bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #114784 - Urgau:many-improve-invalid_reference_casting-lint, r=est31

Browse source 
Improve `invalid_reference_casting` lint

This PR improves the `invalid_reference_casting` lint:
 - by considering an unlimited number of casts instead only const to mut ptr
 - by also considering ptr-to-integer and integer-to-ptr casts
 - by also taking into account [`ptr::cast`](https://doc.rust-lang.org/std/primitive.pointer.html#method.cast), [`ptr::cast`](https://doc.rust-lang.org/std/primitive.pointer.html#method.cast-1) and [`ptr::cast_const`](https://doc.rust-lang.org/std/primitive.pointer.html#method.cast_const)

Most of this improvements comes from skimming Github Code Search result for [`&mut \*.*as \*const`](https://github.com/search?q=lang%3Arust+%2F%26mut+%5C*.*as+%5C*const%2F&type=code)

r? ``@est31`` (maybe)
This commit is contained in:
Matthias Krüger 2023-08-16 20:10:37 +02:00 • committed by GitHub
commit 2667d853a6
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
6 changed files with 137 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

49
compiler/rustc_lint/src/reference_casting.rs
View file

@ -100,7 +100,7 @@ fn is_cast_from_const_to_mut<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>)
fn from_casts<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
// <expr> as *mut ...
let e = if let ExprKind::Cast(e, t) = e.kind
let mut e = if let ExprKind::Cast(e, t) = e.kind
&& let ty::RawPtr(TypeAndMut { mutbl: Mutability::Mut, .. }) = cx.typeck_results().node_type(t.hir_id).kind() {
e
// <expr>.cast_mut()
@ -112,23 +112,36 @@ fn is_cast_from_const_to_mut<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>)
return None;
};
let e = e.peel_blocks();
// <expr> as *const ...
let e = if let ExprKind::Cast(e, t) = e.kind
&& let ty::RawPtr(TypeAndMut { mutbl: Mutability::Not, .. }) = cx.typeck_results().node_type(t.hir_id).kind() {
e
// ptr::from_ref(<expr>)
} else if let ExprKind::Call(path, [arg]) = e.kind
&& let ExprKind::Path(ref qpath) = path.kind
&& let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
&& cx.tcx.is_diagnostic_item(sym::ptr_from_ref, def_id) {
arg
} else {
return None;
};
Some(e)
let mut had_at_least_one_cast = false;
loop {
e = e.peel_blocks();
// <expr> as *mut/const ... or <expr> as <uint>
e = if let ExprKind::Cast(expr, t) = e.kind
&& matches!(cx.typeck_results().node_type(t.hir_id).kind(), ty::RawPtr(_) | ty::Uint(_)) {
had_at_least_one_cast = true;
expr
// <expr>.cast(), <expr>.cast_mut() or <expr>.cast_const()
} else if let ExprKind::MethodCall(_, expr, [], _) = e.kind
&& let Some(def_id) = cx.typeck_results().type_dependent_def_id(e.hir_id)
&& matches!(
cx.tcx.get_diagnostic_name(def_id),
Some(sym::ptr_cast | sym::const_ptr_cast | sym::ptr_cast_mut | sym::ptr_cast_const)
)
{
had_at_least_one_cast = true;
expr
// ptr::from_ref(<expr>)
} else if let ExprKind::Call(path, [arg]) = e.kind
&& let ExprKind::Path(ref qpath) = path.kind
&& let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
&& cx.tcx.is_diagnostic_item(sym::ptr_from_ref, def_id) {
return Some(arg);
} else if had_at_least_one_cast {
return Some(e);
} else {
return None;
};
}
}
fn from_transmute<'tcx>(