101 lines
2.6 KiB
Rust
101 lines
2.6 KiB
Rust
// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![warn(clippy::all)]
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#![allow(clippy::blacklisted_name)]
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#![warn(clippy::used_underscore_binding)]
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macro_rules! test_macro {
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() => {{
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let _foo = 42;
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_foo + 1
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}};
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}
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/// Test that we lint if we use a binding with a single leading underscore
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fn prefix_underscore(_foo: u32) -> u32 {
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_foo + 1
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}
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/// Test that we lint if we use a `_`-variable defined outside within a macro expansion
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fn in_macro(_foo: u32) {
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println!("{}", _foo);
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assert_eq!(_foo, _foo);
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test_macro!() + 1;
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}
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// Struct for testing use of fields prefixed with an underscore
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struct StructFieldTest {
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_underscore_field: u32,
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}
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/// Test that we lint the use of a struct field which is prefixed with an underscore
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fn in_struct_field() {
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let mut s = StructFieldTest { _underscore_field: 0 };
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s._underscore_field += 1;
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}
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/// Test that we do not lint if the underscore is not a prefix
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fn non_prefix_underscore(some_foo: u32) -> u32 {
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some_foo + 1
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}
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/// Test that we do not lint if we do not use the binding (simple case)
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fn unused_underscore_simple(_foo: u32) -> u32 {
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1
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}
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/// Test that we do not lint if we do not use the binding (complex case). This checks for
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/// compatibility with the built-in `unused_variables` lint.
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fn unused_underscore_complex(mut _foo: u32) -> u32 {
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_foo += 1;
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_foo = 2;
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1
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}
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///Test that we do not lint for multiple underscores
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fn multiple_underscores(__foo: u32) -> u32 {
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__foo + 1
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}
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// Non-variable bindings with preceding underscore
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fn _fn_test() {}
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struct _StructTest;
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enum _EnumTest {
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_Empty,
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_Value(_StructTest),
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}
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/// Test that we do not lint for non-variable bindings
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fn non_variables() {
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_fn_test();
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let _s = _StructTest;
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let _e = match _EnumTest::_Value(_StructTest) {
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_EnumTest::_Empty => 0,
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_EnumTest::_Value(_st) => 1,
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};
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let f = _fn_test;
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f();
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}
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fn main() {
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let foo = 0u32;
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// tests of unused_underscore lint
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let _ = prefix_underscore(foo);
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in_macro(foo);
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in_struct_field();
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// possible false positives
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let _ = non_prefix_underscore(foo);
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let _ = unused_underscore_simple(foo);
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let _ = unused_underscore_complex(foo);
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let _ = multiple_underscores(foo);
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non_variables();
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}
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