transmute_ptr_to_ref suggestion doesn't with some outer expression types

描述

-                mem::transmute::<*mut c_void, &mut Box<FnMut(&Button)>>(data)(&button)
+                &mut *(data as *mut Box<FnMut(&Button)>)(&button)

貢獻者指南

技術棧

rust

領域

tooling

議題類型

bug

難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。

3

預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。

1-3 hours

活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。

stale

清晰度議題是否清楚說明預期改動、驗收標準和下一步。

mostly clear

前置要求

Basic Rust knowledgeUnderstanding of clippy lint structure

新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。

40

研究方向

The issue describes a clippy lint `transmute ptr to ref` that incorrectly suggests replacing `mem::transmute::<*mut c void, &mut Box<FnMut(&Button)>>(data)(&button)` with `&mut *(data as *mut Box<FnMut(&Button)>)(&button)` without parentheses. The fix involves modifying the lint's suggestion code in the clippy repository (likely in `clippy lints/src/transmute.rs`) to wrap the `&mut *...` in parentheses when it appears in a context like a function call. The observation is that the suggestion is syntactically ambiguous without parens. Look for the `transmute ptr to ref` lint implementation, examine how the suggestion is generated (likely using `Applicability` and `span lint and sugg`), and add logic to detect if the expression is used as a callee (e.g., inside a function call) and then add parentheses around the suggested code. Test the change with the provided example and similar cases.