Properly implement STT_COMMON

The BFD configure option, --enable-elf-stt-common, can't be to used to
verify STT_COMMON implementation with the normal binutils build.  Instead,
this patch removes it from BFD.  It adds --elf-stt-common=[no|yes] to ELF
assembler/objcopy and adds -z common/-z nocommon to ld.

A configure option, --enable-elf-stt-common, is added to gas to specify
whether ELF assembler should generate common symbols with the STT_COMMON
type by default.

Since BSF_KEEP_G is never used, it is renamed to BSF_ELF_COMMON for ELF
common symbols.

bfd/

	PR ld/19645
	* bfd.c (bfd): Change flags to 20 bits.
	(BFD_CONVERT_ELF_COMMON): New.
	(BFD_USE_ELF_STT_COMMON): Likewise.
	(BFD_FLAGS_SAVED): Add BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.
	(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
	* configure.ac: Remove --enable-elf-stt-common.
	* elf.c (swap_out_syms): Choose STT_COMMON or STT_OBJECT for
	common symbol depending on BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.
	* elfcode.h (elf_slurp_symbol_table): Set BSF_ELF_COMMON for
	STT_COMMON.
	* elflink.c (bfd_elf_link_mark_dynamic_symbol): Also check
	STT_COMMON.
	(elf_link_convert_common_type): New function.
	(elf_link_output_extsym): Choose STT_COMMON or STT_OBJECT for
	common symbol depending on BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.  Set sym.st_info after sym.st_shndx.
	* elfxx-target.h (TARGET_BIG_SYM): Add BFD_CONVERT_ELF_COMMON
	and BFD_USE_ELF_STT_COMMON to object_flags.
	(TARGET_LITTLE_SYM): Likewise.
	* syms.c (BSF_KEEP_G): Renamed to ...
	(BSF_ELF_COMMON): This.
	* bfd-in2.h: Regenerated.
	* config.in: Likewise.
	* configure: Likewise.

binutils/

	PR ld/19645
	* NEWS: Mention --elf-stt-common= for objcopy.
	* doc/binutils.texi: Document --elf-stt-common= for objcopy.
	* objcopy.c (do_elf_stt_common): New.
	(command_line_switch): Add OPTION_ELF_STT_COMMON.
	(copy_options): Add --elf-stt-common=.
	(copy_usage): Add --elf-stt-common=.
	(copy_object): Also check do_elf_stt_common for ELF targets.
	(copy_file): Handle do_elf_stt_common.
	(copy_main): Handle OPTION_ELF_STT_COMMON.
	* readelf.c (apply_relocations): Support STT_COMMON.
	* testsuite/binutils-all/common-1.s: New file.
	* testsuite/binutils-all/common-1a.d: Likewise.
	* testsuite/binutils-all/common-1b.d: Likewise.
	* testsuite/binutils-all/common-1c.d: Likewise.
	* testsuite/binutils-all/common-1d.d: Likewise.
	* testsuite/binutils-all/common-1e.d: Likewise.
	* testsuite/binutils-all/common-1f.d: Likewise.
	* testsuite/binutils-all/common-2.s: Likewise.
	* testsuite/binutils-all/common-2a.d: Likewise.
	* testsuite/binutils-all/common-2b.d: Likewise.
	* testsuite/binutils-all/common-2c.d: Likewise.
	* testsuite/binutils-all/common-2d.d: Likewise.
	* testsuite/binutils-all/common-2e.d: Likewise.
	* testsuite/binutils-all/common-2f.d: Likewise.
	* testsuite/binutils-all/objcopy.exp
	(objcopy_test_elf_common_symbols): New proc.
	Run objcopy_test_elf_common_symbols for ELF targets

