Initial support for interop with class/struct/union fields. (#5849)

Add a new type, `custom_layout_type`, representing a struct type whose
size, alignment, and field offsets can be manually controlled. Use this
as the object representation type for imported C++ class types (which
also includes struct and union types), allowing us to model C++ class
type layouts. In passing, also add support for incomplete C++ class
types, mapping them into incomplete Carbon class types.

Map C++ fields into Carbon field declarations, allowing direct access to
C++ fields from Carbon. So far, no support is added for base classes nor
anonymous struct or union declarations; those will be added in
subsequent PRs. Also, we don't map C++ access control into Carbon yet,
so all C++ fields are accessible regardless of their access control.

For now we still use a `struct_type` as the object representation for
empty C++ classes, in order to continue to support our existing tests
that convert `{}` to empty C++ class types. This is temporary and should
be removed once we support interop with C++ class initialization.

toolchain/check/testdata/interop/cpp/function/class.carbon

@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/destroy.carbon
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/convert.carbon
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
@@ -27,12 +27,12 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:11: error: forming value of incomplete type `Cpp.C` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo({});
 }
@@ -44,12 +44,11 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+11]]:10: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-  // CHECK:STDERR:   let c: Cpp.C;
-  // CHECK:STDERR:          ^~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+8]]:10: note: in `Cpp` name lookup for `C` [InCppNameLookup]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+10]]:10: error: binding pattern has incomplete type `C` in name binding declaration [IncompleteTypeInBindingDecl]
   // CHECK:STDERR:   let c: Cpp.C;
   // CHECK:STDERR:          ^~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
   // CHECK:STDERR:
   // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+4]]:15: error: expected `=`; `let` declaration must have an initializer [ExpectedInitializerAfterLet]
   // CHECK:STDERR:   let c: Cpp.C;
@@ -77,14 +76,21 @@ library "[[@TEST_NAME]]";
 import Cpp library "double_decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.C` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo1` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo1({});
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.C` [IncompleteTypeInValueConversion]
+  // CHECK:STDERR:   Cpp.foo2({});
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-14]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo2({});
 }
 
@@ -124,7 +130,7 @@ class C {
 
 auto foo(C) -> void;
 
-// --- import_definition_single_data_member_value_param_type.carbon
+// --- fail_todo_import_definition_single_data_member_value_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -132,6 +138,14 @@ import Cpp library "definition_single_data_member_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
+  // CHECK:STDERR: fail_todo_import_definition_single_data_member_value_param_type.carbon:[[@LINE+8]]:11: error: cannot implicitly convert expression of type `{}` to `Cpp.C` [ConversionFailure]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_single_data_member_value_param_type.carbon:[[@LINE+5]]:11: note: type `{}` does not implement interface `Core.ImplicitAs(Cpp.C)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_single_data_member_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
 }
@@ -152,7 +166,7 @@ class C {
 
 auto foo(C) -> void;
 
-// --- import_definition_multiple_data_members_value_param_type.carbon
+// --- fail_todo_import_definition_multiple_data_members_value_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -160,6 +174,14 @@ import Cpp library "definition_multiple_data_members_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
+  // CHECK:STDERR: fail_todo_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+8]]:11: error: cannot implicitly convert expression of type `{}` to `Cpp.C` [ConversionFailure]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+5]]:11: note: type `{}` does not implement interface `Core.ImplicitAs(Cpp.C)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_multiple_data_members_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
 }
@@ -285,19 +307,12 @@ class C;
 
 auto foo(C* _Nonnull) -> void;
 
-// --- fail_todo_import_decl_pointer_param_type.carbon
+// --- import_decl_pointer_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
 import Cpp library "decl_pointer_param_type.h";
 
