circuitpython/py/lexer.c

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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.
*/
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#include <stdio.h>
#include <string.h>
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#include <assert.h>
#include "py/mpstate.h"
#include "py/reader.h"
#include "py/lexer.h"
#include "py/runtime.h"
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#if MICROPY_ENABLE_COMPILER
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#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;
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}
STATIC bool is_physical_newline(mp_lexer_t *lex) {
return lex->chr0 == '\n';
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}
STATIC bool is_char(mp_lexer_t *lex, byte c) {
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return lex->chr0 == c;
}
STATIC bool is_char_or(mp_lexer_t *lex, byte c1, byte c2) {
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return lex->chr0 == c1 || lex->chr0 == c2;
}
STATIC bool is_char_or3(mp_lexer_t *lex, byte c1, byte c2, byte c3) {
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return lex->chr0 == c1 || lex->chr0 == c2 || lex->chr0 == c3;
}
STATIC bool is_char_following(mp_lexer_t *lex, byte c) {
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return lex->chr1 == c;
}
STATIC bool is_char_following_or(mp_lexer_t *lex, byte c1, byte c2) {
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return lex->chr1 == c1 || lex->chr1 == c2;
}
STATIC bool is_char_following_following_or(mp_lexer_t *lex, byte c1, byte c2) {
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return lex->chr2 == c1 || lex->chr2 == c2;
}
STATIC bool is_char_and(mp_lexer_t *lex, byte c1, byte c2) {
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return lex->chr0 == c1 && lex->chr1 == c2;
}
STATIC bool is_whitespace(mp_lexer_t *lex) {
return unichar_isspace(lex->chr0);
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}
STATIC bool is_letter(mp_lexer_t *lex) {
return unichar_isalpha(lex->chr0);
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}
STATIC bool is_digit(mp_lexer_t *lex) {
return unichar_isdigit(lex->chr0);
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}
STATIC bool is_following_digit(mp_lexer_t *lex) {
return unichar_isdigit(lex->chr1);
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}
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;
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}
STATIC bool is_tail_of_identifier(mp_lexer_t *lex) {
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return is_head_of_identifier(lex) || is_digit(lex);
}
STATIC void next_char(mp_lexer_t *lex) {
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if (lex->chr0 == '\n') {
// a new line
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++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';
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}
}
}
STATIC void indent_push(mp_lexer_t *lex, mp_uint_t indent) {
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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;
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}
lex->indent_level[lex->num_indent_level++] = indent;
}
STATIC mp_uint_t indent_top(mp_lexer_t *lex) {
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return lex->indent_level[lex->num_indent_level - 1];
}
STATIC void indent_pop(mp_lexer_t *lex) {
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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 =
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"()[]{},:;@~" // singles
"<e=c<e=" // < <= << <<=
">e=c>e=" // > >= >> >>=
"*e=c*e=" // * *= ** **=
"+e=" // + +=
"-e=e>" // - -= ->
"&e=" // & &=
"|e=" // | |=
"/e=c/e=" // / /= // //=
"%e=" // % %=
"^e=" // ^ ^=
"=e=" // = ==
"!E="; // !=
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// 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,
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};
// must have the same order as enum in lexer.h
// must be sorted according to strcmp
STATIC const char *const tok_kw[] = {
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"False",
"None",
"True",
"__debug__",
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"and",
"as",
"assert",
#if MICROPY_PY_ASYNC_AWAIT
"async",
"await",
#endif
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"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, mp_uint_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
mp_uint_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) {
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bool had_physical_newline = false;
while (!is_end(lex)) {
if (is_physical_newline(lex)) {
if (stop_at_newline && lex->nested_bracket_level == 0) {
break;
}
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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);
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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);
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// 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;
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lex->emit_dent += 1;
} else if (lex->emit_dent > 0) {
lex->tok_kind = MP_TOKEN_INDENT;
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lex->emit_dent -= 1;
} else if (had_physical_newline && lex->nested_bracket_level == 0) {
lex->tok_kind = MP_TOKEN_NEWLINE;
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mp_uint_t num_spaces = lex->column - 1;
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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;
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}
}
} else if (is_end(lex)) {
lex->tok_kind = MP_TOKEN_END;
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} else if (is_string_or_bytes(lex)) {
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// 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.
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// MP_TOKEN_END is used to indicate that this is the first string token
lex->tok_kind = MP_TOKEN_END;
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// 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;
}
}
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// 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;
}
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// Skip any type code characters
if (n_char != 0) {
next_char(lex);
if (n_char == 2) {
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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);
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} while (is_string_or_bytes(lex));
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} else if (is_head_of_identifier(lex)) {
lex->tok_kind = MP_TOKEN_NAME;
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// get first char (add as byte to remain 8-bit clean and support utf-8)
vstr_add_byte(&lex->vstr, CUR_CHAR(lex));
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next_char(lex);
// get tail chars
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while (!is_end(lex) && is_tail_of_identifier(lex)) {
vstr_add_byte(&lex->vstr, CUR_CHAR(lex));
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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;
}
}
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} 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;
}
}
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// get first char
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
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next_char(lex);
// get tail chars
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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');
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next_char(lex);
if (is_char(lex, '+') || is_char(lex, '-')) {
vstr_add_char(&lex->vstr, CUR_CHAR(lex));
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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));
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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;
}
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} else {
// search for encoded delimiter or operator
const char *t = tok_enc;
mp_uint_t tok_enc_index = 0;
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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;
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} else {
// matched a delimiter or operator character
// get the maximum characters for a valid token
t += 1;
mp_uint_t t_index = tok_enc_index;
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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;
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}
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];
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tok_enc_no_match:
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// 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) {
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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) {
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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_maybe(mp_lexer_t);
// check for memory allocation error
if (lex == NULL) {
reader.close(reader.data);
return NULL;
}
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lex->source_name = src_name;
lex->reader = reader;
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lex->line = 1;
lex->column = 1;
lex->emit_dent = 0;
lex->nested_bracket_level = 0;
lex->alloc_indent_level = MICROPY_ALLOC_LEXER_INDENT_INIT;
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lex->num_indent_level = 1;
lex->indent_level = m_new_maybe(uint16_t, lex->alloc_indent_level);
vstr_init(&lex->vstr, 32);
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// check for memory allocation error
// note: vstr_init above may fail on malloc, but so may mp_lexer_to_next below
if (lex->indent_level == NULL) {
mp_lexer_free(lex);
return NULL;
}
// store sentinel for first indentation level
lex->indent_level[0] = 0;
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// 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';
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}
} else if (lex->chr2 == MP_LEXER_EOF) {
if (lex->chr1 == '\r') {
lex->chr1 = '\n';
} else if (lex->chr1 != '\n') {
lex->chr2 = '\n';
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}
}
// 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;
}
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return lex;
}
mp_lexer_t *mp_lexer_new_from_str_len(qstr src_name, const char *str, mp_uint_t len, mp_uint_t free_len) {
mp_reader_t reader;
if (!mp_reader_new_mem(&reader, (const byte*)str, len, free_len)) {
return NULL;
}
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;
int ret = mp_reader_new_file(&reader, filename);
if (ret != 0) {
return NULL;
}
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;
int ret = mp_reader_new_file_from_fd(&reader, fd, close_fd);
if (ret != 0) {
return NULL;
}
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);
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}
}
#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");
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}
#endif
#endif // MICROPY_ENABLE_COMPILER