debugger/break.c

   1 /*
   2  * Debugger break-points handling
   3  *
   4  * Copyright 1994 Martin von Loewis
   5  * Copyright 1995 Alexandre Julliard
   6  * Copyright 1999,2000 Eric Pouech
   7  */
   8
   9 #include "config.h"
  10 #include "debugger.h"
  11
  12 #ifdef __i386__
  13 #define DR7_CONTROL_SHIFT       16
  14 #define DR7_CONTROL_SIZE        4
  15
  16 #define DR7_RW_EXECUTE          (0x0)
  17 #define DR7_RW_WRITE            (0x1)
  18 #define DR7_RW_READ             (0x3)
  19
  20 #define DR7_LEN_1               (0x0)
  21 #define DR7_LEN_2               (0x4)
  22 #define DR7_LEN_4               (0xC)
  23
  24 #define DR7_LOCAL_ENABLE_SHIFT  0
  25 #define DR7_GLOBAL_ENABLE_SHIFT 1
  26 #define DR7_ENABLE_SIZE         2
  27
  28 #define DR7_LOCAL_ENABLE_MASK   (0x55)
  29 #define DR7_GLOBAL_ENABLE_MASK  (0xAA)
  30
  31 #define DR7_CONTROL_RESERVED    (0xFC00)
  32 #define DR7_LOCAL_SLOWDOWN      (0x100)
  33 #define DR7_GLOBAL_SLOWDOWN     (0x200)
  34
  35 #define DR7_ENABLE_MASK(dr)     (1<<(DR7_LOCAL_ENABLE_SHIFT+DR7_ENABLE_SIZE*(dr)))
  36 #define IS_DR7_SET(ctrl,dr)     ((ctrl)&DR7_ENABLE_MASK(dr))
  37 #define INT3          0xcc   /* int 3 opcode */
  38 #endif
  39
  40 #define MAX_BREAKPOINTS 100
  41
  42 static DBG_BREAKPOINT breakpoints[MAX_BREAKPOINTS];
  43
  44 static int next_bp = 1;  /* breakpoint 0 is reserved for step-over */
  45
  46 /***********************************************************************
  47  *           DEBUG_IsStepOverInstr
  48  *
  49  * Determine if the instruction at CS:EIP is an instruction that
  50  * we need to step over (like a call or a repetitive string move).
  51  */
  52 static BOOL DEBUG_IsStepOverInstr(void)
  53 {
  54 #ifdef __i386__
  55     BYTE*       instr;
  56     BYTE        ch;
  57     DBG_ADDR    addr;
  58
  59     addr.seg = DEBUG_context.SegCs;
  60     addr.off = DEBUG_context.Eip;
  61     /* FIXME: old code was using V86BASE(DEBUG_context)
  62      * instead of passing thru DOSMEM_MemoryBase
  63      */
  64     instr = (BYTE*)DEBUG_ToLinear(&addr);
  65
  66     for (;;)
  67     {
  68         if (!DEBUG_READ_MEM(instr, &ch, sizeof(ch)))
  69             return FALSE;
  70
  71         switch (ch)
  72         {
  73           /* Skip all prefixes */
  74
  75         case 0x2e:  /* cs: */
  76         case 0x36:  /* ss: */
  77         case 0x3e:  /* ds: */
  78         case 0x26:  /* es: */
  79         case 0x64:  /* fs: */
  80         case 0x65:  /* gs: */
  81         case 0x66:  /* opcode size prefix */
  82         case 0x67:  /* addr size prefix */
  83         case 0xf0:  /* lock */
  84         case 0xf2:  /* repne */
  85         case 0xf3:  /* repe */
  86             instr++;
  87             continue;
  88
  89           /* Handle call instructions */
  90
  91         case 0xcd:  /* int <intno> */
  92         case 0xe8:  /* call <offset> */
  93         case 0x9a:  /* lcall <seg>:<off> */
  94             return TRUE;
  95
  96         case 0xff:  /* call <regmodrm> */
  97             if (!DEBUG_READ_MEM(instr + 1, &ch, sizeof(ch)))
  98                 return FALSE;
  99             return (((ch & 0x38) == 0x10) || ((ch & 0x38) == 0x18));
 100
 101           /* Handle string instructions */
 102
 103         case 0x6c:  /* insb */
 104         case 0x6d:  /* insw */
 105         case 0x6e:  /* outsb */
 106         case 0x6f:  /* outsw */
 107         case 0xa4:  /* movsb */
 108         case 0xa5:  /* movsw */
 109         case 0xa6:  /* cmpsb */
 110         case 0xa7:  /* cmpsw */
 111         case 0xaa:  /* stosb */
 112         case 0xab:  /* stosw */
 113         case 0xac:  /* lodsb */
 114         case 0xad:  /* lodsw */
 115         case 0xae:  /* scasb */
 116         case 0xaf:  /* scasw */
 117             return TRUE;
 118
 119         default:
 120             return FALSE;
 121         }
 122     }
 123 #else
 124     return FALSE;
 125 #endif
 126 }
 127
 128
 129 /***********************************************************************
 130  *           DEBUG_IsFctReturn
 131  *
 132  * Determine if the instruction at CS:EIP is an instruction that
 133  * is a function return.
