xref: /openbmc/qemu/qapi/string-output-visitor.c (revision effd60c8)
1 /*
2  * String printing Visitor
3  *
4  * Copyright Red Hat, Inc. 2012-2016
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
9  * See the COPYING.LIB file in the top-level directory.
10  *
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qemu/cutils.h"
15 #include "qapi/string-output-visitor.h"
16 #include "qapi/visitor-impl.h"
17 #include <math.h>
18 #include "qemu/range.h"
19 
20 enum ListMode {
21     LM_NONE,             /* not traversing a list of repeated options */
22     LM_STARTED,          /* next_list() ready to be called */
23 
24     LM_IN_PROGRESS,      /* next_list() has been called.
25                           *
26                           * Generating the next list link will consume the most
27                           * recently parsed QemuOpt instance of the repeated
28                           * option.
29                           *
30                           * Parsing a value into the list link will examine the
31                           * next QemuOpt instance of the repeated option, and
32                           * possibly enter LM_SIGNED_INTERVAL or
33                           * LM_UNSIGNED_INTERVAL.
34                           */
35 
36     LM_SIGNED_INTERVAL,  /* next_list() has been called.
37                           *
38                           * Generating the next list link will consume the most
39                           * recently stored element from the signed interval,
40                           * parsed from the most recent QemuOpt instance of the
41                           * repeated option. This may consume QemuOpt itself
42                           * and return to LM_IN_PROGRESS.
43                           *
44                           * Parsing a value into the list link will store the
45                           * next element of the signed interval.
46                           */
47 
48     LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
49 
50     LM_END,              /* next_list() called, about to see last element. */
51 };
52 
53 typedef enum ListMode ListMode;
54 
55 struct StringOutputVisitor
56 {
57     Visitor visitor;
58     bool human;
59     GString *string;
60     char **result;
61     ListMode list_mode;
62     union {
63         int64_t s;
64         uint64_t u;
65     } range_start, range_end;
66     GList *ranges;
67     void *list; /* Only needed for sanity checking the caller */
68     unsigned int struct_nesting;
69 };
70 
71 static StringOutputVisitor *to_sov(Visitor *v)
72 {
73     return container_of(v, StringOutputVisitor, visitor);
74 }
75 
76 static void string_output_set(StringOutputVisitor *sov, char *string)
77 {
78     switch (sov->list_mode) {
79     case LM_STARTED:
80         sov->list_mode = LM_IN_PROGRESS;
81         /* fall through */
82     case LM_NONE:
83         if (sov->string) {
84             g_string_free(sov->string, true);
85         }
86         sov->string = g_string_new(string);
87         g_free(string);
88         break;
89 
90     case LM_IN_PROGRESS:
91     case LM_END:
92         g_string_append(sov->string, ", ");
93         g_string_append(sov->string, string);
94         break;
95 
96     default:
97         abort();
98     }
99 }
100 
101 static void string_output_append(StringOutputVisitor *sov, int64_t a)
102 {
103     Range *r = g_malloc0(sizeof(*r));
104 
105     range_set_bounds(r, a, a);
106     sov->ranges = range_list_insert(sov->ranges, r);
107 }
108 
109 static void string_output_append_range(StringOutputVisitor *sov,
110                                        int64_t s, int64_t e)
111 {
112     Range *r = g_malloc0(sizeof(*r));
113 
114     range_set_bounds(r, s, e);
115     sov->ranges = range_list_insert(sov->ranges, r);
116 }
117 
118 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
119                           bool human)
120 {
121     if (range_lob(r) != range_upb(r)) {
122         if (human) {
123             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
124                                    range_lob(r), range_upb(r));
125 
126         } else {
127             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
128                                    range_lob(r), range_upb(r));
129         }
130     } else {
131         if (human) {
132             g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
133         } else {
134             g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
