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     unsigned int seg2;
 330     BYTE ch;
 331
 332     assert(_value->cookie == DV_TARGET || _value->cookie == DV_HOST);
 333
 334 #ifdef __i386__
 335     DEBUG_FixAddress( &value.addr, DEBUG_context.SegCs );
 336 #endif
 337
 338     if( value.type != NULL && value.type == DEBUG_TypeIntConst )
 339     {
 340        /*
 341         * We know that we have the actual offset stored somewhere
 342         * else in 32-bit space.  Grab it, and we
 343         * should be all set.
 344         */
 345        seg2 = value.addr.seg;
 346        value.addr.seg = 0;
 347        value.addr.off = DEBUG_GetExprValue(&value, NULL);
 348        value.addr.seg = seg2;
 349     }
 350
 351     if ((num = DEBUG_FindBreakpoint(&value.addr, DBG_BREAK)) >= 1)
 352     {
 353        breakpoints[num].refcount++;
 354        return;
 355     }
 356
 357     if (!DEBUG_READ_MEM_VERBOSE((void*)DEBUG_ToLinear( &value.addr ), &ch, sizeof(ch)))
 358         return;
 359
 360     if ((num = DEBUG_InitXPoint(DBG_BREAK, &value.addr)) == -1)
 361        return;
 362
 363     breakpoints[num].u.b.opcode = ch;
 364     breakpoints[num].u.b.func = func;
 365
 366     DEBUG_Printf( DBG_CHN_MESG, "Breakpoint %d at ", num );
 367     DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32 : 16,
 368                         TRUE );
 369     DEBUG_Printf( DBG_CHN_MESG, "\n" );
 370 }
 371
 372 /***********************************************************************
 373  *           DEBUG_AddBreakpointFromId
 374  *
 375  * Add a breakpoint from a function name (and eventually a line #)
 376  */
 377 void    DEBUG_AddBreakpointFromId(const char *name, int lineno)
 378 {
 379    DBG_VALUE value;
 380
 381    if (DEBUG_GetSymbolValue(name, lineno, &value, TRUE))
 382       DEBUG_AddBreakpoint(&value, NULL);
 383    else
 384       DEBUG_Printf(DBG_CHN_MESG, "Unable to add breakpoint\n");
 385 }
 386
 387 /***********************************************************************
 388  *           DEBUG_AddBreakpointFromLineno
 389  *
 390  * Add a breakpoint from a line number in current file
 391  */
 392 void    DEBUG_AddBreakpointFromLineno(int lineno)
 393 {
 394    DBG_VALUE                    value;
 395
 396    DEBUG_GetCurrentAddress(&value.addr);
 397
 398    if (lineno != -1) {
 399       struct name_hash* nh;
 400
 401       DEBUG_FindNearestSymbol(&value.addr, TRUE, &nh, 0, NULL);
 402       if (nh == NULL) {
 403          DEBUG_Printf(DBG_CHN_MESG,"Unable to add breakpoint\n");
 404          return;
 405       }
 406       DEBUG_GetLineNumberAddr(nh, lineno, &value.addr, TRUE);
 407    }
 408
 409    value.type = NULL;
 410    value.cookie = DV_TARGET;
 411    DEBUG_AddBreakpoint( &value, NULL );
 412 }
 413
 414  /***********************************************************************
 415  *           DEBUG_AddWatchpoint
 416  *
 417  * Add a watchpoint.
 418  */
 419 void DEBUG_AddWatchpoint( const DBG_VALUE *_value, BOOL is_write )
 420 {
 421    DBG_VALUE    value = *_value;
 422    int          num, reg = -1;
 423    unsigned     seg2;
 424    DWORD        mask = 0;
 425
 426    assert(_value->cookie == DV_TARGET || _value->cookie == DV_HOST);
 427
 428 #ifdef __i386__
 429    DEBUG_FixAddress( &value.addr, DEBUG_context.SegCs );
 430 #endif
 431
 432    if ( value.type != NULL && value.type == DEBUG_TypeIntConst )
 433    {
 434       /*
 435        * We know that we have the actual offset stored somewhere
 436        * else in 32-bit space.  Grab it, and we
 437        * should be all set.
