From 63dc0fa7e98ce8e7ca369c6f3fff59da295f50cb Mon Sep 17 00:00:00 2001
From: Michael Marshall <43034299+mmphys@users.noreply.github.com>
Date: Thu, 4 Apr 2019 16:00:17 +0100
Subject: [PATCH] Fixed memory leak ... without breaking semantics of prior
 code. Possibly should change the semantics? For Peter / Antonin to comment

---
 Grid/qcd/smearing/StoutSmearing.h | 78 ++++++++++++++++++++++---------
 1 file changed, 56 insertions(+), 22 deletions(-)

diff --git a/Grid/qcd/smearing/StoutSmearing.h b/Grid/qcd/smearing/StoutSmearing.h
index 23a6b290..e4e11a63 100644
--- a/Grid/qcd/smearing/StoutSmearing.h
+++ b/Grid/qcd/smearing/StoutSmearing.h
@@ -1,5 +1,34 @@
+/*************************************************************************************
+ 
+ Grid physics library, www.github.com/paboyle/Grid
+ 
+ Source file: ./lib/qcd/smearing/StoutSmearing.h
+ 
+ Copyright (C) 2019
+ 
+ Author: unknown
+ Author: Felix Erben <ferben@ed.ac.uk>
+ Author: Michael Marshall <Michael.Marshall@ed.ac.uk>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+ 
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ 
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ 
+ See the full license in the file "LICENSE" in the top level distribution
+ directory
+ *************************************************************************************/
 /*
-  @file stoutSmear.hpp
+  @file StoutSmearing.h
   @brief Declares Stout smearing class
 */
 #ifndef STOUT_SMEAR_
@@ -12,37 +41,42 @@ namespace QCD {
 template <class Gimpl>
 class Smear_Stout : public Smear<Gimpl> {
  private:
-  const Smear<Gimpl>* SmearBase;
-  inline std::vector<double> rho3D(double rho, int orthogdim){ 
+  // Smear<Gimpl>* ownership semantics:
+  //    Smear<Gimpl>* passed in to constructor are owned by caller, so we don't delete them here
+  //    Smear<Gimpl>* created within constructor need to be deleted as part of the destructor
+  const Smear<Gimpl>* SmearBase; // Not owned by this object, so not deleted at destruction
+  const std::unique_ptr<Smear<Gimpl>> OwnedBase; // deleted at destruction
+
+public:
+  INHERIT_GIMPL_TYPES(Gimpl)
+
+  // only anticipated to be used from default constructor, but might as well be visible
+  inline static std::vector<double> rho3D(double rho = 1.0, int orthogdim = -1){
     std::vector<double> rho3d(Nd*Nd);
     for (int mu=0; mu<Nd; mu++)
       for (int nu=0; nu<Nd; nu++)
-        rho3d[mu + Nd * nu] = (mu == orthogdim || nu == orthogdim) ? 0.0:rho;
+        rho3d[mu + Nd * nu] = (mu == orthogdim || nu == orthogdim) ? 0.0 : rho;
     return rho3d;
   };
- public:
-  INHERIT_GIMPL_TYPES(Gimpl)
 
-  Smear_Stout(Smear<Gimpl>* base) : SmearBase(base) {
-    assert(Nc == 3);//                  "Stout smearing currently implemented only for Nc==3");
+  /*! Stout smearing with base explicitly specified */
+  Smear_Stout(Smear<Gimpl>* base) : SmearBase{base} {
+    assert(Nc == 3 && "Stout smearing currently implemented only for Nc==3");
   }
 
-  /*! Default constructor */
-/*  Smear_Stout(double rho = 1.0) : SmearBase(new Smear_APE<Gimpl>(rho)) {
-    assert(Nc == 3);//                  "Stout smearing currently implemented only for Nc==3");
-  } */
+  /*! Construct stout smearing object from explicitly specified rho matrix */
+  Smear_Stout(const std::vector<double>& rho_)
+    : OwnedBase{new Smear_APE<Gimpl>(rho_)}, SmearBase{OwnedBase.get()} {
+    assert(Nc == 3 && "Stout smearing currently implemented only for Nc==3");
+    }
 
-  /*! general constructor */
-   Smear_Stout(std::vector<double>& rho_) : SmearBase(new Smear_APE<Gimpl>(rho_)) {
-     assert(Nc == 3 && "Stout smearing currently implemented only for Nc==3");
-   }
+  /*! Default constructor. rho is constant in all directions, optionally except for orthogonal dimension */
+  Smear_Stout(double rho = 1.0, int orthogdim = -1)
+    : OwnedBase{new Smear_APE<Gimpl>(rho3D(rho,orthogdim))}, SmearBase{OwnedBase.get()} {
+    assert(Nc == 3 && "Stout smearing currently implemented only for Nc==3");
+  }
 
-   /*! 3D constructor */
-  Smear_Stout(double rho = 1.0, int orthogdim = -1) :  SmearBase{new Smear_APE<Gimpl>(rho3D(rho,orthogdim))} {
-     assert(Nc == 3 && "Stout smearing currently implemented only for Nc==3");
-   }
-
-  ~Smear_Stout() {delete SmearBase;}
+  ~Smear_Stout() {}  // delete SmearBase...
 
   void smear(GaugeField& u_smr, const GaugeField& U) const {
     GaugeField C(U._grid);