diff --git a/toolchain/check/import_cpp.cpp b/toolchain/check/import_cpp.cpp
index 520932e5cf6a..c755b1e233e9 100644
--- a/toolchain/check/import_cpp.cpp
+++ b/toolchain/check/import_cpp.cpp
@@ -507,7 +507,7 @@ static auto BuildClassDecl(Context& context,
 // returns a corresponding complete type witness instruction.
 // TODO: Remove recursion into mapping field types.
 // NOLINTNEXTLINE(misc-no-recursion)
-static auto ImportClassObjectRepr(Context& context,
+static auto ImportClassObjectRepr(Context& context, SemIR::ClassId class_id,
                                   SemIR::ImportIRInstId import_ir_inst_id,
                                   SemIR::TypeInstId class_type_inst_id,
                                   const clang::CXXRecordDecl* clang_def)
@@ -516,7 +516,7 @@ static auto ImportClassObjectRepr(Context& context,
   // representation. This allows our tests to continue to pass while we don't
   // properly support initializing imported C++ classes.
   // TODO: Remove this.
-  if (clang_def->isEmpty()) {
+  if (clang_def->isEmpty() && !clang_def->getNumBases()) {
     return context.types().GetAsTypeInstId(AddInst(
         context,
         MakeImportedLocIdAndInst(
@@ -540,7 +540,55 @@ static auto ImportClassObjectRepr(Context& context,
   static_assert(SemIR::CustomLayoutId::FirstFieldIndex == 2);
 
   // TODO: Import vptr(s).
-  // TODO: Import bases.
+
+  // Import bases.
+  for (const auto& base : clang_def->bases()) {
+    if (base.isVirtual()) {
+      // TODO: Handle virtual bases. We don't actually know where they go in the
+      // layout. We may also want to use a different size in the layout for
+      // `partial C`, excluding the virtual base. It's also not entirely safe to
+      // just skip over the virtual base, as the type we would construct would
+      // have a misleading size.
+      context.TODO(import_ir_inst_id, "class with virtual bases");
+      return SemIR::ErrorInst::TypeInstId;
+    }
+
+    auto [base_type_inst_id, base_type_id] =
+        MapType(context, import_ir_inst_id, base.getType());
+    if (!base_type_id.has_value()) {
+      // TODO: If the base class's type can't be mapped, skip it.
+      continue;
+    }
+
+    auto base_decl_id = AddInst(
+        context,
+        MakeImportedLocIdAndInst(
+            context, import_ir_inst_id,
+            SemIR::BaseDecl{.type_id = GetUnboundElementType(
+                                context, class_type_inst_id, base_type_inst_id),
+                            .base_type_inst_id = base_type_inst_id,
+                            .index = SemIR::ElementIndex(fields.size())}));
+
+    // If there's exactly one base class, treat it as a Carbon base class too.
+    // TODO: Improve handling for the case where the class has multiple base
+    // classes.
+    if (clang_def->getNumBases() == 1) {
+      auto& class_info = context.classes().Get(class_id);
+      CARBON_CHECK(!class_info.base_id.has_value());
+      class_info.base_id = base_decl_id;
+    }
+
+    auto* base_class = base.getType()->getAsCXXRecordDecl();
+    CARBON_CHECK(base_class, "Base class {0} is not a class",
+                 base.getType().getAsString());
+
+    auto base_offset = base.isVirtual()
+                           ? clang_layout.getVBaseClassOffset(base_class)
+                           : clang_layout.getBaseClassOffset(base_class);
+    layout.push_back(base_offset.getQuantity());
+    fields.push_back(
+        {.name_id = SemIR::NameId::Base, .type_inst_id = base_type_inst_id});
+  }
 
   // Import fields.
   for (auto* decl : clang_def->decls()) {
@@ -644,8 +692,8 @@ static auto BuildClassDefinition(Context& context,
   context.inst_block_stack().Push();
 
   // Compute the class's object representation.
-  auto object_repr_id = ImportClassObjectRepr(context, import_ir_inst_id,
-                                              class_inst_id, clang_def);
+  auto object_repr_id = ImportClassObjectRepr(
+      context, class_id, import_ir_inst_id, class_inst_id, clang_def);
   class_info.complete_type_witness_id = AddInst<SemIR::CompleteTypeWitness>(
       context, import_ir_inst_id,
       {.type_id = GetSingletonType(context, SemIR::WitnessType::TypeInstId),
@@ -1195,7 +1243,7 @@ static auto GetDependentUnimportedTypeDecls(const Context& context,
       if (!IsClangDeclImported(context, record_decl)) {
         return {record_decl};
       }
-      // TODO: Also collect field types.
+      // TODO: Also collect base and field types.
     }
   }
 
diff --git a/toolchain/check/testdata/interop/cpp/class/base.carbon b/toolchain/check/testdata/interop/cpp/class/base.carbon
new file mode 100644
index 000000000000..bee72302efe4
--- /dev/null
+++ b/toolchain/check/testdata/interop/cpp/class/base.carbon
@@ -0,0 +1,954 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/primitives.carbon
+// EXTRA-ARGS: --dump-sem-ir-ranges=ignore
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/base.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/base.carbon
+
+// --- derived_to_base_conversion.h
+
+class Base {};
+class Derived : public Base {};
+
+// --- use_derived_to_base_conversion.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "derived_to_base_conversion.h";
+
+//@dump-sem-ir-begin
+fn ConvertPtr(d: Cpp.Derived*) -> Cpp.Base* {
+  return d;
+}
+//@dump-sem-ir-end
+
+fn AcceptVal(b: Cpp.Base);
+
+//@dump-sem-ir-begin
+fn ConvertVal(d: Cpp.Derived) {
+  AcceptVal(d);
+}
+//@dump-sem-ir-end
+
+// --- static_member.h
+
+class Base {
+ public:
+  static auto base_fn() -> void;
+};
+
+class Derived : public Base {
+ public:
+  static auto derived_fn() -> void;
+};
+
+// --- use_static_member.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "static_member.h";
+
+fn MyF() {
+  //@dump-sem-ir-begin
+  Cpp.Base.base_fn();
+  Cpp.Derived.base_fn();
+  Cpp.Derived.derived_fn();
+  //@dump-sem-ir-end
+}
+
+// --- base_field.h
+
+struct Base {
+  int a;
+  int b;
+};
+
+struct Derived : Base {
+  int b;
+};
+
+// --- use_base_field.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "base_field.h";
+
+fn AccessDirect(d: Cpp.Derived) -> i32 {
+  //@dump-sem-ir-begin
+  return d.a;
+  //@dump-sem-ir-end
+}
+
+fn AccessQualified(d: Cpp.Derived) -> i32 {
+  //@dump-sem-ir-begin
+  return d.(Cpp.Base.b);
+  //@dump-sem-ir-end
+}
+
+// --- base_method.h
+
+struct Base {
+  void f() const;
+  void g() const;
+};
+
+struct Derived : Base {
+  void g() const;
+};
+
+// --- use_base_method.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "base_method.h";
+
+fn CallDirect(d: Cpp.Derived) {
+  //@dump-sem-ir-begin
+  d.f();
+  //@dump-sem-ir-end
+}
+
+fn CallQualified(d: Cpp.Derived) {
+  //@dump-sem-ir-begin
+  d.(Cpp.Base.g)();
+  //@dump-sem-ir-end
+}
+
+// --- multiple_inheritance.h
+
+struct A { int a; };
+struct B { int b; };
+struct C : A, B {};
+
+// --- fail_todo_use_multiple_inheritance.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "multiple_inheritance.h";
+
+fn ConvertA(p: Cpp.C*) -> Cpp.A* {
+  // CHECK:STDERR: fail_todo_use_multiple_inheritance.carbon:[[@LINE+7]]:3: error: cannot implicitly convert expression of type `Cpp.C*` to `Cpp.A*` [ConversionFailure]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_use_multiple_inheritance.carbon:[[@LINE+4]]:3: note: type `Cpp.C*` does not implement interface `Core.ImplicitAs(Cpp.A*)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
+  return p;
+}
+
+fn ConvertB(p: Cpp.C*) -> Cpp.B* {
+  // CHECK:STDERR: fail_todo_use_multiple_inheritance.carbon:[[@LINE+7]]:3: error: cannot implicitly convert expression of type `Cpp.C*` to `Cpp.B*` [ConversionFailure]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_use_multiple_inheritance.carbon:[[@LINE+4]]:3: note: type `Cpp.C*` does not implement interface `Core.ImplicitAs(Cpp.B*)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
+  return p;
+}
+
+// --- virtual_inheritance.h
+
+struct A { int a; };
+struct B : virtual A {};
+
+// --- fail_todo_use_virtual_inheritance.carbon
+
+library "[[@TEST_NAME]]";
+
+// CHECK:STDERR: fail_todo_use_virtual_inheritance.carbon:[[@LINE+2]]:1: in import [InImport]
+// CHECK:STDERR: ./virtual_inheritance.h:3: error: semantics TODO: `class with virtual bases` [SemanticsTodo]
+import Cpp library "virtual_inheritance.h";
+
+// CHECK:STDERR: fail_todo_use_virtual_inheritance.carbon:[[@LINE+4]]:15: note: in `Cpp` name lookup for `B` [InCppNameLookup]
+// CHECK:STDERR: fn Convert(p: Cpp.B*) -> Cpp.A* {
+// CHECK:STDERR:               ^~~~~
+// CHECK:STDERR:
+fn Convert(p: Cpp.B*) -> Cpp.A* {
+  // CHECK:STDERR: fail_todo_use_virtual_inheritance.carbon:[[@LINE+7]]:3: error: cannot implicitly convert expression of type `Cpp.B*` to `Cpp.A*` [ConversionFailure]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_use_virtual_inheritance.carbon:[[@LINE+4]]:3: note: type `Cpp.B*` does not implement interface `Core.ImplicitAs(Cpp.A*)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR:   return p;
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
+  return p;
+}
+
+// CHECK:STDOUT: --- use_derived_to_base_conversion.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
+// CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %Derived.elem: type = unbound_element_type %Derived, %Base [concrete]
+// CHECK:STDOUT:   %.52d: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete]
+// CHECK:STDOUT:   %complete_type.fd1: <witness> = complete_type_witness %.52d [concrete]
+// CHECK:STDOUT:   %ptr.ddb: type = ptr_type %Derived [concrete]
+// CHECK:STDOUT:   %pattern_type.5c8: type = pattern_type %ptr.ddb [concrete]
+// CHECK:STDOUT:   %ptr.fb2: type = ptr_type %Base [concrete]
+// CHECK:STDOUT:   %pattern_type.72a: type = pattern_type %ptr.fb2 [concrete]
+// CHECK:STDOUT:   %ConvertPtr.type: type = fn_type @ConvertPtr [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %ConvertPtr: %ConvertPtr.type = struct_value () [concrete]
+// CHECK:STDOUT:   %pattern_type.a3a: type = pattern_type %Base [concrete]
+// CHECK:STDOUT:   %AcceptVal.type: type = fn_type @AcceptVal [concrete]
+// CHECK:STDOUT:   %AcceptVal: %AcceptVal.type = struct_value () [concrete]
+// CHECK:STDOUT:   %pattern_type.5de: type = pattern_type %Derived [concrete]
+// CHECK:STDOUT:   %ConvertVal.type: type = fn_type @ConvertVal [concrete]
+// CHECK:STDOUT:   %ConvertVal: %ConvertVal.type = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .Derived = %Derived.decl
+// CHECK:STDOUT:     .Base = %Base.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
+// CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .ConvertPtr = %ConvertPtr.decl
+// CHECK:STDOUT:     .AcceptVal = %AcceptVal.decl
+// CHECK:STDOUT:     .ConvertVal = %ConvertVal.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "derived_to_base_conversion.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ConvertPtr.decl: %ConvertPtr.type = fn_decl @ConvertPtr [concrete = constants.%ConvertPtr] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5c8 = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5c8 = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.72a = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.72a = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %Cpp.ref.loc7_35: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:     %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
+// CHECK:STDOUT:     %ptr.loc7_43: type = ptr_type %Base.ref [concrete = constants.%ptr.fb2]
+// CHECK:STDOUT:     %d.param: %ptr.ddb = value_param call_param0
+// CHECK:STDOUT:     %.loc7: type = splice_block %ptr.loc7_29 [concrete = constants.%ptr.ddb] {
+// CHECK:STDOUT:       %Cpp.ref.loc7_18: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:       %ptr.loc7_29: type = ptr_type %Derived.ref [concrete = constants.%ptr.ddb]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %ptr.ddb = bind_name d, %d.param
+// CHECK:STDOUT:     %return.param: ref %ptr.fb2 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %ptr.fb2 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %AcceptVal.decl: %AcceptVal.type = fn_decl @AcceptVal [concrete = constants.%AcceptVal] {
+// CHECK:STDOUT:     %b.patt: %pattern_type.a3a = binding_pattern b [concrete]
+// CHECK:STDOUT:     %b.param_patt: %pattern_type.a3a = value_param_pattern %b.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %b.param: %Base = value_param call_param0
+// CHECK:STDOUT:     %.loc12: type = splice_block %Base.ref [concrete = constants.%Base] {
+// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %b: %Base = bind_name b, %b.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ConvertVal.decl: %ConvertVal.type = fn_decl @ConvertVal [concrete = constants.%ConvertVal] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5de = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5de = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %d.param: %Derived = value_param call_param0
+// CHECK:STDOUT:     %.loc15: type = splice_block %Derived.ref [concrete = constants.%Derived] {
+// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %Derived = bind_name d, %d.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Derived {
+// CHECK:STDOUT:   %.1: %Derived.elem = base_decl imports.%Base.decl, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete = constants.%.52d]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.fd1]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Derived
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Base {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type.357]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Base
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @ConvertPtr(%d.param: %ptr.ddb) -> %ptr.fb2 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %d.ref: %ptr.ddb = name_ref d, %d
+// CHECK:STDOUT:   %.loc8_11.1: ref %Derived = deref %d.ref
+// CHECK:STDOUT:   %.loc8_11.2: ref %Base = class_element_access %.loc8_11.1, element0
+// CHECK:STDOUT:   %addr: %ptr.fb2 = addr_of %.loc8_11.2
+// CHECK:STDOUT:   %.loc8_11.3: %ptr.fb2 = converted %d.ref, %addr
+// CHECK:STDOUT:   return %.loc8_11.3
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @AcceptVal(%b.param: %Base);
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @ConvertVal(%d.param: %Derived) {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %AcceptVal.ref: %AcceptVal.type = name_ref AcceptVal, file.%AcceptVal.decl [concrete = constants.%AcceptVal]
+// CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
+// CHECK:STDOUT:   %.loc16_13.1: ref %Base = class_element_access %d.ref, element0
+// CHECK:STDOUT:   %.loc16_13.2: ref %Base = converted %d.ref, %.loc16_13.1
+// CHECK:STDOUT:   %.loc16_13.3: %Base = bind_value %.loc16_13.2
+// CHECK:STDOUT:   %AcceptVal.call: init %empty_tuple.type = call %AcceptVal.ref(%.loc16_13.3)
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_static_member.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %MyF.type: type = fn_type @MyF [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %MyF: %MyF.type = struct_value () [concrete]
+// CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %Base.base_fn.type: type = fn_type @Base.base_fn [concrete]
+// CHECK:STDOUT:   %Base.base_fn: %Base.base_fn.type = struct_value () [concrete]
+// CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
+// CHECK:STDOUT:   %Derived.elem: type = unbound_element_type %Derived, %Base [concrete]
+// CHECK:STDOUT:   %.52d: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete]
+// CHECK:STDOUT:   %complete_type.fd1: <witness> = complete_type_witness %.52d [concrete]
+// CHECK:STDOUT:   %Derived.derived_fn.type: type = fn_type @Derived.derived_fn [concrete]
+// CHECK:STDOUT:   %Derived.derived_fn: %Derived.derived_fn.type = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .Base = %Base.decl
+// CHECK:STDOUT:     .Derived = %Derived.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
+// CHECK:STDOUT:   %Base.base_fn.decl: %Base.base_fn.type = fn_decl @Base.base_fn [concrete = constants.%Base.base_fn] {} {}
+// CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
+// CHECK:STDOUT:   %Derived.derived_fn.decl: %Derived.derived_fn.type = fn_decl @Derived.derived_fn [concrete = constants.%Derived.derived_fn] {} {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .MyF = %MyF.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "static_member.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %MyF.decl: %MyF.type = fn_decl @MyF [concrete = constants.%MyF] {} {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Base {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type.357]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Base
+// CHECK:STDOUT:   .base_fn = imports.%Base.base_fn.decl
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Derived {
+// CHECK:STDOUT:   %.1: %Derived.elem = base_decl imports.%Base.decl, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete = constants.%.52d]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.fd1]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Derived
+// CHECK:STDOUT:   .base_fn = imports.%Base.base_fn.decl
+// CHECK:STDOUT:   .derived_fn = imports.%Derived.derived_fn.decl
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @MyF() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
+// CHECK:STDOUT:   %base_fn.ref.loc8: %Base.base_fn.type = name_ref base_fn, imports.%Base.base_fn.decl [concrete = constants.%Base.base_fn]
+// CHECK:STDOUT:   %Base.base_fn.call.loc8: init %empty_tuple.type = call %base_fn.ref.loc8()
+// CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Derived.ref.loc9: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:   %base_fn.ref.loc9: %Base.base_fn.type = name_ref base_fn, imports.%Base.base_fn.decl [concrete = constants.%Base.base_fn]
+// CHECK:STDOUT:   %Base.base_fn.call.loc9: init %empty_tuple.type = call %base_fn.ref.loc9()
+// CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Derived.ref.loc10: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:   %derived_fn.ref: %Derived.derived_fn.type = name_ref derived_fn, imports.%Derived.derived_fn.decl [concrete = constants.%Derived.derived_fn]
+// CHECK:STDOUT:   %Derived.derived_fn.call: init %empty_tuple.type = call %derived_fn.ref()
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @Base.base_fn();
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @Derived.derived_fn();
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_base_field.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
+// CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %Base.elem: type = unbound_element_type %Base, %i32 [concrete]
+// CHECK:STDOUT:   %.807: type = custom_layout_type {size=8, align=4, .a@0: %i32, .b@4: %i32} [concrete]
+// CHECK:STDOUT:   %complete_type.e3e: <witness> = complete_type_witness %.807 [concrete]
+// CHECK:STDOUT:   %Derived.elem.b4e: type = unbound_element_type %Derived, %Base [concrete]
+// CHECK:STDOUT:   %Derived.elem.16d: type = unbound_element_type %Derived, %i32 [concrete]
+// CHECK:STDOUT:   %.f26: type = custom_layout_type {size=12, align=4, .base@0: %Base, .b@8: %i32} [concrete]
+// CHECK:STDOUT:   %complete_type.0bc: <witness> = complete_type_witness %.f26 [concrete]
+// CHECK:STDOUT:   %pattern_type.5de: type = pattern_type %Derived [concrete]
+// CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
+// CHECK:STDOUT:   %AccessDirect.type: type = fn_type @AccessDirect [concrete]
+// CHECK:STDOUT:   %AccessDirect: %AccessDirect.type = struct_value () [concrete]
+// CHECK:STDOUT:   %AccessQualified.type: type = fn_type @AccessQualified [concrete]
+// CHECK:STDOUT:   %AccessQualified: %AccessQualified.type = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .Derived = %Derived.decl
+// CHECK:STDOUT:     .Base = %Base.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
+// CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/parts/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .AccessDirect = %AccessDirect.decl
+// CHECK:STDOUT:     .AccessQualified = %AccessQualified.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "base_field.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %AccessDirect.decl: %AccessDirect.type = fn_decl @AccessDirect [concrete = constants.%AccessDirect] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5de = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5de = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.7ce = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.7ce = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %d.param: %Derived = value_param call_param0
+// CHECK:STDOUT:     %.loc6: type = splice_block %Derived.ref [concrete = constants.%Derived] {
+// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %Derived = bind_name d, %d.param
+// CHECK:STDOUT:     %return.param: ref %i32 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %AccessQualified.decl: %AccessQualified.type = fn_decl @AccessQualified [concrete = constants.%AccessQualified] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5de = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5de = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.7ce = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.7ce = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %d.param: %Derived = value_param call_param0
+// CHECK:STDOUT:     %.loc12: type = splice_block %Derived.ref [concrete = constants.%Derived] {
+// CHECK:STDOUT:       %Cpp.ref.loc12: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %Derived = bind_name d, %d.param
+// CHECK:STDOUT:     %return.param: ref %i32 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Derived {
+// CHECK:STDOUT:   %.1: %Derived.elem.b4e = base_decl imports.%Base.decl, element0 [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.2: %Derived.elem.16d = field_decl b, element1 [concrete]
+// CHECK:STDOUT:   %.3: type = custom_layout_type {size=12, align=4, .base@0: %Base, .b@8: %i32} [concrete = constants.%.f26]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.3 [concrete = constants.%complete_type.0bc]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Derived
+// CHECK:STDOUT:   .a = @Base.%.1
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Base {
+// CHECK:STDOUT:   %int_32.1: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32.1: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.1: %Base.elem = field_decl a, element0 [concrete]
+// CHECK:STDOUT:   %int_32.2: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32.2: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.2: %Base.elem = field_decl b, element1 [concrete]
+// CHECK:STDOUT:   %.3: type = custom_layout_type {size=8, align=4, .a@0: %i32, .b@4: %i32} [concrete = constants.%.807]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.3 [concrete = constants.%complete_type.e3e]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Base
+// CHECK:STDOUT:   .b = %.2
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @AccessDirect(%d.param: %Derived) -> %i32 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
+// CHECK:STDOUT:   %a.ref: %Base.elem = name_ref a, @Base.%.1 [concrete = @Base.%.1]
+// CHECK:STDOUT:   %.loc8_11.1: ref %Base = class_element_access %d.ref, element0
+// CHECK:STDOUT:   %.loc8_11.2: ref %Base = converted %d.ref, %.loc8_11.1
+// CHECK:STDOUT:   %.loc8_11.3: ref %i32 = class_element_access %.loc8_11.2, element0
+// CHECK:STDOUT:   %.loc8_11.4: %i32 = bind_value %.loc8_11.3
+// CHECK:STDOUT:   return %.loc8_11.4
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @AccessQualified(%d.param: %Derived) -> %i32 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
+// CHECK:STDOUT:   %Cpp.ref.loc14: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
+// CHECK:STDOUT:   %b.ref: %Base.elem = name_ref b, @Base.%.2 [concrete = @Base.%.2]
+// CHECK:STDOUT:   %.loc14_11.1: ref %Base = class_element_access %d.ref, element0
+// CHECK:STDOUT:   %.loc14_11.2: ref %Base = converted %d.ref, %.loc14_11.1
+// CHECK:STDOUT:   %.loc14_11.3: ref %i32 = class_element_access %.loc14_11.2, element1
+// CHECK:STDOUT:   %.loc14_11.4: %i32 = bind_value %.loc14_11.3
+// CHECK:STDOUT:   return %.loc14_11.4
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_base_method.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
+// CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %Derived.elem: type = unbound_element_type %Derived, %Base [concrete]
+// CHECK:STDOUT:   %.52d: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete]
+// CHECK:STDOUT:   %complete_type.fd1: <witness> = complete_type_witness %.52d [concrete]
+// CHECK:STDOUT:   %pattern_type.5de: type = pattern_type %Derived [concrete]
+// CHECK:STDOUT:   %CallDirect.type: type = fn_type @CallDirect [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %CallDirect: %CallDirect.type = struct_value () [concrete]
+// CHECK:STDOUT:   %pattern_type.a3a: type = pattern_type %Base [concrete]
+// CHECK:STDOUT:   %Base.f.type: type = fn_type @Base.f [concrete]
+// CHECK:STDOUT:   %Base.f: %Base.f.type = struct_value () [concrete]
+// CHECK:STDOUT:   %CallQualified.type: type = fn_type @CallQualified [concrete]
+// CHECK:STDOUT:   %CallQualified: %CallQualified.type = struct_value () [concrete]
+// CHECK:STDOUT:   %Base.g.type: type = fn_type @Base.g [concrete]
+// CHECK:STDOUT:   %Base.g: %Base.g.type = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .Derived = %Derived.decl
+// CHECK:STDOUT:     .Base = %Base.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
+// CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
+// CHECK:STDOUT:   %Base.f.decl: %Base.f.type = fn_decl @Base.f [concrete = constants.%Base.f] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.a3a = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.a3a = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %self.param: %Base = value_param call_param0
+// CHECK:STDOUT:     %self: %Base = bind_name self, %self.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Base.g.decl: %Base.g.type = fn_decl @Base.g [concrete = constants.%Base.g] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.a3a = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.a3a = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %self.param: %Base = value_param call_param0
+// CHECK:STDOUT:     %self: %Base = bind_name self, %self.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .CallDirect = %CallDirect.decl
+// CHECK:STDOUT:     .CallQualified = %CallQualified.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "base_method.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %CallDirect.decl: %CallDirect.type = fn_decl @CallDirect [concrete = constants.%CallDirect] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5de = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5de = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %d.param: %Derived = value_param call_param0
+// CHECK:STDOUT:     %.loc6: type = splice_block %Derived.ref [concrete = constants.%Derived] {
+// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %Derived = bind_name d, %d.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %CallQualified.decl: %CallQualified.type = fn_decl @CallQualified [concrete = constants.%CallQualified] {
+// CHECK:STDOUT:     %d.patt: %pattern_type.5de = binding_pattern d [concrete]
+// CHECK:STDOUT:     %d.param_patt: %pattern_type.5de = value_param_pattern %d.patt, call_param0 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %d.param: %Derived = value_param call_param0
+// CHECK:STDOUT:     %.loc12: type = splice_block %Derived.ref [concrete = constants.%Derived] {
+// CHECK:STDOUT:       %Cpp.ref.loc12: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %Derived.ref: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %d: %Derived = bind_name d, %d.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Derived {
+// CHECK:STDOUT:   %.1: %Derived.elem = base_decl imports.%Base.decl, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=1, align=1, .base@0: %Base} [concrete = constants.%.52d]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.fd1]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Derived
+// CHECK:STDOUT:   .f = imports.%Base.f.decl
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @Base {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type.357]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%Base
+// CHECK:STDOUT:   .g = imports.%Base.g.decl
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @CallDirect(%d.param: %Derived) {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
+// CHECK:STDOUT:   %f.ref: %Base.f.type = name_ref f, imports.%Base.f.decl [concrete = constants.%Base.f]
+// CHECK:STDOUT:   %Base.f.bound: <bound method> = bound_method %d.ref, %f.ref
+// CHECK:STDOUT:   %.loc8_3.1: ref %Base = class_element_access %d.ref, element0
+// CHECK:STDOUT:   %.loc8_3.2: ref %Base = converted %d.ref, %.loc8_3.1
+// CHECK:STDOUT:   %.loc8_3.3: %Base = bind_value %.loc8_3.2
+// CHECK:STDOUT:   %Base.f.call: init %empty_tuple.type = call %Base.f.bound(%.loc8_3.3)
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @Base.f(%self.param: %Base);
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @CallQualified(%d.param: %Derived) {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
+// CHECK:STDOUT:   %Cpp.ref.loc14: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
+// CHECK:STDOUT:   %g.ref: %Base.g.type = name_ref g, imports.%Base.g.decl [concrete = constants.%Base.g]
+// CHECK:STDOUT:   %Base.g.bound: <bound method> = bound_method %d.ref, %g.ref
+// CHECK:STDOUT:   %.loc14_3.1: ref %Base = class_element_access %d.ref, element0
+// CHECK:STDOUT:   %.loc14_3.2: ref %Base = converted %d.ref, %.loc14_3.1
+// CHECK:STDOUT:   %.loc14_3.3: %Base = bind_value %.loc14_3.2
+// CHECK:STDOUT:   %Base.g.call: init %empty_tuple.type = call %Base.g.bound(%.loc14_3.3)
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @Base.g(%self.param: %Base);
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_multiple_inheritance.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %A: type = class_type @A [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %A.elem: type = unbound_element_type %A, %i32 [concrete]
+// CHECK:STDOUT:   %.79a: type = custom_layout_type {size=4, align=4, .a@0: %i32} [concrete]
+// CHECK:STDOUT:   %complete_type.33a: <witness> = complete_type_witness %.79a [concrete]
+// CHECK:STDOUT:   %C.elem.1e5: type = unbound_element_type %C, %A [concrete]
+// CHECK:STDOUT:   %B: type = class_type @B [concrete]
+// CHECK:STDOUT:   %B.elem: type = unbound_element_type %B, %i32 [concrete]
+// CHECK:STDOUT:   %.903: type = custom_layout_type {size=4, align=4, .b@0: %i32} [concrete]
+// CHECK:STDOUT:   %complete_type.fb9: <witness> = complete_type_witness %.903 [concrete]
+// CHECK:STDOUT:   %C.elem.874: type = unbound_element_type %C, %B [concrete]
+// CHECK:STDOUT:   %.dba: type = custom_layout_type {size=8, align=4, .base@0: %A, .base@4: %B} [concrete]
+// CHECK:STDOUT:   %complete_type.1ad: <witness> = complete_type_witness %.dba [concrete]
+// CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
+// CHECK:STDOUT:   %pattern_type.a31: type = pattern_type %ptr.d9e [concrete]
+// CHECK:STDOUT:   %ptr.270: type = ptr_type %A [concrete]
+// CHECK:STDOUT:   %pattern_type.bcf: type = pattern_type %ptr.270 [concrete]
+// CHECK:STDOUT:   %ConvertA.type: type = fn_type @ConvertA [concrete]
+// CHECK:STDOUT:   %ConvertA: %ConvertA.type = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT:   %ptr.a04: type = ptr_type %B [concrete]
+// CHECK:STDOUT:   %pattern_type.837: type = pattern_type %ptr.a04 [concrete]
+// CHECK:STDOUT:   %ConvertB.type: type = fn_type @ConvertB [concrete]
+// CHECK:STDOUT:   %ConvertB: %ConvertB.type = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:     .A = %A.decl
+// CHECK:STDOUT:     .B = %B.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
+// CHECK:STDOUT:   %A.decl: type = class_decl @A [concrete = constants.%A] {} {}
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/parts/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %B.decl: type = class_decl @B [concrete = constants.%B] {} {}
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/parts/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .ConvertA = %ConvertA.decl
+// CHECK:STDOUT:     .ConvertB = %ConvertB.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "multiple_inheritance.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ConvertA.decl: %ConvertA.type = fn_decl @ConvertA [concrete = constants.%ConvertA] {
+// CHECK:STDOUT:     %p.patt: %pattern_type.a31 = binding_pattern p [concrete]
+// CHECK:STDOUT:     %p.param_patt: %pattern_type.a31 = value_param_pattern %p.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.bcf = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.bcf = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %Cpp.ref.loc6_27: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:     %A.ref: type = name_ref A, imports.%A.decl [concrete = constants.%A]
+// CHECK:STDOUT:     %ptr.loc6_32: type = ptr_type %A.ref [concrete = constants.%ptr.270]
+// CHECK:STDOUT:     %p.param: %ptr.d9e = value_param call_param0
+// CHECK:STDOUT:     %.loc6: type = splice_block %ptr.loc6_21 [concrete = constants.%ptr.d9e] {
+// CHECK:STDOUT:       %Cpp.ref.loc6_16: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %C.ref: type = name_ref C, imports.%C.decl [concrete = constants.%C]
+// CHECK:STDOUT:       %ptr.loc6_21: type = ptr_type %C.ref [concrete = constants.%ptr.d9e]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %p: %ptr.d9e = bind_name p, %p.param
+// CHECK:STDOUT:     %return.param: ref %ptr.270 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %ptr.270 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ConvertB.decl: %ConvertB.type = fn_decl @ConvertB [concrete = constants.%ConvertB] {
+// CHECK:STDOUT:     %p.patt: %pattern_type.a31 = binding_pattern p [concrete]
+// CHECK:STDOUT:     %p.param_patt: %pattern_type.a31 = value_param_pattern %p.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.837 = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.837 = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %Cpp.ref.loc17_27: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:     %B.ref: type = name_ref B, imports.%B.decl [concrete = constants.%B]
+// CHECK:STDOUT:     %ptr.loc17_32: type = ptr_type %B.ref [concrete = constants.%ptr.a04]
+// CHECK:STDOUT:     %p.param: %ptr.d9e = value_param call_param0
+// CHECK:STDOUT:     %.loc17: type = splice_block %ptr.loc17_21 [concrete = constants.%ptr.d9e] {
+// CHECK:STDOUT:       %Cpp.ref.loc17_16: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %C.ref: type = name_ref C, imports.%C.decl [concrete = constants.%C]
+// CHECK:STDOUT:       %ptr.loc17_21: type = ptr_type %C.ref [concrete = constants.%ptr.d9e]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %p: %ptr.d9e = bind_name p, %p.param
+// CHECK:STDOUT:     %return.param: ref %ptr.a04 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %ptr.a04 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT:   %.1: %C.elem.1e5 = base_decl imports.%A.decl, element0 [concrete]
+// CHECK:STDOUT:   %.2: %C.elem.874 = base_decl imports.%B.decl, element1 [concrete]
+// CHECK:STDOUT:   %.3: type = custom_layout_type {size=8, align=4, .base@0: %A, .base@4: %B} [concrete = constants.%.dba]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.3 [concrete = constants.%complete_type.1ad]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @A {
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.1: %A.elem = field_decl a, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=4, align=4, .a@0: %i32} [concrete = constants.%.79a]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.33a]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%A
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @B {
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.1: %B.elem = field_decl b, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=4, align=4, .b@0: %i32} [concrete = constants.%.903]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.fb9]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%B
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @ConvertA(%p.param: %ptr.d9e) -> %ptr.270 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %p.ref: %ptr.d9e = name_ref p, %p
+// CHECK:STDOUT:   %.loc14: %ptr.270 = converted %p.ref, <error> [concrete = <error>]
+// CHECK:STDOUT:   return <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @ConvertB(%p.param: %ptr.d9e) -> %ptr.a04 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %p.ref: %ptr.d9e = name_ref p, %p
+// CHECK:STDOUT:   %.loc25: %ptr.a04 = converted %p.ref, <error> [concrete = <error>]
+// CHECK:STDOUT:   return <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_todo_use_virtual_inheritance.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %B: type = class_type @B [concrete]
+// CHECK:STDOUT:   %ptr.a04: type = ptr_type %B [concrete]
+// CHECK:STDOUT:   %pattern_type.837: type = pattern_type %ptr.a04 [concrete]
+// CHECK:STDOUT:   %A: type = class_type @A [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %A.elem: type = unbound_element_type %A, %i32 [concrete]
+// CHECK:STDOUT:   %.79a: type = custom_layout_type {size=4, align=4, .a@0: %i32} [concrete]
+// CHECK:STDOUT:   %complete_type.33a: <witness> = complete_type_witness %.79a [concrete]
+// CHECK:STDOUT:   %ptr.270: type = ptr_type %A [concrete]
+// CHECK:STDOUT:   %pattern_type.bcf: type = pattern_type %ptr.270 [concrete]
+// CHECK:STDOUT:   %Convert.type: type = fn_type @Convert [concrete]
+// CHECK:STDOUT:   %Convert: %Convert.type = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
+// CHECK:STDOUT:     .B = %B.decl
+// CHECK:STDOUT:     .A = %A.decl
+// CHECK:STDOUT:     import Cpp//...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %B.decl: type = class_decl @B [concrete = constants.%B] {} {}
+// CHECK:STDOUT:   %A.decl: type = class_decl @A [concrete = constants.%A] {} {}
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/parts/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/parts/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .Cpp = imports.%Cpp
+// CHECK:STDOUT:     .Convert = %Convert.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %Cpp.import_cpp = import_cpp {
+// CHECK:STDOUT:     import Cpp "virtual_inheritance.h"
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Convert.decl: %Convert.type = fn_decl @Convert [concrete = constants.%Convert] {
+// CHECK:STDOUT:     %p.patt: %pattern_type.837 = binding_pattern p [concrete]
+// CHECK:STDOUT:     %p.param_patt: %pattern_type.837 = value_param_pattern %p.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.bcf = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.bcf = out_param_pattern %return.patt, call_param1 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %Cpp.ref.loc12_26: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:     %A.ref: type = name_ref A, imports.%A.decl [concrete = constants.%A]
+// CHECK:STDOUT:     %ptr.loc12_31: type = ptr_type %A.ref [concrete = constants.%ptr.270]
+// CHECK:STDOUT:     %p.param: %ptr.a04 = value_param call_param0
+// CHECK:STDOUT:     %.loc12: type = splice_block %ptr.loc12_20 [concrete = constants.%ptr.a04] {
+// CHECK:STDOUT:       %Cpp.ref.loc12_15: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:       %B.ref: type = name_ref B, imports.%B.decl [concrete = constants.%B]
+// CHECK:STDOUT:       %ptr.loc12_20: type = ptr_type %B.ref [concrete = constants.%ptr.a04]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %p: %ptr.a04 = bind_name p, %p.param
+// CHECK:STDOUT:     %return.param: ref %ptr.270 = out_param call_param1
+// CHECK:STDOUT:     %return: ref %ptr.270 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @B {
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness <error> [concrete = <error>]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%B
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @A {
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   %.1: %A.elem = field_decl a, element0 [concrete]
+// CHECK:STDOUT:   %.2: type = custom_layout_type {size=4, align=4, .a@0: %i32} [concrete = constants.%.79a]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %.2 [concrete = constants.%complete_type.33a]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%A
+// CHECK:STDOUT:   import Cpp//...
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @Convert(%p.param: %ptr.a04) -> %ptr.270 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %p.ref: %ptr.a04 = name_ref p, %p
+// CHECK:STDOUT:   %.loc20: %ptr.270 = converted %p.ref, <error> [concrete = <error>]
+// CHECK:STDOUT:   return <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/class/class.carbon b/toolchain/check/testdata/interop/cpp/class/class.carbon
index 92fdf49964c6..ea511cb9c4d5 100644
--- a/toolchain/check/testdata/interop/cpp/class/class.carbon
+++ b/toolchain/check/testdata/interop/cpp/class/class.carbon
@@ -182,67 +182,6 @@ fn MyF(bar : Cpp.Bar*) {
 }
 //@dump-sem-ir-end
 
-// ============================================================================
-// Inheritance static
-// ============================================================================
-
-// --- inheritance_static.h
-
-class Bar1 {
- public:
-  static auto foo1() -> void;
-};
-
-class Bar2 : public Bar1 {
- public:
-  static auto foo2() -> void;
-};
-
-// --- import_inheritance_static.carbon
-
-library "[[@TEST_NAME]]";
-
-import Cpp library "inheritance_static.h";
-
-fn MyF() {
-  //@dump-sem-ir-begin
-  Cpp.Bar1.foo1();
-  Cpp.Bar2.foo1();
-  Cpp.Bar2.foo2();
-  //@dump-sem-ir-end
-}
-
-// ============================================================================
-// Inheritance pointers
-// ============================================================================
-
-// --- inheritance_pointers.h
-
-class Bar1 {};
-class Bar2 : public Bar1 {};
-
-// --- fail_todo_import_inheritance_pointers.carbon
-
-library "[[@TEST_NAME]]";
-
-import Cpp library "inheritance_pointers.h";
-
-//@dump-sem-ir-begin
-fn MyF1(bar: Cpp.Bar1*);
-// TODO: Support C++ inheritance.
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE+10]]:33: error: cannot implicitly convert expression of type `Cpp.Bar2*` to `Cpp.Bar1*` [ConversionFailure]
-// CHECK:STDERR: fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-// CHECK:STDERR:                                 ^~~
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE+7]]:33: note: type `Cpp.Bar2*` does not implement interface `Core.ImplicitAs(Cpp.Bar1*)` [MissingImplInMemberAccessNote]
-// CHECK:STDERR: fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-// CHECK:STDERR:                                 ^~~
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE-8]]:9: note: initializing function parameter [InCallToFunctionParam]
-// CHECK:STDERR: fn MyF1(bar: Cpp.Bar1*);
-// CHECK:STDERR:         ^~~~~~~~~~~~~~
-// CHECK:STDERR:
-fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-//@dump-sem-ir-end
-
 // ============================================================================
 // Dynamic
 // ============================================================================
@@ -564,111 +503,6 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_inheritance_static.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %Bar1: type = class_type @Bar1 [concrete]
-// CHECK:STDOUT:   %Bar1.foo1.type: type = fn_type @Bar1.foo1 [concrete]
-// CHECK:STDOUT:   %Bar1.foo1: %Bar1.foo1.type = struct_value () [concrete]
-// CHECK:STDOUT:   %Bar2: type = class_type @Bar2 [concrete]
-// CHECK:STDOUT:   %Bar2.foo2.type: type = fn_type @Bar2.foo2 [concrete]
-// CHECK:STDOUT:   %Bar2.foo2: %Bar2.foo2.type = struct_value () [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .Bar1 = %Bar1.decl
-// CHECK:STDOUT:     .Bar2 = %Bar2.decl
-// CHECK:STDOUT:     import Cpp//...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Bar1.decl: type = class_decl @Bar1 [concrete = constants.%Bar1] {} {}
-// CHECK:STDOUT:   %Bar1.foo1.decl: %Bar1.foo1.type = fn_decl @Bar1.foo1 [concrete = constants.%Bar1.foo1] {} {}
-// CHECK:STDOUT:   %Bar2.decl: type = class_decl @Bar2 [concrete = constants.%Bar2] {} {}
-// CHECK:STDOUT:   %Bar2.foo2.decl: %Bar2.foo2.type = fn_decl @Bar2.foo2 [concrete = constants.%Bar2.foo2] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar1.ref: type = name_ref Bar1, imports.%Bar1.decl [concrete = constants.%Bar1]
-// CHECK:STDOUT:   %foo1.ref.loc8: %Bar1.foo1.type = name_ref foo1, imports.%Bar1.foo1.decl [concrete = constants.%Bar1.foo1]
-// CHECK:STDOUT:   %Bar1.foo1.call.loc8: init %empty_tuple.type = call %foo1.ref.loc8()
-// CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar2.ref.loc9: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:   %foo1.ref.loc9: %Bar1.foo1.type = name_ref foo1, imports.%Bar1.foo1.decl [concrete = constants.%Bar1.foo1]
-// CHECK:STDOUT:   %Bar1.foo1.call.loc9: init %empty_tuple.type = call %foo1.ref.loc9()
-// CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar2.ref.loc10: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:   %foo2.ref: %Bar2.foo2.type = name_ref foo2, imports.%Bar2.foo2.decl [concrete = constants.%Bar2.foo2]
-// CHECK:STDOUT:   %Bar2.foo2.call: init %empty_tuple.type = call %foo2.ref()
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_inheritance_pointers.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %Bar1: type = class_type @Bar1 [concrete]
-// CHECK:STDOUT:   %ptr.f68: type = ptr_type %Bar1 [concrete]
-// CHECK:STDOUT:   %pattern_type.3cc: type = pattern_type %ptr.f68 [concrete]
-// CHECK:STDOUT:   %MyF1.type: type = fn_type @MyF1 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %MyF1: %MyF1.type = struct_value () [concrete]
-// CHECK:STDOUT:   %Bar2: type = class_type @Bar2 [concrete]
-// CHECK:STDOUT:   %ptr.eca: type = ptr_type %Bar2 [concrete]
-// CHECK:STDOUT:   %pattern_type.92a: type = pattern_type %ptr.eca [concrete]
-// CHECK:STDOUT:   %MyF2.type: type = fn_type @MyF2 [concrete]
-// CHECK:STDOUT:   %MyF2: %MyF2.type = struct_value () [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .Bar1 = %Bar1.decl
-// CHECK:STDOUT:     .Bar2 = %Bar2.decl
-// CHECK:STDOUT:     import Cpp//...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Bar1.decl: type = class_decl @Bar1 [concrete = constants.%Bar1] {} {}
-// CHECK:STDOUT:   %Bar2.decl: type = class_decl @Bar2 [concrete = constants.%Bar2] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   %MyF1.decl: %MyF1.type = fn_decl @MyF1 [concrete = constants.%MyF1] {
-// CHECK:STDOUT:     %bar.patt: %pattern_type.3cc = binding_pattern bar [concrete]
-// CHECK:STDOUT:     %bar.param_patt: %pattern_type.3cc = value_param_pattern %bar.patt, call_param0 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %bar.param: %ptr.f68 = value_param call_param0
-// CHECK:STDOUT:     %.loc7: type = splice_block %ptr [concrete = constants.%ptr.f68] {
-// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:       %Bar1.ref: type = name_ref Bar1, imports.%Bar1.decl [concrete = constants.%Bar1]
-// CHECK:STDOUT:       %ptr: type = ptr_type %Bar1.ref [concrete = constants.%ptr.f68]
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %bar: %ptr.f68 = bind_name bar, %bar.param
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %MyF2.decl: %MyF2.type = fn_decl @MyF2 [concrete = constants.%MyF2] {
-// CHECK:STDOUT:     %bar.patt: %pattern_type.92a = binding_pattern bar [concrete]
-// CHECK:STDOUT:     %bar.param_patt: %pattern_type.92a = value_param_pattern %bar.patt, call_param0 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %bar.param: %ptr.eca = value_param call_param0
-// CHECK:STDOUT:     %.loc19_23: type = splice_block %ptr [concrete = constants.%ptr.eca] {
-// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:       %Bar2.ref: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:       %ptr: type = ptr_type %Bar2.ref [concrete = constants.%ptr.eca]
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %bar: %ptr.eca = bind_name bar, %bar.param
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF1(%bar.param: %ptr.f68);
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF2(%bar.param: %ptr.eca) {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %MyF1.ref: %MyF1.type = name_ref MyF1, file.%MyF1.decl [concrete = constants.%MyF1]
-// CHECK:STDOUT:   %bar.ref: %ptr.eca = name_ref bar, %bar
-// CHECK:STDOUT:   %.loc19_33: %ptr.f68 = converted %bar.ref, <error> [concrete = <error>]
-// CHECK:STDOUT:   %MyF1.call: init %empty_tuple.type = call %MyF1.ref(<error>)
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
 // CHECK:STDOUT: --- import_dynamic.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
diff --git a/toolchain/check/testdata/interop/cpp/class/struct.carbon b/toolchain/check/testdata/interop/cpp/class/struct.carbon
index bf8053c5a343..dea7f1a12022 100644
--- a/toolchain/check/testdata/interop/cpp/class/struct.carbon
+++ b/toolchain/check/testdata/interop/cpp/class/struct.carbon
@@ -180,65 +180,6 @@ fn MyF(bar : Cpp.Bar*) {
 }
 //@dump-sem-ir-end
 
-// ============================================================================
-// Inheritance static
-// ============================================================================
-
-// --- inheritance_static.h
-
-struct Bar1 {
-  static auto foo1() -> void;
-};
-
-struct Bar2 : public Bar1 {
-  static auto foo2() -> void;
-};
-
-// --- import_inheritance_static.carbon
-
-library "[[@TEST_NAME]]";
-
-import Cpp library "inheritance_static.h";
-
-fn MyF() {
-  //@dump-sem-ir-begin
-  Cpp.Bar1.foo1();
-  Cpp.Bar2.foo1();
-  Cpp.Bar2.foo2();
-  //@dump-sem-ir-end
-}
-
-// ============================================================================
-// Inheritance pointers
-// ============================================================================
-
-// --- inheritance_pointers.h
-
-struct Bar1 {};
-struct Bar2 : public Bar1 {};
-
-// --- fail_todo_import_inheritance_pointers.carbon
-
-library "[[@TEST_NAME]]";
-
-import Cpp library "inheritance_pointers.h";
-
-//@dump-sem-ir-begin
-fn MyF1(bar: Cpp.Bar1*);
-// TODO: Support C++ inheritance.
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE+10]]:33: error: cannot implicitly convert expression of type `Cpp.Bar2*` to `Cpp.Bar1*` [ConversionFailure]
-// CHECK:STDERR: fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-// CHECK:STDERR:                                 ^~~
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE+7]]:33: note: type `Cpp.Bar2*` does not implement interface `Core.ImplicitAs(Cpp.Bar1*)` [MissingImplInMemberAccessNote]
-// CHECK:STDERR: fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-// CHECK:STDERR:                                 ^~~
-// CHECK:STDERR: fail_todo_import_inheritance_pointers.carbon:[[@LINE-8]]:9: note: initializing function parameter [InCallToFunctionParam]
-// CHECK:STDERR: fn MyF1(bar: Cpp.Bar1*);
-// CHECK:STDERR:         ^~~~~~~~~~~~~~
-// CHECK:STDERR:
-fn MyF2(bar : Cpp.Bar2*) { MyF1(bar); }
-//@dump-sem-ir-end
-
 // ============================================================================
 // Dynamic
 // ============================================================================
@@ -576,111 +517,6 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_inheritance_static.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %Bar1: type = class_type @Bar1 [concrete]
-// CHECK:STDOUT:   %Bar1.foo1.type: type = fn_type @Bar1.foo1 [concrete]
-// CHECK:STDOUT:   %Bar1.foo1: %Bar1.foo1.type = struct_value () [concrete]
-// CHECK:STDOUT:   %Bar2: type = class_type @Bar2 [concrete]
-// CHECK:STDOUT:   %Bar2.foo2.type: type = fn_type @Bar2.foo2 [concrete]
-// CHECK:STDOUT:   %Bar2.foo2: %Bar2.foo2.type = struct_value () [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .Bar1 = %Bar1.decl
-// CHECK:STDOUT:     .Bar2 = %Bar2.decl
-// CHECK:STDOUT:     import Cpp//...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Bar1.decl: type = class_decl @Bar1 [concrete = constants.%Bar1] {} {}
-// CHECK:STDOUT:   %Bar1.foo1.decl: %Bar1.foo1.type = fn_decl @Bar1.foo1 [concrete = constants.%Bar1.foo1] {} {}
-// CHECK:STDOUT:   %Bar2.decl: type = class_decl @Bar2 [concrete = constants.%Bar2] {} {}
-// CHECK:STDOUT:   %Bar2.foo2.decl: %Bar2.foo2.type = fn_decl @Bar2.foo2 [concrete = constants.%Bar2.foo2] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar1.ref: type = name_ref Bar1, imports.%Bar1.decl [concrete = constants.%Bar1]
-// CHECK:STDOUT:   %foo1.ref.loc8: %Bar1.foo1.type = name_ref foo1, imports.%Bar1.foo1.decl [concrete = constants.%Bar1.foo1]
-// CHECK:STDOUT:   %Bar1.foo1.call.loc8: init %empty_tuple.type = call %foo1.ref.loc8()
-// CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar2.ref.loc9: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:   %foo1.ref.loc9: %Bar1.foo1.type = name_ref foo1, imports.%Bar1.foo1.decl [concrete = constants.%Bar1.foo1]
-// CHECK:STDOUT:   %Bar1.foo1.call.loc9: init %empty_tuple.type = call %foo1.ref.loc9()
-// CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   %Bar2.ref.loc10: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:   %foo2.ref: %Bar2.foo2.type = name_ref foo2, imports.%Bar2.foo2.decl [concrete = constants.%Bar2.foo2]
-// CHECK:STDOUT:   %Bar2.foo2.call: init %empty_tuple.type = call %foo2.ref()
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_inheritance_pointers.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %Bar1: type = class_type @Bar1 [concrete]
-// CHECK:STDOUT:   %ptr.f68: type = ptr_type %Bar1 [concrete]
-// CHECK:STDOUT:   %pattern_type.3cc: type = pattern_type %ptr.f68 [concrete]
-// CHECK:STDOUT:   %MyF1.type: type = fn_type @MyF1 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %MyF1: %MyF1.type = struct_value () [concrete]
-// CHECK:STDOUT:   %Bar2: type = class_type @Bar2 [concrete]
-// CHECK:STDOUT:   %ptr.eca: type = ptr_type %Bar2 [concrete]
-// CHECK:STDOUT:   %pattern_type.92a: type = pattern_type %ptr.eca [concrete]
-// CHECK:STDOUT:   %MyF2.type: type = fn_type @MyF2 [concrete]
-// CHECK:STDOUT:   %MyF2: %MyF2.type = struct_value () [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .Bar1 = %Bar1.decl
-// CHECK:STDOUT:     .Bar2 = %Bar2.decl
-// CHECK:STDOUT:     import Cpp//...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Bar1.decl: type = class_decl @Bar1 [concrete = constants.%Bar1] {} {}
-// CHECK:STDOUT:   %Bar2.decl: type = class_decl @Bar2 [concrete = constants.%Bar2] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   %MyF1.decl: %MyF1.type = fn_decl @MyF1 [concrete = constants.%MyF1] {
-// CHECK:STDOUT:     %bar.patt: %pattern_type.3cc = binding_pattern bar [concrete]
-// CHECK:STDOUT:     %bar.param_patt: %pattern_type.3cc = value_param_pattern %bar.patt, call_param0 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %bar.param: %ptr.f68 = value_param call_param0
-// CHECK:STDOUT:     %.loc7: type = splice_block %ptr [concrete = constants.%ptr.f68] {
-// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:       %Bar1.ref: type = name_ref Bar1, imports.%Bar1.decl [concrete = constants.%Bar1]
-// CHECK:STDOUT:       %ptr: type = ptr_type %Bar1.ref [concrete = constants.%ptr.f68]
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %bar: %ptr.f68 = bind_name bar, %bar.param
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %MyF2.decl: %MyF2.type = fn_decl @MyF2 [concrete = constants.%MyF2] {
-// CHECK:STDOUT:     %bar.patt: %pattern_type.92a = binding_pattern bar [concrete]
-// CHECK:STDOUT:     %bar.param_patt: %pattern_type.92a = value_param_pattern %bar.patt, call_param0 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %bar.param: %ptr.eca = value_param call_param0
-// CHECK:STDOUT:     %.loc19_23: type = splice_block %ptr [concrete = constants.%ptr.eca] {
-// CHECK:STDOUT:       %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:       %Bar2.ref: type = name_ref Bar2, imports.%Bar2.decl [concrete = constants.%Bar2]
-// CHECK:STDOUT:       %ptr: type = ptr_type %Bar2.ref [concrete = constants.%ptr.eca]
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %bar: %ptr.eca = bind_name bar, %bar.param
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF1(%bar.param: %ptr.f68);
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @MyF2(%bar.param: %ptr.eca) {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %MyF1.ref: %MyF1.type = name_ref MyF1, file.%MyF1.decl [concrete = constants.%MyF1]
-// CHECK:STDOUT:   %bar.ref: %ptr.eca = name_ref bar, %bar
-// CHECK:STDOUT:   %.loc19_33: %ptr.f68 = converted %bar.ref, <error> [concrete = <error>]
-// CHECK:STDOUT:   %MyF1.call: init %empty_tuple.type = call %MyF1.ref(<error>)
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
 // CHECK:STDOUT: --- import_dynamic.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
diff --git a/toolchain/lower/testdata/interop/cpp/base.carbon b/toolchain/lower/testdata/interop/cpp/base.carbon
new file mode 100644
index 000000000000..5a1a20199e7e
--- /dev/null
+++ b/toolchain/lower/testdata/interop/cpp/base.carbon
@@ -0,0 +1,166 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/int.carbon
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/interop/cpp/base.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/interop/cpp/base.carbon
+
+// --- structs.h
+
+struct A {
+  int a;
+
+  void f() {}
+};
+
+struct B : A {
+  int b;
+};
+
+// --- convert.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "structs.h";
+
+fn ConvertPtr(p: Cpp.B*) -> Cpp.A* {
+  return p;
+}
+
+fn AcceptVal(a: Cpp.A);
+
+fn ConvertVal(b: Cpp.B) {
+  AcceptVal(b);
+}
+
+// --- access_field.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "structs.h";
+
+fn AccessVal(b: Cpp.B) -> i32 {
+  return b.a;
+}
+
+// --- call_method.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "structs.h";
+
+fn Call(b: Cpp.B*) {
+  b->f();
+}
+
+// CHECK:STDOUT: ; ModuleID = 'convert.carbon'
+// CHECK:STDOUT: source_filename = "convert.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: define ptr @_CConvertPtr.Main(ptr %p) !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc7_11.2.base = getelementptr inbounds nuw [8 x i8], ptr %p, i32 0, i32 0, !dbg !10
+// CHECK:STDOUT:   ret ptr %.loc7_11.2.base, !dbg !10
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_CAcceptVal.Main(ptr)
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CConvertVal.Main(ptr %b) !dbg !11 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc13_13.1.base = getelementptr inbounds nuw [8 x i8], ptr %b, i32 0, i32 0, !dbg !12
+// CHECK:STDOUT:   call void @_CAcceptVal.Main(ptr %.loc13_13.1.base), !dbg !13
+// CHECK:STDOUT:   ret void, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "convert.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "ConvertPtr", linkageName: "_CConvertPtr.Main", scope: null, file: !6, line: 6, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 7, column: 3, scope: !7)
+// CHECK:STDOUT: !11 = distinct !DISubprogram(name: "ConvertVal", linkageName: "_CConvertVal.Main", scope: null, file: !6, line: 12, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !12 = !DILocation(line: 13, column: 13, scope: !11)
+// CHECK:STDOUT: !13 = !DILocation(line: 13, column: 3, scope: !11)
+// CHECK:STDOUT: !14 = !DILocation(line: 12, column: 1, scope: !11)
+// CHECK:STDOUT: ; ModuleID = 'access_field.carbon'
+// CHECK:STDOUT: source_filename = "access_field.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: define i32 @_CAccessVal.Main(ptr %b) !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc7_11.1.base = getelementptr inbounds nuw [8 x i8], ptr %b, i32 0, i32 0, !dbg !10
+// CHECK:STDOUT:   %.loc7_11.3.a = getelementptr inbounds nuw [4 x i8], ptr %.loc7_11.1.base, i32 0, i32 0, !dbg !10
+// CHECK:STDOUT:   %.loc7_11.4 = load i32, ptr %.loc7_11.3.a, align 4, !dbg !10
+// CHECK:STDOUT:   ret i32 %.loc7_11.4, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "access_field.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "AccessVal", linkageName: "_CAccessVal.Main", scope: null, file: !6, line: 6, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 7, column: 10, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 7, column: 3, scope: !7)
+// CHECK:STDOUT: ; ModuleID = 'call_method.carbon'
+// CHECK:STDOUT: source_filename = "call_method.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: $_ZN1A1fEv = comdat any
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CCall.Main(ptr %b) !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc7_4.3.base = getelementptr inbounds nuw [8 x i8], ptr %b, i32 0, i32 0, !dbg !10
+// CHECK:STDOUT:   call void @_ZN1A1fEv(ptr %.loc7_4.3.base), !dbg !10
+// CHECK:STDOUT:   ret void, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: mustprogress noinline nounwind optnone
+// CHECK:STDOUT: define linkonce_odr dso_local void @_ZN1A1fEv(ptr nonnull align 4 dereferenceable(4) %this) #0 comdat align 2 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %this.addr = alloca ptr, align 8
+// CHECK:STDOUT:   store ptr %this, ptr %this.addr, align 8
+// CHECK:STDOUT:   %this1 = load ptr, ptr %this.addr, align 8
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { mustprogress noinline nounwind optnone "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "call_method.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "Call", linkageName: "_CCall.Main", scope: null, file: !6, line: 6, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 7, column: 3, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 6, column: 1, scope: !7)