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+7]]:9: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-// CHECK:STDERR: fn F(c: Cpp.C*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+4]]:9: note: in `Cpp` name lookup for `C` [InCppNameLookup]
-// CHECK:STDERR: fn F(c: Cpp.C*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR:
 fn F(c: Cpp.C*) {
   //@dump-sem-ir-begin
   Cpp.foo(c);
@@ -343,12 +358,12 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: function returns incomplete type `Cpp.C` [IncompleteTypeInFunctionReturnType]
   // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_return_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon: note: return type declared here [IncompleteReturnTypeHere]
   // CHECK:STDERR:
   Cpp.foo();
 }
@@ -385,7 +400,7 @@ class C;
 
 auto foo() -> C* _Nonnull;
 
-// --- fail_todo_import_decl_pointer_return_type.carbon
+// --- import_decl_pointer_return_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -393,13 +408,6 @@ import Cpp library "decl_pointer_return_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR:
   Cpp.foo();
   //@dump-sem-ir-end
 }
@@ -455,7 +463,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
@@ -472,7 +479,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_definition_single_data_member_value_param_type.carbon
+// CHECK:STDOUT: --- fail_todo_import_definition_single_data_member_value_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
@@ -480,10 +487,6 @@ fn F() {
 // CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.type.1b3: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%C) [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.21b: %T.as.Destroy.impl.Op.type.1b3 = struct_value () [concrete]
-// CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -501,24 +504,14 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
-// CHECK:STDOUT:   %.loc8_12.3: init %C = class_init (), %.loc8_12.2 [concrete = constants.%C.val]
-// CHECK:STDOUT:   %.loc8_12.4: ref %C = temporary %.loc8_12.2, %.loc8_12.3
-// CHECK:STDOUT:   %.loc8_12.5: ref %C = converted %.loc8_12.1, %.loc8_12.4
-// CHECK:STDOUT:   %.loc8_12.6: %C = bind_value %.loc8_12.5
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%.loc8_12.6)
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.bound: <bound method> = bound_method %.loc8_12.2, constants.%T.as.Destroy.impl.Op.21b
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8_12.2, %T.as.Destroy.impl.Op.specific_fn
-// CHECK:STDOUT:   %addr: %ptr.d9e = addr_of %.loc8_12.2
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.call: init %empty_tuple.type = call %bound_method(%addr)
+// CHECK:STDOUT:   %.loc16_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc16_12.2: %C = converted %.loc16_12.1, <error> [concrete = <error>]
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_definition_multiple_data_members_value_param_type.carbon
+// CHECK:STDOUT: --- fail_todo_import_definition_multiple_data_members_value_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
@@ -526,10 +519,6 @@ fn F() {
 // CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.type.1b3: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%C) [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.21b: %T.as.Destroy.impl.Op.type.1b3 = struct_value () [concrete]
-// CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -547,20 +536,10 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
-// CHECK:STDOUT:   %.loc8_12.3: init %C = class_init (), %.loc8_12.2 [concrete = constants.%C.val]
-// CHECK:STDOUT:   %.loc8_12.4: ref %C = temporary %.loc8_12.2, %.loc8_12.3
-// CHECK:STDOUT:   %.loc8_12.5: ref %C = converted %.loc8_12.1, %.loc8_12.4
-// CHECK:STDOUT:   %.loc8_12.6: %C = bind_value %.loc8_12.5
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%.loc8_12.6)
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.bound: <bound method> = bound_method %.loc8_12.2, constants.%T.as.Destroy.impl.Op.21b
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8_12.2, %T.as.Destroy.impl.Op.specific_fn
-// CHECK:STDOUT:   %addr: %ptr.d9e = addr_of %.loc8_12.2
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.call: init %empty_tuple.type = call %bound_method(%addr)
+// CHECK:STDOUT:   %.loc16_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc16_12.2: %C = converted %.loc16_12.1, <error> [concrete = <error>]
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -600,7 +579,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
@@ -667,7 +645,6 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %N1.ref: <namespace> = name_ref N1, imports.%N1 [concrete = imports.%N1]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_15.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_15.2: ref %C = temporary_storage
@@ -720,7 +697,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
@@ -786,7 +762,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %C.ref: type = name_ref C, imports.%C.decl [concrete = constants.%C]
 // CHECK:STDOUT:   %bar.ref: %C.bar.type = name_ref bar, imports.%C.bar.decl [concrete = constants.%C.bar]
 // CHECK:STDOUT:   %C.bar.call: init %empty_tuple.type = call %bar.ref()
@@ -841,7 +816,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %C = temporary_storage
@@ -862,9 +836,11 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_decl_pointer_param_type.carbon
+// CHECK:STDOUT: --- import_decl_pointer_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %ptr: type = ptr_type %C [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
@@ -872,10 +848,11 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .C = <error>
+// CHECK:STDOUT:     .C = %C.decl
 // CHECK:STDOUT:     .foo = %foo.decl
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
 // CHECK:STDOUT:   %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -883,12 +860,12 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%c.param: <error>) {
+// CHECK:STDOUT: fn @F(%c.param: %ptr) {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Cpp.ref.loc15: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %c.ref: <error> = name_ref c, %c
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
+// CHECK:STDOUT:   %c.ref: %ptr = name_ref c, %c
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%c.ref)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -952,7 +929,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_11.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %foo.call: init %C = call %foo.ref() to %.loc8_11.1
@@ -965,9 +941,11 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_decl_pointer_return_type.carbon
+// CHECK:STDOUT: --- import_decl_pointer_return_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %ptr: type = ptr_type %C [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -988,7 +966,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %foo.call: init <error> = call %foo.ref()
+// CHECK:STDOUT:   %foo.call: init %ptr = call %foo.ref()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -1016,7 +994,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %foo.call: init %ptr = call %foo.ref()
 // CHECK:STDOUT:   <elided>

