在C中，编译时找到全局const变量值

Question

const int hello= 0x1111;
int main(){
}

I build a really simple code, and compile it with

gcc t.c -g -o t.out

Can I use objdump or nm or any tools to make sure the const variable value? I always find address of variable "hello", but cannot find value

Anyone can help me, thanks a lot

Answer 1

The example code

const int hello = 0xdeadbeef;
int main()
{
  return 0;
}

compile with

gcc-4.9   -W -Wall -Wextra -pedantic  -std=c11 fortests.c -o fortests

dump the content with

objdump -xDSs fortests | less

(dumped a bit too much, but costs nothing, so ... meh ...) and search for hello

0000000000400594 g     O .rodata        0000000000000004              hello

That means it is in the section .rodata . We explicitly asked objdump to list the contents of all sections, so here we have it, the value 0xdeadbeef .

Contents of section .rodata:
  400590 01000200 efbeadde                    ........ 
                  ^^^^^^^^
             here ||||||||

And it should be clear by now, why you had trouble to find it.