AztecProtocol · fcarreiro · Feb 19, 2025 · Feb 19, 2025
diff --git a/yarn-project/simulator/src/avm/avm_context.ts b/yarn-project/simulator/src/avm/avm_context.ts
@@ -4,6 +4,7 @@ import { type Fr } from '@aztec/foundation/fields';
 import { type AvmExecutionEnvironment } from './avm_execution_environment.js';
 import { type Gas, gasToGasLeft } from './avm_gas.js';
 import { AvmMachineState } from './avm_machine_state.js';
+import type { AvmSimulator } from './avm_simulator.js';
 import { type AvmPersistableStateManager } from './journal/journal.js';
 
 /**
@@ -24,6 +25,10 @@ export class AvmContext {
     public machineState: AvmMachineState,
   ) {}
 
+  // This is needed to break a dependency cycle created by the CALL opcode,
+  // which needs to create a new simulator but cannot depend directly on AvmSimulator.
+  public provideSimulator?: (ctx: this) => Promise<AvmSimulator>;
+
   /**
    * Prepare a new AVM context that will be ready for an external/nested call
    * - Fork the world state journal

diff --git a/yarn-project/simulator/src/avm/avm_simulator.ts b/yarn-project/simulator/src/avm/avm_simulator.ts
@@ -44,9 +44,12 @@ export class AvmSimulator {
   // only. Otherwise, use build() below.
   constructor(
     private context: AvmContext,
-    private instructionSet: InstructionSet = INSTRUCTION_SET(),
+    private instructionSet: InstructionSet = INSTRUCTION_SET,
     enableTallying = false,
   ) {
+    // This will be used by the CALL opcode to create a new simulator. It is required to
+    // avoid a dependency cycle.
+    context.provideSimulator = AvmSimulator.build;
     assert(
       context.machineState.gasLeft.l2Gas <= MAX_L2_GAS_PER_TX_PUBLIC_PORTION,
       `Cannot allocate more than ${MAX_L2_GAS_PER_TX_PUBLIC_PORTION} to the AVM for execution.`,

diff --git a/yarn-project/simulator/src/avm/fixtures/index.ts b/yarn-project/simulator/src/avm/fixtures/index.ts
@@ -13,7 +13,7 @@ import merge from 'lodash.merge';
 
 import { resolveAssertionMessageFromRevertData, traverseCauseChain } from '../../common.js';
 import { type PublicSideEffectTraceInterface } from '../../public/side_effect_trace_interface.js';
-import { type WorldStateDB } from '../../server.js';
+import { AvmSimulator, type WorldStateDB } from '../../server.js';
 import { AvmContext } from '../avm_context.js';
 import { AvmExecutionEnvironment } from '../avm_execution_environment.js';
 import { AvmMachineState } from '../avm_machine_state.js';
@@ -34,11 +34,13 @@ export function initContext(overrides?: {
   env?: AvmExecutionEnvironment;
   machineState?: AvmMachineState;
 }): AvmContext {
-  return new AvmContext(
+  const ctx = new AvmContext(
     overrides?.persistableState || initPersistableStateManager(),
     overrides?.env || initExecutionEnvironment(),
     overrides?.machineState || initMachineState(),
   );
+  ctx.provideSimulator = AvmSimulator.build;
+  return ctx;
 }
 
 /** Creates an empty state manager with mocked host storage. */

diff --git a/yarn-project/simulator/src/avm/opcodes/external_calls.ts b/yarn-project/simulator/src/avm/opcodes/external_calls.ts
@@ -1,7 +1,6 @@
 import type { AvmContext } from '../avm_context.js';
 import { type AvmContractCallResult } from '../avm_contract_call_result.js';
 import { type Field, TypeTag, Uint1 } from '../avm_memory_types.js';
-import { AvmSimulator } from '../avm_simulator.js';
 import { Opcode, OperandType } from '../serialization/instruction_serialization.js';
 import { Addressing } from './addressing_mode.js';
 import { Instruction } from './instruction.js';
@@ -62,7 +61,7 @@ abstract class ExternalCall extends Instruction {
     const aztecAddress = callAddress.toAztecAddress();
     const nestedContext = context.createNestedContractCallContext(aztecAddress, calldata, allocatedGas, callType);
 
