Revert of Add web compat workarounds for ES2015 RegExp semantics (patchset #3...

Revert of Add web compat workarounds for ES2015 RegExp semantics (patchset #3 id:40001 of https://codereview.chromium.org/1543723002/ )

Reason for revert:
Breaks nosnap: http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap/builds/5883

Original issue's description:
> Add web compat workarounds for ES2015 RegExp semantics
>
> Unexpectedly, websites depend on doing feature testing with
> RegExp.prototype.sticky and browser testing with RegExp.prototype.toString().
> ES2015 newly throws exceptions for both of these. In order to enable shipping
> new ES2015 semantics, this patch puts in narrow workarounds for those two
> cases, keeping their old behavior. UseCounters are added for how often
> those particular cases come up, so we can see if it can be deprecated.
>
> R=yangguo
> BUG=v8:4637,v8:4617
> LOG=Y
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/98f819c3e0c92d54a306cdacadda73cf96d21b52
> Cr-Commit-Position: refs/heads/master@{#32997}

TBR=yangguo@google.com,yangguo@chromium.org,littledan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4637,v8:4617

Review URL: https://codereview.chromium.org/1546493003

Cr-Commit-Position: refs/heads/master@{#32999}

include/v8.h

@@ -5411,8 +5411,6 @@ class V8_EXPORT Isolate {
     kSloppyMode = 8,
     kStrictMode = 9,
     kStrongMode = 10,
-    kRegExpPrototypeStickyGetter = 11,
-    kRegExpPrototypeToString = 12,
     kUseCounterFeatureCount  // This enum value must be last.
   };
 

src/js/harmony-regexp.js

@@ -12,7 +12,6 @@
 // Imports
 
 var GlobalRegExp = global.RegExp;
-var GlobalRegExpPrototype = GlobalRegExp.prototype;
 var MakeTypeError;
 var regExpFlagsSymbol = utils.ImportNow("regexp_flags_symbol");
 
@@ -38,17 +37,10 @@ function RegExpGetFlags() {
   return result;
 }
 
-const kRegExpPrototypeStickyGetter = 11;
 
 // ES6 21.2.5.12.
 function RegExpGetSticky() {
   if (!IS_REGEXP(this)) {
-    // Compat fix: RegExp.prototype.sticky == undefined; UseCounter tracks it
-    // TODO(littledan): Remove this workaround or standardize it
-    if (this === GlobalRegExpPrototype) {
-      %IncrementUseCounter(kRegExpPrototypeStickyGetter);
-      return UNDEFINED;
-    }
     throw MakeTypeError(kRegExpNonRegExp, "RegExp.prototype.sticky");
   }
   return !!REGEXP_STICKY(this);

src/js/regexp.js

@@ -270,17 +270,8 @@ function TrimRegExp(regexp) {
 }
 
 
-const kRegExpPrototypeToString = 12;
-
 function RegExpToString() {
   if (!IS_REGEXP(this)) {
-    // RegExp.prototype.toString() returns '/(?:)/' as a compatibility fix;
-    // a UseCounter is incremented to track it.
-    // TODO(littledan): Remove this workaround or standardize it
-    if (this === GlobalRegExpPrototype) {
-      %IncrementUseCounter(kRegExpPrototypeToString);
-      return '/(?:)/';
-    }
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'RegExp.prototype.toString', this);
   }
@@ -500,8 +491,7 @@ function RegExpGetSource() {
 // -------------------------------------------------------------------
 
 %FunctionSetInstanceClassName(GlobalRegExp, 'RegExp');
-const GlobalRegExpPrototype = new GlobalObject();
-%FunctionSetPrototype(GlobalRegExp, GlobalRegExpPrototype);
+%FunctionSetPrototype(GlobalRegExp, new GlobalObject());
 %AddNamedProperty(
     GlobalRegExp.prototype, 'constructor', GlobalRegExp, DONT_ENUM);
 %SetCode(GlobalRegExp, RegExpConstructor);

src/runtime/runtime-internal.cc

@@ -460,14 +460,5 @@ RUNTIME_FUNCTION(Runtime_CreateListFromArrayLike) {
   return *result;
 }
 
-
-RUNTIME_FUNCTION(Runtime_IncrementUseCounter) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_SMI_ARG_CHECKED(counter, 0);
-  isolate->CountUsage(static_cast<v8::Isolate::UseCounterFeature>(counter));
-  return isolate->heap()->undefined_value();
-}
-
 }  // namespace internal
 }  // namespace v8

src/runtime/runtime.h

@@ -346,8 +346,7 @@ namespace internal {
   F(IncrementStatsCounter, 1, 1)              \
   F(ThrowConstructedNonConstructable, 1, 1)   \
   F(ThrowCalledNonCallable, 1, 1)             \
-  F(CreateListFromArrayLike, 1, 1)            \
-  F(IncrementUseCounter, 1, 1)
+  F(CreateListFromArrayLike, 1, 1)
 
 
 #define FOR_EACH_INTRINSIC_JSON(F) \

test/cctest/test-regexp.cc

@@ -28,7 +28,6 @@
 #include <cstdlib>
 #include <sstream>
 
-#include "include/v8.h"
 #include "src/v8.h"
 
