hdefs.c

unix下调试内存泄露的工具源代码

   return n;
}

static UChar mkModRegRM ( UChar mod, UChar reg, UChar regmem )
{
   return toUChar( ((mod & 3) << 6) 
                   | ((reg & 7) << 3) 
                   | (regmem & 7) );
}

static UChar mkSIB ( Int shift, Int regindex, Int regbase )
{
   return toUChar( ((shift & 3) << 6) 
                   | ((regindex & 7) << 3) 
                   | (regbase & 7) );
}

static UChar* emit32 ( UChar* p, UInt w32 )
{
   *p++ = toUChar( w32        & 0x000000FF);
   *p++ = toUChar((w32 >>  8) & 0x000000FF);
   *p++ = toUChar((w32 >> 16) & 0x000000FF);
   *p++ = toUChar((w32 >> 24) & 0x000000FF);
   return p;
}

/* Does a sign-extend of the lowest 8 bits give 
   the original number? */
static Bool fits8bits ( UInt w32 )
{
   Int i32 = (Int)w32;
   return toBool(i32 == ((i32 << 24) >> 24));
}


/* Forming mod-reg-rm bytes and scale-index-base bytes.

     greg,  0(ereg)    |  ereg != ESP && ereg != EBP
                       =  00 greg ereg

     greg,  d8(ereg)   |  ereg != ESP
                       =  01 greg ereg, d8

     greg,  d32(ereg)  |  ereg != ESP
                       =  10 greg ereg, d32

     greg,  d8(%esp)   =  01 greg 100, 0x24, d8

     -----------------------------------------------

     greg,  d8(base,index,scale)  
               |  index != ESP
               =  01 greg 100, scale index base, d8

     greg,  d32(base,index,scale)
               |  index != ESP
               =  10 greg 100, scale index base, d32
*/
static UChar* doAMode_M ( UChar* p, HReg greg, X86AMode* am ) 
{
   if (am->tag == Xam_IR) {
      if (am->Xam.IR.imm == 0 
          && am->Xam.IR.reg != hregX86_ESP()
          && am->Xam.IR.reg != hregX86_EBP() ) {
         *p++ = mkModRegRM(0, iregNo(greg), iregNo(am->Xam.IR.reg));
         return p;
      }
      if (fits8bits(am->Xam.IR.imm)
          && am->Xam.IR.reg != hregX86_ESP()) {
         *p++ = mkModRegRM(1, iregNo(greg), iregNo(am->Xam.IR.reg));
         *p++ = toUChar(am->Xam.IR.imm & 0xFF);
         return p;
      }
      if (am->Xam.IR.reg != hregX86_ESP()) {
         *p++ = mkModRegRM(2, iregNo(greg), iregNo(am->Xam.IR.reg));
         p = emit32(p, am->Xam.IR.imm);
         return p;
      }
      if (am->Xam.IR.reg == hregX86_ESP()
          && fits8bits(am->Xam.IR.imm)) {
 	 *p++ = mkModRegRM(1, iregNo(greg), 4);
         *p++ = 0x24;
         *p++ = toUChar(am->Xam.IR.imm & 0xFF);
         return p;
      }
      ppX86AMode(am);
      vpanic("doAMode_M: can't emit amode IR");
      /*NOTREACHED*/
   }
   if (am->tag == Xam_IRRS) {
      if (fits8bits(am->Xam.IRRS.imm)
          && am->Xam.IRRS.index != hregX86_ESP()) {
         *p++ = mkModRegRM(1, iregNo(greg), 4);
         *p++ = mkSIB(am->Xam.IRRS.shift, am->Xam.IRRS.index, 
                                          am->Xam.IRRS.base);
         *p++ = toUChar(am->Xam.IRRS.imm & 0xFF);
         return p;
      }
      if (am->Xam.IRRS.index != hregX86_ESP()) {
         *p++ = mkModRegRM(2, iregNo(greg), 4);
         *p++ = mkSIB(am->Xam.IRRS.shift, am->Xam.IRRS.index,
                                          am->Xam.IRRS.base);
         p = emit32(p, am->Xam.IRRS.imm);
         return p;
      }
      ppX86AMode(am);
      vpanic("doAMode_M: can't emit amode IRRS");
      /*NOTREACHED*/
   }
   vpanic("doAMode_M: unknown amode");
   /*NOTREACHED*/
}


