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Cleanup manual_non_exhaustive

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This commit is contained in:
Jason Newcomb 2022-04-06 09:53:20 -04:00
parent 6e20a634e7
commit b0f8a31551
1 changed files with 32 additions and 51 deletions
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83
clippy_lints/src/manual_non_exhaustive.rs
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@ -2,8 +2,7 @@ use clippy_utils::attrs::is_doc_hidden;
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::source::snippet_opt;
use clippy_utils::{is_lint_allowed, meets_msrv, msrvs};
use if_chain::if_chain;
use rustc_ast::ast::{self, FieldDef, VisibilityKind};
use rustc_ast::ast::{self, VisibilityKind};
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::Applicability;
use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
@ -104,55 +103,34 @@ impl EarlyLintPass for ManualNonExhaustiveStruct {
}
if let ast::ItemKind::Struct(variant_data, _) = &item.kind {
if let ast::VariantData::Unit(..) = variant_data {
let (fields, delimiter) = match variant_data {
ast::VariantData::Struct(fields, _) => (&**fields, '{'),
ast::VariantData::Tuple(fields, _) => (&**fields, '('),
ast::VariantData::Unit(_) => return,
};
if fields.len() <= 1 {
return;
}
check_manual_non_exhaustive_struct(cx, item, variant_data);
}
}
extract_msrv_attr!(EarlyContext);
}
fn check_manual_non_exhaustive_struct(cx: &EarlyContext<'_>, item: &ast::Item, data: &ast::VariantData) {
fn is_private(field: &FieldDef) -> bool {
matches!(field.vis.kind, VisibilityKind::Inherited)
}
fn is_non_exhaustive_marker(field: &FieldDef) -> bool {
is_private(field) && field.ty.kind.is_unit() && field.ident.map_or(true, |n| n.as_str().starts_with('_'))
}
fn find_header_span(cx: &EarlyContext<'_>, item: &ast::Item, data: &ast::VariantData) -> Span {
let delimiter = match data {
ast::VariantData::Struct(..) => '{',
ast::VariantData::Tuple(..) => '(',
ast::VariantData::Unit(_) => unreachable!("`VariantData::Unit` is already handled above"),
};
cx.sess().source_map().span_until_char(item.span, delimiter)
}
let fields = data.fields();
let private_fields = fields.iter().filter(|f| is_private(f)).count();
let public_fields = fields.iter().filter(|f| f.vis.kind.is_pub()).count();
if_chain! {
if private_fields == 1 && public_fields >= 1 && public_fields == fields.len() - 1;
if let Some(marker) = fields.iter().find(|f| is_non_exhaustive_marker(f));
then {
span_lint_and_then(
cx,
MANUAL_NON_EXHAUSTIVE,
item.span,
"this seems like a manual implementation of the non-exhaustive pattern",
|diag| {
if_chain! {
if !item.attrs.iter().any(|attr| attr.has_name(sym::non_exhaustive));
let header_span = find_header_span(cx, item, data);
if let Some(snippet) = snippet_opt(cx, header_span);
then {
let mut iter = fields.iter().filter_map(|f| match f.vis.kind {
VisibilityKind::Public => None,
VisibilityKind::Inherited => Some(Ok(f)),
_ => Some(Err(())),
});
if let Some(Ok(field)) = iter.next()
&& iter.next().is_none()
&& field.ty.kind.is_unit()
&& field.ident.map_or(true, |name| name.as_str().starts_with('_'))
{
span_lint_and_then(
cx,
MANUAL_NON_EXHAUSTIVE,
item.span,
"this seems like a manual implementation of the non-exhaustive pattern",
|diag| {
if !item.attrs.iter().any(|attr| attr.has_name(sym::non_exhaustive))
&& let header_span = cx.sess().source_map().span_until_char(item.span, delimiter)
&& let Some(snippet) = snippet_opt(cx, header_span)
{
diag.span_suggestion(
header_span,
"add the attribute",
@ -160,11 +138,14 @@ fn check_manual_non_exhaustive_struct(cx: &EarlyContext<'_>, item: &ast::Item, d
Applicability::Unspecified,
);
}
diag.span_help(field.span, "remove this field");
}
diag.span_help(marker.span, "remove this field");
});
);
}
}
}
extract_msrv_attr!(EarlyContext);
}
impl<'tcx> LateLintPass<'tcx> for ManualNonExhaustiveEnum {