mirror of https://github.com/rust-lang/rust.git
Rollup merge of #130758 - compiler-errors:ctype-recursion-limit, r=jieyouxu
Revert "Add recursion limit to FFI safety lint" It's not necessarily clear if warning when we hit the recursion limit is the right thing to do, first of all. **More importantly**, this PR was implemented incorrectly in the first place; it was not decrementing the recursion limit when stepping out of a type, so it would trigger when a ctype has more than RECURSION_LIMIT fields *anywhere* in the type's set of recursively reachable fields. Reverts #130598 Reopens #130310 Fixes #130757
This commit is contained in:
commit
fa1bd9b06a
|
@ -395,8 +395,6 @@ lint_improper_ctypes_opaque = opaque types have no C equivalent
|
|||
lint_improper_ctypes_pat_help = consider using the base type instead
|
||||
|
||||
lint_improper_ctypes_pat_reason = pattern types have no C equivalent
|
||||
|
||||
lint_improper_ctypes_recursion_limit_reached = type is infinitely recursive
|
||||
lint_improper_ctypes_slice_help = consider using a raw pointer instead
|
||||
|
||||
lint_improper_ctypes_slice_reason = slices have no C equivalent
|
||||
|
|
|
@ -592,8 +592,6 @@ struct CTypesVisitorState<'tcx> {
|
|||
/// The original type being checked, before we recursed
|
||||
/// to any other types it contains.
|
||||
base_ty: Ty<'tcx>,
|
||||
/// Number of times we recursed while checking the type
|
||||
recursion_depth: usize,
|
||||
}
|
||||
|
||||
enum FfiResult<'tcx> {
|
||||
|
@ -899,23 +897,12 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
|
|||
|
||||
// Protect against infinite recursion, for example
|
||||
// `struct S(*mut S);`.
|
||||
// FIXME: A recursion limit is necessary as well, for irregular
|
||||
// recursive types.
|
||||
if !acc.cache.insert(ty) {
|
||||
return FfiSafe;
|
||||
}
|
||||
|
||||
// Additional recursion check for more complex types like
|
||||
// `struct A<T> { v: *const A<A<T>>, ... }` for which the
|
||||
// cache check above won't be enough (fixes #130310)
|
||||
if !tcx.recursion_limit().value_within_limit(acc.recursion_depth) {
|
||||
return FfiUnsafe {
|
||||
ty: acc.base_ty,
|
||||
reason: fluent::lint_improper_ctypes_recursion_limit_reached,
|
||||
help: None,
|
||||
};
|
||||
}
|
||||
|
||||
acc.recursion_depth += 1;
|
||||
|
||||
match *ty.kind() {
|
||||
ty::Adt(def, args) => {
|
||||
if let Some(boxed) = ty.boxed_ty()
|
||||
|
@ -1261,8 +1248,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
|
|||
return;
|
||||
}
|
||||
|
||||
let mut acc =
|
||||
CTypesVisitorState { cache: FxHashSet::default(), base_ty: ty, recursion_depth: 0 };
|
||||
let mut acc = CTypesVisitorState { cache: FxHashSet::default(), base_ty: ty };
|
||||
match self.check_type_for_ffi(&mut acc, ty) {
|
||||
FfiResult::FfiSafe => {}
|
||||
FfiResult::FfiPhantom(ty) => {
|
||||
|
|
|
@ -0,0 +1,15 @@
|
|||
//@ known-bug: rust-lang/rust#130310
|
||||
|
||||
use std::marker::PhantomData;
|
||||
|
||||
#[repr(C)]
|
||||
struct A<T> {
|
||||
a: *const A<A<T>>,
|
||||
p: PhantomData<T>,
|
||||
}
|
||||
|
||||
extern "C" {
|
||||
fn f(a: *const A<()>);
|
||||
}
|
||||
|
||||
fn main() {}
|
|
@ -1,20 +0,0 @@
|
|||
// Regression test for #130310
|
||||
// Tests that we do not fall into infinite
|
||||
// recursion while checking FFI safety of
|
||||
// recursive types like `A<T>` below
|
||||
|
||||
//@ build-pass
|
||||
use std::marker::PhantomData;
|
||||
|
||||
#[repr(C)]
|
||||
struct A<T> {
|
||||
a: *const A<A<T>>, // Recursive because of this field
|
||||
p: PhantomData<T>,
|
||||
}
|
||||
|
||||
extern "C" {
|
||||
fn f(a: *const A<()>);
|
||||
//~^ WARN `extern` block uses type `*const A<()>`, which is not FFI-safe
|
||||
}
|
||||
|
||||
fn main() {}
|
|
@ -1,11 +0,0 @@
|
|||
warning: `extern` block uses type `*const A<()>`, which is not FFI-safe
|
||||
--> $DIR/improper-types-stack-overflow-130310.rs:16:13
|
||||
|
|
||||
LL | fn f(a: *const A<()>);
|
||||
| ^^^^^^^^^^^^ not FFI-safe
|
||||
|
|
||||
= note: type is infinitely recursive
|
||||
= note: `#[warn(improper_ctypes)]` on by default
|
||||
|
||||
warning: 1 warning emitted
|
||||
|
|
@ -0,0 +1,32 @@
|
|||
//@ check-pass
|
||||
|
||||
#![recursion_limit = "5"]
|
||||
#![allow(unused)]
|
||||
#![deny(improper_ctypes)]
|
||||
|
||||
#[repr(C)]
|
||||
struct F1(*const ());
|
||||
#[repr(C)]
|
||||
struct F2(*const ());
|
||||
#[repr(C)]
|
||||
struct F3(*const ());
|
||||
#[repr(C)]
|
||||
struct F4(*const ());
|
||||
#[repr(C)]
|
||||
struct F5(*const ());
|
||||
#[repr(C)]
|
||||
struct F6(*const ());
|
||||
|
||||
#[repr(C)]
|
||||
struct B {
|
||||
f1: F1,
|
||||
f2: F2,
|
||||
f3: F3,
|
||||
f4: F4,
|
||||
f5: F5,
|
||||
f6: F6,
|
||||
}
|
||||
|
||||
extern "C" fn foo(_: B) {}
|
||||
|
||||
fn main() {}
|
Loading…
Reference in New Issue