Proposal: log binary data for Solidity

The program_id is not needed on "Program return data: " because it
always preceeded by the program invoke message, so no need to repeat
the program id. Also rename this to "Program return: " since "data"
is redundant.

programs/bpf/rust/log_data/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "solana-bpf-rust-log-data"
+version = "1.8.0"
+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/"
+documentation = "https://docs.rs/solana-bpf-rust-log-data"
+edition = "2018"
+
+[dependencies]
+solana-program = { path = "../../../../sdk/program", version = "=1.8.0" }
+
+[features]
+default = ["program"]
+program = []
+
+[lib]
+crate-type = ["lib", "cdylib"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

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

@@ -0,0 +1,24 @@
+//! @brief Example Rust-based BPF program that uses sol_log_data syscall
+
+#![cfg(feature = "program")]
+
+use solana_program::{
+    account_info::AccountInfo, entrypoint, entrypoint::ProgramResult, log::sol_log_data,
+    program::set_return_data, pubkey::Pubkey,
+};
+
+entrypoint!(process_instruction);
+#[allow(clippy::cognitive_complexity)]
+fn process_instruction(
+    _program_id: &Pubkey,
+    _accounts: &[AccountInfo],
+    instruction_data: &[u8],
+) -> ProgramResult {
+    let fields: Vec<&[u8]> = instruction_data.split(|e| *e == 0).collect();
+
+    set_return_data(&[0x08, 0x01, 0x44]);
+
+    sol_log_data(&fields);
+
+    Ok(())
+}