Rollup of 7 pull requests

compiler/rustc_abi/src/lib.rs

@@ -36,6 +36,7 @@ even other Rust compilers, such as rust-analyzer!
 
 */
 
+use std::cmp::min;
 use std::fmt;
 #[cfg(feature = "nightly")]
 use std::iter::Step;
@@ -1060,14 +1061,8 @@ impl Align {
     /// Either `1 << (pointer_bits - 1)` or [`Align::MAX`], whichever is smaller.
     #[inline]
     pub fn max_for_target(tdl: &TargetDataLayout) -> Align {
-        let pointer_bits = tdl.pointer_size().bits();
-        if let Ok(pointer_bits) = u8::try_from(pointer_bits)
-            && pointer_bits <= Align::MAX.pow2
-        {
-            Align { pow2: pointer_bits - 1 }
-        } else {
-            Align::MAX
-        }
+        let pointer_bits = u8::try_from(tdl.pointer_size().bits()).unwrap();
+        min(Align { pow2: pointer_bits - 1 }, Align::MAX)
     }
 
     #[inline]

compiler/rustc_const_eval/src/const_eval/valtrees.rs

@@ -1,4 +1,5 @@
 use rustc_abi::{BackendRepr, FieldIdx, VariantIdx};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_middle::mir::interpret::{EvalToValTreeResult, GlobalId, ValTreeCreationError};
 use rustc_middle::traits::ObligationCause;
@@ -17,13 +18,15 @@ use crate::interpret::{
     intern_const_alloc_recursive,
 };
 
-#[instrument(skip(ecx), level = "debug")]
+#[instrument(skip(ecx, visited, settled), level = "debug")]
 fn branches<'tcx>(
     ecx: &CompileTimeInterpCx<'tcx>,
     place: &MPlaceTy<'tcx>,
     field_count: usize,
     variant: Option<VariantIdx>,
     num_nodes: &mut usize,
+    visited: &mut FxHashSet<MPlaceTy<'tcx>>,
+    settled: &mut FxHashMap<MPlaceTy<'tcx>, EvalToValTreeResult<'tcx>>,
 ) -> EvalToValTreeResult<'tcx> {
     let place = match variant {
         Some(variant) => ecx.project_downcast(place, variant).unwrap(),
@@ -45,7 +48,7 @@ fn branches<'tcx>(
 
     for i in 0..field_count {
         let field = ecx.project_field(&place, FieldIdx::from_usize(i)).unwrap();
-        let valtree = const_to_valtree_inner(ecx, &field, num_nodes)?;
+        let valtree = const_to_valtree_inner(ecx, &field, num_nodes, visited, settled)?;
         branches.push(ty::Const::new_value(*ecx.tcx, valtree, field.layout.ty));
     }
 
@@ -57,39 +60,53 @@ fn branches<'tcx>(
     Ok(ty::ValTree::from_branches(*ecx.tcx, branches))
 }
 
-#[instrument(skip(ecx), level = "debug")]
+#[instrument(skip(ecx, visited, settled), level = "debug")]
 fn slice_branches<'tcx>(
     ecx: &CompileTimeInterpCx<'tcx>,
     place: &MPlaceTy<'tcx>,
     num_nodes: &mut usize,
+    visited: &mut FxHashSet<MPlaceTy<'tcx>>,
+    settled: &mut FxHashMap<MPlaceTy<'tcx>, EvalToValTreeResult<'tcx>>,
 ) -> EvalToValTreeResult<'tcx> {
     let n = place.len(ecx).unwrap_or_else(|_| panic!("expected to use len of place {place:?}"));
 
     let mut elems = Vec::with_capacity(n as usize);
     for i in 0..n {
         let place_elem = ecx.project_index(place, i).unwrap();
-        let valtree = const_to_valtree_inner(ecx, &place_elem, num_nodes)?;
+        let valtree = const_to_valtree_inner(ecx, &place_elem, num_nodes, visited, settled)?;
         elems.push(ty::Const::new_value(*ecx.tcx, valtree, place_elem.layout.ty));
     }
 
     Ok(ty::ValTree::from_branches(*ecx.tcx, elems))
 }
 
-#[instrument(skip(ecx), level = "debug")]
+#[instrument(skip(ecx, visited, settled), level = "debug")]
 fn const_to_valtree_inner<'tcx>(
     ecx: &CompileTimeInterpCx<'tcx>,
     place: &MPlaceTy<'tcx>,
     num_nodes: &mut usize,
+    visited: &mut FxHashSet<MPlaceTy<'tcx>>,
+    settled: &mut FxHashMap<MPlaceTy<'tcx>, EvalToValTreeResult<'tcx>>,
 ) -> EvalToValTreeResult<'tcx> {
     let tcx = *ecx.tcx;
     let ty = place.layout.ty;
     debug!("ty kind: {:?}", ty.kind());
 
