Auto merge of #99422 - Dylan-DPC:rollup-htjofm6, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #98839 (Add assertion that `transmute_copy`'s U is not larger than T)
 - #98998 (Remove branch target prologues from `#[naked] fn`)
 - #99198 (add missing null ptr check in alloc example)
 - #99344 (rustdoc: avoid inlining items with duplicate `(type, name)`)
 - #99351 (Use `typeck_results` to get accurate qpath res for arg mismatch error)
 - #99378 (interpret/visitor: add missing early return)
 - #99394 (Add regression test for #95230)

Failed merges:

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

12 files changed, 164 insertions, 10 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index d6260b8ca06..671b40dbfe6 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -57,11 +57,43 @@ impl<'tcx> Clean<'tcx, Item> for DocModule<'tcx> {
                 .map(|(item, renamed)| clean_maybe_renamed_foreign_item(cx, item, *renamed)),
         );
         items.extend(self.mods.iter().map(|x| x.clean(cx)));
-        items.extend(
-            self.items
-                .iter()
-                .flat_map(|(item, renamed)| clean_maybe_renamed_item(cx, item, *renamed)),
-        );
+
+        // Split up imports from all other items.
+        //
+        // This covers the case where somebody does an import which should pull in an item,
+        // but there's already an item with the same namespace and same name. Rust gives
+        // priority to the not-imported one, so we should, too.
+        let mut inserted = FxHashSet::default();
+        items.extend(self.items.iter().flat_map(|(item, renamed)| {
+            // First, lower everything other than imports.
+            if matches!(item.kind, hir::ItemKind::Use(..)) {
+                return Vec::new();
+            }
+            let v = clean_maybe_renamed_item(cx, item, *renamed);
+            for item in &v {
+                if let Some(name) = item.name {
+                    inserted.insert((item.type_(), name));
+                }
+            }
+            v
+        }));
+        items.extend(self.items.iter().flat_map(|(item, renamed)| {
+            // Now we actually lower the imports, skipping everything else.
+            if !matches!(item.kind, hir::ItemKind::Use(..)) {
+                return Vec::new();
+            }
+            let mut v = clean_maybe_renamed_item(cx, item, *renamed);
+            v.drain_filter(|item| {
+                if let Some(name) = item.name {
+                    // If an item with the same type and name already exists,
+                    // it takes priority over the inlined stuff.
+                    !inserted.insert((item.type_(), name))
+                } else {
+                    false
+                }
+            });
+            v
+        }));
 
         // determine if we should display the inner contents or
         // the outer `mod` item for the source code.
diff --git a/src/test/assembly/aarch64-naked-fn-no-bti-prolog.rs b/src/test/assembly/aarch64-naked-fn-no-bti-prolog.rs
new file mode 100644
index 00000000000..79b0bb2d7ee
--- /dev/null
+++ b/src/test/assembly/aarch64-naked-fn-no-bti-prolog.rs
@@ -0,0 +1,21 @@
+// compile-flags: -C no-prepopulate-passes -Zbranch-protection=bti
+// assembly-output: emit-asm
+// needs-asm-support
+// only-aarch64
+
+#![crate_type = "lib"]
+#![feature(naked_functions)]
+use std::arch::asm;
+
+// The problem at hand: Rust has adopted a fairly strict meaning for "naked functions",
+// meaning "no prologue whatsoever, no, really, not one instruction."
+// Unfortunately, aarch64's "branch target identification" works via hints at landing sites.
+// LLVM implements this via making sure of that, even for functions with the naked attribute.
+// So, we must emit an appropriate instruction instead!
+#[no_mangle]
+#[naked]
+pub unsafe extern "C" fn _hlt() -> ! {
+    // CHECK-NOT: hint #34
+    // CHECK: hlt #0x1
+    asm!("hlt #1", options(noreturn))
+}
diff --git a/src/test/assembly/x86_64-naked-fn-no-cet-prolog.rs b/src/test/assembly/x86_64-naked-fn-no-cet-prolog.rs
new file mode 100644
index 00000000000..bedcded731d
--- /dev/null
+++ b/src/test/assembly/x86_64-naked-fn-no-cet-prolog.rs
@@ -0,0 +1,24 @@
+// compile-flags: -C no-prepopulate-passes -Zcf-protection=full
+// assembly-output: emit-asm
+// needs-asm-support
+// only-x86_64
+
+#![crate_type = "lib"]
+#![feature(naked_functions)]
+use std::arch::asm;
+
+// The problem at hand: Rust has adopted a fairly strict meaning for "naked functions",
+// meaning "no prologue whatsoever, no, really, not one instruction."
+// Unfortunately, x86's control-flow enforcement, specifically indirect branch protection,
+// works by using an instruction for each possible landing site,
+// and LLVM implements this via making sure of that.
+#[no_mangle]
+#[naked]
+pub unsafe extern "sysv64" fn will_halt() -> ! {
+    // CHECK-NOT: endbr{{32|64}}
+    // CHECK: hlt
+    asm!("hlt", options(noreturn))
+}
+
+// what about aarch64?
+// "branch-protection"=false
diff --git a/src/test/codegen/naked-noinline.rs b/src/test/codegen/naked-noinline.rs
index 13bc139ecd0..c0ac69f4ed7 100644
--- a/src/test/codegen/naked-noinline.rs
+++ b/src/test/codegen/naked-noinline.rs
@@ -28,4 +28,4 @@ pub unsafe fn g() {
     f();
 }
 
-// CHECK: attributes [[ATTR]] = { naked noinline{{.*}} }
+// CHECK: attributes [[ATTR]] = { naked{{.*}}noinline{{.*}} }
diff --git a/src/test/rustdoc/auxiliary/issue-99221-aux.rs b/src/test/rustdoc/auxiliary/issue-99221-aux.rs
new file mode 100644
index 00000000000..e061e42b29d
--- /dev/null
+++ b/src/test/rustdoc/auxiliary/issue-99221-aux.rs
@@ -0,0 +1,20 @@
+pub struct Option;
+impl Option {
+    pub fn unwrap(self) {}
+}
+
+mod macros {
+    use crate::Option;
+    /// [`Option::unwrap`]
+    #[macro_export]
+    macro_rules! print {
+        () => ()
+    }
+}
+
+mod structs {
+    use crate::Option;
+    /// [`Option::unwrap`]
+    pub struct Print;
+}
+pub use structs::Print;
diff --git a/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name-submodule.rs b/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name-submodule.rs
new file mode 100644
index 00000000000..e74881d387d
--- /dev/null
+++ b/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name-submodule.rs
@@ -0,0 +1,19 @@
+// aux-build:issue-99221-aux.rs
+// build-aux-docs
+// ignore-cross-compile
+
+#![crate_name = "foo"]
+
+#[macro_use]
+extern crate issue_99221_aux;
+
+pub use issue_99221_aux::*;
+
+// @count foo/index.html '//a[@class="macro"]' 1
+
+mod inner {
+    #[macro_export]
+    macro_rules! print {
+        () => ()
+    }
+}
diff --git a/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name.rs b/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name.rs
new file mode 100644
index 00000000000..46d59654b99
--- /dev/null
+++ b/src/test/rustdoc/issue-99221-multiple-macro-rules-w-same-name.rs
@@ -0,0 +1,17 @@
+// aux-build:issue-99221-aux.rs
+// build-aux-docs
+// ignore-cross-compile
+
+#![crate_name = "foo"]
+
+#[macro_use]
+extern crate issue_99221_aux;
+
+pub use issue_99221_aux::*;
+
+// @count foo/index.html '//a[@class="macro"]' 1
+
+#[macro_export]
+macro_rules! print {
+    () => ()
+}
diff --git a/src/test/rustdoc/issue-99221-multiple-structs-w-same-name.rs b/src/test/rustdoc/issue-99221-multiple-structs-w-same-name.rs
new file mode 100644
index 00000000000..41e64726a32
--- /dev/null
+++ b/src/test/rustdoc/issue-99221-multiple-structs-w-same-name.rs
@@ -0,0 +1,14 @@
+// aux-build:issue-99221-aux.rs
+// build-aux-docs
+// ignore-cross-compile
+
+#![crate_name = "foo"]
+
+#[macro_use]
+extern crate issue_99221_aux;
+
+pub use issue_99221_aux::*;
+
+// @count foo/index.html '//a[@class="struct"][@title="foo::Print struct"]' 1
+
+pub struct Print;
diff --git a/src/test/ui/hrtb/issue-95230.rs b/src/test/ui/hrtb/issue-95230.rs
new file mode 100644
index 00000000000..92c506eabb7
--- /dev/null
+++ b/src/test/ui/hrtb/issue-95230.rs
@@ -0,0 +1,7 @@
+// check-pass
+
+pub struct Bar
+where
+    for<'a> &'a mut Self:;
+
+fn main() {}
diff --git a/src/test/ui/type-alias-enum-variants/enum-variant-generic-args.stderr b/src/test/ui/type-alias-enum-variants/enum-variant-generic-args.stderr
index 5467f61bee4..a922d7a5e41 100644
--- a/src/test/ui/type-alias-enum-variants/enum-variant-generic-args.stderr
+++ b/src/test/ui/type-alias-enum-variants/enum-variant-generic-args.stderr
@@ -7,7 +7,7 @@ LL |     fn ts_variant() {
 LL |         Self::TSVariant(());
    |         --------------- ^^ expected type parameter `T`, found `()`
    |         |
-   |         arguments to this function are incorrect
+   |         arguments to this enum variant are incorrect
    |
    = note: expected type parameter `T`
                    found unit type `()`
@@ -55,7 +55,7 @@ LL | impl<T> Enum<T> {
 LL |         Self::<()>::TSVariant(());
    |         --------------------- ^^ expected type parameter `T`, found `()`
    |         |
-   |         arguments to this function are incorrect
+   |         arguments to this enum variant are incorrect
    |
    = note: expected type parameter `T`
                    found unit type `()`
diff --git a/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.rs b/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.rs
index d012687533b..3a8712f2ae5 100644
--- a/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.rs
+++ b/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.rs
@@ -18,6 +18,6 @@ impl E2 {
 }
 
 fn main() {
-    <E>::V(); //~ ERROR this function takes 1 argument but 0 arguments were supplied
+    <E>::V(); //~ ERROR this enum variant takes 1 argument but 0 arguments were supplied
     let _: u8 = <E2>::V; //~ ERROR mismatched types
 }
diff --git a/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.stderr b/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.stderr
index 6ae2aa1dc77..006253f8432 100644
--- a/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.stderr
+++ b/src/test/ui/type-alias-enum-variants/enum-variant-priority-higher-than-other-inherent.stderr
@@ -1,4 +1,4 @@
-error[E0061]: this function takes 1 argument but 0 arguments were supplied
+error[E0061]: this enum variant takes 1 argument but 0 arguments were supplied
   --> $DIR/enum-variant-priority-higher-than-other-inherent.rs:21:5
    |
 LL |     <E>::V();