Start migrating some Wasmtime crates to no_std

.github/workflows/main.yml

@@ -360,6 +360,19 @@ jobs:
     - run: cargo check -p wasmtime-c-api --no-default-features --features wat
     - run: cargo check -p wasmtime-c-api --no-default-features --features wasi
 
+    # Checks for no_std support, ensure that crates can build on a no_std
+    # target
+    - run: rustup target add x86_64-unknown-none
+    - run: cargo check -p wasmtime-jit-icache-coherence
+      env:
+        CARGO_BUILD_TARGET: x86_64-unknown-none
+    - run: cargo check -p wasmtime-component-util
+      env:
+        CARGO_BUILD_TARGET: x86_64-unknown-none
+    - run: cargo check -p wasmtime-asm-macros
+      env:
+        CARGO_BUILD_TARGET: x86_64-unknown-none
+
     # Check that wasmtime-runtime compiles with panic=abort since there's some
     # #[cfg] for specifically panic=abort there.
     - run: cargo check -p wasmtime-runtime

Cargo.toml

@@ -32,14 +32,14 @@ wasmtime-cranelift = { workspace = true, optional = true }
 wasmtime-environ = { workspace = true }
 wasmtime-explorer = { workspace = true, optional = true }
 wasmtime-wast = { workspace = true, optional = true }
-wasi-common = { workspace = true, default-features = true, features = ["exit" ], optional = true }
+wasi-common = { workspace = true, default-features = true, features = ["exit"], optional = true }
 wasmtime-wasi = { workspace = true, default-features = true, optional = true }
 wasmtime-wasi-nn = { workspace = true, optional = true }
 wasmtime-wasi-threads = { workspace = true, optional = true }
 wasmtime-wasi-http = { workspace = true, optional = true }
 wasmtime-runtime = { workspace = true, optional = true }
 clap = { workspace = true }
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 target-lexicon = { workspace = true }
 once_cell = { workspace = true }
 listenfd = { version = "1.0.0", optional = true }
@@ -104,7 +104,7 @@ object = { workspace = true }
 windows-sys = { workspace = true, features = ["Win32_System_Memory"] }
 
 [build-dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 
 [profile.release.build-override]
 opt-level = 0
@@ -248,7 +248,7 @@ wit-component = "0.206.0"
 # --------------------------
 object = { version = "0.33", default-features = false, features = ['read_core', 'elf', 'std'] }
 gimli = { version = "0.28.0", default-features = false, features = ['read', 'std'] }
-anyhow = "1.0.22"
+anyhow = { version = "1.0.22", default-features = false }
 windows-sys = "0.52.0"
 env_logger = "0.10"
 log = { version = "0.4.8", default-features = false }

cranelift/codegen/Cargo.toml

@@ -16,7 +16,7 @@ edition.workspace = true
 workspace = true
 
 [dependencies]
-anyhow = { workspace = true, optional = true }
+anyhow = { workspace = true, optional = true, features = ['std'] }
 bumpalo = "3"
 capstone = { workspace = true, optional = true }
 cranelift-codegen-shared = { path = "./shared", version = "0.108.0" }

cranelift/module/Cargo.toml

@@ -17,7 +17,7 @@ workspace = true
 cranelift-codegen = { workspace = true }
 cranelift-control = { workspace = true }
 hashbrown = { workspace = true, optional = true }
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 serde = { workspace = true, optional = true }
 serde_derive = { workspace = true, optional = true }
 

cranelift/reader/Cargo.toml

@@ -13,7 +13,7 @@ edition.workspace = true
 workspace = true
 
 [dependencies]
-anyhow.workspace = true
+anyhow = { workspace = true, features = ['std'] }
 cranelift-codegen = { workspace = true }
 smallvec = { workspace = true }
 target-lexicon = { workspace = true }

crates/asm-macros/src/lib.rs

@@ -6,6 +6,8 @@
 //! function) and additionally handles visibility across platforms. All symbols
 //! should be visible to Rust but not visible externally outside of a `*.so`.
 
+#![no_std]
+
 cfg_if::cfg_if! {
     if #[cfg(target_os = "macos")] {
         #[macro_export]

crates/cache/Cargo.toml

@@ -12,7 +12,7 @@ edition.workspace = true
 workspace = true
 
 [dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 base64 = "0.21.0"
 postcard = { workspace = true }
 directories-next = "2.0"

crates/component-util/src/lib.rs

@@ -1,3 +1,5 @@
+#![no_std]
+
 /// Represents the possible sizes in bytes of the discriminant of a variant type in the component model
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum DiscriminantSize {

crates/environ/Cargo.toml

@@ -14,7 +14,7 @@ edition.workspace = true
 workspace = true
 
 [dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 postcard = { workspace = true }
 cpp_demangle = { version = "0.4.3", optional = true }
 cranelift-entity = { workspace = true }

crates/jit-icache-coherence/Cargo.toml

@@ -13,6 +13,7 @@ workspace = true
 
 [dependencies]
 cfg-if = { workspace = true }
+anyhow = { workspace = true }
 
 [target.'cfg(target_os = "windows")'.dependencies.windows-sys]
 workspace = true

crates/jit-icache-coherence/src/lib.rs

@@ -34,7 +34,7 @@
 //! #   len: usize,
 //! # }
 //! #
-//! # fn main() -> io::Result<()> {
+//! # fn main() -> anyhow::Result<()> {
 //! #
 //! # let run_code = || {};
 //! # let code = vec![0u8; 64];
@@ -67,8 +67,9 @@
 //!
 //! [ARM Community - Caches and Self-Modifying Code]: https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/caches-and-self-modifying-code
 
