add component-model-async/lift.wast test

crates/fuzzing/src/generators/config.rs

@@ -139,6 +139,7 @@ impl Config {
             extended_const,
             wide_arithmetic,
             component_model_more_flags,
+            component_model_async,
             simd,
 
             hogs_memory: _,
@@ -151,6 +152,7 @@ impl Config {
         self.module_config.function_references_enabled =
             function_references.or(gc).unwrap_or(false);
         self.module_config.component_model_more_flags = component_model_more_flags.unwrap_or(false);
+        self.module_config.component_model_async = component_model_async.unwrap_or(false);
 
         // Enable/disable proposals that wasm-smith has knobs for which will be
         // read when creating `wasmtime::Config`.
@@ -266,6 +268,7 @@ impl Config {
             .wasm_wide_arithmetic(self.module_config.config.wide_arithmetic_enabled)
             .wasm_extended_const(self.module_config.config.extended_const_enabled)
             .wasm_component_model_more_flags(self.module_config.component_model_more_flags)
+            .wasm_component_model_async(self.module_config.component_model_async)
             .native_unwind_info(cfg!(target_os = "windows") || self.wasmtime.native_unwind_info)
             .cranelift_nan_canonicalization(self.wasmtime.canonicalize_nans)
             .cranelift_opt_level(self.wasmtime.opt_level.to_wasmtime())

crates/fuzzing/src/generators/module.rs

@@ -16,6 +16,7 @@ pub struct ModuleConfig {
     // config-to-`wasmtime::Config` translation.
     pub function_references_enabled: bool,
     pub component_model_more_flags: bool,
+    pub component_model_async: bool,
 }
 
 impl<'a> Arbitrary<'a> for ModuleConfig {
@@ -62,6 +63,7 @@ impl<'a> Arbitrary<'a> for ModuleConfig {
 
         Ok(ModuleConfig {
             component_model_more_flags: false,
+            component_model_async: false,
             function_references_enabled: config.gc_enabled,
             config,
         })

crates/misc/component-test-util/Cargo.toml

@@ -11,7 +11,7 @@ publish = false
 env_logger = { workspace = true }
 anyhow = { workspace = true }
 arbitrary = { workspace = true, features = ["derive"] }
-wasmtime = { workspace = true, features = ["component-model", "async"] }
+wasmtime = { workspace = true, features = ["component-model", "async", "component-model-async"] }
 wasmtime-environ = { workspace = true }
 wasmtime-wast-util = { path = '../../wast-util' }
 target-lexicon = { workspace = true }

crates/misc/component-test-util/src/lib.rs

@@ -166,6 +166,7 @@ pub fn apply_test_config(config: &mut Config, test_config: &wasmtime_wast_util::
         extended_const,
         wide_arithmetic,
         component_model_more_flags,
+        component_model_async,
         nan_canonicalization,
         simd,
 
@@ -184,6 +185,7 @@ pub fn apply_test_config(config: &mut Config, test_config: &wasmtime_wast_util::
     let extended_const = extended_const.unwrap_or(false);
     let wide_arithmetic = wide_arithmetic.unwrap_or(false);
     let component_model_more_flags = component_model_more_flags.unwrap_or(false);
+    let component_model_async = component_model_async.unwrap_or(false);
     let nan_canonicalization = nan_canonicalization.unwrap_or(false);
     let relaxed_simd = relaxed_simd.unwrap_or(false);
 
@@ -210,5 +212,6 @@ pub fn apply_test_config(config: &mut Config, test_config: &wasmtime_wast_util::
         .wasm_extended_const(extended_const)
         .wasm_wide_arithmetic(wide_arithmetic)
         .wasm_component_model_more_flags(component_model_more_flags)
+        .wasm_component_model_async(component_model_async)
         .cranelift_nan_canonicalization(nan_canonicalization);
 }

crates/wasmtime/src/config.rs

@@ -1111,6 +1111,19 @@ impl Config {
         self
     }
 
+    /// Configures whether components support the async ABI [proposal] for
+    /// lifting and lowering functions, as well as `stream`, `future`, and
+    /// `error-context` types.
+    ///
+    /// Please note that Wasmtime's support for this feature is _very_ incomplete.
+    ///
+    /// [proposal]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/Async.md
+    #[cfg(feature = "component-model-async")]
+    pub fn wasm_component_model_async(&mut self, enable: bool) -> &mut Self {
+        self.wasm_feature(WasmFeatures::COMPONENT_MODEL_ASYNC, enable);
+        self
+    }
+
     /// Configures which compilation strategy will be used for wasm modules.
     ///
     /// This method can be used to configure which compiler is used for wasm

crates/wasmtime/src/engine/serialization.rs

@@ -202,6 +202,7 @@ struct WasmFeatures {
     custom_page_sizes: bool,
     component_model_more_flags: bool,
     component_model_multiple_returns: bool,
+    component_model_async: bool,
     gc_types: bool,
     wide_arithmetic: bool,
 }
@@ -253,7 +254,6 @@ impl Metadata<'_> {
         assert!(!shared_everything_threads);
         assert!(!legacy_exceptions);
         assert!(!stack_switching);
-        assert!(!component_model_async);
 
