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|
use super::{TRANSMUTE_BYTES_TO_STR, TRANSMUTE_PTR_TO_PTR};
use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
use clippy_utils::source::snippet;
use clippy_utils::sugg;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{Expr, Mutability};
use rustc_lint::LateContext;
use rustc_middle::ty::{self, Ty};
/// Checks for `transmute_bytes_to_str` and `transmute_ptr_to_ptr` lints.
/// Returns `true` if either one triggered, otherwise returns `false`.
pub(super) fn check<'tcx>(
cx: &LateContext<'tcx>,
e: &'tcx Expr<'_>,
from_ty: Ty<'tcx>,
to_ty: Ty<'tcx>,
arg: &'tcx Expr<'_>,
const_context: bool,
) -> bool {
let mut triggered = false;
if let (ty::Ref(_, ty_from, from_mutbl), ty::Ref(_, ty_to, to_mutbl)) = (&from_ty.kind(), &to_ty.kind()) {
if_chain! {
if let (&ty::Slice(slice_ty), &ty::Str) = (&ty_from.kind(), &ty_to.kind());
if let ty::Uint(ty::UintTy::U8) = slice_ty.kind();
if from_mutbl == to_mutbl;
then {
let postfix = if *from_mutbl == Mutability::Mut {
"_mut"
} else {
""
};
let snippet = snippet(cx, arg.span, "..");
span_lint_and_sugg(
cx,
TRANSMUTE_BYTES_TO_STR,
e.span,
&format!("transmute from a `{from_ty}` to a `{to_ty}`"),
"consider using",
if const_context {
format!("std::str::from_utf8_unchecked{postfix}({snippet})")
} else {
format!("std::str::from_utf8{postfix}({snippet}).unwrap()")
},
Applicability::MaybeIncorrect,
);
triggered = true;
} else {
if (cx.tcx.erase_regions(from_ty) != cx.tcx.erase_regions(to_ty))
&& !const_context {
span_lint_and_then(
cx,
TRANSMUTE_PTR_TO_PTR,
e.span,
"transmute from a reference to a reference",
|diag| if let Some(arg) = sugg::Sugg::hir_opt(cx, arg) {
let ty_from_and_mut = ty::TypeAndMut {
ty: *ty_from,
mutbl: *from_mutbl
};
let ty_to_and_mut = ty::TypeAndMut { ty: *ty_to, mutbl: *to_mutbl };
let sugg_paren = arg
.as_ty(cx.tcx.mk_ptr(ty_from_and_mut))
.as_ty(cx.tcx.mk_ptr(ty_to_and_mut));
let sugg = if *to_mutbl == Mutability::Mut {
sugg_paren.mut_addr_deref()
} else {
sugg_paren.addr_deref()
};
diag.span_suggestion(
e.span,
"try",
sugg,
Applicability::Unspecified,
);
},
);
triggered = true;
}
}
}
}
triggered
}
|
