1 | use crate::internals::symbol::*; |
2 | use crate::internals::{ungroup, Ctxt}; |
3 | use proc_macro2::{Spacing, Span, TokenStream, TokenTree}; |
4 | use quote::ToTokens; |
5 | use std::borrow::Cow; |
6 | use std::collections::BTreeSet; |
7 | use std::iter::FromIterator; |
8 | use syn::meta::ParseNestedMeta; |
9 | use syn::parse::ParseStream; |
10 | use syn::punctuated::Punctuated; |
11 | use syn::{parse_quote, token, Ident, Lifetime, Token}; |
12 | |
13 | // This module handles parsing of `#[serde(...)]` attributes. The entrypoints |
14 | // are `attr::Container::from_ast`, `attr::Variant::from_ast`, and |
15 | // `attr::Field::from_ast`. Each returns an instance of the corresponding |
16 | // struct. Note that none of them return a Result. Unrecognized, malformed, or |
17 | // duplicated attributes result in a span_err but otherwise are ignored. The |
18 | // user will see errors simultaneously for all bad attributes in the crate |
19 | // rather than just the first. |
20 | |
21 | pub use crate::internals::case::RenameRule; |
22 | |
23 | struct Attr<'c, T> { |
24 | cx: &'c Ctxt, |
25 | name: Symbol, |
26 | tokens: TokenStream, |
27 | value: Option<T>, |
28 | } |
29 | |
30 | impl<'c, T> Attr<'c, T> { |
31 | fn none(cx: &'c Ctxt, name: Symbol) -> Self { |
32 | Attr { |
33 | cx, |
34 | name, |
35 | tokens: TokenStream::new(), |
36 | value: None, |
37 | } |
38 | } |
39 | |
40 | fn set<A: ToTokens>(&mut self, obj: A, value: T) { |
41 | let tokens = obj.into_token_stream(); |
42 | |
43 | if self.value.is_some() { |
44 | let msg = format!("duplicate serde attribute `{}`" , self.name); |
45 | self.cx.error_spanned_by(tokens, msg); |
46 | } else { |
47 | self.tokens = tokens; |
48 | self.value = Some(value); |
49 | } |
50 | } |
51 | |
52 | fn set_opt<A: ToTokens>(&mut self, obj: A, value: Option<T>) { |
53 | if let Some(value) = value { |
54 | self.set(obj, value); |
55 | } |
56 | } |
57 | |
58 | fn set_if_none(&mut self, value: T) { |
59 | if self.value.is_none() { |
60 | self.value = Some(value); |
61 | } |
62 | } |
63 | |
64 | fn get(self) -> Option<T> { |
65 | self.value |
66 | } |
67 | |
68 | fn get_with_tokens(self) -> Option<(TokenStream, T)> { |
69 | match self.value { |
70 | Some(v) => Some((self.tokens, v)), |
71 | None => None, |
72 | } |
73 | } |
74 | } |
75 | |
76 | struct BoolAttr<'c>(Attr<'c, ()>); |
77 | |
78 | impl<'c> BoolAttr<'c> { |
79 | fn none(cx: &'c Ctxt, name: Symbol) -> Self { |
80 | BoolAttr(Attr::none(cx, name)) |
81 | } |
82 | |
83 | fn set_true<A: ToTokens>(&mut self, obj: A) { |
84 | self.0.set(obj, ()); |
85 | } |
86 | |
87 | fn get(&self) -> bool { |
88 | self.0.value.is_some() |
89 | } |
90 | } |
91 | |
92 | struct VecAttr<'c, T> { |
93 | cx: &'c Ctxt, |
94 | name: Symbol, |
95 | first_dup_tokens: TokenStream, |
96 | values: Vec<T>, |
97 | } |
98 | |
99 | impl<'c, T> VecAttr<'c, T> { |
100 | fn none(cx: &'c Ctxt, name: Symbol) -> Self { |
101 | VecAttr { |
102 | cx, |
103 | name, |
104 | first_dup_tokens: TokenStream::new(), |
105 | values: Vec::new(), |
106 | } |
107 | } |
108 | |
109 | fn insert<A: ToTokens>(&mut self, obj: A, value: T) { |
110 | if self.values.len() == 1 { |
111 | self.first_dup_tokens = obj.into_token_stream(); |
112 | } |
113 | self.values.push(value); |
114 | } |
115 | |
116 | fn at_most_one(mut self) -> Option<T> { |
117 | if self.values.len() > 1 { |
118 | let dup_token = self.first_dup_tokens; |
119 | let msg = format!("duplicate serde attribute `{}`" , self.name); |
120 | self.cx.error_spanned_by(dup_token, msg); |
121 | None |
122 | } else { |
123 | self.values.pop() |
124 | } |
125 | } |
126 | |
127 | fn get(self) -> Vec<T> { |
128 | self.values |
129 | } |
130 | } |
131 | |
132 | pub struct Name { |
133 | serialize: String, |
134 | serialize_renamed: bool, |
135 | deserialize: String, |
136 | deserialize_renamed: bool, |
137 | deserialize_aliases: BTreeSet<String>, |
138 | } |
139 | |
140 | fn unraw(ident: &Ident) -> String { |
141 | ident.to_string().trim_start_matches("r#" ).to_owned() |
142 | } |
143 | |
144 | impl Name { |
145 | fn from_attrs( |
146 | source_name: String, |
147 | ser_name: Attr<String>, |
148 | de_name: Attr<String>, |
149 | de_aliases: Option<VecAttr<String>>, |
150 | ) -> Name { |
151 | let mut alias_set = BTreeSet::new(); |
152 | if let Some(de_aliases) = de_aliases { |
153 | for alias_name in de_aliases.get() { |
154 | alias_set.insert(alias_name); |
155 | } |
156 | } |
157 | |
158 | let ser_name = ser_name.get(); |
159 | let ser_renamed = ser_name.is_some(); |
160 | let de_name = de_name.get(); |
161 | let de_renamed = de_name.is_some(); |
162 | Name { |
163 | serialize: ser_name.unwrap_or_else(|| source_name.clone()), |
164 | serialize_renamed: ser_renamed, |
165 | deserialize: de_name.unwrap_or(source_name), |
166 | deserialize_renamed: de_renamed, |
167 | deserialize_aliases: alias_set, |
168 | } |
169 | } |
170 | |
171 | /// Return the container name for the container when serializing. |
172 | pub fn serialize_name(&self) -> &str { |
173 | &self.serialize |
174 | } |
175 | |
176 | /// Return the container name for the container when deserializing. |
177 | pub fn deserialize_name(&self) -> &str { |
178 | &self.deserialize |
179 | } |
180 | |
181 | fn deserialize_aliases(&self) -> &BTreeSet<String> { |
182 | &self.deserialize_aliases |
183 | } |
184 | } |
185 | |
186 | #[derive(Copy, Clone)] |
187 | pub struct RenameAllRules { |
188 | serialize: RenameRule, |
189 | deserialize: RenameRule, |
190 | } |
191 | |
192 | impl RenameAllRules { |
193 | /// Returns a new `RenameAllRules` with the individual rules of `self` and |
194 | /// `other_rules` joined by `RenameRules::or`. |
195 | pub fn or(self, other_rules: Self) -> Self { |
196 | Self { |
197 | serialize: self.serialize.or(other_rules.serialize), |
198 | deserialize: self.deserialize.or(other_rules.deserialize), |
199 | } |
200 | } |
201 | } |
202 | |
203 | /// Represents struct or enum attribute information. |
204 | pub struct Container { |
205 | name: Name, |
206 | transparent: bool, |
207 | deny_unknown_fields: bool, |
208 | default: Default, |
209 | rename_all_rules: RenameAllRules, |
210 | rename_all_fields_rules: RenameAllRules, |
211 | ser_bound: Option<Vec<syn::WherePredicate>>, |
212 | de_bound: Option<Vec<syn::WherePredicate>>, |
213 | tag: TagType, |
214 | type_from: Option<syn::Type>, |
215 | type_try_from: Option<syn::Type>, |
216 | type_into: Option<syn::Type>, |
217 | remote: Option<syn::Path>, |
218 | identifier: Identifier, |
219 | has_flatten: bool, |
220 | serde_path: Option<syn::Path>, |
221 | is_packed: bool, |
222 | /// Error message generated when type can't be deserialized |
223 | expecting: Option<String>, |
224 | non_exhaustive: bool, |
225 | } |
226 | |
227 | /// Styles of representing an enum. |
228 | pub enum TagType { |
229 | /// The default. |
230 | /// |
231 | /// ```json |
232 | /// {"variant1": {"key1": "value1", "key2": "value2"}} |
233 | /// ``` |
234 | External, |
235 | |
236 | /// `#[serde(tag = "type")]` |
237 | /// |
238 | /// ```json |
239 | /// {"type": "variant1", "key1": "value1", "key2": "value2"} |
240 | /// ``` |
241 | Internal { tag: String }, |
242 | |
243 | /// `#[serde(tag = "t", content = "c")]` |
244 | /// |
245 | /// ```json |
246 | /// {"t": "variant1", "c": {"key1": "value1", "key2": "value2"}} |
247 | /// ``` |
248 | Adjacent { tag: String, content: String }, |
249 | |
250 | /// `#[serde(untagged)]` |
251 | /// |
252 | /// ```json |
253 | /// {"key1": "value1", "key2": "value2"} |
254 | /// ``` |
255 | None, |
256 | } |
257 | |
258 | /// Whether this enum represents the fields of a struct or the variants of an |
259 | /// enum. |
260 | #[derive(Copy, Clone)] |
261 | pub enum Identifier { |
262 | /// It does not. |
263 | No, |
264 | |
265 | /// This enum represents the fields of a struct. All of the variants must be |
266 | /// unit variants, except possibly one which is annotated with |
267 | /// `#[serde(other)]` and is a newtype variant. |
268 | Field, |
269 | |
270 | /// This enum represents the variants of an enum. All of the variants must |
271 | /// be unit variants. |
272 | Variant, |
273 | } |
274 | |
275 | impl Identifier { |
276 | #[cfg (feature = "deserialize_in_place" )] |
277 | pub fn is_some(self) -> bool { |
278 | match self { |
279 | Identifier::No => false, |
280 | Identifier::Field | Identifier::Variant => true, |
281 | } |
282 | } |
283 | } |
284 | |
285 | impl Container { |
286 | /// Extract out the `#[serde(...)]` attributes from an item. |
287 | pub fn from_ast(cx: &Ctxt, item: &syn::DeriveInput) -> Self { |
288 | let mut ser_name = Attr::none(cx, RENAME); |
289 | let mut de_name = Attr::none(cx, RENAME); |
290 | let mut transparent = BoolAttr::none(cx, TRANSPARENT); |
291 | let mut deny_unknown_fields = BoolAttr::none(cx, DENY_UNKNOWN_FIELDS); |
292 | let mut default = Attr::none(cx, DEFAULT); |
293 | let mut rename_all_ser_rule = Attr::none(cx, RENAME_ALL); |
294 | let mut rename_all_de_rule = Attr::none(cx, RENAME_ALL); |
295 | let mut rename_all_fields_ser_rule = Attr::none(cx, RENAME_ALL_FIELDS); |
296 | let mut rename_all_fields_de_rule = Attr::none(cx, RENAME_ALL_FIELDS); |
297 | let mut ser_bound = Attr::none(cx, BOUND); |
298 | let mut de_bound = Attr::none(cx, BOUND); |
299 | let mut untagged = BoolAttr::none(cx, UNTAGGED); |
300 | let mut internal_tag = Attr::none(cx, TAG); |
301 | let mut content = Attr::none(cx, CONTENT); |
302 | let mut type_from = Attr::none(cx, FROM); |
303 | let mut type_try_from = Attr::none(cx, TRY_FROM); |
304 | let mut type_into = Attr::none(cx, INTO); |
305 | let mut remote = Attr::none(cx, REMOTE); |
306 | let mut field_identifier = BoolAttr::none(cx, FIELD_IDENTIFIER); |
307 | let mut variant_identifier = BoolAttr::none(cx, VARIANT_IDENTIFIER); |
308 | let mut serde_path = Attr::none(cx, CRATE); |
309 | let mut expecting = Attr::none(cx, EXPECTING); |
310 | let mut non_exhaustive = false; |
311 | |
312 | for attr in &item.attrs { |
313 | if attr.path() != SERDE { |
314 | non_exhaustive |= |
315 | matches!(&attr.meta, syn::Meta::Path(path) if path == NON_EXHAUSTIVE); |
316 | continue; |
317 | } |
318 | |
319 | if let syn::Meta::List(meta) = &attr.meta { |
320 | if meta.tokens.is_empty() { |
321 | continue; |
322 | } |
323 | } |
324 | |
325 | if let Err(err) = attr.parse_nested_meta(|meta| { |
326 | if meta.path == RENAME { |
327 | // #[serde(rename = "foo")] |
328 | // #[serde(rename(serialize = "foo", deserialize = "bar"))] |
329 | let (ser, de) = get_renames(cx, RENAME, &meta)?; |
330 | ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value)); |
331 | de_name.set_opt(&meta.path, de.as_ref().map(syn::LitStr::value)); |
332 | } else if meta.path == RENAME_ALL { |
333 | // #[serde(rename_all = "foo")] |
334 | // #[serde(rename_all(serialize = "foo", deserialize = "bar"))] |
335 | let one_name = meta.input.peek(Token![=]); |
336 | let (ser, de) = get_renames(cx, RENAME_ALL, &meta)?; |
337 | if let Some(ser) = ser { |
338 | match RenameRule::from_str(&ser.value()) { |
339 | Ok(rename_rule) => rename_all_ser_rule.set(&meta.path, rename_rule), |
340 | Err(err) => cx.error_spanned_by(ser, err), |
341 | } |
342 | } |
343 | if let Some(de) = de { |
344 | match RenameRule::from_str(&de.value()) { |
345 | Ok(rename_rule) => rename_all_de_rule.set(&meta.path, rename_rule), |
346 | Err(err) => { |
347 | if !one_name { |
348 | cx.error_spanned_by(de, err); |
349 | } |
350 | } |
351 | } |
352 | } |
353 | } else if meta.path == RENAME_ALL_FIELDS { |
354 | // #[serde(rename_all_fields = "foo")] |
355 | // #[serde(rename_all_fields(serialize = "foo", deserialize = "bar"))] |
356 | let one_name = meta.input.peek(Token![=]); |
357 | let (ser, de) = get_renames(cx, RENAME_ALL_FIELDS, &meta)?; |
358 | |
359 | match item.data { |
360 | syn::Data::Enum(_) => { |
361 | if let Some(ser) = ser { |
362 | match RenameRule::from_str(&ser.value()) { |
363 | Ok(rename_rule) => { |
364 | rename_all_fields_ser_rule.set(&meta.path, rename_rule); |
365 | } |
366 | Err(err) => cx.error_spanned_by(ser, err), |
367 | } |
368 | } |
369 | if let Some(de) = de { |
370 | match RenameRule::from_str(&de.value()) { |
371 | Ok(rename_rule) => { |
372 | rename_all_fields_de_rule.set(&meta.path, rename_rule); |
373 | } |
374 | Err(err) => { |
375 | if !one_name { |
376 | cx.error_spanned_by(de, err); |
377 | } |
378 | } |
379 | } |
380 | } |
381 | } |
382 | syn::Data::Struct(_) => { |
383 | let msg = "#[serde(rename_all_fields)] can only be used on enums" ; |
384 | cx.syn_error(meta.error(msg)); |
385 | } |
386 | syn::Data::Union(_) => { |
387 | let msg = "#[serde(rename_all_fields)] can only be used on enums" ; |
388 | cx.syn_error(meta.error(msg)); |
389 | } |
390 | } |
391 | } else if meta.path == TRANSPARENT { |
392 | // #[serde(transparent)] |
393 | transparent.set_true(meta.path); |
394 | } else if meta.path == DENY_UNKNOWN_FIELDS { |
395 | // #[serde(deny_unknown_fields)] |
396 | deny_unknown_fields.set_true(meta.path); |
397 | } else if meta.path == DEFAULT { |
398 | if meta.input.peek(Token![=]) { |
399 | // #[serde(default = "...")] |
400 | if let Some(path) = parse_lit_into_expr_path(cx, DEFAULT, &meta)? { |
401 | match &item.data { |
402 | syn::Data::Struct(syn::DataStruct { fields, .. }) => match fields { |
403 | syn::Fields::Named(_) | syn::Fields::Unnamed(_) => { |
404 | default.set(&meta.path, Default::Path(path)); |
405 | } |
406 | syn::Fields::Unit => { |
407 | let msg = "#[serde(default = \"... \")] can only be used on structs that have fields" ; |
408 | cx.syn_error(meta.error(msg)); |
409 | } |
410 | }, |
411 | syn::Data::Enum(_) => { |
412 | let msg = "#[serde(default = \"... \")] can only be used on structs" ; |
413 | cx.syn_error(meta.error(msg)); |
414 | } |
415 | syn::Data::Union(_) => { |
416 | let msg = "#[serde(default = \"... \")] can only be used on structs" ; |
417 | cx.syn_error(meta.error(msg)); |
418 | } |
419 | } |
420 | } |
421 | } else { |
422 | // #[serde(default)] |
423 | match &item.data { |
424 | syn::Data::Struct(syn::DataStruct { fields, .. }) => match fields { |
425 | syn::Fields::Named(_) | syn::Fields::Unnamed(_) => { |
426 | default.set(meta.path, Default::Default); |
427 | } |
428 | syn::Fields::Unit => { |
429 | let msg = "#[serde(default)] can only be used on structs that have fields" ; |
430 | cx.error_spanned_by(fields, msg); |
431 | } |
432 | }, |
433 | syn::Data::Enum(_) => { |
434 | let msg = "#[serde(default)] can only be used on structs" ; |
435 | cx.syn_error(meta.error(msg)); |
436 | } |
437 | syn::Data::Union(_) => { |
438 | let msg = "#[serde(default)] can only be used on structs" ; |
439 | cx.syn_error(meta.error(msg)); |
440 | } |
441 | } |
442 | } |
443 | } else if meta.path == BOUND { |
444 | // #[serde(bound = "T: SomeBound")] |
445 | // #[serde(bound(serialize = "...", deserialize = "..."))] |
446 | let (ser, de) = get_where_predicates(cx, &meta)?; |
447 | ser_bound.set_opt(&meta.path, ser); |
448 | de_bound.set_opt(&meta.path, de); |
449 | } else if meta.path == UNTAGGED { |
450 | // #[serde(untagged)] |
451 | match item.data { |
452 | syn::Data::Enum(_) => { |
453 | untagged.set_true(&meta.path); |
454 | } |
455 | syn::Data::Struct(_) => { |
456 | let msg = "#[serde(untagged)] can only be used on enums" ; |
457 | cx.syn_error(meta.error(msg)); |
458 | } |
459 | syn::Data::Union(_) => { |
460 | let msg = "#[serde(untagged)] can only be used on enums" ; |
461 | cx.syn_error(meta.error(msg)); |
462 | } |
463 | } |
464 | } else if meta.path == TAG { |
465 | // #[serde(tag = "type")] |
466 | if let Some(s) = get_lit_str(cx, TAG, &meta)? { |
467 | match &item.data { |
468 | syn::Data::Enum(_) => { |
469 | internal_tag.set(&meta.path, s.value()); |
470 | } |
471 | syn::Data::Struct(syn::DataStruct { fields, .. }) => match fields { |
472 | syn::Fields::Named(_) => { |
473 | internal_tag.set(&meta.path, s.value()); |
474 | } |
475 | syn::Fields::Unnamed(_) | syn::Fields::Unit => { |
