1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![allow(non_snake_case)]
13 // Error messages for EXXXX errors.
14 // Each message should start and end with a new line, and be wrapped to 80 characters.
15 // In vim you can `:set tw=80` and use `gq` to wrap paragraphs. Use `:set tw=0` to disable.
16 register_long_diagnostics! {
19 In types, the `+` type operator has low precedence, so it is often necessary
28 w: &'a Foo + Copy, // error, use &'a (Foo + Copy)
29 x: &'a Foo + 'a, // error, use &'a (Foo + 'a)
30 y: &'a mut Foo + 'a, // error, use &'a mut (Foo + 'a)
31 z: fn() -> Foo + 'a, // error, use fn() -> (Foo + 'a)
35 More details can be found in [RFC 438].
37 [RFC 438]: https://github.com/rust-lang/rfcs/pull/438
41 The `not` cfg-predicate was malformed.
43 Erroneous code example:
46 #[cfg(not())] // error: expected 1 cfg-pattern
52 The `not` predicate expects one cfg-pattern. Example:
55 #[cfg(not(target_os = "linux"))] // ok!
61 For more information about the cfg attribute, read:
62 https://doc.rust-lang.org/reference.html#conditional-compilation
66 An unknown predicate was used inside the `cfg` attribute.
68 Erroneous code example:
71 #[cfg(unknown())] // error: invalid predicate `unknown`
77 The `cfg` attribute supports only three kinds of predicates:
86 #[cfg(not(target_os = "linux"))] // ok!
92 For more information about the cfg attribute, read:
93 https://doc.rust-lang.org/reference.html#conditional-compilation
97 Attribute contains same meta item more than once.
99 Erroneous code example:
101 ```compile_fail,E0538
104 note="First deprecation note.",
105 note="Second deprecation note." // error: multiple same meta item
107 fn deprecated_function() {}
110 Meta items are the key-value pairs inside of an attribute. Each key may only be
111 used once in each attribute.
113 To fix the problem, remove all but one of the meta items with the same key.
120 note="First deprecation note."
122 fn deprecated_function() {}
127 An unknown meta item was used.
129 Erroneous code example:
131 ```compile_fail,E0541
134 // error: unknown meta item
135 reason="Example invalid meta item. Should be 'note'")
137 fn deprecated_function() {}
140 Meta items are the key-value pairs inside of an attribute. The keys provided
141 must be one of the valid keys for the specified attribute.
143 To fix the problem, either remove the unknown meta item, or rename it if you
144 provided the wrong name.
146 In the erroneous code example above, the wrong name was provided, so changing
147 to a correct one it will fix the error. Example:
152 note="This is a valid meta item for the deprecated attribute."
154 fn deprecated_function() {}
159 A unrecognized representation attribute was used.
161 Erroneous code example:
163 ```compile_fail,E0552
164 #[repr(D)] // error: unrecognized representation hint
170 You can use a `repr` attribute to tell the compiler how you want a struct or
171 enum to be laid out in memory.
173 Make sure you're using one of the supported options:
182 For more information about specifying representations, see the ["Alternative
183 Representations" section] of the Rustonomicon.
185 ["Alternative Representations" section]: https://doc.rust-lang.org/nomicon/other-reprs.html
189 Feature attributes are only allowed on the nightly release channel. Stable or
190 beta compilers will not comply.
192 Example of erroneous code (on a stable compiler):
194 ```ignore (depends on release channel)
195 #![feature(non_ascii_idents)] // error: #![feature] may not be used on the
196 // stable release channel
199 If you need the feature, make sure to use a nightly release of the compiler
200 (but be warned that the feature may be removed or altered in the future).
