[colbymchenry]

Summary

Step 3 of C++ member-chain calls, after #2626 (outside types) and #2627 (project classes). The type of x.member was read from x's class alone, so a member that class inherits was never found, and the call fell back to its bare method name. The commonest case is RocksDB's Options, which declares no members of its own and inherits all of them from DBOptions and ColumnFamilyOptions:

• options.statistics->getTickerCount(…) was guessed;
• options.table_factory.reset(…) on a std::shared_ptr linked to FSWritableFilePtr::reset.

Why this step

A temporary diagnostic on main recorded why each chain call that still fell through couldn't be typed. Across leveldb, fmt, protobuf and rocksdb:

Reason	Calls
member declared in a base class	2,801 (rocksdb 2,604: Options' statistics 648, table_factory 552, listeners 169, prefix_extractor 153, …)
the chain's base has no type	875
a class the index doesn't hold (e.g. protobuf's generated _impl_)	626
member found nowhere	337
other	245

How

cppExpressionType's member branch now uses cppInheritedDataMember, the lookup the calling class's own members already use (#2533):

1. the class's own declaration first;
2. then the classes it derives from, through their base edges, to depth 4;
3. a base that depends on the class's template parameters is skipped unless a using-declaration brings the name in.

Steps 1 and 2 then apply as before: an inherited library-typed member links to no project method, and an inherited project-typed member links to its class's method.

Validation

Kit A/B against main e8ec7fd8:

Repo	Removed	Added	Retargeted	Same target, now typed
rocksdb	1,410	634	392	184
protobuf	0	2	149	55
leveldb, fmt, redis	identical

• Removed: bare-name guesses on inherited std::shared_ptr and std::vector members:
  • options.table_factory.reset(…) / prefix_extractor / merge_operator → FSWritableFilePtr::reset (654);
  • options_.db_paths.emplace_back(…) → autovector::emplace_back (256).
• Added:
  • options.statistics->getTickerCount(…) → Statistics (432);
  • options_.rate_limiter->GetTotalRequests() → RateLimiter (51);
  • options.comparator->Name() → Comparator (26).
• Retargeted: to the member's declared class: DummyOldStats → Statistics, DB → Env, ClockCacheShard → Cache, and tracked_locks_->GetPointLockStatus() → LockTracker.
• protobuf: generated this_._internal_metadata_.Clear<…>(), MergeFrom<…> and unknown_fields<…> now reach internal::InternalMetadata, the member every message inherits from MessageLite. Before, they reached the message's own Clear or Any::MergeFrom.

All 50 random sites read by hand were correct: 12 removals, 12 additions and 12 retargets in rocksdb, plus 12 retargets and both additions in protobuf.

Tests. __tests__/cpp-member-chain-base-members.test.ts (5 tests):

• a member inherited from either base;
• a member two levels up;
• an inherited std::shared_ptr's own reset();
• an inherited member further down a chain;
• a control: the class's own member before a base's of the same name.

4 of the 5 fail on main; the control passes on both. All 3 mutations are killed: own class only, bases before own, and one level of bases only.

Full suite: 588 files and 7,229 tests pass, apart from 2 timeouts in git-index-currency.test.ts under load. That file passes 13/13 twice on its own and also timed out on main earlier today.

The CHANGELOG gets sentences in the existing unreleased C++ data-member bullet. Re-index C++ projects after upgrading.

🤖 Generated with Claude Code