gas/

	PR ld/19645
	* NEWS: Mention --enable-elf-stt-common and --elf-stt-common=
	for ELF assemblers.
	* as.c (flag_use_elf_stt_common): New.
	(show_usage): Add --elf-stt-common=.
	(option_values): Add OPTION_ELF_STT_COMMON.
	(std_longopts): Add --elf-stt-common=.
	(parse_args): Handle --elf-stt-common=.
	* as.h (flag_use_elf_stt_common): New.
	* config.in: Regenerated.
	* configure: Likewise.
	* configure.ac: Add --enable-elf-stt-common and define
	DEFAULT_GENERATE_ELF_STT_COMMON.
	* gas/write.c (write_object_file): Set BFD_CONVERT_ELF_COMMON
	and BFD_USE_ELF_STT_COMMON if flag_use_elf_stt_common is set.
	* doc/as.texinfo: Document --elf-stt-common=.
	* testsuite/gas/elf/common3.s: New file.
	* testsuite/gas/elf/common3a.d: Likewise.
	* testsuite/gas/elf/common3b.d: Likewise.
	* testsuite/gas/elf/common4.s: Likewise.
	* testsuite/gas/elf/common4a.d: Likewise.
	* testsuite/gas/elf/common4b.d: Likewise.
	* testsuite/gas/i386/dw2-compress-3b.d: Likewise.
	* testsuite/gas/i386/dw2-compressed-3b.d: Likewise.
	* testsuite/gas/elf/elf.exp: Run common3a, common3b, common4a
	and common4b.
	* testsuite/gas/i386/dw2-compress-3.d: Renamed to ...
	* testsuite/gas/i386/dw2-compress-3a.d: This.  Pass
	--elf-stt-common=no to as.
	* testsuite/gas/i386/dw2-compressed-3.d: Renamed to ...
	* testsuite/gas/i386/dw2-compressed-3a.d: This.  Pass
	--elf-stt-common=no to as.
	* testsuite/gas/i386/i386.exp: Run dw2-compress-3a,
	dw2-compress-3b, dw2-compressed-3a and dw2-compressed-3b instead
	of dw2-compress-3 and dw2-compressed-3.

include/

	PR ld/19645
	* bfdlink.h (bfd_link_elf_stt_common): New enum.
	(bfd_link_info): Add elf_stt_common.

ld/

	PR ld/19645
	* NEWS: Mention -z common/-z nocommon for ELF targets.
	* emultempl/elf32.em (gld${EMULATION_NAME}_handle_option): Handle
	-z common and -z nocommon.
	* ld.texinfo: Document -z common/-z nocommon.
	* lexsup.c (elf_shlib_list_options): Add -z common/-z nocommon.
	* testsuite/ld-elf/tls_common.exp: Test --elf-stt-common=no and
	--elf-stt-common=yes with assembler.
	* testsuite/ld-elfcomm/common-1.s: New file.
	* testsuite/ld-elfcomm/common-1a.d: Likewise.
	* testsuite/ld-elfcomm/common-1b.d: Likewise.
	* testsuite/ld-elfcomm/common-1c.d: Likewise.
	* testsuite/ld-elfcomm/common-1d.d: Likewise.
	* testsuite/ld-elfcomm/common-1e.d: Likewise.
	* testsuite/ld-elfcomm/common-1f.d: Likewise.
	* testsuite/ld-elfcomm/common-2.s: Likewise.
	* testsuite/ld-elfcomm/common-2a.d: Likewise.
	* testsuite/ld-elfcomm/common-2b.d: Likewise.
	* testsuite/ld-elfcomm/common-2c.d: Likewise.
	* testsuite/ld-elfcomm/common-2d.d: Likewise.
	* testsuite/ld-elfcomm/common-2e.d: Likewise.
	* testsuite/ld-elfcomm/common-2f.d: Likewise.
	* testsuite/ld-elfcomm/common-3a.rd: Likewise.
	* testsuite/ld-elfcomm/common-3b.rd: Likewise.
	* testsuite/ld-i386/pr19645.d: Likewise.
	* testsuite/ld-i386/pr19645.s: Likewise.
	* testsuite/ld-x86-64/largecomm-1.s: Likewise.
	* testsuite/ld-x86-64/largecomm-1a.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1b.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1c.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1d.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1e.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1f.d: Likewise.
	* testsuite/ld-x86-64/pr19645.d: Likewise.
	* testsuite/ld-x86-64/pr19645.s: Likewise.
	* testsuite/ld-elfcomm/elfcomm.exp: Test --elf-stt-common=yes
	with assembler.
	(assembler_generates_commons): Removed.
	Run -z common/-z nocommon tests.  Run *.d tests.
	* testsuite/ld-i386/i386.exp: Run pr19645.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-x86-64/dwarfreloc.exp: Test --elf-stt-common with
	assembler.  Test STT_COMMON with readelf.

