1 files changed, 46 insertions, 4 deletions

diff --git a/src/consensus/params.h b/src/consensus/params.h
index 217cb019e1..1ed5ca469f 100644
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2020 The Bitcoin Core developers
+// Copyright (c) 2009-2021 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -11,13 +11,27 @@
 
 namespace Consensus {
 
-enum DeploymentPos
-{
+/**
+ * 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.
+ */
+enum BuriedDeployment : int16_t {
+    // buried deployments get negative values to avoid overlap with DeploymentPos
+    DEPLOYMENT_HEIGHTINCB = std::numeric_limits<int16_t>::min(),
+    DEPLOYMENT_CLTV,
+    DEPLOYMENT_DERSIG,
+    DEPLOYMENT_CSV,
+    DEPLOYMENT_SEGWIT,
+};
+constexpr bool ValidDeployment(BuriedDeployment dep) { return dep <= DEPLOYMENT_SEGWIT; }
+
+enum DeploymentPos : uint16_t {
     DEPLOYMENT_TESTDUMMY,
     DEPLOYMENT_TAPROOT, // Deployment of Schnorr/Taproot (BIPs 340-342)
-    // NOTE: Also add new deployments to VersionBitsDeploymentInfo in versionbits.cpp
+    // NOTE: Also add new deployments to VersionBitsDeploymentInfo in deploymentinfo.cpp
     MAX_VERSION_BITS_DEPLOYMENTS
 };
+constexpr bool ValidDeployment(DeploymentPos dep) { return dep < MAX_VERSION_BITS_DEPLOYMENTS; }
 
 /**
  * Struct for each individual consensus rule change using BIP9.
@@ -29,6 +43,11 @@ struct BIP9Deployment {
     int64_t nStartTime;
     /** Timeout/expiry MedianTime for the deployment attempt. */
     int64_t nTimeout;
+    /** If lock in occurs, delay activation until at least this block
+     *  height.  Note that activation will only occur on a retarget
+     *  boundary.
+     */
+    int min_activation_height{0};
 
     /** Constant for nTimeout very far in the future. */
     static constexpr int64_t NO_TIMEOUT = std::numeric_limits<int64_t>::max();
@@ -38,6 +57,11 @@ struct BIP9Deployment {
      *  process (which takes at least 3 BIP9 intervals). Only tests that specifically test the
      *  behaviour during activation cannot use this. */
     static constexpr int64_t ALWAYS_ACTIVE = -1;
+
+    /** Special value for nStartTime indicating that the deployment is never active.
+     *  This is useful for integrating the code changes for a new feature
+     *  prior to deploying it on some or all networks. */
+    static constexpr int64_t NEVER_ACTIVE = -2;
 };
 
 /**
@@ -90,7 +114,25 @@ struct Params {
      */
     bool signet_blocks{false};
     std::vector<uint8_t> signet_challenge;
+
+    int DeploymentHeight(BuriedDeployment dep) const
+    {
+        switch (dep) {
+        case DEPLOYMENT_HEIGHTINCB:
+            return BIP34Height;
+        case DEPLOYMENT_CLTV:
+            return BIP65Height;
+        case DEPLOYMENT_DERSIG:
+            return BIP66Height;
+        case DEPLOYMENT_CSV:
+            return CSVHeight;
+        case DEPLOYMENT_SEGWIT:
+            return SegwitHeight;
+        } // no default case, so the compiler can warn about missing cases
+        return std::numeric_limits<int>::max();
+    }
 };
+
 } // namespace Consensus
 
 #endif // BITCOIN_CONSENSUS_PARAMS_H