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