mono/metadata/seq-points-data.c

   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
  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
  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
  65 encode_zig_zag (int val)
  66 {
  67         return (val << 1) ^ (val >> 31);
  68 }
  69
  70 static int
  71 decode_zig_zag (guint32 val)
  72 {
  73         int n = val;
  74         return (n >> 1) ^ (-(n & 1));
  75 }
  76
  77 static SeqPointInfoInflated
  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*
  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
 132 mono_seq_point_info_free (gpointer ptr)
 133 {
 134         MonoSeqPointInfo* info = (MonoSeqPointInfo*) ptr;
 135         g_free (info);
 136 }
 137
 138 static int
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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 }