util/error.c

   1 /*
   2  * QEMU Error Objects
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2.  See
  10  * the COPYING.LIB file in the top-level directory.
  11  */
  12
  13 #include "qemu-common.h"
  14 #include "qapi/error.h"
  15 #include "qemu/error-report.h"
  16
  17 struct Error
  18 {
  19     char *msg;
  20     ErrorClass err_class;
  21 };
  22
  23 Error *error_abort;
  24
  25 static void error_setv(Error **errp, ErrorClass err_class,
  26                        const char *fmt, va_list ap)
  27 {
  28     Error *err;
  29     int saved_errno = errno;
  30
  31     if (errp == NULL) {
  32         return;
  33     }
  34     assert(*errp == NULL);
  35
  36     err = g_malloc0(sizeof(*err));
  37     err->msg = g_strdup_vprintf(fmt, ap);
  38     err->err_class = err_class;
  39
  40     if (errp == &error_abort) {
  41         error_report_err(err);
  42         abort();
  43     }
  44
  45     *errp = err;
  46
  47     errno = saved_errno;
  48 }
  49
  50 void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...)
  51 {
  52     va_list ap;
  53
  54     va_start(ap, fmt);
  55     error_setv(errp, err_class, fmt, ap);
  56     va_end(ap);
  57 }
  58
  59 void error_setg(Error **errp, const char *fmt, ...)
  60 {
  61     va_list ap;
  62
  63     va_start(ap, fmt);
  64     error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap);
  65     va_end(ap);
  66 }
  67
  68 void error_setg_errno(Error **errp, int os_errno, const char *fmt, ...)
  69 {
  70     va_list ap;
  71     char *msg;
  72     int saved_errno = errno;
  73
  74     if (errp == NULL) {
  75         return;
  76     }
  77
  78     va_start(ap, fmt);
  79     error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap);
  80     va_end(ap);
  81
  82     if (os_errno != 0) {
  83         msg = (*errp)->msg;
  84         (*errp)->msg = g_strdup_printf("%s: %s", msg, strerror(os_errno));
  85         g_free(msg);
  86     }
  87
  88     errno = saved_errno;
  89 }
  90
  91 void error_setg_file_open(Error **errp, int os_errno, const char *filename)
  92 {
  93     error_setg_errno(errp, os_errno, "Could not open '%s'", filename);
  94 }
  95
  96 #ifdef _WIN32
  97
  98 void error_setg_win32(Error **errp, int win32_err, const char *fmt, ...)
  99 {
 100     va_list ap;
 101     char *msg1, *msg2;
 102
 103     if (errp == NULL) {
 104         return;
 105     }
 106
 107     va_start(ap, fmt);
 108     error_setv(errp, ERROR_CLASS_GENERIC_ERROR, fmt, ap);
 109     va_end(ap);
 110
 111     if (win32_err != 0) {
 112         msg1 = (*errp)->msg;
 113         msg2 = g_win32_error_message(win32_err);
 114         (*errp)->msg = g_strdup_printf("%s: %s (error: %x)", msg1, msg2,
 115                                        (unsigned)win32_err);
 116         g_free(msg2);
 117         g_free(msg1);
 118     }
 119 }
 120
 121 #endif
 122
 123 Error *error_copy(const Error *err)
 124 {
 125     Error *err_new;
 126
 127     err_new = g_malloc0(sizeof(*err));
 128     err_new->msg = g_strdup(err->msg);
 129     err_new->err_class = err->err_class;
 130
 131     return err_new;
 132 }
 133
 134 ErrorClass error_get_class(const Error *err)
 135 {
 136     return err->err_class;
 137 }
 138
 139 const char *error_get_pretty(Error *err)
 140 {
 141     return err->msg;
 142 }
 143
 144 void error_report_err(Error *err)
 145 {
 146     error_report("%s", error_get_pretty(err));
 147     error_free(err);
 148 }
 149
 150 void error_free(Error *err)
 151 {
 152     if (err) {
 153         g_free(err->msg);
 154         g_free(err);
 155     }
 156 }
 157
 158 void error_propagate(Error **dst_errp, Error *local_err)
 159 {
 160     if (local_err && dst_errp == &error_abort) {
 161         error_report_err(local_err);
 162         abort();
 163     } else if (dst_errp && !*dst_errp) {
 164         *dst_errp = local_err;
 165     } else if (local_err) {
 166         error_free(local_err);
 167     }
 168 }