mp_lexer_t *mp_lexer_new(qstr src_name, mp_reader_t reader) { mp_lexer_t *lex = m_new_obj(mp_lexer_t); lex->source_name = src_name; lex->reader = reader; lex->line = 1; lex->column = (size_t)-2; // account for 3 dummy bytes lex->emit_dent = 0; lex->nested_bracket_level = 0; lex->alloc_indent_level = MICROPY_ALLOC_LEXER_INDENT_INIT; lex->num_indent_level = 1; lex->indent_level = m_new(uint16_t, lex->alloc_indent_level); vstr_init(&lex->vstr, 32); // store sentinel for first indentation level lex->indent_level[0] = 0; // load lexer with start of file, advancing lex->column to 1 // start with dummy bytes and use next_char() for proper EOL/EOF handling lex->chr0 = lex->chr1 = lex->chr2 = 0; next_char(lex); next_char(lex); next_char(lex); // preload first token mp_lexer_to_next(lex); // Check that the first token is in the first column. If it's not then we // convert the token kind to INDENT so that the parser gives a syntax error. if (lex->tok_column != 1) { lex->tok_kind = MP_TOKEN_INDENT; } return lex; }
STATIC void execute_from_lexer(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, bool is_repl) { if (lex == NULL) { return; } if (0) { // just tokenise while (!mp_lexer_is_kind(lex, MP_TOKEN_END)) { mp_token_show(mp_lexer_cur(lex)); mp_lexer_to_next(lex); } mp_lexer_free(lex); return; } mp_parse_error_kind_t parse_error_kind; mp_parse_node_t pn = mp_parse(lex, input_kind, &parse_error_kind); if (pn == MP_PARSE_NODE_NULL) { // parse error mp_parse_show_exception(lex, parse_error_kind); mp_lexer_free(lex); return; } qstr source_name = mp_lexer_source_name(lex); mp_lexer_free(lex); /* printf("----------------\n"); mp_parse_node_print(pn, 0); printf("----------------\n"); */ mp_obj_t module_fun = mp_compile(pn, source_name, emit_opt, is_repl); if (module_fun == mp_const_none) { // compile error return; } if (compile_only) { return; } // execute it nlr_buf_t nlr; if (nlr_push(&nlr) == 0) { mp_call_function_0(module_fun); nlr_pop(); } else { // uncaught exception mp_obj_print_exception((mp_obj_t)nlr.ret_val); } }
mp_lexer_t *mp_lexer_new(qstr src_name, mp_reader_t reader) { mp_lexer_t *lex = m_new_obj(mp_lexer_t); lex->source_name = src_name; lex->reader = reader; lex->line = 1; lex->column = 1; lex->emit_dent = 0; lex->nested_bracket_level = 0; lex->alloc_indent_level = MICROPY_ALLOC_LEXER_INDENT_INIT; lex->num_indent_level = 1; lex->indent_level = m_new(uint16_t, lex->alloc_indent_level); vstr_init(&lex->vstr, 32); // store sentinel for first indentation level lex->indent_level[0] = 0; // preload characters lex->chr0 = reader.readbyte(reader.data); lex->chr1 = reader.readbyte(reader.data); lex->chr2 = reader.readbyte(reader.data); // if input stream is 0, 1 or 2 characters long and doesn't end in a newline, then insert a newline at the end if (lex->chr0 == MP_LEXER_EOF) { lex->chr0 = '\n'; } else if (lex->chr1 == MP_LEXER_EOF) { if (lex->chr0 == '\r') { lex->chr0 = '\n'; } else if (lex->chr0 != '\n') { lex->chr1 = '\n'; } } else if (lex->chr2 == MP_LEXER_EOF) { if (lex->chr1 == '\r') { lex->chr1 = '\n'; } else if (lex->chr1 != '\n') { lex->chr2 = '\n'; } } // preload first token mp_lexer_to_next(lex); // Check that the first token is in the first column. If it's not then we // convert the token kind to INDENT so that the parser gives a syntax error. if (lex->tok_column != 1) { lex->tok_kind = MP_TOKEN_INDENT; } return lex; }
