I\'m currently working on some bugs in my assembler code. Please help edit or st

ID: 3600098 • Letter: I

Question

I'm currently working on some bugs in my assembler code. Please help edit or start over which ever you prefer. Will Rate, thank you!
BUGS:

Infinite loop when there is no ‘END’

For some reason, the ‘FIRST’ is read by the program and counted but its treated like a comment as well.

Registers address need to change to HEX.

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

// Phase 2.h

#ifndef phase2_h
#define phase2_h
#include <unistd.h>
#include <stdlib.h>

void read_line(void);
void assemble(char *inFile);

struct optab{
char code[10],objcode[10];
}
myoptab[25] = {
{"ADD", "18"},
{"AND", "58"},
{"COMP", "28"},
{"DIV", "24"},
{"J", "3C"},
{"JEQ", "30"},
{"JGT", "34"},
{"JLT", "38"},
{"JSUB", "48"},
{"LDA", "00"},
{"LDCH", "50"},
{"LDL", "08"},
{"LDX", "20"},
{"MUL", "20"},
{"OR", "44"},
{"RD", "D8"},
{"RSUB", "4C"},
{"STA", "0C"},
{"STCH", "54"},
{"STL", "14"},
{"STX", "10"},
{"SUB", "1C"},
{"TD","E0"},
{"TIX", "2C"},
{"WD", "DC"},
};

struct SYMTAB
{
char symbol[15];
int addr;
}

mysymtab[20];

int startaddr;
int locctr;
int symcount=0;
int length;
char line[20],label[8],opcode[8],operand[8],programname[10];

int dupsym=0;
int nostart=0;
int noend=0;
int manybyte=0;
int noop=0;
int validop=0;
int memover=0;

void pass_one(char *inFile)
{
int sym_there = 0;
int sym_tracker = 0;
int op_there = 0;

FILE *input,*inter;
input=fopen(inFile,"r");
inter=fopen("inter.txt","w");

fgets(line,20,input);
read_line();

if (strcmp(opcode, "START") == 0)
{
startaddr=atoi(operand);
locctr=startaddr;
strcpy(programname,label);
fprintf(inter,"%d %s",locctr, line);
fgets(line,20,input);
read_line();
}
else
{
programname[0]='';
startaddr=0;
locctr=0;
nostart = 1;
}

while (strcmp(opcode,"END") != 0 )
{
if (strcmp(&line[0],".") != 0)
{
if (strcmp(label,"/0") != 0)
{
if (strcmp(mysymtab[0].symbol, "") == 0)
{
//DO NOTHING
}
if (strcmp(mysymtab[0].symbol, label) == 0)
{
sym_there = 1;
}
else
{
for (int i = 0; strcmp(mysymtab[i].symbol, "") != 0; i++)
{
if (strcmp(label,mysymtab[i+1].symbol) == 0)
{
sym_there = 1;
break;
}
}
}
if (sym_there == 1)
{
dupsym = 1;
sym_there = 0;
}
else
{
for (int i = 0; i < 20; i++)
{
if (strcmp(mysymtab[i].symbol, "") != 0)
{
sym_tracker++;
}
}
memcpy(mysymtab[sym_tracker].symbol, label, 10);
mysymtab[sym_tracker].addr = locctr;
sym_tracker = 0;
}

for (int i = 1; i < 25; i++)
{
if (strcmp(myoptab[i].code, opcode) == 0)
{
op_there = 1;
break;
}
}

if(op_there == 1)
{
locctr += 3;
op_there = 0;
}
else if (strcmp(opcode, "WORD") == 0)
{
locctr += 3;
}
else if (strcmp(opcode, "RESW") == 0)
{
locctr += atoi(operand)*3;
}
else if (strcmp(opcode, "RESB") == 0)
{
locctr += atoi(operand);
}
else if (strcmp(opcode, "BYTE") == 0)
{
int j = 0;
for (int i = 2; strcmp(&operand[i], "") != 0; i++)
{
if (strcmp(&operand[i], "'") != 0)
{
j++;
}
}
locctr += j;
}
else
{
noop = 1;
}
}
}
fprintf(inter, "%s %d ", line, locctr);
fgets(line,20,input);
read_line();
}
fprintf(inter, "%s %d ", line, locctr);
length = locctr - startaddr;

fprintf(inter," Symbol Table ");
fprintf(inter,"_____________________________________ ");
for (int i = 0; i < 10; i++)
{
if (strcmp(mysymtab[i].symbol, "") != 0)
fprintf(inter, "%s %d", mysymtab[i].symbol, mysymtab[i].addr);
fprintf(inter, " ");
}
/*
fprintf(inter, " Op Table ");
fprintf(inter, "_____________________________________ ");
for (int i = 0; strcmp(myoptab[i].code,"") != 0; i++)
{
fprintf(inter, "%s", myoptab[i].code);
fprintf(inter, " ");
}
*/

fclose(inter);
fclose(input);
}

void read_line()
{
char buff[8],word1[8],word2[8],word3[8];
int i,j=0,count=0;
label[0]=opcode[0]=operand[0]=word1[0]=word2[0]=word3[0]='';

for(i=0;line[i]!='';i++)
{
if(line[i]!=' ')
buff[j++]=line[i];
else
{
buff[j]='';
strcpy(word3,word2);
strcpy(word2,word1);
strcpy(word1,buff);
j=0;
count++;
}
}

buff[j-1]='';

strcpy(word3,word2);
strcpy(word2,word1);
strcpy(word1,buff);

switch(count)
{
case 0:
strcpy(opcode,word1);
break;
case 1:
{
strcpy(opcode,word2);
strcpy(operand,word1);

}
break;
case 2:{
strcpy(label,word3);
strcpy(opcode,word2);
strcpy(operand,word1);

}
break;
}
}

void assemble(char *inFile)
{
pass_one(inFile);
}

#endif /* phase2_h */

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

I'm follwing this pseudo code/algorithm:

.read first input line and write to intermediate file

.if OPCODE = ‘START’ then

{ save #{OPERAND} as starting address

initialize LOCCTR to starting address

read next input line and write to intermediate file

}

else set LOCCTR=0

.while OPCODE != ‘END’ do

{ if this is not a comment line then

handle line 1

read next input line and write to intermediate file

}

.save (LOCCTR – starting address) as program length

.If there is a symbol in the LABEL field then

{ search SYMTAB for LABEL

if found then set error flag (duplicate label)

else insert (LABEL, LOCCTR) into SYMTAB }

.search OPTAB for OPCODE

.if found then add 3 to LOCCTR

else if OPCODE = ‘WORD’ then add 3 to LOCCTR

else if OPCODE = ‘RESB’ then add #[OPERAND] to LOCCTR

else if OPCODE = ‘RESW’ then add 3* #[OPERAND] to LOCCTR

else if OPCODE = ‘BYTE’ then

{ find length of constant in bytes

add length to LOCCTR }

else set error flag (invalid operation code)

Explanation / Answer

#ifndef phase2_h
#define phase2_h
#include <unistd.h>
#include <stdlib.h>

void read_line(void);
void assemble(char *inFile);

struct SYMTAB
{
char symbol[15];
int addr;
}

mysymtab[20];

int startaddr;
int locctr;
int symcount=0;
int length;
char line[20],label[8],opcode[8],operand[8],programname[10];

int dupsym=0;
int nostart=0;
int noend=0;
int manybyte=0;
int noop=0;
int validop=0;
int memover=0;

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