Auto merge of #131076 - lukas-code:doc-stab2, r=notriddle

rustdoc: rewrite stability inheritance as a doc pass

Since doc inlining can almost arbitrarily change the module hierarchy, we can't just use the HIR ancestors of an item to compute its effective stability. This PR moves the stability inheritance that I implemented in https://github.com/rust-lang/rust/pull/130798 into a new doc pass `propagate-stability` that runs after doc inlining and uses the post-inlining ancestors of an item to correctly compute its effective stability.

fixes https://github.com/rust-lang/rust/issues/131020

r? `@notriddle`

1 files changed, 41 insertions, 8 deletions

diff --git a/tests/rustdoc/stability.rs b/tests/rustdoc/stability.rs
index de855b43ba5..fc72154cad8 100644
--- a/tests/rustdoc/stability.rs
+++ b/tests/rustdoc/stability.rs
@@ -25,28 +25,61 @@ pub struct ZzStable;
 
 #[unstable(feature = "unstable", issue = "none")]
 pub mod unstable {
-    //@ !hasraw stability/unstable/struct.Foo.html '//span[@class="since"]'
+    //@ !hasraw stability/unstable/struct.StableInUnstable.html \
+    //      '//span[@class="since"]'
     //@ has - '//div[@class="stab unstable"]' 'experimental'
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub struct Foo;
+    pub struct StableInUnstable;
+
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub mod stable_in_unstable {
+        //@ !hasraw stability/unstable/stable_in_unstable/struct.Inner.html \
+        //      '//span[@class="since"]'
+        //@ has - '//div[@class="stab unstable"]' 'experimental'
+        #[stable(feature = "rust1", since = "1.0.0")]
+        pub struct Inner;
+    }
 }
 
 #[stable(feature = "rust2", since = "2.2.2")]
 pub mod stable_later {
-    //@ has stability/stable_later/struct.Bar.html '//span[@class="since"]' '2.2.2'
+    //@ has stability/stable_later/struct.StableInLater.html \
+    //      '//span[@class="since"]' '2.2.2'
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub struct Bar;
+    pub struct StableInLater;
+
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub mod stable_in_later {
+        //@ has stability/stable_later/stable_in_later/struct.Inner.html \
+        //      '//span[@class="since"]' '2.2.2'
+        #[stable(feature = "rust1", since = "1.0.0")]
+        pub struct Inner;
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 pub mod stable_earlier {
-    //@ has stability/stable_earlier/struct.Foo.html '//span[@class="since"]' '1.0.0'
+    //@ has stability/stable_earlier/struct.StableInUnstable.html \
+    //      '//span[@class="since"]' '1.0.0'
+    #[doc(inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use crate::unstable::StableInUnstable;
+
+    //@ has stability/stable_earlier/stable_in_unstable/struct.Inner.html \
+    //      '//span[@class="since"]' '1.0.0'
+    #[doc(inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use crate::unstable::stable_in_unstable;
+
+    //@ has stability/stable_earlier/struct.StableInLater.html \
+    //      '//span[@class="since"]' '1.0.0'
     #[doc(inline)]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub use crate::unstable::Foo;
+    pub use crate::stable_later::StableInLater;
 
-    //@ has stability/stable_earlier/struct.Bar.html '//span[@class="since"]' '1.0.0'
+    //@ has stability/stable_earlier/stable_in_later/struct.Inner.html \
+    //      '//span[@class="since"]' '1.0.0'
     #[doc(inline)]
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub use crate::stable_later::Bar;
+    pub use crate::stable_later::stable_in_later;
 }