1 use rustc_ast::ast::{MetaItem, NestedMetaItem};
2 use rustc_attr as attr;
3 use rustc_data_structures::fx::FxHashMap;
4 use rustc_errors::{struct_span_err, ErrorReported};
5 use rustc_hir::def_id::DefId;
6 use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
7 use rustc_parse_format::{ParseMode, Parser, Piece, Position};
8 use rustc_span::symbol::{kw, sym, Symbol};
11 #[derive(Clone, Debug)]
12 pub struct OnUnimplementedFormatString(Symbol);
15 pub struct OnUnimplementedDirective {
16 pub condition: Option<MetaItem>,
17 pub subcommands: Vec<OnUnimplementedDirective>,
18 pub message: Option<OnUnimplementedFormatString>,
19 pub label: Option<OnUnimplementedFormatString>,
20 pub note: Option<OnUnimplementedFormatString>,
21 pub enclosing_scope: Option<OnUnimplementedFormatString>,
25 pub struct OnUnimplementedNote {
26 pub message: Option<String>,
27 pub label: Option<String>,
28 pub note: Option<String>,
29 pub enclosing_scope: Option<String>,
39 let mut diag = struct_span_err!(tcx.sess, span, E0232, "{}", message);
40 diag.span_label(span, label);
41 if let Some(note) = note {
48 impl<'tcx> OnUnimplementedDirective {
52 items: &[NestedMetaItem],
55 ) -> Result<Self, ErrorReported> {
56 let mut errored = false;
57 let mut item_iter = items.iter();
59 let condition = if is_root {
68 "empty `on`-clause in `#[rustc_on_unimplemented]`",
69 "empty on-clause here",
78 "invalid `on`-clause in `#[rustc_on_unimplemented]`",
79 "invalid on-clause here",
83 attr::eval_condition(cond, &tcx.sess.parse_sess, Some(tcx.features()), &mut |_| true);
87 let mut message = None;
90 let mut enclosing_scope = None;
91 let mut subcommands = vec![];
93 let parse_value = |value_str| {
94 OnUnimplementedFormatString::try_parse(tcx, trait_def_id, value_str, span).map(Some)
97 for item in item_iter {
98 if item.has_name(sym::message) && message.is_none() {
99 if let Some(message_) = item.value_str() {
100 message = parse_value(message_)?;
103 } else if item.has_name(sym::label) && label.is_none() {
104 if let Some(label_) = item.value_str() {
105 label = parse_value(label_)?;
108 } else if item.has_name(sym::note) && note.is_none() {
109 if let Some(note_) = item.value_str() {
110 note = parse_value(note_)?;
113 } else if item.has_name(sym::enclosing_scope) && enclosing_scope.is_none() {
114 if let Some(enclosing_scope_) = item.value_str() {
115 enclosing_scope = parse_value(enclosing_scope_)?;
118 } else if item.has_name(sym::on)
124 if let Some(items) = item.meta_item_list() {
125 if let Ok(subcommand) =
126 Self::parse(tcx, trait_def_id, &items, item.span(), false)
128 subcommands.push(subcommand);
140 "this attribute must have a valid value",
141 "expected value here",
142 Some(r#"eg `#[rustc_on_unimplemented(message="foo")]`"#),
149 Ok(OnUnimplementedDirective {
164 ) -> Result<Option<Self>, ErrorReported> {
165 let attrs = tcx.get_attrs(impl_def_id);
167 let attr = if let Some(item) = attr::find_by_name(&attrs, sym::rustc_on_unimplemented) {
173 let result = if let Some(items) = attr.meta_item_list() {
174 Self::parse(tcx, trait_def_id, &items, attr.span, true).map(Some)
175 } else if let Some(value) = attr.value_str() {
176 Ok(Some(OnUnimplementedDirective {
180 label: Some(OnUnimplementedFormatString::try_parse(
187 enclosing_scope: None,
190 return Err(ErrorReported);
192 debug!("of_item({:?}/{:?}) = {:?}", trait_def_id, impl_def_id, result);
199 trait_ref: ty::TraitRef<'tcx>,
200 options: &[(Symbol, Option<String>)],
201 ) -> OnUnimplementedNote {
202 let mut message = None;
203 let mut label = None;
205 let mut enclosing_scope = None;
206 info!("evaluate({:?}, trait_ref={:?}, options={:?})", self, trait_ref, options);
208 for command in self.subcommands.iter().chain(Some(self)).rev() {
209 if let Some(ref condition) = command.condition {
210 if !attr::eval_condition(
212 &tcx.sess.parse_sess,
213 Some(tcx.features()),
215 c.ident().map_or(false, |ident| {
216 options.contains(&(ident.name, c.value_str().map(|s| s.to_string())))
220 debug!("evaluate: skipping {:?} due to condition", command);
224 debug!("evaluate: {:?} succeeded", command);
225 if let Some(ref message_) = command.message {
226 message = Some(message_.clone());
229 if let Some(ref label_) = command.label {
230 label = Some(label_.clone());
233 if let Some(ref note_) = command.note {
234 note = Some(note_.clone());
237 if let Some(ref enclosing_scope_) = command.enclosing_scope {
238 enclosing_scope = Some(enclosing_scope_.clone());
242 let options: FxHashMap<Symbol, String> =
243 options.iter().filter_map(|(k, v)| v.as_ref().map(|v| (*k, v.to_owned()))).collect();
244 OnUnimplementedNote {
245 label: label.map(|l| l.format(tcx, trait_ref, &options)),
246 message: message.map(|m| m.format(tcx, trait_ref, &options)),
247 note: note.map(|n| n.format(tcx, trait_ref, &options)),
248 enclosing_scope: enclosing_scope.map(|e_s| e_s.format(tcx, trait_ref, &options)),
253 impl<'tcx> OnUnimplementedFormatString {
259 ) -> Result<Self, ErrorReported> {
260 let result = OnUnimplementedFormatString(from);
261 result.verify(tcx, trait_def_id, err_sp)?;
270 ) -> Result<(), ErrorReported> {
271 let name = tcx.item_name(trait_def_id);
272 let generics = tcx.generics_of(trait_def_id);
273 let s = self.0.as_str();
274 let parser = Parser::new(&s, None, None, false, ParseMode::Format);
275 let mut result = Ok(());
276 for token in parser {
278 Piece::String(_) => (), // Normal string, no need to check it
279 Piece::NextArgument(a) => match a.position {
280 // `{Self}` is allowed
281 Position::ArgumentNamed(s) if s == kw::SelfUpper => (),
282 // `{ThisTraitsName}` is allowed
283 Position::ArgumentNamed(s) if s == name => (),
284 // `{from_method}` is allowed
285 Position::ArgumentNamed(s) if s == sym::from_method => (),
286 // `{from_desugaring}` is allowed
287 Position::ArgumentNamed(s) if s == sym::from_desugaring => (),
288 // `{ItemContext}` is allowed
289 Position::ArgumentNamed(s) if s == sym::ItemContext => (),
290 // So is `{A}` if A is a type parameter
291 Position::ArgumentNamed(s) => {
292 match generics.params.iter().find(|param| param.name == s) {
299 "there is no parameter `{}` on trait `{}`",
304 result = Err(ErrorReported);
308 // `{:1}` and `{}` are not to be used
309 Position::ArgumentIs(_) | Position::ArgumentImplicitlyIs(_) => {
314 "only named substitution parameters are allowed"
317 result = Err(ErrorReported);
329 trait_ref: ty::TraitRef<'tcx>,
330 options: &FxHashMap<Symbol, String>,
332 let name = tcx.item_name(trait_ref.def_id);
333 let trait_str = tcx.def_path_str(trait_ref.def_id);
334 let generics = tcx.generics_of(trait_ref.def_id);
335 let generic_map = generics
338 .filter_map(|param| {
339 let value = match param.kind {
340 GenericParamDefKind::Type { .. } | GenericParamDefKind::Const => {
341 trait_ref.substs[param.index as usize].to_string()
343 GenericParamDefKind::Lifetime => return None,
345 let name = param.name;
348 .collect::<FxHashMap<Symbol, String>>();
349 let empty_string = String::new();
351 let s = self.0.as_str();
352 let parser = Parser::new(&s, None, None, false, ParseMode::Format);
353 let item_context = (options.get(&sym::ItemContext)).unwrap_or(&empty_string);
356 Piece::String(s) => s,
357 Piece::NextArgument(a) => match a.position {
358 Position::ArgumentNamed(s) => match generic_map.get(&s) {
360 None if s == name => &trait_str,
362 if let Some(val) = options.get(&s) {
364 } else if s == sym::from_desugaring || s == sym::from_method {
365 // don't break messages using these two arguments incorrectly
367 } else if s == sym::ItemContext {
371 "broken on_unimplemented {:?} for {:?}: \
372 no argument matching {:?}",
380 _ => bug!("broken on_unimplemented {:?} - bad format arg", self.0),