toolchain/check/testdata/interop/cpp/function/in_template.carbon

@@ -77,7 +77,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %Y.ref: type = name_ref Y, imports.%X.decl [concrete = constants.%X]
 // CHECK:STDOUT:   %f.ref: %X.f.type = name_ref f, imports.%X.f.decl [concrete = constants.%X.f]
 // CHECK:STDOUT:   %int_42: Core.IntLiteral = int_value 42 [concrete = constants.%int_42.20e]

toolchain/check/testdata/interop/cpp/function/pointer.carbon

@@ -229,7 +229,6 @@ fn F() {
 // CHECK:STDOUT:   assign %s.var, %.loc8_3
 // CHECK:STDOUT:   %.loc8_13: type = splice_block %S.ref [concrete = constants.%S] {
 // CHECK:STDOUT:     %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:     %S.ref: type = name_ref S, imports.%S.decl [concrete = constants.%S]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %s: ref %S = bind_name s, %s.var
@@ -292,7 +291,6 @@ fn F() {
 // CHECK:STDOUT:   assign %s.var, %.loc8_3
 // CHECK:STDOUT:   %.loc8_13: type = splice_block %S.ref.loc8 [concrete = constants.%S] {
 // CHECK:STDOUT:     %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:     %S.ref.loc8: type = name_ref S, imports.%S.decl [concrete = constants.%S]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %s: ref %S = bind_name s, %s.var
@@ -560,7 +558,6 @@ fn F() {
 // CHECK:STDOUT:   assign %s.var, %.loc8_3
 // CHECK:STDOUT:   %.loc8_13: type = splice_block %S.ref [concrete = constants.%S] {
 // CHECK:STDOUT:     %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:     %S.ref: type = name_ref S, imports.%S.decl [concrete = constants.%S]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %s: ref %S = bind_name s, %s.var

toolchain/check/testdata/interop/cpp/function/struct.carbon

@@ -27,12 +27,12 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:11: error: forming value of incomplete type `Cpp.S` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo({});
 }
@@ -44,12 +44,11 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+11]]:10: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-  // CHECK:STDERR:   let s: Cpp.S;
-  // CHECK:STDERR:          ^~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+8]]:10: note: in `Cpp` name lookup for `S` [InCppNameLookup]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+10]]:10: error: binding pattern has incomplete type `S` in name binding declaration [IncompleteTypeInBindingDecl]
   // CHECK:STDERR:   let s: Cpp.S;
   // CHECK:STDERR:          ^~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
   // CHECK:STDERR:
   // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+4]]:15: error: expected `=`; `let` declaration must have an initializer [ExpectedInitializerAfterLet]
   // CHECK:STDERR:   let s: Cpp.S;
@@ -77,14 +76,21 @@ library "[[@TEST_NAME]]";
 import Cpp library "double_decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.S` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo1` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo1({});
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.S` [IncompleteTypeInValueConversion]
+  // CHECK:STDERR:   Cpp.foo2({});
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-14]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo2({});
 }
 
