Build System: Add support for __atomic built-in operators.

Add a check to configure.ac for __atomic_fetch_add support.  If found
use the __atomic built-in operators for ast_atomic_dec_and_test and
ast_atomic_fetchadd_int.

ASTERISK~27619

Change-Id: I65b4feb02bae368904ed0fb03f585c05f50a690e

1 files changed, 29 insertions, 2 deletions

diff --git a/configure b/configure
index 867643ecb..f000c66f1 100755
--- a/configure
+++ b/configure
@@ -17893,8 +17893,8 @@ fi
 done
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for compiler atomic operations" >&5
-$as_echo_n "checking for compiler atomic operations... " >&6; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for compiler sync operations" >&5
+$as_echo_n "checking for compiler sync operations... " >&6; }
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -17920,6 +17920,33 @@ fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for compiler atomic operations" >&5
+$as_echo_n "checking for compiler atomic operations... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+int foo1; int foo2 = __atomic_fetch_add(&foo1, 1, __ATOMIC_RELAXED);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+$as_echo "#define HAVE_C_ATOMICS 1" >>confdefs.h
+
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+
 # glibc, AFAIK, is the only C library that makes printing a NULL to a string safe.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking if your system printf is NULL-safe." >&5
 $as_echo_n "checking if your system printf is NULL-safe.... " >&6; }