use const cast for old OpenMPI version

Old versions of OpenMPI are missing const specifiers for input arguments
in
functions like MPI_Allgather. Introduce a macro to cast away const in
these
cases.

diff --git a/include/deal.II/base/mpi.h b/include/deal.II/base/mpi.h
index d2482be792ea35c64e66361d1a06b85ecf2a8f08..82c643d1c6cea82647216253b7d6e268816a9739 100644 (file)
--- a/include/deal.II/base/mpi.h
+++ b/include/deal.II/base/mpi.h
@@ -58,6 +58,33 @@ class SymmetricTensor;
 template <typename Number>
 class SparseMatrix;
 
+
+// Helper macro to remove const from the pointer arguments to some MPI_*
+// functions.
+//
+// This is needed as the input arguments of functions like MPI_Allgather() are
+// not marked as const in OpenMPI 1.6.5.
+#ifdef DEAL_II_WITH_MPI
+#  if DEAL_II_MPI_VERSION_GTE(3, 0)
+// We are good, no casts are needed.
+#    define DEAL_II_MPI_CONST_CAST(expr) (expr)
+#  else
+
+#    include <type_traits>
+
+// This monster of a macro will:
+// 1. remove *
+// 2. remove const
+// 3. add *
+// 4. const_cast the given expression to this new type.
+#    define DEAL_II_MPI_CONST_CAST(expr)                                       \
+      const_cast<                                                              \
+        std::remove_const<std::remove_pointer<decltype(expr)>::type>::type *>( \
+        expr)
+
+#  endif
+#endif
+
 namespace Utilities
 {
   /**

diff --git a/source/distributed/tria.cc b/source/distributed/tria.cc
index f5dfbd5a691ad624a4fab236945d6fb409b40078..9d4d9727be6cac0563522a397e0e56ace748be6a 100644 (file)
--- a/source/distributed/tria.cc
+++ b/source/distributed/tria.cc
@@ -1812,7 +1812,7 @@ namespace parallel
 
         MPI_File fh;
         ierr = MPI_File_open(mpi_communicator,
-                             fname_fixed.c_str(),
+                             DEAL_II_MPI_CONST_CAST(fname_fixed.c_str()),
                              MPI_MODE_CREATE | MPI_MODE_WRONLY,
                              info,
                              &fh);
@@ -1836,9 +1836,11 @@ namespace parallel
         // it is sufficient to let only the first processor perform this task.
         if (myrank == 0)
           {
+            const unsigned int *data = sizes_fixed_cumulative.data();
+
             ierr = MPI_File_write_at(fh,
                                      0,
-                                     sizes_fixed_cumulative.data(),
+                                     DEAL_II_MPI_CONST_CAST(data),
                                      sizes_fixed_cumulative.size(),
                                      MPI_UNSIGNED,
                                      MPI_STATUS_IGNORE);
@@ -1849,12 +1851,14 @@ namespace parallel
         const unsigned int offset_fixed =
           sizes_fixed_cumulative.size() * sizeof(unsigned int);
 
+        const char *data = src_data_fixed.data();
+
         ierr = MPI_File_write_at(
           fh,
           offset_fixed +
             parallel_forest->global_first_quadrant[myrank] *
               sizes_fixed_cumulative.back(), // global position in file
-          src_data_fixed.data(),
+          DEAL_II_MPI_CONST_CAST(data),
           src_data_fixed.size(), // local buffer
           MPI_CHAR,
           MPI_STATUS_IGNORE);
@@ -1880,7 +1884,7 @@ namespace parallel
 
           MPI_File fh;
           ierr = MPI_File_open(mpi_communicator,
-                               fname_variable.c_str(),
+                               DEAL_II_MPI_CONST_CAST(fname_variable.c_str()),
                                MPI_MODE_CREATE | MPI_MODE_WRONLY,
                                info,
                                &fh);
@@ -1896,15 +1900,19 @@ namespace parallel
           AssertThrowMPI(ierr);
 
