mirror of https://gitee.com/openkylin/qemu.git
705 lines
16 KiB
C
705 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 <stdarg.h>
|
|
|
|
#include "qemu-common.h"
|
|
#include "qapi/qmp/qstring.h"
|
|
#include "qapi/qmp/qint.h"
|
|
#include "qapi/qmp/qdict.h"
|
|
#include "qapi/qmp/qlist.h"
|
|
#include "qapi/qmp/qfloat.h"
|
|
#include "qapi/qmp/qbool.h"
|
|
#include "qapi/qmp/json-parser.h"
|
|
#include "qapi/qmp/json-lexer.h"
|
|
#include "qapi/qmp/qerror.h"
|
|
|
|
typedef struct JSONParserContext
|
|
{
|
|
Error *err;
|
|
struct {
|
|
QObject **buf;
|
|
size_t pos;
|
|
size_t count;
|
|
} tokens;
|
|
} 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, va_list *ap);
|
|
|
|
/**
|
|
* Token manipulators
|
|
*
|
|
* tokens are dictionaries that contain a type, a string value, and geometry information
|
|
* about a token identified by the lexer. These are routines that make working with
|
|
* these objects a bit easier.
|
|
*/
|
|
static const char *token_get_value(QObject *obj)
|
|
{
|
|
return qdict_get_str(qobject_to_qdict(obj), "token");
|
|
}
|
|
|
|
static JSONTokenType token_get_type(QObject *obj)
|
|
{
|
|
return qdict_get_int(qobject_to_qdict(obj), "type");
|
|
}
|
|
|
|
static int token_is_operator(QObject *obj, char op)
|
|
{
|
|
const char *val;
|
|
|
|
if (token_get_type(obj) != JSON_OPERATOR) {
|
|
return 0;
|
|
}
|
|
|
|
val = token_get_value(obj);
|
|
|
|
return (val[0] == op) && (val[1] == 0);
|
|
}
|
|
|
|
static int token_is_keyword(QObject *obj, const char *value)
|
|
{
|
|
if (token_get_type(obj) != JSON_KEYWORD) {
|
|
return 0;
|
|
}
|
|
|
|
return strcmp(token_get_value(obj), value) == 0;
|
|
}
|
|
|
|
static int token_is_escape(QObject *obj, const char *value)
|
|
{
|
|
if (token_get_type(obj) != JSON_ESCAPE) {
|
|
return 0;
|
|
}
|
|
|
|
return (strcmp(token_get_value(obj), value) == 0);
|
|
}
|
|
|
|
/**
|
|
* Error handler
|
|
*/
|
|
static void GCC_FMT_ATTR(3, 4) parse_error(JSONParserContext *ctxt,
|
|
QObject *token, const char *msg, ...)
|
|
{
|
|
va_list ap;
|
|
char message[1024];
|
|
va_start(ap, msg);
|
|
vsnprintf(message, sizeof(message), msg, ap);
|
|
va_end(ap);
|
|
if (ctxt->err) {
|
|
error_free(ctxt->err);
|
|
ctxt->err = NULL;
|
|
}
|
|
error_set(&ctxt->err, QERR_JSON_PARSE_ERROR, message);
|
|
}
|
|
|
|
/**
|
|
* String helpers
|
|
*
|
|
* These helpers are used to unescape strings.
|
|
*/
|
|
static void wchar_to_utf8(uint16_t wchar, char *buffer, size_t buffer_length)
|
|
{
|
|
if (wchar <= 0x007F) {
|
|
BUG_ON(buffer_length < 2);
|
|
|
|
buffer[0] = wchar & 0x7F;
|
|
buffer[1] = 0;
|
|
} else if (wchar <= 0x07FF) {
|
|
BUG_ON(buffer_length < 3);
|
|
|
|
buffer[0] = 0xC0 | ((wchar >> 6) & 0x1F);
|
|
buffer[1] = 0x80 | (wchar & 0x3F);
|
|
buffer[2] = 0;
|
|
} else {
|
|
BUG_ON(buffer_length < 4);
|
|
|
|
buffer[0] = 0xE0 | ((wchar >> 12) & 0x0F);
|
|
buffer[1] = 0x80 | ((wchar >> 6) & 0x3F);
|
|
buffer[2] = 0x80 | (wchar & 0x3F);
|
|
buffer[3] = 0;
|
|
}
|
|
}
|
|
|
|
static int hex2decimal(char ch)
|
|
{
|
|
if (ch >= '0' && ch <= '9') {
|
|
return (ch - '0');
|
|
} else if (ch >= 'a' && ch <= 'f') {
|
|
return 10 + (ch - 'a');
|
|
} else if (ch >= 'A' && ch <= 'F') {
|
|
return 10 + (ch - 'A');
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* parse_string(): Parse a json string and return a QObject
|
|
*
|
|
* string
|
|
* ""
|
|
* " chars "
|
|
* chars
|
|
* char
|
|
* char chars
|
|
* char
|
|
* any-Unicode-character-
|
|
* except-"-or-\-or-
|
|
* control-character
|
|
* \"
|
|
* \\
|
|
* \/
|
|
* \b
|
|
* \f
|
|
* \n
|
|
* \r
|
|
* \t
|
|
* \u four-hex-digits
|
|
*/
|
|
static QString *qstring_from_escaped_str(JSONParserContext *ctxt, QObject *token)
|
|
{
|
|
const char *ptr = token_get_value(token);
|
|
QString *str;
|
|
int double_quote = 1;
|
|
|
|
if (*ptr == '"') {
|
|
double_quote = 1;
|
|
} else {
|
|
double_quote = 0;
|
|
}
|
|
ptr++;
|
|
|
|
str = qstring_new();
|
|
while (*ptr &&
|
|
((double_quote && *ptr != '"') || (!double_quote && *ptr != '\''))) {
|
|
if (*ptr == '\\') {
|
|
ptr++;
|
|
|
|
switch (*ptr) {
|
|
case '"':
|
|
qstring_append(str, "\"");
|
|
ptr++;
|
|
break;
|
|
case '\'':
|
|
qstring_append(str, "'");
|
|
ptr++;
|
|
break;
|
|
case '\\':
|
|
qstring_append(str, "\\");
|
|
ptr++;
|
|
break;
|
|
case '/':
|
|
qstring_append(str, "/");
|
|
ptr++;
|
|
break;
|
|
case 'b':
|
|
qstring_append(str, "\b");
|
|
ptr++;
|
|
break;
|
|
case 'f':
|
|
qstring_append(str, "\f");
|
|
ptr++;
|
|
break;
|
|
case 'n':
|
|
qstring_append(str, "\n");
|
|
ptr++;
|
|
break;
|
|
case 'r':
|
|
qstring_append(str, "\r");
|
|
ptr++;
|
|
break;
|
|
case 't':
|
|
qstring_append(str, "\t");
|
|
ptr++;
|
|
break;
|
|
case 'u': {
|
|
uint16_t unicode_char = 0;
|
|
char utf8_char[4];
|
|
int i = 0;
|
|
|
|
ptr++;
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
if (qemu_isxdigit(*ptr)) {
|
|
unicode_char |= hex2decimal(*ptr) << ((3 - i) * 4);
|
|
} else {
|
|
parse_error(ctxt, token,
|
|
"invalid hex escape sequence in string");
|
|
goto out;
|
|
}
|
|
ptr++;
|
|
}
|
|
|
|
wchar_to_utf8(unicode_char, utf8_char, sizeof(utf8_char));
|
|
qstring_append(str, utf8_char);
|
|
} break;
|
|
default:
|
|
parse_error(ctxt, token, "invalid escape sequence in string");
|
|
goto out;
|
|
}
|
|
} else {
|
|
char dummy[2];
|
|
|
|
dummy[0] = *ptr++;
|
|
dummy[1] = 0;
|
|
|
|
qstring_append(str, dummy);
|
|
}
|
|
}
|
|
|
|
return str;
|
|
|
|
out:
|
|
QDECREF(str);
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parser_context_pop_token(JSONParserContext *ctxt)
|
|
{
|
|
QObject *token;
|
|
g_assert(ctxt->tokens.pos < ctxt->tokens.count);
|
|
token = ctxt->tokens.buf[ctxt->tokens.pos];
|
|
ctxt->tokens.pos++;
|
|
return token;
|
|
}
|
|
|
|
/* Note: parser_context_{peek|pop}_token do not increment the
|
|
* token object's refcount. In both cases the references will continue
|
|
* to be tracked and cleaned up in parser_context_free(), so do not
|
|
* attempt to free the token object.
|
|
*/
|
|
static QObject *parser_context_peek_token(JSONParserContext *ctxt)
|
|
{
|
|
QObject *token;
|
|
g_assert(ctxt->tokens.pos < ctxt->tokens.count);
|
|
token = ctxt->tokens.buf[ctxt->tokens.pos];
|
|
return token;
|
|
}
|
|
|
|
static JSONParserContext parser_context_save(JSONParserContext *ctxt)
|
|
{
|
|
JSONParserContext saved_ctxt = {0};
|
|
saved_ctxt.tokens.pos = ctxt->tokens.pos;
|
|
saved_ctxt.tokens.count = ctxt->tokens.count;
|
|
saved_ctxt.tokens.buf = ctxt->tokens.buf;
|
|
return saved_ctxt;
|
|
}
|
|
|
|
static void parser_context_restore(JSONParserContext *ctxt,
|
|
JSONParserContext saved_ctxt)
|
|
{
|
|
ctxt->tokens.pos = saved_ctxt.tokens.pos;
|
|
ctxt->tokens.count = saved_ctxt.tokens.count;
|
|
ctxt->tokens.buf = saved_ctxt.tokens.buf;
|
|
}
|
|
|
|
static void tokens_append_from_iter(QObject *obj, void *opaque)
|
|
{
|
|
JSONParserContext *ctxt = opaque;
|
|
g_assert(ctxt->tokens.pos < ctxt->tokens.count);
|
|
ctxt->tokens.buf[ctxt->tokens.pos++] = obj;
|
|
qobject_incref(obj);
|
|
}
|
|
|
|
static JSONParserContext *parser_context_new(QList *tokens)
|
|
{
|
|
JSONParserContext *ctxt;
|
|
size_t count;
|
|
|
|
if (!tokens) {
|
|
return NULL;
|
|
}
|
|
|
|
count = qlist_size(tokens);
|
|
if (count == 0) {
|
|
return NULL;
|
|
}
|
|
|
|
ctxt = g_malloc0(sizeof(JSONParserContext));
|
|
ctxt->tokens.pos = 0;
|
|
ctxt->tokens.count = count;
|
|
ctxt->tokens.buf = g_malloc(count * sizeof(QObject *));
|
|
qlist_iter(tokens, tokens_append_from_iter, ctxt);
|
|
ctxt->tokens.pos = 0;
|
|
|
|
return ctxt;
|
|
}
|
|
|
|
/* to support error propagation, ctxt->err must be freed separately */
|
|
static void parser_context_free(JSONParserContext *ctxt)
|
|
{
|
|
int i;
|
|
if (ctxt) {
|
|
for (i = 0; i < ctxt->tokens.count; i++) {
|
|
qobject_decref(ctxt->tokens.buf[i]);
|
|
}
|
|
g_free(ctxt->tokens.buf);
|
|
g_free(ctxt);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Parsing rules
|
|
*/
|
|
static int parse_pair(JSONParserContext *ctxt, QDict *dict, va_list *ap)
|
|
{
|
|
QObject *key = NULL, *token = NULL, *value, *peek;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
peek = parser_context_peek_token(ctxt);
|
|
if (peek == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
|
|
key = parse_value(ctxt, ap);
|
|
if (!key || qobject_type(key) != QTYPE_QSTRING) {
|
|
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_is_operator(token, ':')) {
|
|
parse_error(ctxt, token, "missing : in object pair");
|
|
goto out;
|
|
}
|
|
|
|
value = parse_value(ctxt, ap);
|
|
if (value == NULL) {
|
|
parse_error(ctxt, token, "Missing value in dict");
|
|
goto out;
|
|
}
|
|
|
|
qdict_put_obj(dict, qstring_get_str(qobject_to_qstring(key)), value);
|
|
|
|
qobject_decref(key);
|
|
|
|
return 0;
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
qobject_decref(key);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static QObject *parse_object(JSONParserContext *ctxt, va_list *ap)
|
|
{
|
|
QDict *dict = NULL;
|
|
QObject *token, *peek;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
if (!token_is_operator(token, '{')) {
|
|
goto out;
|
|
}
|
|
token = NULL;
|
|
|
|
dict = qdict_new();
|
|
|
|
peek = parser_context_peek_token(ctxt);
|
|
if (peek == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
|
|
if (!token_is_operator(peek, '}')) {
|
|
if (parse_pair(ctxt, dict, ap) == -1) {
|
|
goto out;
|
|
}
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
|
|
while (!token_is_operator(token, '}')) {
|
|
if (!token_is_operator(token, ',')) {
|
|
parse_error(ctxt, token, "expected separator in dict");
|
|
goto out;
|
|
}
|
|
token = NULL;
|
|
|
|
if (parse_pair(ctxt, dict, ap) == -1) {
|
|
goto out;
|
|
}
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
}
|
|
token = NULL;
|
|
} else {
|
|
token = parser_context_pop_token(ctxt);
|
|
token = NULL;
|
|
}
|
|
|
|
return QOBJECT(dict);
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
QDECREF(dict);
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parse_array(JSONParserContext *ctxt, va_list *ap)
|
|
{
|
|
QList *list = NULL;
|
|
QObject *token, *peek;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
if (!token_is_operator(token, '[')) {
|
|
token = NULL;
|
|
goto out;
|
|
}
|
|
token = NULL;
|
|
|
|
list = qlist_new();
|
|
|
|
peek = parser_context_peek_token(ctxt);
|
|
if (peek == NULL) {
|
|
parse_error(ctxt, NULL, "premature EOI");
|
|
goto out;
|
|
}
|
|
|
|
if (!token_is_operator(peek, ']')) {
|
|
QObject *obj;
|
|
|
|
obj = parse_value(ctxt, ap);
|
|
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_is_operator(token, ']')) {
|
|
if (!token_is_operator(token, ',')) {
|
|
parse_error(ctxt, token, "expected separator in list");
|
|
goto out;
|
|
}
|
|
|
|
token = NULL;
|
|
|
|
obj = parse_value(ctxt, ap);
|
|
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;
|
|
}
|
|
}
|
|
|
|
token = NULL;
|
|
} else {
|
|
token = parser_context_pop_token(ctxt);
|
|
token = NULL;
|
|
}
|
|
|
|
return QOBJECT(list);
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
QDECREF(list);
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parse_keyword(JSONParserContext *ctxt)
|
|
{
|
|
QObject *token, *ret;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
if (token_get_type(token) != JSON_KEYWORD) {
|
|
goto out;
|
|
}
|
|
|
|
if (token_is_keyword(token, "true")) {
|
|
ret = QOBJECT(qbool_from_int(true));
|
|
} else if (token_is_keyword(token, "false")) {
|
|
ret = QOBJECT(qbool_from_int(false));
|
|
} else {
|
|
parse_error(ctxt, token, "invalid keyword `%s'", token_get_value(token));
|
|
goto out;
|
|
}
|
|
|
|
return ret;
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parse_escape(JSONParserContext *ctxt, va_list *ap)
|
|
{
|
|
QObject *token = NULL, *obj;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
if (ap == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
if (token_is_escape(token, "%p")) {
|
|
obj = va_arg(*ap, QObject *);
|
|
} else if (token_is_escape(token, "%i")) {
|
|
obj = QOBJECT(qbool_from_int(va_arg(*ap, int)));
|
|
} else if (token_is_escape(token, "%d")) {
|
|
obj = QOBJECT(qint_from_int(va_arg(*ap, int)));
|
|
} else if (token_is_escape(token, "%ld")) {
|
|
obj = QOBJECT(qint_from_int(va_arg(*ap, long)));
|
|
} else if (token_is_escape(token, "%lld") ||
|
|
token_is_escape(token, "%I64d")) {
|
|
obj = QOBJECT(qint_from_int(va_arg(*ap, long long)));
|
|
} else if (token_is_escape(token, "%s")) {
|
|
obj = QOBJECT(qstring_from_str(va_arg(*ap, const char *)));
|
|
} else if (token_is_escape(token, "%f")) {
|
|
obj = QOBJECT(qfloat_from_double(va_arg(*ap, double)));
|
|
} else {
|
|
goto out;
|
|
}
|
|
|
|
return obj;
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parse_literal(JSONParserContext *ctxt)
|
|
{
|
|
QObject *token, *obj;
|
|
JSONParserContext saved_ctxt = parser_context_save(ctxt);
|
|
|
|
token = parser_context_pop_token(ctxt);
|
|
if (token == NULL) {
|
|
goto out;
|
|
}
|
|
|
|
switch (token_get_type(token)) {
|
|
case JSON_STRING:
|
|
obj = QOBJECT(qstring_from_escaped_str(ctxt, token));
|
|
break;
|
|
case JSON_INTEGER:
|
|
obj = QOBJECT(qint_from_int(strtoll(token_get_value(token), NULL, 10)));
|
|
break;
|
|
case JSON_FLOAT:
|
|
/* FIXME dependent on locale */
|
|
obj = QOBJECT(qfloat_from_double(strtod(token_get_value(token), NULL)));
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
return obj;
|
|
|
|
out:
|
|
parser_context_restore(ctxt, saved_ctxt);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static QObject *parse_value(JSONParserContext *ctxt, va_list *ap)
|
|
{
|
|
QObject *obj;
|
|
|
|
obj = parse_object(ctxt, ap);
|
|
if (obj == NULL) {
|
|
obj = parse_array(ctxt, ap);
|
|
}
|
|
if (obj == NULL) {
|
|
obj = parse_escape(ctxt, ap);
|
|
}
|
|
if (obj == NULL) {
|
|
obj = parse_keyword(ctxt);
|
|
}
|
|
if (obj == NULL) {
|
|
obj = parse_literal(ctxt);
|
|
}
|
|
|
|
return obj;
|
|
}
|
|
|
|
QObject *json_parser_parse(QList *tokens, va_list *ap)
|
|
{
|
|
return json_parser_parse_err(tokens, ap, NULL);
|
|
}
|
|
|
|
QObject *json_parser_parse_err(QList *tokens, va_list *ap, Error **errp)
|
|
{
|
|
JSONParserContext *ctxt = parser_context_new(tokens);
|
|
QObject *result;
|
|
|
|
if (!ctxt) {
|
|
return NULL;
|
|
}
|
|
|
|
result = parse_value(ctxt, ap);
|
|
|
|
error_propagate(errp, ctxt->err);
|
|
|
|
parser_context_free(ctxt);
|
|
|
|
return result;
|
|
}
|