CGNS version 4.2.0

INTRODUCTION

This document describes the difference between CGNS 4.1.2 and
CGNS 4.2.0 and contains information on known problems in
CGNS 4.2.0.

Links to the CGNS current released source code can be found at:

http://cgns.org/download.html

User documentation for the current release can be found at:

http://cgns.org/CGNS_docs_current/midlevel/index.html

For more information, see the CGNS home page:

http://cgns.org

CONTENTS

• New Features
• Support for new platforms and languages
• Bug Fixes since CGNS 4.1.2
• Known Problems

New Features

Configuration:
-------------
* The default was changed from 32-bit to 64-bit building of CGNS, PR#216
* The minimum CMake version was changed to 3.8.

Library:
--------
* New C and Fortran APIs that allows for reading/writing datatypes 
  that are different from cgsize_t:
        cg_section_general_write(_f)
        cg_section_initialize(_f)
        cg_parent_data_write(_f)
        cg_elements_general_write(_f)
        cg_poly_elements_general_write(_f)
        cg_elements_general_read(_f)
        cg_poly_elements_general_read(_f)
        cg_parent_elements_general_read(_f)
        cg_parent_elements_position_general_read(_f)
  CGNS-212
* Added a diskless option for creating a CGNS file in memory 
  (i.e. uses HDF5 "core" file driver), and then to optionally
  persist the memory to disk. Enablable through cg_configure.
  CGNS-239
* Mapping of X4/X8 was lost when moving from ADF to HDF5.
  This fix reintroduces it as an experimental feature.
  It uses an H5T_COMPOUND and is compatible with the standard C99 complex type.

  Depending on the application, people can still store each part of a complex number 
  in separate arrays by prefixing with Re or Im the name of the array, CGNS-202

Parallel Library:
-----------------
* Tuned the parallel library algorithms to improve metadata type operations, PR#238,#236

Fortran Library:
----------------
* Add Fortran wrapper for cg_configure, CGNS-243

Tools:
------
* Experimental support for conversion of FamilySpecified BC for AFLR3 file format, PR#247
* Added check on node names according to SIDS (check that dot and slash are not at 
  the start of the name, see:https://cgns.github.io/CGNS_docs_current/hdf5/general.html) and 
  added warning if ZoneBC_t is missing while zone surfaces are present in a 3D mesh.

Bug Fixes since CGNS 4.1.2 release

Library:
-------
* Fixed test_convert_elem failing with NAG 7.0 and gcc 10, CGNS-231
* Fixed cg_configure always reporting a false error 
  when using adfh parameters, CGNS-241
* Made the parameter CG_MODE_CLOSED private since it only 
  used internally, CGNS-240
* Fixed an issue with too many MPI communicators being created when
  many CGNS files are open, CGNS-109
* Fixed issue of cg_open failing after calling cgp_open, CGNS-141
* Fixed MPI_Recv in test_poly_unstructured, PR#224
* Fixed MPI_Allgather in test_poly_unstructured #223
* VS 2019 issues: Fixed shared library builds on windows, 
  Rearranged header files, fixed #if/#ifdef bug, PR#208
* Misc. compiler issues and added check C99 Complex support 
  at compile time to enable it, PR#202 
* Fixed cgio_copy_node() failing with INVALID_DATA_TYPE error 
  when HDF5 backend is employed, PR#198

Fortran:
--------
* Fixed test cgread_f03 failing for arch ppc64el, CGNS-179
* Fixed "Fortran types mismatch between actual argument" errors
  with gfortran 10.x, CGNS-227

Configuration:
-------------
* Fixed configure issues with tcl, tk, CGNS-147
* Fixed build failures with HDF 1.10.3, CGNS-143
* Removed zlib and szip header checks when linking directory is provided
  removed header checking for standard locations, CGNS-233
* Added warning about using gfortran 10.2 as a result of a compiler
  bug, CGNS-246


Tools:
------
* Fixed issue with cgnstools not being able to read hdf5 files, CGNS-203
* Fixed cgnscheck's strange warning about non-boundary elements, CGNS-234
* Added cgnscheck a warning for BC that should be of type FamilySpecified, PR#206
* Added .desktop startup files for GUI cgnstools, PR#200
* Allow relocation of cgnstools dir, PR#199

Known Problems

************ FORTRAN ************

* A gfortran bug in version 10.2 broke Fortran mapping and caused cg_goto_f 
 to segfault. All other versions of gfortran are suitable.
 (ref. CGNS-246, GNU BUG 100149)

* A bug in gfortran (all versions) causes cg_configure_f to fail,
  GNU BUG 99982. Other Fortran compilers are fine.

************ FORTRAN END ********

************ CGNSVIEW ************

* cgnsview for OSX is not viewing properly and cgnsview under Windows 
  may fail to compile due to tcl/tk incompatibility. 

************ CGNSVIEW END ********

* For other issues, see https://cgnsorg.atlassian.net

Supported Platforms

The following platforms are supported and have been tested for this release.
They are built with the configure process unless specified otherwise.

Linux 3.10.0-1127.10.1.el7    gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
#1 SMP ppc64 GNU/Linux        g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
(echidna)                     GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)

Linux 2.6.32-573.18.1.el6     IBM XL C/C++ V13.1
#1 SMP ppc64 GNU/Linux        IBM XL Fortran V15.1
(ostrich)                     

Linux 3.10.0-327.10.1.el7     GNU C (gcc), Fortran (gfortran), C++ (g++)
#1 SMP x86_64 GNU/Linux       compilers:
(jelly/kituo/moohan)          Version 4.8.5 20150623 (Red Hat 4.8.5-39)
                                 Versions 4.9.3, 5.3.0, 6.3.0, 7.2.0
                                          8.3.0, 9.1.0, 10.1.0
                              Intel(R) C (icc), C++ (icpc), Fortran (icc)
                              compilers:
                                 Version 17.0.0.098 Build 20160721
                              MPICH 3.3 compiled with GCC 7.2.0
                              OpenMPI 4.0.0 compiled with GCC 7.2.0
                              NAG Fortran Compiler Release 7.0(Yurakuchho) Build 7011

SunOS 5.11 11.4.5.12.5.0      Sun C 5.15 SunOS_sparc 2017/05/30
32- and 64-bit                Studio 12.6 Fortran 95 8.8 SunOS_sparc 2017/05/30
(hedgehog)                    Sun C++ 5.15 SunOS_sparc 2017/05/30

Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 18 (cmake)
                              Visual Studio 2017 w/ Intel Fortran 19 (cmake)
                              Visual Studio 2019 w/ Intel Fortran 19 (cmake)
                              Visual Studio 2019 w/ MSMPI 10.1 (cmake)

macOS High Sierra 10.13.6     Apple LLVM version 10.0.0 (clang-1000.10.44.4)
64-bit                        gfortran GNU Fortran (GCC) 6.3.0
(bear)                        Intel icc/icpc/ifort version 19.0.4.233 20190416

macOS Mojave 10.14.6          Apple LLVM version 10.0.1 (clang-1001.0.46.4)
64-bit                        gfortran GNU Fortran (GCC) 6.3.0
(bobcat)                      Intel icc/icpc/ifort version 19.0.4.233 20190416

Tested Configuration Features Summary

In the table below
      y   = tested
      n   = not tested in this release
      x   = not working in this release

[1] Parallel