1 files changed, 52 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/util/bug.rs b/compiler/rustc_middle/src/util/bug.rs
new file mode 100644
index 00000000000..0903ef50898
--- /dev/null
+++ b/compiler/rustc_middle/src/util/bug.rs
@@ -0,0 +1,52 @@
+// These functions are used by macro expansion for bug! and span_bug!
+
+use crate::ty::{tls, TyCtxt};
+use rustc_span::{MultiSpan, Span};
+use std::fmt;
+use std::panic::Location;
+
+#[cold]
+#[inline(never)]
+#[track_caller]
+pub fn bug_fmt(args: fmt::Arguments<'_>) -> ! {
+    // this wrapper mostly exists so I don't have to write a fully
+    // qualified path of None::<Span> inside the bug!() macro definition
+    opt_span_bug_fmt(None::<Span>, args, Location::caller());
+}
+
+#[cold]
+#[inline(never)]
+#[track_caller]
+pub fn span_bug_fmt<S: Into<MultiSpan>>(span: S, args: fmt::Arguments<'_>) -> ! {
+    opt_span_bug_fmt(Some(span), args, Location::caller());
+}
+
+fn opt_span_bug_fmt<S: Into<MultiSpan>>(
+    span: Option<S>,
+    args: fmt::Arguments<'_>,
+    location: &Location<'_>,
+) -> ! {
+    tls::with_opt(move |tcx| {
+        let msg = format!("{}: {}", location, args);
+        match (tcx, span) {
+            (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, &msg),
+            (Some(tcx), None) => tcx.sess.diagnostic().bug(&msg),
+            (None, _) => panic!(msg),
+        }
+    });
+    unreachable!();
+}
+
+/// A query to trigger a `delay_span_bug`. Clearly, if one has a `tcx` one can already trigger a
+/// `delay_span_bug`, so what is the point of this? It exists to help us test `delay_span_bug`'s
+/// interactions with the query system and incremental.
+pub fn trigger_delay_span_bug(tcx: TyCtxt<'_>, key: rustc_hir::def_id::DefId) {
+    tcx.sess.delay_span_bug(
+        tcx.def_span(key),
+        "delayed span bug triggered by #[rustc_error(delay_span_bug_from_inside_query)]",
+    );
+}
+
+pub fn provide(providers: &mut crate::ty::query::Providers) {
+    *providers = crate::ty::query::Providers { trigger_delay_span_bug, ..*providers };
+}