[AST][NFC] Pack CXXNullPtrLiteralExpr

Use the newly available space in the bit-fields of Stmt.
This saves one pointer per CXXNullPtrLiteralExpr.

llvm-svn: 347063

clang/include/clang/AST/ExprCXX.h

@@ -582,22 +582,21 @@ public:
 ///
 /// Introduced in C++11, the only literal of type \c nullptr_t is \c nullptr.
 class CXXNullPtrLiteralExpr : public Expr {
-  SourceLocation Loc;
-
 public:
-  CXXNullPtrLiteralExpr(QualType Ty, SourceLocation l)
+  CXXNullPtrLiteralExpr(QualType Ty, SourceLocation Loc)
       : Expr(CXXNullPtrLiteralExprClass, Ty, VK_RValue, OK_Ordinary, false,
-             false, false, false),
-        Loc(l) {}
+             false, false, false) {
+    CXXNullPtrLiteralExprBits.Loc = Loc;
+  }
 
   explicit CXXNullPtrLiteralExpr(EmptyShell Empty)
       : Expr(CXXNullPtrLiteralExprClass, Empty) {}
 
-  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
-  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
+  SourceLocation getBeginLoc() const { return getLocation(); }
+  SourceLocation getEndLoc() const { return getLocation(); }
 
-  SourceLocation getLocation() const { return Loc; }
-  void setLocation(SourceLocation L) { Loc = L; }
+  SourceLocation getLocation() const { return CXXNullPtrLiteralExprBits.Loc; }
+  void setLocation(SourceLocation L) { CXXNullPtrLiteralExprBits.Loc = L; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXNullPtrLiteralExprClass;

clang/include/clang/AST/Stmt.h

@@ -514,6 +514,15 @@ protected:
     SourceLocation Loc;
   };
 
+  class CXXNullPtrLiteralExprBitfields {
+    friend class CXXNullPtrLiteralExpr;
+
+    unsigned : NumExprBits;
+
+    /// The location of the null pointer literal.
+    SourceLocation Loc;
+  };
+
   class TypeTraitExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
@@ -613,6 +622,7 @@ protected:
 
     // C++ Expressions
     CXXBoolLiteralExprBitfields CXXBoolLiteralExprBits;
+    CXXNullPtrLiteralExprBitfields CXXNullPtrLiteralExprBits;
     TypeTraitExprBitfields TypeTraitExprBits;
     ExprWithCleanupsBitfields ExprWithCleanupsBits;