RFC: [PATCH] Make default compression gABI compliant

H.J. Lu hjl.tools@gmail.com
Sun Jul 12 19:57:00 GMT 2015


All programs in binutils+gdb git repo now support gABI compression
with the SHF_COMPRESSED bit.  This patch makes the zlib-gabi option
as compression default for gas, gold, ld and objcopy, instead of the
zlib-gnu option whose outputs are incompatible with gABI.

Tested on Linux/x86-64 with assembler defaulting to
--compress-debug-sections=zlib-gabi.

Any comments, objections?

Thanks.

H.J.
---
binutils/

	* objcopy.c (copy_file): Set BFD_COMPRESS_GABI if not
	zlib-gnu.
	* doc/binutils.texi: Change --compress-debug-sections and
	--compress-debug-sections=zlib to zlib-gabi.

binutils/testsuite/

	* binutils-all/compress.exp: Update.

gas/

	* as.c (parse_args): Make --compress-debug-sections and
	--compress-debug-sections=zlib the same as
	--compress-debug-sections=zlib-gabi.
	* doc/as.texinfo: Change --compress-debug-sections and
	--compress-debug-sections=zlib to zlib-gabi.

gold/

	* compressed_output.cc (Output_compressed_section::set_final_data_size):
	Make --compress-debug-sections=zlib the same as
	--compress-debug-sections=zlib-gabi.
	* testsuite/Makefile.am (flagstest_compress_debug_sections.check):
	Expect ".debug_.*" with the SHF_COMPRESSED bit, instead of
	".zdebug_".
	* testsuite/Makefile.in: Regenerated.

ld/

	* emultempl/elf32.em (gld${EMULATION_NAME}_handle_option): Make
	--compress-debug-sections=zlib the same as
	--compress-debug-sections=zlib-gabi.
	* ld.texinfo: Change --compress-debug-sections=zlib to zlib-gabi.

ld/testsuite/

	* ld-elf/zlibbegin.rS: Updated to .debug_.* with the
	SHF_COMPRESSED bit.
	* ld-elf/zlibnormal.rS: Likewise.
---
 binutils/doc/binutils.texi                   | 16 +++++++++-------
 binutils/objcopy.c                           |  2 +-
 binutils/testsuite/binutils-all/compress.exp | 23 ++++++++++++++---------
 gas/as.c                                     |  4 ++--
 gas/doc/as.texinfo                           | 17 ++++++++++-------
 gold/compressed_output.cc                    |  7 +++----
 gold/testsuite/Makefile.am                   |  4 ++--
 gold/testsuite/Makefile.in                   |  4 ++--
 ld/emultempl/elf32.em                        |  2 +-
 ld/ld.texinfo                                |  9 +++++----
 ld/testsuite/ld-elf/zlibbegin.rS             |  2 +-
 ld/testsuite/ld-elf/zlibnormal.rS            |  2 +-
 12 files changed, 51 insertions(+), 41 deletions(-)

diff --git a/binutils/doc/binutils.texi b/binutils/doc/binutils.texi
index 0781036..466f125 100644
--- a/binutils/doc/binutils.texi
+++ b/binutils/doc/binutils.texi
@@ -1844,10 +1844,9 @@ It can also be a useful way of reducing the size of a @option{--just-symbols}
 linker input file.
 
 @item --compress-debug-sections
-Compress DWARF debug sections using zlib.  The debug sections are
-renamed to begin with @samp{.zdebug} instead of @samp{.debug}.  Note -
-if compression would actually make a section @emph{larger} then it is
-not compressed or renamed.
+Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
+ELF ABI.  Note - if compression would actually make a section
+@emph{larger}, then it is not compressed.
 
 @item --compress-debug-sections=none
 @itemx --compress-debug-sections=zlib
@@ -1857,10 +1856,13 @@ For ELF files, these options control how DWARF debug sections are
 compressed.  @option{--compress-debug-sections=none} is equivalent
 to @option{--nocompress-debug-sections}.
 @option{--compress-debug-sections=zlib} and
-@option{--compress-debug-sections=zlib-gnu} are equivalent to
+@option{--compress-debug-sections=zlib-gabi} are equivalent to
 @option{--compress-debug-sections}.
-@option{--compress-debug-sections=zlib-gabi} compresses
-DWARF debug sections with SHF_COMPRESSED from the ELF ABI.
+@option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
+sections using zlib.  The debug sections are renamed to begin with
+@samp{.zdebug} instead of @samp{.debug}.  Note - if compression would
+actually make a section @emph{larger}, then it is not compressed nor
+renamed.
 
