Auto merge of rust-lang#120123 - lcnr:sadboi-compat, r=jackh726

use implied bounds compat mode in MIR borrowck

cc
- rust-lang#119956
- rust-lang#118553

This should hopefully fix bevy 🤔 `cargo test` ends up freezing my computer though, cargo build went from err to ok however 😁

r? `@jackh726`

compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs

@@ -48,14 +48,22 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ImpliedOutlivesBounds<'tcx> {
             param_env.and(ty)
         });
 
-        tcx.implied_outlives_bounds(canonicalized)
+        if tcx.sess.opts.unstable_opts.no_implied_bounds_compat {
+            tcx.implied_outlives_bounds(canonicalized)
+        } else {
+            tcx.implied_outlives_bounds_compat(canonicalized)
+        }
     }
 
     fn perform_locally_with_next_solver(
         ocx: &ObligationCtxt<'_, 'tcx>,
         key: ParamEnvAnd<'tcx, Self>,
     ) -> Result<Self::QueryResponse, NoSolution> {
-        compute_implied_outlives_bounds_inner(ocx, key.param_env, key.value.ty)
+        if ocx.infcx.tcx.sess.opts.unstable_opts.no_implied_bounds_compat {
+            compute_implied_outlives_bounds_inner(ocx, key.param_env, key.value.ty)
+        } else {
+            compute_implied_outlives_bounds_compat_inner(ocx, key.param_env, key.value.ty)
+        }
     }
 }
 

tests/ui/associated-inherent-types/issue-111404-1.rs

@@ -10,6 +10,5 @@ impl<'a> Foo<fn(&'a ())> {
 fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {}
 //~^ ERROR higher-ranked subtype error
 //~| ERROR higher-ranked subtype error
-//~| ERROR higher-ranked subtype error
 
 fn main() {}

tests/ui/associated-inherent-types/issue-111404-1.stderr

@@ -12,13 +12,5 @@ LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {}
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: higher-ranked subtype error
-  --> $DIR/issue-111404-1.rs:10:1
-   |
-LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 

tests/ui/implied-bounds/bevy_world_query.rs

@@ -19,7 +19,9 @@ impl<Q: WorldQuery + 'static> SystemParam for Query<Q> {
 
 pub struct ParamSet<T: SystemParam>(T) where T::State: Sized;
 
-fn handler<'a>(_: ParamSet<Query<&'a u8>>) {}
+fn handler<'a>(x: ParamSet<Query<&'a u8>>) {
+    let _: ParamSet<_> = x;
+}
 
 fn ref_handler<'a>(_: &ParamSet<Query<&'a u8>>) {}
 

tests/ui/implied-bounds/normalization-nested.lifetime.stderr

@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/normalization-nested.rs:40:5
+   |
+LL | pub fn test_borrowck<'x>(_: Map<Vec<&'x ()>>, s: &'x str) -> &'static str {
+   |                      -- lifetime `'x` defined here
+LL |     s
+   |     ^ returning this value requires that `'x` must outlive `'static`
+
+error: aborting due to 1 previous error
+

tests/ui/implied-bounds/normalization-nested.rs

@@ -1,22 +1,27 @@
 // Test for normalization of projections that appear in the item bounds
 // (versus those that appear directly in the input types).
 //
-// revisions: param_ty lifetime
-// check-pass
+// revisions: param_ty lifetime param_ty_no_compat lifetime_no_compat
+
+//[param_ty] check-pass
+//[param_ty_no_compat] check-pass
+//[lifetime_no_compat] check-pass
+//[param_ty_no_compat] compile-flags: -Zno-implied-bounds-compat
+//[lifetime_no_compat] compile-flags: -Zno-implied-bounds-compat
 
 pub trait Iter {
     type Item;
 }
 
-#[cfg(param_ty)]
+#[cfg(any(param_ty, param_ty_no_compat))]
 impl<X, I> Iter for I
 where
     I: IntoIterator<Item = X>,
 {
     type Item = X;
 }
 
-#[cfg(lifetime)]
+#[cfg(any(lifetime, lifetime_no_compat))]
 impl<'x, I> Iter for I
 where
     I: IntoIterator<Item = &'x ()>,
@@ -33,6 +38,7 @@ pub fn test_wfcheck<'x>(_: Map<Vec<&'x ()>>) {}
 
 pub fn test_borrowck<'x>(_: Map<Vec<&'x ()>>, s: &'x str) -> &'static str {
     s
+    //[lifetime]~^ ERROR lifetime may not live long enough
 }
 
 fn main() {}

tests/ui/inference/issue-80409.rs

@@ -1,12 +1,17 @@
 // This should not pass, because `usize: Fsm` does not hold. However, it currently ICEs.
 
-// check-fail
-// known-bug: #80409
-// failure-status: 101
-// normalize-stderr-test "note: .*\n\n" -> ""
-// normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
-// normalize-stderr-test "(error: internal compiler error: [^:]+):\d+:\d+: " -> "$1:LL:CC: "
-// rustc-env:RUST_BACKTRACE=0
+// ignore-tidy-linelength
+
+// revisions: compat no-compat
+//[compat] check-pass
+//[no-compat] compile-flags: -Zno-implied-bounds-compat
+//[no-compat] check-fail
+//[no-compat] known-bug: #80409
+//[no-compat] failure-status: 101
+//[no-compat] normalize-stderr-test "note: .*\n\n" -> ""
+//[no-compat] normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
+//[no-compat] normalize-stderr-test "(error: internal compiler error: [^:]+):\d+:\d+: " -> "$1:LL:CC: "
+//[no-compat] rustc-env:RUST_BACKTRACE=0
 
 #![allow(unreachable_code, unused)]