util/error.c

   1 /*
   2  * QEMU Error Objects
   3  *
   4  * Copyright IBM, Corp. 2011
   5  * Copyright (C) 2011-2015 Red Hat, Inc.
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <aliguori@us.ibm.com>
   9  *  Markus Armbruster <armbru@redhat.com>,
  10  *
  11  * This work is licensed under the terms of the GNU LGPL, version 2.  See
  12  * the COPYING.LIB file in the top-level directory.
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qapi/error.h"
  17 #include "qemu-common.h"
  18 #include "qemu/error-report.h"
  19
  20 struct Error
  21 {
  22     char *msg;
  23     ErrorClass err_class;
  24     const char *src, *func;
  25     int line;
  26     GString *hint;
  27 };
  28
  29 Error *error_abort;
  30 Error *error_fatal;
  31
  32 static void error_handle_fatal(Error **errp, Error *err)
  33 {
  34     if (errp == &error_abort) {
  35         fprintf(stderr, "Unexpected error in %s() at %s:%d:\n",
  36                 err->func, err->src, err->line);
  37         error_report_err(err);
  38         abort();
  39     }
  40     if (errp == &error_fatal) {
  41         error_report_err(err);
  42         exit(1);
  43     }
  44 }
  45
  46 static void error_setv(Error **errp,
  47                        const char *src, int line, const char *func,
  48                        ErrorClass err_class, const char *fmt, va_list ap,
  49                        const char *suffix)
  50 {
  51     Error *err;
  52     int saved_errno = errno;
  53
  54     if (errp == NULL) {
  55         return;
  56     }
  57     assert(*errp == NULL);
  58
  59     err = g_malloc0(sizeof(*err));
  60     err->msg = g_strdup_vprintf(fmt, ap);
  61     if (suffix) {
  62         char *msg = err->msg;
  63         err->msg = g_strdup_printf("%s: %s", msg, suffix);
  64         g_free(msg);
  65     }
  66     err->err_class = err_class;
  67     err->src = src;
  68     err->line = line;
  69     err->func = func;
  70
  71     error_handle_fatal(errp, err);
  72     *errp = err;
  73
  74     errno = saved_errno;
  75 }
  76
  77 void error_set_internal(Error **errp,
  78                         const char *src, int line, const char *func,
  79                         ErrorClass err_class, const char *fmt, ...)
  80 {
  81     va_list ap;
  82
  83     va_start(ap, fmt);
  84     error_setv(errp, src, line, func, err_class, fmt, ap, NULL);
  85     va_end(ap);
  86 }
  87
  88 void error_setg_internal(Error **errp,
  89                          const char *src, int line, const char *func,
  90                          const char *fmt, ...)
  91 {
  92     va_list ap;
  93
  94     va_start(ap, fmt);
  95     error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR, fmt, ap, NULL);
  96     va_end(ap);
  97 }
  98
  99 void error_setg_errno_internal(Error **errp,
 100                                const char *src, int line, const char *func,
 101                                int os_errno, const char *fmt, ...)
 102 {
 103     va_list ap;
 104     int saved_errno = errno;
 105
 106     if (errp == NULL) {
 107         return;
 108     }
 109
 110     va_start(ap, fmt);
 111     error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR, fmt, ap,
 112                os_errno != 0 ? strerror(os_errno) : NULL);
 113     va_end(ap);
 114
 115     errno = saved_errno;
 116 }
 117
 118 void error_setg_file_open_internal(Error **errp,
 119                                    const char *src, int line, const char *func,
 120                                    int os_errno, const char *filename)
 121 {
 122     error_setg_errno_internal(errp, src, line, func, os_errno,
 123                               "Could not open '%s'", filename);
 124 }
 125
 126 void error_vprepend(Error **errp, const char *fmt, va_list ap)
 127 {
 128     GString *newmsg;
 129
 130     if (!errp) {
 131         return;
 132     }
 133
 134     newmsg = g_string_new(NULL);
 135     g_string_vprintf(newmsg, fmt, ap);
 136     g_string_append(newmsg, (*errp)->msg);
 137     (*errp)->msg = g_string_free(newmsg, 0);
 138 }
 139
 140 void error_prepend(Error **errp, const char *fmt, ...)
