Add L2OO output root fetching

packages/contracts-bedrock/.gas-snapshot

@@ -85,35 +85,35 @@ FaucetTest:test_nonAdmin_drip_fails() (gas: 262520)
 FaucetTest:test_receive_succeeds() (gas: 17401)
 FaucetTest:test_withdraw_nonAdmin_reverts() (gas: 13145)
 FaucetTest:test_withdraw_succeeds() (gas: 78359)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 501901)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 508725)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 505444)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 508601)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 507940)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 500666)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 507490)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 504209)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 505366)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 504705)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 502209)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 508989)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 505730)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 508887)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 508226)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 500974)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 507754)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 504495)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 505652)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 504991)
 FaultDisputeGame_Test:test_extraData_succeeds() (gas: 17449)
-FaultDisputeGame_Test:test_gameData_succeeds() (gas: 17917)
+FaultDisputeGame_Test:test_gameData_succeeds() (gas: 17939)
 FaultDisputeGame_Test:test_gameStart_succeeds() (gas: 10293)
 FaultDisputeGame_Test:test_gameType_succeeds() (gas: 8238)
-FaultDisputeGame_Test:test_initialRootClaimData_succeeds() (gas: 17647)
-FaultDisputeGame_Test:test_move_clockCorrectness_succeeds() (gas: 419119)
-FaultDisputeGame_Test:test_move_clockTimeExceeded_reverts() (gas: 26377)
+FaultDisputeGame_Test:test_initialRootClaimData_succeeds() (gas: 17669)
+FaultDisputeGame_Test:test_move_clockCorrectness_succeeds() (gas: 419317)
+FaultDisputeGame_Test:test_move_clockTimeExceeded_reverts() (gas: 26399)
 FaultDisputeGame_Test:test_move_defendRoot_reverts() (gas: 13338)
-FaultDisputeGame_Test:test_move_duplicateClaim_reverts() (gas: 104032)
-FaultDisputeGame_Test:test_move_gameDepthExceeded_reverts() (gas: 411304)
-FaultDisputeGame_Test:test_move_gameNotInProgress_reverts() (gas: 10946)
-FaultDisputeGame_Test:test_move_nonExistentParent_reverts() (gas: 24611)
-FaultDisputeGame_Test:test_move_simpleAttack_succeeds() (gas: 108112)
-FaultDisputeGame_Test:test_resolve_challengeContested_succeeds() (gas: 226468)
+FaultDisputeGame_Test:test_move_duplicateClaim_reverts() (gas: 104076)
+FaultDisputeGame_Test:test_move_gameDepthExceeded_reverts() (gas: 411414)
+FaultDisputeGame_Test:test_move_gameNotInProgress_reverts() (gas: 10968)
+FaultDisputeGame_Test:test_move_nonExistentParent_reverts() (gas: 24633)
+FaultDisputeGame_Test:test_move_simpleAttack_succeeds() (gas: 108178)
+FaultDisputeGame_Test:test_resolve_challengeContested_succeeds() (gas: 226490)
 FaultDisputeGame_Test:test_resolve_notInProgress_reverts() (gas: 9702)
-FaultDisputeGame_Test:test_resolve_rootContested_succeeds() (gas: 110621)
+FaultDisputeGame_Test:test_resolve_rootContested_succeeds() (gas: 110643)
 FaultDisputeGame_Test:test_resolve_rootUncontestedClockNotExpired_succeeds() (gas: 21482)
 FaultDisputeGame_Test:test_resolve_rootUncontested_succeeds() (gas: 27311)
-FaultDisputeGame_Test:test_resolve_teamDeathmatch_succeeds() (gas: 398750)
+FaultDisputeGame_Test:test_resolve_teamDeathmatch_succeeds() (gas: 398794)
 FaultDisputeGame_Test:test_rootClaim_succeeds() (gas: 8203)
 FeeVault_Test:test_constructor_succeeds() (gas: 18185)
 GasBenchMark_L1CrossDomainMessenger:test_sendMessage_benchmark_0() (gas: 352113)

