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/* Special .init and .fini section support.
Copyright (C) 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* This file is compiled into assembly code which is then surrounded by the
lines `cat > crtcommon.tmp <<\EOF_common' and `EOF_common' and thus
becomes a shell script which creates three files of assembly code.
* The first file is crti.s-new; this puts a function prologue at the
beginning of the .init and .fini sections and defines global symbols for
those addresses, so they can be called as functions.
* The second file is crtn.s-new; this puts the corresponding function
epilogues in the .init and .fini sections.
* The third file is crtcommon.tmp, which is whatever miscellaneous cruft
the compiler generated at the end; it should be appended to both crti.s-new
and crtn.s-new. */
#include <stdlib.h>
#ifdef HAVE_ELF
/* These declarations make the functions go in the right sections when
we define them below. GCC syntax does not allow the attribute
specifications to be in the function definitions themselves. */
void _init (void) __attribute__ ((section (".init")));
void _fini (void) __attribute__ ((section (".fini")));
#define SECTION(x) /* Put nothing extra before the defn. */
#else
/* Some non-ELF systems support .init and .fini sections,
but the __attribute__ syntax only works for ELF. */
#define SECTION(x) asm (".section " x);
#endif
/* End the here document containing the initial common code.
Then move the output file crtcommon.tmp to crti.s-new and crtn.s-new. */
asm ("\nEOF_common\n\
rm -f crti.s-new crtn.s-new\n\
mv crtcommon.tmp crti.s-new\n\
cp crti.s-new crtn.s-new");
/* Extract a `.end' if one is produced by the compiler. */
asm ("fgrep .end >/dev/null 2>&1 <<\\EOF.end && need_end=yes");
void
useless_function (void)
{
return;
}
asm ("\nEOF.end\n");
/* Find out how much alignment is produced by the compiler. */
asm ("align=`awk '$1==\".align\" { if ($2>max) max=$2; } END { print max; }' \
<<\\EOF.align");
void
useless_function2 (void (*foo) (void))
{
if (foo)
(*foo) ();
}
asm ("\nEOF.align\n`\n");
/* Append the .init prologue to crti.s-new. */
asm ("cat >> crti.s-new <<\\EOF.crti.init");
SECTION (".init")
void
_init (void)
{
/* We cannot use the normal constructor mechanism in gcrt1.o because it
appears before crtbegin.o in the link, so the header elt of .ctors
would come after the elt for __gmon_start__. One approach is for
gcrt1.o to reference a symbol which would be defined by some library
module which has a constructor; but then user code's constructors
would come first, and not be profiled. */
extern void __gmon_start__ (void); weak_extern (__gmon_start__)
if (__gmon_start__)
__gmon_start__ ();
/* End the here document containing the .init prologue code.
Then fetch the .section directive just written and append that
to crtn.s-new, followed by the function epilogue. */
asm ("\n\
EOF.crti.init\n\
test -n \"$align\" && echo .align $align >> crti.s-new\n\
test -n \"$need_end\" && echo .end _init >> crti.s-new\n\
fgrep .init crti.s-new >>crtn.s-new\n\
fgrep -v .end >> crtn.s-new <<\\EOF.crtn.init");
}
/* End the here document containing the .init epilogue code.
Then append the .fini prologue to crti.s-new. */
asm ("\nEOF.crtn.init\
\n\
cat >> crti.s-new <<\\EOF.crti.fini");
/* Global variable which says whether we have a statically or dynamically
linked program. If > 0, static, for < 0 dynamic, == 0 means yet to
be determined (see init-first.c). */
int __libc_is_static = 0;
SECTION (".fini")
void
_fini (void)
{
/* End the here document containing the .fini prologue code.
Then fetch the .section directive just written and append that
to crtn.s-new, followed by the function epilogue. */
asm ("\nEOF.crti.fini\n\
test -n \"$align\" && echo .align $align >> crti.s-new\n\
test -n \"$need_end\" && echo .end _fini >> crti.s-new\n\
cat > /dev/null <<\\EOF.fini.skip");
{
/* Let GCC know that _fini is not a leaf function by having a dummy
function call here. We arrange for this call to be omitted from
either crt file. */
extern void i_am_not_a_leaf (void);
i_am_not_a_leaf ();
}
asm ("\nEOF.fini.skip\
\n\
fgrep .fini crti.s-new >>crtn.s-new\n\
fgrep -v .end >> crtn.s-new <<\\EOF.crtn.fini");
}
/* End the here document containing the .fini epilogue code.
Finally, put the remainder of the generated assembly into crtcommon.tmp. */
asm ("\nEOF.crtn.fini\
\n\
cat > crtcommon.tmp <<\\EOF_common");
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