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( !DEBUG_GrabAddress(&value, TRUE) ) return;
 332
 333     if ((num = DEBUG_FindBreakpoint(&value.addr, DBG_BREAK)) >= 1)
 334     {
 335        breakpoints[num].refcount++;
 336        return;
 337     }
 338
 339     if (!DEBUG_READ_MEM_VERBOSE((void*)DEBUG_ToLinear( &value.addr ), &ch, sizeof(ch)))
 340         return;
 341
 342     if ((num = DEBUG_InitXPoint(DBG_BREAK, &value.addr)) == -1)
 343        return;
 344
 345     breakpoints[num].u.b.opcode = ch;
 346     breakpoints[num].u.b.func = func;
 347
 348     DEBUG_Printf( DBG_CHN_MESG, "Breakpoint %d at ", num );
 349     DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32 : 16,
 350                         TRUE );
 351     DEBUG_Printf( DBG_CHN_MESG, "\n" );
 352 }
 353
 354 /***********************************************************************
 355  *           DEBUG_AddBreakpointFromId
 356  *
 357  * Add a breakpoint from a function name (and eventually a line #)
 358  */
 359 void    DEBUG_AddBreakpointFromId(const char *name, int lineno)
 360 {
 361    DBG_VALUE value;
 362
 363    if (DEBUG_GetSymbolValue(name, lineno, &value, TRUE))
 364       DEBUG_AddBreakpoint(&value, NULL);
 365    else
 366       DEBUG_Printf(DBG_CHN_MESG, "Unable to add breakpoint\n");
 367 }
 368
 369 /***********************************************************************
 370  *           DEBUG_AddBreakpointFromLineno
 371  *
 372  * Add a breakpoint from a line number in current file
 373  */
 374 void    DEBUG_AddBreakpointFromLineno(int lineno)
 375 {
 376    DBG_VALUE                    value;
 377
 378    DEBUG_GetCurrentAddress(&value.addr);
 379
 380    if (lineno != -1) {
 381       struct name_hash* nh;
 382
 383       DEBUG_FindNearestSymbol(&value.addr, TRUE, &nh, 0, NULL);
 384       if (nh == NULL) {
 385          DEBUG_Printf(DBG_CHN_MESG,"Unable to add breakpoint\n");
 386          return;
 387       }
 388       DEBUG_GetLineNumberAddr(nh, lineno, &value.addr, TRUE);
 389    }
 390
 391    value.type = NULL;
 392    value.cookie = DV_TARGET;
 393    DEBUG_AddBreakpoint( &value, NULL );
 394 }
 395
 396  /***********************************************************************
 397  *           DEBUG_AddWatchpoint
 398  *
 399  * Add a watchpoint.
 400  */
 401 void DEBUG_AddWatchpoint( const DBG_VALUE *_value, BOOL is_write )
 402 {
 403    DBG_VALUE    value = *_value;
 404    int          num, reg = -1;
 405    unsigned     seg2;
 406    DWORD        mask = 0;
 407
 408    assert(_value->cookie == DV_TARGET || _value->cookie == DV_HOST);
 409
 410 #ifdef __i386__
 411    DEBUG_FixAddress( &value.addr, DEBUG_context.SegCs );
 412 #endif
 413
 414    if ( value.type != NULL && value.type == DEBUG_TypeIntConst )
 415    {
 416       /*
 417        * We know that we have the actual offset stored somewhere
 418        * else in 32-bit space.  Grab it, and we
 419        * should be all set.
 420        */
 421       seg2 = value.addr.seg;
 422       value.addr.seg = 0;
 423       value.addr.off = DEBUG_GetExprValue(&value, NULL);
 424       value.addr.seg = seg2;
 425    }
 426
 427    for (num = 1; num < next_bp; num++)
 428    {
 429       if (breakpoints[num].refcount && breakpoints[num].enabled &&
 430           breakpoints[num].type == DBG_WATCH) {
 431          mask |= (1 << breakpoints[num].u.w.reg);
 432       }
 433    }
 434 #ifdef __i386__
 435    for (reg = 0; reg < 4 && (mask & (1 << reg)); reg++);
 436    if (reg == 4)
 437    {
 438       DEBUG_Printf(DBG_CHN_MESG, "All i386 hardware watchpoints have been set. Delete some\n");
 439       return;
 440    }
 441 #endif
 442
 443    if ((num = DEBUG_InitXPoint(DBG_WATCH, &value.addr)) == -1)
 444       return;
 445
 446    breakpoints[num].u.w.len = 4 - 1;
 447    if (_value->type && DEBUG_GetObjectSize(_value->type) < 4)
 448       breakpoints[num].u.w.len = 2 - 1;
 449
 450    if (!DEBUG_GetWatchedValue( num, &breakpoints[num].u.w.oldval))
 451    {
 452       DEBUG_Printf(DBG_CHN_MESG, "Bad address. Watchpoint not set\n");
 453       breakpoints[num].refcount = 0;
 454    }
 455
 456    breakpoints[num].u.w.rw = (is_write) ? TRUE : FALSE;
 457    breakpoints[reg].u.w.reg = reg;
 458
 459    DEBUG_Printf( DBG_CHN_MESG, "Watchpoint %d at ", num );
 460    DEBUG_PrintAddress( &breakpoints[num].addr, breakpoints[num].is32 ? 32:16, TRUE );
 461    DEBUG_Printf( DBG_CHN_MESG, "\n" );
 462 }
 463
 464 /***********************************************************************
 465  *           DEBUG_AddWathpointFromId
 466  *
 467  * Add a watchpoint from a symbol name (and eventually a line #)
 468  */
 469 void    DEBUG_AddWatchpointFromId(const char *name, int lineno)
 470 {
 471    DBG_VALUE value;
 472
 473    if( DEBUG_GetSymbolValue(name, lineno, &value, TRUE) )
 474       DEBUG_AddWatchpoint( &value, 1 );
 475    else
 476       DEBUG_Printf(DBG_CHN_MESG, "Unable to add watchpoint\n");
 477 }
 478
 479 /***********************************************************************
 480  *           DEBUG_DelBreakpoint
 481  *
 482  * Delete a breakpoint.
 483  */
 484 void DEBUG_DelBreakpoint( int num )
 485 {
 486     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 487     {
 488         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 489         return;
 490     }
 491
 492     if (--breakpoints[num].refcount > 0)
 493        return;
 494
 495     if( breakpoints[num].condition != NULL )
 496     {
 497        DEBUG_FreeExpr(breakpoints[num].condition);
 498        breakpoints[num].condition = NULL;
 499     }
 500
 501     breakpoints[num].enabled = FALSE;
 502     breakpoints[num].refcount = 0;
 503     breakpoints[num].skipcount = 0;
 504 }
 505
 506 /***********************************************************************
 507  *           DEBUG_EnableBreakpoint
 508  *
 509  * Enable or disable a break point.
 510  */
 511 void DEBUG_EnableBreakpoint( int num, BOOL enable )
 512 {
 513     if ((num <= 0) || (num >= next_bp) || breakpoints[num].refcount == 0)
 514     {
 515         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 516         return;
 517     }
 518     breakpoints[num].enabled = (enable) ? TRUE : FALSE;
 519     breakpoints[num].skipcount = 0;
 520 }
 521
 522
 523 /***********************************************************************
 524  *           DEBUG_FindTriggeredWatchpoint
 525  *
 526  * Lookup the watchpoints to see if one has been triggered
 527  * Return >= (watch point index) if one is found and *oldval is set to
 528  *      the value watched before the TRAP
 529  * Return -1 if none found (*oldval is undetermined)
 530  *
 531  * Unfortunately, Linux does *NOT* (A REAL PITA) report with ptrace
 532  * the DR6 register value, so we have to look with our own need the
 533  * cause of the TRAP.
 534  * -EP
 535  */
 536 static int DEBUG_FindTriggeredWatchpoint(LPDWORD oldval)
 537 {
 538    int                          found = -1;
 539 #ifdef __i386__
 540    int                          i;
 541
 542    /* Method 1 => get triggered watchpoint from context (doesn't work on Linux
 543     * 2.2.x). This should be fixed in >= 2.2.16
 544     */
 545    for (i = 0; i < next_bp; i++)
 546    {
 547       DWORD val = 0;
 548
 549       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 550           breakpoints[i].type == DBG_WATCH &&
 551           (DEBUG_context.Dr6 & (1 << breakpoints[i].u.w.reg)))
 552       {
 553          DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 554
 555          *oldval = breakpoints[i].u.w.oldval;
 556          if (DEBUG_GetWatchedValue(i, &val)) {
 557             breakpoints[i].u.w.oldval = val;
 558             return i;
 559          }
 560       }
 561    }
 562
 563    /* Method 1 failed, trying method 2 */
 564
 565    /* Method 2 => check if value has changed among registered watchpoints
 566     * this really sucks, but this is how gdb 4.18 works on my linux box
 567     * -EP
 568     */
 569    for (i = 0; i < next_bp; i++)
 570    {
 571       DWORD val = 0;
 572
 573       if (breakpoints[i].refcount && breakpoints[i].enabled &&
 574           breakpoints[i].type == DBG_WATCH &&
 575           DEBUG_GetWatchedValue(i, &val))
 576       {
 577          *oldval = breakpoints[i].u.w.oldval;
 578          if (val != *oldval)
 579          {
 580             DEBUG_context.Dr6 &= ~(1 << breakpoints[i].u.w.reg);
 581             breakpoints[i].u.w.oldval = val;
 582             found = i;
 583             /* cannot break, because two watch points may have been triggered on
 584              * the same access
 585              * only one will be reported to the user (FIXME ?)
 586              */
 587          }
 588       }
 589    }
 590 #endif
 591    return found;
 592 }
 593
 594 /***********************************************************************
 595  *           DEBUG_InfoBreakpoints
 596  *
 597  * Display break points information.
 598  */
 599 void DEBUG_InfoBreakpoints(void)
 600 {
 601     int i;
 602
 603     DEBUG_Printf( DBG_CHN_MESG, "Breakpoints:\n" );
 604     for (i = 1; i < next_bp; i++)
 605     {
 606         if (breakpoints[i].refcount && breakpoints[i].type == DBG_BREAK)
 607         {
 608             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 609             DEBUG_PrintAddress( &breakpoints[i].addr,
 610                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 611             DEBUG_Printf( DBG_CHN_MESG, " (%u)\n", breakpoints[i].refcount );
 612             if( breakpoints[i].condition != NULL )
 613             {
 614                 DEBUG_Printf(DBG_CHN_MESG, "\t\tstop when  ");
 615                 DEBUG_DisplayExpr(breakpoints[i].condition);
 616                 DEBUG_Printf(DBG_CHN_MESG, "\n");
 617             }
 618         }
 619     }
 620     DEBUG_Printf( DBG_CHN_MESG, "Watchpoints:\n" );
 621     for (i = 1; i < next_bp; i++)
 622     {
 623         if (breakpoints[i].refcount && breakpoints[i].type == DBG_WATCH)
 624         {
 625             DEBUG_Printf( DBG_CHN_MESG, "%d: %c ", i, breakpoints[i].enabled ? 'y' : 'n');
 626             DEBUG_PrintAddress( &breakpoints[i].addr,
 627                                 breakpoints[i].is32 ? 32 : 16, TRUE);
 628             DEBUG_Printf( DBG_CHN_MESG, " on %d byte%s (%c)\n",
 629                      breakpoints[i].u.w.len + 1,
 630                      breakpoints[i].u.w.len > 0 ? "s" : "",
 631                      breakpoints[i].u.w.rw ? 'W' : 'R');
 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 }
 641
 642 /***********************************************************************
 643  *           DEBUG_ShallBreak
 644  *
 645  * Check whether or not the condition (bp / skipcount) of a break/watch
 646  * point are met.
 647  */
 648 static  BOOL DEBUG_ShallBreak( int bpnum )
 649 {
 650     if ( breakpoints[bpnum].condition != NULL )
 651     {
 652         DBG_VALUE value = DEBUG_EvalExpr(breakpoints[bpnum].condition);
 653
 654         if ( value.type == NULL )
 655         {
 656             /*
 657              * Something wrong - unable to evaluate this expression.
