feat(avm): Add TransactionFee opcode to simulator (AztecProtocol#6210)

Adds the TransactionFee opcode to the AVM simulator, which retrieves the
environment's computed transactionFee.

avm-transpiler/src/opcodes.rs

@@ -24,6 +24,7 @@ pub enum AvmOpcode {
     SENDER,
     FEEPERL2GAS,
     FEEPERDAGAS,
+    TRANSACTIONFEE,
     CONTRACTCALLDEPTH,
     CHAINID,
     VERSION,
@@ -100,6 +101,7 @@ impl AvmOpcode {
             AvmOpcode::SENDER => "SENDER",
             AvmOpcode::FEEPERL2GAS => "FEEPERL2GAS",
             AvmOpcode::FEEPERDAGAS => "FEEPERDAGAS",
+            AvmOpcode::TRANSACTIONFEE => "TRANSACTIONFEE",
             AvmOpcode::CONTRACTCALLDEPTH => "CONTRACTCALLDEPTH",
             // Execution Environment - Globals
             AvmOpcode::CHAINID => "CHAINID",

avm-transpiler/src/transpile.rs

@@ -743,6 +743,7 @@ fn handle_getter_instruction(
         "avmOpcodeSender" => AvmOpcode::SENDER,
         "avmOpcodeFeePerL2Gas" => AvmOpcode::FEEPERL2GAS,
         "avmOpcodeFeePerDaGas" => AvmOpcode::FEEPERDAGAS,
+        "avmOpcodeTransactionFee" => AvmOpcode::TRANSACTIONFEE,
         "avmOpcodeChainId" => AvmOpcode::CHAINID,
         "avmOpcodeVersion" => AvmOpcode::VERSION,
         "avmOpcodeBlockNumber" => AvmOpcode::BLOCKNUMBER,

barretenberg/cpp/src/barretenberg/vm/avm_trace/avm_opcode.hpp

@@ -43,6 +43,7 @@ enum class OpCode : uint8_t {
     SENDER,
     FEEPERL2GAS,
     FEEPERDAGAS,
+    TRANSACTIONFEE,
     CONTRACTCALLDEPTH,
     // Execution Environment - Globals
     CHAINID,

docs/docs/protocol-specs/public-vm/_nested-context.md

@@ -19,6 +19,7 @@ nestedExecutionEnvironment = ExecutionEnvironment {
     storageAddress: isDelegateCall ? context.storageAddress : M[addrOffset],
     feePerL2Gas: context.environment.feePerL2Gas,
     feePerDaGas: context.environment.feePerDaGas,
+    transactionFee: context.environment.transactionFee,
     contractCallDepth: context.contractCallDepth + 1,
     contractCallPointer: context.worldStateAccessTrace.contractCalls.length + 1,
     globals: context.globals,

docs/docs/protocol-specs/public-vm/avm-circuit.md

@@ -187,6 +187,7 @@ AvmSessionInputs {
     contractCallDepth: field,
     isStaticCall: boolean,
     isDelegateCall: boolean,
+    transactionFee: field,
     // Initializes Machine State
     l2GasLeft: field,
     daGasLeft: field,

docs/docs/protocol-specs/public-vm/context.mdx

@@ -7,8 +7,9 @@ Many terms and definitions here are borrowed from the [Ethereum Yellow Paper](ht
 An **execution context** contains the information and state relevant to a contract call's execution. When a contract call is made, an execution context is [initialized](#context-initialization) before the contract code's execution begins.
 
 #### _AvmContext_
+
 | Field                                                     | Type                    |
-| ---                                                       | ---                     |
+| --------------------------------------------------------- | ----------------------- |
 | environment                                               | `ExecutionEnvironment`  |
 | [machineState](./state#machine-state)                     | `MachineState`          |
 | [worldState](./state#avm-world-state)                     | `AvmWorldState`         |
@@ -21,30 +22,33 @@ An **execution context** contains the information and state relevant to a contra
 A context's **execution environment** remains constant throughout a contract call's execution. When a contract call initializes its execution context, it [fully specifies the execution environment](#context-initialization).
 
