Rollup merge of #130282 - compiler-errors:over-overflow, r=BoxyUwU

Do not report an excessive number of overflow errors for an ever-growing deref impl

Check that we don't first hit the recursion limit in `get_field_candidates_considering_privacy` before probing for methods when we have a method lookup failure and we want to see if `.field.method()` exists. We also silence overflow error messages if we're probing for methods for diagnostics.

Also renames some functions to make it clearer that they're only for diagnostics, and sprinkle some `Autoderef::silence_errors` around to silence unnecessary overflow errors that come from diagnostics.

Fixes #130224.

2 files changed, 37 insertions, 0 deletions

diff --git a/tests/ui/methods/probe-error-on-infinite-deref.rs b/tests/ui/methods/probe-error-on-infinite-deref.rs
new file mode 100644
index 00000000000..85c1c0c09c1
--- /dev/null
+++ b/tests/ui/methods/probe-error-on-infinite-deref.rs
@@ -0,0 +1,16 @@
+use std::ops::Deref;
+
+// Make sure that method probe error reporting doesn't get too tangled up
+// on this infinite deref impl. See #130224.
+
+struct Wrap<T>(T);
+impl<T> Deref for Wrap<T> {
+    type Target = Wrap<Wrap<T>>;
+    fn deref(&self) -> &Wrap<Wrap<T>> { todo!() }
+}
+
+fn main() {
+    Wrap(1).lmao();
+    //~^ ERROR reached the recursion limit
+    //~| ERROR no method named `lmao`
+}
diff --git a/tests/ui/methods/probe-error-on-infinite-deref.stderr b/tests/ui/methods/probe-error-on-infinite-deref.stderr
new file mode 100644
index 00000000000..57a9ca2eaa8
--- /dev/null
+++ b/tests/ui/methods/probe-error-on-infinite-deref.stderr
@@ -0,0 +1,21 @@
+error[E0055]: reached the recursion limit while auto-dereferencing `Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<Wrap<{integer}>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>`
+  --> $DIR/probe-error-on-infinite-deref.rs:13:13
+   |
+LL |     Wrap(1).lmao();
+   |             ^^^^ deref recursion limit reached
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`probe_error_on_infinite_deref`)
+
+error[E0599]: no method named `lmao` found for struct `Wrap<{integer}>` in the current scope
+  --> $DIR/probe-error-on-infinite-deref.rs:13:13
+   |
+LL | struct Wrap<T>(T);
+   | -------------- method `lmao` not found for this struct
+...
+LL |     Wrap(1).lmao();
+   |             ^^^^ method not found in `Wrap<{integer}>`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0055, E0599.
+For more information about an error, try `rustc --explain E0055`.