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Commit | Line | Data |
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74b04a01 XL |
1 | use rustc_ast::ast::{self, AssocTyConstraint, AssocTyConstraintKind, NodeId}; |
2 | use rustc_ast::ast::{GenericParam, GenericParamKind, PatKind, RangeEnd, VariantData}; | |
3 | use rustc_ast::attr; | |
4 | use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor}; | |
dfeec247 XL |
5 | use rustc_errors::{struct_span_err, Handler}; |
6 | use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP}; | |
7 | use rustc_feature::{Features, GateIssue, UnstableFeatures}; | |
74b04a01 | 8 | use rustc_session::parse::{feature_err, feature_err_issue, ParseSess}; |
dfeec247 | 9 | use rustc_span::source_map::Spanned; |
f9f354fc | 10 | use rustc_span::symbol::{sym, Symbol}; |
dfeec247 | 11 | use rustc_span::Span; |
dfeec247 XL |
12 | |
13 | use log::debug; | |
14 | ||
15 | macro_rules! gate_feature_fn { | |
16 | ($cx: expr, $has_feature: expr, $span: expr, $name: expr, $explain: expr) => {{ | |
17 | let (cx, has_feature, span, name, explain) = (&*$cx, $has_feature, $span, $name, $explain); | |
18 | let has_feature: bool = has_feature(&$cx.features); | |
19 | debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature); | |
20 | if !has_feature && !span.allows_unstable($name) { | |
21 | feature_err_issue(cx.parse_sess, name, span, GateIssue::Language, explain).emit(); | |
22 | } | |
23 | }}; | |
24 | } | |
25 | ||
26 | macro_rules! gate_feature_post { | |
27 | ($cx: expr, $feature: ident, $span: expr, $explain: expr) => { | |
28 | gate_feature_fn!($cx, |x: &Features| x.$feature, $span, sym::$feature, $explain) | |
29 | }; | |
30 | } | |
31 | ||
32 | pub fn check_attribute(attr: &ast::Attribute, parse_sess: &ParseSess, features: &Features) { | |
33 | PostExpansionVisitor { parse_sess, features }.visit_attribute(attr) | |
34 | } | |
35 | ||
36 | struct PostExpansionVisitor<'a> { | |
37 | parse_sess: &'a ParseSess, | |
38 | features: &'a Features, | |
39 | } | |
40 | ||
41 | impl<'a> PostExpansionVisitor<'a> { | |
42 | fn check_abi(&self, abi: ast::StrLit) { | |
43 | let ast::StrLit { symbol_unescaped, span, .. } = abi; | |
44 | ||
45 | match &*symbol_unescaped.as_str() { | |
46 | // Stable | |
47 | "Rust" | "C" | "cdecl" | "stdcall" | "fastcall" | "aapcs" | "win64" | "sysv64" | |
48 | | "system" => {} | |
49 | "rust-intrinsic" => { | |
50 | gate_feature_post!(&self, intrinsics, span, "intrinsics are subject to change"); | |
51 | } | |
52 | "platform-intrinsic" => { | |
53 | gate_feature_post!( | |
54 | &self, | |
55 | platform_intrinsics, | |
56 | span, | |
57 | "platform intrinsics are experimental and possibly buggy" | |
58 | ); | |
59 | } | |
60 | "vectorcall" => { | |
61 | gate_feature_post!( | |
62 | &self, | |
63 | abi_vectorcall, | |
64 | span, | |
65 | "vectorcall is experimental and subject to change" | |
66 | ); | |
67 | } | |
68 | "thiscall" => { | |
69 | gate_feature_post!( | |
70 | &self, | |
71 | abi_thiscall, | |
72 | span, | |
73 | "thiscall is experimental and subject to change" | |
74 | ); | |
75 | } | |
76 | "rust-call" => { | |
77 | gate_feature_post!( | |
78 | &self, | |
79 | unboxed_closures, | |
80 | span, | |
81 | "rust-call ABI is subject to change" | |
82 | ); | |
83 | } | |
84 | "ptx-kernel" => { | |
85 | gate_feature_post!( | |
86 | &self, | |
87 | abi_ptx, | |
88 | span, | |
89 | "PTX ABIs are experimental and subject to change" | |
