// 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/lookup/fail_todo_undefined_impl.carbon
// TIP: To dump output, run:
// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon

interface I {
  fn F();
}

class C {
  // This doesn't match `impl C as I` below under proposal #3763.

  extend impl as I;
}

fn F() -> i32 {
  // CHECK:STDERR: fail_todo_undefined_impl.carbon:[[@LINE+8]]:10: error: accessing member from impl before the end of its definition [ImplAccessMemberBeforeComplete]
  // CHECK:STDERR:   return C.F();
  // CHECK:STDERR:          ^~~
  // CHECK:STDERR:
  // CHECK:STDERR: fail_todo_undefined_impl.carbon:[[@LINE-8]]:3: error: impl declared but not defined [ImplMissingDefinition]
  // CHECK:STDERR:   extend impl as I;
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
  return C.F();
}

// TODO: This should be written `impl C.(Self as I)` or `impl C.(as I)`, once
// that is supported.
impl C as I {
  fn F() {}
}

// CHECK:STDOUT: --- fail_todo_undefined_impl.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %I.type: type = facet_type <@I> [template]
// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic]
// CHECK:STDOUT:   %F.type.cf0: type = fn_type @F.1 [template]
// CHECK:STDOUT:   %F.bc6: %F.type.cf0 = struct_value () [template]
// CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type %I.type [template]
// CHECK:STDOUT:   %assoc0: %I.assoc_type = assoc_entity element0, @I.%F.decl [template]
// CHECK:STDOUT:   %C: type = class_type @C [template]
// CHECK:STDOUT:   %impl_witness.85b: <witness> = impl_witness (<error>) [template]
// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [template]
// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [template]
// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template]
// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [template]
// CHECK:STDOUT:   %F.type.b25: type = fn_type @F.2 [template]
// CHECK:STDOUT:   %F.c41: %F.type.b25 = struct_value () [template]
// CHECK:STDOUT:   %I.facet.b45: %I.type = facet_value %C, %impl_witness.85b [template]
// CHECK:STDOUT:   %.575: type = fn_type_with_self_type %F.type.cf0, %I.facet.b45 [template]
// CHECK:STDOUT:   %impl_witness.054: <witness> = impl_witness (@impl.2.%F.decl) [template]
// CHECK:STDOUT:   %F.type.5d6: type = fn_type @F.3 [template]
// CHECK:STDOUT:   %F.a2e: %F.type.5d6 = struct_value () [template]
// CHECK:STDOUT:   %I.facet.4ac: %I.type = facet_value %C, %impl_witness.054 [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [template] {
// CHECK:STDOUT:     .Int = %Core.Int
// CHECK:STDOUT:     import Core//prelude
// CHECK:STDOUT:     import Core//prelude/...
// 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:     .F = %F.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:   %F.decl: %F.type.b25 = fn_decl @F.2 [template = constants.%F.c41] {
// CHECK:STDOUT:     %return.patt: %i32 = return_slot_pattern
// CHECK:STDOUT:     %return.param_patt: %i32 = out_param_pattern %return.patt, runtime_param0
// CHECK:STDOUT:   } {
// CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
// CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
// CHECK:STDOUT:     %return.param: ref %i32 = out_param runtime_param0
// CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
// CHECK:STDOUT:   }
// CHECK:STDOUT:   impl_decl @impl.2 [template] {} {
// CHECK:STDOUT:     %C.ref: type = name_ref C, file.%C.decl [template = constants.%C]
// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (@impl.2.%F.decl) [template = constants.%impl_witness.054]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: interface @I {
// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
// CHECK:STDOUT:   %F.decl: %F.type.cf0 = fn_decl @F.1 [template = constants.%F.bc6] {} {}
// CHECK:STDOUT:   %assoc0: %I.assoc_type = assoc_entity element0, %F.decl [template = constants.%assoc0]
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
// CHECK:STDOUT:   .Self = %Self
// CHECK:STDOUT:   .F = %assoc0
// CHECK:STDOUT:   witness = (%F.decl)
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: impl @impl.1: %Self.ref as %I.ref;
// CHECK:STDOUT:
// CHECK:STDOUT: impl @impl.2: %C.ref as %I.ref {
// CHECK:STDOUT:   %F.decl: %F.type.5d6 = fn_decl @F.3 [template = constants.%F.a2e] {} {}
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
// CHECK:STDOUT:   .F = %F.decl
// CHECK:STDOUT:   witness = file.%impl_witness
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: class @C {
// CHECK:STDOUT:   impl_decl @impl.1 [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:   %impl_witness: <witness> = impl_witness (<error>) [template = constants.%impl_witness.85b]
// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [template = constants.%complete_type.357]
// CHECK:STDOUT:   complete_type_witness = %complete_type
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
// CHECK:STDOUT:   .Self = constants.%C
// CHECK:STDOUT:   extend @impl.1.%I.ref
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: generic fn @F.1(@I.%Self: %I.type) {
// CHECK:STDOUT:   fn();
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F.2() -> %i32 {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   %C.ref: type = name_ref C, file.%C.decl [template = constants.%C]
// CHECK:STDOUT:   %F.ref: %I.assoc_type = name_ref F, @I.%assoc0 [template = constants.%assoc0]
// CHECK:STDOUT:   %impl.elem0: %.575 = impl_witness_access constants.%impl_witness.85b, element0 [template = <error>]
// CHECK:STDOUT:   return <error>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F.3() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: specific @F.1(constants.%Self) {}
// CHECK:STDOUT:
// CHECK:STDOUT: specific @F.1(constants.%I.facet.4ac) {}
// CHECK:STDOUT: