62 lines
2.2 KiB
Rust
62 lines
2.2 KiB
Rust
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//! lint on `use`ing all variants of an enum
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use rustc::lint::{LateLintPass, LintPass, LateContext, LintArray, LintContext};
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use rustc_front::hir::*;
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use rustc::front::map::Node::NodeItem;
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use rustc::front::map::PathElem::PathName;
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use rustc::middle::ty::TyEnum;
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use utils::span_lint;
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use syntax::codemap::Span;
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use syntax::ast::NodeId;
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/// **What it does:** Warns when `use`ing all variants of an enum
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///
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/// **Why is this bad?** It is usually better style to use the prefixed name of an enum variant, rather than importing variants
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///
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/// **Known problems:** Old-style enums that prefix the variants are still around
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///
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/// **Example:** `use std::cmp::Ordering::*;`
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declare_lint! { pub ENUM_GLOB_USE, Allow,
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"finds use items that import all variants of an enum" }
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pub struct EnumGlobUse;
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impl LintPass for EnumGlobUse {
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fn get_lints(&self) -> LintArray {
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lint_array!(ENUM_GLOB_USE)
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}
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}
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impl LateLintPass for EnumGlobUse {
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fn check_mod(&mut self, cx: &LateContext, m: &Mod, _: Span, _: NodeId) {
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// only check top level `use` statements
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for item in &m.item_ids {
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self.lint_item(cx, cx.krate.item(item.id));
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}
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}
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}
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impl EnumGlobUse {
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fn lint_item(&self, cx: &LateContext, item: &Item) {
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if item.vis == Visibility::Public {
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return; // re-exports are fine
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}
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if let ItemUse(ref item_use) = item.node {
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if let ViewPath_::ViewPathGlob(_) = item_use.node {
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let def = cx.tcx.def_map.borrow()[&item.id];
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if let Some(NodeItem(it)) = cx.tcx.map.get_if_local(def.def_id()) {
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if let ItemEnum(..) = it.node {
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span_lint(cx, ENUM_GLOB_USE, item.span, "don't use glob imports for enum variants");
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}
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} else {
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if let Some(&PathName(_)) = cx.sess().cstore.item_path(def.def_id()).last() {
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if let TyEnum(..) = cx.sess().cstore.item_type(&cx.tcx, def.def_id()).ty.sty {
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span_lint(cx, ENUM_GLOB_USE, item.span, "don't use glob imports for enum variants");
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}
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}
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}
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}
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}
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}
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}
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