In jsonb_plpython.c, suppress warning message from gcc 10.

tglsfdc · tglsfdc · commit a06921816370 · 2020-01-30T18:26:12.000-05:00
Very recent gcc complains that PLyObject_ToJsonbValue could return a pointer to a local variable. I think it's wrong; but the coding is fragile enough, and the savings of one palloc() minimal enough, that it seems better to just do a palloc() all the time. (My other idea of tweaking the if-condition doesn't suppress the warning.) Back-patch to v11 where this code was introduced. Discussion: https://postgr.es/m/21547.1580170366@sss.pgh.pa.us
diff --git a/contrib/jsonb_plpython/jsonb_plpython.c b/contrib/jsonb_plpython/jsonb_plpython.c
@@ -410,7 +410,6 @@ PLyNumber_ToJsonbValue(PyObject *obj, JsonbValue *jbvNum)
 static JsonbValue *
 PLyObject_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state, bool is_elem)
 {
-	JsonbValue	buf;
 	JsonbValue *out;
 
 	if (!(PyString_Check(obj) || PyUnicode_Check(obj)))
@@ -421,11 +420,7 @@ PLyObject_ToJsonbValue(PyObject *obj, JsonbParseState **jsonb_state, bool is_ele
 			return PLyMapping_ToJsonbValue(obj, jsonb_state);
 	}
 
-	/* Allocate JsonbValue in heap only if it is raw scalar value. */
-	if (*jsonb_state)
-		out = &buf;
-	else
-		out = palloc(sizeof(JsonbValue));
+	out = palloc(sizeof(JsonbValue));
 
 	if (obj == Py_None)
 		out->type = jbvNull;
