[AST][NFC] Pack CXXDefaultArgExpr

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

llvm-svn: 347137

3 files changed, 30 insertions, 26 deletions

diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
index 847a9fe2a17..3a1755d86a7 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -1059,26 +1059,24 @@ public:
 /// corresponding parameter's default argument, when the call did not
 /// explicitly supply arguments for all of the parameters.
 class CXXDefaultArgExpr final : public Expr {
+  friend class ASTStmtReader;
+
   /// The parameter whose default is being used.
   ParmVarDecl *Param;
 
-  /// The location where the default argument expression was used.
-  SourceLocation Loc;
-
-  CXXDefaultArgExpr(StmtClass SC, SourceLocation Loc, ParmVarDecl *param)
+  CXXDefaultArgExpr(StmtClass SC, SourceLocation Loc, ParmVarDecl *Param)
       : Expr(SC,
-             param->hasUnparsedDefaultArg()
-               ? param->getType().getNonReferenceType()
-               : param->getDefaultArg()->getType(),
-             param->getDefaultArg()->getValueKind(),
-             param->getDefaultArg()->getObjectKind(), false, false, false,
+             Param->hasUnparsedDefaultArg()
+                 ? Param->getType().getNonReferenceType()
+                 : Param->getDefaultArg()->getType(),
+             Param->getDefaultArg()->getValueKind(),
+             Param->getDefaultArg()->getObjectKind(), false, false, false,
              false),
-        Param(param), Loc(Loc) {}
+        Param(Param) {
+    CXXDefaultArgExprBits.Loc = Loc;
+  }
 
 public:
-  friend class ASTStmtReader;
-  friend class ASTStmtWriter;
-
   CXXDefaultArgExpr(EmptyShell Empty) : Expr(CXXDefaultArgExprClass, Empty) {}
 
   // \p Param is the parameter whose default argument is used by this
@@ -1093,23 +1091,18 @@ public:
   ParmVarDecl *getParam() { return Param; }
 
   // Retrieve the actual argument to the function call.
-  const Expr *getExpr() const {
-    return getParam()->getDefaultArg();
-  }
-  Expr *getExpr() {
-    return getParam()->getDefaultArg();
-  }
+  const Expr *getExpr() const { return getParam()->getDefaultArg(); }
+  Expr *getExpr() { return getParam()->getDefaultArg(); }
 
-  /// Retrieve the location where this default argument was actually
-  /// used.
-  SourceLocation getUsedLocation() const { return Loc; }
+  /// Retrieve the location where this default argument was actually used.
+  SourceLocation getUsedLocation() const { return CXXDefaultArgExprBits.Loc; }
 
   /// Default argument expressions have no representation in the
   /// source, so they have an empty source range.
-  SourceLocation getBeginLoc() const LLVM_READONLY { return SourceLocation(); }
-  SourceLocation getEndLoc() const LLVM_READONLY { return SourceLocation(); }
+  SourceLocation getBeginLoc() const { return SourceLocation(); }
+  SourceLocation getEndLoc() const { return SourceLocation(); }
 
-  SourceLocation getExprLoc() const LLVM_READONLY { return Loc; }
+  SourceLocation getExprLoc() const { return getUsedLocation(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXDefaultArgExprClass;
diff --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
index 34667d1df56..258678bdd19 100644
--- a/clang/include/clang/AST/Stmt.h
+++ b/clang/include/clang/AST/Stmt.h
@@ -548,6 +548,16 @@ protected:
     SourceLocation ThrowLoc;
   };
 
+  class CXXDefaultArgExprBitfields {
+    friend class ASTStmtReader;
+    friend class CXXDefaultArgExpr;
+
+    unsigned : NumExprBits;
+
+    /// The location where the default argument expression was used.
+    SourceLocation Loc;
+  };
+
   class TypeTraitExprBitfields {
     friend class ASTStmtReader;
     friend class ASTStmtWriter;
@@ -650,6 +660,7 @@ protected:
     CXXNullPtrLiteralExprBitfields CXXNullPtrLiteralExprBits;
     CXXThisExprBitfields CXXThisExprBits;
     CXXThrowExprBitfields CXXThrowExprBits;
+    CXXDefaultArgExprBitfields CXXDefaultArgExprBits;
     TypeTraitExprBitfields TypeTraitExprBits;
     ExprWithCleanupsBitfields ExprWithCleanupsBits;
 
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 184ae372231..cf39ccc5e00 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -1481,7 +1481,7 @@ void ASTStmtReader::VisitCXXThrowExpr(CXXThrowExpr *E) {
 void ASTStmtReader::VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) {
   VisitExpr(E);
   E->Param = ReadDeclAs<ParmVarDecl>();
-  E->Loc = ReadSourceLocation();
+  E->CXXDefaultArgExprBits.Loc = ReadSourceLocation();
 }
 
 void ASTStmtReader::VisitCXXDefaultInitExpr(CXXDefaultInitExpr *E) {