 141 {
 142     va_list ap;
 143
 144     va_start(ap, fmt);
 145     error_vprepend(errp, fmt, ap);
 146     va_end(ap);
 147 }
 148
 149 void error_append_hint(Error **errp, const char *fmt, ...)
 150 {
 151     va_list ap;
 152     int saved_errno = errno;
 153     Error *err;
 154
 155     if (!errp) {
 156         return;
 157     }
 158     err = *errp;
 159     assert(err && errp != &error_abort && errp != &error_fatal);
 160
 161     if (!err->hint) {
 162         err->hint = g_string_new(NULL);
 163     }
 164     va_start(ap, fmt);
 165     g_string_append_vprintf(err->hint, fmt, ap);
 166     va_end(ap);
 167
 168     errno = saved_errno;
 169 }
 170
 171 #ifdef _WIN32
 172
 173 void error_setg_win32_internal(Error **errp,
 174                                const char *src, int line, const char *func,
 175                                int win32_err, const char *fmt, ...)
 176 {
 177     va_list ap;
 178     char *suffix = NULL;
 179
 180     if (errp == NULL) {
 181         return;
 182     }
 183
 184     if (win32_err != 0) {
 185         suffix = g_win32_error_message(win32_err);
 186     }
 187
 188     va_start(ap, fmt);
 189     error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR,
 190                fmt, ap, suffix);
 191     va_end(ap);
 192
 193     g_free(suffix);
 194 }
 195
 196 #endif
 197
 198 Error *error_copy(const Error *err)
 199 {
 200     Error *err_new;
 201
 202     err_new = g_malloc0(sizeof(*err));
 203     err_new->msg = g_strdup(err->msg);
 204     err_new->err_class = err->err_class;
 205     err_new->src = err->src;
 206     err_new->line = err->line;
 207     err_new->func = err->func;
 208     if (err->hint) {
 209         err_new->hint = g_string_new(err->hint->str);
 210     }
 211
 212     return err_new;
 213 }
 214
 215 ErrorClass error_get_class(const Error *err)
 216 {
 217     return err->err_class;
 218 }
 219
 220 const char *error_get_pretty(Error *err)
 221 {
 222     return err->msg;
 223 }
 224
 225 void error_report_err(Error *err)
 226 {
 227     error_report("%s", error_get_pretty(err));
 228     if (err->hint) {
 229         error_printf_unless_qmp("%s", err->hint->str);
 230     }
 231     error_free(err);
 232 }
 233
 234 void error_reportf_err(Error *err, const char *fmt, ...)
 235 {
 236     va_list ap;
 237
 238     va_start(ap, fmt);
 239     error_vprepend(&err, fmt, ap);
 240     va_end(ap);
 241     error_report_err(err);
 242 }
 243
 244 void error_free(Error *err)
 245 {
 246     if (err) {
 247         g_free(err->msg);
 248         if (err->hint) {
 249             g_string_free(err->hint, true);
 250         }
 251         g_free(err);
 252     }
 253 }
 254
 255 void error_free_or_abort(Error **errp)
 256 {
 257     assert(errp && *errp);
 258     error_free(*errp);
 259     *errp = NULL;
 260 }
 261
 262 void error_propagate(Error **dst_errp, Error *local_err)
 263 {
 264     if (!local_err) {
 265         return;
 266     }
 267     error_handle_fatal(dst_errp, local_err);
 268     if (dst_errp && !*dst_errp) {
 269         *dst_errp = local_err;
 270     } else {
 271         error_free(local_err);
 272     }
 273 }