allow to modify or remove the postfix for debug builds

[MarDiehl]

closes #4647

[derobins]

Needs a release note, at the very least

[byrnHDF]

I don't like this change as is - first the default can be overridden easiy;
set (CMAKE_DEBUG_POSTFIX "")

Second it is altering a setting that could be relied on due to it being a long standing setting.

[byrnHDF]

I think this is not the way to do this and why just for NOT win32.

[derobins]

I don't like this change as is - first the default can be overridden easiy;
set (CMAKE_DEBUG_POSTFIX "")

Second it is altering a setting that could be relied on due to it being a long standing setting.

The default should be to do what other libraries do and not have a suffix. Anyone who cares about this can change it, but I think most people don't want to change linker commands when building a debug library. Windows is different since the debug library will link to the debug CRT.

[derobins]

As for "long standing settings", 2.0 is the time to do the right thing instead of the traditional thing. Also, this isn't this only a long-standing thing on CMake?

[byrnHDF]

I would add an option here "ENABLE_DEBUG_NAME_EXT" that is normally OFF. That is what this code was supposed to accomplish, just to make it easy and optional.
This way one does not need to remember that if I want an extension that I need to set it on Linux but skip WIN32. Easier to change one setting without regard to platform.

[MarDiehl]

What about making CMAKE_DEBUG_POSTFIX accesible via the commandline, i.e.-DCMAKE_DEBUG_POSTFIX=?

[byrnHDF]

We should just move these settings (the whole if-else) to the cacheinit.cmake file as that is the intended use for that file.

[byrnHDF]

Just replace this with the whole thing:
if(NOT CMAKE_DEBUG_POSTFIX)
if (WIN32)
set (CMAKE_DEBUG_POSTFIX "_D")
else ()
set (CMAKE_DEBUG_POSTFIX "_debug")
endif ()
endif ()

[jhendersonHDF]

@byrnHDF Does this handle setting of a postfix for developer builds of the library?

[byrnHDF]

@byrnHDF Does this handle setting of a postfix for developer builds of the library?

Yes this affects the $CONFIG:Developer>: generator instances

[MarDiehl]

Tested locally, works as expected.
Force pushed to update commit message.

[lrknox]

Needs a release note - probably 2 or 3 lines, one to describe the problem, one to describe the change, and one saying Fixes or Fixed GitHub issue #4647. This should be added to the top of the Bug Fixes / Configuration section at ~ line 743 of release_docs/RELEASE.txt file.

The cause of the netCDF test failures is known and unrelated to this pull request.

[byrnHDF]

Remove default setting of CMAKE_DEBUG_POSTFIX if not set.

Move the default setting of CMAKE_DEBUG_POSTFIX to the cacheinit,cmake file usually used by testing. If CMAKE_DEBUG_POSTFIX is not set with a -D option then CMAKE_DEBUG_POSTFIX will be the default provided by CMake itself,

[MarDiehl]

I find "Remove default setting of CMAKE_DEBUG_POSTFIX if not set." misleading. cacheinit.cmake is part of the release (at least the current), so when building HDF5 the old behavior of having postfixes for debug build is restored.

There is also no such thing as a default provided by CMake.

[byrnHDF]

Remove default setting of CMAKE_DEBUG_POSTFIX if not set.

yes should just be:
Remove default setting of CMAKE_DEBUG_POSTFIX

[byrnHDF]

cacheinit.cmake is provided just for testing and convenience and should only be used if the settings agrree with your expectations. The file can be usedas is with overrides or editing. There are many alternatives. The preferred method now is to use Presets.

This change affects the preferred Presets method by removing the settings. The binaries we build for publication (which do not build debug) use the Presets method. Future changes will be to eliminate the cacheinit.cmake file for a "Testing" CMakeUsersPresets.json file that we would create and use.
Since the default CMake setting for this CMAKE_DEBUG_POSTFIX isn't implemented the result is that it is the empty string, which is what we want.

[byrnHDF]

Change release note

[MarDiehl]

thanks for all the support!