From 6eb0984532600c6e7d838a20f680d81681935e3b Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Tue, 28 Jul 2026 14:06:08 -0700
Subject: [PATCH 1/7] Support JS libraries self-registering their exports via
 EXPORTED_FUNCTIONS

JS library code can already mutate the compile-time EXPORTED_FUNCTIONS set
at library load time, which under MODULARIZE=instance causes jsifier to emit
the symbol with an `export` declaration. This makes that flow fully work by
forwarding the final EXPORTED_FUNCTIONS set back from the JS compiler so the
linker can derive which JS library symbols were exported, and have the
WASM_ESM_INTEGRATION wrapper re-export them.

This is used by binding layers (e.g. wasm-bindgen) that define a public JS
API surface distinct from the wasm export names, registering it from their
generated JS library.
---
 src/jsifier.mjs     |  4 ++++
 test/test_jslib.py  | 31 ++++++++++++++++++++++++++++++-
 tools/building.py   |  4 ++++
 tools/emscripten.py |  8 ++++++++
 tools/link.py       |  4 ++++
 5 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index 77a534648bb78..1f5bcd8335262 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -973,6 +973,10 @@ var proxiedFunctionTable = [
       '//FORWARDED_DATA:' +
         JSON.stringify({
           librarySymbols,
+          // The final EXPORTED_FUNCTIONS set, including any additions made by
+          // JS libraries at load time, so the caller can re-derive which
+          // library symbols were exported.
+          exportedFunctions: Array.from(EXPORTED_FUNCTIONS),
           nativeAliases,
           warnings: warningOccured(),
           asyncFuncs,
diff --git a/test/test_jslib.py b/test/test_jslib.py
index e8d26e1618087..aae4f7ec76053 100644
--- a/test/test_jslib.py
+++ b/test/test_jslib.py
@@ -6,7 +6,7 @@
 from subprocess import PIPE
 
 from common import RunnerCore, copy_asset, create_file, read_file, test_file
-from decorators import also_with_wasm64, also_without_bigint, parameterized
+from decorators import also_with_wasm64, also_without_bigint, parameterized, requires_node_25
 
 from tools.shared import EMCC
 from tools.utils import delete_file
@@ -164,6 +164,35 @@ def test_jslib_exported(self):
     self.do_runf('src.c', 'c calling: 12\njs calling: 10.',
                  cflags=['--js-library', 'lib.js', '-sEXPORTED_FUNCTIONS=_main,_jslibfunc'])
 
+  @parameterized({
+    '': ([],),
+    'esm_integration': (['-sWASM_ESM_INTEGRATION'],),
+  })
+  @requires_node_25
+  def test_jslib_self_export(self, args):
+    # A JS library can add its own symbols to EXPORTED_FUNCTIONS at load time
+    # (e.g. a binding layer registering the public API it defines), making them
+    # ES module exports under MODULARIZE=instance without the user needing to
+    # list them on the command line.
+    self.node_args += ['--no-warnings']
+    create_file('lib.js', '''\
+EXPORTED_FUNCTIONS.add('libExport');
+addToLibrary({
+  $libExport: () => 42,
+});
+''')
+    create_file('main.c', 'int main() { return 0; }')
+    self.run_process([EMCC, 'main.c', '-sMODULARIZE=instance', '-Wno-experimental',
+                      '--js-library', 'lib.js', '-o', 'mod.mjs'] + args + self.get_cflags())
+    create_file('runner.mjs', '''
+      import { strict as assert } from 'assert';
+      import init, { libExport } from './mod.mjs';
+      await init();
+      assert(libExport() == 42);
+      console.log('ok');
+    ''')
+    self.assertContained('ok', self.run_js('runner.mjs'))
+
   def test_jslib_using_asm_lib(self):
     create_file('lib.js', r'''
 addToLibrary({
diff --git a/tools/building.py b/tools/building.py
index fb9a99eceb364..6c0e6db39f53a 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -59,6 +59,10 @@
 _is_ar_cache: dict[str, bool] = {}
 # the exports the user requested
 user_requested_exports: set[str] = set()
+# JS library symbols that ended up in EXPORTED_FUNCTIONS (including additions
+# made by JS libraries themselves at load time), derived from the JS compiler's
+# forwarded data; the WASM_ESM_INTEGRATION wrapper re-exports them.
+exported_js_library_symbols: set[str] = set()
 # A list of feature flags to pass to each binaryen invocation (like `wasm-opt`,
 # etc.). This is received by the first call to binaryen (e.g. `wasm-emscripten-finalize`)
 # which reads it using `--detect-features`.
diff --git a/tools/emscripten.py b/tools/emscripten.py
index 38dfd6cb5c43d..a35db0ce910d8 100644
--- a/tools/emscripten.py
+++ b/tools/emscripten.py
@@ -446,6 +446,14 @@ def emscript(in_wasm, out_wasm, outfile_js, js_syms, finalize=True, base_metadat
 
   report_missing_exports(forwarded_json['librarySymbols'])
 
