Only deduplicate stack traces for good path bugs

compiler/rustc_driver/src/lib.rs

@@ -1199,8 +1199,8 @@ static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send +
  };
 
  // Invoke the default handler, which prints the actual panic message and optionally a backtrace
- // Don't do this for `ExplicitBug`, which has an unhelpful message and backtrace.
- if !info.payload().is::<rustc_errors::ExplicitBug>() {
+ // Don't do this for `GoodPathBug`, which already emits its own more useful backtrace.
+ if !info.payload().is::<rustc_errors::GoodPathBug>() {
  (*DEFAULT_HOOK)(info);
 
  // Separate the output with an empty line
@@ -1237,7 +1237,9 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
 
  // a .span_bug or .bug call has already printed what
  // it wants to print.
- if !info.payload().is::<rustc_errors::ExplicitBug>() {
+ if !info.payload().is::<rustc_errors::ExplicitBug>()
+ && !info.payload().is::<rustc_errors::GoodPathBug>()
+ {
  let mut d = rustc_errors::Diagnostic::new(rustc_errors::Level::Bug, "unexpected panic");
  handler.emit_diagnostic(&mut d);
  }

compiler/rustc_errors/src/lib.rs

@@ -40,12 +40,13 @@ use rustc_span::source_map::SourceMap;
 use rustc_span::HashStableContext;
 use rustc_span::{Loc, Span};
 
+use std::any::Any;
 use std::borrow::Cow;
+use std::fmt;
 use std::hash::Hash;
 use std::num::NonZeroUsize;
 use std::panic;
 use std::path::Path;
-use std::{error, fmt};
 
 use termcolor::{Color, ColorSpec};
 
@@ -361,16 +362,11 @@ pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
 
 /// Signifies that the compiler died with an explicit call to `.bug`
 /// or `.span_bug` rather than a failed assertion, etc.
-#[derive(Copy, Clone, Debug)]
 pub struct ExplicitBug;
 
-impl fmt::Display for ExplicitBug {
- fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- write!(f, "parser internal bug")
- }
-}
-
-impl error::Error for ExplicitBug {}
+/// Signifies that the compiler died with an explicit call to `.delay_good_path_bug`
+/// rather than a failed assertion, etc.
+pub struct GoodPathBug;
 
 pub use diagnostic::{
  AddToDiagnostic, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgValue, DiagnosticId,
@@ -507,7 +503,11 @@ impl Drop for HandlerInner {
 
  if !self.has_errors() {
  let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new());
- self.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
+ self.flush_delayed(
+ bugs,
+ "no errors encountered even though `delay_span_bug` issued",
+ ExplicitBug,
+ );
  }
 
  // FIXME(eddyb) this explains what `delayed_good_path_bugs` are!
@@ -520,6 +520,7 @@ impl Drop for HandlerInner {
  self.flush_delayed(
  bugs.into_iter().map(DelayedDiagnostic::decorate),
  "no warnings or errors encountered even though `delayed_good_path_bugs` issued",
+ GoodPathBug,
  );
  }
 
@@ -1203,7 +1204,11 @@ impl Handler {
  pub fn flush_delayed(&self) {
  let mut inner = self.inner.lock();
  let bugs = std::mem::replace(&mut inner.delayed_span_bugs, Vec::new());
- inner.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
+ inner.flush_delayed(
+ bugs,
+ "no errors encountered even though `delay_span_bug` issued",
+ ExplicitBug,
+ );
  }
 }
 
@@ -1580,6 +1585,7 @@ impl HandlerInner {
  &mut self,
  bugs: impl IntoIterator<Item = Diagnostic>,
  explanation: impl Into<DiagnosticMessage> + Copy,
+ panic_with: impl Any + Send + 'static,
  ) {
  let mut no_bugs = true;
  for mut bug in bugs {
@@ -1607,7 +1613,7 @@ impl HandlerInner {
 
  // Panic with `ExplicitBug` to avoid "unexpected panic" messages.
  if !no_bugs {
- panic::panic_any(ExplicitBug);
+ panic::panic_any(panic_with);
  }
  }