DenseStorage safely copy/swap.

Fixes #2229.

For dynamic matrices with fixed-sized storage, only copy/swap
elements that have been set.  Otherwise, this leads to inefficient
copying, and potential UB for non-initialized elements.

3 files changed, 139 insertions, 66 deletions

diff --git a/test/SafeScalar.h b/test/SafeScalar.h
new file mode 100644
index 000000000..c5cb75717
--- /dev/null
+++ b/test/SafeScalar.h
@@ -0,0 +1,30 @@
+
+// A Scalar that asserts for uninitialized access.
+template<typename T>
+class SafeScalar {
+ public:
+  SafeScalar() : initialized_(false) {}
+  SafeScalar(const SafeScalar& other) {
+    *this = other;
+  }
+  SafeScalar& operator=(const SafeScalar& other) {
+    val_ = T(other);
+    initialized_ = true;
+    return *this;
+  }
+  
+  SafeScalar(T val) : val_(val), initialized_(true) {}
+  SafeScalar& operator=(T val) {
+    val_ = val;
+    initialized_ = true;
+  }
+  
+  operator T() const {
+    VERIFY(initialized_ && "Uninitialized access.");
+    return val_;
+  }
+ 
+ private:
+  T val_;
+  bool initialized_;
+};
diff --git a/test/dense_storage.cpp b/test/dense_storage.cpp
index 7fa25859d..36ccbb02c 100644
--- a/test/dense_storage.cpp
+++ b/test/dense_storage.cpp
@@ -8,17 +8,16 @@
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #include "main.h"
+#include "AnnoyingScalar.h"
+#include "SafeScalar.h"
 
 #include <Eigen/Core>
 
-template <typename T, int Rows, int Cols>
-void dense_storage_copy()
+template <typename T, int Size, int Rows, int Cols>
+void dense_storage_copy(int rows, int cols)
 {
-  static const int Size = ((Rows==Dynamic || Cols==Dynamic) ? Dynamic : Rows*Cols);
-  typedef DenseStorage<T,Size, Rows,Cols, 0> DenseStorageType;
+  typedef DenseStorage<T, Size, Rows, Cols, 0> DenseStorageType;
   
-  const int rows = (Rows==Dynamic) ? 4 : Rows;
-  const int cols = (Cols==Dynamic) ? 3 : Cols;
   const int size = rows*cols;
   DenseStorageType reference(size, rows, cols);
   T* raw_reference = reference.data();
@@ -31,14 +30,11 @@ void dense_storage_copy()
     VERIFY_IS_EQUAL(raw_reference[i], raw_copied_reference[i]);
 }
 
-template <typename T, int Rows, int Cols>
-void dense_storage_assignment()
+template <typename T, int Size, int Rows, int Cols>
+void dense_storage_assignment(int rows, int cols)
 {
-  static const int Size = ((Rows==Dynamic || Cols==Dynamic) ? Dynamic : Rows*Cols);
-  typedef DenseStorage<T,Size, Rows,Cols, 0> DenseStorageType;
+  typedef DenseStorage<T, Size, Rows, Cols, 0> DenseStorageType;
   
-  const int rows = (Rows==Dynamic) ? 4 : Rows;
-  const int cols = (Cols==Dynamic) ? 3 : Cols;
   const int size = rows*cols;
   DenseStorageType reference(size, rows, cols);
   T* raw_reference = reference.data();
@@ -52,6 +48,34 @@ void dense_storage_assignment()
     VERIFY_IS_EQUAL(raw_reference[i], raw_copied_reference[i]);
 }
 
+template <typename T, int Size, int Rows, int Cols>
+void dense_storage_swap(int rows0, int cols0, int rows1, int cols1)
+{
+  typedef DenseStorage<T, Size, Rows, Cols, 0> DenseStorageType;
+  
+  const int size0 = rows0*cols0;
+  DenseStorageType a(size0, rows0, cols0);
+  for (int i=0; i<size0; ++i) {
+    a.data()[i] = static_cast<T>(i);
+  }
+  
+  const int size1 = rows1*cols1;
+  DenseStorageType b(size1, rows1, cols1);
+  for (int i=0; i<size1; ++i) {
+    b.data()[i] = static_cast<T>(-i);
+  }
+  
+  a.swap(b);
+  
+  for (int i=0; i<size0; ++i) {
+    VERIFY_IS_EQUAL(b.data()[i], static_cast<T>(i));
+  }
+  
+  for (int i=0; i<size1; ++i) {
+    VERIFY_IS_EQUAL(a.data()[i], static_cast<T>(-i));
+  }
+}
+
 template<typename T, int Size, std::size_t Alignment>
 void dense_storage_alignment()
 {
@@ -78,30 +102,78 @@ void dense_storage_alignment()
   #endif
 }
 
