Auto merge of #98591 - matthiaskrgr:rollup-7dok1wq, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #98331 (Fix rustdoc argument error)
 - #98506 (Fix span issues in object safety suggestions)
 - #98563 (interpret: refactor allocation info query)
 - #98576 (small regions refactoring)
 - #98577 (Fix "kind" for associated types in trait implementations in rustdoc JSON)
 - #98578 (Remove eddyb from miri failure pings)
 - #98579 (liballoc tests: avoid int2ptr cast)
 - #98581 (Add triagebot mentions.)
 - #98587 (libcore tests: avoid int2ptr casts)

Failed merges:

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

compiler/rustc_borrowck/src/diagnostics/region_name.rs

@@ -879,7 +879,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         }
 
         let mut found = false;
-        tcx.fold_regions(tcx.type_of(body_parent_did), &mut true, |r: ty::Region<'tcx>, _| {
+        tcx.fold_regions(tcx.type_of(body_parent_did), |r: ty::Region<'tcx>, _| {
             if *r == ty::ReEarlyBound(region) {
                 found = true;
             }

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -1009,7 +1009,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
 
         debug!("try_promote_type_test_subject(ty = {:?})", ty);
 
-        let ty = tcx.fold_regions(ty, &mut false, |r, _depth| {
+        let ty = tcx.fold_regions(ty, |r, _depth| {
             let region_vid = self.to_region_vid(r);
 
             // The challenge if this. We have some region variable `r`
@@ -1289,7 +1289,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        tcx.fold_regions(value, &mut false, |r, _db| {
+        tcx.fold_regions(value, |r, _db| {
             let vid = self.to_region_vid(r);
             let scc = self.constraint_sccs.scc(vid);
             let repr = self.scc_representatives[scc];

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -59,7 +59,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             debug!(?concrete_type, ?substs);
 
             let mut subst_regions = vec![self.universal_regions.fr_static];
-            let universal_substs = infcx.tcx.fold_regions(substs, &mut false, |region, _| {
+            let universal_substs = infcx.tcx.fold_regions(substs, |region, _| {
                 if let ty::RePlaceholder(..) = region.kind() {
                     // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs.
                     return region;
@@ -91,7 +91,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             subst_regions.dedup();
 
             let universal_concrete_type =
-                infcx.tcx.fold_regions(concrete_type, &mut false, |region, _| match *region {
+                infcx.tcx.fold_regions(concrete_type, |region, _| match *region {
                     ty::ReVar(vid) => subst_regions
                         .iter()
                         .find(|ur_vid| self.eval_equal(vid, **ur_vid))
@@ -146,7 +146,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        tcx.fold_regions(ty, &mut false, |region, _| match *region {
+        tcx.fold_regions(ty, |region, _| match *region {
             ty::ReVar(vid) => {
                 // Find something that we can name
                 let upper_bound = self.approx_universal_upper_bound(vid);

compiler/rustc_borrowck/src/renumber.rs

@@ -31,7 +31,7 @@ pub fn renumber_regions<'tcx, T>(infcx: &InferCtxt<'_, 'tcx>, value: T) -> T
 where
     T: TypeFoldable<'tcx>,
 {
-    infcx.tcx.fold_regions(value, &mut false, |_region, _depth| {
+    infcx.tcx.fold_regions(value, |_region, _depth| {
         let origin = NllRegionVariableOrigin::Existential { from_forall: false };
         infcx.next_nll_region_var(origin)
     })