 134  */
 135 BOOL DEBUG_IsFctReturn(void)
 136 {
 137 #ifdef __i386__
 138     BYTE*       instr;
 139     BYTE        ch;
 140     DBG_ADDR    addr;
 141
 142     addr.seg = DEBUG_context.SegCs;
 143     addr.off = DEBUG_context.Eip;
 144     /* FIXME: old code was using V86BASE(DEBUG_context)
 145      * instead of passing thru DOSMEM_MemoryBase
 146      */
 147     instr = (BYTE*)DEBUG_ToLinear(&addr);
 148
 149     if (!DEBUG_READ_MEM(instr, &ch, sizeof(ch)))
 150         return FALSE;
 151
 152     return (ch == 0xc2) || (ch == 0xc3);
 153 #else
 154     return FALSE;
 155 #endif
 156 }
 157
 158
 159 /***********************************************************************
 160  *           DEBUG_SetBreakpoints
 161  *
 162  * Set or remove all the breakpoints.
 163  */
 164 void DEBUG_SetBreakpoints( BOOL set )
 165 {
 166    int          i;
 167
 168 #ifdef __i386__
 169    DEBUG_context.Dr7 &= ~DR7_LOCAL_ENABLE_MASK;
 170 #endif
 171
 172    for (i = 0; i < next_bp; i++)
 173    {
 174       if (!(breakpoints[i].refcount && breakpoints[i].enabled))
 175          continue;
 176
 177       switch (breakpoints[i].type) {
 178       case DBG_BREAK:
 179          {
 180 #ifdef __i386__
 181             char ch = set ? INT3 : breakpoints[i].u.b.opcode;
 182
 183             if (!DEBUG_WRITE_MEM( (void*)DEBUG_ToLinear(&breakpoints[i].addr),
 184                                   &ch, sizeof(ch) ))
 185             {
 186                DEBUG_Printf(DBG_CHN_MESG, "Invalid address for breakpoint %d, disabling it\n", i);
 187                breakpoints[i].enabled = FALSE;
 188             }
 189 #endif
 190          }
 191          break;
 192       case DBG_WATCH:
 193          if (set)
 194          {
 195 #ifdef __i386__
 196             DWORD       bits;
 197             int         reg = breakpoints[i].u.w.reg;
 198             LPDWORD     lpdr = NULL;
 199
 200             switch (reg)
 201             {
 202                case 0: lpdr = &DEBUG_context.Dr0; break;
 203                case 1: lpdr = &DEBUG_context.Dr1; break;
 204                case 2: lpdr = &DEBUG_context.Dr2; break;
 205                case 3: lpdr = &DEBUG_context.Dr3; break;
 206                default: RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 207             }
 208
 209             *lpdr = DEBUG_ToLinear(&breakpoints[i].addr);
 210             bits = (breakpoints[i].u.w.rw) ? DR7_RW_WRITE : DR7_RW_READ;
 211             switch (breakpoints[i].u.w.len + 1)
 212             {
 213                case 4: bits |= DR7_LEN_4;       break;
 214                case 2: bits |= DR7_LEN_2;       break;
 215                case 1: bits |= DR7_LEN_1;       break;
 216                default: RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 217             }
 218
 219             DEBUG_context.Dr7 &= ~(0x0F << (DR7_CONTROL_SHIFT + DR7_CONTROL_SIZE * reg));
 220             DEBUG_context.Dr7 |= bits << (DR7_CONTROL_SHIFT + DR7_CONTROL_SIZE * reg);
 221             DEBUG_context.Dr7 |= DR7_ENABLE_MASK(reg) | DR7_LOCAL_SLOWDOWN;
 222 #endif
 223          }
 224          break;
 225       }
 226    }
 227 }
 228
 229 /***********************************************************************
 230  *           DEBUG_FindBreakpoint
 231  *
 232  * Find the breakpoint for a given address. Return the breakpoint
 233  * number or -1 if none.