 ### _ExecutionEnvironment_
-| Field                 | Type                         | Description |
-| ---                   | ---                          | ---         |
-| address               | `AztecAddress`               |  |
-| storageAddress        | `AztecAddress`               |  |
-| sender                | `AztecAddress`               |  |
-| portal                | `EthAddress`                 |  |
-| feePerL2Gas           | `field`                      |  |
-| feePerDaGas           | `field`                      |  |
-| contractCallDepth     | `field`                      | Depth of the current call (how many nested calls deep is it). |
-| contractCallPointer   | `field`                      | Uniquely identifies each contract call processed by an AVM session. An initial call is assigned pointer value of 1 (expanded on in the AVM circuit section's ["Call Pointer"](./avm-circuit#call-pointer) subsection). |
-| globals               | `PublicGlobalVariables`      |  |
-| isStaticCall          | `boolean`                    |  |
-| isDelegateCall        | `boolean`                    |  |
-| calldata              | `[field; <calldata-length>]` |  |
+
+| Field               | Type                         | Description                                                                                                                                                                                                            |
+| ------------------- | ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| address             | `AztecAddress`               |                                                                                                                                                                                                                        |
+| storageAddress      | `AztecAddress`               |                                                                                                                                                                                                                        |
+| sender              | `AztecAddress`               |                                                                                                                                                                                                                        |
+| portal              | `EthAddress`                 |                                                                                                                                                                                                                        |
+| feePerL2Gas         | `field`                      |                                                                                                                                                                                                                        |
+| feePerDaGas         | `field`                      |                                                                                                                                                                                                                        |
+| transactionFee      | `field`                      | Computed transaction fee based on gas fees, inclusion fee, and gas usage. Zero in all phases but teardown.                                                                                                             |
+| contractCallDepth   | `field`                      | Depth of the current call (how many nested calls deep is it).                                                                                                                                                          |
+| contractCallPointer | `field`                      | Uniquely identifies each contract call processed by an AVM session. An initial call is assigned pointer value of 1 (expanded on in the AVM circuit section's ["Call Pointer"](./avm-circuit#call-pointer) subsection). |
+| globals             | `PublicGlobalVariables`      |                                                                                                                                                                                                                        |
+| isStaticCall        | `boolean`                    |                                                                                                                                                                                                                        |
+| isDelegateCall      | `boolean`                    |                                                                                                                                                                                                                        |
+| calldata            | `[field; <calldata-length>]` |                                                                                                                                                                                                                        |
 
 ## Contract Call Results
 
 When a contract call halts, it sets the context's **contract call results** to communicate results to the caller.
 
 ### _ContractCallResults_
-| Field        | Type                       | Description |
-| ---          | ---                        | ---         |
-| reverted     | `boolean`                  |  |
-| output       | `[field; <output-length>]` |  |
+
+| Field    | Type                       | Description |
+| -------- | -------------------------- | ----------- |
+| reverted | `boolean`                  |             |
+| output   | `[field; <output-length>]` |             |
 
 ## Context initialization
 
@@ -117,4 +121,4 @@ INITIAL_CONTRACT_CALL_RESULTS = ContractCallResults {
 
 import NestedContext from "./_nested-context.md";
 
-<NestedContext />
+<NestedContext />

docs/src/preprocess/InstructionSet/InstructionSet.js

@@ -587,6 +587,25 @@ const INSTRUCTION_SET_RAW = [
     "Tag checks": "",
     "Tag updates": "`T[dstOffset] = u32`",
   },
+  {
+    id: "transactionfee",
+    Name: "`TRANSACTIONFEE`",
+    Category: "Execution Environment",
+    Flags: [{ name: "indirect", description: INDIRECT_FLAG_DESCRIPTION }],
+    Args: [
+      {
+        name: "dstOffset",
+        description:
+          "memory offset specifying where to store operation's result",
+      },
+    ],
+    Expression: "`M[dstOffset] = context.environment.transactionFee`",
+    Summary:
+      "Get the computed transaction fee during teardown phase, zero otherwise",
+    Details: "",
+    "Tag checks": "",
+    "Tag updates": "`T[dstOffset] = u32`",
+  },
   {
     id: "contractcalldepth",
     Name: "`CONTRACTCALLDEPTH`",

noir-projects/aztec-nr/aztec/src/context/avm_context.nr

@@ -79,8 +79,7 @@ impl PublicContextInterface for AvmContext {
     }
 
     fn transaction_fee(self) -> Field {
-        assert(false, "'transaction_fee' not implemented!");
-        0
+        transaction_fee()
     }
 
     fn nullifier_exists(self, unsiloed_nullifier: Field, address: AztecAddress) -> bool {
@@ -219,6 +218,9 @@ fn fee_per_l2_gas() -> Field {}
 #[oracle(avmOpcodeFeePerDaGas)]
 fn fee_per_da_gas() -> Field {}
 
+#[oracle(avmOpcodeTransactionFee)]
+fn transaction_fee() -> Field {}
+
 #[oracle(avmOpcodeChainId)]
 fn chain_id() -> Field {}
 

noir-projects/aztec-nr/aztec/src/context/interface.nr

@@ -30,6 +30,7 @@ trait PublicContextInterface {
     fn fee_recipient(self) -> AztecAddress;
     fn fee_per_da_gas(self) -> Field;
     fn fee_per_l2_gas(self) -> Field;
+    fn transaction_fee(self) -> Field;
     fn message_portal(&mut self, recipient: EthAddress, content: Field);
     fn consume_l1_to_l2_message(&mut self, content: Field, secret: Field, sender: EthAddress, leaf_index: Field);
     fn emit_unencrypted_log<T,N,M>(&mut self, log: T);
@@ -54,7 +55,6 @@ trait PublicContextInterface {
         args: [Field]
     ) -> FunctionReturns<RETURNS_COUNT>;
     fn nullifier_exists(self, unsiloed_nullifier: Field, address: AztecAddress) -> bool;
-    fn transaction_fee(self) -> Field;
 }
 
 struct PrivateCallInterface<T> {

noir-projects/aztec-nr/aztec/src/context/public_context.nr

@@ -72,7 +72,7 @@ impl PublicContext {
             unencrypted_logs_hashes: BoundedVec::new(),
             unencrypted_log_preimages_length: 0,
             historical_header: inputs.historical_header,
-            prover_address: AztecAddress::zero(),
+            prover_address: AztecAddress::zero()
         }
     }
 
@@ -144,7 +144,6 @@ impl PublicContext {
     }
 
     pub fn finish(self) -> PublicCircuitPublicInputs {
-
         // Compute the public call stack hashes
         let pub_circuit_pub_inputs = PublicCircuitPublicInputs {
             call_context: self.inputs.call_context, // Done
@@ -358,7 +357,7 @@ fn emit_unencrypted_log_oracle<T>(
     _contract_address: AztecAddress,
     _event_selector: Field,
     _message: T,
-    _counter: u32,
+    _counter: u32
 ) -> Field {}
 
 struct FunctionReturns<N> {

noir-projects/noir-contracts/contracts/avm_test_contract/src/main.nr

@@ -217,6 +217,11 @@ contract AvmTest {
         context.fee_per_da_gas()
     }
 
+    #[aztec(public-vm)]
+    fn get_transaction_fee() -> pub Field {
+        context.transaction_fee()
+    }
+
     #[aztec(public-vm)]
     fn get_chain_id() -> pub Field {
         context.chain_id()

