Auto merge of #91656 - matthiaskrgr:rollup-lk96y6d, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #83744 (Deprecate crate_type and crate_name nested inside #![cfg_attr])
 - #90550 (Update certificates in some Ubuntu 16 images.)
 - #91272 (Print a suggestion when comparing references to primitive types in `const fn`)
 - #91467 (Emphasise that an OsStr[ing] is not necessarily a platform string)
 - #91531 (Do not add `;` to expected tokens list when it's wrong)
 - #91577 (Address some FIXMEs left over from #91475)
 - #91638 (Remove `in_band_lifetimes` from `rustc_mir_transform`)

Failed merges:

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

Author: bors

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -801,7 +801,7 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
                 if let Some(trait_id) = tcx.trait_of_item(callee) {
                     trace!("attempting to call a trait method");
                     if !self.tcx.features().const_trait_impl {
-                        self.check_op(ops::FnCallNonConst);
+                        self.check_op(ops::FnCallNonConst(Some((callee, substs))));
                         return;
                     }
 
@@ -857,7 +857,7 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
                             }
 
                             if !nonconst_call_permission {
-                                self.check_op(ops::FnCallNonConst);
+                                self.check_op(ops::FnCallNonConst(None));
                                 return;
                             }
                         }
@@ -926,7 +926,7 @@ impl Visitor<'tcx> for Checker<'mir, 'tcx> {
                     }
 
                     if !nonconst_call_permission {
-                        self.check_op(ops::FnCallNonConst);
+                        self.check_op(ops::FnCallNonConst(None));
                         return;
                     }
                 }

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -1,12 +1,14 @@
 //! Concrete error types for all operations which may be invalid in a certain const context.
 
-use rustc_errors::{struct_span_err, DiagnosticBuilder};
+use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
-use rustc_middle::mir;
+use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
+use rustc_middle::{mir, ty::AssocKind};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
-use rustc_span::{Span, Symbol};
+use rustc_span::{symbol::Ident, Span, Symbol};
+use rustc_span::{BytePos, Pos};
 
 use super::ConstCx;
 
@@ -72,17 +74,71 @@ impl NonConstOp for FnCallIndirect {
 
 /// A function call where the callee is not marked as `const`.
 #[derive(Debug)]
-pub struct FnCallNonConst;
-impl NonConstOp for FnCallNonConst {
+pub struct FnCallNonConst<'tcx>(pub Option<(DefId, SubstsRef<'tcx>)>);
+impl<'a> NonConstOp for FnCallNonConst<'a> {
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
-        struct_span_err!(
+        let mut err = struct_span_err!(
             ccx.tcx.sess,
             span,
             E0015,
             "calls in {}s are limited to constant functions, \
              tuple structs and tuple variants",
             ccx.const_kind(),
-        )
+        );
+
+        if let FnCallNonConst(Some((callee, substs))) = *self {
+            if let Some(trait_def_id) = ccx.tcx.lang_items().eq_trait() {
+                if let Some(eq_item) = ccx.tcx.associated_items(trait_def_id).find_by_name_and_kind(
+                    ccx.tcx,
+                    Ident::with_dummy_span(sym::eq),
+                    AssocKind::Fn,
+                    trait_def_id,
+                ) {
+                    if callee == eq_item.def_id && substs.len() == 2 {
+                        match (substs[0].unpack(), substs[1].unpack()) {
+                            (GenericArgKind::Type(self_ty), GenericArgKind::Type(rhs_ty))
+                                if self_ty == rhs_ty
+                                    && self_ty.is_ref()
+                                    && self_ty.peel_refs().is_primitive() =>
+                            {
+                                let mut num_refs = 0;
+                                let mut tmp_ty = self_ty;
+                                while let rustc_middle::ty::Ref(_, inner_ty, _) = tmp_ty.kind() {
+                                    num_refs += 1;
+                                    tmp_ty = inner_ty;
+                                }
+                                let deref = "*".repeat(num_refs);
+
+                                if let Ok(call_str) =
+                                    ccx.tcx.sess.source_map().span_to_snippet(span)
+                                {
+                                    if let Some(eq_idx) = call_str.find("==") {
+                                        if let Some(rhs_idx) = call_str[(eq_idx + 2)..]
+                                            .find(|c: char| !c.is_whitespace())
+                                        {
+                                            let rhs_pos = span.lo()
+                                                + BytePos::from_usize(eq_idx + 2 + rhs_idx);
+                                            let rhs_span = span.with_lo(rhs_pos).with_hi(rhs_pos);
+                                            err.multipart_suggestion(
+                                                "consider dereferencing here",
+                                                vec![
+                                                    (span.shrink_to_lo(), deref.clone()),
+                                                    (rhs_span, deref),
+                                                ],
+                                                Applicability::MachineApplicable,
+                                            );
+                                        }
+                                    }
+                                }
+                            }
+                            _ => {}
+                        }
+                    }
+                }
+            }
+        }
+
+        err
     }
 }
 

