1 files changed, 24 insertions, 3 deletions

diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 8a101cf..3121eb1 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -231,7 +231,9 @@ static char *GeneratorExp_fields[]={
         "generators",
 };
 static PyTypeObject *Yield_type;
+_Py_IDENTIFIER(is_from);
 static char *Yield_fields[]={
+        "is_from",
         "value",
 };
 static PyTypeObject *Compare_type;
@@ -810,7 +812,7 @@ static int init_types(void)
         GeneratorExp_type = make_type("GeneratorExp", expr_type,
                                       GeneratorExp_fields, 2);
         if (!GeneratorExp_type) return 0;
-        Yield_type = make_type("Yield", expr_type, Yield_fields, 1);
+        Yield_type = make_type("Yield", expr_type, Yield_fields, 2);
         if (!Yield_type) return 0;
         Compare_type = make_type("Compare", expr_type, Compare_fields, 3);
         if (!Compare_type) return 0;
@@ -1747,13 +1749,14 @@ GeneratorExp(expr_ty elt, asdl_seq * generators, int lineno, int col_offset,
 }
 
 expr_ty
-Yield(expr_ty value, int lineno, int col_offset, PyArena *arena)
+Yield(int is_from, expr_ty value, int lineno, int col_offset, PyArena *arena)
 {
         expr_ty p;
         p = (expr_ty)PyArena_Malloc(arena, sizeof(*p));
         if (!p)
                 return NULL;
         p->kind = Yield_kind;
+        p->v.Yield.is_from = is_from;
         p->v.Yield.value = value;
         p->lineno = lineno;
         p->col_offset = col_offset;
@@ -2795,6 +2798,11 @@ ast2obj_expr(void* _o)
         case Yield_kind:
                 result = PyType_GenericNew(Yield_type, NULL, NULL);
                 if (!result) goto failed;
+                value = ast2obj_int(o->v.Yield.is_from);
+                if (!value) goto failed;
+                if (PyObject_SetAttrString(result, "is_from", value) == -1)
+                        goto failed;
+                Py_DECREF(value);
                 value = ast2obj_expr(o->v.Yield.value);
                 if (!value) goto failed;
                 if (_PyObject_SetAttrId(result, &PyId_value, value) == -1)
@@ -5337,8 +5345,21 @@ obj2ast_expr(PyObject* obj, expr_ty* out, PyArena* arena)
                 return 1;
         }
         if (isinstance) {
+                int is_from;
                 expr_ty value;
 
+                if (_PyObject_HasAttrId(obj, &PyId_is_from)) {
+                        int res;
+                        tmp = _PyObject_GetAttrId(obj, &PyId_is_from);
+                        if (tmp == NULL) goto failed;
+                        res = obj2ast_int(tmp, &is_from, arena);
+                        if (res != 0) goto failed;
+                        Py_XDECREF(tmp);
+                        tmp = NULL;
+                } else {
+                        PyErr_SetString(PyExc_TypeError, "required field \"is_from\" missing from Yield");
+                        return 1;
+                }
                 if (_PyObject_HasAttrId(obj, &PyId_value)) {
                         int res;
                         tmp = _PyObject_GetAttrId(obj, &PyId_value);
@@ -5350,7 +5371,7 @@ obj2ast_expr(PyObject* obj, expr_ty* out, PyArena* arena)
                 } else {
                         value = NULL;
                 }
-                *out = Yield(value, lineno, col_offset, arena);
+                *out = Yield(is_from, value, lineno, col_offset, arena);
                 if (*out == NULL) goto failed;
                 return 0;
         }