add component-model-async/lower.wast test (#10103)

This is another piece of #9582 which I'm splitting out to make review easier.

This test includes a minimal component which lowers an import with the `async`
option.

The rest of the changes fill in some TODOs to make the test pass.

Signed-off-by: Joel Dice <joel.dice@fermyon.com>

Author: dicej

crates/cranelift/src/compiler/component.rs

@@ -280,10 +280,6 @@ impl<'a> TrampolineCompiler<'a> {
             async_,
         } = *options;
 
-        if async_ {
-            todo!()
-        }
-
         // vmctx: *mut VMComponentContext
         host_sig.params.push(ir::AbiParam::new(pointer_type));
         callee_args.push(vmctx);
@@ -350,6 +346,14 @@ impl<'a> TrampolineCompiler<'a> {
                 .iconst(ir::types::I8, i64::from(string_encoding as u8)),
         );
 
+        // async_: bool
+        host_sig.params.push(ir::AbiParam::new(ir::types::I8));
+        callee_args.push(
+            self.builder
+                .ins()
+                .iconst(ir::types::I8, if async_ { 1 } else { 0 }),
+        );
+
         // storage: *mut ValRaw
         host_sig.params.push(ir::AbiParam::new(pointer_type));
         callee_args.push(values_vec_ptr);

crates/wasmtime/src/runtime/component/func/host.rs

@@ -46,6 +46,7 @@ impl HostFunc {
         memory: *mut VMMemoryDefinition,
         realloc: *mut VMFuncRef,
         string_encoding: u8,
+        async_: u8,
         storage: NonNull<MaybeUninit<ValRaw>>,
         storage_len: usize,
     ) -> bool
@@ -66,6 +67,7 @@ impl HostFunc {
                     memory,
                     realloc,
                     StringEncoding::from_u8(string_encoding).unwrap(),
+                    async_ != 0,
                     NonNull::slice_from_raw_parts(storage, storage_len).as_mut(),
                     |store, args| (*data)(store, args),
                 )
@@ -142,6 +144,7 @@ unsafe fn call_host<T, Params, Return, F>(
     memory: *mut VMMemoryDefinition,
     realloc: *mut VMFuncRef,
     string_encoding: StringEncoding,
+    async_: bool,
     storage: &mut [MaybeUninit<ValRaw>],
     closure: F,
 ) -> Result<()>
@@ -150,6 +153,10 @@ where
     Return: Lower,
     F: FnOnce(StoreContextMut<'_, T>, Params) -> Result<Return>,
 {
+    if async_ {
+        todo!()
+    }
+
     /// Representation of arguments to this function when a return pointer is in
     /// use, namely the argument list is followed by a single value which is the
     /// return pointer.
@@ -320,12 +327,17 @@ unsafe fn call_host_dynamic<T, F>(
     memory: *mut VMMemoryDefinition,
     realloc: *mut VMFuncRef,
     string_encoding: StringEncoding,
+    async_: bool,
     storage: &mut [MaybeUninit<ValRaw>],
     closure: F,
 ) -> Result<()>
 where
     F: FnOnce(StoreContextMut<'_, T>, &[Val], &mut [Val]) -> Result<()>,
 {
+    if async_ {
+        todo!()
+    }
+
     let options = Options::new(
         store.0.id(),
         NonNull::new(memory),
@@ -429,6 +441,7 @@ extern "C" fn dynamic_entrypoint<T, F>(
     memory: *mut VMMemoryDefinition,
     realloc: *mut VMFuncRef,
     string_encoding: u8,
+    async_: u8,
     storage: NonNull<MaybeUninit<ValRaw>>,
     storage_len: usize,
 ) -> bool
@@ -447,6 +460,7 @@ where
                 memory,
                 realloc,
                 StringEncoding::from_u8(string_encoding).unwrap(),
+                async_ != 0,
                 NonNull::slice_from_raw_parts(storage, storage_len).as_mut(),
                 |store, params, results| (*data)(store, params, results),
             )

crates/wasmtime/src/runtime/vm/component.rs

@@ -94,6 +94,7 @@ pub struct ComponentInstance {
 ///   option for the canonical ABI options.
 /// * `string_encoding` - this is the configured string encoding for the
 ///   canonical ABI this lowering corresponds to.
+/// * `async_` - whether the caller is using the async ABI.
 /// * `args_and_results` - pointer to stack-allocated space in the caller where
 ///   all the arguments are stored as well as where the results will be written
 ///   to. The size and initialized bytes of this depends on the core wasm type
@@ -117,6 +118,7 @@ pub type VMLoweringCallee = extern "C" fn(
     opt_memory: *mut VMMemoryDefinition,
     opt_realloc: *mut VMFuncRef,
     string_encoding: u8,
+    async_: u8,
     args_and_results: NonNull<mem::MaybeUninit<ValRaw>>,
     nargs_and_results: usize,
 ) -> bool;

crates/wasmtime/src/runtime/vm/interpreter.rs

@@ -379,7 +379,7 @@ impl InterpreterRef<'_> {
             use wasmtime_environ::component::ComponentBuiltinFunctionIndex;
 
             if id == const { HostCall::ComponentLowerImport.index() } {
-                call!(@host VMLoweringCallee(nonnull, nonnull, u32, nonnull, ptr, ptr, u8, nonnull, size) -> bool);
+                call!(@host VMLoweringCallee(nonnull, nonnull, u32, nonnull, ptr, ptr, u8, u8, nonnull, size) -> bool);
             }
 
             macro_rules! component {

crates/wast/src/spectest.rs

@@ -94,6 +94,9 @@ pub fn link_component_spectest<T>(linker: &mut component::Linker<T>) -> Result<(
     use wasmtime::component::{Resource, ResourceType};
 
     let engine = linker.engine().clone();
+    linker
+        .root()
+        .func_wrap("host-echo-u32", |_, v: (u32,)| Ok(v))?;
     linker
         .root()
         .func_wrap("host-return-two", |_, _: ()| Ok((2u32,)))?;

tests/misc_testsuite/component-model-async/lower.wast

@@ -0,0 +1,13 @@
+;;! component_model_async = true
+
+;; async lower
+(component
+  (import "host-echo-u32" (func $foo (param "p1" u32) (result u32)))
+  (core module $libc (memory (export "memory") 1))
+  (core instance $libc (instantiate $libc))
+  (core func $foo (canon lower (func $foo) async (memory $libc "memory")))
+  (core module $m
+    (func (import "" "foo") (param i32 i32) (result i32))
+  )
+  (core instance $i (instantiate $m (with "" (instance (export "foo" (func $foo))))))
+)