Disable legacy-arith by default

Author: macladson

consensus/state_processing/Cargo.toml

@@ -5,9 +5,8 @@ authors = ["Paul Hauner <[email protected]>", "Michael Sproul <michael@sigmapr
 edition = { workspace = true }
 
 [features]
-default = ["legacy-arith"]
+default = []
 fake_crypto = ["bls/fake_crypto"]
-legacy-arith = ["types/legacy-arith"]
 arbitrary-fuzz = [
     "types/arbitrary-fuzz",
     "merkle_proof/arbitrary",
@@ -40,7 +39,7 @@ test_random_derive = { path = "../../common/test_random_derive" }
 tracing = { workspace = true }
 tree_hash = { workspace = true }
 typenum = { workspace = true }
-types = { workspace = true }
+types = { workspace = true, features = ["saturating-arith"] }
 
 [dev-dependencies]
 beacon_chain = { workspace = true }

consensus/types/Cargo.toml

@@ -8,9 +8,10 @@ authors = [
 edition = { workspace = true }
 
 [features]
-default = ["sqlite", "legacy-arith"]
-# Allow saturating arithmetic on slots and epochs. Enabled by default, but deprecated.
-legacy-arith = []
+default = ["sqlite"]
+# Enable +, -, *, /, % operators for Slot and Epoch types.
+# Operations saturate instead of wrapping.
+saturating-arith = []
 sqlite = ["dep:rusqlite"]
 arbitrary = [
     "dep:arbitrary",

consensus/types/src/core/slot_epoch.rs

@@ -22,7 +22,7 @@ use crate::{
     test_utils::TestRandom,
 };
 
-#[cfg(feature = "legacy-arith")]
+#[cfg(feature = "saturating-arith")]
 use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Sub, SubAssign};
 
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]

consensus/types/src/core/slot_epoch_macros.rs

@@ -117,7 +117,7 @@ macro_rules! impl_safe_arith {
 }
 
 // Deprecated: prefer `SafeArith` methods for new code.
-#[cfg(feature = "legacy-arith")]
+#[cfg(feature = "saturating-arith")]
 macro_rules! impl_math_between {
     ($main: ident, $other: ident) => {
         impl Add<$other> for $main {
@@ -321,9 +321,9 @@ macro_rules! impl_common {
         impl_u64_eq_ord!($type);
         impl_safe_arith!($type, $type);
         impl_safe_arith!($type, u64);
-        #[cfg(feature = "legacy-arith")]
+        #[cfg(feature = "saturating-arith")]
         impl_math_between!($type, $type);
-        #[cfg(feature = "legacy-arith")]
+        #[cfg(feature = "saturating-arith")]
         impl_math_between!($type, u64);
         impl_math!($type);
         impl_display!($type);

consensus/types/src/state/committee_cache.rs

@@ -79,7 +79,13 @@ impl CommitteeCache {
             .saturating_sub(spec.min_seed_lookahead)
             .saturating_sub(1u64);
 
-        if reqd_randao_epoch < state.min_randao_epoch() || epoch > state.current_epoch() + 1 {
+        if reqd_randao_epoch < state.min_randao_epoch()
+            || epoch
+                > state
+                    .current_epoch()
+                    .safe_add(1)
+                    .map_err(BeaconStateError::ArithError)?
+        {
             return Err(BeaconStateError::EpochOutOfBounds);
         }