diff options
Diffstat (limited to 'py/parse.c')
| -rw-r--r-- | py/parse.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/py/parse.c b/py/parse.c index ae3fa8ea6..68c761734 100644 --- a/py/parse.c +++ b/py/parse.c @@ -796,9 +796,11 @@ STATIC bool fold_constants(parser_t *parser, uint8_t rule_id, size_t num_args) { #endif STATIC void push_result_rule(parser_t *parser, size_t src_line, uint8_t rule_id, size_t num_args) { - // optimise away parenthesis around an expression if possible + // Simplify and optimise certain rules, to reduce memory usage and simplify the compiler. if (rule_id == RULE_atom_paren) { - // there should be just 1 arg for this rule + // Remove parenthesis around a single expression if possible. + // This atom_paren rule always has a single argument, and after this + // optimisation that argument is either NULL or testlist_comp. mp_parse_node_t pn = peek_result(parser, 0); if (MP_PARSE_NODE_IS_NULL(pn)) { // need to keep parenthesis for () @@ -808,6 +810,34 @@ STATIC void push_result_rule(parser_t *parser, size_t src_line, uint8_t rule_id, // parenthesis around a single expression, so it's just the expression return; } + } else if (rule_id == RULE_testlist_comp) { + // The testlist_comp rule can be the sole argument to either atom_parent + // or atom_bracket, for (...) and [...] respectively. + assert(num_args == 2); + mp_parse_node_t pn = peek_result(parser, 0); + if (MP_PARSE_NODE_IS_STRUCT(pn)) { + mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn; + if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_testlist_comp_3b) { + // tuple of one item, with trailing comma + pop_result(parser); + --num_args; + } else if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_testlist_comp_3c) { + // tuple of many items, convert testlist_comp_3c to testlist_comp + pop_result(parser); + assert(pn == peek_result(parser, 0)); + pns->kind_num_nodes = rule_id | MP_PARSE_NODE_STRUCT_NUM_NODES(pns) << 8; + return; + } else if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_comp_for) { + // generator expression + } else { + // tuple with 2 items + } + } else { + // tuple with 2 items + } + } else if (rule_id == RULE_testlist_comp_3c) { + // steal first arg of outer testlist_comp rule + ++num_args; } #if MICROPY_COMP_CONST_FOLDING @@ -827,6 +857,10 @@ STATIC void push_result_rule(parser_t *parser, size_t src_line, uint8_t rule_id, for (size_t i = num_args; i > 0; i--) { pn->nodes[i - 1] = pop_result(parser); } + if (rule_id == RULE_testlist_comp_3c) { + // need to push something non-null to replace stolen first arg of testlist_comp + push_result_node(parser, (mp_parse_node_t)pn); + } push_result_node(parser, (mp_parse_node_t)pn); } |