Rollup merge of #104628 - alex-pinkus:revert-android-ndk-upgrade, r=pietroalbini

[rust.git] / compiler / rustc_trait_selection / src / traits / error_reporting / mod.rs

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 ad0785d3817e1cf386a7be5762d429a456e481ea..c3547f64b5c9c747e1aa9c7a2804452e95a3f85b 100644 (file)
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -22,6 +22,7 @@
     MultiSpan, Style,
 };
 use rustc_hir as hir;
+use rustc_hir::def::Namespace;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::GenericParam;
@@ -34,6 +35,7 @@
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::ExpectedFound;
 use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::print::{FmtPrinter, Print};
 use rustc_middle::ty::{
     self, SubtypePredicate, ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt, TypeFoldable,
     TypeVisitable,
@@ -109,7 +111,10 @@ fn report_overflow_error<T>(
         suggest_increasing_limit: bool,
     ) -> !
     where
-        T: fmt::Display + TypeFoldable<'tcx>;
+        T: fmt::Display
+            + TypeFoldable<'tcx>
+            + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
+        <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
 
     fn suggest_new_overflow_limit(&self, err: &mut Diagnostic);
 
@@ -468,15 +473,31 @@ fn report_overflow_error<T>(
         suggest_increasing_limit: bool,
     ) -> !
     where
-        T: fmt::Display + TypeFoldable<'tcx>,
+        T: fmt::Display
+            + TypeFoldable<'tcx>
+            + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
+        <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
     {
         let predicate = self.resolve_vars_if_possible(obligation.predicate.clone());
+        let mut pred_str = predicate.to_string();
+        if pred_str.len() > 50 {
+            // We don't need to save the type to a file, we will be talking about this type already
+            // in a separate note when we explain the obligation, so it will be available that way.
+            pred_str = predicate
+                .print(FmtPrinter::new_with_limit(
+                    self.tcx,
+                    Namespace::TypeNS,
+                    rustc_session::Limit(6),
+                ))
+                .unwrap()
+                .into_buffer();
+        }
         let mut err = struct_span_err!(
             self.tcx.sess,
             obligation.cause.span,
             E0275,
             "overflow evaluating the requirement `{}`",
-            predicate
+            pred_str,
         );
 
         if suggest_increasing_limit {
@@ -1708,7 +1729,7 @@ fn type_category(tcx: TyCtxt<'_>, t: Ty<'_>) -> Option<u32> {
                 ty::Bool => Some(0),
                 ty::Char => Some(1),
                 ty::Str => Some(2),
-                ty::Adt(def, _) if tcx.is_diagnostic_item(sym::String, def.did()) => Some(2),
+                ty::Adt(def, _) if Some(def.did()) == tcx.lang_items().string() => Some(2),
                 ty::Int(..)
                 | ty::Uint(..)
                 | ty::Float(..)