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Commit | Line | Data |
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c34b1796 AL |
1 | //! Lints in the Rust compiler. |
2 | //! | |
3 | //! This contains lints which can feasibly be implemented as their own | |
ba9703b0 XL |
4 | //! AST visitor. Also see `rustc_session::lint::builtin`, which contains the |
5 | //! definitions of lints that are emitted directly inside the main compiler. | |
c34b1796 AL |
6 | //! |
7 | //! To add a new lint to rustc, declare it here using `declare_lint!()`. | |
8 | //! Then add code to emit the new lint in the appropriate circumstances. | |
9 | //! You can do that in an existing `LintPass` if it makes sense, or in a | |
10 | //! new `LintPass`, or using `Session::add_lint` elsewhere in the | |
11 | //! compiler. Only do the latter if the check can't be written cleanly as a | |
12 | //! `LintPass` (also, note that such lints will need to be defined in | |
ba9703b0 | 13 | //! `rustc_session::lint::builtin`, not here). |
c34b1796 | 14 | //! |
9fa01778 XL |
15 | //! If you define a new `EarlyLintPass`, you will also need to add it to the |
16 | //! `add_early_builtin!` or `add_early_builtin_with_new!` invocation in | |
17 | //! `lib.rs`. Use the former for unit-like structs and the latter for structs | |
18 | //! with a `pub fn new()`. | |
19 | //! | |
20 | //! If you define a new `LateLintPass`, you will also need to add it to the | |
21 | //! `late_lint_methods!` invocation in `lib.rs`. | |
c34b1796 | 22 | |
9ffffee4 | 23 | use crate::fluent_generated as fluent; |
3dfed10e | 24 | use crate::{ |
49aad941 | 25 | errors::BuiltinEllipsisInclusiveRangePatterns, |
9c376795 | 26 | lints::{ |
add651ee FG |
27 | BuiltinAnonymousParams, BuiltinBoxPointers, BuiltinConstNoMangle, |
28 | BuiltinDeprecatedAttrLink, BuiltinDeprecatedAttrLinkSuggestion, BuiltinDeprecatedAttrUsed, | |
29 | BuiltinDerefNullptr, BuiltinEllipsisInclusiveRangePatternsLint, BuiltinExplicitOutlives, | |
30 | BuiltinExplicitOutlivesSuggestion, BuiltinFeatureIssueNote, BuiltinIncompleteFeatures, | |
31 | BuiltinIncompleteFeaturesHelp, BuiltinInternalFeatures, BuiltinKeywordIdents, | |
9c376795 FG |
32 | BuiltinMissingCopyImpl, BuiltinMissingDebugImpl, BuiltinMissingDoc, |
33 | BuiltinMutablesTransmutes, BuiltinNoMangleGeneric, BuiltinNonShorthandFieldPatterns, | |
34 | BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds, BuiltinTypeAliasGenericBounds, | |
35 | BuiltinTypeAliasGenericBoundsSuggestion, BuiltinTypeAliasWhereClause, | |
add651ee | 36 | BuiltinUngatedAsyncFnTrackCaller, BuiltinUnpermittedTypeInit, |
9c376795 FG |
37 | BuiltinUnpermittedTypeInitSub, BuiltinUnreachablePub, BuiltinUnsafe, |
38 | BuiltinUnstableFeatures, BuiltinUnusedDocComment, BuiltinUnusedDocCommentSub, | |
39 | BuiltinWhileTrue, SuggestChangingAssocTypes, | |
40 | }, | |
add651ee | 41 | EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext, |
3dfed10e | 42 | }; |
74b04a01 XL |
43 | use rustc_ast::tokenstream::{TokenStream, TokenTree}; |
44 | use rustc_ast::visit::{FnCtxt, FnKind}; | |
3dfed10e | 45 | use rustc_ast::{self as ast, *}; |
74b04a01 | 46 | use rustc_ast_pretty::pprust::{self, expr_to_string}; |
c620b35d | 47 | use rustc_errors::{Applicability, LintDiagnostic, MultiSpan}; |
3c0e092e | 48 | use rustc_feature::{deprecated_attributes, AttributeGate, BuiltinAttribute, GateIssue, Stability}; |
dfeec247 XL |
49 | use rustc_hir as hir; |
50 | use rustc_hir::def::{DefKind, Res}; | |
add651ee | 51 | use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID}; |
487cf647 | 52 | use rustc_hir::intravisit::FnKind as HirFnKind; |
add651ee | 53 | use rustc_hir::{Body, FnDecl, GenericParamKind, Node, PatKind, PredicateOrigin}; |
064997fb | 54 | use rustc_middle::lint::in_external_macro; |
add651ee | 55 | use rustc_middle::ty::layout::LayoutOf; |
1b1a35ee | 56 | use rustc_middle::ty::print::with_no_trimmed_paths; |
add651ee FG |
57 | use rustc_middle::ty::GenericArgKind; |
58 | use rustc_middle::ty::ToPredicate; | |
49aad941 | 59 | use rustc_middle::ty::TypeVisitableExt; |
add651ee | 60 | use rustc_middle::ty::{self, Ty, TyCtxt, VariantDef}; |
c620b35d | 61 | use rustc_session::lint::{BuiltinLintDiag, FutureIncompatibilityReason}; |
dfeec247 XL |
62 | use rustc_span::edition::Edition; |
63 | use rustc_span::source_map::Spanned; | |
f9f354fc | 64 | use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
04454e1e | 65 | use rustc_span::{BytePos, InnerSpan, Span}; |
add651ee | 66 | use rustc_target::abi::Abi; |
9c376795 | 67 | use rustc_trait_selection::infer::{InferCtxtExt, TyCtxtInferExt}; |
add651ee | 68 | use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; |
9c376795 | 69 | use rustc_trait_selection::traits::{self, misc::type_allowed_to_implement_copy}; |
e9174d1e | 70 | |
dfeec247 | 71 | use crate::nonstandard_style::{method_context, MethodLateContext}; |
9fa01778 | 72 | |
dfeec247 | 73 | use std::fmt::Write; |
c34b1796 | 74 | |
c620b35d | 75 | // hardwired lints from rustc_lint_defs |
dfeec247 | 76 | pub use rustc_session::lint::builtin::*; |
c34b1796 | 77 | |
b039eaaf | 78 | declare_lint! { |
1b1a35ee XL |
79 | /// The `while_true` lint detects `while true { }`. |
80 | /// | |
81 | /// ### Example | |
82 | /// | |
83 | /// ```rust,no_run | |
84 | /// while true { | |
85 | /// | |
86 | /// } | |
87 | /// ``` | |
88 | /// | |
89 | /// {{produces}} | |
90 | /// | |
91 | /// ### Explanation | |
92 | /// | |
93 | /// `while true` should be replaced with `loop`. A `loop` expression is | |
94 | /// the preferred way to write an infinite loop because it more directly | |
95 | /// expresses the intent of the loop. | |
b039eaaf SL |
96 | WHILE_TRUE, |
97 | Warn, | |
98 | "suggest using `loop { }` instead of `while true { }`" | |
99 | } | |
c34b1796 | 100 | |
532ac7d7 | 101 | declare_lint_pass!(WhileTrue => [WHILE_TRUE]); |
c34b1796 | 102 | |
416331ca XL |
103 | /// Traverse through any amount of parenthesis and return the first non-parens expression. |
104 | fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr { | |
e74abb32 | 105 | while let ast::ExprKind::Paren(sub) = &expr.kind { |
416331ca XL |
106 | expr = sub; |
107 | } | |
108 | expr | |
109 | } | |
110 | ||
111 | impl EarlyLintPass for WhileTrue { | |
9c376795 | 112 | #[inline] |
416331ca | 113 | fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { |
2b03887a | 114 | if let ast::ExprKind::While(cond, _, label) = &e.kind |
49aad941 | 115 | && let ast::ExprKind::Lit(token_lit) = pierce_parens(cond).kind |
487cf647 FG |
116 | && let token::Lit { kind: token::Bool, symbol: kw::True, .. } = token_lit |
117 | && !cond.span.from_expansion() | |
2b03887a FG |
118 | { |
119 | let condition_span = e.span.with_hi(cond.span.hi()); | |
9c376795 | 120 | let replace = format!( |
ed00b5ec FG |
121 | "{}loop", |
122 | label.map_or_else(String::new, |label| format!("{}: ", label.ident,)) | |
123 | ); | |
c0240ec0 | 124 | cx.emit_span_lint( |
ed00b5ec FG |
125 | WHILE_TRUE, |
126 | condition_span, | |
127 | BuiltinWhileTrue { suggestion: condition_span, replace }, | |
128 | ); | |
c34b1796 AL |
129 | } |
130 | } | |
131 | } | |
132 | ||
133 | declare_lint! { | |
1b1a35ee XL |
134 | /// The `box_pointers` lints use of the Box type. |
135 | /// | |
136 | /// ### Example | |
137 | /// | |
138 | /// ```rust,compile_fail | |
139 | /// #![deny(box_pointers)] | |
140 | /// struct Foo { | |
141 | /// x: Box<isize>, | |
142 | /// } | |
143 | /// ``` | |
144 | /// | |
145 | /// {{produces}} | |
146 | /// | |
147 | /// ### Explanation | |
148 | /// | |
149 | /// This lint is mostly historical, and not particularly useful. `Box<T>` | |
150 | /// used to be built into the language, and the only way to do heap | |
151 | /// allocation. Today's Rust can call into other allocators, etc. | |
b039eaaf SL |
152 | BOX_POINTERS, |
153 | Allow, | |
154 | "use of owned (Box type) heap memory" | |
c34b1796 AL |
155 | } |
156 | ||
532ac7d7 | 157 | declare_lint_pass!(BoxPointers => [BOX_POINTERS]); |
b039eaaf SL |
158 | |
159 | impl BoxPointers { | |
5099ac24 FG |
160 | fn check_heap_type(&self, cx: &LateContext<'_>, span: Span, ty: Ty<'_>) { |
161 | for leaf in ty.walk() { | |
ed00b5ec FG |
162 | if let GenericArgKind::Type(leaf_ty) = leaf.unpack() |
163 | && leaf_ty.is_box() | |
164 | { | |
c0240ec0 | 165 | cx.emit_span_lint(BOX_POINTERS, span, BuiltinBoxPointers { ty }); |
c34b1796 AL |
166 | } |
167 | } | |
168 | } | |
169 | } | |
170 | ||
f035d41b XL |
171 | impl<'tcx> LateLintPass<'tcx> for BoxPointers { |
172 | fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { | |
e74abb32 | 173 | match it.kind { |
dfeec247 XL |
174 | hir::ItemKind::Fn(..) |
175 | | hir::ItemKind::TyAlias(..) | |
176 | | hir::ItemKind::Enum(..) | |
177 | | hir::ItemKind::Struct(..) | |
add651ee FG |
178 | | hir::ItemKind::Union(..) => self.check_heap_type( |
179 | cx, | |
180 | it.span, | |
181 | cx.tcx.type_of(it.owner_id).instantiate_identity(), | |
182 | ), | |
dfeec247 | 183 | _ => (), |
d9579d0f | 184 | } |
d9579d0f | 185 | |
b039eaaf | 186 | // If it's a struct, we also have to check the fields' types |
e74abb32 | 187 | match it.kind { |
dfeec247 | 188 | hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => { |
487cf647 | 189 | for field in struct_def.fields() { |
9ffffee4 FG |
190 | self.check_heap_type( |
191 | cx, | |
192 | field.span, | |
add651ee | 193 | cx.tcx.type_of(field.def_id).instantiate_identity(), |
9ffffee4 | 194 | ); |
b039eaaf | 195 | } |
d9579d0f | 196 | } |
c30ab7b3 | 197 | _ => (), |
d9579d0f AL |
198 | } |
199 | } | |
200 | ||
f035d41b | 201 | fn check_expr(&mut self, cx: &LateContext<'_>, e: &hir::Expr<'_>) { |
3dfed10e | 202 | let ty = cx.typeck_results().node_type(e.hir_id); |
b039eaaf | 203 | self.check_heap_type(cx, e.span, ty); |
c34b1796 AL |
204 | } |
205 | } | |
206 | ||
c34b1796 | 207 | declare_lint! { |
1b1a35ee XL |
208 | /// The `non_shorthand_field_patterns` lint detects using `Struct { x: x }` |
209 | /// instead of `Struct { x }` in a pattern. | |
210 | /// | |
211 | /// ### Example | |
212 | /// | |
213 | /// ```rust | |
214 | /// struct Point { | |
215 | /// x: i32, | |
216 | /// y: i32, | |
217 | /// } | |
218 | /// | |
219 | /// | |
220 | /// fn main() { | |
221 | /// let p = Point { | |
222 | /// x: 5, | |
223 | /// y: 5, | |
224 | /// }; | |
225 | /// | |
226 | /// match p { | |
227 | /// Point { x: x, y: y } => (), | |
228 | /// } | |
229 | /// } | |
230 | /// ``` | |
231 | /// | |
232 | /// {{produces}} | |
233 | /// | |
234 | /// ### Explanation | |
235 | /// | |
236 | /// The preferred style is to avoid the repetition of specifying both the | |
237 | /// field name and the binding name if both identifiers are the same. | |
c34b1796 AL |
238 | NON_SHORTHAND_FIELD_PATTERNS, |
239 | Warn, | |
abe05a73 | 240 | "using `Struct { x: x }` instead of `Struct { x }` in a pattern" |
c34b1796 AL |
241 | } |
242 | ||
532ac7d7 | 243 | declare_lint_pass!(NonShorthandFieldPatterns => [NON_SHORTHAND_FIELD_PATTERNS]); |
c34b1796 | 244 | |
f035d41b XL |
245 | impl<'tcx> LateLintPass<'tcx> for NonShorthandFieldPatterns { |
246 | fn check_pat(&mut self, cx: &LateContext<'_>, pat: &hir::Pat<'_>) { | |
dfeec247 XL |
247 | if let PatKind::Struct(ref qpath, field_pats, _) = pat.kind { |
248 | let variant = cx | |
3dfed10e | 249 | .typeck_results() |
dfeec247 XL |
250 | .pat_ty(pat) |
251 | .ty_adt_def() | |
252 | .expect("struct pattern type is not an ADT") | |
f035d41b | 253 | .variant_of_res(cx.qpath_res(qpath, pat.hir_id)); |
3157f602 | 254 | for fieldpat in field_pats { |
e1599b0c | 255 | if fieldpat.is_shorthand { |
3157f602 | 256 | continue; |
b039eaaf | 257 | } |
e1599b0c | 258 | if fieldpat.span.from_expansion() { |
83c7162d XL |
259 | // Don't lint if this is a macro expansion: macro authors |
260 | // shouldn't have to worry about this kind of style issue | |
261 | // (Issue #49588) | |
262 | continue; | |
263 | } | |
dfeec247 | 264 | if let PatKind::Binding(binding_annot, _, ident, None) = fieldpat.pat.kind { |
4b012472 | 265 | if cx.tcx.find_field_index(ident, variant) |
487cf647 | 266 | == Some(cx.typeck_results().field_index(fieldpat.hir_id)) |
dfeec247 | 267 | { |
c0240ec0 | 268 | cx.emit_span_lint( |
2b03887a FG |
269 | NON_SHORTHAND_FIELD_PATTERNS, |
270 | fieldpat.span, | |
9c376795 FG |
271 | BuiltinNonShorthandFieldPatterns { |
272 | ident, | |
273 | suggestion: fieldpat.span, | |
274 | prefix: binding_annot.prefix_str(), | |
2b03887a FG |
275 | }, |
276 | ); | |
c34b1796 AL |
277 | } |
278 | } | |
279 | } | |
280 | } | |
281 | } | |
282 | } | |
283 | ||
c34b1796 | 284 | declare_lint! { |
fe692bf9 FG |
285 | /// The `unsafe_code` lint catches usage of `unsafe` code and other |
286 | /// potentially unsound constructs like `no_mangle`, `export_name`, | |
287 | /// and `link_section`. | |
1b1a35ee XL |
288 | /// |
289 | /// ### Example | |
290 | /// | |
291 | /// ```rust,compile_fail | |
292 | /// #![deny(unsafe_code)] | |
293 | /// fn main() { | |
294 | /// unsafe { | |
295 | /// | |
296 | /// } | |
297 | /// } | |
fe692bf9 FG |
298 | /// |
299 | /// #[no_mangle] | |
300 | /// fn func_0() { } | |
301 | /// | |
302 | /// #[export_name = "exported_symbol_name"] | |
303 | /// pub fn name_in_rust() { } | |
304 | /// | |
305 | /// #[no_mangle] | |
306 | /// #[link_section = ".example_section"] | |
307 | /// pub static VAR1: u32 = 1; | |
1b1a35ee XL |
308 | /// ``` |
309 | /// | |
310 | /// {{produces}} | |
311 | /// | |
312 | /// ### Explanation | |
313 | /// | |
fe692bf9 FG |
314 | /// This lint is intended to restrict the usage of `unsafe` blocks and other |
315 | /// constructs (including, but not limited to `no_mangle`, `link_section` | |
316 | /// and `export_name` attributes) wrong usage of which causes undefined | |
317 | /// behavior. | |
c34b1796 AL |
318 | UNSAFE_CODE, |
319 | Allow, | |
fe692bf9 | 320 | "usage of `unsafe` code and other potentially unsound constructs" |
c34b1796 AL |
321 | } |
322 | ||
532ac7d7 | 323 | declare_lint_pass!(UnsafeCode => [UNSAFE_CODE]); |
c34b1796 | 324 | |
3b2f2976 | 325 | impl UnsafeCode { |
74b04a01 XL |
326 | fn report_unsafe( |
327 | &self, | |
328 | cx: &EarlyContext<'_>, | |
329 | span: Span, | |
c620b35d | 330 | decorate: impl for<'a> LintDiagnostic<'a, ()>, |
74b04a01 | 331 | ) { |
dc9dc135 | 332 | // This comes from a macro that has `#[allow_internal_unsafe]`. |
3b2f2976 XL |
333 | if span.allows_unsafe() { |
334 | return; | |
335 | } | |
336 | ||
c0240ec0 | 337 | cx.emit_span_lint(UNSAFE_CODE, span, decorate); |
923072b8 | 338 | } |
3b2f2976 XL |
339 | } |
340 | ||
0731742a | 341 | impl EarlyLintPass for UnsafeCode { |
9fa01778 | 342 | fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) { |
94222f64 | 343 | if attr.has_name(sym::allow_internal_unsafe) { |
9c376795 | 344 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::AllowInternalUnsafe); |
0731742a XL |
345 | } |
346 | } | |
347 | ||
9c376795 | 348 | #[inline] |
9fa01778 | 349 | fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { |
e74abb32 | 350 | if let ast::ExprKind::Block(ref blk, _) = e.kind { |
dc9dc135 | 351 | // Don't warn about generated blocks; that'll just pollute the output. |
0731742a | 352 | if blk.rules == ast::BlockCheckMode::Unsafe(ast::UserProvided) { |
9c376795 | 353 | self.report_unsafe(cx, blk.span, BuiltinUnsafe::UnsafeBlock); |
c34b1796 AL |
354 | } |
355 | } | |
356 | } | |
357 | ||
9fa01778 | 358 | fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) { |
e74abb32 | 359 | match it.kind { |
2b03887a | 360 | ast::ItemKind::Trait(box ast::Trait { unsafety: ast::Unsafe::Yes(_), .. }) => { |
9c376795 | 361 | self.report_unsafe(cx, it.span, BuiltinUnsafe::UnsafeTrait); |
2b03887a | 362 | } |
c34b1796 | 363 | |
2b03887a | 364 | ast::ItemKind::Impl(box ast::Impl { unsafety: ast::Unsafe::Yes(_), .. }) => { |
9c376795 | 365 | self.report_unsafe(cx, it.span, BuiltinUnsafe::UnsafeImpl); |
2b03887a | 366 | } |
c34b1796 | 367 | |
6a06907d | 368 | ast::ItemKind::Fn(..) => { |
353b0b11 | 369 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::no_mangle) { |
9c376795 | 370 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::NoMangleFn); |
6a06907d | 371 | } |
923072b8 | 372 | |
353b0b11 | 373 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::export_name) { |
9c376795 | 374 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::ExportNameFn); |
6a06907d | 375 | } |
923072b8 | 376 | |
353b0b11 | 377 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::link_section) { |
9c376795 | 378 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::LinkSectionFn); |
923072b8 | 379 | } |
6a06907d XL |
380 | } |
381 | ||
382 | ast::ItemKind::Static(..) => { | |
353b0b11 | 383 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::no_mangle) { |
9c376795 | 384 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::NoMangleStatic); |
6a06907d | 385 | } |
923072b8 | 386 | |
353b0b11 | 387 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::export_name) { |
9c376795 | 388 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::ExportNameStatic); |
6a06907d | 389 | } |
923072b8 | 390 | |
353b0b11 | 391 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::link_section) { |
9c376795 | 392 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::LinkSectionStatic); |
923072b8 | 393 | } |
6a06907d XL |
394 | } |
395 | ||
c620b35d FG |
396 | ast::ItemKind::GlobalAsm(..) => { |
397 | self.report_unsafe(cx, it.span, BuiltinUnsafe::GlobalAsm); | |
398 | } | |
399 | ||
ba9703b0 | 400 | _ => {} |
c34b1796 AL |
401 | } |
402 | } | |
403 | ||
94222f64 XL |
404 | fn check_impl_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) { |
405 | if let ast::AssocItemKind::Fn(..) = it.kind { | |
353b0b11 | 406 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::no_mangle) { |
9c376795 | 407 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::NoMangleMethod); |
94222f64 | 408 | } |
353b0b11 | 409 | if let Some(attr) = attr::find_by_name(&it.attrs, sym::export_name) { |
9c376795 | 410 | self.report_unsafe(cx, attr.span, BuiltinUnsafe::ExportNameMethod); |
94222f64 XL |
411 | } |
412 | } | |
413 | } | |
414 | ||
74b04a01 XL |
415 | fn check_fn(&mut self, cx: &EarlyContext<'_>, fk: FnKind<'_>, span: Span, _: ast::NodeId) { |
416 | if let FnKind::Fn( | |
417 | ctxt, | |
418 | _, | |
419 | ast::FnSig { header: ast::FnHeader { unsafety: ast::Unsafe::Yes(_), .. }, .. }, | |
420 | _, | |
04454e1e | 421 | _, |
74b04a01 XL |
422 | body, |
423 | ) = fk | |
424 | { | |
9c376795 | 425 | let decorator = match ctxt { |
74b04a01 | 426 | FnCtxt::Foreign => return, |
9c376795 FG |
427 | FnCtxt::Free => BuiltinUnsafe::DeclUnsafeFn, |
428 | FnCtxt::Assoc(_) if body.is_none() => BuiltinUnsafe::DeclUnsafeMethod, | |
429 | FnCtxt::Assoc(_) => BuiltinUnsafe::ImplUnsafeMethod, | |
74b04a01 | 430 | }; |
9c376795 | 431 | self.report_unsafe(cx, span, decorator); |
c34b1796 AL |
432 | } |
433 | } | |
434 | } | |
435 | ||
c34b1796 | 436 | declare_lint! { |
1b1a35ee XL |
437 | /// The `missing_docs` lint detects missing documentation for public items. |
438 | /// | |
439 | /// ### Example | |
440 | /// | |
441 | /// ```rust,compile_fail | |
442 | /// #![deny(missing_docs)] | |
443 | /// pub fn foo() {} | |
444 | /// ``` | |
445 | /// | |
446 | /// {{produces}} | |
447 | /// | |
448 | /// ### Explanation | |
449 | /// | |
450 | /// This lint is intended to ensure that a library is well-documented. | |
451 | /// Items without documentation can be difficult for users to understand | |
452 | /// how to use properly. | |
453 | /// | |
454 | /// This lint is "allow" by default because it can be noisy, and not all | |
455 | /// projects may want to enforce everything to be documented. | |
94b46f34 | 456 | pub MISSING_DOCS, |
c34b1796 | 457 | Allow, |
8faf50e0 | 458 | "detects missing documentation for public members", |
e74abb32 | 459 | report_in_external_macro |
c34b1796 AL |
460 | } |
461 | ||
add651ee | 462 | pub struct MissingDoc; |
c34b1796 | 463 | |
532ac7d7 XL |
464 | impl_lint_pass!(MissingDoc => [MISSING_DOCS]); |
465 | ||
94222f64 | 466 | fn has_doc(attr: &ast::Attribute) -> bool { |
dfeec247 XL |
467 | if attr.is_doc_comment() { |
468 | return true; | |
469 | } | |
470 | ||
94222f64 | 471 | if !attr.has_name(sym::doc) { |
0731742a XL |
472 | return false; |
473 | } | |
474 | ||
cdc7bbd5 | 475 | if attr.value_str().is_some() { |
0731742a XL |
476 | return true; |
477 | } | |
478 | ||
479 | if let Some(list) = attr.meta_item_list() { | |
480 | for meta in list { | |
17df50a5 | 481 | if meta.has_name(sym::hidden) { |
0731742a XL |
482 | return true; |
483 | } | |
484 | } | |
485 | } | |
486 | ||
487 | false | |
488 | } | |
489 | ||
c34b1796 | 490 | impl MissingDoc { |
dfeec247 XL |
491 | fn check_missing_docs_attrs( |
492 | &self, | |
f035d41b | 493 | cx: &LateContext<'_>, |
94222f64 | 494 | def_id: LocalDefId, |
ba9703b0 | 495 | article: &'static str, |
dfeec247 XL |
496 | desc: &'static str, |
497 | ) { | |
c34b1796 AL |
498 | // If we're building a test harness, then warning about |
499 | // documentation is probably not really relevant right now. | |
500 | if cx.sess().opts.test { | |
501 | return; | |
502 | } | |
503 | ||
c34b1796 AL |
504 | // Only check publicly-visible items, using the result from the privacy pass. |
505 | // It's an option so the crate root can also use this function (it doesn't | |
dc9dc135 | 506 | // have a `NodeId`). |
94222f64 | 507 | if def_id != CRATE_DEF_ID { |
2b03887a | 508 | if !cx.effective_visibilities.is_exported(def_id) { |
c34b1796 AL |
509 | return; |
510 | } | |
511 | } | |
512 | ||
4b012472 | 513 | let attrs = cx.tcx.hir().attrs(cx.tcx.local_def_id_to_hir_id(def_id)); |
94222f64 | 514 | let has_doc = attrs.iter().any(has_doc); |
c34b1796 | 515 | if !has_doc { |
c0240ec0 | 516 | cx.emit_span_lint( |
2b03887a FG |
517 | MISSING_DOCS, |
518 | cx.tcx.def_span(def_id), | |
9c376795 | 519 | BuiltinMissingDoc { article, desc }, |
2b03887a | 520 | ); |
c34b1796 AL |
521 | } |
522 | } | |
523 | } | |
524 | ||
f035d41b | 525 | impl<'tcx> LateLintPass<'tcx> for MissingDoc { |
c295e0f8 | 526 | fn check_crate(&mut self, cx: &LateContext<'_>) { |
064997fb | 527 | self.check_missing_docs_attrs(cx, CRATE_DEF_ID, "the", "crate"); |
c34b1796 AL |
528 | } |
529 | ||
f035d41b | 530 | fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { |
49aad941 FG |
531 | // Previously the Impl and Use types have been excluded from missing docs, |
532 | // so we will continue to exclude them for compatibility. | |
533 | // | |
534 | // The documentation on `ExternCrate` is not used at the moment so no need to warn for it. | |
535 | if let hir::ItemKind::Impl(..) | hir::ItemKind::Use(..) | hir::ItemKind::ExternCrate(_) = | |
536 | it.kind | |
537 | { | |
538 | return; | |
539 | } | |
c34b1796 | 540 | |
2b03887a | 541 | let (article, desc) = cx.tcx.article_and_description(it.owner_id.to_def_id()); |
2b03887a | 542 | self.check_missing_docs_attrs(cx, it.owner_id.def_id, article, desc); |
c34b1796 AL |
543 | } |
544 | ||
f035d41b | 545 | fn check_trait_item(&mut self, cx: &LateContext<'_>, trait_item: &hir::TraitItem<'_>) { |
2b03887a | 546 | let (article, desc) = cx.tcx.article_and_description(trait_item.owner_id.to_def_id()); |
c34b1796 | 547 | |
2b03887a | 548 | self.check_missing_docs_attrs(cx, trait_item.owner_id.def_id, article, desc); |
c34b1796 AL |
549 | } |
550 | ||
f035d41b | 551 | fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) { |
9ffffee4 FG |
552 | let context = method_context(cx, impl_item.owner_id.def_id); |
553 | ||
554 | match context { | |
555 | // If the method is an impl for a trait, don't doc. | |
556 | MethodLateContext::TraitImpl => return, | |
557 | MethodLateContext::TraitAutoImpl => {} | |
558 | // If the method is an impl for an item with docs_hidden, don't doc. | |
559 | MethodLateContext::PlainImpl => { | |
560 | let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id()); | |
add651ee | 561 | let impl_ty = cx.tcx.type_of(parent).instantiate_identity(); |
9ffffee4 FG |
562 | let outerdef = match impl_ty.kind() { |
563 | ty::Adt(def, _) => Some(def.did()), | |
564 | ty::Foreign(def_id) => Some(*def_id), | |
565 | _ => None, | |
566 | }; | |
567 | let is_hidden = match outerdef { | |
568 | Some(id) => cx.tcx.is_doc_hidden(id), | |
569 | None => false, | |
570 | }; | |
571 | if is_hidden { | |
572 | return; | |
573 | } | |
3c0e092e XL |
574 | } |
575 | } | |
576 | ||
2b03887a FG |
577 | let (article, desc) = cx.tcx.article_and_description(impl_item.owner_id.to_def_id()); |
578 | self.check_missing_docs_attrs(cx, impl_item.owner_id.def_id, article, desc); | |
c34b1796 AL |
579 | } |
580 | ||
1b1a35ee | 581 | fn check_foreign_item(&mut self, cx: &LateContext<'_>, foreign_item: &hir::ForeignItem<'_>) { |
2b03887a FG |
582 | let (article, desc) = cx.tcx.article_and_description(foreign_item.owner_id.to_def_id()); |
583 | self.check_missing_docs_attrs(cx, foreign_item.owner_id.def_id, article, desc); | |
1b1a35ee XL |
584 | } |
585 | ||
6a06907d | 586 | fn check_field_def(&mut self, cx: &LateContext<'_>, sf: &hir::FieldDef<'_>) { |
54a0048b | 587 | if !sf.is_positional() { |
487cf647 | 588 | self.check_missing_docs_attrs(cx, sf.def_id, "a", "struct field") |
c34b1796 AL |
589 | } |
590 | } | |
591 | ||
f035d41b | 592 | fn check_variant(&mut self, cx: &LateContext<'_>, v: &hir::Variant<'_>) { |
487cf647 | 593 | self.check_missing_docs_attrs(cx, v.def_id, "a", "variant"); |
c34b1796 AL |
594 | } |
595 | } | |
596 | ||
597 | declare_lint! { | |
1b1a35ee | 598 | /// The `missing_copy_implementations` lint detects potentially-forgotten |
49aad941 | 599 | /// implementations of [`Copy`] for public types. |
1b1a35ee XL |
600 | /// |
601 | /// [`Copy`]: https://doc.rust-lang.org/std/marker/trait.Copy.html | |
602 | /// | |
603 | /// ### Example | |
604 | /// | |
605 | /// ```rust,compile_fail | |
606 | /// #![deny(missing_copy_implementations)] | |
607 | /// pub struct Foo { | |
608 | /// pub field: i32 | |
609 | /// } | |
610 | /// # fn main() {} | |
611 | /// ``` | |
612 | /// | |
613 | /// {{produces}} | |
614 | /// | |
615 | /// ### Explanation | |
616 | /// | |
617 | /// Historically (before 1.0), types were automatically marked as `Copy` | |
618 | /// if possible. This was changed so that it required an explicit opt-in | |
619 | /// by implementing the `Copy` trait. As part of this change, a lint was | |
620 | /// added to alert if a copyable type was not marked `Copy`. | |
621 | /// | |
622 | /// This lint is "allow" by default because this code isn't bad; it is | |
623 | /// common to write newtypes like this specifically so that a `Copy` type | |
624 | /// is no longer `Copy`. `Copy` types can result in unintended copies of | |
625 | /// large data which can impact performance. | |
c34b1796 AL |
626 | pub MISSING_COPY_IMPLEMENTATIONS, |
627 | Allow, | |
628 | "detects potentially-forgotten implementations of `Copy`" | |
629 | } | |
630 | ||
532ac7d7 | 631 | declare_lint_pass!(MissingCopyImplementations => [MISSING_COPY_IMPLEMENTATIONS]); |
c34b1796 | 632 | |
f035d41b XL |
633 | impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations { |
634 | fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { | |
fe692bf9 | 635 | if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) { |
c34b1796 AL |
636 | return; |
637 | } | |
e74abb32 | 638 | let (def, ty) = match item.kind { |
4b012472 | 639 | hir::ItemKind::Struct(_, ast_generics) => { |
ff7c6d11 | 640 | if !ast_generics.params.is_empty() { |
c34b1796 AL |
641 | return; |
642 | } | |
2b03887a | 643 | let def = cx.tcx.adt_def(item.owner_id); |
fe692bf9 | 644 | (def, Ty::new_adt(cx.tcx, def, ty::List::empty())) |
9e0c209e | 645 | } |
4b012472 | 646 | hir::ItemKind::Union(_, ast_generics) => { |
ff7c6d11 | 647 | if !ast_generics.params.is_empty() { |
9e0c209e SL |
648 | return; |
649 | } | |
2b03887a | 650 | let def = cx.tcx.adt_def(item.owner_id); |
fe692bf9 | 651 | (def, Ty::new_adt(cx.tcx, def, ty::List::empty())) |
c34b1796 | 652 | } |
4b012472 | 653 | hir::ItemKind::Enum(_, ast_generics) => { |
ff7c6d11 | 654 | if !ast_generics.params.is_empty() { |
c34b1796 AL |
655 | return; |
656 | } | |
2b03887a | 657 | let def = cx.tcx.adt_def(item.owner_id); |
fe692bf9 | 658 | (def, Ty::new_adt(cx.tcx, def, ty::List::empty())) |
c34b1796 AL |
659 | } |
660 | _ => return, | |
661 | }; | |
8bb4bdeb | 662 | if def.has_dtor(cx.tcx) { |
c30ab7b3 SL |
663 | return; |
664 | } | |
9c376795 FG |
665 | |
666 | // If the type contains a raw pointer, it may represent something like a handle, | |
667 | // and recommending Copy might be a bad idea. | |
668 | for field in def.all_fields() { | |
669 | let did = field.did; | |
add651ee | 670 | if cx.tcx.type_of(did).instantiate_identity().is_unsafe_ptr() { |
9c376795 FG |
671 | return; |
672 | } | |
673 | } | |
0531ce1d | 674 | let param_env = ty::ParamEnv::empty(); |
2b03887a | 675 | if ty.is_copy_modulo_regions(cx.tcx, param_env) { |
c34b1796 AL |
676 | return; |
677 | } | |
add651ee FG |
678 | if type_implements_negative_copy_modulo_regions(cx.tcx, ty, param_env) { |
679 | return; | |
680 | } | |
ed00b5ec FG |
681 | if def.is_variant_list_non_exhaustive() |
682 | || def.variants().iter().any(|variant| variant.is_field_list_non_exhaustive()) | |
683 | { | |
684 | return; | |
685 | } | |
9c376795 FG |
686 | |
687 | // We shouldn't recommend implementing `Copy` on stateful things, | |
688 | // such as iterators. | |
689 | if let Some(iter_trait) = cx.tcx.get_diagnostic_item(sym::Iterator) | |
ed00b5ec FG |
690 | && cx |
691 | .tcx | |
9c376795 FG |
692 | .infer_ctxt() |
693 | .build() | |
694 | .type_implements_trait(iter_trait, [ty], param_env) | |
695 | .must_apply_modulo_regions() | |
696 | { | |
697 | return; | |
698 | } | |
699 | ||
700 | // Default value of clippy::trivially_copy_pass_by_ref | |
701 | const MAX_SIZE: u64 = 256; | |
702 | ||
703 | if let Some(size) = cx.layout_of(ty).ok().map(|l| l.size.bytes()) { | |
704 | if size > MAX_SIZE { | |
705 | return; | |
706 | } | |
707 | } | |
708 | ||
709 | if type_allowed_to_implement_copy( | |
5e7ed085 FG |
710 | cx.tcx, |
711 | param_env, | |
712 | ty, | |
9ffffee4 | 713 | traits::ObligationCause::misc(item.span, item.owner_id.def_id), |
5e7ed085 FG |
714 | ) |
715 | .is_ok() | |
716 | { | |
c0240ec0 | 717 | cx.emit_span_lint(MISSING_COPY_IMPLEMENTATIONS, item.span, BuiltinMissingCopyImpl); |
c34b1796 AL |
718 | } |
719 | } | |
720 | } | |
721 | ||
add651ee FG |
722 | /// Check whether a `ty` has a negative `Copy` implementation, ignoring outlives constraints. |
723 | fn type_implements_negative_copy_modulo_regions<'tcx>( | |
724 | tcx: TyCtxt<'tcx>, | |
725 | ty: Ty<'tcx>, | |
726 | param_env: ty::ParamEnv<'tcx>, | |
727 | ) -> bool { | |
728 | let trait_ref = ty::TraitRef::new(tcx, tcx.require_lang_item(hir::LangItem::Copy, None), [ty]); | |
e8be2606 | 729 | let pred = ty::TraitPredicate { trait_ref, polarity: ty::PredicatePolarity::Negative }; |
add651ee FG |
730 | let obligation = traits::Obligation { |
731 | cause: traits::ObligationCause::dummy(), | |
732 | param_env, | |
733 | recursion_depth: 0, | |
734 | predicate: ty::Binder::dummy(pred).to_predicate(tcx), | |
735 | }; | |
736 | ||
737 | tcx.infer_ctxt().build().predicate_must_hold_modulo_regions(&obligation) | |
738 | } | |
739 | ||
c34b1796 | 740 | declare_lint! { |
1b1a35ee | 741 | /// The `missing_debug_implementations` lint detects missing |
49aad941 | 742 | /// implementations of [`fmt::Debug`] for public types. |
1b1a35ee XL |
743 | /// |
744 | /// [`fmt::Debug`]: https://doc.rust-lang.org/std/fmt/trait.Debug.html | |
745 | /// | |
746 | /// ### Example | |
747 | /// | |
748 | /// ```rust,compile_fail | |
749 | /// #![deny(missing_debug_implementations)] | |
750 | /// pub struct Foo; | |
751 | /// # fn main() {} | |
752 | /// ``` | |
753 | /// | |
754 | /// {{produces}} | |
755 | /// | |
756 | /// ### Explanation | |
757 | /// | |
758 | /// Having a `Debug` implementation on all types can assist with | |
759 | /// debugging, as it provides a convenient way to format and display a | |
760 | /// value. Using the `#[derive(Debug)]` attribute will automatically | |
761 | /// generate a typical implementation, or a custom implementation can be | |
762 | /// added by manually implementing the `Debug` trait. | |
763 | /// | |
764 | /// This lint is "allow" by default because adding `Debug` to all types can | |
765 | /// have a negative impact on compile time and code size. It also requires | |
766 | /// boilerplate to be added to every type, which can be an impediment. | |
c34b1796 AL |
767 | MISSING_DEBUG_IMPLEMENTATIONS, |
768 | Allow, | |
74b04a01 | 769 | "detects missing implementations of Debug" |
c34b1796 AL |
770 | } |
771 | ||
48663c56 | 772 | #[derive(Default)] |
add651ee | 773 | pub(crate) struct MissingDebugImplementations; |
c34b1796 | 774 | |
532ac7d7 XL |
775 | impl_lint_pass!(MissingDebugImplementations => [MISSING_DEBUG_IMPLEMENTATIONS]); |
776 | ||
f035d41b XL |
777 | impl<'tcx> LateLintPass<'tcx> for MissingDebugImplementations { |
778 | fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { | |
fe692bf9 | 779 | if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) { |
c34b1796 AL |
780 | return; |
781 | } | |
782 | ||
e74abb32 | 783 | match item.kind { |
dfeec247 | 784 | hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) | hir::ItemKind::Enum(..) => {} |
c34b1796 AL |
785 | _ => return, |
786 | } | |
787 | ||
add651ee FG |
788 | // Avoid listing trait impls if the trait is allowed. |
789 | let (level, _) = cx.tcx.lint_level_at_node(MISSING_DEBUG_IMPLEMENTATIONS, item.hir_id()); | |
790 | if level == Level::Allow { | |
791 | return; | |
c34b1796 AL |
792 | } |
793 | ||
add651ee FG |
794 | let Some(debug) = cx.tcx.get_diagnostic_item(sym::Debug) else { return }; |
795 | ||
796 | let has_impl = cx | |
797 | .tcx | |
798 | .non_blanket_impls_for_ty(debug, cx.tcx.type_of(item.owner_id).instantiate_identity()) | |
799 | .next() | |
800 | .is_some(); | |
801 | if !has_impl { | |
c0240ec0 | 802 | cx.emit_span_lint( |
2b03887a FG |
803 | MISSING_DEBUG_IMPLEMENTATIONS, |
804 | item.span, | |
9c376795 | 805 | BuiltinMissingDebugImpl { tcx: cx.tcx, def_id: debug }, |
2b03887a | 806 | ); |
c34b1796 AL |
807 | } |
808 | } | |
809 | } | |
810 | ||
7cac9316 | 811 | declare_lint! { |
1b1a35ee XL |
812 | /// The `anonymous_parameters` lint detects anonymous parameters in trait |
813 | /// definitions. | |
814 | /// | |
815 | /// ### Example | |
816 | /// | |
817 | /// ```rust,edition2015,compile_fail | |
818 | /// #![deny(anonymous_parameters)] | |
819 | /// // edition 2015 | |
820 | /// pub trait Foo { | |
821 | /// fn foo(usize); | |
822 | /// } | |
823 | /// fn main() {} | |
824 | /// ``` | |
825 | /// | |
826 | /// {{produces}} | |
827 | /// | |
828 | /// ### Explanation | |
829 | /// | |
830 | /// This syntax is mostly a historical accident, and can be worked around | |
831 | /// quite easily by adding an `_` pattern or a descriptive identifier: | |
832 | /// | |
833 | /// ```rust | |
834 | /// trait Foo { | |
835 | /// fn foo(_: usize); | |
836 | /// } | |
837 | /// ``` | |
838 | /// | |
839 | /// This syntax is now a hard error in the 2018 edition. In the 2015 | |
cdc7bbd5 | 840 | /// edition, this lint is "warn" by default. This lint |
1b1a35ee XL |
841 | /// enables the [`cargo fix`] tool with the `--edition` flag to |
842 | /// automatically transition old code from the 2015 edition to 2018. The | |
cdc7bbd5 | 843 | /// tool will run this lint and automatically apply the |
1b1a35ee XL |
844 | /// suggested fix from the compiler (which is to add `_` to each |
845 | /// parameter). This provides a completely automated way to update old | |
846 | /// code for a new edition. See [issue #41686] for more details. | |
847 | /// | |
848 | /// [issue #41686]: https://github.com/rust-lang/rust/issues/41686 | |
849 | /// [`cargo fix`]: https://doc.rust-lang.org/cargo/commands/cargo-fix.html | |
7cac9316 | 850 | pub ANONYMOUS_PARAMETERS, |
cdc7bbd5 | 851 | Warn, |
e74abb32 XL |
852 | "detects anonymous parameters", |
853 | @future_incompatible = FutureIncompatibleInfo { | |
136023e0 | 854 | reason: FutureIncompatibilityReason::EditionError(Edition::Edition2018), |
781aab86 | 855 | reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>", |
e74abb32 | 856 | }; |
7cac9316 XL |
857 | } |
858 | ||
532ac7d7 XL |
859 | declare_lint_pass!( |
860 | /// Checks for use of anonymous parameters (RFC 1685). | |
861 | AnonymousParameters => [ANONYMOUS_PARAMETERS] | |
862 | ); | |
7cac9316 XL |
863 | |
864 | impl EarlyLintPass for AnonymousParameters { | |
dfeec247 | 865 | fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) { |
5099ac24 | 866 | if cx.sess().edition() != Edition::Edition2015 { |
cdc7bbd5 XL |
867 | // This is a hard error in future editions; avoid linting and erroring |
868 | return; | |
869 | } | |
3c0e092e | 870 | if let ast::AssocItemKind::Fn(box Fn { ref sig, .. }) = it.kind { |
ba9703b0 XL |
871 | for arg in sig.decl.inputs.iter() { |
872 | if let ast::PatKind::Ident(_, ident, None) = arg.pat.kind { | |
5869c6ff | 873 | if ident.name == kw::Empty { |
2b03887a | 874 | let ty_snip = cx.sess().source_map().span_to_snippet(arg.ty.span); |
94b46f34 | 875 | |
2b03887a FG |
876 | let (ty_snip, appl) = if let Ok(ref snip) = ty_snip { |
877 | (snip.as_str(), Applicability::MachineApplicable) | |
878 | } else { | |
879 | ("<type>", Applicability::HasPlaceholders) | |
880 | }; | |
c0240ec0 | 881 | cx.emit_span_lint( |
2b03887a FG |
882 | ANONYMOUS_PARAMETERS, |
883 | arg.pat.span, | |
9c376795 FG |
884 | BuiltinAnonymousParams { suggestion: (arg.pat.span, appl), ty_snip }, |
885 | ); | |
7cac9316 XL |
886 | } |
887 | } | |
dfeec247 | 888 | } |
7cac9316 XL |
889 | } |
890 | } | |
891 | } | |
892 | ||
9fa01778 | 893 | /// Check for use of attributes which have been deprecated. |
c30ab7b3 SL |
894 | #[derive(Clone)] |
895 | pub struct DeprecatedAttr { | |
896 | // This is not free to compute, so we want to keep it around, rather than | |
897 | // compute it for every attribute. | |
3c0e092e | 898 | depr_attrs: Vec<&'static BuiltinAttribute>, |
c30ab7b3 SL |
899 | } |
900 | ||
532ac7d7 XL |
901 | impl_lint_pass!(DeprecatedAttr => []); |
902 | ||
c30ab7b3 SL |
903 | impl DeprecatedAttr { |
904 | pub fn new() -> DeprecatedAttr { | |
dfeec247 | 905 | DeprecatedAttr { depr_attrs: deprecated_attributes() } |
c30ab7b3 SL |
906 | } |
907 | } | |
908 | ||
c30ab7b3 | 909 | impl EarlyLintPass for DeprecatedAttr { |
9fa01778 | 910 | fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) { |
3c0e092e XL |
911 | for BuiltinAttribute { name, gate, .. } in &self.depr_attrs { |
912 | if attr.ident().map(|ident| ident.name) == Some(*name) { | |
dfeec247 XL |
913 | if let &AttributeGate::Gated( |
914 | Stability::Deprecated(link, suggestion), | |
5869c6ff XL |
915 | name, |
916 | reason, | |
dfeec247 | 917 | _, |
3c0e092e | 918 | ) = gate |
dfeec247 | 919 | { |
9c376795 FG |
920 | let suggestion = match suggestion { |
921 | Some(msg) => { | |
922 | BuiltinDeprecatedAttrLinkSuggestion::Msg { suggestion: attr.span, msg } | |
923 | } | |
924 | None => { | |
925 | BuiltinDeprecatedAttrLinkSuggestion::Default { suggestion: attr.span } | |
926 | } | |
927 | }; | |
c0240ec0 | 928 | cx.emit_span_lint( |
2b03887a FG |
929 | DEPRECATED, |
930 | attr.span, | |
9c376795 | 931 | BuiltinDeprecatedAttrLink { name, reason, link, suggestion }, |
2b03887a | 932 | ); |
c30ab7b3 SL |
933 | } |
934 | return; | |
935 | } | |
936 | } | |
94222f64 | 937 | if attr.has_name(sym::no_start) || attr.has_name(sym::crate_id) { |
c0240ec0 | 938 | cx.emit_span_lint( |
2b03887a FG |
939 | DEPRECATED, |
940 | attr.span, | |
9c376795 FG |
941 | BuiltinDeprecatedAttrUsed { |
942 | name: pprust::path_to_string(&attr.get_normal_item().path), | |
943 | suggestion: attr.span, | |
2b03887a FG |
944 | }, |
945 | ); | |
e1599b0c | 946 | } |
c30ab7b3 SL |
947 | } |
948 | } | |
949 | ||
74b04a01 | 950 | fn warn_if_doc(cx: &EarlyContext<'_>, node_span: Span, node_kind: &str, attrs: &[ast::Attribute]) { |
136023e0 XL |
951 | use rustc_ast::token::CommentKind; |
952 | ||
74b04a01 | 953 | let mut attrs = attrs.iter().peekable(); |
3b2f2976 | 954 | |
74b04a01 XL |
955 | // Accumulate a single span for sugared doc comments. |
956 | let mut sugared_span: Option<Span> = None; | |
3b2f2976 | 957 | |
74b04a01 | 958 | while let Some(attr) = attrs.next() { |
136023e0 XL |
959 | let is_doc_comment = attr.is_doc_comment(); |
960 | if is_doc_comment { | |
74b04a01 | 961 | sugared_span = |
29967ef6 | 962 | Some(sugared_span.map_or(attr.span, |span| span.with_hi(attr.span.hi()))); |
74b04a01 | 963 | } |
3b2f2976 | 964 | |
49aad941 | 965 | if attrs.peek().is_some_and(|next_attr| next_attr.is_doc_comment()) { |
74b04a01 XL |
966 | continue; |
967 | } | |
532ac7d7 | 968 | |
1b1a35ee | 969 | let span = sugared_span.take().unwrap_or(attr.span); |
532ac7d7 | 970 | |
94222f64 | 971 | if is_doc_comment || attr.has_name(sym::doc) { |
9c376795 FG |
972 | let sub = match attr.kind { |
973 | AttrKind::DocComment(CommentKind::Line, _) | AttrKind::Normal(..) => { | |
974 | BuiltinUnusedDocCommentSub::PlainHelp | |
975 | } | |
976 | AttrKind::DocComment(CommentKind::Block, _) => { | |
977 | BuiltinUnusedDocCommentSub::BlockHelp | |
978 | } | |
979 | }; | |
c0240ec0 | 980 | cx.emit_span_lint( |
2b03887a FG |
981 | UNUSED_DOC_COMMENTS, |
982 | span, | |
9c376795 | 983 | BuiltinUnusedDocComment { kind: node_kind, label: node_span, sub }, |
2b03887a | 984 | ); |
3b2f2976 XL |
985 | } |
986 | } | |
987 | } | |
988 | ||
989 | impl EarlyLintPass for UnusedDocComment { | |
532ac7d7 | 990 | fn check_stmt(&mut self, cx: &EarlyContext<'_>, stmt: &ast::Stmt) { |
74b04a01 | 991 | let kind = match stmt.kind { |
c620b35d | 992 | ast::StmtKind::Let(..) => "statements", |
29967ef6 XL |
993 | // Disabled pending discussion in #78306 |
994 | ast::StmtKind::Item(..) => return, | |
532ac7d7 | 995 | // expressions will be reported by `check_expr`. |
74b04a01 XL |
996 | ast::StmtKind::Empty |
997 | | ast::StmtKind::Semi(_) | |
998 | | ast::StmtKind::Expr(_) | |
ba9703b0 | 999 | | ast::StmtKind::MacCall(_) => return, |
532ac7d7 XL |
1000 | }; |
1001 | ||
74b04a01 | 1002 | warn_if_doc(cx, stmt.span, kind, stmt.kind.attrs()); |
3b2f2976 XL |
1003 | } |
1004 | ||
9fa01778 | 1005 | fn check_arm(&mut self, cx: &EarlyContext<'_>, arm: &ast::Arm) { |
4b012472 FG |
1006 | if let Some(body) = &arm.body { |
1007 | let arm_span = arm.pat.span.with_hi(body.span.hi()); | |
1008 | warn_if_doc(cx, arm_span, "match arms", &arm.attrs); | |
1009 | } | |
3b2f2976 XL |
1010 | } |
1011 | ||
781aab86 FG |
1012 | fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &ast::Pat) { |
1013 | if let ast::PatKind::Struct(_, _, fields, _) = &pat.kind { | |
1014 | for field in fields { | |
1015 | warn_if_doc(cx, field.span, "pattern fields", &field.attrs); | |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | ||
9fa01778 | 1020 | fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) { |
74b04a01 | 1021 | warn_if_doc(cx, expr.span, "expressions", &expr.attrs); |
781aab86 FG |
1022 | |
1023 | if let ExprKind::Struct(s) = &expr.kind { | |
1024 | for field in &s.fields { | |
1025 | warn_if_doc(cx, field.span, "expression fields", &field.attrs); | |
1026 | } | |
1027 | } | |
3b2f2976 | 1028 | } |
a2a8927a XL |
1029 | |
1030 | fn check_generic_param(&mut self, cx: &EarlyContext<'_>, param: &ast::GenericParam) { | |
1031 | warn_if_doc(cx, param.ident.span, "generic parameters", ¶m.attrs); | |
1032 | } | |
5e7ed085 FG |
1033 | |
1034 | fn check_block(&mut self, cx: &EarlyContext<'_>, block: &ast::Block) { | |
4b012472 | 1035 | warn_if_doc(cx, block.span, "blocks", block.attrs()); |
5e7ed085 FG |
1036 | } |
1037 | ||
1038 | fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) { | |
1039 | if let ast::ItemKind::ForeignMod(_) = item.kind { | |
064997fb | 1040 | warn_if_doc(cx, item.span, "extern blocks", &item.attrs); |
5e7ed085 FG |
1041 | } |
1042 | } | |
3b2f2976 XL |
1043 | } |
1044 | ||
c34b1796 | 1045 | declare_lint! { |
1b1a35ee XL |
1046 | /// The `no_mangle_const_items` lint detects any `const` items with the |
1047 | /// [`no_mangle` attribute]. | |
1048 | /// | |
1049 | /// [`no_mangle` attribute]: https://doc.rust-lang.org/reference/abi.html#the-no_mangle-attribute | |
1050 | /// | |
1051 | /// ### Example | |
1052 | /// | |
1053 | /// ```rust,compile_fail | |
1054 | /// #[no_mangle] | |
1055 | /// const FOO: i32 = 5; | |
1056 | /// ``` | |
1057 | /// | |
1058 | /// {{produces}} | |
1059 | /// | |
1060 | /// ### Explanation | |
1061 | /// | |
1062 | /// Constants do not have their symbols exported, and therefore, this | |
1063 | /// probably means you meant to use a [`static`], not a [`const`]. | |
1064 | /// | |
1065 | /// [`static`]: https://doc.rust-lang.org/reference/items/static-items.html | |
1066 | /// [`const`]: https://doc.rust-lang.org/reference/items/constant-items.html | |
c34b1796 AL |
1067 | NO_MANGLE_CONST_ITEMS, |
1068 | Deny, | |
1069 | "const items will not have their symbols exported" | |
1070 | } | |
1071 | ||
9cc50fc6 | 1072 | declare_lint! { |
1b1a35ee XL |
1073 | /// The `no_mangle_generic_items` lint detects generic items that must be |
1074 | /// mangled. | |
1075 | /// | |
1076 | /// ### Example | |
1077 | /// | |
1078 | /// ```rust | |
1079 | /// #[no_mangle] | |
1080 | /// fn foo<T>(t: T) { | |
1081 | /// | |
1082 | /// } | |
1083 | /// ``` | |
1084 | /// | |
1085 | /// {{produces}} | |
1086 | /// | |
1087 | /// ### Explanation | |
1088 | /// | |
136023e0 | 1089 | /// A function with generics must have its symbol mangled to accommodate |
1b1a35ee XL |
1090 | /// the generic parameter. The [`no_mangle` attribute] has no effect in |
1091 | /// this situation, and should be removed. | |
1092 | /// | |
1093 | /// [`no_mangle` attribute]: https://doc.rust-lang.org/reference/abi.html#the-no_mangle-attribute | |
9cc50fc6 SL |
1094 | NO_MANGLE_GENERIC_ITEMS, |
1095 | Warn, | |
1096 | "generic items must be mangled" | |
1097 | } | |
1098 | ||
532ac7d7 | 1099 | declare_lint_pass!(InvalidNoMangleItems => [NO_MANGLE_CONST_ITEMS, NO_MANGLE_GENERIC_ITEMS]); |
c34b1796 | 1100 | |
f035d41b XL |
1101 | impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems { |
1102 | fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { | |
6a06907d | 1103 | let attrs = cx.tcx.hir().attrs(it.hir_id()); |
94222f64 XL |
1104 | let check_no_mangle_on_generic_fn = |no_mangle_attr: &ast::Attribute, |
1105 | impl_generics: Option<&hir::Generics<'_>>, | |
1106 | generics: &hir::Generics<'_>, | |
1107 | span| { | |
1108 | for param in | |
1109 | generics.params.iter().chain(impl_generics.map(|g| g.params).into_iter().flatten()) | |
1110 | { | |
1111 | match param.kind { | |
1112 | GenericParamKind::Lifetime { .. } => {} | |
1113 | GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => { | |
c0240ec0 | 1114 | cx.emit_span_lint( |
2b03887a FG |
1115 | NO_MANGLE_GENERIC_ITEMS, |
1116 | span, | |
9c376795 | 1117 | BuiltinNoMangleGeneric { suggestion: no_mangle_attr.span }, |
2b03887a | 1118 | ); |
94222f64 XL |
1119 | break; |
1120 | } | |
1121 | } | |
1122 | } | |
1123 | }; | |
e74abb32 | 1124 | match it.kind { |
4b012472 | 1125 | hir::ItemKind::Fn(.., generics, _) => { |
353b0b11 | 1126 | if let Some(no_mangle_attr) = attr::find_by_name(attrs, sym::no_mangle) { |
94222f64 | 1127 | check_no_mangle_on_generic_fn(no_mangle_attr, None, generics, it.span); |
c34b1796 | 1128 | } |
c30ab7b3 | 1129 | } |
8faf50e0 | 1130 | hir::ItemKind::Const(..) => { |
353b0b11 | 1131 | if attr::contains_name(attrs, sym::no_mangle) { |
9c376795 FG |
1132 | // account for "pub const" (#45562) |
1133 | let start = cx | |
1134 | .tcx | |
1135 | .sess | |
1136 | .source_map() | |
1137 | .span_to_snippet(it.span) | |
1138 | .map(|snippet| snippet.find("const").unwrap_or(0)) | |
1139 | .unwrap_or(0) as u32; | |
1140 | // `const` is 5 chars | |
1141 | let suggestion = it.span.with_hi(BytePos(it.span.lo().0 + start + 5)); | |
1142 | ||
c34b1796 AL |
1143 | // Const items do not refer to a particular location in memory, and therefore |
1144 | // don't have anything to attach a symbol to | |
c0240ec0 | 1145 | cx.emit_span_lint( |
2b03887a FG |
1146 | NO_MANGLE_CONST_ITEMS, |
1147 | it.span, | |
9c376795 | 1148 | BuiltinConstNoMangle { suggestion }, |
2b03887a | 1149 | ); |
c34b1796 AL |
1150 | } |
1151 | } | |
04454e1e FG |
1152 | hir::ItemKind::Impl(hir::Impl { generics, items, .. }) => { |
1153 | for it in *items { | |
94222f64 | 1154 | if let hir::AssocItemKind::Fn { .. } = it.kind { |
353b0b11 FG |
1155 | if let Some(no_mangle_attr) = |
1156 | attr::find_by_name(cx.tcx.hir().attrs(it.id.hir_id()), sym::no_mangle) | |
94222f64 XL |
1157 | { |
1158 | check_no_mangle_on_generic_fn( | |
1159 | no_mangle_attr, | |
1160 | Some(generics), | |
2b03887a | 1161 | cx.tcx.hir().get_generics(it.id.owner_id.def_id).unwrap(), |
94222f64 XL |
1162 | it.span, |
1163 | ); | |
1164 | } | |
1165 | } | |
1166 | } | |
1167 | } | |
c30ab7b3 | 1168 | _ => {} |
c34b1796 AL |
1169 | } |
1170 | } | |
1171 | } | |
1172 | ||
bd371182 | 1173 | declare_lint! { |
1b1a35ee XL |
1174 | /// The `mutable_transmutes` lint catches transmuting from `&T` to `&mut |
1175 | /// T` because it is [undefined behavior]. | |
1176 | /// | |
1177 | /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html | |
1178 | /// | |
1179 | /// ### Example | |
1180 | /// | |
1181 | /// ```rust,compile_fail | |
1182 | /// unsafe { | |
1183 | /// let y = std::mem::transmute::<&i32, &mut i32>(&5); | |
1184 | /// } | |
1185 | /// ``` | |
1186 | /// | |
1187 | /// {{produces}} | |
1188 | /// | |
1189 | /// ### Explanation | |
1190 | /// | |
1191 | /// Certain assumptions are made about aliasing of data, and this transmute | |
1192 | /// violates those assumptions. Consider using [`UnsafeCell`] instead. | |
1193 | /// | |
1194 | /// [`UnsafeCell`]: https://doc.rust-lang.org/std/cell/struct.UnsafeCell.html | |
bd371182 AL |
1195 | MUTABLE_TRANSMUTES, |
1196 | Deny, | |
5099ac24 | 1197 | "transmuting &T to &mut T is undefined behavior, even if the reference is unused" |
bd371182 AL |
1198 | } |
1199 | ||
532ac7d7 | 1200 | declare_lint_pass!(MutableTransmutes => [MUTABLE_TRANSMUTES]); |
bd371182 | 1201 | |
f035d41b XL |
1202 | impl<'tcx> LateLintPass<'tcx> for MutableTransmutes { |
1203 | fn check_expr(&mut self, cx: &LateContext<'_>, expr: &hir::Expr<'_>) { | |
487cf647 | 1204 | if let Some((&ty::Ref(_, _, from_mutbl), &ty::Ref(_, _, to_mutbl))) = |
1b1a35ee | 1205 | get_transmute_from_to(cx, expr).map(|(ty1, ty2)| (ty1.kind(), ty2.kind())) |
ba9703b0 | 1206 | { |
487cf647 | 1207 | if from_mutbl < to_mutbl { |
c0240ec0 | 1208 | cx.emit_span_lint(MUTABLE_TRANSMUTES, expr.span, BuiltinMutablesTransmutes); |
bd371182 | 1209 | } |
bd371182 AL |
1210 | } |
1211 | ||
f035d41b XL |
1212 | fn get_transmute_from_to<'tcx>( |
1213 | cx: &LateContext<'tcx>, | |
dfeec247 XL |
1214 | expr: &hir::Expr<'_>, |
1215 | ) -> Option<(Ty<'tcx>, Ty<'tcx>)> { | |
e74abb32 | 1216 | let def = if let hir::ExprKind::Path(ref qpath) = expr.kind { |
f035d41b | 1217 | cx.qpath_res(qpath, expr.hir_id) |
476ff2be SL |
1218 | } else { |
1219 | return None; | |
1220 | }; | |
48663c56 | 1221 | if let Res::Def(DefKind::Fn, did) = def { |
bd371182 AL |
1222 | if !def_id_is_transmute(cx, did) { |
1223 | return None; | |
1224 | } | |
3dfed10e | 1225 | let sig = cx.typeck_results().node_type(expr.hir_id).fn_sig(cx.tcx); |
041b39d2 | 1226 | let from = sig.inputs().skip_binder()[0]; |
f035d41b | 1227 | let to = sig.output().skip_binder(); |
532ac7d7 | 1228 | return Some((from, to)); |
bd371182 AL |
1229 | } |
1230 | None | |
1231 | } | |
1232 | ||
f035d41b | 1233 | fn def_id_is_transmute(cx: &LateContext<'_>, def_id: DefId) -> bool { |
c620b35d | 1234 | cx.tcx.is_intrinsic(def_id, sym::transmute) |
bd371182 AL |
1235 | } |
1236 | } | |
1237 | } | |
1238 | ||
c34b1796 | 1239 | declare_lint! { |
c0240ec0 FG |
1240 | /// The `unstable_features` lint detects uses of `#![feature]`. |
1241 | /// | |
1242 | /// ### Example | |
1243 | /// | |
1244 | /// ```rust,compile_fail | |
1245 | /// #![deny(unstable_features)] | |
1246 | /// #![feature(test)] | |
1247 | /// ``` | |
1248 | /// | |
1249 | /// {{produces}} | |
1250 | /// | |
1251 | /// ### Explanation | |
1252 | /// | |
1253 | /// In larger nightly-based projects which | |
1254 | /// | |
1255 | /// * consist of a multitude of crates where a subset of crates has to compile on | |
1256 | /// stable either unconditionally or depending on a `cfg` flag to for example | |
1257 | /// allow stable users to depend on them, | |
1258 | /// * don't use nightly for experimental features but for, e.g., unstable options only, | |
1259 | /// | |
1260 | /// this lint may come in handy to enforce policies of these kinds. | |
c34b1796 AL |
1261 | UNSTABLE_FEATURES, |
1262 | Allow, | |
c0240ec0 | 1263 | "enabling unstable features" |
c34b1796 AL |
1264 | } |
1265 | ||
532ac7d7 XL |
1266 | declare_lint_pass!( |
1267 | /// Forbids using the `#[feature(...)]` attribute | |
1268 | UnstableFeatures => [UNSTABLE_FEATURES] | |
1269 | ); | |
b039eaaf | 1270 | |
f035d41b | 1271 | impl<'tcx> LateLintPass<'tcx> for UnstableFeatures { |
3dfed10e | 1272 | fn check_attribute(&mut self, cx: &LateContext<'_>, attr: &ast::Attribute) { |
c0240ec0 FG |
1273 | if attr.has_name(sym::feature) |
1274 | && let Some(items) = attr.meta_item_list() | |
1275 | { | |
1276 | for item in items { | |
1277 | cx.emit_span_lint(UNSTABLE_FEATURES, item.span(), BuiltinUnstableFeatures); | |
62682a34 | 1278 | } |
c34b1796 AL |
1279 | } |
1280 | } | |
1281 | } | |
bd371182 | 1282 | |
487cf647 FG |
1283 | declare_lint! { |
1284 | /// The `ungated_async_fn_track_caller` lint warns when the | |
add651ee FG |
1285 | /// `#[track_caller]` attribute is used on an async function |
1286 | /// without enabling the corresponding unstable feature flag. | |
487cf647 FG |
1287 | /// |
1288 | /// ### Example | |
1289 | /// | |
1290 | /// ```rust | |
1291 | /// #[track_caller] | |
1292 | /// async fn foo() {} | |
1293 | /// ``` | |
1294 | /// | |
1295 | /// {{produces}} | |
1296 | /// | |
1297 | /// ### Explanation | |
1298 | /// | |
1299 | /// The attribute must be used in conjunction with the | |
add651ee | 1300 | /// [`async_fn_track_caller` feature flag]. Otherwise, the `#[track_caller]` |
9c376795 | 1301 | /// annotation will function as a no-op. |
487cf647 | 1302 | /// |
add651ee | 1303 | /// [`async_fn_track_caller` feature flag]: https://doc.rust-lang.org/beta/unstable-book/language-features/async-fn-track-caller.html |
487cf647 FG |
1304 | UNGATED_ASYNC_FN_TRACK_CALLER, |
1305 | Warn, | |
add651ee | 1306 | "enabling track_caller on an async fn is a no-op unless the async_fn_track_caller feature is enabled" |
487cf647 FG |
1307 | } |
1308 | ||
1309 | declare_lint_pass!( | |
9ffffee4 | 1310 | /// Explains corresponding feature flag must be enabled for the `#[track_caller]` attribute to |
487cf647 FG |
1311 | /// do anything |
1312 | UngatedAsyncFnTrackCaller => [UNGATED_ASYNC_FN_TRACK_CALLER] | |
1313 | ); | |
1314 | ||
1315 | impl<'tcx> LateLintPass<'tcx> for UngatedAsyncFnTrackCaller { | |
1316 | fn check_fn( | |
1317 | &mut self, | |
1318 | cx: &LateContext<'_>, | |
1319 | fn_kind: HirFnKind<'_>, | |
1320 | _: &'tcx FnDecl<'_>, | |
1321 | _: &'tcx Body<'_>, | |
1322 | span: Span, | |
9ffffee4 | 1323 | def_id: LocalDefId, |
487cf647 | 1324 | ) { |
781aab86 | 1325 | if fn_kind.asyncness().is_async() |
add651ee | 1326 | && !cx.tcx.features().async_fn_track_caller |
487cf647 | 1327 | // Now, check if the function has the `#[track_caller]` attribute |
353b0b11 | 1328 | && let Some(attr) = cx.tcx.get_attr(def_id, sym::track_caller) |
9ffffee4 | 1329 | { |
c0240ec0 | 1330 | cx.emit_span_lint( |
ed00b5ec FG |
1331 | UNGATED_ASYNC_FN_TRACK_CALLER, |
1332 | attr.span, | |
c0240ec0 | 1333 | BuiltinUngatedAsyncFnTrackCaller { label: span, session: &cx.tcx.sess }, |
ed00b5ec | 1334 | ); |
9ffffee4 | 1335 | } |
487cf647 FG |
1336 | } |
1337 | } | |
1338 | ||
abe05a73 | 1339 | declare_lint! { |
e8be2606 FG |
1340 | /// The `unreachable_pub` lint triggers for `pub` items not reachable from other crates - that |
1341 | /// means neither directly accessible, nor reexported, nor leaked through things like return | |
1342 | /// types. | |
1b1a35ee XL |
1343 | /// |
1344 | /// ### Example | |
1345 | /// | |
1346 | /// ```rust,compile_fail | |
1347 | /// #![deny(unreachable_pub)] | |
1348 | /// mod foo { | |
1349 | /// pub mod bar { | |
1350 | /// | |
1351 | /// } | |
1352 | /// } | |
1353 | /// ``` | |
1354 | /// | |
1355 | /// {{produces}} | |
1356 | /// | |
1357 | /// ### Explanation | |
1358 | /// | |
fe692bf9 FG |
1359 | /// The `pub` keyword both expresses an intent for an item to be publicly available, and also |
1360 | /// signals to the compiler to make the item publicly accessible. The intent can only be | |
1361 | /// satisfied, however, if all items which contain this item are *also* publicly accessible. | |
1362 | /// Thus, this lint serves to identify situations where the intent does not match the reality. | |
1363 | /// | |
1364 | /// If you wish the item to be accessible elsewhere within the crate, but not outside it, the | |
1365 | /// `pub(crate)` visibility is recommended to be used instead. This more clearly expresses the | |
1366 | /// intent that the item is only visible within its own crate. | |
1b1a35ee XL |
1367 | /// |
1368 | /// This lint is "allow" by default because it will trigger for a large | |
1369 | /// amount existing Rust code, and has some false-positives. Eventually it | |
1370 | /// is desired for this to become warn-by-default. | |
0531ce1d | 1371 | pub UNREACHABLE_PUB, |
abe05a73 XL |
1372 | Allow, |
1373 | "`pub` items not reachable from crate root" | |
1374 | } | |
1375 | ||
532ac7d7 XL |
1376 | declare_lint_pass!( |
1377 | /// Lint for items marked `pub` that aren't reachable from other crates. | |
1378 | UnreachablePub => [UNREACHABLE_PUB] | |
1379 | ); | |
abe05a73 XL |
1380 | |
1381 | impl UnreachablePub { | |
dfeec247 XL |
1382 | fn perform_lint( |
1383 | &self, | |
f035d41b | 1384 | cx: &LateContext<'_>, |
dfeec247 | 1385 | what: &str, |
94222f64 | 1386 | def_id: LocalDefId, |
04454e1e | 1387 | vis_span: Span, |
dfeec247 XL |
1388 | exportable: bool, |
1389 | ) { | |
8faf50e0 | 1390 | let mut applicability = Applicability::MachineApplicable; |
2b03887a FG |
1391 | if cx.tcx.visibility(def_id).is_public() && !cx.effective_visibilities.is_reachable(def_id) |
1392 | { | |
04454e1e FG |
1393 | if vis_span.from_expansion() { |
1394 | applicability = Applicability::MaybeIncorrect; | |
1395 | } | |
064997fb | 1396 | let def_span = cx.tcx.def_span(def_id); |
c0240ec0 | 1397 | cx.emit_span_lint( |
2b03887a FG |
1398 | UNREACHABLE_PUB, |
1399 | def_span, | |
9c376795 FG |
1400 | BuiltinUnreachablePub { |
1401 | what, | |
1402 | suggestion: (vis_span, applicability), | |
1403 | help: exportable.then_some(()), | |
2b03887a FG |
1404 | }, |
1405 | ); | |
abe05a73 XL |
1406 | } |
1407 | } | |
1408 | } | |
1409 | ||
f035d41b XL |
1410 | impl<'tcx> LateLintPass<'tcx> for UnreachablePub { |
1411 | fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { | |
04454e1e FG |
1412 | // Do not warn for fake `use` statements. |
1413 | if let hir::ItemKind::Use(_, hir::UseKind::ListStem) = &item.kind { | |
1414 | return; | |
1415 | } | |
2b03887a | 1416 | self.perform_lint(cx, "item", item.owner_id.def_id, item.vis_span, true); |
abe05a73 XL |
1417 | } |
1418 | ||
f035d41b | 1419 | fn check_foreign_item(&mut self, cx: &LateContext<'_>, foreign_item: &hir::ForeignItem<'tcx>) { |
2b03887a | 1420 | self.perform_lint(cx, "item", foreign_item.owner_id.def_id, foreign_item.vis_span, true); |
abe05a73 XL |
1421 | } |
1422 | ||
6a06907d | 1423 | fn check_field_def(&mut self, cx: &LateContext<'_>, field: &hir::FieldDef<'_>) { |
c620b35d | 1424 | if matches!(cx.tcx.parent_hir_node(field.hir_id), Node::Variant(_)) { |
487cf647 FG |
1425 | return; |
1426 | } | |
1427 | self.perform_lint(cx, "field", field.def_id, field.vis_span, false); | |
abe05a73 XL |
1428 | } |
1429 | ||
f035d41b | 1430 | fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) { |
04454e1e | 1431 | // Only lint inherent impl items. |
2b03887a FG |
1432 | if cx.tcx.associated_item(impl_item.owner_id).trait_item_def_id.is_none() { |
1433 | self.perform_lint(cx, "item", impl_item.owner_id.def_id, impl_item.vis_span, false); | |
04454e1e | 1434 | } |
abe05a73 XL |
1435 | } |
1436 | } | |
0531ce1d | 1437 | |
0531ce1d | 1438 | declare_lint! { |
1b1a35ee XL |
1439 | /// The `type_alias_bounds` lint detects bounds in type aliases. |
1440 | /// | |
1441 | /// ### Example | |
1442 | /// | |
1443 | /// ```rust | |
1444 | /// type SendVec<T: Send> = Vec<T>; | |
1445 | /// ``` | |
1446 | /// | |
1447 | /// {{produces}} | |
1448 | /// | |
1449 | /// ### Explanation | |
1450 | /// | |
1451 | /// The trait bounds in a type alias are currently ignored, and should not | |
1452 | /// be included to avoid confusion. This was previously allowed | |
1453 | /// unintentionally; this may become a hard error in the future. | |
0531ce1d XL |
1454 | TYPE_ALIAS_BOUNDS, |
1455 | Warn, | |
1456 | "bounds in type aliases are not enforced" | |
1457 | } | |
1458 | ||
532ac7d7 XL |
1459 | declare_lint_pass!( |
1460 | /// Lint for trait and lifetime bounds in type aliases being mostly ignored. | |
1461 | /// They are relevant when using associated types, but otherwise neither checked | |
1462 | /// at definition site nor enforced at use site. | |
1463 | TypeAliasBounds => [TYPE_ALIAS_BOUNDS] | |
1464 | ); | |
0531ce1d XL |
1465 | |
1466 | impl TypeAliasBounds { | |
9c376795 | 1467 | pub(crate) fn is_type_variable_assoc(qpath: &hir::QPath<'_>) -> bool { |
0531ce1d | 1468 | match *qpath { |
4b012472 | 1469 | hir::QPath::TypeRelative(ty, _) => { |
0531ce1d | 1470 | // If this is a type variable, we found a `T::Assoc`. |
e74abb32 | 1471 | match ty.kind { |
4b012472 | 1472 | hir::TyKind::Path(hir::QPath::Resolved(None, path)) => { |
29967ef6 XL |
1473 | matches!(path.res, Res::Def(DefKind::TyParam, _)) |
1474 | } | |
dfeec247 | 1475 | _ => false, |
0531ce1d XL |
1476 | } |
1477 | } | |
3dfed10e | 1478 | hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => false, |
0531ce1d XL |
1479 | } |
1480 | } | |
0531ce1d XL |
1481 | } |
1482 | ||
f035d41b XL |
1483 | impl<'tcx> LateLintPass<'tcx> for TypeAliasBounds { |
1484 | fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { | |
add651ee FG |
1485 | let hir::ItemKind::TyAlias(hir_ty, type_alias_generics) = &item.kind else { return }; |
1486 | ||
781aab86 FG |