@@ -124,7 +130,7 @@ struct S {
 
 auto foo(S) -> void;
 
-// --- import_definition_single_data_member_value_param_type.carbon
+// --- fail_todo_import_definition_single_data_member_value_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -132,6 +138,11 @@ import Cpp library "definition_single_data_member_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
+  // CHECK:STDERR: fail_todo_import_definition_single_data_member_value_param_type.carbon:[[@LINE+5]]:11: error: name `Core.ImplicitAs` implicitly referenced here, but not found [CoreNameNotFound]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_single_data_member_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
 }
@@ -152,7 +163,7 @@ struct S {
 
 auto foo(S) -> void;
 
-// --- import_definition_multiple_data_members_value_param_type.carbon
+// --- fail_todo_import_definition_multiple_data_members_value_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -160,6 +171,11 @@ import Cpp library "definition_multiple_data_members_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
+  // CHECK:STDERR: fail_todo_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+5]]:11: error: name `Core.ImplicitAs` implicitly referenced here, but not found [CoreNameNotFound]
+  // CHECK:STDERR:   Cpp.foo({});
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_definition_multiple_data_members_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
 }
@@ -284,19 +300,12 @@ struct S;
 
 auto foo(S* _Nonnull) -> void;
 
-// --- fail_todo_import_decl_pointer_param_type.carbon
+// --- import_decl_pointer_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
 import Cpp library "decl_pointer_param_type.h";
 
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+7]]:9: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-// CHECK:STDERR: fn F(s: Cpp.S*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+4]]:9: note: in `Cpp` name lookup for `S` [InCppNameLookup]
-// CHECK:STDERR: fn F(s: Cpp.S*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR:
 fn F(s: Cpp.S*) {
   //@dump-sem-ir-begin
   Cpp.foo(s);
@@ -342,12 +351,12 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: function returns incomplete type `Cpp.S` [IncompleteTypeInFunctionReturnType]
   // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_return_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon: note: return type declared here [IncompleteReturnTypeHere]
   // CHECK:STDERR:
   Cpp.foo();
 }
@@ -384,7 +393,7 @@ struct S;
 
 auto foo() -> S* _Nonnull;
 
