2 use rustc_hir_typeck::{cast, FnCtxt, Inherited};
3 use rustc_lint::LateContext;
4 use rustc_middle::ty::{cast::CastKind, Ty};
5 use rustc_span::DUMMY_SP;
7 // check if the component types of the transmuted collection and the result have different ABI,
9 pub(super) fn is_layout_incompatible<'tcx>(
10 cx: &LateContext<'tcx>,
14 if let Ok(from) = cx.tcx.try_normalize_erasing_regions(cx.param_env, from)
15 && let Ok(to) = cx.tcx.try_normalize_erasing_regions(cx.param_env, to)
16 && let Ok(from_layout) = cx.tcx.layout_of(cx.param_env.and(from))
17 && let Ok(to_layout) = cx.tcx.layout_of(cx.param_env.and(to))
19 from_layout.size != to_layout.size || from_layout.align.abi != to_layout.align.abi
21 // no idea about layout, so don't lint
26 /// Check if the type conversion can be expressed as a pointer cast, instead of
27 /// a transmute. In certain cases, including some invalid casts from array
28 /// references to pointers, this may cause additional errors to be emitted and/or
29 /// ICE error messages. This function will panic if that occurs.
30 pub(super) fn can_be_expressed_as_pointer_cast<'tcx>(
31 cx: &LateContext<'tcx>,
37 AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast,
40 check_cast(cx, e, from_ty, to_ty),
41 Some(PtrPtrCast | PtrAddrCast | AddrPtrCast | ArrayPtrCast | FnPtrPtrCast | FnPtrAddrCast)
45 /// If a cast from `from_ty` to `to_ty` is valid, returns an Ok containing the kind of
46 /// the cast. In certain cases, including some invalid casts from array references
47 /// to pointers, this may cause additional errors to be emitted and/or ICE error
48 /// messages. This function will panic if that occurs.
50 cx: &LateContext<'tcx>,
54 ) -> Option<CastKind> {
55 let hir_id = e.hir_id;
56 let local_def_id = hir_id.owner.def_id;
58 Inherited::build(cx.tcx, local_def_id).enter(|inherited| {
59 let fn_ctxt = FnCtxt::new(&inherited, cx.param_env, hir_id);
61 // If we already have errors, we can't be sure we can pointer cast.
62 assert!(!fn_ctxt.errors_reported_since_creation(), "Newly created FnCtxt contained errors");
64 if let Ok(check) = cast::CastCheck::new(
65 &fn_ctxt, e, from_ty, to_ty,
66 // We won't show any error to the user, so we don't care what the span is here.
69 let res = check.do_check(&fn_ctxt);
71 // do_check's documentation says that it might return Ok and create
72 // errors in the fcx instead of returning Err in some cases. Those cases
73 // should be filtered out before getting here.
75 !fn_ctxt.errors_reported_since_creation(),
76 "`fn_ctxt` contained errors after cast check!"