Support for global var shortcuts in script contexts.

src/arm64/full-codegen-arm64.cc

Index: src/arm64/full-codegen-arm64.cc
diff --git a/src/arm64/full-codegen-arm64.cc b/src/arm64/full-codegen-arm64.cc
index 0345751dfc7c3c6d8047139f388be000e0c99c31..ece201775f96e6ca35ce95fd89731c7c9f54f073 100644
--- a/src/arm64/full-codegen-arm64.cc
+++ b/src/arm64/full-codegen-arm64.cc
@@ -354,7 +354,7 @@ void FullCodeGenerator::Generate() {
         VariableDeclaration* function = scope()->function();
         DCHECK(function->proxy()->var()->mode() == CONST ||
                function->proxy()->var()->mode() == CONST_LEGACY);
-        DCHECK(function->proxy()->var()->location() != Variable::UNALLOCATED);
+        DCHECK(!function->proxy()->var()->IsUnallocatedOrGlobalSlot());
         VisitVariableDeclaration(function);
       }
       VisitDeclarations(scope()->declarations());
@@ -873,7 +873,8 @@ void FullCodeGenerator::VisitVariableDeclaration(
   bool hole_init = mode == LET || mode == CONST || mode == CONST_LEGACY;
 
   switch (variable->location()) {
-    case Variable::UNALLOCATED:
+    case VariableLocation::GLOBAL:
+    case VariableLocation::UNALLOCATED:
       globals_->Add(variable->name(), zone());
       globals_->Add(variable->binding_needs_init()
                         ? isolate()->factory()->the_hole_value()
@@ -881,8 +882,8 @@ void FullCodeGenerator::VisitVariableDeclaration(
                     zone());
       break;
 
-    case Variable::PARAMETER:
-    case Variable::LOCAL:
+    case VariableLocation::PARAMETER:
+    case VariableLocation::LOCAL:
       if (hole_init) {
         Comment cmnt(masm_, "[ VariableDeclaration");
         __ LoadRoot(x10, Heap::kTheHoleValueRootIndex);
@@ -890,7 +891,7 @@ void FullCodeGenerator::VisitVariableDeclaration(
       }
       break;
 
-    case Variable::CONTEXT:
+    case VariableLocation::CONTEXT:
       if (hole_init) {
         Comment cmnt(masm_, "[ VariableDeclaration");
         EmitDebugCheckDeclarationContext(variable);
@@ -901,7 +902,7 @@ void FullCodeGenerator::VisitVariableDeclaration(
       }
       break;
 
-    case Variable::LOOKUP: {
+    case VariableLocation::LOOKUP: {
       Comment cmnt(masm_, "[ VariableDeclaration");
       __ Mov(x2, Operand(variable->name()));
       // Declaration nodes are always introduced in one of four modes.
@@ -932,7 +933,8 @@ void FullCodeGenerator::VisitFunctionDeclaration(
   VariableProxy* proxy = declaration->proxy();
   Variable* variable = proxy->var();
   switch (variable->location()) {
-    case Variable::UNALLOCATED: {
+    case VariableLocation::GLOBAL:
+    case VariableLocation::UNALLOCATED: {
       globals_->Add(variable->name(), zone());
       Handle<SharedFunctionInfo> function =
           Compiler::GetSharedFunctionInfo(declaration->fun(), script(), info_);
@@ -942,15 +944,15 @@ void FullCodeGenerator::VisitFunctionDeclaration(
       break;
     }
 
-    case Variable::PARAMETER:
-    case Variable::LOCAL: {
+    case VariableLocation::PARAMETER:
+    case VariableLocation::LOCAL: {
       Comment cmnt(masm_, "[ Function Declaration");
       VisitForAccumulatorValue(declaration->fun());
       __ Str(result_register(), StackOperand(variable));
       break;
     }
 
-    case Variable::CONTEXT: {
+    case VariableLocation::CONTEXT: {
       Comment cmnt(masm_, "[ Function Declaration");
       EmitDebugCheckDeclarationContext(variable);
       VisitForAccumulatorValue(declaration->fun());
@@ -969,7 +971,7 @@ void FullCodeGenerator::VisitFunctionDeclaration(
       break;
     }
 
