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     g_free((*errp)->msg);
 138     (*errp)->msg = g_string_free(newmsg, 0);
 139 }
 140
 141 void error_prepend(Error **errp, const char *fmt, ...)
 142 {
 143     va_list ap;
 144
 145     va_start(ap, fmt);
 146     error_vprepend(errp, fmt, ap);
 147     va_end(ap);
 148 }
 149
 150 void error_append_hint(Error **errp, const char *fmt, ...)
 151 {
 152     va_list ap;
 153     int saved_errno = errno;
 154     Error *err;
 155
 156     if (!errp) {
 157         return;
 158     }
 159     err = *errp;
 160     assert(err && errp != &error_abort && errp != &error_fatal);
 161
 162     if (!err->hint) {
 163         err->hint = g_string_new(NULL);
 164     }
 165     va_start(ap, fmt);
 166     g_string_append_vprintf(err->hint, fmt, ap);
 167     va_end(ap);
 168
 169     errno = saved_errno;
 170 }
 171
 172 #ifdef _WIN32
 173
 174 void error_setg_win32_internal(Error **errp,
 175                                const char *src, int line, const char *func,
 176                                int win32_err, const char *fmt, ...)
 177 {
 178     va_list ap;
 179     char *suffix = NULL;
 180
 181     if (errp == NULL) {
 182         return;
 183     }
 184
 185     if (win32_err != 0) {
 186         suffix = g_win32_error_message(win32_err);
 187     }
 188
 189     va_start(ap, fmt);
 190     error_setv(errp, src, line, func, ERROR_CLASS_GENERIC_ERROR,
 191                fmt, ap, suffix);
 192     va_end(ap);
 193
 194     g_free(suffix);
 195 }
 196
 197 #endif
 198
 199 Error *error_copy(const Error *err)
 200 {
 201     Error *err_new;
 202
 203     err_new = g_malloc0(sizeof(*err));
 204     err_new->msg = g_strdup(err->msg);
 205     err_new->err_class = err->err_class;
 206     err_new->src = err->src;
 207     err_new->line = err->line;
 208     err_new->func = err->func;
 209     if (err->hint) {
 210         err_new->hint = g_string_new(err->hint->str);
 211     }
 212
 213     return err_new;
 214 }
 215
 216 ErrorClass error_get_class(const Error *err)
 217 {
 218     return err->err_class;
 219 }
 220
 221 const char *error_get_pretty(const Error *err)
 222 {
 223     return err->msg;
 224 }
 225
 226 void error_report_err(Error *err)
 227 {
 228     error_report("%s", error_get_pretty(err));
 229     if (err->hint) {
 230         error_printf_unless_qmp("%s", err->hint->str);
 231     }
 232     error_free(err);
 233 }
 234
 235 void error_reportf_err(Error *err, const char *fmt, ...)
 236 {
 237     va_list ap;
 238
 239     va_start(ap, fmt);
 240     error_vprepend(&err, fmt, ap);
 241     va_end(ap);
 242     error_report_err(err);
 243 }
 244
 245 void error_free(Error *err)
 246 {
 247     if (err) {
 248         g_free(err->msg);
 249         if (err->hint) {
 250             g_string_free(err->hint, true);
 251         }
 252         g_free(err);
 253     }
 254 }
 255
 256 void error_free_or_abort(Error **errp)
 257 {
 258     assert(errp && *errp);
 259     error_free(*errp);
 260     *errp = NULL;
 261 }
 262
 263 void error_propagate(Error **dst_errp, Error *local_err)
 264 {
 265     if (!local_err) {
 266         return;
 267     }
 268     error_handle_fatal(dst_errp, local_err);
 269     if (dst_errp && !*dst_errp) {
 270         *dst_errp = local_err;
 271     } else {
 272         error_free(local_err);
 273     }
 274 }