Merge bitcoin/bitcoin#25388: refactor: move policy constants to policy

0d8e68d7054466925ecd165a871fc0e3f53cdafa refactor: move DEFAULT_*_LIMIT assertions from validation to policy (fanquake)
9c94f3b3a71b6d1c30471cf6a2a4fbadcc351a3f refactor: move EXTRA_DESCENDANT_TX_SIZE_LIMIT to policy/policy.h (fanquake)
39c60362536a868712f5b4c3ba8d04ef811e9e40 refactor: use braced initialization in policy/policy.h (fanquake)
01ccfbe3aaf96be4304640dd0df04d576b50a725 scripted-diff: use static constexpr in policy/policy.h (fanquake)
62d56bb714e98c54051f8564991b2748efa1737c refactor: Move DEFAULT_DESCENDANT_SIZE_LIMIT to policy/policy.h (fanquake)
a34aa4c187d854b410f04df639b19f4ef8e92078 refactor: Move DEFAULT_DESCENDANT_LIMIT to policy/policy.h (fanquake)
05fc5fdc134cdf466b8cce757088b9a550bf0c30 refactor: Move DEFAULT_ANCESTOR_SIZE_LIMIT to policy/policy.h (fanquake)
da8d304960d0e1368e5a08a4107537cab6bea52f refactor: Move DEFAULT_ANCESTOR_LIMIT to policy/policy.h (CAnon)

Pull request description:

  Picks up #25295. Which was a follow up to [a comment in #25254](https://github.com/bitcoin/bitcoin/pull/25254#discussion_r890595318).
  Moves policy constants from validation.h to policy.h.

ACKs for top commit:
  laanwj:
    Code review ACK 0d8e68d7054466925ecd165a871fc0e3f53cdafa
  w0xlt:
    reACK https://github.com/bitcoin/bitcoin/pull/25388/commits/0d8e68d7054466925ecd165a871fc0e3f53cdafa
  darosior:
    ACK 0d8e68d7054466925ecd165a871fc0e3f53cdafa

Tree-SHA512: 79900b09dc3a8020b5053ec734f462cb6e8184ed2b76e9d8afae7fe5331bbc906daaa42c0f622782797d971aaf5698aa0155511ec1d15582cc7675c271664a8d

4 files changed, 46 insertions, 46 deletions

diff --git a/src/policy/packages.h b/src/policy/packages.h
index ba6a3a9a06..564ff50d29 100644
--- a/src/policy/packages.h
+++ b/src/policy/packages.h
@@ -19,6 +19,15 @@ static constexpr uint32_t MAX_PACKAGE_COUNT{25};
 static constexpr uint32_t MAX_PACKAGE_SIZE{101};
 static_assert(MAX_PACKAGE_SIZE * WITNESS_SCALE_FACTOR * 1000 >= MAX_STANDARD_TX_WEIGHT);
 
+// If a package is submitted, it must be within the mempool's ancestor/descendant limits. Since a
+// submitted package must be child-with-unconfirmed-parents (all of the transactions are an ancestor
+// of the child), package limits are ultimately bounded by mempool package limits. Ensure that the
+// defaults reflect this constraint.
+static_assert(DEFAULT_DESCENDANT_LIMIT >= MAX_PACKAGE_COUNT);
+static_assert(DEFAULT_ANCESTOR_LIMIT >= MAX_PACKAGE_COUNT);
+static_assert(DEFAULT_ANCESTOR_SIZE_LIMIT >= MAX_PACKAGE_SIZE);
+static_assert(DEFAULT_DESCENDANT_SIZE_LIMIT >= MAX_PACKAGE_SIZE);
+
 /** A "reason" why a package was invalid. It may be that one or more of the included
  * transactions is invalid or the package itself violates our rules.
  * We don't distinguish between consensus and policy violations right now.
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 94f9623b8a..cd46652efc 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -20,49 +20,63 @@ class CFeeRate;
 class CScript;
 
 /** Default for -blockmaxweight, which controls the range of block weights the mining code will create **/
-static const unsigned int DEFAULT_BLOCK_MAX_WEIGHT = MAX_BLOCK_WEIGHT - 4000;
+static constexpr unsigned int DEFAULT_BLOCK_MAX_WEIGHT{MAX_BLOCK_WEIGHT - 4000};
 /** Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code **/
-static const unsigned int DEFAULT_BLOCK_MIN_TX_FEE = 1000;
+static constexpr unsigned int DEFAULT_BLOCK_MIN_TX_FEE{1000};
 /** The maximum weight for transactions we're willing to relay/mine */
-static const unsigned int MAX_STANDARD_TX_WEIGHT = 400000;
+static constexpr unsigned int MAX_STANDARD_TX_WEIGHT{400000};
 /** The minimum non-witness size for transactions we're willing to relay/mine (1 segwit input + 1 P2WPKH output = 82 bytes) */
-static const unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE = 82;
+static constexpr unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE{82};
 /** Maximum number of signature check operations in an IsStandard() P2SH script */
-static const unsigned int MAX_P2SH_SIGOPS = 15;
+static constexpr unsigned int MAX_P2SH_SIGOPS{15};
 /** The maximum number of sigops we're willing to relay/mine in a single tx */
-static const unsigned int MAX_STANDARD_TX_SIGOPS_COST = MAX_BLOCK_SIGOPS_COST/5;
+static constexpr unsigned int MAX_STANDARD_TX_SIGOPS_COST{MAX_BLOCK_SIGOPS_COST/5};
 /** Default for -maxmempool, maximum megabytes of mempool memory usage */
-static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
+static constexpr unsigned int DEFAULT_MAX_MEMPOOL_SIZE{300};
 /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or BIP 125 replacement **/
-static const unsigned int DEFAULT_INCREMENTAL_RELAY_FEE = 1000;
+static constexpr unsigned int DEFAULT_INCREMENTAL_RELAY_FEE{1000};
 /** Default for -bytespersigop */
-static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
+static constexpr unsigned int DEFAULT_BYTES_PER_SIGOP{20};
 /** Default for -permitbaremultisig */
-static const bool DEFAULT_PERMIT_BAREMULTISIG = true;
+static constexpr bool DEFAULT_PERMIT_BAREMULTISIG{true};
 /** The maximum number of witness stack items in a standard P2WSH script */
-static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS = 100;
+static constexpr unsigned int MAX_STANDARD_P2WSH_STACK_ITEMS{100};
 /** The maximum size in bytes of each witness stack item in a standard P2WSH script */
-static const unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE = 80;
+static constexpr unsigned int MAX_STANDARD_P2WSH_STACK_ITEM_SIZE{80};
 /** The maximum size in bytes of each witness stack item in a standard BIP 342 script (Taproot, leaf version 0xc0) */
-static const unsigned int MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE = 80;
+static constexpr unsigned int MAX_STANDARD_TAPSCRIPT_STACK_ITEM_SIZE{80};
 /** The maximum size in bytes of a standard witnessScript */
-static const unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE = 3600;
+static constexpr unsigned int MAX_STANDARD_P2WSH_SCRIPT_SIZE{3600};
 /** The maximum size of a standard ScriptSig */
-static const unsigned int MAX_STANDARD_SCRIPTSIG_SIZE = 1650;
+static constexpr unsigned int MAX_STANDARD_SCRIPTSIG_SIZE{1650};
 /** Min feerate for defining dust. Historically this has been based on the
  * minRelayTxFee, however changing the dust limit changes which transactions are
  * standard and should be done with care and ideally rarely. It makes sense to
  * only increase the dust limit after prior releases were already not creating
  * outputs below the new threshold */
-static const unsigned int DUST_RELAY_TX_FEE = 3000;
+static constexpr unsigned int DUST_RELAY_TX_FEE{3000};
 /** Default for -minrelaytxfee, minimum relay fee for transactions */
-static const unsigned int DEFAULT_MIN_RELAY_TX_FEE = 1000;
+static constexpr unsigned int DEFAULT_MIN_RELAY_TX_FEE{1000};
+/** Default for -limitancestorcount, max number of in-mempool ancestors */
+static constexpr unsigned int DEFAULT_ANCESTOR_LIMIT{25};
+/** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
+static constexpr unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT{101};
+/** Default for -limitdescendantcount, max number of in-mempool descendants */
+static constexpr unsigned int DEFAULT_DESCENDANT_LIMIT{25};
+/** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
+static constexpr unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT{101};
+/**
+ * An extra transaction can be added to a package, as long as it only has one
+ * ancestor and is no larger than this. Not really any reason to make this
+ * configurable as it doesn't materially change DoS parameters.
+ */
+static constexpr unsigned int EXTRA_DESCENDANT_TX_SIZE_LIMIT{10000};
 /**
  * Standard script verification flags that standard transactions will comply
  * with. However scripts violating these flags may still be present in valid
  * blocks and we must accept those blocks.
  */
-static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VERIFY_FLAGS |
+static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS{MANDATORY_SCRIPT_VERIFY_FLAGS |
                                                              SCRIPT_VERIFY_DERSIG |
                                                              SCRIPT_VERIFY_STRICTENC |
                                                              SCRIPT_VERIFY_MINIMALDATA |
@@ -81,14 +95,14 @@ static constexpr unsigned int STANDARD_SCRIPT_VERIFY_FLAGS = MANDATORY_SCRIPT_VE
                                                              SCRIPT_VERIFY_TAPROOT |
                                                              SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_TAPROOT_VERSION |
                                                              SCRIPT_VERIFY_DISCOURAGE_OP_SUCCESS |
-                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE;
+                                                             SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE};
 
