gcc-11 and cmake related cleanup

[tchaikov]

in hope to get rockdb compiled with GCC-11 without warning

• util/bloom_test: init a variable before using it
  to silence the GCC warning like

  util/bloom_test.cc:1253:31: error: ‘<anonymous>’ may be used uninitialized [-Werror=maybe-uninitialized]
   1253 |   Slice key_slice{key_bytes, 8};
        |                               ^
  ...
  include/rocksdb/slice.h:41:3: note: by argument 2 of type ‘const char*’ to ‘rocksdb::Slice::Slice(const char*, size_t)’ declared here
     41 |   Slice(const char* d, size_t n) : data_(d), size_(n) {}
        |   ^~~~~
  util/bloom_test.cc:1249:3: note: ‘<anonymous>’ declared here
   1249 |   };
        |   ^
  cc1plus: all warnings being treated as errors
  

• cmake: add find_package(uring ...)
  find liburing in a more consistent way. also it is the encouraged way for finding a library.

[mrambacher]

This change generally LGTM.

Can you please put more information into the description/comment as to the exact problems/errors/messages you were seeing (at least for the -Werror and liburing cases)? This might help others who see those errors when searching for comparables.

[mrambacher]

Nit: I think I understand the indent but it looks like tabs instead of spaces.

[tchaikov]

double checked. they are spaces.

[tchaikov]

This change generally LGTM.

Can you please put more information into the description/comment as to the exact problems/errors/messages you were seeing (at least for the -Werror and liburing cases)? This might help others who see those errors when searching for comparables.

hi @mrambacher , i think i did put the detailed error messages in the commit messages . regarding to the liburing change, i am trying to use the modern CMake way to find and expose a library. if you want to have more background on this. i'd happy to provide more reading materials.

[jay-zhuang]

LGTM

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[riversand963]

Thanks @tchaikov for the PR.

i think i did put the detailed error messages in the commit messages

Could you update PR description? The individual commit message of this PR will be lost once merged to main, and the PR description will be the final commit message.

[tchaikov]

Thanks @tchaikov for the PR.

i think i did put the detailed error messages in the commit messages

Could you update PR description? The individual commit message of this PR will be lost once merged to main, and the PR description will be the final commit message.

sure, done. thank you!

@mrambacher i must have misunderstood what you suggested. just realized that i should have updated the PR description. sorry and thanks!