Add error recovery for use foo::self

src/librustc_resolve/build_reduced_graph.rs

@@ -426,7 +426,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
  return;
  }
 
- // Replace `use foo::self;` with `use foo;`
+ // Replace `use foo::{ self };` with `use foo;`
  source = module_path.pop().unwrap();
  if rename.is_none() {
  ident = source.ident;
@@ -454,6 +454,14 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
  span_with_rename,
  },
  );
+
+ // Error recovery: replace `use foo::self;` with `use foo;`
+ if let Some(parent) = module_path.pop() {
+ source = parent;
+ if rename.is_none() {
+ ident = source.ident;
+ }
+ }
  }
 
  // Disallow `use $crate;`

src/test/ui/issues/issue-45829/import-self.rs

@@ -9,7 +9,7 @@ use foo::{self};
 use foo as self;
 //~^ ERROR expected identifier
 
-use foo::self;
+use foo::self; //~ ERROR is defined multiple times
 //~^ ERROR `self` imports are only allowed within a { } list
 
 use foo::A;

src/test/ui/issues/issue-45829/import-self.stderr

@@ -34,6 +34,21 @@ help: you can use `as` to change the binding name of the import
 LL | use foo::{self as other_foo};
  | ^^^^^^^^^^^^^^^^^
 
+error[E0255]: the name `foo` is defined multiple times
+ --> $DIR/import-self.rs:12:5
+ |
+LL | mod foo {
+ | ------- previous definition of the module `foo` here
+...
+LL | use foo::self;
+ | ^^^^^^^^^ `foo` reimported here
+ |
+ = note: `foo` must be defined only once in the type namespace of this module
+help: you can use `as` to change the binding name of the import
+ |
+LL | use foo as other_foo;
+ | ^^^^^^^^^^^^^^^^
+
 error[E0252]: the name `A` is defined multiple times
  --> $DIR/import-self.rs:16:11
  |
@@ -48,7 +63,7 @@ help: you can use `as` to change the binding name of the import
 LL | use foo::{self as OtherA};
  | ^^^^^^^^^^^^^^
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 
 Some errors have detailed explanations: E0252, E0255, E0429.
 For more information about an error, try `rustc --explain E0252`.

src/test/ui/use/use-mod/use-mod-4.stderr

@@ -32,7 +32,7 @@ error[E0432]: unresolved import `foo`
  --> $DIR/use-mod-4.rs:1:5
  |
 LL | use foo::self;
- | ^^^ maybe a missing crate `foo`?
+ | ^^^^^^^^^ no `foo` in the root
 
 error: aborting due to 3 previous errors
 

src/test/ui/use/use-mod/use-mod-5.rs

@@ -0,0 +1,13 @@
+mod foo {
+ pub mod bar {
+ pub fn drop() {}
+ }
+}
+
+use foo::bar::self;
+//~^ ERROR `self` imports are only allowed within a { } list
+
+fn main() {
+ // Because of error recovery this shouldn't error
+ bar::drop();
+}

src/test/ui/use/use-mod/use-mod-5.stderr

@@ -0,0 +1,18 @@
+error[E0429]: `self` imports are only allowed within a { } list
+ --> $DIR/use-mod-5.rs:7:13
+ |
+LL | use foo::bar::self;
+ | ^^^^^^
+ |
+help: Remove `::self`..
+ |
+LL | use foo::bar;
+ | --
+help: ..or add braces around `self`
+ |
+LL | use foo::bar::{self};
+ | ^ ^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0429`.

src/test/ui/use/use-mod/use-mod-6.rs

@@ -0,0 +1,13 @@
+mod foo {
+ pub mod bar {
+ pub fn drop() {}
+ }
+}
+
+use foo::bar::self as abc;
+//~^ ERROR `self` imports are only allowed within a { } list
+
+fn main() {
+ // Because of error recovery this shouldn't error
+ abc::drop();
+}

src/test/ui/use/use-mod/use-mod-6.stderr

@@ -0,0 +1,18 @@
+error[E0429]: `self` imports are only allowed within a { } list
+ --> $DIR/use-mod-6.rs:7:13
+ |
+LL | use foo::bar::self as abc;
+ | ^^^^^^
+ |
+help: Remove `::self`..
+ |
+LL | use foo::bar as abc;
+ | --
+help: ..or add braces around `self`
+ |
+LL | use foo::bar::{self as abc};
+ | ^ ^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0429`.