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.

4 files changed, 158 insertions, 0 deletions

diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index c5c8a99..745e13d 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -250,6 +250,16 @@ final_layout: final_layout.o final_layout_sequence.txt gcctestdir/ld
 final_layout.stdout: final_layout
 	$(TEST_NM) -n --synthetic final_layout > final_layout.stdout
 
+check_SCRIPTS += text_section_grouping.sh
+check_DATA += text_section_grouping.stdout
+MOSTLYCLEANFILES += text_section_grouping
+text_section_grouping.o: text_section_grouping.cc
+	$(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
+text_section_grouping: text_section_grouping.o gcctestdir/ld
+	$(CXXLINK)  -Bgcctestdir/ text_section_grouping.o
+text_section_grouping.stdout: text_section_grouping
+	$(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout 
+
 check_PROGRAMS += icf_virtual_function_folding_test
 MOSTLYCLEANFILES += icf_virtual_function_folding_test
 icf_virtual_function_folding_test.o: icf_virtual_function_folding_test.cc
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 6d9c630..b1058b4 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -81,6 +81,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_safe_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_safe_so_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	final_layout.sh \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_grouping.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_preemptible_functions_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_string_merge_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_sht_rel_addend_test.sh \
@@ -111,6 +112,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_safe_so_test_1.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_safe_so_test_2.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	final_layout.stdout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_grouping.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_preemptible_functions_test.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_string_merge_test.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_sht_rel_addend_test.stdout \
@@ -122,6 +124,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_test icf_keep_unique_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_safe_test icf_safe_so_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	final_layout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_grouping \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	final_layout_sequence.txt \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_virtual_function_folding_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_preemptible_functions_test \
@@ -3701,6 +3704,8 @@ icf_safe_so_test.sh.log: icf_safe_so_test.sh
 	@p='icf_safe_so_test.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 final_layout.sh.log: final_layout.sh
 	@p='final_layout.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
+text_section_grouping.sh.log: text_section_grouping.sh
+	@p='text_section_grouping.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 icf_preemptible_functions_test.sh.log: icf_preemptible_functions_test.sh
 	@p='icf_preemptible_functions_test.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 icf_string_merge_test.sh.log: icf_string_merge_test.sh
@@ -4348,6 +4353,12 @@ uninstall-am:
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK) -Bgcctestdir/ -Wl,--section-ordering-file,final_layout_sequence.txt final_layout.o
 @GCC_TRUE@@NATIVE_LINKER_TRUE@final_layout.stdout: final_layout
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_NM) -n --synthetic final_layout > final_layout.stdout
+@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_grouping.o: text_section_grouping.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_grouping: text_section_grouping.o gcctestdir/ld
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK) -Bgcctestdir/ text_section_grouping.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@text_section_grouping.stdout: text_section_grouping
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_NM) -n --synthetic text_section_grouping > text_section_grouping.stdout
 @GCC_TRUE@@NATIVE_LINKER_TRUE@icf_virtual_function_folding_test.o: icf_virtual_function_folding_test.cc
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXCOMPILE) -O0 -c -ffunction-sections -fPIE -g -o $@ $<
 @GCC_TRUE@@NATIVE_LINKER_TRUE@icf_virtual_function_folding_test: icf_virtual_function_folding_test.o gcctestdir/ld
diff --git a/gold/testsuite/text_section_grouping.cc b/gold/testsuite/text_section_grouping.cc
new file mode 100644
index 0000000..5a3a809
--- /dev/null
+++ b/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;
+}
diff --git a/gold/testsuite/text_section_grouping.sh b/gold/testsuite/text_section_grouping.sh
new file mode 100755
index 0000000..a79836c
--- /dev/null
+++ b/gold/testsuite/text_section_grouping.sh
@@ -0,0 +1,65 @@
+#!/bin/sh
+
+# text_section_grouping.sh -- test
+
+# 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.
+
+set -e
+
+check()
+{
+    awk "
+BEGIN { saw1 = 0; saw2 = 0; err = 0; }
+/.*$2\$/ { saw1 = 1; }
+/.*$3\$/ {
+     saw2 = 1;
+     if (!saw1)
+       {
+	  printf \"layout of $2 and $3 is not right\\n\";
+	  err = 1;
+	  exit 1;
+       }
+    }
+END {
+      if (!saw1 && !err)
+        {
+	  printf \"did not see $2\\n\";
+	  exit 1;
+	}
+      if (!saw2 && !err)
+	{
+	  printf \"did not see $3\\n\";
+	  exit 1;
+	}
+    }" $1
+}
+
+# addr (unlikely_*) < addr (startup_*) < addr (hot_*)
+check text_section_grouping.stdout "unlikely_foo" "startup_foo"
+check text_section_grouping.stdout "startup_foo" "hot_foo"
+check text_section_grouping.stdout "unlikely_bar" "startup_bar"
+check text_section_grouping.stdout "startup_bar" "hot_bar"
+check text_section_grouping.stdout "unlikely_foo" "startup_bar"
+check text_section_grouping.stdout "startup_foo" "hot_bar"