204 A feature attribute named a feature that has been removed.
206 Erroneous code example:
208 ```compile_fail,E0557
209 #![feature(managed_boxes)] // error: feature has been removed
212 Delete the offending feature attribute.
216 A literal was used in an attribute that doesn't support literals.
218 Erroneous code example:
220 ```ignore (compile_fail not working here; see Issue #43707)
221 #![feature(attr_literals)]
223 #[inline("always")] // error: unsupported literal
224 pub fn something() {}
227 Literals in attributes are new and largely unsupported. Work to support literals
228 where appropriate is ongoing. Try using an unquoted name instead:
232 pub fn something() {}
237 A file wasn't found for an out-of-line module.
239 Erroneous code example:
241 ```ignore (compile_fail not working here; see Issue #43707)
242 mod file_that_doesnt_exist; // error: file not found for module
247 Please be sure that a file corresponding to the module exists. If you
248 want to use a module named `file_that_doesnt_exist`, you need to have a file
249 named `file_that_doesnt_exist.rs` or `file_that_doesnt_exist/mod.rs` in the
254 A documentation comment that doesn't document anything was found.
256 Erroneous code example:
258 ```compile_fail,E0585
260 // The following doc comment will fail:
261 /// This is a useless doc comment!
265 Documentation comments need to be followed by items, including functions,
266 types, modules, etc. Examples:
269 /// I'm documenting the following struct:
272 /// I'm documenting the following function:
278 An inclusive range was used with no end.
280 Erroneous code example:
282 ```compile_fail,E0586
284 let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
285 let x = &tmp[1..=]; // error: inclusive range was used with no end
289 An inclusive range needs an end in order to *include* it. If you just need a
290 start and no end, use a non-inclusive range (with `..`):
294 let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
295 let x = &tmp[1..]; // ok!
299 Or put an end to your inclusive range:
303 let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
304 let x = &tmp[1..=3]; // ok!
310 The value of `N` that was specified for `repr(align(N))` was not a power
311 of two, or was greater than 2^29.
313 ```compile_fail,E0589
314 #[repr(align(15))] // error: invalid `repr(align)` attribute: not a power of two
322 An unstable feature was used.
324 Erroneous code example:
327 #[repr(u128)] // error: use of unstable library feature 'repr128'
333 If you're using a stable or a beta version of rustc, you won't be able to use
334 any unstable features. In order to do so, please switch to a nightly version of
335 rustc (by using rustup).
337 If you're using a nightly version of rustc, just add the corresponding feature
338 to be able to use it:
351 The `unwind` attribute was malformed.
353 Erroneous code example:
355 ```ignore (compile_fail not working here; see Issue #43707)
356 #[unwind()] // error: expected one argument
357 pub extern fn something() {}
362 The `#[unwind]` attribute should be used as follows:
364 - `#[unwind(aborts)]` -- specifies that if a non-Rust ABI function
365 should abort the process if it attempts to unwind. This is the safer
366 and preferred option.
368 - `#[unwind(allowed)]` -- specifies that a non-Rust ABI function
369 should be allowed to unwind. This can easily result in Undefined
370 Behavior (UB), so be careful.
372 NB. The default behavior here is "allowed", but this is unspecified
373 and likely to change in the future.
379 register_diagnostics! {
380 E0539, // incorrect meta item
381 E0540, // multiple rustc_deprecated attributes
382 E0542, // missing 'since'
383 E0543, // missing 'reason'
384 E0544, // multiple stability levels
385 E0545, // incorrect 'issue'
386 E0546, // missing 'feature'
387 E0547, // missing 'issue'
388 E0548, // incorrect stability attribute type
389 E0549, // rustc_deprecated attribute must be paired with either stable or unstable attribute
390 E0550, // multiple deprecated attributes
391 E0551, // incorrect meta item
392 E0553, // multiple rustc_const_unstable attributes
393 E0555, // malformed feature attribute, expected #![feature(...)]
394 E0556, // malformed feature, expected just one word
395 E0584, // file for module `..` found at both .. and ..
396 E0629, // missing 'feature' (rustc_const_unstable)
397 E0630, // rustc_const_unstable attribute must be paired with stable/unstable attribute
398 E0693, // incorrect `repr(align)` attribute format
399 E0694, // an unknown tool name found in scoped attributes
400 E0703, // invalid ABI
401 E0704, // incorrect visibility restriction