-use super::{
- ObligationCauseCode, OnUnimplementedDirective, OnUnimplementedNote, PredicateObligation,
-};
+use super::{ObligationCauseCode, PredicateObligation};
use crate::infer::error_reporting::TypeErrCtxt;
+use rustc_ast::{MetaItem, NestedMetaItem};
+use rustc_attr as attr;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::{struct_span_err, ErrorGuaranteed};
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_middle::ty::SubstsRef;
-use rustc_middle::ty::{self, GenericParamDefKind};
-use rustc_span::symbol::sym;
+use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
+use rustc_parse_format::{ParseMode, Parser, Piece, Position};
+use rustc_span::symbol::{kw, sym, Symbol};
+use rustc_span::{Span, DUMMY_SP};
use std::iter;
+use crate::errors::{
+ EmptyOnClauseInOnUnimplemented, InvalidOnClauseInOnUnimplemented, NoValueInOnUnimplemented,
+};
+
use super::InferCtxtPrivExt;
pub trait TypeErrCtxtExt<'tcx> {
flags.push((sym::from_desugaring, Some(format!("{:?}", k))));
}
+ if let ObligationCauseCode::MainFunctionType = obligation.cause.code() {
+ flags.push((sym::cause, Some("MainFunctionType".to_string())));
+ }
+
// Add all types without trimmed paths.
ty::print::with_no_trimmed_paths!({
let generics = self.tcx.generics_of(def_id);
}
}
}
+
+#[derive(Clone, Debug)]
+pub struct OnUnimplementedFormatString(Symbol);
+
+#[derive(Debug)]
+pub struct OnUnimplementedDirective {
+ pub condition: Option<MetaItem>,
+ pub subcommands: Vec<OnUnimplementedDirective>,
+ pub message: Option<OnUnimplementedFormatString>,
+ pub label: Option<OnUnimplementedFormatString>,
+ pub note: Option<OnUnimplementedFormatString>,
+ pub parent_label: Option<OnUnimplementedFormatString>,
+ pub append_const_msg: Option<Option<Symbol>>,
+}
+
+/// For the `#[rustc_on_unimplemented]` attribute
+#[derive(Default)]
+pub struct OnUnimplementedNote {
+ pub message: Option<String>,
+ pub label: Option<String>,
+ pub note: Option<String>,
+ pub parent_label: Option<String>,
+ /// Append a message for `~const Trait` errors. `None` means not requested and
+ /// should fallback to a generic message, `Some(None)` suggests using the default
+ /// appended message, `Some(Some(s))` suggests use the `s` message instead of the
+ /// default one..
+ pub append_const_msg: Option<Option<Symbol>>,
+}
+
+impl<'tcx> OnUnimplementedDirective {
+ fn parse(
+ tcx: TyCtxt<'tcx>,
+ item_def_id: DefId,
+ items: &[NestedMetaItem],
+ span: Span,
+ is_root: bool,
+ ) -> Result<Self, ErrorGuaranteed> {
+ let mut errored = None;
+ let mut item_iter = items.iter();
+
+ let parse_value = |value_str| {
+ OnUnimplementedFormatString::try_parse(tcx, item_def_id, value_str, span).map(Some)
+ };
+
+ let condition = if is_root {
+ None
+ } else {
+ let cond = item_iter
+ .next()
+ .ok_or_else(|| tcx.sess.emit_err(EmptyOnClauseInOnUnimplemented { span }))?