 /** For convenience, standard but not mandatory verify flags. */
-static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
+static constexpr unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS{STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS};
 
 /** Used as the flags parameter to sequence and nLocktime checks in non-consensus code. */
-static constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = LOCKTIME_VERIFY_SEQUENCE |
-                                                               LOCKTIME_MEDIAN_TIME_PAST;
+static constexpr unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS{LOCKTIME_VERIFY_SEQUENCE |
+                                                             LOCKTIME_MEDIAN_TIME_PAST};
 
 CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
 
diff --git a/src/validation.cpp b/src/validation.cpp
index 26ce286c63..b775c85912 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -81,12 +81,6 @@ using node::UnlinkPrunedFiles;
 #define MICRO 0.000001
 #define MILLI 0.001
 
-/**
- * An extra transaction can be added to a package, as long as it only has one
- * ancestor and is no larger than this. Not really any reason to make this
- * configurable as it doesn't materially change DoS parameters.
- */
-static const unsigned int EXTRA_DESCENDANT_TX_SIZE_LIMIT = 10000;
 /** Maximum kilobytes for transactions to store for processing during reorg */
 static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20000;
 /** Time to wait between writing blocks/block index to disk. */
diff --git a/src/validation.h b/src/validation.h
index 70b6c072e6..3b6cd509c6 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -21,6 +21,7 @@
 #include <node/blockstorage.h>
 #include <policy/feerate.h>
 #include <policy/packages.h>
+#include <policy/policy.h>
 #include <script/script_error.h>
 #include <sync.h>
 #include <txdb.h>
@@ -58,24 +59,6 @@ namespace Consensus {
 struct Params;
 } // namespace Consensus
 
-/** Default for -limitancestorcount, max number of in-mempool ancestors */
-static const unsigned int DEFAULT_ANCESTOR_LIMIT = 25;
-/** Default for -limitancestorsize, maximum kilobytes of tx + all in-mempool ancestors */
-static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101;
-/** Default for -limitdescendantcount, max number of in-mempool descendants */
-static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25;
-/** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
-static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101;
-
-// If a package is submitted, it must be within the mempool's ancestor/descendant limits. Since a
-// submitted package must be child-with-unconfirmed-parents (all of the transactions are an ancestor
-// of the child), package limits are ultimately bounded by mempool package limits. Ensure that the
-// defaults reflect this constraint.
-static_assert(DEFAULT_DESCENDANT_LIMIT >= MAX_PACKAGE_COUNT);
-static_assert(DEFAULT_ANCESTOR_LIMIT >= MAX_PACKAGE_COUNT);
-static_assert(DEFAULT_ANCESTOR_SIZE_LIMIT >= MAX_PACKAGE_SIZE);
-static_assert(DEFAULT_DESCENDANT_SIZE_LIMIT >= MAX_PACKAGE_SIZE);
-
 /** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
 static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336;
 /** Maximum number of dedicated script-checking threads allowed */