Auto merge of #140138 - ChrisDenton:rollup-zw7jibi, r=ChrisDenton

Rollup of 5 pull requests

Successful merges:

 - #139981 (Don't compute name of associated item if it's an RPITIT)
 - #140077 (Construct OutputType using macro and print [=FILENAME] help info)
 - #140081 (Update `libc` to 0.2.172)
 - #140094 (Improve diagnostics for pointer arithmetic += and -= (fixes #137391))
 - #140128 (Use correct annotation for CSS pseudo elements)

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

Author: bors

compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs

@@ -486,15 +486,15 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
             let items: &AssocItems = self.tcx.associated_items(self.def_id);
             items
                 .in_definition_order()
-                .filter(|item| item.is_type())
                 .filter(|item| {
-                    !self
-                        .gen_args
-                        .constraints
-                        .iter()
-                        .any(|constraint| constraint.ident.name == item.name())
+                    item.is_type()
+                        && !item.is_impl_trait_in_trait()
+                        && !self
+                            .gen_args
+                            .constraints
+                            .iter()
+                            .any(|constraint| constraint.ident.name == item.name())
                 })
-                .filter(|item| !item.is_impl_trait_in_trait())
                 .map(|item| self.tcx.item_ident(item.def_id).to_string())
                 .collect()
         } else {

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -29,7 +29,7 @@ use rustc_errors::codes::*;
 use rustc_errors::{
     Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, FatalError, struct_span_code_err,
 };
-use rustc_hir::def::{CtorKind, CtorOf, DefKind, Namespace, Res};
+use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::{self as hir, AnonConst, GenericArg, GenericArgs, HirId};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
@@ -1731,9 +1731,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 tcx.associated_items(*trait_def_id)
                         .in_definition_order()
                         .any(|i| {
-                            i.namespace() == Namespace::TypeNS
+                            i.is_type()
+                                && !i.is_impl_trait_in_trait()
                                 && i.ident(tcx).normalize_to_macros_2_0() == assoc_ident
-                                && i.is_type()
                         })
                     // Consider only accessible traits
                     && tcx.visibility(*trait_def_id)

compiler/rustc_hir_typeck/src/op.rs

@@ -234,7 +234,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // us do better coercions than we would be able to do otherwise,
         // particularly for things like `String + &String`.
         let rhs_ty_var = self.next_ty_var(rhs_expr.span);
-
         let result = self.lookup_op_method(
             (lhs_expr, lhs_ty),
             Some((rhs_expr, rhs_ty_var)),
@@ -698,6 +697,57 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 }
 
+                let lhs_name_str = match lhs_expr.kind {
+                    hir::ExprKind::Path(hir::QPath::Resolved(_, path)) => {
+                        path.segments.last().map_or("_".to_string(), |s| s.ident.to_string())
+                    }
+                    _ => self
+                        .tcx
+                        .sess
+                        .source_map()
+                        .span_to_snippet(lhs_expr.span)
+                        .unwrap_or("_".to_string()),
+                };
+
+                if op.span().can_be_used_for_suggestions() {
+                    match op {
+                        Op::AssignOp(Spanned { node: hir::AssignOpKind::AddAssign, .. })
+                            if lhs_ty.is_raw_ptr() && rhs_ty.is_integral() =>
+                        {
+                            err.multipart_suggestion(
+                                "consider using `add` or `wrapping_add` to do pointer arithmetic",
+                                vec![
+                                    (lhs_expr.span.shrink_to_lo(), format!("{} = ", lhs_name_str)),
+                                    (
+                                        lhs_expr.span.between(rhs_expr.span),
+                                        ".wrapping_add(".to_owned(),
+                                    ),
+                                    (rhs_expr.span.shrink_to_hi(), ")".to_owned()),
+                                ],
+                                Applicability::MaybeIncorrect,
+                            );
+                        }
+                        Op::AssignOp(Spanned { node: hir::AssignOpKind::SubAssign, .. }) => {
+                            if lhs_ty.is_raw_ptr() && rhs_ty.is_integral() {
+                                err.multipart_suggestion(
+                                    "consider using `sub` or `wrapping_sub` to do pointer arithmetic",
+                                    vec![
+                                        (lhs_expr.span.shrink_to_lo(), format!("{} = ", lhs_name_str)),
+                                        (
+                                            lhs_expr.span.between(rhs_expr.span),
+                                            ".wrapping_sub(".to_owned(),
+
+                                        ),
+                                        (rhs_expr.span.shrink_to_hi(), ")".to_owned()),
+                                    ],
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+
                 let reported = err.emit();
                 Ty::new_error(self.tcx, reported)
             }