+ .meta_item()
+ .ok_or_else(|| tcx.sess.emit_err(InvalidOnClauseInOnUnimplemented { span }))?;
+ attr::eval_condition(cond, &tcx.sess.parse_sess, Some(tcx.features()), &mut |cfg| {
+ if let Some(value) = cfg.value && let Err(guar) = parse_value(value) {
+ errored = Some(guar);
+ }
+ true
+ });
+ Some(cond.clone())
+ };
+
+ let mut message = None;
+ let mut label = None;
+ let mut note = None;
+ let mut parent_label = None;
+ let mut subcommands = vec![];
+ let mut append_const_msg = None;
+
+ for item in item_iter {
+ if item.has_name(sym::message) && message.is_none() {
+ if let Some(message_) = item.value_str() {
+ message = parse_value(message_)?;
+ continue;
+ }
+ } else if item.has_name(sym::label) && label.is_none() {
+ if let Some(label_) = item.value_str() {
+ label = parse_value(label_)?;
+ continue;
+ }
+ } else if item.has_name(sym::note) && note.is_none() {
+ if let Some(note_) = item.value_str() {
+ note = parse_value(note_)?;
+ continue;
+ }
+ } else if item.has_name(sym::parent_label) && parent_label.is_none() {
+ if let Some(parent_label_) = item.value_str() {
+ parent_label = parse_value(parent_label_)?;
+ continue;
+ }
+ } else if item.has_name(sym::on)
+ && is_root
+ && message.is_none()
+ && label.is_none()
+ && note.is_none()
+ {
+ if let Some(items) = item.meta_item_list() {
+ match Self::parse(tcx, item_def_id, &items, item.span(), false) {
+ Ok(subcommand) => subcommands.push(subcommand),
+ Err(reported) => errored = Some(reported),
+ };
+ continue;
+ }
+ } else if item.has_name(sym::append_const_msg) && append_const_msg.is_none() {
+ if let Some(msg) = item.value_str() {
+ append_const_msg = Some(Some(msg));
+ continue;
+ } else if item.is_word() {
+ append_const_msg = Some(None);
+ continue;
+ }
+ }
+
+ // nothing found
+ tcx.sess.emit_err(NoValueInOnUnimplemented { span: item.span() });
+ }
+
+ if let Some(reported) = errored {
+ Err(reported)
+ } else {
+ Ok(OnUnimplementedDirective {
+ condition,
+ subcommands,
+ message,
+ label,
+ note,
+ parent_label,
+ append_const_msg,
+ })
+ }
+ }
+
+ pub fn of_item(tcx: TyCtxt<'tcx>, item_def_id: DefId) -> Result<Option<Self>, ErrorGuaranteed> {
+ let Some(attr) = tcx.get_attr(item_def_id, sym::rustc_on_unimplemented) else {
+ return Ok(None);
+ };
+
+ let result = if let Some(items) = attr.meta_item_list() {
+ Self::parse(tcx, item_def_id, &items, attr.span, true).map(Some)
+ } else if let Some(value) = attr.value_str() {
+ Ok(Some(OnUnimplementedDirective {
+ condition: None,
+ message: None,
+ subcommands: vec![],
+ label: Some(OnUnimplementedFormatString::try_parse(
+ tcx,
+ item_def_id,
+ value,
+ attr.span,
+ )?),
+ note: None,
+ parent_label: None,
+ append_const_msg: None,
+ }))
+ } else {
+ let reported =
+ tcx.sess.delay_span_bug(DUMMY_SP, "of_item: neither meta_item_list nor value_str");
+ return Err(reported);
+ };
+ debug!("of_item({:?}) = {:?}", item_def_id, result);
+ result
+ }
+
+ pub fn evaluate(
+ &self,
+ tcx: TyCtxt<'tcx>,
+ trait_ref: ty::TraitRef<'tcx>,
+ options: &[(Symbol, Option<String>)],
+ ) -> OnUnimplementedNote {
+ let mut message = None;
+ let mut label = None;
+ let mut note = None;
+ let mut parent_label = None;
+ let mut append_const_msg = None;
+ info!("evaluate({:?}, trait_ref={:?}, options={:?})", self, trait_ref, options);
+
+ let options_map: FxHashMap<Symbol, String> =
+ options.iter().filter_map(|(k, v)| v.as_ref().map(|v| (*k, v.to_owned()))).collect();
+
+ for command in self.subcommands.iter().chain(Some(self)).rev() {
+ if let Some(ref condition) = command.condition && !attr::eval_condition(
+ condition,
+ &tcx.sess.parse_sess,
+ Some(tcx.features()),
+ &mut |cfg| {
+ let value = cfg.value.map(|v| {
+ OnUnimplementedFormatString(v).format(tcx, trait_ref, &options_map)
+ });
+
+ options.contains(&(cfg.name, value))
+ },
+ ) {
+ debug!("evaluate: skipping {:?} due to condition", command);
+ continue;
+ }
+ debug!("evaluate: {:?} succeeded", command);
+ if let Some(ref message_) = command.message {
+ message = Some(message_.clone());
+ }
+
+ if let Some(ref label_) = command.label {
+ label = Some(label_.clone());
+ }
+
+ if let Some(ref note_) = command.note {
+ note = Some(note_.clone());
+ }
+
+ if let Some(ref parent_label_) = command.parent_label {
+ parent_label = Some(parent_label_.clone());
