1 /**
2 * \file
3 * Sequence Points functions
4 *
5 * Authors:
6 * Marcos Henrich (marcos.henrich@xamarin.com)
7 *
8 * Copyright 2015 Xamarin, Inc (http://www.xamarin.com)
9 */
10
11 #include "seq-points-data.h"
12
13 typedef struct {
14 guint8 *data;
15 int len;
16 /* When has_debug_data is set to false only il and native deltas are saved */
17 gboolean has_debug_data;
18 /* When alloc_data is set to true data allocation/deallocation is managed by this structure */
19 gboolean alloc_data;
20 } SeqPointInfoInflated;
21
22 static int
encode_var_int(guint8 * buf,guint8 ** out_buf,int val)23 encode_var_int (guint8 *buf, guint8 **out_buf, int val)
24 {
25 guint8 size = 0;
26
27 do {
28 guint8 byte = val & 0x7f;
29 g_assert (size < 4 && "value has more than 28 bits");
30 val >>= 7;
31 if(val) byte |= 0x80;
32 *(buf++) = byte;
33 size++;
34 } while (val);
35
36 if (out_buf)
37 *out_buf = buf;
38
39 return size;
40 }
41
42 static int
decode_var_int(guint8 * buf,guint8 ** out_buf)43 decode_var_int (guint8* buf, guint8 **out_buf)
44 {
45 guint8* p = buf;
46
47 int low;
48 int b;
49 b = *(p++); low = (b & 0x7f) ; if(!(b & 0x80)) goto done;
50 b = *(p++); low |= (b & 0x7f) << 7; if(!(b & 0x80)) goto done;
51 b = *(p++); low |= (b & 0x7f) << 14; if(!(b & 0x80)) goto done;
52 b = *(p++); low |= (b & 0x7f) << 21; if(!(b & 0x80)) goto done;
53
54 g_assert (FALSE && "value has more than 28 bits");
55
56 done:
57
58 if (out_buf)
59 *out_buf = p;
60
61 return low;
62 }
63
64 static guint32
encode_zig_zag(int val)65 encode_zig_zag (int val)
66 {
67 return (val << 1) ^ (val >> 31);
68 }
69
70 static int
decode_zig_zag(guint32 val)71 decode_zig_zag (guint32 val)
72 {
73 int n = val;
74 return (n >> 1) ^ (-(n & 1));
75 }
76
77 static SeqPointInfoInflated
seq_point_info_inflate(MonoSeqPointInfo * info)78 seq_point_info_inflate (MonoSeqPointInfo *info)
79 {
80 SeqPointInfoInflated info_inflated;
81 guint8 *ptr = (guint8*) info;
82 int value;
83
84 value = decode_var_int (ptr, &ptr);
85
86 info_inflated.len = value >> 2;
87 info_inflated.has_debug_data = (value & 1) != 0;
88 info_inflated.alloc_data = (value & 2) != 0;
89
90 if (info_inflated.alloc_data)
91 info_inflated.data = ptr;
92 else
93 memcpy (&info_inflated.data, ptr, sizeof (guint8*));
94
95 return info_inflated;
96 }
97
98 MonoSeqPointInfo*
mono_seq_point_info_new(int len,gboolean alloc_data,guint8 * data,gboolean has_debug_data,int * out_size)99 mono_seq_point_info_new (int len, gboolean alloc_data, guint8 *data, gboolean has_debug_data, int *out_size)
100 {
101 MonoSeqPointInfo *info;
102 guint8 *info_ptr;
103 guint8 buffer[4];
104 int buffer_len;
105 int value;
106 int data_size;
107
108 value = len << 2;
109 if (has_debug_data)
110 value |= 1;
111 if (alloc_data)
112 value |= 2;
113
114 buffer_len = encode_var_int (buffer, NULL, value);
115
116 *out_size = data_size = buffer_len + (alloc_data? len : sizeof (guint8*));
117 info_ptr = g_new0 (guint8, data_size);
118 info = (MonoSeqPointInfo*) info_ptr;
119
120 memcpy (info_ptr, buffer, buffer_len);
121 info_ptr += buffer_len;
122
123 if (alloc_data)
124 memcpy (info_ptr, data, len);
