Assembler

Description

This repository contains a university course project that implements an assembler program. The assembler translates code written in a defined assembly language into machine code. It processes the input file, detects syntax and semantic errors, and generates an output file compatible with a simulated computer.

Features

• Input Handling: Reads assembly language source files.
• Error Detection: Identifies syntax and semantic errors in the input files.
• Output Generation: Produces machine code files in a format compatible with the simulated hardware.

Assembly Language

The assembly language used in this project is tailored to a simulated computer model. It includes:

• Registers (r0 to r7)
• Memory management
• A set of predefined instructions
• Support for basic arithmetic, branching, and memory operations

Usage

Compile the assembler using the MakeFile:

make

Run the assembler with an input assembly file:

./assembler input.asm

Output Files

The assembler generates three types of output files for valid assembly programs:

1. Object File (input.ob)

The object file contains the complete memory image, including both the code segment and the data segment. The file format is as follows:

• First Line: A header line with two decimal values, separated by a space:
  • The total length of the code segment (in memory words).
  • The total length of the data segment (in memory words).
• Following Lines: Each line represents a memory word and contains:
  • The address of the memory word (in decimal, 4 digits, including leading zeros).
  • The content of the memory word (in octal, 5 digits).
  • There is a single space between the address and the content.

2. Entries File (*.ent)

The entries file contains all the symbols defined as .entry in the assembly program. The format is:

• One line per symbol.
• Each line contains:
  • The symbol name.
  • The address of the symbol (in decimal).
  • A single space separates the symbol name and the address.
• The order of the lines is not significant.

3. . Externals File (*.ext)

The externals file contains the usage of symbols defined as .external in the assembly program. The format is:

• One line per external reference.
• Each line contains:
  • The symbol name.
  • The address in the code segment where the external symbol is referenced (in decimal).
  • A single space separates the symbol name and the address.
• Multiple lines may exist for the same external symbol if it is referenced at multiple locations.
• The order of the lines is not significant.

Examples

1. Failed to open an input file:

   

2. Missing arguments:

   

3. Running Examples/BadFirstRound/tester.as file:

   

4. Running Examples/BadSecondRound/tester.as file: