Thread component-model-implements into the C API

Expose both the `Config` accessor plus API changes necessary to reflect
over this proposal in the C API.

Author: alexcrichton

crates/c-api/include/wasmtime/component/types/component.h

@@ -40,23 +40,23 @@ size_t wasmtime_component_type_import_count(const wasmtime_component_type_t *ty,
 
 /// \brief Retrieves the import with the specified name.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
-bool wasmtime_component_type_import_get(const wasmtime_component_type_t *ty,
-                                        const wasm_engine_t *engine,
-                                        const char *name, size_t name_len,
-                                        struct wasmtime_component_item_t *ret);
+bool wasmtime_component_type_import_get(
+    const wasmtime_component_type_t *ty, const wasm_engine_t *engine,
+    const char *name, size_t name_len,
+    struct wasmtime_component_extern_t **ret);
 
 /// \brief Retrieves the nth import.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
 bool wasmtime_component_type_import_nth(
     const wasmtime_component_type_t *ty, const wasm_engine_t *engine,
     size_t nth, const char **name_ret, size_t *name_len_ret,
-    struct wasmtime_component_item_t *type_ret);
+    struct wasmtime_component_extern_t **ret);
 
 /// \brief Returns the number of exports of a component type.
 WASM_API_EXTERN
@@ -65,23 +65,23 @@ size_t wasmtime_component_type_export_count(const wasmtime_component_type_t *ty,
 
 /// \brief Retrieves the export with the specified name.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
-bool wasmtime_component_type_export_get(const wasmtime_component_type_t *ty,
-                                        const wasm_engine_t *engine,
-                                        const char *name, size_t name_len,
-                                        struct wasmtime_component_item_t *ret);
+bool wasmtime_component_type_export_get(
+    const wasmtime_component_type_t *ty, const wasm_engine_t *engine,
+    const char *name, size_t name_len,
+    struct wasmtime_component_extern_t **ret);
 
 /// \brief Retrieves the nth export.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
 bool wasmtime_component_type_export_nth(
     const wasmtime_component_type_t *ty, const wasm_engine_t *engine,
     size_t nth, const char **name_ret, size_t *name_len_ret,
-    struct wasmtime_component_item_t *type_ret);
+    struct wasmtime_component_extern_t **ret);
 
 /// \brief Value of #wasmtime_component_item_kind_t meaning that
 /// #wasmtime_component_item_t is a component.
@@ -153,6 +153,71 @@ void wasmtime_component_item_clone(const wasmtime_component_item_t *item,
 WASM_API_EXTERN
 void wasmtime_component_item_delete(wasmtime_component_item_t *ptr);
 
+/// \brief Full description of a single component or component instance export
+/// or import.
+///
+/// This carries the type of the item being imported or exported along with
+/// any metadata attached to it such as `(implements "...")` or
+/// `(external-id "...")` annotations.
+///
+/// Note that this structure contains pointers to the original component or
+/// instance type that it's acquired from. This must always be
+/// destroyed/accessed before those original types are destroyed.
+typedef struct wasmtime_component_extern_t wasmtime_component_extern_t;
+
+/// \brief Clones a component extern.
+///
+/// The returned pointer must be deallocated with
+/// `wasmtime_component_extern_delete`.
+///
+/// Note that this does not clone the internal pointers that the
+/// `wasmtime_component_extern_t` struct refers to, so the returned structure
+/// still cannot outlive the original source that this comes from.
+WASM_API_EXTERN
+wasmtime_component_extern_t *
+wasmtime_component_extern_clone(const wasmtime_component_extern_t *e);
+
+/// \brief Returns the type of the item that this import/export refers to.
+///
+/// The returned `wasmtime_component_item_t` must be deallocated with
+/// `wasmtime_component_item_delete`.
+WASM_API_EXTERN
+void wasmtime_component_extern_type(const wasmtime_component_extern_t *e,
+                                    wasmtime_component_item_t *ret);
+
+/// \brief Returns the `implements` attribute of this import/export.
+///
+/// Returns `NULL` if this isn't present. Writes the length of the return value
+/// to `len`. The returned pointer cannot be used outside the lifetime of `e`.
+WASM_API_EXTERN
+const char *
+wasmtime_component_extern_implements(const wasmtime_component_extern_t *e,
+                                     size_t *len);
+
+/// \brief Returns whether this import/export `e` has an `implements` attribute
+/// which matches the `name` provided (which is `len` bytes long).
+///
+/// This returns `false` if `e` has no `implements` attribute. Otherwise this
+/// returns `true` if the attribute is exactly equal to `name` or if it's a
+/// semver-compatible version of `name`. For example `(implements
+/// "a:b/c@1.1.0")` matches both `a:b/c@1.0.0` and `a:b/c@1.2.0`.
+WASM_API_EXTERN
+bool wasmtime_component_extern_is_implements(
+    const wasmtime_component_extern_t *e, const char *name, size_t len);
+
+/// \brief Returns the `external-id` attribute of this import/export.
+///
+/// Returns `NULL` if this isn't present. Writes the length of the return value
+/// to `len`. The returned pointer cannot be used outside the lifetime of `e`.
+WASM_API_EXTERN
+const char *
+wasmtime_component_extern_external_id(const wasmtime_component_extern_t *e,
+                                      size_t *len);
+
+/// \brief Deallocates a component extern.
+WASM_API_EXTERN
+void wasmtime_component_extern_delete(wasmtime_component_extern_t *ptr);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

crates/c-api/include/wasmtime/component/types/component.hh

@@ -22,6 +22,7 @@ namespace wasmtime {
 namespace component {
 
 class ComponentItem;
+class ComponentExtern;
 
