0f5338cd90
The `restriction` group contains many lints which are not about necessarily “bad” things, but style choices — perhaps even style choices which contradict conventional Rust style — or are otherwise very situational. This results in silly wording like “Why is this bad? It isn't, but ...”, which I’ve seen confuse a newcomer at least once. To improve this situation, this commit replaces the “Why is this bad?” section heading with “Why restrict this?”, for most, but not all, restriction lints. I left alone the ones whose placement in the restriction group is more incidental. In order to make this make sense, I had to remove the “It isn't, but” texts from the contents of the sections. Sometimes further changes were needed, or there were obvious fixes to make, and I went ahead and made those changes without attempting to split them into another commit, even though many of them are not strictly necessary for the “Why restrict this?” project.
82 lines
2.5 KiB
Rust
82 lines
2.5 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_help;
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use rustc_ast::ast::{Item, ItemKind};
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use rustc_lint::{EarlyContext, EarlyLintPass};
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use rustc_session::declare_lint_pass;
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declare_clippy_lint! {
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/// ### What it does
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/// Checks whether some but not all fields of a `struct` are public.
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///
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/// Either make all fields of a type public, or make none of them public
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///
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/// ### Why restrict this?
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/// Most types should either be:
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/// * Abstract data types: complex objects with opaque implementation which guard
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/// interior invariants and expose intentionally limited API to the outside world.
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/// * Data: relatively simple objects which group a bunch of related attributes together,
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/// but have no invariants.
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///
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/// ### Example
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/// ```no_run
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/// pub struct Color {
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/// pub r: u8,
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/// pub g: u8,
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/// b: u8,
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/// }
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/// ```
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/// Use instead:
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/// ```no_run
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/// pub struct Color {
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/// pub r: u8,
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/// pub g: u8,
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/// pub b: u8,
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/// }
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/// ```
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#[clippy::version = "1.66.0"]
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pub PARTIAL_PUB_FIELDS,
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restriction,
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"partial fields of a struct are public"
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}
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declare_lint_pass!(PartialPubFields => [PARTIAL_PUB_FIELDS]);
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impl EarlyLintPass for PartialPubFields {
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fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
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let ItemKind::Struct(ref st, _) = item.kind else {
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return;
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};
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let mut fields = st.fields().iter();
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let Some(first_field) = fields.next() else {
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// Empty struct.
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return;
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};
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let all_pub = first_field.vis.kind.is_pub();
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let all_priv = !all_pub;
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let msg = "mixed usage of pub and non-pub fields";
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for field in fields {
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if all_priv && field.vis.kind.is_pub() {
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span_lint_and_help(
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cx,
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PARTIAL_PUB_FIELDS,
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field.vis.span,
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msg,
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None,
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"consider using private field here",
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);
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return;
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} else if all_pub && !field.vis.kind.is_pub() {
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span_lint_and_help(
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cx,
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PARTIAL_PUB_FIELDS,
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field.vis.span,
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msg,
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None,
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"consider using public field here",
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);
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return;
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}
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}
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}
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}
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