         Metadata {
             target: engine.compiler().triple().to_string(),
@@ -278,6 +278,7 @@ impl Metadata<'_> {
                 custom_page_sizes,
                 component_model_more_flags,
                 component_model_multiple_returns,
+                component_model_async,
                 gc_types,
                 wide_arithmetic,
             },
@@ -488,6 +489,7 @@ impl Metadata<'_> {
             custom_page_sizes,
             component_model_more_flags,
             component_model_multiple_returns,
+            component_model_async,
             gc_types,
             wide_arithmetic,
         } = self.features;
@@ -574,6 +576,11 @@ impl Metadata<'_> {
             other.contains(F::COMPONENT_MODEL_MULTIPLE_RETURNS),
             "WebAssembly component model support for multiple returns",
         )?;
+        Self::check_bool(
+            component_model_async,
+            other.contains(F::COMPONENT_MODEL_ASYNC),
+            "WebAssembly component model support for async lifts/lowers, futures, streams, and errors",
+        )?;
         Self::check_cfg_bool(
             cfg!(feature = "gc"),
             "gc",

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

@@ -608,8 +608,7 @@ impl<'a> Instantiator<'a> {
                 }
 
                 GlobalInitializer::ExtractCallback(callback) => {
-                    _ = callback;
-                    todo!()
+                    self.extract_callback(store.0, callback)
                 }
 
                 GlobalInitializer::ExtractPostReturn(post_return) => {
@@ -659,6 +658,16 @@ impl<'a> Instantiator<'a> {
         self.data.state.set_runtime_realloc(realloc.index, func_ref);
     }
 
+    fn extract_callback(&mut self, store: &mut StoreOpaque, callback: &ExtractCallback) {
+        let func_ref = match self.data.lookup_def(store, &callback.def) {
+            crate::runtime::vm::Export::Function(f) => f.func_ref,
+            _ => unreachable!(),
+        };
+        self.data
+            .state
+            .set_runtime_callback(callback.index, func_ref);
+    }
+
     fn extract_post_return(&mut self, store: &mut StoreOpaque, post_return: &ExtractPostReturn) {
         let func_ref = match self.data.lookup_def(store, &post_return.def) {
             crate::runtime::vm::Export::Function(f) => f.func_ref,

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

@@ -375,6 +375,16 @@ impl ComponentInstance {
         }
     }
 
+    /// Same as `set_runtime_memory` but for async callback function pointers.
+    pub fn set_runtime_callback(&mut self, idx: RuntimeCallbackIndex, ptr: NonNull<VMFuncRef>) {
+        unsafe {
+            let storage =
+                self.vmctx_plus_offset_mut::<VmPtr<VMFuncRef>>(self.offsets.runtime_callback(idx));
+            debug_assert!((*storage).as_ptr() as usize == INVALID_PTR);
+            *storage = ptr.into();
+        }
+    }
+
     /// Same as `set_runtime_memory` but for post-return function pointers.
     pub fn set_runtime_post_return(
         &mut self,
@@ -493,6 +503,11 @@ impl ComponentInstance {
                 let offset = self.offsets.runtime_realloc(i);
                 *self.vmctx_plus_offset_mut(offset) = INVALID_PTR;
             }
+            for i in 0..self.offsets.num_runtime_callbacks {
+                let i = RuntimeCallbackIndex::from_u32(i);
+                let offset = self.offsets.runtime_callback(i);
+                *self.vmctx_plus_offset_mut(offset) = INVALID_PTR;
+            }
             for i in 0..self.offsets.num_runtime_post_returns {
                 let i = RuntimePostReturnIndex::from_u32(i);
                 let offset = self.offsets.runtime_post_return(i);
@@ -734,6 +749,11 @@ impl OwnedComponentInstance {
         unsafe { self.instance_mut().set_runtime_realloc(idx, ptr) }
     }
 
+    /// See `ComponentInstance::set_runtime_callback`
+    pub fn set_runtime_callback(&mut self, idx: RuntimeCallbackIndex, ptr: NonNull<VMFuncRef>) {
+        unsafe { self.instance_mut().set_runtime_callback(idx, ptr) }
+    }
+
     /// See `ComponentInstance::set_runtime_post_return`
     pub fn set_runtime_post_return(
         &mut self,

crates/wast-util/src/lib.rs

@@ -185,6 +185,7 @@ macro_rules! foreach_config_option {
             hogs_memory
             nan_canonicalization
             component_model_more_flags
+            component_model_async
             simd
             gc_types
         }

crates/wast/Cargo.toml

@@ -20,4 +20,4 @@ wast = { workspace = true }
 log = { workspace = true }
 
 [features]
-component-model = ['wasmtime/component-model']
+component-model = ['wasmtime/component-model', 'wasmtime/component-model-async']

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

@@ -0,0 +1,26 @@
+;;! component_model_async = true
+
+;; async lift; no callback
+(component
+  (core module $m
+    (func (export "foo") (param i32) unreachable)
+  )
+  (core instance $i (instantiate $m))
+
+  (func (export "foo") (param "p1" u32) (result u32)
+    (canon lift (core func $i "foo") async)
+  )
+)
+
+;; async lift; with callback
+(component
+  (core module $m
+    (func (export "callback") (param i32 i32 i32 i32) (result i32) unreachable)
+    (func (export "foo") (param i32) (result i32) unreachable)
+  )
+  (core instance $i (instantiate $m))
+
+  (func (export "foo") (param "p1" u32) (result u32)
+    (canon lift (core func $i "foo") async (callback (func $i "callback")))
+  )
+)