Why the simple code doesn't compile?
Here is the code:
Code:
#include <stdio.h>
extern end;
extern edata;
extern etext;
int I;
main(int argc, char **argv)
{
int i;
int *ii;
printf("&etext = 0x%lx\n", &etext);
printf("&edata = 0x%lx\n", &edata);
printf("&end = 0x%lx\n", &end);
printf("\n");
ii = (int *) malloc(sizeof(int));
printf("main = 0x%lx\n", main);
printf("&I = 0x%lx\n", &I);
printf("&i = 0x%lx\n", &i);
printf("&argc = 0x%lx\n", &argc);
printf("&ii = 0x%lx\n", &ii);
printf("ii = 0x%lx\n", ii);
}
But the compiler complains:
Code:
g++ -c -g main.cc -o main.o
main.cc:22: error: ISO C++ forbids declaration of `end' with no type
main.cc:23: error: ISO C++ forbids declaration of `edata' with no type
main.cc:24: error: ISO C++ forbids declaration of `etext' with no type