+  # A JS library symbol is exported (MODULARIZE=instance) when it is in
+  # EXPORTED_FUNCTIONS; derive that set rather than tracking it separately. The
+  # forwarded EXPORTED_FUNCTIONS includes additions made by JS libraries
+  # themselves at load time.
+  exported_functions = set(forwarded_json['exportedFunctions'])
+  building.exported_js_library_symbols.update(
+    s for s in forwarded_json['librarySymbols'] if s in exported_functions)
+
   asm_const_pairs = ['%s: %s' % (key, value) for key, value in asm_consts]
   if asm_const_pairs or settings.MAIN_MODULE:
     pre += 'var ASM_CONSTS = {\n  ' + ',  \n '.join(asm_const_pairs) + '\n};\n'
diff --git a/tools/link.py b/tools/link.py
index 8d787765624f0..942ead75e4a13 100644
--- a/tools/link.py
+++ b/tools/link.py
@@ -2195,6 +2195,10 @@ def node_detection_code():
 
 def create_esm_wrapper(wrapper_file, support_target, wasm_target):
   js_exports = building.user_requested_exports.union(settings.EXPORTED_RUNTIME_METHODS)
+  # JS library symbols the support module exports at declaration (including
+  # any the libraries themselves added to EXPORTED_FUNCTIONS at load time);
+  # the wrapper must forward these too.
+  js_exports |= building.exported_js_library_symbols
   js_exports = ', '.join(sorted(js_exports))
 
   wrapper = []

From 40cadd91ad2db973e612c71baa99c3f5f5a24c81 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Tue, 28 Jul 2026 15:28:16 -0700
Subject: [PATCH 2/7] Retrigger CI


From cbe38b1a678009223d4ab39700bc51bc6dd19884 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 5 Aug 2026 11:35:19 -0700
Subject: [PATCH 3/7] Use symbol attributes for JS library exports

---
 .../Interacting-with-code.rst                 |  3 +
 src/jsifier.mjs                               | 19 +++--
 src/modules.mjs                               | 10 ++-
 src/utility.mjs                               |  4 ++
 test/test_jslib.py                            | 72 ++++++++++++++++---
 tools/building.py                             |  8 +--
 tools/emscripten.py                           | 13 ++--
 tools/link.py                                 |  5 +-
 8 files changed, 101 insertions(+), 33 deletions(-)

diff --git a/site/source/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.rst b/site/source/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.rst
index 2d3df59fb45c6..30074c2688bf0 100644
--- a/site/source/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.rst
+++ b/site/source/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.rst
@@ -598,6 +598,9 @@ See the `library_*.js`_ files for other examples.
      by ``_``. In other words ``my_func: function() {},`` becomes
      ``function _my_func() {}``, as all C methods in emscripten have a ``_`` prefix. Keys starting with ``$`` have the ``$``
      stripped and no underscore added.
+   - A library symbol can use ``__force: true`` to be included even when it is
+     not referenced, and ``__export: true`` to be exported when included. Use
+     both decorators to unconditionally include and export a symbol.
 
 
 .. _interacting-with-code-call-function-pointers-from-c:
diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index 1f5bcd8335262..85514857c1827 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -41,7 +41,7 @@ import {
   localFile,
   timer,
 } from './utility.mjs';
-import {LibraryManager, librarySymbols, nativeAliases} from './modules.mjs';
+import {extraLibraryExports, LibraryManager, librarySymbols, nativeAliases} from './modules.mjs';
 
 const addedLibraryItems = {};
 
@@ -421,6 +421,12 @@ export async function runJSify(outputFile, symbolsOnly) {
 
   LibraryManager.load();
 
+  for (const key of Object.keys(LibraryManager.library)) {
+    if (!isDecorator(key) && LibraryManager.library[key + '__force']) {
+      extraLibraryFuncs.push(key);
+    }
+  }
+
   let outputHandle = process.stdout;
   if (outputFile) {
     outputHandle = await fs.open(outputFile, 'w');
@@ -700,6 +706,10 @@ function(${args}) {
 
       librarySymbols.push(mangled);
 
+      if (!isStub && LibraryManager.library[symbol + '__export']) {
+        extraLibraryExports.add(mangled);
+      }
+
       const original = LibraryManager.library[symbol];
       let snippet = original;
       const isUserSymbol = LibraryManager.library[symbol + '__user'];
@@ -838,7 +848,7 @@ function(${args}) {
         contentText = `var ${mangled} = ${snippet};`;
       }
 
-      if (contentText && MODULARIZE == 'instance' && (EXPORT_ALL || EXPORTED_FUNCTIONS.has(mangled)) && !isStub) {
+      if (contentText && MODULARIZE == 'instance' && (EXPORT_ALL || EXPORTED_FUNCTIONS.has(mangled) || extraLibraryExports.has(mangled)) && !isStub) {
         // In MODULARIZE=instance mode mark JS library symbols are exported at
         // the point of declaration.
         contentText = 'export ' + contentText;
@@ -973,10 +983,7 @@ var proxiedFunctionTable = [
       '//FORWARDED_DATA:' +
         JSON.stringify({
           librarySymbols,
-          // The final EXPORTED_FUNCTIONS set, including any additions made by
-          // JS libraries at load time, so the caller can re-derive which
-          // library symbols were exported.
-          exportedFunctions: Array.from(EXPORTED_FUNCTIONS),
+          extraExports: Array.from(extraLibraryExports),
           nativeAliases,
           warnings: warningOccured(),
           asyncFuncs,
diff --git a/src/modules.mjs b/src/modules.mjs
index bc6aa5295f5fa..56178f2d8eddf 100644
--- a/src/modules.mjs
+++ b/src/modules.mjs
@@ -30,6 +30,8 @@ import {preprocess, processMacros} from './parseTools.mjs';
 
 // List of symbols that were added from the library.
 export const librarySymbols = [];
+// Library symbols exported via the `__export` decorator.
+export const extraLibraryExports = new Set();
 // Map of library symbols which are aliases for native symbols
 // e.g. `wasmTable` -> `__indirect_function_table`
 export const nativeAliases = {};
@@ -480,6 +482,10 @@ function exportRuntimeSymbols() {
     if (nativeAliases[name]) {
       return false;
     }
+    // Symbols with `__export` are exported at their declaration site.
+    if (extraLibraryExports.has(name)) {
+      return false;
+    }
     // If requested to be exported, export it.
     if (EXPORTED_RUNTIME_METHODS.has(name)) {
       // Unless we are in MODULARIZE=instance mode then HEAP objects are
@@ -575,6 +581,7 @@ function exportRuntimeSymbols() {
       if (
         !EXPORTED_RUNTIME_METHODS.has(name) &&
         !EXPORTED_FUNCTIONS.has(name) &&
+        !extraLibraryExports.has(name) &&
         !unusedLibSymbols.has(name)
       ) {
         unexported.push(name);
@@ -601,7 +608,7 @@ function exportLibrarySymbols() {
   assert(MODULARIZE != 'instance');
   const results = ['// Begin JS library exports'];
   for (const ident of librarySymbols) {
-    if ((EXPORT_ALL || EXPORTED_FUNCTIONS.has(ident)) && !nativeAliases[ident]) {
+    if ((EXPORT_ALL || EXPORTED_FUNCTIONS.has(ident) || extraLibraryExports.has(ident)) && !nativeAliases[ident]) {
       results.push(exportSymbol(ident));
     }
   }
@@ -621,6 +628,7 @@ addToCompileTimeContext({
   loadStructInfo,
   LibraryManager,
   librarySymbols,
+  extraLibraryExports,
   addToLibrary,
   cDefs,
   cDefine,
diff --git a/src/utility.mjs b/src/utility.mjs
index 7d185e0c89fa5..dd6411879e582 100644
--- a/src/utility.mjs
+++ b/src/utility.mjs
@@ -188,6 +188,8 @@ export function mergeInto(obj, other, options = null) {
           __user: 'boolean',
           __async: ['string', 'boolean'],
           __i53abi: 'boolean',
+          __export: 'boolean',
+          __force: 'boolean',
         };
         const expected = decoratorTypes[decoratorName];
         if (type !== expected && !expected.includes(type)) {
@@ -219,6 +221,8 @@ export const decoratorSuffixes = [
   '__user',
   '__async',
   '__i53abi',
+  '__export',
+  '__force',
 ];
 
 export function isDecorator(ident) {
diff --git a/test/test_jslib.py b/test/test_jslib.py
index aae4f7ec76053..1aabe3fcc455f 100644
--- a/test/test_jslib.py
+++ b/test/test_jslib.py
@@ -166,29 +166,74 @@ def test_jslib_exported(self):
 
   @parameterized({
     '': ([],),
+    'optimized': (['-O3'],),
     'esm_integration': (['-sWASM_ESM_INTEGRATION'],),
+    'esm_integration_optimized': (['-sWASM_ESM_INTEGRATION', '-O3'],),
   })
   @requires_node_25
-  def test_jslib_self_export(self, args):
-    # A JS library can add its own symbols to EXPORTED_FUNCTIONS at load time
-    # (e.g. a binding layer registering the public API it defines), making them
-    # ES module exports under MODULARIZE=instance without the user needing to
-    # list them on the command line.
+  def test_jslib_export_decorators(self, args):
     self.node_args += ['--no-warnings']
     create_file('lib.js', '''\
-EXPORTED_FUNCTIONS.add('libExport');
 addToLibrary({
-  $libExport: () => 42,
+  $dependencyExport__export: true,
+  $dependencyExport: () => 41,
+
+  $forceOnly__deps: ['$dependencyExport'],
+  $forceOnly__force: true,
+  $forceOnly__postset: 'globalThis.forceOnlyIncluded = true',
+  $forceOnly: () => {},
+
+  $forceExport__export: true,
+  $forceExport__force: true,
+  $forceExport: () => 42,
+
+  $unusedExport__export: true,
+  $unusedExport: () => 43,
 });
 ''')
     create_file('main.c', 'int main() { return 0; }')
     self.run_process([EMCC, 'main.c', '-sMODULARIZE=instance', '-Wno-experimental',
+                      '-sEXPORTED_RUNTIME_METHODS=forceExport',
                       '--js-library', 'lib.js', '-o', 'mod.mjs'] + args + self.get_cflags())
     create_file('runner.mjs', '''
       import { strict as assert } from 'assert';
-      import init, { libExport } from './mod.mjs';
+      import init, * as exports from './mod.mjs';
       await init();
-      assert(libExport() == 42);
+      assert.equal(exports.dependencyExport(), 41);
+      assert.equal(exports.forceExport(), 42);
+      assert.equal(exports.forceOnly, undefined);
+      assert.equal(exports.unusedExport, undefined);
+      assert(globalThis.forceOnlyIncluded);
+      console.log('ok');
+    ''')
+    self.assertContained('ok', self.run_js('runner.mjs'))
+
+  def test_jslib_export_decorators_legacy(self):
+    create_file('lib.js', '''\
+addToLibrary({
+  $forceOnly__force: true,
+  $forceOnly__postset: "Module['forceOnlyIncluded'] = true",
+  $forceOnly: () => {},
+
+  $forceExport__export: true,
+  $forceExport__force: true,
+  $forceExport: () => 42,
+
+  $unusedExport__export: true,
+  $unusedExport: () => 43,
+});
+''')
+    create_file('main.c', 'int main() { return 0; }')
+    self.run_process([EMCC, 'main.c', '-sMODULARIZE', '-sEXPORT_ES6',
+                      '--js-library', 'lib.js', '-o', 'mod.mjs'] + self.get_cflags())
+    create_file('runner.mjs', '''
+      import { strict as assert } from 'assert';
+      import createModule from './mod.mjs';
+      const module = await createModule();
+      assert.equal(module.forceExport(), 42);
+      assert.throws(() => module.forceOnly);
+      assert.throws(() => module.unusedExport);
+      assert(module.forceOnlyIncluded);
       console.log('ok');
     ''')
     self.assertContained('ok', self.run_js('runner.mjs'))
@@ -312,6 +357,15 @@ def test_jslib_invalid_decorator(self):
     self.assert_fail([EMCC, test_file('hello_world.c'), '--js-library', 'lib.js'],
                      "lib.js: Decorator (jslibfunc__internal) has wrong type. Expected 'boolean' not 'string'")
 
