res.c

一个C style Assembler的source code

#include <stdlib.h>
#include <stdio.h>
#include "io.h"
#include "ex.h"
#include "st.h"
#include "res.h"

#define R_EXTEND 0x10
Item RTab; int RCur;
static int RMax;

long LVal;

void ResInit(void) {
   RTab = 0, RCur = RMax = 0;
}

void Resolve(Item IP) {
   Exp E = IP->E; byte Code; long PC; Segment Seg;
   byte B, Hi, Lo, Rel; long L;
   if (Phase == 1) E = EvalExp(E);
   if (Phase > 0) StartLine = IP->Line, StartF = IP->File;
   Code = (IP->Tag == 'Q')? 0x11: (IP->Tag == 'P')? 0x01: 0;
TypeCheck:
   switch (E->Tag) {
      case AddrX:
         Seg = SEG(E);
         Rel = IP->Tag != 'R'?
            Seg->Rel:
            (Seg->Rel || IP->Seg->Rel) && IP->Seg != Seg;
         if (Rel) goto DoMap;
         L = (long)(short)Seg->Base + (long)(short)OFFSET(E);
         switch (IP->Tag) {
            case 'B':
               if (Seg->Type != BIT) ERROR("Address type mismatch.");
            break;
            case 'D':
               if (Seg->Type != DATA && Seg->Type != SFR)
                  ERROR("Address type mismatch.");
            break;
            case 'R': case 'L': case 'P': case 'Q':
               if (Seg->Type != CODE) ERROR("Address type mismatch.");
            break;
         }
      break;
      case NumX: L = (long)(short)VALUE(E); break;
      default: goto DoMap;
   }
BoundsCheck:
   switch (IP->Tag) {
      case 'b':
         if (L < -0x80 || L >= 0x100) ERROR("Byte value out of range (%4lx).", L);
      break;
      case 'w':
         if (L < -0x8000L || L >= 0x10000L) ERROR("Word value out of range.");
      break;
      case 'B':
         if (L < 0 || L >= 0x100) ERROR("Bit address out of range.");
      break;
      case 'D':
         if (E->Tag != AddrX) {
            if (L < 0 || L >= 0x100) ERROR("Data address out of range.");
         } else if (Seg->Type == DATA) {
            if (L < 0 || L >= 0x80) ERROR("Register address out of range.");
         } else if (Seg->Type == SFR) {
            if (L < 0x80 || L >= 0x100) ERROR("SFR address out of range.");
         }
      break;
      case 'R':
         L -= (long)(short)IP->Seg->Base + (long)(short)IP->Offset + 1L;
         if (L < -0x80 || L >= 0x80) ERROR("Relative address out of range.");
      break;
      case 'P': case 'Q':
         PC = (long)(short)IP->Seg->Base + (long)(short)IP->Offset + 2L;
         if ((L&0xf800) != (PC&0xf800)) ERROR("Paged address out of range.");
         L = (L << 5)&0xe000 | (Code << 8)&0x1f00 | L&0xff;
      break;
      case 'L':
         if (L < 0 || L >= 0x10000L) ERROR("Code address out of range.");
      break;
      default: FATAL("Internal error (0)");
   }
   if (Phase == 1) {
      fseek(OutF, IP->Seg->Loc + IP->Offset, SEEK_SET); IP->Map = 0;
   }
Generate:
   switch (IP->Tag) {
      case 'b': case 'B': case 'D': case 'R':
         B = L&0xff;
         switch (Phase) {
            case 0: PByte(B); break;
            case 1: PutB(B, OutF); break;
            case 2: IP->Tag = 'b', LVal = B; break;
         }
      return;
      case 'P': case 'Q': case 'w': case 'L':
         Lo = (L >> 8)&0xff, Hi = L&0xff;
         switch (Phase) {
            case 0: PByte(Lo), PByte(Hi); break;
            case 1: PutB(Lo, OutF), PutB(Hi, OutF); break;
            case 2: IP->Tag = 'w', LVal = L&0xffff; break;
         }
      return;
   }
return;
DoMap:
   switch (Phase) {
      case 0: RCur++; L = 0; goto Generate;
      case 1: IP->Map = 1; MarkExp(IP->E = E); break;
      case 2: FATAL("Internal error (1).");
   }
}

void Reloc(byte Code, byte Tag, Exp E) {
   long PC; Segment Seg; byte B; word W; long L; Item IP;
   if (RCur == RMax) {
      RMax += R_EXTEND, RTab = (Item)realloc(RTab, RMax * sizeof *RTab);
      if (RTab == 0) FATAL("Out of memory.");
   }
   IP = &RTab[RCur];
   IP->Tag = Tag, IP->E = E, IP->Seg = SegP, IP->Offset = LOC;
   IP->Map = 0, IP->Line = StartLine, IP->File = StartF;
/* ajmp: Tag = 'P', acall: Tag = 'Q' */
   if (IP->Tag == 'P' && (Code&0x10)) IP->Tag = 'Q';
   Resolve(IP);
}