Add BPF program entrypoint return type (#8111)

programs/bpf/rust/dup_accounts/src/lib.rs

@@ -2,7 +2,8 @@
 
 extern crate solana_sdk;
 use solana_sdk::{
-    account_info::AccountInfo, entrypoint, info, program_error::ProgramError, pubkey::Pubkey,
+    account_info::AccountInfo, entrypoint, entrypoint::ProgramResult, info,
+    program_error::ProgramError, pubkey::Pubkey,
 };
 
 entrypoint!(process_instruction);
@@ -10,7 +11,7 @@ fn process_instruction(
     _program_id: &Pubkey,
     accounts: &[AccountInfo],
     instruction_data: &[u8],
-) -> Result<(), ProgramError> {
+) -> ProgramResult {
     match instruction_data[0] {
         1 => {
             info!("modify first account data");

programs/bpf/rust/error_handling/src/lib.rs

@@ -6,7 +6,9 @@ use num_traits::FromPrimitive;
 
 use solana_sdk::{
     account_info::AccountInfo,
-    entrypoint, info,
+    entrypoint,
+    entrypoint::ProgramResult,
+    info,
     instruction_processor_utils::DecodeError,
     program_error::{PrintProgramError, ProgramError},
     pubkey::Pubkey,
@@ -48,9 +50,7 @@ fn process_instruction(
     _program_id: &Pubkey,
     accounts: &[AccountInfo],
     instruction_data: &[u8],
-) -> Result<(), ProgramError> {
-    ProgramError::CustomError(42).print::<MyError>();
-
+) -> ProgramResult {
     match instruction_data[0] {
         1 => {
             info!("return success");

programs/bpf/rust/external_spend/src/lib.rs

@@ -2,7 +2,7 @@
 
 extern crate solana_sdk;
 use solana_sdk::{
-    account_info::AccountInfo, entrypoint, program_error::ProgramError, pubkey::Pubkey,
+    account_info::AccountInfo, entrypoint, entrypoint::ProgramResult, pubkey::Pubkey,
 };
 
 entrypoint!(process_instruction);
@@ -10,7 +10,7 @@ fn process_instruction(
     _program_id: &Pubkey,
     accounts: &[AccountInfo],
     _instruction_data: &[u8],
-) -> Result<(), ProgramError> {
+) -> ProgramResult {
     // account 0 is the mint and not owned by this program, any debit of its lamports
     // should result in a failed program execution.  Test to ensure that this debit
     // is seen by the runtime and fails as expected

programs/bpf/rust/noop/src/lib.rs

@@ -5,8 +5,7 @@
 extern crate solana_sdk;
 
 use solana_sdk::{
-    account_info::AccountInfo, entrypoint, info, log::*, program_error::ProgramError,
-    pubkey::Pubkey,
+    account_info::AccountInfo, entrypoint, entrypoint::ProgramResult, info, log::*, pubkey::Pubkey,
 };
 
 #[derive(Debug, PartialEq)]
@@ -26,7 +25,7 @@ fn process_instruction(
     program_id: &Pubkey,
     accounts: &[AccountInfo],
     instruction_data: &[u8],
-) -> Result<(), ProgramError> {
+) -> ProgramResult {
     info!("Program identifier:");
     program_id.log();
 

programs/bpf/rust/sysval/src/lib.rs

@@ -4,9 +4,10 @@ extern crate solana_sdk;
 use solana_sdk::{
     account_info::AccountInfo,
     clock::{get_segment_from_slot, DEFAULT_SLOTS_PER_EPOCH, DEFAULT_SLOTS_PER_SEGMENT},
-    entrypoint, info,
+    entrypoint,
+    entrypoint::ProgramResult,
+    info,
     log::Log,
-    program_error::ProgramError,
     pubkey::Pubkey,
     rent,
     sysvar::{
@@ -20,7 +21,7 @@ fn process_instruction(
     _program_id: &Pubkey,
     accounts: &[AccountInfo],
     _instruction_data: &[u8],
-) -> Result<(), ProgramError> {
+) -> ProgramResult {
     // Clock
     info!("Clock identifier:");
     sysvar::clock::id().log();

sdk/src/entrypoint.rs

@@ -7,19 +7,20 @@ use std::{
     cell::RefCell,
     mem::size_of,
     rc::Rc,
+    // Hide Result from bindgen gets confused about generics in non-generic type declarations
+    result::Result as ResultGeneric,
     slice::{from_raw_parts, from_raw_parts_mut},
 };
 
+pub type ProgramResult = ResultGeneric<(), ProgramError>;
+
 /// User implemented function to process an instruction
 ///
 /// program_id: Program ID of the currently executing program
 /// accounts: Accounts passed as part of the instruction
 /// instruction_data: Instruction data
-pub type ProcessInstruction = fn(
-    program_id: &Pubkey,
-    accounts: &[AccountInfo],
-    instruction_data: &[u8],
-) -> Result<(), ProgramError>;
+pub type ProcessInstruction =
+    fn(program_id: &Pubkey, accounts: &[AccountInfo], instruction_data: &[u8]) -> ProgramResult;
 
 /// Programs indicate success with a return value of 0
 pub const SUCCESS: u64 = 0;