Remove MAYBE_WASM2JS settings

Fixes: #23969

Author: sbc100

ChangeLog.md

@@ -59,6 +59,9 @@ See docs/process.md for more on how version tagging works.
   - EXTRA_EXPORTED_RUNTIME_METHODS: Instead use EXPORTED_RUNTIME_METHODS.
   - DEMANGLE_SUPPORT: Instead use the `$demangle` JS libary function.
   (#23975)
+- The `-sMAYBE_WASM2JS` settings was removed.  This is oringally added for
+  debugging purposed, and we now have `-sWASM=2` for folks that want to be able
+  to fall back to js if wasm fails. ()
 
 4.0.5 - 03/12/25
 ----------------

site/source/docs/tools_reference/settings_reference.rst

@@ -3052,21 +3052,6 @@ disable HTML minification altogether.
 
 Default value: true
 
-.. _maybe_wasm2js:
-
-MAYBE_WASM2JS
-=============
-
-Whether we *may* be using wasm2js. This compiles to wasm normally, but lets
-you run wasm2js *later* on the wasm, and you can pick between running the
-normal wasm or that wasm2js code. For details of how to do that, see the
-test_maybe_wasm2js test.  This option can be useful for debugging and
-bisecting.
-
-.. note:: This setting is deprecated
-
-Default value: false
-
 .. _asan_shadow_size:
 
 ASAN_SHADOW_SIZE

src/preamble.js

@@ -20,17 +20,12 @@
 
 {{{ makeModuleReceiveWithVar('wasmBinary') }}}
 
-#if WASM != 2 && MAYBE_WASM2JS
-#if !WASM2JS
-if (Module['doWasm2JS']) {
-#endif
+#if WASM2JS
+#if WASM != 2
+// WASM == 2 includes wasm2js.js separately.
 #include "wasm2js.js"
-#if !WASM2JS
-}
-#endif
 #endif
 
-#if MAYBE_WASM2JS
 if (WebAssembly.isWasm2js) {
   // We don't need to actually download a wasm binary, mark it as present but
   // empty.

src/preamble_minimal.js

@@ -22,14 +22,9 @@ var tempDouble;
 var tempI64;
 #endif
 
-#if WASM != 2 && MAYBE_WASM2JS
-#if !WASM2JS
-if (Module['doWasm2JS']) {
-#endif
+#if WASM2JS && WASM != 2
+// WASM == 2 includes wasm2js.js separately.
 #include "wasm2js.js"
-#if !WASM2JS
-}
-#endif
 #endif
 
 var HEAP8, HEAP16, HEAP32, HEAPU8, HEAPU16, HEAPU32, HEAPF32, HEAPF64,

src/settings.js

@@ -2007,15 +2007,6 @@ var HTML5_SUPPORT_DEFERRING_USER_SENSITIVE_REQUESTS = true;
 // [link]
 var MINIFY_HTML = true;
 
-// Whether we *may* be using wasm2js. This compiles to wasm normally, but lets
-// you run wasm2js *later* on the wasm, and you can pick between running the
-// normal wasm or that wasm2js code. For details of how to do that, see the
-// test_maybe_wasm2js test.  This option can be useful for debugging and
-// bisecting.
-// [link]
-// [deprecated]
-var MAYBE_WASM2JS = false;
-
 // This option is no longer used. The appropriate shadow memory size is now
 // calculated from INITIAL_MEMORY and MAXIMUM_MEMORY. Will be removed in a
 // future release.
@@ -2286,4 +2277,5 @@ var LEGACY_SETTINGS = [
   ['EXTRA_EXPORTED_RUNTIME_METHODS', [[]], 'No longer supported, use EXPORTED_RUNTIME_METHODS'],
   ['SUPPORT_ERRNO', [0], 'No longer supported'],
   ['DEMANGLE_SUPPORT', [0], 'No longer supported'],
+  ['MAYBE_WASM2JS', [0], 'No longer supported (use -sWASM=2)'],
 ];

src/wasm2js.js

@@ -7,13 +7,8 @@
 // wasm2js.js - enough of a polyfill for the WebAssembly object so that we can load
 // wasm2js code that way.
 
-// Emit "var WebAssembly" if definitely using wasm2js. Otherwise, in MAYBE_WASM2JS
-// mode, we can't use a "var" since it would prevent normal wasm from working.
 /** @suppress{duplicate, const} */
-#if WASM2JS || WASM == 2
-var
-#endif
-WebAssembly = {
+var WebAssembly = {
   // Note that we do not use closure quoting (this['buffer'], etc.) on these
   // functions, as they are just meant for internal use. In other words, this is
   // not a fully general polyfill.

test/test_core.py

@@ -8397,24 +8397,6 @@ def test_wasm2js(self):
     self.do_core_test('test_hello_world.c')
     self.assertNotExists('test_hello_world.js.mem')
 
-  @no_sanitize('no wasm2js support yet in sanitizers')
-  @requires_wasm2js
-  def test_maybe_wasm2js(self):
-    if self.is_wasm2js():
-      self.skipTest('redundant to test wasm2js in wasm2js* mode')
-    self.set_setting('MAYBE_WASM2JS')
-    # see that running as wasm works
-    self.do_core_test('test_hello_world.c', emcc_args=['-Wno-deprecated'])
-    # run wasm2js, bundle the code, and use the wasm2js path
-    cmd = [PYTHON, path_from_root('tools/maybe_wasm2js.py'), 'test_hello_world.js', 'test_hello_world.wasm']
-    if self.is_optimizing():
-      cmd += ['-O2']
-    self.run_process(cmd, stdout=open('do_wasm2js.js', 'w'))
-    # remove the wasm to make sure we never use it again
-    os.remove('test_hello_world.wasm')
-    # verify that it runs
-    self.assertContained('hello, world!', self.run_js('do_wasm2js.js'))
-
   @no_asan('no wasm2js support yet in asan')
   @requires_wasm2js
   @parameterized({

tools/link.py

@@ -841,7 +841,6 @@ def limit_incoming_module_api():
     settings.WASM2JS = 1
 
   if settings.WASM2JS:
-    settings.MAYBE_WASM2JS = 1
     # Wasm bigint doesn't make sense with wasm2js, since it controls how the
     # wasm and JS interact.
     if user_settings.get('WASM_BIGINT') and settings.WASM_BIGINT: