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.

12 files changed, 251 insertions, 6 deletions

diff --git a/gas/testsuite/gas/elf/common3.s b/gas/testsuite/gas/elf/common3.s
new file mode 100644
index 0000000..f684da4
--- /dev/null
+++ b/gas/testsuite/gas/elf/common3.s
@@ -0,0 +1 @@
+	.comm foobar,30,4
diff --git a/gas/testsuite/gas/elf/common3a.d b/gas/testsuite/gas/elf/common3a.d
new file mode 100644
index 0000000..fa9d5ce
--- /dev/null
+++ b/gas/testsuite/gas/elf/common3a.d
@@ -0,0 +1,7 @@
+#source: common3.s
+#as: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +COMMON +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/gas/testsuite/gas/elf/common3b.d b/gas/testsuite/gas/elf/common3b.d
new file mode 100644
index 0000000..9481d13
--- /dev/null
+++ b/gas/testsuite/gas/elf/common3b.d
@@ -0,0 +1,7 @@
+#source: common3.s
+#as: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +OBJECT +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/gas/testsuite/gas/elf/common4.s b/gas/testsuite/gas/elf/common4.s
new file mode 100644
index 0000000..bf2c26c
--- /dev/null
+++ b/gas/testsuite/gas/elf/common4.s
@@ -0,0 +1 @@
+	.tls_common foobar,30,4
diff --git a/gas/testsuite/gas/elf/common4a.d b/gas/testsuite/gas/elf/common4a.d
new file mode 100644
index 0000000..fceb01b
--- /dev/null
+++ b/gas/testsuite/gas/elf/common4a.d
@@ -0,0 +1,7 @@
+#source: common4.s
+#as: --elf-stt-common=yes
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/gas/testsuite/gas/elf/common4b.d b/gas/testsuite/gas/elf/common4b.d
new file mode 100644
index 0000000..c18284e
--- /dev/null
+++ b/gas/testsuite/gas/elf/common4b.d
@@ -0,0 +1,7 @@
+#source: common4.s
+#as: --elf-stt-common=no
+#readelf: -s -W
+
+#...
+ +[0-9]+: +0+4 +30 +TLS +GLOBAL +DEFAULT +COM +foobar
+#pass
diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index a2a86dd..fb5619d 100644
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -218,6 +218,10 @@ if { [is_elf_format] } then {
     if { ![istarget "*-*-hpux*"] } then {
 	run_dump_test "common1"
 	run_dump_test "common2"
+	run_dump_test "common3a"
+	run_dump_test "common3b"
+	run_dump_test "common4a"
+	run_dump_test "common4b"
     }
 
     run_dump_test "strtab"
diff --git a/gas/testsuite/gas/i386/dw2-compressed-3.d b/gas/testsuite/gas/i386/dw2-compress-3a.d
index bd2818b..fe19884 100644
--- a/gas/testsuite/gas/i386/dw2-compressed-3.d
+++ b/gas/testsuite/gas/i386/dw2-compress-3a.d
@@ -1,7 +1,7 @@
 #source: dw2-compress-3.s
-#as: --compress-debug-sections=zlib-gabi
+#as: --compress-debug-sections --elf-stt-common=no
 #readelf: -w
-#name: DWARF2 debugging information 3 with SHF_COMPRESSED
+#name: DWARF2 debugging information 3 w/o STT_COMMON
 
 Contents of the .debug_info section:
 
diff --git a/gas/testsuite/gas/i386/dw2-compress-3.d b/gas/testsuite/gas/i386/dw2-compress-3b.d
index d2aa8ef..aa0651e 100644
--- a/gas/testsuite/gas/i386/dw2-compress-3.d
+++ b/gas/testsuite/gas/i386/dw2-compress-3b.d
@@ -1,6 +1,7 @@
-#as: --compress-debug-sections
+#source: dw2-compress-3.s
+#as: --compress-debug-sections --elf-stt-common=yes
 #readelf: -w
-#name: DWARF2 debugging information 3
+#name: DWARF2 debugging information 3 with STT_COMMON
 
 Contents of the .debug_info section:
 
diff --git a/gas/testsuite/gas/i386/dw2-compressed-3a.d b/gas/testsuite/gas/i386/dw2-compressed-3a.d
new file mode 100644
index 0000000..a0d16c7
--- /dev/null
+++ b/gas/testsuite/gas/i386/dw2-compressed-3a.d
@@ -0,0 +1,104 @@
+#source: dw2-compress-3.s
+#as: --compress-debug-sections=zlib-gabi --elf-stt-common=no
+#readelf: -w
+#name: DWARF2 debugging information 3 with SHF_COMPRESSED w/o STT_COMMON
+
+Contents of the .debug_info section:
+
+  Compilation Unit @ offset 0x0:
+   Length:        0x32 \(32-bit\)
+   Version:       4
+   Abbrev Offset: 0x0
+   Pointer Size:  4
+ <0><b>: Abbrev Number: 1 \(DW_TAG_compile_unit\)
+    <c>   DW_AT_producer    : \(indirect string, offset: 0x2\): GNU C 4.8.3
+    <10>   DW_AT_language    : 1	\(ANSI C\)
+    <11>   DW_AT_name        : \(indirect string, offset: 0xe\): dw2-compress-3.c
+    <15>   DW_AT_comp_dir    : \(indirect string, offset: 0x0\): .
+    <19>   DW_AT_stmt_list   : 0x0
+ <1><1d>: Abbrev Number: 2 \(DW_TAG_variable\)
+    <1e>   DW_AT_name        : foo
+    <22>   DW_AT_decl_file   : 1
+    <23>   DW_AT_decl_line   : 1
+    <24>   DW_AT_type        : <0x2e>
+    <28>   DW_AT_external    : 1
+    <28>   DW_AT_location    : 5 byte block: 3 4 0 0 0 	\(DW_OP_addr: 4\)
+ <1><2e>: Abbrev Number: 3 \(DW_TAG_base_type\)
+    <2f>   DW_AT_byte_size   : 4
+    <30>   DW_AT_encoding    : 5	\(signed\)
+    <31>   DW_AT_name        : int
+ <1><35>: Abbrev Number: 0
+
+Contents of the .debug_abbrev section:
+
+  Number TAG \(0x0\)
+   1      DW_TAG_compile_unit    \[has children\]
+    DW_AT_producer     DW_FORM_strp
+    DW_AT_language     DW_FORM_data1
+    DW_AT_name         DW_FORM_strp
+    DW_AT_comp_dir     DW_FORM_strp
+    DW_AT_stmt_list    DW_FORM_sec_offset
+    DW_AT value: 0     DW_FORM value: 0
+   2      DW_TAG_variable    \[no children\]
+    DW_AT_name         DW_FORM_string
+    DW_AT_decl_file    DW_FORM_data1
+    DW_AT_decl_line    DW_FORM_data1
+    DW_AT_type         DW_FORM_ref4
+    DW_AT_external     DW_FORM_flag_present
+    DW_AT_location     DW_FORM_exprloc
+    DW_AT value: 0     DW_FORM value: 0
+   3      DW_TAG_base_type    \[no children\]
+    DW_AT_byte_size    DW_FORM_data1
+    DW_AT_encoding     DW_FORM_data1
+    DW_AT_name         DW_FORM_string
+    DW_AT value: 0     DW_FORM value: 0
+
+Contents of the .debug_aranges section:
+
+  Length:                   20
+  Version:                  2
+  Offset into .debug_info:  0x0
+  Pointer Size:             4
+  Segment Size:             0
+
+    Address    Length
+    00000000 00000000 
+
+Raw dump of debug contents of section .debug_line:
+
+  Offset:                      0x0
+  Length:                      45
+  DWARF Version:               2
+  Prologue Length:             39
+  Minimum Instruction Length:  1
+  Initial value of 'is_stmt':  1
+  Line Base:                   -5
+  Line Range:                  14
+  Opcode Base:                 13
+
+ Opcodes:
+  Opcode 1 has 0 args
+  Opcode 2 has 1 args
+  Opcode 3 has 1 args
+  Opcode 4 has 1 args
+  Opcode 5 has 1 args
+  Opcode 6 has 0 args
+  Opcode 7 has 0 args
+  Opcode 8 has 0 args
+  Opcode 9 has 1 args
+  Opcode 10 has 0 args
+  Opcode 11 has 0 args
+  Opcode 12 has 1 args
+
+ The Directory Table is empty.
+
+ The File Name Table \(offset 0x1c\):
+  Entry	Dir	Time	Size	Name
+  1	0	0	0	dw2-compress-3.c
+
+ No Line Number Statements.
+Contents of the .debug_str section:
+
+  0x00000000 2e00474e 55204320 342e382e 33006477 ..GNU C 4.8.3.dw
+  0x00000010 322d636f 6d707265 73732d33 2e6300   2-compress-3.c.
+
diff --git a/gas/testsuite/gas/i386/dw2-compressed-3b.d b/gas/testsuite/gas/i386/dw2-compressed-3b.d
new file mode 100644
index 0000000..6469ca9
--- /dev/null
+++ b/gas/testsuite/gas/i386/dw2-compressed-3b.d
@@ -0,0 +1,104 @@
+#source: dw2-compress-3.s
+#as: --compress-debug-sections=zlib-gabi --elf-stt-common=yes
+#readelf: -w
+#name: DWARF2 debugging information 3 with SHF_COMPRESSED with STT_COMMON
+
+Contents of the .debug_info section:
+
+  Compilation Unit @ offset 0x0:
+   Length:        0x32 \(32-bit\)
+   Version:       4
+   Abbrev Offset: 0x0
+   Pointer Size:  4
+ <0><b>: Abbrev Number: 1 \(DW_TAG_compile_unit\)
+    <c>   DW_AT_producer    : \(indirect string, offset: 0x2\): GNU C 4.8.3
+    <10>   DW_AT_language    : 1	\(ANSI C\)
+    <11>   DW_AT_name        : \(indirect string, offset: 0xe\): dw2-compress-3.c
+    <15>   DW_AT_comp_dir    : \(indirect string, offset: 0x0\): .
+    <19>   DW_AT_stmt_list   : 0x0
+ <1><1d>: Abbrev Number: 2 \(DW_TAG_variable\)
+    <1e>   DW_AT_name        : foo
+    <22>   DW_AT_decl_file   : 1
+    <23>   DW_AT_decl_line   : 1
+    <24>   DW_AT_type        : <0x2e>
+    <28>   DW_AT_external    : 1
+    <28>   DW_AT_location    : 5 byte block: 3 4 0 0 0 	\(DW_OP_addr: 4\)
+ <1><2e>: Abbrev Number: 3 \(DW_TAG_base_type\)
+    <2f>   DW_AT_byte_size   : 4
+    <30>   DW_AT_encoding    : 5	\(signed\)
+    <31>   DW_AT_name        : int
+ <1><35>: Abbrev Number: 0
+
+Contents of the .debug_abbrev section:
+
+  Number TAG \(0x0\)
+   1      DW_TAG_compile_unit    \[has children\]
+    DW_AT_producer     DW_FORM_strp
+    DW_AT_language     DW_FORM_data1
+    DW_AT_name         DW_FORM_strp
+    DW_AT_comp_dir     DW_FORM_strp
+    DW_AT_stmt_list    DW_FORM_sec_offset
+    DW_AT value: 0     DW_FORM value: 0
+   2      DW_TAG_variable    \[no children\]
+    DW_AT_name         DW_FORM_string
+    DW_AT_decl_file    DW_FORM_data1
+    DW_AT_decl_line    DW_FORM_data1
+    DW_AT_type         DW_FORM_ref4
+    DW_AT_external     DW_FORM_flag_present
+    DW_AT_location     DW_FORM_exprloc
+    DW_AT value: 0     DW_FORM value: 0
+   3      DW_TAG_base_type    \[no children\]
+    DW_AT_byte_size    DW_FORM_data1
+    DW_AT_encoding     DW_FORM_data1
+    DW_AT_name         DW_FORM_string
+    DW_AT value: 0     DW_FORM value: 0
+
+Contents of the .debug_aranges section:
+
+  Length:                   20
+  Version:                  2
+  Offset into .debug_info:  0x0
+  Pointer Size:             4
+  Segment Size:             0
+
+    Address    Length
+    00000000 00000000 
+
+Raw dump of debug contents of section .debug_line:
+
+  Offset:                      0x0
+  Length:                      45
+  DWARF Version:               2
+  Prologue Length:             39
+  Minimum Instruction Length:  1
+  Initial value of 'is_stmt':  1
+  Line Base:                   -5
+  Line Range:                  14
+  Opcode Base:                 13
+
+ Opcodes:
+  Opcode 1 has 0 args
+  Opcode 2 has 1 args
+  Opcode 3 has 1 args
+  Opcode 4 has 1 args
+  Opcode 5 has 1 args
+  Opcode 6 has 0 args
+  Opcode 7 has 0 args
+  Opcode 8 has 0 args
+  Opcode 9 has 1 args
+  Opcode 10 has 0 args
+  Opcode 11 has 0 args
+  Opcode 12 has 1 args
+
+ The Directory Table is empty.
+
+ The File Name Table \(offset 0x1c\):
+  Entry	Dir	Time	Size	Name
+  1	0	0	0	dw2-compress-3.c
+
+ No Line Number Statements.
+Contents of the .debug_str section:
+
+  0x00000000 2e00474e 55204320 342e382e 33006477 ..GNU C 4.8.3.dw
+  0x00000010 322d636f 6d707265 73732d33 2e6300   2-compress-3.c.
+
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 22aca23..f1e7611 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -448,9 +448,11 @@ if [expr [istarget "i*86-*-*"] || [istarget "x86_64-*-*"]] then {
 	run_list_test_stdin "list-2" "-al"
 	run_list_test_stdin "list-3" "-al"
 	run_dump_test "dw2-compress-1"
-	run_dump_test "dw2-compress-3"
+	run_dump_test "dw2-compress-3a"
+	run_dump_test "dw2-compress-3b"
 	run_dump_test "dw2-compressed-1"
-	run_dump_test "dw2-compressed-3"
+	run_dump_test "dw2-compressed-3a"
+	run_dump_test "dw2-compressed-3b"
     }
 }