Flag library as #![no_std], add crate docs (WebAssembly#25)

crates/generate-raw/src/lib.rs

@@ -10,10 +10,46 @@ pub fn generate(wasi: &Path) -> String {
     let mut raw = String::new();
     raw.push_str(
         "\
+//! Raw API bindings to the WebAssembly System Interface (WASI)
+//!
+//! This crate provides Rust API bindings to WASI APIs. All WASI APIs are
+//! exported from this crate and provided with the appropriate type signatures.
+//! This crate is entirely procedurally generated from the `*.witx` files that
+//! describe the WASI API.
+//!
+//! # WASI API Version
+//!
+//! The WASI API is evolving over time. It is both gaining new features as well
+//! as tweaking the ABI of existing features. As a result it's important to
+//! understand what version of this crate you're using and how it relates to
+//! the WASI version of the spec.
+//!
+//! The WASI specification is organized into phases where there is a snapshot
+//! at any one point in time describing the current state of the specification.
+//! This crate implements a particular snapshot. You can find the snapshot
+//! version implemented in this crate in the build metadata of the crate
+//! version number. For example something like:
+//!
+//!     0.8.0+wasi-snapshot-preview1
+//!
+//! Means that this crate's own personal version is 0.8.0 and it implements the
+//! `wasi-snapshot-preview1` snapshot. A major release of this crate (i.e.
+//! bumping the \"0.8.0\") is expected whenever the generated code changes
+//! or a new WASI snapshot is used.
+//!
+//! # Crate Features
+//!
+//! This crate supports one feature, `std`, which implements the standard
+//! `Error` trait for the exported [`Error`] type in this crate. This is
+//! enabled by default but can be disabled to make the library `no_std`
+//! compatible.
+
 // This file is automatically generated, DO NOT EDIT
 //
 // To regenerate this file run the `crates/generate-raw` command
 
+#![no_std]
+
 use core::mem::MaybeUninit;
 
 mod error;

src/error.rs

@@ -45,5 +45,7 @@ impl fmt::Debug for Error {
     }
 }
 
+#[cfg(feature = "std")]
+extern crate std;
 #[cfg(feature = "std")]
 impl std::error::Error for Error {}

src/lib.rs

@@ -1,7 +1,43 @@
+//! Raw API bindings to the WebAssembly System Interface (WASI)
+//!
+//! This crate provides Rust API bindings to WASI APIs. All WASI APIs are
+//! exported from this crate and provided with the appropriate type signatures.
+//! This crate is entirely procedurally generated from the `*.witx` files that
+//! describe the WASI API.
+//!
+//! # WASI API Version
+//!
+//! The WASI API is evolving over time. It is both gaining new features as well
+//! as tweaking the ABI of existing features. As a result it's important to
+//! understand what version of this crate you're using and how it relates to
+//! the WASI version of the spec.
+//!
+//! The WASI specification is organized into phases where there is a snapshot
+//! at any one point in time describing the current state of the specification.
+//! This crate implements a particular snapshot. You can find the snapshot
+//! version implemented in this crate in the build metadata of the crate
+//! version number. For example something like:
+//!
+//!     0.8.0+wasi-snapshot-preview1
+//!
+//! Means that this crate's own personal version is 0.8.0 and it implements the
+//! `wasi-snapshot-preview1` snapshot. A major release of this crate (i.e.
+//! bumping the "0.8.0") is expected whenever the generated code changes
+//! or a new WASI snapshot is used.
+//!
+//! # Crate Features
+//!
+//! This crate supports one feature, `std`, which implements the standard
+//! `Error` trait for the exported [`Error`] type in this crate. This is
+//! enabled by default but can be disabled to make the library `no_std`
+//! compatible.
+
 // This file is automatically generated, DO NOT EDIT
 //
 // To regenerate this file run the `crates/generate-raw` command
 
+#![no_std]
+
 use core::mem::MaybeUninit;
 
 mod error;