Fix memory leaks caused by type comment parsing (#91)

gvanrossum · web-flow · commit c6d7fcbf75c7 · 2019-02-05T16:14:54.000-08:00
Echoes python/cpython#11728 (they were found by the CPython refleak detector, see https://bugs.python.org/issue35879).
diff --git a/ast3/Parser/parsetok.c b/ast3/Parser/parsetok.c
@@ -302,6 +302,7 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
         }
 
         if (type == TYPE_IGNORE) {
+            PyObject_FREE(str);
             if (!growable_int_array_add(&type_ignores, tok->lineno)) {
                 err_ret->error = E_NOMEM;
                 break;
diff --git a/ast3/Python/ast.c b/ast3/Python/ast.c
@@ -740,7 +740,12 @@ new_identifier(const char *n, struct compiling *c)
 static string
 new_type_comment(const char *s, struct compiling *c)
 {
-  return PyUnicode_DecodeUTF8(s, strlen(s), NULL);
+    PyObject *res = PyUnicode_DecodeUTF8(s, strlen(s), NULL);
+    if (PyArena_AddPyObject(c->c_arena, res) < 0) {
+        Py_DECREF(res);
+        return NULL;
+    }
+    return res;
 }
 #define NEW_TYPE_COMMENT(n) new_type_comment(STR(n), c)
 

Original file line number	Diff line number	Diff line change
`@@ -302,6 +302,7 @@ parsetok(struct tok_state tok, grammar g, int start, perrdetail *err_ret,`
`302`	`302`	`}`
`303`	`303`
`304`	`304`	`if (type == TYPE_IGNORE) {`
	`305`	`+ PyObject_FREE(str);`
`305`	`306`	`if (!growable_int_array_add(&type_ignores, tok->lineno)) {`
`306`	`307`	`err_ret->error = E_NOMEM;`
`307`	`308`	`break;`
Original file line number	Diff line number	Diff line change
`@@ -740,7 +740,12 @@ new_identifier(const char n, struct compiling c)`
`740`	`740`	`static string`
`741`	`741`	`new_type_comment(const char s, struct compiling c)`
`742`	`742`	`{`
`743`		`- return PyUnicode_DecodeUTF8(s, strlen(s), NULL);`
	`743`	`+ PyObject *res = PyUnicode_DecodeUTF8(s, strlen(s), NULL);`
	`744`	`+ if (PyArena_AddPyObject(c->c_arena, res) < 0) {`
	`745`	`+ Py_DECREF(res);`
	`746`	`+ return NULL;`
	`747`	`+ }`
	`748`	`+ return res;`
`744`	`749`	`}`
`745`	`750`	`#define NEW_TYPE_COMMENT(n) new_type_comment(STR(n), c)`
`746`	`751`