Use the correct type for Self in generic classes and generic interf…

…aces (#4087)

In a `class C(T:! type)`, the type `Self` should be `C(T)`, not merely
`C`. Similarly, in an `interface I(T:! type)`, the type of self should
be `I(T)`, not merely `I`.

toolchain/check/eval.cpp

@@ -6,6 +6,7 @@
 
 #include "toolchain/base/kind_switch.h"
 #include "toolchain/check/diagnostic_helpers.h"
+#include "toolchain/check/generic.h"
 #include "toolchain/diagnostics/diagnostic_emitter.h"
 #include "toolchain/sem_ir/builtin_function_kind.h"
 #include "toolchain/sem_ir/function.h"
@@ -15,14 +16,6 @@
 
 namespace Carbon::Check {
 
-static auto MakeGenericInstance(Context& context, SemIR::GenericId generic_id,
-                                SemIR::InstBlockId args_id)
-    -> SemIR::GenericInstanceId {
-  auto instance_id = context.generic_instances().GetOrAdd(generic_id, args_id);
-  // TODO: Perform substitution into the generic declaration if needed.
-  return instance_id;
-}
-
 namespace {
 // The evaluation phase for an expression, computed by evaluation. These are
 // ordered so that the phase of an expression is the numerically highest phase

toolchain/check/generic.cpp

@@ -40,4 +40,37 @@ auto FinishGenericDefinition(Context& /*context*/,
   // TODO: Track contents of this generic definition.
 }
 
+auto MakeGenericInstance(Context& context, SemIR::GenericId generic_id,
+                         SemIR::InstBlockId args_id)
+    -> SemIR::GenericInstanceId {
+  auto instance_id = context.generic_instances().GetOrAdd(generic_id, args_id);
+  // TODO: Perform substitution into the generic declaration if needed.
+  return instance_id;
+}
+
+auto MakeGenericSelfInstance(Context& context, SemIR::GenericId generic_id)
+    -> SemIR::GenericInstanceId {
+  // TODO: Remove this once we import generics properly.
+  if (!generic_id.is_valid()) {
+    return SemIR::GenericInstanceId::Invalid;
+  }
+
+  auto& generic = context.generics().Get(generic_id);
+  auto args = context.inst_blocks().Get(generic.bindings_id);
+
+  // Form a canonical argument list for the generic.
+  llvm::SmallVector<SemIR::InstId> arg_ids;
+  arg_ids.reserve(args.size());
+  for (auto arg_id : args) {
+    arg_ids.push_back(context.constant_values().GetConstantInstId(arg_id));
+  }
+  auto args_id = context.inst_blocks().AddCanonical(arg_ids);
+
+  // Build a corresponding instance.
+  // TODO: This could be made more efficient. We don't need to perform
+  // substitution here; we know we want identity mappings for all constants and
+  // types. We could also consider not storing the mapping at all in this case.
+  return MakeGenericInstance(context, generic_id, args_id);
+}
+
 }  // namespace Carbon::Check

toolchain/check/generic.h

@@ -32,6 +32,20 @@ auto FinishGenericRedecl(Context& context, SemIR::InstId decl_id,
 auto FinishGenericDefinition(Context& context, SemIR::GenericId generic_id)
     -> void;
 
+// Builds a new generic instance, or finds an existing one if this instance of
+// this generic has already been referenced. Performs substitution into the
+// declaration, but not the definition, of the generic.
+//
+// `args_id` should be a canonical instruction block referring to constants.
+auto MakeGenericInstance(Context& context, SemIR::GenericId generic_id,
+                         SemIR::InstBlockId args_id)
+    -> SemIR::GenericInstanceId;
+
+// Builds the generic instance corresponding to the generic itself. For example,
+// for a generic `G(T:! type)`, this is `G(T)`.
+auto MakeGenericSelfInstance(Context& context, SemIR::GenericId generic_id)
+    -> SemIR::GenericInstanceId;
+
 }  // namespace Carbon::Check
 
 #endif  // CARBON_TOOLCHAIN_CHECK_GENERIC_H_

toolchain/check/handle_class.cpp

@@ -260,8 +260,8 @@ static auto BuildClassDecl(Context& context, Parse::AnyClassDeclId node_id,
     // declaration.
     auto& class_info = context.classes().Get(class_decl.class_id);
     if (class_info.is_generic()) {
-      // TODO: Build generic arguments representing the parameters.
-      auto instance_id = SemIR::GenericInstanceId::Invalid;
+      auto instance_id =
+          MakeGenericSelfInstance(context, class_info.generic_id);
       class_info.self_type_id = context.GetTypeIdForTypeConstant(
           TryEvalInst(context, SemIR::InstId::Invalid,
                       SemIR::ClassType{.type_id = SemIR::TypeId::TypeType,

toolchain/check/handle_interface.cpp

@@ -3,9 +3,9 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 #include "toolchain/check/context.h"
+#include "toolchain/check/eval.h"
 #include "toolchain/check/generic.h"
 #include "toolchain/check/handle.h"
-#include "toolchain/check/interface.h"
 #include "toolchain/check/merge.h"
 #include "toolchain/check/modifiers.h"
 #include "toolchain/check/name_component.h"
@@ -152,10 +152,18 @@ auto HandleInterfaceDefinitionStart(Context& context,
 
   // Declare and introduce `Self`.
   if (!interface_info.is_defined()) {
-    // TODO: Once we support parameterized interfaces, this won't be the right
-    // type. For `interface X(T:! type)`, the type of `Self` is `X(T)`, whereas
-    // this will be simply `X`.
-    auto self_type_id = context.GetTypeIdForTypeInst(interface_decl_id);
+    SemIR::TypeId self_type_id = SemIR::TypeId::Invalid;
+    if (interface_info.is_generic()) {
+      auto instance_id =
+          MakeGenericSelfInstance(context, interface_info.generic_id);
+      self_type_id = context.GetTypeIdForTypeConstant(
+          TryEvalInst(context, SemIR::InstId::Invalid,
+                      SemIR::InterfaceType{.type_id = SemIR::TypeId::TypeType,
+                                           .interface_id = interface_id,
+                                           .instance_id = instance_id}));
+    } else {
+      self_type_id = context.GetTypeIdForTypeInst(interface_decl_id);
+    }
 
     // We model `Self` as a symbolic binding whose type is the interface.
     // Because there is no equivalent non-symbolic value, we use `Invalid` as

toolchain/check/subst.cpp

@@ -5,6 +5,7 @@
 #include "toolchain/check/subst.h"
 
 #include "toolchain/check/eval.h"
+#include "toolchain/check/generic.h"
 #include "toolchain/sem_ir/copy_on_write_block.h"
 #include "toolchain/sem_ir/ids.h"
 
@@ -77,6 +78,13 @@ static auto PushOperand(Context& context, Worklist& worklist,
         worklist.Push(context.types().GetInstId(type_id));
       }
       break;
+    case SemIR::IdKind::For<SemIR::GenericInstanceId>:
+      if (auto instance_id = static_cast<SemIR::GenericInstanceId>(arg);
+          instance_id.is_valid()) {
+        PushOperand(context, worklist, SemIR::IdKind::For<SemIR::InstBlockId>,
+                    context.generic_instances().Get(instance_id).args_id.index);
+      }
+      break;
     default:
       break;
   }
@@ -128,6 +136,19 @@ static auto PopOperand(Context& context, Worklist& worklist, SemIR::IdKind kind,
       }
       return new_type_block.GetCanonical().index;
     }
+    case SemIR::IdKind::For<SemIR::GenericInstanceId>: {
+      auto instance_id = static_cast<SemIR::GenericInstanceId>(arg);
+      if (!instance_id.is_valid()) {
+        return arg;
+      }
+      auto& instance = context.generic_instances().Get(instance_id);
+      auto args_id =
+          PopOperand(context, worklist, SemIR::IdKind::For<SemIR::InstBlockId>,
+                     instance.args_id.index);
+      return MakeGenericInstance(context, instance.generic_id,
+                                 static_cast<SemIR::InstBlockId>(args_id))
+          .index;
+    }
     default:
       return arg;
   }

toolchain/check/testdata/class/fail_generic_method.carbon

@@ -38,7 +38,7 @@ fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
 // CHECK:STDOUT:   %.2: type = unbound_element_type %Class.2, %T [symbolic]
 // CHECK:STDOUT:   %F.type: type = fn_type @F [template]
 // CHECK:STDOUT:   %F: %F.type = struct_value () [template]
@@ -81,7 +81,7 @@ fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDOUT:   %T.ref.loc12: type = name_ref T, file.%T.loc11_13.2 [symbolic = constants.%T]
 // CHECK:STDOUT:   %.loc12: %.2 = field_decl a, element0 [template]
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%Class.2 [template = constants.%Class.2]
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%Class.2 [symbolic = constants.%Class.2]
 // CHECK:STDOUT:     %self.loc13_8.1: %Class.2 = param self
 // CHECK:STDOUT:     %self.loc13_8.2: %Class.2 = bind_name self, %self.loc13_8.1
 // CHECK:STDOUT:     %T.ref.loc13: type = name_ref T, file.%T.loc11_13.2 [symbolic = constants.%T]

toolchain/check/testdata/class/generic/basic.carbon

@@ -29,8 +29,8 @@ class Class(T:! type) {
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
-// CHECK:STDOUT:   %.2: type = ptr_type %Class.2 [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
+// CHECK:STDOUT:   %.2: type = ptr_type %Class.2 [symbolic]
 // CHECK:STDOUT:   %.3: type = ptr_type %T [symbolic]
 // CHECK:STDOUT:   %GetAddr.type: type = fn_type @GetAddr [template]
 // CHECK:STDOUT:   %GetAddr: %GetAddr.type = struct_value () [template]
@@ -56,8 +56,8 @@ class Class(T:! type) {
 // CHECK:STDOUT: class @Class
 // CHECK:STDOUT:     generic [file.%T.loc11_13.2: type] {
 // CHECK:STDOUT:   %GetAddr.decl: %GetAddr.type = fn_decl @GetAddr [template = constants.%GetAddr] {
-// CHECK:STDOUT:     %Self.ref.loc12: type = name_ref Self, constants.%Class.2 [template = constants.%Class.2]
-// CHECK:STDOUT:     %.loc12_29: type = ptr_type %Class.2 [template = constants.%.2]
+// CHECK:STDOUT:     %Self.ref.loc12: type = name_ref Self, constants.%Class.2 [symbolic = constants.%Class.2]
+// CHECK:STDOUT:     %.loc12_29: type = ptr_type %Class.2 [symbolic = constants.%.2]
 // CHECK:STDOUT:     %self.loc12_19.1: %.2 = param self
 // CHECK:STDOUT:     %self.loc12_19.3: %.2 = bind_name self, %self.loc12_19.1
 // CHECK:STDOUT:     %.loc12_14: %.2 = addr_pattern %self.loc12_19.3
@@ -66,7 +66,7 @@ class Class(T:! type) {
 // CHECK:STDOUT:     %return.var.loc12: ref %.3 = var <return slot>
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %GetValue.decl: %GetValue.type = fn_decl @GetValue [template = constants.%GetValue] {
-// CHECK:STDOUT:     %Self.ref.loc17: type = name_ref Self, constants.%Class.2 [template = constants.%Class.2]
+// CHECK:STDOUT:     %Self.ref.loc17: type = name_ref Self, constants.%Class.2 [symbolic = constants.%Class.2]
 // CHECK:STDOUT:     %self.loc17_15.1: %Class.2 = param self
 // CHECK:STDOUT:     %self.loc17_15.2: %Class.2 = bind_name self, %self.loc17_15.1
 // CHECK:STDOUT:     %T.ref.loc17: type = name_ref T, file.%T.loc11_13.2 [symbolic = constants.%T]

