140 lines
4.6 KiB
C
140 lines
4.6 KiB
C
/* Special .init and .fini section support.
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Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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In addition to the permissions in the GNU Lesser General Public
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License, the Free Software Foundation gives you unlimited
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permission to link the compiled version of this file with other
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programs, and to distribute those programs without any restriction
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coming from the use of this file. (The GNU Lesser General Public
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License restrictions do apply in other respects; for example, they
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cover modification of the file, and distribution when not linked
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into another program.)
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Note that people who make modified versions of this file are not
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obligated to grant this special exception for their modified
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versions; it is their choice whether to do so. The GNU Lesser
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General Public License gives permission to release a modified
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version without this exception; this exception also makes it
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possible to release a modified version which carries forward this
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exception.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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/* This file is compiled into assembly code which is then munged by a sed
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script into two files: crti.s and crtn.s.
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* crti.s puts a function prologue at the beginning of the
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.init and .fini sections and defines global symbols for
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those addresses, so they can be called as functions.
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* crtn.s puts the corresponding function epilogues
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in the .init and .fini sections. */
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#include <stdlib.h>
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/* We use embedded asm for .section unconditionally, as this makes it
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easier to insert the necessary directives into crtn.S. */
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#define SECTION(x) asm (".section " x )
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/* Embed an #include to pull in the alignment and .end directives. */
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asm ("\n#include \"defs.h\"");
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/* The initial common code ends here. */
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asm ("\n/*@HEADER_ENDS*/");
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/* To determine whether we need .end and .align: */
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asm ("\n/*@TESTS_BEGIN*/");
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extern void dummy (void (*foo) (void));
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void
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dummy (void (*foo) (void))
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{
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if (foo)
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(*foo) ();
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}
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asm ("\n/*@TESTS_END*/");
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/* The beginning of _init: */
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asm ("\n/*@_init_PROLOG_BEGINS*/");
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static void
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call_gmon_start(void)
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{
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extern void __gmon_start__ (void) __attribute__ ((weak)); /*weak_extern (__gmon_start__);*/
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void (*gmon_start) (void) = __gmon_start__;
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if (gmon_start)
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gmon_start ();
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}
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SECTION (".init");
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extern void __attribute__ ((section (".init"))) _init (void);
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void
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_init (void)
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{
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/* We cannot use the normal constructor mechanism in gcrt1.o because it
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appears before crtbegin.o in the link, so the header elt of .ctors
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would come after the elt for __gmon_start__. One approach is for
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gcrt1.o to reference a symbol which would be defined by some library
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module which has a constructor; but then user code's constructors
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would come first, and not be profiled. */
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call_gmon_start ();
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asm ("ALIGN");
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asm("END_INIT");
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/* Now the epilog. */
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asm ("\n/*@_init_PROLOG_ENDS*/");
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asm ("\n/*@_init_EPILOG_BEGINS*/");
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SECTION(".init");
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}
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asm ("END_INIT");
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/* End of the _init epilog, beginning of the _fini prolog. */
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asm ("\n/*@_init_EPILOG_ENDS*/");
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asm ("\n/*@_fini_PROLOG_BEGINS*/");
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SECTION (".fini");
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extern void __attribute__ ((section (".fini"))) _fini (void);
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void
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_fini (void)
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{
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/* End of the _fini prolog. */
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asm ("ALIGN");
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asm ("END_FINI");
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asm ("\n/*@_fini_PROLOG_ENDS*/");
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{
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/* Let GCC know that _fini is not a leaf function by having a dummy
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function call here. We arrange for this call to be omitted from
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either crt file. */
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extern void i_am_not_a_leaf (void);
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i_am_not_a_leaf ();
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}
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/* Beginning of the _fini epilog. */
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asm ("\n/*@_fini_EPILOG_BEGINS*/");
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SECTION (".fini");
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}
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asm ("END_FINI");
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/* End of the _fini epilog. Any further generated assembly (e.g. .ident)
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is shared between both crt files. */
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asm ("\n/*@_fini_EPILOG_ENDS*/");
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asm ("\n/*@TRAILER_BEGINS*/");
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/* End of file. */
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