compiler/rustc_expand/src/config.rs

@@ -402,7 +402,24 @@ impl<'a> StripUnconfigured<'a> {
                 );
                 trees.push((bracket_group, Spacing::Alone));
                 let tokens = Some(LazyTokenStream::new(AttrAnnotatedTokenStream::new(trees)));
-                self.process_cfg_attr(attr::mk_attr_from_item(item, tokens, attr.style, span))
+                let attr = attr::mk_attr_from_item(item, tokens, attr.style, span);
+                if attr.has_name(sym::crate_type) {
+                    self.sess.parse_sess.buffer_lint(
+                        rustc_lint_defs::builtin::DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
+                        attr.span,
+                        ast::CRATE_NODE_ID,
+                        "`crate_type` within an `#![cfg_attr] attribute is deprecated`",
+                    );
+                }
+                if attr.has_name(sym::crate_name) {
+                    self.sess.parse_sess.buffer_lint(
+                        rustc_lint_defs::builtin::DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
+                        attr.span,
+                        ast::CRATE_NODE_ID,
+                        "`crate_name` within an `#![cfg_attr] attribute is deprecated`",
+                    );
+                }
+                self.process_cfg_attr(attr)
             })
             .collect()
     }

compiler/rustc_lint_defs/src/builtin.rs

@@ -2960,6 +2960,41 @@ declare_lint! {
     "detects large moves or copies",
 }
 
+declare_lint! {
+    /// The `deprecated_cfg_attr_crate_type_name` lint detects uses of the
+    /// `#![cfg_attr(..., crate_type = "...")]` and
+    /// `#![cfg_attr(..., crate_name = "...")]` attributes to conditionally
+    /// specify the crate type and name in the source code.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// #![cfg_attr(debug_assertions, crate_type = "lib")]
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    ///
+    /// ### Explanation
+    ///
+    /// The `#![crate_type]` and `#![crate_name]` attributes require a hack in
+    /// the compiler to be able to change the used crate type and crate name
+    /// after macros have been expanded. Neither attribute works in combination
+    /// with Cargo as it explicitly passes `--crate-type` and `--crate-name` on
+    /// the commandline. These values must match the value used in the source
+    /// code to prevent an error.
+    ///
+    /// To fix the warning use `--crate-type` on the commandline when running
+    /// rustc instead of `#![cfg_attr(..., crate_type = "...")]` and
+    /// `--crate-name` instead of `#![cfg_attr(..., crate_name = "...")]`.
+    pub DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
+    Warn,
+    "detects usage of `#![cfg_attr(..., crate_type/crate_name = \"...\")]`",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #91632 <https://github.com/rust-lang/rust/issues/91632>",
+    };
+}
+
 declare_lint_pass! {
     /// Does nothing as a lint pass, but registers some `Lint`s
     /// that are used by other parts of the compiler.
@@ -3056,6 +3091,7 @@ declare_lint_pass! {
         NON_EXHAUSTIVE_OMITTED_PATTERNS,
         TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
         DEREF_INTO_DYN_SUPERTRAIT,
+        DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
     ]
 }
 

compiler/rustc_mir_transform/src/add_retag.rs

@@ -34,7 +34,7 @@ fn is_stable(place: PlaceRef<'_>) -> bool {
 }
 
 /// Determine whether this type may be a reference (or box), and thus needs retagging.
-fn may_be_reference(ty: Ty<'tcx>) -> bool {
+fn may_be_reference(ty: Ty<'_>) -> bool {
     match ty.kind() {
         // Primitive types that are not references
         ty::Bool

compiler/rustc_mir_transform/src/check_const_item_mutation.rs

@@ -23,7 +23,7 @@ struct ConstMutationChecker<'a, 'tcx> {
     target_local: Option<Local>,
 }
 
-impl<'a, 'tcx> ConstMutationChecker<'a, 'tcx> {
+impl<'tcx> ConstMutationChecker<'_, 'tcx> {
     fn is_const_item(&self, local: Local) -> Option<DefId> {
         if let Some(box LocalInfo::ConstRef { def_id }) = self.body.local_decls[local].local_info {
             Some(def_id)
@@ -95,7 +95,7 @@ impl<'a, 'tcx> ConstMutationChecker<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for ConstMutationChecker<'a, 'tcx> {
+impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
     fn visit_statement(&mut self, stmt: &Statement<'tcx>, loc: Location) {
         if let StatementKind::Assign(box (lhs, _)) = &stmt.kind {
             // Check for assignment to fields of a constant

compiler/rustc_mir_transform/src/check_packed_ref.rs

@@ -66,7 +66,7 @@ fn builtin_derive_def_id(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
     }
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for PackedRefChecker<'a, 'tcx> {
+impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         // Make sure we know where in the MIR we are.
         self.source_info = terminator.source_info;

compiler/rustc_mir_transform/src/check_unsafety.rs

@@ -46,7 +46,7 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
+impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> {
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         self.source_info = terminator.source_info;
         match terminator.kind {
@@ -244,7 +244,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
+impl<'tcx> UnsafetyChecker<'_, 'tcx> {
     fn require_unsafe(&mut self, kind: UnsafetyViolationKind, details: UnsafetyViolationDetails) {
         // Violations can turn out to be `UnsafeFn` during analysis, but they should not start out as such.
         assert_ne!(kind, UnsafetyViolationKind::UnsafeFn);
@@ -397,7 +397,7 @@ struct UnusedUnsafeVisitor<'a> {
     unsafe_blocks: &'a mut Vec<(hir::HirId, bool)>,
 }
 
