@@ -535,6 +541,14 @@ The verification of WebAssembly type requirements is deferred to the
Note: A follow-on streaming API is documented in the
WebAssembly Web API.
+
+ The namespaceInstance(|namespace|) method, when invoked, performs the following steps:
+ 1. Assert: |namespace| is a [=Module Namespace exotic object=].
+ 1. If |namespace|.\[[Module]] is not a [=WebAssembly Module Record=], [=throw=] a {{TypeError}} exception.
+ 1. Let |module| be |namespace|.\[[Module]].
+ 1. Return |module|.\[[Instance]].
+
+
Modules
@@ -1391,6 +1405,8 @@ To parse a WebAssembly module given a byte sequence |by
1. For each (|moduleName|, name, type) in [=module_imports=](|module|.\[[Module]]),
1. [=set/Append=] |moduleName| to |requestedModules|.
1. Let |moduleRecord| be {
+
+ \[[Instance]]: ~empty~,
\[[Realm]]: |realm|,
\[[Environment]]: ~empty~,
@@ -1470,25 +1486,82 @@ WebAssembly Module Records have the following methods:
ExecuteModule ( [ |promiseCapability| ] ) Concrete Method
1. Assert: |promiseCapability| was not provided.
1. Let |record| be this WebAssembly Module Record.
-1. Let |module| be |record|.\[[ModuleSource]].
-1. Let |imports| be a new, empty [=map=].
-1. For each (|importedModuleName|, |name|, type) in [=module_imports=](|module|.\[[Module]]),
- 1. If |imports|[|importedModuleName|] does not exist, set |imports|[|importedModuleName|] to a new, empty [=map=].
+1. Let |module| be |record|.\[[ModuleSource]].\[[Module]].
+1. Let |imports| be « ».
+1. [=list/iterate|For each=] (|importedModuleName|, |name|, |importtype|) in [=module_imports=](|module|),
1. Let |importedModule| be [$GetImportedModule$](|record|, |importedModuleName|).
- 1. Let |value| be ? |importedModule|.\[[Environment]].GetBindingValue(|name|, true).
- 1. Set |imports|[|importedModuleName|][|name|] to |value|.
-1. Let |importObject| be ! [$OrdinaryObjectCreate$](null).
-1. For each |key| → |value| of |imports|,
- 1. Let |moduleImportsObject| be ! [$OrdinaryObjectCreate$](null).
- 1. For each |importedName| → |importedValue| of |value|,
- 1. Perform ! [$CreateDataPropertyOrThrow$](|moduleImportsObject|, |importedName|, |importedValue|).
- 1. Perform ! [$CreateDataPropertyOrThrow$](|importObject|, |key|, |moduleImportsObject|).
-1. [=Read the imports=] of |module| with imports |importObject|, and let |imports| be the result.
+ 1. Let |resolution| be |importedModule|.ResolveExport(|name|).
+ 1. Assert: |resolution| is a [=ResolvedBinding Record=], as validated during environment initialization.
+ 1. Let |resolvedModule| be |resolution|.\\[[Module]].
+ 1. Let |resolvedName| be |resolution|.\[[BindingName]].
+ 1. If |resolvedModule| is a WebAssembly Module Record,
+ 1. If |resolvedModule|.\[[Instance]] is ~empty~, throw a {LinkError} exception.
+ 1. Assert: |resolvedModule|.\[[Instance]] is a WebAssembly {{Instance}} object.
+ 1. Assert: |resolvedModule|.\[[ModuleSource]] is a WebAssembly {{Module}} object.
+ 1. Let |module| be |resolvedModule|.\[[ModuleSource]].\[[Module]].
+ 1. Let |externval| be [=instance_export=](|resolvedModule|.\[[Instance]], |resolvedName|).
+ 1. Assert: |externval| is not [=error=].
+ 1. Assert: [=module_exports=](|module|) contains an element (|resolvedName|, type).
+ 1. Let |externtype| be the value of |type| for the element (|resolvedName|, |type|) in [=module_exports=](|module|).
+ 1. If |importtype| is not an [=extern subtype=] of |externtype|, throw a {{LinkError}} exception.
+ 1. [=list/Append=] |externval| to |imports|.
+ 1. Otherwise,
+ 1. Let |env| be |resolvedModule|.\[[Environment]].
+ 1. Let |v| be [=?=] |env|.GetBindingValue(|resolvedName|, true).
+ 1. If |importtype| is of the form [=func=] |functype|,
+ 1. If [$IsCallable$](|v|) is false, throw a {{LinkError}} exception.
+ 1. If |v| has a \[[FunctionAddress]] internal slot, and therefore is an [=Exported Function=],
+ 1. Let |funcaddr| be the value of |v|'s \[[FunctionAddress]] internal slot.
+ 1. Otherwise,
+ 1. [=Create a host function=] from |v| and |functype|, and let |funcaddr| be the result.
+ 1. Let index be the number of external functions in |imports|, defining the [=index of the host function=] |funcaddr|.
+ 1. Let |externfunc| be the [=external value=] [=external value|func=] |funcaddr|.
+ 1. [=list/Append=] |externfunc| to |imports|.
+ 1. If |importtype| is of the form [=global=] |mut| |valtype|,
+ 1. Let |store| be the [=surrounding agent=]'s [=associated store=].
+ 1. If |v| [=implements=] {{Global}},
+ 1. Let |globaladdr| be |v|.\[[Global]].
+ 1. Let |targetmut| valuetype be [=global_type=](|store|, |globaladdr|).
+ 1. If |mut| is [=const=] and |targetmut| is [=var=], throw a {{LinkError}} exception.
+ 1. Otherwise,
+ 1. If |valtype| is [=v128=], throw a {{LinkError}} exception.
+ 1. If |mut| is [=var=], throw a {{LinkError}} exception.
+ 1. Let |value| be [=?=] [=ToWebAssemblyValue=](|v|, |valtype|).
+ 1. Let (|store|, |globaladdr|) be [=global_alloc=](|store|, |mut| |valtype|, |value|).
+ 1. Set the [=surrounding agent=]'s [=associated store=] to |store|.
+ 1. Let |externglobal| be [=external value|global=] |globaladdr|.
+ 1. [=list/Append=] |externglobal| to |imports|.
+ 1. If |importtype| is of the form [=mem=] memtype,
+ 1. If |v| does not [=implement=] {{Memory}}, throw a {{LinkError}} exception.
+ 1. Let |externmem| be the [=external value=] [=external value|mem=] |v|.\[[Memory]].
+ 1. [=list/Append=] |externmem| to |imports|.
+ 1. If |importtype| is of the form [=table=] tabletype,
+ 1. If |v| does not [=implement=] {{Table}}, throw a {{LinkError}} exception.
+ 1. Let |tableaddr| be |v|.\[[Table]].
+ 1. Let |externtable| be the [=external value=] [=external value|table=] |tableaddr|.
+ 1. [=list/Append=] |externtable| to |imports|.
1. [=Instantiate the core of a WebAssembly module=] |module| with |imports|, and let |instance| be the result.
-1. For each |name| in the [=export name list=] of |record|,
- 1. Perform ! |record|.\[[Environment]].InitializeBinding(|name|, ! Get(|instance|.\[[Exports]], |name|)).
+1. Set |record|.\[[Instance]] to |instance|.
+1. [=list/iterate|For each=] (|name|, |externtype|) of [=module_exports=](|module|),
+ 1. If |externtype| is of the form [=global=] |mut| |globaltype|,
+ 1. Assert: |externval| is of the form [=external value|global=] |globaladdr|.
+ 1. Let [=external value|global=] |globaladdr| be |externval|.
+ 1. Let |global_value| be [=global_read=](|store|, |globaladdr|).
+ 1. If |globaltype| is not [=v128=],
+ 1. Note: The condition above leaves unsupported JS values as uninitialized in TDZ and therefore as a reference error on
+ access. When integrating with shared globals, they may be excluded here similarly to v128 above.
+ 1. Perform [=!=] |record|.\[[Environment]].InitializeBinding(|name|, [=ToJSValue=](|global_value|)).
+ 1. If |mut| is [=var=], then associate all future mutations of |globaladdr| with the ECMA-262 binding record for |name| in
+ |record|.\[[Environment]], such that |record|.\[[Environment]].GetBindingValue(|resolution|.\[[BindingName]], true)
+ always returns [=ToJSValue=]([=global_read=](|store|, |globaladdr|)) for the current [=surrounding agent=]'s
+ [=associated store=] |store|.
+ 1. Otherwise,
+ 1. Perform ! |record|.\[[Environment]].InitializeBinding(|name|, ! Get(|instance|.\[[Exports]], |name|)).
- Note: exported bindings are left uninitialized, i.e., in TDZ.
+Note: The linking semantics here for Wasm to Wasm modules are identical to the WebAssembly JS API semantics as if passing the
+the exports object as the imports object in instantiation. When linking Wasm module imports to JS module exports, the JS API semantics
+are exactly followed as well. It is only in the case of importing Wasm from JS that WebAssembly.Global unwrapping is observable on the
+WebAssembly Module Record Environment Record.