 234  * If type is DBG_BREAKPOINT, addr is a complete addr
 235  * If type is DBG_WATCHPOINT, only addr.off is meaningful and contains
 236  * linear address
 237  */
 238 static int DEBUG_FindBreakpoint( const DBG_ADDR *addr, int type )
 239 {
 240    int i;
 241
 242    for (i = 0; i < next_bp; i++)
 243    {
 244       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 245           breakpoints[i].type == type )
 246       {
 247          if ((type == DBG_BREAK &&
 248               breakpoints[i].addr.seg == addr->seg &&
 249               breakpoints[i].addr.off == addr->off) ||
 250              (type == DBG_WATCH &&
 251               DEBUG_ToLinear(&breakpoints[i].addr) == addr->off))
 252             return i;
 253       }
 254    }
 255    return -1;
 256 }
 257
 258 /***********************************************************************
 259  *           DEBUG_InitXPoint
 260  *
 261  * Find an empty slot in BP table to add a new break/watch point
 262  */
 263 static  int     DEBUG_InitXPoint(int type, DBG_ADDR* addr)
 264 {
 265    int  num;
 266
 267    for (num = (next_bp < MAX_BREAKPOINTS) ? next_bp++ : 1;
 268         num < MAX_BREAKPOINTS; num++)
 269    {
 270       if (breakpoints[num].refcount == 0)
 271       {
 272          breakpoints[num].refcount = 1;
 273          breakpoints[num].enabled = TRUE;
 274          breakpoints[num].type    = type;
 275          breakpoints[num].skipcount = 0;
 276          breakpoints[num].addr = *addr;
 277          breakpoints[num].is32 = 1;
 278 #ifdef __i386__
 279          if (addr->seg)
 280          {
 281             switch (DEBUG_GetSelectorType( addr->seg ))
 282             {
 283                case 32: break;
 284                case 16: breakpoints[num].is32 = 0; break;
 285                default: RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 286             }
 287          }
 288 #endif
 289          return num;
 290       }
 291    }
 292
 293    DEBUG_Printf( DBG_CHN_MESG, "Too many breakpoints. Please delete some.\n" );
 294    return -1;
 295 }
 296
 297 /***********************************************************************
 298  *           DEBUG_GetWatchedValue
 299  *
 300  * Returns the value watched by watch point 'num'.
 301  */
 302 static  BOOL    DEBUG_GetWatchedValue( int num, LPDWORD val )
 303 {
 304    BYTE         buf[4];
 305
 306    if (!DEBUG_READ_MEM((void*)DEBUG_ToLinear(&breakpoints[num].addr),
 307                        buf, breakpoints[num].u.w.len + 1))
 308       return FALSE;
 309
 310    switch (breakpoints[num].u.w.len + 1)
 311    {
 312       case 4:   *val = *(DWORD*)buf;    break;
 313       case 2:   *val = *(WORD*)buf;     break;
 314       case 1:   *val = *(BYTE*)buf;     break;
 315       default: RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 316    }
 317    return TRUE;
 318 }
 319
 320 /***********************************************************************
 321  *           DEBUG_AddBreakpoint
 322  *
 323  * Add a breakpoint.
 324  */
 325 void DEBUG_AddBreakpoint( const DBG_VALUE *_value, BOOL (*func)(void) )
 326 {
 327     DBG_VALUE value = *_value;
 328     int num;
 329     BYTE ch;
 330
 331     if( value.type != NULL && value.type == DEBUG_TypeIntConst )
 332     {
 333         /*
 334          * We know that we have the actual offset stored somewhere
 335          * else in 32-bit space.  Grab it, and we
 336          * should be all set.
 337          */
 338         unsigned int seg2 = value.addr.seg;
 339         value.addr.seg = 0;
 340         value.addr.off = DEBUG_GetExprValue(&value, NULL);
 341         value.addr.seg = seg2;
 342     }
 343
 344     if ((num = DEBUG_FindBreakpoint(&value.addr, DBG_BREAK)) >= 1)
 345     {
 346        breakpoints[num].refcount++;
 347        return;
 348     }
 349
 350     if (!DEBUG_READ_MEM_VERBOSE((void*)DEBUG_ToLinear( &value.addr ), &ch, sizeof(ch)))
 351     {
 352        DEBUG_Printf( DBG_CHN_MESG, "Invalid address, can't set breakpoint\n");
 353        return;
 354     }
 355
 356     if ((num = DEBUG_InitXPoint(DBG_BREAK, &value.addr)) == -1)
 357        return;
 358
 359     breakpoints[num].u.b.opcode = ch;
 360     breakpoints[num].u.b.func = func;
 361
 362     DEBUG_Printf( DBG_CHN_MESG, "Breakpoint %d at ", num );
 363     DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32 : 16,
 364                         TRUE );
 365     DEBUG_Printf( DBG_CHN_MESG, "\n" );
 366 }
 367
 368 /***********************************************************************
 369  *           DEBUG_AddBreakpointFromId
 370  *
 371  * Add a breakpoint from a function name (and eventually a line #)
 372  */
 373 void    DEBUG_AddBreakpointFromId(const char *name, int lineno)
 374 {
 375    DBG_VALUE value;
 376
 377    if (DEBUG_GetSymbolValue(name, lineno, &value, TRUE))
 378       DEBUG_AddBreakpoint(&value, NULL);
 379    else
 380       DEBUG_Printf(DBG_CHN_MESG, "Unable to add breakpoint\n");
 381 }
 382
 383 /***********************************************************************
 384  *           DEBUG_AddBreakpointFromLineno
 385  *
 386  * Add a breakpoint from a line number in current file
 387  */
 388 void    DEBUG_AddBreakpointFromLineno(int lineno)
 389 {
 390    DBG_VALUE                    value;
 391
 392    DEBUG_GetCurrentAddress(&value.addr);
 393
 394    if (lineno != -1) {
 395       struct name_hash* nh;
 396
 397       DEBUG_FindNearestSymbol(&value.addr, TRUE, &nh, 0, NULL);
 398       if (nh == NULL) {
 399          DEBUG_Printf(DBG_CHN_MESG,"Unable to add breakpoint\n");
 400          return;
 401       }
 402       DEBUG_GetLineNumberAddr(nh, lineno, &value.addr, TRUE);
 403    }
 404
 405    value.type = NULL;
 406    value.cookie = DV_TARGET;
 407    DEBUG_AddBreakpoint( &value, NULL );
 408 }
 409
 410  /***********************************************************************
 411  *           DEBUG_AddWatchpoint
 412  *
 413  * Add a watchpoint.
 414  */
 415 void DEBUG_AddWatchpoint( const DBG_VALUE *_value, BOOL is_write )
 416 {
 417    DBG_VALUE    value = *_value;
 418    int          num, reg = -1;
 419    unsigned     seg2;
 420    DWORD        mask = 0;
 421
 422    assert(_value->cookie == DV_TARGET || _value->cookie == DV_HOST);
 423
 424 #ifdef __i386__
 425    DEBUG_FixAddress( &value.addr, DEBUG_context.SegCs );
 426 #endif
 427
 428    if ( value.type != NULL && value.type == DEBUG_TypeIntConst )
 429    {
 430       /*
 431        * We know that we have the actual offset stored somewhere
 432        * else in 32-bit space.  Grab it, and we
 433        * should be all set.
 434        */
 435       seg2 = value.addr.seg;
 436       value.addr.seg = 0;
 437       value.addr.off = DEBUG_GetExprValue(&value, NULL);
 438       value.addr.seg = seg2;
 439    }
 440
 441    for (num = 1; num < next_bp; num++)
 442    {
 443       if (breakpoints[num].refcount && breakpoints[num].enabled &&
 444           breakpoints[num].type == DBG_WATCH) {
 445          mask |= (1 << breakpoints[num].u.w.reg);
 446       }
 447    }
 448 #ifdef __i386__
 449    for (reg = 0; reg < 4 && (mask & (1 << reg)); reg++);
 450    if (reg == 4)
 451    {
 452       DEBUG_Printf(DBG_CHN_MESG, "All i386 hardware watchpoints have been set. Delete some\n");
 453       return;
 454    }
 455 #endif
 456
 457    if ((num = DEBUG_InitXPoint(DBG_WATCH, &value.addr)) == -1)
 458       return;
 459
 460    breakpoints[num].u.w.len = 4 - 1;
 461    if (_value->type && DEBUG_GetObjectSize(_value->type) < 4)
 462       breakpoints[num].u.w.len = 2 - 1;
 463
 464    if (!DEBUG_GetWatchedValue( num, &breakpoints[num].u.w.oldval))
 465    {
 466       DEBUG_Printf(DBG_CHN_MESG, "Bad address. Watchpoint not set\n");
 467       breakpoints[num].refcount = 0;
 468    }
 469
 470    breakpoints[num].u.w.rw = (is_write) ? TRUE : FALSE;
 471    breakpoints[reg].u.w.reg = reg;
 472
 473    DEBUG_Printf( DBG_CHN_MESG, "Watchpoint %d at ", num );
 474    DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32:16, TRUE );
 475    DEBUG_Printf( DBG_CHN_MESG, "\n" );
 476 }
 477
 478 /***********************************************************************
 479  *           DEBUG_AddWathpointFromId
 480  *
 481  * Add a watchpoint from a symbol name (and eventually a line #)
 482  */
 483 void    DEBUG_AddWatchpointFromId(const char *name, int lineno)
 484 {
 485    DBG_VALUE value;
 486
 487    if( DEBUG_GetSymbolValue(name, lineno, &value, TRUE) )
 488       DEBUG_AddWatchpoint( &value, 1 );
 489    else
 490       DEBUG_Printf(DBG_CHN_MESG, "Unable to add watchpoint\n");
 491 }
 492
 493 /***********************************************************************
 494  *           DEBUG_DelBreakpoint
 495  *
 496  * Delete a breakpoint.
 497  */
 498 void DEBUG_DelBreakpoint( int num )
 499 {
 500     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 501     {
 502         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 503         return;
 504     }
 505
 506     if (--breakpoints[num].refcount > 0)
 507        return;
 508
 509     if( breakpoints[num].condition != NULL )
 510     {
 511        DEBUG_FreeExpr(breakpoints[num].condition);
 512        breakpoints[num].condition = NULL;
 513     }
 514
 515     breakpoints[num].enabled = FALSE;
 516     breakpoints[num].refcount = 0;
 517     breakpoints[num].skipcount = 0;
 518 }
 519
 520 /***********************************************************************
 521  *           DEBUG_EnableBreakpoint
 522  *
 523  * Enable or disable a break point.
 524  */
 525 void DEBUG_EnableBreakpoint( int num, BOOL enable )
 526 {
 527     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 528     {
 529         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 530         return;
 531     }
 532     breakpoints[num].enabled = (enable) ? TRUE : FALSE;
 533     breakpoints[num].skipcount = 0;
 534 }
 535
 536
 537 /***********************************************************************
 538  *           DEBUG_FindTriggeredWatchpoint
 539  *
 540  * Lookup the watchpoints to see if one has been triggered
 541  * Return >= (watch point index) if one is found and *oldval is set to
 542  *      the value watched before the TRAP
 543  * Return -1 if none found (*oldval is undetermined)
 544  *
 545  * Unfortunately, Linux does *NOT* (A REAL PITA) report with ptrace
 546  * the DR6 register value, so we have to look with our own need the
 547  * cause of the TRAP.
 548  * -EP
 549  */
 550 static int DEBUG_FindTriggeredWatchpoint(LPDWORD oldval)
 551 {
 552    int                          found = -1;
 553 #ifdef __i386__
 554    int                          i;
 555
 556    /* Method 1 => get triggered watchpoint from context (doesn't work on Linux
 557     * 2.2.x). This should be fixed in >= 2.2.16
 558     */
 559    for (i = 0; i < next_bp; i++)
 560    {
 561       DWORD val = 0;
 562
 563       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 564           breakpoints[i].type == DBG_WATCH &&
 565           (DEBUG_context.Dr6 & (1 << breakpoints[i].u.w.reg)))
 566       {
 567          DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 568
 569          *oldval = breakpoints[i].u.w.oldval;
 570          if (DEBUG_GetWatchedValue(i, &val)) {
 571             breakpoints[i].u.w.oldval = val;
 572             return i;
 573          }
 574       }
 575    }
 576
 577    /* Method 1 failed, trying method 2 */
 578
 579    /* Method 2 => check if value has changed among registered watchpoints
 580     * this really sucks, but this is how gdb 4.18 works on my linux box
 581     * -EP
 582     */
 583    for (i = 0; i < next_bp; i++)
 584    {
 585       DWORD val = 0;
 586
 587       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 588           breakpoints[i].type == DBG_WATCH &&
 589           DEBUG_GetWatchedValue(i, &val))
 590       {
 591          *oldval = breakpoints[i].u.w.oldval;
 592          if (val != *oldval)
 593          {
 594             DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 595             breakpoints[i].u.w.oldval = val;
 596             found = i;
 597             /* cannot break, because two watch points may have been triggered on
 598              * the same access
 599              * only one will be reported to the user (FIXME ?)
 600              */
 601          }
 602       }
 603    }
 604 #endif
 605    return found;
 606 }
 607
 608 /***********************************************************************
 609  *           DEBUG_InfoBreakpoints
 610  *
 611  * Display break points information.
 612  */
 613 void DEBUG_InfoBreakpoints(void)
 614 {
 615     int i;
 616
 617     DEBUG_Printf( DBG_CHN_MESG, "Breakpoints:\n" );
 618     for (i = 1; i < next_bp; i++)
 619     {
 620         if (breakpoints[i].refcount && breakpoints[i].type == DBG_BREAK)
 621         {
 622             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 623             DEBUG_PrintAddress( &breakpoints[i].addr,
 624                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 625             DEBUG_Printf( DBG_CHN_MESG, " (%u)\n", breakpoints[i].refcount );
 626             if( breakpoints[i].condition != NULL )
 627             {
 628                 DEBUG_Printf(DBG_CHN_MESG, "\t\tstop when  ");
 629                 DEBUG_DisplayExpr(breakpoints[i].condition);
 630                 DEBUG_Printf(DBG_CHN_MESG, "\n");
 631             }
 632         }
 633     }
 634     DEBUG_Printf( DBG_CHN_MESG, "Watchpoints:\n" );
 635     for (i = 1; i < next_bp; i++)
 636     {
 637         if (breakpoints[i].refcount && breakpoints[i].type == DBG_WATCH)
 638         {
 639             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 640             DEBUG_PrintAddress( &breakpoints[i].addr,
 641                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 642             DEBUG_Printf( DBG_CHN_MESG, " on %d byte%s (%c)\n",
 643                      breakpoints[i].u.w.len + 1,
 644                      breakpoints[i].u.w.len > 0 ? "s" : "",
 645                      breakpoints[i].u.w.rw ? 'W' : 'R');
 646             if( breakpoints[i].condition != NULL )
 647             {
 648                 DEBUG_Printf(DBG_CHN_MESG, "\t\tstop when  ");
 649                 DEBUG_DisplayExpr(breakpoints[i].condition);
 650                 DEBUG_Printf(DBG_CHN_MESG, "\n");
 651             }
 652         }
 653     }
 654 }
 655
 656 /***********************************************************************
 657  *           DEBUG_ShallBreak
 658  *
 659  * Check whether or not the condition (bp / skipcount) of a break/watch
 660  * point are met.
