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micropython/py/lexer.c

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/*
* This file is part of the MicroPython 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/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;
}
#if MICROPY_PY_FSTRINGS
STATIC bool is_char_or4(mp_lexer_t *lex, byte c1, byte c2, byte c3, byte c4) {
return lex->chr0 == c1 || lex->chr0 == c2 || lex->chr0 == c3 || lex->chr0 == c4;
}
#endif
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, '\'', '\"')
#if MICROPY_PY_FSTRINGS
|| (is_char_or4(lex, 'r', 'u', 'b', 'f') && is_char_following_or(lex, '\'', '\"'))
|| (((is_char_and(lex, 'r', 'f') || is_char_and(lex, 'f', 'r'))
&& is_char_following_following_or(lex, '\'', '\"')))
#else
|| (is_char_or3(lex, 'r', 'u', 'b') && is_char_following_or(lex, '\'', '\"'))
#endif
|| ((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;
}
// shift the input queue forward
lex->chr0 = lex->chr1;
lex->chr1 = lex->chr2;
// and add the next byte from either the fstring args or the reader
#if MICROPY_PY_FSTRINGS
if (lex->fstring_args_idx) {
// if there are saved chars, then we're currently injecting fstring args
if (lex->fstring_args_idx < lex->fstring_args.len) {
lex->chr2 = lex->fstring_args.buf[lex->fstring_args_idx++];
} else {
// no more fstring arg bytes
lex->chr2 = '\0';
}
if (lex->chr0 == '\0') {
// consumed all fstring data, restore saved input queue
lex->chr0 = lex->chr0_saved;
lex->chr1 = lex->chr1_saved;
lex->chr2 = lex->chr2_saved;
// stop consuming fstring arg data
vstr_reset(&lex->fstring_args);
lex->fstring_args_idx = 0;
}
} else
#endif
{
lex->chr2 = lex->reader.readbyte(lex->reader.data);
}
if (lex->chr1 == '\r') {
// CR is a new line, converted to LF
lex->chr1 = '\n';
if (lex->chr2 == '\n') {
// CR LF is a single new line, throw out the extra LF
lex->chr2 = lex->reader.readbyte(lex->reader.data);
}
}
// check if we need to insert a newline at end of file
if (lex->chr2 == MP_LEXER_EOF && lex->chr1 != MP_LEXER_EOF && lex->chr1 != '\n') {
lex->chr2 = '\n';
}
}
STATIC void indent_push(mp_lexer_t *lex, size_t indent) {
if (lex->num_indent_level >= lex->alloc_indent_level) {
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
// 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=" // : :=
"<e=c<e=" // < <= << <<=
">e=c>e=" // > >= >> >>=
"*e=c*e=" // * *= ** **=
"+e=" // + +=
"-e=e>" // - -= ->
"&e=" // & &=
"|e=" // | |=
"/e=c/e=" // / /= // //=
"%e=" // % %=
"^e=" // ^ ^=
"@e=" // @ @=
"=e=" // = ==
"!."; // start of special cases: != . ...
// 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_SEMICOLON, MP_TOKEN_OP_TILDE,
MP_TOKEN_DEL_COLON, MP_TOKEN_OP_ASSIGN,
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_OP_AT, MP_TOKEN_DEL_AT_EQUAL,
MP_TOKEN_DEL_EQUAL, MP_TOKEN_OP_DBL_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, bool is_fstring) {
// 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;
#if MICROPY_PY_FSTRINGS
if (is_fstring) {
// assume there's going to be interpolation, so prep the injection data
// fstring_args_idx==0 && len(fstring_args)>0 means we're extracting the args.
// only when fstring_args_idx>0 will we consume the arg data
// note: lex->fstring_args will be empty already (it's reset when finished)
vstr_add_str(&lex->fstring_args, ".format(");
}
#endif
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 MICROPY_PY_FSTRINGS
while (is_fstring && is_char(lex, '{')) {
next_char(lex);
if (is_char(lex, '{')) {
// "{{" is passed through unchanged to be handled by str.format
vstr_add_byte(&lex->vstr, '{');
next_char(lex);
} else {
// wrap each argument in (), e.g.
// f"{a,b,}, {c}" --> "{}".format((a,b), (c),)
vstr_add_byte(&lex->fstring_args, '(');
// remember the start of this argument (if we need it for f'{a=}').
size_t i = lex->fstring_args.len;
// Extract characters inside the { until the bracket level
// is zero and we reach the conversion specifier '!',
// format specifier ':', or closing '}'. The conversion
// and format specifiers are left unchanged in the format
// string to be handled by str.format.
// (MicroPython limitation) note: this is completely
// unaware of Python syntax and will not handle any
// expression containing '}' or ':'. e.g. f'{"}"}' or f'
// {foo({})}'. However, detection of the '!' will
// specifically ensure that it's followed by [rs] and
// then either the format specifier or the closing
// brace. This allows the use of e.g. != in expressions.
unsigned int nested_bracket_level = 0;
while (!is_end(lex) && (nested_bracket_level != 0
|| !(is_char_or(lex, ':', '}')
|| (is_char(lex, '!')
&& is_char_following_or(lex, 'r', 's')
&& is_char_following_following_or(lex, ':', '}'))))
) {
unichar c = CUR_CHAR(lex);
if (c == '[' || c == '{') {
nested_bracket_level += 1;
} else if (c == ']' || c == '}') {
nested_bracket_level -= 1;
}
// like the default case at the end of this function, stay 8-bit clean
vstr_add_byte(&lex->fstring_args, c);
next_char(lex);
}
if (lex->fstring_args.buf[lex->fstring_args.len - 1] == '=') {
// if the last character of the arg was '=', then inject "arg=" before the '{'.
// f'{a=}' --> 'a={}'.format(a)
vstr_add_strn(&lex->vstr, lex->fstring_args.buf + i, lex->fstring_args.len - i);
// remove the trailing '='
lex->fstring_args.len--;
}
// close the paren-wrapped arg to .format().
vstr_add_byte(&lex->fstring_args, ')');
// comma-separate args to .format().
vstr_add_byte(&lex->fstring_args, ',');
}
vstr_add_byte(&lex->vstr, '{');
}
#endif
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.
MP_FALLTHROUGH
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_raise_NotImplementedError(MP_ERROR_TEXT("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
if (c < 0x110000 && lex->tok_kind == MP_TOKEN_STRING) {
// Valid unicode character in a str object.
vstr_add_char(&lex->vstr, c);
} else if (c < 0x100 && lex->tok_kind == MP_TOKEN_BYTES) {
// Valid byte in a bytes object.
vstr_add_byte(&lex->vstr, c);
}
#else
if (c < 0x100) {
// Without unicode everything is just added as an 8-bit byte.
vstr_add_byte(&lex->vstr, c);
}
#endif
else {
// Character out of range; this raises a generic SyntaxError.
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);
}
// This function returns whether it has crossed a newline or not.
// It therefore always return true if stop_at_newline is true
STATIC bool skip_whitespace(mp_lexer_t *lex, bool stop_at_newline) {
while (!is_end(lex)) {
if (is_physical_newline(lex)) {
if (stop_at_newline && lex->nested_bracket_level == 0) {
return 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);
}
// will return true on next loop
} else if (is_char_and(lex, '\\', '\n')) {
// line-continuation, so don't return true
next_char(lex);
next_char(lex);
} else {
break;
}
}
return false;
}
void mp_lexer_to_next(mp_lexer_t *lex) {
#if MICROPY_PY_FSTRINGS
if (lex->fstring_args.len && lex->fstring_args_idx == 0) {
// moving onto the next token means the literal string is complete.
// switch into injecting the format args.
vstr_add_byte(&lex->fstring_args, ')');
lex->chr0_saved = lex->chr0;
lex->chr1_saved = lex->chr1;
lex->chr2_saved = lex->chr2;
lex->chr0 = lex->fstring_args.buf[0];
lex->chr1 = lex->fstring_args.buf[1];
lex->chr2 = lex->fstring_args.buf[2];
// we've already extracted 3 chars, but setting this non-zero also
// means we'll start consuming the fstring data
lex->fstring_args_idx = 3;
}
#endif
// start new token text
vstr_reset(&lex->vstr);
// skip white space and comments
// set the newline tokens at the line and column of the preceding line:
// only advance on the pointer until a new line is crossed, save the
// line and column, and then readvance it
bool had_physical_newline = skip_whitespace(lex, true);
// 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) {
// The cursor is at the end of the previous line, pointing to a
// physical newline. Skip any remaining whitespace, comments, and
// newlines.
skip_whitespace(lex, false);
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;
bool is_fstring = 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;
}
#if MICROPY_PY_FSTRINGS
if (is_char_following(lex, 'f')) {
// raw-f-strings unsupported, immediately return (invalid) token.
lex->tok_kind = MP_TOKEN_FSTRING_RAW;
break;
}
#endif
}
#if MICROPY_PY_FSTRINGS
else if (is_char(lex, 'f')) {
if (is_char_following(lex, 'r')) {
// raw-f-strings unsupported, immediately return (invalid) token.
lex->tok_kind = MP_TOKEN_FSTRING_RAW;
break;
}
n_char = 1;
is_fstring = true;
}
#endif
// 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, is_fstring);
// 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 if (is_char(lex, '_')) {
next_char(lex);
} else {
break;
}
}
} 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;
}
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 if (*t == '!') {
// "!=" is a special case because "!" is not a valid operator
if (is_char(lex, '=')) {
next_char(lex);
lex->tok_kind = MP_TOKEN_OP_NOT_EQUAL;
} else {
lex->tok_kind = MP_TOKEN_INVALID;
}
} else if (*t == '.') {
// "." and "..." are special cases because ".." is not a valid operator
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 {
// matched a delimiter or operator character
// get the maximum characters for a valid token
t += 1;
size_t t_index = tok_enc_index;
while (*t == 'c' || *t == 'e') {
t_index += 1;
if (is_char(lex, t[1])) {
next_char(lex);
tok_enc_index = t_index;
if (*t == 'e') {
break;
}
} else if (*t == 'c') {
break;
}
t += 2;
}
// set token kind
lex->tok_kind = tok_enc_kind[tok_enc_index];
// 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 = (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);
#if MICROPY_PY_FSTRINGS
vstr_init(&lex->fstring_args, 0);
lex->fstring_args_idx = 0;
#endif
// 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 unless it is a
// newline. Otherwise 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_NEWLINE) {
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(qstr filename) {
mp_reader_t reader;
mp_reader_new_file(&reader, filename);
return mp_lexer_new(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);
#if MICROPY_PY_FSTRINGS
vstr_clear(&lex->fstring_args);
#endif
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