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1.1 ! root 1: /* Specialized bits of code needed to support construction and ! 2: destruction of file-scope objects in C++ code. ! 3: ! 4: Written by Ron Guilmette ([email protected]) with help from Richard Stallman. ! 5: ! 6: Copyright (C) 1991 Free Software Foundation, Inc. ! 7: ! 8: This file is part of GNU CC. ! 9: ! 10: GNU CC is free software; you can redistribute it and/or modify ! 11: it under the terms of the GNU General Public License as published by ! 12: the Free Software Foundation; either version 2, or (at your option) ! 13: any later version. ! 14: ! 15: GNU CC is distributed in the hope that it will be useful, ! 16: but WITHOUT ANY WARRANTY; without even the implied warranty of ! 17: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ! 18: GNU General Public License for more details. ! 19: ! 20: You should have received a copy of the GNU General Public License ! 21: along with GNU CC; see the file COPYING. If not, write to ! 22: the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ ! 23: ! 24: /* As a special exception, if you link this library with files ! 25: compiled with GCC to produce an executable, this does not cause ! 26: the resulting executable to be covered by the GNU General Public License. ! 27: This exception does not however invalidate any other reasons why ! 28: the executable file might be covered by the GNU General Public License. */ ! 29: ! 30: /* This file is a bit like libgcc1.c/libgcc2.c in that it is compiled ! 31: multiple times and yields multiple .o files. ! 32: ! 33: This file is useful on target machines where the object file format ! 34: supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE). On ! 35: such systems, this file allows us to avoid running collect (or any ! 36: other such slow and painful kludge). Additionally, if the target ! 37: system supports a .init section, this file allows us to support the ! 38: linking of C++ code with a non-C++ main program. ! 39: ! 40: Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then ! 41: this file *will* make use of the .init section. If that symbol is ! 42: not defined however, then the .init section will not be used. ! 43: ! 44: Currently, only ELF and COFF are supported. It is likely however that ! 45: ROSE could also be supported, if someone was willing to do the work to ! 46: make whatever (small?) adaptations are needed. (Some work may be ! 47: needed on the ROSE assembler and linker also.) ! 48: ! 49: This file must be compiled with gcc. */ ! 50: ! 51: /* It is incorrect to include config.h here, because this file is being ! 52: compiled for the target, and hence definitions concerning only the host ! 53: do not apply. */ ! 54: ! 55: #include "tm.h" ! 56: ! 57: #ifndef CTORS_SECTION_ASM_OP ! 58: #define CTORS_SECTION_ASM_OP ".section\t.ctors,\"a\",@progbits" ! 59: #endif ! 60: #ifndef DTORS_SECTION_ASM_OP ! 61: #define DTORS_SECTION_ASM_OP ".section\t.dtors,\"a\",@progbits" ! 62: #endif ! 63: ! 64: #include "gbl-ctors.h" ! 65: ! 66: #ifndef ON_EXIT ! 67: #define ON_EXIT(a, b) ! 68: #endif ! 69: ! 70: #ifdef CRT_BEGIN ! 71: ! 72: #ifdef INIT_SECTION_ASM_OP ! 73: ! 74: /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o ! 75: and once in crtend.o). It must be declared static to avoid a link ! 76: error. Here, we define __do_global_ctors as an externally callable ! 77: function. It is externally callable so that __main can invoke it when ! 78: INVOKE__main is defined. This has the additional effect of forcing cc1 ! 79: to switch to the .text section. */ ! 80: static void __do_global_ctors_aux (); ! 81: void __do_global_ctors () ! 82: { ! 83: #ifdef INVOKE__main /* If __main won't actually call __do_global_ctors ! 84: then it doesn't matter what's inside the function. ! 85: The inside of __do_global_ctors_aux is called ! 