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micropython/py/lexer.c
Damien George 1831034be1 py: Allow lexer to raise exceptions during construction. 
This patch refactors the error handling in the lexer, to simplify it (ie
reduce code size).

A long time ago, when the lexer/parser/compiler were first written, the
lexer and parser were designed so they didn't use exceptions (ie nlr) to
report errors but rather returned an error code.  Over time that has
gradually changed, the parser in particular has more and more ways of
raising exceptions.  Also, the lexer never really handled all errors without
raising, eg there were some memory errors which could raise an exception
(and in these rare cases one would get a fatal nlr-not-handled fault).

This patch accepts the fact that the lexer can raise exceptions in some
cases and allows it to raise exceptions to handle all its errors, which are
for the most part just out-of-memory errors during construction of the
lexer.  This makes the lexer a bit simpler, and also the persistent code
stuff is simplified.

What this means for users of the lexer is that calls to it must be wrapped
in a nlr handler.  But all uses of the lexer already have such an nlr
handler for the parser (and compiler) so that doesn't put any extra burden
on the callers.
2017-03-14 11:52:05 +11:00

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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 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 <stdio.h>
#include <string.h>
#include <assert.h>
#include "py/mpstate.h"
#include "py/reader.h"
#include "py/lexer.h"
#include "py/runtime.h"
#if MICROPY_ENABLE_COMPILER
#define TAB_SIZE (8)
// TODO seems that CPython allows NULL byte in the input stream
// don't know if that's intentional or not, but we don't allow it
#define MP_LEXER_EOF ((unichar)MP_READER_EOF)
#define CUR_CHAR(lex) ((lex)->chr0)
STATIC bool is_end(mp_lexer_t *lex) {
return lex->chr0 == MP_LEXER_EOF;
}
STATIC bool is_physical_newline(mp_lexer_t *lex) {
return lex->chr0 == '\n';
}
STATIC bool is_char(mp_lexer_t *lex, byte c) {
return lex->chr0 == c;
}
STATIC bool is_char_or(mp_lexer_t *lex, byte c1, byte c2) {
return lex->chr0 == c1 || lex->chr0 == c2;
}
STATIC bool is_char_or3(mp_lexer_t *lex, byte c1, byte c2, byte c3) {
return lex->chr0 == c1 || lex->chr0 == c2 || lex->chr0 == c3;
}
STATIC bool is_char_following(mp_lexer_t *lex, byte c) {
return lex->chr1 == c;
}
STATIC bool is_char_following_or(mp_lexer_t *lex, byte c1, byte c2) {
return lex->chr1 == c1 || lex->chr1 == c2;
}
STATIC bool is_char_following_following_or(mp_lexer_t *lex, byte c1, byte c2) {
return lex->chr2 == c1 || lex->chr2 == c2;
}
STATIC bool is_char_and(mp_lexer_t *lex, byte c1, byte c2) {
return lex->chr0 == c1 && lex->chr1 == c2;
}
STATIC bool is_whitespace(mp_lexer_t *lex) {
return unichar_isspace(lex->chr0);
}
STATIC bool is_letter(mp_lexer_t *lex) {
return unichar_isalpha(lex->chr0);
}
STATIC bool is_digit(mp_lexer_t *lex) {
return unichar_isdigit(lex->chr0);
}
STATIC bool is_following_digit(mp_lexer_t *lex) {
return unichar_isdigit(lex->chr1);
}
STATIC bool is_following_base_char(mp_lexer_t *lex) {
const unichar chr1 = lex->chr1 | 0x20;
