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Commit | Line | Data |
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3dfed10e | 1 | use rustc_ast as ast; |
74b04a01 | 2 | use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor}; |
5099ac24 | 3 | use rustc_ast::{AssocConstraint, AssocConstraintKind, NodeId}; |
dc3f5686 | 4 | use rustc_ast::{PatKind, RangeEnd, VariantData}; |
3dfed10e | 5 | use rustc_errors::struct_span_err; |
3c0e092e | 6 | use rustc_feature::{AttributeGate, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP}; |
3dfed10e | 7 | use rustc_feature::{Features, GateIssue}; |
dc3f5686 | 8 | use rustc_session::parse::{feature_err, feature_err_issue}; |
3dfed10e | 9 | use rustc_session::Session; |
dfeec247 | 10 | use rustc_span::source_map::Spanned; |
cdc7bbd5 | 11 | use rustc_span::symbol::sym; |
dfeec247 | 12 | use rustc_span::Span; |
dfeec247 | 13 | |
3dfed10e | 14 | use tracing::debug; |
dfeec247 XL |
15 | |
16 | macro_rules! gate_feature_fn { | |
5869c6ff XL |
17 | ($visitor: expr, $has_feature: expr, $span: expr, $name: expr, $explain: expr, $help: expr) => {{ |
18 | let (visitor, has_feature, span, name, explain, help) = | |
19 | (&*$visitor, $has_feature, $span, $name, $explain, $help); | |
20 | let has_feature: bool = has_feature(visitor.features); | |
21 | debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature); | |
22 | if !has_feature && !span.allows_unstable($name) { | |
23 | feature_err_issue(&visitor.sess.parse_sess, name, span, GateIssue::Language, explain) | |
24 | .help(help) | |
25 | .emit(); | |
26 | } | |
27 | }}; | |
3dfed10e XL |
28 | ($visitor: expr, $has_feature: expr, $span: expr, $name: expr, $explain: expr) => {{ |
29 | let (visitor, has_feature, span, name, explain) = | |
30 | (&*$visitor, $has_feature, $span, $name, $explain); | |
31 | let has_feature: bool = has_feature(visitor.features); | |
dfeec247 XL |
32 | debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature); |
33 | if !has_feature && !span.allows_unstable($name) { | |
3dfed10e XL |
34 | feature_err_issue(&visitor.sess.parse_sess, name, span, GateIssue::Language, explain) |
35 | .emit(); | |
dfeec247 XL |
36 | } |
37 | }}; | |
38 | } | |
39 | ||
40 | macro_rules! gate_feature_post { | |
5869c6ff XL |
41 | ($visitor: expr, $feature: ident, $span: expr, $explain: expr, $help: expr) => { |
42 | gate_feature_fn!($visitor, |x: &Features| x.$feature, $span, sym::$feature, $explain, $help) | |
43 | }; | |
3dfed10e XL |
44 | ($visitor: expr, $feature: ident, $span: expr, $explain: expr) => { |
45 | gate_feature_fn!($visitor, |x: &Features| x.$feature, $span, sym::$feature, $explain) | |
dfeec247 XL |
46 | }; |
47 | } | |
48 | ||
3dfed10e XL |
49 | pub fn check_attribute(attr: &ast::Attribute, sess: &Session, features: &Features) { |
50 | PostExpansionVisitor { sess, features }.visit_attribute(attr) | |
dfeec247 XL |
51 | } |
52 | ||
53 | struct PostExpansionVisitor<'a> { | |
3dfed10e XL |
54 | sess: &'a Session, |
55 | ||
56 | // `sess` contains a `Features`, but this might not be that one. | |
dfeec247 XL |
57 | features: &'a Features, |
58 | } | |
59 | ||
60 | impl<'a> PostExpansionVisitor<'a> { | |
61 | fn check_abi(&self, abi: ast::StrLit) { | |
62 | let ast::StrLit { symbol_unescaped, span, .. } = abi; | |
63 | ||
a2a8927a | 64 | match symbol_unescaped.as_str() { |
dfeec247 XL |
65 | // Stable |
66 | "Rust" | "C" | "cdecl" | "stdcall" | "fastcall" | "aapcs" | "win64" | "sysv64" | |
67 | | "system" => {} | |
68 | "rust-intrinsic" => { | |
69 | gate_feature_post!(&self, intrinsics, span, "intrinsics are subject to change"); | |
70 | } | |
71 | "platform-intrinsic" => { | |
72 | gate_feature_post!( | |
73 | &self, | |
74 | platform_intrinsics, | |
75 | span, | |
76 | "platform intrinsics are experimental and possibly buggy" | |
77 | ); | |
78 | } | |
79 | "vectorcall" => { | |
80 | gate_feature_post!( | |
81 | &self, | |
82 | abi_vectorcall, | |
83 | span, | |
84 | "vectorcall is experimental and subject to change" | |
85 | ); | |
86 | } | |
87 | "thiscall" => { | |
88 | gate_feature_post!( | |
89 | &self, | |
90 | abi_thiscall, | |
91 | span, | |
92 | "thiscall is experimental and subject to change" | |
93 | ); | |
94 | } | |
95 | "rust-call" => { | |
96 | gate_feature_post!( | |
97 | &self, | |
98 | unboxed_closures, | |
99 | span, | |
100 | "rust-call ABI is subject to change" | |
101 | ); | |
102 | } | |
103 | "ptx-kernel" => { | |
104 | gate_feature_post!( | |
105 | &self, | |
106 | abi_ptx, | |
107 | span, | |
108 | "PTX ABIs are experimental and subject to change" | |
109 | ); | |
110 | } | |
111 | "unadjusted" => { | |
112 | gate_feature_post!( | |
113 | &self, | |
114 | abi_unadjusted, | |
115 | span, | |
116 | "unadjusted ABI is an implementation detail and perma-unstable" | |
117 | ); | |
118 | } | |
119 | "msp430-interrupt" => { | |
120 | gate_feature_post!( | |
121 | &self, | |
122 | abi_msp430_interrupt, | |
123 | span, | |
124 | "msp430-interrupt ABI is experimental and subject to change" | |
125 | ); | |
126 | } | |
127 | "x86-interrupt" => { | |
128 | gate_feature_post!( | |
129 | &self, | |
130 | abi_x86_interrupt, | |
131 | span, | |
132 | "x86-interrupt ABI is experimental and subject to change" | |
133 | ); | |
134 | } | |
135 | "amdgpu-kernel" => { | |
136 | gate_feature_post!( | |
137 | &self, | |
138 | abi_amdgpu_kernel, | |
139 | span, | |
140 | "amdgpu-kernel ABI is experimental and subject to change" | |
141 | ); | |
142 | } | |
f035d41b XL |
143 | "avr-interrupt" | "avr-non-blocking-interrupt" => { |
144 | gate_feature_post!( | |
145 | &self, | |
146 | abi_avr_interrupt, | |
147 | span, | |
148 | "avr-interrupt and avr-non-blocking-interrupt ABIs are experimental and subject to change" | |
149 | ); | |
150 | } | |
dfeec247 XL |
151 | "efiapi" => { |
152 | gate_feature_post!( | |
153 | &self, | |
154 | abi_efiapi, | |
155 | span, | |
156 | "efiapi ABI is experimental and subject to change" | |
157 | ); | |
158 | } | |
5869c6ff XL |
159 | "C-cmse-nonsecure-call" => { |
160 | gate_feature_post!( | |
161 | &self, | |
162 | abi_c_cmse_nonsecure_call, | |
163 | span, | |
164 | "C-cmse-nonsecure-call ABI is experimental and subject to change" | |
165 | ); | |
166 | } | |
6a06907d XL |
167 | "C-unwind" => { |
168 | gate_feature_post!( | |
169 | &self, | |
170 | c_unwind, | |
171 | span, | |
172 | "C-unwind ABI is experimental and subject to change" | |
173 | ); | |
174 | } | |
175 | "stdcall-unwind" => { | |
176 | gate_feature_post!( | |
177 | &self, | |
178 | c_unwind, | |
179 | span, | |
180 | "stdcall-unwind ABI is experimental and subject to change" | |
181 | ); | |
182 | } | |
183 | "system-unwind" => { | |
184 | gate_feature_post!( | |
185 | &self, | |
186 | c_unwind, | |
187 | span, | |
188 | "system-unwind ABI is experimental and subject to change" | |
189 | ); | |
190 | } | |
191 | "thiscall-unwind" => { | |
192 | gate_feature_post!( | |
193 | &self, | |
194 | c_unwind, | |
195 | span, | |
196 | "thiscall-unwind ABI is experimental and subject to change" | |
197 | ); | |
198 | } | |
5099ac24 FG |
199 | "cdecl-unwind" => { |
200 | gate_feature_post!( | |
201 | &self, | |
202 | c_unwind, | |
203 | span, | |
204 | "cdecl-unwind ABI is experimental and subject to change" | |
205 | ); | |
206 | } | |
207 | "fastcall-unwind" => { | |
208 | gate_feature_post!( | |
209 | &self, | |
210 | c_unwind, | |
211 | span, | |
212 | "fastcall-unwind ABI is experimental and subject to change" | |
213 | ); | |
214 | } | |
215 | "vectorcall-unwind" => { | |
216 | gate_feature_post!( | |
217 | &self, | |
218 | c_unwind, | |
219 | span, | |
220 | "vectorcall-unwind ABI is experimental and subject to change" | |
221 | ); | |
222 | } | |
223 | "aapcs-unwind" => { | |
224 | gate_feature_post!( | |
225 | &self, | |
226 | c_unwind, | |
227 | span, | |
228 | "aapcs-unwind ABI is experimental and subject to change" | |
229 | ); | |
230 | } | |
231 | "win64-unwind" => { | |
232 | gate_feature_post!( | |
233 | &self, | |
234 | c_unwind, | |
235 | span, | |
236 | "win64-unwind ABI is experimental and subject to change" | |
237 | ); | |
238 | } | |
239 | "sysv64-unwind" => { | |
