Merge #19241: help: Generate checkpoint height from chainparams

916d359 help: Generate checkpoint height from chainparams (Luke Dashjr)

Pull request description:

  Not sure if this is worth putting in Core, but might as well until checkpoints are removed entirely.

ACKs for top commit:
  laanwj:
    re-ACK 916d359

Tree-SHA512: d8eb26b570ee730fdd75ca916507134db5f2f68987a911e33544b7f1c9ccfd1c76b9c9db63056971956b6daf16910f17ecfc197481c2f7b0773afdfbf7d381cf

src/chainparams.h

@@ -23,6 +23,11 @@ typedef std::map<int, uint256> MapCheckpoints;
 
 struct CCheckpointData {
     MapCheckpoints mapCheckpoints;
+
+    int GetHeight() const {
+        const auto& final_checkpoint = mapCheckpoints.rbegin();
+        return final_checkpoint->first /* height */;
+    }
 };
 
 /**

src/init.cpp

@@ -507,7 +507,7 @@ void SetupServerArgs(NodeContext& node)
     argsman.AddArg("-checklevel=<n>", strprintf("How thorough the block verification of -checkblocks is: %s (0-4, default: %u)", Join(CHECKLEVEL_DOC, ", "), DEFAULT_CHECKLEVEL), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-checkblockindex", strprintf("Do a consistency check for the block tree, chainstate, and other validation data structures occasionally. (default: %u, regtest: %u)", defaultChainParams->DefaultConsistencyChecks(), regtestChainParams->DefaultConsistencyChecks()), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-checkmempool=<n>", strprintf("Run checks every <n> transactions (default: %u, regtest: %u)", defaultChainParams->DefaultConsistencyChecks(), regtestChainParams->DefaultConsistencyChecks()), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
-    argsman.AddArg("-checkpoints", strprintf("Enable rejection of any forks from the known historical chain until block 295000 (default: %u)", DEFAULT_CHECKPOINTS_ENABLED), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
+    argsman.AddArg("-checkpoints", strprintf("Enable rejection of any forks from the known historical chain until block %s (default: %u)", defaultChainParams->Checkpoints().GetHeight(), DEFAULT_CHECKPOINTS_ENABLED), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-deprecatedrpc=<method>", "Allows deprecated RPC method(s) to be used", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-dropmessagestest=<n>", "Randomly drop 1 of every <n> network messages", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-stopafterblockimport", strprintf("Stop running after importing blocks from disk (default: %u)", DEFAULT_STOPAFTERBLOCKIMPORT), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);