[proxies] Better print for proxies in d8

Function proxies would not be printed so far since they ended up in Function.prototype.toString which only works with Function as a receiver but no Proxy. Additionally added support for more gracefully dealing with recursive __proto__ structures introduced by proxies.

BUG=v8:1543
LOG=n

Review URL: https://codereview.chromium.org/1530293004

Cr-Commit-Position: refs/heads/master@{#32985}

src/d8.js

@@ -13,6 +13,9 @@ function Stringify(x, depth) {
     depth = stringifyDepthLimit;
   else if (depth === 0)
     return "*";
+  if (IS_PROXY(x)) {
+    return StringifyProxy(x, depth);
+  }
   switch (typeof x) {
     case "undefined":
       return "undefined";
@@ -26,40 +29,56 @@ function Stringify(x, depth) {
       return x.toString();
     case "object":
       if (IS_NULL(x)) return "null";
-      if (x.constructor && x.constructor.name === "Array") {
-        var elems = [];
-        for (var i = 0; i < x.length; ++i) {
-          elems.push(
-            {}.hasOwnProperty.call(x, i) ? Stringify(x[i], depth - 1) : "");
-        }
-        return "[" + elems.join(", ") + "]";
-      }
       try {
-        var string = String(x);
-        if (string && string !== "[object Object]") return string;
-      } catch(e) {}
-      var props = [];
-      var names = Object.getOwnPropertyNames(x);
-      names = names.concat(Object.getOwnPropertySymbols(x));
-      for (var i in names) {
-        var name = names[i];
-        var desc = Object.getOwnPropertyDescriptor(x, name);
-        if (IS_UNDEFINED(desc)) continue;
-        if (IS_SYMBOL(name)) name = "[" + Stringify(name) + "]";
-        if ("value" in desc) {
-          props.push(name + ": " + Stringify(desc.value, depth - 1));
-        }
-        if (desc.get) {
-          var getter = Stringify(desc.get);
-          props.push("get " + name + getter.slice(getter.indexOf('(')));
-        }
-        if (desc.set) {
-          var setter = Stringify(desc.set);
-          props.push("set " + name + setter.slice(setter.indexOf('(')));
-        }
+        return StringifyObject(x, depth);
+      } catch(RangeError) {
+        return "{*}"
       }
-      return "{" + props.join(", ") + "}";
     default:
       return "[crazy non-standard value]";
   }
 }
+
+function StringifyObject(x, depth) {
+  if (x.constructor && x.constructor.name === "Array") {
+    var elems = [];
+    for (var i = 0; i < x.length; ++i) {
+      elems.push(
+        {}.hasOwnProperty.call(x, i) ? Stringify(x[i], depth - 1) : "");
+    }
+    return "[" + elems.join(", ") + "]";
+  }
+  try {
+    var string = String(x);
+    if (string && string !== "[object Object]") return string;
+  } catch(e) {}
+  var props = [];
+  var names = Object.getOwnPropertyNames(x);
+  names = names.concat(Object.getOwnPropertySymbols(x));
+  for (var i in names) {
+    var name = names[i];
+    var desc = Object.getOwnPropertyDescriptor(x, name);
+    if (IS_UNDEFINED(desc)) continue;
+    if (IS_SYMBOL(name)) name = "[" + Stringify(name) + "]";
+    if ("value" in desc) {
+      props.push(name + ": " + Stringify(desc.value, depth - 1));
+    }
+    if (desc.get) {
+      var getter = Stringify(desc.get);
+      props.push("get " + name + getter.slice(getter.indexOf('(')));
+    }
+    if (desc.set) {
+      var setter = Stringify(desc.set);
+      props.push("set " + name + setter.slice(setter.indexOf('(')));
+    }
+  }
+  return "{" + props.join(", ") + "}";
+}
+
+function StringifyProxy(proxy, depth) {
+  var proxy_type = typeof proxy;
+  return '[' + proxy_type + ' Proxy ' + Stringify({
+    target: %JSProxyGetTarget(proxy),
+    handler: %JSProxyGetHandler(proxy)
+  }, depth-1) + ']';
+}

src/js/collection.js

@@ -100,7 +100,7 @@ function GetExistingHash(key) {
     if ((field & 1 /* Name::kHashNotComputedMask */) === 0) {
       return field >>> 2 /* Name::kHashShift */;
     }
-  } else if (IS_RECEIVER(key) && !%_IsJSProxy(key) && !IS_GLOBAL(key)) {
+  } else if (IS_RECEIVER(key) && !IS_PROXY(key) && !IS_GLOBAL(key)) {
     var hash = GET_PRIVATE(key, hashCodeSymbol);
     return hash;
   }

src/js/json.js

@@ -188,7 +188,7 @@ function JSONSerialize(key, holder, replacer, stack, indent, gap) {
 
 
 function JSONStringify(value, replacer, space) {
-  if (%_ArgumentsLength() == 1 && !%_IsJSProxy(value)) {
+  if (%_ArgumentsLength() == 1 && !IS_PROXY(value)) {
     return %BasicJSONStringify(value);
   }
   if (!IS_CALLABLE(replacer) && %is_arraylike(replacer)) {

