Auto merge of #137295 - matthiaskrgr:rollup-tdu3t39, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #135296 (interpret: adjust vtable validity check for higher-ranked types)
 - #137106 (Add customized compare for Link in rustdoc)
 - #137253 (Restrict `bevy_ecs` `ParamSet` hack)
 - #137262 (Make fewer crates depend on `rustc_ast_ir`)
 - #137263 (Register `USAGE_OF_TYPE_IR_INHERENT`, remove inherent usages)
 - #137266 (MIR visitor tweaks)
 - #137269 (Pattern Migration 2024: properly label `&` patterns whose subpatterns are from macro expansions)
 - #137277 (stabilize `inherent_str_constructors`)
 - #137281 (Tweak "expected ident" parse error to avoid talking about doc comments)

r? `@ghost`
`@rustbot` modify labels: rollup

4 files changed, 92 insertions, 1 deletions

diff --git a/src/librustdoc/html/render/sidebar.rs b/src/librustdoc/html/render/sidebar.rs
index 50c09b98db4..64dbaf9083e 100644
--- a/src/librustdoc/html/render/sidebar.rs
+++ b/src/librustdoc/html/render/sidebar.rs
@@ -1,4 +1,5 @@
 use std::borrow::Cow;
+use std::cmp::Ordering;
 
 use rinja::Template;
 use rustc_data_structures::fx::FxHashSet;
@@ -12,6 +13,7 @@ use crate::clean;
 use crate::formats::Impl;
 use crate::formats::item_type::ItemType;
 use crate::html::markdown::{IdMap, MarkdownWithToc};
+use crate::html::render::print_item::compare_names;
 
 #[derive(Clone, Copy)]
 pub(crate) enum ModuleLike {
@@ -77,7 +79,7 @@ impl<'a> LinkBlock<'a> {
 }
 
 /// A link to an item. Content should not be escaped.
-#[derive(PartialOrd, Ord, PartialEq, Eq, Hash, Clone)]
+#[derive(Ord, PartialEq, Eq, Hash, Clone)]
 pub(crate) struct Link<'a> {
     /// The content for the anchor tag and title attr
     name: Cow<'a, str>,
@@ -89,6 +91,20 @@ pub(crate) struct Link<'a> {
     children: Vec<Link<'a>>,
 }
 
+impl PartialOrd for Link<'_> {
+    fn partial_cmp(&self, other: &Link<'_>) -> Option<Ordering> {
+        match compare_names(&self.name, &other.name) {
+            Ordering::Equal => (),
+            result => return Some(result),
+        }
+        (&self.name_html, &self.href, &self.children).partial_cmp(&(
+            &other.name_html,
+            &other.href,
+            &other.children,
+        ))
+    }
+}
+
 impl<'a> Link<'a> {
     pub fn new(href: impl Into<Cow<'a, str>>, name: impl Into<Cow<'a, str>>) -> Self {
         Self { href: href.into(), name: name.into(), children: vec![], name_html: None }
diff --git a/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.rs b/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.rs
new file mode 100644
index 00000000000..7de4aef422a
--- /dev/null
+++ b/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.rs
@@ -0,0 +1,30 @@
+// Test that transmuting from `&dyn Trait<fn(&'static ())>` to `&dyn Trait<for<'a> fn(&'a ())>` is UB.
+//
+// The vtable of `() as Trait<fn(&'static ())>` and `() as Trait<for<'a> fn(&'a ())>` can have
+// different entries and, because in the former the entry for `foo` is vacant, this test will
+// segfault at runtime.
+
+trait Trait<U> {
+    fn foo(&self)
+    where
+        U: HigherRanked,
+    {
+    }
+}
+impl<T, U> Trait<U> for T {}
+
+trait HigherRanked {}
+impl HigherRanked for for<'a> fn(&'a ()) {}
+
+// 2nd candidate is required so that selecting `(): Trait<fn(&'static ())>` will
+// evaluate the candidates and fail the leak check instead of returning the
+// only applicable candidate.
+trait Unsatisfied {}
+impl<T: Unsatisfied> HigherRanked for T {}
+
+fn main() {
+    let x: &dyn Trait<fn(&'static ())> = &();
+    let y: &dyn Trait<for<'a> fn(&'a ())> = unsafe { std::mem::transmute(x) };
+    //~^ ERROR: wrong trait in wide pointer vtable
+    y.foo();
+}
diff --git a/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.stderr b/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.stderr
new file mode 100644
index 00000000000..cfdf279a605
--- /dev/null
+++ b/src/tools/miri/tests/fail/validity/dyn-transmute-inner-binder.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: constructing invalid value: wrong trait in wide pointer vtable: expected `Trait<for<'a> fn(&'a ())>`, but encountered `Trait<fn(&())>`
+  --> tests/fail/validity/dyn-transmute-inner-binder.rs:LL:CC
+   |
+LL |     let y: &dyn Trait<for<'a> fn(&'a ())> = unsafe { std::mem::transmute(x) };
+   |                                                      ^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: wrong trait in wide pointer vtable: expected `Trait<for<'a> fn(&'a ())>`, but encountered `Trait<fn(&())>`
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `main` at tests/fail/validity/dyn-transmute-inner-binder.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+
diff --git a/src/tools/miri/tests/pass/dyn-upcast.rs b/src/tools/miri/tests/pass/dyn-upcast.rs
index 6f8adc09640..875891df233 100644
--- a/src/tools/miri/tests/pass/dyn-upcast.rs
+++ b/src/tools/miri/tests/pass/dyn-upcast.rs
@@ -9,6 +9,7 @@ fn main() {
     drop_principal();
     modulo_binder();
     modulo_assoc();
+    bidirectional_subtyping();
 }
 
 fn vtable_nop_cast() {
@@ -531,3 +532,32 @@ fn modulo_assoc() {
 
     (&() as &dyn Trait as &dyn Middle<()>).say_hello(&0);
 }
+
+fn bidirectional_subtyping() {
+    // Test that transmuting between subtypes of dyn traits is fine, even in the
+    // "wrong direction", i.e. going from a lower-ranked to a higher-ranked dyn trait.
+    // Note that compared to the `dyn-transmute-inner-binder` test, the `for` is on the
+    // *outside* here!
+
+    trait Trait<U: ?Sized> {}
+    impl<T, U: ?Sized> Trait<U> for T {}
+
+    struct Wrapper<T: ?Sized>(T);
+
+    let x: &dyn Trait<fn(&'static ())> = &();
+    let _y: &dyn for<'a> Trait<fn(&'a ())> = unsafe { std::mem::transmute(x) };
+
+    let x: &dyn for<'a> Trait<fn(&'a ())> = &();
+    let _y: &dyn Trait<fn(&'static ())> = unsafe { std::mem::transmute(x) };
+
+    let x: &dyn Trait<dyn Trait<fn(&'static ())>> = &();
+    let _y: &dyn for<'a> Trait<dyn Trait<fn(&'a ())>> = unsafe { std::mem::transmute(x) };
+
+    let x: &dyn for<'a> Trait<dyn Trait<fn(&'a ())>> = &();
+    let _y: &dyn Trait<dyn Trait<fn(&'static ())>> = unsafe { std::mem::transmute(x) };
+
+    // This lowers to a ptr-to-ptr cast (which behaves like a transmute)
+    // and not an unsizing coercion:
+    let x: *const dyn for<'a> Trait<&'a ()> = &();
+    let _y: *const Wrapper<dyn Trait<&'static ()>> = x as _;
+}