+    create_file('lib.js', r'''
+addToLibrary({
+  jslibfunc__export: 'yes',
+  jslibfunc: (x) => {},
+});
+''')
+    self.assert_fail([EMCC, test_file('hello_world.c'), '--js-library', 'lib.js'],
+                     "lib.js: Decorator (jslibfunc__export) has wrong type. Expected 'boolean' not 'string'")
+
   @also_with_wasm64
   @also_without_bigint
   def test_jslib_i53abi(self):
diff --git a/tools/building.py b/tools/building.py
index 6c0e6db39f53a..52d523b52b98e 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -59,10 +59,8 @@
 _is_ar_cache: dict[str, bool] = {}
 # the exports the user requested
 user_requested_exports: set[str] = set()
-# JS library symbols that ended up in EXPORTED_FUNCTIONS (including additions
-# made by JS libraries themselves at load time), derived from the JS compiler's
-# forwarded data; the WASM_ESM_INTEGRATION wrapper re-exports them.
-exported_js_library_symbols: set[str] = set()
+# JS library symbols exported via the `__export` decorator.
+extra_js_exports: set[str] = set()
 # A list of feature flags to pass to each binaryen invocation (like `wasm-opt`,
 # etc.). This is received by the first call to binaryen (e.g. `wasm-emscripten-finalize`)
 # which reads it using `--detect-features`.
@@ -834,7 +832,7 @@ def metadce(js_file, wasm_file, debug_info, last):
     return js_file
   graph = json.loads(txt)
   # ensure that functions expected to be exported to the outside are roots
-  required_symbols = user_requested_exports.union(set(settings.SIDE_MODULE_IMPORTS))
+  required_symbols = user_requested_exports.union(extra_js_exports, settings.SIDE_MODULE_IMPORTS)
   for item in graph:
     if 'export' in item:
       export = asmjs_mangle(item['export'])
diff --git a/tools/emscripten.py b/tools/emscripten.py
index a35db0ce910d8..f9c84a0a93b02 100644
--- a/tools/emscripten.py
+++ b/tools/emscripten.py
@@ -446,13 +446,7 @@ def emscript(in_wasm, out_wasm, outfile_js, js_syms, finalize=True, base_metadat
 
   report_missing_exports(forwarded_json['librarySymbols'])
 
-  # A JS library symbol is exported (MODULARIZE=instance) when it is in
-  # EXPORTED_FUNCTIONS; derive that set rather than tracking it separately. The
-  # forwarded EXPORTED_FUNCTIONS includes additions made by JS libraries
-  # themselves at load time.
-  exported_functions = set(forwarded_json['exportedFunctions'])
-  building.exported_js_library_symbols.update(
-    s for s in forwarded_json['librarySymbols'] if s in exported_functions)
+  building.extra_js_exports.update(forwarded_json['extraExports'])
 
   asm_const_pairs = ['%s: %s' % (key, value) for key, value in asm_consts]
   if asm_const_pairs or settings.MAIN_MODULE:
@@ -972,7 +966,7 @@ def install_debug_wrapper(sym):
 
 
 def should_export(sym):
-  return settings.EXPORT_ALL or (settings.EXPORT_KEEPALIVE and sym in settings.EXPORTED_FUNCTIONS)
+  return settings.EXPORT_ALL or sym in building.extra_js_exports or (settings.EXPORT_KEEPALIVE and sym in settings.EXPORTED_FUNCTIONS)
 
 
 def create_receiving(function_exports, other_exports, library_symbols, aliases):
@@ -994,6 +988,9 @@ def create_receiving(function_exports, other_exports, library_symbols, aliases):
     receiving.append('import {')
     receiving.append('  ' + ',\n  '.join(exports))
     receiving.append(f"}} from './{settings.WASM_BINARY_FILE}';")
+    alias_exports = building.extra_js_exports.intersection(aliases)
+    if alias_exports:
+      receiving.append(f"export {{ {', '.join(sorted(alias_exports))} }};")
 
     if generate_dyncall_assignment:
       receiving.append('\nfunction assignDynCalls() {')
diff --git a/tools/link.py b/tools/link.py
index 942ead75e4a13..45b76a0026573 100644
--- a/tools/link.py
+++ b/tools/link.py
@@ -2195,10 +2195,7 @@ def node_detection_code():
 
 def create_esm_wrapper(wrapper_file, support_target, wasm_target):
   js_exports = building.user_requested_exports.union(settings.EXPORTED_RUNTIME_METHODS)
-  # JS library symbols the support module exports at declaration (including
-  # any the libraries themselves added to EXPORTED_FUNCTIONS at load time);
-  # the wrapper must forward these too.
-  js_exports |= building.exported_js_library_symbols
+  js_exports |= building.extra_js_exports
   js_exports = ', '.join(sorted(js_exports))
 
   wrapper = []

