Data section in a.out

#include <stdio.h>int main(){return 0;}

It gives

   text    data     bss     dec     hex filename    960     248       8    1216     4c0 a.out

when you do

int a;int main(){    char *p = "hello";    return 0;}

it gives

   text    data     bss     dec     hex filename    982     248       8    1238     4d6 a.out

at that time hello is stored in .rodata and the location of that address is stored in char pointer p but here p is stored on stack

and size doesnt shows stack. And i am not sure but .rodata is here calculated in text or dec.

when you write

int a;char *p = "hello";int main(){    return 0;} 

it gives

   text    data     bss     dec     hex filename    966     252       8    1226     4ca a.out

now here again "hello" is stored in .rodata but char pointer takes 4 byte and stored in data so data is increment by 4

For more info http://codingfreak.blogspot.in/2012/03/memory-layout-of-c-program-part-2.html

Actually, that's an implementation detail. The compiler works by an as-is principle. Meaning that as long as the behavior of the program is the same, it's free to exclude any piece of code it wants. In this case, it can skip char* p = "hello" altogether.

The string "hello" is allocated in the section .rodata