 658              */
 659             DEBUG_Printf(DBG_CHN_MESG, "Unable to evaluate expression ");
 660             DEBUG_DisplayExpr(breakpoints[bpnum].condition);
 661             DEBUG_Printf(DBG_CHN_MESG, "\nTurning off condition\n");
 662             DEBUG_AddBPCondition(bpnum, NULL);
 663         }
 664         else if( !DEBUG_GetExprValue( &value, NULL) )
 665         {
 666             return FALSE;
 667         }
 668     }
 669
 670     if ( breakpoints[bpnum].skipcount > 0 && --breakpoints[bpnum].skipcount > 0 )
 671         return FALSE;
 672
 673    if ((breakpoints[bpnum].type == DBG_BREAK) && breakpoints[bpnum].u.b.func)
 674        return breakpoints[bpnum].u.b.func();
 675    return TRUE;
 676 }
 677
 678 /***********************************************************************
 679  *           DEBUG_ShouldContinue
 680  *
 681  * Determine if we should continue execution after a SIGTRAP signal when
 682  * executing in the given mode.
 683  */
 684 BOOL DEBUG_ShouldContinue( DWORD code, enum exec_mode mode, int * count )
 685 {
 686     DBG_ADDR    addr;
 687     int         bpnum;
 688     DWORD       oldval;
 689     int         wpnum;
 690     int         addrlen = 32;
 691     struct symbol_info syminfo;
 692
 693 #ifdef __i386__
 694     /* If not single-stepping, back up over the int3 instruction */
 695     if (code == EXCEPTION_BREAKPOINT)
 696        DEBUG_context.Eip--;
 697 #endif
 698
 699     DEBUG_GetCurrentAddress( &addr );
 700     bpnum = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 701     breakpoints[0].enabled = FALSE;  /* disable the step-over breakpoint */
 702
 703     if ((bpnum != 0) && (bpnum != -1))
 704     {
 705         if (!DEBUG_ShallBreak(bpnum)) return TRUE;
 706
 707         DEBUG_Printf( DBG_CHN_MESG, "Stopped on breakpoint %d at ", bpnum );
 708         syminfo = DEBUG_PrintAddress( &breakpoints[bpnum].addr,
 709                                       breakpoints[bpnum].is32 ? 32 : 16, TRUE );
 710         DEBUG_Printf( DBG_CHN_MESG, "\n" );
 711
 712         if( syminfo.list.sourcefile != NULL )
 713             DEBUG_List(&syminfo.list, NULL, 0);
 714         return FALSE;
 715     }
 716
 717     wpnum = DEBUG_FindTriggeredWatchpoint(&oldval);
 718     if ((wpnum != 0) && (wpnum != -1))
 719     {
 720        /* If not single-stepping, do not back up over the int3 instruction */
 721        if (code == EXCEPTION_BREAKPOINT)
 722        {
 723 #ifdef __i386__
 724            DEBUG_context.Eip++;
 725            addr.off++;
 726 #endif
 727        }
 728        if (!DEBUG_ShallBreak(wpnum)) return TRUE;
 729
 730 #ifdef __i386__
 731        if (addr.seg) addrlen = DEBUG_GetSelectorType( addr.seg );
 732 #endif
 733        DEBUG_Printf(DBG_CHN_MESG, "Stopped on watchpoint %d at ", wpnum);
 734        syminfo = DEBUG_PrintAddress( &addr, addrlen, TRUE );
 735
 736        DEBUG_Printf(DBG_CHN_MESG, " values: old=%lu new=%lu\n",
 737                oldval, breakpoints[wpnum].u.w.oldval);
 738        if (syminfo.list.sourcefile != NULL)
 739           DEBUG_List(&syminfo.list, NULL, 0);
 740        return FALSE;
 741     }
 742
 743     /*
 744      * If our mode indicates that we are stepping line numbers,
 745      * get the current function, and figure out if we are exactly
 746      * on a line number or not.
 747      */
 748     if( mode == EXEC_STEP_OVER || mode == EXEC_STEP_INSTR )
 749     {
 750         if( DEBUG_CheckLinenoStatus(&addr) == AT_LINENUMBER )
 751         {
 752             (*count)--;
 753         }
 754     }
 755     else if( mode == EXEC_STEPI_OVER || mode == EXEC_STEPI_INSTR )
 756     {
 757         (*count)--;
 758     }
 759
 760     if( *count > 0 || mode == EXEC_FINISH )
 761     {
 762         /*
 763          * We still need to execute more instructions.
