Auto merge of #104610 - ouz-a:revert-overflow, r=compiler-errors

Reverts check done by #100757

As my `fix` caused more issues than it resolved it's better to revert it.
( #103274 #104322 https://github.com/rust-lang/rust/issues/104606)

r? `@compiler-errors`

Reopens #95134

compiler/rustc_trait_selection/src/traits/project.rs

@@ -566,22 +566,6 @@ fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
                     .flatten()
                     .unwrap_or_else(|| ty.super_fold_with(self).into())
                 };
-                // For cases like #95134 we would like to catch overflows early
-                // otherwise they slip away and cause ICE.
-                let recursion_limit = self.tcx().recursion_limit();
-                if !recursion_limit.value_within_limit(self.depth)
-                    // HACK: Don't overflow when running cargo doc see #100991
-                    && !self.tcx().sess.opts.actually_rustdoc
-                {
-                    let obligation = Obligation::with_depth(
-                        self.selcx.tcx(),
-                        self.cause.clone(),
-                        recursion_limit.0,
-                        self.param_env,
-                        ty,
-                    );
-                    self.selcx.infcx().err_ctxt().report_overflow_error(&obligation, true);
-                }
                 debug!(
                     ?self.depth,
                     ?ty,

src/test/ui/issues/issue-23122-2.rs

@@ -1,3 +1,4 @@
+// normalize-stderr-test: "long-type-\d+" -> "long-type-hash"
 trait Next {
     type Next: Next;
 }

src/test/ui/issues/issue-23122-2.stderr

@@ -1,10 +1,16 @@
-error[E0275]: overflow evaluating the requirement `<T as Next>::Next`
-  --> $DIR/issue-23122-2.rs:10:17
+error[E0275]: overflow evaluating the requirement `<<<<<<<... as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Sized`
+  --> $DIR/issue-23122-2.rs:11:17
    |
 LL |     type Next = <GetNext<T::Next> as Next>::Next;
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_23122_2`)
+note: required for `GetNext<<<<<<... as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next>` to implement `Next`
+  --> $DIR/issue-23122-2.rs:10:15
+   |
+LL | impl<T: Next> Next for GetNext<T> {
+   |               ^^^^     ^^^^^^^^^^
+   = note: the full type name has been written to '$TEST_BUILD_DIR/issues/issue-23122-2/issue-23122-2.long-type-hash.txt'
 
 error: aborting due to previous error
 

src/test/ui/recursion/issue-83150.stderr

@@ -9,11 +9,9 @@ LL |     func(&mut iter.map(|x| x + 1))
    = help: a `loop` may express intention better if this is on purpose
    = note: `#[warn(unconditional_recursion)]` on by default
 
-error[E0275]: overflow evaluating the requirement `<std::ops::Range<u8> as Iterator>::Item`
+error[E0275]: overflow evaluating the requirement `Map<&mut Map<&mut Map<&mut Map<..., ...>, ...>, ...>, ...>: Iterator`
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_83150`)
-   = note: required for `Map<&mut std::ops::Range<u8>, [closure@$DIR/issue-83150.rs:12:24: 12:27]>` to implement `Iterator`
-   = note: 64 redundant requirements hidden
    = note: required for `&mut Map<&mut Map<&mut Map<..., ...>, ...>, ...>` to implement `Iterator`
    = note: the full type name has been written to '$TEST_BUILD_DIR/recursion/issue-83150/issue-83150.long-type-hash.txt'
 

src/test/ui/recursion/issue-95134.rs

@@ -1,6 +1,8 @@
 // build-fail
+// known-bug: #95134
 // compile-flags: -Copt-level=0
-//~^^ ERROR overflow evaluating the requirement
+// failure-status: 101
+// dont-check-compiler-stderr
 
 pub fn encode_num<Writer: ExampleWriter>(n: u32, mut writer: Writer) -> Result<(), Writer::Error> {
     if n > 15 {

src/test/ui/recursion/issue-95134.stderr

@@ -1,7 +0,0 @@
-error[E0275]: overflow evaluating the requirement `<EmptyWriter as ExampleWriter>::Error`
-   |
-   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_95134`)
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0275`.