[SPLIT_MODULE] Make getWasmImports return Proxy

src/preamble.js

@@ -487,27 +487,39 @@ async function getWasmBinary(binaryFile) {
 
 #if SPLIT_MODULE
 {{{ makeModuleReceiveWithVar('loadSplitModule', undefined, 'instantiateSync') }}}
-var splitModuleProxyHandler = {
-  get(target, prop, receiver) {
-    return (...args) => {
+var splitImportsProxyHandler = {
+  get(target, moduleName, receiver) {
+    if (moduleName.startsWith('placeholder')) {
+      var splitModuleProxyHandler = {
+        get(target, base, receiver) {
+          return (...args) => {
 #if ASYNCIFY == 2
-      throw new Error('Placeholder function "' + prop + '" should not be called when using JSPI.');
+            throw new Error('Placeholder function "' + base + '" should not be called when using JSPI.');
 #else
-      err(`placeholder function called: ${prop}`);
-      var imports = {'primary': wasmExports};
-      // Replace '.wasm' suffix with '.deferred.wasm'.
-      var deferred = wasmBinaryFile.slice(0, -5) + '.deferred.wasm'
-      loadSplitModule(deferred, imports, prop);
-      err('instantiated deferred module, continuing');
+            // TODO: Implement multi-split module loading
+#if RUNTIME_DEBUG
+            dbg(`placeholder function called: ${base}`);
+#endif
+            var imports = {'primary': wasmExports};
+            // Replace '.wasm' suffix with '.deferred.wasm'.
+            loadSplitModule(secondaryFile, imports, base);
+#if RUNTIME_DEBUG
+            dbg('instantiated deferred module, continuing');
+#endif
 #if RELOCATABLE
-      // When the table is dynamically laid out, the placeholder functions names
-      // are offsets from the table base. In the main module, the table base is
-      // always 1.
-      prop = 1 + parseInt(prop);
+            // When the table is dynamically laid out, the placeholder functions names
+            // are offsets from the table base. In the main module, the table base is
+            // always 1.
+            base = 1 + parseInt(base);
 #endif
-      return wasmTable.get({{{ toIndexType('prop') }}})(...args);
+            return wasmTable.get({{{ toIndexType('base') }}})(...args);
 #endif
+          }
+        }
+      };
+      return new Proxy({}, splitModuleProxyHandler);
     }
+    return target[moduleName];
   }
 };
 #endif
@@ -633,6 +645,7 @@ async function instantiateAsync(binary, binaryFile, imports) {
 #endif // SOURCE_PHASE_IMPORTS
 
 #if !WASM_ESM_INTEGRATION
+
 function getWasmImports() {
 #if PTHREADS || WASM_WORKERS || (IMPORTED_MEMORY && MODULARIZE == 'instance')
   assignWasmImports();
@@ -653,21 +666,22 @@ function getWasmImports() {
 #endif
 #endif
   // prepare imports
-  return {
+  var imports = {
 #if MINIFY_WASM_IMPORTED_MODULES
     'a': wasmImports,
 #else // MINIFY_WASM_IMPORTED_MODULES
     'env': wasmImports,
     '{{{ WASI_MODULE_NAME }}}': wasmImports,
 #endif // MINIFY_WASM_IMPORTED_MODULES
-#if SPLIT_MODULE
-    'placeholder': new Proxy({}, splitModuleProxyHandler),
-#endif
 #if RELOCATABLE
     'GOT.mem': new Proxy(wasmImports, GOTHandler),
     'GOT.func': new Proxy(wasmImports, GOTHandler),
 #endif
-  }
+  };
+#if SPLIT_MODULE
+  imports = new Proxy(imports, splitImportsProxyHandler);
+#endif
+  return imports;
 }
 
 // Create the wasm instance.

test/codesize/test_codesize_cxx_wasmfs.json

@@ -2,9 +2,9 @@
   "a.out.js": 7059,
   "a.out.js.gz": 3330,
   "a.out.nodebug.wasm": 169721,
-  "a.out.nodebug.wasm.gz": 62983,
+  "a.out.nodebug.wasm.gz": 62981,
   "total": 176780,
-  "total_gz": 66313,
+  "total_gz": 66311,
   "sent": [
     "__cxa_throw",
     "_abort_js",

test/codesize/test_codesize_file_preload.expected.js

@@ -447,9 +447,10 @@ async function instantiateAsync(binary, binaryFile, imports) {
 
 function getWasmImports() {
   // prepare imports
-  return {
+  var imports = {
     "a": wasmImports
   };
+  return imports;
 }
 
 // Create the wasm instance.

test/codesize/test_codesize_files_wasmfs.json

@@ -2,9 +2,9 @@
   "a.out.js": 5465,
   "a.out.js.gz": 2576,
   "a.out.nodebug.wasm": 50218,
-  "a.out.nodebug.wasm.gz": 18082,
+  "a.out.nodebug.wasm.gz": 18086,
   "total": 55683,
-  "total_gz": 20658,
+  "total_gz": 20662,
   "sent": [
     "a (emscripten_date_now)",
     "b (emscripten_err)",

test/codesize/test_codesize_hello_O0.json

@@ -1,10 +1,10 @@
 {
   "a.out.js": 24070,
   "a.out.js.gz": 8666,
-  "a.out.nodebug.wasm": 15127,
-  "a.out.nodebug.wasm.gz": 7450,
-  "total": 39197,
-  "total_gz": 16116,
+  "a.out.nodebug.wasm": 15119,
+  "a.out.nodebug.wasm.gz": 7444,
+  "total": 39189,
+  "total_gz": 16110,
   "sent": [
     "fd_write"
   ],

test/codesize/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
   "a.out.js": 245829,
-  "a.out.nodebug.wasm": 597724,
-  "total": 843553,
+  "a.out.nodebug.wasm": 597730,
+  "total": 843559,
   "sent": [
     "IMG_Init",
     "IMG_Load",

test/codesize/test_codesize_minimal_O0.expected.js

@@ -658,10 +658,11 @@ async function instantiateAsync(binary, binaryFile, imports) {
 
 function getWasmImports() {
   // prepare imports
-  return {
+  var imports = {
     'env': wasmImports,
     'wasi_snapshot_preview1': wasmImports,
-  }
+  };
+  return imports;
 }
 
 // Create the wasm instance.

test/codesize/test_unoptimized_code_size.json

@@ -1,16 +1,16 @@
 {
-  "hello_world.js": 56566,
-  "hello_world.js.gz": 17601,
-  "hello_world.wasm": 15127,
-  "hello_world.wasm.gz": 7450,
-  "no_asserts.js": 26608,
-  "no_asserts.js.gz": 8874,
-  "no_asserts.wasm": 12227,
-  "no_asserts.wasm.gz": 6010,
-  "strict.js": 54581,
-  "strict.js.gz": 16947,
-  "strict.wasm": 15127,
-  "strict.wasm.gz": 7447,
-  "total": 180236,
-  "total_gz": 64329
+  "hello_world.js": 56592,
+  "hello_world.js.gz": 17608,
+  "hello_world.wasm": 15119,
+  "hello_world.wasm.gz": 7444,
+  "no_asserts.js": 26634,
+  "no_asserts.js.gz": 8883,
+  "no_asserts.wasm": 12219,
+  "no_asserts.wasm.gz": 6005,
+  "strict.js": 54607,
+  "strict.js.gz": 16955,
+  "strict.wasm": 15119,
+  "strict.wasm.gz": 7442,
+  "total": 180290,
+  "total_gz": 64337
 }