169 lines
5.0 KiB
C
169 lines
5.0 KiB
C
/* .init/.fini section handling + C++ global constructor/destructor handling.
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This file is based on crtstuff.c, sol2-crti.S, sol2-crtn.S.
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Copyright (C) 1996-2020 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Declare a pointer to void function type. */
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typedef void (*func_ptr) (void);
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#ifdef CRT_INIT
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/* NOTE: In order to be able to support SVR4 shared libraries, we arrange
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to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
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__DTOR_END__ } per root executable and also one set of these symbols
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per shared library. So in any given whole process image, we may have
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multiple definitions of each of these symbols. In order to prevent
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these definitions from conflicting with one another, and in order to
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ensure that the proper lists are used for the initialization/finalization
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of each individual shared library (respectively), we give these symbols
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only internal (i.e. `static') linkage, and we also make it a point to
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refer to only the __CTOR_END__ symbol in crtfini.o and the __DTOR_LIST__
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symbol in crtinit.o, where they are defined. */
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static func_ptr __CTOR_LIST__[1]
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__attribute__ ((used, section (".ctors")))
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= { (func_ptr) (-1) };
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static func_ptr __DTOR_LIST__[1]
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__attribute__ ((used, section (".dtors")))
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= { (func_ptr) (-1) };
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/* Run all the global destructors on exit from the program. */
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/* Some systems place the number of pointers in the first word of the
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table. On SVR4 however, that word is -1. In all cases, the table is
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null-terminated. On SVR4, we start from the beginning of the list and
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invoke each per-compilation-unit destructor routine in order
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until we find that null.
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Note that this function MUST be static. There will be one of these
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functions in each root executable and one in each shared library, but
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although they all have the same code, each one is unique in that it
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refers to one particular associated `__DTOR_LIST__' which belongs to the
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same particular root executable or shared library file. */
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static void __do_global_dtors (void)
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asm ("__do_global_dtors") __attribute__ ((used, section (".text")));
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static void
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__do_global_dtors (void)
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{
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func_ptr *p;
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for (p = __DTOR_LIST__ + 1; *p; p++)
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(*p) ();
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}
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/* .init section start.
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This must appear at the start of the .init section. */
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asm ("\n\
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.section .init,\"ax\",@progbits\n\
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.balign 4\n\
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.global __init\n\
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__init:\n\
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push fp\n\
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push lr\n\
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mv fp,sp\n\
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seth r0, #shigh(__fini)\n\
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add3 r0, r0, #low(__fini)\n\
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bl atexit\n\
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.fillinsn\n\
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");
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/* .fini section start.
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This must appear at the start of the .init section. */
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asm ("\n\
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.section .fini,\"ax\",@progbits\n\
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.balign 4\n\
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.global __fini\n\
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__fini:\n\
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push fp\n\
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push lr\n\
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mv fp,sp\n\
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bl __do_global_dtors\n\
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.fillinsn\n\
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");
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#endif /* CRT_INIT */
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#ifdef CRT_FINI
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/* Put a word containing zero at the end of each of our two lists of function
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addresses. Note that the words defined here go into the .ctors and .dtors
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sections of the crtend.o file, and since that file is always linked in
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last, these words naturally end up at the very ends of the two lists
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contained in these two sections. */
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static func_ptr __CTOR_END__[1]
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__attribute__ ((used, section (".ctors")))
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= { (func_ptr) 0 };
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static func_ptr __DTOR_END__[1]
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__attribute__ ((used, section (".dtors")))
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= { (func_ptr) 0 };
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/* Run all global constructors for the program.
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Note that they are run in reverse order. */
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static void __do_global_ctors (void)
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asm ("__do_global_ctors") __attribute__ ((used, section (".text")));
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static void
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__do_global_ctors (void)
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{
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func_ptr *p;
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for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
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(*p) ();
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}
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/* .init section end.
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This must live at the end of the .init section. */
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asm ("\n\
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.section .init,\"ax\",@progbits\n\
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bl __do_global_ctors\n\
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mv sp,fp\n\
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pop lr\n\
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pop fp\n\
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jmp lr\n\
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.fillinsn\n\
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");
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/* .fini section end.
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This must live at the end of the .fini section. */
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asm ("\n\
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.section .fini,\"ax\",@progbits\n\
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mv sp,fp\n\
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pop lr\n\
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pop fp\n\
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jmp lr\n\
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.fillinsn\n\
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");
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#endif /* CRT_FINI */
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