Group text sections with prefixes .text.unlikely,.text.hot and .text.startup

by default.


2012-12-18  Sriraman Tallam  <tmsriram@google.com>

	* layout.cc (Layout::is_section_name_prefix_grouped): New function.
	* layout.h (Layout::is_section_name_prefix_grouped): New function.
	* output.cc (Output_section::add_input_section): Check if section
	name contains special prefix.  Keep input sections to sort such
	sections.
	(Output_section::Input_section_sort_section_order_index_compare
	 ::operator()): Group sections according to prefixes.
	* (Output_section::sort_attached_input_sections): Add condition
	to Input_section_entry constructor call.
	* testsuite/Makefile.am (text_section_grouping): New test.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/text_section_grouping.cc: New file.
	* testsuite/text_section_grouping.sh: New file.

gold/testsuite/text_section_grouping.cc

@@ -0,0 +1,72 @@
+// text_section_grouping.cc -- a test case for gold
+
+// Copyright 2012 Free Software Foundation, Inc.
+// Written by Sriraman Tallam <tmsriram@google.com>.
+
+// This file is part of gold.
+
+// This program 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 of the License, or
+// (at your option) any later version.
+
+// This program 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 this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+// The goal of this program is to verify if .text sections are grouped
+// according to prefix.  .text.unlikely, .text.startup and .text.hot should
+// be grouped and placed together.
+
+extern "C"
+__attribute__ ((section(".text.hot.foo")))
+int hot_foo()
+{
+  return 1;
+}
+
+extern "C"
+__attribute__ ((section(".text.startup.foo")))
+int startup_foo()
+{
+  return 1;
+}
+
+extern "C"
+__attribute__ ((section(".text.unlikely.foo")))
+int unlikely_foo()
+{
+  return 1;
+}
+
+extern "C"
+__attribute__ ((section(".text.hot.bar")))
+int hot_bar()
+{
+  return 1;
+}
+
+extern "C"
+__attribute__ ((section(".text.startup.bar")))
+int startup_bar()
+{
+  return 1;
+}
+
+extern "C"
+__attribute__ ((section(".text.unlikely.bar")))
+int unlikely_bar()
+{
+  return 1;
+}
+
+int main()
+{
+  return 1;
+}