diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs index 54a331a490444..0cd9e36a92771 100644 --- a/compiler/rustc_driver_impl/src/lib.rs +++ b/compiler/rustc_driver_impl/src/lib.rs @@ -1500,13 +1500,31 @@ pub fn init_rustc_env_logger(early_dcx: &EarlyDiagCtxt) { /// This allows tools to enable rust logging without having to magically match rustc's /// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to choose -/// the values directly rather than having to set an environment variable. +/// the logger config directly rather than having to set an environment variable. pub fn init_logger(early_dcx: &EarlyDiagCtxt, cfg: rustc_log::LoggerConfig) { if let Err(error) = rustc_log::init_logger(cfg) { early_dcx.early_fatal(error.to_string()); } } +/// This allows tools to enable rust logging without having to magically match rustc's +/// tracing crate version. In contrast to `init_rustc_env_logger`, it allows you to +/// choose the logger config directly rather than having to set an environment variable. +/// Moreover, in contrast to `init_logger`, it allows you to add a custom tracing layer +/// via `build_subscriber`, for example `|| Registry::default().with(custom_layer)`. +pub fn init_logger_with_additional_layer( + early_dcx: &EarlyDiagCtxt, + cfg: rustc_log::LoggerConfig, + build_subscriber: F, +) where + F: FnOnce() -> T, + T: rustc_log::BuildSubscriberRet, +{ + if let Err(error) = rustc_log::init_logger_with_additional_layer(cfg, build_subscriber) { + early_dcx.early_fatal(error.to_string()); + } +} + /// Install our usual `ctrlc` handler, which sets [`rustc_const_eval::CTRL_C_RECEIVED`]. /// Making this handler optional lets tools can install a different handler, if they wish. pub fn install_ctrlc_handler() { diff --git a/compiler/rustc_log/src/lib.rs b/compiler/rustc_log/src/lib.rs index 1bb502ca3d062..df648bbd48951 100644 --- a/compiler/rustc_log/src/lib.rs +++ b/compiler/rustc_log/src/lib.rs @@ -43,6 +43,7 @@ use tracing_subscriber::filter::{Directive, EnvFilter, LevelFilter}; use tracing_subscriber::fmt::FmtContext; use tracing_subscriber::fmt::format::{self, FormatEvent, FormatFields}; use tracing_subscriber::layer::SubscriberExt; +use tracing_subscriber::{Layer, Registry}; /// The values of all the environment variables that matter for configuring a logger. /// Errors are explicitly preserved so that we can share error handling. @@ -72,6 +73,36 @@ impl LoggerConfig { /// Initialize the logger with the given values for the filter, coloring, and other options env variables. pub fn init_logger(cfg: LoggerConfig) -> Result<(), Error> { + init_logger_with_additional_layer(cfg, || Registry::default()) +} + +/// Trait alias for the complex return type of `build_subscriber` in +/// [init_logger_with_additional_layer]. A [Registry] with any composition of [tracing::Subscriber]s +/// (e.g. `Registry::default().with(custom_layer)`) should be compatible with this type. +/// Having an alias is also useful so rustc_driver_impl does not need to explicitly depend on +/// `tracing_subscriber`. +pub trait BuildSubscriberRet: + tracing::Subscriber + for<'span> tracing_subscriber::registry::LookupSpan<'span> + Send + Sync +{ +} + +impl< + T: tracing::Subscriber + for<'span> tracing_subscriber::registry::LookupSpan<'span> + Send + Sync, +> BuildSubscriberRet for T +{ +} + +/// Initialize the logger with the given values for the filter, coloring, and other options env variables. +/// Additionally add a custom layer to collect logging and tracing events via `build_subscriber`, +/// for example: `|| Registry::default().with(custom_layer)`. +pub fn init_logger_with_additional_layer( + cfg: LoggerConfig, + build_subscriber: F, +) -> Result<(), Error> +where + F: FnOnce() -> T, + T: BuildSubscriberRet, +{ let filter = match cfg.filter { Ok(env) => EnvFilter::new(env), _ => EnvFilter::default().add_directive(Directive::from(LevelFilter::WARN)), @@ -124,7 +155,7 @@ pub fn init_logger(cfg: LoggerConfig) -> Result<(), Error> { Err(_) => {} // no wraptree } - let subscriber = tracing_subscriber::Registry::default().with(filter).with(layer); + let subscriber = build_subscriber().with(layer.with_filter(filter)); match cfg.backtrace { Ok(backtrace_target) => { let fmt_layer = tracing_subscriber::fmt::layer()