Fix ICE in improper_ctypes_definitions lint

The lint panicked for an input like 'extern "C" fn(Option<&<T as FooTrait>::FooType>)' because the type T therein cannot be normalized. The normalization failure caused SizeSkeleton::compute() to return an error and trigger a panic in the unwrap().
This commit is contained in:
Gurinder Singh 2023-09-09 12:30:25 +05:30
parent 5ede940894
commit e7c51320db
3 changed files with 27 additions and 11 deletions

View File

@ -917,8 +917,8 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
// At this point, the field's type is known to be nonnull and the parent enum is Option-like.
// If the computed size for the field and the enum are different, the nonnull optimization isn't
// being applied (and we've got a problem somewhere).
let compute_size_skeleton = |t| SizeSkeleton::compute(t, tcx, param_env).unwrap();
if !compute_size_skeleton(ty).same_size(compute_size_skeleton(field_ty)) {
let compute_size_skeleton = |t| SizeSkeleton::compute(t, tcx, param_env).ok();
if !compute_size_skeleton(ty)?.same_size(compute_size_skeleton(field_ty)?) {
bug!("improper_ctypes: Option nonnull optimization not applied?");
}

View File

@ -24,6 +24,13 @@ enum BadUnion {
type Foo = extern "C" fn([u8]);
//~^ ERROR `extern` fn uses type `[u8]`, which is not FFI-safe
pub trait FooTrait {
type FooType;
}
pub type Foo2<T> = extern "C" fn(Option<&<T as FooTrait>::FooType>);
//~^ ERROR `extern` fn uses type `Option<&<T as FooTrait>::FooType>`, which is not FFI-safe
pub struct FfiUnsafe;
#[allow(improper_ctypes_definitions)]

View File

@ -66,8 +66,17 @@ LL | type Foo = extern "C" fn([u8]);
= help: consider using a raw pointer instead
= note: slices have no C equivalent
error: `extern` fn uses type `Option<&<T as FooTrait>::FooType>`, which is not FFI-safe
--> $DIR/lint-ctypes-94223.rs:31:20
|
LL | pub type Foo2<T> = extern "C" fn(Option<&<T as FooTrait>::FooType>);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
|
= help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
= note: enum has no representation hint
error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
--> $DIR/lint-ctypes-94223.rs:34:17
--> $DIR/lint-ctypes-94223.rs:41:17
|
LL | pub static BAD: extern "C" fn(FfiUnsafe) = f;
| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@ -75,13 +84,13 @@ LL | pub static BAD: extern "C" fn(FfiUnsafe) = f;
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout
note: the type is defined here
--> $DIR/lint-ctypes-94223.rs:27:1
--> $DIR/lint-ctypes-94223.rs:34:1
|
LL | pub struct FfiUnsafe;
| ^^^^^^^^^^^^^^^^^^^^
error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
--> $DIR/lint-ctypes-94223.rs:37:30
--> $DIR/lint-ctypes-94223.rs:44:30
|
LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUnsafe)> = Ok(f);
| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@ -89,13 +98,13 @@ LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUns
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout
note: the type is defined here
--> $DIR/lint-ctypes-94223.rs:27:1
--> $DIR/lint-ctypes-94223.rs:34:1
|
LL | pub struct FfiUnsafe;
| ^^^^^^^^^^^^^^^^^^^^
error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
--> $DIR/lint-ctypes-94223.rs:37:56
--> $DIR/lint-ctypes-94223.rs:44:56
|
LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUnsafe)> = Ok(f);
| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@ -103,13 +112,13 @@ LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUns
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout
note: the type is defined here
--> $DIR/lint-ctypes-94223.rs:27:1
--> $DIR/lint-ctypes-94223.rs:34:1
|
LL | pub struct FfiUnsafe;
| ^^^^^^^^^^^^^^^^^^^^
error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
--> $DIR/lint-ctypes-94223.rs:41:22
--> $DIR/lint-ctypes-94223.rs:48:22
|
LL | pub const BAD_CONST: extern "C" fn(FfiUnsafe) = f;
| ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@ -117,10 +126,10 @@ LL | pub const BAD_CONST: extern "C" fn(FfiUnsafe) = f;
= help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
= note: this struct has unspecified layout
note: the type is defined here
--> $DIR/lint-ctypes-94223.rs:27:1
--> $DIR/lint-ctypes-94223.rs:34:1
|
LL | pub struct FfiUnsafe;
| ^^^^^^^^^^^^^^^^^^^^
error: aborting due to 11 previous errors
error: aborting due to 12 previous errors