refactor clone

sdk/program/src/clock.rs

@@ -1,5 +1,10 @@
 //! Provides information about the network's clock which is made up of ticks, slots, etc...
 
+use {
+    crate::{clone_zeroed, copy_field},
+    std::mem::MaybeUninit,
+};
+
 // The default tick rate that the cluster attempts to achieve.  Note that the actual tick
 // rate at any given time should be expected to drift
 pub const DEFAULT_TICKS_PER_SECOND: u64 = 160;
@@ -105,7 +110,7 @@ pub type UnixTimestamp = i64;
 ///  as the network progresses).
 ///
 #[repr(C)]
-#[derive(Serialize, Clone, Deserialize, Debug, Default, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Default, PartialEq)]
 pub struct Clock {
     /// the current network/bank Slot
     pub slot: Slot,
@@ -121,3 +126,36 @@ pub struct Clock {
     /// timestamp_correction and timestamp_bounding features
     pub unix_timestamp: UnixTimestamp,
 }
+
+impl Clone for Clock {
+    fn clone(&self) -> Self {
+        clone_zeroed(|cloned: &mut MaybeUninit<Self>| {
+            let ptr = cloned.as_mut_ptr();
+            unsafe {
+                copy_field!(ptr, self, slot);
+                copy_field!(ptr, self, epoch_start_timestamp);
+                copy_field!(ptr, self, epoch);
+                copy_field!(ptr, self, leader_schedule_epoch);
+                copy_field!(ptr, self, unix_timestamp);
+            }
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_clone() {
+        let clock = Clock {
+            slot: 1,
+            epoch_start_timestamp: 2,
+            epoch: 3,
+            leader_schedule_epoch: 4,
+            unix_timestamp: 5,
+        };
+        let cloned_clock = clock.clone();
+        assert_eq!(cloned_clock, clock);
+    }
+}

sdk/program/src/epoch_schedule.rs

@@ -2,6 +2,10 @@
 
 /// 1 Epoch = 400 * 8192 ms ~= 55 minutes
 pub use crate::clock::{Epoch, Slot, DEFAULT_SLOTS_PER_EPOCH};
+use {
+    crate::{clone_zeroed, copy_field},
+    std::mem::MaybeUninit,
+};
 
 /// The number of slots before an epoch starts to calculate the leader schedule.
 ///  Default is an entire epoch, i.e. leader schedule for epoch X is calculated at
@@ -17,7 +21,7 @@ pub const MAX_LEADER_SCHEDULE_EPOCH_OFFSET: u64 = 3;
 pub const MINIMUM_SLOTS_PER_EPOCH: u64 = 32;
 
 #[repr(C)]
-#[derive(Debug, Clone, Copy, PartialEq, Deserialize, Serialize, AbiExample)]
+#[derive(Debug, Copy, PartialEq, Deserialize, Serialize, AbiExample)]
 #[serde(rename_all = "camelCase")]
 pub struct EpochSchedule {
     /// The maximum number of slots in each epoch.
@@ -47,6 +51,21 @@ impl Default for EpochSchedule {
     }
 }
 
+impl Clone for EpochSchedule {
+    fn clone(&self) -> Self {
+        clone_zeroed(|cloned: &mut MaybeUninit<Self>| {
+            let ptr = cloned.as_mut_ptr();
+            unsafe {
+                copy_field!(ptr, self, slots_per_epoch);
+                copy_field!(ptr, self, leader_schedule_slot_offset);
+                copy_field!(ptr, self, warmup);
+                copy_field!(ptr, self, first_normal_epoch);
+                copy_field!(ptr, self, first_normal_slot);
+            }
+        })
+    }
+}
+
 impl EpochSchedule {
     pub fn new(slots_per_epoch: u64) -> Self {
         Self::custom(slots_per_epoch, slots_per_epoch, true)
@@ -229,4 +248,18 @@ mod tests {
             assert!(last_slots_in_epoch == slots_per_epoch);
         }
     }
+
+    #[test]
+    fn test_clone() {
+        let epoch_schedule = EpochSchedule {
+            slots_per_epoch: 1,
+            leader_schedule_slot_offset: 2,
+            warmup: true,
+            first_normal_epoch: 4,
+            first_normal_slot: 5,
+        };
+        #[allow(clippy::clone_on_copy)]
+        let cloned_epoch_schedule = epoch_schedule.clone();
+        assert_eq!(cloned_epoch_schedule, epoch_schedule);
+    }
 }

sdk/program/src/fee_calculator.rs

@@ -4,7 +4,7 @@ use {
     log::*,
 };
 
