chore: conservatively use log::info instead of println for some expre…

…ssions (#3766)

# Description

If you want to see info level logs, you can do `NOIR_LOG=info nargo
compile` by default if that environment variable is not set, then it
will only print out error level logs

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*



## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [ ] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

---------

Co-authored-by: Tom French <[email protected]>

Cargo.toml

@@ -120,6 +120,7 @@ const_format = "0.2.30"
 num-bigint = "0.4"
 num-traits = "0.2"
 similar-asserts = "1.5.0"
+log = "0.4.17"
 
 [profile.dev]
 # This is required to be able to run `cargo test` in acvm_js due to the `locals exceeds maximum` error.

acvm-repo/acvm_js/Cargo.toml

@@ -26,9 +26,9 @@ wasm-bindgen-futures.workspace = true
 console_error_panic_hook.workspace = true
 gloo-utils.workspace = true
 js-sys.workspace = true
+log.workspace = true
 
 serde = { version = "1.0.136", features = ["derive"] }
-log = "0.4.17"
 wasm-logger = "0.2.0"
 const-str = "0.5.5"
 

compiler/noirc_evaluator/src/ssa/opt/flatten_cfg.rs

@@ -935,7 +935,6 @@ mod test {
         // }
         let ssa = ssa.flatten_cfg();
         let main = ssa.main();
-        println!("{ssa}");
         assert_eq!(main.reachable_blocks().len(), 1);
 
         let store_count = count_instruction(main, |ins| matches!(ins, Instruction::Store { .. }));

compiler/wasm/Cargo.toml

@@ -24,8 +24,8 @@ js-sys.workspace = true
 cfg-if.workspace = true
 console_error_panic_hook.workspace = true
 gloo-utils.workspace = true
+log.workspace = true
 
-log = "0.4.17"
 wasm-logger = "0.2.0"
 
 # This is an unused dependency, we are adding it

tooling/backend_interface/Cargo.toml

@@ -16,6 +16,7 @@ thiserror.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 bb_abstraction_leaks.workspace = true
+log.workspace = true
 
 tempfile = "3.6.0"
 

tooling/backend_interface/src/lib.rs

@@ -116,15 +116,15 @@ impl Backend {
 
                 // If version doesn't match then download the correct version.
                 Ok(version_string) => {
-                    println!("`{ACVM_BACKEND_BARRETENBERG}` version `{version_string}` is different from expected `{BB_VERSION}`. Downloading expected version...");
+                    log::warn!("`{ACVM_BACKEND_BARRETENBERG}` version `{version_string}` is different from expected `{BB_VERSION}`. Downloading expected version...");
                     let bb_url = std::env::var("BB_BINARY_URL")
                         .unwrap_or_else(|_| bb_abstraction_leaks::BB_DOWNLOAD_URL.to_owned());
                     download_backend(&bb_url, binary_path)?;
                 }
 
                 // If `bb` fails to report its version, then attempt to fix it by re-downloading the binary.
                 Err(_) => {
-                    println!("Could not determine version of `{ACVM_BACKEND_BARRETENBERG}`. Downloading expected version...");
+                    log::warn!("Could not determine version of `{ACVM_BACKEND_BARRETENBERG}`. Downloading expected version...");
                     let bb_url = std::env::var("BB_BINARY_URL")
                         .unwrap_or_else(|_| bb_abstraction_leaks::BB_DOWNLOAD_URL.to_owned());
                     download_backend(&bb_url, binary_path)?;

tooling/backend_interface/src/proof_system.rs

@@ -43,7 +43,7 @@ impl Backend {
         if let Ok(backend_info) = self.get_backend_info() {
             (backend_info.0, backend_info.1)
         } else {
-            println!("No valid backend found, defaulting to Plonk with width 3 and all opcodes supported");
+            log::warn!("No valid backend found, defaulting to Plonk with width 3 and all opcodes supported");
             (Language::PLONKCSat { width: 3 }, BackendOpcodeSupport::all())
         }
     }

tooling/nargo_cli/Cargo.toml

@@ -46,6 +46,7 @@ hex.workspace = true
 similar-asserts.workspace = true
 termcolor = "1.1.2"
 color-eyre = "0.6.2"
+env_logger = "0.9.0"
 tokio = { version = "1.0", features = ["io-std"] }
 
 # Backends

tooling/nargo_cli/src/main.rs

@@ -12,10 +12,14 @@ mod cli;
 mod errors;
 
 use color_eyre::config::HookBuilder;
+use env_logger::{Builder, Env};
 
 const PANIC_MESSAGE: &str = "This is a bug. We may have already fixed this in newer versions of Nargo so try searching for similar issues at https://github.com/noir-lang/noir/issues/.\nIf there isn't an open issue for this bug, consider opening one at https://github.com/noir-lang/noir/issues/new?labels=bug&template=bug_report.yml";
 
 fn main() {
+    let env = Env::default().filter_or("NOIR_LOG", "error"); // Default to 'error' if NOIR_LOG is not set
+    Builder::from_env(env).init();
+
     // Register a panic hook to display more readable panic messages to end-users
     let (panic_hook, _) =
         HookBuilder::default().display_env_section(false).panic_section(PANIC_MESSAGE).into_hooks();