rust: Bump Solana crates to v2.1

#### Problem

Version 2.1 of the Solana crates is out, but all of the Rust programs
are still on v2.0.

#### Summary of changes

Bump crates to v2.1, Rust to 1.81, and use component crates wherever
possible. The CPI program has a higher CU usage also, so update the
README to reflect that.

Cargo.toml

@@ -8,3 +8,9 @@ members = [
 ]
 resolver = "2"
 
+[workspace.lints.rust.unexpected_cfgs]
+level = "warn"
+check-cfg = [
+    'cfg(target_os, values("solana"))',
+    'cfg(feature, values("frozen-abi", "no-entrypoint"))',
+]

README.md

@@ -179,7 +179,7 @@ the address and `invoke_signed` to CPI to the system program.
 
 | Language | CU Usage | CU Usage (minus syscalls) |
 | --- | --- | --- |
-| Rust | 3662 | 1162 |
+| Rust | 3698 | 1198 |
 | Zig | 2825 | 325 |
 | C | 3122 | 622 |
 | Rust (pinocchio) | 2816 | 316 |

cpi/Cargo.toml

@@ -7,11 +7,19 @@ edition = "2021"
 test-sbf = []
 
 [dependencies]
-solana-program = "2.0.3"
+solana-account-info = "2.1.0"
+solana-cpi = "2.1.0"
+solana-program = "2.1.0"
+solana-program-entrypoint = "2.1.0"
+solana-program-error = "2.1.0"
+solana-pubkey = "2.1.0"
 
 [dev-dependencies]
-solana-program-test = "2.0.3"
-solana-sdk = "2.0.3"
+solana-program-test = "2.1.0"
+solana-sdk = "2.1.0"
 
 [lib]
 crate-type = ["cdylib", "lib"]
+
+[lints]
+workspace = true

cpi/src/lib.rs

@@ -2,16 +2,16 @@
 #![deny(missing_docs)]
 #![forbid(unsafe_code)]
 
-use solana_program::{
-    account_info::{next_account_info, AccountInfo},
-    entrypoint::ProgramResult,
-    program::invoke_signed,
-    program_error::ProgramError,
-    pubkey::Pubkey,
-    system_instruction,
+use {
+    solana_account_info::{next_account_info, AccountInfo},
+    solana_cpi::invoke_signed,
+    solana_program::system_instruction, // replace with solana_system_interface
+    solana_program_entrypoint::ProgramResult,
+    solana_program_error::ProgramError,
+    solana_pubkey::Pubkey,
 };
 
-solana_program::entrypoint!(process_instruction);
+solana_program_entrypoint::entrypoint!(process_instruction);
 
 /// Amount of bytes of account data to allocate
 pub const SIZE: usize = 42;

cpi/tests/functional.rs

@@ -31,7 +31,7 @@ async fn test_cross_program_invocation() {
         },
     );
 
-    let (mut banks_client, payer, recent_blockhash) = program_test.start().await;
+    let (banks_client, payer, recent_blockhash) = program_test.start().await;
 
     let mut transaction = Transaction::new_with_payer(
         &[Instruction::new_with_bincode(

helloworld/Cargo.toml

@@ -4,11 +4,17 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-solana-program = "2"
+solana-msg = "2.1"
+solana-program-entrypoint = "2.1"
 
 [dev-dependencies]
-solana-program-test = "2"
-solana-sdk = "2"
+solana-instruction = "2.1"
+solana-program-test = "2.1"
+solana-pubkey = "2.1"
+solana-sdk = "2.1"
 
 [lib]
 crate-type = ["cdylib", "lib"]
+
+[lints]
+workspace = true

helloworld/src/lib.rs

@@ -1,4 +1,4 @@
-use solana_program::msg;
+use solana_msg::msg;
 
 #[no_mangle]
 pub extern "C" fn entrypoint(_: *mut u8) -> u64 {
@@ -7,5 +7,5 @@ pub extern "C" fn entrypoint(_: *mut u8) -> u64 {
 }
 #[cfg(target_os = "solana")]
 #[no_mangle]
-fn custom_panic(info: &core::panic::PanicInfo<'_>) {}
-solana_program::custom_heap_default!();
+fn custom_panic(_info: &core::panic::PanicInfo<'_>) {}
+solana_program_entrypoint::custom_heap_default!();

