gcc/config/arc/initfini.c

   1 /* .init/.fini section handling + C++ global constructor/destructor handling.
   2    This file is based on crtstuff.c, sol2-crti.asm, sol2-crtn.asm.
   3
   4 Copyright (C) 1995, 1997, 1998 Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 In addition to the permissions in the GNU General Public License, the
  14 Free Software Foundation gives you unlimited permission to link the
  15 compiled version of this file into combinations with other programs,
  16 and to distribute those combinations without any restriction coming
  17 from the use of this file.  (The General Public License restrictions
  18 do apply in other respects; for example, they cover modification of
  19 the file, and distribution when not linked into a combine
  20 executable.)
  21
  22 GCC is distributed in the hope that it will be useful,
  23 but WITHOUT ANY WARRANTY; without even the implied warranty of
  24 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25 GNU General Public License for more details.
  26
  27 You should have received a copy of the GNU General Public License
  28 along with GCC; see the file COPYING.  If not, write to
  29 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  30 Boston, MA 02110-1301, USA.  */
  31
  32 /*  Declare a pointer to void function type.  */
  33 typedef void (*func_ptr) (void);
  34
  35 #ifdef CRT_INIT
  36
  37 /* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
  38    to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
  39    __DTOR_END__ } per root executable and also one set of these symbols
  40    per shared library.  So in any given whole process image, we may have
  41    multiple definitions of each of these symbols.  In order to prevent
  42    these definitions from conflicting with one another, and in order to
  43    ensure that the proper lists are used for the initialization/finalization
  44    of each individual shared library (respectively), we give these symbols
  45    only internal (i.e. `static') linkage, and we also make it a point to
  46    refer to only the __CTOR_END__ symbol in crtfini.o and the __DTOR_LIST__
  47    symbol in crtinit.o, where they are defined.  */
  48
  49 static func_ptr __CTOR_LIST__[1] __attribute__ ((section (".ctors")))
  50      = { (func_ptr) (-1) };
  51
  52 static func_ptr __DTOR_LIST__[1] __attribute__ ((section (".dtors")))
  53      = { (func_ptr) (-1) };
  54
  55 /* Run all the global destructors on exit from the program.  */
  56
  57 /* Some systems place the number of pointers in the first word of the
  58    table.  On SVR4 however, that word is -1.  In all cases, the table is
  59    null-terminated.  On SVR4, we start from the beginning of the list and
  60    invoke each per-compilation-unit destructor routine in order
  61    until we find that null.
  62
  63    Note that this function MUST be static.  There will be one of these
  64    functions in each root executable and one in each shared library, but
  65    although they all have the same code, each one is unique in that it
  66    refers to one particular associated `__DTOR_LIST__' which belongs to the
  67    same particular root executable or shared library file.  */
  68
  69 static void __do_global_dtors (void)
  70 asm ("__do_global_dtors") __attribute__ ((section (".text")));
  71
  72 static void
  73 __do_global_dtors (void)
  74 {
  75   func_ptr *p;
  76   for (p = __DTOR_LIST__ + 1; *p; p++)
  77     (*p) ();
  78 }
  79
  80 /* .init section start.
  81    This must appear at the start of the .init section.  */
  82
  83 asm ("\n\
  84         .section .init\n\
  85         .global init\n\
  86         .word 0\n\
  87 init:\n\
  88         st blink,[sp,4]\n\
  89         st fp,[sp]\n\
  90         mov fp,sp\n\
  91         sub sp,sp,16\n\
  92 ");
  93
  94 /* .fini section start.
  95    This must appear at the start of the .init section.  */
  96
  97 asm ("\n\
  98         .section .fini\n\
  99         .global fini\n\
 100         .word 0\n\
 101 fini:\n\
 102         st blink,[sp,4]\n\
 103         st fp,[sp]\n\
 104         mov fp,sp\n\
 105         sub sp,sp,16\n\
 106         bl.nd __do_global_dtors\n\
 107 ");
 108
 109 #endif /* CRT_INIT */
 110
 111 #ifdef CRT_FINI
 112
 113 /* Put a word containing zero at the end of each of our two lists of function
 114    addresses.  Note that the words defined here go into the .ctors and .dtors
 115    sections of the crtend.o file, and since that file is always linked in
 116    last, these words naturally end up at the very ends of the two lists
 117    contained in these two sections.  */
 118
 119 static func_ptr __CTOR_END__[1] __attribute__ ((section (".ctors")))
 120      = { (func_ptr) 0 };
 121
 122 static func_ptr __DTOR_END__[1] __attribute__ ((section (".dtors")))
 123      = { (func_ptr) 0 };
 124
 125 /* Run all global constructors for the program.
 126    Note that they are run in reverse order.  */
 127
 128 static void __do_global_ctors (void)
 129 asm ("__do_global_ctors") __attribute__ ((section (".text")));
 130
 131 static void
 132 __do_global_ctors (void)
 133 {
 134   func_ptr *p;
 135   for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
 136     (*p) ();
 137 }
 138
 139 /* .init section end.
 140    This must live at the end of the .init section.  */
 141
 142 asm ("\n\
 143         .section .init\n\
 144         bl.nd __do_global_ctors\n\
 145         ld blink,[fp,4]\n\
 146         j.d blink\n\
 147         ld.a fp,[sp,16]\n\
 148 ");
 149
 150 /* .fini section end.
 151    This must live at the end of the .fini section.  */
 152
 153 asm ("\n\
 154         .section .fini\n\
 155         ld blink,[fp,4]\n\
 156         j.d blink\n\
 157         ld.a fp,[sp,16]\n\
 158 ");
 159
 160 #endif /* CRT_FINI */