[wasm] Add a JavaScript utility to make it easier to build WASM modules from JavaScript.

test/mjsunit/wasm/test-wasm-module-builder.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-wasm
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+var debug = (arguments[0] == "debug");
+
+(function BasicTest() {
+  var module = new WasmModuleBuilder();
+  module.AddMemory(1, 2, false);
+  module.AddFunction("foo", [kAstI32])
+      .AddBody([kExprI8Const, 11])
+      .ExportAs("blarg");
+
+  var buffer = module.ToBuffer(debug);
+  var instance = _WASMEXP_.instantiateModule(buffer);
+  assertEquals(11, instance.exports.blarg());
+})();
+
+(function ImportTest() {
+  var module = new WasmModuleBuilder();
+  var index = module.AddImport("print", [kAstStmt, kAstI32]);
+  module.AddFunction("foo", [kAstStmt])
+      .AddBody([kExprCallImport, index, kExprI8Const, 13])
+      .ExportAs("main");
+
+  var buffer = module.ToBuffer(debug);
+  var instance = _WASMEXP_.instantiateModule(buffer, {print: print});
+  print("should print 13! ");
+  instance.exports.main();
+})();
+
+(function LocalsTest() {
+  var module = new WasmModuleBuilder();
+  module.AddFunction(undefined, [kAstI32, kAstI32])
+      .AddLocals({i32_count: 1})
+      .AddBody([kExprSetLocal, 1, kExprGetLocal, 0])
+      .ExportAs("main");
+
+  var buffer = module.ToBuffer(debug);
+  var instance = _WASMEXP_.instantiateModule(buffer);
+  assertEquals(19, instance.exports.main(19));
+  assertEquals(27777, instance.exports.main(27777));
+})();
+
+(function CallTest() {
+  var module = new WasmModuleBuilder();
+  module.AddFunction("add", [kAstI32, kAstI32, kAstI32])
+      .AddBody([kExprI32Add, kExprGetLocal, 0, kExprGetLocal, 1])
+          module.AddFunction("main", [kAstI32, kAstI32, kAstI32])

[binji, 2016/03/04 05:13:26]

weird indentation here. missing semicolon on the prev line?

[titzer, 2016/03/05 01:26:22]

Good catch. Semicolon insertion to the rescue :-)

+      .AddBody([kExprCallFunction, 0, kExprGetLocal, 0, kExprGetLocal, 1])
+      .ExportAs("main");
+
+  var instance = module.Instantiate();
+  assertEquals(44, instance.exports.main(11, 33));
+  assertEquals(7777, instance.exports.main(2222, 5555));
+})();
+
+(function IndirectCallTest() {
+  var module = new WasmModuleBuilder();
+  module.AddFunction("add", [kAstI32, kAstI32, kAstI32]).AddBody([
+    kExprI32Add, kExprGetLocal, 0, kExprGetLocal, 1
+  ]);
+  module.AddFunction("main", [kAstI32, kAstI32, kAstI32, kAstI32])
+      .AddBody([
+        kExprCallIndirect, 0, kExprGetLocal, 0, kExprGetLocal, 1, kExprGetLocal,
+        2
+      ])
+      .ExportAs("main");
+  module.AppendToFunctionTable([0]);
+
+  var instance = module.Instantiate();
+  assertEquals(44, instance.exports.main(0, 11, 33));
+  assertEquals(7777, instance.exports.main(0, 2222, 5555));
+  assertThrows(function() { instance.exports.main(1, 1, 1); });
+})();
+
+(function DataSegmentTest() {
+  var module = new WasmModuleBuilder();
+  module.AddMemory(1, 1, false);
+  module.AddFunction("load", [kAstI32, kAstI32])
+      .AddBody([kExprI32LoadMem, 0, kExprGetLocal, 0])
+      .ExportAs("load");
+  module.AddDataSegment(0, [9, 9, 9, 9], true);
+
+  var buffer = module.ToBuffer(debug);
+  var instance = _WASMEXP_.instantiateModule(buffer);
+  assertEquals(151587081, instance.exports.load(0));
+})();