lint: fix ImproperCTypes edge case for unsized structs due to foreign types
This commit is contained in:
niacdoial
parent
1d52131043
commit
7962a2de3a
3 changed files with 119 additions and 32 deletions
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@ -740,6 +740,69 @@ enum FfiResult<'tcx> {
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},
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}
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pub(crate) fn is_unsized_because_foreign<'tcx, 'a>(
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cx: &'a LateContext<'tcx>,
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ty: Ty<'tcx>,
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) -> Result<bool, ()> {
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let tcx = cx.tcx;
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if ty.is_sized(tcx, cx.typing_env()) {
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Err(())
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} else {
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Ok(match ty.kind() {
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ty::Slice(_) => false,
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ty::Str => false,
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ty::Dynamic(..) => false,
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ty::Foreign(..) => true,
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ty::Alias(ty::Opaque, ..) => todo!("why"),
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ty::Adt(def, args) => {
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// for now assume: boxes and phantoms don't mess with this
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match def.adt_kind() {
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AdtKind::Union | AdtKind::Enum => true,
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AdtKind::Struct => {
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if let Some(sym::cstring_type | sym::cstr_type) =
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tcx.get_diagnostic_name(def.did())
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{
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return Ok(false);
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}
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// FIXME: how do we deal with non-exhaustive unsized structs/unions?
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if def.non_enum_variant().fields.is_empty() {
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bug!("empty unsized struct/union. what?");
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}
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let variant = def.non_enum_variant();
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// only the last field may be unsized
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let n_fields = variant.fields.len();
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let last_field = &variant.fields[(n_fields - 1).into()];
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let field_ty = last_field.ty(cx.tcx, args);
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let field_ty = cx
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.tcx
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.try_normalize_erasing_regions(cx.typing_env(), field_ty)
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.unwrap_or(field_ty);
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return Ok(is_unsized_because_foreign(cx, field_ty).unwrap());
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}
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}
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}
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ty::Tuple(tuple) => {
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// only the last field may be unsized
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let n_fields = tuple.len();
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let field_ty: Ty<'tcx> = tuple[n_fields - 1];
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//let field_ty = last_field.ty(cx.tcx, args);
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let field_ty = cx
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.tcx
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.try_normalize_erasing_regions(cx.typing_env(), field_ty)
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.unwrap_or(field_ty);
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is_unsized_because_foreign(cx, field_ty).unwrap()
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}
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t => {
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bug!("we shouldn't be looking if this is unsized for a reason or another: {:?}", t)
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}
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})
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}
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}
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pub(crate) fn nonnull_optimization_guaranteed<'tcx>(
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tcx: TyCtxt<'tcx>,
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def: ty::AdtDef<'tcx>,
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@ -1044,7 +1107,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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ty::Adt(def, args) => {
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if let Some(inner_ty) = ty.boxed_ty() {
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if inner_ty.is_sized(tcx, self.cx.typing_env())
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|| matches!(inner_ty.kind(), ty::Foreign(..))
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|| is_unsized_because_foreign(self.cx, inner_ty).unwrap()
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{
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// discussion on declaration vs definition:
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// see the `ty::RawPtr(inner_ty, _) | ty::Ref(_, inner_ty, _)` arm
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@ -1249,7 +1312,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
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ty::RawPtr(inner_ty, _) | ty::Ref(_, inner_ty, _) => {
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if inner_ty.is_sized(tcx, self.cx.typing_env())
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|| matches!(inner_ty.kind(), ty::Foreign(..))
