// 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
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon
// TIP: To dump output, run:
// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon

interface I;

class C {
  // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE+6]]:3: error: `extend impl` requires a definition for interface `I`
  // CHECK:STDERR:   extend impl as I;
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
  // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE-6]]:1: note: interface was forward declared here
  // CHECK:STDERR: interface I;
  // CHECK:STDERR: ^~~~~~~~~~~~
  extend impl as I;
}

// CHECK:STDOUT: --- fail_extend_undefined_interface.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %I.type: type = interface_type @I [template]
// CHECK:STDOUT:   %C: type = class_type @C [template]
// CHECK:STDOUT:   %.1: type = struct_type {} [template]
// CHECK:STDOUT:   %.2: <witness> = complete_type_witness %.1 [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [template] {
// CHECK:STDOUT:     import Core//prelude
// CHECK:STDOUT:     import Core//prelude/operators
// CHECK:STDOUT:     import Core//prelude/types
// CHECK:STDOUT:     import Core//prelude/operators/arithmetic
// CHECK:STDOUT:     import Core//prelude/operators/as
// CHECK:STDOUT:     import Core//prelude/operators/bitwise
// CHECK:STDOUT:     import Core//prelude/operators/comparison
// CHECK:STDOUT:     import Core//prelude/types/bool
// CHECK:STDOUT:   }
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .Core = imports.%Core
// CHECK:STDOUT:     .I = %I.decl
// CHECK:STDOUT:     .C = %C.decl
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %Core.import = import Core
// CHECK:STDOUT:   %I.decl: type = interface_decl @I [template = constants.%I.type] {} {}
// CHECK:STDOUT:   %C.decl: type = class_decl @C [template = constants.%C] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: interface @I;
// CHECK:STDOUT:
// CHECK:STDOUT: impl @impl: %Self.ref as %I.ref;
// CHECK:STDOUT:
// CHECK:STDOUT: class @C {
// CHECK:STDOUT:   impl_decl @impl [template] {} {
// CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%C [template = constants.%C]
// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %.loc21: <witness> = complete_type_witness %.1 [template = constants.%.2]
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
// CHECK:STDOUT:   .Self = constants.%C
// CHECK:STDOUT:   has_error
// CHECK:STDOUT: }
// CHECK:STDOUT: