Add wbind and wbindArray API.

Author: juj

src/library.js

@@ -3508,7 +3508,7 @@ LibraryManager.library = {
 #if ASSERTIONS
     assert(wasmTable.get(ptr), 'missing table entry in dynCall: ' + ptr);
 #endif
-    return wasmTable.get(ptr).apply(null, args)
+    return wasmTable.get(ptr).apply(null, args);
 #endif
   },
 
@@ -3532,6 +3532,46 @@ LibraryManager.library = {
     }
   },
 
+#if SHRINK_LEVEL == 0
+  // A mirror copy of contents of wasmTable in JS side, to avoid relatively
+  // slow wasmTable.get() call. Only used when not compiling with -Os or -Oz.
+  _wasmTableMirror: [],
+
+  $wbind__deps: ['_wasmTableMirror'],
+  $wbind: function(funcPtr) {
+    var func = __wasmTableMirror[funcPtr];
+    if (!func) {
+      if (funcPtr >= __wasmTableMirror.length) __wasmTableMirror.length = funcPtr + 1;
+      __wasmTableMirror[funcPtr] = func = wasmTable.get(funcPtr);
+    }
+    return func;
+  },
+
+  $wbindArray__deps: ['$wbind'],
+#else
+  $wbind: function(funcPtr) {
+    // In -Os and -Oz builds, do not implement a JS side wasm table mirror for small
+    // code size, but directly access wasmTable, which is a bit slower as uncached.
+    return wasmTable.get(funcPtr);
+  },
+#endif
+
+  // A helper that binds a wasm function into a form that can be called by passing all
+  // the parameters in an array, e.g. wbindArray(func)([param1, param2, ..., paramN]).
+  $wbindArray: function(funcPtr) {
+    var func = wbind(funcPtr);
+#if SHRINK_LEVEL == 0
+    // In optimized for speed builds, do a micro-optimization for the scenario when the
+    // target function does not take in any parameters.
+    return func.length
+      ? function(args) { return func.apply(null, args); }
+      : function() { return func(); }
+#else
+    // In optimized for size builds, conserve code size.
+    return function(args) { return func.apply(null, args); };
+#endif
+  },
+
   // Callable in pthread without __proxy needed.
   emscripten_exit_with_live_runtime__sig: 'v',
 #if !MINIMAL_RUNTIME

src/parseTools.js

@@ -1012,7 +1012,7 @@ Please update to new syntax.`);
     if (DYNCALLS) {
       return `(function(cb, ${args}) { ${returnExpr} getDynCaller("${sig}", cb)(${args}) })`;
     } else {
-      return `(function(cb, ${args}) { ${returnExpr} wasmTable.get(cb)(${args}) })`;
+      return `(function(cb, ${args}) { ${returnExpr} wbind(cb)(${args}) })`;
     }
   }
 
@@ -1024,7 +1024,7 @@ Please update to new syntax.`);
       return `(function() { ${returnExpr} ${dyncall}.call(null, ${funcPtr}); })`;
     }
   } else {
-    return `wasmTable.get(${funcPtr})`;
+    return `wbind(${funcPtr})`;
   }
 }
 

tests/core/test_wbind.c

@@ -0,0 +1,27 @@
+#include <stdint.h>
+#include <assert.h>
+#include <stdio.h>
+
+extern void test_wbind_iijdf(int (*test_func)(int, uint64_t, double, float));
+extern void test_wbind_ji(uint64_t (*test_func)(int));
+
+int test_func_iijdf(int a, uint64_t b, double d, float f)
+{
+	printf("a: %d\n", a);
+	printf("b: %llx\n", b);
+	printf("d: %g\n", d);
+	printf("f: %f\n", f);
+	return 42;
+}
+
+uint64_t test_func_ji(int a)
+{
+	printf("a: %d\n", a);
+	return ((uint64_t)a << 32) | (uint64_t)a;
+}
+
+int main()
+{
+	test_wbind_iijdf(test_func_iijdf);
+	test_wbind_ji(test_func_ji);
+}

tests/core/test_wbind.js

@@ -0,0 +1,19 @@
+mergeInto(LibraryManager.library, {
+  test_wbind_iijdf__deps: ['$wbind', '$wbindArray'],
+  test_wbind_iijdf: function(funcPtr) {
+    var ret = wbind(funcPtr)(1, BigInt(0x300000002), 4.2, 5.3);
+    console.log(ret);
+
+    ret = wbindArray(funcPtr)([1, BigInt(0x300000002), 4.2, 5.3]);
+    console.log(ret);
+  },
+
+  test_wbind_ji__deps: ['$wbind', '$wbindArray'],
+  test_wbind_ji: function(funcPtr) {
+    var ret = wbind(funcPtr)(1);
+    console.log(ret);
+
+    ret = wbindArray(funcPtr)([1]);
+    console.log(ret);
+  }
+});

tests/core/test_wbind.out

@@ -0,0 +1,14 @@
+a: 1
+b: 300000002
+d: 4.2
+f: 5.300000
+42
+a: 1
+b: 300000002
+d: 4.2
+f: 5.300000
+42
+a: 1
+4294967297n
+a: 1
+4294967297n

tests/test_core.py

@@ -396,6 +396,13 @@ def test_i64_invoke_bigint(self):
     self.node_args += ['--experimental-wasm-bigint']
     self.do_core_test('test_i64_invoke_bigint.cpp', js_engines=[config.NODE_JS])
 
+  @no_wasm2js('wasm_bigint')
+  def test_wbind(self):
+    self.set_setting('WASM_BIGINT')
+    self.emcc_args += ['--js-library', test_file('core', 'test_wbind.js')]
+    self.node_args += ['--experimental-wasm-bigint']
+    self.do_core_test('test_wbind.c', js_engines=[config.NODE_JS])
+
   def test_vararg_copy(self):
     self.do_run_in_out_file_test('va_arg', 'test_va_copy.c')