gold, dwp: support zstd compressed input debug sections [PR 29641]

This feature is enabled if config/zstd.m4 uses zstd.
diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index 3ca2d61..97784ab 100644
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -465,6 +465,7 @@
 enum
 {
   ELFCOMPRESS_ZLIB = 1,
+  ELFCOMPRESS_ZSTD = 2,
   ELFCOMPRESS_LOOS = 0x60000000,
   ELFCOMPRESS_HIOS = 0x6fffffff,
   ELFCOMPRESS_LOPROC = 0x70000000,
diff --git a/gold/Makefile.am b/gold/Makefile.am
index 934e366..6c9a91f 100644
--- a/gold/Makefile.am
+++ b/gold/Makefile.am
@@ -34,8 +34,8 @@
 THREADFLAGS = @PTHREAD_CFLAGS@
 THREADLIBS = @PTHREAD_LIBS@
 
-AM_CFLAGS = $(WARN_CFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(THREADFLAGS)
-AM_CXXFLAGS = $(WARN_CXXFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(THREADFLAGS) $(JANSSON_CFLAGS)
+AM_CFLAGS = $(WARN_CFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(ZSTD_CFLAGS) $(THREADFLAGS)
+AM_CXXFLAGS = $(WARN_CXXFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(ZSTD_CFLAGS) $(THREADFLAGS) $(JANSSON_CFLAGS)
 AM_LDFLAGS = $(THREADFLAGS)
 
 AM_CPPFLAGS = \
@@ -187,7 +187,7 @@
 sources_var = main.cc
 deps_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL_DEP)
 ldadd_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(GOLD_LDADD) $(LIBINTL) \
-	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 ldflags_var = $(GOLD_LDFLAGS)
 
 ld_new_SOURCES = $(sources_var)
@@ -201,12 +201,12 @@
 incremental_dump_DEPENDENCIES = $(TARGETOBJS) libgold.a $(LIBIBERTY) \
 	$(LIBINTL_DEP)
 incremental_dump_LDADD = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL) \
-	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 dwp_SOURCES = dwp.cc
 dwp_DEPENDENCIES = libgold.a $(LIBIBERTY) $(LIBINTL_DEP)
 dwp_LDADD = libgold.a $(LIBIBERTY) $(GOLD_LDADD) $(LIBINTL) $(THREADLIBS) \
-	$(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 dwp_LDFLAGS = $(GOLD_LDFLAGS)
 
 CONFIG_STATUS_DEPENDENCIES = $(srcdir)/../bfd/development.sh
diff --git a/gold/Makefile.in b/gold/Makefile.in
index b7b7ad5..c651a4a 100644
--- a/gold/Makefile.in
+++ b/gold/Makefile.in
@@ -135,6 +135,7 @@
 	$(top_srcdir)/../config/po.m4 \
 	$(top_srcdir)/../config/progtest.m4 \
 	$(top_srcdir)/../config/zlib.m4 \
+	$(top_srcdir)/../config/zstd.m4 \
 	$(top_srcdir)/../bfd/warning.m4 $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
@@ -194,7 +195,8 @@
 am__DEPENDENCIES_2 = $(am__DEPENDENCIES_1) libgold.a $(LIBIBERTY) \
 	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1) \
 	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1) \
-	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1)
+	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1) \
+	$(am__DEPENDENCIES_1)
 ld_new_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(ld_new_LDFLAGS) \
 	$(LDFLAGS) -o $@
 @GCC_TRUE@@NATIVE_LINKER_TRUE@am_ld1_OBJECTS = $(am__objects_4)
@@ -601,6 +603,8 @@
 XGETTEXT = @XGETTEXT@
 YACC = @YACC@
 YFLAGS = @YFLAGS@
+ZSTD_CFLAGS = @ZSTD_CFLAGS@
+ZSTD_LIBS = @ZSTD_LIBS@
 abs_builddir = @abs_builddir@
 abs_srcdir = @abs_srcdir@
 abs_top_builddir = @abs_top_builddir@
@@ -673,8 +677,8 @@
 ZLIBINC = @zlibinc@
 THREADFLAGS = @PTHREAD_CFLAGS@
 THREADLIBS = @PTHREAD_LIBS@
-AM_CFLAGS = $(WARN_CFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(THREADFLAGS)
-AM_CXXFLAGS = $(WARN_CXXFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(THREADFLAGS) $(JANSSON_CFLAGS)
+AM_CFLAGS = $(WARN_CFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(ZSTD_CFLAGS) $(THREADFLAGS)
+AM_CXXFLAGS = $(WARN_CXXFLAGS) $(LFS_CFLAGS) $(RANDOM_SEED_CFLAGS) $(ZLIBINC) $(ZSTD_CFLAGS) $(THREADFLAGS) $(JANSSON_CFLAGS)
 AM_LDFLAGS = $(THREADFLAGS)
 AM_CPPFLAGS = \
 	-I$(srcdir) -I$(srcdir)/../include -I$(srcdir)/../elfcpp \
@@ -811,7 +815,7 @@
 sources_var = main.cc
 deps_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL_DEP)
 ldadd_var = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(GOLD_LDADD) $(LIBINTL) \
-	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 ldflags_var = $(GOLD_LDFLAGS)
 ld_new_SOURCES = $(sources_var)
@@ -824,12 +828,12 @@
 	$(LIBINTL_DEP)
 
