In C programming, does compiler ignore all instructions after an operation related to ROM?-CodePudding

I have been doing this exercise of exploring strings in c programming. I found that we can assign a string literal to a pointer also (Like in the code mentioned here!)

#include <stdio.h>

int main(void)
{
    char msg1[] = "Hello";
    char *msg2 = ", Welt";

    printf("the string at msg1 is :%s\n", msg1);
    printf("the string at msg2 is :%s\n", msg2);


    printf("Address of the msg1 is: %p\n",&msg1);
    printf("Address of the msg2 is: %p\n",&msg2);

    printf("Value of the msg1 is: %p\n",msg1);
    printf("Value of the msg2 is: %p\n",msg2);
    
    msg1[1] = 'G';
    msg2[2] = 'X';

    printf("Value of the msg1 is: %p\n",msg1);
    printf("Value of the msg2 is: %p\n",msg2);
    return 0;
}

now when I execute this I get:

C:\Users\ADMIN\Desktop>test
the string at msg1 is :Hello
the string at msg2 is :, Rohit
Address of the msg1 is: 0061FF1A
Address of the msg2 is: 0061FF14
Value of the msg1 is: 0061FF1A
Value of the msg2 is: 00405064

i.e. The last two lines are not even printed! (same results in any platform)

My understanding and my question: I understand that I am assigning a ROM address to the pointer variable called: char *msg2, and am assigning a String Literal: ", Welt" to it. I also know that the FLASH controller at ROM will not allow this Write operation unless there is like a "special permission".(I'm still learning about these kind of processes).

But the thing is that: why are the print messages after that "illegal ROM-write process" are not being executed? is it because the the compiler ignores the instructions after that "illegal ROM-write process" ?

I know that we should NOT play around with ROM access like this in a program, rather use a:

char const *msg2 = ", Welt"; //which will give us an error incase we change something.

SORRY, I've just started Stack Overflow - I will learn to be more professional in the upcoming days

CodePudding user response：

msg2[2] = 'X'; is undefined behavior (UB) as it attempts to change a string literal.

Anything may happen including <messages after that "illegal ROM-write process" are not being executed>.

is it because the the compiler ignores the instructions after that "illegal ROM-write process" ?

If this was true, then that would be defined behavior. It has the possibility of being true today and not tomorrow. Anything may happen as that what UB is all about - uncertainty.