diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 8c00da6c6d..9fb695279b 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -1276,6 +1276,56 @@ DirectFunctionCall9Coll(PGFunction func, Oid collation, Datum arg1, Datum arg2,
 	return result;
 }
 
+/*
+ * These functions work like the DirectFunctionCall functions except that
+ * they use the flinfo parameter to initialise the fcinfo for the call.
+ * It's recommended that the callee only use the fn_extra and fn_mcxt
+ * fields, as other fields will typically describe the calling function
+ * not the callee.  Conversely, the calling function should not have
+ * used fn_extra, unless its use is known to be compatible with the callee's.
+ */
+
+Datum
+CallerFInfoFunctionCall1(PGFunction func, FmgrInfo *flinfo, Oid collation, Datum arg1)
+{
+	FunctionCallInfoData fcinfo;
+	Datum		result;
+
+	InitFunctionCallInfoData(fcinfo, flinfo, 1, collation, NULL, NULL);
+
+	fcinfo.arg[0] = arg1;
+	fcinfo.argnull[0] = false;
+
+	result = (*func) (&fcinfo);
+
+	/* Check for null result, since caller is clearly not expecting one */
+	if (fcinfo.isnull)
+		elog(ERROR, "function %p returned NULL", (void *) func);
+
+	return result;
+}
+
+Datum
+CallerFInfoFunctionCall2(PGFunction func, FmgrInfo *flinfo, Oid collation, Datum arg1, Datum arg2)
+{
+	FunctionCallInfoData fcinfo;
+	Datum		result;
+
+	InitFunctionCallInfoData(fcinfo, flinfo, 2, collation, NULL, NULL);
+
+	fcinfo.arg[0] = arg1;
+	fcinfo.arg[1] = arg2;
+	fcinfo.argnull[0] = false;
+	fcinfo.argnull[1] = false;
+
+	result = (*func) (&fcinfo);
+
+	/* Check for null result, since caller is clearly not expecting one */
+	if (fcinfo.isnull)
+		elog(ERROR, "function %p returned NULL", (void *) func);
+
+	return result;
+}
 
 /*
  * These are for invocation of a previously-looked-up function with a
diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 4d400d2924..0a155acee6 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -483,6 +483,19 @@ extern Datum DirectFunctionCall9Coll(PGFunction func, Oid collation,
 						Datum arg6, Datum arg7, Datum arg8,
 						Datum arg9);
 
+/*
+ * These functions work like the DirectFunctionCall functions except that
+ * they use the flinfo parameter to initialise the fcinfo for the call.
+ * It's recommended that the callee only use the fn_extra and fn_mcxt
+ * fields, as other fields will typically describe the calling function
+ * not the callee.  Conversely, the calling function should not have
+ * used fn_extra, unless its use is known to be compatible with the callee's.
+ */
+extern Datum CallerFInfoFunctionCall1(PGFunction func, FmgrInfo *flinfo,
+						 Oid collation, Datum arg1);
+extern Datum CallerFInfoFunctionCall2(PGFunction func, FmgrInfo *flinfo,
+						 Oid collation, Datum arg1, Datum arg2);
+
 /* These are for invocation of a previously-looked-up function with a
  * directly-computed parameter list.  Note that neither arguments nor result
  * are allowed to be NULL.