+    if let Some(&result) = settled.get(place) {
+        return result;
+    }
+
+    if visited.contains(place) {
+        return Err(ValTreeCreationError::CyclicConst);
+    }
+
     if *num_nodes >= VALTREE_MAX_NODES {
         return Err(ValTreeCreationError::NodesOverflow);
     }
 
-    match ty.kind() {
+    visited.insert(place.clone());
+
+    let result = ensure_sufficient_stack(|| match ty.kind() {
         ty::FnDef(..) => {
             *num_nodes += 1;
             Ok(ty::ValTree::zst(tcx))
@@ -108,7 +125,7 @@ fn const_to_valtree_inner<'tcx>(
             // Since the returned valtree does not contain the type or layout, we can just
             // switch to the base type.
             place.layout = ecx.layout_of(*base).unwrap();
-            ensure_sufficient_stack(|| const_to_valtree_inner(ecx, &place, num_nodes))
+            const_to_valtree_inner(ecx, &place, num_nodes, visited, settled)
         }
 
         ty::RawPtr(_, _) => {
@@ -120,16 +137,16 @@ fn const_to_valtree_inner<'tcx>(
             // We could allow wide raw pointers where both sides are integers in the future,
             // but for now we reject them.
             if matches!(val.layout.backend_repr, BackendRepr::ScalarPair(..)) {
-                return Err(ValTreeCreationError::NonSupportedType(ty));
+                Err(ValTreeCreationError::NonSupportedType(ty))
+            } else {
+                let val = val.to_scalar();
+                // We are in the CTFE machine, so ptr-to-int casts will fail.
+                // This can only be `Ok` if `val` already is an integer.
+                match val.try_to_scalar_int() {
+                    Ok(val) => Ok(ty::ValTree::from_scalar_int(tcx, val)),
+                    Err(_) => Err(ValTreeCreationError::NonSupportedType(ty)),
+                }
             }
-            let val = val.to_scalar();
-            // We are in the CTFE machine, so ptr-to-int casts will fail.
-            // This can only be `Ok` if `val` already is an integer.
-            let Ok(val) = val.try_to_scalar_int() else {
-                return Err(ValTreeCreationError::NonSupportedType(ty));
-            };
-            // It's just a ScalarInt!
-            Ok(ty::ValTree::from_scalar_int(tcx, val))
         }
 
         // Technically we could allow function pointers (represented as `ty::Instance`), but this is not guaranteed to
@@ -138,33 +155,39 @@ fn const_to_valtree_inner<'tcx>(
 
         ty::Ref(_, _, _) => {
             let derefd_place = ecx.deref_pointer(place).report_err()?;
-            const_to_valtree_inner(ecx, &derefd_place, num_nodes)
+            const_to_valtree_inner(ecx, &derefd_place, num_nodes, visited, settled)
         }
 
-        ty::Str | ty::Slice(_) | ty::Array(_, _) => slice_branches(ecx, place, num_nodes),
+        ty::Str | ty::Slice(_) | ty::Array(_, _) => {
+            slice_branches(ecx, place, num_nodes, visited, settled)
+        }
         // Trait objects are not allowed in type level constants, as we have no concept for
         // resolving their backing type, even if we can do that at const eval time. We may
         // hypothetically be able to allow `dyn StructuralPartialEq` trait objects in the future,
         // but it is unclear if this is useful.
         ty::Dynamic(..) => Err(ValTreeCreationError::NonSupportedType(ty)),
 
-        ty::Tuple(elem_tys) => branches(ecx, place, elem_tys.len(), None, num_nodes),
+        ty::Tuple(elem_tys) => {
+            branches(ecx, place, elem_tys.len(), None, num_nodes, visited, settled)
+        }
 
         ty::Adt(def, _) => {
             if def.is_union() {
-                return Err(ValTreeCreationError::NonSupportedType(ty));
+                Err(ValTreeCreationError::NonSupportedType(ty))
             } else if def.variants().is_empty() {
                 bug!("uninhabited types should have errored and never gotten converted to valtree")
+            } else {
+                let variant = ecx.read_discriminant(place).report_err()?;
+                branches(
+                    ecx,
+                    place,
+                    def.variant(variant).fields.len(),
+                    def.is_enum().then_some(variant),
+                    num_nodes,
+                    visited,
+                    settled,
+                )
             }
-
-            let variant = ecx.read_discriminant(place).report_err()?;
-            branches(
-                ecx,
-                place,
-                def.variant(variant).fields.len(),
-                def.is_enum().then_some(variant),
-                num_nodes,
-            )
         }
 
         // FIXME(oli-obk): we could look behind opaque types
@@ -186,7 +209,11 @@ fn const_to_valtree_inner<'tcx>(
         | ty::Coroutine(..)
         | ty::CoroutineWitness(..)
         | ty::UnsafeBinder(_) => Err(ValTreeCreationError::NonSupportedType(ty)),
-    }
+    });
+
+    visited.remove(place);
+    settled.insert(place.clone(), result);
+    result
 }
 
 /// Valtrees don't store the `MemPlaceMeta` that all dynamically sized values have in the interpreter.
@@ -257,7 +284,9 @@ pub(crate) fn eval_to_valtree<'tcx>(
     debug!(?place);
 
     let mut num_nodes = 0;
-    const_to_valtree_inner(&ecx, &place, &mut num_nodes)
+    let mut visited = FxHashSet::default();
+    let mut settled = FxHashMap::default();
+    const_to_valtree_inner(&ecx, &place, &mut num_nodes, &mut visited, &mut settled)
 }
 
 /// Converts a `ValTree` to a `ConstValue`, which is needed after mir

compiler/rustc_middle/src/error.rs

@@ -144,6 +144,15 @@ pub(crate) struct InvalidConstInValtree {
     pub global_const_id: String,
 }
 
+#[derive(Diagnostic)]
+#[diag("constant {$global_const_id} cannot be used as pattern")]
+#[note("constants whose type references itself cannot be used as patterns")]
+pub(crate) struct CyclicConstInValtree {
+    #[primary_span]
+    pub span: Span,
+    pub global_const_id: String,
+}
+
 #[derive(Diagnostic)]
 #[diag("internal compiler error: reentrant incremental verify failure, suppressing message")]
 pub(crate) struct Reentrant;

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -105,6 +105,8 @@ pub enum ValTreeCreationError<'tcx> {
     InvalidConst,
     /// Values of this type, or this particular value, are not supported as valtrees.
     NonSupportedType(Ty<'tcx>),
+    /// Trying to valtree this constant would cause the valtree to have cycles.
+    CyclicConst,
     /// The error has already been handled by const evaluation.
     ErrorHandled(ErrorHandled),
 }

compiler/rustc_middle/src/mir/interpret/queries.rs

@@ -232,6 +232,13 @@ impl<'tcx> TyCtxt<'tcx> {
                         });
                         Err(ReportedErrorInfo::allowed_in_infallible(handled).into())
                     }
+                    ValTreeCreationError::CyclicConst => {
+                        let handled = self.dcx().emit_err(error::CyclicConstInValtree {
+                            span,
+                            global_const_id: cid.display(self),
+                        });
+                        Err(ReportedErrorInfo::allowed_in_infallible(handled).into())
+                    }
                     ValTreeCreationError::ErrorHandled(handled) => Err(handled),
                 }
             }

compiler/rustc_middle/src/ty/mod.rs

@@ -1128,6 +1128,23 @@ impl<'tcx> TypingEnv<'tcx> {
         Self::new(tcx.param_env(def_id), TypingMode::non_body_analysis())
     }
 
+    /// Ideally we just use `TypingMode::PostTypeckUntilBorrowck`.
+    /// But that's not compatible with the old solver yet.
+    ///
+    /// FIXME: this should not be needed in the long term.
+    pub fn post_typeck_until_borrowck_for_mir_build(
+        tcx: TyCtxt<'tcx>,
+        def_id: LocalDefId,
+    ) -> TypingEnv<'tcx> {
+        if tcx.use_typing_mode_post_typeck_until_borrowck() {
+            TypingEnv::new(tcx.param_env(def_id.to_def_id()), ty::TypingMode::borrowck(tcx, def_id))
+        } else {
+            // FIXME(#132279): We're in a body, we should use a typing
+            // mode which reveals the opaque types defined by that body.
+            TypingEnv::non_body_analysis(tcx, def_id)
+        }
+    }
+
     pub fn post_analysis(tcx: TyCtxt<'tcx>, def_id: impl IntoQueryKey<DefId>) -> TypingEnv<'tcx> {
         TypingEnv::new(tcx.param_env_normalized_for_post_analysis(def_id), TypingMode::PostAnalysis)
     }

