[parsing/runtime] Remove InitializeVarGlobal

Change-Id: I2ee0ff9db1bbc8c17a1ad3dea1de1ad996895852
Reviewed-on: https://chromium-review.googlesource.com/474807Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46338}

src/parsing/pattern-rewriter.cc

@@ -191,42 +191,6 @@ void Parser::PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   // 'with' statement or 'catch' block). Global var declarations
   // also need special treatment.
 
-  if (descriptor_->mode == VAR && var_init_scope->is_script_scope()) {
-    // Global variable declarations must be compiled in a specific
-    // way. When the script containing the global variable declaration
-    // is entered, the global variable must be declared, so that if it
-    // doesn't exist (on the global object itself, see ES5 errata) it
-    // gets created with an initial undefined value. This is handled
-    // by the declarations part of the function representing the
-    // top-level global code; see Runtime::DeclareGlobalVariable. If
-    // it already exists (in the object or in a prototype), it is
-    // *not* touched until the variable declaration statement is
-    // executed.
-    //
-    // Executing the variable declaration statement will always
-    // guarantee to give the global object an own property.
-    // This way, global variable declarations can shadow
-    // properties in the prototype chain, but only after the variable
-    // declaration statement has been executed. This is important in
-    // browsers where the global object (window) has lots of
-    // properties defined in prototype objects.
-
-    ZoneList<Expression*>* arguments =
-        new (zone()) ZoneList<Expression*>(3, zone());
-    arguments->Add(
-        factory()->NewStringLiteral(name, descriptor_->declaration_pos),
-        zone());
-    arguments->Add(factory()->NewNumberLiteral(var_init_scope->language_mode(),
-                                               kNoSourcePosition),
-                   zone());
-    arguments->Add(value, zone());
-
-    CallRuntime* initialize = factory()->NewCallRuntime(
-        Runtime::kInitializeVarGlobal, arguments, value->position());
-    block_->statements()->Add(
-        factory()->NewExpressionStatement(initialize, initialize->position()),
-        zone());
-  } else {
   // For 'let' and 'const' declared variables the initialization always
   // assigns to the declared variable.
   // But for var declarations we need to do a new lookup.
@@ -243,9 +207,8 @@ void Parser::PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   }
   Assignment* assignment =
       factory()->NewAssignment(Token::INIT, proxy, value, pos);
-    block_->statements()->Add(
-        factory()->NewExpressionStatement(assignment, pos), zone());
-  }
+  block_->statements()->Add(factory()->NewExpressionStatement(assignment, pos),
+                            zone());
 }
 
 

src/runtime/runtime-scopes.cc

@@ -211,18 +211,6 @@ RUNTIME_FUNCTION(Runtime_DeclareGlobalsForInterpreter) {
   return DeclareGlobals(isolate, declarations, flags, feedback_vector);
 }
 
-RUNTIME_FUNCTION(Runtime_InitializeVarGlobal) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
-  CONVERT_LANGUAGE_MODE_ARG_CHECKED(language_mode, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
-
-  Handle<JSGlobalObject> global(isolate->global_object());
-  RETURN_RESULT_OR_FAILURE(
-      isolate, Object::SetProperty(global, name, value, language_mode));
-}
-
 namespace {
 
 Object* DeclareEvalHelper(Isolate* isolate, Handle<String> name,

src/runtime/runtime.h

@@ -505,7 +505,6 @@ namespace internal {
   F(ThrowConstAssignError, 0, 1)          \
   F(DeclareGlobals, 3, 1)                 \
   F(DeclareGlobalsForInterpreter, 3, 1)   \
-  F(InitializeVarGlobal, 3, 1)            \
   F(DeclareEvalFunction, 2, 1)            \
   F(DeclareEvalVar, 1, 1)                 \
   F(NewSloppyArguments_Generic, 1, 1)     \