yarn-project/simulator/src/avm/avm_gas.ts

@@ -78,6 +78,7 @@ export const GasCosts: Record<Opcode, Gas | typeof DynamicGasCost> = {
   [Opcode.SENDER]: TemporaryDefaultGasCost,
   [Opcode.FEEPERL2GAS]: TemporaryDefaultGasCost,
   [Opcode.FEEPERDAGAS]: TemporaryDefaultGasCost,
+  [Opcode.TRANSACTIONFEE]: TemporaryDefaultGasCost,
   [Opcode.CONTRACTCALLDEPTH]: TemporaryDefaultGasCost,
   [Opcode.CHAINID]: TemporaryDefaultGasCost,
   [Opcode.VERSION]: TemporaryDefaultGasCost,

yarn-project/simulator/src/avm/avm_simulator.test.ts

@@ -199,6 +199,11 @@ describe('AVM simulator: transpiled Noir contracts', () => {
       await testEnvGetter('feePerDaGas', fee, 'get_fee_per_da_gas');
     });
 
+    it('getTransactionFee', async () => {
+      const fee = new Fr(1);
+      await testEnvGetter('transactionFee', fee, 'get_transaction_fee');
+    });
+
     it('chainId', async () => {
       const chainId = new Fr(1);
       await testEnvGetter('chainId', chainId, 'get_chain_id', /*globalVar=*/ true);

yarn-project/simulator/src/avm/opcodes/environment_getters.test.ts

@@ -10,16 +10,25 @@ import {
   Sender,
   StorageAddress,
   Timestamp,
+  TransactionFee,
   Version,
 } from './environment_getters.js';
 
-type EnvInstruction = typeof FeePerL2Gas | typeof FeePerDAGas | typeof Sender | typeof StorageAddress | typeof Address;
+type EnvInstruction =
+  | typeof FeePerL2Gas
+  | typeof FeePerDAGas
+  | typeof Sender
+  | typeof StorageAddress
+  | typeof Address
+  | typeof TransactionFee;
+
 describe.each([
   [FeePerL2Gas, 'feePerL2Gas'],
   [FeePerDAGas, 'feePerDaGas'],
   [Sender, 'sender'],
   [StorageAddress, 'storageAddress'],
   [Address, 'address'],
+  [TransactionFee, 'transactionFee'],
 ])('Environment getters instructions', (clsValue: EnvInstruction, key: string) => {
   it(`${clsValue.name} should (de)serialize correctly`, () => {
     const buf = Buffer.from([

yarn-project/simulator/src/avm/opcodes/environment_getters.ts

@@ -59,6 +59,15 @@ export class FeePerDAGas extends EnvironmentGetterInstruction {
   }
 }
 
+export class TransactionFee extends EnvironmentGetterInstruction {
+  static type: string = 'TRANSACTIONFEE';
+  static readonly opcode: Opcode = Opcode.TRANSACTIONFEE;
+
+  protected getEnvironmentValue(env: AvmExecutionEnvironment) {
+    return env.transactionFee;
+  }
+}
+
 export class ChainId extends EnvironmentGetterInstruction {
   static type: string = 'CHAINID';
   static readonly opcode: Opcode = Opcode.CHAINID;

yarn-project/simulator/src/avm/serialization/bytecode_serialization.ts

@@ -46,6 +46,7 @@ import {
   StorageAddress,
   Sub,
   Timestamp,
+  TransactionFee,
   Version,
   Xor,
 } from '../opcodes/index.js';
@@ -82,6 +83,7 @@ const INSTRUCTION_SET = () =>
     [Sender.opcode, Sender],
     [FeePerL2Gas.opcode, FeePerL2Gas],
     [FeePerDAGas.opcode, FeePerDAGas],
+    [TransactionFee.opcode, TransactionFee],
     //[Contractcalldepth.opcode, Contractcalldepth],
     // Execution Environment - Globals
     [ChainId.opcode, ChainId],

yarn-project/simulator/src/avm/serialization/instruction_serialization.ts

@@ -29,6 +29,7 @@ export enum Opcode {
   SENDER,
   FEEPERL2GAS,
   FEEPERDAGAS,
+  TRANSACTIONFEE,
   CONTRACTCALLDEPTH,
   CHAINID,
   VERSION,