rustc: Apply target features to the entry function

Link: rust-lang/rust#146144

Signed-off-by: Ilikara <[email protected]>

Author: AirFortressIlikara

lang-rust/rustc/autobuild/patches/0001-Add-i486-unknown-linux-gnu-compiler-target.patch

@@ -1,7 +1,7 @@
 From c62e1c6dcc6eeb8db7619b6e30e00657b98f5162 Mon Sep 17 00:00:00 2001
 From: Jiajie Chen <[email protected]>
 Date: Fri, 9 Feb 2024 18:48:33 -0800
-Subject: [PATCH 1/3] Add i486-unknown-linux-gnu compiler target
+Subject: [PATCH 1/4] Add i486-unknown-linux-gnu compiler target
 
 ---
  compiler/rustc_target/src/spec/mod.rs                     | 1 +

lang-rust/rustc/autobuild/patches/0002-ARCHLINUX-compiler-Swap-primary-and-secondary-lib-di.patch

@@ -1,7 +1,7 @@
 From d775cc8d435c34ad5147161c5082775bc1a0f45b Mon Sep 17 00:00:00 2001
 From: "Jan Alexander Steffens (heftig)" <[email protected]>
 Date: Thu, 7 Aug 2025 20:12:53 +0200
-Subject: [PATCH 2/3] ARCHLINUX: compiler: Swap primary and secondary lib dirs
+Subject: [PATCH 2/4] ARCHLINUX: compiler: Swap primary and secondary lib dirs
 
 Arch Linux (editor's note: also AOSC OS) prefers "lib" over "lib64".
 ---

lang-rust/rustc/autobuild/patches/0003-ARCHLINUX-bootstrap-Workaround-for-system-stage0.patch

@@ -1,7 +1,7 @@
 From 4558c3cef1db12eb171c992e12c88a53b79101ed Mon Sep 17 00:00:00 2001
 From: "Jan Alexander Steffens (heftig)" <[email protected]>
 Date: Thu, 7 Aug 2025 19:01:26 +0200
-Subject: [PATCH 3/3] ARCHLINUX: bootstrap: Workaround for system stage0
+Subject: [PATCH 3/4] ARCHLINUX: bootstrap: Workaround for system stage0
 
 See: https://github.com/rust-lang/rust/issues/143735
 ---

lang-rust/rustc/autobuild/patches/0004-compiler-Apply-target-features-to-the-entry-function.patch

@@ -0,0 +1,76 @@
+From 3f3b1288db7f4e21337ddfa107e42211dafebee0 Mon Sep 17 00:00:00 2001
+From: WANG Rui <[email protected]>
+Date: Wed, 3 Sep 2025 11:34:15 +0800
+Subject: [PATCH 4/4] compiler: Apply target features to the entry function
+
+---
+ compiler/rustc_codegen_gcc/src/context.rs     |  4 ++++
+ compiler/rustc_codegen_llvm/src/context.rs    | 10 ++++++++++
+ compiler/rustc_codegen_ssa/src/base.rs        |  1 +
+ compiler/rustc_codegen_ssa/src/traits/misc.rs |  2 ++
+ 4 files changed, 17 insertions(+)
+
+diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
+index ff141ad365..bf873cd156 100644
+--- a/compiler/rustc_codegen_gcc/src/context.rs
++++ b/compiler/rustc_codegen_gcc/src/context.rs
+@@ -489,6 +489,10 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
+         // TODO(antoyo)
+     }
+ 
++    fn apply_target_features(&self, _llfn: Function<'gcc>) {
++        // TODO(antoyo)
++    }
++
+     fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
+         let entry_name = self.sess().target.entry_name.as_ref();
+         if !self.functions.borrow().contains_key(entry_name) {
+diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
+index 0324dff6ff..029855700d 100644
+--- a/compiler/rustc_codegen_llvm/src/context.rs
++++ b/compiler/rustc_codegen_llvm/src/context.rs
+@@ -819,6 +819,16 @@ impl<'ll, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
+         attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs);
+     }
+ 
++    fn apply_target_features(&self, llfn: &'ll Value) {
++        let mut attrs = SmallVec::<[_; 2]>::new();
++        let global_features = self.tcx.global_backend_features(()).iter().map(|s| s.as_str());
++        let target_features: String = global_features.intersperse(",").collect();
++        if !target_features.is_empty() {
++            attrs.push(llvm::CreateAttrStringValue(self.llcx, "target-features", &target_features));
++        }
++        attributes::apply_to_llfn(llfn, llvm::AttributePlace::Function, &attrs);
++    }
++
+     fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
+         let entry_name = self.sess().target.entry_name.as_ref();
+         if self.get_declared_value(entry_name).is_none() {
+diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
+index a3d6c73ba8..9b1a734c6b 100644
+--- a/compiler/rustc_codegen_ssa/src/base.rs
++++ b/compiler/rustc_codegen_ssa/src/base.rs
+@@ -546,6 +546,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+         // `main` should respect same config for frame pointer elimination as rest of code
+         cx.set_frame_pointer_type(llfn);
+         cx.apply_target_cpu_attr(llfn);
++        cx.apply_target_features(llfn);
+ 
+         let llbb = Bx::append_block(cx, llfn, "top");
+         let mut bx = Bx::build(cx, llbb);
+diff --git a/compiler/rustc_codegen_ssa/src/traits/misc.rs b/compiler/rustc_codegen_ssa/src/traits/misc.rs
+index 710fab2790..24218d4ed0 100644
+--- a/compiler/rustc_codegen_ssa/src/traits/misc.rs
++++ b/compiler/rustc_codegen_ssa/src/traits/misc.rs
+@@ -23,6 +23,8 @@ pub trait MiscCodegenMethods<'tcx>: BackendTypes {
+     fn sess(&self) -> &Session;
+     fn set_frame_pointer_type(&self, llfn: Self::Function);
+     fn apply_target_cpu_attr(&self, llfn: Self::Function);
++    /// Apply global target features to a given LLVM function.
++    fn apply_target_features(&self, llfn: Self::Function);
+     /// Declares the extern "C" main function for the entry point. Returns None if the symbol
+     /// already exists.
+     fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function>;
+-- 
+2.51.0
+

lang-rust/rustc/spec

@@ -1,5 +1,5 @@
 VER=1.89.0
-REL=1
+REL=2
 # Note: Uncomment this if we have the last version built and ready.
 SRCS="tbl::https://static.rust-lang.org/dist/rustc-${VER}-src.tar.xz"
 CHKSUMS="sha256::0b9d55610d8270e06c44f459d1e2b7918a5e673809c592abed9b9c600e33d95a"