compiler/rustc_borrowck/src/type_check/constraint_conversion.rs

@@ -23,7 +23,7 @@ pub(crate) struct ConstraintConversion<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     universal_regions: &'a UniversalRegions<'tcx>,
     region_bound_pairs: &'a RegionBoundPairs<'tcx>,
-    implicit_region_bound: Option<ty::Region<'tcx>>,
+    implicit_region_bound: ty::Region<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     locations: Locations,
     span: Span,
@@ -36,7 +36,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
         infcx: &'a InferCtxt<'a, 'tcx>,
         universal_regions: &'a UniversalRegions<'tcx>,
         region_bound_pairs: &'a RegionBoundPairs<'tcx>,
-        implicit_region_bound: Option<ty::Region<'tcx>>,
+        implicit_region_bound: ty::Region<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
         locations: Locations,
         span: Span,
@@ -108,7 +108,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
                 // create new region variables, which can't be done later when
                 // verifying these bounds.
                 if t1.has_placeholders() {
-                    t1 = tcx.fold_regions(t1, &mut false, |r, _| match *r {
+                    t1 = tcx.fold_regions(t1, |r, _| match *r {
                         ty::RePlaceholder(placeholder) => {
                             self.constraints.placeholder_region(self.infcx, placeholder)
                         }
@@ -120,7 +120,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
                     &mut *self,
                     tcx,
                     region_bound_pairs,
-                    implicit_region_bound,
+                    Some(implicit_region_bound),
                     param_env,
                 )
                 .type_must_outlive(origin, t1, r2);

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -61,7 +61,7 @@ pub(crate) struct CreateResult<'tcx> {
 pub(crate) fn create<'tcx>(
     infcx: &InferCtxt<'_, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    implicit_region_bound: Option<ty::Region<'tcx>>,
+    implicit_region_bound: ty::Region<'tcx>,
     universal_regions: &Rc<UniversalRegions<'tcx>>,
     constraints: &mut MirTypeckRegionConstraints<'tcx>,
 ) -> CreateResult<'tcx> {
@@ -223,7 +223,7 @@ struct UniversalRegionRelationsBuilder<'this, 'tcx> {
     infcx: &'this InferCtxt<'this, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     universal_regions: Rc<UniversalRegions<'tcx>>,
-    implicit_region_bound: Option<ty::Region<'tcx>>,
+    implicit_region_bound: ty::Region<'tcx>,
     constraints: &'this mut MirTypeckRegionConstraints<'tcx>,
 
     // outputs:

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -230,7 +230,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 self.infcx,
                 &self.borrowck_context.universal_regions,
                 &self.region_bound_pairs,
-                Some(self.implicit_region_bound),
+                self.implicit_region_bound,
                 self.param_env,
                 Locations::All(DUMMY_SP),
                 DUMMY_SP,

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -157,7 +157,7 @@ pub(crate) fn type_check<'mir, 'tcx>(
     } = free_region_relations::create(
         infcx,
         param_env,
-        Some(implicit_region_bound),
+        implicit_region_bound,
         universal_regions,
         &mut constraints,
     );
@@ -1142,7 +1142,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             self.infcx,
             self.borrowck_context.universal_regions,
             self.region_bound_pairs,
-            Some(self.implicit_region_bound),
+            self.implicit_region_bound,
             self.param_env,
             locations,
             locations.span(self.body),

compiler/rustc_borrowck/src/universal_regions.rs

@@ -725,7 +725,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        self.tcx.fold_regions(value, &mut false, |_region, _depth| self.next_nll_region_var(origin))
+        self.tcx.fold_regions(value, |_region, _depth| self.next_nll_region_var(origin))
     }
 
     #[instrument(level = "debug", skip(self, indices))]
@@ -817,9 +817,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        tcx.fold_regions(value, &mut false, |region, _| {
-            tcx.mk_region(ty::ReVar(self.to_region_vid(region)))
-        })
+        tcx.fold_regions(value, |region, _| tcx.mk_region(ty::ReVar(self.to_region_vid(region))))
     }
 }
 

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -56,15 +56,14 @@ impl<T: fmt::Display> fmt::Display for MemoryKind<T> {
     }
 }
 
-/// Used by `get_size_and_align` to indicate whether the allocation needs to be live.
-#[derive(Debug, Copy, Clone)]
-pub enum AllocCheck {
-    /// Allocation must be live and not a function pointer.
-    Dereferenceable,
-    /// Allocations needs to be live, but may be a function pointer.
-    Live,
-    /// Allocation may be dead.
-    MaybeDead,
+/// The return value of `get_alloc_info` indicates the "kind" of the allocation.
+pub enum AllocKind {
+    /// A regular live data allocation.
+    LiveData,
+    /// A function allocation (that fn ptrs point to).
+    Function,
+    /// A dead allocation.
+    Dead,
 }
 
