[fullcodegen] Remove deprecated support for lookup variables, eval and with.

src/full-codegen/mips/full-codegen-mips.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.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 789 matching lines @@
       if (variable->binding_needs_init()) {
         Comment cmnt(masm_, "[ VariableDeclaration");
         EmitDebugCheckDeclarationContext(variable);
           __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
           __ sw(at, ContextMemOperand(cp, variable->index()));
           // No write barrier since the_hole_value is in old space.
           PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       }
       break;
 
-    case VariableLocation::LOOKUP: {
-      Comment cmnt(masm_, "[ VariableDeclaration");
-      DCHECK_EQ(VAR, variable->mode());
-      DCHECK(!variable->binding_needs_init());
-      __ li(a2, Operand(variable->name()));
-      __ Push(a2);
-      __ CallRuntime(Runtime::kDeclareEvalVar);
-      PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
-      break;
-    }
-
+    case VariableLocation::LOOKUP:
     case VariableLocation::MODULE:
       UNREACHABLE();
   }
 }
 
 
 void FullCodeGenerator::VisitFunctionDeclaration(
     FunctionDeclaration* declaration) {
   VariableProxy* proxy = declaration->proxy();
   Variable* variable = proxy->var();
@@ skipping 31 matching lines @@
                                 result_register(),
                                 a2,
                                 kRAHasBeenSaved,
                                 kDontSaveFPRegs,
                                 EMIT_REMEMBERED_SET,
                                 OMIT_SMI_CHECK);
       PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       break;
     }
 
-    case VariableLocation::LOOKUP: {
-      Comment cmnt(masm_, "[ FunctionDeclaration");
-      __ li(a2, Operand(variable->name()));
-      PushOperand(a2);
-      // Push initial value for function declaration.
-      VisitForStackValue(declaration->fun());
-      CallRuntimeWithOperands(Runtime::kDeclareEvalFunction);
-      PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
-      break;
-    }
-
+    case VariableLocation::LOOKUP:
     case VariableLocation::MODULE:
       UNREACHABLE();
   }
 }
 
 
 void FullCodeGenerator::DeclareGlobals(Handle<FixedArray> pairs) {
   // Call the runtime to declare the globals.
   __ li(a1, Operand(pairs));
   __ li(a0, Operand(Smi::FromInt(DeclareGlobalsFlags())));
@@ skipping 283 matching lines @@
 void FullCodeGenerator::EmitSetHomeObjectAccumulator(Expression* initializer,
                                                      int offset,
                                                      FeedbackVectorSlot slot) {
   DCHECK(NeedsHomeObject(initializer));
   __ Move(StoreDescriptor::ReceiverRegister(), v0);
   __ lw(StoreDescriptor::ValueRegister(),
         MemOperand(sp, offset * kPointerSize));
   CallStoreIC(slot, isolate()->factory()->home_object_symbol());
 }
 
-
-void FullCodeGenerator::EmitLoadGlobalCheckExtensions(VariableProxy* proxy,
-                                                      TypeofMode typeof_mode,
-                                                      Label* slow) {
-  Register current = cp;
-  Register next = a1;
-  Register temp = a2;
-
-  int to_check = scope()->ContextChainLengthUntilOutermostSloppyEval();
-  for (Scope* s = scope(); to_check > 0; s = s->outer_scope()) {
-    if (!s->NeedsContext()) continue;
-    if (s->calls_sloppy_eval()) {
-      // Check that extension is "the hole".
-      __ lw(temp, ContextMemOperand(current, Context::EXTENSION_INDEX));
-      __ JumpIfNotRoot(temp, Heap::kTheHoleValueRootIndex, slow);
-    }
-    // Load next context in chain.
-    __ lw(next, ContextMemOperand(current, Context::PREVIOUS_INDEX));
-    // Walk the rest of the chain without clobbering cp.
-    current = next;
-    to_check--;
-  }
-
-  // All extension objects were empty and it is safe to use a normal global
-  // load machinery.
-  EmitGlobalVariableLoad(proxy, typeof_mode);
-}
-
-
-MemOperand FullCodeGenerator::ContextSlotOperandCheckExtensions(Variable* var,
-                                                                Label* slow) {
-  DCHECK(var->IsContextSlot());
-  Register context = cp;
-  Register next = a3;
-  Register temp = t0;
-
-  for (Scope* s = scope(); s != var->scope(); s = s->outer_scope()) {
-    if (s->NeedsContext()) {
-      if (s->calls_sloppy_eval()) {
-        // Check that extension is "the hole".
-        __ lw(temp, ContextMemOperand(context, Context::EXTENSION_INDEX));
-        __ JumpIfNotRoot(temp, Heap::kTheHoleValueRootIndex, slow);
-      }
-      __ lw(next, ContextMemOperand(context, Context::PREVIOUS_INDEX));
-      // Walk the rest of the chain without clobbering cp.
-      context = next;
-    }
-  }
-  // Check that last extension is "the hole".
-  __ lw(temp, ContextMemOperand(context, Context::EXTENSION_INDEX));
-  __ JumpIfNotRoot(temp, Heap::kTheHoleValueRootIndex, slow);
-
-  // This function is used only for loads, not stores, so it's safe to
-  // return an cp-based operand (the write barrier cannot be allowed to
-  // destroy the cp register).
-  return ContextMemOperand(context, var->index());
-}
-
-
-void FullCodeGenerator::EmitDynamicLookupFastCase(VariableProxy* proxy,
-                                                  TypeofMode typeof_mode,
-                                                  Label* slow, Label* done) {
-  // Generate fast-case code for variables that might be shadowed by
-  // eval-introduced variables.  Eval is used a lot without
-  // introducing variables.  In those cases, we do not want to
-  // perform a runtime call for all variables in the scope
-  // containing the eval.
-  Variable* var = proxy->var();
-  if (var->mode() == DYNAMIC_GLOBAL) {
-    EmitLoadGlobalCheckExtensions(proxy, typeof_mode, slow);
-    __ Branch(done);
-  } else if (var->mode() == DYNAMIC_LOCAL) {
-    Variable* local = var->local_if_not_shadowed();
-    __ lw(v0, ContextSlotOperandCheckExtensions(local, slow));
-    if (local->binding_needs_init()) {
-      __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
-      __ subu(at, v0, at);  // Sub as compare: at == 0 on eq.
-      __ Branch(done, ne, at, Operand(zero_reg));
-      __ li(a0, Operand(var->name()));
-      __ push(a0);
-      __ CallRuntime(Runtime::kThrowReferenceError);
-    } else {
-      __ Branch(done);
-    }
-  }
-}
-
 void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy,
                                          TypeofMode typeof_mode) {
   // Record position before possible IC call.
   SetExpressionPosition(proxy);
   PrepareForBailoutForId(proxy->BeforeId(), BailoutState::NO_REGISTERS);
   Variable* var = proxy->var();
 
-  // Three cases: global variables, lookup variables, and all other types of
-  // variables.
+  // Two cases: global variables and all other types of variables.
   switch (var->location()) {
     case VariableLocation::UNALLOCATED: {
       Comment cmnt(masm_, "[ Global variable");
       EmitGlobalVariableLoad(proxy, typeof_mode);
       context()->Plug(v0);
       break;
     }
 
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL:
@@ skipping 13 matching lines @@
         __ push(a0);
         __ CallRuntime(Runtime::kThrowReferenceError);
         __ bind(&done);
         context()->Plug(v0);
         break;
       }
       context()->Plug(var);
       break;
     }
 
-    case VariableLocation::LOOKUP: {
-      Comment cmnt(masm_, "[ Lookup variable");
-      Label done, slow;
-      // Generate code for loading from variables potentially shadowed
-      // by eval-introduced variables.
-      EmitDynamicLookupFastCase(proxy, typeof_mode, &slow, &done);
-      __ bind(&slow);
-      __ Push(var->name());
-      Runtime::FunctionId function_id =
-          typeof_mode == NOT_INSIDE_TYPEOF
-              ? Runtime::kLoadLookupSlot
-              : Runtime::kLoadLookupSlotInsideTypeof;
-      __ CallRuntime(function_id);
-      __ bind(&done);
-      context()->Plug(v0);
-      break;
-    }
-
+    case VariableLocation::LOOKUP:
     case VariableLocation::MODULE:
       UNREACHABLE();
   }
 }
 
 
 void FullCodeGenerator::EmitAccessor(ObjectLiteralProperty* property) {
   Expression* expression = (property == NULL) ? NULL : property->value();
   if (expression == NULL) {
     __ LoadRoot(a1, Heap::kNullValueRootIndex);
@@ skipping 761 matching lines @@
     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
     __ Branch(&uninitialized_this, eq, a3, Operand(at));
     __ li(a0, Operand(var->name()));
     __ Push(a0);
     __ CallRuntime(Runtime::kThrowReferenceError);
     __ bind(&uninitialized_this);
     EmitStoreToStackLocalOrContextSlot(var, location);
 
