On nightly, dump ICE backtraces to disk

Implement rust-lang/compiler-team#578.

When an ICE is encountered on nightly releases, the new rustc panic
handler will also write the contents of the backtrace to disk. If any
`delay_span_bug`s are encountered, their backtrace is also added to the
file. The platform and rustc version will also be collected.

1 files changed, 22 insertions, 1 deletions

diff --git a/compiler/rustc_driver_impl/src/session_diagnostics.rs b/compiler/rustc_driver_impl/src/session_diagnostics.rs
index 638b368f702..f7f06b7d0f2 100644
--- a/compiler/rustc_driver_impl/src/session_diagnostics.rs
+++ b/compiler/rustc_driver_impl/src/session_diagnostics.rs
@@ -1,4 +1,4 @@
-use rustc_macros::Diagnostic;
+use rustc_macros::{Diagnostic, Subdiagnostic};
 
 #[derive(Diagnostic)]
 #[diag(driver_impl_rlink_unable_to_read)]
@@ -57,6 +57,27 @@ pub(crate) struct IceVersion<'a> {
 }
 
 #[derive(Diagnostic)]
+#[diag(driver_impl_ice_path)]
+pub(crate) struct IcePath {
+    pub path: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(driver_impl_ice_path_error)]
+pub(crate) struct IcePathError {
+    pub path: String,
+    pub error: String,
+    #[subdiagnostic]
+    pub env_var: Option<IcePathErrorEnv>,
+}
+
+#[derive(Subdiagnostic)]
+#[note(driver_impl_ice_path_error_env)]
+pub(crate) struct IcePathErrorEnv {
+    pub env_var: String,
+}
+
+#[derive(Diagnostic)]
 #[diag(driver_impl_ice_flags)]
 pub(crate) struct IceFlags {
     pub flags: String,