-use crate::utils::{is_normalizable, last_path_segment, snippet};
-use if_chain::if_chain;
-use rustc_hir::{Expr, GenericArg, QPath, TyKind};
+use rustc_hir as hir;
+use rustc_hir::Expr;
+use rustc_hir_typeck::{cast, FnCtxt, Inherited};
use rustc_lint::LateContext;
-use rustc_middle::ty::{self, cast::CastKind, Ty};
+use rustc_middle::ty::{cast::CastKind, Ty};
use rustc_span::DUMMY_SP;
-use rustc_typeck::check::{cast::CastCheck, FnCtxt, Inherited};
-
-/// Gets the snippet of `Bar` in `…::transmute<Foo, &Bar>`. If that snippet is
-/// not available , use
-/// the type's `ToString` implementation. In weird cases it could lead to types
-/// with invalid `'_`
-/// lifetime, but it should be rare.
-pub(super) fn get_type_snippet(cx: &LateContext<'_>, path: &QPath<'_>, to_ref_ty: Ty<'_>) -> String {
- let seg = last_path_segment(path);
- if_chain! {
- if let Some(ref params) = seg.args;
- if !params.parenthesized;
- if let Some(to_ty) = params.args.iter().filter_map(|arg| match arg {
- GenericArg::Type(ty) => Some(ty),
- _ => None,
- }).nth(1);
- if let TyKind::Rptr(_, ref to_ty) = to_ty.kind;
- then {
- return snippet(cx, to_ty.ty.span, &to_ref_ty.to_string()).to_string();
- }
- }
-
- to_ref_ty.to_string()
-}
// check if the component types of the transmuted collection and the result have different ABI,
// size or alignment
pub(super) fn is_layout_incompatible<'tcx>(cx: &LateContext<'tcx>, from: Ty<'tcx>, to: Ty<'tcx>) -> bool {
- let empty_param_env = ty::ParamEnv::empty();
- // check if `from` and `to` are normalizable to avoid ICE (#4968)
- if !(is_normalizable(cx, empty_param_env, from) && is_normalizable(cx, empty_param_env, to)) {
- return false;
- }
- let from_ty_layout = cx.tcx.layout_of(empty_param_env.and(from));
- let to_ty_layout = cx.tcx.layout_of(empty_param_env.and(to));
- if let (Ok(from_layout), Ok(to_layout)) = (from_ty_layout, to_ty_layout) {
- from_layout.size != to_layout.size || from_layout.align != to_layout.align || from_layout.abi != to_layout.abi
+ if let Ok(from) = cx.tcx.try_normalize_erasing_regions(cx.param_env, from)
+ && let Ok(to) = cx.tcx.try_normalize_erasing_regions(cx.param_env, to)
+ && let Ok(from_layout) = cx.tcx.layout_of(cx.param_env.and(from))
+ && let Ok(to_layout) = cx.tcx.layout_of(cx.param_env.and(to))
+ {
+ from_layout.size != to_layout.size || from_layout.align.abi != to_layout.align.abi
} else {
// no idea about layout, so don't lint
false
}
}
-/// Check if the type conversion can be expressed as a pointer cast, instead of
-/// a transmute. In certain cases, including some invalid casts from array
-/// references to pointers, this may cause additional errors to be emitted and/or
-/// ICE error messages. This function will panic if that occurs.
-pub(super) fn can_be_expressed_as_pointer_cast<'tcx>(
- cx: &LateContext<'tcx>,
- e: &'tcx Expr<'_>,
- from_ty: Ty<'tcx>,
- to_ty: Ty<'tcx>,
-) -> bool {
- use CastKind::{AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast};
- matches!(
- check_cast(cx, e, from_ty, to_ty),
- Some(PtrPtrCast | PtrAddrCast | AddrPtrCast | ArrayPtrCast | FnPtrPtrCast | FnPtrAddrCast)
- )
-}
-
/// If a cast from `from_ty` to `to_ty` is valid, returns an Ok containing the kind of
/// the cast. In certain cases, including some invalid casts from array references
/// to pointers, this may cause additional errors to be emitted and/or ICE error
/// messages. This function will panic if that occurs.
-fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> Option<CastKind> {
+pub(super) fn check_cast<'tcx>(
+ cx: &LateContext<'tcx>,
+ e: &'tcx Expr<'_>,
+ from_ty: Ty<'tcx>,
+ to_ty: Ty<'tcx>,
+) -> Option<CastKind> {
let hir_id = e.hir_id;
- let local_def_id = hir_id.owner;
+ let local_def_id = hir_id.owner.def_id;
+
+ let inherited = Inherited::new(cx.tcx, local_def_id);
+ let fn_ctxt = FnCtxt::new(&inherited, cx.param_env, local_def_id);
- Inherited::build(cx.tcx, local_def_id).enter(|inherited| {
- let fn_ctxt = FnCtxt::new(&inherited, cx.param_env, hir_id);
+ // If we already have errors, we can't be sure we can pointer cast.
+ assert!(
+ !fn_ctxt.errors_reported_since_creation(),
+ "Newly created FnCtxt contained errors"
+ );
- // If we already have errors, we can't be sure we can pointer cast.
+ if let Ok(check) = cast::CastCheck::new(
+ &fn_ctxt,
+ e,
+ from_ty,
+ to_ty,
+ // We won't show any error to the user, so we don't care what the span is here.
+ DUMMY_SP,
+ DUMMY_SP,
+ hir::Constness::NotConst,
+ ) {
+ let res = check.do_check(&fn_ctxt);
+
+ // do_check's documentation says that it might return Ok and create
+ // errors in the fcx instead of returning Err in some cases. Those cases
+ // should be filtered out before getting here.
assert!(
!fn_ctxt.errors_reported_since_creation(),
- "Newly created FnCtxt contained errors"
+ "`fn_ctxt` contained errors after cast check!"
);
- if let Ok(check) = CastCheck::new(
- &fn_ctxt, e, from_ty, to_ty,
- // We won't show any error to the user, so we don't care what the span is here.
- DUMMY_SP, DUMMY_SP,
- ) {
- let res = check.do_check(&fn_ctxt);
-
- // do_check's documentation says that it might return Ok and create
- // errors in the fcx instead of returing Err in some cases. Those cases
- // should be filtered out before getting here.
- assert!(
- !fn_ctxt.errors_reported_since_creation(),
- "`fn_ctxt` contained errors after cast check!"
- );
-
- res.ok()
- } else {
- None
- }
- })
+ res.ok()
+ } else {
+ None
+ }
}
projects / rustc.git / blobdiff