90 | ); | |
91 | } | |
92 | "unadjusted" => { | |
93 | gate_feature_post!( | |
94 | &self, | |
95 | abi_unadjusted, | |
96 | span, | |
97 | "unadjusted ABI is an implementation detail and perma-unstable" | |
98 | ); | |
99 | } | |
100 | "msp430-interrupt" => { | |
101 | gate_feature_post!( | |
102 | &self, | |
103 | abi_msp430_interrupt, | |
104 | span, | |
105 | "msp430-interrupt ABI is experimental and subject to change" | |
106 | ); | |
107 | } | |
108 | "x86-interrupt" => { | |
109 | gate_feature_post!( | |
110 | &self, | |
111 | abi_x86_interrupt, | |
112 | span, | |
113 | "x86-interrupt ABI is experimental and subject to change" | |
114 | ); | |
115 | } | |
116 | "amdgpu-kernel" => { | |
117 | gate_feature_post!( | |
118 | &self, | |
119 | abi_amdgpu_kernel, | |
120 | span, | |
121 | "amdgpu-kernel ABI is experimental and subject to change" | |
122 | ); | |
123 | } | |
124 | "efiapi" => { | |
125 | gate_feature_post!( | |
126 | &self, | |
127 | abi_efiapi, | |
128 | span, | |
129 | "efiapi ABI is experimental and subject to change" | |
130 | ); | |
131 | } | |
132 | abi => self | |
133 | .parse_sess | |
134 | .span_diagnostic | |
135 | .delay_span_bug(span, &format!("unrecognized ABI not caught in lowering: {}", abi)), | |
136 | } | |
137 | } | |
138 | ||
139 | fn check_extern(&self, ext: ast::Extern) { | |
140 | if let ast::Extern::Explicit(abi) = ext { | |
141 | self.check_abi(abi); | |
142 | } | |
143 | } | |
144 | ||
145 | fn maybe_report_invalid_custom_discriminants(&self, variants: &[ast::Variant]) { | |
146 | let has_fields = variants.iter().any(|variant| match variant.data { | |
147 | VariantData::Tuple(..) | VariantData::Struct(..) => true, | |
148 | VariantData::Unit(..) => false, | |
149 | }); | |
150 | ||
151 | let discriminant_spans = variants | |
152 | .iter() | |
153 | .filter(|variant| match variant.data { | |
154 | VariantData::Tuple(..) | VariantData::Struct(..) => false, | |
155 | VariantData::Unit(..) => true, | |
156 | }) | |
157 | .filter_map(|variant| variant.disr_expr.as_ref().map(|c| c.value.span)) | |
158 | .collect::<Vec<_>>(); | |
159 | ||
160 | if !discriminant_spans.is_empty() && has_fields { | |
161 | let mut err = feature_err( | |
162 | self.parse_sess, | |
163 | sym::arbitrary_enum_discriminant, | |
164 | discriminant_spans.clone(), | |
165 | "custom discriminant values are not allowed in enums with tuple or struct variants", | |
166 | ); | |
167 | for sp in discriminant_spans { | |
168 | err.span_label(sp, "disallowed custom discriminant"); | |
169 | } | |
170 | for variant in variants.iter() { | |
171 | match &variant.data { | |
172 | VariantData::Struct(..) => { | |
173 | err.span_label(variant.span, "struct variant defined here"); | |
174 | } | |
175 | VariantData::Tuple(..) => { | |
176 | err.span_label(variant.span, "tuple variant defined here"); | |
177 | } | |
178 | VariantData::Unit(..) => {} | |
179 | } | |
180 | } | |
181 | err.emit(); | |
182 | } | |
183 | } | |
184 | ||
185 | fn check_gat(&self, generics: &ast::Generics, span: Span) { | |
186 | if !generics.params.is_empty() { | |
187 | gate_feature_post!( | |
188 | &self, | |
189 | generic_associated_types, | |
190 | span, | |
191 | "generic associated types are unstable" | |
192 | ); | |
193 | } | |
194 | if !generics.where_clause.predicates.is_empty() { | |
195 | gate_feature_post!( | |
196 | &self, | |
197 | generic_associated_types, | |
198 | span, | |
199 | "where clauses on associated types are unstable" | |
200 | ); | |
201 | } | |
202 | } | |
203 | ||
204 | /// Feature gate `impl Trait` inside `type Alias = $type_expr;`. | |
205 | fn check_impl_trait(&self, ty: &ast::Ty) { | |
206 | struct ImplTraitVisitor<'a> { | |
207 | vis: &'a PostExpansionVisitor<'a>, | |
208 | } | |
209 | impl Visitor<'_> for ImplTraitVisitor<'_> { | |
210 | fn visit_ty(&mut self, ty: &ast::Ty) { | |
211 | if let ast::TyKind::ImplTrait(..) = ty.kind { | |
212 | gate_feature_post!( | |
213 | &self.vis, | |
214 | type_alias_impl_trait, | |
215 | ty.span, | |
216 | "`impl Trait` in type aliases is unstable" | |
217 | ); | |
218 | } | |
219 | visit::walk_ty(self, ty); | |
220 | } | |
221 | } | |
222 | ImplTraitVisitor { vis: self }.visit_ty(ty); | |
223 | } | |
224 | } | |
225 | ||
226 | impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { | |
227 | fn visit_attribute(&mut self, attr: &ast::Attribute) { | |
228 | let attr_info = | |
229 | attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)).map(|a| **a); | |
230 | // Check feature gates for built-in attributes. | |
231 | if let Some((.., AttributeGate::Gated(_, name, descr, has_feature))) = attr_info { | |
232 | gate_feature_fn!(self, has_feature, attr.span, name, descr); | |
233 | } | |
234 | // Check unstable flavors of the `#[doc]` attribute. | |
235 | if attr.check_name(sym::doc) { | |
236 | for nested_meta in attr.meta_item_list().unwrap_or_default() { | |
237 | macro_rules! gate_doc { ($($name:ident => $feature:ident)*) => { | |
238 | $(if nested_meta.check_name(sym::$name) { | |
239 | let msg = concat!("`#[doc(", stringify!($name), ")]` is experimental"); | |
240 | gate_feature_post!(self, $feature, attr.span, msg); | |
241 | })* | |
242 | }} | |
243 | ||
244 | gate_doc!( | |
245 | include => external_doc | |
246 | cfg => doc_cfg | |
247 | masked => doc_masked | |
dfeec247 XL |
248 | alias => doc_alias |
249 | keyword => doc_keyword | |
250 | ); | |
251 | } | |
252 | } | |
253 | } | |
254 | ||
f9f354fc | 255 | fn visit_name(&mut self, sp: Span, name: Symbol) { |
dfeec247 XL |
256 | if !name.as_str().is_ascii() { |
257 | gate_feature_post!( | |
258 | &self, | |
259 | non_ascii_idents, | |
ba9703b0 | 260 | self.parse_sess.source_map().guess_head_span(sp), |
dfeec247 XL |
261 | "non-ascii idents are not fully supported" |
262 | ); | |
263 | } | |
264 | } | |
265 | ||
266 | fn visit_item(&mut self, i: &'a ast::Item) { | |
267 | match i.kind { | |
268 | ast::ItemKind::ForeignMod(ref foreign_module) => { | |
269 | if let Some(abi) = foreign_module.abi { | |
270 | self.check_abi(abi); | |
271 | } | |
272 | } | |
273 | ||
274 | ast::ItemKind::Fn(..) => { | |
275 | if attr::contains_name(&i.attrs[..], sym::plugin_registrar) { | |
276 | gate_feature_post!( | |
277 | &self, | |
278 | plugin_registrar, | |
279 | i.span, | |
280 | "compiler plugins are experimental and possibly buggy" | |
281 | ); | |
282 | } | |
283 | if attr::contains_name(&i.attrs[..], sym::start) { | |
284 | gate_feature_post!( | |
285 | &self, | |
286 | start, | |
287 | i.span, | |
288 | "`#[start]` functions are experimental \ | |
ba9703b0 XL |
289 | and their signature may change \ |
290 | over time" | |
dfeec247 XL |
291 | ); |
292 | } | |
293 | if attr::contains_name(&i.attrs[..], sym::main) { | |
294 | gate_feature_post!( | |
295 | &self, | |
296 | main, | |
297 | i.span, | |
298 | "declaration of a non-standard `#[main]` \ | |
ba9703b0 XL |
