The set of all CBlockIndex entries that have as much work as our current tip or more, and transaction data needed to be validated (with BLOCK_VALID_TRANSACTIONS for each block and its parents back to the genesis block or an assumeutxo snapshot block). Entries may be failed, though, and pruning nodes may be missing the data for the block.
Declared in <validation.h>
std::set<CBlockIndex*, node::CBlockIndexWorkComparator> setBlockIndexCandidates;