From d1d44d44f15f32ea4c53abc2dbb35bd8304e582e Mon Sep 17 00:00:00 2001
From: Zalathar <Zalathar@users.noreply.github.com>
Date: Sat, 2 Aug 2025 12:57:30 +1000
Subject: [PATCH] Consolidate all `ProcRes` unwinds into one code path

---
 src/tools/compiletest/src/runtest.rs          | 50 ++++++++++---------
 src/tools/compiletest/src/runtest/rustdoc.rs  |  4 +-
 .../compiletest/src/runtest/rustdoc_json.rs   |  2 +-
 3 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 12a5e55e77b4..b1f8e461aef8 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -354,13 +354,10 @@ impl<'test> TestCx<'test> {
             }
         } else {
             if proc_res.status.success() {
-                {
-                    self.error(&format!("{} test did not emit an error", self.config.mode));
-                    if self.config.mode == crate::common::TestMode::Ui {
-                        println!("note: by default, ui tests are expected not to compile");
-                    }
-                    proc_res.fatal(None, || ());
-                };
+                let err = &format!("{} test did not emit an error", self.config.mode);
+                let extra_note = (self.config.mode == crate::common::TestMode::Ui)
+                    .then_some("note: by default, ui tests are expected not to compile");
+                self.fatal_proc_rec_general(err, extra_note, proc_res, || ());
             }
 
             if !self.props.dont_check_failure_status {
@@ -2010,18 +2007,34 @@ impl<'test> TestCx<'test> {
     }
 
     fn fatal_proc_rec(&self, err: &str, proc_res: &ProcRes) -> ! {
-        self.error(err);
-        proc_res.fatal(None, || ());
+        self.fatal_proc_rec_general(err, None, proc_res, || ());
     }
 
-    fn fatal_proc_rec_with_ctx(
+    /// Underlying implementation of [`Self::fatal_proc_rec`], providing some
+    /// extra capabilities not needed by most callers.
+    fn fatal_proc_rec_general(
         &self,
         err: &str,
+        extra_note: Option<&str>,
         proc_res: &ProcRes,
-        on_failure: impl FnOnce(Self),
+        callback_before_unwind: impl FnOnce(),
     ) -> ! {
         self.error(err);
-        proc_res.fatal(None, || on_failure(*self));
+
+        // Some callers want to print additional notes after the main error message.
+        if let Some(note) = extra_note {
+            println!("{note}");
+        }
+
+        // Print the details and output of the subprocess that caused this test to fail.
+        println!("{}", proc_res.format_info());
+
+        // Some callers want print more context or show a custom diff before the unwind occurs.
+        callback_before_unwind();
+
+        // Use resume_unwind instead of panic!() to prevent a panic message + backtrace from
+        // compiletest, which is unnecessary noise.
+        std::panic::resume_unwind(Box::new(()));
     }
 
     // codegen tests (using FileCheck)
@@ -2080,7 +2093,7 @@ impl<'test> TestCx<'test> {
         if cfg!(target_os = "freebsd") { "ISO-8859-1" } else { "UTF-8" }
     }
 
-    fn compare_to_default_rustdoc(&mut self, out_dir: &Utf8Path) {
+    fn compare_to_default_rustdoc(&self, out_dir: &Utf8Path) {
         if !self.config.has_html_tidy {
             return;
         }
@@ -2982,17 +2995,6 @@ impl ProcRes {
             render("stderr", &self.stderr),
         )
     }
-
-    pub fn fatal(&self, err: Option<&str>, on_failure: impl FnOnce()) -> ! {
-        if let Some(e) = err {
-            println!("\nerror: {}", e);
-        }
-        println!("{}", self.format_info());
-        on_failure();
-        // Use resume_unwind instead of panic!() to prevent a panic message + backtrace from
-        // compiletest, which is unnecessary noise.
-        std::panic::resume_unwind(Box::new(()));
-    }
 }
 
 #[derive(Debug)]
diff --git a/src/tools/compiletest/src/runtest/rustdoc.rs b/src/tools/compiletest/src/runtest/rustdoc.rs
index 236f021ce827..4a143aa5824e 100644
--- a/src/tools/compiletest/src/runtest/rustdoc.rs
+++ b/src/tools/compiletest/src/runtest/rustdoc.rs
@@ -28,8 +28,8 @@ impl TestCx<'_> {
             }
             let res = self.run_command_to_procres(&mut cmd);
             if !res.status.success() {
-                self.fatal_proc_rec_with_ctx("htmldocck failed!", &res, |mut this| {
-                    this.compare_to_default_rustdoc(&out_dir)
+                self.fatal_proc_rec_general("htmldocck failed!", None, &res, || {
+                    self.compare_to_default_rustdoc(&out_dir);
                 });
             }
         }
diff --git a/src/tools/compiletest/src/runtest/rustdoc_json.rs b/src/tools/compiletest/src/runtest/rustdoc_json.rs
index 7c23665c3902..083398f92745 100644
--- a/src/tools/compiletest/src/runtest/rustdoc_json.rs
+++ b/src/tools/compiletest/src/runtest/rustdoc_json.rs
@@ -29,7 +29,7 @@ impl TestCx<'_> {
         );
 
         if !res.status.success() {
-            self.fatal_proc_rec_with_ctx("jsondocck failed!", &res, |_| {
+            self.fatal_proc_rec_general("jsondocck failed!", None, &res, || {
                 println!("Rustdoc Output:");
                 println!("{}", proc_res.format_info());
             })