476 | let msg = "#[serde(tag = \"... \")] can only be used on enums and structs with named fields" ; |
477 | cx.syn_error(meta.error(msg)); |
478 | } |
479 | }, |
480 | syn::Data::Union(_) => { |
481 | let msg = "#[serde(tag = \"... \")] can only be used on enums and structs with named fields" ; |
482 | cx.syn_error(meta.error(msg)); |
483 | } |
484 | } |
485 | } |
486 | } else if meta.path == CONTENT { |
487 | // #[serde(content = "c")] |
488 | if let Some(s) = get_lit_str(cx, CONTENT, &meta)? { |
489 | match &item.data { |
490 | syn::Data::Enum(_) => { |
491 | content.set(&meta.path, s.value()); |
492 | } |
493 | syn::Data::Struct(_) => { |
494 | let msg = "#[serde(content = \"... \")] can only be used on enums" ; |
495 | cx.syn_error(meta.error(msg)); |
496 | } |
497 | syn::Data::Union(_) => { |
498 | let msg = "#[serde(content = \"... \")] can only be used on enums" ; |
499 | cx.syn_error(meta.error(msg)); |
500 | } |
501 | } |
502 | } |
503 | } else if meta.path == FROM { |
504 | // #[serde(from = "Type")] |
505 | if let Some(from_ty) = parse_lit_into_ty(cx, FROM, &meta)? { |
506 | type_from.set_opt(&meta.path, Some(from_ty)); |
507 | } |
508 | } else if meta.path == TRY_FROM { |
509 | // #[serde(try_from = "Type")] |
510 | if let Some(try_from_ty) = parse_lit_into_ty(cx, TRY_FROM, &meta)? { |
511 | type_try_from.set_opt(&meta.path, Some(try_from_ty)); |
512 | } |
513 | } else if meta.path == INTO { |
514 | // #[serde(into = "Type")] |
515 | if let Some(into_ty) = parse_lit_into_ty(cx, INTO, &meta)? { |
516 | type_into.set_opt(&meta.path, Some(into_ty)); |
517 | } |
518 | } else if meta.path == REMOTE { |
519 | // #[serde(remote = "...")] |
520 | if let Some(path) = parse_lit_into_path(cx, REMOTE, &meta)? { |
521 | if is_primitive_path(&path, "Self" ) { |
522 | remote.set(&meta.path, item.ident.clone().into()); |
523 | } else { |
524 | remote.set(&meta.path, path); |
525 | } |
526 | } |
527 | } else if meta.path == FIELD_IDENTIFIER { |
528 | // #[serde(field_identifier)] |
529 | field_identifier.set_true(&meta.path); |
530 | } else if meta.path == VARIANT_IDENTIFIER { |
531 | // #[serde(variant_identifier)] |
532 | variant_identifier.set_true(&meta.path); |
533 | } else if meta.path == CRATE { |
534 | // #[serde(crate = "foo")] |
535 | if let Some(path) = parse_lit_into_path(cx, CRATE, &meta)? { |
536 | serde_path.set(&meta.path, path); |
537 | } |
538 | } else if meta.path == EXPECTING { |
539 | // #[serde(expecting = "a message")] |
540 | if let Some(s) = get_lit_str(cx, EXPECTING, &meta)? { |
541 | expecting.set(&meta.path, s.value()); |
542 | } |
543 | } else { |
544 | let path = meta.path.to_token_stream().to_string().replace(' ' , "" ); |
545 | return Err( |
546 | meta.error(format_args!("unknown serde container attribute `{}`" , path)) |
547 | ); |
548 | } |
549 | Ok(()) |
550 | }) { |
551 | cx.syn_error(err); |
552 | } |
553 | } |
554 | |
555 | let mut is_packed = false; |
556 | for attr in &item.attrs { |
557 | if attr.path() == REPR { |
558 | let _ = attr.parse_args_with(|input: ParseStream| { |
559 | while let Some(token) = input.parse()? { |
560 | if let TokenTree::Ident(ident) = token { |
561 | is_packed |= ident == "packed" ; |
562 | } |
563 | } |
564 | Ok(()) |
565 | }); |
566 | } |
567 | } |
568 | |
569 | Container { |
570 | name: Name::from_attrs(unraw(&item.ident), ser_name, de_name, None), |
571 | transparent: transparent.get(), |
572 | deny_unknown_fields: deny_unknown_fields.get(), |
573 | default: default.get().unwrap_or(Default::None), |
574 | rename_all_rules: RenameAllRules { |
575 | serialize: rename_all_ser_rule.get().unwrap_or(RenameRule::None), |
576 | deserialize: rename_all_de_rule.get().unwrap_or(RenameRule::None), |
577 | }, |
578 | rename_all_fields_rules: RenameAllRules { |
579 | serialize: rename_all_fields_ser_rule.get().unwrap_or(RenameRule::None), |
580 | deserialize: rename_all_fields_de_rule.get().unwrap_or(RenameRule::None), |
581 | }, |
582 | ser_bound: ser_bound.get(), |
583 | de_bound: de_bound.get(), |
584 | tag: decide_tag(cx, item, untagged, internal_tag, content), |
585 | type_from: type_from.get(), |
586 | type_try_from: type_try_from.get(), |
587 | type_into: type_into.get(), |
588 | remote: remote.get(), |
589 | identifier: decide_identifier(cx, item, field_identifier, variant_identifier), |
590 | has_flatten: false, |
591 | serde_path: serde_path.get(), |
592 | is_packed, |
593 | expecting: expecting.get(), |
594 | non_exhaustive, |
595 | } |
596 | } |
597 | |
598 | pub fn name(&self) -> &Name { |
599 | &self.name |
600 | } |
601 | |
602 | pub fn rename_all_rules(&self) -> RenameAllRules { |
603 | self.rename_all_rules |
604 | } |
605 | |
606 | pub fn rename_all_fields_rules(&self) -> RenameAllRules { |
607 | self.rename_all_fields_rules |
608 | } |
609 | |
610 | pub fn transparent(&self) -> bool { |
611 | self.transparent |
612 | } |
613 | |
614 | pub fn deny_unknown_fields(&self) -> bool { |
615 | self.deny_unknown_fields |
616 | } |
617 | |
618 | pub fn default(&self) -> &Default { |
619 | &self.default |
620 | } |
621 | |
622 | pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> { |
623 | self.ser_bound.as_ref().map(|vec| &vec[..]) |
624 | } |
625 | |
626 | pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> { |
627 | self.de_bound.as_ref().map(|vec| &vec[..]) |
628 | } |
629 | |
630 | pub fn tag(&self) -> &TagType { |
631 | &self.tag |
632 | } |
633 | |
634 | pub fn type_from(&self) -> Option<&syn::Type> { |
635 | self.type_from.as_ref() |
636 | } |
637 | |
638 | pub fn type_try_from(&self) -> Option<&syn::Type> { |
639 | self.type_try_from.as_ref() |
640 | } |
641 | |
642 | pub fn type_into(&self) -> Option<&syn::Type> { |
643 | self.type_into.as_ref() |
644 | } |
645 | |
646 | pub fn remote(&self) -> Option<&syn::Path> { |
647 | self.remote.as_ref() |
648 | } |
649 | |
650 | pub fn is_packed(&self) -> bool { |
651 | self.is_packed |
652 | } |
653 | |
654 | pub fn identifier(&self) -> Identifier { |
655 | self.identifier |
656 | } |
657 | |
658 | pub fn has_flatten(&self) -> bool { |
659 | self.has_flatten |
660 | } |
661 | |
662 | pub fn mark_has_flatten(&mut self) { |
663 | self.has_flatten = true; |
664 | } |
665 | |
666 | pub fn custom_serde_path(&self) -> Option<&syn::Path> { |
667 | self.serde_path.as_ref() |
668 | } |
669 | |
670 | pub fn serde_path(&self) -> Cow<syn::Path> { |
671 | self.custom_serde_path() |
672 | .map_or_else(|| Cow::Owned(parse_quote!(_serde)), Cow::Borrowed) |
673 | } |
674 | |
675 | /// Error message generated when type can't be deserialized. |
676 | /// If `None`, default message will be used |
677 | pub fn expecting(&self) -> Option<&str> { |
678 | self.expecting.as_ref().map(String::as_ref) |
679 | } |
680 | |
681 | pub fn non_exhaustive(&self) -> bool { |
682 | self.non_exhaustive |
683 | } |
684 | } |
685 | |
686 | fn decide_tag( |
687 | cx: &Ctxt, |
688 | item: &syn::DeriveInput, |
689 | untagged: BoolAttr, |
690 | internal_tag: Attr<String>, |
691 | content: Attr<String>, |
692 | ) -> TagType { |
693 | match ( |
694 | untagged.0.get_with_tokens(), |
695 | internal_tag.get_with_tokens(), |
696 | content.get_with_tokens(), |
697 | ) { |
698 | (None, None, None) => TagType::External, |
699 | (Some(_), None, None) => TagType::None, |
700 | (None, Some((_, tag)), None) => { |
701 | // Check that there are no tuple variants. |
702 | if let syn::Data::Enum(data) = &item.data { |
703 | for variant in &data.variants { |
704 | match &variant.fields { |
705 | syn::Fields::Named(_) | syn::Fields::Unit => {} |
706 | syn::Fields::Unnamed(fields) => { |
707 | if fields.unnamed.len() != 1 { |
708 | let msg = |
709 | "#[serde(tag = \"... \")] cannot be used with tuple variants" ; |
710 | cx.error_spanned_by(variant, msg); |
711 | break; |
712 | } |
713 | } |
714 | } |
715 | } |
716 | } |
717 | TagType::Internal { tag } |
718 | } |
719 | (Some((untagged_tokens, ())), Some((tag_tokens, _)), None) => { |
720 | let msg = "enum cannot be both untagged and internally tagged" ; |
721 | cx.error_spanned_by(untagged_tokens, msg); |
