rust/tests/ui/feature-gates/issue-43106-gating-of-built...

773 lines
25 KiB
Rust

//~ NOTE not a function
//~| NOTE not a foreign function or static
//~| NOTE cannot be applied to crates
//~| NOTE not an `extern` block
// This test enumerates as many compiler-builtin ungated attributes as
// possible (that is, all the mutually compatible ones), and checks
// that we get "expected" (*) warnings for each in the various weird
// places that users might put them in the syntax.
//
// (*): The word "expected" is in quotes above because the cases where
// warnings are and are not emitted might not match a user's intuition
// nor the rustc developers' intent. I am really just trying to
// capture today's behavior in a test, not so that it become enshrined
// as the absolute behavior going forward, but rather so that we do
// not change the behavior in the future without even being *aware* of
// the change when it happens.
//
// At the time of authoring, the attributes here are listed in the
// order that they occur in `librustc_feature`.
//
// Any builtin attributes that:
//
// - are not stable, or
//
// - could not be included here covering the same cases as the other
// attributes without raising an *error* from rustc (note though
// that warnings are of course expected)
//
// have their own test case referenced by filename in an inline
// comment.
//
// The test feeds numeric inputs to each attribute that accepts them
// without error. We do this for two reasons: (1.) to exercise how
// inputs are handled by each, and (2.) to ease searching for related
// occurrences in the source text.
//@ check-pass
#![feature(test)]
#![warn(unused_attributes, unknown_lints)]
//~^ NOTE the lint level is defined here
//~| NOTE the lint level is defined here
// UNGATED WHITE-LISTED BUILT-IN ATTRIBUTES
#![warn(x5400)] //~ WARN unknown lint: `x5400`
#![allow(x5300)] //~ WARN unknown lint: `x5300`
#![forbid(x5200)] //~ WARN unknown lint: `x5200`
#![deny(x5100)] //~ WARN unknown lint: `x5100`
#![macro_use] // (allowed if no argument; see issue-43160-gating-of-macro_use.rs)
// skipping testing of cfg
// skipping testing of cfg_attr
#![should_panic] //~ WARN `#[should_panic]` only has an effect
#![ignore] //~ WARN `#[ignore]` only has an effect on functions
#![no_implicit_prelude]
#![reexport_test_harness_main = "2900"]
// see gated-link-args.rs
// see issue-43106-gating-of-macro_escape.rs for crate-level; but non crate-level is below at "2700"
// (cannot easily test gating of crate-level #[no_std]; but non crate-level is below at "2600")
#![proc_macro_derive()] //~ WARN `#[proc_macro_derive]` only has an effect
#![doc = "2400"]
#![cold] //~ WARN attribute should be applied to a function
//~^ WARN this was previously accepted
#![link()] //~ WARN attribute should be applied to an `extern` block
//~^ WARN this was previously accepted
#![link_name = "1900"]
//~^ WARN attribute should be applied to a foreign function
//~^^ WARN this was previously accepted by the compiler
#![link_section = "1800"]
//~^ WARN attribute should be applied to a function or static
//~^^ WARN this was previously accepted by the compiler
#![must_use]
//~^ WARN `#[must_use]` has no effect
// see issue-43106-gating-of-stable.rs
// see issue-43106-gating-of-unstable.rs
// see issue-43106-gating-of-deprecated.rs
#![windows_subsystem = "windows"]
// UNGATED CRATE-LEVEL BUILT-IN ATTRIBUTES
#![crate_name = "0900"]
#![crate_type = "bin"] // cannot pass "0800" here
#![crate_id = "10"]
//~^ WARN use of deprecated attribute
//~| HELP remove this attribute
//~| NOTE `#[warn(deprecated)]` on by default
// FIXME(#44232) we should warn that this isn't used.