return chr1 == 'b' || chr1 == 'o' || chr1 == 'x';
}
STATIC bool is_following_odigit(mp_lexer_t *lex) {
return lex->chr1 >= '0' && lex->chr1 <= '7';
}
STATIC bool is_string_or_bytes(mp_lexer_t *lex) {
return is_char_or(lex, '\'', '\"')
|| (is_char_or3(lex, 'r', 'u', 'b') && is_char_following_or(lex, '\'', '\"'))
|| ((is_char_and(lex, 'r', 'b') || is_char_and(lex, 'b', 'r'))
&& is_char_following_following_or(lex, '\'', '\"'));
}
// to easily parse utf-8 identifiers we allow any raw byte with high bit set
STATIC bool is_head_of_identifier(mp_lexer_t *lex) {
return is_letter(lex) || lex->chr0 == '_' || lex->chr0 >= 0x80;
}
STATIC bool is_tail_of_identifier(mp_lexer_t *lex) {
return is_head_of_identifier(lex) || is_digit(lex);
}
STATIC void next_char(mp_lexer_t *lex) {
if (lex->chr0 == '\n') {
// a new line
++lex->line;
lex->column = 1;
} else if (lex->chr0 == '\t') {
// a tab
lex->column = (((lex->column - 1 + TAB_SIZE) / TAB_SIZE) * TAB_SIZE) + 1;
} else {
// a character worth one column
++lex->column;
}
lex->chr0 = lex->chr1;
lex->chr1 = lex->chr2;
lex->chr2 = lex->reader.readbyte(lex->reader.data);
if (lex->chr0 == '\r') {
// CR is a new line, converted to LF
lex->chr0 = '\n';
if (lex->chr1 == '\n') {
// CR LF is a single new line
lex->chr1 = lex->chr2;
lex->chr2 = lex->reader.readbyte(lex->reader.data);
}
}
if (lex->chr2 == MP_LEXER_EOF) {
// EOF, check if we need to insert a newline at end of file
if (lex->chr1 != MP_LEXER_EOF && lex->chr1 != '\n') {
// if lex->chr1 == '\r' then this makes a CR LF which will be converted to LF above
// otherwise it just inserts a LF
lex->chr2 = '\n';
}
}
}
STATIC void indent_push(mp_lexer_t *lex, size_t indent) {
if (lex->num_indent_level >= lex->alloc_indent_level) {
// TODO use m_renew_maybe and somehow indicate an error if it fails... probably by using MP_TOKEN_MEMORY_ERROR
lex->indent_level = m_renew(uint16_t, lex->indent_level, lex->alloc_indent_level, lex->alloc_indent_level + MICROPY_ALLOC_LEXEL_INDENT_INC);
lex->alloc_indent_level += MICROPY_ALLOC_LEXEL_INDENT_INC;
}
lex->indent_level[lex->num_indent_level++] = indent;
}
STATIC size_t indent_top(mp_lexer_t *lex) {
return lex->indent_level[lex->num_indent_level - 1];
}
STATIC void indent_pop(mp_lexer_t *lex) {
lex->num_indent_level -= 1;
}
// some tricky operator encoding:
// <op> = begin with <op>, if this opchar matches then begin here
// e<op> = end with <op>, if this opchar matches then end
// E<op> = mandatory end with <op>, this opchar must match, then end
// c<op> = continue with <op>, if this opchar matches then continue matching
// this means if the start of two ops are the same then they are equal til the last char
STATIC const char *const tok_enc =
"()[]{},:;@~" // singles
"<e=c<e=" // < <= << <<=
">e=c>e=" // > >= >> >>=
"*e=c*e=" // * *= ** **=
"+e=" // + +=
"-e=e>" // - -= ->
"&e=" // & &=
"|e=" // | |=
"/e=c/e=" // / /= // //=
"%e=" // % %=
"^e=" // ^ ^=
"=e=" // = ==
"!E="; // !=
// TODO static assert that number of tokens is less than 256 so we can safely make this table with byte sized entries
STATIC const uint8_t tok_enc_kind[] = {
MP_TOKEN_DEL_PAREN_OPEN, MP_TOKEN_DEL_PAREN_CLOSE,
MP_TOKEN_DEL_BRACKET_OPEN, MP_TOKEN_DEL_BRACKET_CLOSE,
MP_TOKEN_DEL_BRACE_OPEN, MP_TOKEN_DEL_BRACE_CLOSE,
MP_TOKEN_DEL_COMMA, MP_TOKEN_DEL_COLON, MP_TOKEN_DEL_SEMICOLON, MP_TOKEN_DEL_AT, MP_TOKEN_OP_TILDE,
MP_TOKEN_OP_LESS, MP_TOKEN_OP_LESS_EQUAL, MP_TOKEN_OP_DBL_LESS, MP_TOKEN_DEL_DBL_LESS_EQUAL,
MP_TOKEN_OP_MORE, MP_TOKEN_OP_MORE_EQUAL, MP_TOKEN_OP_DBL_MORE, MP_TOKEN_DEL_DBL_MORE_EQUAL,
MP_TOKEN_OP_STAR, MP_TOKEN_DEL_STAR_EQUAL, MP_TOKEN_OP_DBL_STAR, MP_TOKEN_DEL_DBL_STAR_EQUAL,
MP_TOKEN_OP_PLUS, MP_TOKEN_DEL_PLUS_EQUAL,
MP_TOKEN_OP_MINUS, MP_TOKEN_DEL_MINUS_EQUAL, MP_TOKEN_DEL_MINUS_MORE,
MP_TOKEN_OP_AMPERSAND, MP_TOKEN_DEL_AMPERSAND_EQUAL,
MP_TOKEN_OP_PIPE, MP_TOKEN_DEL_PIPE_EQUAL,
MP_TOKEN_OP_SLASH, MP_TOKEN_DEL_SLASH_EQUAL, MP_TOKEN_OP_DBL_SLASH, MP_TOKEN_DEL_DBL_SLASH_EQUAL,
MP_TOKEN_OP_PERCENT, MP_TOKEN_DEL_PERCENT_EQUAL,
MP_TOKEN_OP_CARET, MP_TOKEN_DEL_CARET_EQUAL,
MP_TOKEN_DEL_EQUAL, MP_TOKEN_OP_DBL_EQUAL,
MP_TOKEN_OP_NOT_EQUAL,
};
// must have the same order as enum in lexer.h
// must be sorted according to strcmp
STATIC const char *const tok_kw[] = {
"False",
"None",
"True",
"__debug__",
"and",
"as",
"assert",
#if MICROPY_PY_ASYNC_AWAIT
"async",
"await",
#endif
"break",
"class",
"continue",
"def",
"del",
"elif",
"else",
"except",
"finally",
"for",
"from",
"global",
"if",
"import",
"in",
"is",
"lambda",
"nonlocal",
"not",
"or",
"pass",
"raise",
"return",
"try",
"while",
"with",
"yield",
};
// This is called with CUR_CHAR() before first hex digit, and should return with
// it pointing to last hex digit
// num_digits must be greater than zero
STATIC bool get_hex(mp_lexer_t *lex, size_t num_digits, mp_uint_t *result) {
mp_uint_t num = 0;
while (num_digits-- != 0) {
next_char(lex);
unichar c = CUR_CHAR(lex);
if (!unichar_isxdigit(c)) {
return false;
}
num = (num << 4) + unichar_xdigit_value(c);
}
*result = num;
return true;
}
STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw) {
// get first quoting character
char quote_char = '\'';
if (is_char(lex, '\"')) {
quote_char = '\"';
}
next_char(lex);
// work out if it's a single or triple quoted literal
size_t num_quotes;
if (is_char_and(lex, quote_char, quote_char)) {
// triple quotes
next_char(lex);
next_char(lex);
num_quotes = 3;
} else {
// single quotes
num_quotes = 1;
}
size_t n_closing = 0;
while (!is_end(lex) && (num_quotes > 1 || !is_char(lex, '\n')) && n_closing < num_quotes) {
if (is_char(lex, quote_char)) {
n_closing += 1;
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
} else {
n_closing = 0;
if (is_char(lex, '\\')) {
next_char(lex);
unichar c = CUR_CHAR(lex);
if (is_raw) {
// raw strings allow escaping of quotes, but the backslash is also emitted
vstr_add_char(&lex->vstr, '\\');
} else {
switch (c) {
// note: "c" can never be MP_LEXER_EOF because next_char
// always inserts a newline at the end of the input stream
case '\n': c = MP_LEXER_EOF; break; // backslash escape the newline, just ignore it
case '\\': break;
case '\'': break;
case '"': break;
case 'a': c = 0x07; break;
case 'b': c = 0x08; break;
case 't': c = 0x09; break;
case 'n': c = 0x0a; break;
case 'v': c = 0x0b; break;
case 'f': c = 0x0c; break;
case 'r': c = 0x0d; break;
case 'u':
case 'U':
if (lex->tok_kind == MP_TOKEN_BYTES) {
// b'\u1234' == b'\\u1234'
vstr_add_char(&lex->vstr, '\\');
break;
}
// Otherwise fall through.
case 'x':
{
mp_uint_t num = 0;
if (!get_hex(lex, (c == 'x' ? 2 : c == 'u' ? 4 : 8), &num)) {
// not enough hex chars for escape sequence
lex->tok_kind = MP_TOKEN_INVALID;
}
c = num;
break;
}
case 'N':
// Supporting '\N{LATIN SMALL LETTER A}' == 'a' would require keeping the
// entire Unicode name table in the core. As of Unicode 6.3.0, that's nearly
// 3MB of text; even gzip-compressed and with minimal structure, it'll take
// roughly half a meg of storage. This form of Unicode escape may be added
// later on, but it's definitely not a priority right now. -- CJA 20140607
mp_not_implemented("unicode name escapes");
break;
default:
if (c >= '0' && c <= '7') {
// Octal sequence, 1-3 chars
size_t digits = 3;
mp_uint_t num = c - '0';
while (is_following_odigit(lex) && --digits != 0) {
next_char(lex);
num = num * 8 + (CUR_CHAR(lex) - '0');
}
c = num;
} else {
// unrecognised escape character; CPython lets this through verbatim as '\' and then the character
vstr_add_char(&lex->vstr, '\\');
}
break;
}
}
if (c != MP_LEXER_EOF) {
if (MICROPY_PY_BUILTINS_STR_UNICODE_DYNAMIC) {
if (c < 0x110000 && lex->tok_kind == MP_TOKEN_STRING) {
vstr_add_char(&lex->vstr, c);
} else if (c < 0x100 && lex->tok_kind == MP_TOKEN_BYTES) {
vstr_add_byte(&lex->vstr, c);
} else {
// unicode character out of range
// this raises a generic SyntaxError; could provide more info
lex->tok_kind = MP_TOKEN_INVALID;
}
} else {
// without unicode everything is just added as an 8-bit byte
if (c < 0x100) {
vstr_add_byte(&lex->vstr, c);
} else {
// 8-bit character out of range
// this raises a generic SyntaxError; could provide more info
lex->tok_kind = MP_TOKEN_INVALID;
}
}
}
} else {
// Add the "character" as a byte so that we remain 8-bit clean.
// This way, strings are parsed correctly whether or not they contain utf-8 chars.
vstr_add_byte(&lex->vstr, CUR_CHAR(lex));
}
}
next_char(lex);
}
// check we got the required end quotes
if (n_closing < num_quotes) {
lex->tok_kind = MP_TOKEN_LONELY_STRING_OPEN;
}
// cut off the end quotes from the token text
vstr_cut_tail_bytes(&lex->vstr, n_closing);
}
STATIC bool skip_whitespace(mp_lexer_t *lex, bool stop_at_newline) {
bool had_physical_newline = false;
while (!is_end(lex)) {
if (is_physical_newline(lex)) {
if (stop_at_newline && lex->nested_bracket_level == 0) {
break;
}
had_physical_newline = true;
next_char(lex);
} else if (is_whitespace(lex)) {
next_char(lex);
} else if (is_char(lex, '#')) {
next_char(lex);
while (!is_end(lex) && !is_physical_newline(lex)) {
next_char(lex);
}
// had_physical_newline will be set on next loop
} else if (is_char_and(lex, '\\', '\n')) {
// line-continuation, so don't set had_physical_newline
next_char(lex);
next_char(lex);
} else {
break;
}
}
return had_physical_newline;
}
void mp_lexer_to_next(mp_lexer_t *lex) {
// start new token text
vstr_reset(&lex->vstr);
// skip white space and comments
bool had_physical_newline = skip_whitespace(lex, false);
// set token source information
lex->tok_line = lex->line;
lex->tok_column = lex->column;
if (lex->emit_dent < 0) {
lex->tok_kind = MP_TOKEN_DEDENT;
lex->emit_dent += 1;
} else if (lex->emit_dent > 0) {
lex->tok_kind = MP_TOKEN_INDENT;
lex->emit_dent -= 1;
} else if (had_physical_newline && lex->nested_bracket_level == 0) {
lex->tok_kind = MP_TOKEN_NEWLINE;
size_t num_spaces = lex->column - 1;
if (num_spaces == indent_top(lex)) {
} else if (num_spaces > indent_top(lex)) {
indent_push(lex, num_spaces);
lex->emit_dent += 1;
} else {
while (num_spaces < indent_top(lex)) {
indent_pop(lex);
lex->emit_dent -= 1;
}
if (num_spaces != indent_top(lex)) {
lex->tok_kind = MP_TOKEN_DEDENT_MISMATCH;
}
}
} else if (is_end(lex)) {
lex->tok_kind = MP_TOKEN_END;
} else if (is_string_or_bytes(lex)) {
// a string or bytes literal
// Python requires adjacent string/bytes literals to be automatically
// concatenated. We do it here in the tokeniser to make efficient use of RAM,
// because then the lexer's vstr can be used to accumulate the string literal,
// in contrast to creating a parse tree of strings and then joining them later
// in the compiler. It's also more compact in code size to do it here.
// MP_TOKEN_END is used to indicate that this is the first string token
lex->tok_kind = MP_TOKEN_END;
// Loop to accumulate string/bytes literals
do {
// parse type codes
bool is_raw = false;
mp_token_kind_t kind = MP_TOKEN_STRING;
int n_char = 0;
if (is_char(lex, 'u')) {
n_char = 1;
} else if (is_char(lex, 'b')) {
kind = MP_TOKEN_BYTES;
n_char = 1;
if (is_char_following(lex, 'r')) {
is_raw = true;
n_char = 2;
}
} else if (is_char(lex, 'r')) {
is_raw = true;
n_char = 1;
if (is_char_following(lex, 'b')) {
kind = MP_TOKEN_BYTES;
n_char = 2;
}
}
// Set or check token kind
if (lex->tok_kind == MP_TOKEN_END) {
lex->tok_kind = kind;
} else if (lex->tok_kind != kind) {
// Can't concatenate string with bytes
break;
}
// Skip any type code characters
if (n_char != 0) {
next_char(lex);
if (n_char == 2) {
next_char(lex);
}
}
// Parse the literal
parse_string_literal(lex, is_raw);
// Skip whitespace so we can check if there's another string following
skip_whitespace(lex, true);
} while (is_string_or_bytes(lex));
} else if (is_head_of_identifier(lex)) {
lex->tok_kind = MP_TOKEN_NAME;
// get first char (add as byte to remain 8-bit clean and support utf-8)
vstr_add_byte(&lex->vstr, CUR_CHAR(lex));
next_char(lex);
// get tail chars
while (!is_end(lex) && is_tail_of_identifier(lex)) {
vstr_add_byte(&lex->vstr, CUR_CHAR(lex));
next_char(lex);
}
// Check if the name is a keyword.
// We also check for __debug__ here and convert it to its value. This is
// so the parser gives a syntax error on, eg, x.__debug__. Otherwise, we
// need to check for this special token in many places in the compiler.
const char *s = vstr_null_terminated_str(&lex->vstr);
for (size_t i = 0; i < MP_ARRAY_SIZE(tok_kw); i++) {
int cmp = strcmp(s, tok_kw[i]);
if (cmp == 0) {
lex->tok_kind = MP_TOKEN_KW_FALSE + i;
if (lex->tok_kind == MP_TOKEN_KW___DEBUG__) {
lex->tok_kind = (MP_STATE_VM(mp_optimise_value) == 0 ? MP_TOKEN_KW_TRUE : MP_TOKEN_KW_FALSE);
}
break;
} else if (cmp < 0) {
// Table is sorted and comparison was less-than, so stop searching
break;
}
}
} else if (is_digit(lex) || (is_char(lex, '.') && is_following_digit(lex))) {
bool forced_integer = false;
if (is_char(lex, '.')) {
lex->tok_kind = MP_TOKEN_FLOAT_OR_IMAG;
} else {
lex->tok_kind = MP_TOKEN_INTEGER;
if (is_char(lex, '0') && is_following_base_char(lex)) {
forced_integer = true;
}
}
// get first char
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
next_char(lex);
// get tail chars
while (!is_end(lex)) {
if (!forced_integer && is_char_or(lex, 'e', 'E')) {
lex->tok_kind = MP_TOKEN_FLOAT_OR_IMAG;
vstr_add_char(&lex->vstr, 'e');
next_char(lex);
if (is_char(lex, '+') || is_char(lex, '-')) {
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
next_char(lex);
}
} else if (is_letter(lex) || is_digit(lex) || is_char(lex, '.')) {
if (is_char_or3(lex, '.', 'j', 'J')) {
lex->tok_kind = MP_TOKEN_FLOAT_OR_IMAG;
}
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
next_char(lex);
} else {
break;
}
}
} else if (is_char(lex, '.')) {
// special handling for . and ... operators, because .. is not a valid operator
// get first char
next_char(lex);
if (is_char_and(lex, '.', '.')) {
next_char(lex);
next_char(lex);
lex->tok_kind = MP_TOKEN_ELLIPSIS;
} else {
lex->tok_kind = MP_TOKEN_DEL_PERIOD;
}
} else {
// search for encoded delimiter or operator
const char *t = tok_enc;
size_t tok_enc_index = 0;
for (; *t != 0 && !is_char(lex, *t); t += 1) {
if (*t == 'e' || *t == 'c') {
t += 1;
} else if (*t == 'E') {
tok_enc_index -= 1;
t += 1;
}
tok_enc_index += 1;
}
next_char(lex);
if (*t == 0) {
// didn't match any delimiter or operator characters
lex->tok_kind = MP_TOKEN_INVALID;
} else {
// matched a delimiter or operator character
// get the maximum characters for a valid token
t += 1;
size_t t_index = tok_enc_index;
for (;;) {
for (; *t == 'e'; t += 1) {
t += 1;
t_index += 1;
if (is_char(lex, *t)) {
next_char(lex);
tok_enc_index = t_index;
break;
}
}
if (*t == 'E') {
t += 1;
if (is_char(lex, *t)) {
next_char(lex);
tok_enc_index = t_index;
} else {
lex->tok_kind = MP_TOKEN_INVALID;
goto tok_enc_no_match;
}
break;
}
if (*t == 'c') {
t += 1;
t_index += 1;
if (is_char(lex, *t)) {
next_char(lex);
tok_enc_index = t_index;
t += 1;
} else {
break;
}
} else {
break;
}
}
// set token kind
lex->tok_kind = tok_enc_kind[tok_enc_index];
tok_enc_no_match:
// compute bracket level for implicit line joining
if (lex->tok_kind == MP_TOKEN_DEL_PAREN_OPEN || lex->tok_kind == MP_TOKEN_DEL_BRACKET_OPEN || lex->tok_kind == MP_TOKEN_DEL_BRACE_OPEN) {
lex->nested_bracket_level += 1;
} else if (lex->tok_kind == MP_TOKEN_DEL_PAREN_CLOSE || lex->tok_kind == MP_TOKEN_DEL_BRACKET_CLOSE || lex->tok_kind == MP_TOKEN_DEL_BRACE_CLOSE) {
lex->nested_bracket_level -= 1;
}
}
}
}
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;
}
mp_lexer_t *mp_lexer_new_from_str_len(qstr src_name, const char *str, size_t len, size_t free_len) {
mp_reader_t reader;
mp_reader_new_mem(&reader, (const byte*)str, len, free_len);
return mp_lexer_new(src_name, reader);
}
#if MICROPY_READER_POSIX || MICROPY_READER_VFS
mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
mp_reader_t reader;
mp_reader_new_file(&reader, filename);
return mp_lexer_new(qstr_from_str(filename), reader);
}
#if MICROPY_HELPER_LEXER_UNIX
mp_lexer_t *mp_lexer_new_from_fd(qstr filename, int fd, bool close_fd) {
mp_reader_t reader;
mp_reader_new_file_from_fd(&reader, fd, close_fd);
return mp_lexer_new(filename, reader);
}
#endif
#endif
void mp_lexer_free(mp_lexer_t *lex) {
if (lex) {
lex->reader.close(lex->reader.data);
vstr_clear(&lex->vstr);
m_del(uint16_t, lex->indent_level, lex->alloc_indent_level);
m_del_obj(mp_lexer_t, lex);
}
}
#if 0
// This function is used to print the current token and should only be
// needed to debug the lexer, so it's not available via a config option.
void mp_lexer_show_token(const mp_lexer_t *lex) {
printf("(" UINT_FMT ":" UINT_FMT ") kind:%u str:%p len:%zu", lex->tok_line, lex->tok_column, lex->tok_kind, lex->vstr.buf, lex->vstr.len);
if (lex->vstr.len > 0) {
const byte *i = (const byte *)lex->vstr.buf;
const byte *j = (const byte *)i + lex->vstr.len;
printf(" ");
while (i < j) {
unichar c = utf8_get_char(i);
i = utf8_next_char(i);
if (unichar_isprint(c)) {
printf("%c", (int)c);
} else {
printf("?");
}
}
}
printf("\n");
}
#endif
#endif // MICROPY_ENABLE_COMPILER
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