-// --- fail_todo_import_decl_pointer_return_type.carbon
+// --- import_decl_pointer_return_type.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -392,13 +401,6 @@ import Cpp library "decl_pointer_return_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR:
   Cpp.foo();
   //@dump-sem-ir-end
 }
@@ -454,7 +456,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
@@ -471,7 +472,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_definition_single_data_member_value_param_type.carbon
+// CHECK:STDOUT: --- fail_todo_import_definition_single_data_member_value_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
@@ -479,10 +480,6 @@ fn F() {
 // CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %S.val: %S = struct_value () [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.type.642: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%S) [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.ab5: %T.as.Destroy.impl.Op.type.642 = struct_value () [concrete]
-// CHECK:STDOUT:   %ptr.5c7: type = ptr_type %S [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -500,24 +497,14 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
-// CHECK:STDOUT:   %.loc8_12.3: init %S = class_init (), %.loc8_12.2 [concrete = constants.%S.val]
-// CHECK:STDOUT:   %.loc8_12.4: ref %S = temporary %.loc8_12.2, %.loc8_12.3
-// CHECK:STDOUT:   %.loc8_12.5: ref %S = converted %.loc8_12.1, %.loc8_12.4
-// CHECK:STDOUT:   %.loc8_12.6: %S = bind_value %.loc8_12.5
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%.loc8_12.6)
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.bound: <bound method> = bound_method %.loc8_12.2, constants.%T.as.Destroy.impl.Op.ab5
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8_12.2, %T.as.Destroy.impl.Op.specific_fn
-// CHECK:STDOUT:   %addr: %ptr.5c7 = addr_of %.loc8_12.2
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.call: init %empty_tuple.type = call %bound_method(%addr)
+// CHECK:STDOUT:   %.loc13_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.2: %S = converted %.loc13_12.1, <error> [concrete = <error>]
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- import_definition_multiple_data_members_value_param_type.carbon
+// CHECK:STDOUT: --- fail_todo_import_definition_multiple_data_members_value_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
@@ -525,10 +512,6 @@ fn F() {
 // CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %S.val: %S = struct_value () [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.type.642: type = fn_type @T.as.Destroy.impl.Op, @T.as.Destroy.impl(%S) [concrete]
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.ab5: %T.as.Destroy.impl.Op.type.642 = struct_value () [concrete]
-// CHECK:STDOUT:   %ptr.5c7: type = ptr_type %S [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -546,20 +529,10 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
-// CHECK:STDOUT:   %.loc8_12.3: init %S = class_init (), %.loc8_12.2 [concrete = constants.%S.val]
-// CHECK:STDOUT:   %.loc8_12.4: ref %S = temporary %.loc8_12.2, %.loc8_12.3
-// CHECK:STDOUT:   %.loc8_12.5: ref %S = converted %.loc8_12.1, %.loc8_12.4
-// CHECK:STDOUT:   %.loc8_12.6: %S = bind_value %.loc8_12.5
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%.loc8_12.6)
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.bound: <bound method> = bound_method %.loc8_12.2, constants.%T.as.Destroy.impl.Op.ab5
-// CHECK:STDOUT:   <elided>
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8_12.2, %T.as.Destroy.impl.Op.specific_fn
-// CHECK:STDOUT:   %addr: %ptr.5c7 = addr_of %.loc8_12.2
-// CHECK:STDOUT:   %T.as.Destroy.impl.Op.call: init %empty_tuple.type = call %bound_method(%addr)
+// CHECK:STDOUT:   %.loc13_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.2: %S = converted %.loc13_12.1, <error> [concrete = <error>]
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -599,7 +572,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
@@ -666,7 +638,6 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %N1.ref: <namespace> = name_ref N1, imports.%N1 [concrete = imports.%N1]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_15.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_15.2: ref %S = temporary_storage
@@ -719,7 +690,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
@@ -785,7 +755,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %S.ref: type = name_ref S, imports.%S.decl [concrete = constants.%S]
 // CHECK:STDOUT:   %bar.ref: %S.bar.type = name_ref bar, imports.%S.bar.decl [concrete = constants.%S.bar]
 // CHECK:STDOUT:   %S.bar.call: init %empty_tuple.type = call %bar.ref()
@@ -840,7 +809,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %S = temporary_storage
@@ -861,9 +829,11 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_decl_pointer_param_type.carbon
+// CHECK:STDOUT: --- import_decl_pointer_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %S: type = class_type @S [concrete]
+// CHECK:STDOUT:   %ptr: type = ptr_type %S [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
@@ -871,10 +841,11 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .S = <error>
+// CHECK:STDOUT:     .S = %S.decl
 // CHECK:STDOUT:     .foo = %foo.decl
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %S.decl: type = class_decl @S [concrete = constants.%S] {} {}
 // CHECK:STDOUT:   %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -882,12 +853,12 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%s.param: <error>) {
+// CHECK:STDOUT: fn @F(%s.param: %ptr) {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Cpp.ref.loc15: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %s.ref: <error> = name_ref s, %s
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
+// CHECK:STDOUT:   %s.ref: %ptr = name_ref s, %s
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%s.ref)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -951,7 +922,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_11.1: ref %S = temporary_storage
 // CHECK:STDOUT:   %foo.call: init %S = call %foo.ref() to %.loc8_11.1
@@ -964,9 +934,11 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_decl_pointer_return_type.carbon
+// CHECK:STDOUT: --- import_decl_pointer_return_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %S: type = class_type @S [concrete]
+// CHECK:STDOUT:   %ptr: type = ptr_type %S [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -987,7 +959,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %foo.call: init <error> = call %foo.ref()
+// CHECK:STDOUT:   %foo.call: init %ptr = call %foo.ref()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -1015,7 +987,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %foo.call: init %ptr = call %foo.ref()
 // CHECK:STDOUT:   <elided>

