Skip to content

Recover import instead of use in item #97819

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 8, 2022
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
69 changes: 49 additions & 20 deletions compiler/rustc_parse/src/parser/item.rs
Original file line number Diff line number Diff line change
Expand Up @@ -204,25 +204,7 @@ impl<'a> Parser<'a> {
let mut def = || mem::replace(def, Defaultness::Final);

let info = if self.eat_keyword(kw::Use) {
// USE ITEM
let tree = self.parse_use_tree()?;

// If wildcard or glob-like brace syntax doesn't have `;`,
// the user may not know `*` or `{}` should be the last.
if let Err(mut e) = self.expect_semi() {
match tree.kind {
UseTreeKind::Glob => {
e.note("the wildcard token must be last on the path");
}
UseTreeKind::Nested(..) => {
e.note("glob-like brace syntax must be last on the path");
}
_ => (),
}
return Err(e);
}

(Ident::empty(), ItemKind::Use(tree))
self.parse_use_item()?
} else if self.check_fn_front_matter(def_final) {
// FUNCTION ITEM
let (ident, sig, generics, body) = self.parse_fn(attrs, fn_parse_mode, lo, vis)?;
Expand Down Expand Up @@ -288,7 +270,12 @@ impl<'a> Parser<'a> {
} else if let IsMacroRulesItem::Yes { has_bang } = self.is_macro_rules_item() {
// MACRO_RULES ITEM
self.parse_item_macro_rules(vis, has_bang)?
} else if vis.kind.is_pub() && self.isnt_macro_invocation() {
} else if self.isnt_macro_invocation()
&& (self.token.is_ident_named(Symbol::intern("import"))
|| self.token.is_ident_named(Symbol::intern("using")))
{
return self.recover_import_as_use();
} else if self.isnt_macro_invocation() && vis.kind.is_pub() {
self.recover_missing_kw_before_item()?;
return Ok(None);
} else if macros_allowed && self.check_path() {
Expand All @@ -300,6 +287,48 @@ impl<'a> Parser<'a> {
Ok(Some(info))
}

fn recover_import_as_use(&mut self) -> PResult<'a, Option<(Ident, ItemKind)>> {
let span = self.token.span;
let token_name = super::token_descr(&self.token);
let snapshot = self.create_snapshot_for_diagnostic();
self.bump();
match self.parse_use_item() {
Ok(u) => {
self.struct_span_err(span, format!("expected item, found {token_name}"))
.span_suggestion_short(
span,
"items are imported using the `use` keyword",
"use".to_owned(),
Applicability::MachineApplicable,
)
.emit();
Ok(Some(u))
}
Err(e) => {
e.cancel();
self.restore_snapshot(snapshot);
Ok(None)
}
}
}

fn parse_use_item(&mut self) -> PResult<'a, (Ident, ItemKind)> {
let tree = self.parse_use_tree()?;
if let Err(mut e) = self.expect_semi() {
match tree.kind {
UseTreeKind::Glob => {
e.note("the wildcard token must be last on the path");
}
UseTreeKind::Nested(..) => {
e.note("glob-like brace syntax must be last on the path");
}
_ => (),
}
return Err(e);
}
Ok((Ident::empty(), ItemKind::Use(tree)))
}

/// When parsing a statement, would the start of a path be an item?
pub(super) fn is_path_start_item(&mut self) -> bool {
self.is_kw_followed_by_ident(kw::Union) // no: `union::b`, yes: `union U { .. }`
Expand Down
15 changes: 15 additions & 0 deletions src/test/ui/did_you_mean/use_instead_of_import.fixed
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
// run-rustfix

use std::{
//~^ ERROR expected item, found `import`
io::Write,
rc::Rc,
};

pub use std::io;
//~^ ERROR expected item, found `using`

fn main() {
let x = Rc::new(1);
let _ = write!(io::stdout(), "{:?}", x);
}
15 changes: 15 additions & 0 deletions src/test/ui/did_you_mean/use_instead_of_import.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
// run-rustfix

import std::{
//~^ ERROR expected item, found `import`
io::Write,
rc::Rc,
};

pub using std::io;
//~^ ERROR expected item, found `using`

fn main() {
let x = Rc::new(1);
let _ = write!(io::stdout(), "{:?}", x);
}
14 changes: 14 additions & 0 deletions src/test/ui/did_you_mean/use_instead_of_import.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,14 @@
error: expected item, found `import`
--> $DIR/use_instead_of_import.rs:3:1
|
LL | import std::{
| ^^^^^^ help: items are imported using the `use` keyword

error: expected item, found `using`
--> $DIR/use_instead_of_import.rs:9:5
|
LL | pub using std::io;
| ^^^^^ help: items are imported using the `use` keyword

error: aborting due to 2 previous errors