Port C API to new Context API

lib/api/src/sys/context.rs

@@ -65,6 +65,14 @@ impl<T> Context<T> {
     pub fn store(&self) -> &Store {
         &self.inner.store
     }
+
+    /// For use with the C API
+    /// # Safety
+    ///
+    /// This is unsafe.
+    pub unsafe fn transmute_data<U>(&mut self) -> &mut Context<U> {
+        core::mem::transmute::<&mut Self, &mut Context<U>>(self)
+    }
 }
 
 /// A temporary handle to a [`Context`].

lib/api/src/sys/externals/mod.rs

@@ -44,7 +44,7 @@ impl Extern {
     }
 
     /// Create an `Extern` from an `wasmer_engine::Export`.
-    pub(crate) fn from_vm_extern(ctx: &mut impl AsContextMut, vm_extern: VMExtern) -> Self {
+    pub fn from_vm_extern(ctx: &mut impl AsContextMut, vm_extern: VMExtern) -> Self {
         match vm_extern {
             VMExtern::Function(f) => Self::Function(Function::from_vm_extern(ctx, f)),
             VMExtern::Memory(m) => Self::Memory(Memory::from_vm_extern(ctx, m)),
@@ -63,7 +63,8 @@ impl Extern {
         }
     }
 
-    pub(crate) fn to_vm_extern(&self) -> VMExtern {
+    /// To `VMExtern`.
+    pub fn to_vm_extern(&self) -> VMExtern {
         match self {
             Self::Function(f) => f.to_vm_extern(),
             Self::Global(g) => g.to_vm_extern(),

lib/c-api/Cargo.toml

@@ -85,4 +85,4 @@ jit = ["universal"]
 #emscripten = ["wasmer-emscripten"]
 
 [build-dependencies]
-cbindgen = "0.19"
+cbindgen = "0.24"

lib/c-api/src/wasm_c_api/context.rs

@@ -0,0 +1,40 @@
+use crate::wasm_c_api::store::wasm_store_t;
+use libc::c_void;
+use wasmer_api::Context;
+
+/// Opaque type representing a WebAssembly context.
+#[allow(non_camel_case_types)]
+pub struct wasm_context_t {
+    pub(crate) inner: Context<*mut c_void>,
+}
+
+impl core::fmt::Debug for wasm_context_t {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(fmt, "wasm_context_t")
+    }
+}
+
+/// Creates a new WebAssembly Context given a specific [engine][super::engine].
+///
+/// # Example
+///
+/// See the module's documentation.
+#[no_mangle]
+pub unsafe extern "C" fn wasm_context_new(
+    store: Option<&wasm_store_t>,
+    data: *mut c_void,
+) -> Option<Box<wasm_context_t>> {
+    let store = store?;
+
+    Some(Box::new(wasm_context_t {
+        inner: Context::new(&store.inner, data),
+    }))
+}
+
+/// Deletes a WebAssembly context.
+///
+/// # Example
+///
+/// See the module's documentation.
+#[no_mangle]
+pub unsafe extern "C" fn wasm_context_delete(_context: Option<Box<wasm_context_t>>) {}