helloworld/tests/functional.rs

@@ -1,18 +1,18 @@
 use {
-    solana_program::instruction::Instruction,
+    solana_instruction::Instruction,
     solana_program_test::{tokio, ProgramTest},
     solana_sdk::{signature::Signer, transaction::Transaction},
 };
 mod program {
-    solana_program::declare_id!("1og1111111111111111111111111111111111111111");
+    solana_pubkey::declare_id!("1og1111111111111111111111111111111111111111");
 }
 fn program_test() -> ProgramTest {
     ProgramTest::new("solana_program_rosetta_helloworld", program::id(), None)
 }
 #[tokio::test]
 async fn call() {
     let pt = program_test();
-    let mut context = pt.start_with_context().await;
+    let context = pt.start_with_context().await;
     let blockhash = context.banks_client.get_latest_blockhash().await.unwrap();
     let transaction = Transaction::new_signed_with_payer(
         &[Instruction {

transfer-lamports/Cargo.toml

@@ -4,15 +4,21 @@ version = "1.0.0"
 edition = "2021"
 
 [features]
-no-entrypoint = []
 test-sbf = []
 
 [dependencies]
-solana-program = "2.0.3"
+solana-account-info = "2.1.0"
+solana-program-entrypoint = "2.1.0"
+solana-program-error = "2.1.0"
+solana-pubkey = "2.1.0"
 
 [dev-dependencies]
-solana-program-test = "2.0.3"
-solana-sdk = "2.0.3"
+solana-instruction = "2.1.0"
+solana-program-test = "2.1.0"
+solana-sdk = "2.1.0"
 
 [lib]
 crate-type = ["cdylib", "lib"]
+
+[lints]
+workspace = true

transfer-lamports/src/entrypoint.rs

@@ -1,14 +1,2 @@
 //! Program entrypoint
 
-#![cfg(not(feature = "no-entrypoint"))]
-
-use solana_program::{account_info::AccountInfo, entrypoint::ProgramResult, pubkey::Pubkey};
-
-solana_program::entrypoint!(process_instruction);
-fn process_instruction(
-    program_id: &Pubkey,
-    accounts: &[AccountInfo],
-    instruction_data: &[u8],
-) -> ProgramResult {
-    crate::processor::process_instruction(program_id, accounts, instruction_data)
-}

transfer-lamports/src/lib.rs

@@ -1,6 +1,35 @@
 //! A program demonstrating the transfer of lamports
 #![deny(missing_docs)]
 #![forbid(unsafe_code)]
+#![allow(clippy::arithmetic_side_effects)]
 
-mod entrypoint;
-pub mod processor;
+use {
+    solana_account_info::{next_account_info, AccountInfo},
+    solana_program_error::ProgramResult,
+    solana_pubkey::Pubkey,
+};
+
+solana_program_entrypoint::entrypoint!(process_instruction);
+
+/// Instruction processor
+pub fn process_instruction(
+    _program_id: &Pubkey,
+    accounts: &[AccountInfo],
+    instruction_data: &[u8],
+) -> ProgramResult {
+    // Create an iterator to safely reference accounts in the slice
+    let account_info_iter = &mut accounts.iter();
+    let transfer_amount = u64::from_le_bytes(instruction_data.try_into().unwrap());
+
+    // As part of the program specification the first account is the source
+    // account and the second is the destination account
+    let source_info = next_account_info(account_info_iter)?;
+    let destination_info = next_account_info(account_info_iter)?;
+
+    // Withdraw five lamports from the source
+    **source_info.try_borrow_mut_lamports()? -= transfer_amount;
+    // Deposit five lamports into the destination
+    **destination_info.try_borrow_mut_lamports()? += transfer_amount;
+
+    Ok(())
+}

transfer-lamports/tests/functional.rs

@@ -1,9 +1,7 @@
 use {
-    solana_program::{
-        instruction::{AccountMeta, Instruction},
-        pubkey::Pubkey,
-    },
+    solana_instruction::{AccountMeta, Instruction},
     solana_program_test::*,
+    solana_pubkey::Pubkey,
     solana_sdk::{account::Account, signature::Signer, transaction::Transaction},
     std::str::FromStr,
 };
@@ -38,7 +36,7 @@ async fn test_lamport_transfer() {
             ..Account::default()
         },
     );
-    let (mut banks_client, payer, recent_blockhash) = program_test.start().await;
+    let (banks_client, payer, recent_blockhash) = program_test.start().await;
 
     let mut transaction = Transaction::new_with_payer(
         &[Instruction::new_with_bincode(