test/sizeoverflow.cpp

// 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); \
  }

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));
}

EIGEN_DECLARE_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);
}