Add workaround for libxml2-caused exceptions.

* These may occur during mpich 4.1.x startup.

Makefile.am

@@ -83,6 +83,8 @@ EXTRA_DIST = util/sunf95preproc-wrapper \
 	config/checkdoc/mpich_4.0.x_ddt_transfer.txt \
 	config/checkpatch/mpich_4.0.x_ddt_transfer.patch \
 	config/checksrc/mpich_4.0.x_ddt_transfer.c \
+	config/checkdoc/mpi_fortran_startup.txt \
+	config/checksrc/mpi_fortran_startup.f90 \
 	contrib/00nagfor-libtool-patch/README.txt \
 	contrib/00nagfor-libtool-patch/nagfor-libtool-2.4.2.patch \
 	contrib/00nagfor-libtool-patch/nagfor-libtool-2.4.6.patch \

config/checkdoc/mpi_fortran_startup.txt

+This test checks that the Fortran run-time is configured correctly.
+
+Unfortunately, the following cases are known where this might not be
+the case:
+
+1. Some versions of MPICH need libxml2 of which in turn there are
+   older versions which raise arithmetic exceptions due to divisions
+   by zero (which is UB) being executed in xmlXPathInit.
+   This then causes issues with builds that have floating point
+   run-time checks enabled, like the ifort -fpe0 option.

config/checksrc/mpi_fortran_startup.f90

+!>
+!! @file mpi_fortran_startup.f90
+!! @brief Test startup of MPI-parallel Fortran programs
+!!
+!! @copyright Copyright  (C)  2023 Jörg Behrens <behrens@dkrz.de>
+!!                                 Moritz Hanke <hanke@dkrz.de>
+!!                                 Thomas Jahns <jahns@dkrz.de>
+!!
+!! @author Jörg Behrens <behrens@dkrz.de>
+!!         Moritz Hanke <hanke@dkrz.de>
+!!         Thomas Jahns <jahns@dkrz.de>
+!!
+!
+! Maintainer: Jörg Behrens <behrens@dkrz.de>
+!             Moritz Hanke <hanke@dkrz.de>
+!             Thomas Jahns <jahns@dkrz.de>
+! URL: https://dkrz-sw.gitlab-pages.dkrz.de/yaxt/
+!
+! Redistribution and use in source and binary forms, with or without
+! modification, are  permitted provided that the following conditions are
+! met:
+!
+! Redistributions of source code must retain the above copyright notice,
+! this list of conditions and the following disclaimer.
+!
+! Redistributions in binary form must reproduce the above copyright
+! notice, this list of conditions and the following disclaimer in the
+! documentation and/or other materials provided with the distribution.
+!
+! Neither the name of the DKRZ GmbH nor the names of its contributors
+! may be used to endorse or promote products derived from this software
+! without specific prior written permission.
+!
+! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+! IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+! TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+! PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+! OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+! EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+! PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+! LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+! NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+!
+! acx_mpirun_num_tasks=2
+PROGRAM mpi_hello
+!  INCLUDE "mpif.h"
+  USE mpi
+  USE iso_c_binding
+
+  INTERFACE
+    SUBROUTINE posix_exit(code) BIND(c, name="exit")
+      IMPORT :: c_int
+      INTEGER(c_int), VALUE, INTENT(in) :: code
+    END SUBROUTINE posix_exit
+  END INTERFACE
+
+  INTEGER :: ierror, comm_size, comm_rank
+  INTEGER :: procnum, acx_mpirun_num_tasks
+  CALL mpi_init(ierror)
+  CALL handle_mpi_error(ierror)
+  CALL mpi_comm_rank(mpi_comm_world, comm_rank, ierror)
+  CALL handle_mpi_error(ierror)
+  CALL mpi_comm_size(mpi_comm_world, comm_size, ierror)
+  CALL handle_mpi_error(ierror)
+  acx_mpirun_num_tasks = 2
+  procnum = 1
+  CALL mpi_allreduce(mpi_in_place, procnum, 1, mpi_integer, &
+       mpi_sum, mpi_comm_world, ierror)
+  IF (procnum /= acx_mpirun_num_tasks) THEN
+    CALL mpi_abort(mpi_comm_world, 1, ierror)
+  END IF
+  CALL mpi_finalize(ierror)
+  CALL handle_mpi_error(ierror)
+CONTAINS
+  SUBROUTINE handle_mpi_error(ierror)
+    INTEGER, INTENT(in) :: ierror
+
+    INTEGER :: msg_len, msg_ierror
+    CHARACTER(len=MPI_MAX_ERROR_STRING) :: msg
+
+    IF (ierror /= MPI_SUCCESS) THEN
+      CALL mpi_error_string(ierror, msg, msg_len, msg_ierror)
+      WRITE (0, *) msg(1:msg_len)
+      FLUSH(0)
+      CALL posix_exit(1_c_int)
+    END IF
+  END SUBROUTINE handle_mpi_error
+
+END PROGRAM mpi_hello
+!
+! Local Variables:
+! f90-continuation-indent: 5
+! coding: utf-8
+! indent-tabs-mode: nil
+! show-trailing-whitespace: t
+! require-trailing-newline: t
+! End:
+!

