Hi all,

I am trying to extract some part of C source code defined under certain Macro statements
for example this is a code

#include<stdio.h>
#include<unistd.h>

int main(void)
{

int my_int = 10 ;

#ifdef TEST_MACRO
int his_int = 20 ;
#else
int other_int = 40;
#endif

printf( "Test Program\n");

#ifdef TEST_MACRO
printf("his_int=%d\n",his_int);
#else
printf("other_int=%d\n",other_int) ;
#endif

printf("my_int=%d\n",my_int);

return 0 ;

}

Now after some processing using m4 I want following type of output

#include<stdio.h>
#include<unistd.h>
int main(void)
{

int my_int = 10 ;


int his_int = 20 ;




printf( "Test Program\n");


printf("his_int=%d\n",his_int);




printf("my_int=%d\n",my_int);

return 0 ;

}

using gcc -E is ofcourse one way of doing this but Is it possible using m4?
Please any body tell me !!!

I don't know what m4 is, but it is also posible by running GCC with -DTEST_MACRO flag. Like so:

gcc -DTEST_MACRO -o myprog input.c

Hi _Nerd, Thanks for replying,
m4 is a generic macro processor. For more information on this please refer to the man page of this command

Yes, you are right using your solution I will get compiled ELF executable file. But my requirement is not that, I need output in the form of c soruce itself and removed unwanted code part.