Patchwork PATCH: PR target/46770: Use .init_array/.fini_array sections

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Submitter H.J. Lu
Date Dec. 7, 2010, 3:54 p.m.
Message ID <20101207155451.GA25694@intel.com>
Download mbox | patch
Permalink /patch/74569/
State New
Headers show

Comments

H.J. Lu - Dec. 7, 2010, 3:54 p.m.
Hi,

This patch uses .init_array/.fini_array sections if they work and
are needed. Some platforms use .init_array/.fini_array sections by
default.  So checking --enable-initfini-array alone isn't sufficient.
I added use_initfini_array.  Each platform should set it if
.init_array/.fini_array sections should be used.

This patch only changes Linux/x86.  OK for trunk if there are no
regressions on Linux/x86-64?

Thanks.


H.J.
----
2010-12-07  H.J. Lu  <hongjiu.lu@intel.com>

	PR target/46770
	* config.gcc: Use initfini-array.o if supported.

	* config/initfini-array.c: New.
	* config/initfini-array.h: Likewise.
	* config/t-initfini-array: Likewise.
Joseph S. Myers - Dec. 7, 2010, 4:31 p.m.
On Tue, 7 Dec 2010, H.J. Lu wrote:

> @@ -2698,6 +2698,7 @@ 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

Please update the comment at the top of config.gcc listing the variables 
it sets, and put a default (empty or "no") setting of this variable along 
with the other defaults as well.

> +#include "tree.h"

What is tree.h needed for here?

> +	$(TREE_H) $(GCC_H)

I think you mean $(GGC_H) not $(GCC_H) (which is gcc.h, the header for the 
driver).

Patch

diff --git a/gcc/config.gcc b/gcc/config.gcc
index dfbf2c5..12d2aae 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -2698,6 +2698,7 @@  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="${tmake_file} i386/t-gmm_malloc i386/t-i386"
@@ -3050,6 +3051,16 @@  if test x$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..d5fd40f
--- /dev/null
+++ b/gcc/config/initfini-array.c
@@ -0,0 +1,79 @@ 
+/* Definitions for ELF systems with .init_array/.fini_array section
+   Copyright (C) 2010
+   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 "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..115996e
--- /dev/null
+++ b/gcc/config/initfini-array.h
@@ -0,0 +1,33 @@ 
+/* Definitions for ELF systems with .init_array/.fini_array section
+   support.
+   Copyright (C) 2010
+   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/>.  */
+
+#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..6987d76
--- /dev/null
+++ b/gcc/config/t-initfini-array
@@ -0,0 +1,23 @@ 
+# Copyright (C) 2010
+# 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) $(GCC_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<