Auto merge of #89449 - Manishearth:rollup-3alb61f, r=Manishearth

Rollup of 7 pull requests

Successful merges:

 - #85223 (rustdoc: Clarified the attribute which prompts the warning)
 - #88847 (platform-support.md: correct ARMv7+MUSL platform triple notes)
 - #88963 (Coerce const FnDefs to implement const Fn traits )
 - #89376 (Fix use after drop in self-profile with llvm events)
 - #89422 (Replace whitespaces in doctests' name with dashes)
 - #89440 (Clarify a sentence in the documentation of Vec (#84488))
 - #89441 (Normalize after substituting via `field.ty()`)

Failed merges:

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

Author: bors

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -406,13 +406,15 @@ pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
         None
     };
 
-    let llvm_selfprofiler = if cgcx.prof.llvm_recording_enabled() {
-        let mut llvm_profiler = LlvmSelfProfiler::new(cgcx.prof.get_self_profiler().unwrap());
-        &mut llvm_profiler as *mut _ as *mut c_void
+    let mut llvm_profiler = if cgcx.prof.llvm_recording_enabled() {
+        Some(LlvmSelfProfiler::new(cgcx.prof.get_self_profiler().unwrap()))
     } else {
-        std::ptr::null_mut()
+        None
     };
 
+    let llvm_selfprofiler =
+        llvm_profiler.as_mut().map(|s| s as *mut _ as *mut c_void).unwrap_or(std::ptr::null_mut());
+
     let extra_passes = config.passes.join(",");
 
     // FIXME: NewPM doesn't provide a facility to pass custom InlineParams.

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -6,23 +6,6 @@ use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::Symbol;
 use rustc_target::spec::abi::Abi;
 
-/// Whether the `def_id` counts as const fn in your current crate, considering all active
-/// feature gates
-pub fn is_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-    tcx.is_const_fn_raw(def_id)
-        && match is_unstable_const_fn(tcx, def_id) {
-            Some(feature_name) => {
-                // has a `rustc_const_unstable` attribute, check whether the user enabled the
-                // corresponding feature gate.
-                tcx.features().declared_lib_features.iter().any(|&(sym, _)| sym == feature_name)
-            }
-            // functions without const stability are either stable user written
-            // const fn or the user is using feature gates and we thus don't
-            // care what they do
-            None => true,
-        }
-}
-
 /// Whether the `def_id` is an unstable const fn and what feature gate is necessary to enable it
 pub fn is_unstable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Symbol> {
     if tcx.is_const_fn_raw(def_id) {
@@ -77,7 +60,7 @@ fn is_const_fn_raw(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 }
 
 fn is_promotable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
-    is_const_fn(tcx, def_id)
+    tcx.is_const_fn(def_id)
         && match tcx.lookup_const_stability(def_id) {
             Some(stab) => {
                 if cfg!(debug_assertions) && stab.promotable {

compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -26,7 +26,6 @@ use rustc_index::vec::{Idx, IndexVec};
 use std::cell::Cell;
 use std::{cmp, iter, mem};
 
-use crate::const_eval::{is_const_fn, is_unstable_const_fn};
 use crate::transform::check_consts::{is_lang_panic_fn, qualifs, ConstCx};
 use crate::transform::MirPass;
 
@@ -658,9 +657,7 @@ impl<'tcx> Validator<'_, 'tcx> {
 
         let is_const_fn = match *fn_ty.kind() {
             ty::FnDef(def_id, _) => {
-                is_const_fn(self.tcx, def_id)
-                    || is_unstable_const_fn(self.tcx, def_id).is_some()
-                    || is_lang_panic_fn(self.tcx, def_id)
+                self.tcx.is_const_fn_raw(def_id) || is_lang_panic_fn(self.tcx, def_id)
             }
             _ => false,
         };
@@ -1081,7 +1078,7 @@ pub fn is_const_fn_in_array_repeat_expression<'tcx>(
                 if let ty::FnDef(def_id, _) = *literal.ty().kind() {
                     if let Some((destination_place, _)) = destination {
                         if destination_place == place {
-                            if is_const_fn(ccx.tcx, def_id) {
+                            if ccx.tcx.is_const_fn(def_id) {
                                 return true;
                             }
                         }

compiler/rustc_middle/src/traits/select.rs

@@ -120,7 +120,9 @@ pub enum SelectionCandidate<'tcx> {
 
     /// Implementation of a `Fn`-family trait by one of the anonymous
     /// types generated for a fn pointer type (e.g., `fn(int) -> int`)
-    FnPointerCandidate,
+    FnPointerCandidate {
+        is_const: bool,
+    },
 
     /// Builtin implementation of `DiscriminantKind`.
     DiscriminantKindCandidate,

compiler/rustc_middle/src/ty/context.rs

@@ -2701,6 +2701,29 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn lifetime_scope(self, id: HirId) -> Option<LifetimeScopeForPath> {
         self.lifetime_scope_map(id.owner).and_then(|mut map| map.remove(&id.local_id))
     }
+
+    /// Whether the `def_id` counts as const fn in the current crate, considering all active
+    /// feature gates
+    pub fn is_const_fn(self, def_id: DefId) -> bool {
+        if self.is_const_fn_raw(def_id) {
+            match self.lookup_const_stability(def_id) {
+                Some(stability) if stability.level.is_unstable() => {
+                    // has a `rustc_const_unstable` attribute, check whether the user enabled the
+                    // corresponding feature gate.
+                    self.features()
+                        .declared_lib_features
+                        .iter()
+                        .any(|&(sym, _)| sym == stability.feature)
+                }
+                // functions without const stability are either stable user written
+                // const fn or the user is using feature gates and we thus don't
+                // care what they do
+                _ => true,
+            }
+        } else {
+            false
+        }
+    }
 }
 
 impl TyCtxtAt<'tcx> {

compiler/rustc_middle/src/ty/mod.rs

@@ -1638,8 +1638,8 @@ impl ReprOptions {
 }
 
 impl<'tcx> FieldDef {
-    /// Returns the type of this field. The `subst` is typically obtained
-    /// via the second field of `TyKind::AdtDef`.
+    /// Returns the type of this field. The resulting type is not normalized. The `subst` is
+    /// typically obtained via the second field of `TyKind::AdtDef`.
     pub fn ty(&self, tcx: TyCtxt<'tcx>, subst: SubstsRef<'tcx>) -> Ty<'tcx> {
         tcx.type_of(self.did).subst(tcx, subst)
     }

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

@@ -1154,6 +1154,8 @@ impl<'p, 'tcx> Fields<'p, 'tcx> {
 
         variant.fields.iter().enumerate().filter_map(move |(i, field)| {
             let ty = field.ty(cx.tcx, substs);
+            // `field.ty()` doesn't normalize after substituting.
+            let ty = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
             let is_visible = adt.is_enum() || field.vis.is_accessible_from(cx.module, cx.tcx);
             let is_uninhabited = cx.is_uninhabited(ty);
 
@@ -1671,7 +1673,7 @@ impl<'p, 'tcx> fmt::Debug for DeconstructedPat<'p, 'tcx> {
                 write!(f, "{}", hi)
             }
             IntRange(range) => write!(f, "{:?}", range), // Best-effort, will render e.g. `false` as `0..=0`
-            Wildcard | Missing { .. } | NonExhaustive => write!(f, "_"),
+            Wildcard | Missing { .. } | NonExhaustive => write!(f, "_ : {:?}", self.ty),
             Or => {
                 for pat in self.iter_fields() {
                     write!(f, "{}{:?}", start_or_continue(" | "), pat)?;

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

@@ -781,8 +781,7 @@ fn is_useful<'p, 'tcx>(
 
     assert!(rows.iter().all(|r| r.len() == v.len()));
 
-    // FIXME(Nadrieril): Hack to work around type normalization issues (see #72476).
-    let ty = matrix.heads().next().map_or(v.head().ty(), |r| r.ty());
+    let ty = v.head().ty();
     let is_non_exhaustive = cx.is_foreign_non_exhaustive_enum(ty);
     let pcx = PatCtxt { cx, ty, span: v.head().span(), is_top_level, is_non_exhaustive };
 

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -476,7 +476,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     ..
                 } = self_ty.fn_sig(self.tcx()).skip_binder()
                 {
-                    candidates.vec.push(FnPointerCandidate);
+                    candidates.vec.push(FnPointerCandidate { is_const: false });
                 }
             }
             // Provide an impl for suitable functions, rejecting `#[target_feature]` functions (RFC 2396).
@@ -489,7 +489,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 } = self_ty.fn_sig(self.tcx()).skip_binder()
                 {
                     if self.tcx().codegen_fn_attrs(def_id).target_features.is_empty() {
-                        candidates.vec.push(FnPointerCandidate);
+                        candidates
+                            .vec
+                            .push(FnPointerCandidate { is_const: self.tcx().is_const_fn(def_id) });
                     }
                 }
             }

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -92,7 +92,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Ok(ImplSource::Generator(vtable_generator))
             }
 
-            FnPointerCandidate => {
+            FnPointerCandidate { .. } => {
                 let data = self.confirm_fn_pointer_candidate(obligation)?;
                 Ok(ImplSource::FnPointer(data))
             }