Address feedback: misc clean ups

lib/api/src/instance.rs

@@ -130,6 +130,14 @@ impl Instance {
             exports,
         };
 
+        // # Safety
+        // `initialize_host_envs` should be called after instantiation but before
+        // returning an `Instance` to the user. We set up the host environments
+        // via `WasmerEnv::init_with_instance`.
+        //
+        // This usage is correct because we pass a valid pointer to `instance` and the
+        // correct error type returned by `WasmerEnv::init_with_instance` as a generic
+        // parameter.
         unsafe {
             instance
                 .handle

lib/c-api/src/wasm_c_api/wasi/mod.rs

@@ -174,12 +174,12 @@ pub extern "C" fn wasi_env_new(mut config: Box<wasi_config_t>) -> Option<Box<was
 #[no_mangle]
 pub extern "C" fn wasi_env_delete(_state: Option<Box<wasi_env_t>>) {}
 
+/// This function is deprecated. You may safely remove all calls to it and everything
+/// will continue to work.
 // Dead code: deprecate or remove
+#[allow(unused_variables)]
 #[no_mangle]
-pub extern "C" fn wasi_env_set_instance(
-    _env: &mut wasi_env_t,
-    _instance: &wasm_instance_t,
-) -> bool {
+pub extern "C" fn wasi_env_set_instance(env: &mut wasi_env_t, instance: &wasm_instance_t) -> bool {
     /*
     let memory = if let Ok(memory) = instance.inner.exports.get_memory("memory") {
         memory
@@ -192,9 +192,12 @@ pub extern "C" fn wasi_env_set_instance(
     true
 }
 
+/// This function is deprecated. You may safely remove all calls to it and everything
+/// will continue to work.
 // Dead code: deprecate or remove
+#[allow(unused_variables)]
 #[no_mangle]
-pub extern "C" fn wasi_env_set_memory(_env: &mut wasi_env_t, _memory: &wasm_memory_t) {
+pub extern "C" fn wasi_env_set_memory(env: &mut wasi_env_t, memory: &wasm_memory_t) {
     //env.inner.set_memory(memory.inner.clone());
 }
 

lib/c-api/wasmer_wasm.h

@@ -145,11 +145,19 @@ intptr_t wasi_env_read_stdout(wasi_env_t *env, char *buffer, uintptr_t buffer_le
 #endif
 
 #if defined(WASMER_WASI_ENABLED)
-bool wasi_env_set_instance(wasi_env_t *_env, const wasm_instance_t *_instance);
+/**
+ * This function is deprecated. You may safely remove all calls to it and everything
+ * will continue to work.
+ */
+bool wasi_env_set_instance(wasi_env_t *env, const wasm_instance_t *instance);
 #endif
 
 #if defined(WASMER_WASI_ENABLED)
-void wasi_env_set_memory(wasi_env_t *_env, const wasm_memory_t *_memory);
+/**
+ * This function is deprecated. You may safely remove all calls to it and everything
+ * will continue to work.
+ */
+void wasi_env_set_memory(wasi_env_t *env, const wasm_memory_t *memory);
 #endif
 
 #if defined(WASMER_WASI_ENABLED)

lib/vm/src/instance.rs

@@ -1163,6 +1163,7 @@ impl InstanceHandle {
     /// - This function must be called with the correct `Err` type parameter: the error type is not
     ///   visible to code in `wasmer_vm`, so it's the caller's responsibility to ensure these
     ///   functions are called with the correct type.
+    /// - `instance_ptr` must point to a valid `wasmer::Instance`.
     pub unsafe fn initialize_host_envs<Err: Sized>(
         &mut self,
         instance_ptr: *const std::ffi::c_void,

lib/wasi/src/lib.rs

@@ -82,7 +82,8 @@ impl WasiEnv {
 
     /// Get a reference to the memory
     pub fn memory(&self) -> &Memory {
-        self.memory_ref().unwrap()
+        self.memory_ref()
+            .expect("Memory should be set on `WasiEnv` first")
     }
 
     pub(crate) fn get_memory_and_wasi_state(