-    case Variable::LOOKUP: {
+    case VariableLocation::LOOKUP: {
       Comment cmnt(masm_, "[ Function Declaration");
       __ Mov(x2, Operand(variable->name()));
       __ Mov(x1, Smi::FromInt(NONE));
@@ -987,20 +989,21 @@ void FullCodeGenerator::VisitImportDeclaration(ImportDeclaration* declaration) {
   VariableProxy* proxy = declaration->proxy();
   Variable* variable = proxy->var();
   switch (variable->location()) {
-    case Variable::UNALLOCATED:
+    case VariableLocation::GLOBAL:
+    case VariableLocation::UNALLOCATED:
       // TODO(rossberg)
       break;
 
-    case Variable::CONTEXT: {
+    case VariableLocation::CONTEXT: {
       Comment cmnt(masm_, "[ ImportDeclaration");
       EmitDebugCheckDeclarationContext(variable);
       // TODO(rossberg)
       break;
     }
 
-    case Variable::PARAMETER:
-    case Variable::LOCAL:
-    case Variable::LOOKUP:
+    case VariableLocation::PARAMETER:
+    case VariableLocation::LOCAL:
+    case VariableLocation::LOOKUP:
       UNREACHABLE();
   }
 }
@@ -1478,7 +1481,8 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
   // Three cases: global variables, lookup variables, and all other types of
   // variables.
   switch (var->location()) {
-    case Variable::UNALLOCATED: {
+    case VariableLocation::GLOBAL:
+    case VariableLocation::UNALLOCATED: {
       Comment cmnt(masm_, "Global variable");
       __ Ldr(LoadDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
       __ Mov(LoadDescriptor::NameRegister(), Operand(var->name()));
@@ -1489,9 +1493,9 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
       break;
     }
 
-    case Variable::PARAMETER:
-    case Variable::LOCAL:
-    case Variable::CONTEXT: {
+    case VariableLocation::PARAMETER:
+    case VariableLocation::LOCAL:
+    case VariableLocation::CONTEXT: {
       Comment cmnt(masm_, var->IsContextSlot()
                               ? "Context variable"
                               : "Stack variable");
@@ -1561,7 +1565,7 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
       break;
     }
 
-    case Variable::LOOKUP: {
+    case VariableLocation::LOOKUP: {
       Label done, slow;
       // Generate code for loading from variables potentially shadowed by
       // eval-introduced variables.
@@ -2423,7 +2427,7 @@ void FullCodeGenerator::EmitStoreToStackLocalOrContextSlot(
 void FullCodeGenerator::EmitVariableAssignment(Variable* var, Token::Value op,
                                                FeedbackVectorICSlot slot) {
   ASM_LOCATION("FullCodeGenerator::EmitVariableAssignment");
-  if (var->IsUnallocated()) {
+  if (var->IsUnallocatedOrGlobalSlot()) {
     // Global var, const, or let.
     __ Mov(StoreDescriptor::NameRegister(), Operand(var->name()));
     __ Ldr(StoreDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
@@ -4486,7 +4490,7 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
         // "delete this" is allowed.
         bool is_this = var->HasThisName(isolate());
         DCHECK(is_sloppy(language_mode()) || is_this);
-        if (var->IsUnallocated()) {
+        if (var->IsUnallocatedOrGlobalSlot()) {
           __ Ldr(x12, GlobalObjectMemOperand());
           __ Mov(x11, Operand(var->name()));
           __ Mov(x10, Smi::FromInt(SLOPPY));
@@ -4841,7 +4845,7 @@ void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
   DCHECK(!context()->IsEffect());
   DCHECK(!context()->IsTest());
   VariableProxy* proxy = expr->AsVariableProxy();
-  if (proxy != NULL && proxy->var()->IsUnallocated()) {
+  if (proxy != NULL && proxy->var()->IsUnallocatedOrGlobalSlot()) {
     Comment cmnt(masm_, "Global variable");
     __ Ldr(LoadDescriptor::ReceiverRegister(), GlobalObjectMemOperand());
     __ Mov(LoadDescriptor::NameRegister(), Operand(proxy->name()));