 764          */
 765         return TRUE;
 766     }
 767
 768     /*
 769      * If we are about to stop, then print out the source line if we
 770      * have it.
 771      */
 772     if (mode != EXEC_CONT && mode != EXEC_PASS && mode != EXEC_FINISH)
 773     {
 774         DEBUG_FindNearestSymbol( &addr, TRUE, NULL, 0, &syminfo.list);
 775         if( syminfo.list.sourcefile != NULL )
 776         {
 777             DEBUG_List(&syminfo.list, NULL, 0);
 778         }
 779     }
 780
 781 #ifdef __i386__
 782     /* If there's no breakpoint and we are not single-stepping, then we     */
 783     /* must have encountered an int3 in the Windows program; let's skip it. */
 784     if ((bpnum == -1) && code == EXCEPTION_BREAKPOINT)
 785         DEBUG_context.Eip++;
 786 #endif
 787
 788     /* no breakpoint, continue if in continuous mode */
 789     return (mode == EXEC_CONT || mode == EXEC_PASS || mode == EXEC_FINISH);
 790 }
 791
 792 /***********************************************************************
 793  *           DEBUG_SuspendExecution
 794  *
 795  * Remove all breakpoints before entering the debug loop
 796  */
 797 void    DEBUG_SuspendExecution( void )
 798 {
 799    DEBUG_SetBreakpoints( FALSE );
 800    breakpoints[0] = DEBUG_CurrThread->stepOverBP;
 801 }
 802
 803 /***********************************************************************
 804  *           DEBUG_RestartExecution
 805  *
 806  * Set the breakpoints to the correct state to restart execution
 807  * in the given mode.
 808  */
 809 enum exec_mode DEBUG_RestartExecution( enum exec_mode mode, int count )
 810 {
 811     DBG_ADDR addr;
 812     DBG_ADDR addr2;
 813     int bp;
 814     int delta;
 815     int status;
 816     enum exec_mode ret_mode;
 817     DWORD instr;
 818     unsigned char ch;
 819
 820     DEBUG_GetCurrentAddress( &addr );
 821
 822     /*
 823      * This is the mode we will be running in after we finish.  We would like
 824      * to be able to modify this in certain cases.
 825      */
 826     ret_mode = mode;
 827
 828     bp = DEBUG_FindBreakpoint( &addr, DBG_BREAK );
 829     if ( bp != -1 && bp != 0)
 830       {
 831         /*
 832          * If we have set a new value, then save it in the BP number.
 833          */
 834         if( count != 0 && mode == EXEC_CONT )
 835           {
 836             breakpoints[bp].skipcount = count;
 837           }
 838         mode = EXEC_STEPI_INSTR;  /* If there's a breakpoint, skip it */
 839       }
 840     else
 841       {
 842         if( mode == EXEC_CONT && count > 1 )
 843           {
 844             DEBUG_Printf(DBG_CHN_MESG, "Not stopped at any breakpoint; argument ignored.\n");
 845           }
 846       }
 847
 848     if( mode == EXEC_FINISH && DEBUG_IsFctReturn() )
 849       {
 850         mode = ret_mode = EXEC_STEPI_INSTR;
 851       }
 852
 853     instr = DEBUG_ToLinear( &addr );
 854     DEBUG_READ_MEM((void*)instr, &ch, sizeof(ch));
 855     /*
 856      * See if the function we are stepping into has debug info
 857      * and line numbers.  If not, then we step over it instead.
 858      * FIXME - we need to check for things like thunks or trampolines,
 859      * as the actual function may in fact have debug info.
 860      */
 861     if( ch == 0xe8 )
 862       {
 863         DEBUG_READ_MEM((void*)(instr + 1), &delta, sizeof(delta));
 864         addr2 = addr;
 865         DEBUG_Disasm(&addr2, FALSE);
 866         addr2.off += delta;
 867
 868         status = DEBUG_CheckLinenoStatus(&addr2);
 869         /*
 870          * Anytime we have a trampoline, step over it.
