Bug 1066234 - Part 5: Implement JSOP_OBJWITHPROTO. (r=jorendorff)

js/src/vm/Interpreter.cpp

@@ -1650,7 +1650,6 @@ CASE(EnableInterruptsPseudoOpcode)
 /* Various 1-byte no-ops. */
 CASE(JSOP_NOP)
 CASE(JSOP_UNUSED2)
-CASE(JSOP_UNUSED83)
 CASE(JSOP_UNUSED92)
 CASE(JSOP_UNUSED103)
 CASE(JSOP_UNUSED104)
@@ -3576,6 +3575,19 @@ CASE(JSOP_FUNWITHPROTO)
 }
 END_CASE(JSOP_FUNWITHPROTO)
 
+CASE(JSOP_OBJWITHPROTO)
+{
+    RootedObject &proto = rootObject0;
+    proto = REGS.sp[-1].toObjectOrNull();
+
+    JSObject *obj = NewObjectWithGivenProto<PlainObject>(cx, proto, cx->global());
+    if (!obj)
+        goto error;
+
+    REGS.sp[-1].setObject(*obj);
+}
+END_CASE(JSOP_OBJWITHPROTO)
+
 DEFAULT()
 {
     char numBuf[12];

js/src/vm/Opcodes.h

@@ -768,8 +768,15 @@
      *   nuses: (argc+2)
      */ \
     macro(JSOP_NEW,       82, js_new_str,   NULL,         3, -1,  1,  JOF_UINT16|JOF_INVOKE|JOF_TYPESET) \
-    \
-    macro(JSOP_UNUSED83,  83, "unused83",   NULL,         1,  0,  0,  JOF_BYTE) \
+    /*
+     * Pushes newly created object onto the stack with provided [[Prototype]].
+     *
+     *   Category: Literals
+     *   Type: Object
+     *   Operands:
+     *   Stack: proto => obj
+     */ \
+    macro(JSOP_OBJWITHPROTO,  83, "objwithproto",   NULL,         1,  1,  1,  JOF_BYTE) \
     \
     /*
      * Fast get op for function arguments and local variables.

js/src/vm/Xdr.h

@@ -29,7 +29,7 @@ namespace js {
  *
  *  https://developer.mozilla.org/en-US/docs/SpiderMonkey/Internals/Bytecode
  */
-static const uint32_t XDR_BYTECODE_VERSION_SUBTRAHEND = 254;
+static const uint32_t XDR_BYTECODE_VERSION_SUBTRAHEND = 255;
 static const uint32_t XDR_BYTECODE_VERSION =
     uint32_t(0xb973c0de - XDR_BYTECODE_VERSION_SUBTRAHEND);