Migrate to thiserror (#7177)

* Migrate to thiserror

* Discourage the use of other modules' Result alias

`io::Result` set a bad precedent. Don't import other `Result`
aliases.

programs/budget/Cargo.toml

@@ -17,6 +17,7 @@ num-traits = "0.2"
 serde = "1.0.103"
 serde_derive = "1.0.103"
 solana-sdk = { path = "../../sdk", version = "0.22.0" }
+thiserror = "1.0"
 
 [dev-dependencies]
 solana-runtime = { path = "../../runtime", version = "0.22.0" }

programs/budget/src/budget_instruction.rs

@@ -10,9 +10,11 @@ use solana_sdk::{
     pubkey::Pubkey,
     system_instruction,
 };
+use thiserror::Error;
 
-#[derive(Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
+#[derive(Error, Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum BudgetError {
+    #[error("destination missing")]
     DestinationMissing,
 }
 
@@ -22,19 +24,6 @@ impl<T> DecodeError<T> for BudgetError {
     }
 }
 
-impl std::fmt::Display for BudgetError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                BudgetError::DestinationMissing => "destination missing",
-            }
-        )
-    }
-}
-impl std::error::Error for BudgetError {}
-
 /// An instruction to progress the smart contract.
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub enum BudgetInstruction {

programs/ownable/Cargo.toml

@@ -15,6 +15,7 @@ serde_derive = "1.0.103"
 solana-sdk = { path = "../../sdk", version = "0.22.0" }
 num-derive = "0.3"
 num-traits = "0.2"
+thiserror = "1.0"
 
 [dev-dependencies]
 solana-runtime = { path = "../../runtime", version = "0.22.0" }

programs/ownable/src/ownable_instruction.rs

@@ -5,9 +5,11 @@ use solana_sdk::{
     pubkey::Pubkey,
     system_instruction,
 };
+use thiserror::Error;
 
-#[derive(Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
+#[derive(Error, Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum OwnableError {
+    #[error("incorrect error")]
     IncorrectOwner,
 }
 
@@ -17,19 +19,6 @@ impl<T> DecodeError<T> for OwnableError {
     }
 }
 
-impl std::fmt::Display for OwnableError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                OwnableError::IncorrectOwner => "incorrect owner",
-            }
-        )
-    }
-}
-impl std::error::Error for OwnableError {}
-
 fn initialize_account(account_pubkey: &Pubkey, owner_pubkey: &Pubkey) -> Instruction {
     let keys = vec![AccountMeta::new(*account_pubkey, false)];
     Instruction::new(crate::id(), &owner_pubkey, keys)

programs/stake/Cargo.toml

@@ -21,6 +21,7 @@ solana-metrics = { path = "../../metrics", version = "0.22.0" }
 solana-sdk = { path = "../../sdk", version = "0.22.0" }
 solana-vote-program = { path = "../vote", version = "0.22.0" }
 solana-config-program = { path = "../config", version = "0.22.0" }
+thiserror = "1.0"
 
 [lib]
 crate-type = ["lib", "cdylib"]

programs/stake/src/stake_instruction.rs

@@ -15,33 +15,32 @@ use solana_sdk::{
         self, clock::Clock, rent::Rent, rewards::Rewards, stake_history::StakeHistory, Sysvar,
     },
 };
+use thiserror::Error;
 
 /// Reasons the stake might have had an error
-#[derive(Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
+#[derive(Error, Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum StakeError {
+    #[error("not enough credits to redeem")]
     NoCreditsToRedeem,
+
+    #[error("lockup has not yet expired")]
     LockupInForce,
+
+    #[error("stake already deactivated")]
     AlreadyDeactivated,
+
+    #[error("one re-delegation permitted per epoch")]
     TooSoonToRedelegate,
+
+    #[error("split amount is more than is staked")]
     InsufficientStake,
 }
+
 impl<E> DecodeError<E> for StakeError {
     fn type_of() -> &'static str {
         "StakeError"
     }
 }
-impl std::fmt::Display for StakeError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        match self {
-            StakeError::NoCreditsToRedeem => write!(f, "not enough credits to redeem"),
-            StakeError::LockupInForce => write!(f, "lockup has not yet expired"),
-            StakeError::AlreadyDeactivated => write!(f, "stake already deactivated"),
-            StakeError::TooSoonToRedelegate => write!(f, "one re-delegation permitted per epoch"),
-            StakeError::InsufficientStake => write!(f, "split amount is more than is staked"),
-        }
-    }
-}
-impl std::error::Error for StakeError {}
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
 pub enum StakeInstruction {

programs/vest/Cargo.toml

@@ -18,6 +18,7 @@ serde = "1.0.103"
 serde_derive = "1.0.103"
 solana-sdk = { path = "../../sdk", version = "0.22.0" }
 solana-config-program = { path = "../config", version = "0.22.0" }
+thiserror = "1.0"
 
 [dev-dependencies]
 solana-runtime = { path = "../../runtime", version = "0.22.0" }

programs/vest/src/vest_instruction.rs

@@ -9,10 +9,14 @@ use solana_sdk::{
     pubkey::Pubkey,
     system_instruction,
 };
+use thiserror::Error;
 
-#[derive(Debug, Clone, PartialEq, FromPrimitive)]
+#[derive(Error, Debug, Clone, PartialEq, FromPrimitive)]
 pub enum VestError {
+    #[error("destination missing")]
     DestinationMissing,
+
+    #[error("unauthorized")]
     Unauthorized,
 }
 

programs/vote/Cargo.toml

@@ -18,6 +18,7 @@ serde_derive = "1.0.103"
 solana-logger = { path = "../../logger", version = "0.22.0" }
 solana-metrics = { path = "../../metrics", version = "0.22.0" }
 solana-sdk = { path = "../../sdk", version = "0.22.0" }
+thiserror = "1.0"
 
 [lib]
 crate-type = ["lib", "cdylib"]

programs/vote/src/vote_instruction.rs

@@ -17,13 +17,21 @@ use solana_sdk::{
     system_instruction,
     sysvar::{self, clock::Clock, slot_hashes::SlotHashes, Sysvar},
 };
+use thiserror::Error;
 
 /// Reasons the stake might have had an error
-#[derive(Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
+#[derive(Error, Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
 pub enum VoteError {
+    #[error("vote already recorded or not in slot hashes history")]
     VoteTooOld,
+
+    #[error("vote slots do not match bank history")]
     SlotsMismatch,
+
+    #[error("vote hash does not match bank hash")]
     SlotHashMismatch,
+
+    #[error("vote has no slots, invalid")]
     EmptySlots,
 }
 impl<E> DecodeError<E> for VoteError {
@@ -32,22 +40,6 @@ impl<E> DecodeError<E> for VoteError {
     }
 }
 
-impl std::fmt::Display for VoteError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                VoteError::VoteTooOld => "vote already recorded or not in slot hashes history",
-                VoteError::SlotsMismatch => "vote slots do not match bank history",
-                VoteError::SlotHashMismatch => "vote hash does not match bank hash",
-                VoteError::EmptySlots => "vote has no slots, invalid",
-            }
-        )
-    }
-}
-impl std::error::Error for VoteError {}
-
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub enum VoteInstruction {
     /// Initialize the VoteState for this `vote account`