Auto merge of #143267 - matthiaskrgr:rollup-suvzar6, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang/rust#143125 (Disable f16 on Aarch64 without neon for llvm < 20.1.1)
 - rust-lang/rust#143156 (inherit `#[align]` from trait method prototypes)
 - rust-lang/rust#143178 (rustdoc default faviocon)
 - rust-lang/rust#143234 (Replace `ItemCtxt::report_placeholder_type_error` match with a call to `TyCtxt::def_descr`)
 - rust-lang/rust#143245 (mbe: Add tests and restructure metavariable expressions)
 - rust-lang/rust#143257 (Upgrade dependencies in run-make-support)
 - rust-lang/rust#143263 (linkify CodeSuggestion in doc comments)
 - rust-lang/rust#143264 (fix: Emit suggestion filename if primary diagnostic span is dummy)

Failed merges:

 - rust-lang/rust#143251 (bootstrap: add build.tidy-extra-checks option)

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

1 files changed, 65 insertions, 17 deletions

diff --git a/tests/codegen/align-fn.rs b/tests/codegen/align-fn.rs
index 267da060240..90073ff3081 100644
--- a/tests/codegen/align-fn.rs
+++ b/tests/codegen/align-fn.rs
@@ -1,10 +1,10 @@
-//@ compile-flags: -C no-prepopulate-passes -Z mir-opt-level=0
+//@ compile-flags: -C no-prepopulate-passes -Z mir-opt-level=0 -Clink-dead-code
 
 #![crate_type = "lib"]
 #![feature(fn_align)]
 
 // CHECK: align 16
-#[no_mangle]
+#[unsafe(no_mangle)]
 #[align(16)]
 pub fn fn_align() {}
 
@@ -12,12 +12,12 @@ pub struct A;
 
 impl A {
     // CHECK: align 16
-    #[no_mangle]
+    #[unsafe(no_mangle)]
     #[align(16)]
     pub fn method_align(self) {}
 
     // CHECK: align 16
-    #[no_mangle]
+    #[unsafe(no_mangle)]
     #[align(16)]
     pub fn associated_fn() {}
 }
@@ -25,46 +25,94 @@ impl A {
 trait T: Sized {
     fn trait_fn() {}
 
-    // CHECK: align 32
-    #[align(32)]
     fn trait_method(self) {}
+
+    #[align(8)]
+    fn trait_method_inherit_low(self);
+
+    #[align(32)]
+    fn trait_method_inherit_high(self);
+
+    #[align(32)]
+    fn trait_method_inherit_default(self) {}
+
+    #[align(4)]
+    #[align(128)]
+    #[align(8)]
+    fn inherit_highest(self) {}
 }
 
 impl T for A {
-    // CHECK: align 16
-    #[no_mangle]
+    // CHECK-LABEL: trait_fn
+    // CHECK-SAME: align 16
+    #[unsafe(no_mangle)]
     #[align(16)]
     fn trait_fn() {}
 
-    // CHECK: align 16
-    #[no_mangle]
+    // CHECK-LABEL: trait_method
+    // CHECK-SAME: align 16
+    #[unsafe(no_mangle)]
     #[align(16)]
     fn trait_method(self) {}
-}
 
-impl T for () {}
+    // The prototype's align is ignored because the align here is higher.
+    // CHECK-LABEL: trait_method_inherit_low
+    // CHECK-SAME: align 16
+    #[unsafe(no_mangle)]
+    #[align(16)]
+    fn trait_method_inherit_low(self) {}
+
+    // The prototype's align is used because it is higher.
+    // CHECK-LABEL: trait_method_inherit_high
+    // CHECK-SAME: align 32
+    #[unsafe(no_mangle)]
+    #[align(16)]
+    fn trait_method_inherit_high(self) {}
+
+    // The prototype's align inherited.
+    // CHECK-LABEL: trait_method_inherit_default
+    // CHECK-SAME: align 32
+    #[unsafe(no_mangle)]
+    fn trait_method_inherit_default(self) {}
+
+    // The prototype's highest align inherited.
+    // CHECK-LABEL: inherit_highest
+    // CHECK-SAME: align 128
+    #[unsafe(no_mangle)]
+    #[align(32)]
+    #[align(64)]
+    fn inherit_highest(self) {}
+}
 
-pub fn foo() {
-    ().trait_method();
+trait HasDefaultImpl: Sized {
+    // CHECK-LABEL: inherit_from_default_method
+    // CHECK-LABEL: inherit_from_default_method
+    // CHECK-SAME: align 32
+    #[align(32)]
+    fn inherit_from_default_method(self) {}
 }
 
+pub struct InstantiateDefaultMethods;
+
+impl HasDefaultImpl for InstantiateDefaultMethods {}
+
 // CHECK-LABEL: align_specified_twice_1
 // CHECK-SAME: align 64
-#[no_mangle]
+#[unsafe(no_mangle)]
 #[align(32)]
 #[align(64)]
 pub fn align_specified_twice_1() {}
 
 // CHECK-LABEL: align_specified_twice_2
 // CHECK-SAME: align 128
-#[no_mangle]
+#[unsafe(no_mangle)]
 #[align(128)]
 #[align(32)]
 pub fn align_specified_twice_2() {}
 
 // CHECK-LABEL: align_specified_twice_3
 // CHECK-SAME: align 256
-#[no_mangle]
+#[unsafe(no_mangle)]
 #[align(32)]
 #[align(256)]
 pub fn align_specified_twice_3() {}