configure.ac

@@ -437,6 +437,10 @@ ACX_MPI_DEFECTS(,,
          XT_WORKAROUND_MPI_CPPFLAGS="-I$ac_pwd/$acx_yaksa_add_workaround ${XT_WORKAROUND_MPI_CPPFLAGS-$CPPFLAGS}"],
         [AC_MSG_WARN([Cannot apply MPICH YAKSA datatype bug work-around.])
          mpi_defect_fail_action])],
+     [mpi_fortran_startup],
+     [AC_MSG_WARN([known problem detected, attempting work-around!])
+      ACX_LIBXML2_WORKAROUND(,[mpi_fortran_startup.f90],
+        [AC_LIBOBJ([xt_xmlXPathInit])])],
      [mpich_unweighted_topo_comm_dup],
      [AC_MSG_WARN([known MPICH 3.0-3.4.2 problem detected, activating work-around!])
       AC_DEFINE([NEED_MPICH_UNWEIGHTED_COMM_DUP_WORKAROUND],,

m4/acx_libxml2_workaround.m4

+dnl acx_libxml2_workaround.m4 --- test whether libxml2 can be
+dnl run-time-patched to work around a known problem executing division
+dnl by zero during xmlXPathInit
+dnl
+dnl Copyright  (C)  2023  Thomas Jahns <jahns@dkrz.de>
+dnl
+dnl Keywords: configure configure.ac autoconf libxml2 xmlXPathInit SIGFPE
+dnl Author: Thomas Jahns <jahns@dkrz.de>
+dnl Maintainer: Thomas Jahns <jahns@dkrz.de>
+dnl URL: https://www.dkrz.de/redmine/projects/scales-ppm
+dnl
+dnl Redistribution and use in source and binary forms, with or without
+dnl modification, are  permitted provided that the following conditions are
+dnl met:
+dnl
+dnl Redistributions of source code must retain the above copyright notice,
+dnl this list of conditions and the following disclaimer.
+dnl
+dnl Redistributions in binary form must reproduce the above copyright
+dnl notice, this list of conditions and the following disclaimer in the
+dnl documentation and/or other materials provided with the distribution.
+dnl
+dnl Neither the name of the DKRZ GmbH nor the names of its contributors
+dnl may be used to endorse or promote products derived from this software
+dnl without specific prior written permission.
+dnl
+dnl THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+dnl IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+dnl TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+dnl PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+dnl OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+dnl EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+dnl PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+dnl PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+dnl LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+dnl NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+dnl SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+dnl
+dnl
+dnl ACX_LIBXML2_WORKAROUND([TEST-SOURCE-DIR=config/checksrc],
+dnl                 [LIST-OF-WORK-AROUND-TESTS],
+dnl                 [ACTION-IF-WORKAROUND-SUCCEEDS],
+dnl                 [ACTION-IF-WORKAROUND-FAILED=AC_MSG_FAILURE],
+dnl                 [WORKAROUND-FILE=src/mpi-workarounds/xt_xmlXPathInit.c])
+dnl
+dnl Assumes CC and CFLAGS are setup for MPI.
+dnl Then builds files needed for work-around in addition to test programs
+dnl and checks if linking with those fixes the issue.
+dnl See ACX_MPI_DEFECTS for further description of tests.
+AC_DEFUN([ACX_LIBXML2_WORKAROUND],
+  [AC_LANG_PUSH([C])
+   dnl 1. detect libxml2 version
+   dnl currently skipped, only one implementation known to be needed
+   dnl so far
+   acx_saved_LIBS=$LIBS
+   acx_saved_CPPFLAGS=$CPPFLAGS
+   acx_is_affected_libxml2=:
+   dnl 2. copy workaround source into place for configure logic
+   acx_temp="m4_default([$5],[src/mpi-workarounds/])"
+   for acx_workaround in xt_xmlXPathInit xt_xmlInitParser \
+     xt_xmlInitParser.c_def
+   do
+     AS_IF([test "$acx_workaround" = xt_xmlInitParser.c_def],
+       [acx_workaround=xt_xmlInitParser
+        CPPFLAGS="$CPPFLAGS -DXT_LIBXML_INCLUDE_SUBDIR"])
+     cp "$srcdir/$acx_temp/${acx_workaround}.c" conftest.c
+     dnl 3. build fixed xt_xmlXPathInit.c
+     AC_COMPILE_IFELSE(,
+       [ACX_MV_OBJ([conftest],[xt_workaround])],
+       [rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+        continue])
+     dnl 4. verify listed tests now succeed
+     LIBS="xt_workaround.$ac_objext -lxml2 $LIBS"
+     acx_libxml2_check_dir=`echo "acx_mpi_check_src_" | sed 's@/@<:@^/@:>@*$[]@@'`
+     ACX_MPI_DEFECTS([$acx_libxml2_check_dir],, [acx_is_affected_libxml2=false], [$2])
+     rm -f xt_workaround.*
+   done
+   LIBS=$acx_saved_LIBS
+   dnl 5. execute action corresponding to outcome of tests
+   AS_IF([$acx_is_affected_libxml2],
+     [$3
+      AS_IF([test "x$CPPFLAGS" != "x$acx_saved_CPPFLAGS"],
+        [AC_DEFINE([XT_LIBXML_INCLUDE_SUBDIR],,
+          [are libxml header files buried in sub-directory?])])],
+     [m4_default([$4],
+        [AC_MSG_FAILURE(
+           [Cannot apply libxml2 SIGFPE bug work-around.])])])
+   CPPFLAGS=$acx_saved_CPPFLAGS
+   AC_LANG_POP([C])])
+dnl
+dnl Local Variables:
+dnl mode: autoconf
+dnl license-project-url: "https://www.dkrz.de/redmine/projects/scales-ppm"
+dnl license-default: "bsd"
+dnl End:

