From 0381f59426799b7b6a8d0a9bbe60090cc44f5e90 Mon Sep 17 00:00:00 2001
From: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Date: Mon, 6 Oct 2025 15:28:00 +0100
Subject: [PATCH] Fix issue with callsite inline attribute not being applied
 sometimes.

If the calling function had more target features enabled than the
callee than the attribute wasn't being applied as the arguments for
the check had been swapped round. Also includes target features that
are part of the global set as the warning was checking those but when
adding the attribute they were not checked.

Add a codegen-llvm test to check that the attribute is actually
applied as previously only the warning was being checked.
---
 compiler/rustc_codegen_llvm/src/builder.rs   | 10 ++++--
 tests/codegen-llvm/inline-always-callsite.rs | 37 ++++++++++++++++++++
 2 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 tests/codegen-llvm/inline-always-callsite.rs

diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 08da90d535da1..2bd3cb9442d7b 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -17,7 +17,7 @@ use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_hir::def_id::DefId;
 use rustc_middle::bug;
-use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
+use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrs, TargetFeature, TargetFeatureKind};
 use rustc_middle::ty::layout::{
     FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasTypingEnv, LayoutError, LayoutOfHelpers,
     TyAndLayout,
@@ -1428,14 +1428,18 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             // Attributes on the function definition being called
             let fn_defn_attrs = self.cx.tcx.codegen_fn_attrs(instance.def_id());
             if let Some(fn_call_attrs) = fn_call_attrs
-                && !fn_call_attrs.target_features.is_empty()
                 // If there is an inline attribute and a target feature that matches
                 // we will add the attribute to the callsite otherwise we'll omit
                 // this and not add the attribute to prevent soundness issues.
                 && let Some(inlining_rule) = attributes::inline_attr(&self.cx, self.cx.tcx, instance)
                 && self.cx.tcx.is_target_feature_call_safe(
-                    &fn_call_attrs.target_features,
                     &fn_defn_attrs.target_features,
+                    &fn_call_attrs.target_features.iter().cloned().chain(
+                        self.cx.tcx.sess.target_features.iter().map(|feat| TargetFeature {
+                            name: *feat,
+                            kind: TargetFeatureKind::Implied,
+                        })
+                    ).collect::<Vec<_>>(),
                 )
             {
                 attributes::apply_to_callsite(
diff --git a/tests/codegen-llvm/inline-always-callsite.rs b/tests/codegen-llvm/inline-always-callsite.rs
new file mode 100644
index 0000000000000..c47113e3bf3ab
--- /dev/null
+++ b/tests/codegen-llvm/inline-always-callsite.rs
@@ -0,0 +1,37 @@
+//@ add-core-stubs
+//@ compile-flags: --target aarch64-unknown-linux-gnu -Zinline-mir=no -C no-prepopulate-passes
+//@ needs-llvm-components: aarch64
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items, target_feature_inline_always)]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+#[inline(always)]
+#[target_feature(enable = "neon")]
+#[no_mangle]
+pub fn single_target_feature() -> i32 {
+    42
+}
+
+#[inline(always)]
+#[target_feature(enable = "neon,i8mm")]
+#[no_mangle]
+// CHECK: define noundef i32 @multiple_target_features() unnamed_addr #1 {
+pub fn multiple_target_features() -> i32 {
+    // CHECK: %_0 = call noundef i32 @single_target_feature() #3
+    single_target_feature()
+}
+
+#[no_mangle]
+// CHECK: define noundef i32 @inherits_from_global() unnamed_addr #2 {
+pub fn inherits_from_global() -> i32 {
+    unsafe {
+        // CHECK: %_0 = call noundef i32 @single_target_feature() #3
+        single_target_feature()
+    }
+}
+
+// CHECK: attributes #3 = { alwaysinline nounwind }