Make HDF5 presence compulsory

Former-commit-id: 14c8273c8618b7c5eacb2caf1e9d49570205e95c

configure.ac

@@ -222,9 +222,13 @@ AC_CHECK_LIB([z],[gzopen],[
     ],[])
 
 
-# Check for HDF5.
+# Check for HDF5. This is required.
 AX_LIB_HDF5
 
+if test "$with_hdf5" != "yes"; then
+    AC_MSG_ERROR([Could not find a working HDF5 library])
+fi
+
 # We want to know if this HDF5 supports MPI and whether we should use it.
 # The default is to use MPI support if it is available, i.e. this is
 # a parallel HDF5.

m4/ax_lib_hdf5.m4

@@ -22,6 +22,8 @@
 #     yes  - do check for HDF5 library in standard locations.
 #     path - complete path to the HDF5 helper script h5cc or h5pcc.
 #
+#   SWIFT modification: HDF5 is required, so only path is described.
+#
 #   If HDF5 is successfully found, this macro calls
 #
 #     AC_SUBST(HDF5_VERSION)
@@ -110,7 +112,7 @@ fi
 dnl Add a default --with-hdf5 configuration option.
 AC_ARG_WITH([hdf5],
   AS_HELP_STRING(
-    [--with-hdf5=[yes/no/PATH]],
+    [--with-hdf5=[PATH]],
     m4_case(m4_normalize([$1]),
             [serial],   [location of h5cc for serial HDF5 configuration],
             [parallel], [location of h5pcc for parallel HDF5 configuration],
@@ -160,15 +162,15 @@ if test "$with_hdf5" = "yes"; then
             [serial],  [
 Unable to locate serial HDF5 compilation helper script 'h5cc'.
 Please specify --with-hdf5=<LOCATION> as the full path to h5cc.
-HDF5 support is being disabled (equivalent to --with-hdf5=no).
+HDF5 support is being disabled.
 ],            [parallel],[
 Unable to locate parallel HDF5 compilation helper script 'h5pcc'.
 Please specify --with-hdf5=<LOCATION> as the full path to h5pcc.
-HDF5 support is being disabled (equivalent to --with-hdf5=no).
+HDF5 support is being disabled.
 ],            [
 Unable to locate HDF5 compilation helper scripts 'h5cc' or 'h5pcc'.
 Please specify --with-hdf5=<LOCATION> as the full path to h5cc or h5pcc.
-HDF5 support is being disabled (equivalent to --with-hdf5=no).
+HDF5 support is being disabled.
 ]))
         with_hdf5="no"
         with_hdf5_fortran="no"