1 files changed, 30 insertions, 0 deletions
diff --git a/third_party/rust/proc-macro-error/src/imp/fallback.rs b/third_party/rust/proc-macro-error/src/imp/fallback.rs
new file mode 100644
index 0000000000..ad1f730bfc
--- /dev/null
+++ b/third_party/rust/proc-macro-error/src/imp/fallback.rs
@@ -0,0 +1,30 @@
+//! This implementation uses self-written stable facilities.
+
+use crate::{
+    abort_now, check_correctness,
+    diagnostic::{Diagnostic, Level},
+};
+use std::cell::RefCell;
+
+pub fn abort_if_dirty() {
+    check_correctness();
+    ERR_STORAGE.with(|storage| {
+        if !storage.borrow().is_empty() {
+            abort_now()
+        }
+    });
+}
+
+pub(crate) fn cleanup() -> Vec<Diagnostic> {
+    ERR_STORAGE.with(|storage| storage.replace(Vec::new()))
+}
+
+pub(crate) fn emit_diagnostic(diag: Diagnostic) {
+    if diag.level == Level::Error {
+        ERR_STORAGE.with(|storage| storage.borrow_mut().push(diag));
+    }
+}
+
+thread_local! {
+    static ERR_STORAGE: RefCell<Vec<Diagnostic>> = RefCell::new(Vec::new());
+}