   } else {
     DCHECK(var->mode() != CONST || op == Token::INIT);
-    if (var->IsLookupSlot()) {
-      // Assignment to var.
-      __ Push(var->name());
-      __ Push(v0);
-      __ CallRuntime(is_strict(language_mode())
-                         ? Runtime::kStoreLookupSlot_Strict
-                         : Runtime::kStoreLookupSlot_Sloppy);
-    } else {
-      // Assignment to var or initializing assignment to let/const in harmony
-      // mode.
-      DCHECK((var->IsStackAllocated() || var->IsContextSlot()));
-      MemOperand location = VarOperand(var, a1);
-      if (FLAG_debug_code && var->mode() == LET && op == Token::INIT) {
-        // Check for an uninitialized let binding.
-        __ lw(a2, location);
-        __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
-        __ Check(eq, kLetBindingReInitialization, a2, Operand(t0));
-      }
-      EmitStoreToStackLocalOrContextSlot(var, location);
+    DCHECK((var->IsStackAllocated() || var->IsContextSlot()));
+    DCHECK(!var->IsLookupSlot());
+    // Assignment to var or initializing assignment to let/const in harmony
+    // mode.
+    MemOperand location = VarOperand(var, a1);
+    if (FLAG_debug_code && var->mode() == LET && op == Token::INIT) {
+      // Check for an uninitialized let binding.
+      __ lw(a2, location);
+      __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
+      __ Check(eq, kLetBindingReInitialization, a2, Operand(t0));
     }
+    EmitStoreToStackLocalOrContextSlot(var, location);
   }
 }
 
 
 void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
   // Assignment to a property, using a named store IC.
   Property* prop = expr->target()->AsProperty();
   DCHECK(prop != NULL);
   DCHECK(prop->key()->IsLiteral());
 
@@ skipping 210 matching lines @@
   __ lw(a1, MemOperand(sp, (arg_count + 1) * kPointerSize));
   __ li(a0, Operand(arg_count));
   CallIC(code);
   OperandStackDepthDecrement(arg_count + 1);
 
   RecordJSReturnSite(expr);
   RestoreContext();
   context()->DropAndPlug(1, v0);
 }
 
