Auto merge of rust-lang#89629 - GuillaumeGomez:rollup-s4r8me6, r=GuillaumeGomez

Rollup of 7 pull requests

Successful merges:

 - rust-lang#89298 (Issue 89193 - Fix ICE when using `usize` and `isize` with SIMD gathers )
 - rust-lang#89461 (Add `deref_into_dyn_supertrait` lint.)
 - rust-lang#89477 (Move items related to computing diffs to a separate file)
 - rust-lang#89559 (RustWrapper: adapt for LLVM API change)
 - rust-lang#89585 (Emit item no type error even if type inference fails)
 - rust-lang#89596 (Make cfg imply doc(cfg))
 - rust-lang#89615 (Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts)

Failed merges:

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

Author: bors

Cargo.lock

@@ -4454,6 +4454,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_infer",
+ "rustc_lint_defs",
  "rustc_macros",
  "rustc_middle",
  "rustc_parse_format",

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -279,6 +279,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 
                 gate_doc!(
                     cfg => doc_cfg
+                    cfg_hide => doc_cfg_hide
                     masked => doc_masked
                     notable_trait => doc_notable_trait
                     keyword => doc_keyword

compiler/rustc_borrowck/src/consumers.rs

@@ -31,7 +31,7 @@ pub fn get_body_with_borrowck_facts<'tcx>(
     def: ty::WithOptConstParam<LocalDefId>,
 ) -> BodyWithBorrowckFacts<'tcx> {
     let (input_body, promoted) = tcx.mir_promoted(def);
-    tcx.infer_ctxt().enter(|infcx| {
+    tcx.infer_ctxt().with_opaque_type_inference(def.did).enter(|infcx| {
         let input_body: &Body<'_> = &input_body.borrow();
         let promoted: &IndexVec<_, _> = &promoted.borrow();
         *super::do_mir_borrowck(&infcx, input_body, promoted, true).1.unwrap()

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -20,7 +20,7 @@ use rustc_middle::ty::{self, Ty};
 use rustc_middle::{bug, span_bug};
 use rustc_span::{sym, symbol::kw, Span, Symbol};
 use rustc_target::abi::{self, HasDataLayout, Primitive};
-use rustc_target::spec::PanicStrategy;
+use rustc_target::spec::{HasTargetSpec, PanicStrategy};
 
 use std::cmp::Ordering;
 use std::iter;
@@ -1190,11 +1190,28 @@ fn generic_simd_intrinsic(
     // FIXME: use:
     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Function.h#L182
     //  https://github.com/llvm-mirror/llvm/blob/master/include/llvm/IR/Intrinsics.h#L81
-    fn llvm_vector_str(elem_ty: Ty<'_>, vec_len: u64, no_pointers: usize) -> String {
+    fn llvm_vector_str(
+        elem_ty: Ty<'_>,
+        vec_len: u64,
+        no_pointers: usize,
+        bx: &Builder<'a, 'll, 'tcx>,
+    ) -> String {
         let p0s: String = "p0".repeat(no_pointers);
         match *elem_ty.kind() {
-            ty::Int(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
-            ty::Uint(v) => format!("v{}{}i{}", vec_len, p0s, v.bit_width().unwrap()),
+            ty::Int(v) => format!(
+                "v{}{}i{}",
+                vec_len,
+                p0s,
+                // Normalize to prevent crash if v: IntTy::Isize
+                v.normalize(bx.target_spec().pointer_width).bit_width().unwrap()
+            ),
+            ty::Uint(v) => format!(
+                "v{}{}i{}",
+                vec_len,
+                p0s,
+                // Normalize to prevent crash if v: UIntTy::Usize
+                v.normalize(bx.target_spec().pointer_width).bit_width().unwrap()
+            ),
             ty::Float(v) => format!("v{}{}f{}", vec_len, p0s, v.bit_width()),
             _ => unreachable!(),
         }
@@ -1330,11 +1347,11 @@ fn generic_simd_intrinsic(
 
