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Re: Fix build with compiler defining __i686 (bug 411)


On Fri, 3 Feb 2012, Roland McGrath wrote:

> > I don't think the changes to initfini files regarding __i686 are any 
> > stranger than the existing arrangements.
> 
> It's just that it's piling on to what's already more than strange enough.
> I suspect we can in short order settle on cleanup to make a plain crt[in].S
> per machine, with minimal macroization such that pt-crt[in].S is a generic
> one #include'ing crt[in].S with macros defined so as to unconditionally
> call __pthread_initialize_minimal_internal rather than to conditionally
> call __gmon_start.

This patch adds support for building the crt files from
{pt-,}crt[in].S in sysdeps directories.  The existing makefile rules
are kept to support unconverted targets and to provide a way to
generate a starting point for those files for target maintainers to
clean up, test and check in (csu/crt[in].S and nptl/crt[in].S in the
object directory are that starting point).  Copyright/license notices
are taken from the existing initfini source files.

Tested on x86, also tested with just the makefile changes to verify
that in that case the objects build OK with the old rules and with no
changes in shared library disassembly.

(Presume that if this goes in I'll send a separate message to draw the
attention of architecture maintainers to this new mechanism that is
preferred for implementing this code, describing how to do the
conversion for a target.)

2012-02-05  Joseph Myers  <joseph@codesourcery.com>

	* csu/Makefile: Support crti.S and crtn.S in source directory.
	* sysdeps/i386/crti.S, sysdeps/i386/crtn.S: New.  Based on
	compiler output for sysdeps/generic/initfini.c.

nptl:
2012-02-05  Joseph Myers  <joseph@codesourcery.com>

	* Makefile: Support pt-crti.S and pt-crtn.S in source directory.
	* sysdeps/unix/sysv/linux/i386/pt-crti.S,
	sysdeps/unix/sysv/linux/i386/pt-crtn.S: New.  Based on compiler
	output for sysdeps/pthread/initfini.c.

diff --git a/csu/Makefile b/csu/Makefile
index 601264d..9f05c51 100644
--- a/csu/Makefile
+++ b/csu/Makefile
@@ -84,6 +84,17 @@ crtstuff = crti crtn
 
 install-lib += $(crtstuff:=.o)
 extra-objs += $(crtstuff:=.o)
+
+ifneq (,$(wildcard $(sysdirs:%=%/crti.S)))
+
+vpath crti.S $(sysdirs)
+vpath crtn.S $(sysdirs)
+
+CFLAGS-crti.S = -g0
+CFLAGS-crtn.S = -g0
+
+else
+
 generated += $(crtstuff:=.S) initfini.s defs.h
 omit-deps += $(crtstuff)
 
@@ -122,6 +133,8 @@ $(objpfx)defs.h: $(objpfx)initfini.s
 
 endif
 
+endif
+
 extra-objs += abi-note.o init.o
 asm-CPPFLAGS += -I$(objpfx).
 
diff --git a/nptl/Makefile b/nptl/Makefile
index 0c317b0..e7c0efb 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -335,15 +335,19 @@ ifneq (,$(patsubst .,,$(multidir)))
 generated-dirs := $(firstword $(subst /, , $(multidir)))
 crti-objs += $(multidir)/crti.o
 crtn-objs += $(multidir)/crtn.o
+ifeq (,$(wildcard $(sysdirs:%=%/pt-crti.S)))
 omit-deps += $(multidir)/crti $(multidir)/crtn
+endif
 $(objpfx)$(multidir):
 	mkdir -p $@
 endif
 extra-objs += $(crti-objs) $(crtn-objs)
+ifeq (,$(wildcard $(sysdirs:%=%/pt-crti.S)))
 omit-deps += crti crtn
 
 CFLAGS-pt-initfini.s = -g0 -fPIC -fno-inline-functions $(fno-unit-at-a-time)
 endif
+endif
 
 CFLAGS-flockfile.c = -D_IO_MTSAFE_IO
 CFLAGS-ftrylockfile.c = -D_IO_MTSAFE_IO
@@ -542,15 +546,33 @@ $(addprefix $(objpfx),$(tests) $(test-srcs)): $(objpfx)libpthread.a
 endif
 
 ifeq ($(build-shared),yes)
+ifeq (,$(wildcard $(sysdirs:%=%/pt-crti.S)))
 vpath pt-initfini.c $(sysdirs)
 
