Config,Darwin: Allow for configuring Darwin to use embedded runpath.

Recent Darwin versions place contraints on the use of run paths
specified in environment variables.  This breaks some assumptions
in the GCC build.

This change allows the user to configure a Darwin build to use
'@rpath/libraryname.dylib' in library names and then to add an
embedded runpath to executables (and libraries with dependents).

The embedded runpath is added by default unless the user adds
'-nodefaultrpaths' to the link line.

For an installed compiler, it means that any executable built with
that compiler will reference the runtimes installed with the
compiler (equivalent to hard-coding the library path into the name
of the library).

During build-time configurations  any "-B" entries will be added to
the runpath thus the newly-built libraries will be found by exes.

Since the install name is set in libtool, that decision needs to be
available here (but might also cause dependent ones in Makefiles,
so we need to export a conditional).

This facility is not available for Darwin 8 or earlier, however the
existing environment variable runpath does work there.

We default this on for systems where the external DYLD_LIBRARY_PATH
does not work and off for Darwin 8 or earlier.  For systems that can
use either method, if the value is unset, we use the default (which
is currently DYLD_LIBRARY_PATH).

ChangeLog:

	* configure: Regenerate.
	* configure.ac: Do not add default runpaths to GCC exes
	when we are building -static-libstdc++/-static-libgcc (the
	default).
	* libtool.m4: Add 'enable-darwin-at-runpath'.  Act  on the
	enable flag to alter Darwin libraries to use @rpath names.

gcc/ChangeLog:

	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* config/darwin.h: Handle Darwin rpaths.
	* config/darwin.opt: Handle Darwin rpaths.
	* Makefile.in:  Handle Darwin rpaths.

gcc/ada/ChangeLog:

	* gcc-interface/Makefile.in: Handle Darwin rpaths.

gcc/jit/ChangeLog:
	* Make-lang.in: Handle Darwin rpaths.

libatomic/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libbacktrace/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libcc1/ChangeLog:

	* configure: Regenerate.

libffi/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.

libgcc/ChangeLog:

	* config/t-slibgcc-darwin: Generate libgcc_s
	with an @rpath name.
	* config.host: Handle Darwin rpaths.

libgfortran/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths

libgm2/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* libm2cor/Makefile.am: Handle Darwin rpaths.
	* libm2cor/Makefile.in: Regenerate.
	* libm2iso/Makefile.am: Handle Darwin rpaths.
	* libm2iso/Makefile.in: Regenerate.
	* libm2log/Makefile.am: Handle Darwin rpaths.
	* libm2log/Makefile.in: Regenerate.
	* libm2min/Makefile.am: Handle Darwin rpaths.
	* libm2min/Makefile.in: Regenerate.
	* libm2pim/Makefile.am: Handle Darwin rpaths.
	* libm2pim/Makefile.in: Regenerate.

libgomp/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths

libitm/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libobjc/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libphobos/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* libdruntime/Makefile.am: Handle Darwin rpaths.
	* libdruntime/Makefile.in: Regenerate.
	* src/Makefile.am: Handle Darwin rpaths.
	* src/Makefile.in: Regenerate.

libquadmath/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libsanitizer/ChangeLog:

	* asan/Makefile.am: Handle Darwin rpaths.
	* asan/Makefile.in: Regenerate.
	* configure: Regenerate.
	* hwasan/Makefile.am: Handle Darwin rpaths.
	* hwasan/Makefile.in: Regenerate.
	* lsan/Makefile.am: Handle Darwin rpaths.
	* lsan/Makefile.in: Regenerate.
	* tsan/Makefile.am: Handle Darwin rpaths.
	* tsan/Makefile.in: Regenerate.
	* ubsan/Makefile.am: Handle Darwin rpaths.
	* ubsan/Makefile.in: Regenerate.

libssp/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libstdc++-v3/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* src/Makefile.am: Handle Darwin rpaths.
	* src/Makefile.in: Regenerate.

libvtv/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

lto-plugin/ChangeLog:
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

zlib/ChangeLog:
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

8 files changed, 222 insertions, 17 deletions

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index a25a1e3..bc6a76f 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1198,6 +1198,8 @@ LANG_MAKEFRAGS = @all_lang_makefrags@
 # Used by gcc/jit/Make-lang.in
 LD_VERSION_SCRIPT_OPTION = @ld_version_script_option@
 LD_SONAME_OPTION = @ld_soname_option@
+@ENABLE_DARWIN_AT_RPATH_TRUE@DARWIN_RPATH = @rpath
+@ENABLE_DARWIN_AT_RPATH_FALSE@DARWIN_RPATH = ${libdir}
 
 # Flags to pass to recursive makes.
 # CC is set by configure.
@@ -2027,9 +2029,12 @@ cs-tconfig.h: Makefile
 	$(SHELL) $(srcdir)/mkconfig.sh tconfig.h
 
 cs-tm.h: Makefile
-	TARGET_CPU_DEFAULT="$(target_cpu_default)" \
-	HEADERS="$(tm_include_list)" DEFINES="$(tm_defines)" \
-	$(SHELL) $(srcdir)/mkconfig.sh tm.h
+@ENABLE_DARWIN_AT_RPATH_FALSE@	TARGET_CPU_DEFAULT="$(target_cpu_default)" \
+@ENABLE_DARWIN_AT_RPATH_FALSE@	HEADERS="$(tm_include_list)" DEFINES="$(tm_defines)" \
+@ENABLE_DARWIN_AT_RPATH_FALSE@	$(SHELL) $(srcdir)/mkconfig.sh tm.h
+@ENABLE_DARWIN_AT_RPATH_TRUE@	TARGET_CPU_DEFAULT="$(target_cpu_default)" \
+@ENABLE_DARWIN_AT_RPATH_TRUE@	HEADERS="$(tm_include_list)" DEFINES="$(tm_defines) DARWIN_AT_RPATH=1" \
+@ENABLE_DARWIN_AT_RPATH_TRUE@	$(SHELL) $(srcdir)/mkconfig.sh tm.h
 
 cs-tm_p.h: Makefile
 	TARGET_CPU_DEFAULT="" \
diff --git a/gcc/aclocal.m4 b/gcc/aclocal.m4
index 6be36df..126e09b 100644
--- a/gcc/aclocal.m4
+++ b/gcc/aclocal.m4
@@ -12,6 +12,56 @@
 # PARTICULAR PURPOSE.
 
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
+# AM_CONDITIONAL                                            -*- Autoconf -*-
+
+# Copyright (C) 1997-2017 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# AM_CONDITIONAL(NAME, SHELL-CONDITION)
+# -------------------------------------
+# Define a conditional.
+AC_DEFUN([AM_CONDITIONAL],
+[AC_PREREQ([2.52])dnl
+ m4_if([$1], [TRUE],  [AC_FATAL([$0: invalid condition: $1])],
+       [$1], [FALSE], [AC_FATAL([$0: invalid condition: $1])])dnl
+AC_SUBST([$1_TRUE])dnl
+AC_SUBST([$1_FALSE])dnl
+_AM_SUBST_NOTMAKE([$1_TRUE])dnl
+_AM_SUBST_NOTMAKE([$1_FALSE])dnl
+m4_define([_AM_COND_VALUE_$1], [$2])dnl
+if $2; then
+  $1_TRUE=
+  $1_FALSE='#'
+else
+  $1_TRUE='#'
+  $1_FALSE=
+fi
+AC_CONFIG_COMMANDS_PRE(
+[if test -z "${$1_TRUE}" && test -z "${$1_FALSE}"; then
+  AC_MSG_ERROR([[conditional "$1" was never defined.
+Usually this means the macro was only invoked conditionally.]])
+fi])])
+
+# Copyright (C) 2006-2017 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# _AM_SUBST_NOTMAKE(VARIABLE)
+# ---------------------------
+# Prevent Automake from outputting VARIABLE = @VARIABLE@ in Makefile.in.
+# This macro is traced by Automake.
+AC_DEFUN([_AM_SUBST_NOTMAKE])
+
+# AM_SUBST_NOTMAKE(VARIABLE)
+# --------------------------
+# Public sister of _AM_SUBST_NOTMAKE.
+AC_DEFUN([AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE($@)])
+
 m4_include([../libtool.m4])
 m4_include([../ltoptions.m4])
 m4_include([../ltsugar.m4])
diff --git a/gcc/ada/gcc-interface/Makefile.in b/gcc/ada/gcc-interface/Makefile.in
index b5243a2..ad7cf50 100644
--- a/gcc/ada/gcc-interface/Makefile.in
+++ b/gcc/ada/gcc-interface/Makefile.in
@@ -794,12 +794,15 @@ gnatlib-shared-darwin:
 		$(GNATRTL_NONTASKING_OBJS) $(LIBGNAT_OBJS) \
 		$(SO_OPTS) \
 		-Wl,-install_name,@rpath/libgnat$(hyphen)$(LIBRARY_VERSION)$(soext) \
-		$(MISCLIB)
+		-nodefaultrpaths -Wl,-rpath,@loader_path/,-rpath,@loader_path/.. \
+		-Wl,-rpath,@loader_path/../../../../ $(MISCLIB)
 	cd $(RTSDIR); $(GCC_FOR_ADA_RTS) -dynamiclib $(PICFLAG_FOR_TARGET) \
 		-o libgnarl$(hyphen)$(LIBRARY_VERSION)$(soext) \
 		$(GNATRTL_TASKING_OBJS) \
 		$(SO_OPTS) \
 		-Wl,-install_name,@rpath/libgnarl$(hyphen)$(LIBRARY_VERSION)$(soext) \
+		-nodefaultrpaths -Wl,-rpath,@loader_path/,-rpath,@loader_path/.. \
+		-Wl,-rpath,@loader_path/../../../../ \
 		$(THREADSLIB) -Wl,libgnat$(hyphen)$(LIBRARY_VERSION)$(soext)
 	cd $(RTSDIR); $(LN_S) libgnat$(hyphen)$(LIBRARY_VERSION)$(soext) \
 		libgnat$(soext)
diff --git a/gcc/config/darwin.h b/gcc/config/darwin.h
index 2ee66c1..ae7d5c6 100644
--- a/gcc/config/darwin.h
+++ b/gcc/config/darwin.h
@@ -309,6 +309,18 @@ extern GTY(()) int darwin_ms_struct;
 #define DARWIN_CC1_SPEC							\
   "%<dynamic %<force_cpusubtype_ALL %<multiply_defined* %<dynamiclib"
 
+/* When we are using embedded runpaths DARWIN_AT_RPATH is set. */
+#if DARWIN_AT_RPATH
+# define DARWIN_RPATH_LINK \
+"%{!r:%{!nostdlib:%{!nodefaultrpaths:%(darwin_rpaths)}}}"
+# define DARWIN_SHARED_LIBGCC "-lgcc_s.1.1"
+#else
+# define DARWIN_RPATH_LINK ""
+# define DARWIN_SHARED_LIBGCC \
+"%:version-compare(!> 10.11 mmacosx-version-min= -lgcc_s.1.1) \
+ %:version-compare(>= 10.11 mmacosx-version-min= -lemutls_w) "
+#endif
+
 #define SUBSUBTARGET_OVERRIDE_OPTIONS					\
   do {									\
     darwin_override_options ();						\
@@ -403,7 +415,8 @@ extern GTY(()) int darwin_ms_struct;
     DARWIN_NOPIE_SPEC \
     DARWIN_RDYNAMIC \
     DARWIN_NOCOMPACT_UNWIND \
-    "}}}}}}} %<pie %<no-pie %<rdynamic %<X %<rpath "
+    DARWIN_RPATH_LINK \
+    "}}}}}}} %<pie %<no-pie %<rdynamic %<X %<rpath %<nodefaultrpaths "
 
 /* Spec that controls whether the debug linker is run automatically for
    a link step.  This needs to be done if there is a source file on the
@@ -518,8 +531,7 @@ extern GTY(()) int darwin_ms_struct;
     %:version-compare(!> 10.6 mmacosx-version-min= -lgcc_eh)		  \
     %:version-compare(>= 10.6 mmacosx-version-min= -lemutls_w);		  \
    shared-libgcc|fexceptions|fobjc-exceptions|fgnu-runtime:		  \
-    %:version-compare(!> 10.11 mmacosx-version-min= -lgcc_s.1.1)	  \
-    %:version-compare(>= 10.11 mmacosx-version-min= -lemutls_w)		  \
+   " DARWIN_SHARED_LIBGCC "						  \
     %:version-compare(!> 10.3.9 mmacosx-version-min= -lgcc_eh)		  \
     %:version-compare(>< 10.3.9 10.5 mmacosx-version-min= -lgcc_s.10.4)   \
     %:version-compare(>< 10.5 10.6 mmacosx-version-min= -lgcc_s.10.5);	  \
@@ -554,7 +566,8 @@ extern GTY(()) int darwin_ms_struct;
   { "darwin_crt2", DARWIN_CRT2_SPEC },					\
   { "darwin_crt3", DARWIN_CRT3_SPEC },					\
   { "darwin_dylib1", DARWIN_DYLIB1_SPEC },				\
-  { "darwin_bundle1", DARWIN_BUNDLE1_SPEC },
+  { "darwin_bundle1", DARWIN_BUNDLE1_SPEC },				\
+  { "darwin_rpaths", DARWIN_RPATH_SPEC },
 
