Add sysdeps/init_array to produce empty crt[in].o and use .preinit_array for gcrt1.o

This commit is contained in:
Roland McGrath 2013-03-12 12:47:36 -07:00
parent e6b5a29364
commit 9967e003b3
7 changed files with 131 additions and 0 deletions

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@ -1,3 +1,16 @@
2013-03-12 Roland McGrath <roland@hack.frob.com>
* sysdeps/init_array/elf-init.c: New file.
* csu/elf-init.c
(__libc_csu_init) [!NO_INITFINI]: Conditionalize _init call on this.
(__libc_csu_fini) [!NO_INITFINI]: Conditionalize _fini call on this.
* csu/gmon-start.c [GMON_START_ARRAY_SECTION]: Don't define
__gmon_start__ as global, but as static with a .preinit_array pointer.
* sysdeps/init_array/gmon-start.c: New file. Use that.
* sysdeps/init_array/crti.S: New file, empty except for comments.
* sysdeps/init_array/crtn.S: Likewise.
2013-03-11 Ondřej Bílka <neleai@seznam.cz>
* sysdeps/x86_64/memset.S: Remove USE_MULTIARCH conditional for

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@ -49,10 +49,13 @@ extern void (*__fini_array_start []) (void) attribute_hidden;
extern void (*__fini_array_end []) (void) attribute_hidden;
#ifndef NO_INITFINI
/* These function symbols are provided for the .init/.fini section entry
points automagically by the linker. */
extern void _init (void);
extern void _fini (void);
#endif
/* These functions are passed to __libc_start_main by the startup code.
These get statically linked into each program. For dynamically linked
@ -76,7 +79,9 @@ __libc_csu_init (int argc, char **argv, char **envp)
}
#endif
#ifndef NO_INITFINI
_init ();
#endif
const size_t size = __init_array_end - __init_array_start;
for (size_t i = 0; i < size; i++)
@ -94,6 +99,8 @@ __libc_csu_fini (void)
while (i-- > 0)
(*__fini_array_start [i]) ();
# ifndef NO_INITFINI
_fini ();
# endif
#endif
}

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@ -59,10 +59,17 @@ extern char etext[];
# endif
#endif
#ifdef GMON_START_ARRAY_SECTION
static void __gmon_start__ (void);
static void (*const gmon_start_initializer) (void)
__attribute__ ((used, section (GMON_START_ARRAY_SECTION))) = &__gmon_start__;
static
#else
/* We cannot use the normal constructor mechanism to call
__gmon_start__ because gcrt1.o appears before crtbegin.o in the link.
Instead crti.o calls it specially. */
extern void __gmon_start__ (void);
#endif
void
__gmon_start__ (void)

13
sysdeps/init_array/crti.S Normal file
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@ -0,0 +1,13 @@
/* Dummy crti file.
In this configuration, crti.o and crtn.o are both empty because the
.init_array/.fini_array sections are used exclusively.
Older ports cannot use this because even if the linker used to
build libc itself has .init_array support, we don't want to produce
a crt[in].o that presume a linker that new will be used to link
other things later.
But new configurations without compatibility concerns for
toolchains without .init_array support can use this to avoid the
superfluous .init and .fini boilerplate code. */

13
sysdeps/init_array/crtn.S Normal file
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@ -0,0 +1,13 @@
/* Dummy crtn file.
In this configuration, crti.o and crtn.o are both empty because the
.init_array/.fini_array sections are used exclusively.
Older ports cannot use this because even if the linker used to
build libc itself has .init_array support, we don't want to produce
a crt[in].o that presume a linker that new will be used to link
other things later.
But new configurations without compatibility concerns for
toolchains without .init_array support can use this to avoid the
superfluous .init and .fini boilerplate code. */

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@ -0,0 +1,37 @@
/* Startup support for ELF initializers/finalizers in the main executable.
Copyright (C) 2013 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#define NO_INITFINI
#include <csu/elf-init.c>

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@ -0,0 +1,41 @@
/* gmon startup hook using .preinit_array.
Copyright (C) 2013 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/* Instead of defining __gmon_start__ globally in gcrt1.o, we make it
static and just put a pointer to it into the .preinit_array section. */
#define GMON_START_ARRAY_SECTION ".preinit_array"
#include <csu/gmon-start.c>