programs/winedbg/memory.c

   1 /*
   2  * Debugger memory handling
   3  *
   4  * Copyright 1993 Eric Youngdale
   5  * Copyright 1995 Alexandre Julliard
   6  * Copyright 2000-2005 Eric Pouech
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 #include "config.h"
  24 #include "wine/port.h"
  25
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <stdio.h>
  29
  30 #include "debugger.h"
  31 #include "wine/debug.h"
  32
  33 WINE_DEFAULT_DEBUG_CHANNEL(winedbg);
  34
  35 void* be_cpu_linearize(HANDLE hThread, const ADDRESS64* addr)
  36 {
  37     assert(addr->Mode == AddrModeFlat);
  38     return (void*)(DWORD_PTR)addr->Offset;
  39 }
  40
  41 unsigned be_cpu_build_addr(HANDLE hThread, const CONTEXT* ctx, ADDRESS64* addr,
  42                            unsigned seg, unsigned long offset)
  43 {
  44     addr->Mode    = AddrModeFlat;
  45     addr->Segment = 0; /* don't need segment */
  46     addr->Offset  = offset;
  47     return TRUE;
  48 }
  49
  50 void* memory_to_linear_addr(const ADDRESS64* addr)
  51 {
  52     return be_cpu->linearize(dbg_curr_thread->handle, addr);
  53 }
  54
  55 BOOL memory_get_current_pc(ADDRESS64* addr)
  56 {
  57     assert(be_cpu->get_addr);
  58     return be_cpu->get_addr(dbg_curr_thread->handle, &dbg_context,
  59                             be_cpu_addr_pc, addr);
  60 }
  61
  62 BOOL memory_get_current_stack(ADDRESS64* addr)
  63 {
  64     assert(be_cpu->get_addr);
  65     return be_cpu->get_addr(dbg_curr_thread->handle, &dbg_context,
  66                             be_cpu_addr_stack, addr);
  67 }
  68
  69 BOOL memory_get_current_frame(ADDRESS64* addr)
  70 {
  71     assert(be_cpu->get_addr);
  72     return be_cpu->get_addr(dbg_curr_thread->handle, &dbg_context,
  73                             be_cpu_addr_frame, addr);
  74 }
  75
  76 static void     memory_report_invalid_addr(const void* addr)
  77 {
  78     ADDRESS64   address;
  79
  80     address.Mode    = AddrModeFlat;
  81     address.Segment = 0;
  82     address.Offset  = (unsigned long)addr;
  83     dbg_printf("*** Invalid address ");
  84     print_address(&address, FALSE);
  85     dbg_printf(" ***\n");
  86 }
  87
  88 /***********************************************************************
  89  *           memory_read_value
  90  *
  91  * Read a memory value.
  92  */
  93 BOOL memory_read_value(const struct dbg_lvalue* lvalue, DWORD size, void* result)
  94 {
  95     BOOL ret = FALSE;
  96
  97     if (lvalue->cookie == DLV_TARGET)
  98     {
  99         void*   linear = memory_to_linear_addr(&lvalue->addr);
 100         if (!(ret = dbg_read_memory(linear, result, size)))
 101             memory_report_invalid_addr(linear);
 102     }
 103     else
 104     {
 105         if (lvalue->addr.Offset)
 106         {
 107             memcpy(result, (void*)(DWORD_PTR)lvalue->addr.Offset, size);
 108             ret = TRUE;
 109         }
 110     }
 111     return ret;
 112 }
 113
 114 /***********************************************************************
 115  *           memory_write_value
 116  *
 117  * Store a value in memory.
 118  */
 119 BOOL memory_write_value(const struct dbg_lvalue* lvalue, DWORD size, void* value)
 120 {
 121     BOOL        ret = TRUE;
 122     DWORD64     os;
 123
 124     os = ~(DWORD64)size;
 125     types_get_info(&lvalue->type, TI_GET_LENGTH, &os);
 126     assert(size == os);
 127
 128     /* FIXME: only works on little endian systems */
 129     if (lvalue->cookie == DLV_TARGET)
 130     {
 131         void*       linear = memory_to_linear_addr(&lvalue->addr);
 132         if (!(ret = dbg_write_memory(linear, value, size)))
 133             memory_report_invalid_addr(linear);
 134     }
 135     else
 136     {
 137         memcpy((void*)(DWORD_PTR)lvalue->addr.Offset, value, size);
 138     }
 139     return ret;
 140 }
 141
 142 /***********************************************************************
 143  *           memory_examine
 144  *
 145  * Implementation of the 'x' command.
 146  */
 147 void memory_examine(const struct dbg_lvalue *lvalue, int count, char format)
 148 {
 149     int                 i;
 150     char                buffer[256];
 151     ADDRESS64           addr;
 152     void               *linear;
 153
 154     types_extract_as_address(lvalue, &addr);
 155     linear = memory_to_linear_addr(&addr);
 156
 157     if (format != 'i' && count > 1)
 158     {
 159         print_address(&addr, FALSE);
 160         dbg_printf(": ");
 161     }
 162
 163     switch (format)
 164     {
 165     case 'u':
 166         if (count == 1) count = 256;
 167         memory_get_string(dbg_curr_process, linear,
 168                           TRUE, TRUE, buffer, min(count, sizeof(buffer)));
 169         dbg_printf("%s\n", buffer);
 170         return;
 171     case 's':
 172         if (count == 1) count = 256;
 173         memory_get_string(dbg_curr_process, linear,
 174                           TRUE, FALSE, buffer, min(count, sizeof(buffer)));
 175         dbg_printf("%s\n", buffer);
 176         return;
 177     case 'i':
 178         while (count-- && memory_disasm_one_insn(&addr));
 179         return;
 180     case 'g':
 181         while (count--)
 182         {
 183             GUID guid;
 184             if (!dbg_read_memory(linear, &guid, sizeof(guid)))
 185             {
 186                 memory_report_invalid_addr(linear);
 187                 break;
 188             }
 189             dbg_printf("{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}\n",
 190                        guid.Data1, guid.Data2, guid.Data3,
 191                        guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],
 192                        guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]);
 193             linear = (char*)linear + sizeof(guid);
 194             addr.Offset += sizeof(guid);
 195             if (count)
 196             {
 197                 print_address(&addr, FALSE);
 198                 dbg_printf(": ");
 199             }
 200         }
 201         return;
 202
 203 #define DO_DUMP2(_t,_l,_f,_vv) {                                        \
 204             _t _v;                                                      \
 205             for (i = 0; i < count; i++) {                               \
 206                 if (!dbg_read_memory(linear, &_v, sizeof(_t)))          \
 207                 { memory_report_invalid_addr(linear); break; }          \
 208                 dbg_printf(_f, (_vv));                                  \
 209                 addr.Offset += sizeof(_t);                              \
 210                 linear = (char*)linear + sizeof(_t);                    \
 211                 if ((i % (_l)) == (_l) - 1 && i != count - 1)           \
 212                 {                                                       \
 213                     dbg_printf("\n");                                   \
 214                     print_address(&addr, FALSE);                        \
 215                     dbg_printf(": ");                                   \
 216                 }                                                       \
 217             }                                                           \
 218             dbg_printf("\n");                                           \
 219         }
 220 #define DO_DUMP(_t,_l,_f) DO_DUMP2(_t,_l,_f,_v)
 221
 222     case 'x': DO_DUMP(int, 4, " %8.8x"); break;
 223     case 'd': DO_DUMP(unsigned int, 4, " %4.4d"); break;
 224     case 'w': DO_DUMP(unsigned short, 8, " %04x"); break;
 225     case 'a':
 226         if (sizeof(DWORD_PTR) == 4)
 227         {
 228             DO_DUMP(DWORD_PTR, 4, " %8.8lx");
 229         }
 230         else
 231         {
 232             DO_DUMP(DWORD_PTR, 2, " %16.16lx");
 233         }
 234         break;
 235     case 'c': DO_DUMP2(char, 32, " %c", (_v < 0x20) ? ' ' : _v); break;
 236     case 'b': DO_DUMP2(char, 16, " %02x", (_v) & 0xff); break;
 237     }
 238 }
 239
 240 BOOL memory_get_string(struct dbg_process* pcs, void* addr, BOOL in_debuggee,
 241                        BOOL unicode, char* buffer, int size)
 242 {
 243     SIZE_T      sz;
 244     WCHAR*      buffW;
 245
 246     buffer[0] = 0;
 247     if (!addr) return FALSE;
