Require async types when lift/lower uses async

This is an adjustment to the validation of component-model-async
functions and types to correspond to WebAssembly/component-model#646.
Specifically when using the `async` option to lift or lower a function
it's now required that the component model type is additionally `async`.
This means, for example, that `canon lower` of a sync-typed function
cannot use the `async` ABI option. Additionally `canon lift` cannot use
`async` if the destination component function type is synchronous.

This notably required a number of updates throughout tests. My personal
judgement on the required updates here is that everything was originally
written without `async` function types since that didn't exist, then
most of these weren't updated, but should have been, once `async` was
added as a function type. In that sense I don't feel these are
reflective of real-world breakage, but instead I think it's reflective
of the history of the implementation's development.

Author: alexcrichton

crates/wasmparser/src/validator/component.rs

@@ -395,6 +395,18 @@ impl CanonicalOptions {
         Ok(self)
     }
 
+    fn check_asyncness(&self, ty: &ComponentFuncType, offset: usize) -> Result<()> {
+        // The `async` canonical ABI option is only allowed with `async`-typed
+        // functions.
+        if self.concurrency.is_async() && !ty.async_ {
+            bail!(
+                offset,
+                "the `async` canonical option requires an async function type",
+            );
+        }
+        Ok(())
+    }
+
     pub(crate) fn check_core_type(
         &self,
         types: &mut TypeAlloc,
@@ -1303,6 +1315,7 @@ impl ComponentState {
         // export signature
         let mut options = self.check_options(types, options, offset)?;
         options.check_lift(types, self, core_ty_id, offset)?;
+        options.check_asyncness(ty, offset)?;
         let func_ty = ty.lower(types, &options, Abi::Lift, offset)?;
         let lowered_core_ty_id = func_ty.intern(types, offset);
 
@@ -1359,6 +1372,8 @@ impl ComponentState {
         // the expected canonical ABI import signature.
         let options = self.check_options(types, options, offset)?;
         options.check_lower(offset)?;
+        options.check_asyncness(ty, offset)?;
+
         let func_ty = ty.lower(types, &options, Abi::Lower, offset)?;
         let ty_id = func_ty.intern(types, offset);
 

crates/wit-component/src/dummy.rs

@@ -90,6 +90,7 @@ fn push_imported_func(
     func: &Function,
     mangling: ManglingAndAbi,
 ) {
+    let mangling = mangling.for_func(func);
     let sig = resolve.wasm_signature(mangling.import_variant(), func);
 
     let (module, name) = resolve.wasm_import_name(mangling, WasmImport::Func { interface, func });
@@ -352,6 +353,7 @@ fn push_func_export(
     func: &Function,
     mangling: ManglingAndAbi,
 ) {
+    let mangling = mangling.for_func(func);
     let sig = resolve.wasm_signature(mangling.export_variant(), func);
     let name = resolve.wasm_export_name(
         mangling,

crates/wit-component/tests/components/async-builtins/component.wat

@@ -235,17 +235,17 @@
       (with "" (instance $fixup-args))
     )
   )
-  (type (;0;) (func (param "s" string) (result string)))
+  (type (;0;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift-stackful]foo" (core func $"[async-lift-stackful]foo" (;33;)))
   (func $foo (;0;) (type 0) (canon lift (core func $"[async-lift-stackful]foo") (memory $memory) (realloc $realloc) string-encoding=utf8 async))
   (export $"#func1 foo" (@name "foo") (;1;) "foo" (func $foo))
-  (type (;1;) (func (param "s" string) (result string)))
+  (type (;1;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift-stackful]foo:foo/bar#foo" (core func $"[async-lift-stackful]foo:foo/bar#foo" (;34;)))
   (func $"#func2 foo" (@name "foo") (;2;) (type 1) (canon lift (core func $"[async-lift-stackful]foo:foo/bar#foo") (memory $memory) (realloc $realloc) string-encoding=utf8 async))
   (component $foo:foo/bar-shim-component (;0;)
-    (type (;0;) (func (param "s" string) (result string)))
+    (type (;0;) (func async (param "s" string) (result string)))
     (import "import-func-foo" (func (;0;) (type 0)))
-    (type (;1;) (func (param "s" string) (result string)))
+    (type (;1;) (func async (param "s" string) (result string)))
     (export (;1;) "foo" (func 0) (func (type 1)))
   )
   (instance $foo:foo/bar-shim-instance (;0;) (instantiate $foo:foo/bar-shim-component

