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[Carlo Wood <carlo@runaway.xs4all.nl>]

                                  added #pragma interface
   text    data     bss   total	  to header file:
 351515   10404    3920  365839   select.h
 351786   10404    3920  366110   iodbbuf_fd.h
 352362   10404    3920  366686   listen_sock.h
 352362   10404    3920  366686   listen_sock_dtct.h
 352426   10404    3920  366750    -
 353303   10436    3920  367659   sock.h
 354257   10464    3928  368649   events.h
 355505   10488    3940  369933   timing.h
 361015   11296    4048  376359   traits.h

Interesting is that the size *grows* 3% by *adding* a "#pragma interface"
just to traits.h :)...

The bad cases however are at the top: The cases in which adding
"#pragma interface" indeed makes the (text) size shrink.

I'd charaterize these "winners" as the ones that are included in the
most source files and/or contain functions that are used the most often.
There is no reason to assume they do something special, except being
used a lot.

"sys.h" for instance is #included in EVERY source file, before ANY
other header file is included (including system header files).

A test file with only '#include "libr/sys.h"' in it, compiled
with -E, and skipping all empty lines and comments gives:

==============================================================================
extern "C" { 
typedef unsigned char __u_char;
typedef unsigned short __u_short;
typedef unsigned int __u_int;
typedef unsigned long __u_long;
typedef unsigned long long int __u_quad_t;
typedef long long int __quad_t;
typedef __quad_t *__qaddr_t;
typedef __u_quad_t __dev_t;		 
typedef __u_int __uid_t;		 
typedef __u_int __gid_t;		 
typedef __u_long __ino_t;		 
typedef __u_int __mode_t;		 
typedef __u_int __nlink_t; 		 
typedef long int __off_t;		 
typedef __quad_t __loff_t;		 
typedef int __pid_t;			 
typedef int __ssize_t;			 
typedef struct
  {
    int __val[2];
  } __fsid_t;				 
typedef int __daddr_t;			 
typedef char *__caddr_t;
typedef long int __time_t;
typedef long int __swblk_t;		 
\f
typedef long int __clock_t;
typedef unsigned long int __fd_mask;
typedef struct
  {
    __fd_mask fds_bits[1024  / (8 * sizeof (__fd_mask)) ];
  } __fd_set;
typedef int __key_t;
typedef unsigned short int __ipc_pid_t;
typedef __u_char u_char;
typedef __u_short u_short;
typedef __u_int u_int;
typedef __u_long u_long;
typedef __quad_t quad_t;
typedef __u_quad_t u_quad_t;
typedef __fsid_t fsid_t;
typedef __dev_t dev_t;
typedef __gid_t gid_t;
typedef __ino_t ino_t;
typedef __mode_t mode_t;
typedef __nlink_t nlink_t;
typedef __off_t off_t;
typedef __loff_t loff_t;
typedef __pid_t pid_t;
typedef __uid_t uid_t;
typedef __ssize_t ssize_t;
typedef __daddr_t daddr_t;
typedef __caddr_t caddr_t;
typedef __key_t key_t;
typedef __time_t time_t;
typedef unsigned int size_t;
typedef unsigned long int ulong;
typedef unsigned short int ushort;
typedef unsigned int uint;
typedef int int8_t __attribute__ ((__mode__ (  __QI__ ))) ;
typedef unsigned int u_int8_t __attribute__ ((__mode__ (  __QI__ ))) ;
typedef int int16_t __attribute__ ((__mode__ (  __HI__ ))) ;
typedef unsigned int u_int16_t __attribute__ ((__mode__ (  __HI__ ))) ;
typedef int int32_t __attribute__ ((__mode__ (  __SI__ ))) ;
typedef unsigned int u_int32_t __attribute__ ((__mode__ (  __SI__ ))) ;
typedef int int64_t __attribute__ ((__mode__ (  __DI__ ))) ;
typedef unsigned int u_int64_t __attribute__ ((__mode__ (  __DI__ ))) ;
typedef int register_t __attribute__ ((__mode__ (__word__)));
struct timespec
  {
    long int tv_sec;		 
    long int tv_nsec;		 
  };
extern "C" { 
struct timeval;
typedef __fd_mask fd_mask;
typedef __fd_set fd_set;
extern int __select  (int __nfds, __fd_set *__readfds,
			  __fd_set *__writefds, __fd_set *__exceptfds,
			  struct timeval *__timeout)  ;
extern int select  (int __nfds, __fd_set *__readfds,
			__fd_set *__writefds, __fd_set *__exceptfds,
			struct timeval *__timeout)  ;
extern int __pselect  (int __nfds, __fd_set *__readfds,
			   __fd_set *__writefds, __fd_set *__exceptfds,
			   struct timespec *__timeout)  ;
extern int pselect  (int __nfds, __fd_set *__readfds,
			 __fd_set *__writefds, __fd_set *__exceptfds,
			 struct timespec *__timeout)  ;
} 
} 
const unsigned int malloc_overhead_c = 0;
typedef int sa_handler_param_type;
static const char rcs_ident_sys_sys_h[] __attribute__ ((unused)) =   "$Id: sys.h,v 1.1.1.1 1998/06/17 16:02:19 carlo Exp $" ; 
==============================================================================

So, a clue could perhaps be that a `typedef' uses space in the text segment?
(In a duplicating way)

Note that all of these typedefs come from system header files that were
included from sys.h.  It surprices me that "#pragma interface" seems to
have influence in this case.  Perhaps I should start to include all my
system headers from own headers, so I can add a "#pragma interface" in
front of it (the system headers do not contain a "#pragma interface" by
themselfs).

If I can provide any other info, please let me know.
Hopefully things get easier once I can release libr (I am waiting for
Qt-2.0 to be released because I want to use its QPL).

After adding "#pragma interface" only in those header files where it
makes the text segment shrink, I could get it as small as:

   text    data     bss     dec     hex filename
 329351    9680    3780  342811   53b1b ../../lib/libr.so.0.2.5

which is 10% smaller than the worsed case...

Regard,

 Carlo Wood  <carlo@runaway.xs4all.nl>