 /// The value of a function pointer.
@@ -360,8 +359,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             align,
             CheckInAllocMsg::MemoryAccessTest,
             |alloc_id, offset, tag| {
-                let (size, align) =
-                    self.get_alloc_size_and_align(alloc_id, AllocCheck::Dereferenceable)?;
+                let (size, align) = self.get_live_alloc_size_and_align(alloc_id)?;
                 Ok((size, align, (alloc_id, offset, tag)))
             },
         )
@@ -379,15 +377,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         msg: CheckInAllocMsg,
     ) -> InterpResult<'tcx> {
         self.check_and_deref_ptr(ptr, size, Some(align), msg, |alloc_id, _, _| {
-            let check = match msg {
-                CheckInAllocMsg::DerefTest | CheckInAllocMsg::MemoryAccessTest => {
-                    AllocCheck::Dereferenceable
-                }
-                CheckInAllocMsg::PointerArithmeticTest
-                | CheckInAllocMsg::OffsetFromTest
-                | CheckInAllocMsg::InboundsTest => AllocCheck::Live,
-            };
-            let (size, align) = self.get_alloc_size_and_align(alloc_id, check)?;
+            let (size, align) = self.get_live_alloc_size_and_align(alloc_id)?;
             Ok((size, align, ()))
         })?;
         Ok(())
@@ -655,30 +645,19 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
     /// Obtain the size and alignment of an allocation, even if that allocation has
     /// been deallocated.
-    ///
-    /// If `liveness` is `AllocCheck::MaybeDead`, this function always returns `Ok`.
-    pub fn get_alloc_size_and_align(
-        &self,
-        id: AllocId,
-        liveness: AllocCheck,
-    ) -> InterpResult<'tcx, (Size, Align)> {
+    pub fn get_alloc_info(&self, id: AllocId) -> (Size, Align, AllocKind) {
         // # Regular allocations
         // Don't use `self.get_raw` here as that will
         // a) cause cycles in case `id` refers to a static
         // b) duplicate a global's allocation in miri
         if let Some((_, alloc)) = self.memory.alloc_map.get(id) {
-            return Ok((alloc.size(), alloc.align));
+            return (alloc.size(), alloc.align, AllocKind::LiveData);
         }
 
         // # Function pointers
         // (both global from `alloc_map` and local from `extra_fn_ptr_map`)
         if self.get_fn_alloc(id).is_some() {
-            return if let AllocCheck::Dereferenceable = liveness {
-                // The caller requested no function pointers.
-                throw_ub!(DerefFunctionPointer(id))
-            } else {
-                Ok((Size::ZERO, Align::ONE))
-            };
+            return (Size::ZERO, Align::ONE, AllocKind::Function);
         }
 
         // # Statics
@@ -690,32 +669,38 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // Use size and align of the type.
                 let ty = self.tcx.type_of(did);
                 let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
-                Ok((layout.size, layout.align.abi))
+                (layout.size, layout.align.abi, AllocKind::LiveData)
             }
             Some(GlobalAlloc::Memory(alloc)) => {
                 // Need to duplicate the logic here, because the global allocations have
                 // different associated types than the interpreter-local ones.
                 let alloc = alloc.inner();
-                Ok((alloc.size(), alloc.align))
+                (alloc.size(), alloc.align, AllocKind::LiveData)
             }
             Some(GlobalAlloc::Function(_)) => bug!("We already checked function pointers above"),
             // The rest must be dead.
             None => {
-                if let AllocCheck::MaybeDead = liveness {
-                    // Deallocated pointers are allowed, we should be able to find
-                    // them in the map.
-                    Ok(*self
-                        .memory
-                        .dead_alloc_map
-                        .get(&id)
-                        .expect("deallocated pointers should all be recorded in `dead_alloc_map`"))
-                } else {
-                    throw_ub!(PointerUseAfterFree(id))
-                }
+                // Deallocated pointers are allowed, we should be able to find
+                // them in the map.
+                let (size, align) = *self
+                    .memory
+                    .dead_alloc_map
+                    .get(&id)
+                    .expect("deallocated pointers should all be recorded in `dead_alloc_map`");
+                (size, align, AllocKind::Dead)
             }
         }
     }
 
