[esm-integration] Enable DYNCALLS (#24374)

Now that #24399 has landed we can support dyncalls in ESM integration
mode.

Author: sbc100

site/source/docs/compiling/Modularized-Output.rst

@@ -168,9 +168,7 @@ Some additional limitations are:
 * :ref:`abort_on_wasm_exceptions` is not supported (requires wrapping wasm
   exports).
 
-* :ref:`dyncalls` is not supported (depends on the ``Module`` global)
-
-* :ref:`asyncify` is not supported (depends on :ref:`dyncalls`)
+* :ref:`asyncify` is not supported (depends on ``wasmExports`` global)
 
 * Setting :ref:`wasm` to ``0`` is not supported.
 

src/postamble.js

@@ -314,6 +314,10 @@ export default async function init(moduleArg = {}) {
   processModuleArgs();
 #if WASM_ESM_INTEGRATION
   updateMemoryViews();
+#if DYNCALLS && '$dynCalls' in addedLibraryItems
+
+  assignDynCalls();
+#endif
 #else
   wasmExports = await createWasm();
 #endif

test/test_core.py

@@ -7020,7 +7020,6 @@ def test_EXPORTED_RUNTIME_METHODS(self):
     self.do_core_test('EXPORTED_RUNTIME_METHODS.c')
 
   @also_with_minimal_runtime
-  @no_esm_integration('WASM_ESM_INTEGRATION is not compatible with DYNCALLS')
   def test_dyncall_specific(self):
     if self.get_setting('WASM_BIGINT') != 0 and not self.is_wasm2js():
       # define DYNCALLS because this test does test calling them directly, and
@@ -7047,8 +7046,6 @@ def test_dyncall_specific(self):
     'legacy': (['-sDYNCALLS'],),
   })
   def test_dyncall_pointers(self, args):
-    if args and self.get_setting('WASM_ESM_INTEGRATION'):
-      self.skipTest('WASM_ESM_INTEGRATION is not compatible with DYNCALLS')
     self.do_core_test('test_dyncall_pointers.c', emcc_args=args)
 
   @also_with_wasm_bigint

tools/emscripten.py

@@ -928,18 +928,35 @@ def should_export(sym):
 
 
 def create_receiving(function_exports, tag_exports):
+  generate_dyncall_assignment = settings.DYNCALLS and '$dynCall' in settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE
   receiving = ['\n// Imports from the Wasm binary.']
 
   if settings.WASM_ESM_INTEGRATION:
-    exports = tag_exports + list(function_exports.keys())
-    exports = [f'{f} as {asmjs_mangle(f)}' for f in exports]
+    exported_symbols = tag_exports + list(function_exports.keys())
+    exports = []
+    for sym in exported_symbols:
+      mangled = asmjs_mangle(sym)
+      if mangled != sym:
+        exports.append(f'{sym} as {mangled}')
+      else:
+        exports.append(sym)
     if not settings.IMPORTED_MEMORY:
       exports.append('memory as wasmMemory')
     if not settings.RELOCATABLE:
       exports.append('__indirect_function_table as wasmTable')
     receiving.append('import {')
     receiving.append('  ' + ',\n  '.join(exports))
     receiving.append(f"}} from './{settings.WASM_BINARY_FILE}';")
+
+    if generate_dyncall_assignment:
+      receiving.append('\nfunction assignDynCalls() {')
+      receiving.append('  // Construct dynCalls mapping')
+      for sym in function_exports:
+        if sym.startswith('dynCall_'):
+          sig_str = sym.replace('dynCall_', '')
+          receiving.append(f"  dynCalls['{sig_str}'] = {sym};")
+      receiving.append('}')
+
     return '\n'.join(receiving) + '\n\n'
 
   # When not declaring asm exports this section is empty and we instead programmatically export
@@ -952,7 +969,6 @@ def create_receiving(function_exports, tag_exports):
   # var _main;
   # function assignWasmExports(wasmExport) {
   #   _main = wasmExports["_main"];
-  generate_dyncall_assignment = settings.DYNCALLS and '$dynCall' in settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE
   exports = {name: sig for name, sig in function_exports.items() if name != building.WASM_CALL_CTORS}
 
   if settings.ASSERTIONS:
@@ -981,7 +997,7 @@ def create_receiving(function_exports, tag_exports):
   receiving.append('\nfunction assignWasmExports(wasmExports) {')
   for sym, sig in exports.items():
     mangled = asmjs_mangle(sym)
-    if generate_dyncall_assignment and mangled.startswith('dynCall_'):
+    if generate_dyncall_assignment and sym.startswith('dynCall_'):
       sig_str = sym.replace('dynCall_', '')
       dynCallAssignment = f"dynCalls['{sig_str}'] = "
     else:

tools/link.py

@@ -814,8 +814,6 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
       exit_with_error('WASM_ESM_INTEGRATION is not compatible with dynamic linking')
     if settings.ASYNCIFY == 1:
       exit_with_error('WASM_ESM_INTEGRATION is not compatible with -sASYNCIFY=1')
-    if settings.DYNCALLS:
-      exit_with_error('WASM_ESM_INTEGRATION is not compatible with DYNCALLS')
     if settings.WASM_WORKERS or settings.PTHREADS:
       exit_with_error('WASM_ESM_INTEGRATION is not compatible with multi-threading')
     if settings.USE_OFFSET_CONVERTER: