Errors in Assembly Language

section .data
    msg db 'hello world', 0
    msg_len equ $ - msg

section .text
    global _start

_start:
    ; Write the message to stdout
    mov eax, 4          ; syscall number for sys_write
    mov ebx, 1          ; file descriptor 1 is stdout
    mov ecx, msg        ; message to write
    mov edx, msg_len    ; message length
    int 0x80            ; call kernel

    ; Exit the program
    mov eax, 1          ; syscall number for sys_exit
    xor ebx, ebx        ; return 0 status
    int 0x80            ; call kernel

In Assembly, error handling is typically managed through checking return values of system calls or comparing specific registers. Unlike high-level languages, there’s no built-in error type or exception handling mechanism.

Here’s an example of how you might implement a function that checks for errors:

section .data
    error_msg db 'Error: Invalid argument', 0
    error_len equ $ - error_msg

section .text
    global _start

_start:
    ; Call our function
    mov eax, 42         ; Argument for our function
    call check_argument

    ; Exit program
    mov eax, 1
    xor ebx, ebx
    int 0x80

check_argument:
    ; Compare argument with 42
    cmp eax, 42
    je .error           ; If equal, jump to error

    ; If not equal, return success
    mov eax, 0          ; Return 0 (no error)
    ret

.error:
    ; Print error message
    mov eax, 4
    mov ebx, 1
    mov ecx, error_msg
    mov edx, error_len
    int 0x80

    ; Return error code
    mov eax, 1          ; Return 1 (error)
    ret

In this example, the check_argument function checks if the input is equal to 42. If it is, it prints an error message and returns 1 (indicating an error). Otherwise, it returns 0 (indicating success).

To use this function:

1. Call check_argument with a value in eax.
2. After the call, check eax for the return value (0 for success, 1 for error).

This approach mimics the error handling pattern in the original code, where functions return an error value that needs to be checked by the caller.

Remember that in Assembly, you have to manage all aspects of error handling manually, including defining error codes, checking return values, and deciding how to proceed based on those values.

To compile and run this Assembly program (assuming x86 architecture and Linux):

$ nasm -f elf program.asm
$ ld -m elf_i386 -o program program.o
$ ./program

This will assemble the code, link it into an executable, and run it. The program will either exit silently (if no error occurred) or print the error message.