PING: PATCH: PR target/46770: Use .init_array/.fini_array sections
H.J. Lu
hjl.tools@gmail.com
Fri Jul 22 12:31:00 GMT 2011
On Sun, Jun 19, 2011 at 1:01 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Sun, Jun 19, 2011 at 8:39 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>
>>>> I can't approve the configury changes and would like to defer
>>>> to target maintainers for the target specific changes. That said,
>>>> I'm not familiar enough with the area of the patch. But yes,
>>>> it's stage1 now - so if anyone else wants to approve this patch...
>>>
>>> My first attempt:
>>>
>>> http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00589.html
>>>
>>> only affects x86. I changed it to generic based on the
>>> feedbacks. But other target maintainers show no interests.
>>> Should I make it x86 only first? Each target can enable it
>>> if needed.
>>>
>>
>> I am enclosing 2 patches here. One only affects Linux/x86
>> and the other covers all targets. I tested both versions on
>> Linux/x86 without any regressions. Since I only got OK from
>> one target maintainer and I have been pinging on this patch
>> for more than 6 months, I'd like to get it enabled for Linux/x86
>> soon.
>>
>> Uros, can I check in Linux/x86 version if there are no full feedbacks
>> from the rest of target maintainers for more than 48hours. We can
>> enable other targets on a target by target basis later.
>
> Sorry, but I don't feel confident enough to review the patch in this
> part of the compiler. I would prefer if somebody else approves it.
>
Hi Jakub,
Can you review this change?
Thanks.
--
H.J.
----
2011-06-19 H.J. Lu <hongjiu.lu@intel.com>
PR target/46770
* config.gcc (use_initfini_array): New variable.
Use initfini-array.o for Linux/x86 if supported.
* crtstuff.c: Don't generate .ctors nor .dtors sections if
NO_CTORS_DTORS_SECTIONS is defined.
* config/initfini-array.c: New.
* config/initfini-array.h: Likewise.
* config/t-initfini-array: Likewise.
-------------- next part --------------
2011-06-19 H.J. Lu <hongjiu.lu@intel.com>
PR target/46770
* config.gcc (use_initfini_array): New variable.
Use initfini-array.o for Linux/x86 if supported.
* crtstuff.c: Don't generate .ctors nor .dtors sections if
NO_CTORS_DTORS_SECTIONS is defined.
* config/initfini-array.c: New.
* config/initfini-array.h: Likewise.
* config/t-initfini-array: Likewise.
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 2cf92d2..e0a253d 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -186,6 +186,9 @@
# configure_default_options
# Set to an initializer for configure_default_options
# in configargs.h, based on --with-cpu et cetera.
+#
+# use_initfini_array If set to yes, .init_array/.fini_array sections
+# will be used if they work.
# The following variables are used in each case-construct to build up the
# outgoing variables:
@@ -238,6 +241,7 @@ default_gnu_indirect_function=no
target_gtfiles=
need_64bit_hwint=
need_64bit_isa=
+use_initfini_array=
# Don't carry these over build->host->target. Please.
xm_file=
@@ -2660,6 +2664,7 @@ esac
case ${target} in
i[34567]86-*-linux* | x86_64-*-linux*)
tmake_file="${tmake_file} i386/t-pmm_malloc i386/t-i386"
+ use_initfini_array=yes
;;
i[34567]86-*-* | x86_64-*-*)
tmake_file="${tmake_file} i386/t-gmm_malloc i386/t-i386"
@@ -3046,6 +3051,16 @@ if test x$with_schedule = x; then
esac
fi
+# Support --enable-initfini-array. Use initfini-array.h only if
+# use_initfini_array is also set to yes. Some platforms don't need it
+# even if enable_initfini_array is yes.
+if test x$enable_initfini_array$use_initfini_array = xyesyes; then
+ tm_file="${tm_file} initfini-array.h"
+ tmake_file="${tmake_file} t-initfini-array"
+ extra_objs="$extra_objs initfini-array.o"
+ target_gtfiles="$target_gtfiles \$(srcdir)/config/initfini-array.c"
+fi
+
# Validate and mark as valid any --with options supported
# by this target. In order to use a particular --with option
# you must list it in supported_defaults; validating the value
diff --git a/gcc/config/initfini-array.c b/gcc/config/initfini-array.c
new file mode 100644
index 0000000..c042769
--- /dev/null
+++ b/gcc/config/initfini-array.c
@@ -0,0 +1,80 @@
+/* Definitions for ELF systems with .init_array/.fini_array section
+ Copyright (C) 2011
+ Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "target.h"
+#include "output.h"
+#include "tree.h"
+#include "initfini-array.h"
+#include "ggc.h"
+
+static GTY(()) section *init_array_section;
+static GTY(()) section *fini_array_section;
+
+void
+elf_initfini_array_init_sections (void)
+{
+ init_array_section = get_unnamed_section (0, output_section_asm_op,
+ "\t.section\t.init_array");
+ fini_array_section = get_unnamed_section (0, output_section_asm_op,
+ "\t.section\t.fini_array");
+}
+
+static section *
+get_elf_initfini_array_priority_section (int priority,
+ bool constructor_p)
+{
+ section *sec;
+ if (priority != DEFAULT_INIT_PRIORITY)
+ {
+ char buf[18];
+ sprintf (buf, "%s.%.5u",
+ constructor_p ? ".init_array" : ".fini_array",
+ priority);
+ sec = get_section (buf, SECTION_WRITE, NULL_TREE);
+ }
+ else
+ sec = constructor_p ? init_array_section : fini_array_section;
+ return sec;
+}
+
+/* Use .init_array section for constructors. */
+
+void
+elf_init_array_asm_out_constructor (rtx symbol, int priority)
+{
+ section *sec = get_elf_initfini_array_priority_section (priority,
+ true);
+ assemble_addr_to_section (symbol, sec);
+}
+
+/* Use .fini_array section for destructors. */
+
+void
+elf_fini_array_asm_out_destructor (rtx symbol, int priority)
+{
+ section *sec = get_elf_initfini_array_priority_section (priority,
+ false);
+ assemble_addr_to_section (symbol, sec);
+}
+
+#include "gt-initfini-array.h"
diff --git a/gcc/config/initfini-array.h b/gcc/config/initfini-array.h
new file mode 100644
index 0000000..cba7eca
--- /dev/null
+++ b/gcc/config/initfini-array.h
@@ -0,0 +1,46 @@
+/* Definitions for ELF systems with .init_array/.fini_array section
+ support.
