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.

sdk/program/Cargo.toml

@@ -36,10 +36,12 @@ thiserror = "1.0"
 
 [target.'cfg(not(target_arch = "bpf"))'.dependencies]
 bitflags = "1.3.1"
+base64 = "0.13"
 curve25519-dalek = "3.0.0"
 libsecp256k1 = "0.6.0"
 rand = "0.7.0"
 solana-logger = { path = "../../logger", version = "=1.8.0" }
+itertools = "0.10.1"
 
 [dev-dependencies]
 static_assertions = "1.1.0"

sdk/program/src/log.rs

@@ -85,6 +85,23 @@ extern "C" {
     fn sol_log_64_(arg1: u64, arg2: u64, arg3: u64, arg4: u64, arg5: u64);
 }
 
+/// Print some slices as base64
+///
+/// @param data - The slices to print
+pub fn sol_log_data(data: &[&[u8]]) {
+    #[cfg(target_arch = "bpf")]
+    {
+        extern "C" {
+            fn sol_log_data(data: *const u8, data_len: u64);
+        }
+
+        unsafe { sol_log_data(data as *const _ as *const u8, data.len() as u64) };
+    }
+
+    #[cfg(not(target_arch = "bpf"))]
+    crate::program_stubs::sol_log_data(data);
+}
+
 /// Print the hexadecimal representation of a slice
 ///
 /// @param slice - The array to print

sdk/program/src/program_stubs.rs

@@ -6,6 +6,7 @@ use crate::{
     account_info::AccountInfo, entrypoint::ProgramResult, instruction::Instruction,
     program_error::UNSUPPORTED_SYSVAR, pubkey::Pubkey,
 };
+use itertools::Itertools;
 use std::sync::{Arc, RwLock};
 
 lazy_static::lazy_static! {
@@ -51,7 +52,7 @@ pub trait SyscallStubs: Sync + Send {
     unsafe fn sol_memcpy(&self, dst: *mut u8, src: *const u8, n: usize) {
         // cannot be overlapping
         if dst as usize + n > src as usize && src as usize > dst as usize {
-            panic!("memcpy does not support oveerlapping regions");
+            panic!("memcpy does not support overlapping regions");
         }
         std::ptr::copy_nonoverlapping(src, dst, n as usize);
     }
@@ -84,6 +85,9 @@ pub trait SyscallStubs: Sync + Send {
         None
     }
     fn sol_set_return_data(&mut self, _data: &[u8]) {}
+    fn sol_log_data(&self, fields: &[&[u8]]) {
+        println!("data: {}", fields.iter().map(base64::encode).join(" "));
+    }
 }
 
 struct DefaultSyscallStubs {}
@@ -165,3 +169,7 @@ pub(crate) fn sol_get_return_data() -> Option<(Pubkey, Vec<u8>)> {
 pub(crate) fn sol_set_return_data(data: &[u8]) {
     SYSCALL_STUBS.write().unwrap().sol_set_return_data(data)
 }
+
+pub(crate) fn sol_log_data(data: &[&[u8]]) {
+    SYSCALL_STUBS.read().unwrap().sol_log_data(data)
+}