 248     if (in_debuggee)
 249     {
 250         BOOL ret;
 251
 252         if (!unicode) ret = pcs->process_io->read(pcs->handle, addr, buffer, size, &sz);
 253         else
 254         {
 255             buffW = HeapAlloc(GetProcessHeap(), 0, size * sizeof(WCHAR));
 256             ret = pcs->process_io->read(pcs->handle, addr, buffW, size * sizeof(WCHAR), &sz);
 257             WideCharToMultiByte(CP_ACP, 0, buffW, sz / sizeof(WCHAR), buffer, size,
 258                                 NULL, NULL);
 259             HeapFree(GetProcessHeap(), 0, buffW);
 260         }
 261         if (size) buffer[size-1] = 0;
 262         return ret;
 263     }
 264     else
 265     {
 266         lstrcpynA(buffer, addr, size);
 267     }
 268     return TRUE;
 269 }
 270
 271 BOOL memory_get_string_indirect(struct dbg_process* pcs, void* addr, BOOL unicode, WCHAR* buffer, int size)
 272 {
 273     void*       ad;
 274     SIZE_T      sz;
 275
 276     buffer[0] = 0;
 277     if (addr &&
 278         pcs->process_io->read(pcs->handle, addr, &ad, sizeof(ad), &sz) && sz == sizeof(ad) && ad)
 279     {
 280         LPSTR buff;
 281         BOOL ret;
 282
 283         if (unicode)
 284             ret = pcs->process_io->read(pcs->handle, ad, buffer, size * sizeof(WCHAR), &sz) && sz != 0;
 285         else
 286         {
 287             if ((buff = HeapAlloc(GetProcessHeap(), 0, size)))
 288             {
 289                 ret = pcs->process_io->read(pcs->handle, ad, buff, size, &sz) && sz != 0;
 290                 MultiByteToWideChar(CP_ACP, 0, buff, sz, buffer, size);
 291                 HeapFree(GetProcessHeap(), 0, buff);
 292             }
 293             else ret = FALSE;
 294         }
 295         if (size) buffer[size-1] = 0;
 296         return ret;
 297     }
 298     return FALSE;
 299 }
 300
 301 /*
 302  * Convert an address offset to hex string. If mode == 32, treat offset as
 303  * 32 bits (discard upper 32 bits), if mode == 64 use all 64 bits, if mode == 0
 304  * treat as either 32 or 64 bits, depending on whether we're running as
 305  * Wine32 or Wine64.
 306  */
 307 char* memory_offset_to_string(char *str, DWORD64 offset, unsigned mode)
 308 {
 309     if (mode != 32 && mode != 64)
 310     {
 311 #ifdef _WIN64
 312         mode = 64;
 313 #else
 314         mode = 32;
 315 #endif
 316     }
 317
 318     if (mode == 32)
 319         sprintf(str, "0x%08x", (unsigned int) offset);
 320     else
 321         sprintf(str, "0x%08x%08x", (unsigned int)(offset >> 32),
 322                 (unsigned int)offset);
 323
 324     return str;
 325 }
 326
 327 static void dbg_print_longlong(LONGLONG sv, BOOL is_signed)
 328 {
 329     char      tmp[24], *ptr = tmp + sizeof(tmp) - 1;
 330     ULONGLONG uv, div;
 331     *ptr = '\0';
 332     if (is_signed && sv < 0)    uv = -sv;
 333     else                        { uv = sv; is_signed = FALSE; }
 334     for (div = 10; uv; div *= 10, uv /= 10)
 335         *--ptr = '0' + (uv % 10);
 336     if (ptr == tmp + sizeof(tmp) - 1) *--ptr = '0';
 337     if (is_signed) *--ptr = '-';
 338     dbg_printf("%s", ptr);
 339 }
 340
 341 static void print_typed_basic(const struct dbg_lvalue* lvalue)
 342 {
 343     LONGLONG            val_int;
 344     void*               val_ptr;
 345     long double         val_real;
 346     DWORD64             size64;
 347     DWORD               tag, size, count, bt;
 348     struct dbg_type     type = lvalue->type;
 349     struct dbg_type     sub_type;
 350     struct dbg_lvalue   sub_lvalue;
 351
 352     if (!types_get_real_type(&type, &tag)) return;
 353
 354     switch (tag)
 355     {
 356     case SymTagBaseType:
 357         if (!types_get_info(&type, TI_GET_LENGTH, &size64) ||
 358             !types_get_info(&type, TI_GET_BASETYPE, &bt))
 359         {
 360             WINE_ERR("Couldn't get information\n");
 361             RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 362         }
 363         size = (DWORD)size64;
 364         switch (bt)
 365         {
 366         case btInt:
 367         case btLong:
 368             if (!be_cpu->fetch_integer(lvalue, size, TRUE, &val_int)) return;
 369             if (size == 1) goto print_char;
 370             dbg_print_longlong(val_int, TRUE);
 371             break;