722 | cx.error_spanned_by(tag_tokens, msg); |
723 | TagType::External // doesn't matter, will error |
724 | } |
725 | (None, None, Some((content_tokens, _))) => { |
726 | let msg = "#[serde(tag = \"... \", content = \"... \")] must be used together" ; |
727 | cx.error_spanned_by(content_tokens, msg); |
728 | TagType::External |
729 | } |
730 | (Some((untagged_tokens, ())), None, Some((content_tokens, _))) => { |
731 | let msg = "untagged enum cannot have #[serde(content = \"... \")]" ; |
732 | cx.error_spanned_by(untagged_tokens, msg); |
733 | cx.error_spanned_by(content_tokens, msg); |
734 | TagType::External |
735 | } |
736 | (None, Some((_, tag)), Some((_, content))) => TagType::Adjacent { tag, content }, |
737 | (Some((untagged_tokens, ())), Some((tag_tokens, _)), Some((content_tokens, _))) => { |
738 | let msg = "untagged enum cannot have #[serde(tag = \"... \", content = \"... \")]" ; |
739 | cx.error_spanned_by(untagged_tokens, msg); |
740 | cx.error_spanned_by(tag_tokens, msg); |
741 | cx.error_spanned_by(content_tokens, msg); |
742 | TagType::External |
743 | } |
744 | } |
745 | } |
746 | |
747 | fn decide_identifier( |
748 | cx: &Ctxt, |
749 | item: &syn::DeriveInput, |
750 | field_identifier: BoolAttr, |
751 | variant_identifier: BoolAttr, |
752 | ) -> Identifier { |
753 | match ( |
754 | &item.data, |
755 | field_identifier.0.get_with_tokens(), |
756 | variant_identifier.0.get_with_tokens(), |
757 | ) { |
758 | (_, None, None) => Identifier::No, |
759 | (_, Some((field_identifier_tokens, ())), Some((variant_identifier_tokens, ()))) => { |
760 | let msg = |
761 | "#[serde(field_identifier)] and #[serde(variant_identifier)] cannot both be set" ; |
762 | cx.error_spanned_by(field_identifier_tokens, msg); |
763 | cx.error_spanned_by(variant_identifier_tokens, msg); |
764 | Identifier::No |
765 | } |
766 | (syn::Data::Enum(_), Some(_), None) => Identifier::Field, |
767 | (syn::Data::Enum(_), None, Some(_)) => Identifier::Variant, |
768 | (syn::Data::Struct(syn::DataStruct { struct_token, .. }), Some(_), None) => { |
769 | let msg = "#[serde(field_identifier)] can only be used on an enum" ; |
770 | cx.error_spanned_by(struct_token, msg); |
771 | Identifier::No |
772 | } |
773 | (syn::Data::Union(syn::DataUnion { union_token, .. }), Some(_), None) => { |
774 | let msg = "#[serde(field_identifier)] can only be used on an enum" ; |
775 | cx.error_spanned_by(union_token, msg); |
776 | Identifier::No |
777 | } |
778 | (syn::Data::Struct(syn::DataStruct { struct_token, .. }), None, Some(_)) => { |
779 | let msg = "#[serde(variant_identifier)] can only be used on an enum" ; |
780 | cx.error_spanned_by(struct_token, msg); |
781 | Identifier::No |
782 | } |
783 | (syn::Data::Union(syn::DataUnion { union_token, .. }), None, Some(_)) => { |
784 | let msg = "#[serde(variant_identifier)] can only be used on an enum" ; |
785 | cx.error_spanned_by(union_token, msg); |
786 | Identifier::No |
787 | } |
788 | } |
789 | } |
790 | |
791 | /// Represents variant attribute information |
792 | pub struct Variant { |
793 | name: Name, |
794 | rename_all_rules: RenameAllRules, |
795 | ser_bound: Option<Vec<syn::WherePredicate>>, |
796 | de_bound: Option<Vec<syn::WherePredicate>>, |
797 | skip_deserializing: bool, |
798 | skip_serializing: bool, |
799 | other: bool, |
800 | serialize_with: Option<syn::ExprPath>, |
801 | deserialize_with: Option<syn::ExprPath>, |
802 | borrow: Option<BorrowAttribute>, |
803 | untagged: bool, |
804 | } |
805 | |
806 | struct BorrowAttribute { |
807 | path: syn::Path, |
808 | lifetimes: Option<BTreeSet<syn::Lifetime>>, |
809 | } |
810 | |
811 | impl Variant { |
812 | pub fn from_ast(cx: &Ctxt, variant: &syn::Variant) -> Self { |
813 | let mut ser_name = Attr::none(cx, RENAME); |
814 | let mut de_name = Attr::none(cx, RENAME); |
815 | let mut de_aliases = VecAttr::none(cx, RENAME); |
816 | let mut skip_deserializing = BoolAttr::none(cx, SKIP_DESERIALIZING); |
817 | let mut skip_serializing = BoolAttr::none(cx, SKIP_SERIALIZING); |
818 | let mut rename_all_ser_rule = Attr::none(cx, RENAME_ALL); |
819 | let mut rename_all_de_rule = Attr::none(cx, RENAME_ALL); |
820 | let mut ser_bound = Attr::none(cx, BOUND); |
821 | let mut de_bound = Attr::none(cx, BOUND); |
822 | let mut other = BoolAttr::none(cx, OTHER); |
823 | let mut serialize_with = Attr::none(cx, SERIALIZE_WITH); |
824 | let mut deserialize_with = Attr::none(cx, DESERIALIZE_WITH); |
825 | let mut borrow = Attr::none(cx, BORROW); |
826 | let mut untagged = BoolAttr::none(cx, UNTAGGED); |
827 | |
828 | for attr in &variant.attrs { |
829 | if attr.path() != SERDE { |
830 | continue; |
831 | } |
832 | |
833 | if let syn::Meta::List(meta) = &attr.meta { |
834 | if meta.tokens.is_empty() { |
835 | continue; |
836 | } |
837 | } |
838 | |
839 | if let Err(err) = attr.parse_nested_meta(|meta| { |
840 | if meta.path == RENAME { |
841 | // #[serde(rename = "foo")] |
842 | // #[serde(rename(serialize = "foo", deserialize = "bar"))] |
843 | let (ser, de) = get_multiple_renames(cx, &meta)?; |
844 | ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value)); |
845 | for de_value in de { |
846 | de_name.set_if_none(de_value.value()); |
847 | de_aliases.insert(&meta.path, de_value.value()); |
848 | } |
849 | } else if meta.path == ALIAS { |
850 | // #[serde(alias = "foo")] |
851 | if let Some(s) = get_lit_str(cx, ALIAS, &meta)? { |
852 | de_aliases.insert(&meta.path, s.value()); |
853 | } |
854 | } else if meta.path == RENAME_ALL { |
855 | // #[serde(rename_all = "foo")] |
856 | // #[serde(rename_all(serialize = "foo", deserialize = "bar"))] |
857 | let one_name = meta.input.peek(Token![=]); |
858 | let (ser, de) = get_renames(cx, RENAME_ALL, &meta)?; |
859 | if let Some(ser) = ser { |
860 | match RenameRule::from_str(&ser.value()) { |
861 | Ok(rename_rule) => rename_all_ser_rule.set(&meta.path, rename_rule), |
862 | Err(err) => cx.error_spanned_by(ser, err), |
863 | } |
864 | } |
865 | if let Some(de) = de { |
866 | match RenameRule::from_str(&de.value()) { |
867 | Ok(rename_rule) => rename_all_de_rule.set(&meta.path, rename_rule), |
868 | Err(err) => { |
869 | if !one_name { |
870 | cx.error_spanned_by(de, err); |
871 | } |
872 | } |
873 | } |
874 | } |
875 | } else if meta.path == SKIP { |
876 | // #[serde(skip)] |
877 | skip_serializing.set_true(&meta.path); |
878 | skip_deserializing.set_true(&meta.path); |
879 | } else if meta.path == SKIP_DESERIALIZING { |
880 | // #[serde(skip_deserializing)] |
881 | skip_deserializing.set_true(&meta.path); |
882 | } else if meta.path == SKIP_SERIALIZING { |
883 | // #[serde(skip_serializing)] |
884 | skip_serializing.set_true(&meta.path); |
885 | } else if meta.path == OTHER { |
886 | // #[serde(other)] |
887 | other.set_true(&meta.path); |
888 | } else if meta.path == BOUND { |
889 | // #[serde(bound = "T: SomeBound")] |
890 | // #[serde(bound(serialize = "...", deserialize = "..."))] |
891 | let (ser, de) = get_where_predicates(cx, &meta)?; |
892 | ser_bound.set_opt(&meta.path, ser); |
893 | de_bound.set_opt(&meta.path, de); |
894 | } else if meta.path == WITH { |
895 | // #[serde(with = "...")] |
896 | if let Some(path) = parse_lit_into_expr_path(cx, WITH, &meta)? { |
897 | let mut ser_path = path.clone(); |
898 | ser_path |
899 | .path |
900 | .segments |
901 | .push(Ident::new("serialize" , Span::call_site()).into()); |
902 | serialize_with.set(&meta.path, ser_path); |
903 | let mut de_path = path; |
904 | de_path |
905 | .path |
906 | .segments |
907 | .push(Ident::new("deserialize" , Span::call_site()).into()); |
908 | deserialize_with.set(&meta.path, de_path); |
909 | } |
910 | } else if meta.path == SERIALIZE_WITH { |
911 | // #[serde(serialize_with = "...")] |
912 | if let Some(path) = parse_lit_into_expr_path(cx, SERIALIZE_WITH, &meta)? { |
913 | serialize_with.set(&meta.path, path); |
914 | } |
915 | } else if meta.path == DESERIALIZE_WITH { |
916 | // #[serde(deserialize_with = "...")] |
917 | if let Some(path) = parse_lit_into_expr_path(cx, DESERIALIZE_WITH, &meta)? { |
918 | deserialize_with.set(&meta.path, path); |
919 | } |
920 | } else if meta.path == BORROW { |
921 | let borrow_attribute = if meta.input.peek(Token![=]) { |
922 | // #[serde(borrow = "'a + 'b")] |
923 | let lifetimes = parse_lit_into_lifetimes(cx, &meta)?; |
924 | BorrowAttribute { |
925 | path: meta.path.clone(), |
926 | lifetimes: Some(lifetimes), |
927 | } |
928 | } else { |
929 | // #[serde(borrow)] |
930 | BorrowAttribute { |
931 | path: meta.path.clone(), |
932 | lifetimes: None, |
933 | } |
934 | }; |
935 | match &variant.fields { |
936 | syn::Fields::Unnamed(fields) if fields.unnamed.len() == 1 => { |
937 | borrow.set(&meta.path, borrow_attribute); |
938 | } |
939 | _ => { |
940 | let msg = "#[serde(borrow)] may only be used on newtype variants" ; |
941 | cx.error_spanned_by(variant, msg); |
942 | } |
943 | } |
944 | } else if meta.path == UNTAGGED { |
945 | untagged.set_true(&meta.path); |
946 | } else { |
947 | let path = meta.path.to_token_stream().to_string().replace(' ' , "" ); |
948 | return Err( |
949 | meta.error(format_args!("unknown serde variant attribute `{}`" , path)) |
950 | ); |
951 | } |
952 | Ok(()) |
953 | }) { |
954 | cx.syn_error(err); |
955 | } |
956 | } |
957 | |
958 | Variant { |
959 | name: Name::from_attrs(unraw(&variant.ident), ser_name, de_name, Some(de_aliases)), |
960 | rename_all_rules: RenameAllRules { |
961 | serialize: rename_all_ser_rule.get().unwrap_or(RenameRule::None), |
962 | deserialize: rename_all_de_rule.get().unwrap_or(RenameRule::None), |
963 | }, |
964 | ser_bound: ser_bound.get(), |
965 | de_bound: de_bound.get(), |
966 | skip_deserializing: skip_deserializing.get(), |
967 | skip_serializing: skip_serializing.get(), |
968 | other: other.get(), |
969 | serialize_with: serialize_with.get(), |
970 | deserialize_with: deserialize_with.get(), |
971 | borrow: borrow.get(), |
972 | untagged: untagged.get(), |
973 | } |
974 | } |
975 | |
976 | pub fn name(&self) -> &Name { |
977 | &self.name |
978 | } |
979 | |
980 | pub fn aliases(&self) -> &BTreeSet<String> { |
981 | self.name.deserialize_aliases() |
982 | } |
983 | |
984 | pub fn rename_by_rules(&mut self, rules: RenameAllRules) { |
985 | if !self.name.serialize_renamed { |
986 | self.name.serialize = rules.serialize.apply_to_variant(&self.name.serialize); |
987 | } |
988 | if !self.name.deserialize_renamed { |
989 | self.name.deserialize = rules.deserialize.apply_to_variant(&self.name.deserialize); |
990 | } |
991 | self.name |
992 | .deserialize_aliases |
993 | .insert(self.name.deserialize.clone()); |
994 | } |
995 | |
996 | pub fn rename_all_rules(&self) -> RenameAllRules { |
997 | self.rename_all_rules |
998 | } |
999 | |
1000 | pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> { |
1001 | self.ser_bound.as_ref().map(|vec| &vec[..]) |
1002 | } |
1003 | |
1004 | pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> { |
1005 | self.de_bound.as_ref().map(|vec| &vec[..]) |
1006 | } |
1007 | |
1008 | pub fn skip_deserializing(&self) -> bool { |
1009 | self.skip_deserializing |
1010 | } |
1011 | |
1012 | pub fn skip_serializing(&self) -> bool { |
1013 | self.skip_serializing |
1014 | } |
1015 | |
1016 | pub fn other(&self) -> bool { |
1017 | self.other |
1018 | } |
1019 | |
1020 | pub fn serialize_with(&self) -> Option<&syn::ExprPath> { |
1021 | self.serialize_with.as_ref() |
1022 | } |
1023 | |
1024 | pub fn deserialize_with(&self) -> Option<&syn::ExprPath> { |
1025 | self.deserialize_with.as_ref() |
1026 | } |
1027 | |
1028 | pub fn untagged(&self) -> bool { |
1029 | self.untagged |
1030 | } |
1031 | } |
1032 | |
1033 | /// Represents field attribute information |
1034 | pub struct Field { |
1035 | name: Name, |
1036 | skip_serializing: bool, |
1037 | skip_deserializing: bool, |
1038 | skip_serializing_if: Option<syn::ExprPath>, |
1039 | default: Default, |
1040 | serialize_with: Option<syn::ExprPath>, |
1041 | deserialize_with: Option<syn::ExprPath>, |
1042 | ser_bound: Option<Vec<syn::WherePredicate>>, |
1043 | de_bound: Option<Vec<syn::WherePredicate>>, |
1044 | borrowed_lifetimes: BTreeSet<syn::Lifetime>, |
1045 | getter: Option<syn::ExprPath>, |
1046 | flatten: bool, |
1047 | transparent: bool, |
1048 | } |
1049 | |
1050 | /// Represents the default to use for a field when deserializing. |
1051 | pub enum Default { |
1052 | /// Field must always be specified because it does not have a default. |
1053 | None, |
1054 | /// The default is given by `std::default::Default::default()`. |
1055 | Default, |
1056 | /// The default is given by this function. |
1057 | Path(syn::ExprPath), |
1058 | } |
1059 | |
1060 | impl Default { |
1061 | pub fn is_none(&self) -> bool { |
1062 | match self { |
1063 | Default::None => true, |
1064 | Default::Default | Default::Path(_) => false, |
1065 | } |
1066 | } |
1067 | } |
1068 | |
1069 | impl Field { |
1070 | /// Extract out the `#[serde(...)]` attributes from a struct field. |
1071 | pub fn from_ast( |
1072 | cx: &Ctxt, |
1073 | index: usize, |
1074 | field: &syn::Field, |
1075 | attrs: Option<&Variant>, |
1076 | container_default: &Default, |
1077 | ) -> Self { |
1078 | let mut ser_name = Attr::none(cx, RENAME); |
1079 | let mut de_name = Attr::none(cx, RENAME); |
1080 | let mut de_aliases = VecAttr::none(cx, RENAME); |
1081 | let mut skip_serializing = BoolAttr::none(cx, SKIP_SERIALIZING); |
1082 | let mut skip_deserializing = BoolAttr::none(cx, SKIP_DESERIALIZING); |
1083 | let mut skip_serializing_if = Attr::none(cx, SKIP_SERIALIZING_IF); |
1084 | let mut default = Attr::none(cx, DEFAULT); |
1085 | let mut serialize_with = Attr::none(cx, SERIALIZE_WITH); |
1086 | let mut deserialize_with = Attr::none(cx, DESERIALIZE_WITH); |
1087 | let mut ser_bound = Attr::none(cx, BOUND); |
1088 | let mut de_bound = Attr::none(cx, BOUND); |
1089 | let mut borrowed_lifetimes = Attr::none(cx, BORROW); |
1090 | let mut getter = Attr::none(cx, GETTER); |
1091 | let mut flatten = BoolAttr::none(cx, FLATTEN); |
1092 | |
1093 | let ident = match &field.ident { |
1094 | Some(ident) => unraw(ident), |
1095 | None => index.to_string(), |
1096 | }; |
1097 | |
1098 | if let Some(borrow_attribute) = attrs.and_then(|variant| variant.borrow.as_ref()) { |
1099 | if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, field) { |
1100 | if let Some(lifetimes) = &borrow_attribute.lifetimes { |
1101 | for lifetime in lifetimes { |
1102 | if !borrowable.contains(lifetime) { |
1103 | let msg = |
1104 | format!("field `{}` does not have lifetime {}" , ident, lifetime); |
1105 | cx.error_spanned_by(field, msg); |
1106 | } |
1107 | } |
1108 | borrowed_lifetimes.set(&borrow_attribute.path, lifetimes.clone()); |
1109 | } else { |
1110 | borrowed_lifetimes.set(&borrow_attribute.path, borrowable); |
1111 | } |
1112 | } |
1113 | } |
1114 | |
1115 | for attr in &field.attrs { |
1116 | if attr.path() != SERDE { |
1117 | continue; |
1118 | } |
1119 | |
1120 | if let syn::Meta::List(meta) = &attr.meta { |
1121 | if meta.tokens.is_empty() { |
1122 | continue; |
1123 | } |
1124 | } |
1125 | |
1126 | if let Err(err) = attr.parse_nested_meta(|meta| { |
1127 | if meta.path == RENAME { |
1128 | // #[serde(rename = "foo")] |
1129 | // #[serde(rename(serialize = "foo", deserialize = "bar"))] |
1130 | let (ser, de) = get_multiple_renames(cx, &meta)?; |
1131 | ser_name.set_opt(&meta.path, ser.as_ref().map(syn::LitStr::value)); |
1132 | for de_value in de { |
1133 | de_name.set_if_none(de_value.value()); |
1134 | de_aliases.insert(&meta.path, de_value.value()); |
1135 | } |
1136 | } else if meta.path == ALIAS { |
1137 | // #[serde(alias = "foo")] |
1138 | if let Some(s) = get_lit_str(cx, ALIAS, &meta)? { |
1139 | de_aliases.insert(&meta.path, s.value()); |
1140 | } |
1141 | } else if meta.path == DEFAULT { |
1142 | if meta.input.peek(Token![=]) { |
1143 | // #[serde(default = "...")] |
1144 | if let Some(path) = parse_lit_into_expr_path(cx, DEFAULT, &meta)? { |
1145 | default.set(&meta.path, Default::Path(path)); |
1146 | } |
1147 | } else { |
1148 | // #[serde(default)] |
1149 | default.set(&meta.path, Default::Default); |
1150 | } |
1151 | } else if meta.path == SKIP_SERIALIZING { |
1152 | // #[serde(skip_serializing)] |
1153 | skip_serializing.set_true(&meta.path); |
1154 | } else if meta.path == SKIP_DESERIALIZING { |
1155 | // #[serde(skip_deserializing)] |
1156 | skip_deserializing.set_true(&meta.path); |
1157 | } else if meta.path == SKIP { |
1158 | // #[serde(skip)] |
1159 | skip_serializing.set_true(&meta.path); |
1160 | skip_deserializing.set_true(&meta.path); |
1161 | } else if meta.path == SKIP_SERIALIZING_IF { |
1162 | // #[serde(skip_serializing_if = "...")] |
1163 | if let Some(path) = parse_lit_into_expr_path(cx, SKIP_SERIALIZING_IF, &meta)? { |
1164 | skip_serializing_if.set(&meta.path, path); |
1165 | } |
1166 | } else if meta.path == SERIALIZE_WITH { |
1167 | // #[serde(serialize_with = "...")] |
1168 | if let Some(path) = parse_lit_into_expr_path(cx, SERIALIZE_WITH, &meta)? { |
1169 | serialize_with.set(&meta.path, path); |
1170 | } |
1171 | } else if meta.path == DESERIALIZE_WITH { |
1172 | // #[serde(deserialize_with = "...")] |
1173 | if let Some(path) = parse_lit_into_expr_path(cx, DESERIALIZE_WITH, &meta)? { |
1174 | deserialize_with.set(&meta.path, path); |
1175 | } |
1176 | } else if meta.path == WITH { |
1177 | // #[serde(with = "...")] |
1178 | if let Some(path) = parse_lit_into_expr_path(cx, WITH, &meta)? { |
1179 | let mut ser_path = path.clone(); |
1180 | ser_path |
1181 | .path |
1182 | .segments |
1183 | .push(Ident::new("serialize" , Span::call_site()).into()); |
1184 | serialize_with.set(&meta.path, ser_path); |
1185 | let mut de_path = path; |
1186 | de_path |
1187 | .path |
1188 | .segments |
1189 | .push(Ident::new("deserialize" , Span::call_site()).into()); |
1190 | deserialize_with.set(&meta.path, de_path); |
1191 | } |
1192 | } else if meta.path == BOUND { |
1193 | // #[serde(bound = "T: SomeBound")] |
1194 | // #[serde(bound(serialize = "...", deserialize = "..."))] |
1195 | let (ser, de) = get_where_predicates(cx, &meta)?; |
1196 | ser_bound.set_opt(&meta.path, ser); |
1197 | de_bound.set_opt(&meta.path, de); |
1198 | } else if meta.path == BORROW { |
1199 | if meta.input.peek(Token![=]) { |
1200 | // #[serde(borrow = "'a + 'b")] |
1201 | let lifetimes = parse_lit_into_lifetimes(cx, &meta)?; |
1202 | if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, field) { |
1203 | for lifetime in &lifetimes { |
1204 | if !borrowable.contains(lifetime) { |
1205 | let msg = format!( |
1206 | "field `{}` does not have lifetime {}" , |
1207 | ident, lifetime, |
1208 | ); |
1209 | cx.error_spanned_by(field, msg); |
1210 | } |
1211 | } |
1212 | borrowed_lifetimes.set(&meta.path, lifetimes); |
1213 | } |
1214 | } else { |
1215 | // #[serde(borrow)] |
1216 | if let Ok(borrowable) = borrowable_lifetimes(cx, &ident, field) { |
1217 | borrowed_lifetimes.set(&meta.path, borrowable); |
1218 | } |
1219 | } |
1220 | } else if meta.path == GETTER { |
1221 | // #[serde(getter = "...")] |
1222 | if let Some(path) = parse_lit_into_expr_path(cx, GETTER, &meta)? { |
1223 | getter.set(&meta.path, path); |
1224 | } |
1225 | } else if meta.path == FLATTEN { |
1226 | // #[serde(flatten)] |
1227 | flatten.set_true(&meta.path); |
1228 | } else { |
1229 | let path = meta.path.to_token_stream().to_string().replace(' ' , "" ); |
1230 | return Err( |
1231 | meta.error(format_args!("unknown serde field attribute `{}`" , path)) |
1232 | ); |
1233 | } |
1234 | Ok(()) |
1235 | }) { |
1236 | cx.syn_error(err); |
1237 | } |
1238 | } |
1239 | |
1240 | // Is skip_deserializing, initialize the field to Default::default() unless a |
1241 | // different default is specified by `#[serde(default = "...")]` on |
1242 | // ourselves or our container (e.g. the struct we are in). |
1243 | if let Default::None = *container_default { |
1244 | if skip_deserializing.0.value.is_some() { |
1245 | default.set_if_none(Default::Default); |
1246 | } |
1247 | } |
1248 | |
1249 | let mut borrowed_lifetimes = borrowed_lifetimes.get().unwrap_or_default(); |
1250 | if !borrowed_lifetimes.is_empty() { |
1251 | // Cow<str> and Cow<[u8]> never borrow by default: |
1252 | // |
1253 | // impl<'de, 'a, T: ?Sized> Deserialize<'de> for Cow<'a, T> |
1254 | // |
1255 | // A #[serde(borrow)] attribute enables borrowing that corresponds |
1256 | // roughly to these impls: |
1257 | // |
1258 | // impl<'de: 'a, 'a> Deserialize<'de> for Cow<'a, str> |
1259 | // impl<'de: 'a, 'a> Deserialize<'de> for Cow<'a, [u8]> |
1260 | if is_cow(&field.ty, is_str) { |
1261 | let mut path = syn::Path { |
1262 | leading_colon: None, |
1263 | segments: Punctuated::new(), |
1264 | }; |
1265 | let span = Span::call_site(); |
1266 | path.segments.push(Ident::new("_serde" , span).into()); |
1267 | path.segments.push(Ident::new("__private" , span).into()); |
1268 | path.segments.push(Ident::new("de" , span).into()); |
1269 | path.segments |
1270 | .push(Ident::new("borrow_cow_str" , span).into()); |
1271 | let expr = syn::ExprPath { |
1272 | attrs: Vec::new(), |
1273 | qself: None, |
1274 | path, |
1275 | }; |
1276 | deserialize_with.set_if_none(expr); |
1277 | } else if is_cow(&field.ty, is_slice_u8) { |
1278 | let mut path = syn::Path { |
1279 | leading_colon: None, |
1280 | segments: Punctuated::new(), |
1281 | }; |
1282 | let span = Span::call_site(); |
1283 | path.segments.push(Ident::new("_serde" , span).into()); |
1284 | path.segments.push(Ident::new("__private" , span).into()); |
1285 | path.segments.push(Ident::new("de" , span).into()); |
1286 | path.segments |
1287 | .push(Ident::new("borrow_cow_bytes" , span).into()); |
1288 | let expr = syn::ExprPath { |
1289 | attrs: Vec::new(), |
1290 | qself: None, |
1291 | path, |
1292 | }; |
1293 | deserialize_with.set_if_none(expr); |
1294 | } |
1295 | } else if is_implicitly_borrowed(&field.ty) { |
1296 | // Types &str and &[u8] are always implicitly borrowed. No need for |
1297 | // a #[serde(borrow)]. |
1298 | collect_lifetimes(&field.ty, &mut borrowed_lifetimes); |
1299 | } |
1300 | |
1301 | Field { |
1302 | name: Name::from_attrs(ident, ser_name, de_name, Some(de_aliases)), |
1303 | skip_serializing: skip_serializing.get(), |
1304 | skip_deserializing: skip_deserializing.get(), |
1305 | skip_serializing_if: skip_serializing_if.get(), |
1306 | default: default.get().unwrap_or(Default::None), |
1307 | serialize_with: serialize_with.get(), |
1308 | deserialize_with: deserialize_with.get(), |
1309 | ser_bound: ser_bound.get(), |
1310 | de_bound: de_bound.get(), |
1311 | borrowed_lifetimes, |
1312 | getter: getter.get(), |
1313 | flatten: flatten.get(), |
1314 | transparent: false, |
1315 | } |
1316 | } |
1317 | |
1318 | pub fn name(&self) -> &Name { |
1319 | &self.name |
1320 | } |
1321 | |
1322 | pub fn aliases(&self) -> &BTreeSet<String> { |
1323 | self.name.deserialize_aliases() |
1324 | } |
1325 | |
1326 | pub fn rename_by_rules(&mut self, rules: RenameAllRules) { |
1327 | if !self.name.serialize_renamed { |
1328 | self.name.serialize = rules.serialize.apply_to_field(&self.name.serialize); |
1329 | } |
1330 | if !self.name.deserialize_renamed { |
1331 | self.name.deserialize = rules.deserialize.apply_to_field(&self.name.deserialize); |
1332 | } |
1333 | self.name |
1334 | .deserialize_aliases |
1335 | .insert(self.name.deserialize.clone()); |
1336 | } |
1337 | |
1338 | pub fn skip_serializing(&self) -> bool { |
1339 | self.skip_serializing |
1340 | } |
1341 | |
1342 | pub fn skip_deserializing(&self) -> bool { |
1343 | self.skip_deserializing |
1344 | } |
1345 | |
1346 | pub fn skip_serializing_if(&self) -> Option<&syn::ExprPath> { |
1347 | self.skip_serializing_if.as_ref() |
1348 | } |
1349 | |
1350 | pub fn default(&self) -> &Default { |
1351 | &self.default |
1352 | } |
1353 | |
1354 | pub fn serialize_with(&self) -> Option<&syn::ExprPath> { |
1355 | self.serialize_with.as_ref() |
1356 | } |
1357 | |
1358 | pub fn deserialize_with(&self) -> Option<&syn::ExprPath> { |