299 | function may change over time, for now \ |
300 | a top-level `fn main()` is required" | |
dfeec247 XL |
301 | ); |
302 | } | |
303 | } | |
304 | ||
305 | ast::ItemKind::Struct(..) => { | |
306 | for attr in attr::filter_by_name(&i.attrs[..], sym::repr) { | |
307 | for item in attr.meta_item_list().unwrap_or_else(Vec::new) { | |
308 | if item.check_name(sym::simd) { | |
309 | gate_feature_post!( | |
310 | &self, | |
311 | repr_simd, | |
312 | attr.span, | |
313 | "SIMD types are experimental and possibly buggy" | |
314 | ); | |
315 | } | |
316 | } | |
317 | } | |
318 | } | |
319 | ||
320 | ast::ItemKind::Enum(ast::EnumDef { ref variants, .. }, ..) => { | |
321 | for variant in variants { | |
322 | match (&variant.data, &variant.disr_expr) { | |
323 | (ast::VariantData::Unit(..), _) => {} | |
324 | (_, Some(disr_expr)) => gate_feature_post!( | |
325 | &self, | |
326 | arbitrary_enum_discriminant, | |
327 | disr_expr.value.span, | |
328 | "discriminants on non-unit variants are experimental" | |
329 | ), | |
330 | _ => {} | |
331 | } | |
332 | } | |
333 | ||
334 | let has_feature = self.features.arbitrary_enum_discriminant; | |
335 | if !has_feature && !i.span.allows_unstable(sym::arbitrary_enum_discriminant) { | |
336 | self.maybe_report_invalid_custom_discriminants(&variants); | |
337 | } | |
338 | } | |
339 | ||
ba9703b0 XL |
340 | ast::ItemKind::Impl { polarity, defaultness, ref of_trait, .. } => { |
341 | if let ast::ImplPolarity::Negative(span) = polarity { | |
dfeec247 XL |
342 | gate_feature_post!( |
343 | &self, | |
ba9703b0 XL |
344 | negative_impls, |
345 | span.to(of_trait.as_ref().map(|t| t.path.span).unwrap_or(span)), | |
dfeec247 | 346 | "negative trait bounds are not yet fully implemented; \ |
ba9703b0 | 347 | use marker types for now" |
dfeec247 XL |
348 | ); |
349 | } | |
350 | ||
74b04a01 | 351 | if let ast::Defaultness::Default(_) = defaultness { |
dfeec247 XL |
352 | gate_feature_post!(&self, specialization, i.span, "specialization is unstable"); |
353 | } | |
354 | } | |
355 | ||
356 | ast::ItemKind::Trait(ast::IsAuto::Yes, ..) => { | |
357 | gate_feature_post!( | |
358 | &self, | |
359 | optin_builtin_traits, | |
360 | i.span, | |
361 | "auto traits are experimental and possibly buggy" | |
362 | ); | |
363 | } | |
364 | ||
365 | ast::ItemKind::TraitAlias(..) => { | |
366 | gate_feature_post!(&self, trait_alias, i.span, "trait aliases are experimental"); | |
367 | } | |
368 | ||
ba9703b0 | 369 | ast::ItemKind::MacroDef(ast::MacroDef { macro_rules: false, .. }) => { |
dfeec247 XL |
370 | let msg = "`macro` is experimental"; |
371 | gate_feature_post!(&self, decl_macro, i.span, msg); | |
372 | } | |
373 | ||
74b04a01 | 374 | ast::ItemKind::TyAlias(_, _, _, Some(ref ty)) => self.check_impl_trait(&ty), |
dfeec247 XL |
375 | |
376 | _ => {} | |
377 | } | |
378 | ||
379 | visit::walk_item(self, i); | |
380 | } | |
381 | ||
382 | fn visit_foreign_item(&mut self, i: &'a ast::ForeignItem) { | |
383 | match i.kind { | |
384 | ast::ForeignItemKind::Fn(..) | ast::ForeignItemKind::Static(..) => { | |
385 | let link_name = attr::first_attr_value_str_by_name(&i.attrs, sym::link_name); | |
386 | let links_to_llvm = match link_name { | |
387 | Some(val) => val.as_str().starts_with("llvm."), | |
388 | _ => false, | |
389 | }; | |
390 | if links_to_llvm { | |
391 | gate_feature_post!( | |
392 | &self, | |
393 | link_llvm_intrinsics, | |
394 | i.span, | |
395 | "linking to LLVM intrinsics is experimental" | |
396 | ); | |
397 | } | |
398 | } | |
74b04a01 | 399 | ast::ForeignItemKind::TyAlias(..) => { |
dfeec247 XL |
400 | gate_feature_post!(&self, extern_types, i.span, "extern types are experimental"); |
401 | } | |
ba9703b0 | 402 | ast::ForeignItemKind::MacCall(..) => {} |
dfeec247 XL |
403 | } |
404 | ||
405 | visit::walk_foreign_item(self, i) | |
406 | } | |
407 | ||
408 | fn visit_ty(&mut self, ty: &'a ast::Ty) { | |
409 | match ty.kind { | |
410 | ast::TyKind::BareFn(ref bare_fn_ty) => { | |
411 | self.check_extern(bare_fn_ty.ext); | |
412 | } | |
413 | ast::TyKind::Never => { | |
414 | gate_feature_post!(&self, never_type, ty.span, "the `!` type is experimental"); | |
415 | } | |
416 | _ => {} | |
417 | } | |
418 | visit::walk_ty(self, ty) | |
419 | } | |
420 | ||
74b04a01 XL |
421 | fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FnRetTy) { |
422 | if let ast::FnRetTy::Ty(ref output_ty) = *ret_ty { | |
dfeec247 XL |
423 | if let ast::TyKind::Never = output_ty.kind { |
424 | // Do nothing. | |
425 | } else { | |
426 | self.visit_ty(output_ty) | |
427 | } | |
428 | } | |
429 | } | |
430 | ||
431 | fn visit_expr(&mut self, e: &'a ast::Expr) { | |
432 | match e.kind { | |
433 | ast::ExprKind::Box(_) => { | |
434 | gate_feature_post!( | |
435 | &self, | |
436 | box_syntax, | |
437 | e.span, | |
438 | "box expression syntax is experimental; you can call `Box::new` instead" | |
439 | ); | |
440 | } | |
441 | ast::ExprKind::Type(..) => { | |
442 | // To avoid noise about type ascription in common syntax errors, only emit if it | |
443 | // is the *only* error. | |
444 | if self.parse_sess.span_diagnostic.err_count() == 0 { | |
445 | gate_feature_post!( | |
446 | &self, | |
447 | type_ascription, | |
448 | e.span, | |
449 | "type ascription is experimental" | |
450 | ); | |
451 | } | |
452 | } | |
453 | ast::ExprKind::TryBlock(_) => { | |
454 | gate_feature_post!(&self, try_blocks, e.span, "`try` expression is experimental"); | |
455 | } | |
456 | ast::ExprKind::Block(_, opt_label) => { | |
457 | if let Some(label) = opt_label { | |
458 | gate_feature_post!( | |
459 | &self, | |
460 | label_break_value, | |
461 | label.ident.span, | |
462 | "labels on blocks are unstable" | |
463 | ); | |
464 | } | |
465 | } | |
466 | _ => {} | |
467 | } | |
468 | visit::walk_expr(self, e) | |
469 | } | |
470 | ||
471 | fn visit_pat(&mut self, pattern: &'a ast::Pat) { | |
472 | match &pattern.kind { | |
473 | PatKind::Box(..) => { | |
474 | gate_feature_post!( | |
475 | &self, | |
476 | box_patterns, | |
477 | pattern.span, | |
478 | "box pattern syntax is experimental" | |
479 | ); | |
480 | } | |
481 | PatKind::Range(_, _, Spanned { node: RangeEnd::Excluded, .. }) => { | |
482 | gate_feature_post!( | |
483 | &self, | |
484 | exclusive_range_pattern, | |
485 | pattern.span, | |
486 | "exclusive range pattern syntax is experimental" | |
487 | ); | |
488 | } | |
489 | _ => {} | |
490 | } | |
491 | visit::walk_pat(self, pattern) | |
492 | } | |
493 | ||
74b04a01 | 494 | fn visit_fn(&mut self, fn_kind: FnKind<'a>, span: Span, _: NodeId) { |
dfeec247 | 495 | if let Some(header) = fn_kind.header() { |
74b04a01 | 496 | // Stability of const fn methods are covered in `visit_assoc_item` below. |
dfeec247 | 497 | self.check_extern(header.ext); |
74b04a01 XL |
498 | |
499 | if let (ast::Const::Yes(_), ast::Extern::Implicit) | |
500 | | (ast::Const::Yes(_), ast::Extern::Explicit(_)) = (header.constness, header.ext) | |
