#include<stdio.h>
#include<string.h>
#include<stdlib.h>
void chk_label();
void chk_opcode();
void READ_LINE();
struct optab
{
char code[10],objcode[10];
}myoptab[3]={
{"LDA","00"},
{"JMP","01"},
{"STA","02"}
};
struct symtab{
char symbol[10];
int addr;
}mysymtab[10];
int startaddr,locctr,symcount=0,length;
char line[20],label[8],opcode[8],operand[8],programname[10];
void PASS1()
{
FILE *input,*inter;
input=fopen("input.txt","r");
inter=fopen("inter.txt","w");
printf("LOCATION LABEL\tOPERAND\tOPCODE\n");
printf("_____________________________________");
fgets(line,20,input);
READ_LINE();
if(!strcmp(opcode,"START"))
{
startaddr=atoi(operand);
locctr=startaddr;
strcpy(programname,label);
fprintf(inter,"%s",line);
fgets(line,20,input);
}
else
{
programname[0]='\0';
startaddr=0;
locctr=0;
}
printf("\n %d\t %s\t%s\t %s",locctr,label,opcode,operand);
while(strcmp(line,"END")!=0)
{
READ_LINE();
printf("\n %d\t %s \t%s\t %s",locctr,label,opcode,operand);
if(label[0]!='\0')
chk_label();
chk_opcode();
fprintf(inter,"%s %s %s\n",label,opcode,operand);
fgets(line,20,input);
}
printf("\n %d\t\t%s",locctr,line);
fprintf(inter,"%s",line);
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]='\0';
for(i=0;line[i]!='\0';i++)
{
if(line[i]!=' ')
buff[j++]=line[i];
else
{
buff[j]='\0';
strcpy(word3,word2);
strcpy(word2,word1);
strcpy(word1,buff);
j=0;
count++;
}
}
buff[j-1]='\0';
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 chk_label()
{
int k,dupsym=0;
for(k=0;k<symcount;k++)
if(!strcmp(label,mysymtab[k].symbol))
{
mysymtab[k].addr=-1;
dupsym=1;
break;
}
if(!dupsym)
{
strcpy(mysymtab[symcount].symbol,label);
mysymtab[symcount++].addr=locctr;
}
}
void chk_opcode()
{
int k=0,found=0;
for(k=0;k<3;k++)
if(!strcmp(opcode,myoptab[k].code))
{
locctr+=3;
found=1;
break;
}
if(!found)
{
if(!strcmp( opcode,"WORD"))
locctr+=3;
else if (!strcmp(opcode,"RESW"))
locctr+=(3*atoi(operand));
else if(!strcmp(opcode,"RESB"))
locctr+=atoi(operand);
}
}
int main()
{
PASS1();
length=locctr-startaddr;
}
1) Instruction format and addressing modes. 2) Relocation. For details refer "System Software By L.L.Beck" BY:: SUNIL SHARMA (sunil13982@gmail.com)
There are two types of compilers one-pass and multi-pass. Pass means that some of inner operations are repeated several times. If we have one-pass compiler and this source code: i++; i++; i++; Inside compiler it would generate: i = i + 1; i = i + 1; i = i + 1; If compiler would be two-pass: i = i + 3; The more passes compiler has, the better optimized code it can generate, but it is slower because it must repeat some steps again.
chupa lao jinu answer chahida ithe vaje ............kam kar koi nahi te search maran lag jande.............
Language processor consist of two phases 1.Analysis phase 2.Synthesis phase Language processor pass is the processing of every statement in a source program, or its equivalent representation to preform language processing function pass 1-It analyses the source program and notes relevant information. pass 2- It synthesizes the target program
I do not know, ask your teacher.Why, for example Python, PHP, Pearl and JavaScript work without compiler; C, Pascal, Cobol and Fortan work without interpreter.None work "without assembler compiler and interpreter" so the question cannot be answered as asked because there is no answer.If we want to write a program without an assembler, compiler or interpreter; it is an easy answer. You hand assemble, that is where you manually enter the machine code. In the early days this was the only way to program a computer. Having done some hand assembly I have to things to say about it.1) it is not as hard as it might appear to be but it is painfully slow to do.2) why bother when there are excellent compilers available.
pass 1 assembler is assembler which convert assembly level language into machine level language in one pass only
Two main options for the design of assembler are: 1. One pass assembler 2. Multi-pass assembler One pass assemblers generally have problem of "forward referencing" which is resolved by using mulitpasses
In theory the only advantage is Speed simply because one pass is faster than two passes. However a properly written two pass assembler can be faster than a poorly written one pass assembler because the two pass assembler spends alot less time doing memory intensive lookups, look-aheads, and back-tracking.
To the question, It is an low level language An assembly language is use to write programs : 1.Games 2.Operating system 3.Utility program 4.compiler/assembler/interpreter 5.Virus 6.Defragmenter 7.Device driver
1) Instruction format and addressing modes. 2) Relocation. For details refer "System Software By L.L.Beck" BY:: SUNIL SHARMA (sunil13982@gmail.com)
error reporting in a two pass assembler 1)Syntax errors like missing commas etc 2)Invalid opcode 3)Duplicate definition of symbol 4)Undefined symbol 5)Missing START 6)Missing END 7)Symbol defined but not used(actually its warning)
There are two types of compilers one-pass and multi-pass. Pass means that some of inner operations are repeated several times. If we have one-pass compiler and this source code: i++; i++; i++; Inside compiler it would generate: i = i + 1; i = i + 1; i = i + 1; If compiler would be two-pass: i = i + 3; The more passes compiler has, the better optimized code it can generate, but it is slower because it must repeat some steps again.
The Microsoft Macro Assembler (abbreviated MASM) is an x86 high-level assembler for DOS and Microsoft Windows.Microsoft Assembeler for MS DosM As MToday, MASM is still the most popular assembler,[1] despite competition from new products such as NASM and Yasm, FASM, and HLA.
chupa lao jinu answer chahida ithe vaje ............kam kar koi nahi te search maran lag jande.............
normally every assembler has two passes. pass 1 and pass 2. wen v start compiling the program object code is generated. wen there are no forward references we could generate the object code in first pass itself. unfortunately writing programs without forward reference is tedious and hence we go for second pass to generate the objectcode of the remaining .
Language processor consist of two phases 1.Analysis phase 2.Synthesis phase Language processor pass is the processing of every statement in a source program, or its equivalent representation to preform language processing function pass 1-It analyses the source program and notes relevant information. pass 2- It synthesizes the target program
hi i used ProcessBuilder to run the program but i m stuck with how to pass input to the executable. If i run that .exe file in cmd it asks to "enter your choice (1/2/3)" How to pass the choice from my java code?