15 files changed, 124 insertions, 0 deletions

diff --git a/binutils/testsuite/binutils-all/common-1.s b/binutils/testsuite/binutils-all/common-1.s
new file mode 100644
index 0000000..f684da4
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1.s
@@ -0,0 +1 @@
+	.comm foobar,30,4
diff --git a/binutils/testsuite/binutils-all/common-1a.d b/binutils/testsuite/binutils-all/common-1a.d
new file mode 100644
index 0000000..f8c6fea
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1a.d
@@ -0,0 +1,8 @@
+#source: common-1.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +COMMON +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-1b.d b/binutils/testsuite/binutils-all/common-1b.d
new file mode 100644
index 0000000..5a56c6e
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1b.d
@@ -0,0 +1,8 @@
+#source: common-1.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +OBJECT +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-1c.d b/binutils/testsuite/binutils-all/common-1c.d
new file mode 100644
index 0000000..bbdc49e
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1c.d
@@ -0,0 +1,9 @@
+#source: common-1.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#objcopy: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +OBJECT +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-1d.d b/binutils/testsuite/binutils-all/common-1d.d
new file mode 100644
index 0000000..c0df029
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1d.d
@@ -0,0 +1,9 @@
+#source: common-1.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#objcopy: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +COMMON +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-1e.d b/binutils/testsuite/binutils-all/common-1e.d
new file mode 100644
index 0000000..9f84955
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1e.d
@@ -0,0 +1,9 @@
+#source: common-1.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#objcopy: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +COMMON +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-1f.d b/binutils/testsuite/binutils-all/common-1f.d
new file mode 100644
index 0000000..bdbdca5
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-1f.d
@@ -0,0 +1,9 @@
+#source: common-1.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#objcopy: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +OBJECT +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2.s b/binutils/testsuite/binutils-all/common-2.s
new file mode 100644
index 0000000..bf2c26c
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2.s
@@ -0,0 +1 @@
+	.tls_common foobar,30,4
diff --git a/binutils/testsuite/binutils-all/common-2a.d b/binutils/testsuite/binutils-all/common-2a.d
new file mode 100644
index 0000000..75e6217
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2a.d
@@ -0,0 +1,8 @@
+#source: common-2.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2b.d b/binutils/testsuite/binutils-all/common-2b.d
new file mode 100644
index 0000000..7c7a194
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2b.d
@@ -0,0 +1,8 @@
+#source: common-2.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2c.d b/binutils/testsuite/binutils-all/common-2c.d
new file mode 100644
index 0000000..c203dd2
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2c.d
@@ -0,0 +1,9 @@
+#source: common-2.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#objcopy: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2d.d b/binutils/testsuite/binutils-all/common-2d.d
new file mode 100644
index 0000000..da221d6
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2d.d
@@ -0,0 +1,9 @@
+#source: common-2.s
+#as: --elf-stt-common=yes
+#PROG: objcopy
+#objcopy: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2e.d b/binutils/testsuite/binutils-all/common-2e.d
new file mode 100644
index 0000000..04b1faf
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2e.d
@@ -0,0 +1,9 @@
+#source: common-2.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#objcopy: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/common-2f.d b/binutils/testsuite/binutils-all/common-2f.d
new file mode 100644
index 0000000..4748e5d
--- /dev/null
+++ b/binutils/testsuite/binutils-all/common-2f.d
@@ -0,0 +1,9 @@
+#source: common-2.s
+#as: --elf-stt-common=no
+#PROG: objcopy
+#objcopy: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/binutils/testsuite/binutils-all/objcopy.exp b/binutils/testsuite/binutils-all/objcopy.exp
index b2c54ea..c348578 100644
--- a/binutils/testsuite/binutils-all/objcopy.exp
+++ b/binutils/testsuite/binutils-all/objcopy.exp
@@ -1005,6 +1005,23 @@ proc objcopy_test_symbol_manipulation {} {
     }
 }
 
+proc objcopy_test_elf_common_symbols {} {
+    global srcdir
+    global subdir
+
+    # hpux has a non-standard common directive.
+    if { [istarget "*-*-hpux*"] } then {
+	return
+    }
+
+    set test_list [lsort [glob -nocomplain $srcdir/$subdir/common-*.d]]
+    foreach t $test_list {
+        # We need to strip the ".d", but can leave the dirname.
+        verbose [file rootname $t]
+        run_dump_test [file rootname $t]
+    }
+}
+
 # ia64 specific tests
 if { ([istarget "ia64-*-elf*"]
        || [istarget "ia64-*-linux*"]) } {
@@ -1014,6 +1031,7 @@ if { ([istarget "ia64-*-elf*"]
 # ELF specific tests
 if [is_elf_format] {
     objcopy_test_symbol_manipulation
+    objcopy_test_elf_common_symbols
     objcopy_test "ELF unknown section type" unknown.s
     objcopy_test_readelf "ELF group" group.s
     objcopy_test_readelf "ELF group" group-2.s