1359 | self.deserialize_with.as_ref() |
1360 | } |
1361 | |
1362 | pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> { |
1363 | self.ser_bound.as_ref().map(|vec| &vec[..]) |
1364 | } |
1365 | |
1366 | pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> { |
1367 | self.de_bound.as_ref().map(|vec| &vec[..]) |
1368 | } |
1369 | |
1370 | pub fn borrowed_lifetimes(&self) -> &BTreeSet<syn::Lifetime> { |
1371 | &self.borrowed_lifetimes |
1372 | } |
1373 | |
1374 | pub fn getter(&self) -> Option<&syn::ExprPath> { |
1375 | self.getter.as_ref() |
1376 | } |
1377 | |
1378 | pub fn flatten(&self) -> bool { |
1379 | self.flatten |
1380 | } |
1381 | |
1382 | pub fn transparent(&self) -> bool { |
1383 | self.transparent |
1384 | } |
1385 | |
1386 | pub fn mark_transparent(&mut self) { |
1387 | self.transparent = true; |
1388 | } |
1389 | } |
1390 | |
1391 | type SerAndDe<T> = (Option<T>, Option<T>); |
1392 | |
1393 | fn get_ser_and_de<'c, T, F, R>( |
1394 | cx: &'c Ctxt, |
1395 | attr_name: Symbol, |
1396 | meta: &ParseNestedMeta, |
1397 | f: F, |
1398 | ) -> syn::Result<(VecAttr<'c, T>, VecAttr<'c, T>)> |
1399 | where |
1400 | T: Clone, |
1401 | F: Fn(&Ctxt, Symbol, Symbol, &ParseNestedMeta) -> syn::Result<R>, |
1402 | R: Into<Option<T>>, |
1403 | { |
1404 | let mut ser_meta = VecAttr::none(cx, attr_name); |
1405 | let mut de_meta = VecAttr::none(cx, attr_name); |
1406 | |
1407 | let lookahead = meta.input.lookahead1(); |
1408 | if lookahead.peek(Token![=]) { |
1409 | if let Some(both) = f(cx, attr_name, attr_name, meta)?.into() { |
1410 | ser_meta.insert(&meta.path, both.clone()); |
1411 | de_meta.insert(&meta.path, both); |
1412 | } |
1413 | } else if lookahead.peek(token::Paren) { |
1414 | meta.parse_nested_meta(|meta| { |
1415 | if meta.path == SERIALIZE { |
1416 | if let Some(v) = f(cx, attr_name, SERIALIZE, &meta)?.into() { |
1417 | ser_meta.insert(&meta.path, v); |
1418 | } |
1419 | } else if meta.path == DESERIALIZE { |
1420 | if let Some(v) = f(cx, attr_name, DESERIALIZE, &meta)?.into() { |
1421 | de_meta.insert(&meta.path, v); |
1422 | } |
1423 | } else { |
1424 | return Err(meta.error(format_args!( |
1425 | "malformed {0} attribute, expected `{0}(serialize = ..., deserialize = ...)`" , |
1426 | attr_name, |
1427 | ))); |
1428 | } |
1429 | Ok(()) |
1430 | })?; |
1431 | } else { |
1432 | return Err(lookahead.error()); |
1433 | } |
1434 | |
1435 | Ok((ser_meta, de_meta)) |
1436 | } |
1437 | |
1438 | fn get_renames( |
1439 | cx: &Ctxt, |
1440 | attr_name: Symbol, |
1441 | meta: &ParseNestedMeta, |
1442 | ) -> syn::Result<SerAndDe<syn::LitStr>> { |
1443 | let (ser, de) = get_ser_and_de(cx, attr_name, meta, get_lit_str2)?; |
1444 | Ok((ser.at_most_one(), de.at_most_one())) |
1445 | } |
1446 | |
1447 | fn get_multiple_renames( |
1448 | cx: &Ctxt, |
1449 | meta: &ParseNestedMeta, |
1450 | ) -> syn::Result<(Option<syn::LitStr>, Vec<syn::LitStr>)> { |
1451 | let (ser, de) = get_ser_and_de(cx, RENAME, meta, get_lit_str2)?; |
1452 | Ok((ser.at_most_one(), de.get())) |
1453 | } |
1454 | |
1455 | fn get_where_predicates( |
1456 | cx: &Ctxt, |
1457 | meta: &ParseNestedMeta, |
1458 | ) -> syn::Result<SerAndDe<Vec<syn::WherePredicate>>> { |
1459 | let (ser, de) = get_ser_and_de(cx, BOUND, meta, parse_lit_into_where)?; |
1460 | Ok((ser.at_most_one(), de.at_most_one())) |
1461 | } |
1462 | |
1463 | fn get_lit_str( |
1464 | cx: &Ctxt, |
1465 | attr_name: Symbol, |
1466 | meta: &ParseNestedMeta, |
1467 | ) -> syn::Result<Option<syn::LitStr>> { |
1468 | get_lit_str2(cx, attr_name, attr_name, meta) |
1469 | } |
1470 | |
1471 | fn get_lit_str2( |
1472 | cx: &Ctxt, |
1473 | attr_name: Symbol, |
1474 | meta_item_name: Symbol, |
1475 | meta: &ParseNestedMeta, |
1476 | ) -> syn::Result<Option<syn::LitStr>> { |
1477 | let expr: syn::Expr = meta.value()?.parse()?; |
1478 | let mut value = &expr; |
1479 | while let syn::Expr::Group(e) = value { |
1480 | value = &e.expr; |
1481 | } |
1482 | if let syn::Expr::Lit(syn::ExprLit { |
1483 | lit: syn::Lit::Str(lit), |
1484 | .. |
1485 | }) = value |
1486 | { |
1487 | let suffix = lit.suffix(); |
1488 | if !suffix.is_empty() { |
1489 | cx.error_spanned_by( |
1490 | lit, |
1491 | format!("unexpected suffix `{}` on string literal" , suffix), |
1492 | ); |
1493 | } |
1494 | Ok(Some(lit.clone())) |
1495 | } else { |
1496 | cx.error_spanned_by( |
1497 | expr, |
1498 | format!( |
1499 | "expected serde {} attribute to be a string: `{} = \"... \"`" , |
1500 | attr_name, meta_item_name |
1501 | ), |
1502 | ); |
1503 | Ok(None) |
1504 | } |
1505 | } |
1506 | |
1507 | fn parse_lit_into_path( |
1508 | cx: &Ctxt, |
1509 | attr_name: Symbol, |
1510 | meta: &ParseNestedMeta, |
1511 | ) -> syn::Result<Option<syn::Path>> { |
1512 | let string = match get_lit_str(cx, attr_name, meta)? { |
1513 | Some(string) => string, |
1514 | None => return Ok(None), |
1515 | }; |
1516 | |
1517 | Ok(match string.parse() { |
1518 | Ok(path) => Some(path), |
1519 | Err(_) => { |
1520 | cx.error_spanned_by( |
1521 | &string, |
1522 | format!("failed to parse path: {:?}" , string.value()), |
1523 | ); |
1524 | None |
1525 | } |
1526 | }) |
1527 | } |
1528 | |
1529 | fn parse_lit_into_expr_path( |
1530 | cx: &Ctxt, |
1531 | attr_name: Symbol, |
1532 | meta: &ParseNestedMeta, |
1533 | ) -> syn::Result<Option<syn::ExprPath>> { |
1534 | let string = match get_lit_str(cx, attr_name, meta)? { |
1535 | Some(string) => string, |
1536 | None => return Ok(None), |
1537 | }; |
1538 | |
1539 | Ok(match string.parse() { |
1540 | Ok(expr) => Some(expr), |
1541 | Err(_) => { |
1542 | cx.error_spanned_by( |
1543 | &string, |
1544 | format!("failed to parse path: {:?}" , string.value()), |
1545 | ); |
1546 | None |
1547 | } |
1548 | }) |
1549 | } |
1550 | |
1551 | fn parse_lit_into_where( |
1552 | cx: &Ctxt, |
1553 | attr_name: Symbol, |
1554 | meta_item_name: Symbol, |
1555 | meta: &ParseNestedMeta, |
1556 | ) -> syn::Result<Vec<syn::WherePredicate>> { |
1557 | let string = match get_lit_str2(cx, attr_name, meta_item_name, meta)? { |
1558 | Some(string) => string, |
1559 | None => return Ok(Vec::new()), |
1560 | }; |
1561 | |
1562 | Ok( |
1563 | match string.parse_with(Punctuated::<syn::WherePredicate, Token![,]>::parse_terminated) { |
1564 | Ok(predicates) => Vec::from_iter(predicates), |
1565 | Err(err) => { |
1566 | cx.error_spanned_by(string, err); |
1567 | Vec::new() |
1568 | } |
1569 | }, |
1570 | ) |
1571 | } |
1572 | |
1573 | fn parse_lit_into_ty( |
1574 | cx: &Ctxt, |
1575 | attr_name: Symbol, |
1576 | meta: &ParseNestedMeta, |
1577 | ) -> syn::Result<Option<syn::Type>> { |
1578 | let string = match get_lit_str(cx, attr_name, meta)? { |
1579 | Some(string) => string, |
1580 | None => return Ok(None), |
1581 | }; |
1582 | |
1583 | Ok(match string.parse() { |
1584 | Ok(ty) => Some(ty), |
1585 | Err(_) => { |
1586 | cx.error_spanned_by( |
1587 | &string, |
1588 | format!("failed to parse type: {} = {:?}" , attr_name, string.value()), |
1589 | ); |
1590 | None |
1591 | } |
1592 | }) |
1593 | } |
1594 | |
1595 | // Parses a string literal like "'a + 'b + 'c" containing a nonempty list of |
1596 | // lifetimes separated by `+`. |
1597 | fn parse_lit_into_lifetimes( |
1598 | cx: &Ctxt, |
1599 | meta: &ParseNestedMeta, |
1600 | ) -> syn::Result<BTreeSet<syn::Lifetime>> { |
1601 | let string = match get_lit_str(cx, BORROW, meta)? { |
1602 | Some(string) => string, |
1603 | None => return Ok(BTreeSet::new()), |
1604 | }; |
1605 | |
1606 | if let Ok(lifetimes) = string.parse_with(|input: ParseStream| { |
1607 | let mut set = BTreeSet::new(); |
1608 | while !input.is_empty() { |
1609 | let lifetime: Lifetime = input.parse()?; |
1610 | if !set.insert(lifetime.clone()) { |
1611 | cx.error_spanned_by( |
1612 | &string, |
1613 | format!("duplicate borrowed lifetime `{}`" , lifetime), |
1614 | ); |
1615 | } |
1616 | if input.is_empty() { |
1617 | break; |
1618 | } |
1619 | input.parse::<Token![+]>()?; |
1620 | } |
1621 | Ok(set) |
1622 | }) { |
1623 | if lifetimes.is_empty() { |
1624 | cx.error_spanned_by(string, "at least one lifetime must be borrowed" ); |
1625 | } |
1626 | return Ok(lifetimes); |
1627 | } |
1628 | |
1629 | cx.error_spanned_by( |
1630 | &string, |
1631 | format!("failed to parse borrowed lifetimes: {:?}" , string.value()), |
1632 | ); |
1633 | Ok(BTreeSet::new()) |
1634 | } |
1635 | |
1636 | fn is_implicitly_borrowed(ty: &syn::Type) -> bool { |
1637 | is_implicitly_borrowed_reference(ty) || is_option(ty, is_implicitly_borrowed_reference) |
1638 | } |
1639 | |
1640 | fn is_implicitly_borrowed_reference(ty: &syn::Type) -> bool { |
1641 | is_reference(ty, is_str) || is_reference(ty, is_slice_u8) |
1642 | } |
1643 | |
1644 | // Whether the type looks like it might be `std::borrow::Cow<T>` where elem="T". |
1645 | // This can have false negatives and false positives. |
1646 | // |
1647 | // False negative: |
1648 | // |
1649 | // use std::borrow::Cow as Pig; |
1650 | // |
1651 | // #[derive(Deserialize)] |
1652 | // struct S<'a> { |
1653 | // #[serde(borrow)] |
1654 | // pig: Pig<'a, str>, |
1655 | // } |
1656 | // |
1657 | // False positive: |
1658 | // |
1659 | // type str = [i16]; |
1660 | // |
1661 | // #[derive(Deserialize)] |
1662 | // struct S<'a> { |
1663 | // #[serde(borrow)] |
1664 | // cow: Cow<'a, str>, |
1665 | // } |
1666 | fn is_cow(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool { |
1667 | let path = match ungroup(ty) { |
1668 | syn::Type::Path(ty) => &ty.path, |
1669 | _ => { |
1670 | return false; |
1671 | } |
1672 | }; |
1673 | let seg = match path.segments.last() { |
1674 | Some(seg) => seg, |
1675 | None => { |
1676 | return false; |
1677 | } |
1678 | }; |
1679 | let args = match &seg.arguments { |
1680 | syn::PathArguments::AngleBracketed(bracketed) => &bracketed.args, |
1681 | _ => { |
1682 | return false; |
1683 | } |
1684 | }; |
1685 | seg.ident == "Cow" |
1686 | && args.len() == 2 |
1687 | && match (&args[0], &args[1]) { |
1688 | (syn::GenericArgument::Lifetime(_), syn::GenericArgument::Type(arg)) => elem(arg), |
1689 | _ => false, |
1690 | } |
1691 | } |
1692 | |
1693 | fn is_option(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool { |
1694 | let path = match ungroup(ty) { |
1695 | syn::Type::Path(ty) => &ty.path, |
1696 | _ => { |
1697 | return false; |
1698 | } |
1699 | }; |
1700 | let seg = match path.segments.last() { |
1701 | Some(seg) => seg, |
1702 | None => { |
1703 | return false; |
1704 | } |
1705 | }; |
1706 | let args = match &seg.arguments { |
1707 | syn::PathArguments::AngleBracketed(bracketed) => &bracketed.args, |
1708 | _ => { |
1709 | return false; |
1710 | } |
1711 | }; |
1712 | seg.ident == "Option" |
1713 | && args.len() == 1 |
1714 | && match &args[0] { |
1715 | syn::GenericArgument::Type(arg) => elem(arg), |
1716 | _ => false, |
1717 | } |
1718 | } |
1719 | |
1720 | // Whether the type looks like it might be `&T` where elem="T". This can have |
1721 | // false negatives and false positives. |
1722 | // |
1723 | // False negative: |
1724 | // |
1725 | // type Yarn = str; |
1726 | // |
1727 | // #[derive(Deserialize)] |
1728 | // struct S<'a> { |
1729 | // r: &'a Yarn, |
1730 | // } |
1731 | // |
1732 | // False positive: |
1733 | // |
1734 | // type str = [i16]; |
1735 | // |
1736 | // #[derive(Deserialize)] |
1737 | // struct S<'a> { |
1738 | // r: &'a str, |
1739 | // } |
1740 | fn is_reference(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool { |
1741 | match ungroup(ty) { |
1742 | syn::Type::Reference(ty) => ty.mutability.is_none() && elem(&ty.elem), |
1743 | _ => false, |
1744 | } |
1745 | } |
1746 | |
1747 | fn is_str(ty: &syn::Type) -> bool { |
1748 | is_primitive_type(ty, "str" ) |
1749 | } |
1750 | |
1751 | fn is_slice_u8(ty: &syn::Type) -> bool { |
1752 | match ungroup(ty) { |
1753 | syn::Type::Slice(ty) => is_primitive_type(&ty.elem, "u8" ), |
1754 | _ => false, |
1755 | } |
1756 | } |
1757 | |
1758 | fn is_primitive_type(ty: &syn::Type, primitive: &str) -> bool { |
1759 | match ungroup(ty) { |
1760 | syn::Type::Path(ty) => ty.qself.is_none() && is_primitive_path(&ty.path, primitive), |
1761 | _ => false, |
1762 | } |
1763 | } |
1764 | |
1765 | fn is_primitive_path(path: &syn::Path, primitive: &str) -> bool { |
1766 | path.leading_colon.is_none() |
1767 | && path.segments.len() == 1 |
1768 | && path.segments[0].ident == primitive |
1769 | && path.segments[0].arguments.is_empty() |
1770 | } |
1771 | |
1772 | // All lifetimes that this type could borrow from a Deserializer. |
1773 | // |
1774 | // For example a type `S<'a, 'b>` could borrow `'a` and `'b`. On the other hand |
1775 | // a type `for<'a> fn(&'a str)` could not borrow `'a` from the Deserializer. |
1776 | // |
1777 | // This is used when there is an explicit or implicit `#[serde(borrow)]` |
1778 | // attribute on the field so there must be at least one borrowable lifetime. |
1779 | fn borrowable_lifetimes( |
1780 | cx: &Ctxt, |
1781 | name: &str, |
1782 | field: &syn::Field, |
1783 | ) -> Result<BTreeSet<syn::Lifetime>, ()> { |
1784 | let mut lifetimes = BTreeSet::new(); |
1785 | collect_lifetimes(&field.ty, &mut lifetimes); |
1786 | if lifetimes.is_empty() { |
1787 | let msg = format!("field `{}` has no lifetimes to borrow" , name); |
1788 | cx.error_spanned_by(field, msg); |
1789 | Err(()) |
1790 | } else { |
1791 | Ok(lifetimes) |
1792 | } |
1793 | } |
1794 | |
1795 | fn collect_lifetimes(ty: &syn::Type, out: &mut BTreeSet<syn::Lifetime>) { |
1796 | match ty { |
1797 | syn::Type::Slice(ty) => { |
1798 | collect_lifetimes(&ty.elem, out); |
1799 | } |
1800 | syn::Type::Array(ty) => { |
1801 | collect_lifetimes(&ty.elem, out); |
1802 | } |
1803 | syn::Type::Ptr(ty) => { |
1804 | collect_lifetimes(&ty.elem, out); |
1805 | } |
1806 | syn::Type::Reference(ty) => { |
1807 | out.extend(ty.lifetime.iter().cloned()); |
1808 | collect_lifetimes(&ty.elem, out); |
1809 | } |
1810 | syn::Type::Tuple(ty) => { |
1811 | for elem in &ty.elems { |
1812 | collect_lifetimes(elem, out); |
1813 | } |
1814 | } |
1815 | syn::Type::Path(ty) => { |
1816 | if let Some(qself) = &ty.qself { |
1817 | collect_lifetimes(&qself.ty, out); |
1818 | } |
1819 | for seg in &ty.path.segments { |
1820 | if let syn::PathArguments::AngleBracketed(bracketed) = &seg.arguments { |
1821 | for arg in &bracketed.args { |
1822 | match arg { |
1823 | syn::GenericArgument::Lifetime(lifetime) => { |
1824 | out.insert(lifetime.clone()); |
1825 | } |
1826 | syn::GenericArgument::Type(ty) => { |
1827 | collect_lifetimes(ty, out); |
1828 | } |
1829 | syn::GenericArgument::AssocType(binding) => { |
1830 | collect_lifetimes(&binding.ty, out); |
1831 | } |
1832 | _ => {} |
1833 | } |
1834 | } |
1835 | } |
1836 | } |
1837 | } |
1838 | syn::Type::Paren(ty) => { |
1839 | collect_lifetimes(&ty.elem, out); |
1840 | } |
1841 | syn::Type::Group(ty) => { |
1842 | collect_lifetimes(&ty.elem, out); |
1843 | } |
1844 | syn::Type::Macro(ty) => { |
1845 | collect_lifetimes_from_tokens(ty.mac.tokens.clone(), out); |
1846 | } |
1847 | syn::Type::BareFn(_) |
1848 | | syn::Type::Never(_) |
1849 | | syn::Type::TraitObject(_) |
1850 | | syn::Type::ImplTrait(_) |
1851 | | syn::Type::Infer(_) |
1852 | | syn::Type::Verbatim(_) => {} |
1853 | |
1854 | #[cfg_attr (all(test, exhaustive), deny(non_exhaustive_omitted_patterns))] |
1855 | _ => {} |
1856 | } |
1857 | } |
1858 | |
1859 | fn collect_lifetimes_from_tokens(tokens: TokenStream, out: &mut BTreeSet<syn::Lifetime>) { |
1860 | let mut iter = tokens.into_iter(); |
1861 | while let Some(tt) = iter.next() { |
1862 | match &tt { |
1863 | TokenTree::Punct(op) if op.as_char() == ' \'' && op.spacing() == Spacing::Joint => { |
1864 | if let Some(TokenTree::Ident(ident)) = iter.next() { |
1865 | out.insert(syn::Lifetime { |
1866 | apostrophe: op.span(), |
1867 | ident, |
1868 | }); |
1869 | } |
1870 | } |
1871 | TokenTree::Group(group) => { |
1872 | let tokens = group.stream(); |
1873 | collect_lifetimes_from_tokens(tokens, out); |
1874 | } |
1875 | _ => {} |
1876 | } |
1877 | } |
1878 | } |
1879 | |