Struct ImproperCTypesVisitor 

struct ImproperCTypesVisitor<'a, 'tcx> {
    cx: &'a LateContext<'tcx>,
    cache: FxHashSet<Ty<'tcx>>,
    base_ty: Ty<'tcx>,
    base_fn_mode: CItemKind,
}

Visitor used to recursively traverse MIR types and evaluate FFI-safety. It uses check_* methods as entrypoints to be called elsewhere, and visit_* methods to recurse.

Fields

cx: &'a LateContext<'tcx>

cache: FxHashSet<Ty<'tcx>>

To prevent problems with recursive types, add a types-in-check cache.

base_ty: Ty<'tcx>

The original type being checked, before we recursed to any other types it contains.

base_fn_mode: CItemKind

Implementations

impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx>

fn new( cx: &'a LateContext<'tcx>, base_ty: Ty<'tcx>, base_fn_mode: CItemKind, ) -> Self

fn check_field_type_for_ffi( &mut self, state: VisitorState, field: &FieldDef, args: GenericArgsRef<'tcx>, ) -> FfiResult<'tcx>

Checks if the given field’s type is “ffi-safe”.

fn check_variant_for_ffi( &mut self, state: VisitorState, ty: Ty<'tcx>, def: AdtDef<'tcx>, variant: &VariantDef, args: GenericArgsRef<'tcx>, ) -> FfiResult<'tcx>

Checks if the given VariantDef’s field types are “ffi-safe”.

fn visit_type(&mut self, state: VisitorState, ty: Ty<'tcx>) -> FfiResult<'tcx>

Checks if the given type is “ffi-safe” (has a stable, well-defined representation which can be exported to C code).

fn visit_for_opaque_ty(&mut self, ty: Ty<'tcx>) -> Option<FfiResult<'tcx>>

fn check_for_array_ty(&mut self, ty: Ty<'tcx>) -> Option<FfiResult<'tcx>>

Check if the type is array and emit an unsafe type lint.

fn check_type(&mut self, state: VisitorState, ty: Ty<'tcx>) -> FfiResult<'tcx>

Determine the FFI-safety of a single (MIR) type, given the context of how it is used.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 56 bytes