 871          */
 872         if( ((mode == EXEC_STEP_OVER) || (mode == EXEC_STEPI_OVER))
 873             && status == FUNC_IS_TRAMPOLINE )
 874           {
 875 #if 0
 876             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into trampoline at %x (no lines)\n",
 877                     addr2.off);
 878 #endif
 879             mode = EXEC_STEP_OVER_TRAMPOLINE;
 880           }
 881
 882         if( mode == EXEC_STEP_INSTR && status == FUNC_HAS_NO_LINES )
 883           {
 884 #if 0
 885             DEBUG_Printf(DBG_CHN_MESG, "Not stepping into function at %x (no lines)\n",
 886                     addr2.off);
 887 #endif
 888             mode = EXEC_STEP_OVER;
 889           }
 890       }
 891
 892
 893     if( mode == EXEC_STEP_INSTR )
 894       {
 895         if( DEBUG_CheckLinenoStatus(&addr) == FUNC_HAS_NO_LINES )
 896           {
 897             DEBUG_Printf(DBG_CHN_MESG, "Single stepping until exit from function, \n");
 898             DEBUG_Printf(DBG_CHN_MESG, "which has no line number information.\n");
 899
 900             ret_mode = mode = EXEC_FINISH;
 901           }
 902       }
 903
 904     switch(mode)
 905     {
 906     case EXEC_CONT: /* Continuous execution */
 907     case EXEC_PASS: /* Continue, passing exception */
 908 #ifdef __i386__
 909         DEBUG_context.EFlags &= ~STEP_FLAG;
 910 #endif
 911         DEBUG_SetBreakpoints( TRUE );
 912         break;
 913
 914     case EXEC_STEP_OVER_TRAMPOLINE:
 915       /*
 916        * This is the means by which we step over our conversion stubs
 917        * in callfrom*.s and callto*.s.  We dig the appropriate address
 918        * off the stack, and we set the breakpoint there instead of the
 919        * address just after the call.
 920        */
 921 #ifdef __i386__
 922       DEBUG_READ_MEM((void*)(DEBUG_context.Esp +
 923                              2 * sizeof(unsigned int)),
 924                      &addr.off, sizeof(addr.off));
 925       DEBUG_context.EFlags &= ~STEP_FLAG;
 926 #endif
 927       breakpoints[0].addr    = addr;
 928       breakpoints[0].enabled = TRUE;
 929       breakpoints[0].refcount = 1;
 930       breakpoints[0].skipcount = 0;
 931       DEBUG_READ_MEM((void*)DEBUG_ToLinear( &addr ), &breakpoints[0].u.b.opcode,
 932                      sizeof(char));
 933       DEBUG_SetBreakpoints( TRUE );
 934       break;
 935
 936     case EXEC_FINISH:
 937     case EXEC_STEPI_OVER:  /* Stepping over a call */
 938     case EXEC_STEP_OVER:  /* Stepping over a call */
 939         if (DEBUG_IsStepOverInstr())
 940         {
 941 #ifdef __i386__
 942             DEBUG_context.EFlags &= ~STEP_FLAG;
 943 #endif
 944             DEBUG_Disasm(&addr, FALSE);
 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         /* else fall through to single-stepping */
 955
 956     case EXEC_STEP_INSTR: /* Single-stepping an instruction */
 957     case EXEC_STEPI_INSTR: /* Single-stepping an instruction */
 958 #ifdef __i386__
 959         DEBUG_context.EFlags |= STEP_FLAG;
 960 #endif
 961         break;
 962     default:
 963         RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 964     }
 965     DEBUG_CurrThread->stepOverBP = breakpoints[0];
 966     return ret_mode;
 967 }
 968
 969 int
 970 DEBUG_AddBPCondition(int num, struct expr * exp)
 971 {
 972     if ((num <= 0) || (num >= next_bp) || !breakpoints[num].refcount)
 973     {
 974         DEBUG_Printf( DBG_CHN_MESG, "Invalid breakpoint number %d\n", num );
 975         return FALSE;
 976     }
 977
 978     if( breakpoints[num].condition != NULL )
 979       {
 980         DEBUG_FreeExpr(breakpoints[num].condition);
 981         breakpoints[num].condition = NULL;
 982       }
 983
 984     if( exp != NULL )
 985       {
 986         breakpoints[num].condition = DEBUG_CloneExpr(exp);
 987       }
 988
 989    return TRUE;
 990 }