diff --git a/src/librustc_resolve/error_reporting.rs b/src/librustc_resolve/error_reporting.rs
index def67923322aa..50ab8ef9c7be7 100644
--- a/src/librustc_resolve/error_reporting.rs
+++ b/src/librustc_resolve/error_reporting.rs
@@ -26,7 +26,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
span: Span,
path: Vec<Segment>,
parent_scope: &ParentScope<'b>,
- ) -> Option<Vec<Segment>> {
+ ) -> Option<(Vec<Segment>, Option<String>)> {
debug!("make_path_suggestion: span={:?} path={:?}", span, path);
// If we don't have a path to suggest changes to, then return.
if path.is_empty() {
@@ -65,13 +65,13 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
span: Span,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'b>,
- ) -> Option<Vec<Segment>> {
+ ) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `self` and check if that is valid.
path[0].ident.name = keywords::SelfValue.name();
let result = self.resolve_path(None, &path, None, parent_scope, false, span, CrateLint::No);
debug!("make_missing_self_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result {
- Some(path)
+ Some((path, None))
} else {
None
}
@@ -89,13 +89,20 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
span: Span,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'b>,
- ) -> Option<Vec<Segment>> {
+ ) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `crate` and check if that is valid.
path[0].ident.name = keywords::Crate.name();
let result = self.resolve_path(None, &path, None, parent_scope, false, span, CrateLint::No);
debug!("make_missing_crate_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result {
- Some(path)
+ Some((
+ path,
+ Some(
+ "`use` statements changed in Rust 2018; read more at \
+ <https://doc.rust-lang.org/edition-guide/rust-2018/module-system/path-\
+ clarity.html>".to_string()
+ ),
+ ))
} else {
None
}
@@ -113,13 +120,13 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
span: Span,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'b>,
- ) -> Option<Vec<Segment>> {
+ ) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `crate` and check if that is valid.
path[0].ident.name = keywords::Super.name();
let result = self.resolve_path(None, &path, None, parent_scope, false, span, CrateLint::No);
debug!("make_missing_super_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result {
- Some(path)
+ Some((path, None))
} else {
None
}
@@ -140,7 +147,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
span: Span,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'b>,
- ) -> Option<Vec<Segment>> {
+ ) -> Option<(Vec<Segment>, Option<String>)> {
// Need to clone else we can't call `resolve_path` without a borrow error. We also store
// into a `BTreeMap` so we can get consistent ordering (and therefore the same diagnostic)
// each time.
@@ -162,7 +169,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
debug!("make_external_crate_suggestion: name={:?} path={:?} result={:?}",
name, path, result);
if let PathResult::Module(..) = result {
- return Some(path)
+ return Some((path, None));
}
}
diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs
index 3ca0a9f7f1b97..359640ccda2b1 100644
--- a/src/librustc_resolve/resolve_imports.rs
+++ b/src/librustc_resolve/resolve_imports.rs
@@ -707,7 +707,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
}
}
});
- } else if let Some((span, err)) = error {
+ } else if let Some((span, err, note)) = error {
errors = true;
if let SingleImport { source, ref result, .. } = import.subclass {
@@ -737,7 +737,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
&import.subclass,
span,
);
- error_vec.push((span, path, err));
+ error_vec.push((span, path, err, note));
seen_spans.insert(span);
prev_root_id = import.root_id;
}
@@ -829,27 +829,45 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
}
}
- fn throw_unresolved_import_error(&self, error_vec: Vec<(Span, String, String)>,
- span: Option<MultiSpan>) {
+ fn throw_unresolved_import_error(
+ &self,
+ error_vec: Vec<(Span, String, String, Option<String>)>,
+ span: Option<MultiSpan>,
+ ) {
let max_span_label_msg_count = 10; // upper limit on number of span_label message.
