1 files changed, 66 insertions, 0 deletions

diff --git a/meta/recipes-devtools/rust/files/0001-libunwind-Use-gcs-instead-of-gcs-target-attribute.patch b/meta/recipes-devtools/rust/files/0001-libunwind-Use-gcs-instead-of-gcs-target-attribute.patch
new file mode 100644
index 0000000000..a704671fb9
--- /dev/null
+++ b/meta/recipes-devtools/rust/files/0001-libunwind-Use-gcs-instead-of-gcs-target-attribute.patch
@@ -0,0 +1,66 @@
+From e4f4094de8ddcbe6d5ff1cdf782d2b89e0563903 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Wed, 30 Apr 2025 19:51:19 -0700
+Subject: [PATCH] libunwind: Use +gcs instead of gcs target attribute
+
+__attribute__((target("gcs"))) does not work with gcc
+
+GCC-15 has added gcs intrinsics [1] but the syntax for enabling it is
+slightly different. This syntax works with clang too.
+
+With gcc15 compiler libunwind's check for this macros is succeeding and it
+ends up enabling 'gcs' by using function attribute, this works with clang
+but not with gcc but '+gcs' works with both
+
+We can see this in rust compiler bootstrap for aarch64/musl when system
+uses gcc15, it ends up with these errors
+
+Building libunwind.a for aarch64-poky-linux-musl
+cargo:warning=/mnt/b/yoe/master/sources/poky/build/tmp/work/cortexa57-poky-linux-musl/rust/1.85.1/rustc-1.85.1-src/src/llvm-project/libunwind/src/UnwindLevel1.c:191:1: error: arch extension 'gcs' should be prefixed by '+'
+cargo:warning=  191 | unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
+cargo:warning=      | ^~~~~~~~~~~~~
+cargo:warning=/mnt/b/yoe/master/sources/poky/build/tmp/work/cortexa57-poky-linux-musl/rust/1.85.1/rustc-1.85.1-src/src/llvm-project/libunwind/src/UnwindLevel1.c:337:22: error: arch extension 'gcs' should be prefixed by '+'
+cargo:warning=  337 |                      _Unwind_Stop_Fn stop, void *stop_parameter) {
+cargo:warning=      |                      ^~~~~~~~~~~~~~~
+
+[1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=5a6af707f0af
+
+Upstream-Status: Submitted [https://github.com/llvm/llvm-project/pull/138077]
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ src/llvm-project/libunwind/src/UnwindLevel1.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/src/llvm-project/libunwind/src/UnwindLevel1.c
++++ b/src/llvm-project/libunwind/src/UnwindLevel1.c
+@@ -185,7 +185,7 @@ extern int __unw_step_stage2(unw_cursor_
+ 
+ #if defined(_LIBUNWIND_USE_GCS)
+ // Enable the GCS target feature to permit gcspop instructions to be used.
+-__attribute__((target("gcs")))
++__attribute__((target("+gcs")))
+ #endif
+ static _Unwind_Reason_Code
+ unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
+@@ -329,7 +329,7 @@ unwind_phase2(unw_context_t *uc, unw_cur
+ 
+ #if defined(_LIBUNWIND_USE_GCS)
+ // Enable the GCS target feature to permit gcspop instructions to be used.
+-__attribute__((target("gcs")))
++__attribute__((target("+gcs")))
+ #endif
+ static _Unwind_Reason_Code
+ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
+--- a/src/llvm-project/libunwind/src/cet_unwind.h
++++ b/src/llvm-project/libunwind/src/cet_unwind.h
+@@ -42,7 +42,8 @@
+ #include <arm_acle.h>
+ 
+ // We can only use GCS if arm_acle.h defines the GCS intrinsics.
+-#ifdef _CHKFEAT_GCS
++// Enable gcs with clang for now, gcc does not build unwindlevel1.c correctly
++#if defined(_CHKFEAT_GCS) && defined(__clang__)
+ #define _LIBUNWIND_USE_GCS 1
+ #endif
+