Add deep freeze feature (XLS-77d) (#5187)

- spec: XRPLF/XRPL-Standards#220
- amendment: "DeepFreeze"
- implemented deep freeze spec to allow token issuers to prevent currency holders from being able to acquire more of these tokens.
- in combination with normal freeze, deep freeze effectively prevents any balance trust line balance change of a currency holder (except direct issuer <-> holder payments).
- added 2 new invariant checks to verify that deep freeze cannot be enacted without normal freeze and transfer is not frozen.
- made some fixes to existing freeze handling.

Co-authored-by: Ed Hennis <ed@ripple.com>
Co-authored-by: Howard Hinnant <howard.hinnant@gmail.com>

include/xrpl/protocol/Feature.h

@@ -80,7 +80,7 @@ namespace detail {
 // Feature.cpp. Because it's only used to reserve storage, and determine how
 // large to make the FeatureBitset, it MAY be larger. It MUST NOT be less than
 // the actual number of amendments. A LogicError on startup will verify this.
-static constexpr std::size_t numFeatures = 108;
+static constexpr std::size_t numFeatures = 109;
 
 /** Amendments that this server supports and the default voting behavior.
    Whether they are enabled depends on the Rules defined in the validated

include/xrpl/protocol/LedgerFormats.h

@@ -162,10 +162,12 @@ enum LedgerSpecificFlags {
     lsfHighAuth = 0x00080000,
     lsfLowNoRipple = 0x00100000,
     lsfHighNoRipple = 0x00200000,
-    lsfLowFreeze = 0x00400000,   // True, low side has set freeze flag
-    lsfHighFreeze = 0x00800000,  // True, high side has set freeze flag
-    lsfAMMNode = 0x01000000,     // True, trust line to AMM. Used by client
-                                 // apps to identify payments via AMM.
+    lsfLowFreeze = 0x00400000,      // True, low side has set freeze flag
+    lsfHighFreeze = 0x00800000,     // True, high side has set freeze flag
+    lsfLowDeepFreeze = 0x02000000,  // True, low side has set deep freeze flag
+    lsfHighDeepFreeze = 0x04000000, // True, high side has set deep freeze flag
+    lsfAMMNode = 0x01000000,        // True, trust line to AMM. Used by client
+                                    // apps to identify payments via AMM.
 
     // ltSIGNER_LIST
     lsfOneOwnerCount = 0x00010000,  // True, uses only one OwnerCount

include/xrpl/protocol/TxFlags.h

@@ -124,10 +124,12 @@ enum TrustSetFlags : uint32_t {
     tfClearNoRipple = 0x00040000,
     tfSetFreeze = 0x00100000,
     tfClearFreeze = 0x00200000,
+    tfSetDeepFreeze = 0x00400000,
+    tfClearDeepFreeze = 0x00800000,
 };
 constexpr std::uint32_t tfTrustSetMask =
     ~(tfUniversal | tfSetfAuth | tfSetNoRipple | tfClearNoRipple | tfSetFreeze |
-      tfClearFreeze);
+      tfClearFreeze | tfSetDeepFreeze | tfClearDeepFreeze);
 
 // EnableAmendment flags:
 enum EnableAmendmentFlags : std::uint32_t {

include/xrpl/protocol/detail/features.macro

@@ -29,6 +29,7 @@
 // If you add an amendment here, then do not forget to increment `numFeatures`
 // in include/xrpl/protocol/Feature.h.
 
+XRPL_FEATURE(DeepFreeze,                 Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(PermissionedDomains,        Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(DynamicNFT,                 Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(Credentials,                Supported::yes, VoteBehavior::DefaultNo)
@@ -139,3 +140,4 @@ XRPL_FIX    (NFTokenNegOffer,       Supported::yes, VoteBehavior::Obsolete)
 XRPL_FIX    (NFTokenDirV1,          Supported::yes, VoteBehavior::Obsolete)
 XRPL_FEATURE(NonFungibleTokensV1,   Supported::yes, VoteBehavior::Obsolete)
 XRPL_FEATURE(CryptoConditionsSuite, Supported::yes, VoteBehavior::Obsolete)
+

include/xrpl/protocol/jss.h

@@ -330,6 +330,8 @@ JSS(force);                 // in: catalogue
 JSS(forward);               // in: AccountTx
 JSS(freeze);                // out: AccountLines
 JSS(freeze_peer);           // out: AccountLines
+JSS(deep_freeze);           // out: AccountLines
+JSS(deep_freeze_peer);      // out: AccountLines
 JSS(frozen_balances);       // out: GatewayBalances
 JSS(full);                  // in: LedgerClearer, handlers/Ledger
 JSS(full_reply);            // out: PathFind