- let (span, msg) = if error_vec.is_empty() {
- (span.unwrap(), "unresolved import".to_string())
+ let (span, msg, note) = if error_vec.is_empty() {
+ (span.unwrap(), "unresolved import".to_string(), None)
} else {
- let span = MultiSpan::from_spans(error_vec.clone().into_iter()
- .map(|elem: (Span, String, String)| { elem.0 })
- .collect());
+ let span = MultiSpan::from_spans(
+ error_vec.clone().into_iter()
+ .map(|elem: (Span, String, String, Option<String>)| elem.0)
+ .collect()
+ );
+
+ let note: Option<String> = error_vec.clone().into_iter()
+ .filter_map(|elem: (Span, String, String, Option<String>)| elem.3)
+ .last();
+
let path_vec: Vec<String> = error_vec.clone().into_iter()
- .map(|elem: (Span, String, String)| { format!("`{}`", elem.1) })
+ .map(|elem: (Span, String, String, Option<String>)| format!("`{}`", elem.1))
.collect();
let path = path_vec.join(", ");
- let msg = format!("unresolved import{} {}",
- if path_vec.len() > 1 { "s" } else { "" }, path);
- (span, msg)
+ let msg = format!(
+ "unresolved import{} {}",
+ if path_vec.len() > 1 { "s" } else { "" },
+ path
+ );
+
+ (span, msg, note)
};
+
let mut err = struct_span_err!(self.resolver.session, span, E0432, "{}", &msg);
for span_error in error_vec.into_iter().take(max_span_label_msg_count) {
err.span_label(span_error.0, span_error.2);
}
+ if let Some(note) = note {
+ err.note(¬e);
+ }
err.emit();
}
@@ -945,7 +963,10 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
}
// If appropriate, returns an error to report.
- fn finalize_import(&mut self, directive: &'b ImportDirective<'b>) -> Option<(Span, String)> {
+ fn finalize_import(
+ &mut self,
+ directive: &'b ImportDirective<'b>
+ ) -> Option<(Span, String, Option<String>)> {
self.current_module = directive.parent_scope.module;
let ImportDirective { ref module_path, span, .. } = *directive;
@@ -969,15 +990,16 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
return None;
}
PathResult::Failed(span, msg, true) => {
- return if let Some(suggested_path) = self.make_path_suggestion(
+ return if let Some((suggested_path, note)) = self.make_path_suggestion(
span, module_path.clone(), &directive.parent_scope
) {
Some((
span,
- format!("Did you mean `{}`?", Segment::names_to_string(&suggested_path))
+ format!("Did you mean `{}`?", Segment::names_to_string(&suggested_path)),
+ note,
))
} else {
- Some((span, msg))
+ Some((span, msg, None))
};
},
_ => return None,
@@ -1002,8 +1024,11 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
if let ModuleOrUniformRoot::Module(module) = module {
if module.def_id() == directive.parent_scope.module.def_id() {
// Importing a module into itself is not allowed.
- return Some((directive.span,
- "Cannot glob-import a module into itself.".to_string()));
+ return Some((
+ directive.span,
+ "Cannot glob-import a module into itself.".to_string(),
+ None,
+ ));
}
}
if !is_prelude &&
@@ -1101,7 +1126,7 @@ impl<'a, 'b:'a, 'c: 'b> ImportResolver<'a, 'b, 'c> {
}
}
};
- Some((span, msg))
+ Some((span, msg, None))
} else {
// `resolve_ident_in_module` reported a privacy error.
self.import_dummy_binding(directive);
diff --git a/src/test/ui/rust-2018/local-path-suggestions-2018.stderr b/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
index 97bf748881f29..2293f4b001749 100644
--- a/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
+++ b/src/test/ui/rust-2018/local-path-suggestions-2018.stderr
@@ -3,6 +3,8 @@ error[E0432]: unresolved import `foo`
|
LL | use foo::Bar;
| ^^^ Did you mean `crate::foo`?
+ |
+ = note: `use` statements changed in Rust 2018; read more at <https://doc.rust-lang.org/edition-guide/rust-2018/module-system/path-clarity.html>
error[E0432]: unresolved import `foo`
--> $DIR/local-path-suggestions-2018.rs:27:5