[AST] Pack CXXBoolLiteralExpr, CXXNullPtrLiteralExpr and CXXThisExpr

[riccibruno]

Summary

Use the newly available space in the bit-fields of Stmt to
store some data from CXXBoolLiteralExpr, CXXNullPtrLiteralExpr
and CXXThisExpr.

This cuts the size of each of these classes by 1 pointer.

[riccibruno]

Fix some typos in the added comments in Stmt.h

[riccibruno]

Broken down and sent for review individually.

include/clang/AST/ExprCXX.h

public:
 
   static bool classof(const Stmt *S) {
     return S->getStmtClass() == UserDefinedLiteralClass;
   }
 };
 
 /// A boolean literal, per ([C++ lex.bool] Boolean literals).
 class CXXBoolLiteralExpr : public Expr {
-  bool Value;
-  SourceLocation Loc;
-
 public:
-  CXXBoolLiteralExpr(bool val, QualType Ty, SourceLocation l)
+  CXXBoolLiteralExpr(bool Val, QualType Ty, SourceLocation Loc)
       : Expr(CXXBoolLiteralExprClass, Ty, VK_RValue, OK_Ordinary, false, false,
-             false, false),
-        Value(val), Loc(l) {}
+             false, false) {
+    CXXBoolLiteralExprBits.Value = Val;
+    CXXBoolLiteralExprBits.Loc = Loc;
+  }
 
   explicit CXXBoolLiteralExpr(EmptyShell Empty)
       : Expr(CXXBoolLiteralExprClass, Empty) {}
 
-  bool getValue() const { return Value; }
-  void setValue(bool V) { Value = V; }
+  bool getValue() const { return CXXBoolLiteralExprBits.Value; }
+  void setValue(bool V) { CXXBoolLiteralExprBits.Value = V; }
 
-  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 CXXBoolLiteralExprBits.Loc; }
+  void setLocation(SourceLocation L) { CXXBoolLiteralExprBits.Loc = L; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXBoolLiteralExprClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
 };
 
 /// The null pointer literal (C++11 [lex.nullptr])
 ///
 /// 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;
   }
 
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }

 /// \code
 /// class Foo {
 /// public:
 ///   void bar();
 ///   void test() { this->bar(); }
 /// };
 /// \endcode
 class CXXThisExpr : public Expr {
-  SourceLocation Loc;
-  bool Implicit : 1;
-
 public:
-  CXXThisExpr(SourceLocation L, QualType Type, bool isImplicit)
-      : Expr(CXXThisExprClass, Type, VK_RValue, OK_Ordinary,
+  CXXThisExpr(SourceLocation L, QualType Ty, bool IsImplicit)
+      : Expr(CXXThisExprClass, Ty, VK_RValue, OK_Ordinary,
              // 'this' is type-dependent if the class type of the enclosing
              // member function is dependent (C++ [temp.dep.expr]p2)
-             Type->isDependentType(), Type->isDependentType(),
-             Type->isInstantiationDependentType(),
-             /*ContainsUnexpandedParameterPack=*/false),
-        Loc(L), Implicit(isImplicit) {}
+             Ty->isDependentType(), Ty->isDependentType(),
+             Ty->isInstantiationDependentType(),
+             /*ContainsUnexpandedParameterPack=*/false) {
+    CXXThisExprBits.IsImplicit = IsImplicit;
+    CXXThisExprBits.Loc = L;
+  }
 
   CXXThisExpr(EmptyShell Empty) : Expr(CXXThisExprClass, Empty) {}
 
-  SourceLocation getLocation() const { return Loc; }
-  void setLocation(SourceLocation L) { Loc = L; }
+  SourceLocation getLocation() const { return CXXThisExprBits.Loc; }
+  void setLocation(SourceLocation L) { CXXThisExprBits.Loc = L; }
 
-  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
-  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
+  SourceLocation getBeginLoc() const { return getLocation(); }
+  SourceLocation getEndLoc() const { return getLocation(); }
 
-  bool isImplicit() const { return Implicit; }
-  void setImplicit(bool I) { Implicit = I; }
+  bool isImplicit() const { return CXXThisExprBits.IsImplicit; }
+  void setImplicit(bool I) { CXXThisExprBits.IsImplicit = I; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXThisExprClass;
   }
 
   // Iterators
   child_range children() {
     return child_range(child_iterator(), child_iterator());

include/clang/AST/Stmt.h

class BinaryOperatorBitfields {
     /// This is only meaningful for operations on floating
     /// point types and 0 otherwise.
     unsigned FPFeatures : 3;
 
     /// The location of the operator.
     SourceLocation OpLoc;
   };
 
-  class ExprWithCleanupsBitfields {
-    friend class ASTStmtReader; // deserialization
-    friend class ExprWithCleanups;
-
-    unsigned : NumExprBits;
-
-    // When false, it must not have side effects.
-    unsigned CleanupsHaveSideEffects : 1;
-
-    unsigned NumObjects : 32 - 1 - NumExprBits;
-  };
-
   class ParenListExprBitfields {
     friend class ASTStmtReader;
     friend class ParenListExpr;
 
     unsigned : NumExprBits;
 
     /// The number of expressions in the paren list.
     unsigned NumExprs;
class OpaqueValueExprBitfields {
 
     unsigned : NumExprBits;
 
