Normalize substs before resolving instance in NoopMethodCall lint

Author: compiler-errors

compiler/rustc_lint/src/noop_method_call.rs

@@ -46,7 +46,7 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
         };
         // We only care about method calls corresponding to the `Clone`, `Deref` and `Borrow`
         // traits and ignore any other method call.
-        let (trait_id, did) = match cx.typeck_results().type_dependent_def(expr.hir_id) {
+        let did = match cx.typeck_results().type_dependent_def(expr.hir_id) {
             // Verify we are dealing with a method/associated function.
             Some((DefKind::AssocFn, did)) => match cx.tcx.trait_of_item(did) {
                 // Check that we're dealing with a trait method for one of the traits we care about.
@@ -56,21 +56,22 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
                         Some(sym::Borrow | sym::Clone | sym::Deref)
                     ) =>
                 {
-                    (trait_id, did)
+                    did
                 }
                 _ => return,
             },
             _ => return,
         };
-        let substs = cx.typeck_results().node_substs(expr.hir_id);
+        let substs = cx
+            .tcx
+            .normalize_erasing_regions(cx.param_env, cx.typeck_results().node_substs(expr.hir_id));
         if substs.needs_subst() {
             // We can't resolve on types that require monomorphization, so we don't handle them if
             // we need to perform substitution.
             return;
         }
-        let param_env = cx.tcx.param_env(trait_id);
         // Resolve the trait method instance.
-        let Ok(Some(i)) = ty::Instance::resolve(cx.tcx, param_env, did, substs) else {
+        let Ok(Some(i)) = ty::Instance::resolve(cx.tcx, cx.param_env, did, substs) else {
             return
         };
         // (Re)check that it implements the noop diagnostic.

src/test/ui/const-generics/generic_const_exprs/issue-102074.rs

@@ -0,0 +1,23 @@
+// check-pass
+// Checks that the NoopMethodCall lint doesn't call Instance::resolve on unresolved consts
+
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+#[derive(Debug, Clone)]
+pub struct Aes128CipherKey([u8; Aes128Cipher::KEY_LEN]);
+
+impl Aes128CipherKey {
+    pub fn new(key: &[u8; Aes128Cipher::KEY_LEN]) -> Self {
+        Self(key.clone())
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Aes128Cipher;
+
+impl Aes128Cipher {
+    const KEY_LEN: usize = 16;
+}
+
+fn main() {}