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Re: [RFC] Provide crt[in].S for x86-64


On 02/08/2012 04:45 PM, Joseph S. Myers wrote:
> That #else case looks wrong, you still need to call the function 
> (directly) in the non-weak case, and the final addq and ret should only be 
> in the epilogue in crtn.S, not in crti.S, so that all the other functions 
> other objects contribute to the .init section are called.

Fixed.  Slightly tested on x86_64-redhat-linux.  Ok?

2012-02-09  Marek Polacek  <polacek@redhat.com>

	* sysdeps/x86_64/crti.S: New file.
	* sysdeps/x86_64/crtn.S: New file.
	* sysdeps/x86_64/elf/initfini.c: Remove file.

--- libc/sysdeps/x86_64/crtn.S.mp	2012-02-08 15:33:53.221898023 +0100
+++ libc/sysdeps/x86_64/crtn.S	2012-02-09 16:05:17.704562797 +0100
@@ -0,0 +1,47 @@
+/* Special .init and .fini section support for x86-64.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Marek Polacek <polacek@redhat.com>, 2012.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* crtn.S puts function epilogues in the .init and .fini sections
+   corresponding to the prologues in crti.S. */
+
+	.section .init,"ax",@progbits
+	addq $8, %rsp
+	ret
+
+	.section .fini,"ax",@progbits
+	addq $8, %rsp
+	ret
--- libc/sysdeps/x86_64/crti.S.mp	2012-02-08 15:33:49.198888609 +0100
+++ libc/sysdeps/x86_64/crti.S	2012-02-09 15:39:08.897691482 +0100
@@ -0,0 +1,82 @@
+/* Special .init and .fini section support for x86-64.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Marek Polacek <polacek@redhat.com>, 2012.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+/* crti.S 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 symbols _init and _fini are
+   magic and cause the linker to emit DT_INIT and DT_FINI.  */
+
+#include <libc-symbols.h>
+#include <sysdep.h>
+
+#ifndef PREINIT_FUNCTION
+# define PREINIT_FUNCTION __gmon_start__
+#endif
+
+#ifndef PREINIT_FUNCTION_WEAK
+# define PREINIT_FUNCTION_WEAK 1
+#endif
+
+#if PREINIT_FUNCTION_WEAK
+	weak_extern (PREINIT_FUNCTION)
+#else
+	.hidden PREINIT_FUNCTION
+#endif
+
+	.section .init,"ax",@progbits
+	.p2align 2
+	.globl _init
+	.type _init, @function
+_init:
+	/* Maintain 16-byte stack alignment for called functions.  */
+	subq $8, %rsp
+#if PREINIT_FUNCTION_WEAK
+	movq PREINIT_FUNCTION@GOTPCREL(%rip), %rax
+	testq %rax, %rax
+	je .Lno_weak_fn
+	call PREINIT_FUNCTION@PLT
+.Lno_weak_fn:
+#else
+	call PREINIT_FUNCTION
+#endif
+
+	.section .fini,"ax",@progbits
+	.p2align 2
+	.globl _fini
+	.type _fini, @function
+_fini:
+	subq $8, %rsp

	Marek


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