merge-script 81e67d9aa1
Merge bitcoin/bitcoin#34179: refactor: Enable transparent lookup for setBlockIndexCandidates to remove const_cast
3bd98b45084d3029465110a99e2486d48944ded8 refactor: use transparent comparator for setBlockIndexCandidates lookups (joaonevess)

Pull request description:

  ### Rationale

  This PR improves code safety by removing a `const_cast` in `src/validation.cpp`.

  Currently, `setBlockIndexCandidates` stores mutable `CBlockIndex*`. However, validation logic (like `CVerifyDB`) often holds `const CBlockIndex*`. Previously, checking for existence in the set required casting away constness. While currently benign, this bypasses compiler safety checks and could mask accidental modifications in future refactors.

  ### Description

  1.  **Enable Heterogeneous Lookup:** Added `using is_transparent = void;` to `CBlockIndexWorkComparator` in `src/node/blockstorage.h`. This allows the `std::set` to natively accept `const CBlockIndex*` for lookup (utilizing C++14 heterogeneous lookup).
  2.  **Remove Cast:** Removed the now unnecessary `const_cast<CBlockIndex*>` in `src/validation.cpp`, allowing the compiler to strictly enforce const-correctness.

  ### Notes

  - **Refactoring only:** No behavioral change.
  - **Verification:** `validation_tests` and `blockmanager_tests` pass.

ACKs for top commit:
  maflcko:
    review ACK 3bd98b45084d3029465110a99e2486d48944ded8 🚪
  frankomosh:
    ACK 3bd98b45084d3029465110a99e2486d48944ded8. Good use of transparent comparator to eliminate `const_cast` in this specific code path.
  sedited:
    ACK 3bd98b45084d3029465110a99e2486d48944ded8

Tree-SHA512: 0f76bdce2a54b759dfec99633afce1e95586e62f4057ecf1e82eed1a073eb8ecb2d659ccbf28a7a139f0aa09a30f058ac6966cafdfbf1f2ee878fa2d86b2c487
2026-02-02 08:49:02 +01:00
..

src/node/

The src/node/ directory contains code that needs to access node state (state in CChain, CBlockIndex, CCoinsView, CTxMemPool, and similar classes).

Code in src/node/ is meant to be segregated from code in src/wallet/ and src/qt/, to ensure wallet and GUI code changes don't interfere with node operation, to allow wallet and GUI code to run in separate processes, and to perhaps eventually allow wallet and GUI code to be maintained in separate source repositories.

As a rule of thumb, code in one of the src/node/, src/wallet/, or src/qt/ directories should avoid calling code in the other directories directly, and only invoke it indirectly through the more limited src/interfaces/ classes.

This directory is at the moment sparsely populated. Eventually more substantial files like src/validation.cpp and src/txmempool.cpp might be moved there.