Part two of dynCall removal (#12059)

This change now passes flags to binaryen to limit the creation
of the dynCall functions and removes more internal use of the
legacy dynCall functions.

See #12002

Author: sbc100

emcc.py

@@ -1267,6 +1267,12 @@ def check(input_file):
     if shared.Settings.RELOCATABLE:
       shared.Settings.ALLOW_TABLE_GROWTH = 1
 
+    if shared.Settings.ASYNCIFY:
+      # See: https://github.com/emscripten-core/emscripten/issues/12065
+      # See: https://github.com/emscripten-core/emscripten/issues/12066
+      shared.Settings.USE_LEGACY_DYNCALLS = 1
+      shared.Settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$getDynCaller']
+
     # Reconfigure the cache now that settings have been applied. Some settings
     # such as LTO and SIDE_MODULE/MAIN_MODULE effect which cache directory we use.
     shared.reconfigure_cache()
@@ -1522,19 +1528,20 @@ def check(input_file):
         'removeRunDependency',
       ]
 
-    if not shared.Settings.MINIMAL_RUNTIME or (shared.Settings.USE_PTHREADS or shared.Settings.EXIT_RUNTIME):
+    if not shared.Settings.MINIMAL_RUNTIME or shared.Settings.EXIT_RUNTIME:
       # MINIMAL_RUNTIME only needs callRuntimeCallbacks in certain cases, but the normal runtime
       # always does.
-      shared.Settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$callRuntimeCallbacks']
+      shared.Settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$callRuntimeCallbacks', '$dynCall']
 
     if shared.Settings.USE_PTHREADS:
       # memalign is used to ensure allocated thread stacks are aligned.
       shared.Settings.EXPORTED_FUNCTIONS += ['_memalign', '_malloc']
 
-      # dynCall_ii is used to call pthread entry points in worker.js (as
+      # dynCall is used to call pthread entry points in worker.js (as
       # metadce does not consider worker.js, which is external, we must
-      # consider it a user export, i.e., one which can never be removed).
-      building.user_requested_exports += ['dynCall_ii']
+      # consider it an export, i.e., one which can never be removed).
+      shared.Settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$dynCall']
+      shared.Settings.EXPORTED_FUNCTIONS += ['dynCall']
 
       if shared.Settings.MINIMAL_RUNTIME:
         building.user_requested_exports += ['exit']

emscripten.py

@@ -549,6 +549,13 @@ def finalize_wasm(temp_files, infile, outfile, memfile, DEBUG):
     args.append('-g')
   if shared.Settings.WASM_BIGINT:
     args.append('--bigint')
+
+  if not shared.Settings.USE_LEGACY_DYNCALLS:
+    if shared.Settings.WASM_BIGINT:
+      args.append('--no-dyncalls')
+    else:
+      args.append('--dyncalls-i64')
+
   if shared.Settings.LEGALIZE_JS_FFI != 1:
     args.append('--no-legalize-javascript-ffi')
   if not shared.Settings.MEM_INIT_IN_WASM:

src/Fetch.js

@@ -454,28 +454,28 @@ function emscripten_start_fetch(fetch, successcb, errorcb, progresscb, readystat
 #if FETCH_DEBUG
     console.log('fetch: operation success. e: ' + e);
 #endif
-    if (onsuccess) {{{ makeDynCall('vi') }}}(onsuccess, fetch);
+    if (onsuccess) {{{ makeDynCall('vi', 'onsuccess') }}}(fetch);
     else if (successcb) successcb(fetch);
   };
 
   var reportProgress = function(fetch, xhr, e) {
-    if (onprogress) {{{ makeDynCall('vi') }}}(onprogress, fetch);
+    if (onprogress) {{{ makeDynCall('vi', 'onprogress') }}}(fetch);
     else if (progresscb) progresscb(fetch);
   };
 
   var reportError = function(fetch, xhr, e) {
 #if FETCH_DEBUG
     console.error('fetch: operation failed: ' + e);
 #endif
-    if (onerror) {{{ makeDynCall('vi') }}}(onerror, fetch);
+    if (onerror) {{{ makeDynCall('vi', 'onerror') }}}(fetch);
     else if (errorcb) errorcb(fetch);
   };
 
   var reportReadyStateChange = function(fetch, xhr, e) {
 #if FETCH_DEBUG
     console.log('fetch: ready state change. e: ' + e);
 #endif
-    if (onreadystatechange) {{{ makeDynCall('vi') }}}(onreadystatechange, fetch);
+    if (onreadystatechange) {{{ makeDynCall('vi', 'onreadystatechange') }}}(fetch);
     else if (readystatechangecb) readystatechangecb(fetch);
   };
 
@@ -495,14 +495,14 @@ function emscripten_start_fetch(fetch, successcb, errorcb, progresscb, readystat
 #if FETCH_DEBUG
       console.log('fetch: IndexedDB store succeeded.');
 #endif
-      if (onsuccess) {{{ makeDynCall('vi') }}}(onsuccess, fetch);
+      if (onsuccess) {{{ makeDynCall('vi', 'onsuccess') }}}(fetch);
       else if (successcb) successcb(fetch);
     };
     var storeError = function(fetch, xhr, e) {
 #if FETCH_DEBUG
       console.error('fetch: IndexedDB store failed.');
 #endif
-      if (onsuccess) {{{ makeDynCall('vi') }}}(onsuccess, fetch);
+      if (onsuccess) {{{ makeDynCall('vi', 'onsuccess') }}}(fetch);
       else if (successcb) successcb(fetch);
     };
     __emscripten_fetch_cache_data(Fetch.dbInstance, fetch, xhr.response, storeSuccess, storeError);

src/embind/embind.js

@@ -1062,42 +1062,20 @@ var LibraryEmbind = {
 #endif
   },
 
-  $embind__requireFunction__deps: ['$readLatin1String', '$throwBindingError'],
+  $embind__requireFunction__deps: ['$readLatin1String', '$throwBindingError', '$getDynCaller'],
   $embind__requireFunction: function(signature, rawFunction) {
     signature = readLatin1String(signature);
 
-    function makeDynCaller(dynCall) {
-#if DYNAMIC_EXECUTION == 0
-      var argCache = [rawFunction];
-      return function() {
-          argCache.length = arguments.length + 1;
-          for (var i = 0; i < arguments.length; i++) {
-            argCache[i + 1] = arguments[i];
-          }
-          return dynCall.apply(null, argCache);
-      };
-#else
-        var args = [];
-        for (var i = 1; i < signature.length; ++i) {
-            args.push('a' + i);
-        }
-
-        var name = 'dynCall_' + signature + '_' + rawFunction;
-        var body = 'return function ' + name + '(' + args.join(', ') + ') {\n';
-        body    += '    return dynCall(rawFunction' + (args.length ? ', ' : '') + args.join(', ') + ');\n';
-        body    += '};\n';
-
-        return (new Function('dynCall', 'rawFunction', body))(dynCall, rawFunction);
+    function makeDynCaller() {
+#if !USE_LEGACY_DYNCALLS
+      if (signature.indexOf('j') == -1) {
+        return wasmTable.get(rawFunction);
+      }
 #endif
+      return getDynCaller(signature, rawFunction);
     }
 
-#if MINIMAL_RUNTIME
-    var dc = asm['dynCall_' + signature];
-#else
-    var dc = Module['dynCall_' + signature];
-#endif
-    var fp = makeDynCaller(dc);
-
+    var fp = makeDynCaller();
     if (typeof fp !== "function") {
         throwBindingError("unknown function pointer with signature " + signature + ": " + rawFunction);
     }

src/library.js

@@ -3872,7 +3872,7 @@ LibraryManager.library = {
     var trace = _emscripten_get_callstack_js();
     var parts = trace.split('\n');
     for (var i = 0; i < parts.length; i++) {
-      var ret = {{{ makeDynCall('iii') }}}(func, 0, arg);
+      var ret = {{{ makeDynCall('iii', 'func') }}}(0, arg);
       if (ret !== 0) return;
     }
   },
@@ -3921,7 +3921,7 @@ LibraryManager.library = {
   emscripten_scan_stack: function(func) {
     var base = STACK_BASE; // TODO verify this is right on pthreads
     var end = stackSave();
-    {{{ makeDynCall('vii') }}}(func, Math.min(base, end), Math.max(base, end));
+    {{{ makeDynCall('vii', 'func') }}}(Math.min(base, end), Math.max(base, end));
   },
 
