[module-splitting] Remove jspi-split-module (#8200)

This no longer used by emscripten, and the TODO suggests it should be
removed.

Author: sbc100

src/ir/module-splitting.cpp

@@ -320,9 +320,6 @@ struct ModuleSplitter {
   // replace.
   std::unordered_map<Name, std::map<size_t, Name>> placeholderMap;
 
-  // Internal name of the LOAD_SECONDARY_MODULE function.
-  Name internalLoadSecondaryModule;
-
   // Map from original secondary function name to its trampoline
   std::unordered_map<Name, Name> trampolineMap;
 
@@ -367,26 +364,14 @@ struct ModuleSplitter {
 };
 
 void ModuleSplitter::setupJSPI() {
-  // Support the first version of JSPI, where the JSPI pass added the load
-  // secondary module export.
-  // TODO: remove this when the new JSPI API is only supported.
-  if (auto* loadSecondary = primary.getExportOrNull(LOAD_SECONDARY_MODULE);
-      loadSecondary && loadSecondary->kind == ExternalKind::Function) {
-    internalLoadSecondaryModule = *loadSecondary->getInternalName();
-    // Remove the exported LOAD_SECONDARY_MODULE function since it's only needed
-    // internally.
-    primary.removeExport(LOAD_SECONDARY_MODULE);
-  } else {
-    // Add an imported function to load the secondary module.
-    auto import = Builder::makeFunction(
-      ModuleSplitting::LOAD_SECONDARY_MODULE,
-      Type(Signature(Type::none, Type::none), NonNullable, Inexact),
-      {});
-    import->module = ENV;
-    import->base = ModuleSplitting::LOAD_SECONDARY_MODULE;
-    primary.addFunction(std::move(import));
-    internalLoadSecondaryModule = ModuleSplitting::LOAD_SECONDARY_MODULE;
-  }
+  // Add an imported function to load the secondary module.
+  auto import = Builder::makeFunction(
+    ModuleSplitting::LOAD_SECONDARY_MODULE,
+    Type(Signature(Type::none, Type::none), NonNullable, Inexact),
+    {});
+  import->module = ENV;
+  import->base = ModuleSplitting::LOAD_SECONDARY_MODULE;
+  primary.addFunction(std::move(import));
   Builder builder(primary);
   // Add a global to track whether the secondary module has been loaded yet.
   primary.addGlobal(builder.makeGlobal(LOAD_SECONDARY_STATUS,
@@ -600,7 +585,7 @@ Expression* ModuleSplitter::maybeLoadSecondary(Builder& builder,
   auto* loadSecondary = builder.makeIf(
     builder.makeUnary(EqZInt32,
                       builder.makeGlobalGet(LOAD_SECONDARY_STATUS, Type::i32)),
-    builder.makeCall(internalLoadSecondaryModule, {}, Type::none));
+    builder.makeCall(ModuleSplitting::LOAD_SECONDARY_MODULE, {}, Type::none));
   return builder.makeSequence(loadSecondary, callIndirect);
 }
 

src/passes/JSPI.cpp

@@ -32,7 +32,7 @@
 //
 // Convert a module to be compatible with JavaScript promise integration (JSPI).
 // Promising exports will be wrapped with a function that will handle storing
-// the suspsender that is passed in as the first param from a "promising"
+// the suspender that is passed in as the first param from a "promising"
 // `WebAssembly.Function`. Suspending imports will also be wrapped, but they
 // will take the stored suspender and pass it as the first param to the imported
 // function that should be created from a "suspending" `WebAssembly.Function`.
@@ -50,12 +50,6 @@
 //      Wrap each export in the comma-separated list. Similar to jspi-imports,
 //      wildcards and separate files are supported.
 //
-//   --pass-arg=jspi-split-module
-//
-//      Enables integration with wasm-split. A JSPI'ed function named
-//      `__load_secondary_module` will be injected that is used by wasm-split to
-//      load a secondary module.
-//
 
 namespace wasm {
 
@@ -93,22 +87,6 @@ struct JSPI : public Pass {
       read_possible_response_file(getArgumentOrDefault("jspi-exports", "")));
     String::Split listedExports(stateChangingExports, ",");
 
-    bool wasmSplit = hasArgument("jspi-split-module");
-    if (wasmSplit) {
-      // Make an import for the load secondary module function so a JSPI wrapper
-      // version will be created.
-      auto import = Builder::makeFunction(
-        ModuleSplitting::LOAD_SECONDARY_MODULE,
-        Type(Signature(Type::none, Type::none), NonNullable, Inexact),
-        {});
-      import->module = ENV;
-      import->base = ModuleSplitting::LOAD_SECONDARY_MODULE;
-      module->addFunction(std::move(import));
-      listedImports.push_back(
-        ENV.toString() + "." +
-        ModuleSplitting::LOAD_SECONDARY_MODULE.toString());
-    }
-
     // Create a global to store the suspender that is passed into exported
     // functions and will then need to be passed out to the imported functions.
     Name suspender = Names::getValidGlobalName(*module, "suspender");
@@ -168,7 +146,7 @@ struct JSPI : public Pass {
       if (im->imported() &&
           canChangeState(getFullFunctionName(im->module, im->base),
                          listedImports)) {
-        makeWrapperForImport(im, module, suspender, wasmSplit);
+        makeWrapperForImport(im, module, suspender);
       }
     }
   }
@@ -221,10 +199,7 @@ struct JSPI : public Pass {
     return module->addFunction(std::move(wrapperFunc))->name;
   }
 
-  void makeWrapperForImport(Function* im,
-                            Module* module,
-                            Name suspender,
-                            bool wasmSplit) {
+  void makeWrapperForImport(Function* im, Module* module, Name suspender) {
     Builder builder(*module);
     auto wrapperIm = std::make_unique<Function>();
     wrapperIm->name = Names::getValidFunctionName(
@@ -278,15 +253,6 @@ struct JSPI : public Pass {
     wrapperIm->type =
       Type(Signature(Type(params), call->type), NonNullable, Inexact);
 
-    if (wasmSplit && im->name == ModuleSplitting::LOAD_SECONDARY_MODULE) {
-      // In non-debug builds the name of the JSPI wrapper function for loading
-      // the secondary module will be removed. Create an export of it so that
-      // wasm-split can find it.
-      module->addExport(
-        builder.makeExport(ModuleSplitting::LOAD_SECONDARY_MODULE,
-                           ModuleSplitting::LOAD_SECONDARY_MODULE,
-                           ExternalKind::Function));
-    }
     module->removeFunction(im->name);
     module->addFunction(std::move(stub));
     module->addFunction(std::move(wrapperIm));