ENH: convert reserved field to version, set new version to 1

So that we can keep track of expansions of the PyUFuncObject.

2 files changed, 5 insertions, 3 deletions

diff --git a/numpy/core/include/numpy/ufuncobject.h b/numpy/core/include/numpy/ufuncobject.h
index a191e5766..7fe5e9f82 100644
--- a/numpy/core/include/numpy/ufuncobject.h
+++ b/numpy/core/include/numpy/ufuncobject.h
@@ -130,8 +130,8 @@ typedef struct _tagPyUFuncObject {
         /* The number of elements in 'functions' and 'data' */
         int ntypes;
 
-        /* Used to be unused field 'check_return' */
-        int reserved1;
+        /* Used to be unused field 'check_return', repurposed in 1.16 */
+        int version;
 
         /* The name of the ufunc */
         const char *name;
@@ -210,6 +210,8 @@ typedef struct _tagPyUFuncObject {
          */
         npy_uint32 iter_flags;
 
+        /* New in version 1 and above */
+
         /*
          * sizes of frozen core dimensions, or -1 if unset
          */
diff --git a/numpy/core/src/umath/ufunc_object.c b/numpy/core/src/umath/ufunc_object.c
index 47a4d876b..e7031557e 100644
--- a/numpy/core/src/umath/ufunc_object.c
+++ b/numpy/core/src/umath/ufunc_object.c
@@ -4654,7 +4654,7 @@ PyUFunc_FromFuncAndDataAndSignature(PyUFuncGenericFunction *func, void **data,
     }
     PyObject_Init((PyObject *)ufunc, &PyUFunc_Type);
 
-    ufunc->reserved1 = 0;
+    ufunc->version = 1;  /* NumPy 1.16 and up */
     ufunc->reserved2 = NULL;
 
     ufunc->nin = nin;