feat(vm): implement TIP-2935 serve historical block hashes from state#6686
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yanghang8612 wants to merge 3 commits intotronprotocol:developfrom
Open
feat(vm): implement TIP-2935 serve historical block hashes from state#6686yanghang8612 wants to merge 3 commits intotronprotocol:developfrom
yanghang8612 wants to merge 3 commits intotronprotocol:developfrom
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Port EIP-2935 to TRON: store recent block hashes in a system contract's storage so smart contracts can access up to 8191 blocks of history beyond the BLOCKHASH opcode's 256-block window. - New proposal ALLOW_TVM_PRAGUE(95), fork-gated by VERSION_4_8_2. - On activation, deploy the EIP-2935 runtime bytecode + ContractCapsule (version=0) + AccountCapsule(type=CONTRACT) at the canonical address 0x0000F90827F1C53a10cb7A02335B175320002935 via direct CodeStore / ContractStore / AccountStore writes. - On every block, before the transaction loop, write the parent block hash to StorageRowStore at slot (blockNum - 1) % 8191. The storage key layout replicates Storage.compose() for contractVersion=0 (addrHash[0:16] || slotKey[16:32]) so the written rows are readable via VM SLOAD. - BLOCKHASH opcode semantics unchanged; new storage is accessed by user contracts via STATICCALL to the deployed bytecode. Tests: round-trip equivalence (direct-write key = VM compose key), deploy idempotency, ring buffer modulo, end-to-end activation flow, and full VM repository read-back.
Proposal activation deploys the HistoryStorage contract via ProposalService, but a node started with committee.allowTvmPrague=1 would flip the flag on through the CommonParameter fallback without the contract ever being written to CodeStore/ContractStore/AccountStore. External STATICCALLs would then hit an empty account. - Add HistoryBlockHashUtil.deployIfMissing(Manager), called from Manager.init right after updateDynamicStoreByConfig so the bytecode is guaranteed present before any block is applied. - Guard write() against blockNum <= 0 so (0 - 1) % 8191 = -1 in Java can never corrupt a slot if the hook is ever reached for genesis. - Add integration tests covering the proposal-persisted, config-fallback, and already-deployed paths, plus block-1 writes genesis hash to slot 0 and the genesis no-op.
…hUtil Collapse the redundant getChainBaseManager() indirection — Manager already exposes getCodeStore/getContractStore/getAccountStore/getStorageRowStore/ getDynamicPropertiesStore pass-throughs.
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alan-eth
reviewed
Apr 16, 2026
| * Called once from ProposalService when ALLOW_TVM_PRAGUE activates. | ||
| */ | ||
| public static void deploy(Manager manager) { | ||
| byte[] addr = HISTORY_STORAGE_ADDRESS; |
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The idempotent deploy() with per-store has() checks and the genesis guard in write() are really clean.
Minor: would it be helpful to add a log line in deploy() / deployIfMissing() for easier troubleshooting during upgrades?
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What does this PR do?
Implements TIP-2935 (port of EIP-2935 "Serve Historical Block Hashes from State") for java-tron.
ALLOW_TVM_PRAGUE(ID95), fork-gated byVERSION_4_8_2.SmartContract(version = 0) +CONTRACT-type account at the 20-byte address0x0000F90827F1C53a10cb7A02335B175320002935(TRON:410000F90827F1C53a10cb7A02335B175320002935). The three writes go toCodeStore/ContractStore/AccountStorevia normal revoking-store puts — no synthetic transaction, no new actuator.StorageRowStoreat slot(block.num - 1) % 8191. The storage-key composition exactly replicatesStorage.compose()forcontractVersion=0(sha3(addr)[0:16] || slotKey[16:32]), so the direct-written rows are readable via a normal VMSLOADwhen user contractsSTATICCALLthe deployed bytecode.BLOCKHASHopcode semantics are unchanged (still the 256-block window).Why are these changes required?
The 256-block
BLOCKHASHwindow is too short for many workloads (rollups, stateless clients, multi-block fraud proofs, long-dated oracle signatures). EIP-2935 is the industry-standard solution on Ethereum (Prague, May 2025). Bringing it to TVM gives TRON DApps the same guarantees and — because we keep the same address and bytecode — lets cross-chain contracts hardcode0x0000F908…2935and work unchanged on both chains.This PR has been tested by:
HistoryBlockHashUtilTest(5 cases): storage-key round-trip equivalence withStorage.compose(), deploy populates Code/Contract/Account, deploy idempotency, slot-correctness, ring-buffer modulo wrap.HistoryBlockHashIntegrationTest(4 cases): activation flow, per-block write after activation, gated off before activation, and a full VM round-trip that reads the written hash back throughRepositoryImpl.getStorageValue— proving the read path composes the same key as our write path.ProposalUtilTest.validateCheck: newtestAllowTvmPragueProposalcovering pre-fork rejection, bad-value rejection, already-enabled rejection, and the valid path../gradlew :framework:compileJava :framework:compileTestJava— OK../gradlew lint— OK../gradlew :framework:test --tests "…HistoryBlockHash…" --tests "…ProposalUtilTest.validateCheck"— all pass.Follow up
410000F90827F1C53a10cb7A02335B175320002935has never held a contract / balance (deployment would collide otherwise).STATICCALLtoget(blockNum)from a Solidity contract on Nile.Extra details
Implementation notes on how this diverges from geth's Prague system-call pattern (direct-write instead of system call, proposal activation instead of genesis pre-alloc, one-block activation gap) are summarized in the TIP issue comment.