packages/contracts-bedrock/scripts/Deploy.s.sol

@@ -698,7 +698,8 @@ contract Deploy is Deployer {
                     _absolutePrestate: absolutePrestate,
                     _maxGameDepth: cfg.faultGameMaxDepth(),
                     _gameDuration: Duration.wrap(uint64(cfg.faultGameMaxDuration())),
-                    _vm: faultVm
+                    _vm: faultVm,
+                    _l2OO: L2OutputOracle(mustGetAddress("L2OutputOracleProxy"))
                 }));
                 console.log("DisputeGameFactory: set `FaultDisputeGame` implementation");
             }

packages/contracts-bedrock/src/cannon/PreimageKeyLib.sol

@@ -36,11 +36,7 @@ library PreimageKeyLib {
     /// @notice Computes and returns the key for a global keccak pre-image.
     /// @param _preimage The pre-image.
     /// @return key_ The pre-image key.
-    function keccak256PreimageKey(bytes memory _preimage)
-        internal
-        pure
-        returns (bytes32 key_)
-    {
+    function keccak256PreimageKey(bytes memory _preimage) internal pure returns (bytes32 key_) {
         assembly {
             // Grab the size of the `_preimage`
             let size := mload(_preimage)

packages/contracts-bedrock/src/cannon/PreimageOracle.sol

@@ -71,7 +71,11 @@ contract PreimageOracle {
     ///      │          4 │ L2 Block Number │
     ///      │          5 │ Chain ID        │
     ///      └────────────┴─────────────────┘
-    function loadLocalData(uint256 _ident, bytes32 _word, uint8 _size) external {
+    function loadLocalData(
+        uint256 _ident,
+        bytes32 _word,
+        uint8 _size
+    ) external {
         // Compute the localized key from the given local identifier.
         bytes32 key = PreimageKeyLib.localizeIdent(_ident);
 

packages/contracts-bedrock/src/dispute/FaultDisputeGame.sol

@@ -6,8 +6,10 @@ import { IFaultDisputeGame } from "./interfaces/IFaultDisputeGame.sol";
 import { IInitializable } from "./interfaces/IInitializable.sol";
 import { IBondManager } from "./interfaces/IBondManager.sol";
 import { IBigStepper, IPreimageOracle } from "./interfaces/IBigStepper.sol";
+import { L2OutputOracle } from "../L1/L2OutputOracle.sol";
 
 import { Clone } from "../libraries/Clone.sol";
+import { Types } from "../libraries/Types.sol";
 import { Semver } from "../universal/Semver.sol";
 import { LibHashing } from "./lib/LibHashing.sol";
 import { LibPosition } from "./lib/LibPosition.sol";
@@ -33,9 +35,12 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
     /// @notice The duration of the game.
     Duration public immutable GAME_DURATION;
 
-    /// @notice A hypervisor that performs single instruction steps on a fault proof program trace.
+    /// @notice An onchain VM that performs single instruction steps on a fault proof program trace.
     IBigStepper public immutable VM;
 
+    /// @notice The trusted L2OutputOracle contract.
+    L2OutputOracle public immutable L2_OUTPUT_ORACLE;
+
     /// @notice The root claim's position is always at gindex 1.
     Position internal constant ROOT_POSITION = Position.wrap(1);
 
@@ -62,12 +67,14 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         Claim _absolutePrestate,
         uint256 _maxGameDepth,
         Duration _gameDuration,
-        IBigStepper _vm
+        IBigStepper _vm,
+        L2OutputOracle _l2oo
     ) Semver(0, 0, 3) {
         ABSOLUTE_PRESTATE = _absolutePrestate;
         MAX_GAME_DEPTH = _maxGameDepth;
         GAME_DURATION = _gameDuration;
         VM = _vm;
+        L2_OUTPUT_ORACLE = _l2oo;
     }
 