240 | gate_feature_post!( | |
241 | &self, | |
242 | c_unwind, | |
243 | span, | |
244 | "sysv64-unwind ABI is experimental and subject to change" | |
245 | ); | |
246 | } | |
cdc7bbd5 XL |
247 | "wasm" => { |
248 | gate_feature_post!( | |
249 | &self, | |
250 | wasm_abi, | |
251 | span, | |
252 | "wasm ABI is experimental and subject to change" | |
253 | ); | |
254 | } | |
dfeec247 | 255 | abi => self |
3dfed10e | 256 | .sess |
dfeec247 XL |
257 | .parse_sess |
258 | .span_diagnostic | |
259 | .delay_span_bug(span, &format!("unrecognized ABI not caught in lowering: {}", abi)), | |
260 | } | |
261 | } | |
262 | ||
263 | fn check_extern(&self, ext: ast::Extern) { | |
264 | if let ast::Extern::Explicit(abi) = ext { | |
265 | self.check_abi(abi); | |
266 | } | |
267 | } | |
268 | ||
dc3f5686 XL |
269 | fn maybe_report_invalid_custom_discriminants(&self, variants: &[ast::Variant]) { |
270 | let has_fields = variants.iter().any(|variant| match variant.data { | |
271 | VariantData::Tuple(..) | VariantData::Struct(..) => true, | |
272 | VariantData::Unit(..) => false, | |
273 | }); | |
274 | ||
275 | let discriminant_spans = variants | |
276 | .iter() | |
277 | .filter(|variant| match variant.data { | |
278 | VariantData::Tuple(..) | VariantData::Struct(..) => false, | |
279 | VariantData::Unit(..) => true, | |
280 | }) | |
281 | .filter_map(|variant| variant.disr_expr.as_ref().map(|c| c.value.span)) | |
282 | .collect::<Vec<_>>(); | |
283 | ||
284 | if !discriminant_spans.is_empty() && has_fields { | |
285 | let mut err = feature_err( | |
286 | &self.sess.parse_sess, | |
287 | sym::arbitrary_enum_discriminant, | |
288 | discriminant_spans.clone(), | |
289 | "custom discriminant values are not allowed in enums with tuple or struct variants", | |
290 | ); | |
291 | for sp in discriminant_spans { | |
292 | err.span_label(sp, "disallowed custom discriminant"); | |
293 | } | |
294 | for variant in variants.iter() { | |
295 | match &variant.data { | |
296 | VariantData::Struct(..) => { | |
297 | err.span_label(variant.span, "struct variant defined here"); | |
298 | } | |
299 | VariantData::Tuple(..) => { | |
300 | err.span_label(variant.span, "tuple variant defined here"); | |
301 | } | |
302 | VariantData::Unit(..) => {} | |
303 | } | |
304 | } | |
305 | err.emit(); | |
306 | } | |
307 | } | |
308 | ||
dfeec247 XL |
309 | fn check_gat(&self, generics: &ast::Generics, span: Span) { |
310 | if !generics.params.is_empty() { | |
311 | gate_feature_post!( | |
312 | &self, | |
313 | generic_associated_types, | |
314 | span, | |
315 | "generic associated types are unstable" | |
316 | ); | |
317 | } | |
318 | if !generics.where_clause.predicates.is_empty() { | |
319 | gate_feature_post!( | |
320 | &self, | |
321 | generic_associated_types, | |
322 | span, | |
323 | "where clauses on associated types are unstable" | |
324 | ); | |
325 | } | |
326 | } | |
327 | ||
328 | /// Feature gate `impl Trait` inside `type Alias = $type_expr;`. | |
329 | fn check_impl_trait(&self, ty: &ast::Ty) { | |
330 | struct ImplTraitVisitor<'a> { | |
331 | vis: &'a PostExpansionVisitor<'a>, | |
332 | } | |
333 | impl Visitor<'_> for ImplTraitVisitor<'_> { | |
334 | fn visit_ty(&mut self, ty: &ast::Ty) { | |
335 | if let ast::TyKind::ImplTrait(..) = ty.kind { | |
336 | gate_feature_post!( | |
337 | &self.vis, | |
94222f64 | 338 | type_alias_impl_trait, |
dfeec247 XL |
339 | ty.span, |
340 | "`impl Trait` in type aliases is unstable" | |
341 | ); | |
342 | } | |
343 | visit::walk_ty(self, ty); | |
344 | } | |
345 | } | |
346 | ImplTraitVisitor { vis: self }.visit_ty(ty); | |
347 | } | |
348 | } | |
349 | ||
350 | impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { | |
351 | fn visit_attribute(&mut self, attr: &ast::Attribute) { | |
3c0e092e | 352 | let attr_info = attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)); |
dfeec247 | 353 | // Check feature gates for built-in attributes. |
3c0e092e XL |
354 | if let Some(BuiltinAttribute { |
355 | gate: AttributeGate::Gated(_, name, descr, has_feature), | |
356 | .. | |
357 | }) = attr_info | |
358 | { | |
359 | gate_feature_fn!(self, has_feature, attr.span, *name, descr); | |
dfeec247 XL |
360 | } |
361 | // Check unstable flavors of the `#[doc]` attribute. | |
94222f64 | 362 | if attr.has_name(sym::doc) { |
dfeec247 XL |
363 | for nested_meta in attr.meta_item_list().unwrap_or_default() { |
364 | macro_rules! gate_doc { ($($name:ident => $feature:ident)*) => { | |
3dfed10e | 365 | $(if nested_meta.has_name(sym::$name) { |
dfeec247 XL |
366 | let msg = concat!("`#[doc(", stringify!($name), ")]` is experimental"); |
367 | gate_feature_post!(self, $feature, attr.span, msg); | |
368 | })* | |
369 | }} | |
370 | ||
371 | gate_doc!( | |
dfeec247 | 372 | cfg => doc_cfg |
c295e0f8 | 373 | cfg_hide => doc_cfg_hide |
dfeec247 | 374 | masked => doc_masked |
cdc7bbd5 | 375 | notable_trait => doc_notable_trait |
dfeec247 | 376 | ); |
3c0e092e XL |
377 | |
378 | if nested_meta.has_name(sym::keyword) { | |
379 | let msg = "`#[doc(keyword)]` is meant for internal use only"; | |
380 | gate_feature_post!(self, rustdoc_internals, attr.span, msg); | |
381 | } | |
dfeec247 XL |
382 | } |
383 | } | |
17df50a5 XL |
384 | |
385 | // Check for unstable modifiers on `#[link(..)]` attribute | |
94222f64 | 386 | if attr.has_name(sym::link) { |
17df50a5 XL |
387 | for nested_meta in attr.meta_item_list().unwrap_or_default() { |
388 | if nested_meta.has_name(sym::modifiers) { | |
389 | gate_feature_post!( | |
390 | self, | |
391 | native_link_modifiers, | |
392 | nested_meta.span(), | |
393 | "native link modifiers are experimental" | |
394 | ); | |
395 | ||
396 | if let Some(modifiers) = nested_meta.value_str() { | |
397 | for modifier in modifiers.as_str().split(',') { | |
a2a8927a | 398 | if let Some(modifier) = modifier.strip_prefix(&['+', '-']) { |
17df50a5 XL |
399 | macro_rules! gate_modifier { ($($name:literal => $feature:ident)*) => { |
400 | $(if modifier == $name { | |
401 | let msg = concat!("`#[link(modifiers=\"", $name, "\")]` is unstable"); | |
402 | gate_feature_post!( | |
403 | self, | |
404 | $feature, | |
405 | nested_meta.name_value_literal_span().unwrap(), | |
406 | msg | |
407 | ); | |
408 | })* | |
409 | }} | |
410 | ||
411 | gate_modifier!( | |
412 | "bundle" => native_link_modifiers_bundle | |
413 | "verbatim" => native_link_modifiers_verbatim | |
414 | "whole-archive" => native_link_modifiers_whole_archive | |
415 | "as-needed" => native_link_modifiers_as_needed | |
416 | ); | |
417 | } | |
418 | } | |
419 | } | |
420 | } | |
421 | } | |
422 | } | |
dfeec247 XL |
423 | } |
424 | ||
dfeec247 XL |
425 | fn visit_item(&mut self, i: &'a ast::Item) { |
426 | match i.kind { | |
427 | ast::ItemKind::ForeignMod(ref foreign_module) => { | |
428 | if let Some(abi) = foreign_module.abi { | |
429 | self.check_abi(abi); | |
430 | } | |
431 | } | |
432 | ||
433 | ast::ItemKind::Fn(..) => { | |
a2a8927a | 434 | if self.sess.contains_name(&i.attrs, sym::start) { |
dfeec247 XL |
435 | gate_feature_post!( |
436 | &self, | |
437 | start, | |
438 | i.span, | |
439 | "`#[start]` functions are experimental \ | |
ba9703b0 XL |
440 | and their signature may change \ |
441 | over time" | |
dfeec247 XL |
442 | ); |
443 | } | |
dfeec247 XL |
444 | } |
445 | ||
446 | ast::ItemKind::Struct(..) => { | |
a2a8927a | 447 | for attr in self.sess.filter_by_name(&i.attrs, sym::repr) { |
dfeec247 | 448 | for item in attr.meta_item_list().unwrap_or_else(Vec::new) { |
3dfed10e | 449 | if item.has_name(sym::simd) { |
dfeec247 XL |
450 | gate_feature_post!( |
451 | &self, | |
452 | repr_simd, | |
453 | attr.span, | |
454 | "SIMD types are experimental and possibly buggy" | |
455 | ); | |
456 | } | |
457 | } | |
458 | } | |
459 | } | |
460 | ||
dc3f5686 XL |
461 | ast::ItemKind::Enum(ast::EnumDef { ref variants, .. }, ..) => { |
462 | for variant in variants { | |
463 | match (&variant.data, &variant.disr_expr) { | |
464 | (ast::VariantData::Unit(..), _) => {} | |
465 | (_, Some(disr_expr)) => gate_feature_post!( | |
466 | &self, | |
467 | arbitrary_enum_discriminant, | |
468 | disr_expr.value.span, | |
469 | "discriminants on non-unit variants are experimental" | |
470 | ), | |
471 | _ => {} | |
472 | } | |
473 | } | |
474 | ||
475 | let has_feature = self.features.arbitrary_enum_discriminant; | |
476 | if !has_feature && !i.span.allows_unstable(sym::arbitrary_enum_discriminant) { | |
477 | self.maybe_report_invalid_custom_discriminants(&variants); | |
478 | } | |
479 | } | |
480 | ||
3c0e092e | 481 | ast::ItemKind::Impl(box ast::Impl { polarity, defaultness, ref of_trait, .. }) => { |
ba9703b0 | 482 | if let ast::ImplPolarity::Negative(span) = polarity { |
dfeec247 XL |
483 | gate_feature_post!( |
484 | &self, | |
ba9703b0 | 485 | negative_impls, |
5869c6ff | 486 | span.to(of_trait.as_ref().map_or(span, |t| t.path.span)), |
dfeec247 | 487 | "negative trait bounds are not yet fully implemented; \ |
ba9703b0 | 488 | use marker types for now" |
dfeec247 XL |
489 | ); |
490 | } | |
491 | ||
74b04a01 | 492 | if let ast::Defaultness::Default(_) = defaultness { |
dfeec247 XL |
493 | gate_feature_post!(&self, specialization, i.span, "specialization is unstable"); |
494 | } | |
495 | } | |
496 | ||
3c0e092e | 497 | ast::ItemKind::Trait(box ast::Trait { is_auto: ast::IsAuto::Yes, .. }) => { |
dfeec247 XL |
498 | gate_feature_post!( |
499 | &self, | |
fc512014 | 500 | auto_traits, |
dfeec247 XL |
501 | i.span, |
502 | "auto traits are experimental and possibly buggy" | |
503 | ); | |
504 | } | |
505 | ||
506 | ast::ItemKind::TraitAlias(..) => { | |
507 | gate_feature_post!(&self, trait_alias, i.span, "trait aliases are experimental"); | |
508 | } | |
509 | ||
ba9703b0 | 510 | ast::ItemKind::MacroDef(ast::MacroDef { macro_rules: false, .. }) => { |
dfeec247 XL |
511 | let msg = "`macro` is experimental"; |
512 | gate_feature_post!(&self, decl_macro, i.span, msg); | |
513 | } | |
514 | ||
3c0e092e | 515 | ast::ItemKind::TyAlias(box ast::TyAlias { ty: Some(ref ty), .. }) => { |
5869c6ff XL |
516 | self.check_impl_trait(&ty) |
517 | } | |
dfeec247 XL |
518 | |
519 | _ => {} | |
520 | } | |
521 | ||
522 | visit::walk_item(self, i); | |
523 | } | |
524 | ||
525 | fn visit_foreign_item(&mut self, i: &'a ast::ForeignItem) { | |
526 | match i.kind { | |
527 | ast::ForeignItemKind::Fn(..) | ast::ForeignItemKind::Static(..) => { | |
3dfed10e | 528 | let link_name = self.sess.first_attr_value_str_by_name(&i.attrs, sym::link_name); |
5869c6ff XL |
529 | let links_to_llvm = |
530 | link_name.map_or(false, |val| val.as_str().starts_with("llvm.")); | |
dfeec247 XL |
531 | if links_to_llvm { |
532 | gate_feature_post!( | |
533 | &self, | |
534 | link_llvm_intrinsics, | |
535 | i.span, | |
536 | "linking to LLVM intrinsics is experimental" | |
537 | ); | |
538 | } | |
539 | } | |
74b04a01 | 540 | ast::ForeignItemKind::TyAlias(..) => { |
dfeec247 XL |
541 | gate_feature_post!(&self, extern_types, i.span, "extern types are experimental"); |
542 | } | |
ba9703b0 | 543 | ast::ForeignItemKind::MacCall(..) => {} |
dfeec247 XL |
544 | } |
545 | ||
546 | visit::walk_foreign_item(self, i) | |
547 | } | |
548 | ||
549 | fn visit_ty(&mut self, ty: &'a ast::Ty) { | |
550 | match ty.kind { | |
551 | ast::TyKind::BareFn(ref bare_fn_ty) => { | |
552 | self.check_extern(bare_fn_ty.ext); | |
553 | } | |
554 | ast::TyKind::Never => { | |
555 | gate_feature_post!(&self, never_type, ty.span, "the `!` type is experimental"); | |
556 | } | |
557 | _ => {} | |
558 | } | |
559 | visit::walk_ty(self, ty) | |
560 | } | |
561 | ||
74b04a01 XL |
562 | fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FnRetTy) { |
563 | if let ast::FnRetTy::Ty(ref output_ty) = *ret_ty { | |
dfeec247 XL |
564 | if let ast::TyKind::Never = output_ty.kind { |
565 | // Do nothing. | |
566 | } else { | |
567 | self.visit_ty(output_ty) | |
568 | } | |
569 | } | |
570 | } | |
571 | ||
572 | fn visit_expr(&mut self, e: &'a ast::Expr) { | |
573 | match e.kind { | |
574 | ast::ExprKind::Box(_) => { | |
575 | gate_feature_post!( | |
576 | &self, | |
577 | box_syntax, | |
578 | e.span, | |
579 | "box expression syntax is experimental; you can call `Box::new` instead" | |
580 | ); | |
581 | } | |