crates/wit-component/tests/components/async-builtins/component.wit.print

@@ -1,6 +1,6 @@
 package root:component;
 
 world root {
-  export foo: func(s: string) -> string;
+  export foo: async func(s: string) -> string;
   export foo:foo/bar;
 }

crates/wit-component/tests/components/async-builtins/module.wit

@@ -1,10 +1,10 @@
 package foo:foo;
 
 interface bar {
-  foo: func(s: string) -> string;
+  foo: async func(s: string) -> string;
 }
 
 world module {
   export bar;
-  export foo: func(s: string) -> string;
+  export foo: async func(s: string) -> string;
 }

crates/wit-component/tests/components/async-export-with-callback/component.wat

@@ -32,20 +32,20 @@
   )
   (core instance $main (;0;) (instantiate $main))
   (alias core export $main "memory" (core memory $memory (;0;)))
-  (type (;0;) (func (param "s" string) (result string)))
+  (type (;0;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift]foo" (core func $"[async-lift]foo" (;0;)))
   (alias core export $main "cabi_realloc" (core func $cabi_realloc (;1;)))
   (alias core export $main "[callback][async-lift]foo" (core func $"[callback][async-lift]foo" (;2;)))
   (func $foo (;0;) (type 0) (canon lift (core func $"[async-lift]foo") (memory $memory) (realloc $cabi_realloc) string-encoding=utf8 async (callback $"[callback][async-lift]foo")))
   (export $"#func1 foo" (@name "foo") (;1;) "foo" (func $foo))
-  (type (;1;) (func (param "s" string) (result string)))
+  (type (;1;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift]foo:foo/bar#foo" (core func $"[async-lift]foo:foo/bar#foo" (;3;)))
   (alias core export $main "[callback][async-lift]foo:foo/bar#foo" (core func $"[callback][async-lift]foo:foo/bar#foo" (;4;)))
   (func $"#func2 foo" (@name "foo") (;2;) (type 1) (canon lift (core func $"[async-lift]foo:foo/bar#foo") (memory $memory) (realloc $cabi_realloc) string-encoding=utf8 async (callback $"[callback][async-lift]foo:foo/bar#foo")))
   (component $foo:foo/bar-shim-component (;0;)
-    (type (;0;) (func (param "s" string) (result string)))
+    (type (;0;) (func async (param "s" string) (result string)))
     (import "import-func-foo" (func (;0;) (type 0)))
-    (type (;1;) (func (param "s" string) (result string)))
+    (type (;1;) (func async (param "s" string) (result string)))
     (export (;1;) "foo" (func 0) (func (type 1)))
   )
   (instance $foo:foo/bar-shim-instance (;0;) (instantiate $foo:foo/bar-shim-component

crates/wit-component/tests/components/async-export-with-callback/component.wit.print

@@ -1,6 +1,6 @@
 package root:component;
 
 world root {
-  export foo: func(s: string) -> string;
+  export foo: async func(s: string) -> string;
   export foo:foo/bar;
 }

crates/wit-component/tests/components/async-export-with-callback/module.wit

@@ -1,10 +1,10 @@
 package foo:foo;
 
 interface bar {
-  foo: func(s: string) -> string;
+  foo: async func(s: string) -> string;
 }
 
 world module {
   export bar;
-  export foo: func(s: string) -> string;
+  export foo: async func(s: string) -> string;
 }