toolchain/check/testdata/class/generic/call.carbon

@@ -73,7 +73,7 @@ var a: Class(5, i32*);
 // CHECK:STDOUT:   %N: i32 = bind_symbolic_name N 1 [symbolic]
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T, %N) [symbolic]
 // CHECK:STDOUT:   %.2: type = struct_type {} [template]
 // CHECK:STDOUT:   %.3: type = ptr_type i32 [template]
 // CHECK:STDOUT:   %.4: i32 = int_literal 5 [template]
@@ -142,7 +142,7 @@ var a: Class(5, i32*);
 // CHECK:STDOUT:   %N: i32 = bind_symbolic_name N 1 [symbolic]
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T, %N) [symbolic]
 // CHECK:STDOUT:   %.2: type = struct_type {} [template]
 // CHECK:STDOUT:   %.3: type = ptr_type i32 [template]
 // CHECK:STDOUT: }
@@ -195,7 +195,7 @@ var a: Class(5, i32*);
 // CHECK:STDOUT:   %N: i32 = bind_symbolic_name N 1 [symbolic]
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T, %N) [symbolic]
 // CHECK:STDOUT:   %.2: type = struct_type {} [template]
 // CHECK:STDOUT:   %.3: type = ptr_type i32 [template]
 // CHECK:STDOUT:   %.4: i32 = int_literal 1 [template]
@@ -252,7 +252,7 @@ var a: Class(5, i32*);
 // CHECK:STDOUT:   %N: i32 = bind_symbolic_name N 1 [symbolic]
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T, %N) [symbolic]
 // CHECK:STDOUT:   %.2: type = struct_type {} [template]
 // CHECK:STDOUT:   %.3: i32 = int_literal 5 [template]
 // CHECK:STDOUT:   %.4: type = ptr_type i32 [template]

toolchain/check/testdata/class/generic/fail_todo_use.carbon

@@ -43,8 +43,8 @@ fn Run() -> i32 {
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
-// CHECK:STDOUT:   %.2: type = ptr_type %Class.2 [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
+// CHECK:STDOUT:   %.2: type = ptr_type %Class.2 [symbolic]
 // CHECK:STDOUT:   %.3: type = ptr_type %T [symbolic]
 // CHECK:STDOUT:   %Get.type: type = fn_type @Get [template]
 // CHECK:STDOUT:   %Get: %Get.type = struct_value () [template]
@@ -85,8 +85,8 @@ fn Run() -> i32 {
 // CHECK:STDOUT: class @Class
 // CHECK:STDOUT:     generic [file.%T.loc11_13.2: type] {
 // CHECK:STDOUT:   %Get.decl: %Get.type = fn_decl @Get [template = constants.%Get] {
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%Class.2 [template = constants.%Class.2]
-// CHECK:STDOUT:     %.loc12_25: type = ptr_type %Class.2 [template = constants.%.2]
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%Class.2 [symbolic = constants.%Class.2]
+// CHECK:STDOUT:     %.loc12_25: type = ptr_type %Class.2 [symbolic = constants.%.2]
 // CHECK:STDOUT:     %self.loc12_15.1: %.2 = param self
 // CHECK:STDOUT:     %self.loc12_15.3: %.2 = bind_name self, %self.loc12_15.1
 // CHECK:STDOUT:     %.loc12_10: %.2 = addr_pattern %self.loc12_15.3

toolchain/check/testdata/class/generic/import.carbon

@@ -95,13 +95,13 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
 // CHECK:STDOUT:   %CompleteClass.type: type = generic_class_type @CompleteClass [template]
 // CHECK:STDOUT:   %CompleteClass.1: %CompleteClass.type = struct_value () [template]
-// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass [template]
+// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass, (%T) [symbolic]
 // CHECK:STDOUT:   %Int32.type: type = fn_type @Int32 [template]
 // CHECK:STDOUT:   %Int32: %Int32.type = struct_value () [template]
-// CHECK:STDOUT:   %.2: type = unbound_element_type %CompleteClass.2, i32 [template]
+// CHECK:STDOUT:   %.2: type = unbound_element_type %CompleteClass.2, i32 [symbolic]
 // CHECK:STDOUT:   %F.type.1: type = fn_type @F.1 [template]
 // CHECK:STDOUT:   %F.1: %F.type.1 = struct_value () [template]
 // CHECK:STDOUT:   %.3: type = struct_type {.n: i32} [template]
@@ -182,13 +182,13 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
 // CHECK:STDOUT:   %.2: type = unbound_element_type %Class.2, %T [symbolic]
 // CHECK:STDOUT:   %.3: type = struct_type {.x: %T} [symbolic]
 // CHECK:STDOUT:   %CompleteClass.type: type = generic_class_type @CompleteClass [template]
 // CHECK:STDOUT:   %CompleteClass.1: %CompleteClass.type = struct_value () [template]
 // CHECK:STDOUT:   %.4: type = struct_type {.n: i32} [template]
-// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass [template]
+// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass, (%T) [symbolic]
 // CHECK:STDOUT:   %Int32.type: type = fn_type @Int32 [template]
 // CHECK:STDOUT:   %Int32: %Int32.type = struct_value () [template]
 // CHECK:STDOUT:   %CompleteClass.3: type = class_type @CompleteClass, (i32) [template]
@@ -270,8 +270,8 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %CompleteClass.type: type = generic_class_type @CompleteClass [template]
 // CHECK:STDOUT:   %CompleteClass.1: %CompleteClass.type = struct_value () [template]
 // CHECK:STDOUT:   %.2: type = struct_type {.n: i32} [template]
-// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass [template]
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T 0, <unexpected instref inst+26> [symbolic]
+// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass, (%T) [symbolic]
 // CHECK:STDOUT:   %CompleteClass.3: type = class_type @CompleteClass, (i32) [template]
 // CHECK:STDOUT:   %.3: type = ptr_type %.2 [template]
 // CHECK:STDOUT:   %F.type.1: type = fn_type @F.1 [template]
@@ -352,13 +352,13 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %CompleteClass.type: type = generic_class_type @CompleteClass [template]
 // CHECK:STDOUT:   %CompleteClass.1: %CompleteClass.type = struct_value () [template]
 // CHECK:STDOUT:   %.2: type = struct_type {.n: i32} [template]
-// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass [template]
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T 0, <unexpected instref inst+26> [symbolic]
+// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass, (%T) [symbolic]
 // CHECK:STDOUT:   %CompleteClass.3: type = class_type @CompleteClass, (i32) [template]
 // CHECK:STDOUT:   %.3: type = ptr_type %.2 [template]
 // CHECK:STDOUT:   %F.type: type = fn_type @F [template]
 // CHECK:STDOUT:   %F: %F.type = struct_value () [template]
-// CHECK:STDOUT:   %.4: type = unbound_element_type %CompleteClass.2, i32 [template]
+// CHECK:STDOUT:   %.4: type = unbound_element_type %CompleteClass.2, i32 [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -427,8 +427,8 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %CompleteClass.type: type = generic_class_type @CompleteClass [template]
 // CHECK:STDOUT:   %CompleteClass.1: %CompleteClass.type = struct_value () [template]
 // CHECK:STDOUT:   %.2: type = struct_type {.n: i32} [template]
-// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass [template]
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T 0, <unexpected instref inst+17> [symbolic]
+// CHECK:STDOUT:   %CompleteClass.2: type = class_type @CompleteClass, (%T) [symbolic]
 // CHECK:STDOUT:   %Int32.type: type = fn_type @Int32 [template]
 // CHECK:STDOUT:   %Int32: %Int32.type = struct_value () [template]
 // CHECK:STDOUT:   %.3: type = ptr_type i32 [template]
@@ -495,11 +495,11 @@ class Class(U:! type) {
 // CHECK:STDOUT:   %Class.type: type = generic_class_type @Class [template]
 // CHECK:STDOUT:   %.1: type = tuple_type () [template]
 // CHECK:STDOUT:   %Class.1: %Class.type = struct_value () [template]
-// CHECK:STDOUT:   %Class.2: type = class_type @Class [template]
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T 0, <unexpected instref inst+14> [symbolic]
+// CHECK:STDOUT:   %Class.2: type = class_type @Class, (%T) [symbolic]
 // CHECK:STDOUT:   %.type: type = generic_class_type @.1 [template]
 // CHECK:STDOUT:   %.2: %.type = struct_value () [template]
-// CHECK:STDOUT:   %.3: type = class_type @.1 [template]
+// CHECK:STDOUT:   %.3: type = class_type @.1, (%U) [symbolic]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {