| /* |
| * JSON Parser |
| * |
| * 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 "qemu/osdep.h" |
| #include "qemu/ctype.h" |
| #include "qemu/cutils.h" |
| #include "qemu/unicode.h" |
| #include "qapi/error.h" |
| #include "qapi/qmp/qbool.h" |
| #include "qapi/qmp/qdict.h" |
| #include "qapi/qmp/qlist.h" |
| #include "qapi/qmp/qnull.h" |
| #include "qapi/qmp/qnum.h" |
| #include "qapi/qmp/qstring.h" |
| #include "json-parser-int.h" |
| |
| struct JSONToken { |
| JSONTokenType type; |
| int x; |
| int y; |
| char str[]; |
| }; |
| |
| typedef struct JSONParserContext |
| { |
| Error *err; |
| JSONToken *current; |
| GQueue *buf; |
| va_list *ap; |
| } JSONParserContext; |
| |
| #define BUG_ON(cond) assert(!(cond)) |
| |
| /** |
| * TODO |
| * |
| * 0) make errors meaningful again |
| * 1) add geometry information to tokens |
| * 3) should we return a parsed size? |
| * 4) deal with premature EOI |
| */ |
| |
| static QObject *parse_value(JSONParserContext *ctxt); |
| |
| /** |
| * Error handler |
| */ |
| static void GCC_FMT_ATTR(3, 4) parse_error(JSONParserContext *ctxt, |
| JSONToken *token, const char *msg, ...) |
| { |
| va_list ap; |
| char message[1024]; |
| |
| if (ctxt->err) { |
| return; |
| } |
| va_start(ap, msg); |
| vsnprintf(message, sizeof(message), msg, ap); |
| va_end(ap); |
| error_setg(&ctxt->err, "JSON parse error, %s", message); |
| } |
| |
| static int cvt4hex(const char *s) |
| { |
| int cp, i; |
| |
| cp = 0; |
| for (i = 0; i < 4; i++) { |
| if (!qemu_isxdigit(s[i])) { |
| return -1; |
| } |
| cp <<= 4; |
| if (s[i] >= '0' && s[i] <= '9') { |
| cp |= s[i] - '0'; |
| } else if (s[i] >= 'a' && s[i] <= 'f') { |
| cp |= 10 + s[i] - 'a'; |
| } else if (s[i] >= 'A' && s[i] <= 'F') { |
| cp |= 10 + s[i] - 'A'; |
| } else { |
| return -1; |
| } |
| } |
| return cp; |
| } |
| |
| /** |
| * parse_string(): Parse a JSON string |
| * |
| * From RFC 8259 "The JavaScript Object Notation (JSON) Data |
| * Interchange Format": |
| * |
| * char = unescaped / |
| * escape ( |
| * %x22 / ; " quotation mark U+0022 |
| * %x5C / ; \ reverse solidus U+005C |
| * %x2F / ; / solidus U+002F |
| * %x62 / ; b backspace U+0008 |
| * %x66 / ; f form feed U+000C |
| * %x6E / ; n line feed U+000A |
| * %x72 / ; r carriage return U+000D |
| * %x74 / ; t tab U+0009 |
| * %x75 4HEXDIG ) ; uXXXX U+XXXX |
| * escape = %x5C ; \ |
| * quotation-mark = %x22 ; " |
| * unescaped = %x20-21 / %x23-5B / %x5D-10FFFF |
| * |
| * Extensions over RFC 8259: |
| * - Extra escape sequence in strings: |
| * 0x27 (apostrophe) is recognized after escape, too |
| * - Single-quoted strings: |
| * Like double-quoted strings, except they're delimited by %x27 |
| * (apostrophe) instead of %x22 (quotation mark), and can't contain |
| * unescaped apostrophe, but can contain unescaped quotation mark. |
| * |
| * Note: |
| * - Encoding is modified UTF-8. |
| * - Invalid Unicode characters are rejected. |
| * - Control characters \x00..\x1F are rejected by the lexer. |
| */ |
| static QString *parse_string(JSONParserContext *ctxt, JSONToken *token) |
| { |
| const char *ptr = token->str; |
| QString *str; |
| char quote; |
| const char *beg; |
| int cp, trailing; |
| char *end; |
| ssize_t len; |
| char utf8_buf[5]; |
| |
| assert(*ptr == '"' || *ptr == '\''); |
| quote = *ptr++; |
| str = qstring_new(); |
| |
| while (*ptr != quote) { |
| assert(*ptr); |
| switch (*ptr) { |
| case '\\': |
| beg = ptr++; |
| switch (*ptr++) { |
| case '"': |
| qstring_append_chr(str, '"'); |
| break; |
| case '\'': |
| qstring_append_chr(str, '\''); |
| break; |
| case '\\': |
| qstring_append_chr(str, '\\'); |
| break; |
| case '/': |
| qstring_append_chr(str, '/'); |
| break; |
| case 'b': |
| qstring_append_chr(str, '\b'); |
| break; |
| case 'f': |
| qstring_append_chr(str, '\f'); |
| break; |
| case 'n': |
| qstring_append_chr(str, '\n'); |
| break; |
| case 'r': |
| qstring_append_chr(str, '\r'); |
| break; |
| case 't': |
| qstring_append_chr(str, '\t'); |
| break; |
| case 'u': |
| cp = cvt4hex(ptr); |
| ptr += 4; |
| |
| /* handle surrogate pairs */ |
| if (cp >= 0xD800 && cp <= 0xDBFF |
| && ptr[0] == '\\' && ptr[1] == 'u') { |
| /* leading surrogate followed by \u */ |
| cp = 0x10000 + ((cp & 0x3FF) << 10); |
| trailing = cvt4hex(ptr + 2); |
| if (trailing >= 0xDC00 && trailing <= 0xDFFF) { |
| /* followed by trailing surrogate */ |
| cp |= trailing & 0x3FF; |
| ptr += 6; |
| } else { |
| cp = -1; /* invalid */ |
| } |
| } |
| |
| if (mod_utf8_encode(utf8_buf, sizeof(utf8_buf), cp) < 0) { |
| parse_error(ctxt, token, |
| "%.*s is not a valid Unicode character", |
| (int)(ptr - beg), beg); |
| goto out; |
| } |
| qstring_append(str, utf8_buf); |
| break; |
| default: |
| parse_error(ctxt, token, "invalid escape sequence in string"); |
| goto out; |
| } |
| break; |
| case '%': |
| if (ctxt->ap) { |
| if (ptr[1] != '%') { |
| parse_error(ctxt, token, "can't interpolate into string"); |
| goto out; |
| } |
| ptr++; |
| } |
| /* fall through */ |
| default: |
| cp = mod_utf8_codepoint(ptr, 6, &end); |
| if (cp < 0) { |
| parse_error(ctxt, token, "invalid UTF-8 sequence in string"); |
| goto out; |
| } |
| ptr = end; |
| len = mod_utf8_encode(utf8_buf, sizeof(utf8_buf), cp); |
| assert(len >= 0); |
| qstring_append(str, utf8_buf); |
| } |
| } |
| |
| return str; |
| |
| out: |
| qobject_unref(str); |
| return NULL; |
| } |
| |
| /* Note: the token object returned by parser_context_peek_token or |
| * parser_context_pop_token is deleted as soon as parser_context_pop_token |
| * is called again. |
| */ |
| static JSONToken *parser_context_pop_token(JSONParserContext *ctxt) |
| { |
| g_free(ctxt->current); |
| ctxt->current = g_queue_pop_head(ctxt->buf); |
| return ctxt->current; |
| } |
| |
| static JSONToken *parser_context_peek_token(JSONParserContext *ctxt) |
| { |
| return g_queue_peek_head(ctxt->buf); |
| } |
| |
| /** |
| * Parsing rules |
| */ |
| static int parse_pair(JSONParserContext *ctxt, QDict *dict) |
| { |
| QObject *value; |
| QString *key = NULL; |
| JSONToken *peek, *token; |
| |
| peek = parser_context_peek_token(ctxt); |
| if (peek == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| key = qobject_to(QString, parse_value(ctxt)); |
| if (!key) { |
| parse_error(ctxt, peek, "key is not a string in object"); |
| goto out; |
| } |
| |
| token = parser_context_pop_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| if (token->type != JSON_COLON) { |
| parse_error(ctxt, token, "missing : in object pair"); |
| goto out; |
| } |
| |
| value = parse_value(ctxt); |
| if (value == NULL) { |
| parse_error(ctxt, token, "Missing value in dict"); |
| goto out; |
| } |
| |
| if (qdict_haskey(dict, qstring_get_str(key))) { |
| parse_error(ctxt, token, "duplicate key"); |
| goto out; |
| } |
| |
| qdict_put_obj(dict, qstring_get_str(key), value); |
| |
| qobject_unref(key); |
| |
| return 0; |
| |
| out: |
| qobject_unref(key); |
| |
| return -1; |
| } |
| |
| static QObject *parse_object(JSONParserContext *ctxt) |
| { |
| QDict *dict = NULL; |
| JSONToken *token, *peek; |
| |
| token = parser_context_pop_token(ctxt); |
| assert(token && token->type == JSON_LCURLY); |
| |
| dict = qdict_new(); |
| |
| peek = parser_context_peek_token(ctxt); |
| if (peek == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| if (peek->type != JSON_RCURLY) { |
| if (parse_pair(ctxt, dict) == -1) { |
| goto out; |
| } |
| |
| token = parser_context_pop_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| while (token->type != JSON_RCURLY) { |
| if (token->type != JSON_COMMA) { |
| parse_error(ctxt, token, "expected separator in dict"); |
| goto out; |
| } |
| |
| if (parse_pair(ctxt, dict) == -1) { |
| goto out; |
| } |
| |
| token = parser_context_pop_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| } |
| } else { |
| (void)parser_context_pop_token(ctxt); |
| } |
| |
| return QOBJECT(dict); |
| |
| out: |
| qobject_unref(dict); |
| return NULL; |
| } |
| |
| static QObject *parse_array(JSONParserContext *ctxt) |
| { |
| QList *list = NULL; |
| JSONToken *token, *peek; |
| |
| token = parser_context_pop_token(ctxt); |
| assert(token && token->type == JSON_LSQUARE); |
| |
| list = qlist_new(); |
| |
| peek = parser_context_peek_token(ctxt); |
| if (peek == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| if (peek->type != JSON_RSQUARE) { |
| QObject *obj; |
| |
| obj = parse_value(ctxt); |
| if (obj == NULL) { |
| parse_error(ctxt, token, "expecting value"); |
| goto out; |
| } |
| |
| qlist_append_obj(list, obj); |
| |
| token = parser_context_pop_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| |
| while (token->type != JSON_RSQUARE) { |
| if (token->type != JSON_COMMA) { |
| parse_error(ctxt, token, "expected separator in list"); |
| goto out; |
| } |
| |
| obj = parse_value(ctxt); |
| if (obj == NULL) { |
| parse_error(ctxt, token, "expecting value"); |
| goto out; |
| } |
| |
| qlist_append_obj(list, obj); |
| |
| token = parser_context_pop_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| goto out; |
| } |
| } |
| } else { |
| (void)parser_context_pop_token(ctxt); |
| } |
| |
| return QOBJECT(list); |
| |
| out: |
| qobject_unref(list); |
| return NULL; |
| } |
| |
| static QObject *parse_keyword(JSONParserContext *ctxt) |
| { |
| JSONToken *token; |
| |
| token = parser_context_pop_token(ctxt); |
| assert(token && token->type == JSON_KEYWORD); |
| |
| if (!strcmp(token->str, "true")) { |
| return QOBJECT(qbool_from_bool(true)); |
| } else if (!strcmp(token->str, "false")) { |
| return QOBJECT(qbool_from_bool(false)); |
| } else if (!strcmp(token->str, "null")) { |
| return QOBJECT(qnull()); |
| } |
| parse_error(ctxt, token, "invalid keyword '%s'", token->str); |
| return NULL; |
| } |
| |
| static QObject *parse_interpolation(JSONParserContext *ctxt) |
| { |
| JSONToken *token; |
| |
| token = parser_context_pop_token(ctxt); |
| assert(token && token->type == JSON_INTERP); |
| |
| if (!strcmp(token->str, "%p")) { |
| return va_arg(*ctxt->ap, QObject *); |
| } else if (!strcmp(token->str, "%i")) { |
| return QOBJECT(qbool_from_bool(va_arg(*ctxt->ap, int))); |
| } else if (!strcmp(token->str, "%d")) { |
| return QOBJECT(qnum_from_int(va_arg(*ctxt->ap, int))); |
| } else if (!strcmp(token->str, "%ld")) { |
| return QOBJECT(qnum_from_int(va_arg(*ctxt->ap, long))); |
| } else if (!strcmp(token->str, "%lld")) { |
| return QOBJECT(qnum_from_int(va_arg(*ctxt->ap, long long))); |
| } else if (!strcmp(token->str, "%" PRId64)) { |
| return QOBJECT(qnum_from_int(va_arg(*ctxt->ap, int64_t))); |
| } else if (!strcmp(token->str, "%u")) { |
| return QOBJECT(qnum_from_uint(va_arg(*ctxt->ap, unsigned int))); |
| } else if (!strcmp(token->str, "%lu")) { |
| return QOBJECT(qnum_from_uint(va_arg(*ctxt->ap, unsigned long))); |
| } else if (!strcmp(token->str, "%llu")) { |
| return QOBJECT(qnum_from_uint(va_arg(*ctxt->ap, unsigned long long))); |
| } else if (!strcmp(token->str, "%" PRIu64)) { |
| return QOBJECT(qnum_from_uint(va_arg(*ctxt->ap, uint64_t))); |
| } else if (!strcmp(token->str, "%s")) { |
| return QOBJECT(qstring_from_str(va_arg(*ctxt->ap, const char *))); |
| } else if (!strcmp(token->str, "%f")) { |
| return QOBJECT(qnum_from_double(va_arg(*ctxt->ap, double))); |
| } |
| parse_error(ctxt, token, "invalid interpolation '%s'", token->str); |
| return NULL; |
| } |
| |
| static QObject *parse_literal(JSONParserContext *ctxt) |
| { |
| JSONToken *token; |
| |
| token = parser_context_pop_token(ctxt); |
| assert(token); |
| |
| switch (token->type) { |
| case JSON_STRING: |
| return QOBJECT(parse_string(ctxt, token)); |
| case JSON_INTEGER: { |
| /* |
| * Represent JSON_INTEGER as QNUM_I64 if possible, else as |
| * QNUM_U64, else as QNUM_DOUBLE. Note that qemu_strtoi64() |
| * and qemu_strtou64() fail with ERANGE when it's not |
| * possible. |
| * |
| * qnum_get_int() will then work for any signed 64-bit |
| * JSON_INTEGER, qnum_get_uint() for any unsigned 64-bit |
| * integer, and qnum_get_double() both for any JSON_INTEGER |
| * and any JSON_FLOAT (with precision loss for integers beyond |
| * 53 bits) |
| */ |
| int ret; |
| int64_t value; |
| uint64_t uvalue; |
| |
| ret = qemu_strtoi64(token->str, NULL, 10, &value); |
| if (!ret) { |
| return QOBJECT(qnum_from_int(value)); |
| } |
| assert(ret == -ERANGE); |
| |
| if (token->str[0] != '-') { |
| ret = qemu_strtou64(token->str, NULL, 10, &uvalue); |
| if (!ret) { |
| return QOBJECT(qnum_from_uint(uvalue)); |
| } |
| assert(ret == -ERANGE); |
| } |
| } |
| /* fall through to JSON_FLOAT */ |
| case JSON_FLOAT: |
| /* FIXME dependent on locale; a pervasive issue in QEMU */ |
| /* FIXME our lexer matches RFC 8259 in forbidding Inf or NaN, |
| * but those might be useful extensions beyond JSON */ |
| return QOBJECT(qnum_from_double(strtod(token->str, NULL))); |
| default: |
| abort(); |
| } |
| } |
| |
| static QObject *parse_value(JSONParserContext *ctxt) |
| { |
| JSONToken *token; |
| |
| token = parser_context_peek_token(ctxt); |
| if (token == NULL) { |
| parse_error(ctxt, NULL, "premature EOI"); |
| return NULL; |
| } |
| |
| switch (token->type) { |
| case JSON_LCURLY: |
| return parse_object(ctxt); |
| case JSON_LSQUARE: |
| return parse_array(ctxt); |
| case JSON_INTERP: |
| return parse_interpolation(ctxt); |
| case JSON_INTEGER: |
| case JSON_FLOAT: |
| case JSON_STRING: |
| return parse_literal(ctxt); |
| case JSON_KEYWORD: |
| return parse_keyword(ctxt); |
| default: |
| parse_error(ctxt, token, "expecting value"); |
| return NULL; |
| } |
| } |
| |
| JSONToken *json_token(JSONTokenType type, int x, int y, GString *tokstr) |
| { |
| JSONToken *token = g_malloc(sizeof(JSONToken) + tokstr->len + 1); |
| |
| token->type = type; |
| memcpy(token->str, tokstr->str, tokstr->len); |
| token->str[tokstr->len] = 0; |
| token->x = x; |
| token->y = y; |
| return token; |
| } |
| |
| QObject *json_parser_parse(GQueue *tokens, va_list *ap, Error **errp) |
| { |
| JSONParserContext ctxt = { .buf = tokens, .ap = ap }; |
| QObject *result; |
| |
| result = parse_value(&ctxt); |
| assert(ctxt.err || g_queue_is_empty(ctxt.buf)); |
| |
| error_propagate(errp, ctxt.err); |
| |
| while (!g_queue_is_empty(ctxt.buf)) { |
| parser_context_pop_token(&ctxt); |
| } |
| g_free(ctxt.current); |
| |
| return result; |
| } |
