gcc/config/i386/cygming-crtbegin.c

   1 /* crtbegin object for windows32 targets.
   2    Copyright (C) 2007  Free Software Foundation, Inc.
   3
   4    Contributed by Danny Smith <dannysmith@users.sourceforge.net>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 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, but WITHOUT ANY
  23 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  24 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  25 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 the Free
  29 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  30 02111-1307, USA.  */
  31
  32 /* Target machine header files require this define. */
  33 #define IN_LIBGCC2
  34
  35 #include "auto-host.h"
  36 #include "tconfig.h"
  37 #include "tsystem.h"
  38 #include "coretypes.h"
  39 #include "tm.h"
  40 #include "unwind-dw2-fde.h"
  41
  42 #define WIN32_LEAN_AND_MEAN
  43 #include <windows.h>
  44
  45 #ifndef LIBGCC_SONAME
  46 #define LIBGCC_SONAME "libgcc_s.dll"
  47 #endif
  48
  49 #ifndef LIBGCJ_SONAME
  50 #define LIBGCJ_SONAME "libgcj_s.dll"
  51 #endif
  52
  53
  54 /* Make the declarations weak.  This is critical for
  55    _Jv_RegisterClasses because it lives in libgcj.a  */
  56 extern void __register_frame_info (const void *, struct object *)
  57                                    TARGET_ATTRIBUTE_WEAK;
  58 extern void *__deregister_frame_info (const void *)
  59                                       TARGET_ATTRIBUTE_WEAK;
  60 extern void _Jv_RegisterClasses (const void *) TARGET_ATTRIBUTE_WEAK;
  61
  62 #if defined(HAVE_LD_RO_RW_SECTION_MIXING)
  63 # define EH_FRAME_SECTION_CONST const
  64 #else
  65 # define EH_FRAME_SECTION_CONST
  66 #endif
  67
  68 /* Stick a label at the beginning of the frame unwind info so we can
  69    register/deregister it with the exception handling library code.  */
  70 #if DWARF2_UNWIND_INFO
  71 static EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
  72   __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
  73   = { };
  74
  75 static struct object obj;
  76 #endif
  77
  78 #if TARGET_USE_JCR_SECTION
  79 static void *__JCR_LIST__[]
  80   __attribute__ ((unused, section(JCR_SECTION_NAME), aligned(4)))
  81   = { };
  82 #endif
  83
  84 /* Pull in references from libgcc.a(unwind-dw2-fde.o) in the
  85    startfile. These are referenced by a ctor and dtor in crtend.o.  */
  86 extern void __gcc_register_frame (void);
  87 extern void __gcc_deregister_frame (void);
  88
  89 void
  90 __gcc_register_frame (void)
  91 {
  92 #if DWARF2_UNWIND_INFO
  93 /* Weak undefined symbols won't be pulled in from dlls; hence
  94    we first test if the dll is already loaded and, if so,
  95    get the symbol's address at run-time.  If the dll is not loaded,
  96    fallback to weak linkage to static archive.  */
  97
  98   void (*register_frame_fn) (const void *, struct object *);
  99   HANDLE h = GetModuleHandle (LIBGCC_SONAME);
 100   if (h)
 101     register_frame_fn = (void (*) (const void *, struct object *))
 102                         GetProcAddress (h, "__register_frame_info");
 103   else
 104     register_frame_fn = __register_frame_info;
 105   if (register_frame_fn)
 106      register_frame_fn (__EH_FRAME_BEGIN__, &obj);
 107 #endif
 108
 109 #if TARGET_USE_JCR_SECTION
 110   if (__JCR_LIST__[0])
 111     {
 112       void (*register_class_fn) (const void *);
 113       HANDLE h = GetModuleHandle (LIBGCJ_SONAME);
 114       if (h)
 115         register_class_fn = (void (*) (const void *))
 116                              GetProcAddress (h, "_Jv_RegisterClasses");
 117       else
 118         register_class_fn = _Jv_RegisterClasses;
 119
 120       if (register_class_fn)
 121         register_class_fn (__JCR_LIST__);
 122     }
 123 #endif
 124 }
 125
 126 void
 127 __gcc_deregister_frame (void)
 128 {
 129 #if DWARF2_UNWIND_INFO
 130   void *  (*deregister_frame_fn) (const void *);
 131   HANDLE h = GetModuleHandle (LIBGCC_SONAME);
 132   if (h)
 133     deregister_frame_fn = (void* (*) (const void *))
 134                           GetProcAddress (h, "__deregister_frame_info");
 135   else
 136     deregister_frame_fn = __deregister_frame_info;
 137   if (deregister_frame_fn)
 138      deregister_frame_fn (__EH_FRAME_BEGIN__);
 139 #endif
 140 }