[es6] Parameter scopes for sloppy eval

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index a04ae66bb61649a19b6499083108f8729acd387e..4fe42cdc81c6c0aa30317c96daf47d843bc54faa 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -391,6 +391,7 @@ const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
   V(ALIASED_ARGUMENTS_ENTRY_TYPE)                               \
   V(BOX_TYPE)                                                   \
   V(PROTOTYPE_INFO_TYPE)                                        \
+  V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_TYPE)              \
                                                                 \
   V(FIXED_ARRAY_TYPE)                                           \
   V(FIXED_DOUBLE_ARRAY_TYPE)                                    \
@@ -507,7 +508,10 @@ const int kStubMinorKeyBits = kSmiValueSize - kStubMajorKeyBits - 1;
   V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
   V(DEBUG_INFO, DebugInfo, debug_info)                                       \
   V(BREAK_POINT_INFO, BreakPointInfo, break_point_info)                      \
-  V(PROTOTYPE_INFO, PrototypeInfo, prototype_info)
+  V(PROTOTYPE_INFO, PrototypeInfo, prototype_info)                           \
+  V(SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION,                                \
+    SloppyBlockWithEvalContextExtension,                                     \
+    sloppy_block_with_eval_context_extension)
 
 // We use the full 8 bits of the instance_type field to encode heap object
 // instance types.  The high-order bit (bit 7) is set if the object is not a
@@ -685,6 +689,7 @@ enum InstanceType {
   WEAK_CELL_TYPE,
   PROPERTY_CELL_TYPE,
   PROTOTYPE_INFO_TYPE,
+  SLOPPY_BLOCK_WITH_EVAL_CONTEXT_EXTENSION_TYPE,
 
   // All the following types are subtypes of JSReceiver, which corresponds to
   // objects in the JS sense. The first and the last type in this range are
@@ -3748,6 +3753,9 @@ class ScopeInfo : public FixedArray {
   // Return the language mode of this scope.
   LanguageMode language_mode();
 
+  // True if this scope is a (var) declaration scope.
+  bool is_declaration_scope();
+
   // Does this scope make a sloppy eval call?
   bool CallsSloppyEval() { return CallsEval() && is_sloppy(language_mode()); }
 
@@ -3971,8 +3979,11 @@ class ScopeInfo : public FixedArray {
   STATIC_ASSERT(LANGUAGE_END == 3);
   class LanguageModeField
       : public BitField<LanguageMode, CallsEvalField::kNext, 2> {};
+  class DeclarationScopeField
+      : public BitField<bool, LanguageModeField::kNext, 1> {};
   class ReceiverVariableField
-      : public BitField<VariableAllocationInfo, LanguageModeField::kNext, 2> {};
+      : public BitField<VariableAllocationInfo, DeclarationScopeField::kNext,
+                        2> {};
   class FunctionVariableField
       : public BitField<VariableAllocationInfo, ReceiverVariableField::kNext,
                         2> {};
@@ -5835,6 +5846,32 @@ class PrototypeInfo : public Struct {
 };
 
 
+// Pair used to store both a ScopeInfo and an extension object in the extension
+// slot of a block context. Needed in the rare case where a declaration block
+// scope (a "varblock" as used to desugar parameter destructuring) also contains
+// a sloppy direct eval. (In no other case both are needed at the same time.)
+class SloppyBlockWithEvalContextExtension : public Struct {
+ public:
+  // [scope_info]: Scope info.
+  DECL_ACCESSORS(scope_info, ScopeInfo)
+  // [extension]: Extension object.
+  DECL_ACCESSORS(extension, JSObject)
+
+  DECLARE_CAST(SloppyBlockWithEvalContextExtension)
+
+  // Dispatched behavior.
+  DECLARE_PRINTER(SloppyBlockWithEvalContextExtension)
+  DECLARE_VERIFIER(SloppyBlockWithEvalContextExtension)
+
+  static const int kScopeInfoOffset = HeapObject::kHeaderSize;
+  static const int kExtensionOffset = kScopeInfoOffset + kPointerSize;
+  static const int kSize = kExtensionOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SloppyBlockWithEvalContextExtension);
+};
+
+
 // Script describes a script which has been added to the VM.
 class Script: public Struct {
  public: