1 use crate::utils::{match_def_path, match_type, paths, span_help_and_lint, span_lint, walk_ptrs_ty};
2 use if_chain::if_chain;
4 use rustc::hir::def::{DefKind, Res};
5 use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
7 use rustc::lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintArray, LintPass};
8 use rustc::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
9 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
10 use syntax::ast::{Crate as AstCrate, ItemKind, Name};
11 use syntax::source_map::Span;
12 use syntax_pos::symbol::LocalInternedString;
14 declare_clippy_lint! {
15 /// **What it does:** Checks for various things we like to keep tidy in clippy.
17 /// **Why is this bad?** We like to pretend we're an example of tidy code.
19 /// **Known problems:** None.
21 /// **Example:** Wrong ordering of the util::paths constants.
22 pub CLIPPY_LINTS_INTERNAL,
24 "various things that will negatively affect your clippy experience"
27 declare_clippy_lint! {
28 /// **What it does:** Ensures every lint is associated to a `LintPass`.
30 /// **Why is this bad?** The compiler only knows lints via a `LintPass`. Without
31 /// putting a lint to a `LintPass::get_lints()`'s return, the compiler will not
32 /// know the name of the lint.
34 /// **Known problems:** Only checks for lints associated using the
35 /// `declare_lint_pass!`, `impl_lint_pass!`, and `lint_array!` macros.
39 /// declare_lint! { pub LINT_1, ... }
40 /// declare_lint! { pub LINT_2, ... }
41 /// declare_lint! { pub FORGOTTEN_LINT, ... }
43 /// declare_lint_pass!(Pass => [LINT_1, LINT_2]);
44 /// // missing FORGOTTEN_LINT
46 pub LINT_WITHOUT_LINT_PASS,
48 "declaring a lint without associating it in a LintPass"
51 declare_clippy_lint! {
52 /// **What it does:** Checks for calls to `cx.span_lint*` and suggests to use the `utils::*`
53 /// variant of the function.
55 /// **Why is this bad?** The `utils::*` variants also add a link to the Clippy documentation to the
56 /// warning/error messages.
58 /// **Known problems:** None.
63 /// cx.span_lint(LINT_NAME, "message");
68 /// utils::span_lint(cx, LINT_NAME, "message");
70 pub COMPILER_LINT_FUNCTIONS,
72 "usage of the lint functions of the compiler instead of the utils::* variant"
75 declare_lint_pass!(ClippyLintsInternal => [CLIPPY_LINTS_INTERNAL]);
77 impl EarlyLintPass for ClippyLintsInternal {
78 fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &AstCrate) {
79 if let Some(utils) = krate
83 .find(|item| item.ident.name.as_str() == "utils")
85 if let ItemKind::Mod(ref utils_mod) = utils.node {
86 if let Some(paths) = utils_mod.items.iter().find(|item| item.ident.name.as_str() == "paths") {
87 if let ItemKind::Mod(ref paths_mod) = paths.node {
88 let mut last_name: Option<LocalInternedString> = None;
89 for item in &*paths_mod.items {
90 let name = item.ident.as_str();
91 if let Some(ref last_name) = last_name {
92 if **last_name > *name {
95 CLIPPY_LINTS_INTERNAL,
97 "this constant should be before the previous constant due to lexical \
102 last_name = Some(name);
111 #[derive(Clone, Debug, Default)]
112 pub struct LintWithoutLintPass {
113 declared_lints: FxHashMap<Name, Span>,
114 registered_lints: FxHashSet<Name>,
117 impl_lint_pass!(LintWithoutLintPass => [LINT_WITHOUT_LINT_PASS]);
119 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LintWithoutLintPass {
120 fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
121 if let hir::ItemKind::Static(ref ty, MutImmutable, _) = item.node {
122 if is_lint_ref_type(cx, ty) {
123 self.declared_lints.insert(item.ident.name, item.span);
125 } else if let hir::ItemKind::Impl(.., Some(ref trait_ref), _, ref impl_item_refs) = item.node {
127 if let hir::TraitRef{path, ..} = trait_ref;
128 if let Res::Def(DefKind::Trait, def_id) = path.res;
129 if match_def_path(cx, def_id, &paths::LINT_PASS);
131 let mut collector = LintCollector {
132 output: &mut self.registered_lints,
135 let body_id = cx.tcx.hir().body_owned_by(
138 .find(|iiref| iiref.ident.as_str() == "get_lints")
139 .expect("LintPass needs to implement get_lints")
142 collector.visit_expr(&cx.tcx.hir().body(body_id).value);
148 fn check_crate_post(&mut self, cx: &LateContext<'a, 'tcx>, _: &'tcx Crate) {
149 for (lint_name, &lint_span) in &self.declared_lints {
150 // When using the `declare_tool_lint!` macro, the original `lint_span`'s
151 // file points to "<rustc macros>".
