New upstream version 1.52.1+dfsg1

[rustc.git] / src / tools / clippy / clippy_lints / src / transmute / crosspointer_transmute.rs

diff --git a/src/tools/clippy/clippy_lints/src/transmute/crosspointer_transmute.rs b/src/tools/clippy/clippy_lints/src/transmute/crosspointer_transmute.rs
new file mode 100644 (file)
index 0000000..ce87def
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/transmute/crosspointer_transmute.rs
@@ -0,0 +1,37 @@
+use super::CROSSPOINTER_TRANSMUTE;
+use crate::utils::span_lint;
+use rustc_hir::Expr;
+use rustc_lint::LateContext;
+use rustc_middle::ty::{self, Ty};
+
+/// Checks for `crosspointer_transmute` lint.
+/// Returns `true` if it's triggered, otherwise returns `false`.
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> bool {
+    match (&from_ty.kind(), &to_ty.kind()) {
+        (ty::RawPtr(from_ptr), _) if from_ptr.ty == to_ty => {
+            span_lint(
+                cx,
+                CROSSPOINTER_TRANSMUTE,
+                e.span,
+                &format!(
+                    "transmute from a type (`{}`) to the type that it points to (`{}`)",
+                    from_ty, to_ty
+                ),
+            );
+            true
+        },
+        (_, ty::RawPtr(to_ptr)) if to_ptr.ty == from_ty => {
+            span_lint(
+                cx,
+                CROSSPOINTER_TRANSMUTE,
+                e.span,
+                &format!(
+                    "transmute from a type (`{}`) to a pointer to that type (`{}`)",
+                    from_ty, to_ty
+                ),
+            );
+            true
+        },
+        _ => false,
+    }
+}