-#[derive(Serialize, Deserialize, Default, PartialEq, Eq, Clone, Debug, AbiExample)]
+#[derive(Serialize, Deserialize, Default, PartialEq, Eq, Clone, Copy, Debug, AbiExample)]
 #[serde(rename_all = "camelCase")]
 pub struct FeeCalculator {
     // The current cost of a signature  This amount may increase/decrease over time based on

sdk/program/src/lib.rs

@@ -226,6 +226,25 @@ macro_rules! unchecked_div_by_const {
     }};
 }
 
+use std::{mem::MaybeUninit, ptr::write_bytes};
+
+#[macro_export]
+macro_rules! copy_field {
+    ($ptr:expr, $self:ident, $field:ident) => {
+        std::ptr::addr_of_mut!((*$ptr).$field).write($self.$field)
+    };
+}
+
+pub fn clone_zeroed<T, F>(clone: F) -> T
+where
+    F: Fn(&mut MaybeUninit<T>),
+{
+    let mut value = MaybeUninit::<T>::uninit();
+    unsafe { write_bytes(&mut value, 0, 1) }
+    clone(&mut value);
+    unsafe { value.assume_init() }
+}
+
 #[cfg(test)]
 mod tests {
     use super::unchecked_div_by_const;

sdk/program/src/rent.rs

@@ -1,9 +1,13 @@
 #![allow(clippy::integer_arithmetic)]
 //! configuration for network rent
-use crate::clock::DEFAULT_SLOTS_PER_EPOCH;
+
+use {
+    crate::{clock::DEFAULT_SLOTS_PER_EPOCH, clone_zeroed, copy_field},
+    std::mem::MaybeUninit,
+};
 
 #[repr(C)]
-#[derive(Serialize, Deserialize, PartialEq, Clone, Copy, Debug, AbiExample)]
+#[derive(Serialize, Deserialize, PartialEq, Copy, Debug, AbiExample)]
 pub struct Rent {
     /// Rental rate
     pub lamports_per_byte_year: u64,
@@ -41,6 +45,19 @@ impl Default for Rent {
     }
 }
 
+impl Clone for Rent {
+    fn clone(&self) -> Self {
+        clone_zeroed(|cloned: &mut MaybeUninit<Self>| {
+            let ptr = cloned.as_mut_ptr();
+            unsafe {
+                copy_field!(ptr, self, lamports_per_byte_year);
+                copy_field!(ptr, self, exemption_threshold);
+                copy_field!(ptr, self, burn_percent);
+            }
+        })
+    }
+}
+
 impl Rent {
     /// calculate how much rent to burn from the collected rent
     pub fn calculate_burn(&self, rent_collected: u64) -> (u64, u64) {
@@ -183,4 +200,16 @@ mod tests {
         assert!(RentDue::Exempt.is_exempt());
         assert!(!RentDue::Paying(0).is_exempt());
     }
+
+    #[test]
+    fn test_clone() {
+        let rent = Rent {
+            lamports_per_byte_year: 1,
+            exemption_threshold: 2.2,
+            burn_percent: 3,
+        };
+        #[allow(clippy::clone_on_copy)]
+        let cloned_rent = rent.clone();
+        assert_eq!(cloned_rent, rent);
+    }
 }

sdk/program/src/sysvar/fees.rs

@@ -2,8 +2,12 @@
 //!
 #![allow(deprecated)]
 
-use crate::{
-    fee_calculator::FeeCalculator, impl_sysvar_get, program_error::ProgramError, sysvar::Sysvar,
+use {
+    crate::{
+        clone_zeroed, copy_field, fee_calculator::FeeCalculator, impl_sysvar_get,
+        program_error::ProgramError, sysvar::Sysvar,
+    },
+    std::mem::MaybeUninit,
 };
 
 crate::declare_deprecated_sysvar_id!("SysvarFees111111111111111111111111111111111", Fees);
@@ -13,15 +17,27 @@ crate::declare_deprecated_sysvar_id!("SysvarFees11111111111111111111111111111111
     note = "Please do not use, will no longer be available in the future"
 )]
 #[repr(C)]
-#[derive(Serialize, Deserialize, Clone, Debug, Default, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Default, PartialEq)]
 pub struct Fees {
     pub fee_calculator: FeeCalculator,
 }
+
+impl Clone for Fees {
+    fn clone(&self) -> Self {
+        clone_zeroed(|cloned: &mut MaybeUninit<Self>| {
+            let ptr = cloned.as_mut_ptr();
+            unsafe {
+                copy_field!(ptr, self, fee_calculator);
+            }
+        })
+    }
+}
+
 impl Fees {
     pub fn new(fee_calculator: &FeeCalculator) -> Self {
         #[allow(deprecated)]
         Self {
-            fee_calculator: fee_calculator.clone(),
+            fee_calculator: *fee_calculator,
         }
     }
 }
@@ -29,3 +45,19 @@ impl Fees {
 impl Sysvar for Fees {
     impl_sysvar_get!(sol_get_fees_sysvar);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_clone() {
+        let fees = Fees {
+            fee_calculator: FeeCalculator {
+                lamports_per_signature: 1,
+            },
+        };
+        let cloned_fees = fees.clone();
+        assert_eq!(cloned_fees, fees);
+    }
+}