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

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

Index: test/mjsunit/wasm/test-wasm-module-builder.js
diff --git a/test/mjsunit/wasm/test-wasm-module-builder.js b/test/mjsunit/wasm/test-wasm-module-builder.js
new file mode 100644
index 0000000000000000000000000000000000000000..05c19c657df35c6af9c45b2843e1ddba94362518
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+++ b/test/mjsunit/wasm/test-wasm-module-builder.js
@@ -0,0 +1,90 @@
+// 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 = (((typeof arguments) != undefined) && 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])
+        .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));
+})();