 @item --decompress-debug-sections
 Decompress DWARF debug sections using zlib.  The original section
diff --git a/binutils/objcopy.c b/binutils/objcopy.c
index d6516e0..bb6ca44 100644
--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -2607,7 +2607,7 @@ copy_file (const char *input_filename, const char *output_filename,
       ibfd->flags |= BFD_COMPRESS;
       /* Don't check if input is ELF here since this information is
 	 only available after bfd_check_format_matches is called.  */
-      if (do_debug_sections == compress_gabi_zlib)
+      if (do_debug_sections != compress_gnu_zlib)
 	ibfd->flags |= BFD_COMPRESS_GABI;
       break;
     case decompress:
diff --git a/binutils/testsuite/binutils-all/compress.exp b/binutils/testsuite/binutils-all/compress.exp
index abff197..4dac503 100644
--- a/binutils/testsuite/binutils-all/compress.exp
+++ b/binutils/testsuite/binutils-all/compress.exp
@@ -39,7 +39,12 @@ if { ![binutils_assemble_flags $srcdir/$subdir/dw2-1.S ${compressedfile}.o --com
     return
 }
 
-set got [remote_exec host "cmp ${testfile}.o ${compressedfile}.o"]
+if { ![binutils_assemble_flags $srcdir/$subdir/dw2-1.S ${compressedfile}gnu.o --compress-debug-sections=zlib-gnu] } then {
+    unsupported "compressed debug sections with zlib-gnu"
+    return
+}
+
+set got [remote_exec host "cmp ${testfile}.o ${compressedfile}gnu.o"]
 # Use it to set up xfail.
 set exec_output [lindex $got 1]
 if [string match "" $exec_output] then {
@@ -136,8 +141,8 @@ if ![string match "" $got] then {
 
 # Xfail this test if there are no compressed sections.
 setup_xfail "$compression_used$target_triplet"
-set testname "objcopy compress debug sections in archive"
-set got [binutils_run $OBJCOPY "--compress-debug-sections ${copyfile}.a ${compressedcopyfile}.a"]
+set testname "objcopy compress debug sections in archive with zlib-gnu"
+set got [binutils_run $OBJCOPY "--compress-debug-sections=zlib-gnu ${copyfile}.a ${compressedcopyfile}.a"]
 if ![string match "" $got] then {
     fail "objcopy ($testname)"
 } else {
@@ -228,13 +233,13 @@ if { ![binutils_assemble_flags $srcdir/$subdir/dw2-1.S ${compressedfile}gnu.o --
     return
 }
 
-set src1 ${compressedfile}gnu.o
+set src1 ${compressedfile}gabi.o
 set src2 ${compressedfile}.o
 set status [remote_exec build cmp "${src1} ${src2}"]
 set exec_output [lindex $status 1]
 set exec_output [prune_warnings $exec_output]
 if ![string match "" $exec_output] then {
-    fail "compressed debug sections with zlib-gnu"
+    fail "compressed debug sections with zlib-gabi"
     return
 }
 
@@ -248,13 +253,13 @@ if { ![binutils_assemble_flags $srcdir/$subdir/dw2-2.S ${compressedfile2}gnu.o -
     return
 }
 
-set src1 ${compressedfile2}gnu.o
+set src1 ${compressedfile2}gabi.o
 set src2 ${compressedfile2}.o
 set status [remote_exec build cmp "${src1} ${src2}"]
 set exec_output [lindex $status 1]
 set exec_output [prune_warnings $exec_output]
 if ![string match "" $exec_output] then {
-    fail "compressed debug sections with zlib-gnu"
+    fail "compressed debug sections with zlib-gabi"
     return
 }
 
@@ -292,13 +297,13 @@ if { ![binutils_assemble_flags $srcdir/$subdir/dw2-3.S ${compressedfile3}gnu.o -
     return
 }
 
