Auto merge of #85690 - bstrie:m2_arena, r=jackh726,nagisa

[rust.git] / src / tools / clippy / clippy_lints / src / ptr.rs

diff --git a/src/tools/clippy/clippy_lints/src/ptr.rs b/src/tools/clippy/clippy_lints/src/ptr.rs
index dba3b1805cd595df2029aa7c67ce823e8b8423c8..c0d1f1eb6e65ece72a714c7c2587636c5ac7e2a4 100644 (file)
--- a/src/tools/clippy/clippy_lints/src/ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/ptr.rs
@@ -4,7 +4,7 @@
 use clippy_utils::ptr::get_spans;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::{is_type_diagnostic_item, match_type, walk_ptrs_hir_ty};
-use clippy_utils::{expr_path_res, is_lint_allowed, match_any_def_paths, paths};
+use clippy_utils::{expr_path_res, is_lint_allowed, match_any_diagnostic_items, paths};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{
@@ -20,16 +20,19 @@
 use std::borrow::Cow;
 
 declare_clippy_lint! {
-    /// **What it does:** This lint checks for function arguments of type `&String`
+    /// ### What it does
+    /// This lint checks for function arguments of type `&String`
     /// or `&Vec` unless the references are mutable. It will also suggest you
     /// replace `.clone()` calls with the appropriate `.to_owned()`/`to_string()`
     /// calls.
     ///
-    /// **Why is this bad?** Requiring the argument to be of the specific size
+    /// ### Why is this bad?
+    /// Requiring the argument to be of the specific size
     /// makes the function less useful for no benefit; slices in the form of `&[T]`
     /// or `&str` usually suffice and can be obtained from other types, too.
     ///
-    /// **Known problems:** The lint does not follow data. So if you have an
+    /// ### Known problems
+    /// The lint does not follow data. So if you have an
     /// argument `x` and write `let y = x; y.clone()` the lint will not suggest
     /// changing that `.clone()` to `.to_owned()`.
     ///
@@ -59,7 +62,7 @@
     /// other crates referencing it, of which you may not be aware. Carefully
     /// deprecate the function before applying the lint suggestions in this case.
     ///
-    /// **Example:**
+    /// ### Example
     /// ```ignore
     /// // Bad
     /// fn foo(&Vec<u32>) { .. }
@@ -73,15 +76,15 @@
 }
 
 declare_clippy_lint! {
-    /// **What it does:** This lint checks for equality comparisons with `ptr::null`
+    /// ### What it does
+    /// This lint checks for equality comparisons with `ptr::null`
     ///
-    /// **Why is this bad?** It's easier and more readable to use the inherent
+    /// ### Why is this bad?
+    /// It's easier and more readable to use the inherent
     /// `.is_null()`
     /// method instead
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// ```ignore
     /// // Bad
     /// if x == ptr::null {
@@ -99,19 +102,22 @@
 }
 
 declare_clippy_lint! {
-    /// **What it does:** This lint checks for functions that take immutable
+    /// ### What it does
+    /// This lint checks for functions that take immutable
     /// references and return mutable ones.
     ///
-    /// **Why is this bad?** This is trivially unsound, as one can create two
+    /// ### Why is this bad?
+    /// This is trivially unsound, as one can create two
     /// mutable references from the same (immutable!) source.
     /// This [error](https://github.com/rust-lang/rust/issues/39465)
     /// actually lead to an interim Rust release 1.15.1.
     ///
-    /// **Known problems:** To be on the conservative side, if there's at least one
+    /// ### Known problems
+    /// To be on the conservative side, if there's at least one
     /// mutable reference with the output lifetime, this lint will not trigger.
     /// In practice, this case is unlikely anyway.
     ///
-    /// **Example:**
+    /// ### Example
     /// ```ignore
     /// fn foo(&Foo) -> &mut Bar { .. }
     /// ```
@@ -121,13 +127,13 @@
 }
 
 declare_clippy_lint! {
-    /// **What it does:** This lint checks for invalid usages of `ptr::null`.
-    ///
-    /// **Why is this bad?** This causes undefined behavior.
+    /// ### What it does
+    /// This lint checks for invalid usages of `ptr::null`.
     ///
-    /// **Known problems:** None.
+    /// ### Why is this bad?
+    /// This causes undefined behavior.
     ///
-    /// **Example:**
+    /// ### Example
     /// ```ignore
     /// // Bad. Undefined behavior
     /// unsafe { std::slice::from_raw_parts(ptr::null(), 0); }
@@ -419,7 +425,7 @@ fn get_rptr_lm<'tcx>(ty: &'tcx Ty<'tcx>) -> Option<(&'tcx Lifetime, Mutability,
 fn is_null_path(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     if let ExprKind::Call(pathexp, []) = expr.kind {
         expr_path_res(cx, pathexp).opt_def_id().map_or(false, |id| {
-            match_any_def_paths(cx, id, &[&paths::PTR_NULL, &paths::PTR_NULL_MUT]).is_some()
+            match_any_diagnostic_items(cx, id, &[sym::ptr_null, sym::ptr_null_mut]).is_some()
         })
     } else {
         false