Hardfork.hasEIP1153

import { Hardfork } from 'tevm'

function getReentrancyLockImplementation(fork: BrandedHardfork) {
  if (fork.hasEIP1153()) {
    // Solidity pseudocode:
    // uint256 locked;  // transient storage
    // modifier nonReentrant() {
    //   assembly { if tload(0) { revert(0, 0) } }
    //   assembly { tstore(0, 1) }
    //   _;
    //   assembly { tstore(0, 0) }
    // }
    return {
      type: "transient",
      gas: 200  // 100 TSTORE + 100 TLOAD
    }
  }

  return {
    type: "storage",
    gas: 20_200  // SSTORE + SLOAD (cold)
  }
}

// Transient storage saves ~20k gas per lock

import { Hardfork } from 'tevm'

function useTransientCache(fork: BrandedHardfork): boolean {
  // Use transient storage for intermediate calculations
  // that don't need to persist
  return fork.hasEIP1153()
}

import { Hardfork } from 'tevm'

function supportsTransientMessaging(fork: BrandedHardfork): boolean {
  // Enable contract-to-contract data passing
  // without permanent storage
  return fork.hasEIP1153()
}

import { Hardfork } from 'tevm'

function getFlashLoanImplementation(fork: BrandedHardfork) {
  if (fork.hasEIP1153()) {
    return "transient"  // Track loan state in transient storage
  }

  return "storage"  // Must use expensive SSTORE/SLOAD
}

import { Hardfork } from 'tevm'

function estimateReentrancyLockGas(fork: BrandedHardfork): number {
  if (fork.hasEIP1153()) {
    // TLOAD + TSTORE + TSTORE
    return 100 + 100 + 100  // 300 gas
  }

  // SLOAD (cold) + SSTORE (cold) + SSTORE (cold)
  return 2_100 + 20_000 + 2_900  // 25,000 gas
}

// Savings: ~24,700 gas per reentrancy lock

import { Hardfork, CANCUN } from 'tevm'

function validateTransientStorage(config: NetworkConfig) {
  const fork = Hardfork(config.hardfork)

  if (fork.hasEIP1153()) {
    console.log("Transient storage available - use for reentrancy locks")
  } else {
    console.log("Transient storage not available - using permanent storage")
  }
}

import { Hardfork } from 'tevm'

function getSoliditySettings(fork: BrandedHardfork) {
  return {
    evmVersion: fork.hasEIP1153() ? "cancun" : "shanghai",
    viaIR: true  // Required for transient storage optimization
  }
}