HIR ty lowering stuff

Author: BoxyUwU

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2264,21 +2264,23 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 .unwrap_or_else(|guar| Const::new_error(tcx, guar))
             }
             hir::ConstArgKind::Struct(qpath, inits) => {
-                self.lower_struct_expr_const_arg(hir_id, qpath, inits, const_arg.span())
+                self.lower_const_arg_struct(hir_id, qpath, inits, const_arg.span())
             }
-            hir::ConstArgKind::Anon(anon) => self.lower_anon_const(anon),
+            hir::ConstArgKind::Anon(anon) => self.lower_const_arg_anon(anon),
             hir::ConstArgKind::Infer(span, ()) => self.ct_infer(None, span),
             hir::ConstArgKind::Error(_, e) => ty::Const::new_error(tcx, e),
         }
     }
 
-    fn lower_struct_expr_const_arg(
+    fn lower_const_arg_struct(
         &self,
         hir_id: HirId,
         qpath: hir::QPath<'tcx>,
         inits: &'tcx [&'tcx hir::ConstArgExprField<'tcx>],
         span: Span,
     ) -> Const<'tcx> {
+        // FIXME(mgca): try to deduplicate this function with
+        // the equivalent HIR typeck logic.
         let tcx = self.tcx();
 
         let non_adt_or_variant_res = || {
@@ -2330,7 +2332,8 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             .fields
             .iter()
             .map(|field_def| {
-                // FIXME(mgca): we aren't really handling privacy or stability at all but we should
+                // FIXME(mgca): we aren't really handling privacy, stability,
+                // or macro hygeniene but we should.
                 let mut init_expr =
                     inits.iter().filter(|init_expr| init_expr.field.name == field_def.name);
 
@@ -2477,7 +2480,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
 
     /// Literals are eagerly converted to a constant, everything else becomes `Unevaluated`.
     #[instrument(skip(self), level = "debug")]
-    fn lower_anon_const(&self, anon: &AnonConst) -> Const<'tcx> {
+    fn lower_const_arg_anon(&self, anon: &AnonConst) -> Const<'tcx> {
         let tcx = self.tcx();
 
         let expr = &tcx.hir_body(anon.body).value;

tests/ui/const-generics/mgca/adt_expr_erroneuous_inits.rs

@@ -2,6 +2,9 @@
 #![expect(incomplete_features)]
 #![crate_type = "lib"]
 
+// Miscellaneous assortment of invalid cases of directly represented
+// `ConstArgKind::Struct`'s under mgca.
+
 #[derive(Eq, PartialEq, std::marker::ConstParamTy)]
 struct Foo<T> { field: T }
 

tests/ui/const-generics/mgca/adt_expr_erroneuous_inits.stderr

@@ -1,5 +1,5 @@
 error[E0422]: cannot find struct, variant or union type `Fooo` in this scope
-  --> $DIR/adt_expr_erroneuous_inits.rs:17:17
+  --> $DIR/adt_expr_erroneuous_inits.rs:20:17
    |
 LL | struct Foo<T> { field: T }
    | ------------- similarly named struct `Foo` defined here
@@ -14,31 +14,31 @@ LL +     accepts::<{ Foo::<u8> { field: const { 1 } }}>();
    |
 
 error[E0574]: expected struct, variant or union type, found function `NonStruct`
-  --> $DIR/adt_expr_erroneuous_inits.rs:20:17
+  --> $DIR/adt_expr_erroneuous_inits.rs:23:17
    |
 LL |     accepts::<{ NonStruct { }}>();
    |                 ^^^^^^^^^ not a struct, variant or union type
 
 error: struct expression with missing field initialiser for `field`
-  --> $DIR/adt_expr_erroneuous_inits.rs:13:17
+  --> $DIR/adt_expr_erroneuous_inits.rs:16:17
    |
 LL |     accepts::<{ Foo::<u8> { }}>();
    |                 ^^^^^^^^^
 
 error: struct expression with multiple initialisers for `field`
-  --> $DIR/adt_expr_erroneuous_inits.rs:15:49
+  --> $DIR/adt_expr_erroneuous_inits.rs:18:49
    |
 LL |     accepts::<{ Foo::<u8> { field: const { 1 }, field: const { 2} }}>();
    |                                                 ^^^^^^^^^^^^^^^^^
 
 error: struct expression with invalid base path
-  --> $DIR/adt_expr_erroneuous_inits.rs:17:17
+  --> $DIR/adt_expr_erroneuous_inits.rs:20:17
    |
 LL |     accepts::<{ Fooo::<u8> { field: const { 1 } }}>();
    |                 ^^^^^^^^^^
 
 error: struct expression with invalid base path
-  --> $DIR/adt_expr_erroneuous_inits.rs:20:17
+  --> $DIR/adt_expr_erroneuous_inits.rs:23:17
    |
 LL |     accepts::<{ NonStruct { }}>();
    |                 ^^^^^^^^^

tests/ui/const-generics/mgca/adt_expr_fields_type_check.rs

@@ -1,5 +1,5 @@
 //@ check-pass
-// This should error
+// FIXME(mgca): This should error
 
 #![feature(min_generic_const_args, adt_const_params)]
 #![expect(incomplete_features)]