1 1.1 mrg /* crtbegin object for windows32 targets. 2 1.10 mrg Copyright (C) 2007-2022 Free Software Foundation, Inc. 3 1.1 mrg 4 1.1 mrg Contributed by Danny Smith <dannysmith (at) users.sourceforge.net> 5 1.1 mrg 6 1.1 mrg This file is part of GCC. 7 1.1 mrg 8 1.1 mrg GCC is free software; you can redistribute it and/or modify it under 9 1.1 mrg the terms of the GNU General Public License as published by the Free 10 1.1 mrg Software Foundation; either version 3, or (at your option) any later 11 1.1 mrg version. 12 1.1 mrg 13 1.1 mrg GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 1.1 mrg WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 1.1 mrg FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 1.1 mrg for more details. 17 1.1 mrg 18 1.1 mrg Under Section 7 of GPL version 3, you are granted additional 19 1.1 mrg permissions described in the GCC Runtime Library Exception, version 20 1.1 mrg 3.1, as published by the Free Software Foundation. 21 1.1 mrg 22 1.1 mrg You should have received a copy of the GNU General Public License and 23 1.1 mrg a copy of the GCC Runtime Library Exception along with this program; 24 1.1 mrg see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 25 1.1 mrg <http://www.gnu.org/licenses/>. */ 26 1.1 mrg 27 1.1 mrg /* Target machine header files require this define. */ 28 1.1 mrg #define IN_LIBGCC2 29 1.1 mrg 30 1.1 mrg #include "auto-host.h" 31 1.1 mrg #include "tconfig.h" 32 1.1 mrg #include "tsystem.h" 33 1.1 mrg #include "coretypes.h" 34 1.1 mrg #include "tm.h" 35 1.1 mrg #include "libgcc_tm.h" 36 1.1 mrg #include "unwind-dw2-fde.h" 37 1.1 mrg 38 1.1 mrg #define WIN32_LEAN_AND_MEAN 39 1.1 mrg #include <windows.h> 40 1.1 mrg 41 1.1 mrg #ifndef LIBGCC_SONAME 42 1.1 mrg #define LIBGCC_SONAME "libgcc_s.dll" 43 1.1 mrg #endif 44 1.1 mrg 45 1.3 mrg #if DWARF2_UNWIND_INFO 46 1.1 mrg /* Make the declarations weak. This is critical for 47 1.1 mrg _Jv_RegisterClasses because it lives in libgcj.a */ 48 1.3 mrg extern void __register_frame_info (__attribute__((unused)) const void *, 49 1.3 mrg __attribute__((unused)) struct object *) 50 1.1 mrg TARGET_ATTRIBUTE_WEAK; 51 1.3 mrg extern void *__deregister_frame_info (__attribute__((unused)) const void *) 52 1.1 mrg TARGET_ATTRIBUTE_WEAK; 53 1.3 mrg 54 1.3 mrg /* Work around for current cygwin32 build problems (Bug gas/16858). 55 1.3 mrg Compile weak default functions only for 64-bit systems, 56 1.3 mrg when absolutely necessary. */ 57 1.3 mrg #ifdef __x86_64__ 58 1.3 mrg TARGET_ATTRIBUTE_WEAK void 59 1.3 mrg __register_frame_info (__attribute__((unused)) const void *p, 60 1.3 mrg __attribute__((unused)) struct object *o) 61 1.3 mrg { 62 1.3 mrg } 63 1.3 mrg 64 1.3 mrg TARGET_ATTRIBUTE_WEAK void * 65 1.3 mrg __deregister_frame_info (__attribute__((unused)) const void *p) 66 1.3 mrg { 67 1.3 mrg return (void*) 0; 68 1.3 mrg } 69 1.3 mrg #endif 70 1.3 mrg #endif /* DWARF2_UNWIND_INFO */ 71 1.3 mrg 72 1.1 mrg #if defined(HAVE_LD_RO_RW_SECTION_MIXING) 73 1.1 mrg # define EH_FRAME_SECTION_CONST const 74 1.1 mrg #else 75 1.1 mrg # define EH_FRAME_SECTION_CONST 76 1.1 mrg #endif 77 1.1 mrg 78 1.1 mrg /* Stick a label at the beginning of the frame unwind info so we can 79 1.1 mrg register/deregister it with the exception handling library code. */ 80 1.1 