feat!(precompile): gas refund

crates/chainspec/src/hardfork.rs

@@ -37,6 +37,7 @@ hardfork!(
 
 impl TempoHardfork {
     /// Returns `true` if this hardfork is Moderato or later.
+    #[inline]
     pub fn is_moderato(self) -> bool {
         self >= Self::Moderato
     }
@@ -144,7 +145,6 @@ mod tests {
     #[test]
     fn test_is_moderato() {
         assert!(!TempoHardfork::Adagio.is_moderato());
-
         assert!(TempoHardfork::Moderato.is_moderato());
     }
 

crates/precompiles/src/lib.rs

@@ -26,7 +26,7 @@ use crate::{
     nonce::NonceManager,
     path_usd::PathUSD,
     stablecoin_exchange::StablecoinExchange,
-    storage::evm::EvmPrecompileStorageProvider,
+    storage::{PrecompileStorageProvider, evm::EvmPrecompileStorageProvider},
     tip_account_registrar::TipAccountRegistrar,
     tip_fee_manager::TipFeeManager,
     tip20::{TIP20Token, address_to_token_id_unchecked, is_tip20},
@@ -277,6 +277,20 @@ fn mutate_void<T: SolCall>(
     f(sender, call).into_precompile_result(0, |()| Bytes::new())
 }
 
+#[inline]
+fn fill_precompile_output(
+    mut output: PrecompileOutput,
+    storage: &mut impl PrecompileStorageProvider,
+) -> PrecompileOutput {
+    output.gas_used = storage.gas_used();
+
+    // add refund only if it is not reverted
+    if !output.reverted && storage.spec().is_allegretto() {
+        output.gas_refunded = storage.gas_refunded();
+    }
+    output
+}
+
 /// Helper function to return an unknown function selector error
 ///
 /// Before Moderato: Returns a generic PrecompileError::Other

crates/precompiles/src/nonce/dispatch.rs

@@ -1,6 +1,6 @@
 use crate::{
-    Precompile, input_cost, nonce::NonceManager, storage::PrecompileStorageProvider,
-    unknown_selector, view,
+    Precompile, fill_precompile_output, input_cost, nonce::NonceManager,
+    storage::PrecompileStorageProvider, unknown_selector, view,
 };
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
@@ -33,10 +33,7 @@ impl<S: PrecompileStorageProvider> Precompile for NonceManager<'_, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/path_usd/dispatch.rs

@@ -1,5 +1,5 @@
 use crate::{
-    Precompile, input_cost, metadata, mutate, mutate_void,
+    Precompile, fill_precompile_output, input_cost, metadata, mutate, mutate_void,
     path_usd::PathUSD,
     storage::{ContractStorage, PrecompileStorageProvider},
     tip20::{IRolesAuth, ITIP20},
@@ -218,10 +218,7 @@ impl<S: PrecompileStorageProvider> Precompile for PathUSD<'_, S> {
             _ => Err(PrecompileError::Other("Unknown selector".into())),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.token.storage().gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.token.storage()))
     }
 }
 

crates/precompiles/src/stablecoin_exchange/dispatch.rs

@@ -5,7 +5,7 @@ use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
 
 use crate::{
-    Precompile, input_cost, mutate, mutate_void,
+    Precompile, fill_precompile_output, input_cost, mutate, mutate_void,
     stablecoin_exchange::{IStablecoinExchange, StablecoinExchange},
     storage::PrecompileStorageProvider,
     unknown_selector, view,
@@ -183,10 +183,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for StablecoinExchange<'a, S>
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/storage/evm.rs

@@ -13,6 +13,7 @@ pub struct EvmPrecompileStorageProvider<'a> {
     internals: EvmInternals<'a>,
     chain_id: u64,
     gas_remaining: u64,
+    gas_refunded: i64,
     gas_limit: u64,
     spec: TempoHardfork,
 }
@@ -29,6 +30,7 @@ impl<'a> EvmPrecompileStorageProvider<'a> {
             internals,
             chain_id,
             gas_remaining: gas_limit,
+            gas_refunded: 0,
             gas_limit,
             spec,
         }
@@ -103,6 +105,12 @@ impl<'a> PrecompileStorageProvider for EvmPrecompileStorageProvider<'a> {
             result.is_cold,
         ))?;
 
+        // refund gas.
+        self.refund_gas(revm::interpreter::gas::sstore_refund(
+            SpecId::AMSTERDAM,
+            &result.data,
+        ));
+
         Ok(())
     }
 
@@ -165,11 +173,21 @@ impl<'a> PrecompileStorageProvider for EvmPrecompileStorageProvider<'a> {
         Ok(())
     }
 
+    #[inline]
+    fn refund_gas(&mut self, gas: i64) {
+        self.gas_refunded = self.gas_refunded.saturating_add(gas);
+    }
+
     #[inline]
     fn gas_used(&self) -> u64 {
         self.gas_limit - self.gas_remaining
     }
 