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|| is_unsized_because_foreign(self.cx, inner_ty).unwrap()
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{
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// there's a nuance on what this lint should do for function definitions
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// (touched upon in https://github.com/rust-lang/rust/issues/66220 and https://github.com/rust-lang/rust/pull/72700)
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@ -1,4 +1,5 @@
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#![feature(rustc_private)]
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#![feature(extern_types)]
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#![allow(private_interfaces)]
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#![deny(improper_ctypes)]
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@ -6,7 +7,9 @@
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use std::cell::UnsafeCell;
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use std::marker::PhantomData;
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use std::ffi::{c_int, c_uint};
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use std::fmt::Debug;
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unsafe extern "C" {type UnsizedOpaque;}
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trait Bar { }
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trait Mirror { type It: ?Sized; }
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impl<T: ?Sized> Mirror for T { type It = Self; }
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@ -39,6 +42,16 @@ pub struct TransparentLifetime<'a>(*const u8, PhantomData<&'a ()>);
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pub struct TransparentUnit<U>(f32, PhantomData<U>);
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#[repr(transparent)]
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pub struct TransparentCustomZst(i32, ZeroSize);
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#[repr(C)]
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pub struct UnsizedStructBecauseForeign {
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sized: u32,
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unszd: UnsizedOpaque,
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}
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#[repr(C)]
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pub struct UnsizedStructBecauseDyn {
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sized: u32,
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unszd: dyn Debug,
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}
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#[repr(C)]
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pub struct ZeroSizeWithPhantomData(::std::marker::PhantomData<i32>);
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@ -72,6 +85,9 @@ extern "C" {
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pub fn transparent_fn(p: TransparentBadFn); //~ ERROR: uses type `Box<u32>`
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pub fn raw_array(arr: [u8; 8]); //~ ERROR: uses type `[u8; 8]`
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pub fn struct_unsized_ptr_no_metadata(p: &UnsizedStructBecauseForeign);
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pub fn struct_unsized_ptr_has_metadata(p: &UnsizedStructBecauseDyn); //~ ERROR uses type `&UnsizedStructBecauseDyn`
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pub fn no_niche_a(a: Option<UnsafeCell<extern fn()>>);
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//~^ ERROR: uses type `Option<UnsafeCell<extern "C" fn()>>`
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pub fn no_niche_b(b: Option<UnsafeCell<&i32>>);
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@ -1,5 +1,5 @@
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error: `extern` block uses type `Foo`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:47:28
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--> $DIR/lint-ctypes.rs:60:28
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LL | pub fn ptr_type1(size: *const Foo);
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| ^^^^^^^^^^ not FFI-safe
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@ -8,18 +8,18 @@ LL | pub fn ptr_type1(size: *const Foo);
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= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
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= note: this struct has unspecified layout
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note: the type is defined here
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--> $DIR/lint-ctypes.rs:25:1
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--> $DIR/lint-ctypes.rs:28:1
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LL | pub struct Foo;
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| ^^^^^^^^^^^^^^
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note: the lint level is defined here
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--> $DIR/lint-ctypes.rs:4:9
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--> $DIR/lint-ctypes.rs:5:9
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LL | #![deny(improper_ctypes)]
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| ^^^^^^^^^^^^^^^
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error: `extern` block uses type `Foo`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:48:28
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--> $DIR/lint-ctypes.rs:61:28
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LL | pub fn ptr_type2(size: *const Foo);
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| ^^^^^^^^^^ not FFI-safe
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@ -28,13 +28,13 @@ LL | pub fn ptr_type2(size: *const Foo);
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= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
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= note: this struct has unspecified layout
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note: the type is defined here
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--> $DIR/lint-ctypes.rs:25:1
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--> $DIR/lint-ctypes.rs:28:1
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LL | pub struct Foo;
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| ^^^^^^^^^^^^^^
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error: `extern` block uses type `((),)`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:50:25
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--> $DIR/lint-ctypes.rs:63:25
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LL | pub fn ptr_tuple(p: *const ((),));
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| ^^^^^^^^^^^^ not FFI-safe
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@ -44,7 +44,7 @@ LL | pub fn ptr_tuple(p: *const ((),));
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= note: tuples have unspecified layout
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error: `extern` block uses type `&[u32]`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:51:26
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--> $DIR/lint-ctypes.rs:64:26
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LL | pub fn slice_type(p: &[u32]);
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| ^^^^^^ not FFI-safe
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@ -53,7 +53,7 @@ LL | pub fn slice_type(p: &[u32]);
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= note: this reference to an unsized rust type contains metadata, which makes it incompatible with a C pointer
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error: `extern` block uses type `&str`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:52:24
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--> $DIR/lint-ctypes.rs:65:24
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LL | pub fn str_type(p: &str);
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| ^^^^ not FFI-safe
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@ -71,7 +71,7 @@ LL | pub fn box_type(p: Box<u32>);
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= note: this struct has unspecified layout
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error: `extern` block uses type `Option<Box<u32>>`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:54:28
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--> $DIR/lint-ctypes.rs:67:28
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LL | pub fn opt_box_type(p: Option<Box<u32>>);
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| ^^^^^^^^^^^^^^^^ not FFI-safe
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@ -80,7 +80,7 @@ LL | pub fn opt_box_type(p: Option<Box<u32>>);
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= note: enum has no representation hint
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error: `extern` block uses type `char`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:56:25
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--> $DIR/lint-ctypes.rs:69:25
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LL | pub fn char_type(p: char);
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| ^^^^ not FFI-safe
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@ -89,7 +89,7 @@ LL | pub fn char_type(p: char);
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= note: the `char` type has no C equivalent
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error: `extern` block uses type `i128`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:57:25
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--> $DIR/lint-ctypes.rs:70:25
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LL | pub fn i128_type(p: i128);
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| ^^^^ not FFI-safe
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@ -97,7 +97,7 @@ LL | pub fn i128_type(p: i128);
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= note: 128-bit integers don't currently have a known stable ABI
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error: `extern` block uses type `u128`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:58:25
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--> $DIR/lint-ctypes.rs:71:25
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LL | pub fn u128_type(p: u128);
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| ^^^^ not FFI-safe
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@ -105,7 +105,7 @@ LL | pub fn u128_type(p: u128);
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= note: 128-bit integers don't currently have a known stable ABI
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error: `extern` block uses type `&dyn Bar`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:59:26
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--> $DIR/lint-ctypes.rs:72:26
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LL | pub fn trait_type(p: &dyn Bar);
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| ^^^^^^^^ not FFI-safe
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@ -113,7 +113,7 @@ LL | pub fn trait_type(p: &dyn Bar);
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= note: this reference to an unsized rust type contains metadata, which makes it incompatible with a C pointer
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error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:60:26
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--> $DIR/lint-ctypes.rs:73:26
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LL | pub fn tuple_type(p: (i32, i32));
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| ^^^^^^^^^^ not FFI-safe
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@ -122,7 +122,7 @@ LL | pub fn tuple_type(p: (i32, i32));
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= note: tuples have unspecified layout
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error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:61:27
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--> $DIR/lint-ctypes.rs:74:27
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LL | pub fn tuple_type2(p: I32Pair);
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| ^^^^^^^ not FFI-safe
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@ -131,7 +131,7 @@ LL | pub fn tuple_type2(p: I32Pair);
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= note: tuples have unspecified layout
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error: `extern` block uses type `ZeroSize`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:62:25
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--> $DIR/lint-ctypes.rs:75:25
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LL | pub fn zero_size(p: ZeroSize);
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| ^^^^^^^^ not FFI-safe
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@ -139,26 +139,26 @@ LL | pub fn zero_size(p: ZeroSize);
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= help: consider adding a member to this struct
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= note: this struct has no fields
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note: the type is defined here
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--> $DIR/lint-ctypes.rs:21:1
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--> $DIR/lint-ctypes.rs:24:1
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LL | pub struct ZeroSize;
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| ^^^^^^^^^^^^^^^^^^^
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error: `extern` block uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:63:33
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--> $DIR/lint-ctypes.rs:76:33
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LL | pub fn zero_size_phantom(p: ZeroSizeWithPhantomData);
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| ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
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= note: composed only of `PhantomData`
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note: the type is defined here
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--> $DIR/lint-ctypes.rs:44:1
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--> $DIR/lint-ctypes.rs:57:1
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LL | pub struct ZeroSizeWithPhantomData(::std::marker::PhantomData<i32>);
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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error: `extern` block uses type `PhantomData<bool>`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:66:12
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--> $DIR/lint-ctypes.rs:79:12
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LL | -> ::std::marker::PhantomData<bool>;
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
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@ -166,7 +166,7 @@ LL | -> ::std::marker::PhantomData<bool>;
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= note: composed only of `PhantomData`
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error: `extern` block uses type `fn()`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:67:23
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--> $DIR/lint-ctypes.rs:80:23
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LL | pub fn fn_type(p: RustFn);
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| ^^^^^^ not FFI-safe
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@ -175,7 +175,7 @@ LL | pub fn fn_type(p: RustFn);
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= note: this function pointer has Rust-specific calling convention
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error: `extern` block uses type `fn()`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:68:24
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--> $DIR/lint-ctypes.rs:81:24
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LL | pub fn fn_type2(p: fn());
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| ^^^^ not FFI-safe
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@ -193,7 +193,7 @@ LL | pub fn fn_contained(p: RustBadRet);
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= note: this struct has unspecified layout
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error: `extern` block uses type `i128`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:70:32
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--> $DIR/lint-ctypes.rs:83:32
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LL | pub fn transparent_i128(p: TransparentI128);
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| ^^^^^^^^^^^^^^^ not FFI-safe
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@ -201,7 +201,7 @@ LL | pub fn transparent_i128(p: TransparentI128);
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= note: 128-bit integers don't currently have a known stable ABI
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error: `extern` block uses type `&str`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:71:31
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--> $DIR/lint-ctypes.rs:84:31
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LL | pub fn transparent_str(p: TransparentStr);
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| ^^^^^^^^^^^^^^ not FFI-safe
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@ -219,7 +219,7 @@ LL | pub fn transparent_fn(p: TransparentBadFn);
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= note: this struct has unspecified layout
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error: `extern` block uses type `[u8; 8]`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:73:27
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--> $DIR/lint-ctypes.rs:86:27
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LL | pub fn raw_array(arr: [u8; 8]);
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| ^^^^^^^ not FFI-safe
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@ -227,8 +227,16 @@ LL | pub fn raw_array(arr: [u8; 8]);
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= help: consider passing a pointer to the array
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= note: passing raw arrays by value is not FFI-safe
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error: `extern` block uses type `&UnsizedStructBecauseDyn`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:89:47
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LL | pub fn struct_unsized_ptr_has_metadata(p: &UnsizedStructBecauseDyn);
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| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
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|
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= note: this reference to an unsized rust type contains metadata, which makes it incompatible with a C pointer
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error: `extern` block uses type `Option<UnsafeCell<extern "C" fn()>>`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:75:26
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--> $DIR/lint-ctypes.rs:91:26
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LL | pub fn no_niche_a(a: Option<UnsafeCell<extern fn()>>);
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
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@ -237,7 +245,7 @@ LL | pub fn no_niche_a(a: Option<UnsafeCell<extern fn()>>);
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= note: enum has no representation hint
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error: `extern` block uses type `Option<UnsafeCell<&i32>>`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:77:26
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--> $DIR/lint-ctypes.rs:93:26
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LL | pub fn no_niche_b(b: Option<UnsafeCell<&i32>>);
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| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
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@ -246,7 +254,7 @@ LL | pub fn no_niche_b(b: Option<UnsafeCell<&i32>>);
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= note: enum has no representation hint
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error: `extern` block uses type `u128`, which is not FFI-safe
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--> $DIR/lint-ctypes.rs:80:34
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--> $DIR/lint-ctypes.rs:96:34
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LL | pub static static_u128_type: u128;
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| ^^^^ not FFI-safe
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@ -254,11 +262,11 @@ LL | pub static static_u128_type: u128;
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= note: 128-bit integers don't currently have a known stable ABI
|
||||
|
||||
error: `extern` block uses type `u128`, which is not FFI-safe
|
||||
--> $DIR/lint-ctypes.rs:81:40
|
||||
--> $DIR/lint-ctypes.rs:97:40
|
||||
|
|
||||
LL | pub static static_u128_array_type: [u128; 16];
|
||||
| ^^^^^^^^^^ not FFI-safe
|
||||
|
|
||||
= note: 128-bit integers don't currently have a known stable ABI
|
||||
|
||||
error: aborting due to 27 previous errors
|
||||
error: aborting due to 29 previous errors
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue