Add script context with context-allocated "const this"

src/arm/full-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 3086 matching lines @@
   CallIC(ic);
 
   RecordJSReturnSite(expr);
   // Restore context register.
   __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   context()->DropAndPlug(1, r0);
 }
 
 
 void FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
-  // r5: copy of the first argument or undefined if it doesn't exist.
+  // r4: copy of the first argument or undefined if it doesn't exist.
   if (arg_count > 0) {
-    __ ldr(r5, MemOperand(sp, arg_count * kPointerSize));
+    __ ldr(r4, MemOperand(sp, arg_count * kPointerSize));
   } else {
-    __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
   }
 
-  // r4: the receiver of the enclosing function.
-  __ ldr(r4, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-
   // r3: the receiver of the enclosing function.
-  Variable* this_var = scope()->LookupThis();
-  DCHECK_NOT_NULL(this_var);
-  __ ldr(r3, VarOperand(this_var, r3));
+  __ ldr(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
 
   // r2: language mode.
   __ mov(r2, Operand(Smi::FromInt(language_mode())));
 
   // r1: the start position of the scope the calls resides in.
   __ mov(r1, Operand(Smi::FromInt(scope()->start_position())));
 
   // Do the runtime call.
-  __ Push(r5);
   __ Push(r4, r3, r2, r1);
-  __ CallRuntime(Runtime::kResolvePossiblyDirectEval, 6);
+  __ CallRuntime(Runtime::kResolvePossiblyDirectEval, 5);
 }
 
 
 void FullCodeGenerator::EmitInitializeThisAfterSuper(
     SuperCallReference* super_ref, FeedbackVectorICSlot slot) {
   Variable* this_var = super_ref->this_var()->var();
   GetVar(r1, this_var);
   __ CompareRoot(r1, Heap::kTheHoleValueRootIndex);
   Label uninitialized_this;
   __ b(eq, &uninitialized_this);
@@ skipping 11 matching lines @@
   // We want to verify that RecordJSReturnSite gets called on all paths
   // through this function.  Avoid early returns.
   expr->return_is_recorded_ = false;
 #endif
 
   Comment cmnt(masm_, "[ Call");
   Expression* callee = expr->expression();
   Call::CallType call_type = expr->GetCallType(isolate());
 
   if (call_type == Call::POSSIBLY_EVAL_CALL) {
-    // In a call to eval, we first call RuntimeHidden_ResolvePossiblyDirectEval
-    // to resolve the function we need to call and the receiver of the
-    // call.  Then we call the resolved function using the given
-    // arguments.
+    // In a call to eval, we first call
+    // RuntimeHidden_asResolvePossiblyDirectEval to resolve the function we need
+    // to call.  Then we call the resolved function using the given arguments.
     ZoneList<Expression*>* args = expr->arguments();
     int arg_count = args->length();
 
     { PreservePositionScope pos_scope(masm()->positions_recorder());
       VisitForStackValue(callee);
       __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
       __ push(r2);  // Reserved receiver slot.
 
       // Push the arguments.
       for (int i = 0; i < arg_count; i++) {
         VisitForStackValue(args->at(i));
       }
 
       // Push a copy of the function (found below the arguments) and
       // resolve eval.
       __ ldr(r1, MemOperand(sp, (arg_count + 1) * kPointerSize));
       __ push(r1);
       EmitResolvePossiblyDirectEval(arg_count);
 
-      // The runtime call returns a pair of values in r0 (function) and
-      // r1 (receiver). Touch up the stack with the right values.
+      // Touch up the stack with the resolved function.
       __ str(r0, MemOperand(sp, (arg_count + 1) * kPointerSize));
-      __ str(r1, MemOperand(sp, arg_count * kPointerSize));
 
       PrepareForBailoutForId(expr->EvalOrLookupId(), NO_REGISTERS);
     }
 
     // Record source position for debugger.
     SetSourcePosition(expr->position());
     CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
     __ ldr(r1, MemOperand(sp, (arg_count + 1) * kPointerSize));
     __ CallStub(&stub);
     RecordJSReturnSite(expr);
@@ skipping 1576 matching lines @@
 
       if (property != NULL) {
         VisitForStackValue(property->obj());
         VisitForStackValue(property->key());
         __ mov(r1, Operand(Smi::FromInt(language_mode())));
         __ push(r1);
         __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
         context()->Plug(r0);
       } else if (proxy != NULL) {
         Variable* var = proxy->var();
-        // Delete of an unqualified identifier is disallowed in strict mode
-        // but "delete this" is allowed.
-        DCHECK(is_sloppy(language_mode()) || var->is_this());
+        // Delete of an unqualified identifier is disallowed in strict mode but
+        // "delete this" is allowed.
+        bool is_this = var->HasThisName(isolate());
+        DCHECK(is_sloppy(language_mode()) || is_this);
         if (var->IsUnallocated()) {
           __ ldr(r2, GlobalObjectOperand());
           __ mov(r1, Operand(var->name()));
           __ mov(r0, Operand(Smi::FromInt(SLOPPY)));
           __ Push(r2, r1, r0);
           __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION);
           context()->Plug(r0);
         } else if (var->IsStackAllocated() || var->IsContextSlot()) {
           // Result of deleting non-global, non-dynamic variables is false.
           // The subexpression does not have side effects.
-          context()->Plug(var->is_this());
+          context()->Plug(is_this);
         } else {
           // Non-global variable.  Call the runtime to try to delete from the
           // context where the variable was introduced.
           DCHECK(!context_register().is(r2));
           __ mov(r2, Operand(var->name()));
           __ Push(context_register(), r2);
           __ CallRuntime(Runtime::kDeleteLookupSlot, 2);
           context()->Plug(r0);
         }
       } else {
@@ skipping 792 matching lines @@
   DCHECK(interrupt_address ==
          isolate->builtins()->OsrAfterStackCheck()->entry());
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM