src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ptr.rs

   1 use super::TRANSMUTE_PTR_TO_PTR;
   2 use clippy_utils::diagnostics::span_lint_and_then;
   3 use clippy_utils::sugg;
   4 use rustc_errors::Applicability;
   5 use rustc_hir::Expr;
   6 use rustc_lint::LateContext;
   7 use rustc_middle::ty::{self, Ty};
   8
   9 /// Checks for `transmute_ptr_to_ptr` lint.
  10 /// Returns `true` if it's triggered, otherwise returns `false`.
  11 pub(super) fn check<'tcx>(
  12     cx: &LateContext<'tcx>,
  13     e: &'tcx Expr<'_>,
  14     from_ty: Ty<'tcx>,
  15     to_ty: Ty<'tcx>,
  16     arg: &'tcx Expr<'_>,
  17 ) -> bool {
  18     match (&from_ty.kind(), &to_ty.kind()) {
  19         (ty::RawPtr(_), ty::RawPtr(to_ty)) => {
  20             span_lint_and_then(
  21                 cx,
  22                 TRANSMUTE_PTR_TO_PTR,
  23                 e.span,
  24                 "transmute from a pointer to a pointer",
  25                 |diag| {
  26                     if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
  27                         let sugg = arg.as_ty(cx.tcx.mk_ptr(*to_ty));
  28                         diag.span_suggestion(e.span, "try", sugg, Applicability::Unspecified);
  29                     }
  30                 },
  31             );
  32             true
  33         },
  34         _ => false,
  35     }
  36 }