86: automatically in that case. ! 87: And the Alliant fx2800 linker crashes ! 88: on this reference. So prevent the crash. */ ! 89: __do_global_ctors_aux (); ! 90: #endif ! 91: } ! 92: ! 93: asm (INIT_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ ! 94: ! 95: /* On some svr4 systems, the .init section preamble code provided in ! 96: crti.o may do some evil things which we have to undo before we reach ! 97: the function prologue code for __do_global_ctors (directly below). ! 98: For such systems, define the macro INIT_SECTION_PREAMBLE to ! 99: expand into the code needed to undo the actions of the crti.o file. */ ! 100: ! 101: #ifdef INIT_SECTION_PREAMBLE ! 102: INIT_SECTION_PREAMBLE; ! 103: #endif ! 104: ! 105: /* A routine to invoke all of the global constructors upon entry to the ! 106: program. We put this into the .init section (for systems that have ! 107: such a thing) so that we can properly perform the construction of ! 108: file-scope static-storage C++ objects within shared libraries. */ ! 109: ! 110: static void ! 111: __do_global_ctors_aux () /* prologue goes in .init section */ ! 112: { ! 113: #ifdef FORCE_INIT_SECTION_ALIGN ! 114: FORCE_INIT_SECTION_ALIGN; /* Explicit align before switch to .text */ ! 115: #endif ! 116: asm (TEXT_SECTION_ASM_OP); /* don't put epilogue and body in .init */ ! 117: DO_GLOBAL_CTORS_BODY; ! 118: ON_EXIT (__do_global_dtors, 0); ! 119: } ! 120: ! 121: #endif /* defined(INIT_SECTION_ASM_OP) */ ! 122: ! 123: /* Force cc1 to switch to .data section. */ ! 124: static func_ptr force_to_data[0] = { }; ! 125: ! 126: /* The -1 is a flag to __do_global_[cd]tors ! 127: indicating that this table does not start with a count of elements. */ ! 128: #ifdef CTOR_LIST_BEGIN ! 129: CTOR_LIST_BEGIN; ! 130: #else ! 131: asm (CTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ ! 132: func_ptr __CTOR_LIST__[1] = { (func_ptr) (-1) }; ! 133: #endif ! 134: ! 135: #ifdef DTOR_LIST_BEGIN ! 136: DTOR_LIST_BEGIN; ! 137: #else ! 138: asm (DTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ ! 139: func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) }; ! 140: #endif ! 141: ! 142: #endif /* defined(CRT_BEGIN) */ ! 143: ! 144: #ifdef CRT_END ! 145: ! 146: #ifdef INIT_SECTION_ASM_OP ! 147: ! 148: /* A routine to invoke all of the global constructors upon entry to the ! 149: program. We put this into the .init section (for systems that have ! 150: such a thing) so that we can properly perform the construction of ! 151: file-scope static-storage C++ objects within shared libraries. ! 152: ! 153: This must be virtually identical to the one above so that we can ! 154: insure that the function prologue from the one above works correctly ! 155: with the epilogue from this one. (They will both go into the .init ! 156: section as the first and last things (respectively) that the linker ! 157: will put in that section.) ! 158: */ ! 159: ! 160: static void ! 161: __do_global_ctors_aux () /* prologue goes in .text section */ ! 162: { ! 163: asm (INIT_SECTION_ASM_OP); ! 164: DO_GLOBAL_CTORS_BODY; ! 165: ON_EXIT (__do_global_dtors, 0); ! 166: } /* epilogue and body go in .init section */ ! 167: ! 168: #endif /* defined(INIT_SECTION_ASM_OP) */ ! 169: ! 170: /* Force cc1 to switch to .data section. */ ! 171: static func_ptr force_to_data[0] = { }; ! 172: ! 173: #ifdef CTOR_LIST_END ! 174: CTOR_LIST_END; ! 175: #else ! 176: asm (CTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ ! 177: func_ptr __CTOR_END__[1] = { (func_ptr) 0 }; ! 178: #endif ! 179: ! 180: #ifdef DTOR_LIST_END ! 181: DTOR_LIST_END; ! 182: #else ! 183: asm (DTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ ! 184: func_ptr __DTOR_END__[1] = { (func_ptr) 0 }; ! 185: #endif ! 186: ! 187: #endif /* defined(CRT_END) */
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