/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2013-2017 Damien P. George * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include #include #include #include // for ssize_t #include #include #include "py/lexer.h" #include "py/parse.h" #include "py/parsenum.h" #include "py/runtime.h" #include "py/objint.h" #include "py/objstr.h" #include "py/builtin.h" #if MICROPY_ENABLE_COMPILER #define RULE_ACT_ARG_MASK (0x0f) #define RULE_ACT_KIND_MASK (0x30) #define RULE_ACT_ALLOW_IDENT (0x40) #define RULE_ACT_ADD_BLANK (0x80) #define RULE_ACT_OR (0x10) #define RULE_ACT_AND (0x20) #define RULE_ACT_LIST (0x30) #define RULE_ARG_KIND_MASK (0xf000) #define RULE_ARG_ARG_MASK (0x0fff) #define RULE_ARG_TOK (0x1000) #define RULE_ARG_RULE (0x2000) #define RULE_ARG_OPT_RULE (0x3000) // *FORMAT-OFF* enum { // define rules with a compile function #define DEF_RULE(rule, comp, kind, ...) RULE_##rule, #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC RULE_const_object, // special node for a constant, generic Python object // define rules without a compile function #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) RULE_##rule, #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC }; // Define an array of actions corresponding to each rule static const uint8_t rule_act_table[] = { #define or(n) (RULE_ACT_OR | n) #define and(n) (RULE_ACT_AND | n) #define and_ident(n) (RULE_ACT_AND | n | RULE_ACT_ALLOW_IDENT) #define and_blank(n) (RULE_ACT_AND | n | RULE_ACT_ADD_BLANK) #define one_or_more (RULE_ACT_LIST | 2) #define list (RULE_ACT_LIST | 1) #define list_with_end (RULE_ACT_LIST | 3) #define DEF_RULE(rule, comp, kind, ...) kind, #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC 0, // RULE_const_object #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) kind, #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC #undef or #undef and #undef and_ident #undef and_blank #undef one_or_more #undef list #undef list_with_end }; // Define the argument data for each rule, as a combined array static const uint16_t rule_arg_combined_table[] = { #define tok(t) (RULE_ARG_TOK | MP_TOKEN_##t) #define rule(r) (RULE_ARG_RULE | RULE_##r) #define opt_rule(r) (RULE_ARG_OPT_RULE | RULE_##r) #define DEF_RULE(rule, comp, kind, ...) __VA_ARGS__, #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) __VA_ARGS__, #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC #undef tok #undef rule #undef opt_rule }; // Macro to create a list of N identifiers where N is the number of variable arguments to the macro #define RULE_EXPAND(x) x #define RULE_PADDING(rule, ...) RULE_PADDING2(rule, __VA_ARGS__, RULE_PADDING_IDS(rule)) #define RULE_PADDING2(rule, ...) RULE_EXPAND(RULE_PADDING3(rule, __VA_ARGS__)) #define RULE_PADDING3(rule, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, ...) __VA_ARGS__ #define RULE_PADDING_IDS(r) PAD13_##r, PAD12_##r, PAD11_##r, PAD10_##r, PAD9_##r, PAD8_##r, PAD7_##r, PAD6_##r, PAD5_##r, PAD4_##r, PAD3_##r, PAD2_##r, PAD1_##r, // Use an enum to create constants specifying how much room a rule takes in rule_arg_combined_table enum { #define DEF_RULE(rule, comp, kind, ...) RULE_PADDING(rule, __VA_ARGS__) #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) RULE_PADDING(rule, __VA_ARGS__) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC }; // Macro to compute the start of a rule in rule_arg_combined_table #define RULE_ARG_OFFSET(rule, ...) RULE_ARG_OFFSET2(rule, __VA_ARGS__, RULE_ARG_OFFSET_IDS(rule)) #define RULE_ARG_OFFSET2(rule, ...) RULE_EXPAND(RULE_ARG_OFFSET3(rule, __VA_ARGS__)) #define RULE_ARG_OFFSET3(rule, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, ...) _14 #define RULE_ARG_OFFSET_IDS(r) PAD13_##r, PAD12_##r, PAD11_##r, PAD10_##r, PAD9_##r, PAD8_##r, PAD7_##r, PAD6_##r, PAD5_##r, PAD4_##r, PAD3_##r, PAD2_##r, PAD1_##r, PAD0_##r, // Use the above enum values to create a table of offsets for each rule's arg // data, which indexes rule_arg_combined_table. The offsets require 9 bits of // storage but only the lower 8 bits are stored here. The 9th bit is computed // in get_rule_arg using the FIRST_RULE_WITH_OFFSET_ABOVE_255 constant. static const uint8_t rule_arg_offset_table[] = { #define DEF_RULE(rule, comp, kind, ...) RULE_ARG_OFFSET(rule, __VA_ARGS__) & 0xff, #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC 0, // RULE_const_object #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) RULE_ARG_OFFSET(rule, __VA_ARGS__) & 0xff, #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC }; // Define a constant that's used to determine the 9th bit of the values in rule_arg_offset_table static const size_t FIRST_RULE_WITH_OFFSET_ABOVE_255 = #define DEF_RULE(rule, comp, kind, ...) RULE_ARG_OFFSET(rule, __VA_ARGS__) >= 0x100 ? RULE_##rule : #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) RULE_ARG_OFFSET(rule, __VA_ARGS__) >= 0x100 ? RULE_##rule : #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC 0; #if MICROPY_DEBUG_PARSE_RULE_NAME // Define an array of rule names corresponding to each rule static const char *const rule_name_table[] = { #define DEF_RULE(rule, comp, kind, ...) #rule, #define DEF_RULE_NC(rule, kind, ...) #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC "", // RULE_const_object #define DEF_RULE(rule, comp, kind, ...) #define DEF_RULE_NC(rule, kind, ...) #rule, #include "py/grammar.h" #undef DEF_RULE #undef DEF_RULE_NC }; #endif // *FORMAT-ON* typedef struct _rule_stack_t { size_t src_line : (8 * sizeof(size_t) - 8); // maximum bits storing source line number size_t rule_id : 8; // this must be large enough to fit largest rule number size_t arg_i; // this dictates the maximum nodes in a "list" of things } rule_stack_t; typedef struct _mp_parse_chunk_t { size_t alloc; union { size_t used; struct _mp_parse_chunk_t *next; } union_; byte data[]; } mp_parse_chunk_t; typedef struct _parser_t { size_t rule_stack_alloc; size_t rule_stack_top; rule_stack_t *rule_stack; size_t result_stack_alloc; size_t result_stack_top; mp_parse_node_t *result_stack; mp_lexer_t *lexer; mp_parse_tree_t tree; mp_parse_chunk_t *cur_chunk; #if MICROPY_COMP_CONST mp_map_t consts; #endif } parser_t; static void push_result_rule(parser_t *parser, size_t src_line, uint8_t rule_id, size_t num_args); static const uint16_t *get_rule_arg(uint8_t r_id) { size_t off = rule_arg_offset_table[r_id]; if (r_id >= FIRST_RULE_WITH_OFFSET_ABOVE_255) { off |= 0x100; } return &rule_arg_combined_table[off]; } static void *parser_alloc(parser_t *parser, size_t num_bytes) { // use a custom memory allocator to store parse nodes sequentially in large chunks mp_parse_chunk_t *chunk = parser->cur_chunk; if (chunk != NULL && chunk->union_.used + num_bytes > chunk->alloc) { // not enough room at end of previously allocated chunk so try to grow mp_parse_chunk_t *new_data = (mp_parse_chunk_t *)m_renew_maybe(byte, chunk, sizeof(mp_parse_chunk_t) + chunk->alloc, sizeof(mp_parse_chunk_t) + chunk->alloc + num_bytes, false); if (new_data == NULL) { // could not grow existing memory; shrink it to fit previous (void)m_renew_maybe(byte, chunk, sizeof(mp_parse_chunk_t) + chunk->alloc, sizeof(mp_parse_chunk_t) + chunk->union_.used, false); chunk->alloc = chunk->union_.used; chunk->union_.next = parser->tree.chunk; parser->tree.chunk = chunk; chunk = NULL; } else { // could grow existing memory chunk->alloc += num_bytes; } } if (chunk == NULL) { // no previous chunk, allocate a new chunk size_t alloc = MICROPY_ALLOC_PARSE_CHUNK_INIT; if (alloc < num_bytes) { alloc = num_bytes; } chunk = (mp_parse_chunk_t *)m_new(byte, sizeof(mp_parse_chunk_t) + alloc); chunk->alloc = alloc; chunk->union_.used = 0; parser->cur_chunk = chunk; } byte *ret = chunk->data + chunk->union_.used; chunk->union_.used += num_bytes; return ret; } #if MICROPY_COMP_CONST_TUPLE static void parser_free_parse_node_struct(parser_t *parser, mp_parse_node_struct_t *pns) { mp_parse_chunk_t *chunk = parser->cur_chunk; if (chunk->data <= (byte *)pns && (byte *)pns < chunk->data + chunk->union_.used) { size_t num_bytes = sizeof(mp_parse_node_struct_t) + sizeof(mp_parse_node_t) * MP_PARSE_NODE_STRUCT_NUM_NODES(pns); chunk->union_.used -= num_bytes; } } #endif static void push_rule(parser_t *parser, size_t src_line, uint8_t rule_id, size_t arg_i) { if (parser->rule_stack_top >= parser->rule_stack_alloc) { rule_stack_t *rs = m_renew(rule_stack_t, parser->rule_stack, parser->rule_stack_alloc, parser->rule_stack_alloc + MICROPY_ALLOC_PARSE_RULE_INC); parser->rule_stack = rs; parser->rule_stack_alloc += MICROPY_ALLOC_PARSE_RULE_INC; } rule_stack_t *rs = &parser->rule_stack[parser->rule_stack_top++]; rs->src_line = src_line; rs->rule_id = rule_id; rs->arg_i = arg_i; } static void push_rule_from_arg(parser_t *parser, size_t arg) { assert((arg & RULE_ARG_KIND_MASK) == RULE_ARG_RULE || (arg & RULE_ARG_KIND_MASK) == RULE_ARG_OPT_RULE); size_t rule_id = arg & RULE_ARG_ARG_MASK; push_rule(parser, parser->lexer->tok_line, rule_id, 0); } static uint8_t pop_rule(parser_t *parser, size_t *arg_i, size_t *src_line) { parser->rule_stack_top -= 1; uint8_t rule_id = parser->rule_stack[parser->rule_stack_top].rule_id; *arg_i = parser->rule_stack[parser->rule_stack_top].arg_i; *src_line = parser->rule_stack[parser->rule_stack_top].src_line; return rule_id; } #if MICROPY_COMP_CONST_TUPLE static uint8_t peek_rule(parser_t *parser, size_t n) { assert(parser->rule_stack_top > n); return parser->rule_stack[parser->rule_stack_top - 1 - n].rule_id; } #endif bool mp_parse_node_get_int_maybe(mp_parse_node_t pn, mp_obj_t *o) { if (MP_PARSE_NODE_IS_SMALL_INT(pn)) { *o = MP_OBJ_NEW_SMALL_INT(MP_PARSE_NODE_LEAF_SMALL_INT(pn)); return true; } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_const_object)) { mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn; *o = mp_parse_node_extract_const_object(pns); return mp_obj_is_int(*o); } else { return false; } } #if MICROPY_COMP_CONST_TUPLE || MICROPY_COMP_CONST static bool mp_parse_node_is_const(mp_parse_node_t pn) { if (MP_PARSE_NODE_IS_SMALL_INT(pn)) { // Small integer. return true; } else if (MP_PARSE_NODE_IS_LEAF(pn)) { // Possible str, or constant literal. uintptr_t kind = MP_PARSE_NODE_LEAF_KIND(pn); if (kind == MP_PARSE_NODE_STRING) { return true; } else if (kind == MP_PARSE_NODE_TOKEN) { uintptr_t arg = MP_PARSE_NODE_LEAF_ARG(pn); return arg == MP_TOKEN_KW_NONE || arg == MP_TOKEN_KW_FALSE || arg == MP_TOKEN_KW_TRUE || arg == MP_TOKEN_ELLIPSIS; } } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_const_object)) { // Constant object. return true; } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_atom_paren)) { // Possible empty tuple. mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn; return MP_PARSE_NODE_IS_NULL(pns->nodes[0]); } return false; } static mp_obj_t mp_parse_node_convert_to_obj(mp_parse_node_t pn) { assert(mp_parse_node_is_const(pn)); if (MP_PARSE_NODE_IS_SMALL_INT(pn)) { mp_int_t arg = MP_PARSE_NODE_LEAF_SMALL_INT(pn); #if MICROPY_DYNAMIC_COMPILER mp_uint_t sign_mask = -((mp_uint_t)1 << (mp_dynamic_compiler.small_int_bits - 1)); if (!((arg & sign_mask) == 0 || (arg & sign_mask) == sign_mask)) { // Integer doesn't fit in a small-int, so create a multi-precision int object. return mp_obj_new_int_from_ll(arg); } #endif return MP_OBJ_NEW_SMALL_INT(arg); } else if (MP_PARSE_NODE_IS_LEAF(pn)) { uintptr_t kind = MP_PARSE_NODE_LEAF_KIND(pn); uintptr_t arg = MP_PARSE_NODE_LEAF_ARG(pn); if (kind == MP_PARSE_NODE_STRING) { return MP_OBJ_NEW_QSTR(arg); } else { assert(MP_PARSE_NODE_LEAF_KIND(pn) == MP_PARSE_NODE_TOKEN); switch (arg) { case MP_TOKEN_KW_NONE: return mp_const_none; case MP_TOKEN_KW_FALSE: return mp_const_false; case MP_TOKEN_KW_TRUE: return mp_const_true; default: assert(arg == MP_TOKEN_ELLIPSIS); return MP_OBJ_FROM_PTR(&mp_const_ellipsis_obj); } } } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_const_object)) { mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn; return mp_parse_node_extract_const_object(pns); } else { assert(MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_atom_paren)); assert(MP_PARSE_NODE_IS_NULL(((mp_parse_node_struct_t *)pn)->nodes[0])); return mp_const_empty_tuple; } } #endif static bool parse_node_is_const_bool(mp_parse_node_t pn, bool value) { // Returns true if 'pn' is a constant whose boolean value is equivalent to 'value' #if MICROPY_COMP_CONST_TUPLE || MICROPY_COMP_CONST return mp_parse_node_is_const(pn) && mp_obj_is_true(mp_parse_node_convert_to_obj(pn)) == value; #else return MP_PARSE_NODE_IS_TOKEN_KIND(pn, value ? MP_TOKEN_KW_TRUE : MP_TOKEN_KW_FALSE) || (MP_PARSE_NODE_IS_SMALL_INT(pn) && !!MP_PARSE_NODE_LEAF_SMALL_INT(pn) == value); #endif } bool mp_parse_node_is_const_false(mp_parse_node_t pn) { return parse_node_is_const_bool(pn, false); } bool mp_parse_node_is_const_true(mp_parse_node_t pn) { return parse_node_is_const_bool(pn, true); } size_t mp_parse_node_extract_list(mp_parse_node_t *pn, size_t pn_kind, mp_parse_node_t **nodes) { if (MP_PARSE_NODE_IS_NULL(*pn)) { *nodes = NULL; return 0; } else if (MP_PARSE_NODE_IS_LEAF(*pn)) { *nodes = pn; return 1; } else { mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)(*pn); if (MP_PARSE_NODE_STRUCT_KIND(pns) != pn_kind) { *nodes = pn; return 1; } else { *nodes = pns->nodes; return MP_PARSE_NODE_STRUCT_NUM_NODES(pns); } } } #if MICROPY_DEBUG_PRINTERS void mp_parse_node_print(const mp_print_t *print, mp_parse_node_t pn, size_t indent) { if (MP_PARSE_NODE_IS_STRUCT(pn)) { mp_printf(print, "[% 4d] ", (int)((mp_parse_node_struct_t *)pn)->source_line); } else { mp_printf(print, " "); } for (size_t i = 0; i < indent; i++) { mp_printf(print, " "); } if (MP_PARSE_NODE_IS_NULL(pn)) { mp_printf(print, "NULL\n"); } else if (MP_PARSE_NODE_IS_SMALL_INT(pn)) { mp_int_t arg = MP_PARSE_NODE_LEAF_SMALL_INT(pn); mp_printf(print, "int(" INT_FMT ")\n", arg); } else if (MP_PARSE_NODE_IS_LEAF(pn)) { uintptr_t arg = MP_PARSE_NODE_LEAF_ARG(pn); switch (MP_PARSE_NODE_LEAF_KIND(pn)) { case MP_PARSE_NODE_ID: mp_printf(print, "id(%s)\n", qstr_str(arg)); break; case MP_PARSE_NODE_STRING: mp_printf(print, "str(%s)\n", qstr_str(arg)); break; default: assert(MP_PARSE_NODE_LEAF_KIND(pn) == MP_PARSE_NODE_TOKEN); mp_printf(print, "tok(%u)\n", (uint)arg); break; } } else { // node must be a mp_parse_node_struct_t mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn; if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_const_object) { mp_obj_t obj = mp_parse_node_extract_const_object(pns); #if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D mp_printf(print, "literal const(%016llx)=", obj); #else mp_printf(print, "literal const(%p)=", obj); #endif mp_obj_print_helper(print, obj, PRINT_REPR); mp_printf(print, "\n"); } else { size_t n = MP_PARSE_NODE_STRUCT_NUM_NODES(pns); #if MICROPY_DEBUG_PARSE_RULE_NAME mp_printf(print, "%s(%u) (n=%u)\n", rule_name_table[MP_PARSE_NODE_STRUCT_KIND(pns)], (uint)MP_PARSE_NODE_STRUCT_KIND(pns), (uint)n); #else mp_printf(print, "rule(%u) (n=%u)\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns), (uint)n); #endif for (size_t i = 0; i < n; i++) { mp_parse_node_print(print, pns->nodes[i], indent + 2); } } } } #endif // MICROPY_DEBUG_PRINTERS /* static void result_stack_show(const mp_print_t *print, parser_t *parser) { mp_printf(print, "result stack, most recent first\n"); for (ssize_t i = parser->result_stack_top - 1; i >= 0; i--) { mp_parse_node_print(print, parser->result_stack[i], 0); } } */ static mp_parse_node_t pop_result(parser_t *parser) { assert(parser->result_stack_top > 0); return parser->result_stack[--parser->result_stack_top]; } static mp_parse_node_t peek_result(parser_t *parser, size_t pos) { 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->result_stack_top >= parser->result_stack_alloc) { mp_parse_node_t *stack = m_renew(mp_parse_node_t, parser->result_stack, parser->result_stack_alloc, parser->result_stack_alloc + MICROPY_ALLOC_PARSE_RESULT_INC); parser->result_stack = stack; parser->result_stack_alloc += MICROPY_ALLOC_PARSE_RESULT_INC; } parser->result_stack[parser->result_stack_top++] = pn; } static mp_parse_node_t make_node_const_object(parser_t *parser, size_t src_line, mp_obj_t obj) { mp_parse_node_struct_t *pn = parser_alloc(parser, sizeof(mp_parse_node_struct_t) + sizeof(mp_obj_t)); pn->source_line = src_line; #if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D // nodes are 32-bit pointers, but need to store 64-bit object pn->kind_num_nodes = RULE_const_object | (2 << 8); pn->nodes[0] = (uint64_t)obj; pn->nodes[1] = (uint64_t)obj >> 32; #else pn->kind_num_nodes = RULE_const_object | (1 << 8); pn->nodes[0] = (uintptr_t)obj; #endif return (mp_parse_node_t)pn; } // Create a parse node representing a constant object, possibly optimising the case of // an integer, by putting the (small) integer value directly in the parse node itself. static mp_parse_node_t make_node_const_object_optimised(parser_t *parser, size_t src_line, mp_obj_t obj) { if (mp_obj_is_small_int(obj)) { mp_int_t val = MP_OBJ_SMALL_INT_VALUE(obj); #if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_D // A parse node is only 32-bits and the small-int value must fit in 31-bits if (((val ^ (val << 1)) & 0xffffffff80000000) != 0) { return make_node_const_object(parser, src_line, obj); } #endif #if MICROPY_DYNAMIC_COMPILER // Check that the integer value fits in target runtime's small-int mp_uint_t sign_mask = -((mp_uint_t)1 << (mp_dynamic_compiler.small_int_bits - 1)); if (!((val & sign_mask) == 0 || (val & sign_mask) == sign_mask)) { return make_node_const_object(parser, src_line, obj); } #endif return mp_parse_node_new_small_int(val); } else { return make_node_const_object(parser, src_line, obj); } } static void push_result_token(parser_t *parser, uint8_t rule_id) { mp_parse_node_t pn; mp_lexer_t *lex = parser->lexer; if (lex->tok_kind == MP_TOKEN_NAME) { qstr id = qstr_from_strn(lex->vstr.buf, lex->vstr.len); #if MICROPY_COMP_CONST // if name is a standalone identifier, look it up in the table of dynamic constants mp_map_elem_t *elem; if (rule_id == RULE_atom && (elem = mp_map_lookup(&parser->consts, MP_OBJ_NEW_QSTR(id), MP_MAP_LOOKUP)) != NULL) { pn = make_node_const_object_optimised(parser, lex->tok_line, elem->value); } else { pn = mp_parse_node_new_leaf(MP_PARSE_NODE_ID, id); } #else (void)rule_id; pn = mp_parse_node_new_leaf(MP_PARSE_NODE_ID, id); #endif } else if (lex->tok_kind == MP_TOKEN_INTEGER) { mp_obj_t o = mp_parse_num_integer(lex->vstr.buf, lex->vstr.len, 0, lex); pn = make_node_const_object_optimised(parser, lex->tok_line, o); } else if (lex->tok_kind == MP_TOKEN_FLOAT_OR_IMAG) { mp_obj_t o = mp_parse_num_float(lex->vstr.buf, lex->vstr.len, true, lex); pn = make_node_const_object(parser, lex->tok_line, o); } else if (lex->tok_kind == MP_TOKEN_STRING) { // Don't automatically intern all strings. Doc strings (which are usually large) // will be discarded by the compiler, and so we shouldn't intern them. qstr qst = MP_QSTRnull; if (lex->vstr.len <= MICROPY_ALLOC_PARSE_INTERN_STRING_LEN) { // intern short strings qst = qstr_from_strn(lex->vstr.buf, lex->vstr.len); } else { // check if this string is already interned qst = qstr_find_strn(lex->vstr.buf, lex->vstr.len); } if (qst != MP_QSTRnull) { // qstr exists, make a leaf node pn = mp_parse_node_new_leaf(MP_PARSE_NODE_STRING, qst); } else { // not interned, make a node holding a pointer to the string object mp_obj_t o = mp_obj_new_str_copy(&mp_type_str, (const byte *)lex->vstr.buf, lex->vstr.len); pn = make_node_const_object(parser, lex->tok_line, o); } } else if (lex->tok_kind == MP_TOKEN_BYTES) { // make a node holding a pointer to the bytes object mp_obj_t o = mp_obj_new_bytes((const byte *)lex->vstr.buf, lex->vstr.len); pn = make_node_const_object(parser, lex->tok_line, o); } else { pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, lex->tok_kind); } push_result_node(parser, pn); } #if MICROPY_COMP_CONST_FOLDING #if MICROPY_COMP_MODULE_CONST static const mp_rom_map_elem_t mp_constants_table[] = { #if MICROPY_PY_ERRNO { MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mp_module_errno) }, #endif #if MICROPY_PY_UCTYPES { MP_ROM_QSTR(MP_QSTR_uctypes), MP_ROM_PTR(&mp_module_uctypes) }, #endif // Extra constants as defined by a port MICROPY_PORT_CONSTANTS }; static MP_DEFINE_CONST_MAP(mp_constants_map, mp_constants_table); #endif #if MICROPY_COMP_CONST_FOLDING_COMPILER_WORKAROUND // Some versions of the xtensa-esp32-elf-gcc compiler generate wrong code if this // function is static, so provide a hook for them to work around this problem. MP_NOINLINE #endif static bool fold_logical_constants(parser_t *parser, uint8_t rule_id, size_t *num_args) { if (rule_id == RULE_or_test || rule_id == RULE_and_test) { // folding for binary logical ops: or and size_t copy_to = *num_args; for (size_t i = copy_to; i > 0;) { mp_parse_node_t pn = peek_result(parser, --i); parser->result_stack[parser->result_stack_top - copy_to] = pn; if (i == 0) { // always need to keep the last value break; } if (rule_id == RULE_or_test) { if (mp_parse_node_is_const_true(pn)) { // break; } else if (!mp_parse_node_is_const_false(pn)) { copy_to -= 1; } } else { // RULE_and_test if (mp_parse_node_is_const_false(pn)) { break; } else if (!mp_parse_node_is_const_true(pn)) { copy_to -= 1; } } } copy_to -= 1; // copy_to now contains number of args to pop // pop and discard all the short-circuited expressions for (size_t i = 0; i < copy_to; ++i) { pop_result(parser); } *num_args -= copy_to; // we did a complete folding if there's only 1 arg left return *num_args == 1; } else if (rule_id == RULE_not_test_2) { // folding for unary logical op: not mp_parse_node_t pn = peek_result(parser, 0); if (mp_parse_node_is_const_false(pn)) { pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, MP_TOKEN_KW_TRUE); } else if (mp_parse_node_is_const_true(pn)) { pn = mp_parse_node_new_leaf(MP_PARSE_NODE_TOKEN, MP_TOKEN_KW_FALSE); } else { return false; } pop_result(parser); push_result_node(parser, pn); return true; } return false; } static bool fold_constants(parser_t *parser, uint8_t rule_id, size_t num_args) { // this code does folding of arbitrary integer expressions, eg 1 + 2 * 3 + 4 // it does not do partial folding, eg 1 + 2 + x -> 3 + x mp_obj_t arg0; if (rule_id == RULE_expr || rule_id == RULE_xor_expr || rule_id == RULE_and_expr || rule_id == RULE_power) { // folding for binary ops: | ^ & ** mp_parse_node_t pn = peek_result(parser, num_args - 1); if (!mp_parse_node_get_int_maybe(pn, &arg0)) { return false; } mp_binary_op_t op; if (rule_id == RULE_expr) { op = MP_BINARY_OP_OR; } else if (rule_id == RULE_xor_expr) { op = MP_BINARY_OP_XOR; } else if (rule_id == RULE_and_expr) { op = MP_BINARY_OP_AND; } else { op = MP_BINARY_OP_POWER; } for (ssize_t i = num_args - 2; i >= 0; --i) { pn = peek_result(parser, i); mp_obj_t arg1; if (!mp_parse_node_get_int_maybe(pn, &arg1)) { return false; } if (op == MP_BINARY_OP_POWER && mp_obj_int_sign(arg1) < 0) { // ** can't have negative rhs return false; } arg0 = mp_binary_op(op, arg0, arg1); } } else if (rule_id == RULE_shift_expr || rule_id == RULE_arith_expr || rule_id == RULE_term) { // folding for binary ops: << >> + - * @ / % // mp_parse_node_t pn = peek_result(parser, num_args - 1); if (!mp_parse_node_get_int_maybe(pn, &arg0)) { return false; } for (ssize_t i = num_args - 2; i >= 1; i -= 2) { pn = peek_result(parser, i - 1); mp_obj_t arg1; if (!mp_parse_node_get_int_maybe(pn, &arg1)) { return false; } mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, i)); if (tok == MP_TOKEN_OP_AT || tok == MP_TOKEN_OP_SLASH) { // Can't fold @ or / return false; } mp_binary_op_t op = MP_BINARY_OP_LSHIFT + (tok - MP_TOKEN_OP_DBL_LESS); int rhs_sign = mp_obj_int_sign(arg1); if (op <= MP_BINARY_OP_RSHIFT) { // << and >> can't have negative rhs if (rhs_sign < 0) { return false; } } else if (op >= MP_BINARY_OP_FLOOR_DIVIDE) { // % and // can't have zero rhs if (rhs_sign == 0) { return false; } } arg0 = mp_binary_op(op, arg0, arg1); } } else if (rule_id == RULE_factor_2) { // folding for unary ops: + - ~ mp_parse_node_t pn = peek_result(parser, 0); if (!mp_parse_node_get_int_maybe(pn, &arg0)) { return false; } mp_token_kind_t tok = MP_PARSE_NODE_LEAF_ARG(peek_result(parser, 1)); mp_unary_op_t op; if (tok == MP_TOKEN_OP_TILDE) { op = MP_UNARY_OP_INVERT; } else { assert(tok == MP_TOKEN_OP_PLUS || tok == MP_TOKEN_OP_MINUS); // should be op = MP_UNARY_OP_POSITIVE + (tok - MP_TOKEN_OP_PLUS); } arg0 = mp_unary_op(op, arg0); #if MICROPY_COMP_CONST } else if (rule_id == RULE_expr_stmt) { mp_parse_node_t pn1 = peek_result(parser, 0); if (!MP_PARSE_NODE_IS_NULL(pn1) && !(MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_expr_stmt_augassign) || MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_expr_stmt_assign_list))) { // this node is of the form = mp_parse_node_t pn0 = peek_result(parser, 1); if (MP_PARSE_NODE_IS_ID(pn0) && MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_atom_expr_normal) && MP_PARSE_NODE_IS_ID(((mp_parse_node_struct_t *)pn1)->nodes[0]) && MP_PARSE_NODE_LEAF_ARG(((mp_parse_node_struct_t *)pn1)->nodes[0]) == MP_QSTR_const && MP_PARSE_NODE_IS_STRUCT_KIND(((mp_parse_node_struct_t *)pn1)->nodes[1], RULE_trailer_paren) ) { // code to assign dynamic constants: id = const(value) // get the id qstr id = MP_PARSE_NODE_LEAF_ARG(pn0); // get the value mp_parse_node_t pn_value = ((mp_parse_node_struct_t *)((mp_parse_node_struct_t *)pn1)->nodes[1])->nodes[0]; if (!mp_parse_node_is_const(pn_value)) { mp_obj_t exc = mp_obj_new_exception_msg(&mp_type_SyntaxError, MP_ERROR_TEXT("not a constant")); mp_obj_exception_add_traceback(exc, parser->lexer->source_name, ((mp_parse_node_struct_t *)pn1)->source_line, MP_QSTRnull); nlr_raise(exc); } mp_obj_t value = mp_parse_node_convert_to_obj(pn_value); // store the value in the table of dynamic constants mp_map_elem_t *elem = mp_map_lookup(&parser->consts, MP_OBJ_NEW_QSTR(id), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND); assert(elem->value == MP_OBJ_NULL); elem->value = value; // If the constant starts with an underscore then treat it as a private // variable and don't emit any code to store the value to the id. if (qstr_str(id)[0] == '_') { pop_result(parser); // pop const(value) pop_result(parser); // pop id push_result_rule(parser, 0, RULE_pass_stmt, 0); // replace with "pass" return true; } // replace const(value) with value pop_result(parser); push_result_node(parser, pn_value); // finished folding this assignment, but we still want it to be part of the tree return false; } } return false; #endif #if MICROPY_COMP_MODULE_CONST } else if (rule_id == RULE_atom_expr_normal) { mp_parse_node_t pn0 = peek_result(parser, 1); mp_parse_node_t pn1 = peek_result(parser, 0); if (!(MP_PARSE_NODE_IS_ID(pn0) && MP_PARSE_NODE_IS_STRUCT_KIND(pn1, RULE_trailer_period))) { return false; } // id1.id2 // look it up in constant table, see if it can be replaced with an integer mp_parse_node_struct_t *pns1 = (mp_parse_node_struct_t *)pn1; assert(MP_PARSE_NODE_IS_ID(pns1->nodes[0])); qstr q_base = MP_PARSE_NODE_LEAF_ARG(pn0); qstr q_attr = MP_PARSE_NODE_LEAF_ARG(pns1->nodes[0]); mp_map_elem_t *elem = mp_map_lookup((mp_map_t *)&mp_constants_map, MP_OBJ_NEW_QSTR(q_base), MP_MAP_LOOKUP); if (elem == NULL) { return false; } mp_obj_t dest[2]; mp_load_method_maybe(elem->value, q_attr, dest); if (!(dest[0] != MP_OBJ_NULL && mp_obj_is_int(dest[0]) && dest[1] == MP_OBJ_NULL)) { return false; } arg0 = dest[0]; #endif } else { return false; } // success folding this rule for (size_t i = num_args; i > 0; i--) { pop_result(parser); } push_result_node(parser, make_node_const_object_optimised(parser, 0, arg0)); return true; } #endif // MICROPY_COMP_CONST_FOLDING #if MICROPY_COMP_CONST_TUPLE static bool build_tuple_from_stack(parser_t *parser, size_t src_line, size_t num_args) { for (size_t i = num_args; i > 0;) { mp_parse_node_t pn = peek_result(parser, --i); if (!mp_parse_node_is_const(pn)) { return false; } } mp_obj_tuple_t *tuple = MP_OBJ_TO_PTR(mp_obj_new_tuple(num_args, NULL)); for (size_t i = num_args; i > 0;) { mp_parse_node_t pn = pop_result(parser); tuple->items[--i] = mp_parse_node_convert_to_obj(pn); if (MP_PARSE_NODE_IS_STRUCT(pn)) { parser_free_parse_node_struct(parser, (mp_parse_node_struct_t *)pn); } } push_result_node(parser, make_node_const_object(parser, src_line, MP_OBJ_FROM_PTR(tuple))); return true; } static bool build_tuple(parser_t *parser, size_t src_line, uint8_t rule_id, size_t num_args) { if (rule_id == RULE_testlist_comp) { if (peek_rule(parser, 0) == RULE_atom_paren) { // Tuple of the form "(a,)". return build_tuple_from_stack(parser, src_line, num_args); } } if (rule_id == RULE_testlist_comp_3c) { assert(peek_rule(parser, 0) == RULE_testlist_comp_3b); assert(peek_rule(parser, 1) == RULE_testlist_comp); if (peek_rule(parser, 2) == RULE_atom_paren) { // Tuple of the form "(a, b)". if (build_tuple_from_stack(parser, src_line, num_args)) { parser->rule_stack_top -= 2; // discard 2 rules return true; } } } if (rule_id == RULE_testlist_star_expr || rule_id == RULE_testlist || rule_id == RULE_subscriptlist) { // Tuple of the form: // - x = a, b // - return a, b // - for x in a, b: pass // - x[a, b] return build_tuple_from_stack(parser, src_line, num_args); } return false; } #endif static void push_result_rule(parser_t *parser, size_t src_line, uint8_t rule_id, size_t num_args) { // Simplify and optimise certain rules, to reduce memory usage and simplify the compiler. if (rule_id == RULE_atom_paren) { // 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 () } else if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, RULE_testlist_comp)) { // need to keep parenthesis for (a, b, ...) } else { // 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 if (fold_logical_constants(parser, rule_id, &num_args)) { // we folded this rule so return straight away return; } if (fold_constants(parser, rule_id, num_args)) { // we folded this rule so return straight away return; } #endif #if MICROPY_COMP_CONST_TUPLE if (build_tuple(parser, src_line, rule_id, num_args)) { // we built a tuple from this rule so return straight away return; } #endif mp_parse_node_struct_t *pn = parser_alloc(parser, sizeof(mp_parse_node_struct_t) + sizeof(mp_parse_node_t) * num_args); pn->source_line = src_line; pn->kind_num_nodes = (rule_id & 0xff) | (num_args << 8); 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); } mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) { // Set exception handler to free the lexer if an exception is raised. MP_DEFINE_NLR_JUMP_CALLBACK_FUNCTION_1(ctx, mp_lexer_free, lex); nlr_push_jump_callback(&ctx.callback, mp_call_function_1_from_nlr_jump_callback); // initialise parser and allocate memory for its stacks parser_t parser; parser.rule_stack_alloc = MICROPY_ALLOC_PARSE_RULE_INIT; parser.rule_stack_top = 0; parser.rule_stack = m_new(rule_stack_t, parser.rule_stack_alloc); parser.result_stack_alloc = MICROPY_ALLOC_PARSE_RESULT_INIT; parser.result_stack_top = 0; parser.result_stack = m_new(mp_parse_node_t, parser.result_stack_alloc); parser.lexer = lex; parser.tree.chunk = NULL; parser.cur_chunk = NULL; #if MICROPY_COMP_CONST mp_map_init(&parser.consts, 0); #endif // work out the top-level rule to use, and push it on the stack size_t top_level_rule; switch (input_kind) { case MP_PARSE_SINGLE_INPUT: top_level_rule = RULE_single_input; break; case MP_PARSE_EVAL_INPUT: top_level_rule = RULE_eval_input; break; default: top_level_rule = RULE_file_input; } push_rule(&parser, lex->tok_line, top_level_rule, 0); // parse! bool backtrack = false; for (;;) { next_rule: if (parser.rule_stack_top == 0) { break; } // Pop the next rule to process it size_t i; // state for the current rule size_t rule_src_line; // source line for the first token matched by the current rule uint8_t rule_id = pop_rule(&parser, &i, &rule_src_line); uint8_t rule_act = rule_act_table[rule_id]; const uint16_t *rule_arg = get_rule_arg(rule_id); size_t n = rule_act & RULE_ACT_ARG_MASK; #if 0 // debugging printf("depth=" UINT_FMT " ", parser.rule_stack_top); for (int j = 0; j < parser.rule_stack_top; ++j) { printf(" "); } printf("%s n=" UINT_FMT " i=" UINT_FMT " bt=%d\n", rule_name_table[rule_id], n, i, backtrack); #endif switch (rule_act & RULE_ACT_KIND_MASK) { case RULE_ACT_OR: if (i > 0 && !backtrack) { goto next_rule; } else { backtrack = false; } for (; i < n; ++i) { uint16_t kind = rule_arg[i] & RULE_ARG_KIND_MASK; if (kind == RULE_ARG_TOK) { if (lex->tok_kind == (rule_arg[i] & RULE_ARG_ARG_MASK)) { push_result_token(&parser, rule_id); mp_lexer_to_next(lex); goto next_rule; } } else { assert(kind == RULE_ARG_RULE); if (i + 1 < n) { push_rule(&parser, rule_src_line, rule_id, i + 1); // save this or-rule } push_rule_from_arg(&parser, rule_arg[i]); // push child of or-rule goto next_rule; } } backtrack = true; break; case RULE_ACT_AND: { // failed, backtrack if we can, else syntax error if (backtrack) { assert(i > 0); if ((rule_arg[i - 1] & RULE_ARG_KIND_MASK) == RULE_ARG_OPT_RULE) { // an optional rule that failed, so continue with next arg push_result_node(&parser, MP_PARSE_NODE_NULL); backtrack = false; } else { // a mandatory rule that failed, so propagate backtrack if (i > 1) { // already eaten tokens so can't backtrack goto syntax_error; } else { goto next_rule; } } } // progress through the rule for (; i < n; ++i) { if ((rule_arg[i] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { // need to match a token mp_token_kind_t tok_kind = rule_arg[i] & RULE_ARG_ARG_MASK; if (lex->tok_kind == tok_kind) { // matched token if (tok_kind == MP_TOKEN_NAME) { push_result_token(&parser, rule_id); } mp_lexer_to_next(lex); } else { // failed to match token if (i > 0) { // already eaten tokens so can't backtrack goto syntax_error; } else { // this rule failed, so backtrack backtrack = true; goto next_rule; } } } else { push_rule(&parser, rule_src_line, rule_id, i + 1); // save this and-rule push_rule_from_arg(&parser, rule_arg[i]); // push child of and-rule goto next_rule; } } assert(i == n); // matched the rule, so now build the corresponding parse_node #if !MICROPY_ENABLE_DOC_STRING // this code discards lonely statements, such as doc strings if (input_kind != MP_PARSE_SINGLE_INPUT && rule_id == RULE_expr_stmt && peek_result(&parser, 0) == MP_PARSE_NODE_NULL) { mp_parse_node_t p = peek_result(&parser, 1); if ((MP_PARSE_NODE_IS_LEAF(p) && !MP_PARSE_NODE_IS_ID(p)) || MP_PARSE_NODE_IS_STRUCT_KIND(p, RULE_const_object)) { pop_result(&parser); // MP_PARSE_NODE_NULL pop_result(&parser); // const expression (leaf or RULE_const_object) // Pushing the "pass" rule here will overwrite any RULE_const_object // entry that was on the result stack, allowing the GC to reclaim // the memory from the const object when needed. push_result_rule(&parser, rule_src_line, RULE_pass_stmt, 0); break; } } #endif // count number of arguments for the parse node i = 0; size_t num_not_nil = 0; for (size_t x = n; x > 0;) { --x; if ((rule_arg[x] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { mp_token_kind_t tok_kind = rule_arg[x] & RULE_ARG_ARG_MASK; if (tok_kind == MP_TOKEN_NAME) { // only tokens which were names are pushed to stack i += 1; num_not_nil += 1; } } else { // rules are always pushed if (peek_result(&parser, i) != MP_PARSE_NODE_NULL) { num_not_nil += 1; } i += 1; } } if (num_not_nil == 1 && (rule_act & RULE_ACT_ALLOW_IDENT)) { // this rule has only 1 argument and should not be emitted mp_parse_node_t pn = MP_PARSE_NODE_NULL; for (size_t x = 0; x < i; ++x) { mp_parse_node_t pn2 = pop_result(&parser); if (pn2 != MP_PARSE_NODE_NULL) { pn = pn2; } } push_result_node(&parser, pn); } else { // this rule must be emitted if (rule_act & RULE_ACT_ADD_BLANK) { // and add an extra blank node at the end (used by the compiler to store data) push_result_node(&parser, MP_PARSE_NODE_NULL); i += 1; } push_result_rule(&parser, rule_src_line, rule_id, i); } break; } default: { assert((rule_act & RULE_ACT_KIND_MASK) == RULE_ACT_LIST); // n=2 is: item item* // n=1 is: item (sep item)* // n=3 is: item (sep item)* [sep] bool had_trailing_sep; if (backtrack) { list_backtrack: had_trailing_sep = false; if (n == 2) { if (i == 1) { // fail on item, first time round; propagate backtrack goto next_rule; } else { // fail on item, in later rounds; finish with this rule backtrack = false; } } else { if (i == 1) { // fail on item, first time round; propagate backtrack goto next_rule; } else if ((i & 1) == 1) { // fail on item, in later rounds; have eaten tokens so can't backtrack if (n == 3) { // list allows trailing separator; finish parsing list had_trailing_sep = true; backtrack = false; } else { // list doesn't allowing trailing separator; fail goto syntax_error; } } else { // fail on separator; finish parsing list backtrack = false; } } } else { for (;;) { size_t arg = rule_arg[i & 1 & n]; if ((arg & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { if (lex->tok_kind == (arg & RULE_ARG_ARG_MASK)) { if (i & 1 & n) { // separators which are tokens are not pushed to result stack } else { push_result_token(&parser, rule_id); } mp_lexer_to_next(lex); // got element of list, so continue parsing list i += 1; } else { // couldn't get element of list i += 1; backtrack = true; goto list_backtrack; } } else { assert((arg & RULE_ARG_KIND_MASK) == RULE_ARG_RULE); push_rule(&parser, rule_src_line, rule_id, i + 1); // save this list-rule push_rule_from_arg(&parser, arg); // push child of list-rule goto next_rule; } } } assert(i >= 1); // compute number of elements in list, result in i i -= 1; if ((n & 1) && (rule_arg[1] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { // don't count separators when they are tokens i = (i + 1) / 2; } if (i == 1) { // list matched single item if (had_trailing_sep) { // if there was a trailing separator, make a list of a single item push_result_rule(&parser, rule_src_line, rule_id, i); } else { // just leave single item on stack (ie don't wrap in a list) } } else { push_result_rule(&parser, rule_src_line, rule_id, i); } break; } } } #if MICROPY_COMP_CONST mp_map_deinit(&parser.consts); #endif // truncate final chunk and link into chain of chunks if (parser.cur_chunk != NULL) { (void)m_renew_maybe(byte, parser.cur_chunk, sizeof(mp_parse_chunk_t) + parser.cur_chunk->alloc, sizeof(mp_parse_chunk_t) + parser.cur_chunk->union_.used, false); parser.cur_chunk->alloc = parser.cur_chunk->union_.used; parser.cur_chunk->union_.next = parser.tree.chunk; parser.tree.chunk = parser.cur_chunk; } if ( lex->tok_kind != MP_TOKEN_END // check we are at the end of the token stream || parser.result_stack_top == 0 // check that we got a node (can fail on empty input) ) { syntax_error:; mp_obj_t exc; if (lex->tok_kind == MP_TOKEN_INDENT) { exc = mp_obj_new_exception_msg(&mp_type_IndentationError, MP_ERROR_TEXT("unexpected indent")); } else if (lex->tok_kind == MP_TOKEN_DEDENT_MISMATCH) { exc = mp_obj_new_exception_msg(&mp_type_IndentationError, MP_ERROR_TEXT("unindent doesn't match any outer indent level")); #if MICROPY_PY_FSTRINGS } else if (lex->tok_kind == MP_TOKEN_MALFORMED_FSTRING) { exc = mp_obj_new_exception_msg(&mp_type_SyntaxError, MP_ERROR_TEXT("malformed f-string")); #endif } else { exc = mp_obj_new_exception_msg(&mp_type_SyntaxError, MP_ERROR_TEXT("invalid syntax")); } // add traceback to give info about file name and location // we don't have a 'block' name, so just pass the NULL qstr to indicate this mp_obj_exception_add_traceback(exc, lex->source_name, lex->tok_line, MP_QSTRnull); nlr_raise(exc); } // get the root parse node that we created assert(parser.result_stack_top == 1); parser.tree.root = parser.result_stack[0]; // free the memory that we don't need anymore m_del(rule_stack_t, parser.rule_stack, parser.rule_stack_alloc); m_del(mp_parse_node_t, parser.result_stack, parser.result_stack_alloc); // Deregister exception handler and free the lexer. nlr_pop_jump_callback(true); return parser.tree; } void mp_parse_tree_clear(mp_parse_tree_t *tree) { mp_parse_chunk_t *chunk = tree->chunk; while (chunk != NULL) { mp_parse_chunk_t *next = chunk->union_.next; m_del(byte, chunk, sizeof(mp_parse_chunk_t) + chunk->alloc); chunk = next; } tree->chunk = NULL; // Avoid dangling pointer that may live on stack } #endif // MICROPY_ENABLE_COMPILER