     ////////////////////////////////////////////////////////////////
@@ -256,7 +263,10 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         } else if (_ident == 2) {
             // Load the earliest output root that commits to the passed L2 block number
             // into the game's local context in the preimage oracle.
-            // TODO(clabby): Add an immutable for the L2OO.
+            Types.OutputProposal memory proposal = L2_OUTPUT_ORACLE.getL2OutputAfter(
+                l2BlockNumber()
+            );
+            oracle.loadLocalData(_ident, proposal.outputRoot, 32);
         } else if (_ident == 3) {
             // Load the root claim into the game's local context in the preimage oracle.
             oracle.loadLocalData(_ident, Claim.unwrap(rootClaim()), 32);

packages/contracts-bedrock/src/dispute/interfaces/IBigStepper.sol

@@ -39,5 +39,9 @@ interface IBigStepper {
 /// @notice Temporary interface for the `IPreimageOracle`. Remove once we've upgraded
 ///         the cannon contracts to a newer version of solc.
 interface IPreimageOracle {
-    function loadLocalData(uint256 _ident, bytes32 _word, uint8 _size) external;
+    function loadLocalData(
+        uint256 _ident,
+        bytes32 _word,
+        uint8 _size
+    ) external;
 }

packages/contracts-bedrock/test/FaultDisputeGame.t.sol

@@ -4,8 +4,9 @@ pragma solidity ^0.8.15;
 import { Test } from "forge-std/Test.sol";
 import { Vm } from "forge-std/Vm.sol";
 import { DisputeGameFactory_Init } from "./DisputeGameFactory.t.sol";
-import { DisputeGameFactory } from "../src/dispute/DisputeGameFactory.sol";
-import { FaultDisputeGame } from "../src/dispute/FaultDisputeGame.sol";
+import { DisputeGameFactory } from "../dispute/DisputeGameFactory.sol";
+import { FaultDisputeGame } from "../dispute/FaultDisputeGame.sol";
+import { L2OutputOracle } from "../L1/L2OutputOracle.sol";
 
 import "../libraries/DisputeTypes.sol";
 import "../libraries/DisputeErrors.sol";
@@ -28,12 +29,14 @@ contract FaultDisputeGame_Init is DisputeGameFactory_Init {
 
     function init(Claim rootClaim, Claim absolutePrestate) public {
         super.setUp();
+
         // Deploy an implementation of the fault game
         gameImpl = new FaultDisputeGame(
             absolutePrestate,
             4,
             Duration.wrap(7 days),
-            new AlphabetVM(absolutePrestate)
+            new AlphabetVM(absolutePrestate),
+            L2OutputOracle(deployNoop())
         );
         // Register the game implementation with the factory.
         factory.setImplementation(GAME_TYPE, gameImpl);
@@ -893,12 +896,7 @@ contract AlphabetVM is IBigStepper {
 
     constructor(Claim _absolutePrestate) {
         ABSOLUTE_PRESTATE = _absolutePrestate;
-        // Deploy a noop preimage oracle
-        assembly {
-            mstore(0x00, 0x60016000F3)
-            let size := 5
-            sstore(oracle.slot, create(0, sub(0x20, size), size))
-        }
+        oracle = IPreimageOracle(deployNoop());
     }
 
     /// @inheritdoc IBigStepper
@@ -922,3 +920,16 @@ contract AlphabetVM is IBigStepper {
         postState_ = keccak256(abi.encode(traceIndex, claim + 1));
     }
 }
+
+////////////////////////////////////////////////////////////////
+//                          HELPERS                           //
+////////////////////////////////////////////////////////////////
+
+/// @notice Deploys a noop contract.
+function deployNoop() returns (address noop_) {
+    assembly {
+        mstore(0x00, 0x60016000F3)
+        let size := 5
+        noop_ := create(0, sub(0x20, size), size)
+    }
+}