Implement the R_AARCH64_NONE relocation.

According to "ELF for the ARM(r) 64-bit Architecture (AArch64)",
this relocation can be used "to prevent removal of sections that
might otherwise appear to be unused."

gold/
	* aarch64-reloc.def (NONE): New relocation.
	* aarch64.cc (Target_aarch64::Scan::local): Handle R_AARCH64_NONE.
	(Target_aarch64::Scan::global): Likewise.
	* testsuite/Makefile.am (aarch64_reloc_none): New test.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/aarch64_reloc_none.s: New test source file.
	* testsuite/aarch64_reloc_none.sh: New test script.

7 files changed, 129 insertions, 9 deletions

diff --git a/gold/ChangeLog b/gold/ChangeLog
index 8b293cd..a5f6898 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,13 @@
+2016-06-28  Igor Kudrin  <ikudrin@accesssoftek.com>
+
+	* aarch64-reloc.def (NONE): New relocation.
+	* aarch64.cc (Target_aarch64::Scan::local): Handle R_AARCH64_NONE.
+	(Target_aarch64::Scan::global): Likewise.
+	* testsuite/Makefile.am (aarch64_reloc_none): New test.
+	* testsuite/Makefile.in: Regenerate.
+	* testsuite/aarch64_reloc_none.s: New test source file.
+	* testsuite/aarch64_reloc_none.sh: New test script.
+
 2016-06-28  Sriraman Tallam  <tmsriram@google.com>
 
 	* x86_64.cc (Lazy_view): New class.
diff --git a/gold/aarch64-reloc.def b/gold/aarch64-reloc.def
index f33929b..763d372 100644
--- a/gold/aarch64-reloc.def
+++ b/gold/aarch64-reloc.def
@@ -32,6 +32,9 @@
 // Type----------------------------+         |              |    |      |                       |     |                                              |
 // Name                            |         |              |    |      |                       |     |                                              |
 //  |                              |         |              |    |      |                       |     |                                              |
+ARD(NONE                         , STATIC  , NONE       ,   Y,  -1,    0,0                ,    0,0  , 0                    ,                         DATA  )
+// Above is from Table 4-5, Null relocation codes
+
 ARD(ABS64                        , STATIC ,  DATA       ,   Y,  -1,    0,0                ,    0,0  , Symbol::ABSOLUTE_REF ,                         DATA  )
 ARD(ABS32                        , STATIC ,  DATA       ,   Y,  -1,   31,32               ,    0,0  , Symbol::ABSOLUTE_REF ,                         DATA  )
 ARD(ABS16                        , STATIC ,  DATA       ,   Y,  -1,   15,16               ,    0,0  , Symbol::ABSOLUTE_REF ,                         DATA  )
diff --git a/gold/aarch64.cc b/gold/aarch64.cc
index 3d03c11..db9f06c 100644
--- a/gold/aarch64.cc
+++ b/gold/aarch64.cc
@@ -5967,6 +5967,9 @@ Target_aarch64<size, big_endian>::Scan::local(
 
   switch (r_type)
     {
+    case elfcpp::R_AARCH64_NONE:
+      break;
+
     case elfcpp::R_AARCH64_ABS32:
     case elfcpp::R_AARCH64_ABS16:
       if (parameters->options().output_is_position_independent())
@@ -6226,6 +6229,9 @@ Target_aarch64<size, big_endian>::Scan::global(
 
   switch (r_type)
     {
+    case elfcpp::R_AARCH64_NONE:
+      break;
+
     case elfcpp::R_AARCH64_ABS16:
     case elfcpp::R_AARCH64_ABS32:
     case elfcpp::R_AARCH64_ABS64:
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index 9d4326b..3b0dcc6 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -3502,6 +3502,21 @@ MOSTLYCLEANFILES += arm_farcall_thumb_arm arm_farcall_thumb_arm_5t
 
 endif DEFAULT_TARGET_ARM
 
+if DEFAULT_TARGET_AARCH64
+
+check_SCRIPTS += aarch64_reloc_none.sh
+check_DATA += aarch64_reloc_none.stdout
+aarch64_reloc_none.o: aarch64_reloc_none.s
+	$(TEST_AS) -o $@ $<
+aarch64_reloc_none: aarch64_reloc_none.o ../ld-new
+	../ld-new -o $@ aarch64_reloc_none.o --gc-sections
+aarch64_reloc_none.stdout: aarch64_reloc_none
+	$(TEST_NM) $< > $@
+
+MOSTLYCLEANFILES += aarch64_reloc_none
+
+endif DEFAULT_TARGET_AARCH64
+
 if DEFAULT_TARGET_S390
 
 check_SCRIPTS += split_s390.sh
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 894e6dd..b398ee9 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -892,8 +892,11 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_farcall_thumb_thumb_6m \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_farcall_thumb_arm \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_farcall_thumb_arm_5t
-@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_89 = split_s390.sh
-@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_90 = split_s390_z1.stdout split_s390_z2.stdout split_s390_z3.stdout \
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_89 = aarch64_reloc_none.sh
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_90 = aarch64_reloc_none.stdout
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_91 = aarch64_reloc_none
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_92 = split_s390.sh
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_93 = split_s390_z1.stdout split_s390_z2.stdout split_s390_z3.stdout \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_z4.stdout split_s390_n1.stdout split_s390_n2.stdout \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_a1.stdout split_s390_a2.stdout split_s390_z1_ns.stdout \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_z2_ns.stdout split_s390_z3_ns.stdout split_s390_z4_ns.stdout \
@@ -905,7 +908,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390x_z4_ns.stdout split_s390x_n1_ns.stdout \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390x_n2_ns.stdout split_s390x_r.stdout
 
-@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_91 = split_s390_z1 split_s390_z2 split_s390_z3 \
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_94 = split_s390_z1 split_s390_z2 split_s390_z3 \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_z4 split_s390_n1 split_s390_n2 split_s390_a1 \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_a2 split_s390_z1_ns split_s390_z2_ns split_s390_z3_ns \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390_z4_ns split_s390_n1_ns split_s390_n2_ns split_s390_r \
@@ -914,10 +917,10 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390x_z1_ns split_s390x_z2_ns split_s390x_z3_ns \
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_s390x_z4_ns split_s390x_n1_ns split_s390x_n2_ns split_s390x_r
 
-@DEFAULT_TARGET_X86_64_TRUE@am__append_92 = *.dwo *.dwp
-@DEFAULT_TARGET_X86_64_TRUE@am__append_93 = dwp_test_1.sh \
+@DEFAULT_TARGET_X86_64_TRUE@am__append_95 = *.dwo *.dwp
+@DEFAULT_TARGET_X86_64_TRUE@am__append_96 = dwp_test_1.sh \
 @DEFAULT_TARGET_X86_64_TRUE@	dwp_test_2.sh
-@DEFAULT_TARGET_X86_64_TRUE@am__append_94 = dwp_test_1.stdout \
+@DEFAULT_TARGET_X86_64_TRUE@am__append_97 = dwp_test_1.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@	dwp_test_2.stdout
 subdir = testsuite
 DIST_COMMON = $(srcdir)/Makefile.in $(srcdir)/Makefile.am
@@ -2626,7 +2629,7 @@ MOSTLYCLEANFILES = *.so *.syms *.stdout $(am__append_4) \
 	$(am__append_68) $(am__append_71) $(am__append_73) \
 	$(am__append_76) $(am__append_79) $(am__append_82) \
 	$(am__append_85) $(am__append_88) $(am__append_91) \
-	$(am__append_92)
+	$(am__append_94) $(am__append_95)
 
 # We will add to these later, for each individual test.  Note
 # that we add each test under check_SCRIPTS or check_PROGRAMS;
@@ -2636,13 +2639,15 @@ check_SCRIPTS = $(am__append_2) $(am__append_21) $(am__append_27) \
 	$(am__append_43) $(am__append_47) $(am__append_50) \
 	$(am__append_66) $(am__append_69) $(am__append_74) \
 	$(am__append_77) $(am__append_80) $(am__append_83) \
-	$(am__append_86) $(am__append_89) $(am__append_93)
+	$(am__append_86) $(am__append_89) $(am__append_92) \
+	$(am__append_96)
 check_DATA = $(am__append_3) $(am__append_22) $(am__append_28) \
 	$(am__append_31) $(am__append_37) $(am__append_40) \
 	$(am__append_44) $(am__append_48) $(am__append_51) \
 	$(am__append_67) $(am__append_70) $(am__append_75) \
 	$(am__append_78) $(am__append_81) $(am__append_84) \
-	$(am__append_87) $(am__append_90) $(am__append_94)
+	$(am__append_87) $(am__append_90) $(am__append_93) \
+	$(am__append_97)
 BUILT_SOURCES = $(am__append_34)
 TESTS = $(check_SCRIPTS) $(check_PROGRAMS)
 