 incremental_dump_LDADD = $(TARGETOBJS) libgold.a $(LIBIBERTY) $(LIBINTL) \
-	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	 $(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 dwp_SOURCES = dwp.cc
 dwp_DEPENDENCIES = libgold.a $(LIBIBERTY) $(LIBINTL_DEP)
 dwp_LDADD = libgold.a $(LIBIBERTY) $(GOLD_LDADD) $(LIBINTL) $(THREADLIBS) \
-	$(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 dwp_LDFLAGS = $(GOLD_LDFLAGS)
 CONFIG_STATUS_DEPENDENCIES = $(srcdir)/../bfd/development.sh
diff --git a/gold/NEWS b/gold/NEWS
index 5f161d0..f9d2f5c 100644
--- a/gold/NEWS
+++ b/gold/NEWS
@@ -1,3 +1,5 @@
+* gold and dwp now support zstd compressed debug sections.
+
 Changes in 1.16:
 
 * Improve warning messages for relocations that refer to discarded sections.
diff --git a/gold/aclocal.m4 b/gold/aclocal.m4
index 6a0cd72..e4bdc46 100644
--- a/gold/aclocal.m4
+++ b/gold/aclocal.m4
@@ -1208,4 +1208,5 @@
 m4_include([../config/po.m4])
 m4_include([../config/progtest.m4])
 m4_include([../config/zlib.m4])
+m4_include([../config/zstd.m4])
 m4_include([../bfd/warning.m4])
diff --git a/gold/compressed_output.cc b/gold/compressed_output.cc
index 4ebc339..9980175 100644
--- a/gold/compressed_output.cc
+++ b/gold/compressed_output.cc
@@ -22,6 +22,9 @@
 
 #include "gold.h"
 #include <zlib.h>
+#ifdef HAVE_ZSTD
+#include <zstd.h>
+#endif
 #include "parameters.h"
 #include "options.h"
 #include "compressed_output.h"
@@ -148,45 +151,38 @@
   if ((sh_flags & elfcpp::SHF_COMPRESSED) != 0)
     {
       unsigned int compression_header_size;
+      unsigned int ch_type;
       if (size == 32)
 	{
 	  compression_header_size = elfcpp::Elf_sizes<32>::chdr_size;
 	  if (big_endian)
-	    {
-	      elfcpp::Chdr<32, true> chdr(compressed_data);
-	      if (chdr.get_ch_type() != elfcpp::ELFCOMPRESS_ZLIB)
-		return false;
-	    }
+	    ch_type = elfcpp::Chdr<32, true> (compressed_data).get_ch_type();
 	  else
-	    {
-	      elfcpp::Chdr<32, false> chdr(compressed_data);
-	      if (chdr.get_ch_type() != elfcpp::ELFCOMPRESS_ZLIB)
-		return false;
-	    }
+	    ch_type = elfcpp::Chdr<32, false>(compressed_data).get_ch_type();
 	}
       else if (size == 64)
 	{
 	  compression_header_size = elfcpp::Elf_sizes<64>::chdr_size;
 	  if (big_endian)
-	    {
-	      elfcpp::Chdr<64, true> chdr(compressed_data);
-	      if (chdr.get_ch_type() != elfcpp::ELFCOMPRESS_ZLIB)
-		return false;
-	    }
+	    ch_type = elfcpp::Chdr<64, true>(compressed_data).get_ch_type();
 	  else
-	    {
-	      elfcpp::Chdr<64, false> chdr(compressed_data);
-	      if (chdr.get_ch_type() != elfcpp::ELFCOMPRESS_ZLIB)
-		return false;
-	    }
+	    ch_type = elfcpp::Chdr<64, false>(compressed_data).get_ch_type();
 	}
       else
 	gold_unreachable();
 