 372         case btUInt:
 373         case btULong:
 374             if (!be_cpu->fetch_integer(lvalue, size, FALSE, &val_int)) return;
 375             dbg_print_longlong(val_int, FALSE);
 376             break;
 377         case btFloat:
 378             if (!be_cpu->fetch_float(lvalue, size, &val_real)) return;
 379             dbg_printf("%Lf", val_real);
 380             break;
 381         case btChar:
 382             if (!be_cpu->fetch_integer(lvalue, size, TRUE, &val_int)) return;
 383             /* FIXME: should do the same for a Unicode character (size == 2) */
 384         print_char:
 385             if (size == 1 && (val_int < 0x20 || val_int > 0x80))
 386                 dbg_printf("%d", (int)val_int);
 387             else if (size == 2)
 388             {
 389                 WCHAR   wch = (WCHAR)val_int;
 390                 dbg_outputW(&wch, 1);
 391             }
 392             else
 393                 dbg_printf("'%c'", (char)val_int);
 394             break;
 395         case btBool:
 396             if (!be_cpu->fetch_integer(lvalue, size, TRUE, &val_int)) return;
 397             dbg_printf("%s", val_int ? "true" : "false");
 398             break;
 399         default:
 400             WINE_FIXME("Unsupported basetype %u\n", bt);
 401             break;
 402         }
 403         break;
 404     case SymTagPointerType:
 405         if (!types_deref(lvalue, &sub_lvalue))
 406         {
 407             dbg_printf("Internal symbol error: unable to access memory location %p",
 408                        memory_to_linear_addr(&lvalue->addr));
 409             break;
 410         }
 411         val_ptr = memory_to_linear_addr(&sub_lvalue.addr);
 412         if (types_get_real_type(&sub_lvalue.type, &tag) && tag == SymTagBaseType &&
 413             types_get_info(&sub_lvalue.type, TI_GET_BASETYPE, &bt) &&
 414             types_get_info(&sub_lvalue.type, TI_GET_LENGTH, &size64))
 415         {
 416             char    buffer[1024];
 417
 418             if (!val_ptr) dbg_printf("0x0");
 419             else if (((bt == btChar || bt == btInt) && size64 == 1) || (bt == btUInt && size64 == 2))
 420             {
 421                 if (memory_get_string(dbg_curr_process, val_ptr, sub_lvalue.cookie == DLV_TARGET,
 422                                       size64 == 2, buffer, sizeof(buffer)))
 423                     dbg_printf("\"%s\"", buffer);
 424                 else
 425                     dbg_printf("*** invalid address %p ***", val_ptr);
 426                 break;
 427             }
 428         }
 429         dbg_printf("%p", val_ptr);
 430         break;
 431     case SymTagArrayType:
 432     case SymTagUDT:
 433         if (!memory_read_value(lvalue, sizeof(val_ptr), &val_ptr)) return;
 434         dbg_printf("%p", val_ptr);
 435         break;
 436     case SymTagEnum:
 437         {
 438             BOOL        ok = FALSE;
 439
 440             /* FIXME: it depends on underlying type for enums
 441              * (not supported yet in dbghelp)
 442              * Assuming 4 as for an int
 443              */
 444             if (!be_cpu->fetch_integer(lvalue, 4, TRUE, &val_int)) return;
 445
 446             if (types_get_info(&type, TI_GET_CHILDRENCOUNT, &count))
 447             {
 448                 char                    buffer[sizeof(TI_FINDCHILDREN_PARAMS) + 256 * sizeof(DWORD)];
 449                 TI_FINDCHILDREN_PARAMS* fcp = (TI_FINDCHILDREN_PARAMS*)buffer;
 450                 WCHAR*                  ptr;
 451                 char                    tmp[256];
 452                 VARIANT                 variant;
 453                 int                     i;
 454
 455                 fcp->Start = 0;
 456                 while (count)
 457                 {
 458                     fcp->Count = min(count, 256);
 459                     if (types_get_info(&type, TI_FINDCHILDREN, fcp))
 460                     {
 461                         sub_type.module = type.module;
 462                         for (i = 0; i < min(fcp->Count, count); i++)
 463                         {
 464                             sub_type.id = fcp->ChildId[i];
 465                             if (!types_get_info(&sub_type, TI_GET_VALUE, &variant))
 466                                 continue;
 467                             switch (variant.n1.n2.vt)
 468                             {
 469                             case VT_I4: ok = (val_int == variant.n1.n2.n3.lVal); break;
 470                             default: WINE_FIXME("Unsupported variant type (%u)\n", variant.n1.n2.vt);
 471                             }
 472                             if (ok)
 473                             {
 474                                 ptr = NULL;
 475                                 types_get_info(&sub_type, TI_GET_SYMNAME, &ptr);
 476                                 if (!ptr) continue;
 477                                 WideCharToMultiByte(CP_ACP, 0, ptr, -1, tmp, sizeof(tmp), NULL, NULL);
 478                                 HeapFree(GetProcessHeap(), 0, ptr);
 479                                 dbg_printf("%s", tmp);
 480                                 count = 0; /* so that we'll get away from outter loop */
 481                                 break;
 482                             }
 483                         }
 484                     }
 485                     count -= min(count, 256);
 486                     fcp->Start += 256;
 487                 }
 488             }
 489             if (!ok) dbg_print_longlong(val_int, TRUE);
 490         }
 491         break;
 492     default:
 493         WINE_FIXME("Unsupported tag %u\n", tag);
 494         break;
 495     }
 496 }
 497
 498 /***********************************************************************
 499  *           print_basic
 500  *
 501  * Implementation of the 'print' command.
 502  */
 503 void print_basic(const struct dbg_lvalue* lvalue, char format)
 504 {
 505     if (lvalue->type.id == dbg_itype_none)
 506     {
 507         dbg_printf("Unable to evaluate expression\n");
 508         return;
 509     }
 510
 511     if (format != 0)
 512     {
 513         unsigned size;
 514         LONGLONG res = types_extract_as_longlong(lvalue, &size);
 515         DWORD hi;
 516         WCHAR wch;
 517
 518         /* FIXME: this implies i386 byte ordering */
 519         switch (format)
 520         {
 521         case 'x':
 522             hi = (ULONG64)res >> 32;
 523             if (size == 8 && hi)
 524                 dbg_printf("0x%x%08x", hi, (DWORD)res);
 525             else
 526                 dbg_printf("0x%x", (DWORD)res);
 527             return;
 528
 529         case 'd':
 530             dbg_print_longlong(res, TRUE);
 531             dbg_printf("\n");
 532             return;
 533
 534         case 'c':
 535             dbg_printf("%d = '%c'", (char)(res & 0xff), (char)(res & 0xff));
 536             return;
 537
 538         case 'u':
 539             wch = (WCHAR)(res & 0xFFFF);
 540             dbg_printf("%d = '", wch);
 541             dbg_outputW(&wch, 1);
 542             dbg_printf("'");
 543             return;
 544
 545         case 'i':
 546         case 's':
 547         case 'w':
 548         case 'b':
 549             dbg_printf("Format specifier '%c' is meaningless in 'print' command\n", format);
 550         }
 551     }
 552     if (lvalue->type.id == dbg_itype_segptr)
 553     {
 554         dbg_print_longlong(types_extract_as_longlong(lvalue, NULL), TRUE);
 555         dbg_printf("\n");
 556     }
 557     else print_typed_basic(lvalue);
 558 }
 559
 560 void print_bare_address(const ADDRESS64* addr)
 561 {
 562     char hexbuf[MAX_OFFSET_TO_STR_LEN];
 563
 564     switch (addr->Mode)
 565     {
 566     case AddrModeFlat:
 567         dbg_printf("%s", memory_offset_to_string(hexbuf, addr->Offset, 0));
 568         break;
 569     case AddrModeReal:
 570     case AddrMode1616:
 571         dbg_printf("0x%04x:0x%04x", addr->Segment, (unsigned) addr->Offset);
 572         break;
 573     case AddrMode1632:
 574         dbg_printf("0x%04x:%s", addr->Segment,
 575                    memory_offset_to_string(hexbuf, addr->Offset, 32));
 576         break;
 577     default:
 578         dbg_printf("Unknown mode %x\n", addr->Mode);
 579         break;
 580     }
 581 }
 582
 583 /***********************************************************************
 584  *           print_address
 585  *
 586  * Print an 16- or 32-bit address, with the nearest symbol if any.
 587  */
 588 void print_address(const ADDRESS64* addr, BOOLEAN with_line)
 589 {
 590     char                buffer[sizeof(SYMBOL_INFO) + 256];
 591     SYMBOL_INFO*        si = (SYMBOL_INFO*)buffer;
 592     void*               lin = memory_to_linear_addr(addr);
 593     DWORD64             disp64;
 594     DWORD               disp;
 595
 596     print_bare_address(addr);
 597
 598     si->SizeOfStruct = sizeof(*si);
 599     si->MaxNameLen   = 256;
 600     if (!SymFromAddr(dbg_curr_process->handle, (DWORD_PTR)lin, &disp64, si)) return;
 601     dbg_printf(" %s", si->Name);
 602     if (disp64) dbg_printf("+0x%lx", (DWORD_PTR)disp64);
 603     if (with_line)
 604     {
 605         IMAGEHLP_LINE64             il;
 606         IMAGEHLP_MODULE             im;
 607
 608         il.SizeOfStruct = sizeof(il);
 609         if (SymGetLineFromAddr64(dbg_curr_process->handle, (DWORD_PTR)lin, &disp, &il))
 610             dbg_printf(" [%s:%u]", il.FileName, il.LineNumber);
 611         im.SizeOfStruct = sizeof(im);
 612         if (SymGetModuleInfo(dbg_curr_process->handle, (DWORD_PTR)lin, &im))
 613             dbg_printf(" in %s", im.ModuleName);
 614     }
 615 }
 616
 617 BOOL memory_disasm_one_insn(ADDRESS64* addr)
 618 {
 619     char        ch;
 620
 621     print_address(addr, TRUE);
 622     dbg_printf(": ");
 623     if (!dbg_read_memory(memory_to_linear_addr(addr), &ch, sizeof(ch)))
 624     {
 625         dbg_printf("-- no code accessible --\n");
 626         return FALSE;
 627     }
 628     be_cpu->disasm_one_insn(addr, TRUE);
 629     dbg_printf("\n");
 630     return TRUE;
 631 }
 632
 633 void memory_disassemble(const struct dbg_lvalue* xstart,
 634                         const struct dbg_lvalue* xend, int instruction_count)
 635 {
 636     static ADDRESS64 last = {0,0,0};
 637     int stop = 0;
 638     int i;
 639
 640     if (!xstart && !xend)
 641     {
 642         if (!last.Segment && !last.Offset) memory_get_current_pc(&last);
 643     }
 644     else
 645     {
 646         if (xstart)
 647             types_extract_as_address(xstart, &last);
 648         if (xend)
 649             stop = types_extract_as_integer(xend);
 650     }
 651     for (i = 0; (instruction_count == 0 || i < instruction_count)  &&
 652                 (stop == 0 || last.Offset <= stop); i++)
 653         memory_disasm_one_insn(&last);
 654 }
 655
 656 BOOL memory_get_register(DWORD regno, DWORD_PTR** value, char* buffer, int len)
 657 {
 658     const struct dbg_internal_var*  div;
 659
 660     /* negative register values are wine's dbghelp hacks
 661      * see dlls/dbghelp/dbghelp_internal.h for the details
 662      */
 663     switch (regno)
 664     {
 665     case -1:
 666         if (buffer) snprintf(buffer, len, "<internal error>");
 667         return FALSE;
 668     case -2:
 669         if (buffer) snprintf(buffer, len, "<couldn't compute location>");
 670         return FALSE;
 671     case -3:
 672         if (buffer) snprintf(buffer, len, "<is not available>");
 673         return FALSE;
 674     case -4:
 675         if (buffer) snprintf(buffer, len, "<couldn't read memory>");
 676         return FALSE;
 677     }
 678
 679     for (div = dbg_context_vars; div->name; div++)
 680     {
 681         if (div->val == regno)
 682         {
 683             if (dbg_curr_thread->curr_frame != 0)
 684             {
 685                 if (!stack_get_register_current_frame(regno, value))
 686                 {
 687                     if (buffer) snprintf(buffer, len, "<register %s not in topmost frame>", div->name);
 688                     return FALSE;
 689                 }
 690             }
 691             else
 692                 *value = div->pval;
 693
 694             if (buffer) lstrcpynA(buffer, div->name, len);
 695             return TRUE;
 696         }
 697     }
 698     if (buffer) snprintf(buffer, len, "<unknown register %u>", regno);
 699     return FALSE;
 700 }