$as_echo "#define HAVE_AARCH64_BTI 1" >>confdefs.h
fi
+
+# Check if glibc is built with return address signing, i.e.
+# if -mbranch-protection=pac-ret is on. We need this because
+# pac-ret relies on unwinder support so it's not safe to use
+# it in assembly code unconditionally, but there is no
+# feature test macro for it in gcc.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if pac-ret is enabled" >&5
+$as_echo_n "checking if pac-ret is enabled... " >&6; }
+if ${libc_cv_aarch64_pac_ret+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c <<EOF
+int bar (void);
+int foo (void) { return bar () + 1; }
+EOF
+ libc_cv_aarch64_pac_ret=no
+ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; } \
+ && { ac_try='grep -q -E '\''(hint( | )+25|paciasp)'\'' conftest.s'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }
+ then
+ libc_cv_aarch64_pac_ret=yes
+ fi
+ rm -rf conftest.*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_aarch64_pac_ret" >&5
+$as_echo "$libc_cv_aarch64_pac_ret" >&6; }
+if test $libc_cv_aarch64_pac_ret = yes; then
+ $as_echo "#define HAVE_AARCH64_PAC_RET 1" >>confdefs.h
+
+fi
if test $libc_cv_aarch64_bti = yes; then
AC_DEFINE(HAVE_AARCH64_BTI)
fi
+
+# Check if glibc is built with return address signing, i.e.
+# if -mbranch-protection=pac-ret is on. We need this because
+# pac-ret relies on unwinder support so it's not safe to use
+# it in assembly code unconditionally, but there is no
+# feature test macro for it in gcc.
+AC_CACHE_CHECK([if pac-ret is enabled], [libc_cv_aarch64_pac_ret], [dnl
+ cat > conftest.c <<EOF
+int bar (void);
+int foo (void) { return bar () + 1; }
+EOF
+ libc_cv_aarch64_pac_ret=no
+ if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -o conftest.s conftest.c]) \
+ && AC_TRY_COMMAND([grep -q -E '\''(hint( | )+25|paciasp)'\'' conftest.s])
+ then
+ libc_cv_aarch64_pac_ret=yes
+ fi
+ rm -rf conftest.*])
+if test $libc_cv_aarch64_pac_ret = yes; then
+ AC_DEFINE(HAVE_AARCH64_PAC_RET)
+fi