gcc/ada/initialize.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                           I N I T I A L I Z E                            *
   6  *                                                                          *
   7  *                          C Implementation File                           *
   8  *                                                                          *
   9  *          Copyright (C) 1992-2005, Free Software Foundation, Inc.         *
  10  *                                                                          *
  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  12  * terms of the  GNU General Public License as published  by the Free Soft- *
  13  * ware  Foundation;  either version 2,  or (at your option) any later ver- *
  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  15  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License *
  17  * for  more details.  You should have  received  a copy of the GNU General *
  18  * Public License  distributed with GNAT;  see file COPYING.  If not, write *
  19  * to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, *
  20  * Boston, MA 02110-1301, USA.                                              *
  21  *                                                                          *
  22  * As a  special  exception,  if you  link  this file  with other  files to *
  23  * produce an executable,  this file does not by itself cause the resulting *
  24  * executable to be covered by the GNU General Public License. This except- *
  25  * ion does not  however invalidate  any other reasons  why the  executable *
  26  * file might be covered by the  GNU Public License.                        *
  27  *                                                                          *
  28  * GNAT was originally developed  by the GNAT team at  New York University. *
  29  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  30  *                                                                          *
  31  ****************************************************************************/
  32
  33 /*  This unit provides default implementation for __gnat_initialize ()
  34     which is called before the elaboration of the partition. It is provided
  35     in a separate file/object so that users can replace it easily.
  36     The default implementation should be null on most targets. */
  37
  38 /* The following include is here to meet the published VxWorks requirement
  39    that the __vxworks header appear before any other include. */
  40 #ifdef __vxworks
  41 #include "vxWorks.h"
  42 #endif
  43
  44 #ifdef IN_RTS
  45 #include "tconfig.h"
  46 #include "tsystem.h"
  47 #else
  48 #include "config.h"
  49 #include "system.h"
  50 #endif
  51
  52 #include "raise.h"
  53
  54 /******************************************/
  55 /* __gnat_initialize (NT-mingw32 Version) */
  56 /******************************************/
  57
  58 #if defined (__MINGW32__)
  59 #include <windows.h>
  60
  61 extern void __gnat_init_float (void);
  62 extern void __gnat_plist_init (void);
  63 extern void __gnat_install_SEH_handler (void *);
  64
  65 void
  66 __gnat_initialize (void *eh)
  67 {
  68    /* Initialize floating-point coprocessor. This call is needed because
  69       the MS libraries default to 64-bit precision instead of 80-bit
  70       precision, and we require the full precision for proper operation,
  71       given that we have set Max_Digits etc with this in mind */
  72    __gnat_init_float ();
  73
  74    /* Initialize a lock for a process handle list - see adaint.c for the
  75       implementation of __gnat_portable_no_block_spawn, __gnat_portable_wait */
  76    __gnat_plist_init();
  77
  78    /* Note that we do not activate this for the compiler itself to avoid a
  79       bootstrap path problem.  Older version of gnatbind will generate a call
  80       to __gnat_initialize() without argument. Therefore we cannot use eh in
  81       this case.  It will be possible to remove the following #ifdef at some
  82       point.  */
  83 #ifdef IN_RTS
  84    /* Install the Structured Exception handler.  */
  85    if (eh)
  86      __gnat_install_SEH_handler (eh);
  87 #endif
  88 }
  89
  90 /******************************************/
  91 /* __gnat_initialize (init_float version) */
  92 /******************************************/
  93
  94 #elif defined (__INTERIX) || defined (__Lynx__) || \
  95       defined (__FreeBSD__) || defined(__NetBSD__)
  96
  97 extern void __gnat_init_float (void);
  98
  99 void
 100 __gnat_initialize (void *eh ATTRIBUTE_UNUSED)
 101 {
 102    __gnat_init_float ();
 103 }
 104
 105 /***************************************/
 106 /* __gnat_initialize (VxWorks Version) */
 107 /***************************************/
 108
 109 #elif defined(__vxworks)
 110
 111 extern void __gnat_init_float (void);
 112
 113 void
 114 __gnat_initialize (void *eh)
 115 {
 116   __gnat_init_float ();
 117
 118   /* On targets where we might be using the ZCX scheme, we need to register
 119      the frame tables.
 120
 121      For applications loaded as a set of "modules", the crtstuff objects
 122      linked in (crtbegin/end) are tailored to provide this service a-la C++
 123      constructor fashion, typically triggered by the VxWorks loader.  This is
 124      achieved by way of a special variable declaration in the crt object, the
 125      name of which has been deduced by analyzing the output of the "munching"
 126      step documented for C++.  The de-registration is handled symetrically,
 127      a-la C++ destructor fashion and typically triggered by the dynamic
 128      unloader.  Note that since the tables shall be registered against a
 129      common datastructure, libgcc should be one of the modules (vs beeing
 130      partially linked against all the others at build time) and shall be
 131      loaded first.
 132
 133      For applications linked with the kernel, the scheme above would lead to
 134      duplicated symbols because the VxWorks kernel build "munches" by default.
 135      To prevent those conflicts, we link against crtbegin/endS objects that
 136      don't include the special variable and directly call the appropriate
 137      function here. We'll never unload that, so there is no de-registration to
 138      worry about.
 139
 140      For whole applications loaded as a single module, we may use one scheme
 141      or the other, except for the mixed Ada/C++ case in which the first scheme
 142      would fail for the same reason as in the linked-with-kernel situation.
 143
 144      We can differentiate by looking at the __module_has_ctors value provided
 145      by each class of crt objects. As of today, selecting the crt set with the
 146      ctors/dtors capabilities (first scheme above) is triggered by adding
 147      "-dynamic" to the gcc *link* command line options. Selecting the other
 148      set of crt objects is achieved by "-static" instead.
 149
 150      This is a first approach, tightly synchronized with a number of GCC
 151      configuration and crtstuff changes. We need to ensure that those changes
 152      are there to activate this circuitry.  */
 153
 154 #if (__GNUC__ >= 3) && (defined (_ARCH_PPC) || defined (__ppc))
 155  {
 156    /* The scheme described above is only useful for the actual ZCX case, and
 157       we don't want any reference to the crt provided symbols otherwise.  We
 158       may not link with any of the crt objects in the non-ZCX case, e.g. from
 159       documented procedures instructing the use of -nostdlib, and references
 160       to the ctors symbols here would just remain unsatisfied.
 161
 162       We have no way to avoid those references in the right conditions in this
 163       C module, because we have nothing like a IN_ZCX_RTS macro.  This aspect
 164       is then deferred to an Ada routine, which can do that based on a test
 165       against a constant System flag value.  */
 166
 167    extern void __gnat_vxw_setup_for_eh (void);
 168    __gnat_vxw_setup_for_eh ();
 169  }
 170 #endif
 171 }
 172
 173 #else
 174
 175 /* For all other versions of GNAT, the initialize routine and handler
 176    installation do nothing */
 177
 178 /***************************************/
 179 /* __gnat_initialize (Default Version) */
 180 /***************************************/
 181
 182 void
 183 __gnat_initialize (void *eh ATTRIBUTE_UNUSED)
 184 {
 185 }
 186
 187 #endif