py: Check explicitly for memory allocation failure in parser.
Previously, a failed malloc/realloc would throw an exception, which was
not caught. I think it's better to keep the parser free from NLR
(exception throwing), hence this patch.
diff --git a/py/parse.c b/py/parse.c
index 1381f12..6c899ce 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -86,6 +86,8 @@
} rule_stack_t;
typedef struct _parser_t {
+ bool had_memory_error;
+
uint rule_stack_alloc;
uint rule_stack_top;
rule_stack_t *rule_stack;
@@ -97,9 +99,21 @@
mp_lexer_t *lexer;
} parser_t;
+STATIC inline void memory_error(parser_t *parser) {
+ parser->had_memory_error = true;
+}
+
STATIC void push_rule(parser_t *parser, int src_line, const rule_t *rule, int arg_i) {
+ if (parser->had_memory_error) {
+ return;
+ }
if (parser->rule_stack_top >= parser->rule_stack_alloc) {
- parser->rule_stack = m_renew(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc * 2);
+ rule_stack_t *rs = m_renew_maybe(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc * 2);
+ if (rs == NULL) {
+ memory_error(parser);
+ return;
+ }
+ parser->rule_stack = rs;
parser->rule_stack_alloc *= 2;
}
rule_stack_t *rs = &parser->rule_stack[parser->rule_stack_top++];
@@ -116,6 +130,7 @@
}
STATIC void pop_rule(parser_t *parser, const rule_t **rule, uint *arg_i, uint *src_line) {
+ assert(!parser->had_memory_error);
parser->rule_stack_top -= 1;
*rule = rules[parser->rule_stack[parser->rule_stack_top].rule_id];
*arg_i = parser->rule_stack[parser->rule_stack_top].arg_i;
@@ -129,15 +144,6 @@
return (mp_parse_node_t)(kind | (arg << 5));
}
-//int num_parse_nodes_allocated = 0;
-mp_parse_node_struct_t *parse_node_new_struct(int src_line, int rule_id, int num_args) {
- mp_parse_node_struct_t *pn = m_new_obj_var(mp_parse_node_struct_t, mp_parse_node_t, num_args);
- pn->source_line = src_line;
- pn->kind_num_nodes = (rule_id & 0xff) | (num_args << 8);
- //num_parse_nodes_allocated += 1;
- return pn;
-}
-
uint mp_parse_node_free(mp_parse_node_t pn) {
uint cnt = 0;
if (MP_PARSE_NODE_IS_STRUCT(pn)) {
@@ -211,18 +217,32 @@
*/
STATIC mp_parse_node_t pop_result(parser_t *parser) {
+ if (parser->had_memory_error) {
+ return MP_PARSE_NODE_NULL;
+ }
assert(parser->result_stack_top > 0);
return parser->result_stack[--parser->result_stack_top];
}
STATIC mp_parse_node_t peek_result(parser_t *parser, int pos) {
+ if (parser->had_memory_error) {
+ return MP_PARSE_NODE_NULL;
+ }
assert(parser->result_stack_top > pos);
return parser->result_stack[parser->result_stack_top - 1 - pos];
}
STATIC void push_result_node(parser_t *parser, mp_parse_node_t pn) {
+ if (parser->had_memory_error) {
+ return;
+ }
if (parser->result_stack_top >= parser->result_stack_alloc) {
- parser->result_stack = m_renew(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc * 2);
+ mp_parse_node_t *pn = m_renew_maybe(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc * 2);
+ if (pn == NULL) {
+ memory_error(parser);
+ return;
+ }
+ parser->result_stack = pn;
parser->result_stack_alloc *= 2;
}
parser->result_stack[parser->result_stack_top++] = pn;
@@ -283,7 +303,13 @@
}
STATIC void push_result_rule(parser_t *parser, int src_line, const rule_t *rule, int num_args) {
- mp_parse_node_struct_t *pn = parse_node_new_struct(src_line, rule->rule_id, num_args);
+ mp_parse_node_struct_t *pn = m_new_obj_var_maybe(mp_parse_node_struct_t, mp_parse_node_t, num_args);
+ if (pn == NULL) {
+ memory_error(parser);
+ return;
+ }
+ pn->source_line = src_line;
+ pn->kind_num_nodes = (rule->rule_id & 0xff) | (num_args << 8);
for (int i = num_args; i > 0; i--) {
pn->nodes[i - 1] = pop_result(parser);
}
@@ -296,6 +322,8 @@
parser_t *parser = m_new_obj(parser_t);
+ parser->had_memory_error = false;
+
parser->rule_stack_alloc = 64;
parser->rule_stack_top = 0;
parser->rule_stack = m_new(rule_stack_t, parser->rule_stack_alloc);
@@ -327,7 +355,7 @@
for (;;) {
next_rule:
- if (parser->rule_stack_top == 0) {
+ if (parser->rule_stack_top == 0 || parser->had_memory_error) {
break;
}
@@ -596,6 +624,16 @@
}
}
+ mp_parse_node_t result;
+
+ // check if we had a memory error
+ if (parser->had_memory_error) {
+ *parse_error_kind_out = MP_PARSE_ERROR_MEMORY;
+ result = MP_PARSE_NODE_NULL;
+ goto finished;
+
+ }
+
// check we are at the end of the token stream
if (!mp_lexer_is_kind(lex, MP_TOKEN_END)) {
goto syntax_error;
@@ -609,7 +647,7 @@
// get the root parse node that we created
assert(parser->result_stack_top == 1);
- mp_parse_node_t result = parser->result_stack[0];
+ result = parser->result_stack[0];
finished:
// free the memory that we don't need anymore