Added safe conversion from size_t to int.

CMakeLists_files.cmake

@@ -164,6 +164,7 @@ if(CUDA_FOUND)
   list (APPEND PUBLIC_HEADER_FILES opm/simulators/linalg/cuistl/detail/CuMatrixDescription.hpp)
   list (APPEND PUBLIC_HEADER_FILES opm/simulators/linalg/cuistl/detail/CuSparseResource.hpp)
   list (APPEND PUBLIC_HEADER_FILES opm/simulators/linalg/cuistl/detail/CuSparseResource_impl.hpp)
+  list (APPEND PUBLIC_HEADER_FILES opm/simulators/linalg/cuistl/detail/safe_conversion.hpp)
 
 
 
@@ -252,6 +253,8 @@ if(CUDA_FOUND)
   list(APPEND TEST_SOURCE_FILES tests/cuistl/test_cusparse_handle.cpp)
   list(APPEND TEST_SOURCE_FILES tests/cuistl/test_cuvector.cpp)
   list(APPEND TEST_SOURCE_FILES tests/cuistl/test_cusparsematrix.cpp)
+  list(APPEND TEST_SOURCE_FILES tests/cuistl/test_safe_conversion.cpp)
+
 endif()
 if(OPENCL_FOUND)
   list(APPEND TEST_SOURCE_FILES tests/test_openclSolver.cpp)

opm/simulators/linalg/cuistl/detail/safe_conversion.hpp

@@ -0,0 +1,63 @@
+/*
+  Copyright 2023 SINTEF AS
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM 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 3 of the License, or
+  (at your option) any later version.
+
+  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef OPM_CUISTL_SAFE_CONVERSION_HPP
+#define OPM_CUISTL_SAFE_CONVERSION_HPP
+
+
+
+#include <fmt/format.h>
+#include <limits>
+#include <opm/common/ErrorMacros.hpp>
+
+
+/**
+ * Provides various utilities for doing signed to unsigned conversion, unsigned to signed, 32 bits to 64 bits and 64
+ * bits to 32 bits.
+ *
+ * The main use case within cuistl is that the cusparse library requires signed int for all its size parameters,
+ * while Dune::BlockVector (and relatives) use signed size_t.
+ */
+
+namespace Opm::cuistl::detail
+{
+
+/**
+ * @brief convert converts a (on most relevant platform) 64 bits unsigned size_t to a signed 32 bits signed  int
+ * @param s the unsigned integer
+ * @throw std::invalid_argument exception if s is out of range for an int
+ * @return converted s to int if s is within the range of int
+ *
+ * @todo This can be done for more generic types, but then it is probably wise to wait for C++20's cmp-functions
+ */
+int
+convert(size_t s)
+{
+    if (s > size_t(std::numeric_limits<int>::max())) {
+        OPM_THROW(std::invalid_argument,
+                  fmt::format("Trying to convert {} to int, but it is out of range. Maximum possible int: {}. ",
+                              s,
+                              std::numeric_limits<int>::max()));
+    }
+
+    // We know it will be in range here:
+    return int(s);
+}
+} // namespace Opm::cuistl::detail
+
+#endif

tests/cuistl/test_safe_conversion.cpp

@@ -0,0 +1,41 @@
+/*
+  Copyright 2023 SINTEF AS
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM 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 3 of the License, or
+  (at your option) any later version.
+
+  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <config.h>
+
+#define BOOST_TEST_MODULE TestSafeConversion
+
+#include <boost/test/unit_test.hpp>
+#include <opm/simulators/linalg/cuistl/detail/safe_conversion.hpp>
+
+BOOST_AUTO_TEST_CASE(TestThrowsOutofRange)
+{
+    BOOST_CHECK_THROW(Opm::cuistl::detail::convert(size_t(std::numeric_limits<int>::max()) + size_t(1));
+                      , std::invalid_argument);
+}
+
+BOOST_AUTO_TEST_CASE(TestConvertInRange)
+{
+    // This might seem slow, but it is really fast:
+    for (size_t i = 0; i <= size_t(1024 * 1024); ++i) {
+        BOOST_CHECK_EQUAL(int(i), Opm::cuistl::detail::convert(i));
+    }
+
+    BOOST_CHECK_EQUAL(std::numeric_limits<int>::max(),
+                      Opm::cuistl::detail::convert(size_t(std::numeric_limits<int>::max())));
+}