Trace execution of bootstrap commands

src/bootstrap/src/core/build_steps/compile.rs

@@ -30,7 +30,7 @@ use crate::utils::exec::command;
 use crate::utils::helpers::{
     exe, get_clang_cl_resource_dir, is_debug_info, is_dylib, symlink_dir, t, up_to_date,
 };
-use crate::{CLang, Compiler, DependencyType, GitRepo, LLVM_TOOLS, Mode};
+use crate::{CLang, Compiler, DependencyType, GitRepo, LLVM_TOOLS, Mode, trace_cmd};
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Std {
@@ -2234,6 +2234,9 @@ pub fn stream_cargo(
     cb: &mut dyn FnMut(CargoMessage<'_>),
 ) -> bool {
     let mut cmd = cargo.into_cmd();
+
+    let _run_span = trace_cmd!(cmd);
+
     let cargo = cmd.as_command_mut();
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.

src/bootstrap/src/lib.rs

@@ -905,6 +905,8 @@ impl Build {
             return CommandOutput::default();
         }
 
+        let _run_span = trace_cmd!(command);
+
         let created_at = command.get_created_location();
         let executed_at = std::panic::Location::caller();
 

src/bootstrap/src/utils/exec.rs

@@ -329,3 +329,25 @@ impl Default for CommandOutput {
         }
     }
 }
+
+/// Helper trait to format both Command and BootstrapCommand as a short execution line,
+/// without all the other details (e.g. environment variables).
+#[allow(unused)]
+pub trait FormatShortCmd {
+    fn format_short_cmd(&self) -> String;
+}
+
+impl FormatShortCmd for BootstrapCommand {
+    fn format_short_cmd(&self) -> String {
+        self.command.format_short_cmd()
+    }
+}
+
+impl FormatShortCmd for Command {
+    fn format_short_cmd(&self) -> String {
+        let program = Path::new(self.get_program());
+        let mut line = vec![program.file_name().unwrap().to_str().unwrap()];
+        line.extend(self.get_args().into_iter().map(|arg| arg.to_str().unwrap()));
+        line.join(" ")
+    }
+}

src/bootstrap/src/utils/helpers.rs

@@ -13,11 +13,11 @@ use std::{env, fs, io, str};
 use build_helper::util::fail;
 use object::read::archive::ArchiveFile;
 
-use crate::LldMode;
 use crate::core::builder::Builder;
 use crate::core::config::{Config, TargetSelection};
 use crate::utils::exec::{BootstrapCommand, command};
 pub use crate::utils::shared_helpers::{dylib_path, dylib_path_var};
+use crate::{LldMode, trace_cmd};
 
 #[cfg(test)]
 mod tests;
@@ -265,6 +265,8 @@ pub fn make(host: &str) -> PathBuf {
 
 #[track_caller]
 pub fn output(cmd: &mut Command) -> String {
+    let _run_span = trace_cmd!(cmd);
+
     let output = match cmd.stderr(Stdio::inherit()).output() {
         Ok(status) => status,
         Err(e) => fail(&format!("failed to execute command: {cmd:?}\nERROR: {e}")),

src/bootstrap/src/utils/tracing.rs

@@ -47,3 +47,22 @@ macro_rules! error {
         ::tracing::error!($($tokens)*)
     }
 }
+
+#[macro_export]
+macro_rules! trace_cmd {
+    ($cmd:expr) => {
+        {
+            #[allow(unused)]
+            use $crate::utils::exec::FormatShortCmd;
+
+            #[cfg(feature = "tracing")]
+            ::tracing::span!(
+                target: "COMMAND",
+                ::tracing::Level::TRACE,
+                "executing command",
+                cmd = $cmd.format_short_cmd(),
+                full_cmd = ?$cmd
+            ).entered()
+        }
+    };
+}