Skip to content

Commit

Permalink
Move code to diagnostics.rs
Browse files Browse the repository at this point in the history
  • Loading branch information
@estebank
estebank committed Feb 5, 2020
1 parent 49f9bf8 commit 1beac2b
Show file tree
Hide file tree
Showing 2 changed files with 214 additions and 200 deletions.
298 changes: 207 additions & 91 deletions src/librustc_resolve/diagnostics.rs
View file
Expand Up @@ -8,6 +8,7 @@ use rustc_ast_pretty::pprust;
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder};
use rustc_feature::BUILTIN_ATTRIBUTES;
use rustc_hir as hir;
use rustc_hir::def::Namespace::{self, *};
use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind};
use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
Expand All @@ -19,7 +20,7 @@ use syntax::ast::{self, Ident, Path};
use syntax::util::lev_distance::find_best_match_for_name;

use crate::imports::{ImportDirective, ImportDirectiveSubclass, ImportResolver};
use crate::lifetimes::{ElisionFailureInfo, MissingLifetimeSpot};
use crate::lifetimes::{ElisionFailureInfo, LifetimeContext};
use crate::path_names_to_string;
use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind};
use crate::{BindingError, CrateLint, HasGenericParams, LegacyScope, Module, ModuleOrUniformRoot};
Expand Down Expand Up @@ -48,6 +49,40 @@ crate struct ImportSuggestion {
pub path: Path,
}

crate enum MissingLifetimeSpot<'tcx> {
Generics(&'tcx hir::Generics<'tcx>),
HigherRanked { span: Span, span_type: ForLifetimeSpanType },
}

crate enum ForLifetimeSpanType {
BoundEmpty,
BoundTail,
TypeEmpty,
TypeTail,
}

impl ForLifetimeSpanType {
crate fn descr(&self) -> &'static str {
match self {
Self::BoundEmpty | Self::BoundTail => "bound",
Self::TypeEmpty | Self::TypeTail => "type",
}
}

crate fn suggestion(&self, sugg: &str) -> String {
match self {
Self::BoundEmpty | Self::TypeEmpty => format!("for<{}> ", sugg),
Self::BoundTail | Self::TypeTail => format!(", {}", sugg),
}
}
}

impl<'tcx> Into<MissingLifetimeSpot<'tcx>> for &'tcx hir::Generics<'tcx> {
fn into(self) -> MissingLifetimeSpot<'tcx> {
MissingLifetimeSpot::Generics(self)
}
}

/// Adjust the impl span so that just the `impl` keyword is taken by removing
/// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
/// everything after the first whitespace (`"impl Iterator for A" -> "impl"`).
Expand Down Expand Up @@ -1457,104 +1492,185 @@ crate fn show_candidates(
}
}

crate fn report_missing_lifetime_specifiers(
sess: &Session,
span: Span,
count: usize,
) -> DiagnosticBuilder<'_> {
struct_span_err!(sess, span, E0106, "missing lifetime specifier{}", pluralize!(count))
}
impl<'tcx> LifetimeContext<'_, 'tcx> {
crate fn report_missing_lifetime_specifiers(
&self,
span: Span,
count: usize,
) -> DiagnosticBuilder<'tcx> {
struct_span_err!(
self.tcx.sess,
span,
E0106,
"missing lifetime specifier{}",
pluralize!(count)
)
}

