From 9e2f9edd7f79c1e11339277bfb83a0c888740438 Mon Sep 17 00:00:00 2001
From: Jules Bertholet <julesbertholet@quoi.xyz>
Date: Mon, 15 Sep 2025 21:43:13 -0400
Subject: Don’t suggest foreign `doc(hidden)` types in E0277 diagnostics
MIME-Version: 1.0
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---
 tests/ui/proc-macro/quote/not-quotable.stderr      |  4 +-
 tests/ui/suggestions/auxiliary/hidden-struct.rs    | 26 +++++++++++--
 .../suggestions/dont-suggest-foreign-doc-hidden.rs | 18 +++++++--
 .../dont-suggest-foreign-doc-hidden.stderr         | 44 +++++++++++++++++++---
 4 files changed, 78 insertions(+), 14 deletions(-)

(limited to 'tests')

diff --git a/tests/ui/proc-macro/quote/not-quotable.stderr b/tests/ui/proc-macro/quote/not-quotable.stderr
index d1c3d06f2b6..62a02638e54 100644
--- a/tests/ui/proc-macro/quote/not-quotable.stderr
+++ b/tests/ui/proc-macro/quote/not-quotable.stderr
@@ -15,8 +15,8 @@ LL |     let _ = quote! { $ip };
              Cow<'_, T>
              Option<T>
              Rc<T>
-             RepInterp<T>
-           and 25 others
+             bool
+           and 24 others
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/suggestions/auxiliary/hidden-struct.rs b/tests/ui/suggestions/auxiliary/hidden-struct.rs
index 30d69acac20..1f495a9f222 100644
--- a/tests/ui/suggestions/auxiliary/hidden-struct.rs
+++ b/tests/ui/suggestions/auxiliary/hidden-struct.rs
@@ -1,3 +1,5 @@
+// `Foo` and `Bar` should not be suggested in diagnostics of dependents
+
 #[doc(hidden)]
 pub mod hidden {
     pub struct Foo;
@@ -5,13 +7,29 @@ pub mod hidden {
 
 pub mod hidden1 {
     #[doc(hidden)]
-    pub struct Foo;
+    pub struct Bar;
 }
 
+// `Baz` and `Quux` *should* be suggested in diagnostics of dependents
 
 #[doc(hidden)]
-pub(crate) mod hidden2 {
-    pub struct Bar;
+pub mod hidden2 {
+    pub struct Baz;
+}
+
+pub use hidden2::Baz;
+
+#[doc(hidden)]
+pub(crate) mod hidden3 {
+    pub struct Quux;
 }
 
-pub use hidden2::Bar;
+pub use hidden3::Quux;
+
+pub trait Marker {}
+
+impl Marker for Option<u32> {}
+impl Marker for hidden::Foo {}
+impl Marker for hidden1::Bar {}
+impl Marker for Baz {}
+impl Marker for Quux {}
diff --git a/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.rs b/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.rs
index 281975dcc2f..a83e496f270 100644
--- a/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.rs
+++ b/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.rs
@@ -1,5 +1,4 @@
 //@ aux-build:hidden-struct.rs
-//@ compile-flags: --crate-type lib
 
 extern crate hidden_struct;
 
@@ -9,7 +8,20 @@ mod local {
 }
 
 pub fn test(_: Foo) {}
-//~^ ERROR cannot find type `Foo` in this scope
+//~^ ERROR [E0412]
 
 pub fn test2(_: Bar) {}
-//~^ ERROR cannot find type `Bar` in this scope
+//~^ ERROR [E0412]
+
+pub fn test3(_: Baz) {}
+//~^ ERROR [E0412]
+
+pub fn test4(_: Quux) {}
+//~^ ERROR [E0412]
+
+fn test5<T: hidden_struct::Marker>() {}
+
+fn main() {
+    test5::<i32>();
+    //~^ ERROR [E0277]
+}
diff --git a/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.stderr b/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.stderr
index 7fb4d95ff9b..7036708756d 100644
--- a/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.stderr
+++ b/tests/ui/suggestions/dont-suggest-foreign-doc-hidden.stderr
@@ -1,5 +1,5 @@
 error[E0412]: cannot find type `Foo` in this scope
-  --> $DIR/dont-suggest-foreign-doc-hidden.rs:11:16
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:10:16
    |
 LL | pub fn test(_: Foo) {}
    |                ^^^ not found in this scope
@@ -10,16 +10,50 @@ LL + use local::Foo;
    |
 
 error[E0412]: cannot find type `Bar` in this scope
-  --> $DIR/dont-suggest-foreign-doc-hidden.rs:14:17
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:13:17
    |
 LL | pub fn test2(_: Bar) {}
    |                 ^^^ not found in this scope
+
+error[E0412]: cannot find type `Baz` in this scope
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:16:17
+   |
+LL | pub fn test3(_: Baz) {}
+   |                 ^^^ not found in this scope
    |
 help: consider importing this struct
    |
-LL + use hidden_struct::Bar;
+LL + use hidden_struct::Baz;
+   |
+
+error[E0412]: cannot find type `Quux` in this scope
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:19:17
+   |
+LL | pub fn test4(_: Quux) {}
+   |                 ^^^^ not found in this scope
+   |
+help: consider importing this struct
+   |
+LL + use hidden_struct::Quux;
+   |
+
+error[E0277]: the trait bound `i32: Marker` is not satisfied
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:25:13
+   |
+LL |     test5::<i32>();
+   |             ^^^ the trait `Marker` is not implemented for `i32`
+   |
+   = help: the following other types implement trait `Marker`:
+             Baz
+             Option<u32>
+             Quux
+note: required by a bound in `test5`
+  --> $DIR/dont-suggest-foreign-doc-hidden.rs:22:13
    |
+LL | fn test5<T: hidden_struct::Marker>() {}
+   |             ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `test5`
 
-error: aborting due to 2 previous errors
+error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0412`.
+Some errors have detailed explanations: E0277, E0412.
+For more information about an error, try `rustc --explain E0277`.
-- 
cgit 1.4.1-3-g733a5