Simplify and generalize implementation of output mode

src/bootstrap/src/lib.rs

@@ -23,7 +23,7 @@
 use std::fs::{self, File};
 use std::io;
 use std::path::{Path, PathBuf};
-use std::process::{Command, Output, Stdio};
+use std::process::{Command, Stdio};
 use std::str;
 use std::sync::OnceLock;
 use std::time::SystemTime;
@@ -41,7 +41,7 @@
 use crate::core::config::{flags, LldMode};
 use crate::core::config::{DryRun, Target};
 use crate::core::config::{LlvmLibunwind, TargetSelection};
-use crate::utils::exec::{BehaviorOnFailure, BootstrapCommand, CommandOutput, OutputMode};
+use crate::utils::exec::{BehaviorOnFailure, BootstrapCommand, CommandOutput};
 use crate::utils::helpers::{self, dir_is_empty, exe, libdir, mtime, output, symlink_dir};
 
 mod core;
@@ -943,18 +943,10 @@ fn run<C: AsMut<BootstrapCommand>>(&self, mut command: C) -> CommandOutput {
 
         self.verbose(|| println!("running: {command:?}"));
 
-        let output: io::Result<Output> = match command.output_mode {
-            OutputMode::Print => command.command.status().map(|status| Output {
-                status,
-                stdout: vec![],
-                stderr: vec![],
-            }),
-            OutputMode::CaptureAll => command.command.output(),
-            OutputMode::CaptureStdout => {
-                command.command.stderr(Stdio::inherit());
-                command.command.output()
-            }
-        };
+        command.command.stdout(command.stdout.stdio());
+        command.command.stderr(command.stderr.stdio());
+
+        let output = command.command.output();
 
         use std::fmt::Write;
 
@@ -973,16 +965,15 @@ fn run<C: AsMut<BootstrapCommand>>(&self, mut command: C) -> CommandOutput {
                 .unwrap();
 
                 let output: CommandOutput = output.into();
-                // If the output mode is OutputMode::Print, the output has already been printed to
-                // stdout/stderr, and we thus don't have anything captured to print anyway.
-                if matches!(command.output_mode, OutputMode::CaptureAll | OutputMode::CaptureStdout)
-                {
-                    writeln!(message, "\nSTDOUT ----\n{}", output.stdout().trim()).unwrap();
 
-                    // Stderr is added to the message only if it was captured
-                    if matches!(command.output_mode, OutputMode::CaptureAll) {
-                        writeln!(message, "\nSTDERR ----\n{}", output.stderr().trim()).unwrap();
-                    }
+                // If the output mode is OutputMode::Capture, we can now print the output.
+                // If it is OutputMode::Print, then the output has already been printed to
+                // stdout/stderr, and we thus don't have anything captured to print anyway.
+                if command.stdout.captures() {
+                    writeln!(message, "\nSTDOUT ----\n{}", output.stdout().trim()).unwrap();
+                }
+                if command.stderr.captures() {
+                    writeln!(message, "\nSTDERR ----\n{}", output.stderr().trim()).unwrap();
                 }
                 output
             }

src/bootstrap/src/utils/exec.rs

@@ -1,6 +1,6 @@
 use std::ffi::OsStr;
 use std::path::Path;
-use std::process::{Command, CommandArgs, CommandEnvs, ExitStatus, Output};
+use std::process::{Command, CommandArgs, CommandEnvs, ExitStatus, Output, Stdio};
 
 /// What should be done when the command fails.
 #[derive(Debug, Copy, Clone)]
@@ -13,19 +13,30 @@ pub enum BehaviorOnFailure {
     Ignore,
 }
 
-/// How should the output of the command be handled (whether it should be captured or printed).
+/// How should the output of a specific stream of the command (stdout/stderr) be handled
+/// (whether it should be captured or printed).
 #[derive(Debug, Copy, Clone)]
 pub enum OutputMode {
-    /// Prints the stdout/stderr of the command to stdout/stderr of bootstrap (by inheriting these
-    /// streams).
-    /// Corresponds to calling `cmd.status()`.
+    /// Prints the stream by inheriting it from the bootstrap process.
     Print,
-    /// Captures the stdout and stderr of the command into memory.
-    /// Corresponds to calling `cmd.output()`.
-    CaptureAll,
-    /// Captures the stdout of the command into memory, inherits stderr.
-    /// Corresponds to calling `cmd.output()`.
-    CaptureStdout,
+    /// Captures the stream into memory.
+    Capture,
+}
+
+impl OutputMode {
+    pub fn captures(&self) -> bool {
+        match self {
+            OutputMode::Print => false,
+            OutputMode::Capture => true,
+        }
+    }
+
+    pub fn stdio(&self) -> Stdio {
+        match self {
+            OutputMode::Print => Stdio::inherit(),
+            OutputMode::Capture => Stdio::piped(),
+        }
+    }
 }
 
 /// Wrapper around `std::process::Command`.
@@ -45,7 +56,8 @@ pub enum OutputMode {
 pub struct BootstrapCommand {
     pub command: Command,
     pub failure_behavior: BehaviorOnFailure,
-    pub output_mode: OutputMode,
+    pub stdout: OutputMode,
+    pub stderr: OutputMode,
     // Run the command even during dry run
     pub run_always: bool,
 }
@@ -113,14 +125,14 @@ pub fn run_always(&mut self) -> &mut Self {
         self
     }
 
-    /// Capture the output of the command, do not print it.
+    /// Capture all output of the command, do not print it.
     pub fn capture(self) -> Self {
-        Self { output_mode: OutputMode::CaptureAll, ..self }
+        Self { stdout: OutputMode::Capture, stderr: OutputMode::Capture, ..self }
     }
 
     /// Capture stdout of the command, do not print it.
     pub fn capture_stdout(self) -> Self {
-        Self { output_mode: OutputMode::CaptureStdout, ..self }
+        Self { stdout: OutputMode::Capture, ..self }
     }
 }
 
@@ -137,7 +149,8 @@ fn from(command: Command) -> Self {
         Self {
             command,
             failure_behavior: BehaviorOnFailure::Exit,
-            output_mode: OutputMode::Print,
+            stdout: OutputMode::Print,
+            stderr: OutputMode::Print,
             run_always: false,
         }
     }