Auto merge of #112563 - matthiaskrgr:rollup-ebetrzi, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #112302 (Suggest using `ptr::null_mut` when user provided `ptr::null` to a function expecting `ptr::null_mut`)
 - #112416 (Fix debug ICE for extern type with where clauses)
 - #112527 (Add windows_sys type definitions for ARM32 manually)
 - #112546 (new solver: extend assert to other aliases)

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

6 files changed, 62 insertions, 9 deletions

diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index 04ed2767876..a0979bbda54 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -364,7 +364,12 @@ impl<'a> AstValidator<'a> {
         self.err_handler().emit_err(errors::BoundInContext { span, ctx });
     }
 
-    fn check_foreign_ty_genericless(&self, generics: &Generics, where_span: Span) {
+    fn check_foreign_ty_genericless(
+        &self,
+        generics: &Generics,
+        before_where_clause: &TyAliasWhereClause,
+        after_where_clause: &TyAliasWhereClause,
+    ) {
         let cannot_have = |span, descr, remove_descr| {
             self.err_handler().emit_err(errors::ExternTypesCannotHave {
                 span,
@@ -378,9 +383,14 @@ impl<'a> AstValidator<'a> {
             cannot_have(generics.span, "generic parameters", "generic parameters");
         }
 
-        if !generics.where_clause.predicates.is_empty() {
-            cannot_have(where_span, "`where` clauses", "`where` clause");
-        }
+        let check_where_clause = |where_clause: &TyAliasWhereClause| {
+            if let TyAliasWhereClause(true, where_clause_span) = where_clause {
+                cannot_have(*where_clause_span, "`where` clauses", "`where` clause");
+            }
+        };
+
+        check_where_clause(before_where_clause);
+        check_where_clause(after_where_clause);
     }
 
     fn check_foreign_kind_bodyless(&self, ident: Ident, kind: &str, body: Option<Span>) {
@@ -1039,7 +1049,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 self.check_defaultness(fi.span, *defaultness);
                 self.check_foreign_kind_bodyless(fi.ident, "type", ty.as_ref().map(|b| b.span));
                 self.check_type_no_bounds(bounds, "`extern` blocks");
-                self.check_foreign_ty_genericless(generics, where_clauses.0.1);
+                self.check_foreign_ty_genericless(generics, &where_clauses.0, &where_clauses.1);
                 self.check_foreign_item_ascii_only(fi.ident);
             }
             ForeignItemKind::Static(_, _, body) => {
diff --git a/compiler/rustc_hir_typeck/messages.ftl b/compiler/rustc_hir_typeck/messages.ftl
index 4728edd837a..c1c58db5764 100644
--- a/compiler/rustc_hir_typeck/messages.ftl
+++ b/compiler/rustc_hir_typeck/messages.ftl
@@ -89,6 +89,8 @@ hir_typeck_suggest_boxing_note = for more on the distinction between the stack a
 
 hir_typeck_suggest_boxing_when_appropriate = store this in the heap by calling `Box::new`
 
+hir_typeck_suggest_ptr_null_mut = consider using `core::ptr::null_mut` instead
+
 hir_typeck_union_pat_dotdot = `..` cannot be used in union patterns
 
 hir_typeck_union_pat_multiple_fields = union patterns should have exactly one field
diff --git a/compiler/rustc_hir_typeck/src/errors.rs b/compiler/rustc_hir_typeck/src/errors.rs
index 5161a366ae7..6b4168d8944 100644
--- a/compiler/rustc_hir_typeck/src/errors.rs
+++ b/compiler/rustc_hir_typeck/src/errors.rs
@@ -298,6 +298,17 @@ pub enum SuggestBoxing {
     },
 }
 
+#[derive(Subdiagnostic)]
+#[suggestion(
+    hir_typeck_suggest_ptr_null_mut,
+    applicability = "maybe-incorrect",
+    code = "core::ptr::null_mut()"
+)]
+pub struct SuggestPtrNullMut {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(hir_typeck_no_associated_item, code = "E0599")]
 pub struct NoAssociatedItem {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 48c3d6f08de..4a3e28ffce9 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -1,4 +1,5 @@
 use crate::coercion::CoerceMany;
+use crate::errors::SuggestPtrNullMut;
 use crate::fn_ctxt::arg_matrix::{ArgMatrix, Compatibility, Error, ExpectedIdx, ProvidedIdx};
 use crate::gather_locals::Declaration;
 use crate::method::MethodCallee;
@@ -814,6 +815,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
             }
 
+            self.suggest_ptr_null_mut(
+                expected_ty,
+                provided_ty,
+                provided_args[*provided_idx],
+                &mut err,
+            );
+
             // Call out where the function is defined
             self.label_fn_like(
                 &mut err,
@@ -1271,6 +1279,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err.emit();
     }
 
+    fn suggest_ptr_null_mut(
+        &self,
+        expected_ty: Ty<'tcx>,
+        provided_ty: Ty<'tcx>,
+        arg: &hir::Expr<'tcx>,
+        err: &mut rustc_errors::DiagnosticBuilder<'tcx, ErrorGuaranteed>,
+    ) {
+        if let ty::RawPtr(ty::TypeAndMut { mutbl: hir::Mutability::Mut, .. }) = expected_ty.kind()
+            && let ty::RawPtr(ty::TypeAndMut { mutbl: hir::Mutability::Not, .. }) = provided_ty.kind()
+            && let hir::ExprKind::Call(callee, _) = arg.kind
+            && let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = callee.kind
+            && let Res::Def(_, def_id) = path.res
+            && self.tcx.get_diagnostic_item(sym::ptr_null) == Some(def_id)
+        {
+            // The user provided `ptr::null()`, but the function expects
+            // `ptr::null_mut()`.
+            err.subdiagnostic(SuggestPtrNullMut {
+                span: arg.span
+            });
+        }
+    }
+
     // AST fragment checking
     pub(in super::super) fn check_lit(
         &self,
diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
index 7a80ee98cb3..bb2bd2faec2 100644
--- a/compiler/rustc_infer/src/infer/combine.rs
+++ b/compiler/rustc_infer/src/infer/combine.rs
@@ -34,7 +34,7 @@ use rustc_middle::infer::unify_key::{ConstVarValue, ConstVariableValue};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::relate::{RelateResult, TypeRelation};
-use rustc_middle::ty::{self, AliasKind, InferConst, ToPredicate, Ty, TyCtxt, TypeVisitableExt};
+use rustc_middle::ty::{self, InferConst, ToPredicate, Ty, TyCtxt, TypeVisitableExt};
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::DUMMY_SP;
 
@@ -103,12 +103,12 @@ impl<'tcx> InferCtxt<'tcx> {
 
             // We don't expect `TyVar` or `Fresh*` vars at this point with lazy norm.
             (
-                ty::Alias(AliasKind::Projection, _),
+                ty::Alias(..),
                 ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)),
             )
             | (
                 ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)),
-                ty::Alias(AliasKind::Projection, _),
+                ty::Alias(..),
             ) if self.next_trait_solver() => {
                 bug!()
             }
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index f32ff0442a4..1b749b9c854 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -320,7 +320,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         candidates
     }
 
-    /// If the self type of a goal is a projection, computing the relevant candidates is difficult.
+    /// If the self type of a goal is an alias, computing the relevant candidates is difficult.
     ///
     /// To deal with this, we first try to normalize the self type and add the candidates for the normalized
     /// self type to the list of candidates in case that succeeds. We also have to consider candidates with the