New option -z,keep-text-section prefix.

This option does not merge certain text sections with prefixes
.text.hot, .text.unlikely, .text.startup and .text.exit.

	* layout.cc (Layout::default_section_order): Check for text section
	prefixes.
	(Layout::text_section_name_mapping): New static member.
	(Layout::text_section_name_mapping_count): New static member.
	(Layout::match_section_name): New static function.
	(Layout::output_section_name): Check for text section prefixes.
	* layout.h (Output_section_order::ORDER_TEXT_HOT): New enum value.
	(Output_section_order::ORDER_TEXT_STARTUP): New enum value.
	(Output_section_order::ORDER_TEXT_EXIT): New enum value.
	(Output_section_order::ORDER_TEXT_UNLIKELY): New enum value.
	(Layout::text_section_name_mapping): New static member.
	(Layout::text_section_name_mapping_count): New static member.
	(Layout::match_section_name): New static function.
	* options.h (keep_text_section_prefix): New -z option.
	* testsuite/Makefile.am (keep_text_section_prefix): New test.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/keep_text_section_prefix.cc: New test source.
	* testsuite/keep_text_section_prefix.sh: New test script.

4 files changed, 155 insertions, 0 deletions

diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index bb486ed..a732b53 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -354,6 +354,18 @@ text_unlikely_segment: text_unlikely_segment.o gcctestdir/ld
 text_unlikely_segment_readelf.stdout: text_unlikely_segment
 	$(TEST_READELF) -Wl $< >$@
 
+check_SCRIPTS += keep_text_section_prefix.sh
+check_DATA += keep_text_section_prefix_readelf.stdout keep_text_section_prefix_nm.stdout
+MOSTLYCLEANFILES += keep_text_section_prefix
+keep_text_section_prefix.o: keep_text_section_prefix.cc
+	$(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
+keep_text_section_prefix: keep_text_section_prefix.o gcctestdir/ld
+	$(CXXLINK)  -Bgcctestdir/ -Wl,-z,keep-text-section-prefix keep_text_section_prefix.o
+keep_text_section_prefix_readelf.stdout: keep_text_section_prefix
+	$(TEST_READELF) -Wl $< >$@
+keep_text_section_prefix_nm.stdout: keep_text_section_prefix
+	$(TEST_NM) -n $< >$@
+
 check_PROGRAMS += icf_virtual_function_folding_test
 MOSTLYCLEANFILES += icf_virtual_function_folding_test icf_virtual_function_folding_test.map
 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 ec851d5..6f61eae 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -101,6 +101,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_grouping.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	section_sorting_name.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_unlikely_segment.sh \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	keep_text_section_prefix.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 \
@@ -129,6 +130,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_no_grouping.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	section_sorting_name.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_unlikely_segment_readelf.stdout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	keep_text_section_prefix_readelf.stdout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	keep_text_section_prefix_nm.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 \
@@ -155,6 +158,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_section_no_grouping \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	section_sorting_name \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	text_unlikely_segment \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	keep_text_section_prefix \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_virtual_function_folding_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_virtual_function_folding_test.map \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	icf_preemptible_functions_test \
@@ -5233,6 +5237,8 @@ section_sorting_name.sh.log: section_sorting_name.sh
 	@p='section_sorting_name.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 text_unlikely_segment.sh.log: text_unlikely_segment.sh
 	@p='text_unlikely_segment.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
+keep_text_section_prefix.sh.log: keep_text_section_prefix.sh
+	@p='keep_text_section_prefix.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
@@ -6108,6 +6114,14 @@ uninstall-am:
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK)  -Bgcctestdir/ -Wl,-z,text-unlikely-segment text_unlikely_segment.o
 @GCC_TRUE@@NATIVE_LINKER_TRUE@text_unlikely_segment_readelf.stdout: text_unlikely_segment
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -Wl $< >$@
+@GCC_TRUE@@NATIVE_LINKER_TRUE@keep_text_section_prefix.o: keep_text_section_prefix.cc
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@keep_text_section_prefix: keep_text_section_prefix.o gcctestdir/ld
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK)  -Bgcctestdir/ -Wl,-z,keep-text-section-prefix keep_text_section_prefix.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@keep_text_section_prefix_readelf.stdout: keep_text_section_prefix
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -Wl $< >$@
+@GCC_TRUE@@NATIVE_LINKER_TRUE@keep_text_section_prefix_nm.stdout: keep_text_section_prefix
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_NM) -n $< >$@
 @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/keep_text_section_prefix.cc b/gold/testsuite/keep_text_section_prefix.cc
new file mode 100644
index 0000000..1395d4c
--- /dev/null
+++ b/gold/testsuite/keep_text_section_prefix.cc
@@ -0,0 +1,52 @@
+/* keep_text_section_prefix.cc -- a test case for gold
+
+   Copyright (C) 2018 onwards 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.  */
+
+extern "C" {
+__attribute__((section(".text.unlikely.foo")))
+int unlikely_foo(void) {
+  return 0;
+}
+
+__attribute__((section(".text.hot.foo")))
+int hot_foo(void) {
+  return 0;
+}
+
+__attribute__((section(".text.startup.foo")))
+int startup_foo(void) {
+  return 0;
+}
+
+__attribute__((section(".text.exit.foo")))
+int exit_foo(void) {
+  return 0;
+}
+
+__attribute__((section(".text.foo")))
+int regular_foo(void) {
+  return 0;
+}
+
+int main(void) {
+  return 0;
+}
+}
diff --git a/gold/testsuite/keep_text_section_prefix.sh b/gold/testsuite/keep_text_section_prefix.sh
new file mode 100755
index 0000000..44a2b47
--- /dev/null
+++ b/gold/testsuite/keep_text_section_prefix.sh
@@ -0,0 +1,77 @@
+#!/bin/sh
+
+# keep_text_section_prefix.sh -- test
+
+# Copyright (C) 2018 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 separated
+# according to their prefix. .text.hot, .text.unlikely, .text.startup and
+# .text.exit must be separated in the final binary.
+
+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
+}
+
+check_str()
+{
+    if ! grep -q "$2" "$1"
+    then
+	echo "Did not find expected output in $1:"
+	echo "   $2"
+	echo ""
+	echo "Actual output below:"
+	cat "$1"
+	exit 1
+    fi
+}
+
+check_str keep_text_section_prefix_readelf.stdout ".text.hot .text .text.startup .text.exit .text.unlikely"
+
+check keep_text_section_prefix_nm.stdout "hot_foo" "regular_foo"
+check keep_text_section_prefix_nm.stdout "regular_foo" "startup_foo"
+check keep_text_section_prefix_nm.stdout "startup_foo" "exit_foo"
+check keep_text_section_prefix_nm.stdout "exit_foo" "unlikely_foo"