582 | ast::ExprKind::Type(..) => { | |
583 | // To avoid noise about type ascription in common syntax errors, only emit if it | |
584 | // is the *only* error. | |
3dfed10e | 585 | if self.sess.parse_sess.span_diagnostic.err_count() == 0 { |
dfeec247 XL |
586 | gate_feature_post!( |
587 | &self, | |
588 | type_ascription, | |
589 | e.span, | |
590 | "type ascription is experimental" | |
591 | ); | |
592 | } | |
593 | } | |
594 | ast::ExprKind::TryBlock(_) => { | |
595 | gate_feature_post!(&self, try_blocks, e.span, "`try` expression is experimental"); | |
596 | } | |
3c0e092e XL |
597 | ast::ExprKind::Block(_, Some(label)) => { |
598 | gate_feature_post!( | |
599 | &self, | |
600 | label_break_value, | |
601 | label.ident.span, | |
602 | "labels on blocks are unstable" | |
603 | ); | |
dfeec247 XL |
604 | } |
605 | _ => {} | |
606 | } | |
607 | visit::walk_expr(self, e) | |
608 | } | |
609 | ||
610 | fn visit_pat(&mut self, pattern: &'a ast::Pat) { | |
611 | match &pattern.kind { | |
136023e0 XL |
612 | PatKind::Slice(pats) => { |
613 | for pat in pats { | |
614 | let inner_pat = match &pat.kind { | |
615 | PatKind::Ident(.., Some(pat)) => pat, | |
616 | _ => pat, | |
617 | }; | |
618 | if let PatKind::Range(Some(_), None, Spanned { .. }) = inner_pat.kind { | |
619 | gate_feature_post!( | |
620 | &self, | |
621 | half_open_range_patterns, | |
622 | pat.span, | |
623 | "`X..` patterns in slices are experimental" | |
624 | ); | |
625 | } | |
626 | } | |
627 | } | |
dfeec247 XL |
628 | PatKind::Box(..) => { |
629 | gate_feature_post!( | |
630 | &self, | |
631 | box_patterns, | |
632 | pattern.span, | |
633 | "box pattern syntax is experimental" | |
634 | ); | |
635 | } | |
136023e0 | 636 | PatKind::Range(_, Some(_), Spanned { node: RangeEnd::Excluded, .. }) => { |
dfeec247 XL |
637 | gate_feature_post!( |
638 | &self, | |
639 | exclusive_range_pattern, | |
640 | pattern.span, | |
641 | "exclusive range pattern syntax is experimental" | |
642 | ); | |
643 | } | |
644 | _ => {} | |
645 | } | |
646 | visit::walk_pat(self, pattern) | |
647 | } | |
648 | ||
74b04a01 | 649 | fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) { |
dfeec247 | 650 | if let Some(header) = fn_kind.header() { |
74b04a01 | 651 | // Stability of const fn methods are covered in `visit_assoc_item` below. |
dfeec247 | 652 | self.check_extern(header.ext); |
74b04a01 XL |
653 | |
654 | if let (ast::Const::Yes(_), ast::Extern::Implicit) | |
655 | | (ast::Const::Yes(_), ast::Extern::Explicit(_)) = (header.constness, header.ext) | |
656 | { | |
657 | gate_feature_post!( | |
658 | &self, | |
659 | const_extern_fn, | |
660 | span, | |
661 | "`const extern fn` definitions are unstable" | |
662 | ); | |
663 | } | |
dfeec247 XL |
664 | } |
665 | ||
74b04a01 | 666 | if fn_kind.ctxt() != Some(FnCtxt::Foreign) && fn_kind.decl().c_variadic() { |
dfeec247 XL |
667 | gate_feature_post!(&self, c_variadic, span, "C-variadic functions are unstable"); |
668 | } | |
669 | ||
74b04a01 | 670 | visit::walk_fn(self, fn_kind, span) |
dfeec247 XL |
671 | } |
672 | ||
5099ac24 FG |
673 | fn visit_assoc_constraint(&mut self, constraint: &'a AssocConstraint) { |
674 | if let AssocConstraintKind::Bound { .. } = constraint.kind { | |
ba9703b0 | 675 | gate_feature_post!( |
dfeec247 XL |
676 | &self, |
677 | associated_type_bounds, | |
678 | constraint.span, | |
679 | "associated type bounds are unstable" | |
ba9703b0 | 680 | ) |
dfeec247 | 681 | } |
5099ac24 | 682 | visit::walk_assoc_constraint(self, constraint) |
dfeec247 XL |
683 | } |
684 | ||
74b04a01 | 685 | fn visit_assoc_item(&mut self, i: &'a ast::AssocItem, ctxt: AssocCtxt) { |
ba9703b0 | 686 | let is_fn = match i.kind { |
cdc7bbd5 | 687 | ast::AssocItemKind::Fn(_) => true, |
3c0e092e | 688 | ast::AssocItemKind::TyAlias(box ast::TyAlias { ref generics, ref ty, .. }) => { |
74b04a01 | 689 | if let (Some(_), AssocCtxt::Trait) = (ty, ctxt) { |
dfeec247 XL |
690 | gate_feature_post!( |
691 | &self, | |
692 | associated_type_defaults, | |
74b04a01 | 693 | i.span, |
dfeec247 XL |
694 | "associated type defaults are unstable" |