 438        */
 439       seg2 = value.addr.seg;
 440       value.addr.seg = 0;
 441       value.addr.off = DEBUG_GetExprValue(&value, NULL);
 442       value.addr.seg = seg2;
 443    }
 444
 445    for (num = 1; num < next_bp; num++)
 446    {
 447       if (breakpoints[num].refcount && breakpoints[num].enabled &&
 448           breakpoints[num].type == DBG_WATCH) {
 449          mask |= (1 << breakpoints[num].u.w.reg);
 450       }
 451    }
 452 #ifdef __i386__
 453    for (reg = 0; reg < 4 && (mask & (1 << reg)); reg++);
 454    if (reg == 4)
 455    {
 456       DEBUG_Printf(DBG_CHN_MESG, "All i386 hardware watchpoints have been set. Delete some\n");
 457       return;
 458    }
 459 #endif
 460
 461    if ((num = DEBUG_InitXPoint(DBG_WATCH, &value.addr)) == -1)
 462       return;
 463
 464    breakpoints[num].u.w.len = 4 - 1;
 465    if (_value->type && DEBUG_GetObjectSize(_value->type) < 4)
 466       breakpoints[num].u.w.len = 2 - 1;
 467
 468    if (!DEBUG_GetWatchedValue( num, &breakpoints[num].u.w.oldval))
 469    {
 470       DEBUG_Printf(DBG_CHN_MESG, "Bad address. Watchpoint not set\n");
 471       breakpoints[num].refcount = 0;
 472    }
 473
 474    breakpoints[num].u.w.rw = (is_write) ? TRUE : FALSE;
 475    breakpoints[reg].u.w.reg = reg;
 476
 477    DEBUG_Printf( DBG_CHN_MESG, "Watchpoint %d at ", num );
 478    DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32:16, TRUE );
 479    DEBUG_Printf( DBG_CHN_MESG, "\n" );
 480 }
 481
 482 /***********************************************************************
 483  *           DEBUG_AddWathpointFromId
 484  *
 485  * Add a watchpoint from a symbol name (and eventually a line #)
 486  */
 487 void    DEBUG_AddWatchpointFromId(const char *name, int lineno)
 488 {
 489    DBG_VALUE value;
 490
 491    if( DEBUG_GetSymbolValue(name, lineno, &value, TRUE) )
 492       DEBUG_AddWatchpoint( &value, 1 );
 493    else
 494       DEBUG_Printf(DBG_CHN_MESG, "Unable to add watchpoint\n");
 495 }
 496
 497 /***********************************************************************
 498  *           DEBUG_DelBreakpoint
 499  *
 500  * Delete a breakpoint.
 501  */
 502 void DEBUG_DelBreakpoint( int num )
 503 {
 504     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 505     {
 506         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 507         return;
 508     }
 509
 510     if (--breakpoints[num].refcount > 0)
 511        return;
 512
 513     if( breakpoints[num].condition != NULL )
 514     {
 515        DEBUG_FreeExpr(breakpoints[num].condition);
 516        breakpoints[num].condition = NULL;
 517     }
 518
 519     breakpoints[num].enabled = FALSE;
 520     breakpoints[num].refcount = 0;
 521     breakpoints[num].skipcount = 0;
 522 }
 523
 524 /***********************************************************************
 525  *           DEBUG_EnableBreakpoint
 526  *
 527  * Enable or disable a break point.
 528  */
 529 void DEBUG_EnableBreakpoint( int num, BOOL enable )
 530 {
 531     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 532     {
 533         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 534         return;
 535     }
 536     breakpoints[num].enabled = (enable) ? TRUE : FALSE;
 537     breakpoints[num].skipcount = 0;
 538 }
 539
 540
 541 /***********************************************************************
 542  *           DEBUG_FindTriggeredWatchpoint
 543  *
 544  * Lookup the watchpoints to see if one has been triggered
 545  * Return >= (watch point index) if one is found and *oldval is set to
 546  *      the value watched before the TRAP
 547  * Return -1 if none found (*oldval is undetermined)
 548  *
 549  * Unfortunately, Linux does *NOT* (A REAL PITA) report with ptrace
 550  * the DR6 register value, so we have to look with our own need the
 551  * cause of the TRAP.
