feat: add wasip3 behind flag

Author: ricochet

.cargo/config.toml

@@ -1,5 +1,7 @@
 [target.wasm32-wasip2]
 # wasmtime is given:
+# * p3 enabled for wasip3 component support (backwards compat with p2)
+# * http enabled for wasi-http tests
 # * AWS auth environment variables, for running the wstd-aws integration tests.
 # * . directory is available at .
-runner = "wasmtime run -Shttp --env AWS_ACCESS_KEY_ID --env AWS_SECRET_ACCESS_KEY --env AWS_SESSION_TOKEN --dir .::."
+runner = "wasmtime run -Wcomponent-model-async -Wcomponent-model-async-builtins -Wcomponent-model-async-stackful -Sp3 -Shttp --env AWS_ACCESS_KEY_ID --env AWS_SECRET_ACCESS_KEY --env AWS_SESSION_TOKEN --dir .::."

.github/workflows/ci.yaml

@@ -51,9 +51,12 @@ jobs:
     - name: check
       run: cargo check --workspace --all --bins --examples
 
-    - name: wstd tests
+    - name: wstd tests (wasip2)
       run: cargo test -p wstd -p wstd-axum --target wasm32-wasip2 -- --nocapture
 
+    - name: wstd tests (wasip3)
+      run: cargo test -p wstd -p wstd-axum --target wasm32-wasip2 --no-default-features --features wasip3 -- --nocapture
+
     - name: test-programs tests
       run: cargo test -p test-programs -- --nocapture
       if: steps.creds.outcome == 'success'

Cargo.toml

@@ -13,8 +13,10 @@ repository.workspace = true
 rust-version.workspace = true
 
 [features]
-default = ["json"]
+default = ["json", "wasip2"]
 json = ["dep:serde", "dep:serde_json"]
+wasip2 = ["dep:wasip2"]
+wasip3 = ["dep:wasip3", "dep:wit-bindgen"]
 
 [dependencies]
 anyhow.workspace = true
@@ -27,7 +29,9 @@ http.workspace = true
 itoa.workspace = true
 pin-project-lite.workspace = true
 slab.workspace = true
-wasip2.workspace = true
+wasip2 = { workspace = true, optional = true }
+wasip3 = { workspace = true, optional = true }
+wit-bindgen = { workspace = true, optional = true }
 wstd-macro.workspace = true
 
 # optional
@@ -95,13 +99,15 @@ test-programs = { path = "test-programs" }
 tower-service = "0.3.3"
 ureq = { version = "3.1", default-features = false, features = ["json"] }
 wasip2 = "1.0"
-wstd = { path = ".", version = "=0.6.6" }
+wasip3 = "0.5"
+wit-bindgen = { version = "0.54", default-features = false, features = ["async", "async-spawn", "inter-task-wakeup"] }
+wstd = { path = ".", version = "=0.6.6", default-features = false }
 wstd-axum = { path = "./axum", version = "=0.6.6" }
 wstd-axum-macro = { path = "./axum/macro", version = "=0.6.6" }
 wstd-macro = { path = "./macro", version = "=0.6.6" }
 
 [package.metadata.docs.rs]
 all-features = true
 targets = [
-    "wasm32-wasip2"
+    "wasm32-wasip2",
 ]

axum/Cargo.toml

@@ -10,10 +10,15 @@ categories.workspace = true
 repository.workspace = true
 rust-version.workspace = true
 
+[features]
+default = ["wasip2"]
+wasip2 = ["wstd/wasip2"]
+wasip3 = ["wstd/wasip3"]
+
 [dependencies]
 axum.workspace = true
 tower-service.workspace = true
-wstd.workspace = true
+wstd = { workspace = true, default-features = false }
 wstd-axum-macro.workspace = true
 
