cdecc858b4
Add a RISC-V 64 (`riscv64`, RV64GC) backend. Co-authored-by: yuyang <756445638@qq.com> Co-authored-by: Chris Fallin <chris@cfallin.org> Co-authored-by: Afonso Bordado <afonsobordado@az8.co>
61 lines
1.9 KiB
Rust
61 lines
1.9 KiB
Rust
//! Trampolines for calling into Wasm from the host and calling the host from
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//! Wasm.
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use crate::VMContext;
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use std::mem;
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/// Given a Wasm function pointer and a `vmctx`, prepare the `vmctx` for calling
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/// into that Wasm function, and return the host-to-Wasm entry trampoline.
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///
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/// Callers must never call Wasm function pointers directly. Callers must
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/// instead call this function and then enter Wasm through the returned
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/// host-to-Wasm trampoline.
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///
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/// # Unsafety
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///
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/// The `vmctx` argument must be valid.
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///
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/// The generic type `T` must be a function pointer type and `func` must be a
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/// pointer to a Wasm function of that signature.
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///
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/// After calling this function, you may not mess with the vmctx or any other
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/// Wasm state until after you've called the trampoline returned by this
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/// function.
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#[inline]
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pub unsafe fn prepare_host_to_wasm_trampoline<T>(vmctx: *mut VMContext, func: T) -> T {
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assert_eq!(mem::size_of::<T>(), mem::size_of::<usize>());
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// Save the callee in the `vmctx`. The trampoline will read this function
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// pointer and tail call to it.
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(*vmctx)
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.instance_mut()
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.set_callee(Some(mem::transmute_copy(&func)));
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// Give callers the trampoline, transmuted into their desired function
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// signature (the trampoline is variadic and works with all signatures).
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mem::transmute_copy(&(host_to_wasm_trampoline as usize))
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}
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extern "C" {
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fn host_to_wasm_trampoline();
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pub(crate) fn wasm_to_host_trampoline();
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}
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cfg_if::cfg_if! {
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if #[cfg(target_arch = "x86_64")] {
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#[macro_use]
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mod x86_64;
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} else if #[cfg(target_arch = "aarch64")] {
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#[macro_use]
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mod aarch64;
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} else if #[cfg(target_arch = "s390x")] {
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#[macro_use]
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mod s390x;
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}else if #[cfg(target_arch = "riscv64")] {
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#[macro_use]
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mod riscv64;
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} else {
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compile_error!("unsupported architecture");
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}
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}
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