+ }
+
+ append_const_msg = command.append_const_msg;
+ }
+
+ OnUnimplementedNote {
+ label: label.map(|l| l.format(tcx, trait_ref, &options_map)),
+ message: message.map(|m| m.format(tcx, trait_ref, &options_map)),
+ note: note.map(|n| n.format(tcx, trait_ref, &options_map)),
+ parent_label: parent_label.map(|e_s| e_s.format(tcx, trait_ref, &options_map)),
+ append_const_msg,
+ }
+ }
+}
+
+impl<'tcx> OnUnimplementedFormatString {
+ fn try_parse(
+ tcx: TyCtxt<'tcx>,
+ item_def_id: DefId,
+ from: Symbol,
+ err_sp: Span,
+ ) -> Result<Self, ErrorGuaranteed> {
+ let result = OnUnimplementedFormatString(from);
+ result.verify(tcx, item_def_id, err_sp)?;
+ Ok(result)
+ }
+
+ fn verify(
+ &self,
+ tcx: TyCtxt<'tcx>,
+ item_def_id: DefId,
+ span: Span,
+ ) -> Result<(), ErrorGuaranteed> {
+ let trait_def_id = if tcx.is_trait(item_def_id) {
+ item_def_id
+ } else {
+ tcx.trait_id_of_impl(item_def_id)
+ .expect("expected `on_unimplemented` to correspond to a trait")
+ };
+ let trait_name = tcx.item_name(trait_def_id);
+ let generics = tcx.generics_of(item_def_id);
+ let s = self.0.as_str();
+ let parser = Parser::new(s, None, None, false, ParseMode::Format);
+ let mut result = Ok(());
+ for token in parser {
+ match token {
+ Piece::String(_) => (), // Normal string, no need to check it
+ Piece::NextArgument(a) => match a.position {
+ Position::ArgumentNamed(s) => {
+ match Symbol::intern(s) {
+ // `{Self}` is allowed
+ kw::SelfUpper => (),
+ // `{ThisTraitsName}` is allowed
+ s if s == trait_name => (),
+ // `{from_method}` is allowed
+ sym::from_method => (),
+ // `{from_desugaring}` is allowed
+ sym::from_desugaring => (),
+ // `{ItemContext}` is allowed
+ sym::ItemContext => (),
+ // `{integral}` and `{integer}` and `{float}` are allowed
+ sym::integral | sym::integer_ | sym::float => (),
+ // So is `{A}` if A is a type parameter
+ s => match generics.params.iter().find(|param| param.name == s) {
+ Some(_) => (),
+ None => {
+ let reported = struct_span_err!(
+ tcx.sess,
+ span,
+ E0230,
+ "there is no parameter `{}` on {}",
+ s,
+ if trait_def_id == item_def_id {
+ format!("trait `{}`", trait_name)
+ } else {
+ "impl".to_string()
+ }
+ )
+ .emit();
+ result = Err(reported);
+ }
+ },
+ }
+ }
+ // `{:1}` and `{}` are not to be used
+ Position::ArgumentIs(..) | Position::ArgumentImplicitlyIs(_) => {
+ let reported = struct_span_err!(
+ tcx.sess,
+ span,
+ E0231,
+ "only named substitution parameters are allowed"
+ )
+ .emit();
+ result = Err(reported);
+ }
+ },
+ }
+ }
+
+ result
+ }
+
+ pub fn format(
+ &self,
+ tcx: TyCtxt<'tcx>,
+ trait_ref: ty::TraitRef<'tcx>,
+ options: &FxHashMap<Symbol, String>,
+ ) -> String {
+ let name = tcx.item_name(trait_ref.def_id);
+ let trait_str = tcx.def_path_str(trait_ref.def_id);
+ let generics = tcx.generics_of(trait_ref.def_id);
+ let generic_map = generics
+ .params
+ .iter()
+ .filter_map(|param| {
+ let value = match param.kind {
+ GenericParamDefKind::Type { .. } | GenericParamDefKind::Const { .. } => {
+ trait_ref.substs[param.index as usize].to_string()
+ }
+ GenericParamDefKind::Lifetime => return None,
+ };
+ let name = param.name;
+ Some((name, value))
+ })
+ .collect::<FxHashMap<Symbol, String>>();
+ let empty_string = String::new();
+
+ let s = self.0.as_str();
+ let parser = Parser::new(s, None, None, false, ParseMode::Format);
+ let item_context = (options.get(&sym::ItemContext)).unwrap_or(&empty_string);
+ parser
+ .map(|p| match p {
+ Piece::String(s) => s,
+ Piece::NextArgument(a) => match a.position {
+ Position::ArgumentNamed(s) => {
+ let s = Symbol::intern(s);
+ match generic_map.get(&s) {
+ Some(val) => val,
+ None if s == name => &trait_str,
+ None => {
+ if let Some(val) = options.get(&s) {
+ val
+ } else if s == sym::from_desugaring || s == sym::from_method {
+ // don't break messages using these two arguments incorrectly
+ &empty_string
+ } else if s == sym::ItemContext {
+ &item_context
+ } else if s == sym::integral {
+ "{integral}"
+ } else if s == sym::integer_ {
+ "{integer}"
+ } else if s == sym::float {
+ "{float}"
+ } else {
+ bug!(
+ "broken on_unimplemented {:?} for {:?}: \
+ no argument matching {:?}",
+ self.0,
+ trait_ref,
+ s
+ )
+ }
+ }
+ }
+ }
+ _ => bug!("broken on_unimplemented {:?} - bad format arg", self.0),
+ },
+ })
+ .collect()
+ }
+}