Merge #1709

1709: feat(c-api) Implement `wasm_module_name` and `wasm_module_set_name` r=Hywan a=Hywan

Until my official proposal made here, WebAssembly/wasm-c-api#157 is accepted or rejected, I implement those functions as “wasmer-specific” API.

Co-authored-by: Ivan Enderlin <[email protected]>

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ### Added
 
+- [#1709](https://github.com/wasmerio/wasmer/pull/1709) Implement `wasm_module_name` and `wasm_module_set_name` in the Wasm(er) C API.
 - [#1700](https://github.com/wasmerio/wasmer/pull/1700) Implement `wasm_externtype_copy` in the Wasm C API.
 
 ## 1.0.0-alpha4 - 2020-10-08

lib/c-api/build.rs

@@ -378,10 +378,12 @@ fn exclude_items_from_wasm_c_api(builder: Builder) -> Builder {
         .exclude_item("wasi_get_start_function")
         .exclude_item("wasi_get_wasi_version")
         .exclude_item("wasi_version_t")
+        .exclude_item("wasm_config_set_compiler")
+        .exclude_item("wasm_config_set_engine")
         .exclude_item("wasm_instance_get_vmctx_ptr")
+        .exclude_item("wasm_module_name")
+        .exclude_item("wasm_module_set_name")
         .exclude_item("wasmer_compiler_t")
         .exclude_item("wasmer_engine_t")
-        .exclude_item("wasm_config_set_compiler")
-        .exclude_item("wasm_config_set_engine")
         .exclude_item("wat2wasm")
 }

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

@@ -1,9 +1,42 @@
 //! Wasmer-specific extensions to the Wasm C API.
 
-use crate::wasm_c_api::instance::wasm_instance_t;
+use super::instance::wasm_instance_t;
+use super::module::wasm_module_t;
+use super::types::wasm_name_t;
 use std::ffi::c_void;
+use std::str;
+use std::sync::Arc;
 
 #[no_mangle]
 pub unsafe extern "C" fn wasm_instance_get_vmctx_ptr(instance: &wasm_instance_t) -> *mut c_void {
     instance.inner.vmctx_ptr() as _
 }
+
+#[no_mangle]
+pub unsafe extern "C" fn wasm_module_name(module: &wasm_module_t, out: &mut wasm_name_t) {
+    let name = match module.inner.name() {
+        Some(name) => name,
+        None => return,
+    };
+
+    *out = name.as_bytes().to_vec().into();
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn wasm_module_set_name(
+    module: &mut wasm_module_t,
+    name: &wasm_name_t,
+) -> bool {
+    let name = match name.into_slice() {
+        Some(name) => match str::from_utf8(name) {
+            Ok(name) => name,
+            Err(_) => return false, // not ideal!
+        },
+        None => return false,
+    };
+
+    match Arc::get_mut(&mut module.inner) {
+        Some(module) => module.set_name(name),
+        None => false,
+    }
+}

lib/c-api/wasmer_wasm.h

@@ -156,6 +156,10 @@ void wasm_config_set_engine(wasm_config_t *config, wasmer_engine_t engine);
 
 void *wasm_instance_get_vmctx_ptr(const wasm_instance_t *instance);
 
+void wasm_module_name(const wasm_module_t *module, wasm_name_t *out);
+
+bool wasm_module_set_name(wasm_module_t *module, const wasm_name_t *name);
+
 /**
  * Gets the length in bytes of the last error if any.
  *