toolchain/check/testdata/interop/cpp/function/union.carbon

@@ -28,12 +28,12 @@ import Cpp library "decl_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+7]]:11: error: forming value of incomplete type `Cpp.U` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon:[[@LINE-7]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
@@ -46,12 +46,11 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+11]]:10: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-  // CHECK:STDERR:   let u: Cpp.U;
-  // CHECK:STDERR:          ^~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+8]]:10: note: in `Cpp` name lookup for `U` [InCppNameLookup]
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+10]]:10: error: binding pattern has incomplete type `U` in name binding declaration [IncompleteTypeInBindingDecl]
   // CHECK:STDERR:   let u: Cpp.U;
   // CHECK:STDERR:          ^~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
   // CHECK:STDERR:
   // CHECK:STDERR: fail_todo_import_decl_value_param_type_previously_imported.carbon:[[@LINE+4]]:15: error: expected `=`; `let` declaration must have an initializer [ExpectedInitializerAfterLet]
   // CHECK:STDERR:   let u: Cpp.U;
@@ -79,14 +78,21 @@ library "[[@TEST_NAME]]";
 import Cpp library "double_decl_value_param_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.U` [IncompleteTypeInValueConversion]
   // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
-  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo1` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo1({});
-  // CHECK:STDERR:   ^~~~~~~~
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo1({});
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE+7]]:12: error: forming value of incomplete type `Cpp.U` [IncompleteTypeInValueConversion]
+  // CHECK:STDERR:   Cpp.foo2({});
+  // CHECK:STDERR:            ^~
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon:[[@LINE-14]]:1: in import [InImport]
+  // CHECK:STDERR: ./double_decl_value_param_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_double_decl_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
+  // CHECK:STDERR:
   Cpp.foo2({});
 }
 
@@ -134,12 +140,10 @@ import Cpp library "definition_single_data_member_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_import_definition_single_data_member_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Non-empty union` [SemanticsTodo]
+  // CHECK:STDERR: fail_import_definition_single_data_member_value_param_type.carbon:[[@LINE+5]]:11: error: name `Core.ImplicitAs` implicitly referenced here, but not found [CoreNameNotFound]
   // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_import_definition_single_data_member_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_import_definition_single_data_member_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
@@ -169,12 +173,10 @@ import Cpp library "definition_multiple_data_members_value_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Non-empty union` [SemanticsTodo]
+  // CHECK:STDERR: fail_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+5]]:11: error: name `Core.ImplicitAs` implicitly referenced here, but not found [CoreNameNotFound]
   // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_import_definition_multiple_data_members_value_param_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo({});
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:           ^~
+  // CHECK:STDERR: fail_import_definition_multiple_data_members_value_param_type.carbon: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:
   Cpp.foo({});
   //@dump-sem-ir-end
@@ -301,19 +303,12 @@ union U;
 
 auto foo(U* _Nonnull) -> void;
 
-// --- fail_todo_import_decl_pointer_param_type.carbon
+// --- import_decl_pointer_param_type.carbon
 
 library "[[@TEST_NAME]]";
 
 import Cpp library "decl_pointer_param_type.h";
 