125 else
126 memcpy (info_ptr, &data, sizeof (guint8*));
127
128 return info;
129 }
130
131 void
mono_seq_point_info_free(gpointer ptr)132 mono_seq_point_info_free (gpointer ptr)
133 {
134 MonoSeqPointInfo* info = (MonoSeqPointInfo*) ptr;
135 g_free (info);
136 }
137
138 static int
seq_point_read(SeqPoint * seq_point,guint8 * ptr,guint8 * buffer_ptr,gboolean has_debug_data)139 seq_point_read (SeqPoint* seq_point, guint8* ptr, guint8* buffer_ptr, gboolean has_debug_data)
140 {
141 int value, i;
142 guint8* ptr0 = ptr;
143
144 value = decode_var_int (ptr, &ptr);
145 seq_point->il_offset += decode_zig_zag (value);
146
147 value = decode_var_int (ptr, &ptr);
148 seq_point->native_offset += decode_zig_zag (value);
149
150 if (has_debug_data) {
151 value = decode_var_int (ptr, &ptr);
152 seq_point->flags = value;
153
154 if (seq_point->flags & MONO_SEQ_POINT_FLAG_EXIT_IL)
155 seq_point->il_offset = METHOD_EXIT_IL_OFFSET;
156
157 value = decode_var_int (ptr, &ptr);
158 seq_point->next_len = value;
159
160 if (seq_point->next_len) {
161 // store next offset and skip it
162 seq_point->next_offset = ptr - buffer_ptr;
163 for (i = 0; i < seq_point->next_len; ++i)
164 decode_var_int (ptr, &ptr);
165 }
166 }
167
168 return ptr - ptr0;
169 }
170
171 gboolean
mono_seq_point_info_add_seq_point(GByteArray * array,SeqPoint * sp,SeqPoint * last_seq_point,GSList * next,gboolean has_debug_data)172 mono_seq_point_info_add_seq_point (GByteArray* array, SeqPoint *sp, SeqPoint *last_seq_point, GSList *next, gboolean has_debug_data)
173 {
174 int il_delta, native_delta;
175 GSList *l;
176 guint8 buffer[4];
177 guint8 len;
178 int flags;
179
180 if (!has_debug_data &&
181 (sp->il_offset == METHOD_ENTRY_IL_OFFSET || sp->il_offset == METHOD_EXIT_IL_OFFSET))
182 return FALSE;
183
184 il_delta = sp->il_offset - last_seq_point->il_offset;
185 native_delta = sp->native_offset - last_seq_point->native_offset;
186
187 flags = sp->flags;
188
189 if (has_debug_data && sp->il_offset == METHOD_EXIT_IL_OFFSET) {
190 il_delta = 0;
191 flags |= MONO_SEQ_POINT_FLAG_EXIT_IL;
192 }
193
194 len = encode_var_int (buffer, NULL, encode_zig_zag (il_delta));
195 g_byte_array_append (array, buffer, len);
196
197 len = encode_var_int (buffer, NULL, encode_zig_zag (native_delta));
198 g_byte_array_append (array, buffer, len);
199
200 if (has_debug_data) {
201 sp->next_offset = array->len;
202 sp->next_len = g_slist_length (next);
203
204 len = encode_var_int (buffer, NULL, flags);
205 g_byte_array_append (array, buffer, len);
206
207 len = encode_var_int (buffer, NULL, sp->next_len);
208 g_byte_array_append (array, buffer, len);
209
210 for (l = next; l; l = l->next) {
211 int next_index = GPOINTER_TO_UINT (l->data);
212 guint8 buffer[4];
213 int len = encode_var_int (buffer, NULL, next_index);
214 g_byte_array_append (array, buffer, len);
215 }
216 }
217
218 return TRUE;
219 }
220
221 gboolean
mono_seq_point_find_next_by_native_offset(MonoSeqPointInfo * info,int native_offset,SeqPoint * seq_point)222 mono_seq_point_find_next_by_native_offset (MonoSeqPointInfo* info, int native_offset, SeqPoint* seq_point)