crate fn add_missing_lifetime_specifiers_label(
err: &mut DiagnosticBuilder<'_>,
source_map: &SourceMap,
span: Span,
count: usize,
lifetime_names: &FxHashSet<ast::Ident>,
snippet: Option<&str>,
missing_named_lifetime_spots: &[MissingLifetimeSpot<'_>],
params: &[ElisionFailureInfo],
) {
if count > 1 {
err.span_label(span, format!("expected {} lifetime parameters", count));
} else {
let suggest_existing = |err: &mut DiagnosticBuilder<'_>, sugg| {
err.span_suggestion(
span,
"consider using the named lifetime",
sugg,
Applicability::MaybeIncorrect,
);
crate fn emit_undeclared_lifetime_error(&self, lifetime_ref: &hir::Lifetime) {
let mut err = struct_span_err!(
self.tcx.sess,
lifetime_ref.span,
E0261,
"use of undeclared lifetime name `{}`",
lifetime_ref
);
err.span_label(lifetime_ref.span, "undeclared lifetime");
for missing in &self.missing_named_lifetime_spots {
match missing {
MissingLifetimeSpot::Generics(generics) => {
let (span, sugg) = match &generics.params {
[] => (generics.span, format!("<{}>", lifetime_ref)),
[param, ..] => (param.span.shrink_to_lo(), format!("{}, ", lifetime_ref)),
};
err.span_suggestion(
span,
&format!("consider introducing lifetime `{}` here", lifetime_ref),
sugg,
Applicability::MaybeIncorrect,
);
}
MissingLifetimeSpot::HigherRanked { span, span_type } => {
err.span_suggestion(
*span,
&format!(
"consider making the {} lifetime-generic with a new `{}` lifetime",
span_type.descr(),
lifetime_ref
),
span_type.suggestion(&lifetime_ref.to_string()),
Applicability::MaybeIncorrect,
);
err.note(
"for more information on higher-ranked polymorphism, visit \
https://doc.rust-lang.org/nomicon/hrtb.html",
);
}
}
}
err.emit();
}

crate fn is_trait_ref_fn_scope(&mut self, trait_ref: &'tcx hir::PolyTraitRef<'tcx>) -> bool {
if let def::Res::Def(_, did) = trait_ref.trait_ref.path.res {
if [
self.tcx.lang_items().fn_once_trait(),
self.tcx.lang_items().fn_trait(),
self.tcx.lang_items().fn_mut_trait(),
]
.contains(&Some(did))
{
let (span, span_type) = match &trait_ref.bound_generic_params {
[] => (trait_ref.span.shrink_to_lo(), ForLifetimeSpanType::BoundEmpty),
[.., bound] => (bound.span.shrink_to_hi(), ForLifetimeSpanType::BoundTail),
};
self.missing_named_lifetime_spots
.push(MissingLifetimeSpot::HigherRanked { span, span_type });
return true;
}
};
let suggest_new = |err: &mut DiagnosticBuilder<'_>, sugg: &str| {
err.span_label(span, "expected named lifetime parameter");

for missing in missing_named_lifetime_spots.iter().rev() {
let mut introduce_suggestion = vec![];
let msg;
let should_break;
introduce_suggestion.push(match missing {
MissingLifetimeSpot::Generics(generics) => {
msg = "consider introducing a named lifetime parameter".to_string();
should_break = true;
match &generics.params {
[] => (generics.span, "<'a>".to_string()),
[param, ..] => (param.span.shrink_to_lo(), "'a, ".to_string()),
false
}

crate fn add_missing_lifetime_specifiers_label(
&self,
err: &mut DiagnosticBuilder<'_>,
span: Span,
count: usize,
lifetime_names: &FxHashSet<ast::Ident>,
params: &[ElisionFailureInfo],
) {
if count > 1 {
err.span_label(span, format!("expected {} lifetime parameters", count));
} else {
let snippet = self.tcx.sess.source_map().span_to_snippet(span).ok();
let suggest_existing = |err: &mut DiagnosticBuilder<'_>, sugg| {
err.span_suggestion(
span,
"consider using the named lifetime",
sugg,
Applicability::MaybeIncorrect,
);
};
let suggest_new = |err: &mut DiagnosticBuilder<'_>, sugg: &str| {
err.span_label(span, "expected named lifetime parameter");

