render compiletest output with render_tests

3 files changed, 224 insertions, 5 deletions

diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index f4abdf1cc57..f10d640a209 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -55,6 +55,7 @@ mod format;
 mod install;
 mod metadata;
 mod native;
+mod render_tests;
 mod run;
 mod sanity;
 mod setup;
diff --git a/src/bootstrap/render_tests.rs b/src/bootstrap/render_tests.rs
new file mode 100644
index 00000000000..6a0600fb708
--- /dev/null
+++ b/src/bootstrap/render_tests.rs
@@ -0,0 +1,220 @@
+//! This module renders the JSON output of libtest into a human-readable form, trying to be as
+//! similar to libtest's native output as possible.
+//!
+//! This is needed because we need to use libtest in JSON mode to extract granluar information
+//! about the executed tests. Doing so suppresses the human-readable output, and (compared to Cargo
+//! and rustc) libtest doesn't include the rendered human-readable output as a JSON field. We had
+//! to reimplement all the rendering logic in this module because of that.
+
+use crate::builder::Builder;
+use std::io::{BufRead, BufReader};
+use std::process::{ChildStdout, Command, Stdio};
+use std::time::Duration;
+
+pub(crate) fn try_run_tests(builder: &Builder<'_>, cmd: &mut Command) -> bool {
+    if builder.config.dry_run() {
+        return true;
+    }
+
+    if !run_tests(builder, cmd) {
+        if builder.fail_fast {
+            crate::detail_exit(1);
+        } else {
+            let mut failures = builder.delayed_failures.borrow_mut();
+            failures.push(format!("{cmd:?}"));
+            false
+        }
+    } else {
+        true
+    }
+}
+
+fn run_tests(builder: &Builder<'_>, cmd: &mut Command) -> bool {
+    cmd.stdout(Stdio::piped());
+
+    builder.verbose(&format!("running: {cmd:?}"));
+
+    let mut process = cmd.spawn().unwrap();
+    let stdout = process.stdout.take().unwrap();
+    let handle = std::thread::spawn(move || Renderer::new(stdout).render_all());
+
+    let result = process.wait().unwrap();
+    handle.join().expect("test formatter thread failed");
+
+    if !result.success() && builder.is_verbose() {
+        println!(
+            "\n\ncommand did not execute successfully: {cmd:?}\n\
+             expected success, got: {result}"
+        );
+    }
+
+    result.success()
+}
+
+struct Renderer {
+    stdout: BufReader<ChildStdout>,
+    failures: Vec<TestOutcome>,
+}
+
+impl Renderer {
+    fn new(stdout: ChildStdout) -> Self {
+        Self { stdout: BufReader::new(stdout), failures: Vec::new() }
+    }
+
+    fn render_all(mut self) {
+        let mut line = String::new();
+        loop {
+            line.clear();
+            match self.stdout.read_line(&mut line) {
+                Ok(_) => {}
+                Err(err) if err.kind() == std::io::ErrorKind::UnexpectedEof => break,
+                Err(err) => panic!("failed to read output of test runner: {err}"),
+            }
+            if line.is_empty() {
+                break;
+            }
+
+            self.render_message(match serde_json::from_str(&line) {
+                Ok(parsed) => parsed,
+                Err(err) => {
+                    panic!("failed to parse libtest json output; error: {err}, line: {line:?}");
+                }
+            });
+        }
+    }
+
+    fn render_test_outcome(&self, outcome: Outcome<'_>, test: &TestOutcome) {
+        // TODO: add support for terse output
+        self.render_test_outcome_verbose(outcome, test);
+    }
+
+    fn render_test_outcome_verbose(&self, outcome: Outcome<'_>, test: &TestOutcome) {
+        if let Some(exec_time) = test.exec_time {
+            println!(
+                "test {} ... {outcome} (in {:.2?})",
+                test.name,
+                Duration::from_secs_f64(exec_time)
+            );
+        } else {
+            println!("test {} ... {outcome}", test.name);
+        }
+    }
+
+    fn render_suite_outcome(&self, outcome: Outcome<'_>, suite: &SuiteOutcome) {
+        if !self.failures.is_empty() {
+            println!("\nfailures:\n");
+            for failure in &self.failures {
+                if let Some(stdout) = &failure.stdout {
+                    println!("---- {} stdout ----", failure.name);
+                    println!("{stdout}");
+                }
+            }
+
+            println!("\nfailures:");
