move-to-facet-valuetype

Author: danakj

toolchain/check/member_access.cpp

@@ -320,18 +320,8 @@ static auto LookupMemberNameInScope(Context& context, SemIR::LocId loc_id,
   if (auto assoc_type =
           context.types().TryGetAs<SemIR::AssociatedEntityType>(type_id)) {
     if (lookup_in_type_of_base) {
+      base_id = MoveToFacetValue(context, base_id);
       SemIR::TypeId base_type_id = context.insts().Get(base_id).type_id();
-      if (auto binding_type =
-              context.types().TryGetAs<SemIR::SymbolicBindingType>(
-                  base_type_id)) {
-        // Move from the type of a symbolic facet value up in typish-ness to its
-        // FacetType to find the type to work with.
-        //
-        // TODO: Look in ScopeStack with the the entity_name_id to find the
-        // facet value.
-        base_id = binding_type->facet_value_inst_id;
-        base_type_id = context.insts().Get(base_id).type_id();
-      }
 
       if (auto facet_type =
               context.types().TryGetAs<SemIR::FacetType>(base_type_id)) {

toolchain/check/name_lookup.cpp

@@ -11,6 +11,7 @@
 #include "toolchain/check/import.h"
 #include "toolchain/check/import_ref.h"
 #include "toolchain/check/member_access.h"
+#include "toolchain/check/type.h"
 #include "toolchain/check/type_completion.h"
 #include "toolchain/diagnostics/format_providers.h"
 #include "toolchain/sem_ir/generic.h"
@@ -272,22 +273,15 @@ auto AppendLookupScopesForConstant(Context& context, SemIR::LocId loc_id,
                                    llvm::SmallVector<LookupScope>* scopes)
     -> bool {
   auto base_id = context.constant_values().GetInstId(base_const_id);
-  auto base = context.insts().Get(base_id);
 
-  if (auto base_as_binding_type = base.TryAs<SemIR::SymbolicBindingType>()) {
-    // Move from the symbolic facet value up in typish-ness to its FacetType to
-    // find a lookup scope.
-    //
-    // TODO: Look in ScopeStack with the the entity_name_id to find the
-    // facet value.
-    auto facet_type_type_id =
-        context.insts()
-            .Get(base_as_binding_type->facet_value_inst_id)
-            .type_id();
-    base_const_id = context.types().GetConstantId(facet_type_type_id);
-    base_id = context.constant_values().GetInstId(base_const_id);
-    base = context.insts().Get(base_id);
+  // TODO: We only want to move from type to FacetType if the original type in
+  // `base_const_id` is `(facet value) as type`. Why do we not want to do this
+  // for other facet values that are not converted to type?
+  if (context.insts().Get(base_id).type_id() == SemIR::TypeType::TypeId) {
+    base_id = MoveToFacetType(context, base_id);
+    base_const_id = context.constant_values().Get(base_id);
   }
+  auto base = context.insts().Get(base_id);
 
   if (auto base_as_namespace = base.TryAs<SemIR::Namespace>()) {
     scopes->push_back(

toolchain/check/type.cpp

@@ -302,4 +302,23 @@ auto GetCanonicalizedFacetTypeOrType(Context& context, SemIR::InstId inst_id)
   }
 }
 
+auto MoveToFacetValue(Context& context, SemIR::InstId inst_id)
+    -> SemIR::InstId {
+  auto type_id = context.insts().Get(inst_id).type_id();
+  if (context.types().Is<SemIR::SymbolicBindingType>(type_id)) {
+    return GetCanonicalizedFacetOrTypeValue(context,
+                                            context.types().GetInstId(type_id));
+  }
+  return inst_id;
+}
+
+auto MoveToFacetType(Context& context, SemIR::InstId inst_id) -> SemIR::InstId {
+  auto facet_value_id = GetCanonicalizedFacetOrTypeValue(context, inst_id);
+  auto type_id = context.insts().Get(facet_value_id).type_id();
+  if (context.types().Is<SemIR::FacetType>(type_id)) {
+    return context.types().GetInstId(type_id);
+  }
+  return facet_value_id;
+}
+
 }  // namespace Carbon::Check

toolchain/check/type.h

@@ -134,6 +134,15 @@ auto GetCanonicalizedFacetOrTypeValue(Context& context,
 auto GetCanonicalizedFacetTypeOrType(Context& context, SemIR::InstId inst_id)
     -> SemIR::TypeInstId;
 
+// If `inst_id` has a type which is a facet value, return the canonicalized
+// facet value, otherwise return `inst_id` unchanged.
+auto MoveToFacetValue(Context& context, SemIR::InstId inst_id) -> SemIR::InstId;
+
+// If `inst_id` is a facet value, return the canonicalized facet value's type
+// (a FacetType or a concrete type value), otherwise return `inst_id`
+// unchanged.
+auto MoveToFacetType(Context& context, SemIR::InstId inst_id) -> SemIR::InstId;
+
 }  // namespace Carbon::Check
 
 #endif  // CARBON_TOOLCHAIN_CHECK_TYPE_H_