From 39bff4bf9c998ba77d12b36b26c604340638fa73 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 6 Apr 2022 21:27:46 -0700
Subject: don't report int/float ambiguity when we have previous errors

---
 .../src/traits/error_reporting/mod.rs              | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

(limited to 'compiler/rustc_trait_selection/src')

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 9998c5bb087..ac98dd5801e 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -36,6 +36,7 @@ use rustc_span::symbol::{kw, sym};
 use rustc_span::{ExpnKind, Span, DUMMY_SP};
 use std::fmt;
 use std::iter;
+use std::ops::ControlFlow;
 
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use crate::traits::query::normalize::AtExt as _;
@@ -2226,9 +2227,10 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
         post.dedup();
 
         if self.is_tainted_by_errors()
-            && crate_names.len() == 1
-            && ["`core`", "`alloc`", "`std`"].contains(&crate_names[0].as_str())
-            && spans.len() == 0
+            && (crate_names.len() == 1
+                && spans.len() == 0
+                && ["`core`", "`alloc`", "`std`"].contains(&crate_names[0].as_str())
+                || predicate.visit_with(&mut HasNumericInferVisitor).is_break())
         {
             // Avoid complaining about other inference issues for expressions like
             // `42 >> 1`, where the types are still `{integer}`, but we want to
@@ -2666,3 +2668,17 @@ impl ArgKind {
         }
     }
 }
+
+struct HasNumericInferVisitor;
+
+impl<'tcx> ty::TypeVisitor<'tcx> for HasNumericInferVisitor {
+    type BreakTy = ();
+
+    fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
+        if matches!(ty.kind(), ty::Infer(ty::FloatVar(_) | ty::IntVar(_))) {
+            ControlFlow::Break(())
+        } else {
+            ControlFlow::CONTINUE
+        }
+    }
+}
-- 
cgit 1.4.1-3-g733a5