Auto merge of #121870 - matthiaskrgr:rollup-mfpa3jx, r=matthiaskrgr

Rollup of 11 pull requests

Successful merges:

 - #111505 (Made `INVALID_DOC_ATTRIBUTES` lint deny by default)
 - #120305 (Delete line if suggestion would replace it with an empty line)
 - #121153 (Suggest removing superfluous semicolon when statements used as expression)
 - #121497 (`-Znext-solver=coherence`: suggest increasing recursion limit)
 - #121634 (Clarify behavior of slice prefix/suffix operations in case of equality)
 - #121706 (match lowering: Remove hacky branch in sort_candidate)
 - #121730 (Add profiling support to AIX)
 - #121750 (match lowering: Separate the `bool` case from other integers in `TestKind`)
 - #121803 (Never say "`Trait` is implemented for `{type error}`")
 - #121811 (Move sanitizer ui tests to sanitizer directory)
 - #121824 (Implement missing ABI structures in StableMIR)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 11 insertions, 0 deletions

diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs
index 51094b781c0..0bf28f520a4 100644
--- a/compiler/rustc_trait_selection/src/solve/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/mod.rs
@@ -42,6 +42,17 @@ pub use fulfill::FulfillmentCtxt;
 pub(crate) use normalize::deeply_normalize_for_diagnostics;
 pub use normalize::{deeply_normalize, deeply_normalize_with_skipped_universes};
 
+/// How many fixpoint iterations we should attempt inside of the solver before bailing
+/// with overflow.
+///
+/// We previously used  `tcx.recursion_limit().0.checked_ilog2().unwrap_or(0)` for this.
+/// However, it feels unlikely that uncreasing the recursion limit by a power of two
+/// to get one more itereation is every useful or desirable. We now instead used a constant
+/// here. If there ever ends up some use-cases where a bigger number of fixpoint iterations
+/// is required, we can add a new attribute for that or revert this to be dependant on the
+/// recursion limit again. However, this feels very unlikely.
+const FIXPOINT_STEP_LIMIT: usize = 8;
+
 #[derive(Debug, Clone, Copy)]
 enum SolverMode {
     /// Ordinary trait solving, using everywhere except for coherence.