can't compile objective-c

[Kendall Bell <kenbell@xxxxxxxxxxxx>]

Any time I try to compile the following:

@interface hello
   - (void) say_hello: (char*) s;
@end

@implementation hello
   - (void) say_hello: (char*) s {
       printf( "%s\n", s );
   }
@end

I get the following error message:


/tmp/cceeQbNJ.o: In function `__objc_gnu_init':
hello.m:(.text+0x58): undefined reference to `__objc_exec_class'

How can I fix this?