 [dev-dependencies]

macro/src/lib.rs

@@ -100,12 +100,6 @@ pub fn attr_macro_test(_attr: TokenStream, item: TokenStream) -> TokenStream {
 pub fn attr_macro_http_server(_attr: TokenStream, item: TokenStream) -> TokenStream {
     let input = parse_macro_input!(item as ItemFn);
 
-    let (run_async, run_await) = if input.sig.asyncness.is_some() {
-        (quote!(async), quote!(.await))
-    } else {
-        (quote!(), quote!())
-    };
-
     let output = &input.sig.output;
     let inputs = &input.sig.inputs;
     let name = &input.sig.ident;
@@ -120,63 +114,32 @@ pub fn attr_macro_http_server(_attr: TokenStream, item: TokenStream) -> TokenStr
         .into();
     }
 
+    // Delegate to wstd's conditionally-compiled declarative macro.
+    // The `cfg` checks in `__http_server_export!` run in wstd's context,
+    // so consumers don't need to define wasip2/wasip3 features themselves.
+    //
+    // We use @async/@sync markers so the declarative macro can construct
+    // the handler call in its own hygiene context (avoiding variable name
+    // mismatches between proc macro and declarative macro scopes)
+    // NOTE: we can avoid this once wasm32-wasip3 is an available target
+    let asyncness = if input.sig.asyncness.is_some() {
+        quote!(@async)
+    } else {
+        quote!(@sync)
+    };
+
+    let run_async = if input.sig.asyncness.is_some() {
+        quote!(async)
+    } else {
+        quote!()
+    };
+
     quote! {
-        struct TheServer;
-
-        impl ::wstd::__internal::wasip2::exports::http::incoming_handler::Guest for TheServer {
-            fn handle(
-                request: ::wstd::__internal::wasip2::http::types::IncomingRequest,
-                response_out: ::wstd::__internal::wasip2::http::types::ResponseOutparam
-            ) {
-                #(#attrs)*
-                #vis #run_async fn __run(#inputs) #output {
-                    #body
-                }
-
-                let responder = ::wstd::http::server::Responder::new(response_out);
-                ::wstd::runtime::block_on(async move {
-                    match ::wstd::http::request::try_from_incoming(request) {
-                        Ok(request) => match __run(request) #run_await {
-                            Ok(response) => { responder.respond(response).await.unwrap() },
-                            Err(err) => responder.fail(err),
-                        }
-                        Err(err) => responder.fail(err),
-                    }
-                })
-            }
+        ::wstd::__http_server_export! {
+            #asyncness
+            { #(#attrs)* #vis #run_async fn __run(#inputs) #output { #body } }
         }
 
-        ::wstd::__internal::wasip2::http::proxy::export!(TheServer with_types_in ::wstd::__internal::wasip2);
-
-        // Provide an actual function named `main`.
-        //
-        // WASI HTTP server components don't use a traditional `main` function.
-        // They export a function named `handle` which takes a `Request`
-        // argument, and which may be called multiple times on the same
-        // instance. To let users write a familiar `fn main` in a file
-        // named src/main.rs, we provide this `wstd::http_server` macro, which
-        // transforms the user's `fn main` into the appropriate `handle`
-        // function.
-        //
-        // However, when the top-level file is named src/main.rs, rustc
-        // requires there to be a function named `main` somewhere in it. This
-        // requirement can be disabled using `#![no_main]`, however we can't
-        // use that automatically because macros can't contain inner
-        // attributes, and we don't want to require users to add `#![no_main]`
-        // in their own code.
-        //
-        // So, we include a definition of a function named `main` here, which
-        // isn't intended to ever be called, and exists just to satify the
-        // requirement for a `main` function.
-        //
-        // Users could use `#![no_main]` if they want to. Or, they could name
-        // their top-level file src/lib.rs and add
-        // ```toml
-        // [lib]
-        // crate-type = ["cdylib"]
-        // ```
-        // to their Cargo.toml. With either of these, this "main" function will
-        // be ignored as dead code.
         fn main() {
             unreachable!("HTTP server components should be run with `handle` rather than `run`")
         }