Do not use --hash-style=both for building glibc shared objects

The comment indicates that --hash-style=both was used to maintain
compatibility with static dlopen, but we had many internal ABI
changes since then, so this compatiblity does not add value anymore.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Makeconfig

@@ -362,15 +362,6 @@ relro-LDFLAGS = -Wl,-z,relro
 LDFLAGS.so += $(relro-LDFLAGS)
 LDFLAGS-rtld += $(relro-LDFLAGS)
 
-ifeq (yes,$(have-hash-style))
-# For the time being we unconditionally use 'both'.  At some time we
-# should declare statically linked code as 'out of luck' and compile
-# with --hash-style=gnu only.
-hashstyle-LDFLAGS = -Wl,--hash-style=both
-LDFLAGS.so += $(hashstyle-LDFLAGS)
-LDFLAGS-rtld += $(hashstyle-LDFLAGS)
-endif
-
 ifeq (no,$(build-pie-default))
 pie-default = $(no-pie-ccflag)
 else # build-pie-default

Makerules

@@ -557,13 +557,6 @@ $(common-objpfx)shlib.lds: $(common-objpfx)config.make $(..)Makerules
 		  -Wl,--verbose 2>/dev/null | \
 	  sed > $@T \
 	      -e '/^=========/,/^=========/!d;/^=========/d' \
-	      $(if $(filter yes,$(have-hash-style)), \
-		   -e 's/^.*\.gnu\.hash[ 	]*:.*$$/  .note.ABI-tag : { *(.note.ABI-tag) } &/' \
-		   -e '/^[ 	]*\.hash[ 	]*:.*$$/{h;d;}' \
-		   -e '/DATA_SEGMENT_ALIGN/{H;g}' \
-		, \
-		   -e 's/^.*\.hash[ 	]*:.*$$/  .note.ABI-tag : { *(.note.ABI-tag) } &/' \
-	       ) \
 	      -e 's/^.*\*(\.dynbss).*$$/& \
 		 PROVIDE(__start___libc_freeres_ptrs = .); \
 		 *(__libc_freeres_ptrs) \

config.make.in

@@ -70,7 +70,6 @@ have-libcap = @have_libcap@
 have-cc-with-libunwind = @libc_cv_cc_with_libunwind@
 fno-unit-at-a-time = @fno_unit_at_a_time@
 bind-now = @bindnow@
-have-hash-style = @libc_cv_hashstyle@
 use-default-link = @use_default_link@
 have-cxx-thread_local = @libc_cv_cxx_thread_local@
 have-loop-to-function = @libc_cv_cc_loop_to_function@

configure

@@ -622,7 +622,6 @@ libc_cv_cc_nofma
 libc_cv_mtls_dialect_gnu2
 fno_unit_at_a_time
 libc_cv_has_glob_dat
-libc_cv_hashstyle
 libc_cv_fpie
 libc_cv_z_execstack
 ASFLAGS_config
@@ -6194,33 +6193,6 @@ $as_echo "$libc_cv_fpie" >&6; }
 
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --hash-style option" >&5
-$as_echo_n "checking for --hash-style option... " >&6; }
-if ${libc_cv_hashstyle+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat > conftest.c <<EOF
-int _start (void) { return 42; }
-EOF
-if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
-			    -fPIC -shared -o conftest.so conftest.c
-			    -Wl,--hash-style=both -nostdlib 1>&5'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }
-then
-  libc_cv_hashstyle=yes
-else
-  libc_cv_hashstyle=no
-fi
-rm -f conftest*
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_hashstyle" >&5
-$as_echo "$libc_cv_hashstyle" >&6; }
-
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for GLOB_DAT reloc" >&5
 $as_echo_n "checking for GLOB_DAT reloc... " >&6; }
 if ${libc_cv_has_glob_dat+:} false; then :

configure.ac

@@ -1360,22 +1360,6 @@ LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no])
 
 AC_SUBST(libc_cv_fpie)
 
-AC_CACHE_CHECK(for --hash-style option,
-	       libc_cv_hashstyle, [dnl
-cat > conftest.c <<EOF
-int _start (void) { return 42; }
-EOF
-if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
-			    -fPIC -shared -o conftest.so conftest.c
-			    -Wl,--hash-style=both -nostdlib 1>&AS_MESSAGE_LOG_FD])
-then
-  libc_cv_hashstyle=yes
-else
-  libc_cv_hashstyle=no
-fi
-rm -f conftest*])
-AC_SUBST(libc_cv_hashstyle)
-
 AC_CACHE_CHECK(for GLOB_DAT reloc,
 	       libc_cv_has_glob_dat, [dnl
 cat > conftest.c <<EOF