-    const simulator = await AvmSimulator.build(nestedContext);
+    const simulator = await context.provideSimulator!(nestedContext);
     const nestedCallResults: AvmContractCallResult = await simulator.execute();
     const success = !nestedCallResults.reverted;
 

diff --git a/yarn-project/simulator/src/avm/serialization/bytecode_serialization.ts b/yarn-project/simulator/src/avm/serialization/bytecode_serialization.ts
@@ -62,94 +62,91 @@ export interface Deserializable {
 }
 
 export type InstructionSet = Map<Opcode, InstructionDeserializer>;
-// TODO(4359): This is a function so that Call and StaticCall can be lazily resolved.
-// This is a temporary solution until we solve the dependency cycle.
-export const INSTRUCTION_SET = () =>
-  new Map<Opcode, InstructionDeserializer>([
-    [Opcode.ADD_8, Add.as(Add.wireFormat8).deserialize],
-    [Opcode.ADD_16, Add.as(Add.wireFormat16).deserialize],
-    [Opcode.SUB_8, Sub.as(Sub.wireFormat8).deserialize],
-    [Opcode.SUB_16, Sub.as(Sub.wireFormat16).deserialize],
-    [Opcode.MUL_8, Mul.as(Mul.wireFormat8).deserialize],
-    [Opcode.MUL_16, Mul.as(Mul.wireFormat16).deserialize],
-    [Opcode.DIV_8, Div.as(Div.wireFormat8).deserialize],
-    [Opcode.DIV_16, Div.as(Div.wireFormat16).deserialize],
-    [Opcode.FDIV_8, FieldDiv.as(FieldDiv.wireFormat8).deserialize],
-    [Opcode.FDIV_16, FieldDiv.as(FieldDiv.wireFormat16).deserialize],
-    [Opcode.EQ_8, Eq.as(Eq.wireFormat8).deserialize],
-    [Opcode.EQ_16, Eq.as(Eq.wireFormat16).deserialize],
-    [Opcode.LT_8, Lt.as(Lt.wireFormat8).deserialize],
-    [Opcode.LT_16, Lt.as(Lt.wireFormat16).deserialize],
-    [Opcode.LTE_8, Lte.as(Lte.wireFormat8).deserialize],
-    [Opcode.LTE_16, Lte.as(Lte.wireFormat16).deserialize],
-    [Opcode.AND_8, And.as(And.wireFormat8).deserialize],
-    [Opcode.AND_16, And.as(And.wireFormat16).deserialize],
-    [Opcode.OR_8, Or.as(Or.wireFormat8).deserialize],
-    [Opcode.OR_16, Or.as(Or.wireFormat16).deserialize],
-    [Opcode.XOR_8, Xor.as(Xor.wireFormat8).deserialize],
-    [Opcode.XOR_16, Xor.as(Xor.wireFormat16).deserialize],
-    [Opcode.NOT_8, Not.as(Not.wireFormat8).deserialize],
-    [Opcode.NOT_16, Not.as(Not.wireFormat16).deserialize],
-    [Opcode.SHL_8, Shl.as(Shl.wireFormat8).deserialize],
-    [Opcode.SHL_16, Shl.as(Shl.wireFormat16).deserialize],
-    [Opcode.SHR_8, Shr.as(Shr.wireFormat8).deserialize],
-    [Opcode.SHR_16, Shr.as(Shr.wireFormat16).deserialize],
-    [Opcode.CAST_8, Cast.as(Cast.wireFormat8).deserialize],
-    [Opcode.CAST_16, Cast.as(Cast.wireFormat16).deserialize],
-    // Execution Environment
-    [Opcode.GETENVVAR_16, GetEnvVar.as(GetEnvVar.wireFormat16).deserialize],
-    [CalldataCopy.opcode, Instruction.deserialize.bind(CalldataCopy)],