 #include "src/ast/ast.h"
@@ -1848,82 +1847,3 @@ TEST(CharacterRangeMerge) {
 TEST(Graph) {
   Execute("\\b\\w+\\b", false, true, true);
 }
-
-
-namespace {
-
-int* global_use_counts = NULL;
-
-void MockUseCounterCallback(v8::Isolate* isolate,
-                            v8::Isolate::UseCounterFeature feature) {
-  ++global_use_counts[feature];
-}
-}
-
-
-// Test that ES2015 RegExp compatibility fixes are in place, that they
-// are not overly broad, and the appropriate UseCounters are incremented
-TEST(UseCountRegExp) {
-  i::FLAG_harmony_regexps = true;
-  v8::Isolate* isolate = CcTest::isolate();
-  v8::HandleScope scope(isolate);
-  LocalContext env;
-  int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
-  global_use_counts = use_counts;
-  CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
-
-  // Compat fix: RegExp.prototype.sticky == undefined; UseCounter tracks it
-  v8::Local<v8::Value> resultSticky = CompileRun("RegExp.prototype.sticky");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(0, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultSticky->IsUndefined());
-
-  // re.sticky has approriate value and doesn't touch UseCounter
-  v8::Local<v8::Value> resultReSticky = CompileRun("/a/.sticky");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(0, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultReSticky->IsFalse());
-
-  // When the getter is caleld on another object, throw an exception
-  // and don't increment the UseCounter
-  v8::Local<v8::Value> resultStickyError = CompileRun(
-      "var exception;"
-      "try { "
-      "  Object.getOwnPropertyDescriptor(RegExp.prototype, 'sticky')"
-      "      .get.call(null);"
-      "} catch (e) {"
-      "  exception = e;"
-      "}"
-      "exception");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(0, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultStickyError->IsObject());
-
-  // RegExp.prototype.toString() returns '/(?:)/' as a compatibility fix;
-  // a UseCounter is incremented to track it.
-  v8::Local<v8::Value> resultToString =
-      CompileRun("RegExp.prototype.toString().length");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultToString->IsInt32());
-  CHECK_EQ(6,
-           resultToString->Int32Value(isolate->GetCurrentContext()).FromJust());
-
-  // .toString() works on normal RegExps
-  v8::Local<v8::Value> resultReToString = CompileRun("/a/.toString().length");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultReToString->IsInt32());
-  CHECK_EQ(
-      3, resultReToString->Int32Value(isolate->GetCurrentContext()).FromJust());
-
-  // .toString() throws on non-RegExps that aren't RegExp.prototype
-  v8::Local<v8::Value> resultToStringError = CompileRun(
-      "var exception;"
-      "try { RegExp.prototype.toString.call(null) }"
-      "catch (e) { exception = e; }"
-      "exception");
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
-  CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeToString]);
-  CHECK(resultToStringError->IsObject());
-}

test/mjsunit/es6/regexp-flags.js

@@ -50,11 +50,7 @@ assertEquals(4, get_count);
 
 
 function testName(name) {
-  if (name === "sticky") {
-    assertEquals(undefined, RegExp.prototype[name]);
-  } else {
-    assertThrows(() => RegExp.prototype[name], TypeError);
-  }
+  assertThrows(() => RegExp.prototype[name], TypeError);
   assertEquals(
       "get " + name,
       Object.getOwnPropertyDescriptor(RegExp.prototype, name).get.name);

test/webkit/fast/js/kde/RegExp-expected.txt

@@ -114,7 +114,7 @@ PASS str.match(/d/gi).toString() is 'D,d'
 PASS /\u0061/.source is '\\u0061'
 PASS 'abc'.match(/\u0062/).toString() is 'b'
 FAIL Object.prototype.toString.apply(RegExp.prototype) should be [object RegExp]. Was [object Object].
-PASS typeof RegExp.prototype.toString() is 'string'
+FAIL typeof RegExp.prototype.toString() should be string. Threw exception TypeError: Method RegExp.prototype.toString called on incompatible receiver [object Object]
 PASS new RegExp().toString() is '/(?:)/'
 PASS (new RegExp('(?:)')).source is '(?:)'
 PASS /(?:)/.toString() is '/(?:)/'

test/webkit/fast/regex/toString-expected.txt

@@ -31,7 +31,7 @@ PASS RegExp('').source is "(?:)"
 FAIL RegExp.prototype.source should be (?:). Threw exception TypeError: RegExp.prototype.source getter called on non-RegExp object
 PASS RegExp('/').toString() is "/\\//"
 PASS RegExp('').toString() is "/(?:)/"
-PASS RegExp.prototype.toString() is "/(?:)/"
+FAIL RegExp.prototype.toString() should be /(?:)/. Threw exception TypeError: Method RegExp.prototype.toString called on incompatible receiver [object Object]
 PASS testForwardSlash("^/$", "/"); is true
 PASS testForwardSlash("^/$", "/"); is true
 PASS testForwardSlash("^\/$", "/"); is true