src/mpi-workarounds/Makefile.am

@@ -49,6 +49,8 @@ libmpi_workaround_la_SOURCES =
 libmpi_workaround_la_LIBADD = $(LIBOBJS) $(xt_mpi_workaround_LIBS) $(MPI_C_LIB)
 endif
 
+EXTRA_DIST = xt_xmlInitParser.c
+
 distclean-local:
 	-rm -rf '$(DEPDIR)'
 

src/mpi-workarounds/xt_xmlInitParser.c

+/**
+ * @file xt_xmlInitParser.c
+ *
+ * Simple workaround for libxml2 versions creating division-by-zero
+ * errors
+ *
+ * @copyright Copyright  (C)  2023 Jörg Behrens <behrens@dkrz.de>
+ *                                 Moritz Hanke <hanke@dkrz.de>
+ *                                 Thomas Jahns <jahns@dkrz.de>
+ *
+ * @author Jörg Behrens <behrens@dkrz.de>
+ *         Moritz Hanke <hanke@dkrz.de>
+ *         Thomas Jahns <jahns@dkrz.de>
+ */
+/*
+ * Maintainer: Jörg Behrens <behrens@dkrz.de>
+ *             Moritz Hanke <hanke@dkrz.de>
+ *             Thomas Jahns <jahns@dkrz.de>
+ * URL: https://dkrz-sw.gitlab-pages.dkrz.de/yaxt/
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are  permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * Neither the name of the DKRZ GmbH nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef XT_LIBXML_INCLUDE_SUBDIR
+#include <libxml2/libxml/parser.h>
+#else
+#include <libxml/parser.h>
+#endif
+
+#include <fenv.h>
+
+static void __attribute__((constructor))
+xt_init_xml_parser_nofpe(void) {
+  fenv_t prev_fenv;
+  fegetenv(&prev_fenv)
+  int prevmask = fedisableexcept(FE_DIVBYZERO);
+  xmlInitParser();
+  fesetenv(&prev_fenv)
+}
+
+
+/*
+ * Local Variables:
+ * c-basic-offset: 2
+ * coding: utf-8
+ * indent-tabs-mode: nil
+ * show-trailing-whitespace: t
+ * require-trailing-newline: t
+ * End:
+ */

src/mpi-workarounds/xt_xmlXPathInit.c

+/**
+ * @file xt_xmlXPathInit.c
+ *
+ * Simple workaround for libxml2 versions creating division-by-zero
+ * errors
+ *
+ * @copyright Copyright  (C)  2023 Jörg Behrens <behrens@dkrz.de>
+ *                                 Moritz Hanke <hanke@dkrz.de>
+ *                                 Thomas Jahns <jahns@dkrz.de>
+ *
+ * @author Jörg Behrens <behrens@dkrz.de>
+ *         Moritz Hanke <hanke@dkrz.de>
+ *         Thomas Jahns <jahns@dkrz.de>
+ */
+/*
+ * Maintainer: Jörg Behrens <behrens@dkrz.de>
+ *             Moritz Hanke <hanke@dkrz.de>
+ *             Thomas Jahns <jahns@dkrz.de>
+ * URL: https://dkrz-sw.gitlab-pages.dkrz.de/yaxt/
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are  permitted provided that the following conditions are
+ * met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * Neither the name of the DKRZ GmbH nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <math.h>
+
+extern double xmlXPathPINF, xmlXPathNINF, xmlXPathNAN;
+
+void
+xmlXPathInit(void) {
+  xmlXPathPINF = INFINITY;
+  xmlXPathNINF = -INFINITY;
+  xmlXPathNAN = NAN;
+}
+
+/*
+ * Local Variables:
+ * c-basic-offset: 2
+ * coding: utf-8
+ * indent-tabs-mode: nil
+ * show-trailing-whitespace: t
+ * require-trailing-newline: t
+ * End:
+ */