From f289a8762837a6b4e5603278c0098ec327ec449e Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Tue, 3 Nov 2020 10:43:17 -0500
Subject: [PATCH] Print a summary of which test suite failed

Especially on CI, where cross-compiling is common and single builder may end up
with multiple hosts and multiple targets, it can be annoying to scroll back to
the nearest start of test marker. This prints out a summary of the test suite
being run directly in compiletest.
---
 src/bootstrap/test.rs                     |  1 +
 src/tools/compiletest/src/common.rs       |  4 +++
 src/tools/compiletest/src/header/tests.rs |  1 +
 src/tools/compiletest/src/main.rs         | 32 +++++++++++++++++++++--
 4 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 6c2c05ac7197e..84d69e52de635 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -1039,6 +1039,7 @@ note: if you're sure you want to do this, please open an issue as to why. In the
         cmd.arg("--src-base").arg(builder.src.join("src/test").join(suite));
         cmd.arg("--build-base").arg(testdir(builder, compiler.host).join(suite));
         cmd.arg("--stage-id").arg(format!("stage{}-{}", compiler.stage, target));
+        cmd.arg("--suite").arg(suite);
         cmd.arg("--mode").arg(mode);
         cmd.arg("--target").arg(target.rustc_target_arg());
         cmd.arg("--host").arg(&*compiler.host.triple);
diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index 2f832b53a9039..24ef98cd784d8 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -224,6 +224,10 @@ pub struct Config {
     /// The test mode, compile-fail, run-fail, ui
     pub mode: Mode,
 
+    /// The test suite (essentially which directory is running, but without the
+    /// directory prefix such as src/test)
+    pub suite: String,
+
     /// The debugger to use in debuginfo mode. Unset otherwise.
     pub debugger: Option<Debugger>,
 
diff --git a/src/tools/compiletest/src/header/tests.rs b/src/tools/compiletest/src/header/tests.rs
index 1f82b137ee6cf..4bcbd89f09510 100644
--- a/src/tools/compiletest/src/header/tests.rs
+++ b/src/tools/compiletest/src/header/tests.rs
@@ -39,6 +39,7 @@ fn config() -> Config {
     let args = &[
         "compiletest",
         "--mode=ui",
+        "--suite=ui",
         "--compile-lib-path=",
         "--run-lib-path=",
         "--rustc-path=",
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 2b2a6cfa8bd6f..2b167ac8e9fb2 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -70,6 +70,12 @@ pub fn parse_config(args: Vec<String>) -> Config {
             "compile-fail | run-fail | run-pass-valgrind | pretty | debug-info | codegen | rustdoc \
              codegen-units | incremental | run-make | ui | js-doc-test | mir-opt | assembly",
         )
+        .reqopt(
+            "",
+            "suite",
+            "which suite of compile tests to run. used for nicer error reporting.",
+            "SUITE",
+        )
         .optopt(
             "",
             "pass",
@@ -201,6 +207,7 @@ pub fn parse_config(args: Vec<String>) -> Config {
         build_base: opt_path(matches, "build-base"),
         stage_id: matches.opt_str("stage-id").unwrap(),
         mode: matches.opt_str("mode").unwrap().parse().expect("invalid mode"),
+        suite: matches.opt_str("suite").unwrap(),
         debugger: None,
         run_ignored,
         filter: matches.free.first().cloned(),
@@ -340,7 +347,7 @@ pub fn run_tests(config: Config) {
             configs.extend(configure_lldb(&config));
         }
     } else {
-        configs.push(config);
+        configs.push(config.clone());
     };
 
     let mut tests = Vec::new();
@@ -351,11 +358,32 @@ pub fn run_tests(config: Config) {
     let res = test::run_tests_console(&opts, tests);
     match res {
         Ok(true) => {}
-        Ok(false) => panic!("Some tests failed"),
+        Ok(false) => {
+            // We want to report that the tests failed, but we also want to give
+            // some indication of just what tests we were running. Especially on
+            // CI, where there can be cross-compiled tests for a lot of
+            // architectures, without this critical information it can be quite
+            // easy to miss which tests failed, and as such fail to reproduce
+            // the failure locally.
+
+            eprintln!(
+                "Some tests failed in compiletest suite={}{} mode={} host={} target={}",
+                config.suite,
+                config.compare_mode.map(|c| format!(" compare_mode={:?}", c)).unwrap_or_default(),
+                config.mode,
+                config.host,
+                config.target
+            );
+
+            std::process::exit(1);
+        }
         Err(e) => {
             // We don't know if tests passed or not, but if there was an error
             // during testing we don't want to just suceeed (we may not have
             // tested something), so fail.
+            //
+            // This should realistically "never" happen, so don't try to make
+            // this a pretty error message.
             panic!("I/O failure during tests: {:?}", e);
         }
     }