695 | ); | |
696 | } | |
dfeec247 XL |
697 | if let Some(ty) = ty { |
698 | self.check_impl_trait(ty); | |
699 | } | |
74b04a01 | 700 | self.check_gat(generics, i.span); |
ba9703b0 | 701 | false |
dfeec247 | 702 | } |
ba9703b0 XL |
703 | _ => false, |
704 | }; | |
705 | if let ast::Defaultness::Default(_) = i.kind.defaultness() { | |
706 | // Limit `min_specialization` to only specializing functions. | |
707 | gate_feature_fn!( | |
708 | &self, | |
709 | |x: &Features| x.specialization || (is_fn && x.min_specialization), | |
710 | i.span, | |
711 | sym::specialization, | |
712 | "specialization is unstable" | |
713 | ); | |
dfeec247 | 714 | } |
74b04a01 | 715 | visit::walk_assoc_item(self, i, ctxt) |
dfeec247 XL |
716 | } |
717 | ||
718 | fn visit_vis(&mut self, vis: &'a ast::Visibility) { | |
1b1a35ee | 719 | if let ast::VisibilityKind::Crate(ast::CrateSugar::JustCrate) = vis.kind { |
dfeec247 XL |
720 | gate_feature_post!( |
721 | &self, | |
722 | crate_visibility_modifier, | |
723 | vis.span, | |
724 | "`crate` visibility modifier is experimental" | |
725 | ); | |
726 | } | |
727 | visit::walk_vis(self, vis) | |
728 | } | |
729 | } | |
730 | ||
3dfed10e XL |
731 | pub fn check_crate(krate: &ast::Crate, sess: &Session) { |
732 | maybe_stage_features(sess, krate); | |
1b1a35ee | 733 | check_incompatible_features(sess); |
3dfed10e | 734 | let mut visitor = PostExpansionVisitor { sess, features: &sess.features_untracked() }; |
dfeec247 | 735 | |
3dfed10e | 736 | let spans = sess.parse_sess.gated_spans.spans.borrow(); |
dfeec247 | 737 | macro_rules! gate_all { |
5869c6ff XL |
738 | ($gate:ident, $msg:literal, $help:literal) => { |
739 | if let Some(spans) = spans.get(&sym::$gate) { | |
740 | for span in spans { | |
741 | gate_feature_post!(&visitor, $gate, *span, $msg, $help); | |
742 | } | |
743 | } | |
744 | }; | |
dfeec247 | 745 | ($gate:ident, $msg:literal) => { |
3dfed10e XL |
746 | if let Some(spans) = spans.get(&sym::$gate) { |
747 | for span in spans { | |
748 | gate_feature_post!(&visitor, $gate, *span, $msg); | |
749 | } | |
dfeec247 XL |
750 | } |
751 | }; | |
752 | } | |
6a06907d XL |
753 | gate_all!( |
754 | if_let_guard, | |
755 | "`if let` guards are experimental", | |
756 | "you can write `if matches!(<expr>, <pattern>)` instead of `if let <pattern> = <expr>`" | |
757 | ); | |
5099ac24 | 758 | gate_all!(let_chains, "`let` expressions in this position are unstable"); |
5869c6ff XL |
759 | gate_all!( |
760 | async_closure, | |
761 | "async closures are unstable", | |
762 | "to use an async block, remove the `||`: `async {`" | |
763 | ); | |
17df50a5 | 764 | gate_all!(more_qualified_paths, "usage of qualified paths in this context is experimental"); |
dfeec247 | 765 | gate_all!(generators, "yield syntax is experimental"); |
dfeec247 | 766 | gate_all!(raw_ref_op, "raw address of syntax is experimental"); |
dfeec247 XL |
767 | gate_all!(const_trait_impl, "const trait impls are experimental"); |
768 | gate_all!(half_open_range_patterns, "half-open range patterns are unstable"); | |
29967ef6 | 769 | gate_all!(inline_const, "inline-const is experimental"); |
3c0e092e | 770 | gate_all!(inline_const_pat, "inline-const in pattern position is experimental"); |
5099ac24 | 771 | gate_all!(associated_const_equality, "associated const equality is incomplete"); |
dfeec247 XL |
772 | |
773 | // All uses of `gate_all!` below this point were added in #65742, | |
774 | // and subsequently disabled (with the non-early gating readded). | |
775 | macro_rules! gate_all { | |
776 | ($gate:ident, $msg:literal) => { | |
777 | // FIXME(eddyb) do something more useful than always | |
778 | // disabling these uses of early feature-gatings. | |
779 | if false { | |
780 | for span in spans.get(&sym::$gate).unwrap_or(&vec![]) { | |
781 | gate_feature_post!(&visitor, $gate, *span, $msg); | |
782 | } | |
783 | } | |
784 | }; | |
785 | } | |
786 | ||
787 | gate_all!(trait_alias, "trait aliases are experimental"); | |
788 | gate_all!(associated_type_bounds, "associated type bounds are unstable"); | |