#![feature(rust1)]
//~^ WARN no longer requires an attribute to enable
//~| NOTE `#[warn(stable_features)]` on by default
#![no_start]
//~^ WARN use of deprecated attribute
//~| HELP remove this attribute
// (cannot easily gating state of crate-level #[no_main]; but non crate-level is below at "0400")
#![no_builtins]
#![recursion_limit = "0200"]
#![type_length_limit = "0100"]
// USES OF BUILT-IN ATTRIBUTES IN OTHER ("UNUSUAL") PLACES
#[warn(x5400)]
//~^ WARN unknown lint: `x5400`
mod warn {
mod inner { #![warn(x5400)] }
//~^ WARN unknown lint: `x5400`
#[warn(x5400)] fn f() { }
//~^ WARN unknown lint: `x5400`
#[warn(x5400)] struct S;
//~^ WARN unknown lint: `x5400`
#[warn(x5400)] type T = S;
//~^ WARN unknown lint: `x5400`
#[warn(x5400)] impl S { }
//~^ WARN unknown lint: `x5400`
}
#[allow(x5300)]
//~^ WARN unknown lint: `x5300`
mod allow {
mod inner { #![allow(x5300)] }
//~^ WARN unknown lint: `x5300`
#[allow(x5300)] fn f() { }
//~^ WARN unknown lint: `x5300`
#[allow(x5300)] struct S;
//~^ WARN unknown lint: `x5300`
#[allow(x5300)] type T = S;
//~^ WARN unknown lint: `x5300`
#[allow(x5300)] impl S { }
//~^ WARN unknown lint: `x5300`
}
#[forbid(x5200)]
//~^ WARN unknown lint: `x5200`
mod forbid {
mod inner { #![forbid(x5200)] }
//~^ WARN unknown lint: `x5200`
#[forbid(x5200)] fn f() { }
//~^ WARN unknown lint: `x5200`
#[forbid(x5200)] struct S;
//~^ WARN unknown lint: `x5200`
#[forbid(x5200)] type T = S;
//~^ WARN unknown lint: `x5200`
#[forbid(x5200)] impl S { }
//~^ WARN unknown lint: `x5200`
}
#[deny(x5100)]
//~^ WARN unknown lint: `x5100`
mod deny {
mod inner { #![deny(x5100)] }
//~^ WARN unknown lint: `x5100`
#[deny(x5100)] fn f() { }
//~^ WARN unknown lint: `x5100`
#[deny(x5100)] struct S;
//~^ WARN unknown lint: `x5100`
#[deny(x5100)] type T = S;
//~^ WARN unknown lint: `x5100`
#[deny(x5100)] impl S { }
//~^ WARN unknown lint: `x5100`
}
#[macro_use]
mod macro_use {
mod inner { #![macro_use] }
#[macro_use] fn f() { }
//~^ `#[macro_use]` only has an effect
#[macro_use] struct S;
//~^ `#[macro_use]` only has an effect
#[macro_use] type T = S;
//~^ `#[macro_use]` only has an effect
#[macro_use] impl S { }
//~^ `#[macro_use]` only has an effect
}
#[macro_export]
//~^ WARN `#[macro_export]` only has an effect on macro definitions
mod macro_export {
mod inner { #![macro_export] }
//~^ WARN `#[macro_export]` only has an effect on macro definitions
#[macro_export] fn f() { }
//~^ WARN `#[macro_export]` only has an effect on macro definitions
#[macro_export] struct S;
//~^ WARN `#[macro_export]` only has an effect on macro definitions
#[macro_export] type T = S;
//~^ WARN `#[macro_export]` only has an effect on macro definitions
#[macro_export] impl S { }
//~^ WARN `#[macro_export]` only has an effect on macro definitions
}
// At time of unit test authorship, if compiling without `--test` then
// non-crate-level #[test] attributes seem to be ignored.
#[test]
mod test { mod inner { #![test] }
fn f() { }
struct S;
type T = S;
impl S { }
}
// At time of unit test authorship, if compiling without `--test` then
// non-crate-level #[bench] attributes seem to be ignored.
#[bench]
mod bench {
mod inner { #![bench] }
#[bench]
struct S;
#[bench]
type T = S;
#[bench]
impl S { }
}
#[path = "3800"]
mod path {
mod inner { #![path="3800"] }
#[path = "3800"] fn f() { }
//~^ WARN `#[path]` only has an effect
#[path = "3800"] struct S;
//~^ WARN `#[path]` only has an effect
#[path = "3800"] type T = S;
//~^ WARN `#[path]` only has an effect
#[path = "3800"] impl S { }
//~^ WARN `#[path]` only has an effect
}
#[automatically_derived]
//~^ WARN `#[automatically_derived]` only has an effect
mod automatically_derived {
mod inner { #![automatically_derived] }
//~^ WARN `#[automatically_derived]
#[automatically_derived] fn f() { }
//~^ WARN `#[automatically_derived]
#[automatically_derived] struct S;
//~^ WARN `#[automatically_derived]
#[automatically_derived] type T = S;
//~^ WARN `#[automatically_derived]
#[automatically_derived] impl S { }
}
#[no_mangle]
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
mod no_mangle {
//~^ NOTE not a free function, impl method or static
mod inner { #![no_mangle] }
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
#[no_mangle] fn f() { }
#[no_mangle] struct S;
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
#[no_mangle] type T = S;
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
#[no_mangle] impl S { }
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
trait Tr {
#[no_mangle] fn foo();
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
#[no_mangle] fn bar() {}
//~^ WARN attribute should be applied to a free function, impl method or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a free function, impl method or static
}
}
#[should_panic]
//~^ WARN `#[should_panic]` only has an effect on
mod should_panic {
mod inner { #![should_panic] }
//~^ WARN `#[should_panic]` only has an effect on
#[should_panic] fn f() { }
#[should_panic] struct S;
//~^ WARN `#[should_panic]` only has an effect on
#[should_panic] type T = S;
//~^ WARN `#[should_panic]` only has an effect on
#[should_panic] impl S { }
//~^ WARN `#[should_panic]` only has an effect on
}
#[ignore]
//~^ WARN `#[ignore]` only has an effect on functions
mod ignore {
mod inner { #![ignore] }
//~^ WARN `#[ignore]` only has an effect on functions