 552  * -EP
 553  */
 554 static int DEBUG_FindTriggeredWatchpoint(LPDWORD oldval)
 555 {
 556    int                          i;
 557    int                          found = -1;
 558
 559    /* Method 1 => get triggered watchpoint from context (doesn't work on Linux
 560     * 2.2.x)
 561     */
 562    for (i = 0; i < next_bp; i++)
 563    {
 564 #ifdef __i386__
 565       DWORD val = 0;
 566
 567       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 568           breakpoints[i].type == DBG_WATCH &&
 569           (DEBUG_context.Dr6 & (1 << breakpoints[i].u.w.reg)))
 570       {
 571          DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 572
 573          *oldval = breakpoints[i].u.w.oldval;
 574          if (DEBUG_GetWatchedValue(i, &val)) {
 575             breakpoints[i].u.w.oldval = val;
 576             return i;
 577          }
 578       }
 579 #endif
 580    }
 581
 582    /* Method 1 failed, trying method2 */
 583
 584    /* Method 2 => check if value has changed among registered watchpoints
 585     * this really sucks, but this is how gdb 4.18 works on my linux box
 586     * -EP
 587     */
 588    for (i = 0; i < next_bp; i++)
 589    {
 590 #ifdef __i386__
 591       DWORD val = 0;
 592
 593       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 594           breakpoints[i].type == DBG_WATCH &&
 595           DEBUG_GetWatchedValue(i, &val))
 596       {
 597          *oldval = breakpoints[i].u.w.oldval;
 598          if (val != *oldval)
 599          {
 600             DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 601             breakpoints[i].u.w.oldval = val;
 602             found = i;
 603             /* cannot break, because two watch points may have been triggered on
 604              * the same acces
 605              * only one will be reported to the user (FIXME ?)
 606              */
 607          }
 608       }
 609 #endif
 610    }
 611    return found;
 612 }
 613
 614 /***********************************************************************
 615  *           DEBUG_InfoBreakpoints
 616  *
 617  * Display break points information.
 618  */
 619 void DEBUG_InfoBreakpoints(void)
 620 {
 621     int i;
 622
 623     DEBUG_Printf( DBG_CHN_MESG, "Breakpoints:\n" );
 624     for (i = 1; i < next_bp; i++)
 625     {
 626         if (breakpoints[i].refcount && breakpoints[i].type == DBG_BREAK)
 627         {
 628             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 629             DEBUG_PrintAddress( &breakpoints[i].addr,
 630                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 631             DEBUG_Printf( DBG_CHN_MESG, " (%u)\n", breakpoints[i].refcount );
 632             if( breakpoints[i].condition != NULL )
 633             {
 634                 DEBUG_Printf(DBG_CHN_MESG, "\t\tstop when  ");
 635                 DEBUG_DisplayExpr(breakpoints[i].condition);
 636                 DEBUG_Printf(DBG_CHN_MESG, "\n");
 637             }
 638         }
 639     }
 640     DEBUG_Printf( DBG_CHN_MESG, "Watchpoints:\n" );
 641     for (i = 1; i < next_bp; i++)
 642     {
 643         if (breakpoints[i].refcount && breakpoints[i].type == DBG_WATCH)
 644         {
 645             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 646             DEBUG_PrintAddress( &breakpoints[i].addr,
 647                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 648             DEBUG_Printf( DBG_CHN_MESG, " on %d byte%s (%c)\n",
 649                      breakpoints[i].u.w.len + 1,
 650                      breakpoints[i].u.w.len > 0 ? "s" : "",
 651                      breakpoints[i].u.w.rw ? 'W' : 'R');
 652             if( breakpoints[i].condition != NULL )
 653             {
 654                 DEBUG_Printf(DBG_CHN_MESG, "\t\tstop when  ");
 655                 DEBUG_DisplayExpr(breakpoints[i].condition);
 656                 DEBUG_Printf(DBG_CHN_MESG, "\n");
 657             }
 658         }
 659     }
 660 }
 661
 662 /***********************************************************************
 663  *           DEBUG_ShallBreak
 664  *
 665  * Check whether or not the condition (bp / skipcount) of a break/watch
 666  * point are met.
 667  */
 668 static  BOOL DEBUG_ShallBreak( int bpnum )
 669 {
 670    if ( breakpoints[bpnum].condition != NULL )
 671    {
 672       DBG_VALUE value = DEBUG_EvalExpr(breakpoints[bpnum].condition);
 673
 674       if ( value.type == NULL )
 675       {
 676          /*
 677           * Something wrong - unable to evaluate this expression.
 678           */
 679          DEBUG_Printf(DBG_CHN_MESG, "Unable to evaluate expression ");
 680          DEBUG_DisplayExpr(breakpoints[bpnum].condition);
 681          DEBUG_Printf(DBG_CHN_MESG, "\nTurning off condition\n");
 682          DEBUG_AddBPCondition(bpnum, NULL);
 683       }
 684       else if( !DEBUG_GetExprValue( &value, NULL) )
 685       {
 686          return FALSE;
 687       }
 688    }
 689
 690    if ( breakpoints[bpnum].skipcount > 0 && --breakpoints[bpnum].skipcount > 0 )
 691       return FALSE;
 692
 693    return (breakpoints[bpnum].u.b.func) ? (breakpoints[bpnum].u.b.func)() : TRUE;
 694 }
 695
 696 /***********************************************************************
 697  *           DEBUG_ShouldContinue
 698  *
 699  * Determine if we should continue execution after a SIGTRAP signal when
 700  * executing in the given mode.
 701  */
 702 BOOL DEBUG_ShouldContinue( DWORD code, enum exec_mode mode, int * count )
 703 {
 704     DBG_ADDR    addr;
 705     int         bpnum;
 706     DWORD       oldval;
 707     int         wpnum;
 708     int         addrlen = 32;
 709     struct symbol_info syminfo;
 710
 711 #ifdef __i386__
 712     /* If not single-stepping, back up over the int3 instruction */
 713     if (code == EXCEPTION_BREAKPOINT)
 714        DEBUG_context.Eip--;
 715 #endif
 716
 717     DEBUG_GetCurrentAddress( &addr );
 718     bpnum = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 719     breakpoints[0].enabled = FALSE;  /* disable the step-over breakpoint */
 720
 721     if ((bpnum != 0) && (bpnum != -1))
 722     {
 723         if (!DEBUG_ShallBreak(bpnum)) return TRUE;
 724
 725         DEBUG_Printf( DBG_CHN_MESG, "Stopped on breakpoint %d at ", bpnum );
 726         syminfo = DEBUG_PrintAddress( &breakpoints[bpnum].addr,
 727                                       breakpoints[bpnum].is32 ? 32 : 16, TRUE );
 728         DEBUG_Printf( DBG_CHN_MESG, "\n" );
 729
 730         if( syminfo.list.sourcefile != NULL )
 731             DEBUG_List(&syminfo.list, NULL, 0);
 732         return FALSE;
 733     }
 734
 735     wpnum = DEBUG_FindTriggeredWatchpoint(&oldval);
 736     if ((wpnum != 0) && (wpnum != -1))
 737     {
 738        /* If not single-stepping, do not back up over the int3 instruction */
 739        if (code == EXCEPTION_BREAKPOINT)
 740        {
 741 #ifdef __i386__
 742            DEBUG_context.Eip++;
 743            addr.off++;
 744 #endif
 745        }
 746        if (!DEBUG_ShallBreak(wpnum)) return TRUE;
 747
 748 #ifdef __i386__
 749        addrlen = !addr.seg? 32 : DEBUG_GetSelectorType( addr.seg );
 750 #endif
 751        DEBUG_Printf(DBG_CHN_MESG, "Stopped on watchpoint %d at ", wpnum);
 752        syminfo = DEBUG_PrintAddress( &addr, addrlen, TRUE );
 753
 754        DEBUG_Printf(DBG_CHN_MESG, " values: old=%lu new=%lu\n",
 755                oldval, breakpoints[wpnum].u.w.oldval);
 756        if (syminfo.list.sourcefile != NULL)
 757           DEBUG_List(&syminfo.list, NULL, 0);
 758        return FALSE;
 759     }
 760
 761     /*
 762      * If our mode indicates that we are stepping line numbers,
 763      * get the current function, and figure out if we are exactly
 764      * on a line number or not.
 765      */
 766     if( mode == EXEC_STEP_OVER || mode == EXEC_STEP_INSTR )
 767     {
 768         if( DEBUG_CheckLinenoStatus(&addr) == AT_LINENUMBER )
 769         {
 770             (*count)--;
 771         }
 772     }
 773     else if( mode == EXEC_STEPI_OVER || mode == EXEC_STEPI_INSTR )
 774     {
 775         (*count)--;
 776     }
 777
 778     if( *count > 0 || mode == EXEC_FINISH )
 779     {
 780         /*
 781          * We still need to execute more instructions.
 782          */
 783         return TRUE;
 784     }
 785
 786     /*
 787      * If we are about to stop, then print out the source line if we
 788      * have it.
 789      */
 790     if (mode != EXEC_CONT && mode != EXEC_PASS && mode != EXEC_FINISH)
 791     {
 792         DEBUG_FindNearestSymbol( &addr, TRUE, NULL, 0, &syminfo.list);
 793         if( syminfo.list.sourcefile != NULL )
 794         {
 795             DEBUG_List(&syminfo.list, NULL, 0);
 796         }
 797     }
 798
 799 #ifdef __i386__
 800     /* If there's no breakpoint and we are not single-stepping, then we     */
 801     /* must have encountered an int3 in the Windows program; let's skip it. */
 802     if ((bpnum == -1) && code == EXCEPTION_BREAKPOINT)
 803         DEBUG_context.Eip++;
 804 #endif
 805
 806     /* no breakpoint, continue if in continuous mode */
 807     return (mode == EXEC_CONT || mode == EXEC_PASS || mode == EXEC_FINISH);
 808 }
 809
 810 /***********************************************************************
 811  *           DEBUG_SuspendExecution
 812  *
 813  * Remove all breakpoints before entering the debug loop
 814  */
 815 void    DEBUG_SuspendExecution( void )
 816 {
 817    DEBUG_SetBreakpoints( FALSE );
 818    breakpoints[0] = DEBUG_CurrThread->stepOverBP;
 819 }
 820
 821 /***********************************************************************
 822  *           DEBUG_RestartExecution
 823  *
 824  * Set the breakpoints to the correct state to restart execution
 825  * in the given mode.
 826  */
 827 enum exec_mode DEBUG_RestartExecution( enum exec_mode mode, int count )
 828 {
 829     DBG_ADDR addr;
 830     DBG_ADDR addr2;
 831     int bp;
 832     int delta;
 833     int status;
 834     enum exec_mode ret_mode;
 835     DWORD instr;
 836     unsigned char ch;
 837
 838     DEBUG_GetCurrentAddress( &addr );
 839
 840     /*
 841      * This is the mode we will be running in after we finish.  We would like
 842      * to be able to modify this in certain cases.
 843      */
 844     ret_mode = mode;
 845
 846     bp = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 847     if ( bp != -1 && bp != 0)
 848       {
 849         /*
 850          * If we have set a new value, then save it in the BP number.
 851          */
 852         if( count != 0 && mode == EXEC_CONT )
 853           {
 854             breakpoints[bp].skipcount = count;
 855           }
 856         mode = EXEC_STEPI_INSTR;  /* If there's a breakpoint, skip it */
 857       }
 858     else
 859       {
 860         if( mode == EXEC_CONT && count > 1 )
 861           {
 862             DEBUG_Printf(DBG_CHN_MESG, "Not stopped at any breakpoint; argument ignored.\n");
 863           }
 864       }
 865
 866     if( mode == EXEC_FINISH && DEBUG_IsFctReturn() )
 867       {
 868         mode = ret_mode = EXEC_STEPI_INSTR;
 869       }
 870
 871     instr = DEBUG_ToLinear( &addr );
 872     DEBUG_READ_MEM((void*)instr, &ch, sizeof(ch));
 873     /*
 874      * See if the function we are stepping into has debug info
 875      * and line numbers.  If not, then we step over it instead.
 876      * FIXME - we need to check for things like thunks or trampolines,
 877      * as the actual function may in fact have debug info.
 878      */
 879     if( ch == 0xe8 )
 880       {
 881         DEBUG_READ_MEM((void*)(instr + 1), &delta, sizeof(delta));
 882         addr2 = addr;
 883         DEBUG_Disasm(&addr2, FALSE);
 884         addr2.off += delta;
 885
 886         status = DEBUG_CheckLinenoStatus(&addr2);
 887         /*
 888          * Anytime we have a trampoline, step over it.
 889          */
 890         if( ((mode == EXEC_STEP_OVER) || (mode == EXEC_STEPI_OVER))
 891             && status == FUNC_IS_TRAMPOLINE )
 892           {
 893 #if 0
 894             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into trampoline at %x (no lines)\n",
 895                     addr2.off);
 896 #endif
 897             mode = EXEC_STEP_OVER_TRAMPOLINE;
 898           }
 899
 900         if( mode == EXEC_STEP_INSTR && status == FUNC_HAS_NO_LINES )
 901           {
 902 #if 0
 903             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into function at %x (no lines)\n",
 904                     addr2.off);
 905 #endif
 906             mode = EXEC_STEP_OVER;
 907           }
 908       }
 909
 910
 911     if( mode == EXEC_STEP_INSTR )
 912       {
 913         if( DEBUG_CheckLinenoStatus(&addr) == FUNC_HAS_NO_LINES )
 914           {
 915             DEBUG_Printf(DBG_CHN_MESG, "Single stepping until exit from function, \n");
 916             DEBUG_Printf(DBG_CHN_MESG, "which has no line number information.\n");
 917
 918             ret_mode = mode = EXEC_FINISH;
 919           }
 920       }
 921
 922     switch(mode)
 923     {
 924     case EXEC_CONT: /* Continuous execution */
 925     case EXEC_PASS: /* Continue, passing exception */
 926 #ifdef __i386__
 927         DEBUG_context.EFlags &= ~STEP_FLAG;
 928 #endif
 929         DEBUG_SetBreakpoints( TRUE );
 930         break;
 931
 932     case EXEC_STEP_OVER_TRAMPOLINE:
 933       /*
 934        * This is the means by which we step over our conversion stubs
 935        * in callfrom*.s and callto*.s.  We dig the appropriate address
 936        * off the stack, and we set the breakpoint there instead of the
 937        * address just after the call.
 938        */
 939 #ifdef __i386__
 940       DEBUG_READ_MEM((void*)(DEBUG_context.Esp +
 941                              2 * sizeof(unsigned int)),
 942                      &addr.off, sizeof(addr.off));
 943       DEBUG_context.EFlags &= ~STEP_FLAG;
 944 #endif
 945       breakpoints[0].addr    = addr;
 946       breakpoints[0].enabled = TRUE;
 947       breakpoints[0].refcount = 1;
 948       breakpoints[0].skipcount = 0;
 949       DEBUG_READ_MEM((void*)DEBUG_ToLinear( &addr ), &breakpoints[0].u.b.opcode,
 950                      sizeof(char));
 951       DEBUG_SetBreakpoints( TRUE );
 952       break;
 953
 954     case EXEC_FINISH:
 955     case EXEC_STEPI_OVER:  /* Stepping over a call */
 956     case EXEC_STEP_OVER:  /* Stepping over a call */
 957         if (DEBUG_IsStepOverInstr())
 958         {
 959 #ifdef __i386__
 960             DEBUG_context.EFlags &= ~STEP_FLAG;
 961 #endif
 962             DEBUG_Disasm(&addr, FALSE);
 963             breakpoints[0].addr    = addr;
 964             breakpoints[0].enabled = TRUE;
 965             breakpoints[0].refcount = 1;
 966             breakpoints[0].skipcount = 0;
 967             DEBUG_READ_MEM((void*)DEBUG_ToLinear( &addr ), &breakpoints[0].u.b.opcode,
 968                            sizeof(char));
 969             DEBUG_SetBreakpoints( TRUE );
 970             break;
 971         }
 972         /* else fall through to single-stepping */
 973
 974     case EXEC_STEP_INSTR: /* Single-stepping an instruction */
 975     case EXEC_STEPI_INSTR: /* Single-stepping an instruction */
 976 #ifdef __i386__
 977         DEBUG_context.EFlags |= STEP_FLAG;
 978 #endif
 979         break;
 980     default:
 981         RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 982     }
 983     DEBUG_CurrThread->stepOverBP = breakpoints[0];
 984     return ret_mode;
 985 }
 986
 987 int
 988 DEBUG_AddBPCondition(int num, struct expr * exp)
 989 {
 990     if ((num <= 0) || (num >= next_bp) || !breakpoints[num].refcount)
 991     {
 992         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 993         return FALSE;
 994     }
 995
 996     if( breakpoints[num].condition != NULL )
 997       {
 998         DEBUG_FreeExpr(breakpoints[num].condition);
 999         breakpoints[num].condition = NULL;
1000       }
1001
1002     if( exp != NULL )
1003       {
1004         breakpoints[num].condition = DEBUG_CloneExpr(exp);
1005       }
1006
1007    return TRUE;
1008 }