-set src1 ${compressedfile3}gnu.o
+set src1 ${compressedfile3}gabi.o
 set src2 ${compressedfile3}.o
 set status [remote_exec build cmp "${src1} ${src2}"]
 set exec_output [lindex $status 1]
 set exec_output [prune_warnings $exec_output]
 if ![string match "" $exec_output] then {
-    fail "compressed debug sections with zlib-gnu"
+    fail "compressed debug sections with zlib-gabi"
     return
 }
 
diff --git a/gas/as.c b/gas/as.c
index b8a5be4..6fb28e9 100644
--- a/gas/as.c
+++ b/gas/as.c
@@ -665,7 +665,7 @@ This program has absolutely no warranty.\n"));
 	      if (strcasecmp (optarg, "none") == 0)
 		flag_compress_debug = COMPRESS_DEBUG_NONE;
 	      else if (strcasecmp (optarg, "zlib") == 0)
-		flag_compress_debug = COMPRESS_DEBUG_GNU_ZLIB;
+		flag_compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
 	      else if (strcasecmp (optarg, "zlib-gnu") == 0)
 		flag_compress_debug = COMPRESS_DEBUG_GNU_ZLIB;
 	      else if (strcasecmp (optarg, "zlib-gabi") == 0)
@@ -679,7 +679,7 @@ This program has absolutely no warranty.\n"));
 #endif
 	    }
 	  else
-	    flag_compress_debug = COMPRESS_DEBUG;
+	    flag_compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
 	  break;
 
 	case OPTION_NOCOMPRESS_DEBUG:
diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo
index 950bf28..70f1b96 100644
--- a/gas/doc/as.texinfo
+++ b/gas/doc/as.texinfo
@@ -625,10 +625,10 @@ Begin in alternate macro mode.
 @end ifclear
 
 @item --compress-debug-sections
-Compress DWARF debug sections using zlib.  The debug sections are renamed
-to begin with @samp{.zdebug}, and the resulting object file may not be
-compatible with older linkers and object file utilities.  Note if compression
-would make a given section @emph{larger} then it is not compressed or renamed.
+Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
+ELF ABI.  The resulting object file may not be compatible with older
+linkers and object file utilities.  Note if compression would make a
+given section @emph{larger} then it is not compressed.
 
 @ifset ELF
 @cindex @samp{--compress-debug-sections=} option
@@ -640,10 +640,13 @@ These options control how DWARF debug sections are compressed.
 @option{--compress-debug-sections=none} is equivalent to
 @option{--nocompress-debug-sections}.
 @option{--compress-debug-sections=zlib} and
-@option{--compress-debug-sections=zlib-gnu} are equivalent to
+@option{--compress-debug-sections=zlib-gabi} are equivalent to
 @option{--compress-debug-sections}.
-@option{--compress-debug-sections=zlib-gabi} compresses
-DWARF debug sections with SHF_COMPRESSED from the ELF ABI.
+@option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
+sections using zlib.  The debug sections are renamed to begin with
+@samp{.zdebug}.  Note if compression would make a given section
+@emph{larger} then it is not compressed nor renamed.
+
 @end ifset
 
 @item --nocompress-debug-sections
diff --git a/gold/compressed_output.cc b/gold/compressed_output.cc
index 2630330..77679fe 100644
--- a/gold/compressed_output.cc
+++ b/gold/compressed_output.cc
@@ -233,11 +233,10 @@ Output_compressed_section::set_final_data_size()
   enum { none, gnu_zlib, gabi_zlib } compress;
   int compression_header_size = 12;
   const int size = parameters->target().get_size();
-  if (strcmp(this->options_->compress_debug_sections(), "zlib") == 0)
+  if (strcmp(this->options_->compress_debug_sections(), "zlib-gnu") == 0)
     compress = gnu_zlib;
-  else if (strcmp(this->options_->compress_debug_sections(), "zlib-gnu") == 0)
-    compress = gnu_zlib;
-  else if (strcmp(this->options_->compress_debug_sections(), "zlib-gabi") == 0)
+  else if (strcmp(this->options_->compress_debug_sections(), "zlib-gabi") == 0
+	   || strcmp(this->options_->compress_debug_sections(), "zlib") == 0)
     {
       compress = gabi_zlib;
       if (size == 32)
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index d2f4668..41186c6 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -1353,9 +1353,9 @@ flagstest_compress_debug_sections.stdout: flagstest_compress_debug_sections
 	$(TEST_READELF) -w $< | sed -e "s/.zdebug_/.debug_/" > $@.tmp
 	mv -f $@.tmp $@
 
