Rollup merge of #121105 - compiler-errors:no-const-ty-overflow, r=oli…

…-obk

Do not report overflow errors on ConstArgHasType goals

This is 10% of a fix for #121090, since it at least means that we no longer mention the `ConstArgHasType` goal as the cause for the overflow. Instead, now we mention:
```
overflow evaluating the requirement `{closure@$DIR/overflow-during-mono.rs:13:41: 13:44}: Sized`
```
which is not much better, but slightly.

r? oli-obk

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -423,6 +423,21 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
  ty::PredicateKind::AliasRelate(..) => {
  bug!("AliasRelate is only used by the new solver")
  }
+ // Compute `ConstArgHasType` above the overflow check below.
+ // This is because this is not ever a useful obligation to report
+ // as the cause of an overflow.
+ ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
+ match self.selcx.infcx.at(&obligation.cause, obligation.param_env).eq(
+ DefineOpaqueTypes::No,
+ ct.ty(),
+ ty,
+ ) {
+ Ok(inf_ok) => ProcessResult::Changed(mk_pending(inf_ok.into_obligations())),
+ Err(_) => ProcessResult::Error(FulfillmentErrorCode::SelectionError(
+ SelectionError::Unimplemented,
+ )),
+ }
+ }
 
  // General case overflow check. Allow `process_trait_obligation`
  // and `process_projection_obligation` to handle checking for
@@ -650,18 +665,6 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
  }
  }
  }
- ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
- match self.selcx.infcx.at(&obligation.cause, obligation.param_env).eq(
- DefineOpaqueTypes::No,
- ct.ty(),
- ty,
- ) {
- Ok(inf_ok) => ProcessResult::Changed(mk_pending(inf_ok.into_obligations())),
- Err(_) => ProcessResult::Error(FulfillmentErrorCode::SelectionError(
- SelectionError::Unimplemented,
- )),
- }
- }
  },
  }
  }

tests/ui/codegen/overflow-during-mono.rs

@@ -0,0 +1,28 @@
+// build-fail
+//~^ ERROR overflow evaluating the requirement
+
+#![recursion_limit = "32"]
+
+fn quicksort<It: Clone + Iterator<Item = T>, I: IntoIterator<IntoIter = It>, T: Ord>(
+ i: I,
+) -> Vec<T> {
+ let mut i = i.into_iter();
+
+ match i.next() {
+ Some(x) => {
+ let less = i.clone().filter(|y| y < &x);
+ let greater = i.filter(|y| &x <= y);
+
+ let mut v = quicksort(less);
+ let u = quicksort(greater);
+ v.push(x);
+ v.extend(u);
+ v
+ }
+ None => vec![],
+ }
+}
+
+fn main() {
+ println!("{:?}", quicksort([5i32, 1, 6, 3, 6, 1, 9, 0, -1, 6, 8]));
+}

tests/ui/codegen/overflow-during-mono.stderr

@@ -0,0 +1,11 @@
+error[E0275]: overflow evaluating the requirement `{closure@$DIR/overflow-during-mono.rs:13:41: 13:44}: Sized`
+ |
+ = help: consider increasing the recursion limit by adding a `#![recursion_limit = "64"]` attribute to your crate (`overflow_during_mono`)
+ = note: required for `Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `Iterator`
+ = note: 31 redundant requirements hidden
+ = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `Iterator`
+ = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `IntoIterator`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0275`.