[Interpreter] Handles legacy constants in strict mode.

src/crankshaft/hydrogen.cc

 // Copyright 2013 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/crankshaft/hydrogen.h"
 
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
 #include "src/ast/ast-numbering.h"
@@ skipping 7003 matching lines @@
 
         HStoreContextSlot::Mode mode;
 
         switch (var->mode()) {
           case LET:
             mode = HStoreContextSlot::kCheckDeoptimize;
             break;
           case CONST:
             return Bailout(kNonInitializerAssignmentToConst);
           case CONST_LEGACY:
-            return ast_context()->ReturnValue(Pop());
+            if (is_strict(function_language_mode())) {
+              return Bailout(kNonInitializerAssignmentToConst);
+            } else {
+              return ast_context()->ReturnValue(Pop());
+            }
           default:
             mode = HStoreContextSlot::kNoCheck;
         }
 
         HValue* context = BuildContextChainWalk(var);
         HStoreContextSlot* instr = Add<HStoreContextSlot>(
             context, var->index(), mode, Top());
         if (instr->HasObservableSideEffects()) {
           Add<HSimulate>(expr->AssignmentId(), REMOVABLE_SIMULATE);
         }
@@ skipping 47 matching lines @@
   if (prop != NULL) {
     HandlePropertyAssignment(expr);
   } else if (proxy != NULL) {
     Variable* var = proxy->var();
 
     if (var->mode() == CONST) {
       if (expr->op() != Token::INIT) {
         return Bailout(kNonInitializerAssignmentToConst);
       }
     } else if (var->mode() == CONST_LEGACY) {
-      if (expr->op() != Token::INIT) {
+      if (expr->op() != Token::INIT && is_strict(function_language_mode())) {
+        return Bailout(kNonInitializerAssignmentToConst);
+      } else if (expr->op() != Token::INIT) {
         CHECK_ALIVE(VisitForValue(expr->value()));
         return ast_context()->ReturnValue(Pop());
       }
 
       if (var->IsStackAllocated()) {
         // We insert a use of the old value to detect unsupported uses of const
         // variables (e.g. initialization inside a loop).
         HValue* old_value = environment()->Lookup(var);
         Add<HUseConst>(old_value);
       }
@@ skipping 6468 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8