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asm.c
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asm.c
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#define _CRT_SECURE_NO_WARNINGS
#include "asm.h"
int main(int argc, char* argv[])
{
FILE *fp = NULL;
Label labels[MEM_SIZE] = { NULL };
Memory memo[MEM_SIZE] = { NULL }; // An array in which we save the Assembly code
// First run - Sets the labels in an array with thier name and address
if (argc < 2) { // No files were sent to the assembler
printf("No files were sent");
exit(1);
}
fp = fopen(argv[1], "r");
if (fp == NULL)
exit(1);
LabelsArr(fp, labels);
fclose(fp);
// Second run - Breaks and sets the code inside the memory array
fp = fopen(argv[1], "r");
if (fp == NULL)
exit(1);
MemoryArr(fp, memo);
fclose(fp);
// Writes the labels address into the memory
SetLabelAddress(memo, labels);
// Writes the memory into the file as an Hexa number
fp = fopen(argv[2], "w");
if (fp == NULL)
exit(1);
WriteToFile(fp, memo);
fclose(fp);
return(0);
}
// Input:
// fp - A pointer to the asm file
// labels - An array of labels and their address
// The function finds the labels and thier addresses and sets them in an array
void LabelsArr(FILE* fp, Label labels[]) {
char line[LINE_LEN];
char current_label[LABEL_LEN];
int label_count = 0;
int pc = 0;
while (!feof(fp)) {
fgets(line, LINE_LEN, fp);
if (FirstCharInLine(line) == '#') //Skip the line if it's just a comment
{
continue;
}
if (FirstCharInLine(line) == '.') //Skip the line if it's .word
{
continue;
}
if (FirstCharInLine(line) == '\n') //Skip the line if it's empty
{
continue;
}
CleanLine(line);
strcpy(current_label, IsItALabel(line));
if (_stricmp(current_label, "0") != 0) { // If current label is indeed a label
labels[label_count].address = pc;
strcpy(labels[label_count].name, current_label);
label_count++;
continue;
}
pc ++;
}
}
char FirstCharInLine(char* line) {
while (*line == ' ' || *line == '\t') {// Ignore spaces and tabs
line++;
}
return *line;
}
// Input:
// line
// The function removes comments from a code line
void CleanLine(char line[]) {
for (char* cp = line; *cp != '\0'; cp++) { // clean line from comments
if (*cp == '#') {
*cp = '\n';
cp++;
*cp = '\0';
break;
}
}
}
// Input:
// line - A string representing a line in the input file
// The function checks if a line is a label line. If so it returns the label name, else returns 0
char *IsItALabel(char line[LINE_LEN]) {
char label[LABEL_LEN] = "0";
char cp[LINE_LEN];
char* end_of_label = NULL;
strcpy(cp, line);
int i = 0;
while (!isalpha(cp[i])) {
if (cp[i] == '\0')
return label;
i++;
}
end_of_label = strchr(cp, ':');
if (end_of_label != NULL) {// The line is a label
*end_of_label = '\0';
return &cp[i];
}
return label;
}
// Input:
// fp - A pointer to the asm file
// memo - The memory array
// The function sets the memory matrix with the code
void MemoryArr(FILE* fp, Memory memo[MEM_SIZE]) {
char line[LINE_LEN], is_label[LABEL_LEN], opcode[11], rd[11], rs[11], rt[11], imm[11];
char* colon_pointer = NULL;
int i = 0, memo_indx = 0;
while (fgets(line, LINE_LEN, fp)) {
i = 0;
if (FirstCharInLine(line) == '#') // If the line is a comment line, skip it
continue;
CleanLine(line);
if (_stricmp(IsItALabel(line), "0") != 0) // The line is a label
continue;
// line is not a label - check if it's blank