-use std::ffi::c_void;
-use std::io::Result;
+#![no_std]
+
+use core::ffi::c_void;
 
 cfg_if::cfg_if! {
     if #[cfg(target_os = "windows")] {
@@ -91,7 +92,7 @@ cfg_if::cfg_if! {
 /// after all calls to [clear_cache].
 ///
 /// If the architecture does not require a pipeline flush, this function does nothing.
-pub fn pipeline_flush_mt() -> Result<()> {
+pub fn pipeline_flush_mt() -> imp::Result<()> {
     imp::pipeline_flush_mt()
 }
 
@@ -103,6 +104,6 @@ pub fn pipeline_flush_mt() -> Result<()> {
 ///
 /// It is necessary to call [pipeline_flush_mt] after this function if you are running in a multi-threaded
 /// environment.
-pub unsafe fn clear_cache(ptr: *const c_void, len: usize) -> Result<()> {
+pub unsafe fn clear_cache(ptr: *const c_void, len: usize) -> imp::Result<()> {
     imp::clear_cache(ptr, len)
 }

crates/jit-icache-coherence/src/libc.rs

@@ -1,11 +1,20 @@
-use std::ffi::c_void;
-use std::io::Result;
+use core::ffi::c_void;
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+extern crate std;
+#[cfg(any(target_os = "linux", target_os = "android"))]
+pub use std::io::Result;
+
+#[cfg(not(any(target_os = "linux", target_os = "android")))]
+pub use anyhow::Result;
 
 #[cfg(all(
     target_arch = "aarch64",
     any(target_os = "linux", target_os = "android")
 ))]
 mod details {
+    extern crate std;
+
     use super::*;
     use libc::{syscall, EINVAL, EPERM};
     use std::io::Error;
@@ -87,20 +96,25 @@ mod details {
     any(target_os = "linux", target_os = "android")
 )))]
 mod details {
-    pub(crate) fn pipeline_flush_mt() -> std::io::Result<()> {
+    // NB: this uses `anyhow::Result` instead of `std::io::Result` to compile on
+    // `no_std`.
+    pub(crate) fn pipeline_flush_mt() -> super::Result<()> {
         Ok(())
     }
 }
+
 #[cfg(all(target_arch = "riscv64", target_os = "linux"))]
 fn riscv_flush_icache(start: u64, end: u64) -> Result<()> {
     cfg_if::cfg_if! {
         if #[cfg(feature = "one-core")] {
-            use std::arch::asm;
+            use core::arch::asm;
             unsafe {
                 asm!("fence.i");
             };
             Ok(())
         } else {
+            extern crate std;
+
             match unsafe {
                 libc::syscall(
                     {

crates/jit-icache-coherence/src/miri.rs

@@ -1,5 +1,5 @@
-use std::ffi::c_void;
-use std::io::Result;
+pub use anyhow::Result;
+use core::ffi::c_void;
 
 pub(crate) fn pipeline_flush_mt() -> Result<()> {
     Ok(())

crates/jit-icache-coherence/src/win.rs

@@ -1,9 +1,13 @@
+extern crate std;
+
 use std::ffi::c_void;
-use std::io::{Error, Result};
+use std::io::Error;
 use windows_sys::Win32::System::Diagnostics::Debug::FlushInstructionCache;
 use windows_sys::Win32::System::Threading::FlushProcessWriteBuffers;
 use windows_sys::Win32::System::Threading::GetCurrentProcess;
 
+pub use std::io::Result;
+
 /// See docs on [crate::pipeline_flush_mt] for a description of what this function is trying to do.
 #[inline]
 pub(crate) fn pipeline_flush_mt() -> Result<()> {

crates/test-programs/Cargo.toml

@@ -10,7 +10,7 @@ license = "Apache-2.0 WITH LLVM-exception"
 workspace = true
 
 [dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 wasi = "0.11.0"
 wasi-nn = "0.6.0"
 wit-bindgen = { workspace = true, features = ['default'] }

crates/wasi-preview1-component-adapter/verify/Cargo.toml

@@ -11,4 +11,4 @@ workspace = true
 [dependencies]
 wasmparser = { workspace = true }
 wat = { workspace = true }
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }

examples/min-platform/Cargo.toml

@@ -9,6 +9,6 @@ rust-version.workspace = true
 workspace = true
 
 [dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true, features = ['std'] }
 libloading = "0.8"
 object = { workspace = true }