     /// The OVE is a unique semantic reference to its source expressio if this
     /// bit is set to true.
     unsigned IsUnique : 1;
   };
 
-  class ObjCIndirectCopyRestoreExprBitfields {
-    friend class ObjCIndirectCopyRestoreExpr;
-
-    unsigned : NumExprBits;
-
-    unsigned ShouldCopy : 1;
-  };
-
   class InitListExprBitfields {
     friend class InitListExpr;
 
     unsigned : NumExprBits;
 
     /// Whether this initializer list originally had a GNU array-range
     /// designator in it. This is a temporary marker used by CodeGen.
     unsigned HadArrayRangeDesignator : 1;
   };
 
+  //===--- C++ expression bitfields classes ---===//
+
+  class CXXBoolLiteralExprBitfields {
+    friend class ASTStmtReader;
+    friend class CXXBoolLiteralExpr;
+
+    unsigned : NumExprBits;
+
+    /// The value of the boolean literal.
+    unsigned Value : 1;
+
+    /// The location of the boolean literal.
+    SourceLocation Loc;
+  };
+
+  class CXXNullPtrLiteralExprBitfields {
+    friend class ASTStmtReader;
+    friend class CXXNullPtrLiteralExpr;
+
+    unsigned : NumExprBits;
+
+    /// The location of the null pointer literal.
+    SourceLocation Loc;
+  };
+
+  class CXXThisExprBitfields {
+    friend class ASTStmtReader;
+    friend class CXXThisExpr;
+
+    unsigned : NumExprBits;
+
+    /// Whether this is an implicit "this".
+    unsigned IsImplicit : 1;
+
+    /// The location of the "this".
+    SourceLocation Loc;
+  };
+
   class TypeTraitExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
     friend class TypeTraitExpr;
 
     unsigned : NumExprBits;
 
     /// The kind of type trait, which is a value of a TypeTrait enumerator.
     unsigned Kind : 8;
 
     /// If this expression is not value-dependent, this indicates whether
     /// the trait evaluated true or false.
     unsigned Value : 1;
 
     /// The number of arguments to this type trait.
     unsigned NumArgs : 32 - 8 - 1 - NumExprBits;
   };
 
+  class ExprWithCleanupsBitfields {
+    friend class ASTStmtReader;
+    friend class ExprWithCleanups;
+
+    unsigned : NumExprBits;
+
+    /// When false, it must not have side effects.
+    unsigned CleanupsHaveSideEffects : 1;
+
+    unsigned NumObjects : 32 - 1 - NumExprBits;
+  };
+
+  //===--- C++ Coroutines TS expression bitfields classes ---===//
+
   class CoawaitExprBitfields {
     friend class CoawaitExpr;
 
     unsigned : NumExprBits;
 
     unsigned IsImplicit : 1;
   };
 
+  //===--- Obj-C expression bitfields classes ---===//
+
+  class ObjCIndirectCopyRestoreExprBitfields {
+    friend class ObjCIndirectCopyRestoreExpr;
+
+    unsigned : NumExprBits;
+
+    unsigned ShouldCopy : 1;
+  };
+
   union {
     // Statements
     StmtBitfields StmtBits;
     NullStmtBitfields NullStmtBits;
     CompoundStmtBitfields CompoundStmtBits;
     LabelStmtBitfields LabelStmtBits;
     AttributedStmtBitfields AttributedStmtBits;
     IfStmtBitfields IfStmtBits;
union {
     UnaryExprOrTypeTraitExprBitfields UnaryExprOrTypeTraitExprBits;
     ArraySubscriptExprBitfields ArraySubscriptExprBits;
     DeclRefExprBitfields DeclRefExprBits;
     UnaryOperatorBitfields UnaryOperatorBits;
     CallExprBitfields CallExprBits;
     MemberExprBitfields MemberExprBits;
     CastExprBitfields CastExprBits;
     BinaryOperatorBitfields BinaryOperatorBits;
-    ExprWithCleanupsBitfields ExprWithCleanupsBits;
     ParenListExprBitfields ParenListExprBits;
     PseudoObjectExprBitfields PseudoObjectExprBits;
     OpaqueValueExprBitfields OpaqueValueExprBits;
-    ObjCIndirectCopyRestoreExprBitfields ObjCIndirectCopyRestoreExprBits;
     InitListExprBitfields InitListExprBits;
+
+    // C++ Expressions
+    CXXBoolLiteralExprBitfields CXXBoolLiteralExprBits;
+    CXXNullPtrLiteralExprBitfields CXXNullPtrLiteralExprBits;
+    CXXThisExprBitfields CXXThisExprBits;
     TypeTraitExprBitfields TypeTraitExprBits;
+    ExprWithCleanupsBitfields ExprWithCleanupsBits;
+
+    // C++ Coroutines TS expressions
     CoawaitExprBitfields CoawaitBits;
+
+    // Obj-C Expressions
+    ObjCIndirectCopyRestoreExprBitfields ObjCIndirectCopyRestoreExprBits;
   };
 
 public:
   // Only allow allocation of Stmts using the allocator in ASTContext
   // or by doing a placement new.
   void* operator new(size_t bytes, const ASTContext& C,
                      unsigned alignment = 8);