#[ignore] fn f() { }
#[ignore] struct S;
//~^ WARN `#[ignore]` only has an effect on functions
#[ignore] type T = S;
//~^ WARN `#[ignore]` only has an effect on functions
#[ignore] impl S { }
//~^ WARN `#[ignore]` only has an effect on functions
}
#[no_implicit_prelude]
mod no_implicit_prelude {
mod inner { #![no_implicit_prelude] }
#[no_implicit_prelude] fn f() { }
//~^ WARN `#[no_implicit_prelude]` only has an effect
#[no_implicit_prelude] struct S;
//~^ WARN `#[no_implicit_prelude]` only has an effect
#[no_implicit_prelude] type T = S;
//~^ WARN `#[no_implicit_prelude]` only has an effect
#[no_implicit_prelude] impl S { }
//~^ WARN `#[no_implicit_prelude]` only has an effect
}
#[reexport_test_harness_main = "2900"]
//~^ WARN crate-level attribute should be
mod reexport_test_harness_main {
mod inner { #![reexport_test_harness_main="2900"] }
//~^ WARN crate-level attribute should be
#[reexport_test_harness_main = "2900"] fn f() { }
//~^ WARN crate-level attribute should be
#[reexport_test_harness_main = "2900"] struct S;
//~^ WARN crate-level attribute should be
#[reexport_test_harness_main = "2900"] type T = S;
//~^ WARN crate-level attribute should be
#[reexport_test_harness_main = "2900"] impl S { }
//~^ WARN crate-level attribute should be
}
// Cannot feed "2700" to `#[macro_escape]` without signaling an error.
#[macro_escape]
//~^ WARN `#[macro_escape]` is a deprecated synonym for `#[macro_use]`
mod macro_escape {
mod inner { #![macro_escape] }
//~^ WARN `#[macro_escape]` is a deprecated synonym for `#[macro_use]`
//~| HELP try an outer attribute: `#[macro_use]`
#[macro_escape] fn f() { }
//~^ WARN `#[macro_escape]` only has an effect
#[macro_escape] struct S;
//~^ WARN `#[macro_escape]` only has an effect
#[macro_escape] type T = S;
//~^ WARN `#[macro_escape]` only has an effect
#[macro_escape] impl S { }
//~^ WARN `#[macro_escape]` only has an effect
}
#[no_std]
//~^ WARN crate-level attribute should be an inner attribute
mod no_std {
mod inner { #![no_std] }
//~^ WARN crate-level attribute should be in the root module
#[no_std] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[no_std] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_std] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_std] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
// At time of authorship, #[proc_macro_derive = "2500"] signals error
// when it occurs on a mod (apart from crate-level). Therefore it goes
// into its own file; see issue-43106-gating-of-proc_macro_derive.rs
#[doc = "2400"]
mod doc {
mod inner { #![doc="2400"] }
#[doc = "2400"] fn f() { }
#[doc = "2400"] struct S;
#[doc = "2400"] type T = S;
#[doc = "2400"] impl S { }
}
#[cold]
//~^ WARN attribute should be applied to a function
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
mod cold {
//~^ NOTE not a function
mod inner { #![cold] }
//~^ WARN attribute should be applied to a function
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function
#[cold] fn f() { }
#[cold] struct S;
//~^ WARN attribute should be applied to a function
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function
#[cold] type T = S;
//~^ WARN attribute should be applied to a function
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function
#[cold] impl S { }
//~^ WARN attribute should be applied to a function
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function
}
#[link_name = "1900"]
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
mod link_name {
//~^ NOTE not a foreign function or static
#[link_name = "1900"]
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| HELP try `#[link(name = "1900")]` instead
extern "C" { }
//~^ NOTE not a foreign function or static
mod inner { #![link_name="1900"] }
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a foreign function or static
#[link_name = "1900"] fn f() { }
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a foreign function or static
#[link_name = "1900"] struct S;
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a foreign function or static
#[link_name = "1900"] type T = S;
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a foreign function or static
#[link_name = "1900"] impl S { }
//~^ WARN attribute should be applied to a foreign function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a foreign function or static
}
#[link_section = "1800"]
//~^ WARN attribute should be applied to a function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
mod link_section {
//~^ NOTE not a function or static
mod inner { #![link_section="1800"] }
//~^ WARN attribute should be applied to a function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function or static
#[link_section = "1800"] fn f() { }
#[link_section = "1800"] struct S;
//~^ WARN attribute should be applied to a function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function or static
#[link_section = "1800"] type T = S;
//~^ WARN attribute should be applied to a function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function or static
#[link_section = "1800"] impl S { }
//~^ WARN attribute should be applied to a function or static [unused_attributes]
//~| WARN this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
//~| NOTE not a function or static
}
// Note that this is a `check-pass` test, so it will never invoke the linker.