+    #[inline]
+    fn gas_refunded(&self) -> i64 {
+        self.gas_refunded
+    }
+
     #[inline]
     fn spec(&self) -> TempoHardfork {
         self.spec

crates/precompiles/src/storage/hashmap.rs

@@ -135,10 +135,18 @@ impl PrecompileStorageProvider for HashMapStorageProvider {
         Ok(())
     }
 
+    fn refund_gas(&mut self, _gas: i64) {
+        // No-op
+    }
+
     fn gas_used(&self) -> u64 {
         0
     }
 
+    fn gas_refunded(&self) -> i64 {
+        0
+    }
+
     fn spec(&self) -> TempoHardfork {
         self.spec
     }

crates/precompiles/src/storage/mod.rs

@@ -47,9 +47,15 @@ pub trait PrecompileStorageProvider {
     /// Deducts gas from the remaining gas and return an error if the gas is insufficient.
     fn deduct_gas(&mut self, gas: u64) -> Result<(), TempoPrecompileError>;
 
+    /// Add refund to the refund gas counter.
+    fn refund_gas(&mut self, gas: i64);
+
     /// Returns the gas used so far.
     fn gas_used(&self) -> u64;
 
+    /// Returns the gas refunded so far.
+    fn gas_refunded(&self) -> i64;
+
     /// Currently active hardfork.
     fn spec(&self) -> TempoHardfork;
 }

crates/precompiles/src/tip20/dispatch.rs

@@ -1,6 +1,6 @@
 use super::ITIP20;
 use crate::{
-    Precompile, input_cost, metadata, mutate, mutate_void,
+    Precompile, fill_precompile_output, input_cost, metadata, mutate, mutate_void,
     storage::PrecompileStorageProvider,
     tip20::{IRolesAuth, TIP20Token},
     unknown_selector, view,
@@ -251,10 +251,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TIP20Token<'a, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/tip20_factory/dispatch.rs

@@ -1,4 +1,6 @@
-use crate::{Precompile, input_cost, mutate, tip20::is_tip20, unknown_selector, view};
+use crate::{
+    Precompile, fill_precompile_output, input_cost, mutate, tip20::is_tip20, unknown_selector, view,
+};
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
 
@@ -36,10 +38,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TIP20Factory<'a, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/tip20_rewards_registry/dispatch.rs

@@ -1,4 +1,4 @@
-use crate::{Precompile, input_cost, mutate_void, unknown_selector};
+use crate::{Precompile, fill_precompile_output, input_cost, mutate_void, unknown_selector};
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
 use tempo_contracts::precompiles::ITIP20RewardsRegistry;
@@ -30,10 +30,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TIP20RewardsRegistry<'a, S
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/tip403_registry/dispatch.rs

@@ -1,4 +1,6 @@
-use crate::{Precompile, input_cost, mutate, mutate_void, unknown_selector, view};
+use crate::{
+    Precompile, fill_precompile_output, input_cost, mutate, mutate_void, unknown_selector, view,
+};
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
 
@@ -69,10 +71,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TIP403Registry<'a, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/tip_account_registrar/dispatch.rs

@@ -1,4 +1,7 @@
-use crate::{Precompile, input_cost, mutate, storage::PrecompileStorageProvider, unknown_selector};
+use crate::{
+    Precompile, fill_precompile_output, input_cost, mutate, storage::PrecompileStorageProvider,
+    unknown_selector,
+};
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
 
@@ -46,10 +49,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TipAccountRegistrar<'a, S>
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/tip_fee_manager/dispatch.rs

@@ -1,7 +1,7 @@
 use crate::{
     Precompile,
     error::TempoPrecompileError,
-    input_cost, mutate, mutate_void,
+    fill_precompile_output, input_cost, mutate, mutate_void,
     storage::PrecompileStorageProvider,
     tip_fee_manager::{IFeeManager, ITIPFeeAMM, TipFeeManager, amm::MIN_LIQUIDITY},
     unknown_selector, view,
@@ -153,10 +153,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for TipFeeManager<'a, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }
 

crates/precompiles/src/validator_config/dispatch.rs

@@ -1,6 +1,7 @@
 use super::{IValidatorConfig, ValidatorConfig};
 use crate::{
-    Precompile, input_cost, mutate_void, storage::PrecompileStorageProvider, unknown_selector, view,
+    Precompile, fill_precompile_output, input_cost, mutate_void,
+    storage::PrecompileStorageProvider, unknown_selector, view,
 };
 use alloy::{primitives::Address, sol_types::SolCall};
 use revm::precompile::{PrecompileError, PrecompileResult};
@@ -61,10 +62,7 @@ impl<'a, S: PrecompileStorageProvider> Precompile for ValidatorConfig<'a, S> {
             _ => unknown_selector(selector, self.storage.gas_used(), self.storage.spec()),
         };
 
-        result.map(|mut res| {
-            res.gas_used = self.storage.gas_used();
-            res
-        })
+        result.map(|res| fill_precompile_output(res, self.storage))
     }
 }