LAZPERF_EXPORT macro is wrong on Windows

[SpaceIm]

LAZPERF_EXPORT macro is defined in lazperf.h: https://github.com/hobu/laz-perf/blob/2e3c316248fa534cdeba1b47b2e9fe1a0ecf5dca/cpp/lazperf/lazperf.hpp#L42-L47

It's broken on Windows.

• If static, this macro should be empty (all OS)
• If shared, this macro should be:
  • Windows: __declspec(dllexport) at build time, and __declspec(dllimport) at consume time
  • others OS: __attribute__((visibility ("default")))

[abellgithub]

What specific problem is the current code causing? What errors/failures are occurring?

[SpaceIm]

I've not tested yet, I'm packaging laz-perf for conan, but I already know it's a wrong logic, probably leading to undefined references or lot of warnings.

[abellgithub]

Then maybe you should test it and report on errors that you find.

…

On Sun, May 30, 2021, 7:31 AM SpaceIm ***@***.***> wrote: I've not tested yet, I'm packaging laz-perf for conan, but I already know it's a wrong logic, probably leading to undefined references or lot of warnings. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#80 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKBMMGXNVPG6XWOYKVS32LTQIOXRANCNFSM45ZH3F3Q> .

[SpaceIm]

The logic should be something like this:

#ifdef LAZPERF_SHARED
#  ifdef _WIN32
#    ifdef LAZPERF_BUILD
#      define LAZPERF_EXPORT __declspec(dllexport)
#    else
#      define LAZPERF_EXPORT __declspec(dllimport)
#    endif
#  else
#    define LAZPERF_EXPORT __attribute__((visibility ("default")))
#  endif
#else
#  define LAZPERF_EXPORT
#endif

Then in CMakeLists.txt in lazperf subfolder:

    target_compile_definitions(${LAZPERF_SHARED_LIB} PRIVATE LAZPERF_BUILD PUBLIC LAZPERF_SHARED)

[abellgithub]

I changed things so that the installed code will, by default, offer __declspec(dllimport), not that it matters much.