crates/wit-component/tests/components/async-export/component.wat

@@ -35,44 +35,44 @@
   (type (;2;) (record (field "a1" 1) (field "a2" 1) (field "a3" 1) (field "a4" 1)))
   (core instance $main (;0;) (instantiate $main))
   (alias core export $main "memory" (core memory $memory (;0;)))
-  (type (;3;) (func (param "s" string) (result string)))
+  (type (;3;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift-stackful]foo" (core func $"[async-lift-stackful]foo" (;0;)))
   (alias core export $main "cabi_realloc" (core func $cabi_realloc (;1;)))
   (func $foo (;0;) (type 3) (canon lift (core func $"[async-lift-stackful]foo") (memory $memory) (realloc $cabi_realloc) string-encoding=utf8 async))
   (export $"#func1 foo" (@name "foo") (;1;) "foo" (func $foo))
-  (type (;4;) (func (param "s" string) (result string)))
+  (type (;4;) (func async (param "s" string) (result string)))
   (alias core export $main "[async-lift-stackful]foo:foo/bar#foo" (core func $"[async-lift-stackful]foo:foo/bar#foo" (;2;)))
   (func $"#func2 foo" (@name "foo") (;2;) (type 4) (canon lift (core func $"[async-lift-stackful]foo:foo/bar#foo") (memory $memory) (realloc $cabi_realloc) string-encoding=utf8 async))
-  (type (;5;) (func (result string)))
+  (type (;5;) (func async (result string)))
   (alias core export $main "[async-lift-stackful]foo:foo/bar#get-string" (core func $"[async-lift-stackful]foo:foo/bar#get-string" (;3;)))
   (func $get-string (;3;) (type 5) (canon lift (core func $"[async-lift-stackful]foo:foo/bar#get-string") (memory $memory) string-encoding=utf8 async))
-  (type (;6;) (func (result 2)))
+  (type (;6;) (func async (result 2)))
   (alias core export $main "[async-lift-stackful]foo:foo/bar#get-big" (core func $"[async-lift-stackful]foo:foo/bar#get-big" (;4;)))
   (func $get-big (;4;) (type 6) (canon lift (core func $"[async-lift-stackful]foo:foo/bar#get-big") (memory $memory) async))
   (component $foo:foo/bar-shim-component (;0;)
-    (type (;0;) (func (param "s" string) (result string)))
+    (type (;0;) (func async (param "s" string) (result string)))
     (import "import-func-foo" (func (;0;) (type 0)))
-    (type (;1;) (func (result string)))
+    (type (;1;) (func async (result string)))
     (import "import-func-get-string" (func (;1;) (type 1)))
     (type (;2;) (record (field "a1" u8) (field "a2" u8) (field "a3" u8) (field "a4" u8)))
     (import "import-type-big3" (type (;3;) (eq 2)))
     (type (;4;) (record (field "a1" 3) (field "a2" 3) (field "a3" 3) (field "a4" 3)))
     (import "import-type-big2" (type (;5;) (eq 4)))
     (type (;6;) (record (field "a1" 5) (field "a2" 5) (field "a3" 5) (field "a4" 5)))
     (import "import-type-big" (type (;7;) (eq 6)))
-    (type (;8;) (func (result 7)))
+    (type (;8;) (func async (result 7)))
     (import "import-func-get-big" (func (;2;) (type 8)))
     (type (;9;) (record (field "a1" u8) (field "a2" u8) (field "a3" u8) (field "a4" u8)))
     (export (;10;) "big3" (type 9))
     (type (;11;) (record (field "a1" 10) (field "a2" 10) (field "a3" 10) (field "a4" 10)))
     (export (;12;) "big2" (type 11))
     (type (;13;) (record (field "a1" 12) (field "a2" 12) (field "a3" 12) (field "a4" 12)))
     (export (;14;) "big" (type 13))
-    (type (;15;) (func (param "s" string) (result string)))
+    (type (;15;) (func async (param "s" string) (result string)))
     (export (;3;) "foo" (func 0) (func (type 15)))
-    (type (;16;) (func (result string)))
+    (type (;16;) (func async (result string)))
     (export (;4;) "get-string" (func 1) (func (type 16)))
-    (type (;17;) (func (result 14)))
+    (type (;17;) (func async (result 14)))
     (export (;5;) "get-big" (func 2) (func (type 17)))
   )
   (instance $foo:foo/bar-shim-instance (;0;) (instantiate $foo:foo/bar-shim-component

crates/wit-component/tests/components/async-export/component.wit.print

@@ -1,6 +1,6 @@
 package root:component;
 
 world root {
-  export foo: func(s: string) -> string;
+  export foo: async func(s: string) -> string;
   export foo:foo/bar;
 }