From cedaaa640edfa2854ea213148a7c0f5ee5dd2f74 Mon Sep 17 00:00:00 2001
From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com>
Date: Wed, 9 Nov 2022 22:00:13 +0100
Subject: [PATCH] Don't ICE on operator trait methods with generic methods

Emit a fatal error instead.
---
 .../locales/en-US/hir_analysis.ftl            |  3 +++
 compiler/rustc_hir_typeck/src/errors.rs       |  8 +++++++
 compiler/rustc_hir_typeck/src/method/mod.rs   |  9 +++++++-
 src/test/ui/traits/invalid_operator_trait.rs  | 23 +++++++++++++++++++
 .../ui/traits/invalid_operator_trait.stderr   |  8 +++++++
 5 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 src/test/ui/traits/invalid_operator_trait.rs
 create mode 100644 src/test/ui/traits/invalid_operator_trait.stderr

diff --git a/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl b/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl
index 74088f4dfbe70..d27edd47470e8 100644
--- a/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl
@@ -150,3 +150,6 @@ hir_analysis_const_bound_for_non_const_trait =
 hir_analysis_self_in_impl_self =
     `Self` is not valid in the self type of an impl block
     .note = replace `Self` with a different type
+
+hir_analysis_op_trait_generic_params =
+    `{$method_name}` must not have any generic parameters
diff --git a/compiler/rustc_hir_typeck/src/errors.rs b/compiler/rustc_hir_typeck/src/errors.rs
index cfb408396da05..afac6e7d94a81 100644
--- a/compiler/rustc_hir_typeck/src/errors.rs
+++ b/compiler/rustc_hir_typeck/src/errors.rs
@@ -125,3 +125,11 @@ pub struct AddMissingParenthesesInRange {
     #[suggestion_part(code = ")")]
     pub right: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_analysis_op_trait_generic_params)]
+pub struct OpMethodGenericParams {
+    #[primary_span]
+    pub span: Span,
+    pub method_name: String,
+}
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
index 2c7b3bbf31c20..4a8b774936543 100644
--- a/compiler/rustc_hir_typeck/src/method/mod.rs
+++ b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -10,6 +10,7 @@ mod suggest;
 pub use self::suggest::SelfSource;
 pub use self::MethodError::*;
 
+use crate::errors::OpMethodGenericParams;
 use crate::{Expectation, FnCtxt};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, Diagnostic};
@@ -443,7 +444,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         let def_id = method_item.def_id;
         let generics = tcx.generics_of(def_id);
-        assert_eq!(generics.params.len(), 0);
+
+        if generics.params.len() != 0 {
+            tcx.sess.emit_fatal(OpMethodGenericParams {
+                span: tcx.def_span(method_item.def_id),
+                method_name: m_name.to_string(),
+            });
+        }
 
         debug!("lookup_in_trait_adjusted: method_item={:?}", method_item);
         let mut obligations = vec![];
diff --git a/src/test/ui/traits/invalid_operator_trait.rs b/src/test/ui/traits/invalid_operator_trait.rs
new file mode 100644
index 0000000000000..7ea3b0d5bac76
--- /dev/null
+++ b/src/test/ui/traits/invalid_operator_trait.rs
@@ -0,0 +1,23 @@
+#![crate_type = "lib"]
+#![feature(lang_items)]
+#![feature(no_core)]
+#![no_core]
+
+#[lang="sized"]
+pub trait Sized {
+    // Empty.
+}
+
+#[lang = "add"]
+trait Add<RHS=Self> {
+    type Output;
+
+    fn add<Y>(self, _: RHS) -> Self::Output;
+    //~^ ERROR `add` must not have any generic parameters
+}
+
+#[allow(unreachable_code)]
+fn ice(a: usize) {
+    let r = loop {};
+    r = r + a;
+}
diff --git a/src/test/ui/traits/invalid_operator_trait.stderr b/src/test/ui/traits/invalid_operator_trait.stderr
new file mode 100644
index 0000000000000..8c6e3695905ee
--- /dev/null
+++ b/src/test/ui/traits/invalid_operator_trait.stderr
@@ -0,0 +1,8 @@
+error: `add` must not have any generic parameters
+  --> $DIR/invalid_operator_trait.rs:15:5
+   |
+LL |     fn add<Y>(self, _: RHS) -> Self::Output;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+