 $(objpfx)pt-initfini.s: pt-initfini.c
 	$(compile.c) -S $(CFLAGS-pt-initfini.s) -finhibit-size-directive \
 		$(patsubst -f%,-fno-%,$(exceptions)) -o $@
+endif
 
 $(objpfx)tst-cleanup0.out: /dev/null $(objpfx)tst-cleanup0
 	$(make-test-out) 2>&1 | cmp - tst-cleanup0.expect > $@
 
+ifneq (,$(wildcard $(sysdirs:%=%/pt-crti.S)))
+
+vpath pt-crti.S $(sysdirs)
+vpath pt-crtn.S $(sysdirs)
+
+CFLAGS-pt-crti.S = -g0
+CFLAGS-pt-crtn.S = -g0
+
+$(objpfx)crti.o: $(objpfx)pt-crti.o
+	ln -f $< $@
+
+$(objpfx)crtn.o: $(objpfx)pt-crtn.o
+	ln -f $< $@
+
+else
+
 # We only have one kind of startup code files.  Static binaries and
 # shared libraries are build using the PIC version.
 $(objpfx)crti.S: $(objpfx)pt-initfini.s
@@ -572,6 +594,8 @@ $(objpfx)crti.o: $(objpfx)crti.S $(objpfx)defs.h
 $(objpfx)crtn.o: $(objpfx)crtn.S $(objpfx)defs.h
 	$(compile.S) -g0 $(ASFLAGS-.os) -o $@
 
+endif
+
 ifneq ($(multidir),.)
 $(objpfx)$(multidir)/crti.o: $(objpfx)crti.o $(objpfx)$(multidir)/
 	ln -f $< $@
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/pt-crti.S b/nptl/sysdeps/unix/sysv/linux/i386/pt-crti.S
new file mode 100644
index 0000000..908185b
--- /dev/null
+++ b/nptl/sysdeps/unix/sysv/linux/i386/pt-crti.S
@@ -0,0 +1,33 @@
+/* Special .init and .fini section support for x86.  NPTL version.
+   Copyright (C) 1995-1997,2000-2002,2012 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 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 Library 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.)
+
+   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; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#define INIT_CALL					\
+  .hidden __pthread_initialize_minimal_internal;	\
+  call __pthread_initialize_minimal_internal
+
+#include <sysdeps/i386/crti.S>
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/pt-crtn.S b/nptl/sysdeps/unix/sysv/linux/i386/pt-crtn.S
new file mode 100644
index 0000000..cc7d177
--- /dev/null
+++ b/nptl/sysdeps/unix/sysv/linux/i386/pt-crtn.S
@@ -0,0 +1 @@
+#include <sysdeps/i386/crtn.S>
diff --git a/sysdeps/i386/crti.S b/sysdeps/i386/crti.S
new file mode 100644
index 0000000..626a15c
--- /dev/null
+++ b/sysdeps/i386/crti.S
@@ -0,0 +1,71 @@
+/* Special .init and .fini section support for x86.
+   Copyright (C) 1995-1997, 2000, 2012 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, 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.  */
+
+#include <libc-symbols.h>
+#include <sysdep.h>
+
+#ifndef INIT_CALL
+#define INIT_CALL				\
+  weak_extern (__gmon_start__);			\
+  movl __gmon_start__@GOT(%ebx), %eax;		\
+  testl %eax, %eax;				\
+  je .Lno_gmon_start;				\
+  call __gmon_start__@PLT;			\
+.Lno_gmon_start:
+#endif
+
+	.section	.init,"ax",@progbits
+	.p2align	2,,3
+	.globl	_init
+	.type	_init, @function
+_init:
+	pushl	%ebx
+	subl	$8, %esp
+	LOAD_PIC_REG (bx)
+	INIT_CALL
+
+	.section	.fini,"ax",@progbits
+	.p2align	2,,3
+	.globl	_fini
+	.type	_fini, @function
+_fini:
+	pushl	%ebx
+	subl	$8, %esp
+	LOAD_PIC_REG (bx)
diff --git a/sysdeps/i386/crtn.S b/sysdeps/i386/crtn.S
new file mode 100644
index 0000000..6417524
--- /dev/null
+++ b/sysdeps/i386/crtn.S
@@ -0,0 +1,48 @@
+/* Special .init and .fini section support for x86.
+   Copyright (C) 1995-1997, 2000, 2012 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, 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
+	addl	$8, %esp
+	popl	%ebx
+	ret
+
+	.section	.fini
+	addl	$8, %esp
+	popl	%ebx
+	ret

-- 
Joseph S. Myers
joseph@codesourcery.com


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