/* Emit a mod-reg-rm byte when the rm bit denotes a reg. */
static UChar* doAMode_R ( UChar* p, HReg greg, HReg ereg ) 
{
   *p++ = mkModRegRM(3, iregNo(greg), iregNo(ereg));
   return p;
}


/* Emit ffree %st(7) */
static UChar* do_ffree_st7 ( UChar* p )
{
   *p++ = 0xDD;
   *p++ = 0xC7;
   return p;
}

/* Emit fstp %st(i), 1 <= i <= 7 */
static UChar* do_fstp_st ( UChar* p, Int i )
{
   vassert(1 <= i && i <= 7);
   *p++ = 0xDD;
   *p++ = toUChar(0xD8+i);
   return p;
}

/* Emit fld %st(i), 0 <= i <= 6 */
static UChar* do_fld_st ( UChar* p, Int i )
{
   vassert(0 <= i && i <= 6);
   *p++ = 0xD9;
   *p++ = toUChar(0xC0+i);
   return p;
}

/* Emit f<op> %st(0) */
static UChar* do_fop1_st ( UChar* p, X86FpOp op )
{
   switch (op) {
      case Xfp_NEG:    *p++ = 0xD9; *p++ = 0xE0; break;
      case Xfp_ABS:    *p++ = 0xD9; *p++ = 0xE1; break;
      case Xfp_SQRT:   *p++ = 0xD9; *p++ = 0xFA; break;
      case Xfp_ROUND:  *p++ = 0xD9; *p++ = 0xFC; break;
      case Xfp_SIN:    *p++ = 0xD9; *p++ = 0xFE; break;
      case Xfp_COS:    *p++ = 0xD9; *p++ = 0xFF; break;
      case Xfp_2XM1:   *p++ = 0xD9; *p++ = 0xF0; break;
      case Xfp_MOV:    break;
      case Xfp_TAN:    p = do_ffree_st7(p); /* since fptan pushes 1.0 */
                       *p++ = 0xD9; *p++ = 0xF2; /* fptan */
                       *p++ = 0xD9; *p++ = 0xF7; /* fincstp */
                       break;
      default: vpanic("do_fop1_st: unknown op");
   }
   return p;
}

/* Emit f<op> %st(i), 1 <= i <= 5 */
static UChar* do_fop2_st ( UChar* p, X86FpOp op, Int i )
{
#  define fake(_n) mkHReg((_n), HRcInt32, False)
   Int subopc;
   switch (op) {
      case Xfp_ADD: subopc = 0; break;
      case Xfp_SUB: subopc = 4; break;
      case Xfp_MUL: subopc = 1; break;
      case Xfp_DIV: subopc = 6; break;
      default: vpanic("do_fop2_st: unknown op");
   }
   *p++ = 0xD8;
   p    = doAMode_R(p, fake(subopc), fake(i));
   return p;
#  undef fake
}

/* Push a 32-bit word on the stack.  The word depends on tags[3:0];
each byte is either 0x00 or 0xFF depending on the corresponding bit in tags[].
*/
static UChar* push_word_from_tags ( UChar* p, UShort tags )
{
   UInt w;
   vassert(0 == (tags & ~0xF));
   if (tags == 0) {
      /* pushl $0x00000000 */
      *p++ = 0x6A;
      *p++ = 0x00;
   }
   else 
   /* pushl $0xFFFFFFFF */
   if (tags == 0xF) {
      *p++ = 0x6A;
      *p++ = 0xFF;
   } else {
      vassert(0); /* awaiting test case */
      w = 0;
      if (tags & 1) w |= 0x000000FF;
      if (tags & 2) w |= 0x0000FF00;
      if (tags & 4) w |= 0x00FF0000;
      if (tags & 8) w |= 0xFF000000;
      *p++ = 0x68;
      p = emit32(p, w);
   }
   return p;
}

