())
-}
+mod helpers;
+// These exports are listed individually to work around Rust's glob import
+// conflict rules. If we glob export `helpers` and `common` together, then
+// the compiler complains about conflicts.
+pub use helpers::abort_internal;
+pub use helpers::decode_error_kind;
+use helpers::err2io;
+pub use helpers::hashmap_random_keys;
+pub use helpers::is_interrupted;
diff --git a/library/std/src/sys/pal/wasi_preview2/mod.rs b/library/std/src/sys/pal/wasi_preview2/mod.rs
new file mode 100644
index 00000000000..b61695015bb
--- /dev/null
+++ b/library/std/src/sys/pal/wasi_preview2/mod.rs
@@ -0,0 +1,78 @@
+//! System bindings for the wasi preview 2 target.
+//!
+//! This is the next evolution of the original wasi target, and is intended to
+//! replace that target over time.
+//!
+//! To begin with, this target mirrors the wasi target 1 to 1, but over
+//! time this will change significantly.
+
+#[path = "../unix/alloc.rs"]
+pub mod alloc;
+#[path = "../wasi/args.rs"]
+pub mod args;
+#[path = "../unix/cmath.rs"]
+pub mod cmath;
+#[path = "../wasi/env.rs"]
+pub mod env;
+#[path = "../wasi/fd.rs"]
+pub mod fd;
+#[path = "../wasi/fs.rs"]
+pub mod fs;
+#[allow(unused)]
+#[path = "../wasm/atomics/futex.rs"]
+pub mod futex;
+#[path = "../wasi/io.rs"]
+pub mod io;
+
+#[path = "../wasi/net.rs"]
+pub mod net;
+#[path = "../wasi/os.rs"]
+pub mod os;
+#[path = "../unix/os_str.rs"]
+pub mod os_str;
+#[path = "../unix/path.rs"]
+pub mod path;
+#[path = "../unsupported/pipe.rs"]
+pub mod pipe;
+#[path = "../unsupported/process.rs"]
+pub mod process;
+#[path = "../wasi/stdio.rs"]
+pub mod stdio;
+#[path = "../wasi/thread.rs"]
+pub mod thread;
+#[path = "../unsupported/thread_local_dtor.rs"]
+pub mod thread_local_dtor;
+#[path = "../unsupported/thread_local_key.rs"]
+pub mod thread_local_key;
+#[path = "../wasi/time.rs"]
+pub mod time;
+
+cfg_if::cfg_if! {
+    if #[cfg(target_feature = "atomics")] {
+        compile_error!("The wasm32-wasi-preview2 target does not support atomics");
+    } else {
+        #[path = "../unsupported/locks/mod.rs"]
+        pub mod locks;
+        #[path = "../unsupported/once.rs"]
+        pub mod once;
+        #[path = "../unsupported/thread_parking.rs"]
+        pub mod thread_parking;
+    }
+}
+
+#[path = "../unsupported/common.rs"]
+#[deny(unsafe_op_in_unsafe_fn)]
+#[allow(unused)]
+mod common;
+pub use common::*;
+
+#[path = "../wasi/helpers.rs"]
+mod helpers;
+// These exports are listed individually to work around Rust's glob import
+// conflict rules. If we glob export `helpers` and `common` together, then
+// the compiler complains about conflicts.
+pub use helpers::abort_internal;
+pub use helpers::decode_error_kind;
+use helpers::err2io;
+pub use helpers::hashmap_random_keys;
+pub use helpers::is_interrupted;