-    [Opcode.RETURNDATASIZE, Instruction.deserialize.bind(ReturndataSize)],
-    [Opcode.RETURNDATACOPY, Instruction.deserialize.bind(ReturndataCopy)],
-
-    // Machine State - Internal Control Flow
-    [Jump.opcode, Instruction.deserialize.bind(Jump)],
-    [JumpI.opcode, Instruction.deserialize.bind(JumpI)],
-    [InternalCall.opcode, Instruction.deserialize.bind(InternalCall)],
-    [InternalReturn.opcode, Instruction.deserialize.bind(InternalReturn)],
-    [Opcode.SET_8, Set.as(Set.wireFormat8).deserialize],
-    [Opcode.SET_16, Set.as(Set.wireFormat16).deserialize],
-    [Opcode.SET_32, Set.as(Set.wireFormat32).deserialize],
-    [Opcode.SET_64, Set.as(Set.wireFormat64).deserialize],
-    [Opcode.SET_128, Set.as(Set.wireFormat128).deserialize],
-    [Opcode.SET_FF, Set.as(Set.wireFormatFF).deserialize],
-    [Opcode.MOV_8, Mov.as(Mov.wireFormat8).deserialize],
-    [Opcode.MOV_16, Mov.as(Mov.wireFormat16).deserialize],
-
-    // World State
-    [SLoad.opcode, Instruction.deserialize.bind(SLoad)], // Public Storage
-    [SStore.opcode, Instruction.deserialize.bind(SStore)], // Public Storage
-    [NoteHashExists.opcode, Instruction.deserialize.bind(NoteHashExists)], // Notes & Nullifiers
-    [EmitNoteHash.opcode, Instruction.deserialize.bind(EmitNoteHash)], // Notes & Nullifiers
-    [NullifierExists.opcode, Instruction.deserialize.bind(NullifierExists)], // Notes & Nullifiers
-    [EmitNullifier.opcode, Instruction.deserialize.bind(EmitNullifier)], // Notes & Nullifiers
-    [L1ToL2MessageExists.opcode, Instruction.deserialize.bind(L1ToL2MessageExists)], // Messages
-
-    // Accrued Substate
-    [EmitUnencryptedLog.opcode, Instruction.deserialize.bind(EmitUnencryptedLog)],
-    [SendL2ToL1Message.opcode, Instruction.deserialize.bind(SendL2ToL1Message)],
-    [GetContractInstance.opcode, Instruction.deserialize.bind(GetContractInstance)],
-
-    // Control Flow - Contract Calls
-    [Call.opcode, Instruction.deserialize.bind(Call)],
-    [StaticCall.opcode, Instruction.deserialize.bind(StaticCall)],
-    [Return.opcode, Instruction.deserialize.bind(Return)],
-    [Opcode.REVERT_8, Revert.as(Revert.wireFormat8).deserialize],
-    [Opcode.REVERT_16, Revert.as(Revert.wireFormat16).deserialize],
-
-    // Misc
-    [DebugLog.opcode, Instruction.deserialize.bind(DebugLog)],
-
-    // Gadgets
-    [EcAdd.opcode, Instruction.deserialize.bind(EcAdd)],
-    [Poseidon2.opcode, Instruction.deserialize.bind(Poseidon2)],
-    [Sha256Compression.opcode, Instruction.deserialize.bind(Sha256Compression)],
-    [KeccakF1600.opcode, Instruction.deserialize.bind(KeccakF1600)],
-    [MultiScalarMul.opcode, Instruction.deserialize.bind(MultiScalarMul)],
-
-    // Conversions
-    [ToRadixBE.opcode, Instruction.deserialize.bind(ToRadixBE)],
-  ]);