223 {
224 SeqPointIterator it;
225 mono_seq_point_iterator_init (&it, info);
226 while (mono_seq_point_iterator_next (&it)) {
227 if (it.seq_point.native_offset >= native_offset) {
228 memcpy (seq_point, &it.seq_point, sizeof (SeqPoint));
229 return TRUE;
230 }
231 }
232
233 return FALSE;
234 }
235
236 gboolean
mono_seq_point_find_prev_by_native_offset(MonoSeqPointInfo * info,int native_offset,SeqPoint * seq_point)237 mono_seq_point_find_prev_by_native_offset (MonoSeqPointInfo* info, int native_offset, SeqPoint* seq_point)
238 {
239 SeqPoint prev_seq_point;
240 gboolean is_first = TRUE;
241 SeqPointIterator it;
242 mono_seq_point_iterator_init (&it, info);
243 while (mono_seq_point_iterator_next (&it) && it.seq_point.native_offset <= native_offset) {
244 memcpy (&prev_seq_point, &it.seq_point, sizeof (SeqPoint));
245 is_first = FALSE;
246 }
247
248 if (!is_first && prev_seq_point.native_offset <= native_offset) {
249 memcpy (seq_point, &prev_seq_point, sizeof (SeqPoint));
250 return TRUE;
251 }
252
253 return FALSE;
254 }
255
256 gboolean
mono_seq_point_find_by_il_offset(MonoSeqPointInfo * info,int il_offset,SeqPoint * seq_point)257 mono_seq_point_find_by_il_offset (MonoSeqPointInfo* info, int il_offset, SeqPoint* seq_point)
258 {
259 SeqPointIterator it;
260 mono_seq_point_iterator_init (&it, info);
261 while (mono_seq_point_iterator_next (&it)) {
262 if (it.seq_point.il_offset == il_offset) {
263 memcpy (seq_point, &it.seq_point, sizeof (SeqPoint));
264 return TRUE;
265 }
266 }
267
268 return FALSE;
269 }
270
271 void
mono_seq_point_init_next(MonoSeqPointInfo * info,SeqPoint sp,SeqPoint * next)272 mono_seq_point_init_next (MonoSeqPointInfo* info, SeqPoint sp, SeqPoint* next)
273 {
274 int i;
275 guint8* ptr;
276 SeqPointIterator it;
277 GArray* seq_points = g_array_new (FALSE, TRUE, sizeof (SeqPoint));
278 SeqPointInfoInflated info_inflated = seq_point_info_inflate (info);
279
280 g_assert (info_inflated.has_debug_data);
281
282 mono_seq_point_iterator_init (&it, info);
283 while (mono_seq_point_iterator_next (&it))
284 g_array_append_vals (seq_points, &it.seq_point, 1);
285
286 ptr = info_inflated.data + sp.next_offset;
287 for (i = 0; i < sp.next_len; i++) {
288 int next_index;
289 next_index = decode_var_int (ptr, &ptr);
290 g_assert (next_index < seq_points->len);
291 memcpy (&next[i], seq_points->data + next_index * sizeof (SeqPoint), sizeof (SeqPoint));
292 }
293
294 g_array_free (seq_points, TRUE);
295 }
296
297 gboolean
mono_seq_point_iterator_next(SeqPointIterator * it)298 mono_seq_point_iterator_next (SeqPointIterator* it)
299 {
300 if (it->ptr >= it->end)
301 return FALSE;
302
303 it->ptr += seq_point_read (&it->seq_point, it->ptr, it->begin, it->has_debug_data);
304
305 return TRUE;
306 }
307
308 void
mono_seq_point_iterator_init(SeqPointIterator * it,MonoSeqPointInfo * info)309 mono_seq_point_iterator_init (SeqPointIterator* it, MonoSeqPointInfo* info)
310 {
311 SeqPointInfoInflated info_inflated = seq_point_info_inflate (info);
312 it->ptr = info_inflated.data;
313 it->begin = info_inflated.data;
314 it->end = it->begin + info_inflated.len;
315 it->has_debug_data = info_inflated.has_debug_data;
316 memset(&it->seq_point, 0, sizeof(SeqPoint));
317 }
318
319 int
mono_seq_point_info_write(MonoSeqPointInfo * info,guint8 * buffer)320 mono_seq_point_info_write (MonoSeqPointInfo* info, guint8* buffer)
321 {
322 guint8* buffer0 = buffer;
323 SeqPointInfoInflated info_inflated = seq_point_info_inflate (info);
324
325 encode_var_int (buffer, &buffer, info_inflated.has_debug_data);
326
327 //Write sequence points
328 encode_var_int (buffer, &buffer, info_inflated.len);
329 memcpy (buffer, info_inflated.data, info_inflated.len);
330 buffer += info_inflated.len;
331
332 return buffer - buffer0;
333 }
334
335 int
mono_seq_point_info_read(MonoSeqPointInfo ** info,guint8 * buffer,gboolean copy)336 mono_seq_point_info_read (MonoSeqPointInfo** info, guint8* buffer, gboolean copy)
337 {
338 guint8* buffer0 = buffer;
339 int size, info_size;
340 gboolean has_debug_data;
341
342 has_debug_data = decode_var_int (buffer, &buffer);
343
344 size = decode_var_int (buffer, &buffer);
345 (*info) = mono_seq_point_info_new (size, copy, buffer, has_debug_data, &info_size);
346 buffer += size;
347
348 return buffer - buffer0;
349 }
350
351 /*
352 * Returns the maximum size of mono_seq_point_info_write.
353 */
354 int
mono_seq_point_info_get_write_size(MonoSeqPointInfo * info)355 mono_seq_point_info_get_write_size (MonoSeqPointInfo* info)
356 {
357 SeqPointInfoInflated info_inflated = seq_point_info_inflate (info);
358
359 //4 is the maximum size required to store the size of the data.
360 //1 is the byte used to store has_debug_data.
361 int size = 4 + 1 + info_inflated.len;
362
363 return size;
364 }
365
366 /*
367 * SeqPointData struct and functions
368 * This is used to store/load/use sequence point from a file
369 */
370
371 void
mono_seq_point_data_init(SeqPointData * data,int entry_capacity)372 mono_seq_point_data_init (SeqPointData *data, int entry_capacity)
373 {
374 data->entry_count = 0;
375 data->entry_capacity = entry_capacity;
376 data->entries = (SeqPointDataEntry *)g_malloc (sizeof (SeqPointDataEntry) * entry_capacity);
377 }
378
379 void
mono_seq_point_data_free(SeqPointData * data)380 mono_seq_point_data_free (SeqPointData *data)
381 {
382 int i;
383 for (i=0; i<data->entry_count; i++) {
384 if (data->entries [i].free_seq_points)
385 g_free (data->entries [i].seq_points);
386 }
387 g_free (data->entries);
388 }
389
390 gboolean
mono_seq_point_data_read(SeqPointData * data,char * path)391 mono_seq_point_data_read (SeqPointData *data, char *path)
392 {
393 guint8 *buffer, *buffer_orig;
394 int entry_count, i;
395 long fsize;
396 FILE *f;
397
398 f = fopen (path, "r");
399 if (!f)
400 return FALSE;
401
402 fseek(f, 0, SEEK_END);
403 fsize = ftell(f);
404 fseek(f, 0, SEEK_SET);
405
406 buffer_orig = buffer = (guint8 *)g_malloc (fsize + 1);
407 fread(buffer_orig, fsize, 1, f);
408 fclose(f);
409
410 entry_count = decode_var_int (buffer, &buffer);
411 mono_seq_point_data_init (data, entry_count);
412 data->entry_count = entry_count;
413
414 for (i=0; i<entry_count; i++) {
415 data->entries [i].method_token = decode_var_int (buffer, &buffer);
416 data->entries [i].method_index = decode_var_int (buffer, &buffer);
417 buffer += mono_seq_point_info_read (&data->entries [i].seq_points, buffer, TRUE);
418 data->entries [i].free_seq_points = TRUE;
419 }
420
421 g_free (buffer_orig);
422 return TRUE;
423 }
424
425 gboolean
mono_seq_point_data_write(SeqPointData * data,char * path)426 mono_seq_point_data_write (SeqPointData *data, char *path)
427 {
428 guint8 *buffer, *buffer_orig;
429 FILE *f;
430 int i, size = 0;
431
432 f = fopen (path, "w+");
433 if (!f)
434 return FALSE;
435
436 for (i=0; i<data->entry_count; i++) {
437 size += mono_seq_point_info_get_write_size (data->entries [i].seq_points);
438 }
439 // Add size of entry_count and native_base_offsets
440 size += 4 + data->entry_count * 4;
441
442 buffer_orig = buffer = (guint8 *)g_malloc (size);
443
444 encode_var_int (buffer, &buffer, data->entry_count);
445
446 for (i=0; i<data->entry_count; i++) {
447 encode_var_int (buffer, &buffer, data->entries [i].method_token);
448 encode_var_int (buffer, &buffer, data->entries [i].method_index);
449 buffer += mono_seq_point_info_write (data->entries [i].seq_points, buffer);
450 }
451
452 fwrite (buffer_orig, 1, buffer - buffer_orig, f);
453 g_free (buffer_orig);
454 fclose (f);
455
456 return TRUE;
457 }
458
459 void
mono_seq_point_data_add(SeqPointData * data,guint32 method_token,guint32 method_index,MonoSeqPointInfo * info)460 mono_seq_point_data_add (SeqPointData *data, guint32 method_token, guint32 method_index, MonoSeqPointInfo* info)
461 {
462 int i;
463
464 g_assert (data->entry_count < data->entry_capacity);
465 i = data->entry_count++;
466 data->entries [i].seq_points = info;
467 data->entries [i].method_token = method_token;
468 data->entries [i].method_index = method_index;
469 data->entries [i].free_seq_points = FALSE;
470 }
471
472 gboolean
mono_seq_point_data_get(SeqPointData * data,guint32 method_token,guint32 method_index,MonoSeqPointInfo ** info)473 mono_seq_point_data_get (SeqPointData *data, guint32 method_token, guint32 method_index, MonoSeqPointInfo** info)
474 {
475 int i;
476
477 for (i=0; i<data->entry_count; i++) {
478 if (data->entries [i].method_token == method_token && (method_index == 0xffffff || data->entries [i].method_index == method_index)) {
479 (*info) = data->entries [i].seq_points;
480 return TRUE;
481 }
482 }
483 return FALSE;
484 }
485
486 gboolean
mono_seq_point_data_get_il_offset(char * path,guint32 method_token,guint32 method_index,guint32 native_offset,guint32 * il_offset)487 mono_seq_point_data_get_il_offset (char *path, guint32 method_token, guint32 method_index, guint32 native_offset, guint32 *il_offset)
488 {
489 SeqPointData sp_data;
490 MonoSeqPointInfo *seq_points;
491 SeqPoint sp;
492
493 if (!mono_seq_point_data_read (&sp_data, path))
494 return FALSE;
495
496 if (!mono_seq_point_data_get (&sp_data, method_token, method_index, &seq_points))
497 return FALSE;
498
499 if (!mono_seq_point_find_prev_by_native_offset (seq_points, native_offset, &sp))
500 return FALSE;
501
502 *il_offset = sp.il_offset;
503
504 return TRUE;
505 }
506