rust/src/test/compile-fail/lint-dead-code-1.rs
Zack M. Davis 1a9dc2e902 dead code lint to say "never constructed" for variants
As reported in #19140, #44083, and #44565, some users were confused when
the dead-code lint reported an enum variant to be "unused" when it was
matched on (but not constructed). This wording change makes it clearer
that the lint is in fact checking for construction.

We continue to say "used" for all other items (it's tempting to say
"called" for functions and methods, but this turns out not to be
correct: functions can be passed as arguments and the dead-code lint
isn't special-casing that or anything).

Resolves #19140.
2017-11-19 10:15:36 -08:00

117 lines
2.9 KiB
Rust

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![no_std]
#![allow(unused_variables)]
#![allow(non_camel_case_types)]
#![allow(non_upper_case_globals)]
#![deny(dead_code)]
#![crate_type="lib"]
pub use foo2::Bar2;
mod foo {
pub struct Bar; //~ ERROR: struct is never used
}
mod foo2 {
pub struct Bar2;
}
pub static pub_static: isize = 0;
static priv_static: isize = 0; //~ ERROR: static item is never used
const used_static: isize = 0;
pub static used_static2: isize = used_static;
const USED_STATIC: isize = 0;
const STATIC_USED_IN_ENUM_DISCRIMINANT: isize = 10;
pub const pub_const: isize = 0;
const priv_const: isize = 0; //~ ERROR: constant item is never used
const used_const: isize = 0;
pub const used_const2: isize = used_const;
const USED_CONST: isize = 1;
const CONST_USED_IN_ENUM_DISCRIMINANT: isize = 11;
pub type typ = *const UsedStruct4;
pub struct PubStruct;
struct PrivStruct; //~ ERROR: struct is never used
struct UsedStruct1 {
#[allow(dead_code)]
x: isize
}
struct UsedStruct2(isize);
struct UsedStruct3;
pub struct UsedStruct4;
// this struct is never used directly, but its method is, so we don't want
// to warn it
struct SemiUsedStruct;
impl SemiUsedStruct {
fn la_la_la() {}
}
struct StructUsedAsField;
pub struct StructUsedInEnum;
struct StructUsedInGeneric;
pub struct PubStruct2 {
#[allow(dead_code)]
struct_used_as_field: *const StructUsedAsField
}
pub enum pub_enum { foo1, bar1 }
pub enum pub_enum2 { a(*const StructUsedInEnum) }
pub enum pub_enum3 {
Foo = STATIC_USED_IN_ENUM_DISCRIMINANT,
Bar = CONST_USED_IN_ENUM_DISCRIMINANT,
}
enum priv_enum { foo2, bar2 } //~ ERROR: enum is never used
enum used_enum {
foo3,
bar3 //~ ERROR variant is never constructed
}
fn f<T>() {}
pub fn pub_fn() {
used_fn();
let used_struct1 = UsedStruct1 { x: 1 };
let used_struct2 = UsedStruct2(1);
let used_struct3 = UsedStruct3;
let e = used_enum::foo3;
SemiUsedStruct::la_la_la();
let i = 1;
match i {
USED_STATIC => (),
USED_CONST => (),
_ => ()
}
f::<StructUsedInGeneric>();
}
fn priv_fn() { //~ ERROR: function is never used
let unused_struct = PrivStruct;
}
fn used_fn() {}
fn foo() { //~ ERROR: function is never used
bar();
let unused_enum = priv_enum::foo2;
}
fn bar() { //~ ERROR: function is never used
foo();
}
// Code with #[allow(dead_code)] should be marked live (and thus anything it
// calls is marked live)
#[allow(dead_code)]
fn g() { h(); }
fn h() {}