Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/test/sizeoverflow.cpp b/test/sizeoverflow.cpp
new file mode 100644
index 0000000..16d6f8d
--- /dev/null
+++ b/test/sizeoverflow.cpp
@@ -0,0 +1,66 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "main.h"
+
+#define VERIFY_THROWS_BADALLOC(a) {                           \
+    bool threw = false;                                       \
+    try {                                                     \
+      a;                                                      \
+    }                                                         \
+    catch (std::bad_alloc&) { threw = true; }                 \
+    VERIFY(threw && "should have thrown bad_alloc: " #a);     \
+  }
+
+typedef DenseIndex Index;
+
+template<typename MatrixType>
+void triggerMatrixBadAlloc(Index rows, Index cols)
+{
+  VERIFY_THROWS_BADALLOC( MatrixType m(rows, cols) );
+  VERIFY_THROWS_BADALLOC( MatrixType m; m.resize(rows, cols) );
+  VERIFY_THROWS_BADALLOC( MatrixType m; m.conservativeResize(rows, cols) );
+}
+
+template<typename VectorType>
+void triggerVectorBadAlloc(Index size)
+{
+  VERIFY_THROWS_BADALLOC( VectorType v(size) );
+  VERIFY_THROWS_BADALLOC( VectorType v; v.resize(size) );
+  VERIFY_THROWS_BADALLOC( VectorType v; v.conservativeResize(size) );
+}
+
+void test_sizeoverflow()
+{
+  // there are 2 levels of overflow checking. first in PlainObjectBase.h we check for overflow in rows*cols computations.
+  // this is tested in tests of the form times_itself_gives_0 * times_itself_gives_0
+  // Then in Memory.h we check for overflow in size * sizeof(T) computations.
+  // this is tested in tests of the form times_4_gives_0 * sizeof(float)
+  
+  size_t times_itself_gives_0 = size_t(1) << (8 * sizeof(Index) / 2);
+  VERIFY(times_itself_gives_0 * times_itself_gives_0 == 0);
+
+  size_t times_4_gives_0 = size_t(1) << (8 * sizeof(Index) - 2);
+  VERIFY(times_4_gives_0 * 4 == 0);
+
+  size_t times_8_gives_0 = size_t(1) << (8 * sizeof(Index) - 3);
+  VERIFY(times_8_gives_0 * 8 == 0);
+
+  triggerMatrixBadAlloc<MatrixXf>(times_itself_gives_0, times_itself_gives_0);
+  triggerMatrixBadAlloc<MatrixXf>(times_itself_gives_0 / 4, times_itself_gives_0);
+  triggerMatrixBadAlloc<MatrixXf>(times_4_gives_0, 1);
+
+  triggerMatrixBadAlloc<MatrixXd>(times_itself_gives_0, times_itself_gives_0);
+  triggerMatrixBadAlloc<MatrixXd>(times_itself_gives_0 / 8, times_itself_gives_0);
+  triggerMatrixBadAlloc<MatrixXd>(times_8_gives_0, 1);
+  
+  triggerVectorBadAlloc<VectorXf>(times_4_gives_0);
+  
+  triggerVectorBadAlloc<VectorXd>(times_8_gives_0);
+}