void do_file(const char *file) { mp_lexer_t *lex = mp_lexer_new_from_file(file); if (lex == NULL) { return; } if (0) { // just tokenise while (!mp_lexer_is_kind(lex, MP_TOKEN_END)) { mp_token_show(mp_lexer_cur(lex)); mp_lexer_to_next(lex); } mp_lexer_free(lex); } else { // parse qstr parse_exc_id; const char *parse_exc_msg; mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_exc_id, &parse_exc_msg); if (pn == MP_PARSE_NODE_NULL) { // parse error mp_lexer_show_error_pythonic_prefix(lex); printf("%s: %s\n", qstr_str(parse_exc_id), parse_exc_msg); mp_lexer_free(lex); return; } mp_lexer_free(lex); if (pn != MP_PARSE_NODE_NULL) { //printf("----------------\n"); //mp_parse_node_print(pn, 0); //printf("----------------\n"); // compile mp_obj_t module_fun = mp_compile(pn, 0, false); //printf("----------------\n"); if (module_fun == mp_const_none) { printf("compile error\n"); } } } }
void do_file(const char *file) { mp_lexer_t *lex = mp_lexer_new_from_file(file); if (lex == NULL) { return; } if (0) { // just tokenise while (lex->tok_kind != MP_TOKEN_END) { mp_lexer_show_token(lex); mp_lexer_to_next(lex); } mp_lexer_free(lex); } else { // parse mp_parse_error_kind_t parse_error_kind; mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_error_kind); if (pn == MP_PARSE_NODE_NULL) { // parse error mp_parse_show_exception(lex, parse_error_kind); mp_lexer_free(lex); return; } mp_lexer_free(lex); if (pn != MP_PARSE_NODE_NULL) { //printf("----------------\n"); //mp_parse_node_print(pn, 0); //printf("----------------\n"); // compile mp_obj_t module_fun = mp_compile(pn, 0, MP_EMIT_OPT_NONE, false); //printf("----------------\n"); if (mp_obj_is_exception_instance(module_fun)) { mp_obj_print_exception(module_fun); } } } }
void do_file(const char *file) { mp_lexer_t *lex = mp_lexer_new_from_file(file); if (lex == NULL) { return; } if (0) { // just tokenise while (!mp_lexer_is_kind(lex, MP_TOKEN_END)) { mp_token_show(mp_lexer_cur(lex)); mp_lexer_to_next(lex); } mp_lexer_free(lex); } else { // parse mp_parse_error_kind_t parse_error_kind; mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_error_kind); if (pn == MP_PARSE_NODE_NULL) { // parse error mp_parse_show_exception(lex, parse_error_kind); mp_lexer_free(lex); return; } mp_lexer_free(lex); if (pn != MP_PARSE_NODE_NULL) { //printf("----------------\n"); //mp_parse_node_print(pn, 0); //printf("----------------\n"); // compile mp_obj_t module_fun = mp_compile(pn, 0, false); //printf("----------------\n"); if (module_fun == mp_const_none) { printf("compile error\n"); } } } }
mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) { // allocate memory for the parser and its stacks parser_t *parser = m_new_obj(parser_t); parser->rule_stack_alloc = 64; parser->rule_stack_top = 0; parser->rule_stack = m_new(rule_stack_t, parser->rule_stack_alloc); parser->result_stack_alloc = 64; parser->result_stack_top = 0; parser->result_stack = m_new(mp_parse_node_t, parser->result_stack_alloc); // work out the top-level rule to use, and push it on the stack int 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, rules[top_level_rule], 0); // parse! uint n, i; bool backtrack = false; const rule_t *rule; mp_token_kind_t tok_kind; bool emit_rule; bool had_trailing_sep; for (;;) { next_rule: if (parser->rule_stack_top == 0) { break; } pop_rule(parser, &rule, &i); n = rule->act & RULE_ACT_ARG_MASK; /* // debugging printf("depth=%d ", parser->rule_stack_top); for (int j = 0; j < parser->rule_stack_top; ++j) { printf(" "); } printf("%s n=%d i=%d bt=%d\n", rule->rule_name, n, i, backtrack); */ switch (rule->act & RULE_ACT_KIND_MASK) { case RULE_ACT_OR: if (i > 0 && !backtrack) { goto next_rule; } else { backtrack = false; } for (; i < n - 1; ++i) { switch (rule->arg[i] & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: if (mp_lexer_is_kind(lex, rule->arg[i] & RULE_ARG_ARG_MASK)) { push_result_token(parser, lex); mp_lexer_to_next(lex); goto next_rule; } break; case RULE_ARG_RULE: push_rule(parser, rule, i + 1); push_rule_from_arg(parser, rule->arg[i]); goto next_rule; default: assert(0); } } if ((rule->arg[i] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { if (mp_lexer_is_kind(lex, rule->arg[i] & RULE_ARG_ARG_MASK)) { push_result_token(parser, lex); mp_lexer_to_next(lex); } else { backtrack = true; goto next_rule; } } else { push_rule_from_arg(parser, rule->arg[i]); } 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) { switch (rule->arg[i] & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: // need to match a token tok_kind = rule->arg[i] & RULE_ARG_ARG_MASK; if (mp_lexer_is_kind(lex, tok_kind)) { // matched token if (tok_kind == MP_TOKEN_NAME) { push_result_token(parser, lex); } 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; } } break; case RULE_ARG_RULE: //if (i + 1 < n) { push_rule(parser, rule, i + 1); //} push_rule_from_arg(parser, rule->arg[i]); goto next_rule; case RULE_ARG_OPT_RULE: push_rule(parser, rule, i + 1); push_rule_from_arg(parser, rule->arg[i]); goto next_rule; default: assert(0); } } assert(i == n); // matched the rule, so now build the corresponding parse_node // count number of arguments for the parse_node i = 0; emit_rule = false; for (int x = 0; x < n; ++x) { if ((rule->arg[x] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { tok_kind = rule->arg[x] & RULE_ARG_ARG_MASK; if (tok_kind >= MP_TOKEN_NAME) { emit_rule = true; } if (tok_kind == MP_TOKEN_NAME) { // only tokens which were names are pushed to stack i += 1; } } else { // rules are always pushed i += 1; } } // always emit these rules, even if they have only 1 argument if (rule->rule_id == RULE_expr_stmt || rule->rule_id == RULE_yield_stmt) { emit_rule = true; } // never emit these rules if they have only 1 argument // NOTE: can't put atom_paren here because we need it to distinguisg, for example, [a,b] from [(a,b)] // TODO possibly put varargslist_name, varargslist_equal here as well if (rule->rule_id == RULE_else_stmt || rule->rule_id == RULE_testlist_comp_3b || rule->rule_id == RULE_import_as_names_paren || rule->rule_id == RULE_typedargslist_name || rule->rule_id == RULE_typedargslist_colon || rule->rule_id == RULE_typedargslist_equal || rule->rule_id == RULE_dictorsetmaker_colon || rule->rule_id == RULE_classdef_2 || rule->rule_id == RULE_with_item_as || rule->rule_id == RULE_assert_stmt_extra || rule->rule_id == RULE_as_name || rule->rule_id == RULE_raise_stmt_from || rule->rule_id == RULE_vfpdef) { emit_rule = false; } // always emit these rules, and add an extra blank node at the end (to be used by the compiler to store data) if (rule->rule_id == RULE_funcdef || rule->rule_id == RULE_classdef || rule->rule_id == RULE_comp_for || rule->rule_id == RULE_lambdef || rule->rule_id == RULE_lambdef_nocond) { emit_rule = true; push_result_node(parser, MP_PARSE_NODE_NULL); i += 1; } int num_not_nil = 0; for (int x = 0; x < i; ++x) { if (peek_result(parser, x) != MP_PARSE_NODE_NULL) { num_not_nil += 1; } } //printf("done and %s n=%d i=%d notnil=%d\n", rule->rule_name, n, i, num_not_nil); if (emit_rule) { push_result_rule(parser, rule, i); } else if (num_not_nil == 0) { push_result_rule(parser, rule, i); // needed for, eg, atom_paren, testlist_comp_3b //result_stack_show(parser); //assert(0); } else if (num_not_nil == 1) { // single result, leave it on stack mp_parse_node_t pn = MP_PARSE_NODE_NULL; for (int 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 { push_result_rule(parser, rule, i); } break; case RULE_ACT_LIST: // n=2 is: item item* // n=1 is: item (sep item)* // n=3 is: item (sep item)* [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 (;;) { uint arg = rule->arg[i & 1 & n]; switch (arg & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: if (mp_lexer_is_kind(lex, arg & RULE_ARG_ARG_MASK)) { if (i & 1 & n) { // separators which are tokens are not pushed to result stack } else { push_result_token(parser, lex); } 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; } break; case RULE_ARG_RULE: push_rule(parser, rule, i + 1); push_rule_from_arg(parser, arg); goto next_rule; default: assert(0); } } } 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, i); } else { // just leave single item on stack (ie don't wrap in a list) } } else { //printf("done list %s %d %d\n", rule->rule_name, n, i); push_result_rule(parser, rule, i); } break; default: assert(0); } } // check we are at the end of the token stream if (!mp_lexer_is_kind(lex, MP_TOKEN_END)) { goto syntax_error; } //printf("--------------\n"); //result_stack_show(parser); //printf("rule stack alloc: %d\n", parser->rule_stack_alloc); //printf("result stack alloc: %d\n", parser->result_stack_alloc); //printf("number of parse nodes allocated: %d\n", num_parse_nodes_allocated); // get the root parse node that we created assert(parser->result_stack_top == 1); mp_parse_node_t result = parser->result_stack[0]; finished: // 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); m_del_obj(parser_t, parser); // return the result return result; syntax_error: // TODO these should raise a proper exception if (mp_lexer_is_kind(lex, MP_TOKEN_INDENT)) { mp_lexer_show_error_pythonic(lex, "IndentationError: unexpected indent"); } else if (mp_lexer_is_kind(lex, MP_TOKEN_DEDENT_MISMATCH)) { mp_lexer_show_error_pythonic(lex, "IndentationError: unindent does not match any outer indentation level"); } else { mp_lexer_show_error_pythonic(lex, "syntax error:"); #ifdef USE_RULE_NAME mp_lexer_show_error(lex, rule->rule_name); #endif mp_token_show(mp_lexer_cur(lex)); } result = MP_PARSE_NODE_NULL; goto finished; }
mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) { // 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, rules[top_level_rule], 0); // parse! size_t n, i; // state for the current rule size_t rule_src_line; // source line for the first token matched by the current rule bool backtrack = false; const rule_t *rule = NULL; for (;;) { next_rule: if (parser.rule_stack_top == 0) { break; } pop_rule(&parser, &rule, &i, &rule_src_line); n = rule->act & RULE_ACT_ARG_MASK; /* // debugging printf("depth=%d ", parser.rule_stack_top); for (int j = 0; j < parser.rule_stack_top; ++j) { printf(" "); } printf("%s n=%d i=%d bt=%d\n", rule->rule_name, n, i, backtrack); */ 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); 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, 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); } 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, 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->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, rules[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, 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); } 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, 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, i); } else { // just leave single item on stack (ie don't wrap in a list) } } else { push_result_rule(&parser, rule_src_line, rule, 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, "unexpected indent"); } else if (lex->tok_kind == MP_TOKEN_DEDENT_MISMATCH) { exc = mp_obj_new_exception_msg(&mp_type_IndentationError, "unindent does not match any outer indentation level"); } else { exc = mp_obj_new_exception_msg(&mp_type_SyntaxError, "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_QSTR_NULL); 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); // we also free the lexer on behalf of the caller mp_lexer_free(lex); return parser.tree; }
// returns standard error codes: 0 for success, 1 for all other errors STATIC int execute_from_lexer(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, bool is_repl) { if (lex == NULL) { return 1; } if (0) { // just tokenise while (!mp_lexer_is_kind(lex, MP_TOKEN_END)) { mp_token_show(mp_lexer_cur(lex)); mp_lexer_to_next(lex); } mp_lexer_free(lex); return 0; } mp_parse_error_kind_t parse_error_kind; mp_parse_node_t pn = mp_parse(lex, input_kind, &parse_error_kind); if (pn == MP_PARSE_NODE_NULL) { // parse error mp_parse_show_exception(lex, parse_error_kind); mp_lexer_free(lex); return 1; } qstr source_name = mp_lexer_source_name(lex); #if MICROPY_PY___FILE__ if (input_kind == MP_PARSE_FILE_INPUT) { mp_store_global(MP_QSTR___file__, MP_OBJ_NEW_QSTR(source_name)); } #endif mp_lexer_free(lex); /* printf("----------------\n"); mp_parse_node_print(pn, 0); printf("----------------\n"); */ mp_obj_t module_fun = mp_compile(pn, source_name, emit_opt, is_repl); if (module_fun == mp_const_none) { // compile error return 1; } if (compile_only) { return 0; } // execute it nlr_buf_t nlr; if (nlr_push(&nlr) == 0) { mp_call_function_0(module_fun); nlr_pop(); return 0; } else { // uncaught exception // check for SystemExit mp_obj_t exc = (mp_obj_t)nlr.ret_val; if (mp_obj_is_subclass_fast(mp_obj_get_type(exc), &mp_type_SystemExit)) { mp_obj_t exit_val = mp_obj_exception_get_value(exc); mp_int_t val; if (!mp_obj_get_int_maybe(exit_val, &val)) { val = 0; } exit(val); } mp_obj_print_exception((mp_obj_t)nlr.ret_val); return 1; } }
mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) { // initialise parser and allocate memory for its stacks parser_t parser; parser.parse_error = PARSE_ERROR_NONE; parser.rule_stack_alloc = MICROPY_ALLOC_PARSE_RULE_INIT; parser.rule_stack_top = 0; parser.rule_stack = m_new_maybe(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_maybe(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 // check if we could allocate the stacks if (parser.rule_stack == NULL || parser.result_stack == NULL) { goto memory_error; } // 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, rules[top_level_rule], 0); // parse! size_t n, i; // state for the current rule size_t rule_src_line; // source line for the first token matched by the current rule bool backtrack = false; const rule_t *rule = NULL; for (;;) { next_rule: if (parser.rule_stack_top == 0 || parser.parse_error) { break; } pop_rule(&parser, &rule, &i, &rule_src_line); n = rule->act & RULE_ACT_ARG_MASK; /* // debugging printf("depth=%d ", parser.rule_stack_top); for (int j = 0; j < parser.rule_stack_top; ++j) { printf(" "); } printf("%s n=%d i=%d bt=%d\n", rule->rule_name, n, i, backtrack); */ 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); 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, 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) { switch (rule->arg[i] & RULE_ARG_KIND_MASK) { case 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); } 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; } } break; } case RULE_ARG_RULE: case RULE_ARG_OPT_RULE: rule_and_no_other_choice: push_rule(&parser, rule_src_line, rule, i + 1); // save this and-rule push_rule_from_arg(&parser, rule->arg[i]); // push child of and-rule goto next_rule; default: assert(0); goto rule_and_no_other_choice; // to help flow control analysis } } 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->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_string)) { pop_result(&parser); // MP_PARSE_NODE_NULL mp_parse_node_t pn = pop_result(&parser); // possibly RULE_string 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_string) { m_del(char, (char*)pns->nodes[0], (size_t)pns->nodes[1]); } } push_result_rule(&parser, rule_src_line, rules[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, i); } break; }
mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_parse_error_kind_t *parse_error_kind_out) { // initialise parser and allocate memory for its stacks parser_t parser; parser.had_memory_error = false; parser.rule_stack_alloc = MICROPY_ALLOC_PARSE_RULE_INIT; parser.rule_stack_top = 0; parser.rule_stack = m_new_maybe(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_maybe(mp_parse_node_t, parser.result_stack_alloc); parser.lexer = lex; // check if we could allocate the stacks if (parser.rule_stack == NULL || parser.result_stack == NULL) { goto memory_error; } // work out the top-level rule to use, and push it on the stack int 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, mp_lexer_cur(lex)->src_line, rules[top_level_rule], 0); // parse! uint n, i; // state for the current rule uint rule_src_line; // source line for the first token matched by the current rule bool backtrack = false; const rule_t *rule = NULL; mp_token_kind_t tok_kind; bool emit_rule; bool had_trailing_sep; for (;;) { next_rule: if (parser.rule_stack_top == 0 || parser.had_memory_error) { break; } pop_rule(&parser, &rule, &i, &rule_src_line); n = rule->act & RULE_ACT_ARG_MASK; /* // debugging printf("depth=%d ", parser.rule_stack_top); for (int j = 0; j < parser.rule_stack_top; ++j) { printf(" "); } printf("%s n=%d i=%d bt=%d\n", rule->rule_name, n, i, backtrack); */ switch (rule->act & RULE_ACT_KIND_MASK) { case RULE_ACT_OR: if (i > 0 && !backtrack) { goto next_rule; } else { backtrack = false; } for (; i < n - 1; ++i) { switch (rule->arg[i] & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: if (mp_lexer_is_kind(lex, rule->arg[i] & RULE_ARG_ARG_MASK)) { push_result_token(&parser, lex); mp_lexer_to_next(lex); goto next_rule; } break; case RULE_ARG_RULE: push_rule(&parser, rule_src_line, rule, i + 1); // save this or-rule push_rule_from_arg(&parser, rule->arg[i]); // push child of or-rule goto next_rule; default: assert(0); } } if ((rule->arg[i] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { if (mp_lexer_is_kind(lex, rule->arg[i] & RULE_ARG_ARG_MASK)) { push_result_token(&parser, lex); mp_lexer_to_next(lex); } else { backtrack = true; goto next_rule; } } else { push_rule_from_arg(&parser, rule->arg[i]); } 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) { switch (rule->arg[i] & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: // need to match a token tok_kind = rule->arg[i] & RULE_ARG_ARG_MASK; if (mp_lexer_is_kind(lex, tok_kind)) { // matched token if (tok_kind == MP_TOKEN_NAME) { push_result_token(&parser, lex); } 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; } } break; case RULE_ARG_RULE: case RULE_ARG_OPT_RULE: push_rule(&parser, rule_src_line, rule, i + 1); // save this and-rule push_rule_from_arg(&parser, rule->arg[i]); // push child of and-rule goto next_rule; default: assert(0); } } assert(i == n); // matched the rule, so now build the corresponding parse_node // count number of arguments for the parse_node i = 0; emit_rule = false; for (int x = 0; x < n; ++x) { if ((rule->arg[x] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) { tok_kind = rule->arg[x] & RULE_ARG_ARG_MASK; if (tok_kind >= MP_TOKEN_NAME) { emit_rule = true; } if (tok_kind == MP_TOKEN_NAME) { // only tokens which were names are pushed to stack i += 1; } } else { // rules are always pushed i += 1; } } #if !MICROPY_EMIT_CPYTHON && !MICROPY_ENABLE_DOC_STRING // this code discards lonely statements, such as doc strings if (input_kind != MP_PARSE_SINGLE_INPUT && rule->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_string)) { pop_result(&parser); pop_result(&parser); push_result_rule(&parser, rule_src_line, rules[RULE_pass_stmt], 0); break; } } #endif // always emit these rules, even if they have only 1 argument if (rule->rule_id == RULE_expr_stmt || rule->rule_id == RULE_yield_stmt) { emit_rule = true; } // never emit these rules if they have only 1 argument // NOTE: can't put atom_paren here because we need it to distinguisg, for example, [a,b] from [(a,b)] // TODO possibly put varargslist_name, varargslist_equal here as well if (rule->rule_id == RULE_else_stmt || rule->rule_id == RULE_testlist_comp_3b || rule->rule_id == RULE_import_as_names_paren || rule->rule_id == RULE_typedargslist_name || rule->rule_id == RULE_typedargslist_colon || rule->rule_id == RULE_typedargslist_equal || rule->rule_id == RULE_dictorsetmaker_colon || rule->rule_id == RULE_classdef_2 || rule->rule_id == RULE_with_item_as || rule->rule_id == RULE_assert_stmt_extra || rule->rule_id == RULE_as_name || rule->rule_id == RULE_raise_stmt_from || rule->rule_id == RULE_vfpdef) { emit_rule = false; } // always emit these rules, and add an extra blank node at the end (to be used by the compiler to store data) if (ADD_BLANK_NODE(rule->rule_id)) { emit_rule = true; push_result_node(&parser, MP_PARSE_NODE_NULL); i += 1; } int num_not_nil = 0; for (int x = 0; x < i; ++x) { if (peek_result(&parser, x) != MP_PARSE_NODE_NULL) { num_not_nil += 1; } } //printf("done and %s n=%d i=%d notnil=%d\n", rule->rule_name, n, i, num_not_nil); if (emit_rule) { push_result_rule(&parser, rule_src_line, rule, i); } else if (num_not_nil == 0) { push_result_rule(&parser, rule_src_line, rule, i); // needed for, eg, atom_paren, testlist_comp_3b //result_stack_show(parser); //assert(0); } else if (num_not_nil == 1) { // single result, leave it on stack mp_parse_node_t pn = MP_PARSE_NODE_NULL; for (int 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 { push_result_rule(&parser, rule_src_line, rule, i); } break; case RULE_ACT_LIST: // n=2 is: item item* // n=1 is: item (sep item)* // n=3 is: item (sep item)* [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 (;;) { uint arg = rule->arg[i & 1 & n]; switch (arg & RULE_ARG_KIND_MASK) { case RULE_ARG_TOK: if (mp_lexer_is_kind(lex, arg & RULE_ARG_ARG_MASK)) { if (i & 1 & n) { // separators which are tokens are not pushed to result stack } else { push_result_token(&parser, lex); } 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; } break; case RULE_ARG_RULE: push_rule(&parser, rule_src_line, rule, i + 1); // save this list-rule push_rule_from_arg(&parser, arg); // push child of list-rule goto next_rule; default: assert(0); } } } 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, i); } else { // just leave single item on stack (ie don't wrap in a list) } } else { //printf("done list %s %d %d\n", rule->rule_name, n, i); push_result_rule(&parser, rule_src_line, rule, i); } break; default: assert(0); } } mp_parse_node_t result; // check if we had a memory error if (parser.had_memory_error) { 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; } //printf("--------------\n"); //result_stack_show(parser); //printf("rule stack alloc: %d\n", parser.rule_stack_alloc); //printf("result stack alloc: %d\n", parser.result_stack_alloc); //printf("number of parse nodes allocated: %d\n", num_parse_nodes_allocated); // get the root parse node that we created assert(parser.result_stack_top == 1); result = parser.result_stack[0]; finished: // 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); // return the result return result; syntax_error: if (mp_lexer_is_kind(lex, MP_TOKEN_INDENT)) { *parse_error_kind_out = MP_PARSE_ERROR_UNEXPECTED_INDENT; } else if (mp_lexer_is_kind(lex, MP_TOKEN_DEDENT_MISMATCH)) { *parse_error_kind_out = MP_PARSE_ERROR_UNMATCHED_UNINDENT; } else { *parse_error_kind_out = MP_PARSE_ERROR_INVALID_SYNTAX; #ifdef USE_RULE_NAME // debugging: print the rule name that failed and the token printf("rule: %s\n", rule->rule_name); #if MICROPY_DEBUG_PRINTERS mp_token_show(mp_lexer_cur(lex)); #endif #endif } result = MP_PARSE_NODE_NULL; goto finished; }