Migrating from HDF5 1.10 to HDF5 1.12

There were many existing functions that were modified in 1.12. Applications created with 1.10 or earlier that use these functions will encounter errors when compiled with 1.12. This page describes how to compile 1.10 and earlier applications with 1.12 without modifying an application, and provides details on the functions that changed for users who wish to update their applications:

• Compiling 1.10 and earlier applications with 1.12
• Functions that changed

For further information, see:

• New Features in 1.12
• Software Changes from release to release
• API Compatibility Macros in HDF5

Compiling 1.10 and earlier applications with 1.12

Applications that were created with earlier HDF5 releases may not compile with 1.12 by default. The API Compatibility Macros in HDF5 allow users to work around this issue. Users can specify a compatibility macro mapping for the version of HDF5 that an application was built with. For example, a 1.10 application can be built with 1.12 using either an application or library mapping as follows:

• To compile an application built with a version of HDF5 that includes deprecated symbols (the default), make sure to pass -DH5_USE_110_API to the compiler. For example:

  Autotools:   h5cc -DH5_USE_110_API (C)

  CMake:       cmake -DCMAKE_C_FLAGS="-DH5_USE_110_API" (and likewise for other CMAKE_<LANG>_FLAGS)

• To build an HDF5 library with the 1.10 APIs specify --with-default-api-version=v110 (Autotools) or -DDEFAULT_API_VERSION:STRING=v110 (CMake).

  Autotools: 

  ./configure --with-default-api-version=v110

  CMake:

  If using the source code packaged with CMake configuration files (CMake-hdf5-1.12.0*), edit HDF5options.cmake, and add this line:

  set(ADD_BUILD_OPTIONS "${ADD_BUILD_OPTIONS} -DDEFAULT_API_VERSION:STRING=v110")

  View the libhdf5.settings file to verify that the library was built with the 1.10 APIs:

  Default API mapping: v110 (under Features:)

However, users will not be able to take advantage of some of the new features in 1.12 if using these compatibility mappings.

Functions that changed

Functions were modified in HDF5 version 1.12 to support a token type used in the Virtual Object Layer (VOL) and to enable 64-bit selection encodings. These changes are described below.

Token Type

In HDF5 1.12, a token type, H5O_token_t, replaced the address type, haddr_t, for representing locations in an HDF5 file. This change better supports the Virtual Object Layer (VOL), as the concept of an "address" does not make sense for many connectors. A token type is a more generic type that can function as both a connector and address location.

This change affected the following functions:

Encoding Properties

These functions were introduced in HDF5 version 1.12 as part of the H5Sencode format change to enable 64-bit selection encodings and a dataspace selection that is tied to a file. See the H5Sencode / H5Sdecode format change RFC for details.