-EIGEN_DECLARE_TEST(dense_storage)
-{
-  dense_storage_copy<int,Dynamic,Dynamic>();  
-  dense_storage_copy<int,Dynamic,3>();
-  dense_storage_copy<int,4,Dynamic>();
-  dense_storage_copy<int,4,3>();
-
-  dense_storage_copy<float,Dynamic,Dynamic>();
-  dense_storage_copy<float,Dynamic,3>();
-  dense_storage_copy<float,4,Dynamic>();  
-  dense_storage_copy<float,4,3>();
+template<typename T>
+void dense_storage_tests() {
+  // Dynamic Storage.
+  dense_storage_copy<T,Dynamic,Dynamic,Dynamic>(4, 3);  
+  dense_storage_copy<T,Dynamic,Dynamic,3>(4, 3);
+  dense_storage_copy<T,Dynamic,4,Dynamic>(4, 3);
+  // Fixed Storage.
+  dense_storage_copy<T,12,4,3>(4, 3);
+  dense_storage_copy<T,12,Dynamic,Dynamic>(4, 3);
+  dense_storage_copy<T,12,4,Dynamic>(4, 3);
+  dense_storage_copy<T,12,Dynamic,3>(4, 3);
+  // Fixed Storage with Uninitialized Elements.
+  dense_storage_copy<T,18,Dynamic,Dynamic>(4, 3);
+  dense_storage_copy<T,18,4,Dynamic>(4, 3);
+  dense_storage_copy<T,18,Dynamic,3>(4, 3);
   
-  dense_storage_assignment<int,Dynamic,Dynamic>();  
-  dense_storage_assignment<int,Dynamic,3>();
-  dense_storage_assignment<int,4,Dynamic>();
-  dense_storage_assignment<int,4,3>();
-
-  dense_storage_assignment<float,Dynamic,Dynamic>();
-  dense_storage_assignment<float,Dynamic,3>();
-  dense_storage_assignment<float,4,Dynamic>();  
-  dense_storage_assignment<float,4,3>(); 
+  // Dynamic Storage.
+  dense_storage_assignment<T,Dynamic,Dynamic,Dynamic>(4, 3);  
+  dense_storage_assignment<T,Dynamic,Dynamic,3>(4, 3);
+  dense_storage_assignment<T,Dynamic,4,Dynamic>(4, 3);
+  // Fixed Storage.
+  dense_storage_assignment<T,12,4,3>(4, 3);
+  dense_storage_assignment<T,12,Dynamic,Dynamic>(4, 3);
+  dense_storage_assignment<T,12,4,Dynamic>(4, 3);
+  dense_storage_assignment<T,12,Dynamic,3>(4, 3);
+  // Fixed Storage with Uninitialized Elements.
+  dense_storage_assignment<T,18,Dynamic,Dynamic>(4, 3);
+  dense_storage_assignment<T,18,4,Dynamic>(4, 3);
+  dense_storage_assignment<T,18,Dynamic,3>(4, 3);
+  
+  // Dynamic Storage.
+  dense_storage_swap<T,Dynamic,Dynamic,Dynamic>(4, 3, 4, 3); 
+  dense_storage_swap<T,Dynamic,Dynamic,Dynamic>(4, 3, 2, 1);  
+  dense_storage_swap<T,Dynamic,Dynamic,Dynamic>(2, 1, 4, 3);
+  dense_storage_swap<T,Dynamic,Dynamic,3>(4, 3, 4, 3);
+  dense_storage_swap<T,Dynamic,Dynamic,3>(4, 3, 2, 3);
+  dense_storage_swap<T,Dynamic,Dynamic,3>(2, 3, 4, 3);
+  dense_storage_swap<T,Dynamic,4,Dynamic>(4, 3, 4, 3);
+  dense_storage_swap<T,Dynamic,4,Dynamic>(4, 3, 4, 1);
+  dense_storage_swap<T,Dynamic,4,Dynamic>(4, 1, 4, 3);
+  // Fixed Storage.
+  dense_storage_swap<T,12,4,3>(4, 3, 4, 3);
+  dense_storage_swap<T,12,Dynamic,Dynamic>(4, 3, 4, 3);
+  dense_storage_swap<T,12,Dynamic,Dynamic>(4, 3, 2, 1);
+  dense_storage_swap<T,12,Dynamic,Dynamic>(2, 1, 4, 3);
+  dense_storage_swap<T,12,4,Dynamic>(4, 3, 4, 3);
+  dense_storage_swap<T,12,4,Dynamic>(4, 3, 4, 1);
+  dense_storage_swap<T,12,4,Dynamic>(4, 1, 4, 3);
+  dense_storage_swap<T,12,Dynamic,3>(4, 3, 4, 3);
+  dense_storage_swap<T,12,Dynamic,3>(4, 3, 2, 3);
+  dense_storage_swap<T,12,Dynamic,3>(2, 3, 4, 3);
+  // Fixed Storage with Uninitialized Elements.
+  dense_storage_swap<T,18,Dynamic,Dynamic>(4, 3, 4, 3);
+  dense_storage_swap<T,18,Dynamic,Dynamic>(4, 3, 2, 1);
+  dense_storage_swap<T,18,Dynamic,Dynamic>(2, 1, 4, 3);
+  dense_storage_swap<T,18,4,Dynamic>(4, 3, 4, 3);
+  dense_storage_swap<T,18,4,Dynamic>(4, 3, 4, 1);
+  dense_storage_swap<T,18,4,Dynamic>(4, 1, 4, 3);
+  dense_storage_swap<T,18,Dynamic,3>(4, 3, 4, 3);
+  dense_storage_swap<T,18,Dynamic,3>(4, 3, 2, 3);
+  dense_storage_swap<T,18,Dynamic,3>(2, 3, 4, 3);
+  
+  dense_storage_alignment<T,16,8>();
+  dense_storage_alignment<T,16,16>();
+  dense_storage_alignment<T,16,32>();
+  dense_storage_alignment<T,16,64>();
+}
 
-  dense_storage_alignment<float,16,8>();
-  dense_storage_alignment<float,16,16>();
-  dense_storage_alignment<float,16,32>();
-  dense_storage_alignment<float,16,64>();
+EIGEN_DECLARE_TEST(dense_storage)
+{
+  dense_storage_tests<int>();
+  dense_storage_tests<float>();
+  dense_storage_tests<SafeScalar<float> >();
+  dense_storage_tests<AnnoyingScalar>();
 }
diff --git a/test/rvalue_types.cpp b/test/rvalue_types.cpp
index c20a32f79..2c9999ce8 100644
--- a/test/rvalue_types.cpp
+++ b/test/rvalue_types.cpp
@@ -13,41 +13,12 @@
 #if EIGEN_HAS_CXX11
 #include "MovableScalar.h"
 #endif
+#include "SafeScalar.h"
 
 #include <Eigen/Core>
 
 using internal::UIntPtr;
 
-// A Scalar that asserts for uninitialized access.
-template<typename T>
-class SafeScalar {
- public:
-  SafeScalar() : initialized_(false) {}
-  SafeScalar(const SafeScalar& other) {
-    *this = other;
-  }
-  SafeScalar& operator=(const SafeScalar& other) {
-    val_ = T(other);
-    initialized_ = true;
-    return *this;
-  }
-  
-  SafeScalar(T val) : val_(val), initialized_(true) {}
-  SafeScalar& operator=(T val) {
-    val_ = val;
-    initialized_ = true;
-  }
-  
-  operator T() const {
-    VERIFY(initialized_ && "Uninitialized access.");
-    return val_;
-  }
- 
- private:
-  T val_;
-  bool initialized_;
-};
-
 #if EIGEN_HAS_RVALUE_REFERENCES
 template <typename MatrixType>
 void rvalue_copyassign(const MatrixType& m)