Bug 480850 - Add JSAPI function JS_New (identical to tracemonkey/rev/869bebcf1f21). r=mrbkap.

js/src/jsapi-tests/Makefile.in

@@ -55,6 +55,7 @@ CPPSRCS = \
   testIntString.cpp \
   testIsAboutToBeFinalized.cpp \
   testLookup.cpp \
+  testNewObject.cpp \
   testPropCache.cpp \
   testTrap.cpp \
   testSameValue.cpp \

js/src/jsapi-tests/testNewObject.cpp

@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=4 sw=4 et tw=99:
+ */
+
+#include "tests.h"
+
+const int N = 1000;
+static jsval argv[N];
+
+static JSBool
+constructHook(JSContext *cx, JSObject *thisobj, uintN argc, jsval *argv, jsval *rval)
+{
+    // Check that arguments were passed properly from JS_New.
+    JSObject *callee = JSVAL_TO_OBJECT(JS_ARGV_CALLEE(argv));
+    if (!thisobj) {
+        JS_ReportError(cx, "test failed, null 'this'");
+        return false;
+    }
+    if (strcmp(JS_GET_CLASS(cx, thisobj)->name, "Object") != 0) {
+        JS_ReportError(cx, "test failed, wrong class for 'this'");
+        return false;
+    }
+    if (argc != 3) {
+        JS_ReportError(cx, "test failed, argc == %d", argc);
+        return false;
+    }
+    if (!JSVAL_IS_INT(argv[2]) || JSVAL_TO_INT(argv[2]) != 2) {
+        JS_ReportError(cx, "test failed, wrong value in argv[2]");
+        return false;
+    }
+    if (!JS_IsConstructing(cx)) {
+        JS_ReportError(cx, "test failed, not constructing");
+        return false;
+    }
+
+    // Perform a side-effect to indicate that this hook was actually called.
+    if (!JS_SetElement(cx, callee, 0, &argv[0]))
+        return false;
+
+    *rval = OBJECT_TO_JSVAL(callee); // return the callee, perversely
+    argv[0] = argv[1] = argv[2] = JSVAL_VOID;  // trash the argv, perversely
+    return true;
+}
+
+BEGIN_TEST(testNewObject_1)
+{
+    jsval v;
+    EVAL("Array", &v);
+    JSObject *Array = JSVAL_TO_OBJECT(v);
+
+    // With no arguments.
+    JSObject *obj = JS_New(cx, Array, 0, NULL);
+    CHECK(obj);
+    jsvalRoot rt(cx, OBJECT_TO_JSVAL(obj));
+    CHECK(JS_IsArrayObject(cx, obj));
+    jsuint len;
+    CHECK(JS_GetArrayLength(cx, obj, &len));
+    CHECK(len == 0);
+
+    // With one argument.
+    argv[0] = INT_TO_JSVAL(4);
+    obj = JS_New(cx, Array, 1, argv);
+    CHECK(obj);
+    rt = OBJECT_TO_JSVAL(obj);
+    CHECK(JS_IsArrayObject(cx, obj));
+    CHECK(JS_GetArrayLength(cx, obj, &len));
+    CHECK(len == 4);
+
+    // With N arguments.
+    JS_ASSERT(INT_FITS_IN_JSVAL(N));
+    for (int i = 0; i < N; i++)
+        argv[i] = INT_TO_JSVAL(i);
+    obj = JS_New(cx, Array, N, argv);
+    CHECK(obj);
+    rt = OBJECT_TO_JSVAL(obj);
+    CHECK(JS_IsArrayObject(cx, obj));
+    CHECK(JS_GetArrayLength(cx, obj, &len));
+    CHECK(len == N);
+    CHECK(JS_GetElement(cx, obj, N - 1, &v));
+    CHECK_SAME(v, INT_TO_JSVAL(N - 1));
+
+    // With JSClass.construct.
+    static JSClass cls = {
+        "testNewObject_1",
+        0,
+        JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, JS_PropertyStub,
+        JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, NULL,
+        NULL, NULL, NULL, constructHook, NULL, NULL, NULL, NULL
+    };
+    JSObject *ctor = JS_NewObject(cx, &cls, NULL, NULL);
+    CHECK(ctor);
+    jsvalRoot rt2(cx, OBJECT_TO_JSVAL(ctor));
+    obj = JS_New(cx, ctor, 3, argv);
+    CHECK(obj);
+    CHECK(obj == ctor);  // constructHook returns ctor, perversely
+    CHECK(JS_GetElement(cx, ctor, 0, &v));
+    CHECK_SAME(v, JSVAL_ZERO);
+    CHECK_SAME(argv[0], JSVAL_ZERO);  // original argv should not have been trashed
+    CHECK_SAME(argv[1], JSVAL_ONE);
+}
+END_TEST(testNewObject_1)

js/src/jsapi.cpp

@@ -4953,6 +4953,31 @@ JS_CallFunctionValue(JSContext *cx, JSObject *obj, jsval fval, uintN argc,
     return ok;
 }
 
+JS_PUBLIC_API(JSObject *)
+JS_New(JSContext *cx, JSObject *ctor, uintN argc, jsval *argv)
+{
+    CHECK_REQUEST(cx);
+
+    // This is not a simple variation of JS_CallFunctionValue because JSOP_NEW
+    // is not a simple variation of JSOP_CALL. We have to determine what class
+    // of object to create, create it, and clamp the return value to an object,
+    // among other details. js_InvokeConstructor does the hard work.
+    void *mark;
+    jsval *vp = js_AllocStack(cx, 2 + argc, &mark);
+    if (!vp)
+        return NULL;
+    vp[0] = OBJECT_TO_JSVAL(ctor);
+    vp[1] = JSVAL_NULL;
+    memcpy(vp + 2, argv, argc * sizeof(jsval));
+
+    JSBool ok = js_InvokeConstructor(cx, argc, JS_TRUE, vp);
+    JSObject *obj = ok ? JSVAL_TO_OBJECT(vp[0]) : NULL;
+
+    js_FreeStack(cx, mark);
+    LAST_FRAME_CHECKS(cx, ok);
+    return obj;
+}
+
 JS_PUBLIC_API(JSOperationCallback)
 JS_SetOperationCallback(JSContext *cx, JSOperationCallback callback)
 {

js/src/jsapi.h

@@ -1678,6 +1678,9 @@ extern JS_PUBLIC_API(JSObject *)
 JS_ConstructObjectWithArguments(JSContext *cx, JSClass *clasp, JSObject *proto,
                                 JSObject *parent, uintN argc, jsval *argv);
 
+extern JS_PUBLIC_API(JSObject *)
+JS_New(JSContext *cx, JSObject *ctor, uintN argc, jsval *argv);
+
 extern JS_PUBLIC_API(JSObject *)
 JS_DefineObject(JSContext *cx, JSObject *obj, const char *name, JSClass *clasp,
                 JSObject *proto, uintN attrs);