for missing in self.missing_named_lifetime_spots.iter().rev() {
let mut introduce_suggestion = vec![];
let msg;
let should_break;
introduce_suggestion.push(match missing {
MissingLifetimeSpot::Generics(generics) => {
msg = "consider introducing a named lifetime parameter".to_string();
should_break = true;
match &generics.params {
[] => (generics.span, "<'a>".to_string()),
[param, ..] => (param.span.shrink_to_lo(), "'a, ".to_string()),
}
}
}
MissingLifetimeSpot::HigherRanked { span, span_type } => {
msg = format!(
"consider making the {} lifetime-generic with a new `'a` lifetime",
span_type.descr(),
);
should_break = false;
err.note(
"for more information on higher-ranked polymorphism, visit \
MissingLifetimeSpot::HigherRanked { span, span_type } => {
msg = format!(
"consider making the {} lifetime-generic with a new `'a` lifetime",
span_type.descr(),
);
should_break = false;
err.note(
"for more information on higher-ranked polymorphism, visit \
https://doc.rust-lang.org/nomicon/hrtb.html",
);
(*span, span_type.suggestion("'a"))
}
});
for param in params {
if let Ok(snippet) = source_map.span_to_snippet(param.span) {
if snippet.starts_with("&") && !snippet.starts_with("&'") {
introduce_suggestion
.push((param.span, format!("&'a {}", &snippet[1..])));
} else if snippet.starts_with("&'_ ") {
introduce_suggestion
.push((param.span, format!("&'a {}", &snippet[4..])));
);
(*span, span_type.suggestion("'a"))
}
});
for param in params {
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(param.span)
{
if snippet.starts_with("&") && !snippet.starts_with("&'") {
introduce_suggestion
.push((param.span, format!("&'a {}", &snippet[1..])));
} else if snippet.starts_with("&'_ ") {
introduce_suggestion
.push((param.span, format!("&'a {}", &snippet[4..])));
}
}
}
introduce_suggestion.push((span, sugg.to_string()));
err.multipart_suggestion(
&msg,
introduce_suggestion,
Applicability::MaybeIncorrect,
);
if should_break {
break;
}
}
introduce_suggestion.push((span, sugg.to_string()));
err.multipart_suggestion(&msg, introduce_suggestion, Applicability::MaybeIncorrect);
if should_break {
break;
}
}
};
};

match (lifetime_names.len(), lifetime_names.iter().next(), snippet) {
(1, Some(name), Some("&")) => {
suggest_existing(err, format!("&{} ", name));
}
(1, Some(name), Some("'_")) => {
suggest_existing(err, name.to_string());
}
(1, Some(name), Some(snippet)) if !snippet.ends_with(">") => {
suggest_existing(err, format!("{}<{}>", snippet, name));
}
(0, _, Some("&")) => {
suggest_new(err, "&'a ");
}
(0, _, Some("'_")) => {
suggest_new(err, "'a");
}
(0, _, Some(snippet)) if !snippet.ends_with(">") => {
suggest_new(err, &format!("{}<'a>", snippet));
}
_ => {
err.span_label(span, "expected lifetime parameter");
match (
lifetime_names.len(),
lifetime_names.iter().next(),
snippet.as_ref().map(|s| s.as_str()),
) {
(1, Some(name), Some("&")) => {
suggest_existing(err, format!("&{} ", name));
}
(1, Some(name), Some("'_")) => {
suggest_existing(err, name.to_string());
}
(1, Some(name), Some(snippet)) if !snippet.ends_with(">") => {
suggest_existing(err, format!("{}<{}>", snippet, name));
}
(0, _, Some("&")) => {
suggest_new(err, "&'a ");
}
(0, _, Some("'_")) => {
suggest_new(err, "'a");
}
(0, _, Some(snippet)) if !snippet.ends_with(">") => {
suggest_new(err, &format!("{}<'a>", snippet));
}
_ => {
err.span_label(span, "expected lifetime parameter");
}
}
}
}
Expand Down

0 comments on commit 1beac2b

Please sign in to comment.