[Solana][readability] PluginType type safety

chains/solana/contracts/programs/ccip-offramp/src/context.rs

@@ -1,4 +1,5 @@
 use anchor_lang::prelude::*;
+use bytemuck::{Pod, Zeroable};
 use solana_program::sysvar::instructions;
 
 use crate::messages::ExecutionReportSingleChain;
@@ -518,7 +519,37 @@ pub struct ExecuteReportContext<'info> {
     // ] x N tokens
 }
 
-#[derive(Copy, Clone, AnchorSerialize, AnchorDeserialize)]
+/// It's not possible to store enums in zero_copy accounts, so we wrap the discriminant
+/// in a struct to store in config.
+#[derive(
+    Copy, Clone, AnchorSerialize, AnchorDeserialize, PartialEq, Eq, InitSpace, Pod, Zeroable,
+)]
+#[repr(C)]
+pub struct ConfigOcrPluginType {
+    discriminant: u8,
+}
+
+impl From<OcrPluginType> for ConfigOcrPluginType {
+    fn from(value: OcrPluginType) -> Self {
+        Self {
+            discriminant: value as u8,
+        }
+    }
+}
+
+impl TryFrom<ConfigOcrPluginType> for OcrPluginType {
+    type Error = CcipOfframpError;
+
+    fn try_from(value: ConfigOcrPluginType) -> std::result::Result<Self, Self::Error> {
+        match value.discriminant {
+            0 => Ok(Self::Commit),
+            1 => Ok(Self::Execution),
+            _ => Err(CcipOfframpError::InvalidPluginType),
+        }
+    }
+}
+
+#[derive(Copy, Clone, AnchorSerialize, AnchorDeserialize, PartialEq, Eq)]
 pub enum OcrPluginType {
     Commit,
     Execution,

chains/solana/contracts/programs/ccip-offramp/src/instructions/interfaces.rs

@@ -5,7 +5,9 @@ use crate::context::{
     PriceOnlyCommitReportContext, SetOcrConfig, TransferOwnership, UpdateConfig, UpdateSourceChain,
 };
 use crate::state::{CodeVersion, Ocr3ConfigInfo, SourceChainConfig};
+use crate::OcrPluginType;
 
+/// To be called by the commit DON.
 pub trait Commit {
     fn commit<'info>(
         &self,
@@ -28,6 +30,7 @@ pub trait Commit {
     ) -> Result<()>;
 }
 
+/// To be called by the execute DON.
 pub trait Execute {
     fn execute<'info>(
         &self,
@@ -45,6 +48,7 @@ pub trait Execute {
     ) -> Result<()>;
 }
 
+/// To be called by the offramp administrator.
 pub trait Admin {
     fn transfer_ownership(
         &self,
@@ -95,7 +99,7 @@ pub trait Admin {
     fn set_ocr_config(
         &self,
         ctx: Context<SetOcrConfig>,
-        plugin_type: u8, // OcrPluginType, u8 used because anchor tests did not work with an enum
+        plugin_type: OcrPluginType,
         config_info: Ocr3ConfigInfo,
         signers: Vec<[u8; 20]>,
         transmitters: Vec<Pubkey>,

chains/solana/contracts/programs/ccip-offramp/src/instructions/v1/admin.rs

@@ -154,15 +154,14 @@ impl Admin for Impl {
     fn set_ocr_config(
         &self,
         ctx: Context<SetOcrConfig>,
-        plugin_type: u8, // OcrPluginType, u8 used because anchor tests did not work with an enum
+        plugin_type: OcrPluginType,
         config_info: Ocr3ConfigInfo,
         signers: Vec<[u8; 20]>,
         transmitters: Vec<Pubkey>,
     ) -> Result<()> {
-        require!(plugin_type < 2, CcipOfframpError::InvalidPluginType);
         let mut config = ctx.accounts.config.load_mut()?;
 
-        let is_commit = plugin_type == OcrPluginType::Commit as u8;
+        let is_commit = plugin_type == OcrPluginType::Commit;
 
         ocr3_set(
             &mut config.ocr3[plugin_type as usize],

chains/solana/contracts/programs/ccip-offramp/src/instructions/v1/commit.rs

@@ -140,7 +140,7 @@ impl Commit for Impl {
             &config.ocr3[OcrPluginType::Commit as usize],
             &ctx.accounts.sysvar_instructions,
             ctx.accounts.authority.key(),
-            OcrPluginType::Commit as u8,
+            OcrPluginType::Commit,
             report_context,
             &Ocr3ReportForCommit(&report),
             Signatures { rs, ss, raw_vs },
@@ -206,7 +206,7 @@ impl Commit for Impl {
             &config.ocr3[OcrPluginType::Commit as usize],
             &ctx.accounts.sysvar_instructions,
             ctx.accounts.authority.key(),
-            OcrPluginType::Commit as u8,
+            OcrPluginType::Commit,
             report_context,
             &Ocr3ReportForCommit(&report),
             Signatures { rs, ss, raw_vs },

