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[improper_ctypes] Stop complaining about repr(usize) and repr(isize) enums

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This dates back to at least #26583. At the time, usize and isize were considered ffi-unsafe to nudge people away from them, but this changed in the aforementioned PR, making it inconsistent to complain about it in enum discriminants. In fact, repr(usize) is probably the best way to interface with `enum Foo : size_t { ... }`.
This commit is contained in:
Robin Kruppe 2018-02-11 21:54:56 +01:00
parent 7ac5e96f4a
commit ae92dfac50
2 changed files with 12 additions and 29 deletions
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29
src/librustc_lint/types.rs
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@ -26,7 +26,6 @@ use std::{i8, i16, i32, i64, u8, u16, u32, u64, f32, f64};
use syntax::ast;
use syntax::abi::Abi;
use syntax::attr;
use syntax_pos::Span;
use syntax::codemap;
@ -402,17 +401,6 @@ fn is_repr_nullable_ptr<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
false
}
fn is_ffi_safe(ty: attr::IntType) -> bool {
match ty {
attr::SignedInt(ast::IntTy::I8) | attr::UnsignedInt(ast::UintTy::U8) |
attr::SignedInt(ast::IntTy::I16) | attr::UnsignedInt(ast::UintTy::U16) |
attr::SignedInt(ast::IntTy::I32) | attr::UnsignedInt(ast::UintTy::U32) |
attr::SignedInt(ast::IntTy::I64) | attr::UnsignedInt(ast::UintTy::U64) |
attr::SignedInt(ast::IntTy::I128) | attr::UnsignedInt(ast::UintTy::U128) => true,
attr::SignedInt(ast::IntTy::Isize) | attr::UnsignedInt(ast::UintTy::Usize) => false
}
}
impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
/// Check if the given type is "ffi-safe" (has a stable, well-defined
/// representation which can be exported to C code).
@ -546,23 +534,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
}
}
if let Some(int_ty) = def.repr.int {
if !is_ffi_safe(int_ty) {
// FIXME: This shouldn't be reachable: we should check
// this earlier.
return FfiUnsafe(FfiError {
message: "enum has unexpected #[repr(...)] attribute",
help: None,
});
}
// Enum with an explicitly sized discriminant; either
// a C-style enum or a discriminated union.
// The layout of enum variants is implicitly repr(C).
// FIXME: Is that correct?
}
// Check the contained variants.
for variant in &def.variants {
for field in &variant.fields {

12
src/test/compile-fail/lint-ctypes-enum.rs
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@ -16,11 +16,23 @@ enum U { A }
enum B { C, D }
enum T { E, F, G }
#[repr(C)]
enum ReprC { A, B, C }
#[repr(u8)]
enum U8 { A, B, C }
#[repr(isize)]
enum Isize { A, B, C }
extern {
fn zf(x: Z);
fn uf(x: U); //~ ERROR found enum without foreign-function-safe
fn bf(x: B); //~ ERROR found enum without foreign-function-safe
fn tf(x: T); //~ ERROR found enum without foreign-function-safe
fn reprc(x: ReprC);
fn u8(x: U8);
fn isize(x: Isize);
}
pub fn main() { }