 661  */
 662 static  BOOL DEBUG_ShallBreak( int bpnum )
 663 {
 664     if ( breakpoints[bpnum].condition != NULL )
 665     {
 666         DBG_VALUE value = DEBUG_EvalExpr(breakpoints[bpnum].condition);
 667
 668         if ( value.type == NULL )
 669         {
 670             /*
 671              * Something wrong - unable to evaluate this expression.
 672              */
 673             DEBUG_Printf(DBG_CHN_MESG, "Unable to evaluate expression ");
 674             DEBUG_DisplayExpr(breakpoints[bpnum].condition);
 675             DEBUG_Printf(DBG_CHN_MESG, "\nTurning off condition\n");
 676             DEBUG_AddBPCondition(bpnum, NULL);
 677         }
 678         else if( !DEBUG_GetExprValue( &value, NULL) )
 679         {
 680             return FALSE;
 681         }
 682     }
 683
 684     if ( breakpoints[bpnum].skipcount > 0 && --breakpoints[bpnum].skipcount > 0 )
 685         return FALSE;
 686
 687    if ((breakpoints[bpnum].type == DBG_BREAK) && breakpoints[bpnum].u.b.func)
 688        return breakpoints[bpnum].u.b.func();
 689    return TRUE;
 690 }
 691
 692 /***********************************************************************
 693  *           DEBUG_ShouldContinue
 694  *
 695  * Determine if we should continue execution after a SIGTRAP signal when
 696  * executing in the given mode.
 697  */
 698 BOOL DEBUG_ShouldContinue( DWORD code, enum exec_mode mode, int * count )
 699 {
 700     DBG_ADDR    addr;
 701     int         bpnum;
 702     DWORD       oldval;
 703     int         wpnum;
 704     int         addrlen = 32;
 705     struct symbol_info syminfo;
 706
 707 #ifdef __i386__
 708     /* If not single-stepping, back up over the int3 instruction */
 709     if (code == EXCEPTION_BREAKPOINT)
 710        DEBUG_context.Eip--;
 711 #endif
 712
 713     DEBUG_GetCurrentAddress( &addr );
 714     bpnum = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 715     breakpoints[0].enabled = FALSE;  /* disable the step-over breakpoint */
 716
 717     if ((bpnum != 0) && (bpnum != -1))
 718     {
 719         if (!DEBUG_ShallBreak(bpnum)) return TRUE;
 720
 721         DEBUG_Printf( DBG_CHN_MESG, "Stopped on breakpoint %d at ", bpnum );
 722         syminfo = DEBUG_PrintAddress( &breakpoints[bpnum].addr,
 723                                       breakpoints[bpnum].is32 ? 32 : 16, TRUE );
 724         DEBUG_Printf( DBG_CHN_MESG, "\n" );
 725
 726         if( syminfo.list.sourcefile != NULL )
 727             DEBUG_List(&syminfo.list, NULL, 0);
 728         return FALSE;
 729     }
 730
 731     wpnum = DEBUG_FindTriggeredWatchpoint(&oldval);
 732     if ((wpnum != 0) && (wpnum != -1))
 733     {
 734        /* If not single-stepping, do not back up over the int3 instruction */
 735        if (code == EXCEPTION_BREAKPOINT)
 736        {
 737 #ifdef __i386__
 738            DEBUG_context.Eip++;
 739            addr.off++;
 740 #endif
 741        }
 742        if (!DEBUG_ShallBreak(wpnum)) return TRUE;
 743
 744 #ifdef __i386__
 745        if (addr.seg) addrlen = DEBUG_GetSelectorType( addr.seg );
 746 #endif
 747        DEBUG_Printf(DBG_CHN_MESG, "Stopped on watchpoint %d at ", wpnum);
 748        syminfo = DEBUG_PrintAddress( &addr, addrlen, TRUE );
 749
 750        DEBUG_Printf(DBG_CHN_MESG, " values: old=%lu new=%lu\n",
 751                oldval, breakpoints[wpnum].u.w.oldval);
 752        if (syminfo.list.sourcefile != NULL)
 753           DEBUG_List(&syminfo.list, NULL, 0);
 754        return FALSE;
 755     }
 756
 757     /*
 758      * If our mode indicates that we are stepping line numbers,
 759      * get the current function, and figure out if we are exactly
 760      * on a line number or not.
 761      */
 762     if( mode == EXEC_STEP_OVER || mode == EXEC_STEP_INSTR )
 763     {
 764         if( DEBUG_CheckLinenoStatus(&addr) == AT_LINENUMBER )
 765         {
 766             (*count)--;
 767         }
 768     }
 769     else if( mode == EXEC_STEPI_OVER || mode == EXEC_STEPI_INSTR )
 770     {
 771         (*count)--;
 772     }
 773
 774     if( *count > 0 || mode == EXEC_FINISH )
 775     {
 776         /*
 777          * We still need to execute more instructions.
 778          */
 779         return TRUE;
 780     }
 781
 782     /*
 783      * If we are about to stop, then print out the source line if we
 784      * have it.
 785      */
 786     if (mode != EXEC_CONT && mode != EXEC_PASS && mode != EXEC_FINISH)
 787     {
 788         DEBUG_FindNearestSymbol( &addr, TRUE, NULL, 0, &syminfo.list);
 789         if( syminfo.list.sourcefile != NULL )
 790         {
 791             DEBUG_List(&syminfo.list, NULL, 0);
 792         }
 793     }
 794
 795 #ifdef __i386__
 796     /* If there's no breakpoint and we are not single-stepping, then we     */
 797     /* must have encountered an int3 in the Windows program; let's skip it. */
 798     if ((bpnum == -1) && code == EXCEPTION_BREAKPOINT)
 799         DEBUG_context.Eip++;
 800 #endif
 801
 802     /* no breakpoint, continue if in continuous mode */
 803     return (mode == EXEC_CONT || mode == EXEC_PASS || mode == EXEC_FINISH);
 804 }
 805
 806 /***********************************************************************
 807  *           DEBUG_SuspendExecution
 808  *
 809  * Remove all breakpoints before entering the debug loop
 810  */
 811 void    DEBUG_SuspendExecution( void )
 812 {
 813    DEBUG_SetBreakpoints( FALSE );
 814    breakpoints[0] = DEBUG_CurrThread->stepOverBP;
 815 }
 816
 817 /***********************************************************************
 818  *           DEBUG_RestartExecution
 819  *
 820  * Set the breakpoints to the correct state to restart execution
 821  * in the given mode.
 822  */
 823 enum exec_mode DEBUG_RestartExecution( enum exec_mode mode, int count )
 824 {
 825     DBG_ADDR addr;
 826     DBG_ADDR addr2;
 827     int bp;
 828     int delta;
 829     int status;
 830     enum exec_mode ret_mode;
 831     DWORD instr;
 832     unsigned char ch;
 833
 834     DEBUG_GetCurrentAddress( &addr );
 835
 836     /*
 837      * This is the mode we will be running in after we finish.  We would like
 838      * to be able to modify this in certain cases.
 839      */
 840     ret_mode = mode;
 841
 842     bp = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 843     if ( bp != -1 && bp != 0)
 844       {
 845         /*
 846          * If we have set a new value, then save it in the BP number.
 847          */
 848         if( count != 0 && mode == EXEC_CONT )
 849           {
 850             breakpoints[bp].skipcount = count;
 851           }
 852         mode = EXEC_STEPI_INSTR;  /* If there's a breakpoint, skip it */
 853       }
 854     else
 855       {
 856         if( mode == EXEC_CONT && count > 1 )
 857           {
 858             DEBUG_Printf(DBG_CHN_MESG, "Not stopped at any breakpoint; argument ignored.\n");
 859           }
 860       }
 861
 862     if( mode == EXEC_FINISH && DEBUG_IsFctReturn() )
 863       {
 864         mode = ret_mode = EXEC_STEPI_INSTR;
 865       }
 866
 867     instr = DEBUG_ToLinear( &addr );
 868     DEBUG_READ_MEM((void*)instr, &ch, sizeof(ch));
 869     /*
 870      * See if the function we are stepping into has debug info
 871      * and line numbers.  If not, then we step over it instead.
 872      * FIXME - we need to check for things like thunks or trampolines,
 873      * as the actual function may in fact have debug info.
 874      */
 875     if( ch == 0xe8 )
 876       {
 877         DEBUG_READ_MEM((void*)(instr + 1), &delta, sizeof(delta));
 878         addr2 = addr;
 879         DEBUG_Disasm(&addr2, FALSE);
 880         addr2.off += delta;
 881
 882         status = DEBUG_CheckLinenoStatus(&addr2);
 883         /*
 884          * Anytime we have a trampoline, step over it.
 885          */
 886         if( ((mode == EXEC_STEP_OVER) || (mode == EXEC_STEPI_OVER))
 887             && status == FUNC_IS_TRAMPOLINE )
 888           {
 889 #if 0
 890             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into trampoline at %x (no lines)\n",
 891                     addr2.off);
 892 #endif
 893             mode = EXEC_STEP_OVER_TRAMPOLINE;
 894           }
 895
 896         if( mode == EXEC_STEP_INSTR && status == FUNC_HAS_NO_LINES )
 897           {
 898 #if 0
 899             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into function at %x (no lines)\n",
 900                     addr2.off);
 901 #endif
 902             mode = EXEC_STEP_OVER;
 903           }
 904       }
 905
 906
 907     if( mode == EXEC_STEP_INSTR )
 908       {
 909         if( DEBUG_CheckLinenoStatus(&addr) == FUNC_HAS_NO_LINES )
 910           {
 911             DEBUG_Printf(DBG_CHN_MESG, "Single stepping until exit from function, \n");
 912             DEBUG_Printf(DBG_CHN_MESG, "which has no line number information.\n");
 913
 914             ret_mode = mode = EXEC_FINISH;
 915           }
 916       }
 917
 918     switch(mode)
 919     {
 920     case EXEC_CONT: /* Continuous execution */
 921     case EXEC_PASS: /* Continue, passing exception */
 922 #ifdef __i386__
 923         DEBUG_context.EFlags &= ~STEP_FLAG;
 924 #endif
 925         DEBUG_SetBreakpoints( TRUE );
 926         break;
 927
 928     case EXEC_STEP_OVER_TRAMPOLINE:
 929       /*
 930        * This is the means by which we step over our conversion stubs
 931        * in callfrom*.s and callto*.s.  We dig the appropriate address
 932        * off the stack, and we set the breakpoint there instead of the
 933        * address just after the call.
 934        */
 935 #ifdef __i386__
 936       DEBUG_READ_MEM((void*)(DEBUG_context.Esp +
 937                              2 * sizeof(unsigned int)),
 938                      &addr.off, sizeof(addr.off));
 939       DEBUG_context.EFlags &= ~STEP_FLAG;
 940 #endif
 941       breakpoints[0].addr    = addr;
 942       breakpoints[0].enabled = TRUE;
 943       breakpoints[0].refcount = 1;
 944       breakpoints[0].skipcount = 0;
 945       DEBUG_READ_MEM((void*)DEBUG_ToLinear( &addr ), &breakpoints[0].u.b.opcode,
 946                      sizeof(char));
 947       DEBUG_SetBreakpoints( TRUE );
 948       break;
 949
 950     case EXEC_FINISH:
 951     case EXEC_STEPI_OVER:  /* Stepping over a call */
 952     case EXEC_STEP_OVER:  /* Stepping over a call */
 953         if (DEBUG_IsStepOverInstr())
 954         {
 955 #ifdef __i386__
 956             DEBUG_context.EFlags &= ~STEP_FLAG;
 957 #endif
 958             DEBUG_Disasm(&addr, FALSE);
 959             breakpoints[0].addr    = addr;
 960             breakpoints[0].enabled = TRUE;
 961             breakpoints[0].refcount = 1;
 962             breakpoints[0].skipcount = 0;
 963             DEBUG_READ_MEM((void*)DEBUG_ToLinear( &addr ), &breakpoints[0].u.b.opcode,
 964                            sizeof(char));
 965             DEBUG_SetBreakpoints( TRUE );
 966             break;
 967         }
 968         /* else fall through to single-stepping */
 969
 970     case EXEC_STEP_INSTR: /* Single-stepping an instruction */
 971     case EXEC_STEPI_INSTR: /* Single-stepping an instruction */
 972 #ifdef __i386__
 973         DEBUG_context.EFlags |= STEP_FLAG;
 974 #endif
 975         break;
 976     default:
 977         RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 978     }
 979     DEBUG_CurrThread->stepOverBP = breakpoints[0];
 980     return ret_mode;
 981 }
 982
 983 int
 984 DEBUG_AddBPCondition(int num, struct expr * exp)
 985 {
 986     if ((num <= 0) || (num >= next_bp) || !breakpoints[num].refcount)
 987     {
 988         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 989         return FALSE;
 990     }
 991
 992     if( breakpoints[num].condition != NULL )
 993       {
 994         DEBUG_FreeExpr(breakpoints[num].condition);
 995         breakpoints[num].condition = NULL;
 996       }
 997
 998     if( exp != NULL )
 999       {
1000         breakpoints[num].condition = DEBUG_CloneExpr(exp);
1001       }
1002
1003    return TRUE;
1004 }