/* * JSON lexer * * Copyright IBM, Corp. 2009 * * Authors: * Anthony Liguori * * 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_I, IN_ESCAPE_I6, IN_ESCAPE_I64, 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_I64] = { ['d'] = IN_ESCAPE_DONE, }, [IN_ESCAPE_I6] = { ['4'] = IN_ESCAPE_I64, }, [IN_ESCAPE_I] = { ['6'] = IN_ESCAPE_I6, }, [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, ['I'] = IN_ESCAPE_I, }, /* 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); }