           // Write sizes of each cell into file simultaneously.
-          ierr =
-            MPI_File_write_at(fh,
-                              parallel_forest->global_first_quadrant[myrank] *
-                                sizeof(int), // global position in file
-                              src_sizes_variable.data(),
-                              src_sizes_variable.size(), // local buffer
-                              MPI_INT,
-                              MPI_STATUS_IGNORE);
-          AssertThrowMPI(ierr);
+          {
+            const int *data = src_sizes_variable.data();
+            ierr =
+              MPI_File_write_at(fh,
+                                parallel_forest->global_first_quadrant[myrank] *
+                                  sizeof(int), // global position in file
+                                DEAL_II_MPI_CONST_CAST(data),
+                                src_sizes_variable.size(), // local buffer
+                                MPI_INT,
+                                MPI_STATUS_IGNORE);
+            AssertThrowMPI(ierr);
+          }
+
 
           const unsigned int offset_variable =
             parallel_forest->global_num_quadrants * sizeof(int);
@@ -1914,7 +1922,7 @@ namespace parallel
 
           // Share information among all processors.
           std::vector<unsigned int> sizes_on_all_procs(n_procs);
-          ierr = MPI_Allgather(&size_on_proc,
+          ierr = MPI_Allgather(DEAL_II_MPI_CONST_CAST(&size_on_proc),
                                1,
                                MPI_UNSIGNED,
                                sizes_on_all_procs.data(),
@@ -1929,6 +1937,8 @@ namespace parallel
                            sizes_on_all_procs.end(),
                            sizes_on_all_procs.begin());
 
+          const char *data = src_data_variable.data();
+
           // Write data consecutively into file.
           ierr = MPI_File_write_at(
             fh,
@@ -1936,7 +1946,7 @@ namespace parallel
               ((myrank == 0) ?
                  0 :
                  sizes_on_all_procs[myrank - 1]), // global position in file
-            src_data_variable.data(),
+            DEAL_II_MPI_CONST_CAST(data),
             src_data_variable.size(), // local buffer
             MPI_CHAR,
             MPI_STATUS_IGNORE);
@@ -1980,8 +1990,11 @@ namespace parallel
         AssertThrowMPI(ierr);
 
         MPI_File fh;
-        ierr = MPI_File_open(
-          mpi_communicator, fname_fixed.c_str(), MPI_MODE_RDONLY, info, &fh);
+        ierr = MPI_File_open(mpi_communicator,
+                             DEAL_II_MPI_CONST_CAST(fname_fixed.c_str()),
+                             MPI_MODE_RDONLY,
+                             info,
+                             &fh);
         AssertThrowMPI(ierr);
 
         ierr = MPI_Info_free(&info);
@@ -2042,7 +2055,7 @@ namespace parallel
 
           MPI_File fh;
           ierr = MPI_File_open(mpi_communicator,
-                               fname_variable.c_str(),
+                               DEAL_II_MPI_CONST_CAST(fname_variable.c_str()),
                                MPI_MODE_RDONLY,
                                info,
                                &fh);
@@ -2073,7 +2086,7 @@ namespace parallel
 
           // share information among all processors
           std::vector<unsigned int> sizes_on_all_procs(n_procs);
-          ierr = MPI_Allgather(&size_on_proc,
+          ierr = MPI_Allgather(DEAL_II_MPI_CONST_CAST(&size_on_proc),
                                1,
                                MPI_UNSIGNED,
                                sizes_on_all_procs.data(),

diff --git a/source/dofs/dof_handler_policy.cc b/source/dofs/dof_handler_policy.cc
index 36bb1a526d387236979f3e7ee47c7045591491a8..b8c4ed6a79e949b07fa16ffe878cd60476c49bbb 100644 (file)
--- a/source/dofs/dof_handler_policy.cc
+++ b/source/dofs/dof_handler_policy.cc
@@ -5079,7 +5079,7 @@ namespace internal
           n_locally_owned_dofs_per_processor(n_cpus);
 
         const int ierr =
-          MPI_Allgather(&n_locally_owned_dofs,
+          MPI_Allgather(DEAL_II_MPI_CONST_CAST(&n_locally_owned_dofs),
                         1,
                         DEAL_II_DOF_INDEX_MPI_TYPE,
                         n_locally_owned_dofs_per_processor.data(),