1487 | // Bounds of lazy type aliases and TAITs are respected. |
1488 | if cx.tcx.type_alias_is_lazy(item.owner_id) { | |
f035d41b XL |
1489 | return; |
1490 | } | |
add651ee FG |
1491 | |
1492 | let ty = cx.tcx.type_of(item.owner_id).skip_binder(); | |
781aab86 | 1493 | if ty.has_inherent_projections() { |
add651ee FG |
1494 | // Bounds of type aliases that contain opaque types or inherent projections are respected. |
1495 | // E.g: `type X = impl Trait;`, `type X = (impl Trait, Y);`, `type X = Type::Inherent;`. | |
49aad941 FG |
1496 | return; |
1497 | } | |
add651ee | 1498 | |
0531ce1d | 1499 | // There must not be a where clause |
04454e1e FG |
1500 | if type_alias_generics.predicates.is_empty() { |
1501 | return; | |
0531ce1d | 1502 | } |
04454e1e FG |
1503 | |
1504 | let mut where_spans = Vec::new(); | |
1505 | let mut inline_spans = Vec::new(); | |
1506 | let mut inline_sugg = Vec::new(); | |
1507 | for p in type_alias_generics.predicates { | |
1508 | let span = p.span(); | |
1509 | if p.in_where_clause() { | |
1510 | where_spans.push(span); | |
1511 | } else { | |
1512 | for b in p.bounds() { | |
1513 | inline_spans.push(b.span()); | |
1514 | } | |
1515 | inline_sugg.push((span, String::new())); | |
0531ce1d XL |
1516 | } |
1517 | } | |
04454e1e FG |
1518 | |
1519 | let mut suggested_changing_assoc_types = false; | |
1520 | if !where_spans.is_empty() { | |
9c376795 FG |
1521 | let sub = (!suggested_changing_assoc_types).then(|| { |
1522 | suggested_changing_assoc_types = true; | |
add651ee | 1523 | SuggestChangingAssocTypes { ty: hir_ty } |
04454e1e | 1524 | }); |
c0240ec0 | 1525 | cx.emit_span_lint( |
9c376795 FG |
1526 | TYPE_ALIAS_BOUNDS, |
1527 | where_spans, | |
1528 | BuiltinTypeAliasWhereClause { | |
1529 | suggestion: type_alias_generics.where_clause_span, | |
1530 | sub, | |
1531 | }, | |
1532 | ); | |
04454e1e FG |
1533 | } |
1534 | ||
1535 | if !inline_spans.is_empty() { | |
9c376795 FG |
1536 | let suggestion = BuiltinTypeAliasGenericBoundsSuggestion { suggestions: inline_sugg }; |
1537 | let sub = (!suggested_changing_assoc_types).then(|| { | |
1538 | suggested_changing_assoc_types = true; | |
add651ee | 1539 | SuggestChangingAssocTypes { ty: hir_ty } |
04454e1e | 1540 | }); |
c0240ec0 | 1541 | cx.emit_span_lint( |
9c376795 FG |
1542 | TYPE_ALIAS_BOUNDS, |
1543 | inline_spans, | |
1544 | BuiltinTypeAliasGenericBounds { suggestion, sub }, | |
1545 | ); | |
04454e1e | 1546 | } |
0531ce1d XL |
1547 | } |
1548 | } | |
1549 | ||
94b46f34 | 1550 | declare_lint! { |
1b1a35ee XL |
1551 | /// The `trivial_bounds` lint detects trait bounds that don't depend on |
1552 | /// any type parameters. | |
1553 | /// | |
1554 | /// ### Example | |
1555 | /// | |
1556 | /// ```rust | |
1557 | /// #![feature(trivial_bounds)] | |
1558 | /// pub struct A where i32: Copy; | |
1559 | /// ``` | |
1560 | /// | |
1561 | /// {{produces}} | |
1562 | /// | |
1563 | /// ### Explanation | |
1564 | /// | |
1565 | /// Usually you would not write a trait bound that you know is always | |
1566 | /// true, or never true. However, when using macros, the macro may not | |
1567 | /// know whether or not the constraint would hold or not at the time when | |
1568 | /// generating the code. Currently, the compiler does not alert you if the | |
1569 | /// constraint is always true, and generates an error if it is never true. | |
1570 | /// The `trivial_bounds` feature changes this to be a warning in both | |
1571 | /// cases, giving macros more freedom and flexibility to generate code, | |
1572 | /// while still providing a signal when writing non-macro code that | |
1573 | /// something is amiss. | |
1574 | /// | |
1575 | /// See [RFC 2056] for more details. This feature is currently only | |
1576 | /// available on the nightly channel, see [tracking issue #48214]. | |
1577 | /// | |
1578 | /// [RFC 2056]: https://github.com/rust-lang/rfcs/blob/master/text/2056-allow-trivial-where-clause-constraints.md | |
1579 | /// [tracking issue #48214]: https://github.com/rust-lang/rust/issues/48214 | |
94b46f34 XL |
1580 | TRIVIAL_BOUNDS, |
1581 | Warn, | |
1582 | "these bounds don't depend on an type parameters" | |
1583 | } | |
1584 | ||
532ac7d7 XL |
1585 | declare_lint_pass!( |
1586 | /// Lint for trait and lifetime bounds that don't depend on type parameters | |
1587 | /// which either do nothing, or stop the item from being used. | |
1588 | TrivialConstraints => [TRIVIAL_BOUNDS] | |
1589 | ); | |
94b46f34 | 1590 | |
f035d41b XL |
1591 | impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { |
1592 | fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) { | |
fe692bf9 | 1593 | use rustc_middle::ty::ClauseKind; |
94b46f34 | 1594 | |
94b46f34 | 1595 | if cx.tcx.features().trivial_bounds { |
2b03887a | 1596 | let predicates = cx.tcx.predicates_of(item.owner_id); |
e74abb32 | 1597 | for &(predicate, span) in predicates.predicates { |
5869c6ff | 1598 | let predicate_kind_name = match predicate.kind().skip_binder() { |
fe692bf9 FG |
1599 | ClauseKind::Trait(..) => "trait", |
1600 | ClauseKind::TypeOutlives(..) | | |
1601 | ClauseKind::RegionOutlives(..) => "lifetime", | |
94b46f34 | 1602 | |
9ffffee4 | 1603 | // `ConstArgHasType` is never global as `ct` is always a param |
fe692bf9 | 1604 | ClauseKind::ConstArgHasType(..) |
94b46f34 XL |
1605 | // Ignore projections, as they can only be global |
1606 | // if the trait bound is global | |
fe692bf9 | 1607 | | ClauseKind::Projection(..) |
94b46f34 | 1608 | // Ignore bounds that a user can't type |
fe692bf9 | 1609 | | ClauseKind::WellFormed(..) |
9ffffee4 | 1610 | // FIXME(generic_const_exprs): `ConstEvaluatable` can be written |
fe692bf9 | 1611 | | ClauseKind::ConstEvaluatable(..) => continue, |
94b46f34 | 1612 | }; |
5099ac24 | 1613 | if predicate.is_global() { |
c0240ec0 | 1614 | cx.emit_span_lint( |
2b03887a FG |
1615 | TRIVIAL_BOUNDS, |
1616 | span, | |
9c376795 | 1617 | BuiltinTrivialBounds { predicate_kind_name, predicate }, |
2b03887a | 1618 | ); |
94b46f34 XL |
1619 | } |
1620 | } | |
1621 | } | |
1622 | } | |
1623 | } | |
1624 | ||
532ac7d7 XL |
1625 | declare_lint_pass!( |
1626 | /// Does nothing as a lint pass, but registers some `Lint`s | |
1627 | /// which are used by other parts of the compiler. | |
1628 | SoftLints => [ | |
1629 | WHILE_TRUE, | |
1630 | BOX_POINTERS, | |
1631 | NON_SHORTHAND_FIELD_PATTERNS, | |
1632 | UNSAFE_CODE, | |
1633 | MISSING_DOCS, | |
1634 | MISSING_COPY_IMPLEMENTATIONS, | |
1635 | MISSING_DEBUG_IMPLEMENTATIONS, | |
1636 | ANONYMOUS_PARAMETERS, | |
1637 | UNUSED_DOC_COMMENTS, | |
532ac7d7 XL |
1638 | NO_MANGLE_CONST_ITEMS, |
1639 | NO_MANGLE_GENERIC_ITEMS, | |
1640 | MUTABLE_TRANSMUTES, | |
1641 | UNSTABLE_FEATURES, | |
532ac7d7 XL |
1642 | UNREACHABLE_PUB, |
1643 | TYPE_ALIAS_BOUNDS, | |
1644 | TRIVIAL_BOUNDS | |
1645 | ] | |
1646 | ); | |
8faf50e0 XL |
1647 | |
1648 | declare_lint! { | |
1b1a35ee XL |
1649 | /// The `ellipsis_inclusive_range_patterns` lint detects the [`...` range |
1650 | /// pattern], which is deprecated. | |
1651 | /// | |
1652 | /// [`...` range pattern]: https://doc.rust-lang.org/reference/patterns.html#range-patterns | |
1653 | /// | |
1654 | /// ### Example | |
1655 | /// | |
c295e0f8 | 1656 | /// ```rust,edition2018 |
1b1a35ee XL |
1657 | /// let x = 123; |
1658 | /// match x { | |
1659 | /// 0...100 => {} | |
1660 | /// _ => {} | |
1661 | /// } | |
1662 | /// ``` | |
1663 | /// | |
1664 | /// {{produces}} | |
1665 | /// | |
1666 | /// ### Explanation | |
1667 | /// | |
1668 | /// The `...` range pattern syntax was changed to `..=` to avoid potential | |
1669 | /// confusion with the [`..` range expression]. Use the new form instead. | |
1670 | /// | |
1671 | /// [`..` range expression]: https://doc.rust-lang.org/reference/expressions/range-expr.html | |
8faf50e0 | 1672 | pub ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, |
dc9dc135 | 1673 | Warn, |
17df50a5 XL |
1674 | "`...` range patterns are deprecated", |
1675 | @future_incompatible = FutureIncompatibleInfo { | |
136023e0 | 1676 | reason: FutureIncompatibilityReason::EditionError(Edition::Edition2021), |
781aab86 | 1677 | reference: "<https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>", |
17df50a5 | 1678 | }; |
8faf50e0 XL |
1679 | } |
1680 | ||
48663c56 XL |
1681 | #[derive(Default)] |
1682 | pub struct EllipsisInclusiveRangePatterns { | |
1683 | /// If `Some(_)`, suppress all subsequent pattern | |
1684 | /// warnings for better diagnostics. | |
1685 | node_id: Option<ast::NodeId>, | |
1686 | } | |
1687 | ||
1688 | impl_lint_pass!(EllipsisInclusiveRangePatterns => [ELLIPSIS_INCLUSIVE_RANGE_PATTERNS]); | |
8faf50e0 XL |
1689 | |
1690 | impl EarlyLintPass for EllipsisInclusiveRangePatterns { | |
48663c56 XL |
1691 | fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &ast::Pat) { |
1692 | if self.node_id.is_some() { | |
1693 | // Don't recursively warn about patterns inside range endpoints. | |
dfeec247 | 1694 | return; |
48663c56 XL |
1695 | } |
1696 | ||
3dfed10e | 1697 | use self::ast::{PatKind, RangeSyntax::DotDotDot}; |
13cf67c4 XL |
1698 | |
1699 | /// If `pat` is a `...` pattern, return the start and end of the range, as well as the span | |
1700 | /// corresponding to the ellipsis. | |
dfeec247 | 1701 | fn matches_ellipsis_pat(pat: &ast::Pat) -> Option<(Option<&Expr>, &Expr, Span)> { |
e74abb32 | 1702 | match &pat.kind { |
dfeec247 XL |
1703 | PatKind::Range( |
1704 | a, | |
1705 | Some(b), | |
1706 | Spanned { span, node: RangeEnd::Included(DotDotDot) }, | |
1707 | ) => Some((a.as_deref(), b, *span)), | |
13cf67c4 XL |
1708 | _ => None, |
1709 | } | |
1710 | } | |
8faf50e0 | 1711 | |
49aad941 | 1712 | let (parentheses, endpoints) = match &pat.kind { |
4b012472 | 1713 | PatKind::Ref(subpat, _) => (true, matches_ellipsis_pat(subpat)), |
13cf67c4 XL |
1714 | _ => (false, matches_ellipsis_pat(pat)), |
1715 | }; | |
1716 | ||
1717 | if let Some((start, end, join)) = endpoints { | |
49aad941 | 1718 | if parentheses { |
48663c56 | 1719 | self.node_id = Some(pat.id); |
4b012472 | 1720 | let end = expr_to_string(end); |
17df50a5 | 1721 | let replace = match start { |
4b012472 | 1722 | Some(start) => format!("&({}..={})", expr_to_string(start), end), |
add651ee | 1723 | None => format!("&(..={end})"), |
17df50a5 XL |
1724 | }; |
1725 | if join.edition() >= Edition::Edition2021 { | |
c0240ec0 | 1726 | cx.sess().dcx().emit_err(BuiltinEllipsisInclusiveRangePatterns { |
f2b60f7d FG |
1727 | span: pat.span, |
1728 | suggestion: pat.span, | |
17df50a5 | 1729 | replace, |
f2b60f7d | 1730 | }); |
17df50a5 | 1731 | } else { |
c0240ec0 | 1732 | cx.emit_span_lint( |
9c376795 FG |
1733 | ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, |
1734 | pat.span, | |
1735 | BuiltinEllipsisInclusiveRangePatternsLint::Parenthesise { | |
1736 | suggestion: pat.span, | |
2b03887a | 1737 | replace, |
9c376795 FG |
1738 | }, |
1739 | ); | |
17df50a5 | 1740 | } |
13cf67c4 | 1741 | } else { |
923072b8 | 1742 | let replace = "..="; |
17df50a5 | 1743 | if join.edition() >= Edition::Edition2021 { |
c0240ec0 | 1744 | cx.sess().dcx().emit_err(BuiltinEllipsisInclusiveRangePatterns { |
f2b60f7d FG |
1745 | span: pat.span, |
1746 | suggestion: join, | |
1747 | replace: replace.to_string(), | |
1748 | }); | |
17df50a5 | 1749 | } else { |
c0240ec0 | 1750 | cx.emit_span_lint( |
9c376795 FG |
1751 | ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, |
1752 | join, | |
1753 | BuiltinEllipsisInclusiveRangePatternsLint::NonParenthesise { | |
1754 | suggestion: join, | |
1755 | }, | |
1756 | ); | |
17df50a5 | 1757 | } |
13cf67c4 | 1758 | }; |
8faf50e0 XL |
1759 | } |
1760 | } | |
48663c56 XL |
1761 | |
1762 | fn check_pat_post(&mut self, _cx: &EarlyContext<'_>, pat: &ast::Pat) { | |
1763 | if let Some(node_id) = self.node_id { | |
1764 | if pat.id == node_id { | |
1765 | self.node_id = None | |
1766 | } | |
1767 | } | |
1768 | } | |
8faf50e0 XL |
1769 | } |
1770 | ||
8faf50e0 | 1771 | declare_lint! { |
e8be2606 | 1772 | /// The `keyword_idents_2018` lint detects edition keywords being used as an |
1b1a35ee XL |
1773 | /// identifier. |
1774 | /// | |
1775 | /// ### Example | |
1776 | /// | |
1777 | /// ```rust,edition2015,compile_fail | |
e8be2606 | 1778 | /// #![deny(keyword_idents_2018)] |
1b1a35ee XL |
1779 | /// // edition 2015 |
1780 | /// fn dyn() {} | |
1781 | /// ``` | |
1782 | /// | |
1783 | /// {{produces}} | |
1784 | /// | |
1785 | /// ### Explanation | |
1786 | /// | |
1787 | /// Rust [editions] allow the language to evolve without breaking | |
1788 | /// backwards compatibility. This lint catches code that uses new keywords | |
1789 | /// that are added to the language that are used as identifiers (such as a | |
1790 | /// variable name, function name, etc.). If you switch the compiler to a | |
1791 | /// new edition without updating the code, then it will fail to compile if | |
1792 | /// you are using a new keyword as an identifier. | |
1793 | /// | |
1794 | /// You can manually change the identifiers to a non-keyword, or use a | |
1795 | /// [raw identifier], for example `r#dyn`, to transition to a new edition. | |
1796 | /// | |
1797 | /// This lint solves the problem automatically. It is "allow" by default | |
1798 | /// because the code is perfectly valid in older editions. The [`cargo | |
1799 | /// fix`] tool with the `--edition` flag will switch this lint to "warn" | |
1800 | /// and automatically apply the suggested fix from the compiler (which is | |
1801 | /// to use a raw identifier). This provides a completely automated way to | |
1802 | /// update old code for a new edition. | |
1803 | /// | |
1804 | /// [editions]: https://doc.rust-lang.org/edition-guide/ | |
1805 | /// [raw identifier]: https://doc.rust-lang.org/reference/identifiers.html | |
1806 | /// [`cargo fix`]: https://doc.rust-lang.org/cargo/commands/cargo-fix.html | |
e8be2606 | 1807 | pub KEYWORD_IDENTS_2018, |
8faf50e0 | 1808 | Allow, |
e74abb32 XL |
1809 | "detects edition keywords being used as an identifier", |
1810 | @future_incompatible = FutureIncompatibleInfo { | |
136023e0 | 1811 | reason: FutureIncompatibilityReason::EditionError(Edition::Edition2018), |
781aab86 | 1812 | reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>", |
e74abb32 | 1813 | }; |
8faf50e0 XL |
1814 | } |
1815 | ||
e8be2606 FG |
1816 | declare_lint! { |
1817 | /// The `keyword_idents_2024` lint detects edition keywords being used as an | |
1818 | /// identifier. | |
1819 | /// | |
1820 | /// ### Example | |
1821 | /// | |
1822 | /// ```rust,edition2015,compile_fail | |
1823 | /// #![deny(keyword_idents_2024)] | |
1824 | /// // edition 2015 | |
1825 | /// fn gen() {} | |
1826 | /// ``` | |
1827 | /// | |
1828 | /// {{produces}} | |
1829 | /// | |
1830 | /// ### Explanation | |
1831 | /// | |
1832 | /// Rust [editions] allow the language to evolve without breaking | |
1833 | /// backwards compatibility. This lint catches code that uses new keywords | |
1834 | /// that are added to the language that are used as identifiers (such as a | |
1835 | /// variable name, function name, etc.). If you switch the compiler to a | |
1836 | /// new edition without updating the code, then it will fail to compile if | |
1837 | /// you are using a new keyword as an identifier. | |
1838 | /// | |
1839 | /// You can manually change the identifiers to a non-keyword, or use a | |
1840 | /// [raw identifier], for example `r#gen`, to transition to a new edition. | |
1841 | /// | |
1842 | /// This lint solves the problem automatically. It is "allow" by default | |
1843 | /// because the code is perfectly valid in older editions. The [`cargo | |
1844 | /// fix`] tool with the `--edition` flag will switch this lint to "warn" | |
