cmake: add BUILD_TESTING, fix MSVC with static + shared

[donny-dont]

Add a new option BUILD_TESTING to control whether or not the library is built with testing. Also fix a library naming conflict when building both static and shared libraries in MSVC by setting a default of _static for STATIC_LIB_SUFFIX.

[donny-dont]

Same as nghttp2/nghttp2#2092 but just for nghttp3. And same as ngtcp2/ngtcp2#1189

[tatsuhiro-t]

cc @vszakats

[vszakats]

I'd suggest changing the description to cmake: add BUILD_TESTING, fix MSVC with static + shared or similar.
ENABLE_STATIC_LIB was already respected before this patch, existing title suggests it wasn't.

[ Since https://github.com/nghttp2/nghttp2/pull/2092 renamed the shared/static enabler variables (I'm not sure about the reasons), now we have a disparity between nghttp2 and nghttp3/ngtcp2. If we want to keep parity, we'd either need to rename those variables in the latter two (breaking compatibility for everyone), or rename back in nghttp2. ]

[donny-dont]

I'd suggest changing the description to cmake: add BUILD_TESTING, fix MSVC with static + shared or similar. ENABLE_STATIC_LIB was already respected before this patch, existing title suggests it wasn't.

Fixed and updated the PR title and description.

[ Since https://github.com/nghttp2/nghttp2/pull/2092 renamed the shared/static enabler variables (I'm not sure about the reasons), now we have a disparity between nghttp2 and nghttp3/ngtcp2. If we want to keep parity, we'd either need to rename those variables in the latter two (breaking compatibility for everyone), or rename back in nghttp2. ]

The actual change happened in nghttp2/nghttp2@d9edee4 which I'm guessing was to align with CMake's built-in variable BUILD_SHARED_LIBS. I didn't want to make that change on anyone's behalf. However the new variable BUILD_TESTING does conform with CMake's conventions.

[vszakats]

I'd suggest changing the description to cmake: add BUILD_TESTING, fix MSVC with static + shared or similar. ENABLE_STATIC_LIB was already respected before this patch, existing title suggests it wasn't.

Fixed and updated the PR title and description.

Thank you, LGTM!

[ Since https://github.com/nghttp2/nghttp2/pull/2092 renamed the shared/static enabler variables (I'm not sure about the reasons), now we have a disparity between nghttp2 and nghttp3/ngtcp2. If we want to keep parity, we'd either need to rename those variables in the latter two (breaking compatibility for everyone), or rename back in nghttp2. ]

The actual change happened in nghttp2/nghttp2@d9edee4 which I'm guessing was to align with CMake's built-in variable BUILD_SHARED_LIBS. I didn't want to make that change on anyone's behalf. However the new variable BUILD_TESTING does conform with CMake's conventions.

Agreed with BUILD_TESTING. And leaving the rest as-is. (Whatever the resolution is for the renames, it's something for a different patch.)

[tatsuhiro-t]

Thank you both. Merged now.