[gouyt13]

Summary

Linking rabitqlib::rabitqlib currently adds RaBitQ's -O3 and -march=native options to downstream compilation. This can override an application's optimization choices and unexpectedly enable host-specific instructions.

Move optimization and native-tuning options to private first-party target configuration. Preserve public C++17, OpenMP, MSVC header definitions, and explicit sanitizer instrumentation/runtime requirements. The library's native-optimization default remains unchanged; a native-built library is still not portable across CPUs.

Add source-tree and installed-consumer checks for evaluated usage requirements, plus coverage of both rotators across IVF and SymphonyQG. Extend CI to cover native, Windows, and sanitized installed consumers, and document the build-policy boundary. No public API, persisted-format, or dependency changes.

Testing

Local Linux x86-64 validation at e963244 using GCC 14.3, Clang 15.0.7, and CMake 3.28.3:

• Reproduced the regression on main (1d4783a): the new consumer check rejects the leaked -O3 option.
• GCC and Clang native add_subdirectory consumers: runtime and option checks passed.
• Installed GCC native consumers in Release, Debug, and custom -O1 configurations: passed. Actual commands retain the consumer's -O1 while keeping RaBitQ's optimization flags private.
• Installed portable consumer and Ninja Multi-Config Release consumer: passed.
• Portable Release C++ suite: 318 passed, one conditional skip, zero failures. The skipped OpenMP placement check passed separately as OpenMPBinding with its required environment.
• Installed ASan/UBSan consumer with leak detection enabled: passed. The first run hit LeakSanitizer's sandbox/ptrace restriction; the same binary passed outside the sandbox without disabling leak detection.
• Changed C++ consumer source passed clang-format 15; branch diff passed git diff --check.

Windows/MSVC, macOS/AppleClang, and ARM64 were not run locally. Python package/wheel and sample builds were not exercised; their updated CMake helper call sites were reviewed. No performance claim is made.