Subject: Re: Compiling NetBSD with another compiler.
To: Bill Stouder-Studenmund <firstname.lastname@example.org>
From: Aleksey Cheusov <email@example.com>
Date: 10/13/2007 13:01:09
> Renaming lets us patch the two things together. With it, your C code that
> is written to call "stat()" really calls "__stat30()" which is the routine
> (stub in libc for the syscall) that expects the new stat structure.
> So that's how we use renaming. We actually like it a lot. :-) We've done
> it a number of times for struct stat...
Thank you all for your answers and detailed explanations
and especialy for a list of exceptions I also asked for.
As far as I understand the following demonstrates
an idea of function renaming.
0 ~> cat main.c
extern int func (void) __RENAME(func_new);
int main (int argc, char **argv)
return func ();
0 ~> cat X.c
int func (void)
int func_new (void)
0 ~> gcc -c -o main.o main.c
0 ~> gcc -c -o X.o X.c
0 ~> nm main.o
00000000 T main
0 ~> nm X.o
00000000 T func
0000000a T func_new
0 ~> gcc -o main main.o X.o
0 ~> ./main
But I still don't understand one aspect.
Why non-portable way of doing this renaming is used instead of
just using macro like
#define func func_new
for the example above. This may work for all compilers, not only gcc and pcc.
Best regards, Aleksey Cheusov.