#[link()]
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
mod link {
//~^ NOTE not an `extern` block
mod inner { #![link()] }
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
//~| NOTE not an `extern` block
#[link()] fn f() { }
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
//~| NOTE not an `extern` block
#[link()] struct S;
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
//~| NOTE not an `extern` block
#[link()] type T = S;
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
//~| NOTE not an `extern` block
#[link()] impl S { }
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
//~| NOTE not an `extern` block
#[link()] extern "Rust" {}
//~^ WARN attribute should be applied to an `extern` block
//~| WARN this was previously accepted
}
struct StructForDeprecated;
#[deprecated]
mod deprecated {
mod inner { #![deprecated] }
#[deprecated] fn f() { }
#[deprecated] struct S1;
#[deprecated] type T = super::StructForDeprecated;
#[deprecated] impl super::StructForDeprecated { }
}
#[must_use] //~ WARN `#[must_use]` has no effect
mod must_use {
mod inner { #![must_use] } //~ WARN `#[must_use]` has no effect
#[must_use] fn f() { }
#[must_use] struct S;
#[must_use] type T = S; //~ WARN `#[must_use]` has no effect
#[must_use] impl S { } //~ WARN `#[must_use]` has no effect
}
#[windows_subsystem = "windows"]
//~^ WARN crate-level attribute should be an inner attribute
mod windows_subsystem {
mod inner { #![windows_subsystem="windows"] }
//~^ WARN crate-level attribute should be in the root module
#[windows_subsystem = "windows"] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[windows_subsystem = "windows"] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[windows_subsystem = "windows"] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[windows_subsystem = "windows"] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
// BROKEN USES OF CRATE-LEVEL BUILT-IN ATTRIBUTES
#[crate_name = "0900"]
//~^ WARN crate-level attribute should be an inner attribute
mod crate_name {
mod inner { #![crate_name="0900"] }
//~^ WARN crate-level attribute should be in the root module
#[crate_name = "0900"] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[crate_name = "0900"] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[crate_name = "0900"] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[crate_name = "0900"] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[crate_type = "0800"]
//~^ WARN crate-level attribute should be an inner attribute
mod crate_type {
mod inner { #![crate_type="0800"] }
//~^ WARN crate-level attribute should be in the root module
#[crate_type = "0800"] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[crate_type = "0800"] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[crate_type = "0800"] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[crate_type = "0800"] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[feature(x0600)]
//~^ WARN crate-level attribute should be an inner attribute
mod feature {
mod inner { #![feature(x0600)] }
//~^ WARN crate-level attribute should be in the root module
#[feature(x0600)] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[feature(x0600)] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[feature(x0600)] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[feature(x0600)] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[no_main]
//~^ WARN crate-level attribute should be an inner attribute
mod no_main_1 {
mod inner { #![no_main] }
//~^ WARN crate-level attribute should be in the root module
#[no_main] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[no_main] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_main] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_main] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[no_builtins]
//~^ WARN crate-level attribute should be an inner attribute
mod no_builtins {
mod inner { #![no_builtins] }
//~^ WARN crate-level attribute should be in the root module
#[no_builtins] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[no_builtins] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_builtins] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[no_builtins] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[recursion_limit="0200"]
//~^ WARN crate-level attribute should be an inner attribute
mod recursion_limit {
mod inner { #![recursion_limit="0200"] }
//~^ WARN crate-level attribute should be in the root module
#[recursion_limit="0200"] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[recursion_limit="0200"] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[recursion_limit="0200"] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[recursion_limit="0200"] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
#[type_length_limit="0100"]
//~^ WARN crate-level attribute should be an inner attribute
mod type_length_limit {
mod inner { #![type_length_limit="0100"] }
//~^ WARN crate-level attribute should be in the root module
#[type_length_limit="0100"] fn f() { }
//~^ WARN crate-level attribute should be an inner attribute
#[type_length_limit="0100"] struct S;
//~^ WARN crate-level attribute should be an inner attribute
#[type_length_limit="0100"] type T = S;
//~^ WARN crate-level attribute should be an inner attribute
#[type_length_limit="0100"] impl S { }
//~^ WARN crate-level attribute should be an inner attribute
}
fn main() {}