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Check for tuple structs

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This commit is contained in:
Nathaniel Hamovitz 2021-10-18 03:03:48 -07:00
parent 2a5a4f07cf
commit 9f402b370c
1 changed files with 10 additions and 17 deletions
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27
clippy_lints/src/trailing_zero_sized_array_without_repr_c.rs
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@ -38,7 +38,6 @@ declare_lint_pass!(TrailingZeroSizedArrayWithoutReprC => [TRAILING_ZERO_SIZED_AR
impl<'tcx> LateLintPass<'tcx> for TrailingZeroSizedArrayWithoutReprC {
fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
dbg!(item.ident);
if is_struct_with_trailing_zero_sized_array(cx, item) {
// NOTE: This is to include attributes on the definition when we print the lint. If the convention
// is to not do that with struct definitions (I'm not sure), then this isn't necessary. (note: if
@ -66,24 +65,18 @@ impl<'tcx> LateLintPass<'tcx> for TrailingZeroSizedArrayWithoutReprC {
}
fn is_struct_with_trailing_zero_sized_array(cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) -> bool {
// TODO: when finalized, replace with an `if_chain`. I have it like this because my rust-analyzer doesn't work when it's an `if_chain`
// First check if last field is an array
if let ItemKind::Struct(data, _) = &item.kind {
if let VariantData::Struct(field_defs, _) = data {
if let Some(last_field) = field_defs.last() {
if let rustc_hir::TyKind::Array(_, length) = last_field.ty.kind {
// Then check if that that array zero-sized
let length_ldid = cx.tcx.hir().local_def_id(length.hir_id);
let length = Const::from_anon_const(cx.tcx, length_ldid);
let length = length.try_eval_usize(cx.tcx, cx.param_env);
// if let Some((Constant::Int(length), _)) = length {
if let Some(length) = length {
length == 0
} else {
false
}
} else {
false
}
let field_defs = data.fields();
if let Some(last_field) = field_defs.last() {
if let rustc_hir::TyKind::Array(_, length) = last_field.ty.kind {
// Then check if that that array zero-sized
let length_ldid = cx.tcx.hir().local_def_id(length.hir_id);
let length = Const::from_anon_const(cx.tcx, length_ldid);
let length = length.try_eval_usize(cx.tcx, cx.param_env);
// if let Some((Constant::Int(length), _)) = length {
if let Some(length) = length { length == 0 } else { false }
} else {
false
}