lynx.h

gcc-you can use this code to learn something about gcc, and inquire further into linux,

/* Definitions for Intel 386 running LynxOS.
   Copyright (C) 1993, 1995, 1996, 2002 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#define TARGET_VERSION fprintf (stderr, " (80386, LYNX BSD syntax)"); 

#define TARGET_OS_CPP_BUILTINS()		\
  do						\
    {						\
	builtin_define_std ("I386");		\
	builtin_define_std ("Lynx");		\
	builtin_define_std ("IBITS32");		\
	builtin_assert ("system=unix");		\
	builtin_assert ("system=lynx");		\
    }						\
  while (0)

/* The prefix to add to user-visible assembler symbols.  */

/* Override the svr3 convention of adding a leading underscore.  */

#undef USER_LABEL_PREFIX
#define USER_LABEL_PREFIX ""

/* Apparently LynxOS clobbers ebx when you call into the OS.  */

#undef CALL_USED_REGISTERS
#define CALL_USED_REGISTERS \
/*ax,dx,cx,bx,si,di,bp,sp,st,st1,st2,st3,st4,st5,st6,st7,arg*/ \
{  1, 1, 1, 1, 0, 0, 0, 1, 1,  1,  1,  1,  1,  1,  1,  1,  1 }

/* Prefix for internally generated assembler labels.  If we aren't using
   underscores, we are using prefix `.'s to identify labels that should
   be ignored, as in `i386/gas.h' [e-mail]  */

#undef  LPREFIX
#define LPREFIX ".L"

/* The prefix to add to user-visible assembler symbols.  */

#undef  USER_LABEL_PREFIX
#define USER_LABEL_PREFIX ""

/* If user-symbols don't have underscores,
   then it must take more than `L' to identify
   a label that should be ignored.  */

/* This is how to store into the string BUF
   the symbol_ref name of an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.
   This is suitable for output with `assemble_name'.  */

#undef  ASM_GENERATE_INTERNAL_LABEL
#define ASM_GENERATE_INTERNAL_LABEL(BUF,PREFIX,NUMBER)	\
  sprintf ((BUF), ".%s%ld", (PREFIX), (long)(NUMBER))

/* This is how to output an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.  */

#undef  ASM_OUTPUT_INTERNAL_LABEL
#define ASM_OUTPUT_INTERNAL_LABEL(FILE,PREFIX,NUM)	\
  fprintf (FILE, ".%s%d:\n", PREFIX, NUM)