+    /// Obtain the size and alignment of a live allocation.
+    pub fn get_live_alloc_size_and_align(&self, id: AllocId) -> InterpResult<'tcx, (Size, Align)> {
+        let (size, align, kind) = self.get_alloc_info(id);
+        if matches!(kind, AllocKind::Dead) {
+            throw_ub!(PointerUseAfterFree(id))
+        }
+        Ok((size, align))
+    }
+
     fn get_fn_alloc(&self, id: AllocId) -> Option<FnVal<'tcx, M::ExtraFnVal>> {
         if let Some(extra) = self.memory.extra_fn_ptr_map.get(&id) {
             Some(FnVal::Other(*extra))
@@ -1187,9 +1172,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let ptr = self.scalar_to_ptr(scalar)?;
                 match self.ptr_try_get_alloc_id(ptr) {
                     Ok((alloc_id, offset, _)) => {
-                        let (size, _align) = self
-                            .get_alloc_size_and_align(alloc_id, AllocCheck::MaybeDead)
-                            .expect("alloc info with MaybeDead cannot fail");
+                        let (size, _align, _kind) = self.get_alloc_info(alloc_id);
                         // If the pointer is out-of-bounds, it may be null.
                         // Note that one-past-the-end (offset == size) is still inbounds, and never null.
                         offset > size

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -23,7 +23,7 @@ pub use self::eval_context::{
 };
 pub use self::intern::{intern_const_alloc_recursive, InternKind};
 pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackPopJump};
-pub use self::memory::{AllocCheck, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
+pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};
 pub use self::operand::{ImmTy, Immediate, OpTy, Operand};
 pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy};
 pub use self::validity::{CtfeValidationMode, RefTracking};

compiler/rustc_driver/src/lib.rs

@@ -932,7 +932,7 @@ fn describe_codegen_flags() {
     print_flag_list("-C", config::CG_OPTIONS);
 }
 
-fn print_flag_list<T>(
+pub fn print_flag_list<T>(
     cmdline_opt: &str,
     flag_list: &[(&'static str, T, &'static str, &'static str)],
 ) {

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs

@@ -79,7 +79,7 @@ pub fn find_param_with_region<'tcx>(
             // May return None; sometimes the tables are not yet populated.
             let ty = fn_sig.inputs()[index];
             let mut found_anon_region = false;
-            let new_param_ty = tcx.fold_regions(ty, &mut false, |r, _| {
+            let new_param_ty = tcx.fold_regions(ty, |r, _| {
                 if r == anon_region {
                     found_anon_region = true;
                     replace_region

compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs

@@ -868,7 +868,7 @@ impl<'tcx> LexicalRegionResolutions<'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        tcx.fold_regions(value, &mut false, |r, _db| match *r {
+        tcx.fold_regions(value, |r, _db| match *r {
             ty::ReVar(rid) => self.resolve_var(rid),
             _ => r,
         })

compiler/rustc_infer/src/infer/outlives/obligations.rs

@@ -141,17 +141,13 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
     ///   `('a, K)` in this list tells us that the bounds in scope
     ///   indicate that `K: 'a`, where `K` is either a generic
     ///   parameter like `T` or a projection like `T::Item`.
-    /// - `implicit_region_bound`: if some, this is a region bound
-    ///   that is considered to hold for all type parameters (the
-    ///   function body).
     /// - `param_env` is the parameter environment for the enclosing function.
     /// - `body_id` is the body-id whose region obligations are being
     ///   processed.
     #[instrument(level = "debug", skip(self, region_bound_pairs_map))]
     pub fn process_registered_region_obligations(
         &self,
         region_bound_pairs_map: &FxHashMap<hir::HirId, RegionBoundPairs<'tcx>>,
-        implicit_region_bound: Option<ty::Region<'tcx>>,
         param_env: ty::ParamEnv<'tcx>,
     ) {
         assert!(
@@ -170,13 +166,8 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
             let sup_type = self.resolve_vars_if_possible(sup_type);
 
             if let Some(region_bound_pairs) = region_bound_pairs_map.get(&body_id) {
-                let outlives = &mut TypeOutlives::new(
-                    self,
-                    self.tcx,
-                    &region_bound_pairs,
-                    implicit_region_bound,
-                    param_env,
-                );
+                let outlives =
+                    &mut TypeOutlives::new(self, self.tcx, &region_bound_pairs, None, param_env);
                 outlives.type_must_outlive(origin, sup_type, sub_region);
             } else {
                 self.tcx.sess.delay_span_bug(