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) 1992-2007, Free Software Foundation, Inc.         *
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  11  * GNAT is free software;  you can  redistribute it  and/or modify it under *
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  14  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
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  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 *
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  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_install_SEH_handler (void *);
  63
  64 #ifndef RTX
  65 /* Do not define for RTX since it is only used for creating child processes
  66    which is not supported in RTX. */
  67 extern void __gnat_plist_init (void);
  68 #endif
  69
  70 void
  71 __gnat_initialize (void *eh)
  72 {
  73    /* Initialize floating-point coprocessor. This call is needed because
  74       the MS libraries default to 64-bit precision instead of 80-bit
  75       precision, and we require the full precision for proper operation,
  76       given that we have set Max_Digits etc with this in mind */
  77    __gnat_init_float ();
  78
  79 #ifndef RTX
  80    /* Initialize a lock for a process handle list - see adaint.c for the
  81       implementation of __gnat_portable_no_block_spawn, __gnat_portable_wait */
  82    __gnat_plist_init();
  83 #endif
  84
  85    /* Note that we do not activate this for the compiler itself to avoid a
  86       bootstrap path problem.  Older version of gnatbind will generate a call
  87       to __gnat_initialize() without argument. Therefore we cannot use eh in
  88       this case.  It will be possible to remove the following #ifdef at some
  89       point.  */
  90 #ifdef IN_RTS
  91    /* Install the Structured Exception handler.  */
  92    if (eh)
  93      __gnat_install_SEH_handler (eh);
  94 #endif
  95 }
  96
  97 /******************************************/
  98 /* __gnat_initialize (init_float version) */
  99 /******************************************/
 100
 101 #elif defined (__Lynx__) || defined (__FreeBSD__) || defined(__NetBSD__) \
 102   || defined (__OpenBSD__)
 103
 104 extern void __gnat_init_float (void);
 105
 106 void
 107 __gnat_initialize (void *eh ATTRIBUTE_UNUSED)
 108 {
 109    __gnat_init_float ();
 110 }
 111
 112 /***************************************/
 113 /* __gnat_initialize (VxWorks Version) */
 114 /***************************************/
 115
 116 #elif defined(__vxworks)
 117
 118 extern void __gnat_init_float (void);
 119
 120 void
 121 __gnat_initialize (void *eh)
 122 {
 123   __gnat_init_float ();
 124
 125   /* On targets where we use the ZCX scheme, we need to register the frame
 126      tables at load/startup time.
 127
 128      For applications loaded as a set of "modules", the crtstuff objects
 129      linked in (crtbegin.o/end.o) are tailored to provide this service
 130      automatically, a-la C++ constructor fashion, triggered by the VxWorks
 131      loader thanks to a special variable declaration in crtbegin.o (_ctors).
 132
 133      Automatic de-registration is handled symmetrically, a-la C++ destructor
 134      fashion (with a _dtors variable also in crtbegin.o) triggered by the
 135      dynamic unloader.
 136
 137      Note that since the tables shall be registered against a common
 138      datastructure, libgcc should be one of the modules (vs being partially
 139      linked against all the others at build time) and shall be loaded first.
 140
 141      For applications linked with the kernel, the scheme above would lead to
 142      duplicated symbols because the VxWorks kernel build "munches" by default,
 143      so we link against crtbeginT.o instead of crtbegin.o, which doesn't
 144      include the special variables. We know which set of crt objects is used
 145      thanks to a boolean indicator present in both sets (__module_has_ctors),
 146      and directly call the appropriate function here in the not-automatic
 147      case. We'll never unload that, so there is no de-registration to worry
 148      about.
 149
 150      For whole applications loaded as a single module, we may use one scheme
 151      or the other, except for the mixed Ada/C++ case in which the first scheme
 152      would fail for the same reason as in the linked-with-kernel situation.
 153
 154      Selecting the crt set with the ctors/dtors capabilities (first scheme
 155      above) is triggered by adding "-dynamic" to the gcc *link* command line
 156      options. Selecting the other set is achieved by using "-static" instead.
 157
 158      This is a first approach, tightly synchronized with a number of GCC
 159      configuration and crtstuff changes. We need to ensure that those changes
 160      are there to activate this circuitry.  */
 161
 162 #if (__GNUC__ >= 3) && (defined (_ARCH_PPC) || defined (__ppc))
 163  {
 164    /* The scheme described above is only useful for the actual ZCX case, and
 165       we don't want any reference to the crt provided symbols otherwise.  We
 166       may not link with any of the crt objects in the non-ZCX case, e.g. from
 167       documented procedures instructing the use of -nostdlib, and references
 168       to the ctors symbols here would just remain unsatisfied.
 169
 170       We have no way to avoid those references in the right conditions in this
 171       C module, because we have nothing like a IN_ZCX_RTS macro.  This aspect
 172       is then deferred to an Ada routine, which can do that based on a test
 173       against a constant System flag value.  */
 174
 175    extern void __gnat_vxw_setup_for_eh (void);
 176    __gnat_vxw_setup_for_eh ();
 177  }
 178 #endif
 179 }
 180
 181 #elif defined(_T_HPUX10) || (!defined(IN_RTS) && defined(_X_HPUX10))
 182
 183 /************************************************/
 184 /* __gnat_initialize (PA-RISC HP-UX 10 Version) */
 185 /************************************************/
 186
 187 extern void __main (void);
 188
 189 void
 190 __gnat_initialize (void *eh ATTRIBUTE_UNUSED)
 191 {
 192   __main ();
 193 }
 194
 195 #else
 196
 197 /* For all other versions of GNAT, the initialize routine and handler
 198    installation do nothing */
 199
 200 /***************************************/
 201 /* __gnat_initialize (Default Version) */
 202 /***************************************/
 203
 204 void
 205 __gnat_initialize (void *eh ATTRIBUTE_UNUSED)
 206 {
 207 }
 208
 209 #endif