feat: gate 256-bit A/B arithmetic behind AT creation version 3#12
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…ersion 3 Introduce AT creation version 3, which keeps version 2's page-size semantics and differs only in function code availability. The eight 256-bit A/B arithmetic function codes (ADD_A_TO_B..DIV_B_BY_A, 0x0140-0x0147) now declare minVersion 3 and FunctionCode.execute() throws IllegalFunctionCodeException for ATs created with an earlier version, exactly as an unknown function code would - verified bit-identical (final packed machine state, steps, PC, balance) against pre-batch commit 070e22c for raw codes 0x0140-0x0148 under version 2. Version 3 is accepted by creation-bytes parsing and toCreationBytes, with a round-trip test. ABArithmeticFunctionCodeTests now run under a version 3 header, plus explicit version-2 fault tests (mutation-checked: removing the gate makes them fail). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Summary
Gates the eight 256-bit A/B arithmetic function codes
0x0140-0x0147(added in #11) behind AT creation version 3, so a consumer chain can control their availability by AT version rather than having them execute unconditionally the moment the jar is repinned.minVersionfield onFunctionCode; the eight arithmetic codes declareminVersion = 3. The gate is the first statement ofFunctionCode.execute()— before any signature/value checks or state mutation — throwingIllegalFunctionCodeExceptionfor version-1/2 ATs.MachineStategains creation version 3, byte-identical to version 2 except opcode availability; creation-bytes parse/round-trip accept it.Why this matters (consensus)
Without version gating, repinning a consumer chain to this jar is a silent flag-day: bytecode containing
0x0140-0x0147faults on the old jar but executes on the new one. Gating by creation version lets the consumer chain reject version-3 deploys until a coordinated activation height, then allow them — no ambiguous window.Backward compatibility (proven)
Version-1/2 execution is bit-identical to the current pinned
33df17djar: for those versions the arithmetic codes fault at the version check exactly as unknown codes did before, charging the same steps, writing no registers, entering the same fatal-error path (only log text differs). Verified by a byte-for-byte machine-state comparison harness against pre-batch070e22c.Verification
mvn -B clean verify: 211 tests, 0 failures.The dual-model review's finding: gating execution by version is necessary but not sufficient — the consuming chain (qortium-core) must also reject deployment of version-3 creation bytes before the activation height (
DeployAtTransaction), or a v3DEPLOY_ATbroadcast pre-activation forks upgraded vs un-upgraded nodes. That Core-side deploy-gate + repin is the companion "phase-2" change. This jar PR is correct in isolation and can be reviewed/merged, but Core must not be repinned to it until the phase-2 deploy-gate lands.🤖 Generated with Claude Code