[petsc-dev] need for HDF5 < 1.8.0 support?

[Jed Brown]

"Smith, Barry F." <bsmith at mcs.anl.gov> writes:

>> On Dec 7, 2018, at 2:25 PM, Jed Brown <jed at jedbrown.org> wrote:
>> 
>> "Smith, Barry F." <bsmith at mcs.anl.gov> writes:
>> 
>>>> On Dec 7, 2018, at 8:56 AM, Jed Brown <jed at jedbrown.org> wrote:
>>>> 
>>>> "Smith, Barry F." <bsmith at mcs.anl.gov> writes:
>>>> 
>>>>> A potential drawback is some users also use HDF5 directly in their code and may be using an older version (people are very slow to change).
>>>> 
>>>> The HDF5 developers were very deliberate about this.  You can still use
>>>> the old API in your own code while linking to the new library.  See
>>>> H5_USE_16_API.
>>>> 
>>>> https://support.hdfgroup.org/HDF5/doc/RM/APICompatMacros.html
>>> 
>>>   This pages is a firehose. Most people who have HDF5 in their code (that someone else probably wrote) will never get through this page to know what to do. 
>
>> 
>> You literally just compile that old code using -DH5_USE_16_API while using new HDF5 libraries and headers.
>
>   Where do you put this -DH5_USE_16_API thing? I literally don't have a clue how my build system works. I would rather just stick to the old version since its worked for the last n years. (This is the average user/developer of package/application A)

I get your point, but instructions are simple and we can't stay in the
dark ages forever.  I think the HDF5 folks did a good job with their API
deprecations.  We'd be upset if people were going through pains to
support petsc-2.2.

./configure CPPFLAGS=-DH5_USE_16_API