mrg #if DWARF2_UNWIND_INFO 81 1.1 mrg static EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[] 82 1.3 mrg __attribute__((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4))) 83 1.1 mrg = { }; 84 1.1 mrg 85 1.1 mrg static struct object obj; 86 1.1 mrg 87 1.1 mrg /* Handle of libgcc's DLL reference. */ 88 1.1 mrg HANDLE hmod_libgcc; 89 1.3 mrg static void * (*deregister_frame_fn) (const void *) = NULL; 90 1.1 mrg #endif 91 1.1 mrg 92 1.3 mrg #ifdef __CYGWIN__ 93 1.3 mrg /* Declare the __dso_handle variable. It should have a unique value 94 1.3 mrg in every shared-object; in a main program its value is zero. The 95 1.3 mrg object should in any case be protected. This means the instance 96 1.3 mrg in one DSO or the main program is not used in another object. The 97 1.3 mrg dynamic linker takes care of this. */ 98 1.3 mrg 99 1.3 mrg #ifdef CRTSTUFFS_O 100 1.3 mrg extern void *__ImageBase; 101 1.3 mrg void *__dso_handle = &__ImageBase; 102 1.3 mrg #else 103 1.3 mrg void *__dso_handle = 0; 104 1.3 mrg #endif 105 1.3 mrg 106 1.3 mrg #endif /* __CYGWIN__ */ 107 1.3 mrg 108 1.3 mrg 109 1.1 mrg /* Pull in references from libgcc.a(unwind-dw2-fde.o) in the 110 1.1 mrg startfile. These are referenced by a ctor and dtor in crtend.o. */ 111 1.1 mrg extern void __gcc_register_frame (void); 112 1.1 mrg extern void __gcc_deregister_frame (void); 113 1.1 mrg 114 1.1 mrg void 115 1.1 mrg __gcc_register_frame (void) 116 1.1 mrg { 117 1.1 mrg #if DWARF2_UNWIND_INFO 118 1.1 mrg /* Weak undefined symbols won't be pulled in from dlls; hence 119 1.1 mrg we first test if the dll is already loaded and, if so, 120 1.1 mrg get the symbol's address at run-time. If the dll is not loaded, 121 1.1 mrg fallback to weak linkage to static archive. */ 122 1.1 mrg 123 1.1 mrg void (*register_frame_fn) (const void *, struct object *); 124 1.1 mrg HANDLE h = GetModuleHandle (LIBGCC_SONAME); 125 1.1 mrg 126 1.1 mrg if (h) 127 1.1 mrg { 128 1.1 mrg /* Increasing the load-count of LIBGCC_SONAME DLL. */ 129 1.1 mrg hmod_libgcc = LoadLibrary (LIBGCC_SONAME); 130 1.1 mrg register_frame_fn = (void (*) (const void *, struct object *)) 131 1.1 mrg GetProcAddress (h, "__register_frame_info"); 132 1.3 mrg deregister_frame_fn = (void* (*) (const void *)) 133 1.3 mrg GetProcAddress (h, "__deregister_frame_info"); 134 1.3 mrg } 135 1.3 mrg else 136 1.3 mrg { 137 1.3 mrg register_frame_fn = __register_frame_info; 138 1.3 mrg deregister_frame_fn = __deregister_frame_info; 139 1.1 mrg } 140 1.1 mrg if (register_frame_fn) 141 1.1 mrg register_frame_fn (__EH_FRAME_BEGIN__, &obj); 142 1.1 mrg #endif 143 1.1 mrg 144 1.3 mrg #if DEFAULT_USE_CXA_ATEXIT 145 1.3 mrg /* If we use the __cxa_atexit method to register C++ dtors 146 1.3 mrg at object construction, also use atexit to register eh frame 147 1.3 mrg info cleanup. */ 148 1.3 mrg atexit(__gcc_deregister_frame); 149 1.3 mrg #endif /* DEFAULT_USE_CXA_ATEXIT */ 150 1.1 mrg } 151 1.1 mrg 152 1.1 mrg void 153 1.1 mrg __gcc_deregister_frame (void) 154 1.1 mrg { 155 1.1 mrg #if DWARF2_UNWIND_INFO 156 1.1 mrg if (deregister_frame_fn) 157 1.1 mrg deregister_frame_fn (__EH_FRAME_BEGIN__); 158 1.1 mrg if (hmod_libgcc) 159 1.1 mrg FreeLibrary (hmod_libgcc); 160 1.1 mrg #endif 161 1.1 mrg } 162
Indexes created Sat Feb 28 05:31:39 UTC 2026