chains/solana/contracts/programs/ccip-offramp/src/instructions/v1/execute.rs

@@ -41,7 +41,7 @@ impl Execute for Impl {
                 &config.ocr3[OcrPluginType::Execution as usize],
                 &ctx.accounts.sysvar_instructions,
                 ctx.accounts.authority.key(),
-                OcrPluginType::Execution as u8,
+                OcrPluginType::Execution,
                 report_context,
                 &Ocr3ReportForExecutionReportSingleChain(&execution_report),
                 Signatures {

chains/solana/contracts/programs/ccip-offramp/src/instructions/v1/ocr3base.rs

@@ -4,6 +4,7 @@ use anchor_lang::solana_program::{keccak, secp256k1_recover::*};
 
 use crate::ocr3base::{ConfigSet, Ocr3Error, Transmitted, MAX_ORACLES};
 use crate::state::{Ocr3Config, Ocr3ConfigInfo};
+use crate::OcrPluginType;
 
 pub const MAX_SIGNERS: usize = MAX_ORACLES;
 pub const MAX_TRANSMITTERS: usize = MAX_ORACLES;
@@ -48,13 +49,13 @@ impl ReportContext {
 
 pub fn ocr3_set(
     ocr3_config: &mut Ocr3Config,
-    plugin_type: u8,
+    plugin_type: OcrPluginType,
     cfg: Ocr3ConfigInfo,
     signers: Vec<[u8; 20]>,
     transmitters: Vec<Pubkey>,
 ) -> Result<()> {
     require!(
-        plugin_type == ocr3_config.plugin_type,
+        plugin_type == ocr3_config.plugin_type.try_into()?,
         Ocr3Error::InvalidPluginType
     );
     require!(cfg.f != 0, Ocr3Error::InvalidConfigFMustBePositive);
@@ -101,7 +102,7 @@ pub fn ocr3_set(
     ocr3_config.config_info.config_digest = cfg.config_digest;
 
     emit!(ConfigSet {
-        ocr_plugin_type: ocr3_config.plugin_type,
+        ocr_plugin_type: ocr3_config.plugin_type.try_into()?,
         config_digest: ocr3_config.config_info.config_digest,
         signers,
         transmitters,
@@ -128,13 +129,13 @@ pub(super) fn ocr3_transmit<R: Ocr3Report>(
     ocr3_config: &Ocr3Config,
     instruction_sysvar: &AccountInfo<'_>,
     transmitter: Pubkey,
-    plugin_type: u8,
+    plugin_type: OcrPluginType,
     report_context: ReportContext,
     report: &R,
     signatures: Signatures,
 ) -> Result<()> {
     require!(
-        plugin_type == ocr3_config.plugin_type,
+        plugin_type == ocr3_config.plugin_type.try_into()?,
         Ocr3Error::InvalidPluginType
     );
 
@@ -189,7 +190,7 @@ pub(super) fn ocr3_transmit<R: Ocr3Report>(
     }
 
     emit!(Transmitted {
-        ocr_plugin_type: ocr3_config.plugin_type,
+        ocr_plugin_type: ocr3_config.plugin_type.try_into()?,
         config_digest: ocr3_config.config_info.config_digest,
         sequence_number: report_context.sequence_number(),
     });

chains/solana/contracts/programs/ccip-offramp/src/lib.rs

@@ -78,8 +78,8 @@ pub mod ccip_offramp {
         config.enable_manual_execution_after = enable_execution_after;
         config.owner = ctx.accounts.authority.key();
         config.ocr3 = [
-            Ocr3Config::new(OcrPluginType::Commit as u8),
-            Ocr3Config::new(OcrPluginType::Execution as u8),
+            Ocr3Config::new(OcrPluginType::Commit),
+            Ocr3Config::new(OcrPluginType::Execution),
         ];
 
         emit!(ConfigSet {
@@ -292,7 +292,7 @@ pub mod ccip_offramp {
     /// * `transmitters` - The list of transmitters.
     pub fn set_ocr_config(
         ctx: Context<SetOcrConfig>,
-        plugin_type: u8, // OcrPluginType, u8 used because anchor tests did not work with an enum
+        plugin_type: OcrPluginType,
         config_info: Ocr3ConfigInfo,
         signers: Vec<[u8; 20]>,
         transmitters: Vec<Pubkey>,

chains/solana/contracts/programs/ccip-offramp/src/ocr3base.rs

@@ -1,5 +1,7 @@
 use anchor_lang::prelude::*;
 
