[esm-integration] Fix handling of EM_JS exports (#24292)

This change also adds a new core test mode for ESM integration and uses
this to run all the variants of test_fs_js_api.

As part of this I also updated the octal constants in test_fs_js_api.c
which are required to be of the new form in strict JS. All code in ES
modules is implicitly in strict mode.

Split out from #24288

See #24060

Author: sbc100

.circleci/config.yml

@@ -800,7 +800,9 @@ jobs:
             core0.test_esm_integration*
             core0.test_pthread_join_and_asyncify
             core0.test_async_ccall_promise_jspi*
-            core0.test_cubescript_jspi"
+            core0.test_cubescript_jspi
+            esm_integration.test_fs_js_api*
+            "
       # Run some basic tests with the minimum version of node that we currently
       # support in the generated code.
       # Keep this in sync with `OLDEST_SUPPORTED_NODE` in `feature_matrix.py`

src/shell.js

@@ -22,7 +22,7 @@
 // can continue to use Module afterwards as well.
 #if MODULARIZE
 #if MODULARIZE == 'instance'
-var Module;
+var Module = {};
 #else
 var Module = moduleArg;
 #endif

test/fs/test_fs_js_api.c

@@ -240,19 +240,19 @@ EM_JS(void, test_fs_close, (), {
 
 void test_fs_mknod() {
   EM_ASM(
-    FS.mknod("mknodtest", 0100000 | 0777 /* S_IFREG | S_RWXU | S_RWXG | S_RWXO */);
+    FS.mknod("mknodtest", 0o100000 | 0o777 /* S_IFREG | S_RWXU | S_RWXG | S_RWXO */);
 
-    FS.create("createtest", 0400 /* S_IRUSR */);
+    FS.create("createtest", 0o400 /* S_IRUSR */);
   );
   struct stat s;
   stat("mknodtest", &s);
 
   assert(S_ISREG(s.st_mode));
-  assert(s.st_mode & 0777);
+  assert(s.st_mode & 0o777);
 
   stat("createtest", &s);
   assert(S_ISREG(s.st_mode));
-  assert(s.st_mode & 0400);
+  assert(s.st_mode & 0o400);
 
   remove("mknodtest");
   remove("createtest");
@@ -382,7 +382,7 @@ void test_fs_mmap() {
 void test_fs_mkdirTree() {
   EM_ASM(
     FS.mkdirTree("/test1/test2/test3"); // Abs path
-    FS.mkdirTree("/readable", 0400 /* S_IRUSR */);
+    FS.mkdirTree("/readable", 0o400 /* S_IRUSR */);
   );
 
   struct stat s;
@@ -394,7 +394,7 @@ void test_fs_mkdirTree() {
   assert(S_ISDIR(s.st_mode));
 
   assert(stat("/readable", &s) == 0);
-  assert(s.st_mode & 0400 /* S_IRUSR */);
+  assert(s.st_mode & 0o400 /* S_IRUSR */);
 
   EM_ASM(
     var ex;

test/runner.py

@@ -71,6 +71,7 @@
   'wasm64',
   'wasm64_v8',
   'wasm64_4gb',
+  'esm_integration',
 ]
 
 # The default core test mode, used when none is specified

test/test_core.py

@@ -45,11 +45,7 @@ def esm_integration(func):
 
   @wraps(func)
   def decorated(self, *args, **kwargs):
-    self.require_node_canary()
-    self.node_args += ['--experimental-wasm-modules', '--no-warnings']
-    self.emcc_args += ['-sWASM_ESM_INTEGRATION', '-Wno-experimental']
-    if self.is_wasm64():
-      self.skipTest('wasm64 requires wasm export wrappers')
+    self.setup_esm_integration()
     func(self, *args, **kwargs)
 
   return decorated
@@ -349,6 +345,14 @@ def should_use_closure(self):
     prohibited = ('-g', '--profiling')
     return all(f not in self.emcc_args for f in prohibited) and any(f in self.emcc_args for f in required)
 
+  def setup_esm_integration(self):
+    self.require_node_canary()
+    self.node_args += ['--experimental-wasm-modules', '--no-warnings']
+    self.set_setting('WASM_ESM_INTEGRATION')
+    self.emcc_args += ['-Wno-experimental']
+    if self.is_wasm64():
+      self.skipTest('wasm64 requires wasm export wrappers')
+
   # Use closure in some tests for some additional coverage
   def maybe_closure(self):
     if '--closure=1' not in self.emcc_args and self.should_use_closure():
@@ -9644,11 +9648,13 @@ def test_modularize_instance_embind(self):
 
 
 # Generate tests for everything
-def make_run(name, emcc_args, settings=None, env=None,
+def make_run(name, emcc_args=None, settings=None, env=None, # noqa
              require_v8=False, v8_args=None,
              require_node=False, node_args=None,
              require_wasm64=False,
              init=None):
+  if emcc_args is None:
+    emcc_args = {}
   if env is None:
     env = {}
   if settings is None:
@@ -9777,6 +9783,8 @@ def setUp(self):
 bigint = make_run('bigint', emcc_args=['--profiling-funcs'], settings={'WASM_BIGINT': 1},
                   init=lambda self: shared.node_bigint_flags(self.get_nodejs()))
 
+esm_integration = make_run('esm_integration', init=lambda self: self.setup_esm_integration())
+
 # Add DEFAULT_TO_CXX=0
 strict = make_run('strict', emcc_args=[], settings={'STRICT': 1})
 strict_js = make_run('strict_js', emcc_args=[], settings={'STRICT_JS': 1})

test/unistd/access.c

@@ -42,17 +42,17 @@ void test_fchmod() {
   chmod("fchmodtest", S_IRUGO | S_IWUGO);
   struct stat fileStats;
   stat("fchmodtest", &fileStats);
-  int mode = fileStats.st_mode & 0777;
+  int mode = fileStats.st_mode & 0o777;
   // Allow S_IXUGO in addtion to S_IWUGO because on windows
   // we always report the execute bit.
   assert(mode == (S_IRUGO | S_IWUGO) || mode == (S_IRUGO | S_IWUGO | S_IXUGO));
 
   EM_ASM(
     var fchmodstream = FS.open("fchmodtest", "r");
-    FS.fchmod(fchmodstream.fd, 0777);
+    FS.fchmod(fchmodstream.fd, 0o777);
   );
   stat("fchmodtest", &fileStats);
-  assert((fileStats.st_mode & 0777) == 0777);
+  assert((fileStats.st_mode & 0o777) == 0o777);
 }
 
 void test_lchmod() {
@@ -61,7 +61,7 @@ void test_lchmod() {
   // so skip this part of the test.
   EM_ASM(
     FS.symlink('writeable', 'symlinkfile');
-    FS.lchmod('symlinkfile', 0777);
+    FS.lchmod('symlinkfile', 0o777);
   );
 
   struct stat symlinkStats;
@@ -80,21 +80,21 @@ void test_chmod_errors() {
   EM_ASM(
     var ex;
     try {
-      FS.chmod("nonexistent", 0777);
+      FS.chmod("nonexistent", 0o777);
     } catch (err) {
       ex = err;
     }
     assert(ex.name === "ErrnoError" && ex.errno === 44 /* ENOENT */);
 
     try {
-      FS.fchmod(99, 0777);
+      FS.fchmod(99, 0o777);
     } catch (err) {
       ex = err;
     }
     assert(ex.name === "ErrnoError" && ex.errno === 8 /* EBADF */);
 
     try {
-      FS.lchmod("nonexistent", 0777);
+      FS.lchmod("nonexistent", 0o777);
     } catch (err) {
       ex = err;
     }

tools/emscripten.py

@@ -755,10 +755,15 @@ def create_em_js(metadata):
     arg_names = [arg.split()[-1].replace('*', '') for arg in args if arg]
     args = ','.join(arg_names)
     func = f'function {name}({args}) {body}'
+    if settings.WASM_ESM_INTEGRATION:
+      # Like JS library function EM_JS functions are exported at the point of
+      # declaration in WASM_ESM_INTEGRATION node.
+      func = f'export {func}'
+    em_js_funcs.append(func)
     if (settings.MAIN_MODULE or settings.ASYNCIFY == 2) and name in metadata.em_js_func_types:
       sig = func_type_to_sig(metadata.em_js_func_types[name])
-      func = func + f'\n{name}.sig = \'{sig}\';'
-    em_js_funcs.append(func)
+      sig = f'{name}.sig = \'{sig}\';'
+      em_js_funcs.append(sig)
 
   return em_js_funcs
 
@@ -826,7 +831,10 @@ def create_sending(metadata, library_symbols):
 
   for name in metadata.imports:
     if name in metadata.em_js_funcs:
-      send_items_map[name] = name
+      # EM_JS functions are exported directly at the declaration site in
+      # WASM_ESM_INTEGRATION mode.
+      if not settings.WASM_ESM_INTEGRATION:
+        send_items_map[name] = name
     else:
       send_items_map[name] = asmjs_mangle(name)
 
@@ -881,16 +889,18 @@ def create_sending(metadata, library_symbols):
   return '{\n  ' + ',\n  '.join(elems) + '\n}'
 
 
-def create_reexports():
+def create_reexports(metadata):
   assert settings.WASM_ESM_INTEGRATION
   exports = '// Re-export imported wasm functions to the JS entry point. These are user-facing and underscore mangled.\n'
   wasm_exports = []
   for exp in building.user_requested_exports:
     if shared.is_c_symbol(exp):
       demangled = shared.demangle_c_symbol_name(exp)
-      if demangled in settings.WASM_EXPORTS:
+      if demangled in metadata.em_js_funcs:
+        wasm_exports.append(f'{demangled} as {exp}')
+      elif demangled in settings.WASM_EXPORTS:
         wasm_exports.append(exp)
-      if demangled == 'main' and '__main_argc_argv' in settings.WASM_EXPORTS:
+      elif demangled == 'main' and '__main_argc_argv' in settings.WASM_EXPORTS:
         wasm_exports.append('_main')
   exports += f"export {{ {', '.join(wasm_exports)} }};\n\n"
   return exports
@@ -1055,7 +1065,7 @@ def create_module(metadata, function_exports, global_exports, tag_exports,librar
     module.append(create_pointer_conversion_wrappers(metadata))
 
   if settings.WASM_ESM_INTEGRATION:
-    module.append(create_reexports())
+    module.append(create_reexports(metadata))
 
   return module