node/chainstate: Decouple from GetTime

Summary:
```
...instead pass in a std::function<int64_t()>
Note that the static_cast is needed (apparently) for the compiler to know which overloaded GetTime to choose.
```

Partial backport of [[bitcoin/bitcoin#23280 | core#23280]]:
bitcoin/bitcoin@05441c2

Depends on D12576.

Test Plan:
  ninja all check-all

Reviewers: #bitcoin_abc, sdulfari

Reviewed By: #bitcoin_abc, sdulfari

Differential Revision: https://reviews.bitcoinabc.org/D12577

Author: dongcarl

src/init.cpp

@@ -2535,7 +2535,8 @@ bool AppInitMain(Config &config, RPCServer &rpcServer,
 
                 rv2 = VerifyLoadedChainstate(
                     chainman, fReset, fReindexChainState, config, check_blocks,
-                    args.GetIntArg("-checklevel", DEFAULT_CHECKLEVEL));
+                    args.GetIntArg("-checklevel", DEFAULT_CHECKLEVEL),
+                    static_cast<int64_t (*)()>(GetTime));
             } catch (const std::exception &e) {
                 LogPrintf("%s\n", e.what());
                 rv2 = ChainstateLoadVerifyError::ERROR_GENERIC_FAILURE;

src/node/chainstate.cpp

@@ -8,7 +8,6 @@
 #include <config.h>
 #include <node/blockstorage.h>
 #include <shutdown.h>
-#include <util/time.h>
 #include <validation.h>
 
 std::optional<ChainstateLoadingError>
@@ -140,7 +139,8 @@ LoadChainstate(bool fReset, ChainstateManager &chainman, CTxMemPool *mempool,
 std::optional<ChainstateLoadVerifyError>
 VerifyLoadedChainstate(ChainstateManager &chainman, bool fReset,
                        bool fReindexChainState, const Config &config,
-                       unsigned int check_blocks, unsigned int check_level) {
+                       unsigned int check_blocks, unsigned int check_level,
+                       std::function<int64_t()> get_unix_time_seconds) {
     auto is_coinsview_empty =
         [&](CChainState *chainstate) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
             return fReset || fReindexChainState ||
@@ -153,7 +153,8 @@ VerifyLoadedChainstate(ChainstateManager &chainman, bool fReset,
         for (CChainState *chainstate : chainman.GetAll()) {
             if (!is_coinsview_empty(chainstate)) {
                 const CBlockIndex *tip = chainstate->m_chain.Tip();
-                if (tip && tip->nTime > GetTime() + MAX_FUTURE_BLOCK_TIME) {
+                if (tip && tip->nTime > get_unix_time_seconds() +
+                                            MAX_FUTURE_BLOCK_TIME) {
                     return ChainstateLoadVerifyError::ERROR_BLOCK_FROM_FUTURE;
                 }
 

src/node/chainstate.h

@@ -70,6 +70,7 @@ enum class ChainstateLoadVerifyError {
 std::optional<ChainstateLoadVerifyError>
 VerifyLoadedChainstate(ChainstateManager &chainman, bool fReset,
                        bool fReindexChainState, const Config &config,
-                       unsigned int check_blocks, unsigned int check_level);
+                       unsigned int check_blocks, unsigned int check_level,
+                       std::function<int64_t()> get_unix_time_seconds);
 
 #endif // BITCOIN_NODE_CHAINSTATE_H