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/*
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 * QError: QEMU Error data-type.
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 *
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 * Copyright (C) 2009 Red Hat Inc.
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 *
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 * Authors:
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 *  Luiz Capitulino <lcapitulino@redhat.com>
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 *
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 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
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 * See the COPYING.LIB file in the top-level directory.
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 */
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#include "qjson.h"
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#include "qerror.h"
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#include "qstring.h"
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#include "sysemu.h"
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#include "qemu-common.h"
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static void qerror_destroy_obj(QObject *obj);
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static const QType qerror_type = {
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    .code = QTYPE_QERROR,
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    .destroy = qerror_destroy_obj,
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};
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/**
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 * The 'desc' parameter is a printf-like string, the format of the format
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 * string is:
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 *
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 * %(KEY)
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 *
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 * Where KEY is a QDict key, which has to be passed to qerror_from_info().
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 *
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 * Example:
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 *
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 * "foo error on device: %(device) slot: %(slot_nr)"
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 *
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 * A single percent sign can be printed if followed by a second one,
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 * for example:
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 *
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 * "running out of foo: %(foo)%%"
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 */
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static const QErrorStringTable qerror_table[] = {
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    {
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        .error_fmt = QERR_COMMAND_NOT_FOUND,
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        .desc      = "The command %(name) has not been found",
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    },
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    {
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        .error_fmt = QERR_DEVICE_ENCRYPTED,
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        .desc      = "The %(device) is encrypted",
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    },
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    {
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        .error_fmt = QERR_DEVICE_LOCKED,
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        .desc      = "Device %(device) is locked",
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    },
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    {
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        .error_fmt = QERR_DEVICE_NOT_ACTIVE,
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        .desc      = "The %(device) device has not been activated by the guest",
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    },
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    {
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        .error_fmt = QERR_DEVICE_NOT_FOUND,
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        .desc      = "The %(device) device has not been found",
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    },
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    {
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        .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
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        .desc      = "Device %(device) is not removable",
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    },
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    {
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        .error_fmt = QERR_FD_NOT_FOUND,
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        .desc      = "Failed to find file descriptor named %(name)",
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    },
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    {
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        .error_fmt = QERR_FD_NOT_SUPPLIED,
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        .desc      = "No file descriptor supplied via SCM_RIGHTS",
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    },
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    {
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        .error_fmt = QERR_OPEN_FILE_FAILED,
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        .desc      = "Could not open '%(filename)'",
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    },
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    {
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        .error_fmt = QERR_INVALID_BLOCK_FORMAT,
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        .desc      = "Invalid block format %(name)",
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    },
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    {
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        .error_fmt = QERR_INVALID_PARAMETER,
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        .desc      = "Invalid parameter %(name)",
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    },
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    {
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        .error_fmt = QERR_INVALID_PARAMETER_TYPE,
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        .desc      = "Invalid parameter type, expected: %(expected)",
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    },
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    {
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        .error_fmt = QERR_INVALID_PASSWORD,
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        .desc      = "The entered password is invalid",
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    },
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    {
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        .error_fmt = QERR_JSON_PARSING,
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        .desc      = "Invalid JSON syntax",
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    },
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    {
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        .error_fmt = QERR_KVM_MISSING_CAP,
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        .desc      = "Using KVM without %(capability), %(feature) unavailable",
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    },
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    {
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        .error_fmt = QERR_MISSING_PARAMETER,
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        .desc      = "Parameter %(name) is missing",
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    },
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    {
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        .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
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        .desc      = "Bad QMP input object",
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    },
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    {
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        .error_fmt = QERR_SET_PASSWD_FAILED,
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        .desc      = "Could not set password",
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    },
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    {
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        .error_fmt = QERR_TOO_MANY_FILES,
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        .desc      = "Too many open files",
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    },
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    {
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        .error_fmt = QERR_UNDEFINED_ERROR,
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        .desc      = "An undefined error has ocurred",
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    },
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    {
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        .error_fmt = QERR_VNC_SERVER_FAILED,
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        .desc      = "Could not start VNC server on %(target)",
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    },
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    {}
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};
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/**
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 * qerror_new(): Create a new QError
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 *
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 * Return strong reference.
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 */
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QError *qerror_new(void)
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{
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    QError *qerr;
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    qerr = qemu_mallocz(sizeof(*qerr));
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    QOBJECT_INIT(qerr, &qerror_type);
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    return qerr;
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}
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static void qerror_abort(const QError *qerr, const char *fmt, ...)
