feat: bundle passthrough component in Go directly

Signed-off-by: Roman Volosatovs <[email protected]>

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "west"
-version = "0.1.0-alpha.1"
+version = "0.1.0-alpha.2"
 description = "WebAssembly component test runtime"
 
 authors.workspace = true
@@ -31,11 +31,6 @@ wasmtime-wasi = { workspace = true }
 wasmtime-wasi-http = { workspace = true }
 wit-component = { workspace = true }
 
-[build-dependencies]
-anyhow = { workspace = true }
-wasi-preview1-component-adapter-provider = { workspace = true }
-wit-component = { workspace = true }
-
 [workspace.dependencies]
 anyhow = "1"
 cbindgen = "0.27"
@@ -49,6 +44,6 @@ wasmtime = "24"
 wasmtime-wasi = "24"
 wasmtime-wasi-http = "24"
 west-passthrough = { version = "0.1.0-alpha.1", path = "./crates/passthrough" }
-west = { version = "0.1.0-alpha.1", path = "." }
+west = { version = "0.1.0-alpha.2", path = "." }
 wit-bindgen = "0.32"
 wit-component = "0.217"

crates/sys/src/ffi.rs

@@ -4,7 +4,7 @@ use core::ptr::{self, null_mut};
 use std::ffi::CString;
 use std::sync::{LazyLock, Mutex};
 
-use crate::{call, instantiate, Config, List, PASSTHROUGH_LEN, PASSTHROUGH_PTR};
+use crate::{call, instantiate, Config};
 
 static ERROR: LazyLock<Mutex<Option<CString>>> = LazyLock::new(Mutex::default);
 
@@ -15,16 +15,6 @@ fn store_error(err: anyhow::Error) {
         .insert(CString::new(format!("{err:?}")).expect("failed to construct error string"));
 }
 
-#[no_mangle]
-pub extern "C" fn default_config() -> Config {
-    Config {
-        wasm: List {
-            ptr: PASSTHROUGH_PTR,
-            len: PASSTHROUGH_LEN,
-        },
-    }
-}
-
 #[no_mangle]
 pub extern "C" fn error_take(buf: *mut c_char, len: usize) -> usize {
     if let Some(err) = ERROR.lock().unwrap().take() {

crates/sys/src/lib.rs

@@ -21,9 +21,6 @@ mod ffi;
 
 static ENGINE: LazyLock<wasmtime::Engine> = LazyLock::new(wasmtime::Engine::default);
 
-pub const PASSTHROUGH_PTR: *const u8 = west::PASSTHROUGH.as_ptr();
-pub const PASSTHROUGH_LEN: usize = west::PASSTHROUGH.len();
-
 #[repr(C)]
 #[derive(Debug)]
 pub struct List<T> {

include/west.h

@@ -12,8 +12,6 @@ typedef struct Config {
   struct List_u8 wasm;
 } Config;
 
-struct Config default_config(void);
-
 uintptr_t error_take(char *buf, uintptr_t len);
 
 uintptr_t error_len(void);

src/lib.rs

@@ -24,8 +24,6 @@ mod bindings {
     });
 }
 
-pub const PASSTHROUGH: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/west_passthrough.wasm"));
-
 struct Ctx {
     wasi: WasiCtx,
     http: WasiHttpCtx,
@@ -175,15 +173,6 @@ pub struct Config<'a> {
     pub wasm: &'a [u8],
 }
 
-impl Default for Config<'_> {
-    fn default() -> Self {
-        Self {
-            engine: Engine::default(),
-            wasm: PASSTHROUGH,
-        }
-    }
-}
-
 pub struct Func<'a> {
     func: wasmtime::component::Func,
     store: &'a mut Store<Ctx>,

west.go

@@ -1,4 +1,6 @@
 //go:generate cargo build -p west-sys --release
+//go:generate cargo build -p west-passthrough --target wasm32-unknown-unknown --release
+//go:generate wasm-tools component new target/wasm32-unknown-unknown/release/west_passthrough.wasm -o lib/passthrough.wasm
 //go:generate go run github.com/ydnar/wasm-tools-go/cmd/[email protected] generate -w imports -o bindings ./wit
 
 package west
@@ -13,6 +15,7 @@ package west
 import "C"
 
 import (
+	_ "embed"
 	"errors"
 	"fmt"
 	"log"
@@ -23,6 +26,9 @@ import (
 	"unsafe"
 )
 
+//go:embed lib/passthrough.wasm
+var Passthrough []byte
+
 var (
 	errorHandlerMu sync.RWMutex
 	errorHandler   atomic.Value
@@ -148,19 +154,20 @@ func NewInstance(conf *Config) (*Instance, error) {
 	var pinner runtime.Pinner
 	defer pinner.Unpin()
 
-	c := C.default_config()
+	wasm := Passthrough
 	if conf != nil {
 		if len(conf.Wasm) > 0 {
-			ptr := unsafe.SliceData(conf.Wasm)
-			pinner.Pin(ptr)
-
-			c.wasm = C.List_u8{
-				ptr: (*C.uchar)(ptr),
-				len: C.ulong(len(conf.Wasm)),
-			}
+			wasm = conf.Wasm
 		}
 	}
-	ptr := C.instance_new(c)
+	wasmPtr := unsafe.SliceData(wasm)
+	pinner.Pin(wasmPtr)
+	ptr := C.instance_new(C.Config{
+		wasm: C.List_u8{
+			ptr: (*C.uchar)(wasmPtr),
+			len: C.ulong(len(wasm)),
+		},
+	})
 	if ptr == nil {
 		n := C.error_len()
 		buf := make([]C.char, n)