compiler/rustc_mir_build/src/builder/mod.rs

@@ -505,9 +505,15 @@ fn construct_fn<'tcx>(
         );
     }
 
-    // FIXME(#132279): This should be able to reveal opaque
-    // types defined during HIR typeck.
-    let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
+    let typing_mode = if tcx.use_typing_mode_post_typeck_until_borrowck() {
+        TypingMode::borrowck(tcx, fn_def)
+    } else {
+        // FIXME(#132279): This should be able to reveal opaque
+        // types defined during HIR typeck.
+        TypingMode::non_body_analysis()
+    };
+
+    let infcx = tcx.infer_ctxt().build(typing_mode);
     let mut builder = Builder::new(
         thir,
         infcx,
@@ -587,9 +593,15 @@ fn construct_const<'a, 'tcx>(
         _ => span_bug!(tcx.def_span(def), "can't build MIR for {:?}", def),
     };
 
-    // FIXME(#132279): We likely want to be able to use the hidden types of
-    // opaques used by this function here.
-    let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
+    let typing_mode = if tcx.use_typing_mode_post_typeck_until_borrowck() {
+        TypingMode::borrowck(tcx, def)
+    } else {
+        // FIXME(#132279): This should be able to reveal opaque
+        // types defined during HIR typeck.
+        TypingMode::non_body_analysis()
+    };
+
+    let infcx = tcx.infer_ctxt().build(typing_mode);
     let mut builder =
         Builder::new(thir, infcx, def, hir_id, span, 0, const_ty, const_ty_span, None);
 

compiler/rustc_mir_build/src/builder/scope.rs

@@ -968,8 +968,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             tcx: self.tcx,
             typeck_results,
             module: self.tcx.parent_module(self.hir_id).to_def_id(),
-            // FIXME(#132279): We're in a body, should handle opaques.
-            typing_env: rustc_middle::ty::TypingEnv::non_body_analysis(self.tcx, self.def_id),
+            typing_env: ty::TypingEnv::post_typeck_until_borrowck_for_mir_build(
+                self.tcx,
+                self.def_id,
+            ),
             dropless_arena: &dropless_arena,
             match_lint_level: self.hir_id,
             whole_match_span: Some(rustc_span::Span::default()),

compiler/rustc_mir_build/src/check_tail_calls.rs

@@ -27,8 +27,7 @@ pub(crate) fn check_tail_calls(tcx: TyCtxt<'_>, def: LocalDefId) -> Result<(), E
         tcx,
         thir,
         found_errors: Ok(()),
-        // FIXME(#132279): we're clearly in a body here.
-        typing_env: ty::TypingEnv::non_body_analysis(tcx, def),
+        typing_env: ty::TypingEnv::post_typeck_until_borrowck_for_mir_build(tcx, def),
         is_closure,
         caller_def_id: def,
     };

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -1093,8 +1093,7 @@ pub(crate) fn check_unsafety(tcx: TyCtxt<'_>, def: LocalDefId) {
         body_target_features,
         assignment_info: None,
         in_union_destructure: false,
-        // FIXME(#132279): we're clearly in a body here.
-        typing_env: ty::TypingEnv::non_body_analysis(tcx, def),
+        typing_env: ty::TypingEnv::post_typeck_until_borrowck_for_mir_build(tcx, def),
         inside_adt: false,
         warnings: &mut warnings,
         suggest_unsafe_block: true,

compiler/rustc_mir_build/src/thir/cx/mod.rs

@@ -99,9 +99,7 @@ impl<'tcx> ThirBuildCx<'tcx> {
         Self {
             tcx,
             thir: Thir::new(body_type),
-            // FIXME(#132279): We're in a body, we should use a typing
-            // mode which reveals the opaque types defined by that body.
-            typing_env: ty::TypingEnv::non_body_analysis(tcx, def),
+            typing_env: ty::TypingEnv::post_typeck_until_borrowck_for_mir_build(tcx, def),
             typeck_results,
             body_owner: def.to_def_id(),
             apply_adjustments: !find_attr!(tcx, hir_id, CustomMir(..)),

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -39,8 +39,7 @@ pub(crate) fn check_match(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Result<(), Err
         tcx,
         thir: &*thir,
         typeck_results,
-        // FIXME(#132279): We're in a body, should handle opaques.
-        typing_env: ty::TypingEnv::non_body_analysis(tcx, def_id),
+        typing_env: ty::TypingEnv::post_typeck_until_borrowck_for_mir_build(tcx, def_id),
         hir_source: tcx.local_def_id_to_hir_id(def_id),
         let_source: LetSource::None,
         pattern_arena: &pattern_arena,