789 | gate_all!(crate_visibility_modifier, "`crate` visibility modifier is experimental"); | |
dfeec247 XL |
790 | gate_all!(decl_macro, "`macro` is experimental"); |
791 | gate_all!(box_patterns, "box pattern syntax is experimental"); | |
792 | gate_all!(exclusive_range_pattern, "exclusive range pattern syntax is experimental"); | |
793 | gate_all!(try_blocks, "`try` blocks are unstable"); | |
794 | gate_all!(label_break_value, "labels on blocks are unstable"); | |
795 | gate_all!(box_syntax, "box expression syntax is experimental; you can call `Box::new` instead"); | |
796 | // To avoid noise about type ascription in common syntax errors, | |
797 | // only emit if it is the *only* error. (Also check it last.) | |
3dfed10e | 798 | if sess.parse_sess.span_diagnostic.err_count() == 0 { |
dfeec247 XL |
799 | gate_all!(type_ascription, "type ascription is experimental"); |
800 | } | |
801 | ||
802 | visit::walk_crate(&mut visitor, krate); | |
803 | } | |
804 | ||
3dfed10e | 805 | fn maybe_stage_features(sess: &Session, krate: &ast::Crate) { |
c295e0f8 XL |
806 | // checks if `#![feature]` has been used to enable any lang feature |
807 | // does not check the same for lib features unless there's at least one | |
808 | // declared lang feature | |
cdc7bbd5 XL |
809 | use rustc_errors::Applicability; |
810 | ||
3dfed10e | 811 | if !sess.opts.unstable_features.is_nightly_build() { |
cdc7bbd5 | 812 | let lang_features = &sess.features_untracked().declared_lang_features; |
c295e0f8 XL |
813 | if lang_features.len() == 0 { |
814 | return; | |
815 | } | |
94222f64 | 816 | for attr in krate.attrs.iter().filter(|attr| attr.has_name(sym::feature)) { |
cdc7bbd5 | 817 | let mut err = struct_span_err!( |
3dfed10e | 818 | sess.parse_sess.span_diagnostic, |
dfeec247 XL |
819 | attr.span, |
820 | E0554, | |
821 | "`#![feature]` may not be used on the {} release channel", | |
822 | option_env!("CFG_RELEASE_CHANNEL").unwrap_or("(unknown)") | |
cdc7bbd5 XL |
823 | ); |
824 | let mut all_stable = true; | |
825 | for ident in | |
5099ac24 | 826 | attr.meta_item_list().into_iter().flatten().flat_map(|nested| nested.ident()) |
cdc7bbd5 XL |
827 | { |
828 | let name = ident.name; | |
829 | let stable_since = lang_features | |
830 | .iter() | |
831 | .flat_map(|&(feature, _, since)| if feature == name { since } else { None }) | |
832 | .next(); | |
833 | if let Some(since) = stable_since { | |
834 | err.help(&format!( | |
835 | "the feature `{}` has been stable since {} and no longer requires \ | |
836 | an attribute to enable", | |
837 | name, since | |
838 | )); | |
839 | } else { | |
840 | all_stable = false; | |
841 | } | |
842 | } | |
843 | if all_stable { | |
844 | err.span_suggestion( | |
845 | attr.span, | |
846 | "remove the attribute", | |
847 | String::new(), | |
848 | Applicability::MachineApplicable, | |
849 | ); | |
850 | } | |
851 | err.emit(); | |
dfeec247 XL |
852 | } |
853 | } | |
854 | } | |
1b1a35ee XL |
855 | |
856 | fn check_incompatible_features(sess: &Session) { | |
857 | let features = sess.features_untracked(); | |
858 | ||
859 | let declared_features = features | |
860 | .declared_lang_features | |
861 | .iter() | |
862 | .copied() | |
863 | .map(|(name, span, _)| (name, span)) | |
864 | .chain(features.declared_lib_features.iter().copied()); | |
865 | ||
866 | for (f1, f2) in rustc_feature::INCOMPATIBLE_FEATURES | |
867 | .iter() | |
868 | .filter(|&&(f1, f2)| features.enabled(f1) && features.enabled(f2)) | |
869 | { | |
870 | if let Some((f1_name, f1_span)) = declared_features.clone().find(|(name, _)| name == f1) { | |
871 | if let Some((f2_name, f2_span)) = declared_features.clone().find(|(name, _)| name == f2) | |
872 | { | |
873 | let spans = vec![f1_span, f2_span]; | |
874 | sess.struct_span_err( | |
875 | spans.clone(), | |
876 | &format!( | |
877 | "features `{}` and `{}` are incompatible, using them at the same time \ | |
878 | is not allowed", | |
879 | f1_name, f2_name | |
880 | ), | |
881 | ) | |
882 | .help("remove one of these features") | |
883 | .emit(); | |
884 | } | |
885 | } | |
886 | } | |
887 | } |