From abe7b9289cb08e2b30ce86d8e83828b05519617b Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 5 Aug 2026 11:57:19 -0700
Subject: [PATCH 4/7] Address JS library export review feedback

---
 src/jsifier.mjs          |  8 ++++----
 src/lib/libasync.js      |  5 +----
 src/lib/libautodebug.js  | 42 +++++++++-------------------------------
 src/lib/libcore.js       |  6 ++++--
 src/lib/libembind_gen.js |  3 +--
 src/lib/libfs.js         |  4 ++++
 src/lib/libfs_shared.js  |  7 -------
 src/lib/libglemu.js      |  3 +--
 src/lib/libwasmfs.js     |  4 ++++
 src/modules.mjs          | 12 ++++--------
 test/test_jslib.py       |  1 -
 11 files changed, 32 insertions(+), 63 deletions(-)

diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index 85514857c1827..29139fe900a78 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -41,7 +41,7 @@ import {
   localFile,
   timer,
 } from './utility.mjs';
-import {extraLibraryExports, LibraryManager, librarySymbols, nativeAliases} from './modules.mjs';
+import {extraExports, LibraryManager, librarySymbols, nativeAliases} from './modules.mjs';
 
 const addedLibraryItems = {};
 
@@ -707,7 +707,7 @@ function(${args}) {
       librarySymbols.push(mangled);
 
       if (!isStub && LibraryManager.library[symbol + '__export']) {
-        extraLibraryExports.add(mangled);
+        extraExports.add(mangled);
       }
 
       const original = LibraryManager.library[symbol];
@@ -848,7 +848,7 @@ function(${args}) {
         contentText = `var ${mangled} = ${snippet};`;
       }
 
-      if (contentText && MODULARIZE == 'instance' && (EXPORT_ALL || EXPORTED_FUNCTIONS.has(mangled) || extraLibraryExports.has(mangled)) && !isStub) {
+      if (contentText && MODULARIZE == 'instance' && (EXPORT_ALL || EXPORTED_FUNCTIONS.has(mangled) || extraExports.has(mangled)) && !isStub) {
         // In MODULARIZE=instance mode mark JS library symbols are exported at
         // the point of declaration.
         contentText = 'export ' + contentText;
@@ -983,7 +983,7 @@ var proxiedFunctionTable = [
       '//FORWARDED_DATA:' +
         JSON.stringify({
           librarySymbols,
-          extraExports: Array.from(extraLibraryExports),
+          extraExports: Array.from(extraExports),
           nativeAliases,
           warnings: warningOccured(),
           asyncFuncs,
diff --git a/src/lib/libasync.js b/src/lib/libasync.js
index 9f9a2d315b1f5..b0d59fa7503df 100644
--- a/src/lib/libasync.js
+++ b/src/lib/libasync.js
@@ -20,6 +20,7 @@ addToLibrary({
   },
 
 #if ASYNCIFY
+  $Asyncify__force: true,
   $Asyncify__deps: ['$runAndAbortIfError', '$callUserCallback',
 #if ASSERTIONS
     '$createNamedFunction',
@@ -627,7 +628,3 @@ addToLibrary({
   },
 #endif // ASYNCIFY
 });
-
-if (ASYNCIFY) {
-  extraLibraryFuncs.push('$Asyncify');
-}
diff --git a/src/lib/libautodebug.js b/src/lib/libautodebug.js
index 461201c02d184..435e8a24be7e6 100644
--- a/src/lib/libautodebug.js
+++ b/src/lib/libautodebug.js
@@ -9,7 +9,7 @@
 #error "Should only be included in AUTODEBUG mode"
 #endif
 
-addToLibrary({
+const LibraryAutodebug = {
   $log_execution: (loc) => dbg('log_execution ' + loc),
   $get_i32: (loc, index, value) => {
     dbg('get_i32 ' + [loc, index, value]);
@@ -131,36 +131,12 @@ addToLibrary({
     dbg('memory_grow_post ' + [loc, result]);
     return result;
   },
-});
+};
 
