revm_handler/
post_execution.rs

1use crate::FrameResult;
2use context::journaled_state::account::JournaledAccountTr;
3use context_interface::{
4    cfg::GasParams,
5    journaled_state::JournalTr,
6    result::{ExecutionResult, HaltReason, HaltReasonTr, ResultGas},
7    Block, Cfg, ContextTr, Database, LocalContextTr, Transaction,
8};
9use interpreter::{Gas, InitialAndFloorGas, SuccessOrHalt};
10use primitives::{hardfork::SpecId, U256};
11
12/// Builds a [`ResultGas`] from the execution [`Gas`] struct and [`InitialAndFloorGas`].
13pub fn build_result_gas(
14    _is_halt: bool,
15    gas: &Gas,
16    init_and_floor_gas: InitialAndFloorGas,
17) -> ResultGas {
18    // `state_gas_spent` is tracked as i64 to allow a child frame's count to go
19    // negative on 0→x→0 restoration; at the top level, post-reconciliation it
20    // is expected to be >= 0 and is clamped defensively before combining with
21    // intrinsic state gas.
22    //
23    // Per the spec, tx_state_gas = intrinsic_state_gas + execution_state_gas,
24    // then reduced by the EIP-7702 per-authorization state-gas refund (which
25    // was also added back to the reservoir budget at tx start).
26    let state_gas = gas
27        .state_gas_spent()
28        .saturating_add_unsigned(init_and_floor_gas.initial_state_gas)
29        .max(0) as u64;
30    let state_gas = state_gas.saturating_sub(init_and_floor_gas.state_refund);
31
32    ResultGas::default()
33        .with_total_gas_spent(
34            gas.limit()
35                .saturating_sub(gas.remaining())
36                .saturating_sub(gas.reservoir()),
37        )
38        .with_refunded(gas.refunded() as u64)
39        .with_floor_gas(init_and_floor_gas.floor_gas())
40        .with_state_gas_spent(state_gas)
41}
42
43/// Ensures minimum gas floor is spent according to EIP-7623.
44///
45/// Per EIP-8037, gas used before refund is `tx.gas - gas_left - state_gas_reservoir`.
46/// The floor applies to this combined total, not just regular gas.
47pub const fn eip7623_check_gas_floor(gas: &mut Gas, init_and_floor_gas: InitialAndFloorGas) {
48    // EIP-7623: Increase calldata cost
49    // EIP-8037: tx_gas_used_before_refund = tx.gas - gas_left - reservoir
50    // The floor must apply to this combined value, not just (limit - remaining).
51    let gas_used_before_refund = gas.total_gas_spent().saturating_sub(gas.reservoir());
52    let gas_used_after_refund = gas_used_before_refund.saturating_sub(gas.refunded() as u64);
53    if gas_used_after_refund < init_and_floor_gas.floor_gas() {
54        // Match execution-specs: when the floor wins, the unused state gas
55        // (reservoir) is absorbed into the floor cost rather than reimbursed
56        // separately. Zeroing it keeps `reimburse_caller`'s
57        // `remaining + reservoir + refunded` sum equal to `limit - floor`.
58        gas.set_spent(init_and_floor_gas.floor_gas());
59        gas.set_reservoir(0);
60        gas.set_refund(0);
61    }
62}
63
64/// Calculates and applies gas refunds based on the configured gas parameters.
65pub fn refund(gas_params: &GasParams, gas: &mut Gas, eip7702_refund: i64) {
66    gas.record_refund(eip7702_refund);
67    gas.set_final_refund(gas_params.max_refund_quotient());
68}
69
70/// Reimburses the caller for unused gas.
71#[inline]
72pub fn reimburse_caller<CTX: ContextTr>(
73    context: &mut CTX,
74    gas: &Gas,
75    additional_refund: U256,
76) -> Result<(), <CTX::Db as Database>::Error> {
77    // If fee charge was disabled (e.g. eth_call simulations), no gas was
78    // deducted from the caller upfront so there is nothing to reimburse.