152 // `compiletest-rs` thinks that's an error in a different file and
153 // just ignores it. This causes the test in compile-fail/lint_pass
154 // not able to capture the error.
155 // Therefore, we need to climb the macro expansion tree and find the
156 // actual span that invoked `declare_tool_lint!`:
157 let lint_span = lint_span
160 .map(|ei| ei.call_site)
161 .expect("unable to get call_site");
163 if !self.registered_lints.contains(lint_name) {
166 LINT_WITHOUT_LINT_PASS,
168 &format!("the lint `{}` is not added to any `LintPass`", lint_name),
175 fn is_lint_ref_type<'tcx>(cx: &LateContext<'_, 'tcx>, ty: &Ty) -> bool {
184 if let TyKind::Path(ref path) = inner.node {
185 if let Res::Def(DefKind::Struct, def_id) = cx.tables.qpath_res(path, inner.hir_id) {
186 return match_def_path(cx, def_id, &paths::LINT);
194 struct LintCollector<'a, 'tcx: 'a> {
195 output: &'a mut FxHashSet<Name>,
196 cx: &'a LateContext<'a, 'tcx>,
199 impl<'a, 'tcx: 'a> Visitor<'tcx> for LintCollector<'a, 'tcx> {
200 fn visit_expr(&mut self, expr: &'tcx Expr) {
201 walk_expr(self, expr);
204 fn visit_path(&mut self, path: &'tcx Path, _: HirId) {
205 if path.segments.len() == 1 {
206 self.output.insert(path.segments[0].ident.name);
209 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
210 NestedVisitorMap::All(&self.cx.tcx.hir())
214 #[derive(Clone, Default)]
215 pub struct CompilerLintFunctions {
216 map: FxHashMap<&'static str, &'static str>,
219 impl CompilerLintFunctions {
220 pub fn new() -> Self {
221 let mut map = FxHashMap::default();
222 map.insert("span_lint", "utils::span_lint");
223 map.insert("struct_span_lint", "utils::span_lint");
224 map.insert("lint", "utils::span_lint");
225 map.insert("span_lint_note", "utils::span_note_and_lint");
226 map.insert("span_lint_help", "utils::span_help_and_lint");
231 impl_lint_pass!(CompilerLintFunctions => [COMPILER_LINT_FUNCTIONS]);
233 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CompilerLintFunctions {
234 fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
236 if let ExprKind::MethodCall(ref path, _, ref args) = expr.node;
237 let fn_name = path.ident;
238 if let Some(sugg) = self.map.get(&*fn_name.as_str());
239 let ty = walk_ptrs_ty(cx.tables.expr_ty(&args[0]));
240 if match_type(cx, ty, &paths::EARLY_CONTEXT)
241 || match_type(cx, ty, &paths::LATE_CONTEXT);
245 COMPILER_LINT_FUNCTIONS,
247 "usage of a compiler lint function",
248 &format!("please use the Clippy variant of this function: `{}`", sugg),