Added package configs and fixed hiredis_ssl on Windows

[heronr]

This change mainly accomplishes 2 things:

1. A CMake build now generates package config files for both hiredis and hiredis_ssl. This enables other CMake projects to use find_package() calls to more easily incorporate hiredis into their project.

2. hiredis_ssl now builds on Windows using the CMake project

I was able to successfully build on both Windows and Linux using these changes.

[heronr]

This should hopefully not be a controversial change. Nevertheless, is it preferred that I actually split this into 2 PRs since it combines 2 unrelated changes?

[heronr]

@michael-grunder Does this seem reasonable? Should I create an issue to correspond with this change?

[michael-grunder]

It does seem reasonable to me but I am not overly familiar with CMake so I would defer to @mnunberg in that respect and @yossigo for the SSL changes (since he wrote the SSL layer).

[yossigo]

Hi @heronr, not a CMake expert but it looks perfectly reasonable to me. Same for the SSL locking changes, thanks!

[michael-grunder]

Thanks for another set of eyes @yossigo!

@heronr I'll fix the conflicts since I broke it with another commit and get this merged before we release 1.0.0.

[yossigo]

@heronr Looking at another CMake related issue now and I noticed this:

SET_TARGET_PROPERTIES(hiredis
    PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS TRUE
    VERSION "${HIREDIS_SONAME}")

Doesn't this make the explicit def files redundant, or the other way around - if explicit export is used perhaps we can avoid WINDOWS_EXPORT_ALL_SYMBOLS?

[michael-grunder]

I added the WINDOWS_EXPORT_ALL_SYMBOLS and removed the .def file in cc9d032.

My motivation was getting our unit tests working in Windows, including the various different ways one might do that (e.g. build with MSVC, MinGW, or Cygwin) as they needed slightly different exports.

I'm happy to fix the conflicts so we can get this merged.

[yossigo]

@michael-grunder Oh okay, haven't really looked around but bumped into this while pushing #780. Thanks!

[michael-grunder]

Hi @heronr I fixed the merge conflicts on your PR in this branch on my fork

The only substantive change I made was using to WINDOWS_EXPORT_ALL_SYMBOLS instead of .def files. That said, I'm quite unfamiliar with the Windows ecosystem so please let me know if there is a reason we shouldn't do that.

If the changes look good to you I'm happy to merge it into master or if you prefer you could merge my modifications into your PR branch and I'll merge this PR.

Thanks for your contribution!

Cheers,
Mike

[heronr]

@michael-grunder , the changes you made look good to me. You can go ahead and merge those changes in. Thank you!

[michael-grunder]

Closing in favor of #783

Edit: These changes have now been merged, thanks again!