-      return zlib_decompress(compressed_data + compression_header_size,
-			     compressed_size - compression_header_size,
-			     uncompressed_data,
-			     uncompressed_size);
+#ifdef HAVE_ZSTD
+      if (ch_type == elfcpp::ELFCOMPRESS_ZSTD)
+	return !ZSTD_isError(
+	    ZSTD_decompress(uncompressed_data, uncompressed_size,
+			    compressed_data + compression_header_size,
+			    compressed_size - compression_header_size));
+#endif
+      if (ch_type == elfcpp::ELFCOMPRESS_ZLIB)
+	return zlib_decompress(compressed_data + compression_header_size,
+			       compressed_size - compression_header_size,
+			       uncompressed_data, uncompressed_size);
+      return false;
     }
 
   const unsigned int zlib_header_size = 12;
diff --git a/gold/config.in b/gold/config.in
index a2000d3..333b2c6 100644
--- a/gold/config.in
+++ b/gold/config.in
@@ -229,6 +229,9 @@
 /* Define to 1 if you have the <windows.h> header file. */
 #undef HAVE_WINDOWS_H
 
+/* Define to 1 if zstd is enabled. */
+#undef HAVE_ZSTD
+
 /* Default library search path */
 #undef LIB_PATH
 
diff --git a/gold/configure b/gold/configure
index 85f62a9..5c6fe2a 100755
--- a/gold/configure
+++ b/gold/configure
@@ -633,9 +633,6 @@
 HAVE_PUBNAMES_TRUE
 JANSSON_LIBS
 JANSSON_CFLAGS
-PKG_CONFIG_LIBDIR
-PKG_CONFIG_PATH
-PKG_CONFIG
 THREADS_FALSE
 THREADS_TRUE
 PTHREAD_CFLAGS
@@ -643,6 +640,13 @@
 PTHREAD_CC
 ax_pthread_config
 SED
+HAVE_ZSTD_FALSE
+HAVE_ZSTD_TRUE
+ZSTD_LIBS
+ZSTD_CFLAGS
+PKG_CONFIG_LIBDIR
+PKG_CONFIG_PATH
+PKG_CONFIG
 zlibinc
 zlibdir
 LIBOBJS
@@ -855,6 +859,7 @@
 with_gold_ldflags
 with_gold_ldadd
 with_system_zlib
+with_zstd
 enable_threads
 enable_jansson
 enable_maintainer_mode
@@ -876,6 +881,8 @@
 PKG_CONFIG
 PKG_CONFIG_PATH
 PKG_CONFIG_LIBDIR
+ZSTD_CFLAGS
+ZSTD_LIBS
 JANSSON_CFLAGS
 JANSSON_LIBS
 CXXCPP'
@@ -1527,6 +1534,8 @@
   --with-gold-ldflags=FLAGS  additional link flags for gold
   --with-gold-ldadd=LIBS     additional libraries for gold
   --with-system-zlib      use installed libz
+  --with-zstd             support zstd compressed debug sections
+                          (default=auto)
 
 Some influential environment variables:
   CC          C compiler command
@@ -1550,6 +1559,8 @@
               directories to add to pkg-config's search path
   PKG_CONFIG_LIBDIR
               path overriding pkg-config's built-in search path
+  ZSTD_CFLAGS C compiler flags for ZSTD, overriding pkg-config
+  ZSTD_LIBS   linker flags for ZSTD, overriding pkg-config
   JANSSON_CFLAGS
               C compiler flags for JANSSON, overriding pkg-config
   JANSSON_LIBS
@@ -8217,7 +8228,7 @@
 
 fi
 
-# Link in zlib if we can.  This allows us to write compressed sections.
+# Link in zlib/zstd if we can.  This allows us to write compressed sections.
 
   # Use the system's zlib library.
   zlibdir="-L\$(top_builddir)/../zlib"
@@ -8236,6 +8247,255 @@
 
 
 
