我如何让编译器向我警告标为pub的未使用代码？ [英] How can I get the compiler to warn me of unused code that is marked pub?

问题描述

关于未使用的私人物品的锈警告：

Rust warns for unused private items:

warning: function is never used: `hmm`
   --> src/example.rs:357:1
    |
357 | fn hmm() {
    | ^^^^^^^^
    |
    = note: #[warn(dead_code)] on by default

我有一些代码标记为 pub 的我知道未被使用的地方。

I have some code marked pub that I know is not being used. How can I get the compiler to warn me of this?

这是在一个库和一系列二进制文件的上下文中，都在同一工作区中的。该库仅由那些二进制文件使用；该库不会被其他任何人占用，并且我也不会上传到crates.io，所以我对所使用的代码有充分的了解。

This is in the context of a library and a series of binaries, all in the same workspace. The library is only used by those binaries; the library isn't being consumed by anybody else and I'm not going to upload to crates.io, so I have full knowledge of the code that's being used.

推荐答案

您无法启用任何功能。根据定义，如果在您的板条箱之外是公共物品，则导入您的板条箱的板条箱可能会使用它；编译器实际上无法告知。这是拥有公共API 的一部分。从公共API中删除某些内容是一项重大更改。

You cannot enable anything to do this. By definition, if something is public outside of your crate, it may be used by the crates that import your crate; there's no way for the compiler to actually tell. This is part of having a public API. Removing something from the public API is a breaking change.

如果您的商品不是从板条箱中导出的，则它是 pub 无关紧要：

If you have an item that's not exported from your crate, the fact that it's pub won't matter:

mod foo {
    pub fn bar() {}
}

fn main() {}

warning: function is never used: `bar`
 --> src/main.rs:2:5
  |
2 |     pub fn bar() {}
  |     ^^^^^^^^^^^^
  |
  = note: #[warn(dead_code)] on by default

相反，不要一开始就将其标记为公开。取而代之的是，要么完全放弃 pub ，要么使用像 pub（crate）这样的可见性修饰符。二进制板条箱基本上应该没有标记为要从板条箱中导出的项目。

Instead, don't mark things as public to start with. Instead, either leave off pub entirely or use a visibility modifier like pub(crate). Binary crates should basically have no items marked for export from the crate.

在您特定的工作空间中，永远不会一个编译器知道所有的时间。例如，如果您的库导出 fn a（）和 fn b（），而一个二进制文件使用 a 和另一个二进制文件使用 b ，则库的任何编译或任何一个二进制文件都不会看到整个图片。最好的情况是会收到大量的误报。

In your specific case of a workspace, there's never a time when a single compiler knows "everything". For example, if your library exports fn a() and fn b() and one binary uses a and another binary uses b, then no compilation of the library or either binary would ever see the whole picture. The "best" case would be getting tons of false positives.

在类似情况下，我不得不从API中删除所有公开的 并编译以查看错误/使用的功能。

In similar situations, I've resorted to removing everything public from the API and compiling to see the errors / used functions.

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