From f59ce8c5a65870564fea08f87c24e6a809e36b60 Mon Sep 17 00:00:00 2001
From: DaniPopes <57450786+DaniPopes@users.noreply.github.com>
Date: Mon, 29 Apr 2024 13:36:10 +0200
Subject: [PATCH] feat(interpreter): add helpers for spending all gas (#1360)

---
 crates/interpreter/src/gas.rs                | 19 +++++++++++++++++++
 crates/revm/src/handler/mainnet/execution.rs |  3 +--
 crates/revm/src/inspector/gas.rs             | 10 ++--------
 crates/revm/src/optimism/handler_register.rs |  3 +--
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/crates/interpreter/src/gas.rs b/crates/interpreter/src/gas.rs
index 387f473774..5d1b5d75ce 100644
--- a/crates/interpreter/src/gas.rs
+++ b/crates/interpreter/src/gas.rs
@@ -35,6 +35,18 @@ impl Gas {
         }
     }
 
+    /// Creates a new `Gas` struct with the given gas limit, but without any gas remaining.
+    #[inline]
+    pub const fn new_spent(limit: u64) -> Self {
+        Self {
+            limit,
+            remaining: 0,
+            remaining_nomem: 0,
+            memory: 0,
+            refunded: 0,
+        }
+    }
+
     /// Returns the gas limit.
     #[inline]
     pub const fn limit(&self) -> u64 {
@@ -79,6 +91,13 @@ impl Gas {
         self.remaining += returned;
     }
 
+    /// Spends all remaining gas.
+    #[inline]
+    pub fn spend_all(&mut self) {
+        self.remaining = 0;
+        self.remaining_nomem = 0;
+    }
+
     /// Records a refund value.
     ///
     /// `refund` can be negative but `self.refunded` should always be positive
diff --git a/crates/revm/src/handler/mainnet/execution.rs b/crates/revm/src/handler/mainnet/execution.rs
index c4985b5445..852dab3721 100644
--- a/crates/revm/src/handler/mainnet/execution.rs
+++ b/crates/revm/src/handler/mainnet/execution.rs
@@ -24,8 +24,7 @@ pub fn frame_return_with_refund_flag<SPEC: Spec>(
     let refunded = gas.refunded();
 
     // Spend the gas limit. Gas is reimbursed when the tx returns successfully.
-    *gas = Gas::new(env.tx.gas_limit);
-    gas.record_cost(env.tx.gas_limit);
+    *gas = Gas::new_spent(env.tx.gas_limit);
 
     match instruction_result {
         return_ok!() => {
diff --git a/crates/revm/src/inspector/gas.rs b/crates/revm/src/inspector/gas.rs
index dc98bcaa95..7542c3d3bf 100644
--- a/crates/revm/src/inspector/gas.rs
+++ b/crates/revm/src/inspector/gas.rs
@@ -60,10 +60,7 @@ impl<DB: Database> Inspector<DB> for GasInspector {
         mut outcome: CallOutcome,
     ) -> CallOutcome {
         if outcome.result.result.is_error() {
-            outcome
-                .result
-                .gas
-                .record_cost(outcome.result.gas.remaining());
+            outcome.result.gas.spend_all();
             self.gas_remaining = 0;
         }
         outcome
@@ -76,10 +73,7 @@ impl<DB: Database> Inspector<DB> for GasInspector {
         mut outcome: CreateOutcome,
     ) -> CreateOutcome {
         if outcome.result.result.is_error() {
-            outcome
-                .result
-                .gas
-                .record_cost(outcome.result.gas.remaining());
+            outcome.result.gas.spend_all();
             self.gas_remaining = 0;
         }
         outcome
diff --git a/crates/revm/src/optimism/handler_register.rs b/crates/revm/src/optimism/handler_register.rs
index 600d6709d0..0d3bcf4048 100644
--- a/crates/revm/src/optimism/handler_register.rs
+++ b/crates/revm/src/optimism/handler_register.rs
@@ -82,8 +82,7 @@ pub fn last_frame_return<SPEC: Spec, EXT, DB: Database>(
     let remaining = gas.remaining();
     let refunded = gas.refunded();
     // Spend the gas limit. Gas is reimbursed when the tx returns successfully.
-    *gas = Gas::new(tx_gas_limit);
-    gas.record_cost(tx_gas_limit);
+    *gas = Gas::new_spent(tx_gas_limit);
 
     match instruction_result {
         return_ok!() => {