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Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15325 ## Summary RocksDB's `.clang-tidy` enables the `clang-analyzer-*` and `bugprone-*` checks. A full scan of the repo still reports 78 findings from these checks in existing code. Each time a nearby line is edited, they come back as noise, and a few of them are real defects. This diff resolves 73 of the 78; upstream has since fixed one more, and the four left are listed under "Intentionally not changed". Some fixes repair real bugs. The rest make the code's intent explicit to the analyzer without changing behavior. Real bugs fixed: - `port/mmap.cc`: `MemMapping::operator=(MemMapping&&)` ran the destructor on `*this`, `memcpy`'d over a non-trivially-copyable object, then placement-new'd the source. That is undefined behavior, and `*this` can be the base subobject of a `TypedMemMapping`. It now moves the members one by one, and the previous mapping is released through a local `MemMapping`. - `port/mmap.h`: `TypedMemMapping::operator=(MemMapping&&)` had no `return *this;`, so calling it was undefined behavior. - `cache/typed_cache.h`: `if constexpr (sizeof(TCreateContext) > 0)` is always true, so the branch meant for empty create contexts (for example `BlobContentsCreator`) could never run. The check is now `!std::is_empty_v<TCreateContext>`. Existing instantiations still call the same `Create` function. - `cassandra_row_merge_test.cc`: the test reused a vector after `std::move`-ing it into `RowValue::Merge(std::vector<RowValue>&&)`. That only worked because `Merge` happens not to consume its input. The test now rebuilds the input. Behavior-preserving changes: - Virtual calls in constructors and destructors are now explicitly qualified (for example `DBImpl::CloseImpl()` in `~DBImpl`). During construction and destruction, dispatch already resolved to these functions. - Stale `/*name=*/` argument comments now match the parameter names. - `unique_ptr::release()` after a successful cache `Insert` (where the cache takes ownership) uses `[[maybe_unused]] T* released = x.release();`, the pattern already used in `table_cache.cc`. - Removed `class Mutex;` and `class StaticMeta;` forward declarations that sat in the wrong namespace. - Added default member initializers for the `TablePropertiesCollectorFactory::Context` fields that its default constructor left uninitialized. - Smaller cleanups: a redundant `cond ? 3 : 3` in a test, `sizeof(std::string)` in a memory estimate, and an explicit `Cleanable` base move via `up_cast`. Tests that intentionally use moved-from objects now carry `NOLINT(bugprone-use-after-move)`, matching the existing convention. Intentionally not changed: enum casts in tests that check invalid-value handling; three `clang-analyzer-core.NullDereference` reports the analyzer can't prove safe (the C API timestamp out-parameters in `db/c.cc`, which are only written when the caller asked for a timestamp, and the waiter-list walk in `util/async_file_reader.cc`); bit-flag enums in public headers (`FileOpenContract`, `OptionTypeFlags`), where OR-combined values are valid; ownership transfers the analyzer can't see across translation units (`partitioned_index_reader.cc`, `fs_posix.cc`); and the intentional two-separator check in `file/filename.cc`. Reviewed By: rban1 Differential Revision: D123186307 fbshipit-source-id: 623e871286b1c73263b1309cb194692194199e0f