mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 12:09:58 +00:00
5ab8558d9b
Our JSON parser is a three stage parser. The first stage tokenizes the stream into a set of lexical tokens. Since the lexical grammar is regular, we can use a finite state machine to model it. The state machine will emit tokens as they are identified. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
328 lines
7.1 KiB
C
328 lines
7.1 KiB
C
/*
|
|
* JSON lexer
|
|
*
|
|
* Copyright IBM, Corp. 2009
|
|
*
|
|
* Authors:
|
|
* Anthony Liguori <aliguori@us.ibm.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
|
|
* See the COPYING.LIB file in the top-level directory.
|
|
*
|
|
*/
|
|
|
|
#include "qstring.h"
|
|
#include "qlist.h"
|
|
#include "qdict.h"
|
|
#include "qint.h"
|
|
#include "qemu-common.h"
|
|
#include "json-lexer.h"
|
|
|
|
/*
|
|
* \"([^\\\"]|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*\"
|
|
* '([^\\']|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*'
|
|
* 0|([1-9][0-9]*(.[0-9]+)?([eE]([-+])?[0-9]+))
|
|
* [{}\[\],:]
|
|
* [a-z]+
|
|
*
|
|
*/
|
|
|
|
enum json_lexer_state {
|
|
ERROR = 0,
|
|
IN_DONE_STRING,
|
|
IN_DQ_UCODE3,
|
|
IN_DQ_UCODE2,
|
|
IN_DQ_UCODE1,
|
|
IN_DQ_UCODE0,
|
|
IN_DQ_STRING_ESCAPE,
|
|
IN_DQ_STRING,
|
|
IN_SQ_UCODE3,
|
|
IN_SQ_UCODE2,
|
|
IN_SQ_UCODE1,
|
|
IN_SQ_UCODE0,
|
|
IN_SQ_STRING_ESCAPE,
|
|
IN_SQ_STRING,
|
|
IN_ZERO,
|
|
IN_DIGITS,
|
|
IN_DIGIT,
|
|
IN_EXP_E,
|
|
IN_MANTISSA,
|
|
IN_MANTISSA_DIGITS,
|
|
IN_NONZERO_NUMBER,
|
|
IN_NEG_NONZERO_NUMBER,
|
|
IN_KEYWORD,
|
|
IN_ESCAPE,
|
|
IN_ESCAPE_L,
|
|
IN_ESCAPE_LL,
|
|
IN_ESCAPE_DONE,
|
|
IN_WHITESPACE,
|
|
IN_OPERATOR_DONE,
|
|
IN_START,
|
|
};
|
|
|
|
#define TERMINAL(state) [0 ... 0x7F] = (state)
|
|
|
|
static const uint8_t json_lexer[][256] = {
|
|
[IN_DONE_STRING] = {
|
|
TERMINAL(JSON_STRING),
|
|
},
|
|
|
|
/* double quote string */
|
|
[IN_DQ_UCODE3] = {
|
|
['0' ... '9'] = IN_DQ_STRING,
|
|
['a' ... 'f'] = IN_DQ_STRING,
|
|
['A' ... 'F'] = IN_DQ_STRING,
|
|
},
|
|
[IN_DQ_UCODE2] = {
|
|
['0' ... '9'] = IN_DQ_UCODE3,
|
|
['a' ... 'f'] = IN_DQ_UCODE3,
|
|
['A' ... 'F'] = IN_DQ_UCODE3,
|
|
},
|
|
[IN_DQ_UCODE1] = {
|
|
['0' ... '9'] = IN_DQ_UCODE2,
|
|
['a' ... 'f'] = IN_DQ_UCODE2,
|
|
['A' ... 'F'] = IN_DQ_UCODE2,
|
|
},
|
|
[IN_DQ_UCODE0] = {
|
|
['0' ... '9'] = IN_DQ_UCODE1,
|
|
['a' ... 'f'] = IN_DQ_UCODE1,
|
|
['A' ... 'F'] = IN_DQ_UCODE1,
|
|
},
|
|
[IN_DQ_STRING_ESCAPE] = {
|
|
['b'] = IN_DQ_STRING,
|
|
['f'] = IN_DQ_STRING,
|
|
['n'] = IN_DQ_STRING,
|
|
['r'] = IN_DQ_STRING,
|
|
['t'] = IN_DQ_STRING,
|
|
['\''] = IN_DQ_STRING,
|
|
['\"'] = IN_DQ_STRING,
|
|
['u'] = IN_DQ_UCODE0,
|
|
},
|
|
[IN_DQ_STRING] = {
|
|
[1 ... 0xFF] = IN_DQ_STRING,
|
|
['\\'] = IN_DQ_STRING_ESCAPE,
|
|
['"'] = IN_DONE_STRING,
|
|
},
|
|
|
|
/* single quote string */
|
|
[IN_SQ_UCODE3] = {
|
|
['0' ... '9'] = IN_SQ_STRING,
|
|
['a' ... 'f'] = IN_SQ_STRING,
|
|
['A' ... 'F'] = IN_SQ_STRING,
|
|
},
|
|
[IN_SQ_UCODE2] = {
|
|
['0' ... '9'] = IN_SQ_UCODE3,
|
|
['a' ... 'f'] = IN_SQ_UCODE3,
|
|
['A' ... 'F'] = IN_SQ_UCODE3,
|
|
},
|
|
[IN_SQ_UCODE1] = {
|
|
['0' ... '9'] = IN_SQ_UCODE2,
|
|
['a' ... 'f'] = IN_SQ_UCODE2,
|
|
['A' ... 'F'] = IN_SQ_UCODE2,
|
|
},
|
|
[IN_SQ_UCODE0] = {
|
|
['0' ... '9'] = IN_SQ_UCODE1,
|
|
['a' ... 'f'] = IN_SQ_UCODE1,
|
|
['A' ... 'F'] = IN_SQ_UCODE1,
|
|
},
|
|
[IN_SQ_STRING_ESCAPE] = {
|
|
['b'] = IN_SQ_STRING,
|
|
['f'] = IN_SQ_STRING,
|
|
['n'] = IN_SQ_STRING,
|
|
['r'] = IN_SQ_STRING,
|
|
['t'] = IN_SQ_STRING,
|
|
['\''] = IN_SQ_STRING,
|
|
['\"'] = IN_SQ_STRING,
|
|
['u'] = IN_SQ_UCODE0,
|
|
},
|
|
[IN_SQ_STRING] = {
|
|
[1 ... 0xFF] = IN_SQ_STRING,
|
|
['\\'] = IN_SQ_STRING_ESCAPE,
|
|
['\''] = IN_DONE_STRING,
|
|
},
|
|
|
|
/* Zero */
|
|
[IN_ZERO] = {
|
|
TERMINAL(JSON_INTEGER),
|
|
['0' ... '9'] = ERROR,
|
|
['.'] = IN_MANTISSA,
|
|
},
|
|
|
|
/* Float */
|
|
[IN_DIGITS] = {
|
|
TERMINAL(JSON_FLOAT),
|
|
['0' ... '9'] = IN_DIGITS,
|
|
},
|
|
|
|
[IN_DIGIT] = {
|
|
['0' ... '9'] = IN_DIGITS,
|
|
},
|
|
|
|
[IN_EXP_E] = {
|
|
['-'] = IN_DIGIT,
|
|
['+'] = IN_DIGIT,
|
|
['0' ... '9'] = IN_DIGITS,
|
|
},
|
|
|
|
[IN_MANTISSA_DIGITS] = {
|
|
TERMINAL(JSON_FLOAT),
|
|
['0' ... '9'] = IN_MANTISSA_DIGITS,
|
|
['e'] = IN_EXP_E,
|
|
['E'] = IN_EXP_E,
|
|
},
|
|
|
|
[IN_MANTISSA] = {
|
|
['0' ... '9'] = IN_MANTISSA_DIGITS,
|
|
},
|
|
|
|
/* Number */
|
|
[IN_NONZERO_NUMBER] = {
|
|
TERMINAL(JSON_INTEGER),
|
|
['0' ... '9'] = IN_NONZERO_NUMBER,
|
|
['e'] = IN_EXP_E,
|
|
['E'] = IN_EXP_E,
|
|
['.'] = IN_MANTISSA,
|
|
},
|
|
|
|
[IN_NEG_NONZERO_NUMBER] = {
|
|
['0'] = IN_ZERO,
|
|
['1' ... '9'] = IN_NONZERO_NUMBER,
|
|
},
|
|
|
|
/* keywords */
|
|
[IN_KEYWORD] = {
|
|
TERMINAL(JSON_KEYWORD),
|
|
['a' ... 'z'] = IN_KEYWORD,
|
|
},
|
|
|
|
/* whitespace */
|
|
[IN_WHITESPACE] = {
|
|
TERMINAL(JSON_SKIP),
|
|
[' '] = IN_WHITESPACE,
|
|
['\t'] = IN_WHITESPACE,
|
|
['\r'] = IN_WHITESPACE,
|
|
['\n'] = IN_WHITESPACE,
|
|
},
|
|
|
|
/* operator */
|
|
[IN_OPERATOR_DONE] = {
|
|
TERMINAL(JSON_OPERATOR),
|
|
},
|
|
|
|
/* escape */
|
|
[IN_ESCAPE_DONE] = {
|
|
TERMINAL(JSON_ESCAPE),
|
|
},
|
|
|
|
[IN_ESCAPE_LL] = {
|
|
['d'] = IN_ESCAPE_DONE,
|
|
},
|
|
|
|
[IN_ESCAPE_L] = {
|
|
['d'] = IN_ESCAPE_DONE,
|
|
['l'] = IN_ESCAPE_LL,
|
|
},
|
|
|
|
[IN_ESCAPE] = {
|
|
['d'] = IN_ESCAPE_DONE,
|
|
['i'] = IN_ESCAPE_DONE,
|
|
['p'] = IN_ESCAPE_DONE,
|
|
['s'] = IN_ESCAPE_DONE,
|
|
['f'] = IN_ESCAPE_DONE,
|
|
['l'] = IN_ESCAPE_L,
|
|
},
|
|
|
|
/* top level rule */
|
|
[IN_START] = {
|
|
['"'] = IN_DQ_STRING,
|
|
['\''] = IN_SQ_STRING,
|
|
['0'] = IN_ZERO,
|
|
['1' ... '9'] = IN_NONZERO_NUMBER,
|
|
['-'] = IN_NEG_NONZERO_NUMBER,
|
|
['{'] = IN_OPERATOR_DONE,
|
|
['}'] = IN_OPERATOR_DONE,
|
|
['['] = IN_OPERATOR_DONE,
|
|
[']'] = IN_OPERATOR_DONE,
|
|
[','] = IN_OPERATOR_DONE,
|
|
[':'] = IN_OPERATOR_DONE,
|
|
['a' ... 'z'] = IN_KEYWORD,
|
|
['%'] = IN_ESCAPE,
|
|
[' '] = IN_WHITESPACE,
|
|
['\t'] = IN_WHITESPACE,
|
|
['\r'] = IN_WHITESPACE,
|
|
['\n'] = IN_WHITESPACE,
|
|
},
|
|
};
|
|
|
|
void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func)
|
|
{
|
|
lexer->emit = func;
|
|
lexer->state = IN_START;
|
|
lexer->token = qstring_new();
|
|
}
|
|
|
|
static int json_lexer_feed_char(JSONLexer *lexer, char ch)
|
|
{
|
|
char buf[2];
|
|
|
|
lexer->x++;
|
|
if (ch == '\n') {
|
|
lexer->x = 0;
|
|
lexer->y++;
|
|
}
|
|
|
|
lexer->state = json_lexer[lexer->state][(uint8_t)ch];
|
|
|
|
switch (lexer->state) {
|
|
case JSON_OPERATOR:
|
|
case JSON_ESCAPE:
|
|
case JSON_INTEGER:
|
|
case JSON_FLOAT:
|
|
case JSON_KEYWORD:
|
|
case JSON_STRING:
|
|
lexer->emit(lexer, lexer->token, lexer->state, lexer->x, lexer->y);
|
|
case JSON_SKIP:
|
|
lexer->state = json_lexer[IN_START][(uint8_t)ch];
|
|
QDECREF(lexer->token);
|
|
lexer->token = qstring_new();
|
|
break;
|
|
case ERROR:
|
|
return -EINVAL;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
buf[0] = ch;
|
|
buf[1] = 0;
|
|
|
|
qstring_append(lexer->token, buf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < size; i++) {
|
|
int err;
|
|
|
|
err = json_lexer_feed_char(lexer, buffer[i]);
|
|
if (err < 0) {
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int json_lexer_flush(JSONLexer *lexer)
|
|
{
|
|
return json_lexer_feed_char(lexer, 0);
|
|
}
|
|
|
|
void json_lexer_destroy(JSONLexer *lexer)
|
|
{
|
|
QDECREF(lexer->token);
|
|
}
|