74 lines
2.4 KiB
Rust
74 lines
2.4 KiB
Rust
//! lint on `use`ing all variants of an enum
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use rustc::hir::*;
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use rustc::hir::def::Def;
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use rustc::hir::map::Node::NodeItem;
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use rustc::lint::{LateLintPass, LintPass, LateContext, LintArray, LintContext};
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use rustc::middle::cstore::DefLike;
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use syntax::ast::NodeId;
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use syntax::codemap::Span;
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use utils::span_lint;
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/// **What it does:** Checks for `use Enum::*`.
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///
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/// **Why is this bad?** It is usually better style to use the prefixed name of
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/// an enumeration variant, rather than importing variants.
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///
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/// **Known problems:** Old-style enumerations that prefix the variants are
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/// still around.
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///
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/// **Example:**
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/// ```rust
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/// use std::cmp::Ordering::*;
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/// ```
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declare_lint! {
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pub ENUM_GLOB_USE,
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Allow,
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"use items that import all variants of an enum"
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}
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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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if let Some(def) = cx.tcx.def_map.borrow().get(&item.id) {
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if let Some(node_id) = cx.tcx.map.as_local_node_id(def.full_def().def_id()) {
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if let Some(NodeItem(it)) = cx.tcx.map.find(node_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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}
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} else {
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let child = cx.sess().cstore.item_children(def.full_def().def_id());
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if let Some(child) = child.first() {
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if let DefLike::DlDef(Def::Variant(..)) = child.def {
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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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}
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