-extraLibraryFuncs.push(
-  '$log_execution',
-  '$get_i32',
-  '$get_i64',
-  '$get_f32',
-  '$get_f64',
-  '$get_funcref',
-  '$get_externref',
-  '$get_anyref',
-  '$get_exnref',
-  '$set_i32',
-  '$set_i64',
-  '$set_f32',
-  '$set_f64',
-  '$set_funcref',
-  '$set_externref',
-  '$set_anyref',
-  '$set_exnref',
-  '$load_ptr',
-  '$load_val_i32',
-  '$load_val_i64',
-  '$load_val_f32',
-  '$load_val_f64',
-  '$store_ptr',
-  '$store_val_i32',
-  '$store_val_i64',
-  '$store_val_f32',
-  '$store_val_f64',
-  '$memory_grow_pre',
-  '$memory_grow_post',
-);
+for (const symbol of Object.keys(LibraryAutodebug)) {
+  if (!isDecorator(symbol)) {
+    LibraryAutodebug[symbol + '__force'] = true;
+  }
+}
+
+addToLibrary(LibraryAutodebug);
diff --git a/src/lib/libcore.js b/src/lib/libcore.js
index a621664b009fd..c5a458c76f197 100644
--- a/src/lib/libcore.js
+++ b/src/lib/libcore.js
@@ -2517,7 +2517,7 @@ function autoAddDeps(lib, name) {
 #if LEGACY_RUNTIME
 // Library functions that were previously included as runtime functions are
 // automatically included when `LEGACY_RUNTIME` is set.
-extraLibraryFuncs.push(
+for (const symbol of [
   '$addFunction',
   '$removeFunction',
   '$AsciiToString',
@@ -2544,7 +2544,9 @@ extraLibraryFuncs.push(
   '$stringToUTF8Array',
   '$stringToUTF8',
   '$lengthBytesUTF8',
-);
+]) {
+  LibraryManager.library[symbol + '__force'] = true;
+}
 #endif
 
 function wrapSyscallFunction(x, library, isWasi) {
diff --git a/src/lib/libembind_gen.js b/src/lib/libembind_gen.js
index c20082e94daf1..132e8deeff214 100644
--- a/src/lib/libembind_gen.js
+++ b/src/lib/libembind_gen.js
@@ -914,6 +914,7 @@ var LibraryEmbind = {
 #endif
   ],
   $emitOutput__postset: () => { addAtPostCtor('emitOutput()'); },
+  $emitOutput__force: true,
   $emitOutput: () => {
     for (const typeId in awaitingDependencies) {
       throwBindingError(`Missing binding for type: '${getTypeName(typeId)}' typeId: ${typeId}`);
@@ -936,6 +937,4 @@ var LibraryEmbind = {
   $PureVirtualError: () => { throw new Error('stub function should not be called'); },
 };
 
-extraLibraryFuncs.push('$emitOutput');
-
 addToLibrary(LibraryEmbind);
diff --git a/src/lib/libfs.js b/src/lib/libfs.js
index 70d3fda1334e7..4907180698353 100644
--- a/src/lib/libfs.js
+++ b/src/lib/libfs.js
@@ -5,6 +5,10 @@
  */
 
 var LibraryFS = {
+#if FORCE_FILESYSTEM
+  // Include FS even when it is not referenced by compiled code.
+  $FS__force: true,
+#endif
   $FS__deps: ['$randomFill', '$PATH', '$PATH_FS', '$TTY', '$MEMFS',
     '$FS_modeStringToFlags',
     '$FS_fileDataToTypedArray',
diff --git a/src/lib/libfs_shared.js b/src/lib/libfs_shared.js
index 838b52309701a..b7206da202c29 100644
--- a/src/lib/libfs_shared.js
+++ b/src/lib/libfs_shared.js
@@ -200,10 +200,3 @@ addToLibrary({
   $FS_readFile__deps: ['$FS'],
   $FS_readFile: 'FS.readFile',
 });
-
-// Normally only the FS things that the compiler sees are needed are included.
-// FORCE_FILESYSTEM makes us always include the FS object, which lets the user
-// call APIs on it from JS freely.
-if (FORCE_FILESYSTEM) {
-  extraLibraryFuncs.push('$FS');
-}
diff --git a/src/lib/libglemu.js b/src/lib/libglemu.js
index 0dbcad1d93e45..872f594ae4491 100644
--- a/src/lib/libglemu.js
+++ b/src/lib/libglemu.js
@@ -34,6 +34,7 @@ var LibraryGLEmulation = {
     'glVertexAttribPointer', 'glActiveTexture', '$stringToNewUTF8',
     '$ptrToString', '$getEmscriptenSupportedExtensions',
   ],
+  $GLEmulation__force: true,
   $GLEmulation__postset: `
     // Forward declare GL functions that are overridden by GLEmulation.
     /**@suppress {duplicate, undefinedVars}*/var _emscripten_glDrawArrays;
@@ -3942,8 +3943,6 @@ var LibraryGLEmulation = {
   gluOrtho2D: (left, right, bottom, top) => _glOrtho(left, right, bottom, top, -1, 1),
 };
 
-extraLibraryFuncs.push('$GLEmulation');
-
 recordGLProcAddressGet(LibraryGLEmulation);
 
 addToLibrary(LibraryGLEmulation);
diff --git a/src/lib/libwasmfs.js b/src/lib/libwasmfs.js
index ebe5d87869ed8..e5c36ba8a9b21 100644
--- a/src/lib/libwasmfs.js
+++ b/src/lib/libwasmfs.js
@@ -5,6 +5,10 @@
  */
 
 addToLibrary({
+#if FORCE_FILESYSTEM
+  // Include FS even when it is not referenced by compiled code.
+  $FS__force: true,
+#endif
   $MEMFS__deps: ['wasmfs_create_memory_backend'],
   $MEMFS: {
     createBackend(opts) {
diff --git a/src/modules.mjs b/src/modules.mjs
index 56178f2d8eddf..a7341ef20f3d1 100644
--- a/src/modules.mjs
+++ b/src/modules.mjs
@@ -31,7 +31,7 @@ import {preprocess, processMacros} from './parseTools.mjs';
 // List of symbols that were added from the library.
 export const librarySymbols = [];
 // Library symbols exported via the `__export` decorator.
-export const extraLibraryExports = new Set();
+export const extraExports = new Set();
 // Map of library symbols which are aliases for native symbols
 // e.g. `wasmTable` -> `__indirect_function_table`
 export const nativeAliases = {};
@@ -482,10 +482,6 @@ function exportRuntimeSymbols() {
     if (nativeAliases[name]) {
       return false;
     }
-    // Symbols with `__export` are exported at their declaration site.
-    if (extraLibraryExports.has(name)) {
-      return false;
-    }
     // If requested to be exported, export it.
     if (EXPORTED_RUNTIME_METHODS.has(name)) {
       // Unless we are in MODULARIZE=instance mode then HEAP objects are
@@ -581,7 +577,7 @@ function exportRuntimeSymbols() {
       if (
         !EXPORTED_RUNTIME_METHODS.has(name) &&
         !EXPORTED_FUNCTIONS.has(name) &&
-        !extraLibraryExports.has(name) &&
+        !extraExports.has(name) &&
         !unusedLibSymbols.has(name)
       ) {
         unexported.push(name);
@@ -608,7 +604,7 @@ function exportLibrarySymbols() {
   assert(MODULARIZE != 'instance');
   const results = ['// Begin JS library exports'];
   for (const ident of librarySymbols) {
-    if ((EXPORT_ALL || EXPORTED_FUNCTIONS.has(ident) || extraLibraryExports.has(ident)) && !nativeAliases[ident]) {
+    if ((EXPORT_ALL || EXPORTED_FUNCTIONS.has(ident) || extraExports.has(ident)) && !nativeAliases[ident]) {
       results.push(exportSymbol(ident));
     }
   }
@@ -628,7 +624,7 @@ addToCompileTimeContext({
   loadStructInfo,
   LibraryManager,
   librarySymbols,
-  extraLibraryExports,
+  extraExports,
   addToLibrary,
   cDefs,
   cDefine,
diff --git a/test/test_jslib.py b/test/test_jslib.py
index 1aabe3fcc455f..9a6c6d4b1f21e 100644
--- a/test/test_jslib.py
+++ b/test/test_jslib.py
@@ -193,7 +193,6 @@ def test_jslib_export_decorators(self, args):
 ''')
     create_file('main.c', 'int main() { return 0; }')
     self.run_process([EMCC, 'main.c', '-sMODULARIZE=instance', '-Wno-experimental',
-                      '-sEXPORTED_RUNTIME_METHODS=forceExport',
                       '--js-library', 'lib.js', '-o', 'mod.mjs'] + args + self.get_cflags())
     create_file('runner.mjs', '''
       import { strict as assert } from 'assert';

From 9accea3c3bd5158a2d5dc0fe4863115b543da033 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 5 Aug 2026 13:13:09 -0700
Subject: [PATCH 5/7] Process forced library symbols during merge

---
 src/jsifier.mjs    | 9 +--------
 src/lib/libcore.js | 2 +-
 src/utility.mjs    | 8 +++++++-
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/jsifier.mjs b/src/jsifier.mjs
index 29139fe900a78..5e58566edb9ba 100644
--- a/src/jsifier.mjs
+++ b/src/jsifier.mjs
@@ -30,6 +30,7 @@ import {
   debugLog,
   error,
   errorOccured,
+  extraLibraryFuncs,
   isDecorator,
   isJsOnlySymbol,
   compileTimeContext,
@@ -45,8 +46,6 @@ import {extraExports, LibraryManager, librarySymbols, nativeAliases} from './mod
 
 const addedLibraryItems = {};
 
-const extraLibraryFuncs = [];
-
 // Experimental feature to check for invalid __deps entries.
 // See `EMCC_CHECK_DEPS` in in the environment to try it out.
 const CHECK_DEPS = process.env.EMCC_CHECK_DEPS;
@@ -421,12 +420,6 @@ export async function runJSify(outputFile, symbolsOnly) {
 
   LibraryManager.load();
 
-  for (const key of Object.keys(LibraryManager.library)) {
-    if (!isDecorator(key) && LibraryManager.library[key + '__force']) {
-      extraLibraryFuncs.push(key);
-    }
-  }
-
   let outputHandle = process.stdout;
   if (outputFile) {
     outputHandle = await fs.open(outputFile, 'w');
diff --git a/src/lib/libcore.js b/src/lib/libcore.js
index c5a458c76f197..3fd173a480749 100644
--- a/src/lib/libcore.js
+++ b/src/lib/libcore.js
@@ -2545,7 +2545,7 @@ for (const symbol of [
   '$stringToUTF8',
   '$lengthBytesUTF8',
 ]) {
-  LibraryManager.library[symbol + '__force'] = true;
+  addToLibrary({[symbol + '__force']: true}, {allowMissing: true});
 }
 #endif
 
diff --git a/src/utility.mjs b/src/utility.mjs
index dd6411879e582..f827f2e7eef76 100644
--- a/src/utility.mjs
+++ b/src/utility.mjs
@@ -96,6 +96,8 @@ function range(size) {
   return Array.from(Array(size).keys());
 }
 