1845 | /// and automatically apply the suggested fix from the compiler (which is | |
1846 | /// to use a raw identifier). This provides a completely automated way to | |
1847 | /// update old code for a new edition. | |
1848 | /// | |
1849 | /// [editions]: https://doc.rust-lang.org/edition-guide/ | |
1850 | /// [raw identifier]: https://doc.rust-lang.org/reference/identifiers.html | |
1851 | /// [`cargo fix`]: https://doc.rust-lang.org/cargo/commands/cargo-fix.html | |
1852 | pub KEYWORD_IDENTS_2024, | |
1853 | Allow, | |
1854 | "detects edition keywords being used as an identifier", | |
1855 | @future_incompatible = FutureIncompatibleInfo { | |
1856 | reason: FutureIncompatibilityReason::EditionError(Edition::Edition2024), | |
1857 | reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>", | |
1858 | }; | |
1859 | } | |
1860 | ||
532ac7d7 XL |
1861 | declare_lint_pass!( |
1862 | /// Check for uses of edition keywords used as an identifier. | |
e8be2606 | 1863 | KeywordIdents => [KEYWORD_IDENTS_2018, KEYWORD_IDENTS_2024] |
532ac7d7 | 1864 | ); |
8faf50e0 | 1865 | |
532ac7d7 | 1866 | struct UnderMacro(bool); |
8faf50e0 | 1867 | |
b7449926 | 1868 | impl KeywordIdents { |
49aad941 FG |
1869 | fn check_tokens(&mut self, cx: &EarlyContext<'_>, tokens: &TokenStream) { |
1870 | for tt in tokens.trees() { | |
8faf50e0 | 1871 | match tt { |
dc9dc135 | 1872 | // Only report non-raw idents. |
064997fb | 1873 | TokenTree::Token(token, _) => { |
c620b35d | 1874 | if let Some((ident, token::IdentIsRaw::No)) = token.ident() { |
dfeec247 XL |
1875 | self.check_ident_token(cx, UnderMacro(true), ident); |
1876 | } | |
8faf50e0 | 1877 | } |
4b012472 | 1878 | TokenTree::Delimited(.., tts) => self.check_tokens(cx, tts), |
8faf50e0 XL |
1879 | } |
1880 | } | |
1881 | } | |
8faf50e0 | 1882 | |
dfeec247 XL |
1883 | fn check_ident_token( |
1884 | &mut self, | |
1885 | cx: &EarlyContext<'_>, | |
1886 | UnderMacro(under_macro): UnderMacro, | |
f9f354fc | 1887 | ident: Ident, |
dfeec247 | 1888 | ) { |
e8be2606 FG |
1889 | let (lint, edition) = match ident.name { |
1890 | kw::Async | kw::Await | kw::Try => (KEYWORD_IDENTS_2018, Edition::Edition2018), | |
1891 | ||
1892 | // rust-lang/rust#56327: Conservatively do not | |
1893 | // attempt to report occurrences of `dyn` within | |
1894 | // macro definitions or invocations, because `dyn` | |
1895 | // can legitimately occur as a contextual keyword | |
1896 | // in 2015 code denoting its 2018 meaning, and we | |
1897 | // do not want rustfix to inject bugs into working | |
1898 | // code by rewriting such occurrences. | |
1899 | // | |
1900 | // But if we see `dyn` outside of a macro, we know | |
1901 | // its precise role in the parsed AST and thus are | |
1902 | // assured this is truly an attempt to use it as | |
1903 | // an identifier. | |
1904 | kw::Dyn if !under_macro => (KEYWORD_IDENTS_2018, Edition::Edition2018), | |
1905 | ||
1906 | kw::Gen => (KEYWORD_IDENTS_2024, Edition::Edition2024), | |
b7449926 | 1907 | |
48663c56 | 1908 | _ => return, |
b7449926 XL |
1909 | }; |
1910 | ||
dc9dc135 | 1911 | // Don't lint `r#foo`. |
e8be2606 FG |
1912 | if ident.span.edition() >= edition |
1913 | || cx.sess().psess.raw_identifier_spans.contains(ident.span) | |
1914 | { | |
b7449926 | 1915 | return; |
8faf50e0 | 1916 | } |
b7449926 | 1917 | |
c0240ec0 | 1918 | cx.emit_span_lint( |
e8be2606 | 1919 | lint, |
2b03887a | 1920 | ident.span, |
e8be2606 | 1921 | BuiltinKeywordIdents { kw: ident, next: edition, suggestion: ident.span }, |
2b03887a | 1922 | ); |
8faf50e0 XL |
1923 | } |
1924 | } | |
0bf4aa26 | 1925 | |
532ac7d7 | 1926 | impl EarlyLintPass for KeywordIdents { |
f2b60f7d | 1927 | fn check_mac_def(&mut self, cx: &EarlyContext<'_>, mac_def: &ast::MacroDef) { |
49aad941 | 1928 | self.check_tokens(cx, &mac_def.body.tokens); |
9fa01778 | 1929 | } |
ba9703b0 | 1930 | fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::MacCall) { |
49aad941 | 1931 | self.check_tokens(cx, &mac.args.tokens); |
532ac7d7 | 1932 | } |
f9f354fc | 1933 | fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: Ident) { |
532ac7d7 | 1934 | self.check_ident_token(cx, UnderMacro(false), ident); |
0bf4aa26 XL |
1935 | } |
1936 | } | |
1937 | ||
532ac7d7 XL |
1938 | declare_lint_pass!(ExplicitOutlivesRequirements => [EXPLICIT_OUTLIVES_REQUIREMENTS]); |
1939 | ||
0bf4aa26 | 1940 | impl ExplicitOutlivesRequirements { |
dc9dc135 | 1941 | fn lifetimes_outliving_lifetime<'tcx>( |
487cf647 | 1942 | inferred_outlives: &'tcx [(ty::Clause<'tcx>, Span)], |
f2b60f7d | 1943 | def_id: DefId, |
dc9dc135 | 1944 | ) -> Vec<ty::Region<'tcx>> { |
dfeec247 XL |
1945 | inferred_outlives |
1946 | .iter() | |
fe692bf9 FG |
1947 | .filter_map(|(clause, _)| match clause.kind().skip_binder() { |
1948 | ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate(a, b)) => match *a { | |
4b012472 | 1949 | ty::ReEarlyParam(ebr) if ebr.def_id == def_id => Some(b), |
3dfed10e XL |
1950 | _ => None, |
1951 | }, | |
dfeec247 XL |
1952 | _ => None, |
1953 | }) | |
1954 | .collect() | |
dc9dc135 | 1955 | } |
0bf4aa26 | 1956 | |
dc9dc135 | 1957 | fn lifetimes_outliving_type<'tcx>( |
487cf647 | 1958 | inferred_outlives: &'tcx [(ty::Clause<'tcx>, Span)], |
dc9dc135 XL |
1959 | index: u32, |
1960 | ) -> Vec<ty::Region<'tcx>> { | |
dfeec247 XL |
1961 | inferred_outlives |
1962 | .iter() | |
fe692bf9 FG |
1963 | .filter_map(|(clause, _)| match clause.kind().skip_binder() { |
1964 | ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(a, b)) => { | |
3dfed10e | 1965 | a.is_param(index).then_some(b) |
0bf4aa26 | 1966 | } |
dfeec247 XL |
1967 | _ => None, |
1968 | }) | |
1969 | .collect() | |
dc9dc135 XL |
1970 | } |
1971 | ||
dc9dc135 XL |
1972 | fn collect_outlives_bound_spans<'tcx>( |
1973 | &self, | |
1974 | tcx: TyCtxt<'tcx>, | |
dfeec247 | 1975 | bounds: &hir::GenericBounds<'_>, |
dc9dc135 | 1976 | inferred_outlives: &[ty::Region<'tcx>], |
9c376795 | 1977 | predicate_span: Span, |
dc9dc135 | 1978 | ) -> Vec<(usize, Span)> { |
9ffffee4 | 1979 | use rustc_middle::middle::resolve_bound_vars::ResolvedArg; |
dc9dc135 XL |
1980 | |
1981 | bounds | |
1982 | .iter() | |
1983 | .enumerate() | |
1984 | .filter_map(|(i, bound)| { | |
9c376795 FG |
1985 | let hir::GenericBound::Outlives(lifetime) = bound else { |
1986 | return None; | |
1987 | }; | |
1988 | ||
9ffffee4 FG |
1989 | let is_inferred = match tcx.named_bound_var(lifetime.hir_id) { |
1990 | Some(ResolvedArg::EarlyBound(def_id)) => inferred_outlives | |
9c376795 | 1991 | .iter() |
4b012472 | 1992 | .any(|r| matches!(**r, ty::ReEarlyParam(ebr) if { ebr.def_id == def_id })), |
9c376795 FG |
1993 | _ => false, |
1994 | }; | |
1995 | ||
1996 | if !is_inferred { | |
1997 | return None; | |
dc9dc135 | 1998 | } |
9c376795 FG |
1999 | |
2000 | let span = bound.span().find_ancestor_inside(predicate_span)?; | |
2001 | if in_external_macro(tcx.sess, span) { | |
2002 | return None; | |
2003 | } | |
2004 | ||
2005 | Some((i, span)) | |
dc9dc135 XL |
2006 | }) |
2007 | .collect() | |
0bf4aa26 XL |
2008 | } |
2009 | ||
2010 | fn consolidate_outlives_bound_spans( | |
2011 | &self, | |
2012 | lo: Span, | |
dfeec247 XL |
2013 | bounds: &hir::GenericBounds<'_>, |
2014 | bound_spans: Vec<(usize, Span)>, | |
0bf4aa26 XL |
2015 | ) -> Vec<Span> { |
2016 | if bounds.is_empty() { | |
2017 | return Vec::new(); | |
2018 | } | |
2019 | if bound_spans.len() == bounds.len() { | |
dfeec247 | 2020 | let (_, last_bound_span) = bound_spans[bound_spans.len() - 1]; |
0bf4aa26 XL |
2021 | // If all bounds are inferable, we want to delete the colon, so |
2022 | // start from just after the parameter (span passed as argument) | |
2023 | vec![lo.to(last_bound_span)] | |
2024 | } else { | |
2025 | let mut merged = Vec::new(); | |
2026 | let mut last_merged_i = None; | |
2027 | ||
2028 | let mut from_start = true; | |
2029 | for (i, bound_span) in bound_spans { | |
2030 | match last_merged_i { | |
dc9dc135 | 2031 | // If the first bound is inferable, our span should also eat the leading `+`. |
0bf4aa26 XL |
2032 | None if i == 0 => { |
2033 | merged.push(bound_span.to(bounds[1].span().shrink_to_lo())); | |
2034 | last_merged_i = Some(0); | |
dfeec247 | 2035 | } |
0bf4aa26 | 2036 | // If consecutive bounds are inferable, merge their spans |
dfeec247 | 2037 | Some(h) if i == h + 1 => { |
0bf4aa26 XL |
2038 | if let Some(tail) = merged.last_mut() { |
2039 | // Also eat the trailing `+` if the first | |
2040 | // more-than-one bound is inferable | |
2041 | let to_span = if from_start && i < bounds.len() { | |
dfeec247 | 2042 | bounds[i + 1].span().shrink_to_lo() |
0bf4aa26 XL |
2043 | } else { |
2044 | bound_span | |
2045 | }; | |
2046 | *tail = tail.to(to_span); | |
2047 | last_merged_i = Some(i); | |
2048 | } else { | |
2049 | bug!("another bound-span visited earlier"); | |
2050 | } | |
dfeec247 | 2051 | } |
0bf4aa26 XL |
2052 | _ => { |
2053 | // When we find a non-inferable bound, subsequent inferable bounds | |
2054 | // won't be consecutive from the start (and we'll eat the leading | |
2055 | // `+` rather than the trailing one) | |
2056 | from_start = false; | |
dfeec247 | 2057 | merged.push(bounds[i - 1].span().shrink_to_hi().to(bound_span)); |
0bf4aa26 XL |
2058 | last_merged_i = Some(i); |
2059 | } | |
2060 | } | |
2061 | } | |
2062 | merged | |
2063 | } | |
2064 | } | |
2065 | } | |
2066 | ||
f035d41b XL |
2067 | impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements { |
2068 | fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) { | |
9ffffee4 | 2069 | use rustc_middle::middle::resolve_bound_vars::ResolvedArg; |
dc9dc135 | 2070 | |
2b03887a | 2071 | let def_id = item.owner_id.def_id; |
9c376795 FG |
2072 | if let hir::ItemKind::Struct(_, hir_generics) |
2073 | | hir::ItemKind::Enum(_, hir_generics) | |
2074 | | hir::ItemKind::Union(_, hir_generics) = item.kind | |
dc9dc135 XL |
2075 | { |
2076 | let inferred_outlives = cx.tcx.inferred_outlives_of(def_id); | |
2077 | if inferred_outlives.is_empty() { | |
2078 | return; | |
2079 | } | |
2080 | ||
2081 | let ty_generics = cx.tcx.generics_of(def_id); | |
fe692bf9 FG |
2082 | let num_where_predicates = hir_generics |
2083 | .predicates | |
2084 | .iter() | |
2085 | .filter(|predicate| predicate.in_where_clause()) | |
2086 | .count(); | |
dc9dc135 | 2087 | |
0bf4aa26 XL |
2088 | let mut bound_count = 0; |
2089 | let mut lint_spans = Vec::new(); | |
0bf4aa26 | 2090 | let mut where_lint_spans = Vec::new(); |
fe692bf9 | 2091 | let mut dropped_where_predicate_count = 0; |
04454e1e | 2092 | for (i, where_predicate) in hir_generics.predicates.iter().enumerate() { |
9c376795 FG |
2093 | let (relevant_lifetimes, bounds, predicate_span, in_where_clause) = |
2094 | match where_predicate { | |
2095 | hir::WherePredicate::RegionPredicate(predicate) => { | |
9ffffee4 FG |
2096 | if let Some(ResolvedArg::EarlyBound(region_def_id)) = |
2097 | cx.tcx.named_bound_var(predicate.lifetime.hir_id) | |
9c376795 | 2098 | { |
a2a8927a | 2099 | ( |
9c376795 FG |
2100 | Self::lifetimes_outliving_lifetime( |
2101 | inferred_outlives, | |
2102 | region_def_id, | |
2103 | ), | |
a2a8927a XL |
2104 | &predicate.bounds, |
2105 | predicate.span, | |
9c376795 | 2106 | predicate.in_where_clause, |
a2a8927a | 2107 | ) |
9c376795 | 2108 | } else { |
dfeec247 XL |
2109 | continue; |
2110 | } | |
dc9dc135 | 2111 | } |
9c376795 FG |
2112 | hir::WherePredicate::BoundPredicate(predicate) => { |
2113 | // FIXME we can also infer bounds on associated types, | |
2114 | // and should check for them here. | |
2115 | match predicate.bounded_ty.kind { | |
2116 | hir::TyKind::Path(hir::QPath::Resolved(None, path)) => { | |
2117 | let Res::Def(DefKind::TyParam, def_id) = path.res else { | |
add651ee FG |
2118 | continue; |
2119 | }; | |
9c376795 FG |
2120 | let index = ty_generics.param_def_id_to_index[&def_id]; |
2121 | ( | |
2122 | Self::lifetimes_outliving_type(inferred_outlives, index), | |
2123 | &predicate.bounds, | |
2124 | predicate.span, | |
2125 | predicate.origin == PredicateOrigin::WhereClause, | |
2126 | ) | |
2127 | } | |
2128 | _ => { | |
2129 | continue; | |
2130 | } | |
2131 | } | |
2132 | } | |
2133 | _ => continue, | |
2134 | }; | |
dc9dc135 XL |
2135 | if relevant_lifetimes.is_empty() { |
2136 | continue; | |
2137 | } | |
2138 | ||
9c376795 FG |
2139 | let bound_spans = self.collect_outlives_bound_spans( |
2140 | cx.tcx, | |
2141 | bounds, | |
2142 | &relevant_lifetimes, | |
2143 | predicate_span, | |
2144 | ); | |
dc9dc135 XL |
2145 | bound_count += bound_spans.len(); |
2146 | ||
2147 | let drop_predicate = bound_spans.len() == bounds.len(); | |
fe692bf9 FG |
2148 | if drop_predicate && in_where_clause { |
2149 | dropped_where_predicate_count += 1; | |
dc9dc135 XL |
2150 | } |
2151 | ||
9ffffee4 FG |
2152 | if drop_predicate { |
2153 | if !in_where_clause { | |
2154 | lint_spans.push(predicate_span); | |
2155 | } else if predicate_span.from_expansion() { | |
2156 | // Don't try to extend the span if it comes from a macro expansion. | |
2157 | where_lint_spans.push(predicate_span); | |
fe692bf9 | 2158 | } else if i + 1 < num_where_predicates { |
9ffffee4 FG |
2159 | // If all the bounds on a predicate were inferable and there are |
2160 | // further predicates, we want to eat the trailing comma. | |
2161 | let next_predicate_span = hir_generics.predicates[i + 1].span(); | |
2162 | if next_predicate_span.from_expansion() { | |
2163 | where_lint_spans.push(predicate_span); | |
2164 | } else { | |
2165 | where_lint_spans | |
2166 | .push(predicate_span.to(next_predicate_span.shrink_to_lo())); | |
2167 | } | |
2168 | } else { | |
2169 | // Eat the optional trailing comma after the last predicate. | |
2170 | let where_span = hir_generics.where_clause_span; | |
2171 | if where_span.from_expansion() { | |
2172 | where_lint_spans.push(predicate_span); | |
2173 | } else { | |
2174 | where_lint_spans.push(predicate_span.to(where_span.shrink_to_hi())); | |
2175 | } | |
2176 | } | |
dc9dc135 | 2177 | } else { |
dfeec247 | 2178 | where_lint_spans.extend(self.consolidate_outlives_bound_spans( |
9c376795 | 2179 | predicate_span.shrink_to_lo(), |
dfeec247 XL |
2180 | bounds, |
2181 | bound_spans, | |
2182 | )); | |
0bf4aa26 XL |
2183 | } |
2184 | } | |
2185 | ||
fe692bf9 | 2186 | // If all predicates in where clause are inferable, drop the entire clause |
0bf4aa26 | 2187 | // (including the `where`) |
fe692bf9 FG |
2188 | if hir_generics.has_where_clause_predicates |
2189 | && dropped_where_predicate_count == num_where_predicates | |
923072b8 FG |
2190 | { |
2191 | let where_span = hir_generics.where_clause_span; | |
dc9dc135 XL |
2192 | // Extend the where clause back to the closing `>` of the |
2193 | // generics, except for tuple struct, which have the `where` | |
2194 | // after the fields of the struct. | |
dfeec247 XL |
2195 | let full_where_span = |
2196 | if let hir::ItemKind::Struct(hir::VariantData::Tuple(..), _) = item.kind { | |
2197 | where_span | |
2198 | } else { | |
2199 | hir_generics.span.shrink_to_hi().to(where_span) | |
2200 | }; | |
9c376795 FG |
2201 | |
2202 | // Due to macro expansions, the `full_where_span` might not actually contain all predicates. | |
2203 | if where_lint_spans.iter().all(|&sp| full_where_span.contains(sp)) { | |
2204 | lint_spans.push(full_where_span); | |
2205 | } else { | |
2206 | lint_spans.extend(where_lint_spans); | |
2207 | } | |
0bf4aa26 XL |
2208 | } else { |
2209 | lint_spans.extend(where_lint_spans); | |
2210 | } | |
2211 | ||
2212 | if !lint_spans.is_empty() { | |
9c376795 FG |
2213 | // Do not automatically delete outlives requirements from macros. |
2214 | let applicability = if lint_spans.iter().all(|sp| sp.can_be_used_for_suggestions()) | |
2215 | { | |
2216 | Applicability::MachineApplicable | |
2217 | } else { | |
2218 | Applicability::MaybeIncorrect | |
2219 | }; | |
2220 | ||
9ffffee4 FG |
2221 | // Due to macros, there might be several predicates with the same span |
2222 | // and we only want to suggest removing them once. | |
2223 | lint_spans.sort_unstable(); | |
2224 | lint_spans.dedup(); | |
2225 | ||
c0240ec0 | 2226 | cx.emit_span_lint( |
2b03887a FG |
2227 | EXPLICIT_OUTLIVES_REQUIREMENTS, |
2228 | lint_spans.clone(), | |
9c376795 FG |
2229 | BuiltinExplicitOutlives { |
2230 | count: bound_count, | |
2231 | suggestion: BuiltinExplicitOutlivesSuggestion { | |
2232 | spans: lint_spans, | |
2233 | applicability, | |
2234 | }, | |
2b03887a FG |
2235 | }, |
2236 | ); | |
0bf4aa26 | 2237 | } |
0bf4aa26 XL |
2238 | } |
2239 | } | |
0bf4aa26 | 2240 | } |
416331ca XL |
2241 | |
2242 | declare_lint! { | |
1b1a35ee XL |
2243 | /// The `incomplete_features` lint detects unstable features enabled with |
2244 | /// the [`feature` attribute] that may function improperly in some or all | |
2245 | /// cases. | |
2246 | /// | |
2247 | /// [`feature` attribute]: https://doc.rust-lang.org/nightly/unstable-book/ | |
2248 | /// | |
2249 | /// ### Example | |
2250 | /// | |
2251 | /// ```rust | |
94222f64 | 2252 | /// #![feature(generic_const_exprs)] |
1b1a35ee XL |
2253 | /// ``` |
2254 | /// | |
2255 | /// {{produces}} | |
2256 | /// | |
2257 | /// ### Explanation | |
2258 | /// | |
2259 | /// Although it is encouraged for people to experiment with unstable | |
2260 | /// features, some of them are known to be incomplete or faulty. This lint | |
2261 | /// is a signal that the feature has not yet been finished, and you may | |
2262 | /// experience problems with it. | |
416331ca XL |
2263 | pub INCOMPLETE_FEATURES, |
2264 | Warn, | |
2265 | "incomplete features that may function improperly in some or all cases" | |
2266 | } | |
2267 | ||
add651ee FG |
2268 | declare_lint! { |
2269 | /// The `internal_features` lint detects unstable features enabled with | |
2270 | /// the [`feature` attribute] that are internal to the compiler or standard | |
2271 | /// library. | |
2272 | /// | |
2273 | /// [`feature` attribute]: https://doc.rust-lang.org/nightly/unstable-book/ | |
2274 | /// | |
2275 | /// ### Example | |
2276 | /// | |
2277 | /// ```rust | |
2278 | /// #![feature(rustc_attrs)] | |
2279 | /// ``` | |
2280 | /// | |
2281 | /// {{produces}} | |
2282 | /// | |
2283 | /// ### Explanation | |
2284 | /// | |
2285 | /// These features are an implementation detail of the compiler and standard | |
2286 | /// library and are not supposed to be used in user code. | |
2287 | pub INTERNAL_FEATURES, | |
2288 | Warn, | |
2289 | "internal features are not supposed to be used" | |
2290 | } | |
2291 | ||
416331ca | 2292 | declare_lint_pass!( |
ed00b5ec | 2293 | /// Check for used feature gates in `INCOMPLETE_FEATURES` in `rustc_feature/src/unstable.rs`. |
add651ee | 2294 | IncompleteInternalFeatures => [INCOMPLETE_FEATURES, INTERNAL_FEATURES] |
416331ca XL |
2295 | ); |
2296 | ||
add651ee | 2297 | impl EarlyLintPass for IncompleteInternalFeatures { |
416331ca | 2298 | fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &ast::Crate) { |
add651ee | 2299 | let features = cx.builder.features(); |
dfeec247 XL |
2300 | features |
2301 | .declared_lang_features | |
2302 | .iter() | |
2303 | .map(|(name, span, _)| (name, span)) | |
416331ca | 2304 | .chain(features.declared_lib_features.iter().map(|(name, span)| (name, span))) |
add651ee | 2305 | .filter(|(&name, _)| features.incomplete(name) || features.internal(name)) |
f9f354fc | 2306 | .for_each(|(&name, &span)| { |
add651ee | 2307 | if features.incomplete(name) { |
ed00b5ec FG |
2308 | let note = rustc_feature::find_feature_issue(name, GateIssue::Language) |
2309 | .map(|n| BuiltinFeatureIssueNote { n }); | |
add651ee FG |
2310 | let help = |
2311 | HAS_MIN_FEATURES.contains(&name).then_some(BuiltinIncompleteFeaturesHelp); | |
ed00b5ec | 2312 | |
c0240ec0 | 2313 | cx.emit_span_lint( |
add651ee FG |
2314 | INCOMPLETE_FEATURES, |
2315 | span, | |
2316 | BuiltinIncompleteFeatures { name, note, help }, | |
2317 | ); | |
2318 | } else { | |
c0240ec0 | 2319 | cx.emit_span_lint(INTERNAL_FEATURES, span, BuiltinInternalFeatures { name }); |
add651ee | 2320 | } |
416331ca XL |
2321 | }); |
2322 | } | |
2323 | } | |
2324 | ||
5869c6ff | 2325 | const HAS_MIN_FEATURES: &[Symbol] = &[sym::specialization]; |
29967ef6 | 2326 | |
416331ca | 2327 | declare_lint! { |
1b1a35ee | 2328 | /// The `invalid_value` lint detects creating a value that is not valid, |
17df50a5 | 2329 | /// such as a null reference. |
1b1a35ee XL |
2330 | /// |
2331 | /// ### Example | |
2332 | /// | |
2333 | /// ```rust,no_run | |
2334 | /// # #![allow(unused)] | |
2335 | /// unsafe { | |
2336 | /// let x: &'static i32 = std::mem::zeroed(); | |
2337 | /// } | |
2338 | /// ``` | |
2339 | /// | |
2340 | /// {{produces}} | |
2341 | /// | |
2342 | /// ### Explanation | |
2343 | /// | |
2344 | /// In some situations the compiler can detect that the code is creating | |
2345 | /// an invalid value, which should be avoided. | |
2346 | /// | |
2347 | /// In particular, this lint will check for improper use of | |
2348 | /// [`mem::zeroed`], [`mem::uninitialized`], [`mem::transmute`], and | |
2349 | /// [`MaybeUninit::assume_init`] that can cause [undefined behavior]. The | |
2350 | /// lint should provide extra information to indicate what the problem is | |
2351 | /// and a possible solution. | |
2352 | /// | |
2353 | /// [`mem::zeroed`]: https://doc.rust-lang.org/std/mem/fn.zeroed.html | |
2354 | /// [`mem::uninitialized`]: https://doc.rust-lang.org/std/mem/fn.uninitialized.html | |
2355 | /// [`mem::transmute`]: https://doc.rust-lang.org/std/mem/fn.transmute.html | |
2356 | /// [`MaybeUninit::assume_init`]: https://doc.rust-lang.org/std/mem/union.MaybeUninit.html#method.assume_init | |
2357 | /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html | |
416331ca XL |
2358 | pub INVALID_VALUE, |
2359 | Warn, | |
17df50a5 | 2360 | "an invalid value is being created (such as a null reference)" |
416331ca XL |
2361 | } |
2362 | ||
2363 | declare_lint_pass!(InvalidValue => [INVALID_VALUE]); | |
2364 | ||
9c376795 FG |
2365 | /// Information about why a type cannot be initialized this way. |
2366 | pub struct InitError { | |
2367 | pub(crate) message: String, | |
2368 | /// Spans from struct fields and similar that can be obtained from just the type. | |
2369 | pub(crate) span: Option<Span>, | |
2370 | /// Used to report a trace through adts. | |
2371 | pub(crate) nested: Option<Box<InitError>>, | |
2372 | } | |
2373 | impl InitError { | |
2374 | fn spanned(self, span: Span) -> InitError { | |
2375 | Self { span: Some(span), ..self } | |
2376 | } | |
2377 | ||
2378 | fn nested(self, nested: impl Into<Option<InitError>>) -> InitError { | |
2379 | assert!(self.nested.is_none()); | |
2380 | Self { nested: nested.into().map(Box::new), ..self } | |
2381 | } | |
2382 | } | |
2383 | ||
2384 | impl<'a> From<&'a str> for InitError { | |
2385 | fn from(s: &'a str) -> Self { | |
2386 | s.to_owned().into() | |
2387 | } | |
2388 | } | |
2389 | impl From<String> for InitError { | |
2390 | fn from(message: String) -> Self { | |
2391 | Self { message, span: None, nested: None } | |
2392 | } | |
2393 | } | |
2394 | ||
f035d41b XL |
2395 | impl<'tcx> LateLintPass<'tcx> for InvalidValue { |
2396 | fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &hir::Expr<'_>) { | |
e1599b0c | 2397 | #[derive(Debug, Copy, Clone, PartialEq)] |
dfeec247 XL |
2398 | enum InitKind { |
2399 | Zeroed, | |
2400 | Uninit, | |
fc512014 | 2401 | } |
416331ca | 2402 | |
e1599b0c | 2403 | /// Test if this constant is all-0. |
dfeec247 | 2404 | fn is_zero(expr: &hir::Expr<'_>) -> bool { |
e1599b0c | 2405 | use hir::ExprKind::*; |
3dfed10e | 2406 | use rustc_ast::LitKind::*; |
e74abb32 | 2407 | match &expr.kind { |
dfeec247 | 2408 | Lit(lit) => { |
e1599b0c XL |
2409 | if let Int(i, _) = lit.node { |
2410 | i == 0 | |
2411 | } else { | |
2412 | false | |
dfeec247 XL |
2413 | } |
2414 | } | |
2415 | Tup(tup) => tup.iter().all(is_zero), | |
2416 | _ => false, | |
e1599b0c XL |
2417 | } |
2418 | } | |
2419 | ||
2420 | /// Determine if this expression is a "dangerous initialization". | |
f035d41b | 2421 | fn is_dangerous_init(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<InitKind> { |
4b012472 | 2422 | if let hir::ExprKind::Call(path_expr, args) = expr.kind { |
60c5eb7d | 2423 | // Find calls to `mem::{uninitialized,zeroed}` methods. |
e74abb32 | 2424 | if let hir::ExprKind::Path(ref qpath) = path_expr.kind { |
f035d41b | 2425 | let def_id = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id()?; |
c295e0f8 XL |
2426 | match cx.tcx.get_diagnostic_name(def_id) { |
2427 | Some(sym::mem_zeroed) => return Some(InitKind::Zeroed), | |
2428 | Some(sym::mem_uninitialized) => return Some(InitKind::Uninit), | |
2429 | Some(sym::transmute) if is_zero(&args[0]) => return Some(InitKind::Zeroed), | |
2430 | _ => {} | |
e1599b0c | 2431 | } |
60c5eb7d | 2432 | } |
f2b60f7d | 2433 | } else if let hir::ExprKind::MethodCall(_, receiver, ..) = expr.kind { |
60c5eb7d | 2434 | // Find problematic calls to `MaybeUninit::assume_init`. |
3dfed10e | 2435 | let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id)?; |
60c5eb7d XL |
2436 | if cx.tcx.is_diagnostic_item(sym::assume_init, def_id) { |
2437 | // This is a call to *some* method named `assume_init`. | |
2438 | // See if the `self` parameter is one of the dangerous constructors. | |
4b012472 | 2439 | if let hir::ExprKind::Call(path_expr, _) = receiver.kind { |
60c5eb7d | 2440 | if let hir::ExprKind::Path(ref qpath) = path_expr.kind { |
f035d41b | 2441 | let def_id = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id()?; |
c295e0f8 XL |
2442 | match cx.tcx.get_diagnostic_name(def_id) { |
2443 | Some(sym::maybe_uninit_zeroed) => return Some(InitKind::Zeroed), | |
2444 | Some(sym::maybe_uninit_uninit) => return Some(InitKind::Uninit), | |
2445 | _ => {} | |
60c5eb7d XL |
2446 | } |
2447 | } | |
2448 | } | |
e1599b0c XL |
2449 | } |
2450 | } | |
2451 | ||
2452 | None | |
2453 | } | |
2454 | ||
2b03887a FG |
2455 | fn variant_find_init_error<'tcx>( |
2456 | cx: &LateContext<'tcx>, | |
487cf647 | 2457 | ty: Ty<'tcx>, |
2b03887a | 2458 | variant: &VariantDef, |
add651ee | 2459 | args: ty::GenericArgsRef<'tcx>, |
2b03887a FG |
2460 | descr: &str, |
2461 | init: InitKind, | |
2462 | ) -> Option<InitError> { | |
487cf647 | 2463 | let mut field_err = variant.fields.iter().find_map(|field| { |
add651ee | 2464 | ty_find_init_error(cx, field.ty(cx.tcx, args), init).map(|mut err| { |
487cf647 FG |
2465 | if !field.did.is_local() { |
2466 | err | |
2467 | } else if err.span.is_none() { | |
2468 | err.span = Some(cx.tcx.def_span(field.did)); | |
2469 | write!(&mut err.message, " (in this {descr})").unwrap(); | |
2470 | err | |
2b03887a | 2471 | } else { |
487cf647 FG |
2472 | InitError::from(format!("in this {descr}")) |
2473 | .spanned(cx.tcx.def_span(field.did)) | |
2474 | .nested(err) | |
2b03887a FG |
2475 | } |
2476 | }) | |
487cf647 FG |
2477 | }); |
2478 | ||
2479 | // Check if this ADT has a constrained layout (like `NonNull` and friends). | |
2480 | if let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(ty)) { | |
2481 | if let Abi::Scalar(scalar) | Abi::ScalarPair(scalar, _) = &layout.abi { | |
2482 | let range = scalar.valid_range(cx); | |
2483 | let msg = if !range.contains(0) { | |
2484 | "must be non-null" | |
2485 | } else if init == InitKind::Uninit && !scalar.is_always_valid(cx) { | |
2486 | // Prefer reporting on the fields over the entire struct for uninit, | |
2487 | // as the information bubbles out and it may be unclear why the type can't | |
2488 | // be null from just its outside signature. | |
2489 | ||
2490 | "must be initialized inside its custom valid range" | |
2491 | } else { | |
2492 | return field_err; | |
2493 | }; | |
2494 | if let Some(field_err) = &mut field_err { | |
2495 | // Most of the time, if the field error is the same as the struct error, | |
2496 | // the struct error only happens because of the field error. | |
2497 | if field_err.message.contains(msg) { | |
2498 | field_err.message = format!("because {}", field_err.message); | |
2499 | } | |
2500 | } | |
2501 | return Some(InitError::from(format!("`{ty}` {msg}")).nested(field_err)); | |
2502 | } | |
2503 | } | |
2504 | field_err | |
3dfed10e XL |
2505 | } |
2506 | ||
416331ca XL |
2507 | /// Return `Some` only if we are sure this type does *not* |
2508 | /// allow zero initialization. | |
e1599b0c | 2509 | fn ty_find_init_error<'tcx>( |
5e7ed085 | 2510 | cx: &LateContext<'tcx>, |
e1599b0c XL |
2511 | ty: Ty<'tcx>, |
2512 | init: InitKind, | |
2513 | ) -> Option<InitError> { | |
e8be2606 FG |
2514 | let ty = cx.tcx.try_normalize_erasing_regions(cx.param_env, ty).unwrap_or(ty); |
2515 | ||
ed00b5ec | 2516 | use rustc_type_ir::TyKind::*; |
1b1a35ee | 2517 | match ty.kind() { |
416331ca | 2518 | // Primitive types that don't like 0 as a value. |
487cf647 FG |
2519 | Ref(..) => Some("references must be non-null".into()), |
2520 | Adt(..) if ty.is_box() => Some("`Box` must be non-null".into()), | |
2521 | FnPtr(..) => Some("function pointers must be non-null".into()), | |
2522 | Never => Some("the `!` type has no valid value".into()), | |
e8be2606 | 2523 | RawPtr(ty, _) if matches!(ty.kind(), Dynamic(..)) => |
dfeec247 XL |
2524 | // raw ptr to dyn Trait |
2525 | { | |
487cf647 | 2526 | Some("the vtable of a wide raw pointer must be non-null".into()) |
dfeec247 | 2527 | } |
e1599b0c | 2528 | // Primitive types with other constraints. |
dfeec247 | 2529 | Bool if init == InitKind::Uninit => { |
487cf647 | 2530 | Some("booleans must be either `true` or `false`".into()) |
dfeec247 XL |
2531 | } |
2532 | Char if init == InitKind::Uninit => { | |
487cf647 | 2533 | Some("characters must be a valid Unicode codepoint".into()) |
dfeec247 | 2534 | } |
f2b60f7d | 2535 | Int(_) | Uint(_) if init == InitKind::Uninit => { |
487cf647 | 2536 | Some("integers must be initialized".into()) |
f2b60f7d | 2537 | } |
487cf647 | 2538 | Float(_) if init == InitKind::Uninit => Some("floats must be initialized".into()), |
e8be2606 | 2539 | RawPtr(_, _) if init == InitKind::Uninit => { |
487cf647 | 2540 | Some("raw pointers must be initialized".into()) |
f2b60f7d | 2541 | } |
2b03887a | 2542 | // Recurse and checks for some compound types. (but not unions) |
add651ee | 2543 | Adt(adt_def, args) if !adt_def.is_union() => { |
2b03887a FG |
2544 | // Handle structs. |
2545 | if adt_def.is_struct() { | |
2546 | return variant_find_init_error( | |
2547 | cx, | |
487cf647 | 2548 | ty, |
2b03887a | 2549 | adt_def.non_enum_variant(), |
add651ee | 2550 | args, |
2b03887a FG |
2551 | "struct field", |
2552 | init, | |
2553 | ); | |
2554 | } | |
2555 | // And now, enums. | |
2556 | let span = cx.tcx.def_span(adt_def.did()); | |
2557 | let mut potential_variants = adt_def.variants().iter().filter_map(|variant| { | |
2558 | let definitely_inhabited = match variant | |
2559 | .inhabited_predicate(cx.tcx, *adt_def) | |
add651ee | 2560 | .instantiate(cx.tcx, args) |
2b03887a FG |
2561 | .apply_any_module(cx.tcx, cx.param_env) |
2562 | { | |
49aad941 | 2563 | // Entirely skip uninhabited variants. |
2b03887a FG |
2564 | Some(false) => return None, |
2565 | // Forward the others, but remember which ones are definitely inhabited. | |
2566 | Some(true) => true, | |
2567 | None => false, | |
2568 | }; | |
2569 | Some((variant, definitely_inhabited)) | |
2570 | }); | |
2571 | let Some(first_variant) = potential_variants.next() else { | |
add651ee FG |
2572 | return Some( |
2573 | InitError::from("enums with no inhabited variants have no valid value") | |
2574 | .spanned(span), | |
2575 | ); | |
2b03887a FG |
2576 | }; |
2577 | // So we have at least one potentially inhabited variant. Might we have two? | |
2578 | let Some(second_variant) = potential_variants.next() else { | |
2579 | // There is only one potentially inhabited variant. So we can recursively check that variant! | |
2580 | return variant_find_init_error( | |
2581 | cx, | |
487cf647 | 2582 | ty, |
4b012472 | 2583 | first_variant.0, |
add651ee | 2584 | args, |
2b03887a FG |
2585 | "field of the only potentially inhabited enum variant", |
2586 | init, | |
2587 | ); | |
2588 | }; | |
2589 | // So we have at least two potentially inhabited variants. | |
2590 | // If we can prove that we have at least two *definitely* inhabited variants, | |
2591 | // then we have a tag and hence leaving this uninit is definitely disallowed. | |
2592 | // (Leaving it zeroed could be okay, depending on which variant is encoded as zero tag.) | |
2593 | if init == InitKind::Uninit { | |
2594 | let definitely_inhabited = (first_variant.1 as usize) | |
2595 | + (second_variant.1 as usize) | |
2596 | + potential_variants | |
2597 | .filter(|(_variant, definitely_inhabited)| *definitely_inhabited) | |
2598 | .count(); | |
2599 | if definitely_inhabited > 1 { | |
487cf647 FG |
2600 | return Some(InitError::from( |
2601 | "enums with multiple inhabited variants have to be initialized to a variant", | |
2602 | ).spanned(span)); | |
3dfed10e | 2603 | } |
416331ca | 2604 | } |
2b03887a FG |
2605 | // We couldn't find anything wrong here. |
2606 | None | |
416331ca XL |
2607 | } |
2608 | Tuple(..) => { | |
2609 | // Proceed recursively, check all fields. | |
5e7ed085 FG |
2610 | ty.tuple_fields().iter().find_map(|field| ty_find_init_error(cx, field, init)) |
2611 | } | |
2612 | Array(ty, len) => { | |
9ffffee4 | 2613 | if matches!(len.try_eval_target_usize(cx.tcx, cx.param_env), Some(v) if v > 0) { |
5e7ed085 FG |
2614 | // Array length known at array non-empty -- recurse. |
2615 | ty_find_init_error(cx, *ty, init) | |
2616 | } else { | |
2617 | // Empty array or size unknown. | |
2618 | None | |
2619 | } | |
416331ca | 2620 | } |
416331ca XL |
2621 | // Conservative fallback. |
2622 | _ => None, | |
2623 | } | |
2624 | } | |
2625 | ||
e1599b0c XL |
2626 | if let Some(init) = is_dangerous_init(cx, expr) { |
2627 | // This conjures an instance of a type out of nothing, | |
2628 | // using zeroed or uninitialized memory. | |
2629 | // We are extremely conservative with what we warn about. | |
3dfed10e | 2630 | let conjured_ty = cx.typeck_results().expr_ty(expr); |
9c376795 FG |
2631 | if let Some(err) = with_no_trimmed_paths!(ty_find_init_error(cx, conjured_ty, init)) { |
2632 | let msg = match init { | |
2633 | InitKind::Zeroed => fluent::lint_builtin_unpermitted_type_init_zeroed, | |
49aad941 | 2634 | InitKind::Uninit => fluent::lint_builtin_unpermitted_type_init_uninit, |
9c376795 FG |
2635 | }; |
2636 | let sub = BuiltinUnpermittedTypeInitSub { err }; | |
c0240ec0 | 2637 | cx.emit_span_lint( |
2b03887a FG |
2638 | INVALID_VALUE, |
2639 | expr.span, | |
9ffffee4 FG |
2640 | BuiltinUnpermittedTypeInit { |
2641 | msg, | |
2642 | ty: conjured_ty, | |
2643 | label: expr.span, | |
2644 | sub, | |
2645 | tcx: cx.tcx, | |
2646 | }, | |
2b03887a | 2647 | ); |
416331ca XL |
2648 | } |
2649 | } | |
2650 | } | |
2651 | } | |
f035d41b | 2652 | |
cdc7bbd5 XL |
2653 | declare_lint! { |
2654 | /// The `deref_nullptr` lint detects when an null pointer is dereferenced, | |
2655 | /// which causes [undefined behavior]. | |
2656 | /// | |
2657 | /// ### Example | |
2658 | /// | |
2659 | /// ```rust,no_run | |
2660 | /// # #![allow(unused)] | |
2661 | /// use std::ptr; | |
2662 | /// unsafe { | |
2663 | /// let x = &*ptr::null::<i32>(); | |
2664 | /// let x = ptr::addr_of!(*ptr::null::<i32>()); | |
2665 | /// let x = *(0 as *const i32); | |
2666 | /// } | |
2667 | /// ``` | |
2668 | /// | |
2669 | /// {{produces}} | |
2670 | /// | |
2671 | /// ### Explanation | |
2672 | /// | |
2673 | /// Dereferencing a null pointer causes [undefined behavior] even as a place expression, | |
2674 | /// like `&*(0 as *const i32)` or `addr_of!(*(0 as *const i32))`. | |
2675 | /// | |
2676 | /// [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html | |
2677 | pub DEREF_NULLPTR, | |
2678 | Warn, | |
2679 | "detects when an null pointer is dereferenced" | |
2680 | } | |
2681 | ||
2682 | declare_lint_pass!(DerefNullPtr => [DEREF_NULLPTR]); | |
2683 | ||
2684 | impl<'tcx> LateLintPass<'tcx> for DerefNullPtr { | |
2685 | fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &hir::Expr<'_>) { | |
2686 | /// test if expression is a null ptr | |
2687 | fn is_null_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool { | |
2688 | match &expr.kind { | |
4b012472 | 2689 | rustc_hir::ExprKind::Cast(expr, ty) => { |
cdc7bbd5 XL |
2690 | if let rustc_hir::TyKind::Ptr(_) = ty.kind { |
2691 | return is_zero(expr) || is_null_ptr(cx, expr); | |
2692 | } | |
2693 | } | |
2694 | // check for call to `core::ptr::null` or `core::ptr::null_mut` | |
4b012472 | 2695 | rustc_hir::ExprKind::Call(path, _) => { |
cdc7bbd5 XL |
2696 | if let rustc_hir::ExprKind::Path(ref qpath) = path.kind { |
2697 | if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id() { | |
c295e0f8 XL |
2698 | return matches!( |
2699 | cx.tcx.get_diagnostic_name(def_id), | |
2700 | Some(sym::ptr_null | sym::ptr_null_mut) | |
2701 | ); | |
cdc7bbd5 XL |
2702 | } |
2703 | } | |
2704 | } | |
2705 | _ => {} | |
2706 | } | |
2707 | false | |
2708 | } | |
2709 | ||
2710 | /// test if expression is the literal `0` | |
2711 | fn is_zero(expr: &hir::Expr<'_>) -> bool { | |
2712 | match &expr.kind { | |
4b012472 | 2713 | rustc_hir::ExprKind::Lit(lit) => { |
cdc7bbd5 XL |
2714 | if let LitKind::Int(a, _) = lit.node { |
2715 | return a == 0; | |
2716 | } | |
2717 | } | |
2718 | _ => {} | |
2719 | } | |
2720 | false | |
2721 | } | |
2722 | ||
3c0e092e XL |
2723 | if let rustc_hir::ExprKind::Unary(rustc_hir::UnOp::Deref, expr_deref) = expr.kind { |
2724 | if is_null_ptr(cx, expr_deref) { | |
c0240ec0 | 2725 | cx.emit_span_lint( |
2b03887a FG |
2726 | DEREF_NULLPTR, |
2727 | expr.span, | |
9c376795 | 2728 | BuiltinDerefNullptr { label: expr.span }, |
2b03887a | 2729 | ); |
cdc7bbd5 XL |
2730 | } |
2731 | } | |
2732 | } | |
2733 | } | |
94222f64 XL |
2734 | |
2735 | declare_lint! { | |
2736 | /// The `named_asm_labels` lint detects the use of named labels in the | |
2737 | /// inline `asm!` macro. | |
2738 | /// | |
2739 | /// ### Example | |
2740 | /// | |
2741 | /// ```rust,compile_fail | |
2b03887a | 2742 | /// # #![feature(asm_experimental_arch)] |
a2a8927a XL |
2743 | /// use std::arch::asm; |
2744 | /// | |
94222f64 XL |
2745 | /// fn main() { |
2746 | /// unsafe { | |
2747 | /// asm!("foo: bar"); | |
2748 | /// } | |
2749 | /// } | |
2750 | /// ``` | |
2751 | /// | |
2752 | /// {{produces}} | |
2753 | /// | |
2754 | /// ### Explanation | |
2755 | /// | |
2756 | /// LLVM is allowed to duplicate inline assembly blocks for any | |
2757 | /// reason, for example when it is in a function that gets inlined. Because | |
2758 | /// of this, GNU assembler [local labels] *must* be used instead of labels | |
2759 | /// with a name. Using named labels might cause assembler or linker errors. | |
2760 | /// | |
a2a8927a | 2761 | /// See the explanation in [Rust By Example] for more details. |
94222f64 XL |
2762 | /// |
2763 | /// [local labels]: https://sourceware.org/binutils/docs/as/Symbol-Names.html#Local-Labels | |
a2a8927a | 2764 | /// [Rust By Example]: https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels |
94222f64 XL |
2765 | pub NAMED_ASM_LABELS, |
2766 | Deny, | |
2767 | "named labels in inline assembly", | |
2768 | } | |
2769 | ||
2770 | declare_lint_pass!(NamedAsmLabels => [NAMED_ASM_LABELS]); | |
2771 | ||
2772 | impl<'tcx> LateLintPass<'tcx> for NamedAsmLabels { | |
9c376795 | 2773 | #[allow(rustc::diagnostic_outside_of_impl)] |
94222f64 XL |
2774 | fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) { |
2775 | if let hir::Expr { | |
c0240ec0 | 2776 | kind: hir::ExprKind::InlineAsm(hir::InlineAsm { template_strs, options, .. }), |
94222f64 XL |
2777 | .. |
2778 | } = expr | |
2779 | { | |
c0240ec0 FG |
2780 | // asm with `options(raw)` does not do replacement with `{` and `}`. |
2781 | let raw = options.contains(InlineAsmOptions::RAW); | |
2782 | ||
94222f64 | 2783 | for (template_sym, template_snippet, template_span) in template_strs.iter() { |
a2a8927a | 2784 | let template_str = template_sym.as_str(); |
94222f64 XL |
2785 | let find_label_span = |needle: &str| -> Option<Span> { |
2786 | if let Some(template_snippet) = template_snippet { | |
2787 | let snippet = template_snippet.as_str(); | |
2788 | if let Some(pos) = snippet.find(needle) { | |
2789 | let end = pos | |
3c0e092e | 2790 | + snippet[pos..] |
94222f64 XL |
2791 | .find(|c| c == ':') |
2792 | .unwrap_or(snippet[pos..].len() - 1); | |
2793 | let inner = InnerSpan::new(pos, end); | |
2794 | return Some(template_span.from_inner(inner)); | |
2795 | } | |
2796 | } | |
2797 | ||
2798 | None | |
2799 | }; | |
2800 | ||
2801 | let mut found_labels = Vec::new(); | |
2802 | ||
2803 | // A semicolon might not actually be specified as a separator for all targets, but it seems like LLVM accepts it always | |
2804 | let statements = template_str.split(|c| matches!(c, '\n' | ';')); | |
2805 | for statement in statements { | |
2806 | // If there's a comment, trim it from the statement | |
2807 | let statement = statement.find("//").map_or(statement, |idx| &statement[..idx]); | |
c0240ec0 FG |
2808 | |
2809 | // In this loop, if there is ever a non-label, no labels can come after it. | |
94222f64 | 2810 | let mut start_idx = 0; |
c0240ec0 | 2811 | 'label_loop: for (idx, _) in statement.match_indices(':') { |
94222f64 XL |
2812 | let possible_label = statement[start_idx..idx].trim(); |
2813 | let mut chars = possible_label.chars(); | |
c0240ec0 FG |
2814 | |
2815 | let Some(start) = chars.next() else { | |
2816 | // Empty string means a leading ':' in this section, which is not a label. | |
2817 | break 'label_loop; | |
a2a8927a | 2818 | }; |
c0240ec0 FG |
2819 | |
2820 | // Whether a { bracket has been seen and its } hasn't been found yet. | |
2821 | let mut in_bracket = false; | |
2822 | ||
2823 | // A label starts with an ASCII alphabetic character or . or _ | |
2824 | // A label can also start with a format arg, if it's not a raw asm block. | |
2825 | if !raw && start == '{' { | |
2826 | in_bracket = true; | |
2827 | } else if !(start.is_ascii_alphabetic() || matches!(start, '.' | '_')) { | |
2828 | break 'label_loop; | |
2829 | } | |
2830 | ||
2831 | // Labels continue with ASCII alphanumeric characters, _, or $ | |
2832 | for c in chars { | |
2833 | // Inside a template format arg, any character is permitted for the puproses of label detection | |
2834 | // because we assume that it can be replaced with some other valid label string later. | |
2835 | // `options(raw)` asm blocks cannot have format args, so they are excluded from this special case. | |
2836 | if !raw && in_bracket { | |
2837 | if c == '{' { | |
2838 | // Nested brackets are not allowed in format args, this cannot be a label. | |
2839 | break 'label_loop; | |
2840 | } | |
2841 | ||
2842 | if c == '}' { | |
2843 | // The end of the format arg. | |
2844 | in_bracket = false; | |
2845 | } | |
2846 | } else if !raw && c == '{' { | |
2847 | // Start of a format arg. | |
2848 | in_bracket = true; | |
2849 | } else { | |
2850 | if !(c.is_ascii_alphanumeric() || matches!(c, '_' | '$')) { | |
2851 | // The potential label had an invalid character inside it, it cannot be a label. | |
2852 | break 'label_loop; | |
2853 | } | |
2854 | } | |
94222f64 XL |
2855 | } |
2856 | ||
c0240ec0 FG |
2857 | // If all characters passed the label checks, this is likely a label. |
2858 | found_labels.push(possible_label); | |
94222f64 XL |
2859 | start_idx = idx + 1; |
2860 | } | |
2861 | } | |
2862 | ||
2863 | debug!("NamedAsmLabels::check_expr(): found_labels: {:#?}", &found_labels); | |
2864 | ||
2865 | if found_labels.len() > 0 { | |
2866 | let spans = found_labels | |
2867 | .into_iter() | |
2868 | .filter_map(|label| find_label_span(label)) | |
2869 | .collect::<Vec<Span>>(); | |
2870 | // If there were labels but we couldn't find a span, combine the warnings and use the template span | |
2871 | let target_spans: MultiSpan = | |
2872 | if spans.len() > 0 { spans.into() } else { (*template_span).into() }; | |
2873 | ||
c0240ec0 | 2874 | cx.span_lint_with_diagnostics( |
94222f64 XL |
2875 | NAMED_ASM_LABELS, |
2876 | Some(target_spans), | |
2b03887a | 2877 | fluent::lint_builtin_asm_labels, |
4b012472 | 2878 | |_| {}, |
c620b35d | 2879 | BuiltinLintDiag::NamedAsmLabel( |
94222f64 XL |
2880 | "only local labels of the form `<number>:` should be used in inline asm" |
2881 | .to_string(), | |
2882 | ), | |
2883 | ); | |
2884 | } | |
2885 | } | |
2886 | } | |
2887 | } | |
2888 | } | |
f2b60f7d FG |
2889 | |
2890 | declare_lint! { | |
2891 | /// The `special_module_name` lint detects module | |
2892 | /// declarations for files that have a special meaning. | |
2893 | /// | |
2894 | /// ### Example | |
2895 | /// | |
2896 | /// ```rust,compile_fail | |
2897 | /// mod lib; | |
2898 | /// | |
2899 | /// fn main() { | |
2900 | /// lib::run(); | |
2901 | /// } | |
2902 | /// ``` | |
2903 | /// | |
2904 | /// {{produces}} | |
2905 | /// | |
2906 | /// ### Explanation | |
2907 | /// | |
2908 | /// Cargo recognizes `lib.rs` and `main.rs` as the root of a | |
2909 | /// library or binary crate, so declaring them as modules | |
2910 | /// will lead to miscompilation of the crate unless configured | |
2911 | /// explicitly. | |
2912 | /// | |
2913 | /// To access a library from a binary target within the same crate, | |
2b03887a | 2914 | /// use `your_crate_name::` as the path instead of `lib::`: |
f2b60f7d FG |
2915 | /// |
2916 | /// ```rust,compile_fail | |
2917 | /// // bar/src/lib.rs | |
2918 | /// fn run() { | |
2919 | /// // ... | |
2920 | /// } | |
2921 | /// | |
2922 | /// // bar/src/main.rs | |
2923 | /// fn main() { | |
2924 | /// bar::run(); | |
2925 | /// } | |
2926 | /// ``` | |
2927 | /// | |
2928 | /// Binary targets cannot be used as libraries and so declaring | |
2929 | /// one as a module is not allowed. | |
2930 | pub SPECIAL_MODULE_NAME, | |
2931 | Warn, | |
2932 | "module declarations for files with a special meaning", | |
2933 | } | |
2934 | ||
2935 | declare_lint_pass!(SpecialModuleName => [SPECIAL_MODULE_NAME]); | |
2936 | ||
2937 | impl EarlyLintPass for SpecialModuleName { | |
2938 | fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &ast::Crate) { | |
2939 | for item in &krate.items { | |
2940 | if let ast::ItemKind::Mod( | |
2941 | _, | |
2942 | ast::ModKind::Unloaded | ast::ModKind::Loaded(_, ast::Inline::No, _), | |
2943 | ) = item.kind | |
2944 | { | |
2945 | if item.attrs.iter().any(|a| a.has_name(sym::path)) { | |
2946 | continue; | |
2947 | } | |
2948 | ||
2949 | match item.ident.name.as_str() { | |
c0240ec0 | 2950 | "lib" => cx.emit_span_lint( |
9c376795 FG |
2951 | SPECIAL_MODULE_NAME, |
2952 | item.span, | |
2953 | BuiltinSpecialModuleNameUsed::Lib, | |
2954 | ), | |
c0240ec0 | 2955 | "main" => cx.emit_span_lint( |
9c376795 FG |
2956 | SPECIAL_MODULE_NAME, |
2957 | item.span, | |
2958 | BuiltinSpecialModuleNameUsed::Main, | |
2959 | ), | |
2960 | _ => continue, | |
f2b60f7d FG |
2961 | } |
2962 | } | |
2963 | } | |
2964 | } | |
2965 | } |