Use v2 map syntax in libgcc-unwind.map if Solaris ld supports it

* configure.ac (solaris_ld_v2_maps): New test.
	* configure: Regenerate.
	* Makefile.in (solaris_ld_v2_maps): New variable.
	* config/t-slibgcc-sld (libgcc-unwind.map): Emit v2 mapfile syntax
	if supported.

From-SVN: r264382

libgcc/ChangeLog

@@ -1,3 +1,11 @@
+2018-09-18  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	* configure.ac (solaris_ld_v2_maps): New test.
+	* configure: Regenerate.
+	* Makefile.in (solaris_ld_v2_maps): New variable.
+	* config/t-slibgcc-sld (libgcc-unwind.map): Emit v2 mapfile syntax
+	if supported.
+
 2018-08-23  Richard Earnshaw  <rearnsha@arm.com>
 
 	PR target/86951

libgcc/Makefile.in

@@ -44,6 +44,7 @@ enable_vtable_verify = @enable_vtable_verify@
 enable_decimal_float = @enable_decimal_float@
 fixed_point = @fixed_point@
 with_aix_soname = @with_aix_soname@
+solaris_ld_v2_maps = @solaris_ld_v2_maps@
 enable_execute_stack = @enable_execute_stack@
 unwind_header = @unwind_header@
 md_unwind_header = @md_unwind_header@

libgcc/config/t-slibgcc-sld

@@ -8,12 +8,23 @@ ifeq ($(enable_shared),yes)
 
 # Linker mapfile to enforce direct binding to libgcc_s unwinder
 # (PR target/59788).
+# Emit v2 mapfile syntax if possible, otherwise ld -z guidance complains
+# every time the mapfile is used.
 libgcc-unwind.map: libgcc-std.ver
+ifeq ($(solaris_ld_v2_maps),yes)
+	@(echo '$$mapfile_version 2';		\
+	echo "SYMBOL_SCOPE {";			\
+	for f in `grep _Unwind_ $< | sort`; do	\
+	  echo "	$$f { FLAGS = EXTERN DIRECT };"; \
+	done;					\
+	echo "};" ) > $@
+else
 	@(echo "{";				\
 	for f in `grep _Unwind_ $< | sort`; do	\
 	  echo "	$$f = EXTERN DIRECT;";	\
 	done;					\
 	echo "};" ) > $@
+endif
 
 # Copy libgcc-unwind.map to the place where gcc will look for it at build-time.
 install-libgcc-unwind-map-forbuild: libgcc-unwind.map

libgcc/configure

@@ -570,6 +570,7 @@ sfp_machine_header
 set_use_emutls
 set_have_cc_tls
 vis_hide
+solaris_ld_v2_maps
 real_host_noncanonical
 accel_dir_suffix
 force_explicit_eh_registry
@@ -5176,6 +5177,26 @@ EOF
   ;;
 esac
 
+# Check if Solaris linker support v2 linker mapfile syntax.
+# Link with -nostartfiles -nodefaultlibs since neither are present while
+# building libgcc.
+case ${host} in
+*-*-solaris2*)
+  solaris_ld_v2_maps=no
+  echo 'int main(void) {return 0;}' > conftest.c
+  echo '$mapfile_version 2' > conftest.map
+  if { ac_try='${CC-cc} -nostartfiles -nodefaultlibs -Wl,-M,conftest.map -o conftest conftest.c 1>&5'
+  { { eval echo "\"\$as_me\":${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
+      solaris_ld_v2_maps=yes
+  fi
+  ;;
+esac
+
+
 # Check if xtensa target is configured for windowed ABI and thus needs to use
 # custom unwind code.
 # This is after config.host so we can augment tmake_file.

libgcc/configure.ac

@@ -459,6 +459,21 @@ EOF
   ;;
 esac
 
+# Check if Solaris linker support v2 linker mapfile syntax.
+# Link with -nostartfiles -nodefaultlibs since neither are present while
+# building libgcc.
+case ${host} in
+*-*-solaris2*)
+  solaris_ld_v2_maps=no
+  echo 'int main(void) {return 0;}' > conftest.c
+  echo '$mapfile_version 2' > conftest.map
+  if AC_TRY_COMMAND([${CC-cc} -nostartfiles -nodefaultlibs -Wl,-M,conftest.map -o conftest conftest.c 1>&AS_MESSAGE_LOG_FD]); then
+      solaris_ld_v2_maps=yes
+  fi
+  ;;
+esac
+AC_SUBST(solaris_ld_v2_maps)
+
 # Check if xtensa target is configured for windowed ABI and thus needs to use
 # custom unwind code.
 # This is after config.host so we can augment tmake_file.