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Diffstat (limited to 'qerror.c')
| -rw-r--r-- | qerror.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/qerror.c b/qerror.c new file mode 100644 index 0000000000..10b0939f62 --- /dev/null +++ b/qerror.c @@ -0,0 +1,260 @@ +/* + * QError: QEMU Error data-type. + * + * Copyright (C) 2009 Red Hat Inc. + * + * Authors: + * Luiz Capitulino <lcapitulino@redhat.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 "qjson.h" +#include "qerror.h" +#include "qstring.h" +#include "sysemu.h" +#include "qemu-common.h" + +static void qerror_destroy_obj(QObject *obj); + +static const QType qerror_type = { + .code = QTYPE_QERROR, + .destroy = qerror_destroy_obj, +}; + +/** + * The 'desc' parameter is a printf-like string, the format of the format + * string is: + * + * %(KEY) + * + * Where KEY is a QDict key, which has to be passed to qerror_from_info(). + * + * Example: + * + * "foo error on device: %(device) slot: %(slot_nr)" + * + * A single percent sign can be printed if followed by a second one, + * for example: + * + * "running out of foo: %(foo)%%" + */ +const QErrorStringTable qerror_table[] = { + {} +}; + +/** + * qerror_new(): Create a new QError + * + * Return strong reference. + */ +QError *qerror_new(void) +{ + QError *qerr; + + qerr = qemu_mallocz(sizeof(*qerr)); + QOBJECT_INIT(qerr, &qerror_type); + + return qerr; +} + +static void qerror_abort(const QError *qerr, const char *fmt, ...) +{ + va_list ap; + + fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func); + fprintf(stderr, "qerror: -> "); + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + + fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr); + abort(); +} + +static void qerror_set_data(QError *qerr, const char *fmt, va_list *va) +{ + QObject *obj; + + obj = qobject_from_jsonv(fmt, va); + if (!obj) { + qerror_abort(qerr, "invalid format '%s'", fmt); + } + if (qobject_type(obj) != QTYPE_QDICT) { + qerror_abort(qerr, "error format is not a QDict '%s'", fmt); + } + + qerr->error = qobject_to_qdict(obj); + + obj = qdict_get(qerr->error, "class"); + if (!obj) { + qerror_abort(qerr, "missing 'class' key in '%s'", fmt); + } + if (qobject_type(obj) != QTYPE_QSTRING) { + qerror_abort(qerr, "'class' key value should be a QString"); + } + + obj = qdict_get(qerr->error, "data"); + if (!obj) { + qerror_abort(qerr, "missing 'data' key in '%s'", fmt); + } + if (qobject_type(obj) != QTYPE_QDICT) { + qerror_abort(qerr, "'data' key value should be a QDICT"); + } +} + +static void qerror_set_desc(QError *qerr, const char *fmt) +{ + int i; + + // FIXME: inefficient loop + + for (i = 0; qerror_table[i].error_fmt; i++) { + if (strcmp(qerror_table[i].error_fmt, fmt) == 0) { + qerr->entry = &qerror_table[i]; + return; + } + } + + qerror_abort(qerr, "error format '%s' not found", fmt); +} + +/** + * qerror_from_info(): Create a new QError from error information + * + * The information consists of: + * + * - file the file name of where the error occurred + * - linenr the line number of where the error occurred + * - func the function name of where the error occurred + * - fmt JSON printf-like dictionary, there must exist keys 'class' and + * 'data' + * - va va_list of all arguments specified by fmt + * + * Return strong reference. + */ +QError *qerror_from_info(const char *file, int linenr, const char *func, + const char *fmt, va_list *va) +{ + QError *qerr; + + qerr = qerror_new(); + qerr->linenr = linenr; + qerr->file = file; + qerr->func = func; + + if (!fmt) { + qerror_abort(qerr, "QDict not specified"); + } + + qerror_set_data(qerr, fmt, va); + qerror_set_desc(qerr, fmt); + + return qerr; +} + +static void parse_error(const QError *qerror, int c) +{ + qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc); +} + +static const char *append_field(QString *outstr, const QError *qerror, + const char *start) +{ + QObject *obj; + QDict *qdict; + QString *key_qs; + const char *end, *key; + + if (*start != '%') + parse_error(qerror, '%'); + start++; + if (*start != '(') + parse_error(qerror, '('); + start++; + + end = strchr(start, ')'); + if (!end) + parse_error(qerror, ')'); + + key_qs = qstring_from_substr(start, 0, end - start - 1); + key = qstring_get_str(key_qs); + + qdict = qobject_to_qdict(qdict_get(qerror->error, "data")); + obj = qdict_get(qdict, key); + if (!obj) { + qerror_abort(qerror, "key '%s' not found in QDict", key); + } + + switch (qobject_type(obj)) { + case QTYPE_QSTRING: + qstring_append(outstr, qdict_get_str(qdict, key)); + break; + case QTYPE_QINT: + qstring_append_int(outstr, qdict_get_int(qdict, key)); + break; + default: + qerror_abort(qerror, "invalid type '%c'", qobject_type(obj)); + } + + QDECREF(key_qs); + return ++end; +} + +/** + * qerror_print(): Print QError data + * + * This function will print the member 'desc' of the specified QError object, + * it uses qemu_error() for this, so that the output is routed to the right + * place (ie. stderr or Monitor's device). + */ +void qerror_print(const QError *qerror) +{ + const char *p; + QString *qstring; + + assert(qerror->entry != NULL); + + qstring = qstring_new(); + + for (p = qerror->entry->desc; *p != '\0';) { + if (*p != '%') { + qstring_append_chr(qstring, *p++); + } else if (*(p + 1) == '%') { + qstring_append_chr(qstring, '%'); + p += 2; + } else { + p = append_field(qstring, qerror, p); + } + } + + qemu_error("%s\n", qstring_get_str(qstring)); + QDECREF(qstring); +} + +/** + * qobject_to_qerror(): Convert a QObject into a QError + */ +QError *qobject_to_qerror(const QObject *obj) +{ + if (qobject_type(obj) != QTYPE_QERROR) { + return NULL; + } + + return container_of(obj, QError, base); +} + +/** + * qerror_destroy_obj(): Free all memory allocated by a QError + */ +static void qerror_destroy_obj(QObject *obj) +{ + QError *qerr; + + assert(obj != NULL); + qerr = qobject_to_qerror(obj); + + QDECREF(qerr->error); + qemu_free(qerr); +} |