[esm-integration] Enabled runtime symbol exports

See emscripten-core#24060

Author: sbc100

src/modules.mjs

@@ -406,6 +406,11 @@ function addMissingLibraryStubs(unusedLibSymbols) {
 }
 
 function exportSymbol(name) {
+  if (WASM_ESM_INTEGRATION) {
+    // In ESM integration mode symbols are exported by being included in
+    // an export { foo, bar } list so we build up the simple list of names
+    return name;
+  }
   if (MODULARIZE === 'instance') {
     return `__exp_${name} = ${name};`;
   }
@@ -416,10 +421,13 @@ function exportSymbol(name) {
 function exportRuntimeSymbols() {
   // optionally export something.
   function maybeExport(name) {
-    // If requested to be exported, export it.  HEAP objects are exported
-    // separately in updateMemoryViews
-    if (EXPORTED_RUNTIME_METHODS.has(name) && !name.startsWith('HEAP')) {
-      return exportSymbol(name);
+    // If requested to be exported, export it.
+    if (EXPORTED_RUNTIME_METHODS.has(name)) {
+      // Unless we are in WASM_ESM_INTEGRATION mode then HEAP objects are
+      // exported separately in updateMemoryViews
+      if (WASM_ESM_INTEGRATION || !name.startsWith('HEAP')) {
+        return exportSymbol(name);
+      }
     }
   }
 
@@ -518,6 +526,10 @@ function exportRuntimeSymbols() {
   const exports = runtimeElements.map(maybeExport);
   const results = exports.filter((name) => name);
 
+  if (WASM_ESM_INTEGRATION) {
+    return '// Runtime exports\nexport { ' + results.join(', ') + ' };\n';
+  }
+
   if (ASSERTIONS && !EXPORT_ALL) {
     // in ASSERTIONS mode we show a useful error if it is used without being
     // exported.  See `unexportedRuntimeSymbol` in runtime_debug.js.
@@ -563,7 +575,7 @@ function exportLibrarySymbols() {
 function exportJSSymbols() {
   // In WASM_ESM_INTEGRATION mode JS library symbols are marked with `export`
   // at the point of declaration.
-  if (WASM_ESM_INTEGRATION) return '';
+  if (WASM_ESM_INTEGRATION) return exportRuntimeSymbols();
   return exportRuntimeSymbols() + '  ' + exportLibrarySymbols();
 }
 

src/postlibrary.js

@@ -34,5 +34,6 @@ function processModuleArgs()
 #endif
 #endif // ASSERTIONS
 
-  {{{ exportJSSymbols() }}}
 }
+
+{{{ exportJSSymbols() }}}

test/core/test_esm_integration.expected.mjs

@@ -0,0 +1,2 @@
+export { __main_argc_argv as main } from './hello_world.wasm';
+export { default, err, HEAPF32, HEAPF64, HEAP8, HEAPU8, HEAP16, HEAPU16, HEAP32, HEAPU32, HEAP64, HEAPU64, stringToNewUTF8 } from './hello_world.support.mjs';

test/test_core.py

@@ -9568,13 +9568,14 @@ def test_esm_integration(self):
     # TODO(sbc): WASM_ESM_INTEGRATION doesn't currently work with closure.
     # self.maybe_closure()
     self.node_args += ['--experimental-wasm-modules', '--no-warnings']
-    self.run_process([EMCC, '-o', 'hello_world.mjs', '-sEXPORTED_FUNCTIONS=_main,stringToNewUTF8', '-sWASM_ESM_INTEGRATION', '-Wno-experimental', test_file('hello_world_argv.c')] + self.get_emcc_args())
+    self.run_process([EMCC, '-o', 'hello_world.mjs', '-sEXPORTED_RUNTIME_METHODS=err', '-sEXPORTED_FUNCTIONS=_main,stringToNewUTF8', '-sWASM_ESM_INTEGRATION', '-Wno-experimental', test_file('hello_world_argv.c')] + self.get_emcc_args())
     create_file('runner.mjs', '''
-      import init, { stringToNewUTF8, main } from "./hello_world.mjs";
+      import init, { err, stringToNewUTF8, main } from "./hello_world.mjs";
       await init({arguments: ['foo', 'bar']});
-      console.log('this is a pointer:', stringToNewUTF8('hello'));
+      err('this is a pointer:', stringToNewUTF8('hello'));
     ''')
     self.assertContained('hello, world! (3)', self.run_js('runner.mjs'))
+    self.assertFileContents(test_file('core/test_esm_integration.expected.mjs'), read_file('hello_world.mjs'))
 
 
 # Generate tests for everything

tools/link.py

@@ -2114,7 +2114,7 @@ def create_worker_file(input_file, target_dir, output_file, options):
 
 def create_esm_wrapper(wrapper_file, support_target, wasm_target):
   wasm_exports = []
-  js_exports = []
+  js_exports = list(settings.EXPORTED_RUNTIME_METHODS)
   for f in settings.USER_EXPORTS:
     if f == '_main' and '__main_argc_argv' in settings.WASM_EXPORTS:
       wasm_exports.append('__main_argc_argv as main')