src/js/macros.py

@@ -88,37 +88,38 @@ define STRING_TO_REGEXP_CACHE_ID = 0;
 # Note: We have special support for typeof(foo) === 'bar' in the compiler.
 #       It will *not* generate a runtime typeof call for the most important
 #       values of 'bar'.
-macro IS_NULL(arg)              = (arg === null);
-macro IS_NULL_OR_UNDEFINED(arg) = (arg == null);
-macro IS_UNDEFINED(arg)         = (arg === (void 0));
-macro IS_NUMBER(arg)            = (typeof(arg) === 'number');
-macro IS_STRING(arg)            = (typeof(arg) === 'string');
-macro IS_BOOLEAN(arg)           = (typeof(arg) === 'boolean');
-macro IS_SYMBOL(arg)            = (typeof(arg) === 'symbol');
-macro IS_OBJECT(arg)            = (typeof(arg) === 'object');
 macro IS_ARRAY(arg)             = (%_IsArray(arg));
+macro IS_ARRAYBUFFER(arg)       = (%_ClassOf(arg) === 'ArrayBuffer');
+macro IS_BOOLEAN(arg)           = (typeof(arg) === 'boolean');
+macro IS_BOOLEAN_WRAPPER(arg)   = (%_ClassOf(arg) === 'Boolean');
+macro IS_DATAVIEW(arg)          = (%_ClassOf(arg) === 'DataView');
 macro IS_DATE(arg)              = (%_IsDate(arg));
+macro IS_ERROR(arg)             = (%_ClassOf(arg) === 'Error');
 macro IS_FUNCTION(arg)          = (%_IsFunction(arg));
-macro IS_REGEXP(arg)            = (%_IsRegExp(arg));
-macro IS_SIMD_VALUE(arg)        = (%_IsSimdValue(arg));
-macro IS_SET(arg)               = (%_ClassOf(arg) === 'Set');
+macro IS_GENERATOR(arg)         = (%_ClassOf(arg) === 'Generator');
+macro IS_GLOBAL(arg)            = (%_ClassOf(arg) === 'global');
 macro IS_MAP(arg)               = (%_ClassOf(arg) === 'Map');
-macro IS_WEAKMAP(arg)           = (%_ClassOf(arg) === 'WeakMap');
-macro IS_WEAKSET(arg)           = (%_ClassOf(arg) === 'WeakSet');
+macro IS_MAP_ITERATOR(arg)      = (%_ClassOf(arg) === 'Map Iterator');
+macro IS_NULL(arg)              = (arg === null);
+macro IS_NULL_OR_UNDEFINED(arg) = (arg == null);
+macro IS_NUMBER(arg)            = (typeof(arg) === 'number');
 macro IS_NUMBER_WRAPPER(arg)    = (%_ClassOf(arg) === 'Number');
-macro IS_STRING_WRAPPER(arg)    = (%_ClassOf(arg) === 'String');
-macro IS_SYMBOL_WRAPPER(arg)    = (%_ClassOf(arg) === 'Symbol');
-macro IS_BOOLEAN_WRAPPER(arg)   = (%_ClassOf(arg) === 'Boolean');
-macro IS_ERROR(arg)             = (%_ClassOf(arg) === 'Error');
+macro IS_OBJECT(arg)            = (typeof(arg) === 'object');
+macro IS_PROXY(arg)             = (%_IsJSProxy(arg));
+macro IS_REGEXP(arg)            = (%_IsRegExp(arg));
 macro IS_SCRIPT(arg)            = (%_ClassOf(arg) === 'Script');
-macro IS_GLOBAL(arg)            = (%_ClassOf(arg) === 'global');
-macro IS_ARRAYBUFFER(arg)       = (%_ClassOf(arg) === 'ArrayBuffer');
-macro IS_DATAVIEW(arg)          = (%_ClassOf(arg) === 'DataView');
-macro IS_SHAREDARRAYBUFFER(arg) = (%_ClassOf(arg) === 'SharedArrayBuffer');
-macro IS_GENERATOR(arg)         = (%_ClassOf(arg) === 'Generator');
+macro IS_SET(arg)               = (%_ClassOf(arg) === 'Set');
 macro IS_SET_ITERATOR(arg)      = (%_ClassOf(arg) === 'Set Iterator');
-macro IS_MAP_ITERATOR(arg)      = (%_ClassOf(arg) === 'Map Iterator');
+macro IS_SHAREDARRAYBUFFER(arg) = (%_ClassOf(arg) === 'SharedArrayBuffer');
+macro IS_SIMD_VALUE(arg)        = (%_IsSimdValue(arg));
+macro IS_STRING(arg)            = (typeof(arg) === 'string');
+macro IS_STRING_WRAPPER(arg)    = (%_ClassOf(arg) === 'String');
 macro IS_STRONG(arg)            = (%IsStrong(arg));
+macro IS_SYMBOL(arg)            = (typeof(arg) === 'symbol');
+macro IS_SYMBOL_WRAPPER(arg)    = (%_ClassOf(arg) === 'Symbol');
+macro IS_UNDEFINED(arg)         = (arg === (void 0));
+macro IS_WEAKMAP(arg)           = (%_ClassOf(arg) === 'WeakMap');
+macro IS_WEAKSET(arg)           = (%_ClassOf(arg) === 'WeakSet');
 