501 | { | |
502 | gate_feature_post!( | |
503 | &self, | |
504 | const_extern_fn, | |
505 | span, | |
506 | "`const extern fn` definitions are unstable" | |
507 | ); | |
508 | } | |
dfeec247 XL |
509 | } |
510 | ||
74b04a01 | 511 | if fn_kind.ctxt() != Some(FnCtxt::Foreign) && fn_kind.decl().c_variadic() { |
dfeec247 XL |
512 | gate_feature_post!(&self, c_variadic, span, "C-variadic functions are unstable"); |
513 | } | |
514 | ||
74b04a01 | 515 | visit::walk_fn(self, fn_kind, span) |
dfeec247 XL |
516 | } |
517 | ||
518 | fn visit_generic_param(&mut self, param: &'a GenericParam) { | |
ba9703b0 XL |
519 | if let GenericParamKind::Const { .. } = param.kind { |
520 | gate_feature_post!( | |
dfeec247 XL |
521 | &self, |
522 | const_generics, | |
523 | param.ident.span, | |
524 | "const generics are unstable" | |
ba9703b0 | 525 | ) |
dfeec247 XL |
526 | } |
527 | visit::walk_generic_param(self, param) | |
528 | } | |
529 | ||
530 | fn visit_assoc_ty_constraint(&mut self, constraint: &'a AssocTyConstraint) { | |
ba9703b0 XL |
531 | if let AssocTyConstraintKind::Bound { .. } = constraint.kind { |
532 | gate_feature_post!( | |
dfeec247 XL |
533 | &self, |
534 | associated_type_bounds, | |
535 | constraint.span, | |
536 | "associated type bounds are unstable" | |
ba9703b0 | 537 | ) |
dfeec247 XL |
538 | } |
539 | visit::walk_assoc_ty_constraint(self, constraint) | |
540 | } | |
541 | ||
74b04a01 | 542 | fn visit_assoc_item(&mut self, i: &'a ast::AssocItem, ctxt: AssocCtxt) { |
ba9703b0 | 543 | let is_fn = match i.kind { |
74b04a01 XL |
544 | ast::AssocItemKind::Fn(_, ref sig, _, _) => { |
545 | if let (ast::Const::Yes(_), AssocCtxt::Trait) = (sig.header.constness, ctxt) { | |
546 | gate_feature_post!(&self, const_fn, i.span, "const fn is unstable"); | |
dfeec247 | 547 | } |
ba9703b0 | 548 | true |
dfeec247 | 549 | } |
74b04a01 XL |
550 | ast::AssocItemKind::TyAlias(_, ref generics, _, ref ty) => { |
551 | if let (Some(_), AssocCtxt::Trait) = (ty, ctxt) { | |
dfeec247 XL |
552 | gate_feature_post!( |
553 | &self, | |
554 | associated_type_defaults, | |
74b04a01 | 555 | i.span, |
dfeec247 XL |
556 | "associated type defaults are unstable" |
557 | ); | |
558 | } | |
dfeec247 XL |
559 | if let Some(ty) = ty { |
560 | self.check_impl_trait(ty); | |
561 | } | |
74b04a01 | 562 | self.check_gat(generics, i.span); |
ba9703b0 | 563 | false |
dfeec247 | 564 | } |
ba9703b0 XL |
565 | _ => false, |
566 | }; | |
567 | if let ast::Defaultness::Default(_) = i.kind.defaultness() { | |
568 | // Limit `min_specialization` to only specializing functions. | |
569 | gate_feature_fn!( | |
570 | &self, | |
571 | |x: &Features| x.specialization || (is_fn && x.min_specialization), | |
572 | i.span, | |
573 | sym::specialization, | |
574 | "specialization is unstable" | |
575 | ); | |
dfeec247 | 576 | } |
74b04a01 | 577 | visit::walk_assoc_item(self, i, ctxt) |
dfeec247 XL |
578 | } |
579 | ||
580 | fn visit_vis(&mut self, vis: &'a ast::Visibility) { | |
581 | if let ast::VisibilityKind::Crate(ast::CrateSugar::JustCrate) = vis.node { | |
582 | gate_feature_post!( | |
583 | &self, | |
584 | crate_visibility_modifier, | |
585 | vis.span, | |
586 | "`crate` visibility modifier is experimental" | |
587 | ); | |
588 | } | |
589 | visit::walk_vis(self, vis) | |
590 | } | |
591 | } | |
592 | ||
593 | pub fn check_crate( | |
594 | krate: &ast::Crate, | |
595 | parse_sess: &ParseSess, | |