 /**
  * \brief Represents the type of a WebAssembly component.
@@ -35,11 +36,17 @@ class ComponentType {
   }
 
   /// Retrieves the import with the specified name.
-  std::optional<ComponentItem> import_get(const Engine &engine,
-                                          std::string_view name) const;
+  ///
+  /// The returned `ComponentExtern` borrows from this type and the engine and
+  /// must not outlive either of them.
+  std::optional<ComponentExtern> import_get(const Engine &engine,
+                                            std::string_view name) const;
 
   /// Retrieves the nth import.
-  std::optional<std::pair<std::string_view, ComponentItem>>
+  ///
+  /// The returned `ComponentExtern` borrows from this type and the engine and
+  /// must not outlive either of them.
+  std::optional<std::pair<std::string_view, ComponentExtern>>
   import_nth(const Engine &engine, size_t nth) const;
 
   /// Returns the number of exports of this component type.
@@ -48,11 +55,17 @@ class ComponentType {
   }
 
   /// Retrieves the export with the specified name.
-  std::optional<ComponentItem> export_get(const Engine &engine,
-                                          std::string_view name) const;
+  ///
+  /// The returned `ComponentExtern` borrows from this type and the engine and
+  /// must not outlive either of them.
+  std::optional<ComponentExtern> export_get(const Engine &engine,
+                                            std::string_view name) const;
 
   /// Retrieves the nth export.
-  std::optional<std::pair<std::string_view, ComponentItem>>
+  ///
+  /// The returned `ComponentExtern` borrows from this type and the engine and
+  /// must not outlive either of them.
+  std::optional<std::pair<std::string_view, ComponentExtern>>
   export_nth(const Engine &engine, size_t nth) const;
 };
 
@@ -170,6 +183,59 @@ public:
   const ValType &type() const;
 };
 
+/**
+ * \brief Full description of a single import or export of a component or a
+ * component instance.
+ *
+ * This carries the type of the item being imported or exported along with any
+ * `(implements "...")` or `(external-id "...")` annotations attached to it.
+ *
+ * Note that this borrows string data from the `ComponentType` or
+ * `ComponentInstanceType` it was acquired from (and the `Engine` used to
+ * acquire it), so it must not outlive either of those. Copies of this class
+ * share the same borrow and are subject to the same restriction.
+ */
+class ComponentExtern {
+  WASMTIME_CLONE_WRAPPER(ComponentExtern, wasmtime_component_extern);
+
+  /// Returns the type of the item that this import/export refers to.
+  ComponentItem type() const;
+
+  /// Returns the `(implements "...")` annotation of this import/export, if
+  /// present.
+  std::optional<std::string_view> implements() const {
+    size_t len = 0;
+    const char *ptr = wasmtime_component_extern_implements(capi(), &len);
+    if (ptr == nullptr) {
+      return std::nullopt;
+    }
+    return std::string_view(ptr, len);
+  }
+
+  /// Returns whether this import/export has an `(implements "...")`
+  /// annotation which is compatible with `name`.
+  ///
+  /// This returns `false` if there is no `implements` annotation. Otherwise
+  /// this returns `true` if the annotation is exactly `name` or a
+  /// semver-compatible version of it, for example `a:b/c@1.1.0` matches
+  /// `a:b/c@1.0.0` and `a:b/c@1.2.0`.
+  bool is_implements(std::string_view name) const {
+    return wasmtime_component_extern_is_implements(capi(), name.data(),
+                                                   name.size());
+  }
+
+  /// Returns the `(external-id "...")` annotation of this import/export, if
+  /// present.
+  std::optional<std::string_view> external_id() const {
+    size_t len = 0;
+    const char *ptr = wasmtime_component_extern_external_id(capi(), &len);
+    if (ptr == nullptr) {
+      return std::nullopt;
+    }
+    return std::string_view(ptr, len);
+  }
+};
+
 } // namespace component
 } // namespace wasmtime
 
@@ -178,60 +244,67 @@ public:
 #include <wasmtime/component/types/module.hh>
 #include <wasmtime/component/types/val.hh>
 
-inline std::optional<wasmtime::component::ComponentItem>
+inline wasmtime::component::ComponentItem
+wasmtime::component::ComponentExtern::type() const {
+  wasmtime_component_item_t item;
+  wasmtime_component_extern_type(capi(), &item);
+  return wasmtime::component::ComponentItem(std::move(item));
+}
+
+inline std::optional<wasmtime::component::ComponentExtern>
 wasmtime::component::ComponentType::import_get(const wasmtime::Engine &engine,
                                                std::string_view name) const {
-  wasmtime_component_item_t item;
-  bool found = wasmtime_component_type_import_get(
-      capi(), engine.capi(), name.data(), name.size(), &item);
+  wasmtime_component_extern_t *e;
+  bool found = wasmtime_component_type_import_get(capi(), engine.capi(),
+                                                  name.data(), name.size(), &e);
   if (!found) {
     return std::nullopt;
   }
-  return wasmtime::component::ComponentItem(std::move(item));
+  return wasmtime::component::ComponentExtern(e);
 }
 
 inline std::optional<
-    std::pair<std::string_view, wasmtime::component::ComponentItem>>
+    std::pair<std::string_view, wasmtime::component::ComponentExtern>>
 wasmtime::component::ComponentType::import_nth(const wasmtime::Engine &engine,
                                                size_t nth) const {
-  wasmtime_component_item_t item;
+  wasmtime_component_extern_t *e;
   const char *name_data;
   size_t name_size;
-  bool found = wasmtime_component_type_import_nth(
-      capi(), engine.capi(), nth, &name_data, &name_size, &item);
+  bool found = wasmtime_component_type_import_nth(capi(), engine.capi(), nth,
+                                                  &name_data, &name_size, &e);
   if (!found) {
     return std::nullopt;
   }
   return std::make_pair(std::string_view(name_data, name_size),
-                        wasmtime::component::ComponentItem(std::move(item)));
+                        wasmtime::component::ComponentExtern(e));
 }
 
-inline std::optional<wasmtime::component::ComponentItem>
+inline std::optional<wasmtime::component::ComponentExtern>
 wasmtime::component::ComponentType::export_get(const wasmtime::Engine &engine,
                                                std::string_view name) const {
-  wasmtime_component_item_t item;
-  bool found = wasmtime_component_type_export_get(
-      capi(), engine.capi(), name.data(), name.size(), &item);
+  wasmtime_component_extern_t *e;
+  bool found = wasmtime_component_type_export_get(capi(), engine.capi(),
+                                                  name.data(), name.size(), &e);
   if (!found) {
     return std::nullopt;
   }
-  return wasmtime::component::ComponentItem(std::move(item));
+  return wasmtime::component::ComponentExtern(e);
 }
 
 inline std::optional<
-    std::pair<std::string_view, wasmtime::component::ComponentItem>>
+    std::pair<std::string_view, wasmtime::component::ComponentExtern>>
 wasmtime::component::ComponentType::export_nth(const wasmtime::Engine &engine,
                                                size_t nth) const {
-  wasmtime_component_item_t item;
+  wasmtime_component_extern_t *e;
   const char *name_data;
   size_t name_size;
-  bool found = wasmtime_component_type_export_nth(
-      capi(), engine.capi(), nth, &name_data, &name_size, &item);
+  bool found = wasmtime_component_type_export_nth(capi(), engine.capi(), nth,
+                                                  &name_data, &name_size, &e);
   if (!found) {
     return std::nullopt;
   }
   return std::make_pair(std::string_view(name_data, name_size),
-                        wasmtime::component::ComponentItem(std::move(item)));
+                        wasmtime::component::ComponentExtern(e));
 }
 
 inline const wasmtime::component::ComponentInstanceType &

crates/c-api/include/wasmtime/component/types/instance.h

@@ -13,7 +13,7 @@
 extern "C" {
 #endif
 
-struct wasmtime_component_item_t;
+struct wasmtime_component_extern_t;
 
 /// \brief Represents the type of a component instance.
 typedef struct wasmtime_component_instance_type
@@ -39,22 +39,23 @@ size_t wasmtime_component_instance_type_export_count(
 
 /// \brief Retrieves the export with the specified name.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
 bool wasmtime_component_instance_type_export_get(
     const wasmtime_component_instance_type_t *ty, const wasm_engine_t *engine,
-    const char *name, size_t name_len, struct wasmtime_component_item_t *ret);
+    const char *name, size_t name_len,
+    struct wasmtime_component_extern_t **ret);
 
 /// \brief Retrieves the nth export.
 ///
-/// The returned `wasmtime_component_item_t` must be deallocated with
-/// `wasmtime_component_item_delete`.
+/// The returned `wasmtime_component_extern_t` must be deallocated with
+/// `wasmtime_component_extern_delete`.
 WASM_API_EXTERN
 bool wasmtime_component_instance_type_export_nth(
     const wasmtime_component_instance_type_t *ty, const wasm_engine_t *engine,
     size_t nth, const char **name_ret, size_t *name_len_ret,
-    struct wasmtime_component_item_t *type_ret);
+    struct wasmtime_component_extern_t **ret);
 
 #ifdef __cplusplus
 } // extern "C"