Preliminary reverse interop support for base classes. (#7059)

Create a Clang AST representation of the base specifier.

toolchain/check/testdata/interop/cpp/class/export/base.carbon

@@ -0,0 +1,56 @@
+// 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/check/testdata/interop/cpp/class/export/base.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/export/base.carbon
+
+// --- derived_to_base.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+base class A {}
+
+class B {
+  extend base: A;
+}
+
+inline Cpp '''
+Carbon::A* Convert(Carbon::B* p) {
+  return p;
+}
+''';
+
+// --- name_lookup.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+base class A {
+  fn F();
+  fn G(n: i32);
+}
+
+class B {
+  extend base: A;
+  fn G();
+}
+
+inline Cpp '''
+void Qualified() {
+  Carbon::B::F();
+  Carbon::B::G();
+}
+
+void MemberAccess(Carbon::A *a, Carbon::B *b) {
+  // TODO: These cause a crash.
+  // b->F();
+  // b->G();
+}
+''';

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

@@ -0,0 +1,120 @@
+// 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/check/testdata/interop/cpp/class/export/class.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/export/class.carbon
+
+// --- static_members.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+class A {
+  fn F() {}
+}
+
+inline Cpp '''
+void G() {
+  Carbon::A::F();
+}
+''';
+
+// --- nested.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+class A {
+  class B {
+    class C {
+    }
+  }
+}
+
+inline Cpp '''
+void G() {
+  Carbon::A::B::C *p = nullptr;
+}
+''';
+
+// --- incomplete.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+class A;
+
+inline Cpp '''
+Carbon::A *p = nullptr;
+''';
+
+// --- fail_incomplete_concrete.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+// CHECK:STDERR: fail_incomplete_concrete.carbon:[[@LINE+4]]:1: error: class was forward declared here [ClassForwardDeclaredHere]
+// CHECK:STDERR: class A;
+// CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
+class A;
+
+inline Cpp '''
+// CHECK:STDERR: fail_incomplete_concrete.carbon:[[@LINE+4]]:11: error: variable has incomplete type 'Carbon::A' [CppInteropParseError]
+// CHECK:STDERR:    16 | Carbon::A a;
+// CHECK:STDERR:       |           ^
+// CHECK:STDERR:
+Carbon::A a;
+''';
+
+// --- fail_todo_monomorphization_failure.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+class B(N:! i32) {
+  var a: array(i8, N);
+}
+
+// TODO: Once we allow this, we should produce an "invalid array bound" error
+// during monomorphization triggered by the C++ code.
+// CHECK:STDERR: fail_todo_monomorphization_failure.carbon:[[@LINE+4]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
+// CHECK:STDERR: alias T = B(-1);
+// CHECK:STDERR:           ^~~~~
+// CHECK:STDERR:
+alias T = B(-1);
+
+inline Cpp '''
+// CHECK:STDERR: fail_todo_monomorphization_failure.carbon:[[@LINE+4]]:9: error: no type named 'T' in namespace 'Carbon' [CppInteropParseError]
+// CHECK:STDERR:    22 | Carbon::T t;
+// CHECK:STDERR:       | ~~~~~~~~^
+// CHECK:STDERR:
+Carbon::T t;
+''';
+
+// --- fail_todo_fields.carbon
+library "[[@TEST_NAME]]";
+
+import Cpp;
+
+class A {
+  var a: i32;
+  var b: i32;
+}
+
+inline Cpp '''
+// CHECK:STDERR: fail_todo_fields.carbon:[[@LINE+7]]:15: error: static assertion failed due to requirement 'sizeof(Carbon::A) == 2 * sizeof(int)' [CppInteropParseError]
+// CHECK:STDERR:    18 | static_assert(sizeof(Carbon::A) == 2 * sizeof(int));
+// CHECK:STDERR:       |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR: fail_todo_fields.carbon:[[@LINE+4]]:33: note: expression evaluates to '1 == 8' [CppInteropParseNote]
+// CHECK:STDERR:    18 | static_assert(sizeof(Carbon::A) == 2 * sizeof(int));
+// CHECK:STDERR:       |               ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
+static_assert(sizeof(Carbon::A) == 2 * sizeof(int));
+''';

toolchain/check/testdata/interop/cpp/class/import/abstract.carbon

@@ -7,9 +7,9 @@
 //
 // 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/abstract.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/abstract.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/abstract.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/abstract.carbon
 
 // --- abstract.h
 

toolchain/check/testdata/interop/cpp/class/import/access.carbon

@@ -6,9 +6,9 @@
 //
 // 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/access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/access.carbon
 
 // ============================================================================
 // Public non-function member

toolchain/check/testdata/interop/cpp/class/import/base.carbon

@@ -6,9 +6,9 @@
 //
 // 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:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/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
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/base.carbon
 
 // --- derived_to_base_conversion.h
 

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

@@ -6,9 +6,9 @@
 //
 // 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/class.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/class.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/class.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/class.carbon
 
 // ============================================================================
 // Declaration

toolchain/check/testdata/interop/cpp/class/import/constructor.carbon

@@ -6,9 +6,9 @@
 //
 // 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/constructor.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/constructor.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/constructor.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/constructor.carbon
 
 // ============================================================================
 // Default constructor

toolchain/check/testdata/interop/cpp/class/import/field.carbon

@@ -6,9 +6,9 @@
 //
 // 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/field.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/field.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/field.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/field.carbon
 
 // --- struct.h
 

toolchain/check/testdata/interop/cpp/class/import/invalid.carbon

@@ -6,9 +6,9 @@
 //
 // 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/invalid.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/invalid.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/invalid.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/invalid.carbon
 
 // --- fail_invalid_base.carbon
 

toolchain/check/testdata/interop/cpp/class/import/method.carbon

@@ -7,9 +7,9 @@
 //
 // 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/method.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/method.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/method.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/method.carbon
 
 // --- object_param_qualifiers.h
 

toolchain/check/testdata/interop/cpp/class/import/nested.carbon

@@ -6,9 +6,9 @@
 //
 // 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/nested.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/nested.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/nested.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/nested.carbon
 
 // --- import_nested_class.carbon
 

toolchain/check/testdata/interop/cpp/class/import/non_aggregate_init.carbon

@@ -7,9 +7,9 @@
 //
 // 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/non_aggregate_init.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/non_aggregate_init.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/non_aggregate_init.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/non_aggregate_init.carbon
 
 // ============================================================================
 // Non-aggregate class should not be initializable from {}

toolchain/check/testdata/interop/cpp/class/import/struct.carbon

@@ -6,9 +6,9 @@
 //
 // 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/struct.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/struct.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/struct.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/struct.carbon
 
 // ============================================================================
 // Declaration

toolchain/check/testdata/interop/cpp/class/import/template.carbon

@@ -6,9 +6,9 @@
 //
 // 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/template.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/template.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/template.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/template.carbon
 
 // --- class_template.h
 

toolchain/check/testdata/interop/cpp/class/import/union.carbon

@@ -6,9 +6,9 @@
 //
 // 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/union.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class/import/union.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/union.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class/import/union.carbon
 
 // ============================================================================
 // Declaration