+export const INSTRUCTION_SET = new Map<Opcode, InstructionDeserializer>([
+  [Opcode.ADD_8, Add.as(Add.wireFormat8).deserialize],
+  [Opcode.ADD_16, Add.as(Add.wireFormat16).deserialize],
+  [Opcode.SUB_8, Sub.as(Sub.wireFormat8).deserialize],
+  [Opcode.SUB_16, Sub.as(Sub.wireFormat16).deserialize],
+  [Opcode.MUL_8, Mul.as(Mul.wireFormat8).deserialize],
+  [Opcode.MUL_16, Mul.as(Mul.wireFormat16).deserialize],
+  [Opcode.DIV_8, Div.as(Div.wireFormat8).deserialize],
+  [Opcode.DIV_16, Div.as(Div.wireFormat16).deserialize],
+  [Opcode.FDIV_8, FieldDiv.as(FieldDiv.wireFormat8).deserialize],
+  [Opcode.FDIV_16, FieldDiv.as(FieldDiv.wireFormat16).deserialize],
+  [Opcode.EQ_8, Eq.as(Eq.wireFormat8).deserialize],
+  [Opcode.EQ_16, Eq.as(Eq.wireFormat16).deserialize],
+  [Opcode.LT_8, Lt.as(Lt.wireFormat8).deserialize],
+  [Opcode.LT_16, Lt.as(Lt.wireFormat16).deserialize],
+  [Opcode.LTE_8, Lte.as(Lte.wireFormat8).deserialize],
+  [Opcode.LTE_16, Lte.as(Lte.wireFormat16).deserialize],
+  [Opcode.AND_8, And.as(And.wireFormat8).deserialize],
+  [Opcode.AND_16, And.as(And.wireFormat16).deserialize],
+  [Opcode.OR_8, Or.as(Or.wireFormat8).deserialize],
+  [Opcode.OR_16, Or.as(Or.wireFormat16).deserialize],
+  [Opcode.XOR_8, Xor.as(Xor.wireFormat8).deserialize],
+  [Opcode.XOR_16, Xor.as(Xor.wireFormat16).deserialize],
+  [Opcode.NOT_8, Not.as(Not.wireFormat8).deserialize],
+  [Opcode.NOT_16, Not.as(Not.wireFormat16).deserialize],
+  [Opcode.SHL_8, Shl.as(Shl.wireFormat8).deserialize],
+  [Opcode.SHL_16, Shl.as(Shl.wireFormat16).deserialize],
+  [Opcode.SHR_8, Shr.as(Shr.wireFormat8).deserialize],
+  [Opcode.SHR_16, Shr.as(Shr.wireFormat16).deserialize],
+  [Opcode.CAST_8, Cast.as(Cast.wireFormat8).deserialize],
+  [Opcode.CAST_16, Cast.as(Cast.wireFormat16).deserialize],
+  // Execution Environment
+  [Opcode.GETENVVAR_16, GetEnvVar.as(GetEnvVar.wireFormat16).deserialize],
+  [CalldataCopy.opcode, Instruction.deserialize.bind(CalldataCopy)],
+  [Opcode.RETURNDATASIZE, Instruction.deserialize.bind(ReturndataSize)],
+  [Opcode.RETURNDATACOPY, Instruction.deserialize.bind(ReturndataCopy)],
+
+  // Machine State - Internal Control Flow
+  [Jump.opcode, Instruction.deserialize.bind(Jump)],
+  [JumpI.opcode, Instruction.deserialize.bind(JumpI)],
+  [InternalCall.opcode, Instruction.deserialize.bind(InternalCall)],
+  [InternalReturn.opcode, Instruction.deserialize.bind(InternalReturn)],
+  [Opcode.SET_8, Set.as(Set.wireFormat8).deserialize],
+  [Opcode.SET_16, Set.as(Set.wireFormat16).deserialize],
+  [Opcode.SET_32, Set.as(Set.wireFormat32).deserialize],
+  [Opcode.SET_64, Set.as(Set.wireFormat64).deserialize],
+  [Opcode.SET_128, Set.as(Set.wireFormat128).deserialize],
+  [Opcode.SET_FF, Set.as(Set.wireFormatFF).deserialize],
+  [Opcode.MOV_8, Mov.as(Mov.wireFormat8).deserialize],
+  [Opcode.MOV_16, Mov.as(Mov.wireFormat16).deserialize],
+
+  // World State
+  [SLoad.opcode, Instruction.deserialize.bind(SLoad)], // Public Storage
+  [SStore.opcode, Instruction.deserialize.bind(SStore)], // Public Storage
+  [NoteHashExists.opcode, Instruction.deserialize.bind(NoteHashExists)], // Notes & Nullifiers
+  [EmitNoteHash.opcode, Instruction.deserialize.bind(EmitNoteHash)], // Notes & Nullifiers
+  [NullifierExists.opcode, Instruction.deserialize.bind(NullifierExists)], // Notes & Nullifiers
+  [EmitNullifier.opcode, Instruction.deserialize.bind(EmitNullifier)], // Notes & Nullifiers
+  [L1ToL2MessageExists.opcode, Instruction.deserialize.bind(L1ToL2MessageExists)], // Messages
+
+  // Accrued Substate
+  [EmitUnencryptedLog.opcode, Instruction.deserialize.bind(EmitUnencryptedLog)],
+  [SendL2ToL1Message.opcode, Instruction.deserialize.bind(SendL2ToL1Message)],
+  [GetContractInstance.opcode, Instruction.deserialize.bind(GetContractInstance)],
+
+  // Control Flow - Contract Calls
+  [Call.opcode, Instruction.deserialize.bind(Call)],
+  [StaticCall.opcode, Instruction.deserialize.bind(StaticCall)],
+  [Return.opcode, Instruction.deserialize.bind(Return)],
+  [Opcode.REVERT_8, Revert.as(Revert.wireFormat8).deserialize],
+  [Opcode.REVERT_16, Revert.as(Revert.wireFormat16).deserialize],
+
+  // Misc
+  [DebugLog.opcode, Instruction.deserialize.bind(DebugLog)],
+
+  // Gadgets
+  [EcAdd.opcode, Instruction.deserialize.bind(EcAdd)],
+  [Poseidon2.opcode, Instruction.deserialize.bind(Poseidon2)],
+  [Sha256Compression.opcode, Instruction.deserialize.bind(Sha256Compression)],
+  [KeccakF1600.opcode, Instruction.deserialize.bind(KeccakF1600)],
+  [MultiScalarMul.opcode, Instruction.deserialize.bind(MultiScalarMul)],
+
+  // Conversions
+  [ToRadixBE.opcode, Instruction.deserialize.bind(ToRadixBE)],
+]);
 
 /**
  * Serializes an array of instructions to bytecode.
@@ -159,10 +156,7 @@ export function encodeToBytecode(instructions: Serializable[]): Buffer {
 }
 
 // For testing only
-export function decodeFromBytecode(
-  bytecode: Buffer,
-  instructionSet: InstructionSet = INSTRUCTION_SET(),
-): Instruction[] {
+export function decodeFromBytecode(bytecode: Buffer, instructionSet: InstructionSet = INSTRUCTION_SET): Instruction[] {
   const instructions: Instruction[] = [];
   let pc = 0;
   while (pc < bytecode.length) {
@@ -177,7 +171,7 @@ export function decodeFromBytecode(
 export function decodeInstructionFromBytecode(
   bytecode: Buffer,
   pc: number,
-  instructionSet: InstructionSet = INSTRUCTION_SET(),
+  instructionSet: InstructionSet = INSTRUCTION_SET,
 ): [Instruction, number] {
   if (pc >= bytecode.length) {
     throw new InvalidProgramCounterError(pc, bytecode.length);