   // misc definitions to avoid unnecessary unresolved symbols being reported
@@ -4004,6 +4004,60 @@ LibraryManager.library = {
     });
   },
 
+#if USE_LEGACY_DYNCALLS || !WASM_BIGINT
+  $dynCallLegacy: function(sig, ptr, args) {
+#if ASSERTIONS
+    assert(('dynCall_' + sig) in Module, 'bad function pointer type - no table for sig \'' + sig + '\'');
+    if (args && args.length) {
+      // j (64-bit integer) must be passed in as two numbers [low 32, high 32].
+      assert(args.length === sig.substring(1).replace(/j/g, '--').length);
+    } else {
+      assert(sig.length == 1);
+    }
+#endif
+    if (args && args.length) {
+      return Module['dynCall_' + sig].apply(null, [ptr].concat(args));
+    }
+    return Module['dynCall_' + sig].call(null, ptr);
+  },
+  $dynCall__deps: ['$dynCallLegacy'],
+
+  // Used in library code to get JS function from wasm function pointer.
+  // All callers should use direct table access where possible and only fall
+  // back to this function if needed.
+  $getDynCaller__deps: ['$dynCall'],
+  $getDynCaller: function(sig, ptr) {
+#if !USE_LEGACY_DYNCALLS
+    assert(sig.indexOf('j') >= 0, 'getDynCaller should only be called with i64 sigs')
+#endif
+    var argCache = [];
+    return function() {
+      argCache.length = arguments.length;
+      for (var i = 0; i < arguments.length; i++) {
+        argCache[i] = arguments[i];
+      }
+      return dynCall(sig, ptr, argCache);
+    };
+  },
+#endif
+
+  $dynCall: function (sig, ptr, args) {
+#if USE_LEGACY_DYNCALLS
+    return dynCallLegacy(sig, ptr, args);
+#else
+#if !WASM_BIGINT
+    // Without WASM_BIGINT support we cannot directly call function with i64 as
+    // part of thier signature, so we rely the dynCall functions generated by
+    // wasm-emscripten-finalize
+    if (sig.indexOf('j') != -1) {
+      return dynCallLegacy(sig, ptr, args);
+    }
+#endif
+
+    return wasmTable.get(ptr).apply(null, args)
+#endif
+  },
+
   $callRuntimeCallbacks: function(callbacks) {
     while(callbacks.length > 0) {
       var callback = callbacks.shift();
@@ -4014,9 +4068,9 @@ LibraryManager.library = {
       var func = callback.func;
       if (typeof func === 'number') {
         if (callback.arg === undefined) {
-          dynCall_v(func);
+          {{{ makeDynCall('v', 'func') }}}();
         } else {
-          dynCall_vi(func, callback.arg);
+          {{{ makeDynCall('vi', 'func') }}}(callback.arg);
         }
       } else {
         func(callback.arg === undefined ? null : callback.arg);

src/library_async.js

@@ -340,7 +340,7 @@ mergeInto(LibraryManager.library, {
       Asyncify.afterUnwind = function() {
         var stackBegin = Asyncify.currData + {{{ C_STRUCTS.asyncify_data_s.__size__ }}};
         var stackEnd = HEAP32[Asyncify.currData >> 2];
-        {{{ makeDynCall('vii') }}}(func, stackBegin, stackEnd);
+        {{{ makeDynCall('vii', 'func') }}}(stackBegin, stackEnd);
         wakeUp();
       };
     });
@@ -401,7 +401,7 @@ mergeInto(LibraryManager.library, {
         {{{ makeSetValue('newFiber', C_STRUCTS.emscripten_fiber_s.entry, 0, 'i32') }}};
 
         var userData = {{{ makeGetValue('newFiber', C_STRUCTS.emscripten_fiber_s.user_data, 'i32') }}};
-        {{{ makeDynCall('vi') }}}(entryPoint, userData);
+        {{{ makeDynCall('vi', 'entryPoint') }}}(userData);
       } else {
         var asyncifyData = newFiber + {{{ C_STRUCTS.emscripten_fiber_s.asyncify_data }}};
         Asyncify.currData = asyncifyData;