596 | features: &Features, | |
597 | unstable: UnstableFeatures, | |
598 | ) { | |
599 | maybe_stage_features(&parse_sess.span_diagnostic, krate, unstable); | |
600 | let mut visitor = PostExpansionVisitor { parse_sess, features }; | |
601 | ||
602 | let spans = parse_sess.gated_spans.spans.borrow(); | |
603 | macro_rules! gate_all { | |
604 | ($gate:ident, $msg:literal) => { | |
605 | for span in spans.get(&sym::$gate).unwrap_or(&vec![]) { | |
606 | gate_feature_post!(&visitor, $gate, *span, $msg); | |
607 | } | |
608 | }; | |
609 | } | |
610 | gate_all!(let_chains, "`let` expressions in this position are experimental"); | |
611 | gate_all!(async_closure, "async closures are unstable"); | |
612 | gate_all!(generators, "yield syntax is experimental"); | |
613 | gate_all!(or_patterns, "or-patterns syntax is experimental"); | |
dfeec247 XL |
614 | gate_all!(raw_ref_op, "raw address of syntax is experimental"); |
615 | gate_all!(const_trait_bound_opt_out, "`?const` on trait bounds is experimental"); | |
616 | gate_all!(const_trait_impl, "const trait impls are experimental"); | |
617 | gate_all!(half_open_range_patterns, "half-open range patterns are unstable"); | |
618 | ||
619 | // All uses of `gate_all!` below this point were added in #65742, | |
620 | // and subsequently disabled (with the non-early gating readded). | |
621 | macro_rules! gate_all { | |
622 | ($gate:ident, $msg:literal) => { | |
623 | // FIXME(eddyb) do something more useful than always | |
624 | // disabling these uses of early feature-gatings. | |
625 | if false { | |
626 | for span in spans.get(&sym::$gate).unwrap_or(&vec![]) { | |
627 | gate_feature_post!(&visitor, $gate, *span, $msg); | |
628 | } | |
629 | } | |
630 | }; | |
631 | } | |
632 | ||
633 | gate_all!(trait_alias, "trait aliases are experimental"); | |
634 | gate_all!(associated_type_bounds, "associated type bounds are unstable"); | |
635 | gate_all!(crate_visibility_modifier, "`crate` visibility modifier is experimental"); | |
636 | gate_all!(const_generics, "const generics are unstable"); | |
637 | gate_all!(decl_macro, "`macro` is experimental"); | |
638 | gate_all!(box_patterns, "box pattern syntax is experimental"); | |
639 | gate_all!(exclusive_range_pattern, "exclusive range pattern syntax is experimental"); | |
640 | gate_all!(try_blocks, "`try` blocks are unstable"); | |
641 | gate_all!(label_break_value, "labels on blocks are unstable"); | |
642 | gate_all!(box_syntax, "box expression syntax is experimental; you can call `Box::new` instead"); | |
643 | // To avoid noise about type ascription in common syntax errors, | |
644 | // only emit if it is the *only* error. (Also check it last.) | |
645 | if parse_sess.span_diagnostic.err_count() == 0 { | |
646 | gate_all!(type_ascription, "type ascription is experimental"); | |
647 | } | |
648 | ||
649 | visit::walk_crate(&mut visitor, krate); | |
650 | } | |
651 | ||
652 | fn maybe_stage_features(span_handler: &Handler, krate: &ast::Crate, unstable: UnstableFeatures) { | |
653 | if !unstable.is_nightly_build() { | |
654 | for attr in krate.attrs.iter().filter(|attr| attr.check_name(sym::feature)) { | |
655 | struct_span_err!( | |
656 | span_handler, | |
657 | attr.span, | |
658 | E0554, | |
659 | "`#![feature]` may not be used on the {} release channel", | |
660 | option_env!("CFG_RELEASE_CHANNEL").unwrap_or("(unknown)") | |
661 | ) | |
662 | .emit(); | |
663 | } | |
664 | } | |
665 | } |