/* Emit an instruction into buf and return the number of bytes used.
   Note that buf is not the insn's final place, and therefore it is
   imperative to emit position-independent code. */

Int emit_X86Instr ( UChar* buf, Int nbuf, X86Instr* i )
{
   UInt irno, opc, opc_rr, subopc_imm, opc_imma, opc_cl, opc_imm, subopc;

   UInt   xtra;
   UChar* p = &buf[0];
   UChar* ptmp;
   vassert(nbuf >= 32);

   /* Wrap an integer as a int register, for use assembling
      GrpN insns, in which the greg field is used as a sub-opcode
      and does not really contain a register. */
#  define fake(_n) mkHReg((_n), HRcInt32, False)

   /* vex_printf("asm  ");ppX86Instr(i); vex_printf("\n"); */

   switch (i->tag) {

   case Xin_Alu32R:
      /* Deal specially with MOV */
      if (i->Xin.Alu32R.op == Xalu_MOV) {
         switch (i->Xin.Alu32R.src->tag) {
            case Xrmi_Imm:
               *p++ = toUChar(0xB8 + iregNo(i->Xin.Alu32R.dst));
               p = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
               goto done;
            case Xrmi_Reg:
               *p++ = 0x89;
               p = doAMode_R(p, i->Xin.Alu32R.src->Xrmi.Reg.reg,
                                i->Xin.Alu32R.dst);
               goto done;
            case Xrmi_Mem:
               *p++ = 0x8B;
               p = doAMode_M(p, i->Xin.Alu32R.dst, 
                                i->Xin.Alu32R.src->Xrmi.Mem.am);
               goto done;
            default:
               goto bad;
         }
      }
      /* MUL */
      if (i->Xin.Alu32R.op == Xalu_MUL) {
         switch (i->Xin.Alu32R.src->tag) {
            case Xrmi_Reg:
               *p++ = 0x0F;
               *p++ = 0xAF;
               p = doAMode_R(p, i->Xin.Alu32R.dst,
                                i->Xin.Alu32R.src->Xrmi.Reg.reg);
               goto done;
            case Xrmi_Mem:
               *p++ = 0x0F;
               *p++ = 0xAF;
               p = doAMode_M(p, i->Xin.Alu32R.dst,
                                i->Xin.Alu32R.src->Xrmi.Mem.am);
               goto done;
            case Xrmi_Imm:
               if (fits8bits(i->Xin.Alu32R.src->Xrmi.Imm.imm32)) {
                  *p++ = 0x6B;
                  p = doAMode_R(p, i->Xin.Alu32R.dst, i->Xin.Alu32R.dst);
                  *p++ = toUChar(0xFF & i->Xin.Alu32R.src->Xrmi.Imm.imm32);
               } else {
                  *p++ = 0x69;
                  p = doAMode_R(p, i->Xin.Alu32R.dst, i->Xin.Alu32R.dst);
                  p = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
               }
               goto done;
            default:
               goto bad;
         }
      }
      /* ADD/SUB/ADC/SBB/AND/OR/XOR/CMP */
      opc = opc_rr = subopc_imm = opc_imma = 0;
      switch (i->Xin.Alu32R.op) {
         case Xalu_ADC: opc = 0x13; opc_rr = 0x11; 
                        subopc_imm = 2; opc_imma = 0x15; break;
         case Xalu_ADD: opc = 0x03; opc_rr = 0x01; 
                        subopc_imm = 0; opc_imma = 0x05; break;
         case Xalu_SUB: opc = 0x2B; opc_rr = 0x29; 
                        subopc_imm = 5; opc_imma = 0x2D; break;
         case Xalu_SBB: opc = 0x1B; opc_rr = 0x19; 
                        subopc_imm = 3; opc_imma = 0x1D; break;
         case Xalu_AND: opc = 0x23; opc_rr = 0x21; 
                        subopc_imm = 4; opc_imma = 0x25; break;
         case Xalu_XOR: opc = 0x33; opc_rr = 0x31; 
                        subopc_imm = 6; opc_imma = 0x35; break;
         case Xalu_OR:  opc = 0x0B; opc_rr = 0x09; 
                        subopc_imm = 1; opc_imma = 0x0D; break;
         case Xalu_CMP: opc = 0x3B; opc_rr = 0x39; 
                        subopc_imm = 7; opc_imma = 0x3D; break;
         default: goto bad;
      }
      switch (i->Xin.Alu32R.src->tag) {
         case Xrmi_Imm:
            if (i->Xin.Alu32R.dst == hregX86_EAX()
                && !fits8bits(i->Xin.Alu32R.src->Xrmi.Imm.imm32)) {
               *p++ = toUChar(opc_imma);
               p = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
            } else
            if (fits8bits(i->Xin.Alu32R.src->Xrmi.Imm.imm32)) {
               *p++ = 0x83; 
               p    = doAMode_R(p, fake(subopc_imm), i->Xin.Alu32R.dst);
               *p++ = toUChar(0xFF & i->Xin.Alu32R.src->Xrmi.Imm.imm32);
            } else {
               *p++ = 0x81; 
               p    = doAMode_R(p, fake(subopc_imm), i->Xin.Alu32R.dst);
               p    = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
            }
            goto done;
         case Xrmi_Reg:
            *p++ = toUChar(opc_rr);
            p = doAMode_R(p, i->Xin.Alu32R.src->Xrmi.Reg.reg,
                             i->Xin.Alu32R.dst);
            goto done;
         case Xrmi_Mem:
            *p++ = toUChar(opc);
            p = doAMode_M(p, i->Xin.Alu32R.dst,
                             i->Xin.Alu32R.src->Xrmi.Mem.am);
            goto done;
         default: 
            goto bad;
      }
      break;

   case Xin_Alu32M:
      /* Deal specially with MOV */
      if (i->Xin.Alu32M.op == Xalu_MOV) {
         switch (i->Xin.Alu32M.src->tag) {
            case Xri_Reg:
               *p++ = 0x89;
               p = doAMode_M(p, i->Xin.Alu32M.src->Xri.Reg.reg,
                                i->Xin.Alu32M.dst);
               goto done;
            case Xri_Imm:
               *p++ = 0xC7;
               p = doAMode_M(p, fake(0), i->Xin.Alu32M.dst);
               p = emit32(p, i->Xin.Alu32M.src->Xri.Imm.imm32);
               goto done;
            default: 
               goto bad;
         }
      }
      /* ADD/SUB/ADC/SBB/AND/OR/XOR/CMP.  MUL is not
         allowed here. */
      opc = subopc_imm = opc_imma = 0;
      switch (i->Xin.Alu32M.op) {
         case Xalu_ADD: opc = 0x01; subopc_imm = 0; break;
         case Xalu_SUB: opc = 0x29; subopc_imm = 5; break;
         default: goto bad;
      }
      switch (i->Xin.Alu32M.src->tag) {
         case Xri_Reg:
            *p++ = toUChar(opc);
            p = doAMode_M(p, i->Xin.Alu32M.src->Xri.Reg.reg,
                             i->Xin.Alu32M.dst);
            goto done;
         case Xri_Imm:
            if (fits8bits(i->Xin.Alu32M.src->Xri.Imm.imm32)) {
               *p++ = 0x83;
               p    = doAMode_M(p, fake(subopc_imm), i->Xin.Alu32M.dst);
               *p++ = toUChar(0xFF & i->Xin.Alu32M.src->Xri.Imm.imm32);
               goto done;
            } else {
               *p++ = 0x81;
               p    = doAMode_M(p, fake(subopc_imm), i->Xin.Alu32M.dst);
               p    = emit32(p, i->Xin.Alu32M.src->Xri.Imm.imm32);
               goto done;
            }
         default: 
            goto bad;
      }
      break;

   case Xin_Sh32:
      opc_cl = opc_imm = subopc = 0;
      switch (i->Xin.Sh32.op) {
         case Xsh_SHR: opc_cl = 0xD3; opc_imm = 0xC1; subopc = 5; break;
         case Xsh_SAR: opc_cl =