+export const extraLibraryFuncs = [];
+
 export function mergeInto(obj, other, options = null) {
   if (options) {
     // check for unintended symbol redefinition
@@ -148,11 +150,11 @@ export function mergeInto(obj, other, options = null) {
       }
 
       const index = key.lastIndexOf('__');
+      const decorated = key.slice(0, index);
       const decoratorName = key.slice(index);
       const type = typeof other[key];
 
       if (decoratorName == '__async') {
-        const decorated = key.slice(0, index);
         if (isJsOnlySymbol(decorated)) {
           error(`__async decorator applied to JS symbol: ${decorated}`);
         }
@@ -196,6 +198,10 @@ export function mergeInto(obj, other, options = null) {
           error(`Decorator (${key}) has wrong type. Expected '${expected}' not '${type}'`);
         }
       }
+
+      if (decoratorName === '__force' && other[key]) {
+        extraLibraryFuncs.push(decorated);
+      }
     }
   }
 

From 8165f40f1c9606d35bbe581d83ca09bd39a4afe3 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 5 Aug 2026 13:16:03 -0700
Subject: [PATCH 6/7] Test JS library export decorators by default

---
 ChangeLog.md       |  2 ++
 test/test_jslib.py | 39 ++++++++++++++++++++++++---------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 809278a81101f..ae8fc1c2ee5ab 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -36,6 +36,8 @@ See docs/process.md for more on how version tagging works.
   when reading the config file.  This change broke emsdk installations that
   contained spaces. (#27421)
 - OpenMP was updated to LLVM 22.1.8 (#27437)
+- JavaScript library symbols can now use the `__force` and `__export`
+  decorators to control inclusion and export visibility. (#27436)
 
 6.0.4 - 07/24/26
 ----------------
diff --git a/test/test_jslib.py b/test/test_jslib.py
index 9a6c6d4b1f21e..4f0236404e71b 100644
--- a/test/test_jslib.py
+++ b/test/test_jslib.py
@@ -171,7 +171,7 @@ def test_jslib_exported(self):
     'esm_integration_optimized': (['-sWASM_ESM_INTEGRATION', '-O3'],),
   })
   @requires_node_25
-  def test_jslib_export_decorators(self, args):
+  def test_jslib_export_decorators_instance(self, args):
     self.node_args += ['--no-warnings']
     create_file('lib.js', '''\
 addToLibrary({
@@ -207,9 +207,13 @@ def test_jslib_export_decorators(self, args):
     ''')
     self.assertContained('ok', self.run_js('runner.mjs'))
 
-  def test_jslib_export_decorators_legacy(self):
+  def test_jslib_export_decorators(self):
     create_file('lib.js', '''\
 addToLibrary({
+  $dependencyExport__export: true,
+  $dependencyExport: () => 41,
+
+  $forceOnly__deps: ['$dependencyExport'],
   $forceOnly__force: true,
   $forceOnly__postset: "Module['forceOnlyIncluded'] = true",
   $forceOnly: () => {},
@@ -222,20 +226,25 @@ def test_jslib_export_decorators_legacy(self):
   $unusedExport: () => 43,
 });
 ''')
-    create_file('main.c', 'int main() { return 0; }')
-    self.run_process([EMCC, 'main.c', '-sMODULARIZE', '-sEXPORT_ES6',
-                      '--js-library', 'lib.js', '-o', 'mod.mjs'] + self.get_cflags())
-    create_file('runner.mjs', '''
-      import { strict as assert } from 'assert';
-      import createModule from './mod.mjs';
-      const module = await createModule();
-      assert.equal(module.forceExport(), 42);
-      assert.throws(() => module.forceOnly);
-      assert.throws(() => module.unusedExport);
-      assert(module.forceOnlyIncluded);
-      console.log('ok');
+    create_file('post.js', '''
+      Module.onRuntimeInitialized = () => {
+        if (Module.dependencyExport() != 41) throw new Error('dependency export failed');
+        if (Module.forceExport() != 42) throw new Error('forced export failed');
+        const isExported = (name) => {
+          try {
+            return Module[name] !== undefined;
+          } catch {
+            return false;
+          }
+        };
+        if (isExported('forceOnly')) throw new Error('force-only symbol was exported');
+        if (isExported('unusedExport')) throw new Error('unused symbol was exported');
+        if (!Module.forceOnlyIncluded) throw new Error('force-only symbol was not included');
+        out('ok');
+      };
     ''')
-    self.assertContained('ok', self.run_js('runner.mjs'))
+    create_file('main.c', 'int main() { return 0; }')
+    self.do_runf('main.c', 'ok\n', cflags=['--js-library', 'lib.js', '--post-js', 'post.js'])
 
   def test_jslib_using_asm_lib(self):
     create_file('lib.js', r'''

From d1fb20316c1df551415bf2e00f005932517fa08b Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Wed, 5 Aug 2026 13:18:40 -0700
Subject: [PATCH 7/7] Move changelog entry to 6.0.6

---
 ChangeLog.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index ae8fc1c2ee5ab..2d95be00c92a4 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -21,6 +21,9 @@ See docs/process.md for more on how version tagging works.
 6.0.7 (in development)
 ----------------------
 
+- JavaScript library symbols can now use the `__force` and `__export`
+  decorators to control inclusion and export visibility. (#27436)
+
 6.0.6 - 08/05/26
 ----------------
 - `DEFAULT_TO_CXX` is now disabled by default. This means that `em++` is now
@@ -36,8 +39,6 @@ See docs/process.md for more on how version tagging works.
   when reading the config file.  This change broke emsdk installations that
   contained spaces. (#27421)
 - OpenMP was updated to LLVM 22.1.8 (#27437)
-- JavaScript library symbols can now use the `__force` and `__export`
-  decorators to control inclusion and export visibility. (#27436)
 
 6.0.4 - 07/24/26
 ----------------