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{
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    va_list ap;
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    fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
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    fprintf(stderr, "qerror: -> ");
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    va_start(ap, fmt);
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    vfprintf(stderr, fmt, ap);
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    va_end(ap);
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    fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
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    abort();
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}
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static void qerror_set_data(QError *qerr, const char *fmt, va_list *va)
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{
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    QObject *obj;
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    obj = qobject_from_jsonv(fmt, va);
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    if (!obj) {
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        qerror_abort(qerr, "invalid format '%s'", fmt);
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    }
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    if (qobject_type(obj) != QTYPE_QDICT) {
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        qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
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    }
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    qerr->error = qobject_to_qdict(obj);
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    obj = qdict_get(qerr->error, "class");
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    if (!obj) {
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        qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
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    }
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    if (qobject_type(obj) != QTYPE_QSTRING) {
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        qerror_abort(qerr, "'class' key value should be a QString");
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    }
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    obj = qdict_get(qerr->error, "data");
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    if (!obj) {
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        qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
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    }
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    if (qobject_type(obj) != QTYPE_QDICT) {
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        qerror_abort(qerr, "'data' key value should be a QDICT");
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    }
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}
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static void qerror_set_desc(QError *qerr, const char *fmt)
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{
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    int i;
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    // FIXME: inefficient loop
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    for (i = 0; qerror_table[i].error_fmt; i++) {
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        if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
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            qerr->entry = &qerror_table[i];
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            return;
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        }
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    }
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    qerror_abort(qerr, "error format '%s' not found", fmt);
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}
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/**
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 * qerror_from_info(): Create a new QError from error information
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 *
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 * The information consists of:
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 *
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 * - file   the file name of where the error occurred
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 * - linenr the line number of where the error occurred
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 * - func   the function name of where the error occurred
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 * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
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 *          'data'
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 * - va     va_list of all arguments specified by fmt
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 *
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 * Return strong reference.
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 */
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QError *qerror_from_info(const char *file, int linenr, const char *func,
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                         const char *fmt, va_list *va)
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{
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    QError *qerr;
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    qerr = qerror_new();
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    qerr->linenr = linenr;
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    qerr->file = file;
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    qerr->func = func;
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    if (!fmt) {
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        qerror_abort(qerr, "QDict not specified");
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    }
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    qerror_set_data(qerr, fmt, va);
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    qerror_set_desc(qerr, fmt);
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    return qerr;
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}
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static void parse_error(const QError *qerror, int c)
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{
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    qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
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}
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static const char *append_field(QString *outstr, const QError *qerror,
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                                const char *start)
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{
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    QObject *obj;
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    QDict *qdict;
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    QString *key_qs;
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    const char *end, *key;
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    if (*start != '%')
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        parse_error(qerror, '%');
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    start++;
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    if (*start != '(')
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        parse_error(qerror, '(');
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    start++;
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    end = strchr(start, ')');
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    if (!end)
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        parse_error(qerror, ')');
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    key_qs = qstring_from_substr(start, 0, end - start - 1);
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    key = qstring_get_str(key_qs);
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    qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
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    obj = qdict_get(qdict, key);
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    if (!obj) {
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        qerror_abort(qerror, "key '%s' not found in QDict", key);
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    }
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    switch (qobject_type(obj)) {
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        case QTYPE_QSTRING:
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            qstring_append(outstr, qdict_get_str(qdict, key));
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            break;
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        case QTYPE_QINT:
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            qstring_append_int(outstr, qdict_get_int(qdict, key));
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            break;
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        default:
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            qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
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    }
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    QDECREF(key_qs);
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    return ++end;
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}
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/**
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 * qerror_human(): Format QError data into human-readable string.
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 *
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 * Formats according to member 'desc' of the specified QError object.
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 */
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QString *qerror_human(const QError *qerror)
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{
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    const char *p;
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    QString *qstring;
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    assert(qerror->entry != NULL);
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    qstring = qstring_new();
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    for (p = qerror->entry->desc; *p != '\0';) {
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        if (*p != '%') {
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            qstring_append_chr(qstring, *p++);
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        } else if (*(p + 1) == '%') {
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            qstring_append_chr(qstring, '%');
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            p += 2;
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        } else {
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            p = append_field(qstring, qerror, p);
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        }
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    }
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    return qstring;
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}
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/**
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 * qerror_print(): Print QError data
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 *
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 * This function will print the member 'desc' of the specified QError object,
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 * it uses qemu_error() for this, so that the output is routed to the right
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 * place (ie. stderr or Monitor's device).
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 */
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void qerror_print(const QError *qerror)
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{
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    QString *qstring = qerror_human(qerror);
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    qemu_error("%s\n", qstring_get_str(qstring));
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    QDECREF(qstring);
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}
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/**
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 * qobject_to_qerror(): Convert a QObject into a QError
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 */
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QError *qobject_to_qerror(const QObject *obj)
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{
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    if (qobject_type(obj) != QTYPE_QERROR) {
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        return NULL;
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    }
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    return container_of(obj, QError, base);
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}
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/**
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 * qerror_destroy_obj(): Free all memory allocated by a QError
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 */
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static void qerror_destroy_obj(QObject *obj)
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{
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    QError *qerr;
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    assert(obj != NULL);
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    qerr = qobject_to_qerror(obj);
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    QDECREF(qerr->error);
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    qemu_free(qerr);
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}