+use crate::OcrPluginType;
+
 #[constant]
 pub const MAX_ORACLES: usize = 16; // can set a maximum of 16 transmitters + 16 signers simultaneously in a single set config tx
 
@@ -41,7 +43,7 @@ pub enum Ocr3Error {
 
 #[event]
 pub struct ConfigSet {
-    pub ocr_plugin_type: u8,
+    pub ocr_plugin_type: OcrPluginType,
     pub config_digest: [u8; 32],
     pub signers: Vec<[u8; 20]>,
     pub transmitters: Vec<Pubkey>,
@@ -50,7 +52,7 @@ pub struct ConfigSet {
 
 #[event]
 pub struct Transmitted {
-    pub ocr_plugin_type: u8,
+    pub ocr_plugin_type: OcrPluginType,
     pub config_digest: [u8; 32],
     pub sequence_number: u64,
 }

chains/solana/contracts/programs/ccip-offramp/src/state.rs

@@ -3,7 +3,7 @@ use std::fmt::Display;
 use anchor_lang::prelude::borsh::{BorshDeserialize, BorshSerialize};
 use anchor_lang::prelude::*;
 
-use crate::CcipOfframpError;
+use crate::{CcipOfframpError, ConfigOcrPluginType, OcrPluginType};
 
 // zero_copy is used to prevent hitting stack/heap memory limits
 #[account(zero_copy)]
@@ -45,19 +45,30 @@ pub struct Ocr3ConfigInfo {
 // signers: pubkey is 20-byte address, secp256k1 curve ECDSA
 // transmitters: 32-byte pubkey, ed25519
 
+#[derive(AnchorSerialize, AnchorDeserialize, InitSpace)]
 #[zero_copy]
-#[derive(AnchorSerialize, AnchorDeserialize, InitSpace, Default)]
 pub struct Ocr3Config {
-    pub plugin_type: u8, // plugin identifier for validation (example: ccip:commit = 0, ccip:execute = 1)
+    pub plugin_type: ConfigOcrPluginType, // plugin identifier for validation (example: ccip:commit = 0, ccip:execute = 1)
     pub config_info: Ocr3ConfigInfo,
     pub signers: [[u8; 20]; 16], // v0.29.0 - anchor IDL does not build with MAX_SIGNERS
     pub transmitters: [[u8; 32]; 16], // v0.29.0 - anchor IDL does not build with MAX_TRANSMITTERS
 }
 
+impl Default for Ocr3Config {
+    fn default() -> Self {
+        Self {
+            plugin_type: OcrPluginType::Commit.into(),
+            config_info: Default::default(),
+            signers: Default::default(),
+            transmitters: Default::default(),
+        }
+    }
+}
+
 impl Ocr3Config {
-    pub fn new(plugin_type: u8) -> Self {
+    pub fn new(plugin_type: OcrPluginType) -> Self {
         Self {
-            plugin_type,
+            plugin_type: plugin_type.into(),
             ..Default::default()
         }
     }

chains/solana/contracts/target/idl/ccip_offramp.json

@@ -452,7 +452,9 @@
       "args": [
         {
           "name": "pluginType",
-          "type": "u8"
+          "type": {
+            "defined": "OcrPluginType"
+          }
         },
         {
           "name": "configInfo",
@@ -1271,6 +1273,22 @@
         ]
       }
     },
+    {
+      "name": "ConfigOcrPluginType",
+      "docs": [
+        "It's not possible to store enums in zero_copy accounts, so we wrap the discriminant",
+        "in a struct to store in config."
+      ],
+      "type": {
+        "kind": "struct",
+        "fields": [
+          {
+            "name": "discriminant",
+            "type": "u8"
+          }
+        ]
+      }
+    },
     {
       "name": "ExecutionReportSingleChain",
       "docs": [
@@ -1510,7 +1528,9 @@
         "fields": [
           {
             "name": "pluginType",
-            "type": "u8"
+            "type": {
+              "defined": "ConfigOcrPluginType"
+            }
           },
           {
             "name": "configInfo",
@@ -1942,7 +1962,9 @@
       "fields": [
         {
           "name": "ocrPluginType",
-          "type": "u8",
+          "type": {
+            "defined": "OcrPluginType"
+          },
           "index": false
         },
         {
@@ -1986,7 +2008,9 @@
       "fields": [
         {
           "name": "ocrPluginType",
-          "type": "u8",
+          "type": {
+            "defined": "OcrPluginType"
+          },
           "index": false
         },
         {