Merge bitcoin/bitcoin#19438: Introduce deploymentstatus

e48826ad87b4f92261f7433e84f48dac9bd9e5c3 tests: remove ComputeBlockVersion shortcut from versionbits tests (Anthony Towns)
c5f36725e877d8eb492383844f8ef7535466b366 [refactor] Move ComputeBlockVersion into VersionBitsCache (Anthony Towns)
4a69b4dbe0d7f504811b67c399da7e6d11e4f805 [move-only] Move ComputeBlockVersion from validation to versionbits (Anthony Towns)
0cfd6c6a8f929d5567ac41f95c21548f115efee5 [refactor] versionbits: make VersionBitsCache a full class (Anthony Towns)
8ee3e0bed5bf2cd3c7a68ca6ba6c65f7b9a72cca [refactor] rpc/blockchain.cpp: SoftForkPushBack (Anthony Towns)
92f48f360da5f425428b761219301f509826bec4 deploymentinfo: Add DeploymentName() (Anthony Towns)
ea68b3a5729f5d240e968388c4f88acffeb27228 [move-only] Rename versionbitsinfo to deploymentinfo (Anthony Towns)
c64b2c6a0f79369624ae96b2e3d579d50aae4de6 scripted-diff: rename versionbitscache (Anthony Towns)
de55304f6e7a8b607e6b3fc7436de50910747b0c [refactor] Add versionbits deployments to deploymentstatus.h (Anthony Towns)
2b0d291da8f479739ff394dd92801da8c40b9f8e [refactor] Add deploymentstatus.h (Anthony Towns)
eccd736f3dc231ac0306ca763c3b72cf8247230a versionbits: Use dedicated lock instead of cs_main (Anthony Towns)
36a4ba0aaaa9b35185d7178994e36bc02cca9887 versionbits: correct doxygen comments (Anthony Towns)

Pull request description:

  Introduces helper functions to make it easy to bury future deployments, along the lines of the suggestion from [11398](https://github.com/bitcoin/bitcoin/pull/11398#issuecomment-335599326) "I would prefer it if a buried deployment wouldn't require all code paths that check the BIP9 status to require changing".

  This provides three functions: `DeploymentEnabled()` which tests if a deployment can ever be active, `DeploymentActiveAt()` which checks if a deployment should be enforced in the given block, and `DeploymentActiveAfter()` which checks if a deployment should be enforced in the block following the given block, and overloads all three to work both with buried deployments and versionbits deployments.

  This adds a dedicated lock for the versionbits cache, which is acquired internally by the versionbits functions, rather than relying on `cs_main`. It also moves moves versionbitscache into deploymentstatus to avoid a circular dependency with validation.

ACKs for top commit:
  jnewbery:
    ACK e48826ad87b4f92261f7433e84f48dac9bd9e5c3
  gruve-p:
    ACK https://github.com/bitcoin/bitcoin/pull/19438/commits/e48826ad87b4f92261f7433e84f48dac9bd9e5c3
  MarcoFalke:
    re-ACK e48826ad87b4f92261f7433e84f48dac9bd9e5c3 🥈

Tree-SHA512: c846ba64436d36f8180046ad551d8b0d9e20509b9bc185aa2639055fc28803dd8ec2d6771ab337e80da0b40009ad959590d5772f84a0bf6199b65190d4155bed

2 files changed, 28 insertions, 23 deletions

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 02f8cec54c..b630458f23 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -10,8 +10,11 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <coins.h>
+#include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
+#include <deploymentinfo.h>
+#include <deploymentstatus.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <index/coinstatsindex.h>
@@ -37,6 +40,7 @@
 #include <util/translation.h>
 #include <validation.h>
 #include <validationinterface.h>
+#include <versionbits.h>
 #include <warnings.h>
 
 #include <stdint.h>
@@ -1343,32 +1347,32 @@ static RPCHelpMan verifychain()
     };
 }
 
-static void BuriedForkDescPushBack(UniValue& softforks, const std::string &name, int softfork_height, int tip_height) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const Consensus::Params& params, Consensus::BuriedDeployment dep)
 {
     // For buried deployments.
     // A buried deployment is one where the height of the activation has been hardcoded into
     // the client implementation long after the consensus change has activated. See BIP 90.
     // Buried deployments with activation height value of
     // std::numeric_limits<int>::max() are disabled and thus hidden.
-    if (softfork_height == std::numeric_limits<int>::max()) return;
+    if (!DeploymentEnabled(params, dep)) return;
 
     UniValue rv(UniValue::VOBJ);
     rv.pushKV("type", "buried");
     // getblockchaininfo reports the softfork as active from when the chain height is
     // one below the activation height
-    rv.pushKV("active", tip_height + 1 >= softfork_height);
-    rv.pushKV("height", softfork_height);
-    softforks.pushKV(name, rv);
+    rv.pushKV("active", DeploymentActiveAfter(active_chain_tip, params, dep));
+    rv.pushKV("height", params.DeploymentHeight(dep));
+    softforks.pushKV(DeploymentName(dep), rv);
 }
 
-static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const std::string &name, const Consensus::Params& consensusParams, Consensus::DeploymentPos id) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+static void SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniValue& softforks, const Consensus::Params& consensusParams, Consensus::DeploymentPos id)
 {
     // For BIP9 deployments.
     // Deployments that are never active are hidden.
     if (consensusParams.vDeployments[id].nStartTime == Consensus::BIP9Deployment::NEVER_ACTIVE) return;
 
     UniValue bip9(UniValue::VOBJ);
-    const ThresholdState thresholdState = VersionBitsState(active_chain_tip, consensusParams, id, versionbitscache);
+    const ThresholdState thresholdState = g_versionbitscache.State(active_chain_tip, consensusParams, id);
     switch (thresholdState) {
     case ThresholdState::DEFINED: bip9.pushKV("status", "defined"); break;
     case ThresholdState::STARTED: bip9.pushKV("status", "started"); break;
@@ -1382,12 +1386,12 @@ static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniVal
     }
     bip9.pushKV("start_time", consensusParams.vDeployments[id].nStartTime);
     bip9.pushKV("timeout", consensusParams.vDeployments[id].nTimeout);
-    int64_t since_height = VersionBitsStateSinceHeight(active_chain_tip, consensusParams, id, versionbitscache);
+    int64_t since_height = g_versionbitscache.StateSinceHeight(active_chain_tip, consensusParams, id);
     bip9.pushKV("since", since_height);
     if (ThresholdState::STARTED == thresholdState)
     {
         UniValue statsUV(UniValue::VOBJ);
-        BIP9Stats statsStruct = VersionBitsStatistics(active_chain_tip, consensusParams, id);
+        BIP9Stats statsStruct = g_versionbitscache.Statistics(active_chain_tip, consensusParams, id);
         statsUV.pushKV("period", statsStruct.period);
         statsUV.pushKV("threshold", statsStruct.threshold);
         statsUV.pushKV("elapsed", statsStruct.elapsed);
@@ -1405,7 +1409,7 @@ static void BIP9SoftForkDescPushBack(const CBlockIndex* active_chain_tip, UniVal
     }
     rv.pushKV("active", ThresholdState::ACTIVE == thresholdState);
 
-    softforks.pushKV(name, rv);
+    softforks.pushKV(DeploymentName(id), rv);
 }
 
 RPCHelpMan getblockchaininfo()
@@ -1502,14 +1506,14 @@ RPCHelpMan getblockchaininfo()
 
     const Consensus::Params& consensusParams = Params().GetConsensus();
     UniValue softforks(UniValue::VOBJ);
-    BuriedForkDescPushBack(softforks, "bip34", consensusParams.BIP34Height, height);
-    BuriedForkDescPushBack(softforks, "bip66", consensusParams.BIP66Height, height);
-    BuriedForkDescPushBack(softforks, "bip65", consensusParams.BIP65Height, height);
-    BuriedForkDescPushBack(softforks, "csv", consensusParams.CSVHeight, height);
-    BuriedForkDescPushBack(softforks, "segwit", consensusParams.SegwitHeight, height);
-    BIP9SoftForkDescPushBack(tip, softforks, "testdummy", consensusParams, Consensus::DEPLOYMENT_TESTDUMMY);
-    BIP9SoftForkDescPushBack(tip, softforks, "taproot", consensusParams, Consensus::DEPLOYMENT_TAPROOT);
-    obj.pushKV("softforks",             softforks);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_HEIGHTINCB);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_DERSIG);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_CLTV);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_CSV);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_SEGWIT);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_TESTDUMMY);
+    SoftForkDescPushBack(tip, softforks, consensusParams, Consensus::DEPLOYMENT_TAPROOT);
+    obj.pushKV("softforks", softforks);
 
     obj.pushKV("warnings", GetWarnings(false).original);
     return obj;
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 327f961196..2762d78493 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -10,6 +10,8 @@
 #include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
+#include <deploymentinfo.h>
+#include <deploymentstatus.h>
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
@@ -34,7 +36,6 @@
 #include <util/translation.h>
 #include <validation.h>
 #include <validationinterface.h>
-#include <versionbitsinfo.h>
 #include <warnings.h>
 
 #include <memory>
@@ -774,7 +775,7 @@ static RPCHelpMan getblocktemplate()
     pblock->nNonce = 0;
 
     // NOTE: If at some point we support pre-segwit miners post-segwit-activation, this needs to take segwit support into consideration
-    const bool fPreSegWit = (pindexPrev->nHeight + 1 < consensusParams.SegwitHeight);
+    const bool fPreSegWit = !DeploymentActiveAfter(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT);
 
     UniValue aCaps(UniValue::VARR); aCaps.push_back("proposal");
 
@@ -840,7 +841,7 @@ static RPCHelpMan getblocktemplate()
     UniValue vbavailable(UniValue::VOBJ);
     for (int j = 0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
         Consensus::DeploymentPos pos = Consensus::DeploymentPos(j);
-        ThresholdState state = VersionBitsState(pindexPrev, consensusParams, pos, versionbitscache);
+        ThresholdState state = g_versionbitscache.State(pindexPrev, consensusParams, pos);
         switch (state) {
             case ThresholdState::DEFINED:
             case ThresholdState::FAILED:
@@ -848,7 +849,7 @@ static RPCHelpMan getblocktemplate()
                 break;
             case ThresholdState::LOCKED_IN:
                 // Ensure bit is set in block version
-                pblock->nVersion |= VersionBitsMask(consensusParams, pos);
+                pblock->nVersion |= g_versionbitscache.Mask(consensusParams, pos);
                 // FALL THROUGH to get vbavailable set...
             case ThresholdState::STARTED:
             {
@@ -857,7 +858,7 @@ static RPCHelpMan getblocktemplate()
                 if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
                     if (!vbinfo.gbt_force) {
                         // If the client doesn't support this, don't indicate it in the [default] version
-                        pblock->nVersion &= ~VersionBitsMask(consensusParams, pos);
+                        pblock->nVersion &= ~g_versionbitscache.Mask(consensusParams, pos);
                     }
                 }
                 break;