Forbid casting to/from a pointer of unknown kind #45735
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r? @pnkfelix (rust_highfive has picked a reviewer for you, use r? to override) |
src/librustc_typeck/check/cast.rs
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| @@ -105,6 +105,9 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { | |||
| // We should really try to normalize here. | |||
| ty::TyProjection(ref pi) => PointerKind::OfProjection(pi), | |||
| ty::TyParam(ref p) => PointerKind::OfParam(p), | |||
| // Insufficient type information; this will be caught later, so just report that this | |||
| // is a thin pointer. | |||
| ty::TyInfer(_) => PointerKind::Thin, | |||
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Does this case occur only by lack of type information? I'm not pretty sure.
shepmaster
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the
S-waiting-on-review
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It's not a good idea to assume things when encountering a use std::fmt;
fn main() {
let x: *const _ = 0 as *const _; // we don't want to allow this if...
let y: Option<*const fmt::Debug> = Some(x) as _;
// ^ later, we have x = *const fmt::Debug
}
fn not_ok() {
let x = 0 as *const i32 as *const _ as *mut _; //~ ERROR ?
}Instead, you should make |
tirr-c
changed the title
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Added a new error code for casting with unknown pointer kind. r? @arielb1 |
src/librustc_typeck/check/cast.rs
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| @@ -457,14 +478,20 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> { | |||
| debug!("check_ptr_ptr_cast m_expr={:?} m_cast={:?}", m_expr, m_cast); | |||
| // ptr-ptr cast. vtables must match. | |||
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| let (expr_kind, cast_kind) = | |||
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This forbids casting an *const _ to an *const u32, please move the check after the following if to avoid breaking user code.
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Updated, but I couldn't trigger the |
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Can't you have |
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@bors r+ |
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📌 Commit 99ada04 has been approved by |
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It just compiles. I'm not sure when inference occurs, but maybe |
kennytm
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Forbid casting to/from a pointer of unknown kind Fixes #45730. Before, it ICE'd when `pointer_kind` encountered `TyInfer`.
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☀️ Test successful - status-appveyor, status-travis |
Fixes #45730.
Before, it ICE'd when
pointer_kindencounteredTyInfer.