From cf4b6059a30d7f4d4663f692adfb243e1dbcad08 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc@chromium.org>
Date: Thu, 25 Sep 2025 17:10:45 -0700
Subject: [PATCH] Fix `addFunction` in `-sWASM=2` mode

Fixes: #25394
---
 src/lib/libaddfunction.js                     | 30 ++++++++++---------
 test/codesize/test_codesize_hello_dylink.json |  4 +--
 test/test_other.py                            | 13 ++++----
 3 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/src/lib/libaddfunction.js b/src/lib/libaddfunction.js
index 72121b87edc09..d059e748732e3 100644
--- a/src/lib/libaddfunction.js
+++ b/src/lib/libaddfunction.js
@@ -77,8 +77,8 @@ addToLibrary({
     return code;
   })),
 
+#if !WASM2JS || WASM == 2
   // Wraps a JS function as a wasm function with a given signature.
-#if !WASM2JS
   $convertJsFunctionToWasm__deps: [
     '$uleb128EncodeWithLen',
 #if WASM_JS_TYPES
@@ -86,12 +86,7 @@ addToLibrary({
 #endif
     '$generateTypePack'
   ],
-#endif
   $convertJsFunctionToWasm: (func, sig) => {
-#if WASM2JS
-    // return func;
-#else // WASM2JS
-
 #if ASSERTIONS && !WASM_BIGINT
     assert(!sig.includes('j'), 'i64 not permitted in function signatures when WASM_BIGINT is disabled');
 #endif
@@ -135,8 +130,8 @@ addToLibrary({
     var instance = new WebAssembly.Instance(module, { 'e': { 'f': func } });
     var wrappedFunc = instance.exports['f'];
     return wrappedFunc;
-#endif // WASM2JS
   },
+#endif // !WASM2JS && WASM != 2
 
   $freeTableIndexes: [],
 
@@ -192,18 +187,21 @@ addToLibrary({
    * 'sig' parameter is required if the function being added is a JS function.
    */
   $addFunction__docs: '/** @param {string=} sig */',
-  $addFunction__deps: ['$convertJsFunctionToWasm', '$getFunctionAddress',
+  $addFunction__deps: ['$getFunctionAddress',
                        '$functionsInTableMap', '$getEmptyTableSlot',
                        '$setWasmTableEntry',
+#if !WASM2JS || WASM == 2
+                       '$convertJsFunctionToWasm',
+#endif
 #if ASSERTIONS >= 2
                        '$getWasmTableEntry', '$wasmTable',
 #endif
   ],
 
   $addFunction: (func, sig) => {
-  #if ASSERTIONS
+#if ASSERTIONS
     assert(typeof func != 'undefined');
-  #endif // ASSERTIONS
+#endif // ASSERTIONS
     // Check if the function is already in the table, to ensure each function
     // gets a unique index.
     var rtn = getFunctionAddress(func);
@@ -213,17 +211,20 @@ addToLibrary({
 
     // It's not in the table, add it now.
 
-  #if ASSERTIONS >= 2
+#if ASSERTIONS >= 2
     // Make sure functionsInTableMap is actually up to date, that is, that this
     // function is not actually in the wasm Table despite not being tracked in
     // functionsInTableMap.
     for (var i = 0; i < wasmTable.length; i++) {
       assert(getWasmTableEntry(i) != func, 'function in Table but not functionsInTableMap');
     }
-  #endif
+#endif
 
     var ret = getEmptyTableSlot();
 
+#if WASM2JS && WASM != 2
+    setWasmTableEntry(ret, func);
+#else
     // Set the new value.
     try {
       // Attempting to call this with JS function will cause of table.set() to fail
@@ -232,12 +233,13 @@ addToLibrary({
       if (!(err instanceof TypeError)) {
         throw err;
       }
-  #if ASSERTIONS
+#if ASSERTIONS
       assert(typeof sig != 'undefined', 'Missing signature argument to addFunction: ' + func);
-  #endif
+#endif
       var wrapped = convertJsFunctionToWasm(func, sig);
       setWasmTableEntry(ret, wrapped);
     }
+#endif
 
     functionsInTableMap.set(func, ret);
 
diff --git a/test/codesize/test_codesize_hello_dylink.json b/test/codesize/test_codesize_hello_dylink.json
index c0b841cf9aca8..8e234836ee9e3 100644
--- a/test/codesize/test_codesize_hello_dylink.json
+++ b/test/codesize/test_codesize_hello_dylink.json
@@ -1,10 +1,10 @@
 {
   "a.out.js": 26946,
-  "a.out.js.gz": 11480,
+  "a.out.js.gz": 11478,
   "a.out.nodebug.wasm": 18567,
   "a.out.nodebug.wasm.gz": 9199,
   "total": 45513,
-  "total_gz": 20679,
+  "total_gz": 20677,
   "sent": [
     "__heap_base",
     "__indirect_function_table",
diff --git a/test/test_other.py b/test/test_other.py
index 86d4797bfafed..51359ae62637a 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -14638,17 +14638,16 @@ def test_windows_nodefs_execution_permission(self):
     self.do_run(src)
 
   @parameterized({
-    'wasm2js': (True,),
-    '': (False,),
+    '': ([],),
+    'wasm2js': (['-sWASM=0'],),
+    'wasm2js_fallback': (['-sWASM=2'],),
   })
-  def test_add_js_function(self, wasm2js):
+  def test_add_js_function(self, args):
     self.set_setting('INVOKE_RUN', 0)
     self.set_setting('WASM_ASYNC_COMPILATION', 0)
     self.set_setting('ALLOW_TABLE_GROWTH')
     self.set_setting('EXPORTED_RUNTIME_METHODS', ['callMain'])
-    if wasm2js:
-      self.set_setting('WASM', 0)
-    self.cflags += ['--post-js', test_file('interop/test_add_function_post.js')]
+    self.cflags += args + ['--post-js', test_file('interop/test_add_function_post.js')]
 
     print('basics')
     self.do_run_in_out_file_test('interop/test_add_function.cpp')
@@ -14656,7 +14655,7 @@ def test_add_js_function(self, wasm2js):
     print('with ALLOW_TABLE_GROWTH=0')
     self.set_setting('ALLOW_TABLE_GROWTH', 0)
     expected = 'Unable to grow wasm table'
-    if wasm2js:
+    if '-sWASM=0' in args:
       # in wasm2js the error message doesn't come from the VM, but from our
       # emulation code. when ASSERTIONS are enabled we show a clear message, but
       # in optimized builds we don't waste code size on that, and the JS engine