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+7]]:9: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
-// CHECK:STDERR: fn F(u: Cpp.U*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR: fail_todo_import_decl_pointer_param_type.carbon:[[@LINE+4]]:9: note: in `Cpp` name lookup for `U` [InCppNameLookup]
-// CHECK:STDERR: fn F(u: Cpp.U*) {
-// CHECK:STDERR:         ^~~~~
-// CHECK:STDERR:
 fn F(u: Cpp.U*) {
   //@dump-sem-ir-begin
   Cpp.foo(u);
@@ -359,12 +354,12 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+7]]:3: error: function returns incomplete type `Cpp.U` [IncompleteTypeInFunctionReturnType]
   // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
-  // CHECK:STDERR:   Cpp.foo();
-  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon:[[@LINE-6]]:1: in import [InImport]
+  // CHECK:STDERR: ./decl_value_return_type.h:2: note: class was forward declared here [ClassForwardDeclaredHere]
+  // CHECK:STDERR: fail_todo_import_decl_value_return_type.carbon: note: return type declared here [IncompleteReturnTypeHere]
   // CHECK:STDERR:
   Cpp.foo();
 }
@@ -409,7 +404,7 @@ import Cpp library "decl_pointer_return_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Record declarations without a definition` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: nullable pointer: U *` [SemanticsTodo]
   // CHECK:STDERR:   Cpp.foo();
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR: fail_todo_import_decl_pointer_return_type.carbon:[[@LINE+4]]:3: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
@@ -501,7 +496,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %U = temporary_storage
@@ -522,9 +516,10 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %U: type = class_type @U [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -543,7 +538,8 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.2: %U = converted %.loc13_12.1, <error> [concrete = <error>]
 // CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -552,9 +548,10 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %U: type = class_type @U [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -573,7 +570,8 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc13_12.2: %U = converted %.loc13_12.1, <error> [concrete = <error>]
 // CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -614,7 +612,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %U = temporary_storage
@@ -681,7 +678,6 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %N1.ref: <namespace> = name_ref N1, imports.%N1 [concrete = imports.%N1]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_15.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_15.2: ref %U = temporary_storage
@@ -734,7 +730,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %U = temporary_storage
@@ -800,7 +795,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %U.ref: type = name_ref U, imports.%U.decl [concrete = constants.%U]
 // CHECK:STDOUT:   %bar.ref: %U.bar.type = name_ref bar, imports.%U.bar.decl [concrete = constants.%U.bar]
 // CHECK:STDOUT:   %U.bar.call: init %empty_tuple.type = call %bar.ref()
@@ -855,7 +849,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_12.1: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %.loc8_12.2: ref %U = temporary_storage
@@ -876,9 +869,11 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_import_decl_pointer_param_type.carbon
+// CHECK:STDOUT: --- import_decl_pointer_param_type.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %U: type = class_type @U [concrete]
+// CHECK:STDOUT:   %ptr: type = ptr_type %U [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %foo.type: type = fn_type @foo [concrete]
 // CHECK:STDOUT:   %foo: %foo.type = struct_value () [concrete]
@@ -886,10 +881,11 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
-// CHECK:STDOUT:     .U = <error>
+// CHECK:STDOUT:     .U = %U.decl
 // CHECK:STDOUT:     .foo = %foo.decl
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
+// CHECK:STDOUT:   %U.decl: type = class_decl @U [concrete = constants.%U] {} {}
 // CHECK:STDOUT:   %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -897,12 +893,12 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%u.param: <error>) {
+// CHECK:STDOUT: fn @F(%u.param: %ptr) {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %Cpp.ref.loc15: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
+// CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
-// CHECK:STDOUT:   %u.ref: <error> = name_ref u, %u
-// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(<error>)
+// CHECK:STDOUT:   %u.ref: %ptr = name_ref u, %u
+// CHECK:STDOUT:   %foo.call: init %empty_tuple.type = call %foo.ref(%u.ref)
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -966,7 +962,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %.loc8_11.1: ref %U = temporary_storage
 // CHECK:STDOUT:   %foo.call: init %U = call %foo.ref() to %.loc8_11.1
@@ -1030,7 +1025,6 @@ fn F() {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
-// CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:   %foo.ref: %foo.type = name_ref foo, imports.%foo.decl [concrete = constants.%foo]
 // CHECK:STDOUT:   %foo.call: init %ptr = call %foo.ref()
 // CHECK:STDOUT:   <elided>