From 1abbd4cd4fa1c18c706505b71ed49cf0fda0ebee Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 24 Apr 2023 17:42:39 +0000
Subject: [PATCH 1/2] Render missing fields in tuple struct/enum as /* private
 fields */

---
 src/librustdoc/html/render/print_item.rs      | 44 +++++++++++++------
 .../const-generics/const-generic-defaults.rs  |  2 +-
 .../const-generics/const-generics-docs.rs     |  4 +-
 tests/rustdoc/issue-88600.rs                  |  4 +-
 .../rustdoc/where.SWhere_Simd_item-decl.html  |  2 +-
 tests/rustdoc/where.alpha_trait_decl.html     |  2 +-
 tests/rustdoc/where.rs                        |  2 +-
 7 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index cb78f903462..066b5d6b36c 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -1315,6 +1315,12 @@ fn print_tuple_struct_fields<'a, 'cx: 'a>(
     s: &'a [clean::Item],
 ) -> impl fmt::Display + 'a + Captures<'cx> {
     display_fn(|f| {
+        if s.iter()
+            .all(|field| matches!(*field.kind, clean::StrippedItem(box clean::StructFieldItem(..))))
+        {
+            return f.write_str("/* private fields */");
+        }
+
         for (i, ty) in s.iter().enumerate() {
             if i > 0 {
                 f.write_str(", ")?;
@@ -1936,21 +1942,31 @@ fn render_struct(
         }
         Some(CtorKind::Fn) => {
             w.write_str("(");
-            for (i, field) in fields.iter().enumerate() {
-                if i > 0 {
-                    w.write_str(", ");
-                }
-                match *field.kind {
-                    clean::StrippedItem(box clean::StructFieldItem(..)) => write!(w, "_"),
-                    clean::StructFieldItem(ref ty) => {
-                        write!(
-                            w,
-                            "{}{}",
-                            visibility_print_with_space(field.visibility(tcx), field.item_id, cx),
-                            ty.print(cx),
-                        )
+            if fields.iter().all(|field| {
+                matches!(*field.kind, clean::StrippedItem(box clean::StructFieldItem(..)))
+            }) {
+                write!(w, "/* private fields */");
+            } else {
+                for (i, field) in fields.iter().enumerate() {
+                    if i > 0 {
+                        w.write_str(", ");
+                    }
+                    match *field.kind {
+                        clean::StrippedItem(box clean::StructFieldItem(..)) => write!(w, "_"),
+                        clean::StructFieldItem(ref ty) => {
+                            write!(
+                                w,
+                                "{}{}",
+                                visibility_print_with_space(
+                                    field.visibility(tcx),
+                                    field.item_id,
+                                    cx
+                                ),
+                                ty.print(cx),
+                            )
+                        }
+                        _ => unreachable!(),
                     }
-                    _ => unreachable!(),
                 }
             }
             w.write_str(")");
diff --git a/tests/rustdoc/const-generics/const-generic-defaults.rs b/tests/rustdoc/const-generics/const-generic-defaults.rs
index f781c6a62f2..7a0a794112d 100644
--- a/tests/rustdoc/const-generics/const-generic-defaults.rs
+++ b/tests/rustdoc/const-generics/const-generic-defaults.rs
@@ -1,5 +1,5 @@
 #![crate_name = "foo"]
 
 // @has foo/struct.Foo.html '//pre[@class="rust item-decl"]' \
-//      'pub struct Foo<const M: usize = 10, const N: usize = M, T = i32>(_);'
+//      'pub struct Foo<const M: usize = 10, const N: usize = M, T = i32>('
 pub struct Foo<const M: usize = 10, const N: usize = M, T = i32>(T);
diff --git a/tests/rustdoc/const-generics/const-generics-docs.rs b/tests/rustdoc/const-generics/const-generics-docs.rs
index 828486a41d4..70a9518f05b 100644
--- a/tests/rustdoc/const-generics/const-generics-docs.rs
+++ b/tests/rustdoc/const-generics/const-generics-docs.rs
@@ -33,7 +33,7 @@ impl Trait<{1 + 2}> for u8 {}
 // @has foo/struct.Foo.html '//pre[@class="rust item-decl"]' \
 //      'pub struct Foo<const N: usize> where u8: Trait<N>'
 pub struct Foo<const N: usize> where u8: Trait<N>;
-// @has foo/struct.Bar.html '//pre[@class="rust item-decl"]' 'pub struct Bar<T, const N: usize>(_)'
+// @has foo/struct.Bar.html '//pre[@class="rust item-decl"]' 'pub struct Bar<T, const N: usize>('
 pub struct Bar<T, const N: usize>([T; N]);
 
 // @has foo/struct.Foo.html '//*[@id="impl-Foo%3CM%3E"]/h3[@class="code-header"]' 'impl<const M: usize> Foo<M>where u8: Trait<M>'
@@ -92,7 +92,7 @@ macro_rules! define_me {
 }
 
 // @has foo/struct.Foz.html '//pre[@class="rust item-decl"]' \
-//      'pub struct Foz<const N: usize>(_);'
+//      'pub struct Foz<const N: usize>(/* private fields */);'
 define_me!(Foz<N>);
 
 trait Q {
diff --git a/tests/rustdoc/issue-88600.rs b/tests/rustdoc/issue-88600.rs
index db0d102b741..f89af472f6e 100644
--- a/tests/rustdoc/issue-88600.rs
+++ b/tests/rustdoc/issue-88600.rs
@@ -8,10 +8,10 @@
 
 // @has issue_88600/enum.FooEnum.html
 pub enum FooEnum {
-    // @has - '//*[@id="variant.HiddenTupleItem"]//h3' 'HiddenTupleItem(_)'
+    // @has - '//*[@id="variant.HiddenTupleItem"]//h3' 'HiddenTupleItem(/* private fields */)'
     // @count - '//*[@id="variant.HiddenTupleItem.field.0"]' 0
     HiddenTupleItem(#[doc(hidden)] H),
-    // @has - '//*[@id="variant.MultipleHidden"]//h3' 'MultipleHidden(_, _)'
+    // @has - '//*[@id="variant.MultipleHidden"]//h3' 'MultipleHidden(/* private fields */)'
     // @count - '//*[@id="variant.MultipleHidden.field.0"]' 0
     // @count - '//*[@id="variant.MultipleHidden.field.1"]' 0
     MultipleHidden(#[doc(hidden)] H, #[doc(hidden)] H),
diff --git a/tests/rustdoc/where.SWhere_Simd_item-decl.html b/tests/rustdoc/where.SWhere_Simd_item-decl.html
index 3e72ba2b74f..46708b9e4e9 100644
--- a/tests/rustdoc/where.SWhere_Simd_item-decl.html
+++ b/tests/rustdoc/where.SWhere_Simd_item-decl.html
@@ -1,3 +1,3 @@
-<pre class="rust item-decl"><code>pub struct Simd&lt;T&gt;(_)
+<pre class="rust item-decl"><code>pub struct Simd&lt;T&gt;(/* private fields */)
 <span class="where">where
     T: <a class="trait" href="trait.MyTrait.html" title="trait foo::MyTrait">MyTrait</a></span>;</code></pre>
diff --git a/tests/rustdoc/where.alpha_trait_decl.html b/tests/rustdoc/where.alpha_trait_decl.html
index a7700055c9a..0c0b2d1ceca 100644
--- a/tests/rustdoc/where.alpha_trait_decl.html
+++ b/tests/rustdoc/where.alpha_trait_decl.html
@@ -1,3 +1,3 @@
-<code>pub struct Alpha&lt;A&gt;(_)
+<code>pub struct Alpha&lt;A&gt;(/* private fields */)
 <span class="where">where
     A: <a class="trait" href="trait.MyTrait.html" title="trait foo::MyTrait">MyTrait</a></span>;</code>
\ No newline at end of file
diff --git a/tests/rustdoc/where.rs b/tests/rustdoc/where.rs
index 2aa9c8b5461..aea02c14039 100644
--- a/tests/rustdoc/where.rs
+++ b/tests/rustdoc/where.rs
@@ -4,7 +4,7 @@
 
 pub trait MyTrait { fn dummy(&self) { } }
 
-// @has foo/struct.Alpha.html '//pre' "pub struct Alpha<A>(_) where A: MyTrait"
+// @has foo/struct.Alpha.html '//pre' "pub struct Alpha<A>(/* private fields */) where A: MyTrait"
 // @snapshot alpha_trait_decl - '//*[@class="rust item-decl"]/code'
 pub struct Alpha<A>(A) where A: MyTrait;
 // @has foo/trait.Bravo.html '//pre' "pub trait Bravo<B>where B: MyTrait"

From c4bb70f51b545d87a29bfb68898e5f4169345f8e Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Wed, 6 Sep 2023 13:26:56 +0200
Subject: [PATCH 2/2] Add regression test for private fields in tuple struct

---
 tests/rustdoc/private-fields-tuple-struct.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 tests/rustdoc/private-fields-tuple-struct.rs

diff --git a/tests/rustdoc/private-fields-tuple-struct.rs b/tests/rustdoc/private-fields-tuple-struct.rs
new file mode 100644
index 00000000000..c6989dd8cdf
--- /dev/null
+++ b/tests/rustdoc/private-fields-tuple-struct.rs
@@ -0,0 +1,15 @@
+// This test checks the diplay of "/* private fields */" sentence in tuple structs.
+#![crate_name = "foo"]
+
+// @has 'foo/struct.A.html' '//*[@class="rust item-decl"]/code' 'pub struct A(pub u8, _);'
+pub struct A(pub u8, u8);
+// @has 'foo/struct.B.html' '//*[@class="rust item-decl"]/code' 'pub struct B(_, pub u8);'
+pub struct B(u8, pub u8);
+// @has 'foo/struct.C.html' '//*[@class="rust item-decl"]/code' 'pub struct C(_, pub u8, _);'
+pub struct C(u8, pub u8, u8);
+// @has 'foo/struct.D.html' '//*[@class="rust item-decl"]/code' 'pub struct D(pub u8, _, pub u8);'
+pub struct D(pub u8, u8, pub u8);
+// @has 'foo/struct.E.html' '//*[@class="rust item-decl"]/code' 'pub struct E(/* private fields */);'
+pub struct E(u8);
+// @has 'foo/struct.F.html' '//*[@class="rust item-decl"]/code' 'pub struct F(/* private fields */);'
+pub struct F(u8, u8);