test/cctest/interpreter/bytecode_expectations/DeclareGlobals.golden

@@ -12,7 +12,7 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 23
 bytecodes: [
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -21,13 +21,8 @@ bytecodes: [
                 B(Mov), R(closure), R(3),
                 B(CallRuntime), U16(Runtime::kDeclareGlobalsForInterpreter), R(1), U8(3),
   /*    0 E> */ B(StackCheck),
-  /*    8 S> */ B(LdaConstant), U8(1),
-                B(Star), R(1),
-                B(LdaZero),
-                B(Star), R(2),
-                B(LdaSmi), I8(1),
-                B(Star), R(3),
-                B(CallRuntime), U16(Runtime::kInitializeVarGlobal), R(1), U8(3),
+  /*    8 S> */ B(LdaSmi), I8(1),
+  /*    8 E> */ B(StaGlobalSloppy), U8(1), U8(5),
                 B(LdaUndefined),
   /*   10 S> */ B(Return),
 ]
@@ -69,7 +64,7 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 40
+bytecode array length: 29
 bytecodes: [
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -78,15 +73,10 @@ bytecodes: [
                 B(Mov), R(closure), R(3),
                 B(CallRuntime), U16(Runtime::kDeclareGlobalsForInterpreter), R(1), U8(3),
   /*    0 E> */ B(StackCheck),
-  /*    8 S> */ B(LdaConstant), U8(1),
-                B(Star), R(1),
-                B(LdaZero),
-                B(Star), R(2),
-                B(LdaSmi), I8(1),
-                B(Star), R(3),
-                B(CallRuntime), U16(Runtime::kInitializeVarGlobal), R(1), U8(3),
+  /*    8 S> */ B(LdaSmi), I8(1),
+  /*    8 E> */ B(StaGlobalSloppy), U8(1), U8(5),
   /*   11 S> */ B(LdaSmi), I8(2),
-  /*   12 E> */ B(StaGlobalSloppy), U8(1), U8(5),
+  /*   12 E> */ B(StaGlobalSloppy), U8(1), U8(7),
                 B(Star), R(0),
   /*   15 S> */ B(Return),
 ]

test/cctest/interpreter/bytecode_expectations/TopLevelObjectLiterals.golden

@@ -12,7 +12,7 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 43
+bytecode array length: 36
 bytecodes: [
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -21,23 +21,20 @@ bytecodes: [
                 B(Mov), R(closure), R(3),
                 B(CallRuntime), U16(Runtime::kDeclareGlobalsForInterpreter), R(1), U8(3),
   /*    0 E> */ B(StackCheck),
-  /*    8 S> */ B(LdaConstant), U8(1),
-                B(Star), R(1),
-                B(LdaZero),
-                B(CreateObjectLiteral), U8(2), U8(6), U8(21), R(3),
-                B(Star), R(2),
-                B(CreateClosure), U8(3), U8(5), U8(0),
-                B(StaNamedOwnProperty), R(3), U8(4), U8(7),
-                B(CallRuntime), U16(Runtime::kInitializeVarGlobal), R(1), U8(3),
+  /*    8 S> */ B(CreateObjectLiteral), U8(1), U8(6), U8(21), R(1),
+                B(CreateClosure), U8(2), U8(5), U8(0),
+                B(StaNamedOwnProperty), R(1), U8(3), U8(7),
+                B(Ldar), R(1),
+  /*    8 E> */ B(StaGlobalSloppy), U8(4), U8(9),
                 B(LdaUndefined),
   /*   33 S> */ B(Return),
 ]
 constant pool: [
   FIXED_ARRAY_TYPE,
-  ONE_BYTE_INTERNALIZED_STRING_TYPE ["a"],
   FIXED_ARRAY_TYPE,
   SHARED_FUNCTION_INFO_TYPE,
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["func"],
+  ONE_BYTE_INTERNALIZED_STRING_TYPE ["a"],
 ]
 handlers: [
 ]

test/debugger/debug/es6/debug-stepin-proxies.js

@@ -53,8 +53,8 @@ assertEquals(42, get);
 
 assertEquals([
   "a0",
-  "b17", "h4b17", "i2b17",  // [[Has]]
-  "c15", "j4c15", "k2c15",  // [[Get]]
+  "b10", "h4b17", "i2b17",  // [[Has]]
+  "c10", "j4c15", "k2c15",  // [[Get]]
   "d0", "l4d11", "m2d11",   // [[Set]]
   "g0"
 ], log);

test/debugger/debug/es6/debug-stepin-string-template.js

@@ -47,8 +47,7 @@ assertNull(exception);
 
 assertEquals([
   "a0",
-  "b44",
-  "b13",
+  "b8",
   "d2b13",
   "e0b13",
   "b25",