while (line[i] == ' ' || line[i] == '\t' || line[i] == ',')
i++;
if (line[i] == '\n')
continue;
//line is ok
strcpy(opcode, NextWord(i, line)); // Gets opcode
i += strlen(opcode);
strcpy(rd, NextWord(i, line)); // Gets rd
//If .word - puts the address in rd and the value in imm
if (_stricmp(opcode, ".word") == 0) { // If .word
int address = (int)strtol(rd, NULL, 0);
i += strlen(rd)+1;
strcpy(memo[address].rd, rd);;
strcpy(rs, NextWord(i, line)); // Gets rs
strcpy(memo[address].imm, rs);
strcpy(memo[address].opcode, ".word");
strcpy(memo[address].rs, "");
strcpy(memo[address].rt, "");
continue;
}
while (line[i] != ',')
i++;
//i += strlen(rd) + 2;
strcpy(rs, NextWord(i, line)); // Gets rs
i++;
while (line[i] != ',')
i++;
//i += strlen(rs) + 2;
strcpy(rt, NextWord(i, line)); // Gets rt
i++;
while (line[i] != ',')
i++;
strcpy(imm, NextWord(i, line)); // Gets imm
strcpy(memo[memo_indx].imm, imm);
strcpy(memo[memo_indx].opcode, opcode);
strcpy(memo[memo_indx].rd, rd);
strcpy(memo[memo_indx].rs, rs);
strcpy(memo[memo_indx].rt, rt);
memo_indx ++;
}
}
// Input:
// start index - Where to start reading
// line - The rest of the line to read
// The function returns the next "word" in the line
const char* NextWord(int start_index, char const line[]) {
char word[LABEL_LEN];
int i = 0;
while (isalnum((int)line[start_index]) == 0 && line[start_index] != '.' && line[start_index] != '$' && line[start_index] != '-')
start_index++;
while (isalnum((int)line[start_index]) != 0 || line[start_index] == '.' || line[start_index] == '$' || line[start_index] == '-') {
word[i] = line[start_index];
start_index++;
i++;
}
word[i] = '\0';
return word;
}
// Input:
// memo - The array of the loaded memory
// labels - The matrix with the labels and thier addresses
// The function changes the labels in the memory to thier addresses
void SetLabelAddress(Memory memo[MEM_SIZE], Label labels[MEM_SIZE]) {
Label* current_label_pointer = labels;
Memory* memo_pointer = memo;
char current_label_name[LABEL_LEN], current_memo_imm[LABEL_LEN], current_label_address[LABEL_LEN];
while (_stricmp(current_label_pointer->name, "") != 0) {
strcpy(current_label_name, current_label_pointer->name); // Label's name
_itoa(current_label_pointer->address, current_label_address, 10); // Label's address as string
while (_stricmp(memo_pointer->opcode, "") != 0) { // Searches for labels in the memory
strcpy(current_memo_imm, memo_pointer->imm);
if (_stricmp(current_memo_imm, current_label_name) == 0) {
strcpy(memo_pointer->imm, current_label_address);
}
memo_pointer++;
}
memo_pointer = memo; // Returns the pointer to the beginning of the memory
current_label_pointer++;
}
}
// Input:
// file pointer and memory array
// The function writes the memory into the file as an Hexa number
void WriteToFile(FILE* fp, Memory memo[MEM_SIZE]) {
char hex_rd = '0', hex_rs = '0', hex_rt = '0';
char* hex_imm=calloc(13, sizeof(char));
char* hex_opcode = calloc(3, sizeof(char));
int memo_indx = 0, num_of_lines_to_print = 0;
num_of_lines_to_print = NumOfLines(memo); // The number of lines that needs to be printed
while (memo_indx <= num_of_lines_to_print) {
if (_stricmp(memo->opcode, "") != 0) {
strcpy(hex_opcode, OpToHex(memo->opcode));
if (memo->imm[0] == '0' && (memo->imm[1] == 'x' || memo->imm[1] == 'X')) { // If it's an hexa number
strcpy(hex_imm, &memo->imm[2]);
concatZeros(hex_imm);
}
else if (atoi(memo->imm)>=0){
strcpy(hex_imm, fromDeci(hex_imm, 16, atoi(memo->imm)));
}
else {
sprintf(hex_imm, "%X", atoi(memo->imm));
strcpy(hex_imm, &hex_imm[5]);
}
hex_rd = RegToHex(memo->rd);
hex_rs = RegToHex(memo->rs);
hex_rt = RegToHex(memo->rt);
if (_stricmp(hex_opcode, "..") == 0) { // If the opcode is .word
if (memo->imm[0] == '0' && (memo->imm[1] == 'x' || memo->imm[1] == 'X')) { //if it's an hexa number
strcpy(hex_imm, &memo->imm[2]);
}
else {
sprintf(hex_imm, "%X", atoll(memo->imm));
}
concatZerosWord(hex_imm);
fputs(hex_imm, fp);
putc('\n', fp);
strcpy(hex_imm, "000");
strcpy(hex_opcode, "00");
hex_rd = '0', hex_rs = '0', hex_rt = '0';
memo_indx++;
memo++;
continue;
}
}
// Writes to file
fputs(hex_opcode, fp);
putc(hex_rd, fp);
putc(hex_rs, fp);
putc(hex_rt, fp);
fputs(hex_imm, fp);
putc('\n', fp);
strcpy(hex_imm, "000");
strcpy(hex_opcode, "00");
hex_rd = '0', hex_rs = '0', hex_rt = '0';
memo_indx++;
memo++;
}
}
// Input:
// memo - An array containing the none blank lines
// The function returns the number of lines that needs to be printed to memin
int NumOfLines(Memory memo[MEM_SIZE]) {
int indx = 4095;
while (indx >= 0) {
if (_stricmp(memo[indx].opcode, "") != 0 || _stricmp(memo[indx].rd, "") != 0 || _stricmp(memo[indx].rs, "") != 0 || _stricmp(memo[indx].rt, "") != 0 || _stricmp(memo[indx].imm, "") != 0)
break;
indx--;
}
return indx;
}
// Input:
// opcode - String to convert
// The function returns the opcode representation in Hexa
char* OpToHex(const char opcode[LABEL_LEN]) {
char* hex_op=calloc(3, sizeof(char));
if (_stricmp(opcode, "add") == 0)
strcpy(hex_op,"00");
else if (_stricmp(opcode, "sub") == 0)
strcpy(hex_op, "01");
else if (_stricmp(opcode, "mul") == 0)
strcpy(hex_op, "02");
else if (_stricmp(opcode, "and") == 0)
strcpy(hex_op, "03");
else if (_stricmp(opcode, "or") == 0)
strcpy(hex_op, "04");
else if (_stricmp(opcode, "xor") == 0)
strcpy(hex_op, "05");
else if (_stricmp(opcode, "sll") == 0)
strcpy(hex_op, "06");
else if (_stricmp(opcode, "sra") == 0)
strcpy(hex_op, "07");
else if (_stricmp(opcode, "srl") == 0)
strcpy(hex_op, "08");
else if (_stricmp(opcode, "beq") == 0)
strcpy(hex_op, "09");
else if (_stricmp(opcode, "bne") == 0)
strcpy(hex_op, "0A");
else if (_stricmp(opcode, "blt") == 0)
strcpy(hex_op, "0B");
else if (_stricmp(opcode, "bgt") == 0)
strcpy(hex_op, "0C");
else if (_stricmp(opcode, "ble") == 0)
strcpy(hex_op, "0D");
else if (_stricmp(opcode, "bge") == 0)
strcpy(hex_op, "0E");
else if (_stricmp(opcode, "jal") == 0) // special case: memory cell is actually the immediate cell
strcpy(hex_op, "0F");
else if (_stricmp(opcode, "lw") == 0)
strcpy(hex_op, "11");
else if (_stricmp(opcode, "sw") == 0)
strcpy(hex_op, "12");
else if (_stricmp(opcode, "reti") == 0) // special case: memory cell is actually the immediate cell
strcpy(hex_op, "13");
else if (_stricmp(opcode, "in") == 0)
strcpy(hex_op, "14");
else if (_stricmp(opcode, "out") == 0)
strcpy(hex_op, "15");
else if (_stricmp(opcode, "halt") == 0) // special case: memory cell is actually the immediate cell
strcpy(hex_op, "16");
else if (_stricmp(opcode, ".word") == 0) // special case: cell was modified by .word
strcpy(hex_op, "..");
return hex_op;
}
// Input:
// register string to convert
// The function returns the register representation in Hexa
char RegToHex(const char reg_name[LABEL_LEN]) {
char hex_op = NULL;
if (_stricmp(reg_name, "$zero") == 0)
hex_op = '0';
else if (_stricmp(reg_name, "$imm") == 0)
hex_op = '1';
else if (_stricmp(reg_name, "$v0") == 0)
hex_op = '2';
else if (_stricmp(reg_name, "$a0") == 0)
hex_op = '3';
else if (_stricmp(reg_name, "$a1") == 0)
hex_op = '4';
else if (_stricmp(reg_name, "$a2") == 0)
hex_op = '5';
else if (_stricmp(reg_name, "$a3") == 0)
hex_op = '6';
else if (_stricmp(reg_name, "$t0") == 0)
hex_op = '7';
else if (_stricmp(reg_name, "$t1") == 0)
hex_op = '8';
else if (_stricmp(reg_name, "$t2") == 0)
hex_op = '9';
else if (_stricmp(reg_name, "$s0") == 0)
hex_op = 'A';
else if (_stricmp(reg_name, "$s1") == 0)
hex_op = 'B';
else if (_stricmp(reg_name, "$s2") == 0)
hex_op = 'C';
else if (_stricmp(reg_name, "$gp") == 0)
hex_op = 'D';
else if (_stricmp(reg_name, "$sp") == 0)
hex_op = 'E';
else if (_stricmp(reg_name, "$ra") == 0)
hex_op = 'F';
return hex_op;
}
// To return char for a value. For example '2'
// is returned for 2. 'A' is returned for 10. 'B'
// for 11
char reVal(int num)
{
if (num >= 0 && num <= 9)
return (char)(num + '0');
else
return (char)(num - 10 + 'A');
}
// Utility function to reverse a string
void strev(char *str)
{
int len = strlen(str);
int i;
for (i = 0; i < len / 2; i++)
{
char temp = str[i];
str[i] = str[len - i - 1];
str[len - i - 1] = temp;
}
}
// Function to convert a given decimal number
// to a base 'base' and
char* fromDeci(char res[], int base, int inputNum)
{
int index = 0; // Initialize index of result
// Convert input number is given base by repeatedly
// dividing it by base and taking remainder
while (inputNum > 0)
{
res[index++] = reVal(inputNum % base);
inputNum /= base;
}
res[index] = '\0';
// Reverse the result
strev(res);
concatZeros(res);
return res;
}
// Input:
// string - the line that is about to be put in the file
// The function adds zeros for the string if it's too short
void concatZeros(char* string)
{
if (strlen(string) == 3) {
return;
}
char* old_value = calloc(strlen(string) + 1, sizeof(char));
strcpy(old_value, string);
int num_zeros = 3 - strlen(string); // The amount of zeros to add
if (num_zeros == 3) {
strcpy(string, "000\0");
strcat(string, old_value);
}
else if (num_zeros == 2) {
strcpy(string, "00\0");
strcat(string, old_value);
}
else if (num_zeros == 1) {
strcpy(string, "0\0");
strcat(string, old_value);
}
free(old_value);
}
// Input:
// string - the line that is about to pe put in the file
// The function adds zeros for .word if the string is too short
void concatZerosWord(char* string)
{
if (strlen(string) == 5) {
return;
}
char* old_value = calloc(strlen(string) + 1, sizeof(char));
strcpy(old_value, string);
int num_zeros = 5 - strlen(string); // The amount of zeros to add
if (num_zeros == 3) {
strcpy(string, "000\0");
strcat(string, old_value);
}
else if (num_zeros == 2) {
strcpy(string, "00\0");
strcat(string, old_value);
}
else if (num_zeros == 4) {
strcpy(string, "0000\0");
strcat(string, old_value);
}
else if (num_zeros == 5) {
strcpy(string, "00000\0");
strcat(string, old_value);
}
else if (num_zeros == 1) {
strcpy(string, "0\0");
strcat(string, old_value);
}
free(old_value);
}