-# Check there are compressed DWARF .zdebug_* sections.
+# Check there are compressed DWARF .debug_* sections.
 flagstest_compress_debug_sections.check: flagstest_compress_debug_sections
-	$(TEST_READELF) -SW $< | grep ".zdebug_" > $@.tmp
+	$(TEST_READELF) -SW $< | egrep ".debug_.* C *" > $@.tmp
 	mv -f $@.tmp $@
 
 # Compare DWARF debug info.
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 1c336c6..563f598 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -5618,9 +5618,9 @@ uninstall-am:
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -w $< | sed -e "s/.zdebug_/.debug_/" > $@.tmp
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	mv -f $@.tmp $@
 
-# Check there are compressed DWARF .zdebug_* sections.
+# Check there are compressed DWARF .debug_* sections.
 @GCC_TRUE@@NATIVE_LINKER_TRUE@flagstest_compress_debug_sections.check: flagstest_compress_debug_sections
-@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -SW $< | grep ".zdebug_" > $@.tmp
+@GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -SW $< | egrep ".debug_.* C *" > $@.tmp
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	mv -f $@.tmp $@
 
 # Compare DWARF debug info.
diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index 14f7963..8a41347 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -2223,7 +2223,7 @@ gld${EMULATION_NAME}_handle_option (int optc)
       if (strcasecmp (optarg, "none") == 0)
 	link_info.compress_debug = COMPRESS_DEBUG_NONE;
       else if (strcasecmp (optarg, "zlib") == 0)
-	link_info.compress_debug = COMPRESS_DEBUG_GNU_ZLIB;
+	link_info.compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
       else if (strcasecmp (optarg, "zlib-gnu") == 0)
 	link_info.compress_debug = COMPRESS_DEBUG_GNU_ZLIB;
       else if (strcasecmp (optarg, "zlib-gabi") == 0)
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 246f545..0503f99 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -2228,11 +2228,12 @@ hash tables.  The default is @code{sysv}.
 @itemx --compress-debug-sections=zlib-gabi
 On ELF platforms , these options control how DWARF debug sections are
 compressed using zlib.  @option{--compress-debug-sections=none} doesn't
-compress DWARF debug sections.  @option{--compress-debug-sections=zlib}
-and @option{--compress-debug-sections=zlib-gnu} compress DWARF debug
+compress DWARF debug sections.
+@option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
 sections and rename debug section names to begin with @samp{.zdebug}
-instead of @samp{.debug}.  @option{--compress-debug-sections=zlib-gabi}
-compresses DWARF debug sections with SHF_COMPRESSED from the ELF ABI.
+instead of @samp{.debug}.  @option{--compress-debug-sections=zlib}
+and @option{--compress-debug-sections=zlib-gabi}
+compress DWARF debug sections with SHF_COMPRESSED from the ELF ABI.
 
 @kindex --reduce-memory-overheads
 @item --reduce-memory-overheads
diff --git a/ld/testsuite/ld-elf/zlibbegin.rS b/ld/testsuite/ld-elf/zlibbegin.rS
index 54de24c..294fdb4 100644
--- a/ld/testsuite/ld-elf/zlibbegin.rS
+++ b/ld/testsuite/ld-elf/zlibbegin.rS
@@ -1,3 +1,3 @@
 #...
- +\[[ 0-9]+\] .zdebug_.* +(PROGBITS|MIPS_DWARF) +0+ +[0-9a-f]+ +[0-9a-f]+ [0-9a-f]+ +0 +0 +1
+ +\[[ 0-9]+\] .debug_.* +(PROGBITS|MIPS_DWARF) +0+ +[0-9a-f]+ +[0-9a-f]+ [0-9a-f]+ +C +0 +0 +1
 #pass
diff --git a/ld/testsuite/ld-elf/zlibnormal.rS b/ld/testsuite/ld-elf/zlibnormal.rS
index 54de24c..294fdb4 100644
--- a/ld/testsuite/ld-elf/zlibnormal.rS
+++ b/ld/testsuite/ld-elf/zlibnormal.rS
@@ -1,3 +1,3 @@
 #...
- +\[[ 0-9]+\] .zdebug_.* +(PROGBITS|MIPS_DWARF) +0+ +[0-9a-f]+ +[0-9a-f]+ [0-9a-f]+ +0 +0 +1
+ +\[[ 0-9]+\] .debug_.* +(PROGBITS|MIPS_DWARF) +0+ +[0-9a-f]+ +[0-9a-f]+ [0-9a-f]+ +C +0 +0 +1
 #pass
-- 
2.4.3



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