@@ -4711,6 +4716,8 @@ arm_farcall_thumb_thumb.sh.log: arm_farcall_thumb_thumb.sh
 	@p='arm_farcall_thumb_thumb.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 arm_farcall_thumb_arm.sh.log: arm_farcall_thumb_arm.sh
 	@p='arm_farcall_thumb_arm.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
+aarch64_reloc_none.sh.log: aarch64_reloc_none.sh
+	@p='aarch64_reloc_none.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 split_s390.sh.log: split_s390.sh
 	@p='split_s390.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 dwp_test_1.sh.log: dwp_test_1.sh
@@ -7100,6 +7107,12 @@ uninstall-am:
 
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@arm_farcall_thumb_arm_5t.o: arm_farcall_thumb_arm.s
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	$(TEST_AS) -march=armv5t -o $@ $<
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@aarch64_reloc_none.o: aarch64_reloc_none.s
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	$(TEST_AS) -o $@ $<
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@aarch64_reloc_none: aarch64_reloc_none.o ../ld-new
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	../ld-new -o $@ aarch64_reloc_none.o --gc-sections
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@aarch64_reloc_none.stdout: aarch64_reloc_none
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	$(TEST_NM) $< > $@
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@split_s390_1_z1.o: split_s390_1_z1.s
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	$(TEST_AS) -m31 -o $@ $<
 @DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@split_s390_1_z2.o: split_s390_1_z2.s
diff --git a/gold/testsuite/aarch64_reloc_none.s b/gold/testsuite/aarch64_reloc_none.s
new file mode 100644
index 0000000..47b8a17
--- /dev/null
+++ b/gold/testsuite/aarch64_reloc_none.s
@@ -0,0 +1,16 @@
+.text

+.global _start

+.type _start, %function

+_start:

+	nop

+.reloc 0, R_AARCH64_NONE, foo

+

+.section .foo,"ax"

+.global foo

+foo:

+	nop

+

+.section .bar,"ax"

+.global bar

+bar:

+	nop

diff --git a/gold/testsuite/aarch64_reloc_none.sh b/gold/testsuite/aarch64_reloc_none.sh
new file mode 100755
index 0000000..abf463d
--- /dev/null
+++ b/gold/testsuite/aarch64_reloc_none.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+
+# aarch64_reloc_none.sh -- test that R_AARCH64_NONE can be used
+# to prevent garbage collecting a section.
+
+# Copyright (C) 2010-2016 Free Software Foundation, Inc.
+# Written by Igor Kudrin <ikudrin@accesssoftek.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 test is to verify that support for the R_AARCH64_NONE
+# relocation is implemented and it can be used to inform a linker that
+# a section should be preserved during garbage collecting.
+# File aarch64_reloc_none.s describes two similar sections, .foo and .bar,
+# but .foo is referenced from .text using R_AARCH64_NONE against symbol foo.
+# When flag --gc-sections is used, .foo and its symbol foo have to be
+# preserved, whereas .bar and its symbol bar have to be discarded.
+
+check()
+{
+    file=$1
+
+    found_bar=`grep -e "\<bar\b" "$file"`
+    if test -n "$found_bar"; then
+	echo "Garbage collection failed to collect bar"
+	echo ""
+	echo "Actual output below:"
+	cat "$file"
+	exit 1
+    fi
+
+    found_foo=`grep -e "\<foo\b" "$file"`
+    if test -z "$found_foo"; then
+	echo "Garbage collection should not discard foo"
+	echo ""
+	echo "Actual output below:"
+	cat "$file"
+	exit 1
+    fi
+}
+
+check aarch64_reloc_none.stdout