py/parse: Fix handling of empty input so it raises an exception.

2 files changed, 6 insertions, 1 deletions

diff --git a/py/grammar.h b/py/grammar.h
index be12b7eb5..3f6668808 100644
--- a/py/grammar.h
+++ b/py/grammar.h
@@ -38,7 +38,7 @@
 // eval_input: testlist NEWLINE* ENDMARKER
 
 DEF_RULE(single_input, nc, or(3), tok(NEWLINE), rule(simple_stmt), rule(compound_stmt))
-DEF_RULE(file_input, nc, and(1), opt_rule(file_input_2))
+DEF_RULE(file_input, c(generic_all_nodes), and(1), opt_rule(file_input_2))
 DEF_RULE(file_input_2, c(generic_all_nodes), one_or_more, rule(file_input_3))
 DEF_RULE(file_input_3, nc, or(2), tok(NEWLINE), rule(stmt))
 DEF_RULE(eval_input, nc, and(2), rule(testlist), opt_rule(eval_input_2))
diff --git a/py/parse.c b/py/parse.c
index ad13a9030..b20fdaacd 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -720,6 +720,11 @@ memory_error:
         goto syntax_error;
     }
 
+    // check that parsing resulted in a parse node (can fail on empty input)
+    if (parser.result_stack_top == 0) {
+        goto syntax_error;
+    }
+
     //result_stack_show(parser);
     //printf("rule stack alloc: %d\n", parser.rule_stack_alloc);
     //printf("result stack alloc: %d\n", parser.result_stack_alloc);