c-api: Add a way to get type of wasmtime_module_t (#3959)

My previous PR at #3958 accidentally removed the only way to get type
information from a `wasmtime_module_t`, so this commit re-adds methods
back in to continue to be able to get import/export information from a
compiled module.

crates/c-api/include/wasmtime/module.h

@@ -59,6 +59,22 @@ WASM_API_EXTERN void wasmtime_module_delete(wasmtime_module_t *m);
  */
 WASM_API_EXTERN wasmtime_module_t *wasmtime_module_clone(wasmtime_module_t *m);
 
+/**
+ * \brief Same as #wasm_module_imports, but for #wasmtime_module_t.
+ */
+WASM_API_EXTERN void wasmtime_module_imports(
+    const wasmtime_module_t *module,
+    wasm_importtype_vec_t *out
+);
+
+/**
+ * \brief Same as #wasm_module_exports, but for #wasmtime_module_t.
+ */
+WASM_API_EXTERN void wasmtime_module_exports(
+    const wasmtime_module_t *module,
+    wasm_exporttype_vec_t *out
+);
+
 /**
  * \brief Validate a WebAssembly binary.
  *

crates/c-api/src/module.rs

@@ -47,10 +47,8 @@ pub unsafe extern "C" fn wasm_module_validate(
     Module::validate(store.store.context().engine(), binary.as_slice()).is_ok()
 }
 
-#[no_mangle]
-pub extern "C" fn wasm_module_exports(module: &wasm_module_t, out: &mut wasm_exporttype_vec_t) {
+fn fill_exports(module: &Module, out: &mut wasm_exporttype_vec_t) {
     let exports = module
-        .module
         .exports()
         .map(|e| {
             Some(Box::new(wasm_exporttype_t::new(
@@ -62,10 +60,8 @@ pub extern "C" fn wasm_module_exports(module: &wasm_module_t, out: &mut wasm_exp
     out.set_buffer(exports);
 }
 
-#[no_mangle]
-pub extern "C" fn wasm_module_imports(module: &wasm_module_t, out: &mut wasm_importtype_vec_t) {
+fn fill_imports(module: &Module, out: &mut wasm_importtype_vec_t) {
     let imports = module
-        .module
         .imports()
         .map(|i| {
             Some(Box::new(wasm_importtype_t::new(
@@ -78,6 +74,16 @@ pub extern "C" fn wasm_module_imports(module: &wasm_module_t, out: &mut wasm_imp
     out.set_buffer(imports);
 }
 
+#[no_mangle]
+pub extern "C" fn wasm_module_exports(module: &wasm_module_t, out: &mut wasm_exporttype_vec_t) {
+    fill_exports(&module.module, out);
+}
+
+#[no_mangle]
+pub extern "C" fn wasm_module_imports(module: &wasm_module_t, out: &mut wasm_importtype_vec_t) {
+    fill_imports(&module.module, out);
+}
+
 #[no_mangle]
 pub extern "C" fn wasm_module_share(module: &wasm_module_t) -> Box<wasm_shared_module_t> {
     Box::new(wasm_shared_module_t {
@@ -144,6 +150,22 @@ pub extern "C" fn wasmtime_module_clone(module: &wasmtime_module_t) -> Box<wasmt
     Box::new(module.clone())
 }
 
+#[no_mangle]
+pub extern "C" fn wasmtime_module_exports(
+    module: &wasmtime_module_t,
+    out: &mut wasm_exporttype_vec_t,
+) {
+    fill_exports(&module.module, out);
+}
+
+#[no_mangle]
+pub extern "C" fn wasmtime_module_imports(
+    module: &wasmtime_module_t,
+    out: &mut wasm_importtype_vec_t,
+) {
+    fill_imports(&module.module, out);
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn wasmtime_module_validate(
     engine: &wasm_engine_t,