Issue #22038: pyatomic.h now uses stdatomic.h or GCC built-in functions for
atomic memory access if available. Patch written by Vitor de Lima and Gustavo
Temple.
diff --git a/configure b/configure
index f9af72d..1ba0e94 100755
--- a/configure
+++ b/configure
@@ -15703,6 +15703,71 @@
esac
fi
+# Check for stdatomic.h
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for stdatomic.h" >&5
+$as_echo_n "checking for stdatomic.h... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+ #include <stdatomic.h>
+ _Atomic int value = ATOMIC_VAR_INIT(1);
+ int main() {
+ int loaded_value = atomic_load(&value);
+ return 0;
+ }
+
+
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ have_stdatomic_h=yes
+else
+ have_stdatomic_h=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_stdatomic_h" >&5
+$as_echo "$have_stdatomic_h" >&6; }
+
+if test "$have_stdatomic_h" = yes; then
+
+$as_echo "#define HAVE_STD_ATOMIC 1" >>confdefs.h
+
+fi
+
+# Check for GCC >= 4.7 __atomic builtins
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for GCC >= 4.7 __atomic builtins" >&5
+$as_echo_n "checking for GCC >= 4.7 __atomic builtins... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+ volatile int val = 1;
+ int main() {
+ __atomic_load_n(&val, __ATOMIC_SEQ_CST);
+ return 0;
+ }
+
+
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+ have_builtin_atomic=yes
+else
+ have_builtin_atomic=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_builtin_atomic" >&5
+$as_echo "$have_builtin_atomic" >&6; }
+
+if test "$have_builtin_atomic" = yes; then
+
+$as_echo "#define HAVE_BUILTIN_ATOMIC 1" >>confdefs.h
+
+fi
+
# ensurepip option
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ensurepip" >&5
$as_echo_n "checking for ensurepip... " >&6; }