// 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/function/definition/no_prelude/extern.carbon
// TIP: To dump output, run:
// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/extern.carbon

// --- extern_def.carbon

library "[[@TEST_NAME]]";

extern fn F() {}

// --- def_for_extern_decl.carbon

library "[[@TEST_NAME]]";

extern fn F();
extern fn F() {}

// --- split_library.carbon

library "[[@TEST_NAME]]";

extern fn F();

// --- split_library.impl.carbon

impl library "[[@TEST_NAME]]";

extern fn F() {}

// --- fail_def_extern_mismatch.carbon

library "[[@TEST_NAME]]";

extern fn F();
// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern` [RedeclExternMismatch]
// CHECK:STDERR: fn F() {}
// CHECK:STDERR: ^~~~~~~~
// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE-4]]:1: note: previously declared here [RedeclPrevDecl]
// CHECK:STDERR: extern fn F();
// CHECK:STDERR: ^~~~~~~~~~~~~~
// CHECK:STDERR:
fn F() {}

// --- fail_def_extern_mismatch_reverse.carbon

library "[[@TEST_NAME]]";

fn F();
// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern` [RedeclExternMismatch]
// CHECK:STDERR: extern fn F() {}
// CHECK:STDERR: ^~~~~~~~~~~~~~~
// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE-4]]:1: note: previously declared here [RedeclPrevDecl]
// CHECK:STDERR: fn F();
// CHECK:STDERR: ^~~~~~~
// CHECK:STDERR:
extern fn F() {}

// --- fail_extern_diag_suppressed.carbon

library "[[@TEST_NAME]]";

extern fn F();
// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant [RedeclRedundant]
// CHECK:STDERR: fn F();
// CHECK:STDERR: ^~~~~~~
// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-4]]:1: note: previously declared here [RedeclPrevDecl]
// CHECK:STDERR: extern fn F();
// CHECK:STDERR: ^~~~~~~~~~~~~~
// CHECK:STDERR:
fn F();
// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern` [RedeclExternMismatch]
// CHECK:STDERR: fn F() {}
// CHECK:STDERR: ^~~~~~~~
// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-12]]:1: note: previously declared here [RedeclPrevDecl]
// CHECK:STDERR: extern fn F();
// CHECK:STDERR: ^~~~~~~~~~~~~~
// CHECK:STDERR:
fn F() {}

// --- fail_extern_decl_after_def.carbon

library "[[@TEST_NAME]]";

fn F() {}
// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant [RedeclRedundant]
// CHECK:STDERR: extern fn F();
// CHECK:STDERR: ^~~~~~~~~~~~~~
// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE-4]]:1: note: previously declared here [RedeclPrevDecl]
// CHECK:STDERR: fn F() {}
// CHECK:STDERR: ^~~~~~~~
// CHECK:STDERR:
extern fn F();

// --- in_impl.carbon

library "[[@TEST_NAME]]";

// --- fail_in_impl.impl.carbon

impl library "[[@TEST_NAME]]";

// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+4]]:1: error: `extern` entities must have a declaration in the API file [ExternRequiresDeclInApiFile]
// CHECK:STDERR: extern fn F() {}
// CHECK:STDERR: ^~~~~~~~~~~~~~~
// CHECK:STDERR:
extern fn F() {}

// CHECK:STDOUT: --- extern_def.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- def_for_extern_decl.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl.loc4
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl.loc4: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc5: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- split_library.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F();
// CHECK:STDOUT:
// CHECK:STDOUT: --- split_library.impl.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %default.import.loc2_6.1 = import <none>
// CHECK:STDOUT:   %default.import.loc2_6.2 = import <none>
// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() [from "split_library.carbon"] {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_def_extern_mismatch.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl.loc4
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl.loc4: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc12: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_def_extern_mismatch_reverse.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl.loc4
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl.loc4: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc12: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_extern_diag_suppressed.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl.loc4
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl.loc4: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc12: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc20: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_extern_decl_after_def.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl.loc4
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %F.decl.loc4: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT:   %F.decl.loc12: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- in_impl.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_in_impl.impl.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT:   %F.type: type = fn_type @F [template]
// CHECK:STDOUT:   %F: %F.type = struct_value () [template]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: file {
// CHECK:STDOUT:   package: <namespace> = namespace [template] {
// CHECK:STDOUT:     .F = %F.decl
// CHECK:STDOUT:   }
// CHECK:STDOUT:   %default.import.loc2_6.1 = import <none>
// CHECK:STDOUT:   %default.import.loc2_6.2 = import <none>
// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: extern fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT:   return
// CHECK:STDOUT: }
// CHECK:STDOUT: