frvbegin.c

linux下的gcc编译器

/* Frv initialization file linked before all user modules
   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
    Contributed by Red Hat, 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.

   This file was originally taken from the file crtstuff.c in the
   main compiler directory, and simplified. */

#include "defaults.h"
#include <stddef.h>
#include "unwind-dw2-fde.h"
#include "gbl-ctors.h"

/*  Declare a pointer to void function type.  */
#define STATIC static

#ifdef __FRV_UNDERSCORE__
#define UNDERSCORE "_"
#else
#define UNDERSCORE ""
#endif

#define INIT_SECTION_NEG_ONE(SECTION, FLAGS, NAME)			\
__asm__ (".section " SECTION "," FLAGS "\n\t"				\
	 ".globl   " UNDERSCORE NAME "\n\t"				\
	 ".type    " UNDERSCORE NAME ",@object\n\t"			\
	 ".p2align  2\n"						\
	 UNDERSCORE NAME ":\n\t"					\
	 ".word     -1\n\t"						\
	 ".previous")

#define INIT_SECTION(SECTION, FLAGS, NAME)				\
__asm__ (".section " SECTION "," FLAGS "\n\t"				\
	 ".globl   " UNDERSCORE NAME "\n\t"				\
	 ".type    " UNDERSCORE NAME ",@object\n\t"			\
	 ".p2align  2\n"						\
	 UNDERSCORE NAME ":\n\t"					\
	 ".previous")

/* Beginning of .ctor/.dtor sections that provides a list of constructors and
   destructors to run.  */

INIT_SECTION_NEG_ONE (".ctors", "\"aw\"", "__CTOR_LIST__");
INIT_SECTION_NEG_ONE (".dtors", "\"aw\"", "__DTOR_LIST__");

/* Beginning of .eh_frame section that provides all of the exception handling
   tables.  */

INIT_SECTION (".eh_frame", "\"aw\"", "__EH_FRAME_BEGIN__");

/* Beginning of .rofixup section that provides a list of pointers that we
   need to adjust.  */

INIT_SECTION (".rofixup", "\"a\"", "__ROFIXUP_LIST__");

extern void __frv_register_eh(void) __attribute__((__constructor__));
extern void __frv_deregister_eh(void) __attribute__((__destructor__));

extern func_ptr __EH_FRAME_BEGIN__[];

/* Register the exeception handling table as the first constructor */
void
__frv_register_eh (void)
{
  static struct object object;
  if (__register_frame_info)
    __register_frame_info (__EH_FRAME_BEGIN__, &object);
}

/* Note, do not declare __{,de}register_frame_info weak as it seems
   to interfere with the pic support.  */

/* Unregister the exeception handling table as a deconstructor */
void
__frv_deregister_eh (void)
{
  static int completed = 0;

  if (completed)
    return;

  if (__deregister_frame_info)
    __deregister_frame_info (__EH_FRAME_BEGIN__);

  completed = 1;
}

/* Run the global destructors */
void
__do_global_dtors ()
{
  static func_ptr *p = __DTOR_LIST__ + 1;
  while (*p)
    {
      p++;
      (*(p-1)) ();
    }
}

/* Run the global constructors */
void
__do_global_ctors ()
{
  unsigned long nptrs = (unsigned long) __CTOR_LIST__[0];
  unsigned i;

  if (nptrs == (unsigned long)-1)
    for (nptrs = 0; __CTOR_LIST__[nptrs + 1] != 0; nptrs++);

  for (i = nptrs; i >= 1; i--)
    __CTOR_LIST__[i] ();

  atexit (__do_global_dtors);
}

/* Subroutine called automatically by `main'.
   Compiling a global function named `main'
   produces an automatic call to this function at the beginning.

   For many systems, this routine calls __do_global_ctors.
   For systems which support a .init section we use the .init section
   to run __do_global_ctors, so we need not do anything here.  */

void
__main ()
{
  /* Support recursive calls to `main': run initializers just once.  */
  static int initialized;
  if (! initialized)
    {
      initialized = 1;
      __do_global_ctors ();
    }
}