-void FullCodeGenerator::EmitResolvePossiblyDirectEval(Call* expr) {
-  int arg_count = expr->arguments()->length();
-  // t4: copy of the first argument or undefined if it doesn't exist.
-  if (arg_count > 0) {
-    __ lw(t4, MemOperand(sp, arg_count * kPointerSize));
-  } else {
-    __ LoadRoot(t4, Heap::kUndefinedValueRootIndex);
-  }
-
-  // t3: the receiver of the enclosing function.
-  __ lw(t3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-
-  // t2: the language mode.
-  __ li(t2, Operand(Smi::FromInt(language_mode())));
-
-  // t1: the start position of the scope the calls resides in.
-  __ li(t1, Operand(Smi::FromInt(scope()->start_position())));
-
-  // t0: the source position of the eval call.
-  __ li(t0, Operand(Smi::FromInt(expr->position())));
-
-  // Do the runtime call.
-  __ Push(t4, t3, t2, t1, t0);
-  __ CallRuntime(Runtime::kResolvePossiblyDirectEval);
-}
-
-
-// See http://www.ecma-international.org/ecma-262/6.0/#sec-function-calls.
-void FullCodeGenerator::PushCalleeAndWithBaseObject(Call* expr) {
-  VariableProxy* callee = expr->expression()->AsVariableProxy();
-  if (callee->var()->IsLookupSlot()) {
-    Label slow, done;
-
-    SetExpressionPosition(callee);
-    // Generate code for loading from variables potentially shadowed by
-    // eval-introduced variables.
-    EmitDynamicLookupFastCase(callee, NOT_INSIDE_TYPEOF, &slow, &done);
-
-    __ bind(&slow);
-    // Call the runtime to find the function to call (returned in v0)
-    // and the object holding it (returned in v1).
-    __ Push(callee->name());
-    __ CallRuntime(Runtime::kLoadLookupSlotForCall);
-    PushOperands(v0, v1);  // Function, receiver.
-    PrepareForBailoutForId(expr->LookupId(), BailoutState::NO_REGISTERS);
-
-    // If fast case code has been generated, emit code to push the
-    // function and receiver and have the slow path jump around this
-    // code.
-    if (done.is_linked()) {
-      Label call;
-      __ Branch(&call);
-      __ bind(&done);
-      // Push function.
-      __ push(v0);
-      // The receiver is implicitly the global receiver. Indicate this
-      // by passing the hole to the call function stub.
-      __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
-      __ push(a1);
-      __ bind(&call);
-    }
-  } else {
-    VisitForStackValue(callee);
-    // refEnv.WithBaseObject()
-    __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
-    PushOperand(a2);  // Reserved receiver slot.
-  }
-}
-
-
-void FullCodeGenerator::EmitPossiblyEvalCall(Call* expr) {
-  // In a call to eval, we first call Runtime_ResolvePossiblyDirectEval
-  // 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();
-  PushCalleeAndWithBaseObject(expr);
-
-  // 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.
-  __ lw(a1, MemOperand(sp, (arg_count + 1) * kPointerSize));
-  __ push(a1);
-  EmitResolvePossiblyDirectEval(expr);
-
-  // Touch up the stack with the resolved function.
-  __ sw(v0, MemOperand(sp, (arg_count + 1) * kPointerSize));
-
-  PrepareForBailoutForId(expr->EvalId(), BailoutState::NO_REGISTERS);
-  // Record source position for debugger.
-  SetCallPosition(expr);
-  Handle<Code> code = CodeFactory::CallIC(isolate(), ConvertReceiverMode::kAny,
-                                          expr->tail_call_mode())
-                          .code();
-  __ li(a3, Operand(SmiFromSlot(expr->CallFeedbackICSlot())));
-  __ lw(a1, MemOperand(sp, (arg_count + 1) * kPointerSize));
-  __ li(a0, Operand(arg_count));
-  __ Call(code, RelocInfo::CODE_TARGET);
-  OperandStackDepthDecrement(arg_count + 1);
-  RecordJSReturnSite(expr);
-  RestoreContext();
-  context()->DropAndPlug(1, v0);
-}
-
-
 void FullCodeGenerator::VisitCallNew(CallNew* expr) {
   Comment cmnt(masm_, "[ CallNew");
   // According to ECMA-262, section 11.2.2, page 44, the function
   // expression in new calls must be evaluated before the
   // arguments.
 
   // Push constructor on the stack.  If it's not a function it's used as
   // receiver for CALL_NON_FUNCTION, otherwise the value on the stack is
   // ignored.g
   DCHECK(!expr->expression()->IsSuperPropertyReference());
@@ skipping 409 matching lines @@
         // Delete of an unqualified identifier is disallowed in strict mode but
         // "delete this" is allowed.
         bool is_this = var->is_this();
         DCHECK(is_sloppy(language_mode()) || is_this);
         if (var->IsUnallocated()) {
           __ LoadGlobalObject(a2);
           __ li(a1, Operand(var->name()));
           __ Push(a2, a1);
           __ CallRuntime(Runtime::kDeleteProperty_Sloppy);
           context()->Plug(v0);
-        } else if (var->IsStackAllocated() || var->IsContextSlot()) {
+        } else {
+          DCHECK(!var->IsLookupSlot());
+          DCHECK(var->IsStackAllocated() || var->IsContextSlot());
           // Result of deleting non-global, non-dynamic variables is false.
           // The subexpression does not have side effects.
           context()->Plug(is_this);
-        } else {
-          // Non-global variable.  Call the runtime to try to delete from the
-          // context where the variable was introduced.
-          __ Push(var->name());
-          __ CallRuntime(Runtime::kDeleteLookupSlot);
-          context()->Plug(v0);
         }
       } else {
         // Result of deleting non-property, non-variable reference is true.
         // The subexpression may have side effects.
         VisitForEffect(expr->expression());
         context()->Plug(true);
       }
       break;
     }
 
@@ skipping 672 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OnStackReplacement()->entry()));
   return ON_STACK_REPLACEMENT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS