591 lines
16 KiB
C
591 lines
16 KiB
C
/*
|
|
* 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;
|
|
GString *str;
|
|
char quote;
|
|
const char *beg;
|
|
int cp, trailing;
|
|
char *end;
|
|
ssize_t len;
|
|
char utf8_buf[5];
|
|
|
|
assert(*ptr == '"' || *ptr == '\'');
|
|
quote = *ptr++;
|
|
str = g_string_new(NULL);
|
|
|
|
while (*ptr != quote) {
|
|
assert(*ptr);
|
|
switch (*ptr) {
|
|
case '\\':
|
|
beg = ptr++;
|
|
switch (*ptr++) {
|
|
case '"':
|
|
g_string_append_c(str, '"');
|
|
break;
|
|
case '\'':
|
|
g_string_append_c(str, '\'');
|
|
break;
|
|
case '\\':
|
|
g_string_append_c(str, '\\');
|
|
break;
|
|
case '/':
|
|
g_string_append_c(str, '/');
|
|
break;
|
|
case 'b':
|
|
g_string_append_c(str, '\b');
|
|
break;
|
|
case 'f':
|
|
g_string_append_c(str, '\f');
|
|
break;
|
|
case 'n':
|
|
g_string_append_c(str, '\n');
|
|
break;
|
|
case 'r':
|
|
g_string_append_c(str, '\r');
|
|
break;
|
|
case 't':
|
|
g_string_append_c(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;
|
|
}
|
|
g_string_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);
|
|
g_string_append(str, utf8_buf);
|
|
}
|
|
}
|
|
|
|
return qstring_from_gstring(str);
|
|
|
|
out:
|
|
g_string_free(str, true);
|
|
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 *key_obj = NULL;
|
|
QString *key;
|
|
QObject *value;
|
|
JSONToken *peek, *token;
|
|
|
|
peek = parser_context_peek_token(ctxt);
|
|
if (peek == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
|
|
key_obj = parse_value(ctxt);
|
|
key = qobject_to(QString, key_obj);
|
|
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_obj);
|
|
return 0;
|
|
|
|
out:
|
|
qobject_unref(key_obj);
|
|
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;
|
|
}
|