rust/library/std/src/sys/pal/wasi, branch master

std: Start supporting WASIp2 natively

2025-08-28T22:07:15+00:00

This commit is the start of an effort to support WASIp2 natively in the standard library. Before this commit the `wasm32-wasip2` target behaved exactly like `wasm32-wasip1` target by importing APIs from the core wasm module `wasi_snapshot_preview1`. These APIs are satisfied by the `wasm-component-ld` target by using an [adapter] which implements WASIp1 in terms of WASIp2. This adapter comes at a cost, however, in terms of runtime indirection and instantiation cost, so ideally the adapter would be removed entirely. The purpose of this adapter was to provide a smoother on-ramp from WASIp1 to WASIp2 when it was originally created. The `wasm32-wasip2` target has been around for long enough now that it's much more established. Additionally the only thing historically blocking using WASIp2 directly was implementation effort. Work is now underway to migrate wasi-libc itself to using WASIp2 directly and now seems as good a time as any to migrate the Rust standard library too. Implementation-wise the milestones here are: * The `wasm32-wasip2` target now also depends on the `wasi` crate at version 0.14.* in addition to the preexisting dependency of 0.11.*. The 0.14.* release series binds WASIp2 APIs instead of WASIp1 APIs. * Some preexisting naming around `mod wasi` or `wasi.rs` was renamed to `wasip1` where appropriate. For example `std::sys::pal::wasi` is now called `std::sys::pal::wasip1`. * More platform-specific WASI modules are now split between WASIp1 and WASIp2. For example getting the current time, randomness, and process arguments now use WASIp2 APIs directly instead of using WASIp1 APIs that require an adapter. It's worth pointing out that this PR does not migrate the entire standard library away from using WASIp1 APIs on the `wasm32-wasip2` target. Everything related to file descriptors and filesystem APIs is still using WASIp1. Migrating that is left for a future PR. In the meantime the goal of this change is to lay the groundwork necessary for migrating in the future. Eventually the goal is to drop the `wasi` 0.11.* dependency on the `wasm32-wasip2` target (the `wasm32-wasip1` target will continue to retain this dependency). [adapter]: https://github.com/bytecodealliance/wasmtime/blob/main/crates/wasi-preview1-component-adapter/README.md

remove deprecated Error::description in impls

2025-08-26T06:36:53+00:00

library: Migrate from `cfg_if` to `cfg_select`

2025-08-16T12:28:31+00:00

Migrate the standard library from using the external `cfg_if` crate to using the now-built-in `cfg_select` macro. This does not yet eliminate the dependency from `library/std/Cargo.toml`, because while the standard library itself no longer uses `cfg_if`, it also incorporates the `backtrace` crate, which does. Migration assisted by the following vim command (after selecting the full `cfg_if!` invocation): ``` '<,'>s/\(cfg_if::\)\?cfg_if/cfg_select/ | '<,'>s/^\( *\)} else {/\1}\r\1_ => {/c | '<,'>s/^\( *\)} else if #\[cfg(\(.*\))\] /\1}\r\1\2 => /e | '<,'>s/if #\[cfg(\(.*\))\] {/\1 => {/e ``` This is imperfect, but substantially accelerated the process. This prompts for confirmation on the `} else {` since that can also appear inside one of the arms. This also requires manual intervention to handle any multi-line conditions.

Constify SystemTime methods

2025-08-12T18:05:47+00:00

Print thread ID in panic message if thread name is unknown

2025-08-06T23:59:47+00:00

`panic!` does not print any identifying information for threads that are unnamed. However, in many cases, the thread ID can be determined. This changes the panic message from something like this: thread '' panicked at src/main.rs:3:5: explicit panic To something like this: thread '' (0xff9bf) panicked at src/main.rs:3:5: explicit panic Stack overflow messages are updated as well. This change applies to both named and unnamed threads. The ID printed is the OS integer thread ID rather than the Rust thread ID, which should also be what debuggers print.

thread name in stack overflow message

2025-07-28T16:09:35+00:00

sleep_until: use clock_nanosleep where possible

2025-07-06T15:36:49+00:00

Using clock nanosleep leads to more accurate sleep times on platforms where it is supported. To enable using clock_nanosleep this makes `sleep_until` platform specific. That unfortunatly requires identical placeholder implementations for the other platforms (windows/mac/wasm etc). we will land platform specific implementations for those later. See the `sleep_until` tracking issue. This requires an accessors for the Instant type. As that accessor is only used on the platforms that have clock_nanosleep it is marked as allow_unused. 32bit time_t targets do not use clock_nanosleep atm, they instead rely on the same placeholder as the other platforms. We could make them use clock_nanosleep too in the future using `__clock_nanosleep_time64`. __clock_nanosleep_time64 is documented at: https://www.gnu.org/software/libc/manual/html_node/64_002dbit-time-symbol-handling.html

Move `sys::pal::os::Env` into `sys::env`

2025-04-22T03:56:43+00:00

Although `Env` (as `Vars`), `Args`, path functions, and OS constants are publicly exposed via `std::env`, their implementations are each self-contained. Keep them separate in `std::sys` and make a new module, `sys::env`, for `Env`.

Combine env consts into std::sys::env_consts

2025-04-19T02:17:08+00:00

Move args into std::sys

2025-04-12T10:10:21+00:00