style: Modernize range-based loops over m_block_index

src/node/blockstorage.cpp

@@ -228,8 +228,8 @@ bool BlockManager::LoadBlockIndex(
     // Calculate nChainWork
     std::vector<std::pair<int, CBlockIndex*>> vSortedByHeight;
     vSortedByHeight.reserve(m_block_index.size());
-    for (std::pair<const uint256, CBlockIndex>& item : m_block_index) {
-        CBlockIndex* pindex = &item.second;
+    for (auto& [_, block_index] : m_block_index) {
+        CBlockIndex* pindex = &block_index;
         vSortedByHeight.push_back(std::make_pair(pindex->nHeight, pindex));
     }
     sort(vSortedByHeight.begin(), vSortedByHeight.end());
@@ -386,8 +386,8 @@ bool BlockManager::LoadBlockIndexDB(ChainstateManager& chainman)
     // Check presence of blk files
     LogPrintf("Checking all blk files are present...\n");
     std::set<int> setBlkDataFiles;
-    for (const std::pair<const uint256, CBlockIndex>& item : m_block_index) {
-        const CBlockIndex* pindex = &item.second;
+    for (const auto& [_, block_index] : m_block_index) {
+        const CBlockIndex* pindex = &block_index;
         if (pindex->nStatus & BLOCK_HAVE_DATA) {
             setBlkDataFiles.insert(pindex->nFile);
         }

src/rpc/blockchain.cpp

@@ -1753,10 +1753,10 @@ static RPCHelpMan getchaintips()
     std::set<const CBlockIndex*> setOrphans;
     std::set<const CBlockIndex*> setPrevs;
 
-    for (const std::pair<const uint256, CBlockIndex>& item : chainman.BlockIndex()) {
-        if (!active_chain.Contains(&item.second)) {
-            setOrphans.insert(&item.second);
-            setPrevs.insert(item.second.pprev);
+    for (const auto& [_, block_index] : chainman.BlockIndex()) {
+        if (!active_chain.Contains(&block_index)) {
+            setOrphans.insert(&block_index);
+            setPrevs.insert(block_index.pprev);
         }
     }
 

src/validation.cpp

@@ -3133,12 +3133,10 @@ bool CChainState::InvalidateBlock(BlockValidationState& state, CBlockIndex* pind
         // it up here, this should be an essentially unobservable error.
         // Loop back over all block index entries and add any missing entries
         // to setBlockIndexCandidates.
-        BlockMap::iterator it = m_blockman.m_block_index.begin();
-        while (it != m_blockman.m_block_index.end()) {
-            if (it->second.IsValid(BLOCK_VALID_TRANSACTIONS) && it->second.HaveTxsDownloaded() && !setBlockIndexCandidates.value_comp()(&it->second, m_chain.Tip())) {
-                setBlockIndexCandidates.insert(&it->second);
+        for (auto& [_, block_index] : m_blockman.m_block_index) {
+            if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveTxsDownloaded() && !setBlockIndexCandidates.value_comp()(&block_index, m_chain.Tip())) {
+                setBlockIndexCandidates.insert(&block_index);
             }
-            it++;
         }
 
         InvalidChainFound(to_mark_failed);
@@ -3157,21 +3155,19 @@ void CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {
     int nHeight = pindex->nHeight;
 
     // Remove the invalidity flag from this block and all its descendants.
-    BlockMap::iterator it = m_blockman.m_block_index.begin();
-    while (it != m_blockman.m_block_index.end()) {
-        if (!it->second.IsValid() && it->second.GetAncestor(nHeight) == pindex) {
-            it->second.nStatus &= ~BLOCK_FAILED_MASK;
-            m_blockman.m_dirty_blockindex.insert(&it->second);
-            if (it->second.IsValid(BLOCK_VALID_TRANSACTIONS) && it->second.HaveTxsDownloaded() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &it->second)) {
-                setBlockIndexCandidates.insert(&it->second);
+    for (auto& [_, block_index] : m_blockman.m_block_index) {
+        if (!block_index.IsValid() && block_index.GetAncestor(nHeight) == pindex) {
+            block_index.nStatus &= ~BLOCK_FAILED_MASK;
+            m_blockman.m_dirty_blockindex.insert(&block_index);
+            if (block_index.IsValid(BLOCK_VALID_TRANSACTIONS) && block_index.HaveTxsDownloaded() && setBlockIndexCandidates.value_comp()(m_chain.Tip(), &block_index)) {
+                setBlockIndexCandidates.insert(&block_index);
             }
-            if (&it->second == m_chainman.m_best_invalid) {
+            if (&block_index == m_chainman.m_best_invalid) {
                 // Reset invalid block marker if it was pointing to one of those.
                 m_chainman.m_best_invalid = nullptr;
             }
-            m_chainman.m_failed_blocks.erase(&it->second);
+            m_chainman.m_failed_blocks.erase(&block_index);
         }
-        it++;
     }
 
     // Remove the invalidity flag from all ancestors too.
@@ -4261,8 +4257,8 @@ void CChainState::CheckBlockIndex()
 
     // Build forward-pointing map of the entire block tree.
     std::multimap<CBlockIndex*,CBlockIndex*> forward;
-    for (std::pair<const uint256, CBlockIndex>& entry : m_blockman.m_block_index) {
-        forward.insert(std::make_pair(entry.second.pprev, &entry.second));
+    for (auto& [_, block_index] : m_blockman.m_block_index) {
+        forward.emplace(block_index.pprev, &block_index);
     }
 
     assert(forward.size() == m_blockman.m_block_index.size());