Add BPf loader finalize test via inner instruction (#15708)

programs/bpf/rust/finalize/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "solana-bpf-rust-finalize"
+version = "1.6.0"
+description = "Solana BPF test program written in Rust"
+authors = ["Solana Maintainers <maintainers@solana.foundation>"]
+repository = "https://github.com/solana-labs/solana"
+license = "Apache-2.0"
+homepage = "https://solana.com/"
+edition = "2018"
+
+[dependencies]
+solana-program = { path = "../../../../sdk/program", version = "1.6.0" }
+
+[lib]
+crate-type = ["cdylib"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

programs/bpf/rust/finalize/Xargo.toml

@@ -0,0 +1,2 @@
+[target.bpfel-unknown-unknown.dependencies.std]
+features = []

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

@@ -0,0 +1,25 @@
+//! @brief Example Rust-based BPF sanity program that finalizes a BPF program
+
+#![allow(unreachable_code)]
+
+extern crate solana_program;
+use solana_program::{
+    account_info::AccountInfo, bpf_loader, entrypoint, entrypoint::ProgramResult,
+    loader_instruction, msg, program::invoke, pubkey::Pubkey,
+};
+
+entrypoint!(process_instruction);
+fn process_instruction(
+    _program_id: &Pubkey,
+    accounts: &[AccountInfo],
+    _instruction_data: &[u8],
+) -> ProgramResult {
+    msg!("Finalize a program");
+    invoke(
+        &loader_instruction::finalize(&accounts[0].key.clone(), &bpf_loader::id()),
+        accounts,
+    )?;
+    msg!("check executable");
+    assert!(accounts[0].executable);
+    Ok(())
+}