         // Type of the vector of pointers:
         let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count);
-        let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
+        let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count, bx);
 
         // Type of the vector of elements:
         let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1);
-        let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
+        let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1, bx);
 
         let llvm_intrinsic =
             format!("llvm.masked.gather.{}.{}", llvm_elem_vec_str, llvm_pointer_vec_str);
@@ -1458,11 +1475,11 @@ fn generic_simd_intrinsic(
 
         // Type of the vector of pointers:
         let llvm_pointer_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count);
-        let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count);
+        let llvm_pointer_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count, bx);
 
         // Type of the vector of elements:
         let llvm_elem_vec_ty = llvm_vector_ty(bx, underlying_ty, in_len, pointer_count - 1);
-        let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1);
+        let llvm_elem_vec_str = llvm_vector_str(underlying_ty, in_len, pointer_count - 1, bx);
 
         let llvm_intrinsic =
             format!("llvm.masked.scatter.{}.{}", llvm_elem_vec_str, llvm_pointer_vec_str);

compiler/rustc_feature/src/active.rs

@@ -675,6 +675,9 @@ declare_features! (
     /// Allows `#[track_caller]` on closures and generators.
     (active, closure_track_caller, "1.57.0", Some(87417), None),
 
+    /// Allows `#[doc(cfg_hide(...))]`.
+    (active, doc_cfg_hide, "1.57.0", Some(43781), None),
+
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------

compiler/rustc_lint_defs/src/builtin.rs

@@ -3051,6 +3051,7 @@ declare_lint_pass! {
         BREAK_WITH_LABEL_AND_LOOP,
         UNUSED_ATTRIBUTES,
         NON_EXHAUSTIVE_OMITTED_PATTERNS,
+        DEREF_INTO_DYN_SUPERTRAIT,
     ]
 }
 
@@ -3512,3 +3513,48 @@ declare_lint! {
     Allow,
     "detect when patterns of types marked `non_exhaustive` are missed",
 }
+
+declare_lint! {
+    /// The `deref_into_dyn_supertrait` lint is output whenever there is a use of the
+    /// `Deref` implementation with a `dyn SuperTrait` type as `Output`.
+    ///
+    /// These implementations will become shadowed when the `trait_upcasting` feature is stablized.
+    /// The `deref` functions will no longer be called implicitly, so there might be behavior change.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// #![deny(deref_into_dyn_supertrait)]
+    /// #![allow(dead_code)]
+    ///
+    /// use core::ops::Deref;
+    ///
+    /// trait A {}
+    /// trait B: A {}
+    /// impl<'a> Deref for dyn 'a + B {
+    ///     type Target = dyn A;
+    ///     fn deref(&self) -> &Self::Target {
+    ///         todo!()
+    ///     }
+    /// }
+    ///
+    /// fn take_a(_: &dyn A) { }
+    ///
+    /// fn take_b(b: &dyn B) {
+    ///     take_a(b);
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// The dyn upcasting coercion feature adds new coercion rules, taking priority
+    /// over certain other coercion rules, which will cause some behavior change.
+    pub DEREF_INTO_DYN_SUPERTRAIT,
+    Warn,
+    "`Deref` implementation usage with a supertrait trait object for output might be shadowed in the future",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #89460 <https://github.com/rust-lang/rust/issues/89460>",
+    };
+}

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -54,7 +54,11 @@ static LLVM_THREAD_LOCAL char *LastError;
 //
 // Notably it exits the process with code 101, unlike LLVM's default of 1.
 static void FatalErrorHandler(void *UserData,
+#if LLVM_VERSION_LT(14, 0)
                               const std::string& Reason,
+#else
+                              const char* Reason,
+#endif
                               bool GenCrashDiag) {
   // Do the same thing that the default error handler does.
   std::cerr << "LLVM ERROR: " << Reason << std::endl;

compiler/rustc_passes/src/check_attr.rs

@@ -938,6 +938,7 @@ impl CheckAttrVisitor<'tcx> {
                         // plugins: removed, but rustdoc warns about it itself
                         sym::alias
                         | sym::cfg
+                        | sym::cfg_hide
                         | sym::hidden
                         | sym::html_favicon_url
                         | sym::html_logo_url

compiler/rustc_span/src/symbol.rs

@@ -399,6 +399,7 @@ symbols! {
         cfg_attr_multi,
         cfg_doctest,
         cfg_eval,
+        cfg_hide,
         cfg_panic,
         cfg_sanitize,
         cfg_target_abi,
@@ -547,6 +548,7 @@ symbols! {
         doc,
         doc_alias,
         doc_cfg,
+        doc_cfg_hide,
         doc_keyword,
         doc_masked,
         doc_notable_trait,

compiler/rustc_trait_selection/Cargo.toml

@@ -17,6 +17,7 @@ rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_infer = { path = "../rustc_infer" }
+rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_query_system = { path = "../rustc_query_system" }
 rustc_session = { path = "../rustc_session" }

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

@@ -6,12 +6,17 @@
 //!
 //! [rustc dev guide]:https://rustc-dev-guide.rust-lang.org/traits/resolution.html#candidate-assembly
 use rustc_hir as hir;
+use rustc_hir::def_id::DefId;
+use rustc_infer::traits::TraitEngine;
 use rustc_infer::traits::{Obligation, SelectionError, TraitObligation};
+use rustc_lint_defs::builtin::DEREF_INTO_DYN_SUPERTRAIT;
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self, Ty, TypeFoldable};
+use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable, WithConstness};
 use rustc_target::spec::abi::Abi;
 
+use crate::traits;
 use crate::traits::coherence::Conflict;
+use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::{util, SelectionResult};
 use crate::traits::{Overflow, Unimplemented};
 
@@ -672,6 +677,55 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         })
     }
 
+    /// Temporary migration for #89190
+    fn need_migrate_deref_output_trait_object(
+        &mut self,
+        ty: Ty<'tcx>,
+        cause: &traits::ObligationCause<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+    ) -> Option<(Ty<'tcx>, DefId)> {
+        let tcx = self.tcx();
+        if tcx.features().trait_upcasting {
+            return None;
+        }
+
+        // <ty as Deref>
+        let trait_ref = ty::TraitRef {
+            def_id: tcx.lang_items().deref_trait()?,
+            substs: tcx.mk_substs_trait(ty, &[]),
+        };
+
+        let obligation = traits::Obligation::new(
+            cause.clone(),
+            param_env,
+            ty::Binder::dummy(trait_ref).without_const().to_predicate(tcx),
+        );
+        if !self.infcx.predicate_may_hold(&obligation) {
+            return None;
+        }
+
+        let mut fulfillcx = traits::FulfillmentContext::new_in_snapshot();
+        let normalized_ty = fulfillcx.normalize_projection_type(
+            &self.infcx,
+            param_env,
+            ty::ProjectionTy {
+                item_def_id: tcx.lang_items().deref_target()?,
+                substs: trait_ref.substs,
+            },
+            cause.clone(),
+        );
+
+        let data = if let ty::Dynamic(ref data, ..) = normalized_ty.kind() {
+            data
+        } else {
+            return None;
+        };
+
+        let def_id = data.principal_def_id()?;
+
+        return Some((normalized_ty, def_id));
+    }
+
     /// Searches for unsizing that might apply to `obligation`.
     fn assemble_candidates_for_unsizing(
         &mut self,
@@ -732,6 +786,30 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         let principal_a = data_a.principal().unwrap();
                         let target_trait_did = principal_def_id_b.unwrap();
                         let source_trait_ref = principal_a.with_self_ty(self.tcx(), source);
+                        if let Some((deref_output_ty, deref_output_trait_did)) = self
+                            .need_migrate_deref_output_trait_object(
+                                source,
+                                &obligation.cause,
+                                obligation.param_env,
+                            )
+                        {
+                            if deref_output_trait_did == target_trait_did {
+                                self.tcx().struct_span_lint_hir(
+                                    DEREF_INTO_DYN_SUPERTRAIT,
+                                    obligation.cause.body_id,
+                                    obligation.cause.span,
+                                    |lint| {
+                                        lint.build(&format!(
+                                            "`{}` implements `Deref` with supertrait `{}` as output",
+                                            source,
+                                            deref_output_ty
+                                        )).emit();
+                                    },
+                                );
+                                return;
+                            }
+                        }
+
                         for (idx, upcast_trait_ref) in
                             util::supertraits(self.tcx(), source_trait_ref).enumerate()
                         {

compiler/rustc_typeck/src/collect/type_of.rs

@@ -752,29 +752,31 @@ fn infer_placeholder_type<'a>(
     // us to improve in typeck so we do that now.
     match tcx.sess.diagnostic().steal_diagnostic(span, StashKey::ItemNoType) {
         Some(mut err) => {
-            // The parser provided a sub-optimal `HasPlaceholders` suggestion for the type.
-            // We are typeck and have the real type, so remove that and suggest the actual type.
-            err.suggestions.clear();
-
-            // Suggesting unnameable types won't help.
-            let mut mk_nameable = MakeNameable::new(tcx);
-            let ty = mk_nameable.fold_ty(ty);
-            let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
-            if let Some(sugg_ty) = sugg_ty {
-                err.span_suggestion(
-                    span,
-                    &format!("provide a type for the {item}", item = kind),
-                    format!("{}: {}", item_ident, sugg_ty),
-                    Applicability::MachineApplicable,
-                );
-            } else {
-                err.span_note(
-                    tcx.hir().body(body_id).value.span,
-                    &format!("however, the inferred type `{}` cannot be named", ty.to_string()),
-                );
+            if !ty.references_error() {
+                // The parser provided a sub-optimal `HasPlaceholders` suggestion for the type.
+                // We are typeck and have the real type, so remove that and suggest the actual type.
+                err.suggestions.clear();
+
+                // Suggesting unnameable types won't help.
+                let mut mk_nameable = MakeNameable::new(tcx);
+                let ty = mk_nameable.fold_ty(ty);
+                let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
+                if let Some(sugg_ty) = sugg_ty {
+                    err.span_suggestion(
+                        span,
+                        &format!("provide a type for the {item}", item = kind),
+                        format!("{}: {}", item_ident, sugg_ty),
+                        Applicability::MachineApplicable,
+                    );
+                } else {
+                    err.span_note(
+                        tcx.hir().body(body_id).value.span,
+                        &format!("however, the inferred type `{}` cannot be named", ty.to_string()),
+                    );
+                }
             }
 
-            err.emit_unless(ty.references_error());
+            err.emit();
         }
         None => {
             let mut diag = bad_placeholder_type(tcx, vec![span], kind);

library/alloc/src/lib.rs

@@ -67,6 +67,10 @@
     issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
     test(no_crate_inject, attr(allow(unused_variables), deny(warnings)))
 )]
+#![cfg_attr(
+    not(bootstrap),
+    doc(cfg_hide(not(test), not(any(test, bootstrap)), target_has_atomic = "ptr"))
+)]
 #![no_std]
 #![needs_allocator]
 #![warn(deprecated_in_future)]
@@ -146,6 +150,8 @@
 #![feature(associated_type_bounds)]
 #![feature(slice_group_by)]
 #![feature(decl_macro)]
+#![feature(doc_cfg)]
+#![cfg_attr(not(bootstrap), feature(doc_cfg_hide))]
 // Allow testing this library
 
 #[cfg(test)]