+
+
+
+
+
+
+if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
+	if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
+set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
+$as_echo "$PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_path_PKG_CONFIG"; then
+  ac_pt_PKG_CONFIG=$PKG_CONFIG
+  # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_ac_pt_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $ac_pt_PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
+if test -n "$ac_pt_PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_pt_PKG_CONFIG" >&5
+$as_echo "$ac_pt_PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_pt_PKG_CONFIG" = x; then
+    PKG_CONFIG=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    PKG_CONFIG=$ac_pt_PKG_CONFIG
+  fi
+else
+  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
+fi
+
+fi
+if test -n "$PKG_CONFIG"; then
+	_pkg_min_version=0.9.0
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking pkg-config is at least version $_pkg_min_version" >&5
+$as_echo_n "checking pkg-config is at least version $_pkg_min_version... " >&6; }
+	if $PKG_CONFIG --atleast-pkgconfig-version $_pkg_min_version; then
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	else
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+		PKG_CONFIG=""
+	fi
+fi
+
+
+# Check whether --with-zstd was given.
+if test "${with_zstd+set}" = set; then :
+  withval=$with_zstd;
+else
+  with_zstd=auto
+fi
+
+
+if test "$with_zstd" != no; then :
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for libzstd >= 1.4.0" >&5
+$as_echo_n "checking for libzstd >= 1.4.0... " >&6; }
+
+if test -n "$ZSTD_CFLAGS"; then
+    pkg_cv_ZSTD_CFLAGS="$ZSTD_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd >= 1.4.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libzstd >= 1.4.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_ZSTD_CFLAGS=`$PKG_CONFIG --cflags "libzstd >= 1.4.0" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$ZSTD_LIBS"; then
+    pkg_cv_ZSTD_LIBS="$ZSTD_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libzstd >= 1.4.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libzstd >= 1.4.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_ZSTD_LIBS=`$PKG_CONFIG --libs "libzstd >= 1.4.0" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+if test $pkg_failed = no; then
+  pkg_save_LDFLAGS="$LDFLAGS"
+  LDFLAGS="$LDFLAGS $pkg_cv_ZSTD_LIBS"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+
+else
+  pkg_failed=yes
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+  LDFLAGS=$pkg_save_LDFLAGS
+fi
+
+
+
+if test $pkg_failed = yes; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        ZSTD_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libzstd >= 1.4.0" 2>&1`
+        else
+	        ZSTD_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libzstd >= 1.4.0" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$ZSTD_PKG_ERRORS" >&5
+
+
+    if test "$with_zstd" = yes; then
+      as_fn_error $? "--with-zstd was given, but pkgconfig/libzstd.pc is not found" "$LINENO" 5
+    fi
+
+elif test $pkg_failed = untried; then
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+    if test "$with_zstd" = yes; then
+      as_fn_error $? "--with-zstd was given, but pkgconfig/libzstd.pc is not found" "$LINENO" 5
+    fi
+
+else
+	ZSTD_CFLAGS=$pkg_cv_ZSTD_CFLAGS
+	ZSTD_LIBS=$pkg_cv_ZSTD_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+
+$as_echo "#define HAVE_ZSTD 1" >>confdefs.h
+
+
+fi
+
+fi
+
+ if test "$pkg_cv_ZSTD_LIBS" != ""; then
+  HAVE_ZSTD_TRUE=
+  HAVE_ZSTD_FALSE='#'
+else
+  HAVE_ZSTD_TRUE='#'
+  HAVE_ZSTD_FALSE=
+fi
+
+
 # Check whether --enable-threads was given.
 if test "${enable_threads+set}" = set; then :
   enableval=$enable_threads; case "${enableval}" in
@@ -10869,6 +11129,10 @@
   as_fn_error $? "conditional \"IFUNC_STATIC\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${HAVE_ZSTD_TRUE}" && test -z "${HAVE_ZSTD_FALSE}"; then
+  as_fn_error $? "conditional \"HAVE_ZSTD\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${THREADS_TRUE}" && test -z "${THREADS_FALSE}"; then
   as_fn_error $? "conditional \"THREADS\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
diff --git a/gold/configure.ac b/gold/configure.ac
index 25fae6b..44e858e 100644
--- a/gold/configure.ac
+++ b/gold/configure.ac
@@ -566,8 +566,10 @@
   AC_LIBOBJ(mremap)
 fi
 
-# Link in zlib if we can.  This allows us to write compressed sections.
+# Link in zlib/zstd if we can.  This allows us to write compressed sections.
 AM_ZLIB
+AC_ZSTD
+AM_CONDITIONAL(HAVE_ZSTD, test "$pkg_cv_ZSTD_LIBS" != "")
 
 AC_ARG_ENABLE([threads],
 [[  --enable-threads[=ARG]  multi-threaded linking [ARG={auto,yes,no}]]],
diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index 843fd0d..482996a 100644
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -149,25 +149,25 @@
 object_unittest_SOURCES = object_unittest.cc
 object_unittest_LDFLAGS = $(THREADFLAGS)
 object_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 check_PROGRAMS += binary_unittest
 binary_unittest_SOURCES = binary_unittest.cc
 binary_unittest_LDFLAGS = $(THREADFLAGS)
 binary_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 check_PROGRAMS += leb128_unittest
 leb128_unittest_SOURCES = leb128_unittest.cc
 leb128_unittest_LDFLAGS = $(THREADFLAGS)
 leb128_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 check_PROGRAMS += overflow_unittest
 overflow_unittest_SOURCES = overflow_unittest.cc
 overflow_unittest_LDFLAGS = $(THREADFLAGS)
 overflow_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 overflow_unittest.o: overflow_unittest.cc
 	$(CXXCOMPILE) -O3 -c -o $@ $<
 
@@ -3120,6 +3120,17 @@
 	$(CXXLINK) -Wl,--gdb-index $<
 gdb_index_test_2_gabi.stdout: gdb_index_test_2_gabi
 	$(TEST_READELF) --debug-dump=gdb_index $< > $@
+if HAVE_ZSTD
+check_SCRIPTS += gdb_index_test_2_zstd.sh
+check_DATA += gdb_index_test_2_zstd.stdout
+MOSTLYCLEANFILES += gdb_index_test_2_zstd.stdout gdb_index_test_2_zstd
+gdb_index_test_cdebug_zstd.o: gdb_index_test.cc
+	$(CXXCOMPILE) -O0 -g -Wa,--compress-debug-sections=zstd -c -o $@ $<
+gdb_index_test_2_zstd: gdb_index_test_cdebug_zstd.o gcctestdir/ld
+	$(CXXLINK) -Wl,--gdb-index $<
+gdb_index_test_2_zstd.stdout: gdb_index_test_2_zstd
+	$(TEST_READELF) --debug-dump=gdb_index $< > $@
+endif
 
 # Another simple C test (DW_AT_high_pc encoding) for --gdb-index.
 check_SCRIPTS += gdb_index_test_3.sh
diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 21804df..2421883 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -846,28 +846,31 @@
 # Test that --gdb-index functions correctly without gcc-generated pubnames.
 
 # Test that --gdb-index functions correctly with compressed debug sections.
-
-# Another simple C test (DW_AT_high_pc encoding) for --gdb-index.
-
-# Test that --gdb-index functions correctly with gcc-generated pubnames.
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_78 = gdb_index_test_1.sh \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2.sh \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2_gabi.sh \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_3.sh \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4.sh
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2_gabi.sh
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_79 = gdb_index_test_1.stdout \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2.stdout \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2_gabi.stdout \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_3.stdout \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4.stdout
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2_gabi.stdout
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_80 = gdb_index_test_1.stdout \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_1 \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2.stdout \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2 \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2_gabi \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2.stdout \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2 \
-@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_3.stdout \
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_2
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@am__append_81 = gdb_index_test_2_zstd.sh
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@am__append_82 = gdb_index_test_2_zstd.stdout
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@am__append_83 = gdb_index_test_2_zstd.stdout gdb_index_test_2_zstd
+
+# Another simple C test (DW_AT_high_pc encoding) for --gdb-index.
+
+# Test that --gdb-index functions correctly with gcc-generated pubnames.
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_84 = gdb_index_test_3.sh \
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4.sh
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_85 = gdb_index_test_3.stdout \
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4.stdout
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@am__append_86 = gdb_index_test_3.stdout \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_3 \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4.stdout \
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	gdb_index_test_4
@@ -882,19 +885,19 @@
 # appropriately aligned.
 
 # Test that the --defsym option copies the symbol type and visibility.
-@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_81 = ehdr_start_test_4.sh \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_87 = ehdr_start_test_4.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	defsym_test.sh
-@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_82 = ehdr_start_test_4.syms \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_88 = ehdr_start_test_4.syms \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	defsym_test.syms
-@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_83 = ehdr_start_test_4 \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_89 = ehdr_start_test_4 \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	defsym_test defsym_test.syms
 @GCC_FALSE@ehdr_start_test_5_DEPENDENCIES =
 @NATIVE_LINKER_FALSE@ehdr_start_test_5_DEPENDENCIES =
-@CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_84 = incremental_test_2 \
+@CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_90 = incremental_test_2 \
 @CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_test_3 \
 @CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_test_4 \
 @CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_test_5
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_85 = two_file_test_tmp_2.o \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_91 = two_file_test_tmp_2.o \
 @DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	two_file_test_tmp_3.o \
 @DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_test_4.base \
 @DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	two_file_test_tmp_4.o \
@@ -904,36 +907,36 @@
 
 # Test the --incremental-unchanged flag with an archive library.
 # The second link should not update the library.
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_86 = incremental_test_6
-@CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_87 = incremental_copy_test \
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_92 = incremental_test_6
+@CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_93 = incremental_copy_test \
 @CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_common_test_1 \
 @CFLAGS_CF_PROTECTION_FALSE@@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@	incremental_comdat_test_1
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_88 = exception_x86_64_bnd_test
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_89 = gnu_property_test.sh
-@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_90 = gnu_property_test.stdout
-@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_91 = pr22266
-@DEFAULT_TARGET_AARCH64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_92 = aarch64_pr23870
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_94 = exception_x86_64_bnd_test
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_95 = gnu_property_test.sh
+@DEFAULT_TARGET_X86_64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_96 = gnu_property_test.stdout
+@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_97 = pr22266
+@DEFAULT_TARGET_AARCH64_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_98 = aarch64_pr23870
 
 # These tests work with native and cross linkers.
 
 # Test script section order.
-@NATIVE_OR_CROSS_LINKER_TRUE@am__append_93 = script_test_10.sh
-@NATIVE_OR_CROSS_LINKER_TRUE@am__append_94 = script_test_10.stdout
-@NATIVE_OR_CROSS_LINKER_TRUE@am__append_95 = script_test_10
+@NATIVE_OR_CROSS_LINKER_TRUE@am__append_99 = script_test_10.sh
+@NATIVE_OR_CROSS_LINKER_TRUE@am__append_100 = script_test_10.stdout
+@NATIVE_OR_CROSS_LINKER_TRUE@am__append_101 = script_test_10
 
 # These tests work with cross linkers only.
-@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_96 = split_i386.sh
-@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_97 = split_i386_1.stdout split_i386_2.stdout \
+@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_102 = split_i386.sh
+@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_103 = split_i386_1.stdout split_i386_2.stdout \
 @DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_i386_3.stdout split_i386_4.stdout split_i386_r.stdout
 
-@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_98 = split_i386_1 split_i386_2 split_i386_3 \
+@DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_104 = split_i386_1 split_i386_2 split_i386_3 \
 @DEFAULT_TARGET_I386_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_i386_4 split_i386_r
 
-@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_99 = split_x86_64.sh \
+@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_105 = split_x86_64.sh \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_plt_1.sh \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_ifunc_1.sh \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_ifunc_2.sh
-@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_100 = split_x86_64_1.stdout \
+@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_106 = split_x86_64_1.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x86_64_2.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x86_64_3.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x86_64_4.stdout \
@@ -941,14 +944,14 @@
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_plt_1.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_ifunc_1.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	bnd_ifunc_2.stdout
-@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_101 = split_x86_64_1 split_x86_64_2 split_x86_64_3 \
+@DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_107 = split_x86_64_1 split_x86_64_2 split_x86_64_3 \
 @DEFAULT_TARGET_X86_64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x86_64_4 split_x86_64_r
 
-@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_102 = split_x32.sh
-@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_103 = split_x32_1.stdout split_x32_2.stdout \
+@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_108 = split_x32.sh
+@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_109 = split_x32_1.stdout split_x32_2.stdout \
 @DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x32_3.stdout split_x32_4.stdout split_x32_r.stdout
 
-@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_104 = split_x32_1 split_x32_2 split_x32_3 \
+@DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_110 = split_x32_1 split_x32_2 split_x32_3 \
 @DEFAULT_TARGET_X32_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	split_x32_4 split_x32_r
 
 
@@ -969,7 +972,7 @@
 # Check Thumb to ARM farcall veneers
 
 # Check handling of --target1-abs, --target1-rel and --target2 options
-@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_105 = arm_abs_global.sh \
+@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_111 = arm_abs_global.sh \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_branch_in_range.sh \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_branch_out_of_range.sh \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_fix_v4bx.sh \
@@ -992,7 +995,7 @@
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target2_got_rel.sh
 
 # The test demonstrates why the constructor of a target object should not access options.
-@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_106 = arm_abs_global.stdout \
+@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_112 = arm_abs_global.stdout \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_bl_in_range.stdout \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_bl_out_of_range.stdout \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	thumb_bl_in_range.stdout \
@@ -1045,7 +1048,7 @@
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target2_abs.stdout \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target2_got_rel.stdout \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target_lazy_init
-@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_107 = arm_abs_global \
+@DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_113 = arm_abs_global \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_bl_in_range \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_bl_out_of_range \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	thumb_bl_in_range \
@@ -1096,20 +1099,20 @@
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target2_abs \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target2_got_rel \
 @DEFAULT_TARGET_ARM_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	arm_target_lazy_init
-@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_108 = aarch64_reloc_none.sh \
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_114 = aarch64_reloc_none.sh \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_relocs.sh \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	pr21430.sh \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_tlsdesc.sh
-@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_109 = aarch64_reloc_none.stdout \
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_115 = aarch64_reloc_none.stdout \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_relocs.stdout \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	pr21430.stdout \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_tlsdesc.stdout
-@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_110 = aarch64_reloc_none \
+@DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_116 = aarch64_reloc_none \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_relocs \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	pr21430 \
 @DEFAULT_TARGET_AARCH64_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@	aarch64_tlsdesc
-@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_111 = split_s390.sh
-@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_112 = split_s390_z1.stdout split_s390_z2.stdout split_s390_z3.stdout \
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_117 = split_s390.sh
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_118 = 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 \
@@ -1121,7 +1124,7 @@
 @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_113 = split_s390_z1 split_s390_z2 split_s390_z3 \
+@DEFAULT_TARGET_S390_TRUE@@NATIVE_OR_CROSS_LINKER_TRUE@am__append_119 = 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 \
@@ -1130,11 +1133,11 @@
 @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_114 = *.dwo *.dwp pr26936a \
+@DEFAULT_TARGET_X86_64_TRUE@am__append_120 = *.dwo *.dwp pr26936a \
 @DEFAULT_TARGET_X86_64_TRUE@	pr26936b retain_1 retain_2
-@DEFAULT_TARGET_X86_64_TRUE@am__append_115 = dwp_test_1.sh \
+@DEFAULT_TARGET_X86_64_TRUE@am__append_121 = dwp_test_1.sh \
 @DEFAULT_TARGET_X86_64_TRUE@	dwp_test_2.sh pr26936.sh retain.sh
-@DEFAULT_TARGET_X86_64_TRUE@am__append_116 = dwp_test_1.stdout \
+@DEFAULT_TARGET_X86_64_TRUE@am__append_122 = dwp_test_1.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@	dwp_test_2.stdout pr26936a.stdout \
 @DEFAULT_TARGET_X86_64_TRUE@	pr26936b.stdout retain_1.out \
 @DEFAULT_TARGET_X86_64_TRUE@	retain_2.out
@@ -1152,6 +1155,7 @@
 	$(top_srcdir)/../config/po.m4 \
 	$(top_srcdir)/../config/progtest.m4 \
 	$(top_srcdir)/../config/zlib.m4 \
+	$(top_srcdir)/../config/zstd.m4 \
 	$(top_srcdir)/../bfd/warning.m4 $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
@@ -1410,6 +1414,7 @@
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1)
 binary_unittest_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
 	$(binary_unittest_LDFLAGS) $(LDFLAGS) -o $@
@@ -1736,6 +1741,7 @@
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1)
 leb128_unittest_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
 	$(leb128_unittest_LDFLAGS) $(LDFLAGS) -o $@
@@ -1760,6 +1766,7 @@
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1)
 object_unittest_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
 	$(object_unittest_LDFLAGS) $(LDFLAGS) -o $@
@@ -1773,6 +1780,7 @@
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1) \
 @NATIVE_OR_CROSS_LINKER_TRUE@	$(am__DEPENDENCIES_1)
 overflow_unittest_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \
 	$(overflow_unittest_LDFLAGS) $(LDFLAGS) -o $@
@@ -2696,6 +2704,8 @@
 XGETTEXT = @XGETTEXT@
 YACC = @YACC@
 YFLAGS = @YFLAGS@
+ZSTD_CFLAGS = @ZSTD_CFLAGS@
+ZSTD_LIBS = @ZSTD_LIBS@
 abs_builddir = @abs_builddir@
 abs_srcdir = @abs_srcdir@
 abs_top_builddir = @abs_top_builddir@
@@ -2843,9 +2853,10 @@
 	$(am__append_36) $(am__append_39) $(am__append_43) \
 	$(am__append_49) $(am__append_53) $(am__append_54) \
 	$(am__append_60) $(am__append_80) $(am__append_83) \
-	$(am__append_85) $(am__append_95) $(am__append_98) \
+	$(am__append_86) $(am__append_89) $(am__append_91) \
 	$(am__append_101) $(am__append_104) $(am__append_107) \
-	$(am__append_110) $(am__append_113) $(am__append_114)
+	$(am__append_110) $(am__append_113) $(am__append_116) \
+	$(am__append_119) $(am__append_120)
 
 # We will add to these later, for each individual test.  Note
 # that we add each test under check_SCRIPTS or check_PROGRAMS;
@@ -2854,18 +2865,20 @@
 	$(am__append_31) $(am__append_37) $(am__append_44) \
 	$(am__append_47) $(am__append_51) $(am__append_55) \
 	$(am__append_58) $(am__append_64) $(am__append_75) \
-	$(am__append_78) $(am__append_81) $(am__append_89) \
-	$(am__append_93) $(am__append_96) $(am__append_99) \
+	$(am__append_78) $(am__append_81) $(am__append_84) \
+	$(am__append_87) $(am__append_95) $(am__append_99) \
 	$(am__append_102) $(am__append_105) $(am__append_108) \
-	$(am__append_111) $(am__append_115)
+	$(am__append_111) $(am__append_114) $(am__append_117) \
+	$(am__append_121)
 check_DATA = $(am__append_3) $(am__append_22) $(am__append_26) \
 	$(am__append_32) $(am__append_38) $(am__append_45) \
 	$(am__append_48) $(am__append_52) $(am__append_56) \
 	$(am__append_59) $(am__append_65) $(am__append_76) \
-	$(am__append_79) $(am__append_82) $(am__append_90) \
-	$(am__append_94) $(am__append_97) $(am__append_100) \
+	$(am__append_79) $(am__append_82) $(am__append_85) \
+	$(am__append_88) $(am__append_96) $(am__append_100) \
 	$(am__append_103) $(am__append_106) $(am__append_109) \
-	$(am__append_112) $(am__append_116)
+	$(am__append_112) $(am__append_115) $(am__append_118) \
+	$(am__append_122)
 BUILT_SOURCES = $(am__append_42)
 TESTS = $(check_SCRIPTS) $(check_PROGRAMS)
 
