1 /*
2  * Error reporting
3  *
4  * Copyright (C) 2010 Red Hat Inc.
5  *
6  * Authors:
7  *  Markus Armbruster <armbru@redhat.com>,
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "monitor/monitor.h"
15 #include "qemu/error-report.h"
16 
17 /*
18  * @report_type is the type of message: error, warning or
19  * informational.
20  */
21 typedef enum {
22     REPORT_TYPE_ERROR,
23     REPORT_TYPE_WARNING,
24     REPORT_TYPE_INFO,
25 } report_type;
26 
27 /* Prepend timestamp to messages */
28 bool message_with_timestamp;
29 bool error_with_guestname;
30 const char *error_guest_name;
31 
error_printf(const char * fmt,...)32 int error_printf(const char *fmt, ...)
33 {
34     va_list ap;
35     int ret;
36 
37     va_start(ap, fmt);
38     ret = error_vprintf(fmt, ap);
39     va_end(ap);
40     return ret;
41 }
42 
error_printf_unless_qmp(const char * fmt,...)43 int error_printf_unless_qmp(const char *fmt, ...)
44 {
45     va_list ap;
46     int ret;
47 
48     va_start(ap, fmt);
49     ret = error_vprintf_unless_qmp(fmt, ap);
50     va_end(ap);
51     return ret;
52 }
53 
54 static Location std_loc = {
55     .kind = LOC_NONE
56 };
57 static Location *cur_loc = &std_loc;
58 
59 /*
60  * Push location saved in LOC onto the location stack, return it.
61  * The top of that stack is the current location.
62  * Needs a matching loc_pop().
63  */
loc_push_restore(Location * loc)64 Location *loc_push_restore(Location *loc)
65 {
66     assert(!loc->prev);
67     loc->prev = cur_loc;
68     cur_loc = loc;
69     return loc;
70 }
71 
72 /*
73  * Initialize *LOC to "nowhere", push it onto the location stack.
74  * The top of that stack is the current location.
75  * Needs a matching loc_pop().
76  * Return LOC.
77  */
loc_push_none(Location * loc)78 Location *loc_push_none(Location *loc)
79 {
80     loc->kind = LOC_NONE;
81     loc->prev = NULL;
82     return loc_push_restore(loc);
83 }
84 
85 /*
86  * Pop the location stack.
87  * LOC must be the current location, i.e. the top of the stack.
88  */
loc_pop(Location * loc)89 Location *loc_pop(Location *loc)
90 {
91     assert(cur_loc == loc && loc->prev);
92     cur_loc = loc->prev;
93     loc->prev = NULL;
94     return loc;
95 }
96 
97 /*
98  * Save the current location in LOC, return LOC.
99  */
loc_save(Location * loc)100 Location *loc_save(Location *loc)
101 {
102     *loc = *cur_loc;
103     loc->prev = NULL;
104     return loc;
105 }
106 
107 /*
108  * Change the current location to the one saved in LOC.
109  */
loc_restore(Location * loc)110 void loc_restore(Location *loc)
111 {
112     Location *prev = cur_loc->prev;
113     assert(!loc->prev);
114     *cur_loc = *loc;
115     cur_loc->prev = prev;
116 }
117 
118 /*
119  * Change the current location to "nowhere in particular".
120  */
loc_set_none(void)121 void loc_set_none(void)
122 {
123     cur_loc->kind = LOC_NONE;
124 }
125 
126 /*
127  * Change the current location to argument ARGV[IDX..IDX+CNT-1].
128  */
loc_set_cmdline(char ** argv,int idx,int cnt)129 void loc_set_cmdline(char **argv, int idx, int cnt)
130 {
131     cur_loc->kind = LOC_CMDLINE;
132     cur_loc->num = cnt;
133     cur_loc->ptr = argv + idx;
134 }
135 
136 /*
137  * Change the current location to file FNAME, line LNO.
138  */
loc_set_file(const char * fname,int lno)139 void loc_set_file(const char *fname, int lno)
140 {
141     assert (fname || cur_loc->kind == LOC_FILE);
142     cur_loc->kind = LOC_FILE;
143     cur_loc->num = lno;
144     if (fname) {
145         cur_loc->ptr = fname;
146     }
147 }
148 
149 static const char *progname;
150 
151 /*
152  * Set the program name for error_print_loc().
153  */
error_set_progname(const char * argv0)154 static void error_set_progname(const char *argv0)
155 {
156     const char *p = strrchr(argv0, '/');
157     progname = p ? p + 1 : argv0;
158 }
159 
error_get_progname(void)160 const char *error_get_progname(void)
161 {
162     return progname;
163 }
164 
165 /*
166  * Print current location to current monitor if we have one, else to stderr.
167  */
print_loc(void)168 static void print_loc(void)
169 {
170     const char *sep = "";
171     int i;
172     const char *const *argp;
173 
174     if (!monitor_cur() && progname) {
175         fprintf(stderr, "%s:", progname);
176         sep = " ";
177     }
178     switch (cur_loc->kind) {
179     case LOC_CMDLINE:
180         argp = cur_loc->ptr;
181         for (i = 0; i < cur_loc->num; i++) {
182             error_printf("%s%s", sep, argp[i]);
183             sep = " ";
184         }
185         error_printf(": ");
186         break;
187     case LOC_FILE:
188         error_printf("%s:", (const char *)cur_loc->ptr);
189         if (cur_loc->num) {
190             error_printf("%d:", cur_loc->num);
191         }
192         error_printf(" ");
193         break;
194     default:
195         error_printf("%s", sep);
196     }
197 }
198 
199 /*
200  * Print a message to current monitor if we have one, else to stderr.
201  * @report_type is the type of message: error, warning or informational.
202  * Format arguments like vsprintf().  The resulting message should be
203  * a single phrase, with no newline or trailing punctuation.
204  * Prepend the current location and append a newline.
205  */
vreport(report_type type,const char * fmt,va_list ap)206 static void vreport(report_type type, const char *fmt, va_list ap)
207 {
208     GTimeVal tv;
209     gchar *timestr;
210 
211     if (message_with_timestamp && !monitor_cur()) {
212         g_get_current_time(&tv);
213         timestr = g_time_val_to_iso8601(&tv);
214         error_printf("%s ", timestr);
215         g_free(timestr);
216     }
217 
218     /* Only prepend guest name if -msg guest-name and -name guest=... are set */
219     if (error_with_guestname && error_guest_name && !monitor_cur()) {
220         error_printf("%s ", error_guest_name);
221     }
222 
223     print_loc();
224 
225     switch (type) {
226     case REPORT_TYPE_ERROR:
227         break;
228     case REPORT_TYPE_WARNING:
229         error_printf("warning: ");
230         break;
231     case REPORT_TYPE_INFO:
232         error_printf("info: ");
233         break;
234     }
235 
236     error_vprintf(fmt, ap);
237     error_printf("\n");
238 }
239 
240 /*
241  * Print an error message to current monitor if we have one, else to stderr.
242  * Format arguments like vsprintf().  The resulting message should be
243  * a single phrase, with no newline or trailing punctuation.
244  * Prepend the current location and append a newline.
245  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
246  */
error_vreport(const char * fmt,va_list ap)247 void error_vreport(const char *fmt, va_list ap)
248 {
249     vreport(REPORT_TYPE_ERROR, fmt, ap);
250 }
251 
252 /*
253  * Print a warning message to current monitor if we have one, else to stderr.
254  * Format arguments like vsprintf().  The resulting message should be
255  * a single phrase, with no newline or trailing punctuation.
256  * Prepend the current location and append a newline.
257  */
warn_vreport(const char * fmt,va_list ap)258 void warn_vreport(const char *fmt, va_list ap)
259 {
260     vreport(REPORT_TYPE_WARNING, fmt, ap);
261 }
262 
263 /*
264  * Print an information message to current monitor if we have one, else to
265  * stderr.
266  * Format arguments like vsprintf().  The resulting message should be
267  * a single phrase, with no newline or trailing punctuation.
268  * Prepend the current location and append a newline.
269  */
info_vreport(const char * fmt,va_list ap)270 void info_vreport(const char *fmt, va_list ap)
271 {
272     vreport(REPORT_TYPE_INFO, fmt, ap);
273 }
274 
275 /*
276  * Print an error message to current monitor if we have one, else to stderr.
277  * Format arguments like sprintf().  The resulting message should be
278  * a single phrase, with no newline or trailing punctuation.
279  * Prepend the current location and append a newline.
280  * It's wrong to call this in a QMP monitor.  Use error_setg() there.
281  */
error_report(const char * fmt,...)282 void error_report(const char *fmt, ...)
283 {
284     va_list ap;
285 
286     va_start(ap, fmt);
287     vreport(REPORT_TYPE_ERROR, fmt, ap);
288     va_end(ap);
289 }
290 
291 /*
292  * Print a warning message to current monitor if we have one, else to stderr.
293  * Format arguments like sprintf(). The resulting message should be a
294  * single phrase, with no newline or trailing punctuation.
295  * Prepend the current location and append a newline.
296  */
warn_report(const char * fmt,...)297 void warn_report(const char *fmt, ...)
298 {
299     va_list ap;
300 
301     va_start(ap, fmt);
302     vreport(REPORT_TYPE_WARNING, fmt, ap);
303     va_end(ap);
304 }
305 
306 /*
307  * Print an information message to current monitor if we have one, else to
308  * stderr.
309  * Format arguments like sprintf(). The resulting message should be a
310  * single phrase, with no newline or trailing punctuation.
311  * Prepend the current location and append a newline.
312  */
info_report(const char * fmt,...)313 void info_report(const char *fmt, ...)
314 {
315     va_list ap;
316 
317     va_start(ap, fmt);
318     vreport(REPORT_TYPE_INFO, fmt, ap);
319     va_end(ap);
320 }
321 
322 /*
323  * Like error_report(), except print just once.
324  * If *printed is false, print the message, and flip *printed to true.
325  * Return whether the message was printed.
326  */
error_report_once_cond(bool * printed,const char * fmt,...)327 bool error_report_once_cond(bool *printed, const char *fmt, ...)
328 {
329     va_list ap;
330 
331     assert(printed);
332     if (*printed) {
333         return false;
334     }
335     *printed = true;
336     va_start(ap, fmt);
337     vreport(REPORT_TYPE_ERROR, fmt, ap);
338     va_end(ap);
339     return true;
340 }
341 
342 /*
343  * Like warn_report(), except print just once.
344  * If *printed is false, print the message, and flip *printed to true.
345  * Return whether the message was printed.
346  */
warn_report_once_cond(bool * printed,const char * fmt,...)347 bool warn_report_once_cond(bool *printed, const char *fmt, ...)
348 {
349     va_list ap;
350 
351     assert(printed);
352     if (*printed) {
353         return false;
354     }
355     *printed = true;
356     va_start(ap, fmt);
357     vreport(REPORT_TYPE_WARNING, fmt, ap);
358     va_end(ap);
359     return true;
360 }
361 
362 static char *qemu_glog_domains;
363 
qemu_log_func(const gchar * log_domain,GLogLevelFlags log_level,const gchar * message,gpointer user_data)364 static void qemu_log_func(const gchar *log_domain,
365                           GLogLevelFlags log_level,
366                           const gchar *message,
367                           gpointer user_data)
368 {
369     switch (log_level & G_LOG_LEVEL_MASK) {
370     case G_LOG_LEVEL_DEBUG:
371     case G_LOG_LEVEL_INFO:
372         /*
373          * Use same G_MESSAGES_DEBUG logic as glib to enable/disable debug
374          * messages
375          */
376         if (qemu_glog_domains == NULL) {
377             break;
378         }
379         if (strcmp(qemu_glog_domains, "all") != 0 &&
380           (log_domain == NULL || !strstr(qemu_glog_domains, log_domain))) {
381             break;
382         }
383         /* Fall through */
384     case G_LOG_LEVEL_MESSAGE:
385         info_report("%s%s%s",
386                     log_domain ?: "", log_domain ? ": " : "", message);
387 
388         break;
389     case G_LOG_LEVEL_WARNING:
390         warn_report("%s%s%s",
391                     log_domain ?: "", log_domain ? ": " : "", message);
392         break;
393     case G_LOG_LEVEL_CRITICAL:
394     case G_LOG_LEVEL_ERROR:
395         error_report("%s%s%s",
396                      log_domain ?: "", log_domain ? ": " : "", message);
397         break;
398     }
399 }
400 
error_init(const char * argv0)401 void error_init(const char *argv0)
402 {
403     /* Set the program name for error_print_loc(). */
404     error_set_progname(argv0);
405 
406     /*
407      * This sets up glib logging so libraries using it also print their logs
408      * through error_report(), warn_report(), info_report().
409      */
410     g_log_set_default_handler(qemu_log_func, NULL);
411     g_warn_if_fail(qemu_glog_domains == NULL);
412     qemu_glog_domains = g_strdup(g_getenv("G_MESSAGES_DEBUG"));
413 }
414