ARROW-4439: [C++] Improve FindBrotli.cmake

[rip-nsk]

No description provided.

[wesm]

rebased

[rip-nsk]

WIP

[xhochy]

Rebased.

[wesm]

I just fixed the Linux build. Could you write in the PR description what you are trying to accomplish with this patch?

[wesm]

Looks like this also broke library detection in the manylinux1 build. I don't have time to fix it right now

[rip-nsk]

I just fixed the Linux build. Could you write in the PR description what you are trying to accomplish with this patch?

The goal of this PR find libraries with respect to BROTLI_STATIC_LIB_SUFFIX/BROTLI_MSVC_STATIC_LIB_SUFFIX (BTW the can be "merged") for case when only static library is available

Difference from previous logic: BROTLI_STATIC_LIB_SUFFIX should be explicitly specified, there are no auto select between "-static" and "" anymore.

[rip-nsk]

I don't know how brotli libs were found in /usr/lib64 in manylinux1 build before this PR.
My ubuntu installs brotli (using manylinux1/scripts/build_brotli.sh) to /usr/lib/x86_64-linux-gnu/libbrotlienc.a where it is successfully found.
lib64 is not present in PATH_SUFFIXES, FIND_LIBRARY_USE_LIB64_PATHS is not specified..
Is it possible that lib64/libbrotlienc.a is cached in image and just working unless something is invalidates make's cache?
update: I almost sure that it cmake cache issue:
flatbuffers (installed using scripts/build_flatbuffers.sh) can't be found because FindFlatbuffers.cmake is looking for flatbuffers in lib/lib64, but actual path is lib/${CMAKE_LIBRARY_ARCHITECTURE}/libflatbuffers.a

[rip-nsk]

@wesm, @xhochy
Any reasons blocks this PR?

[wesm]

The big CMake refactor patch is blocking this. Can you rebase after that goes in?

[wesm]

Can you also write a PR description explaining what issue is being fixed?

[xhochy]

This patch is probably already digested in the things I did in #3688 @rip-nsk Can you have a look there if I have covered all cases?

[rip-nsk]

This patch is probably already digested in the things I did in #3688 @rip-nsk Can you have a look there if I have covered all cases?

As far I can see, #3688 doesn't use BROTLI_STATIC_LIB_SUFFIX, so if it is not equal to some known values (""|"-static"|"_static") library will not be found.
Also, it seems mixes static/shared libraries.

[wesm]

Can you have a look now that the CMake refactor has been merged?

[wesm]

I'm removing this from the 0.13 milestone and moving to 0.14. If you are able to fix this this week we can have a closer look. Please add a PR description for the changelog (there is not description on JIRA either)

[emkornfield]

@rip-nsk do you think you will be able to rebase this to get it reviewed?

[wesm]

ping @rip-nsk

[rip-nsk]

It is hard to "resolve conflicts" with base which is changed so much..
I'll recreate this PR later (not time for now)