79    if context.cfg().is_fee_charge_disabled() {
80        return Ok(());
81    }
82    let basefee = context.block().basefee() as u128;
83    let caller = context.tx().caller();
84    let effective_gas_price = context.tx().effective_gas_price(basefee);
85
86    // Return balance of not spent gas.
87    // Include reservoir gas (EIP-8037) which is also unused and must be reimbursed.
88    let reimbursable = gas.remaining() + gas.reservoir() + gas.refunded() as u64;
89    context
90        .journal_mut()
91        .load_account_mut(caller)?
92        .incr_balance(
93            U256::from(effective_gas_price.saturating_mul(reimbursable as u128))
94                + additional_refund,
95        );
96
97    Ok(())
98}
99
100/// Rewards the beneficiary with transaction fees.
101#[inline]
102pub fn reward_beneficiary<CTX: ContextTr>(
103    context: &mut CTX,
104    gas: &Gas,
105) -> Result<(), <CTX::Db as Database>::Error> {
106    // If fee charge was disabled (e.g. eth_call simulations), the caller was
107    // never charged for gas so there are no fees to transfer to the beneficiary.
108    if context.cfg().is_fee_charge_disabled() {
109        return Ok(());
110    }
111    let (block, tx, cfg, journal, _, _) = context.all_mut();
112    let basefee = block.basefee() as u128;
113    let effective_gas_price = tx.effective_gas_price(basefee);
114
115    // Transfer fee to coinbase/beneficiary.
116    // EIP-1559 discard basefee for coinbase transfer. Basefee amount of gas is discarded.
117    let coinbase_gas_price = if cfg.spec().into().is_enabled_in(SpecId::LONDON) {
118        effective_gas_price.saturating_sub(basefee)
119    } else {
120        effective_gas_price
121    };
122
123    // Reward beneficiary.
124    // Exclude reservoir gas (EIP-8037) from the used gas — reservoir is unused and reimbursed.
125    let effective_used = gas.used().saturating_sub(gas.reservoir());
126    journal
127        .load_account_mut(block.beneficiary())?
128        .incr_balance(U256::from(coinbase_gas_price * effective_used as u128));
129
130    Ok(())
131}
132
133/// Calculate last gas spent and transform internal reason to external.
134///
135/// TODO make Journal FinalOutput more generic.
136pub fn output<CTX: ContextTr<Journal: JournalTr>, HALTREASON: HaltReasonTr>(
137    context: &mut CTX,
138    // TODO, make this more generic and nice.
139    // FrameResult should be a generic that returns gas and interpreter result.
140    result: FrameResult,
141    result_gas: ResultGas,
142) -> ExecutionResult<HALTREASON> {
143    let output = result.output();
144    let instruction_result = result.into_interpreter_result();
145
146    // take logs from journal.
147    let logs = context.journal_mut().take_logs();
148
149    match SuccessOrHalt::<HALTREASON>::from(instruction_result.result) {
150        SuccessOrHalt::Success(reason) => ExecutionResult::Success {
151            reason,
152            gas: result_gas,
153            logs,
154            output,
155        },
156        SuccessOrHalt::Revert => ExecutionResult::Revert {
157            gas: result_gas,
158            logs,
159            output: output.into_data(),
160        },
161        SuccessOrHalt::Halt(reason) => {
162            // Bubble up precompile errors from context when available
163            if matches!(
164                instruction_result.result,
165                interpreter::InstructionResult::PrecompileError
166            ) {
167                if let Some(message) = context.local_mut().take_precompile_error_context() {
168                    return ExecutionResult::Halt {
169                        reason: HALTREASON::from(HaltReason::PrecompileErrorWithContext(message)),
170                        gas: result_gas,
171                        logs,
172                    };
173                }
174            }
175            ExecutionResult::Halt {
176                reason,
177                gas: result_gas,
178                logs,
179            }
180        }
181        // Only two internal return flags.
182        flag @ (SuccessOrHalt::FatalExternalError | SuccessOrHalt::Internal(_)) => {
183            panic!(
184                "Encountered unexpected internal return flag: {flag:?} with instruction result: {instruction_result:?}"
185            )
186        }
187    }
188}
revm_handler/post_execution.rs

revm_handler/
post_execution.rs
