git: d378ddab7966 - stable/13 - libthr: Disable stack unwinding on ARM.

The branch stable/13 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=d378ddab79668c70d174bd20179ac4340dba3e03

commit d378ddab79668c70d174bd20179ac4340dba3e03
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2022-02-10 20:47:08 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2022-02-20 12:29:59 +0000

    libthr: Disable stack unwinding on ARM.
    
    When a thread exits, _Unwind_ForcedUnwind() is used to walk up stack
    frames executing pending cleanups pushed by pthread_cleanup_push().
    The cleanups are popped by thread_unwind_stop() which is passed as a
    callback function to _Unwind_ForcedUnwind().
    
    LLVM's libunwind uses a different function type for the callback on
    32-bit ARM relative to all other platforms.  The previous unwind.h
    header (as well as the unwind.h from libcxxrt) use the non-ARM type on
    all platforms, so this has likely been broken on 32-bit arm since it
    switched to using LLVM's libunwind.
    
    For now, just disable stack unwinding on 32-bit arm to unbreak the
    build until a proper fix is tested.
    
    (cherry picked from commit bbf4df1722060fb78939419476fb624114fb303d)
---
 lib/libthr/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/libthr/Makefile b/lib/libthr/Makefile
index fab83d98ebe0..0b550d995241 100644
--- a/lib/libthr/Makefile
+++ b/lib/libthr/Makefile
@@ -29,6 +29,10 @@ CFLAGS.thr_stack.c+=	-Wno-cast-align
 CFLAGS.rtld_malloc.c+=	-Wno-cast-align
 CFLAGS.thr_symbols.c+=	-Wno-missing-variable-declarations
 
+.if ${MACHINE_CPUARCH} == "arm"
+NO_THREAD_UNWIND_STACK= yes
+.endif
+
 .ifndef NO_THREAD_UNWIND_STACK
 CFLAGS+=-fexceptions
 CFLAGS+=-D_PTHREAD_FORCED_UNWIND