@@ -2881,22 +2894,22 @@
 @NATIVE_OR_CROSS_LINKER_TRUE@object_unittest_SOURCES = object_unittest.cc
 @NATIVE_OR_CROSS_LINKER_TRUE@object_unittest_LDFLAGS = $(THREADFLAGS)
 @NATIVE_OR_CROSS_LINKER_TRUE@object_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 @NATIVE_OR_CROSS_LINKER_TRUE@binary_unittest_SOURCES = binary_unittest.cc
 @NATIVE_OR_CROSS_LINKER_TRUE@binary_unittest_LDFLAGS = $(THREADFLAGS)
 @NATIVE_OR_CROSS_LINKER_TRUE@binary_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 @NATIVE_OR_CROSS_LINKER_TRUE@leb128_unittest_SOURCES = leb128_unittest.cc
 @NATIVE_OR_CROSS_LINKER_TRUE@leb128_unittest_LDFLAGS = $(THREADFLAGS)
 @NATIVE_OR_CROSS_LINKER_TRUE@leb128_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 @NATIVE_OR_CROSS_LINKER_TRUE@overflow_unittest_SOURCES = overflow_unittest.cc
 @NATIVE_OR_CROSS_LINKER_TRUE@overflow_unittest_LDFLAGS = $(THREADFLAGS)
 @NATIVE_OR_CROSS_LINKER_TRUE@overflow_unittest_LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \
-@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(JANSSON_LIBS)
+@NATIVE_OR_CROSS_LINKER_TRUE@	$(THREADLIBS) $(LIBDL) $(ZLIB) $(ZSTD_LIBS) $(JANSSON_LIBS)
 
 @GCC_TRUE@@NATIVE_LINKER_TRUE@large_symbol_alignment_SOURCES = large_symbol_alignment.cc
 @GCC_TRUE@@NATIVE_LINKER_TRUE@large_symbol_alignment_DEPENDENCIES = gcctestdir/ld
@@ -6181,6 +6194,13 @@
 	--log-file $$b.log --trs-file $$b.trs \
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+gdb_index_test_2_zstd.sh.log: gdb_index_test_2_zstd.sh
+	@p='gdb_index_test_2_zstd.sh'; \
+	b='gdb_index_test_2_zstd.sh'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
 gdb_index_test_3.sh.log: gdb_index_test_3.sh
 	@p='gdb_index_test_3.sh'; \
 	b='gdb_index_test_3.sh'; \
@@ -9500,6 +9520,12 @@
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK) -Wl,--gdb-index $<
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_2_gabi.stdout: gdb_index_test_2_gabi
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) --debug-dump=gdb_index $< > $@
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_cdebug_zstd.o: gdb_index_test.cc
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@	$(CXXCOMPILE) -O0 -g -Wa,--compress-debug-sections=zstd -c -o $@ $<
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_2_zstd: gdb_index_test_cdebug_zstd.o gcctestdir/ld
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@	$(CXXLINK) -Wl,--gdb-index $<
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_2_zstd.stdout: gdb_index_test_2_zstd
+@GCC_TRUE@@HAVE_PUBNAMES_TRUE@@HAVE_ZSTD_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) --debug-dump=gdb_index $< > $@
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_3.o: gdb_index_test_3.c
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@	$(COMPILE) -O0 -g -c -o $@ $<
 @GCC_TRUE@@HAVE_PUBNAMES_TRUE@@NATIVE_LINKER_TRUE@gdb_index_test_3: gdb_index_test_3.o gcctestdir/ld
diff --git a/gold/testsuite/gdb_index_test_2_zstd.sh b/gold/testsuite/gdb_index_test_2_zstd.sh
new file mode 100755
index 0000000..d53ad22
--- /dev/null
+++ b/gold/testsuite/gdb_index_test_2_zstd.sh
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# gdb_index_test_2_zstd.sh -- a test case for the --gdb-index option.
+
+# Copyright (C) 2022 Free Software Foundation, Inc.
+
+# 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.
+
+exec ${srcdir}/gdb_index_test_comm.sh gdb_index_test_2_zstd.stdout