Replace C++ bitfields with our own BitFields

src/ast.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/ast.h"
 
 #include <cmath>  // For isfinite.
 #include "src/builtins.h"
 #include "src/code-stubs.h"
 #include "src/contexts.h"
@@ skipping 43 matching lines @@
   Variable* var = var_proxy->var();
   // The global identifier "undefined" is immutable. Everything
   // else could be reassigned.
   return var != NULL && var->location() == Variable::UNALLOCATED &&
          var_proxy->raw_name()->IsOneByteEqualTo("undefined");
 }
 
 
 VariableProxy::VariableProxy(Zone* zone, Variable* var, int position)
     : Expression(zone, position),
-      is_this_(var->is_this()),
-      is_assigned_(false),
-      is_resolved_(false),
+      bit_field_(IsThisField::encode(var->is_this()) |
+                 IsAssignedField::encode(false) |
+                 IsResolvedField::encode(false)),
       variable_feedback_slot_(FeedbackVectorICSlot::Invalid()),
       raw_name_(var->raw_name()),
       interface_(var->interface()) {
   BindTo(var);
 }
 
 
 VariableProxy::VariableProxy(Zone* zone, const AstRawString* name, bool is_this,
                              Interface* interface, int position)
     : Expression(zone, position),
-      is_this_(is_this),
-      is_assigned_(false),
-      is_resolved_(false),
+      bit_field_(IsThisField::encode(is_this) | IsAssignedField::encode(false) |
+                 IsResolvedField::encode(false)),
       variable_feedback_slot_(FeedbackVectorICSlot::Invalid()),
       raw_name_(name),
       interface_(interface) {}
 
 
 void VariableProxy::BindTo(Variable* var) {
   DCHECK(!FLAG_harmony_modules || interface_->IsUnified(var->interface()));
   DCHECK((is_this() && var->is_this()) || raw_name() == var->raw_name());
   // Ideally CONST-ness should match. However, this is very hard to achieve
   // because we don't know the exact semantics of conflicting (const and
   // non-const) multiple variable declarations, const vars introduced via
   // eval() etc.  Const-ness and variable declarations are a complete mess
   // in JS. Sigh...
   set_var(var);
   set_is_resolved();
   var->set_is_used();
 }
 
 
 Assignment::Assignment(Zone* zone, Token::Value op, Expression* target,
                        Expression* value, int pos)
     : Expression(zone, pos),
-      is_uninitialized_(false),
-      key_type_(ELEMENT),
-      store_mode_(STANDARD_STORE),
-      op_(op),
+      bit_field_(IsUninitializedField::encode(false) |
+                 KeyTypeField::encode(ELEMENT) |
+                 StoreModeField::encode(STANDARD_STORE) |
+                 TokenField::encode(op)),
       target_(target),
       value_(value),
       binary_operation_(NULL) {}
 
 
 Token::Value Assignment::binary_op() const {
-  switch (op_) {
+  switch (op()) {
     case Token::ASSIGN_BIT_OR: return Token::BIT_OR;
     case Token::ASSIGN_BIT_XOR: return Token::BIT_XOR;
     case Token::ASSIGN_BIT_AND: return Token::BIT_AND;
     case Token::ASSIGN_SHL: return Token::SHL;
     case Token::ASSIGN_SAR: return Token::SAR;
     case Token::ASSIGN_SHR: return Token::SHR;
     case Token::ASSIGN_ADD: return Token::ADD;
     case Token::ASSIGN_SUB: return Token::SUB;
     case Token::ASSIGN_MUL: return Token::MUL;
     case Token::ASSIGN_DIV: return Token::DIV;
@@ skipping 1011 matching lines @@
 // static
 bool Literal::Match(void* literal1, void* literal2) {
   const AstValue* x = static_cast<Literal*>(literal1)->raw_value();
   const AstValue* y = static_cast<Literal*>(literal2)->raw_value();
   return (x->IsString() && y->IsString() && *x->AsString() == *y->AsString()) ||
          (x->IsNumber() && y->IsNumber() && x->AsNumber() == y->AsNumber());
 }
 
 
 } }  // namespace v8::internal