+ Copyright (C) 2011
+ Free Software Foundation, Inc.
+
+ This file is part of GCC.
+
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GCC 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 General Public
+ License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
+
+/* No need for .ctors/.dtors section since linker can place them in
+ .init_array/.fini_array section. */
+#define NO_CTORS_DTORS_SECTIONS
+
+#undef INIT_SECTION_ASM_OP
+#undef FINI_SECTION_ASM_OP
+
+/* FIXME: INIT_ARRAY_SECTION_ASM_OP and FINI_ARRAY_SECTION_ASM_OP
+ aren't used in any assembly codes. But we have to define
+ them to something. */
+#define INIT_ARRAY_SECTION_ASM_OP Something
+#define FINI_ARRAY_SECTION_ASM_OP Something
+
+#ifndef TARGET_ASM_INIT_SECTIONS
+#define TARGET_ASM_INIT_SECTIONS elf_initfini_array_init_sections
+#endif
+extern void elf_initfini_array_init_sections (void);
+
+/* Use .init_array/.fini_array section for constructors and destructors. */
+#undef TARGET_ASM_CONSTRUCTOR
+#define TARGET_ASM_CONSTRUCTOR elf_init_array_asm_out_constructor
+#undef TARGET_ASM_DESTRUCTOR
+#define TARGET_ASM_DESTRUCTOR elf_fini_array_asm_out_destructor
+extern void elf_init_array_asm_out_constructor (rtx, int);
+extern void elf_fini_array_asm_out_destructor (rtx, int);
diff --git a/gcc/config/t-initfini-array b/gcc/config/t-initfini-array
new file mode 100644
index 0000000..3824ed4
--- /dev/null
+++ b/gcc/config/t-initfini-array
@@ -0,0 +1,23 @@
+# Copyright (C) 2011
+# 2009 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# <http://www.gnu.org/licenses/>.
+
+initfini-array.o: $(srcdir)/config/initfini-array.c gt-initfini-array.h \
+ $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TARGET_H) output.h \
+ $(TREE_H) $(GGC_H)
+ $(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
diff --git a/gcc/crtstuff.c b/gcc/crtstuff.c
index b65f490..bccf44d 100644
--- a/gcc/crtstuff.c
+++ b/gcc/crtstuff.c
@@ -1,7 +1,8 @@
/* Specialized bits of code needed to support construction and
destruction of file-scope objects in C++ code.
Copyright (C) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001
- 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
+ 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011
+ Free Software Foundation, Inc.
Contributed by Ron Guilmette (rfg@monkeys.com).
This file is part of GCC.
@@ -189,6 +190,9 @@ typedef void (*func_ptr) (void);
refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
symbol in crtbegin.o, where they are defined. */
+/* No need for .ctors/.dtors section if linker can place them in
+ .init_array/.fini_array section. */
+#ifndef NO_CTORS_DTORS_SECTIONS
/* The -1 is a flag to __do_global_[cd]tors indicating that this table
does not start with a count of elements. */
#ifdef CTOR_LIST_BEGIN
@@ -219,6 +223,7 @@ STATIC func_ptr __DTOR_LIST__[1]
__attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
= { (func_ptr) (-1) };
#endif /* __DTOR_LIST__ alternatives */
+#endif /* NO_CTORS_DTORS_SECTIONS */
#ifdef USE_EH_FRAME_REGISTRY
/* Stick a label at the beginning of the frame unwind info so we can register
@@ -489,6 +494,9 @@ __do_global_ctors_1(void)
#elif defined(CRT_END) /* ! CRT_BEGIN */
+/* No need for .ctors/.dtors section if linker can place them in
+ .init_array/.fini_array section. */
+#ifndef NO_CTORS_DTORS_SECTIONS
/* Put a word containing zero at the end of each of our two lists of function
addresses. Note that the words defined here go into the .ctors and .dtors
sections of the crtend.o file, and since that file is always linked in
@@ -534,6 +542,7 @@ STATIC func_ptr __DTOR_END__[1]
__attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
= { (func_ptr) 0 };
#endif
+#endif /* NO_CTORS_DTORS_SECTIONS */
#ifdef EH_FRAME_SECTION_NAME
/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
More information about the Gcc-patches
mailing list