+            for failure in &self.failures {
+                println!("    {}", failure.name);
+            }
+        }
+
+        println!(
+            "\ntest result: {outcome}. {} passed; {} failed; {} ignored; {} measured; \
+             {} filtered out; finished in {:.2?}\n",
+            suite.passed,
+            suite.failed,
+            suite.ignored,
+            suite.measured,
+            suite.filtered_out,
+            Duration::from_secs_f64(suite.exec_time)
+        );
+    }
+
+    fn render_message(&mut self, message: Message) {
+        match message {
+            Message::Suite(SuiteMessage::Started { test_count }) => {
+                println!("\nrunning {test_count} tests");
+            }
+            Message::Suite(SuiteMessage::Ok(outcome)) => {
+                self.render_suite_outcome(Outcome::Ok, &outcome);
+            }
+            Message::Suite(SuiteMessage::Failed(outcome)) => {
+                self.render_suite_outcome(Outcome::Failed, &outcome);
+            }
+            Message::Test(TestMessage::Ok(outcome)) => {
+                self.render_test_outcome(Outcome::Ok, &outcome);
+            }
+            Message::Test(TestMessage::Ignored(outcome)) => {
+                self.render_test_outcome(
+                    Outcome::Ignored { reason: outcome.reason.as_deref() },
+                    &outcome,
+                );
+            }
+            Message::Test(TestMessage::Failed(outcome)) => {
+                self.render_test_outcome(Outcome::Failed, &outcome);
+                self.failures.push(outcome);
+            }
+            Message::Test(TestMessage::Started) => {} // Not useful
+            Message::Test(TestMessage::Bench) => todo!("benchmarks are not supported yet"),
+        }
+    }
+}
+
+enum Outcome<'a> {
+    Ok,
+    Failed,
+    Ignored { reason: Option<&'a str> },
+}
+
+impl std::fmt::Display for Outcome<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Outcome::Ok => f.write_str("ok"),
+            Outcome::Failed => f.write_str("FAILED"),
+            Outcome::Ignored { reason: None } => f.write_str("ignored"),
+            Outcome::Ignored { reason: Some(reason) } => write!(f, "ignored, {reason}"),
+        }
+    }
+}
+
+#[derive(serde_derive::Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+enum Message {
+    Suite(SuiteMessage),
+    Test(TestMessage),
+}
+
+#[derive(serde_derive::Deserialize)]
+#[serde(tag = "event", rename_all = "snake_case")]
+enum SuiteMessage {
+    Ok(SuiteOutcome),
+    Failed(SuiteOutcome),
+    Started { test_count: usize },
+}
+
+#[derive(serde_derive::Deserialize)]
+struct SuiteOutcome {
+    passed: usize,
+    failed: usize,
+    ignored: usize,
+    measured: usize,
+    filtered_out: usize,
+    exec_time: f64,
+}
+
+#[derive(serde_derive::Deserialize)]
+#[serde(tag = "event", rename_all = "snake_case")]
+enum TestMessage {
+    Ok(TestOutcome),
+    Failed(TestOutcome),
+    Ignored(TestOutcome),
+    // Ignored messages:
+    Bench,
+    Started,
+}
+
+#[derive(serde_derive::Deserialize)]
+struct TestOutcome {
+    name: String,
+    exec_time: Option<f64>,
+    stdout: Option<String>,
+    reason: Option<String>,
+}
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index b4f1506dc8f..1576326dfb0 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1616,9 +1616,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
             cmd.arg("--verbose");
         }
 
-        if !builder.config.verbose_tests {
-            cmd.arg("--quiet");
-        }
+        cmd.arg("--json");
 
         let mut llvm_components_passed = false;
         let mut copts_passed = false;
@@ -1769,7 +1767,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
             suite, mode, &compiler.host, target
         ));
         let _time = util::timeit(&builder);
-        try_run(builder, &mut cmd);
+        crate::render_tests::try_run_tests(builder, &mut cmd);
 
         if let Some(compare_mode) = compare_mode {
             cmd.arg("--compare-mode").arg(compare_mode);
@@ -1778,7 +1776,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
                 suite, mode, compare_mode, &compiler.host, target
             ));
             let _time = util::timeit(&builder);
-            try_run(builder, &mut cmd);
+            crate::render_tests::try_run_tests(builder, &mut cmd);
         }
     }
 }