-impl<'a, 'tcx> intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'a> {
+impl<'tcx> intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'_> {
     type Map = intravisit::ErasedMap<'tcx>;
 
     fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {

compiler/rustc_mir_transform/src/const_debuginfo.rs

@@ -89,7 +89,7 @@ fn find_optimization_oportunities<'tcx>(body: &Body<'tcx>) -> Vec<(Local, Consta
     eligable_locals
 }
 
-impl<'tcx> Visitor<'tcx> for LocalUseVisitor {
+impl Visitor<'_> for LocalUseVisitor {
     fn visit_local(&mut self, local: &Local, context: PlaceContext, location: Location) {
         if context.is_mutating_use() {
             self.local_mutating_uses[*local] = self.local_mutating_uses[*local].saturating_add(1);

compiler/rustc_mir_transform/src/const_goto.rs

@@ -54,7 +54,7 @@ impl<'tcx> MirPass<'tcx> for ConstGoto {
     }
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for ConstGotoOptimizationFinder<'a, 'tcx> {
+impl<'tcx> Visitor<'tcx> for ConstGotoOptimizationFinder<'_, 'tcx> {
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         let _: Option<_> = try {
             let target = terminator.kind.as_goto()?;

compiler/rustc_mir_transform/src/const_prop.rs

@@ -171,7 +171,7 @@ struct ConstPropMachine<'mir, 'tcx> {
     can_const_prop: IndexVec<Local, ConstPropMode>,
 }
 
-impl<'mir, 'tcx> ConstPropMachine<'mir, 'tcx> {
+impl ConstPropMachine<'_, '_> {
     fn new(
         only_propagate_inside_block_locals: BitSet<Local>,
         can_const_prop: IndexVec<Local, ConstPropMode>,
@@ -308,14 +308,14 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine<'mir, 'tcx>
     }
 
     #[inline(always)]
-    fn stack(
+    fn stack<'a>(
         ecx: &'a InterpCx<'mir, 'tcx, Self>,
     ) -> &'a [Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>] {
         &ecx.machine.stack
     }
 
     #[inline(always)]
-    fn stack_mut(
+    fn stack_mut<'a>(
         ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
     ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>> {
         &mut ecx.machine.stack
@@ -336,7 +336,7 @@ struct ConstPropagator<'mir, 'tcx> {
     source_info: Option<SourceInfo>,
 }
 
-impl<'mir, 'tcx> LayoutOfHelpers<'tcx> for ConstPropagator<'mir, 'tcx> {
+impl<'tcx> LayoutOfHelpers<'tcx> for ConstPropagator<'_, 'tcx> {
     type LayoutOfResult = Result<TyAndLayout<'tcx>, LayoutError<'tcx>>;
 
     #[inline]
@@ -345,21 +345,21 @@ impl<'mir, 'tcx> LayoutOfHelpers<'tcx> for ConstPropagator<'mir, 'tcx> {
     }
 }
 
-impl<'mir, 'tcx> HasDataLayout for ConstPropagator<'mir, 'tcx> {
+impl HasDataLayout for ConstPropagator<'_, '_> {
     #[inline]
     fn data_layout(&self) -> &TargetDataLayout {
         &self.tcx.data_layout
     }
 }
 
-impl<'mir, 'tcx> ty::layout::HasTyCtxt<'tcx> for ConstPropagator<'mir, 'tcx> {
+impl<'tcx> ty::layout::HasTyCtxt<'tcx> for ConstPropagator<'_, 'tcx> {
     #[inline]
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 }
 
-impl<'mir, 'tcx> ty::layout::HasParamEnv<'tcx> for ConstPropagator<'mir, 'tcx> {
+impl<'tcx> ty::layout::HasParamEnv<'tcx> for ConstPropagator<'_, 'tcx> {
     #[inline]
     fn param_env(&self) -> ty::ParamEnv<'tcx> {
         self.param_env
@@ -971,7 +971,7 @@ struct CanConstProp {
 
 impl CanConstProp {
     /// Returns true if `local` can be propagated
-    fn check(
+    fn check<'tcx>(
         tcx: TyCtxt<'tcx>,
         param_env: ParamEnv<'tcx>,
         body: &Body<'tcx>,
@@ -1019,7 +1019,7 @@ impl CanConstProp {
     }
 }
 
-impl<'tcx> Visitor<'tcx> for CanConstProp {
+impl Visitor<'_> for CanConstProp {
     fn visit_local(&mut self, &local: &Local, context: PlaceContext, _: Location) {
         use rustc_middle::mir::visit::PlaceContext::*;
         match context {
@@ -1079,7 +1079,7 @@ impl<'tcx> Visitor<'tcx> for CanConstProp {
     }
 }
 
-impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
+impl<'tcx> MutVisitor<'tcx> for ConstPropagator<'_, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }