Auto merge of #136371 - matthiaskrgr:rollup-0b880v3, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #135840 (omit unused args warnings for intrinsics without body)
 - #135900 (Manually walk into WF obligations in `BestObligation` proof tree visitor)
 - #136163 (Fix off-by-one error causing slice::sort to abort the program)
 - #136266 (fix broken release notes id)
 - #136314 (Use proper type when applying deref adjustment in const)
 - #136348 (miri: make float min/max non-deterministic)
 - #136351 (Add documentation for derive(CoercePointee))

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

Author: bors

RELEASES.md

@@ -16,8 +16,7 @@ Version 1.84.1 (2025-01-30)
 Version 1.84.0 (2025-01-09)
 ==========================
 
-<a id="
-Language"></a>
+<a id="1.84.0-Language"></a>
 
 Language
 --------

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -747,7 +747,13 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     {
         let a: F = self.read_scalar(&args[0])?.to_float()?;
         let b: F = self.read_scalar(&args[1])?.to_float()?;
-        let res = self.adjust_nan(a.min(b), &[a, b]);
+        let res = if a == b {
+            // They are definitely not NaN (those are never equal), but they could be `+0` and `-0`.
+            // Let the machine decide which one to return.
+            M::equal_float_min_max(self, a, b)
+        } else {
+            self.adjust_nan(a.min(b), &[a, b])
+        };
         self.write_scalar(res, dest)?;
         interp_ok(())
     }
@@ -762,7 +768,13 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     {
         let a: F = self.read_scalar(&args[0])?.to_float()?;
         let b: F = self.read_scalar(&args[1])?.to_float()?;
-        let res = self.adjust_nan(a.max(b), &[a, b]);
+        let res = if a == b {
+            // They are definitely not NaN (those are never equal), but they could be `+0` and `-0`.
+            // Let the machine decide which one to return.
+            M::equal_float_min_max(self, a, b)
+        } else {
+            self.adjust_nan(a.max(b), &[a, b])
+        };
         self.write_scalar(res, dest)?;
         interp_ok(())
     }

compiler/rustc_const_eval/src/interpret/machine.rs

@@ -278,6 +278,12 @@ pub trait Machine<'tcx>: Sized {
         F2::NAN
     }
 
+    /// Determines the result of `min`/`max` on floats when the arguments are equal.
+    fn equal_float_min_max<F: Float>(_ecx: &InterpCx<'tcx, Self>, a: F, _b: F) -> F {
+        // By default, we pick the left argument.
+        a
+    }
+
     /// Called before a basic block terminator is executed.
     #[inline]
     fn before_terminator(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> {

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -253,6 +253,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return;
         }
 
+        let mut expr_ty = self.typeck_results.borrow().expr_ty_adjusted(expr);
+
         for a in &adj {
             match a.kind {
                 Adjust::NeverToAny => {
@@ -266,7 +268,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         None,
                         expr.span,
                         overloaded_deref.method_call(self.tcx),
-                        self.tcx.mk_args(&[a.target.into()]),
+                        self.tcx.mk_args(&[expr_ty.into()]),
                     );
                 }
                 Adjust::Deref(None) => {
@@ -283,6 +285,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // No effects to enforce here.
                 }
             }
+
+            expr_ty = a.target;
         }
 
         let autoborrow_mut = adj.iter().any(|adj| {

compiler/rustc_passes/src/liveness.rs

@@ -1522,6 +1522,14 @@ impl<'tcx> Liveness<'_, 'tcx> {
     }
 
     fn warn_about_unused_args(&self, body: &hir::Body<'_>, entry_ln: LiveNode) {
+        if let Some(intrinsic) =
+            self.ir.tcx.intrinsic(self.ir.tcx.hir().body_owner_def_id(body.id()))
+        {
+            if intrinsic.must_be_overridden {
+                return;
+            }
+        }
+
         for p in body.params {
             self.check_unused_vars_in_pat(
                 p.pat,

compiler/rustc_trait_selection/src/solve/delegate.rs

@@ -1,7 +1,7 @@
 use std::ops::Deref;
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{CRATE_DEF_ID, DefId};
 use rustc_infer::infer::canonical::query_response::make_query_region_constraints;
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalExt as _, CanonicalQueryInput, CanonicalVarInfo, CanonicalVarValues,
@@ -98,9 +98,10 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
         param_env: ty::ParamEnv<'tcx>,
         arg: ty::GenericArg<'tcx>,
     ) -> Option<Vec<Goal<'tcx, ty::Predicate<'tcx>>>> {
-        crate::traits::wf::unnormalized_obligations(&self.0, param_env, arg).map(|obligations| {
-            obligations.into_iter().map(|obligation| obligation.into()).collect()
-        })
+        crate::traits::wf::unnormalized_obligations(&self.0, param_env, arg, DUMMY_SP, CRATE_DEF_ID)
+            .map(|obligations| {
+                obligations.into_iter().map(|obligation| obligation.into()).collect()
+            })
     }
 
     fn clone_opaque_types_for_query_response(&self) -> Vec<(ty::OpaqueTypeKey<'tcx>, Ty<'tcx>)> {