 # Macro for ES queries of the type: "Type(O) is Object."
 macro IS_RECEIVER(arg) = (%_IsJSReceiver(arg));

src/js/messages.js

@@ -843,7 +843,7 @@ function FormatStackTrace(obj, raw_stack) {
 
 function GetTypeName(receiver, requireConstructor) {
   if (IS_NULL_OR_UNDEFINED(receiver)) return null;
-  if (%_IsJSProxy(receiver)) return "Proxy";
+  if (IS_PROXY(receiver)) return "Proxy";
 
   var constructor = %GetDataProperty(TO_OBJECT(receiver), "constructor");
   if (!IS_FUNCTION(constructor)) {

src/js/object-observe.js

@@ -192,7 +192,7 @@ function ObserverIsActive(observer, objectInfo) {
 function ObjectInfoGetOrCreate(object) {
   var objectInfo = ObjectInfoGet(object);
   if (IS_UNDEFINED(objectInfo)) {
-    if (!%_IsJSProxy(object)) {
+    if (!IS_PROXY(object)) {
       %SetIsObserved(object);
     }
     objectInfo = {

src/js/proxy.js

@@ -22,7 +22,7 @@ utils.Import(function(from) {
 
 function ProxyCreateRevocable(target, handler) {
   var p = new GlobalProxy(target, handler);
-  return {proxy: p, revoke: () => %RevokeProxy(p)};
+  return {proxy: p, revoke: () => %JSProxyRevoke(p)};
 }
 
 // -------------------------------------------------------------------

src/js/v8natives.js

@@ -500,11 +500,11 @@ function CallTrap2(handler, name, defaultTrap, x, y) {
 // ObjectGetOwnPropertyDescriptor and delete this.
 function GetOwnPropertyJS(obj, v) {
   var p = TO_NAME(v);
-  if (%_IsJSProxy(obj)) {
+  if (IS_PROXY(obj)) {
     // TODO(rossberg): adjust once there is a story for symbols vs proxies.
     if (IS_SYMBOL(v)) return UNDEFINED;
 
-    var handler = %GetHandler(obj);
+    var handler = %JSProxyGetHandler(obj);
     var descriptor = CallTrap1(
                          handler, "getOwnPropertyDescriptor", UNDEFINED, p);
     if (IS_UNDEFINED(descriptor)) return descriptor;
@@ -538,7 +538,7 @@ function DefineProxyProperty(obj, p, attributes, should_throw) {
   // TODO(rossberg): adjust once there is a story for symbols vs proxies.
   if (IS_SYMBOL(p)) return false;
 
-  var handler = %GetHandler(obj);
+  var handler = %JSProxyGetHandler(obj);
   var result = CallTrap2(handler, "defineProperty", UNDEFINED, p, attributes);
   if (!result) {
     if (should_throw) {
@@ -761,7 +761,7 @@ function DefineArrayProperty(obj, p, desc, should_throw) {
 
 // ES5 section 8.12.9, ES5 section 15.4.5.1 and Harmony proxies.
 function DefineOwnProperty(obj, p, desc, should_throw) {
-  if (%_IsJSProxy(obj)) {
+  if (IS_PROXY(obj)) {
     // TODO(rossberg): adjust once there is a story for symbols vs proxies.
     if (IS_SYMBOL(p)) return false;
 

src/runtime/runtime-proxy.cc

@@ -149,7 +149,7 @@ RUNTIME_FUNCTION(Runtime_IsJSProxy) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_GetHandler) {
+RUNTIME_FUNCTION(Runtime_JSProxyGetHandler) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
@@ -157,7 +157,15 @@ RUNTIME_FUNCTION(Runtime_GetHandler) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_RevokeProxy) {
+RUNTIME_FUNCTION(Runtime_JSProxyGetTarget) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
+  return proxy->target();
+}
+
+
+RUNTIME_FUNCTION(Runtime_JSProxyRevoke) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSProxy, proxy, 0);

src/runtime/runtime.h

@@ -543,8 +543,9 @@ namespace internal {
   F(IsJSProxy, 1, 1)                    \
   F(JSProxyCall, -1 /* >= 2 */, 1)      \
   F(JSProxyConstruct, -1 /* >= 3 */, 1) \
-  F(GetHandler, 1, 1)                   \
-  F(RevokeProxy, 1, 1)
+  F(JSProxyGetTarget, 1, 1)             \
+  F(JSProxyGetHandler, 1, 1)            \
+  F(JSProxyRevoke, 1, 1)
 
 #define FOR_EACH_INTRINSIC_REGEXP(F)           \
   F(StringReplaceGlobalRegExpWithString, 4, 1) \