135         }
136     }
137     if (next) {
138         g_string_append(sov->string, ",");
139     }
140 }
141 
142 static bool print_type_int64(Visitor *v, const char *name, int64_t *obj,
143                              Error **errp)
144 {
145     StringOutputVisitor *sov = to_sov(v);
146     GList *l;
147 
148     if (sov->struct_nesting) {
149         return true;
150     }
151 
152     switch (sov->list_mode) {
153     case LM_NONE:
154         string_output_append(sov, *obj);
155         break;
156 
157     case LM_STARTED:
158         sov->range_start.s = *obj;
159         sov->range_end.s = *obj;
160         sov->list_mode = LM_IN_PROGRESS;
161         return true;
162 
163     case LM_IN_PROGRESS:
164         if (sov->range_end.s + 1 == *obj) {
165             sov->range_end.s++;
166         } else {
167             if (sov->range_start.s == sov->range_end.s) {
168                 string_output_append(sov, sov->range_end.s);
169             } else {
170                 assert(sov->range_start.s < sov->range_end.s);
171                 string_output_append_range(sov, sov->range_start.s,
172                                            sov->range_end.s);
173             }
174 
175             sov->range_start.s = *obj;
176             sov->range_end.s = *obj;
177         }
178         return true;
179 
180     case LM_END:
181         if (sov->range_end.s + 1 == *obj) {
182             sov->range_end.s++;
183             assert(sov->range_start.s < sov->range_end.s);
184             string_output_append_range(sov, sov->range_start.s,
185                                        sov->range_end.s);
186         } else {
187             if (sov->range_start.s == sov->range_end.s) {
188                 string_output_append(sov, sov->range_end.s);
189             } else {
190                 assert(sov->range_start.s < sov->range_end.s);
191 
192                 string_output_append_range(sov, sov->range_start.s,
193                                            sov->range_end.s);
194             }
195             string_output_append(sov, *obj);
196         }
197         break;
198 
199     default:
200         abort();
201     }
202 
203     l = sov->ranges;
204     while (l) {
205         Range *r = l->data;
206         format_string(sov, r, l->next != NULL, false);
207         l = l->next;
208     }
209 
210     if (sov->human) {
211         l = sov->ranges;
212         g_string_append(sov->string, " (");
213         while (l) {
214             Range *r = l->data;
215             format_string(sov, r, l->next != NULL, true);
216             l = l->next;
217         }
218         g_string_append(sov->string, ")");
219     }
220 
221     return true;
222 }
223 
224 static bool print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
225                              Error **errp)
226 {
227     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
228     int64_t i = *obj;
229     return print_type_int64(v, name, &i, errp);
230 }
231 
232 static bool print_type_size(Visitor *v, const char *name, uint64_t *obj,
233                             Error **errp)
234 {
235     StringOutputVisitor *sov = to_sov(v);
236     uint64_t val;
237     char *out, *psize;
238 
239     if (sov->struct_nesting) {
240         return true;
241     }
242 
243     if (!sov->human) {
244         out = g_strdup_printf("%"PRIu64, *obj);
245         string_output_set(sov, out);
246         return true;
247     }
248 
249     val = *obj;
250     psize = size_to_str(val);
251     out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
252     string_output_set(sov, out);
253 
254     g_free(psize);
255     return true;
256 }
257 
258 static bool print_type_bool(Visitor *v, const char *name, bool *obj,
259                             Error **errp)
260 {
261     StringOutputVisitor *sov = to_sov(v);
262 
263     if (sov->struct_nesting) {
264         return true;
265     }
266 
267     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
268     return true;
269 }
270 
271 static bool print_type_str(Visitor *v, const char *name, char **obj,
272                            Error **errp)
273 {
274     StringOutputVisitor *sov = to_sov(v);
275     char *out;
276 
277     if (sov->struct_nesting) {
278         return true;
279     }
280 
281     if (sov->human) {
282         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
283     } else {
284         out = g_strdup(*obj ? *obj : "");
285     }
286     string_output_set(sov, out);
287     return true;
288 }
289 
290 static bool print_type_number(Visitor *v, const char *name, double *obj,
291                               Error **errp)
292 {
293     StringOutputVisitor *sov = to_sov(v);
294 
295     if (sov->struct_nesting) {
296         return true;
297     }
298 
299     string_output_set(sov, g_strdup_printf("%.17g", *obj));
300     return true;
301 }
302 
303 static bool print_type_null(Visitor *v, const char *name, QNull **obj,
304                             Error **errp)
305 {
306     StringOutputVisitor *sov = to_sov(v);
307     char *out;
308 
309     if (sov->struct_nesting) {
310         return true;
311     }
312 
313     if (sov->human) {
314         out = g_strdup("<null>");
315     } else {
316         out = g_strdup("");
317     }
318     string_output_set(sov, out);
319     return true;
320 }
321 
322 static bool start_struct(Visitor *v, const char *name, void **obj,
323                          size_t size, Error **errp)
324 {
325     StringOutputVisitor *sov = to_sov(v);
326 
327     sov->struct_nesting++;
328     return true;
329 }
330 
331 static void end_struct(Visitor *v, void **obj)
332 {
333     StringOutputVisitor *sov = to_sov(v);
334 
335     if (--sov->struct_nesting) {
336         return;
337     }
338 
339     /* TODO actually print struct fields */
340     string_output_set(sov, g_strdup("<omitted>"));
341 }
342 
343 static bool
344 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
345            Error **errp)
346 {
347     StringOutputVisitor *sov = to_sov(v);
348 
349     if (sov->struct_nesting) {
350         return true;
351     }
352 
353     /* we can't traverse a list in a list */
354     assert(sov->list_mode == LM_NONE);
355     /* We don't support visits without a list */
356     assert(list);
357     sov->list = list;
358     /* List handling is only needed if there are at least two elements */
359     if (*list && (*list)->next) {
360         sov->list_mode = LM_STARTED;
361     }
362     return true;
363 }
364 
365 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
366 {
367     StringOutputVisitor *sov = to_sov(v);
368     GenericList *ret = tail->next;
369 
370     if (sov->struct_nesting) {
371         return ret;
372     }
373 
374     if (ret && !ret->next) {
375         sov->list_mode = LM_END;
376     }
377     return ret;
378 }
379 
380 static void end_list(Visitor *v, void **obj)
381 {
382     StringOutputVisitor *sov = to_sov(v);
383 
384     if (sov->struct_nesting) {
385         return;
386     }
387 
388     assert(sov->list == obj);
389     assert(sov->list_mode == LM_STARTED ||
390            sov->list_mode == LM_END ||
391            sov->list_mode == LM_NONE ||
392            sov->list_mode == LM_IN_PROGRESS);
393     sov->list_mode = LM_NONE;
394 }
395 
396 static void string_output_complete(Visitor *v, void *opaque)
397 {
398     StringOutputVisitor *sov = to_sov(v);
399 
400     assert(opaque == sov->result);
401     *sov->result = g_string_free(sov->string, false);
402     sov->string = NULL;
403 }
404 
405 static void free_range(void *range, void *dummy)
406 {
407     g_free(range);
408 }
409 
410 static void string_output_free(Visitor *v)
411 {
412     StringOutputVisitor *sov = to_sov(v);
413 
414     if (sov->string) {
415         g_string_free(sov->string, true);
416     }
417 
418     g_list_foreach(sov->ranges, free_range, NULL);
419     g_list_free(sov->ranges);
420     g_free(sov);
421 }
422 
423 Visitor *string_output_visitor_new(bool human, char **result)
424 {
425     StringOutputVisitor *v;
426 
427     v = g_malloc0(sizeof(*v));
428 
429     v->string = g_string_new(NULL);
430     v->human = human;
431     v->result = result;
432     *result = NULL;
433 
434     v->visitor.type = VISITOR_OUTPUT;
435     v->visitor.type_int64 = print_type_int64;
436     v->visitor.type_uint64 = print_type_uint64;
437     v->visitor.type_size = print_type_size;
438     v->visitor.type_bool = print_type_bool;
439     v->visitor.type_str = print_type_str;
440     v->visitor.type_number = print_type_number;
441     v->visitor.type_null = print_type_null;
442     v->visitor.start_struct = start_struct;
443     v->visitor.end_struct = end_struct;
444     v->visitor.start_list = start_list;
445     v->visitor.next_list = next_list;
446     v->visitor.end_list = end_list;
447     v->visitor.complete = string_output_complete;
448     v->visitor.free = string_output_free;
449 
450     return &v->visitor;
451 }
452