 #define DARWIN_CRT1_SPEC						\
   "%:version-compare(!> 10.5 mmacosx-version-min= -lcrt1.o)		\
@@ -580,6 +593,17 @@ extern GTY(()) int darwin_ms_struct;
 "%{!static:%:version-compare(< 10.6 mmacosx-version-min= -lbundle1.o)	\
 	   %{fgnu-tm: -lcrttms.o}}"
 
+#if DARWIN_AT_RPATH
+/* A default rpath, that picks up dependent libraries installed in the same
+   director as one being loaded.  */
+#define DARWIN_RPATH_SPEC \
+  "%:version-compare(>= 10.5 mmacosx-version-min= -rpath) \
+   %:version-compare(>= 10.5 mmacosx-version-min= @loader_path) \
+   %P "
+#else
+#define DARWIN_RPATH_SPEC ""
+#endif
+
 #ifdef HAVE_AS_MMACOSX_VERSION_MIN_OPTION
 /* Emit macosx version (but only major).  */
 #define ASM_MMACOSX_VERSION_MIN_SPEC \
diff --git a/gcc/config/darwin.opt b/gcc/config/darwin.opt
index d655aae..ff624ff 100644
--- a/gcc/config/darwin.opt
+++ b/gcc/config/darwin.opt
@@ -241,6 +241,10 @@ nodefaultexport
 Driver RejectNegative
 Do not add a default symbol exports to modules or dynamic libraries.
 
+nodefaultrpaths
+Driver RejectNegative
+Do not add default run paths (for the compiler library directories) to executables, modules or dynamic libraries.
+
 nofixprebinding
 Driver RejectNegative
 (Obsolete after 10.3.9) Set MH_NOPREFIXBINDING, in an executable.
diff --git a/gcc/configure b/gcc/configure
index 9f5b708..13085f3 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -744,6 +744,8 @@ ORIGINAL_PLUGIN_LD_FOR_TARGET
 gcc_cv_ld
 ORIGINAL_AS_FOR_TARGET
 gcc_cv_as
+ENABLE_DARWIN_AT_RPATH_FALSE
+ENABLE_DARWIN_AT_RPATH_TRUE
 enable_fast_install
 objdir
 OTOOL64
@@ -1009,6 +1011,7 @@ enable_static
 with_pic
 enable_fast_install
 enable_libtool_lock
+enable_darwin_at_rpath
 enable_ld
 enable_gold
 with_plugin_ld
@@ -1744,6 +1747,9 @@ Optional Features:
   --enable-fast-install[=PKGS]
                           optimize for fast installation [default=yes]
   --disable-libtool-lock  avoid locking (might break parallel builds)
+  --enable-darwin-at-rpath
+                          install libraries with @rpath/library-name, requires
+                          rpaths to be added to executables
   --enable-ld[=ARG]       build ld [ARG={default,yes,no}]
   --enable-gold[=ARG]     build gold [ARG={default,yes,no}]
   --enable-gnu-indirect-function
@@ -16393,7 +16399,7 @@ $as_echo "$lt_cv_ld_force_load" >&6; }
       # darwin 5.x (macOS 10.1) onwards we only need to adjust when the
       # deployment target is forced to an earlier version.
       case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host in
-	UNSET,*-darwin[89]*|UNSET,*-darwin[12][0123456789]*)
+	UNSET,*-darwin[89]*|UNSET,*-darwin[12][0-9]*)
 	  ;;
 	10.[012][,.]*)
 	  _lt_dar_allow_undefined='${wl}-flat_namespace ${wl}-undefined ${wl}suppress'
@@ -18098,6 +18104,49 @@ if test -z "$aix_libpath"; then aix_libpath="/usr/lib:/lib"; fi
     darwin* | rhapsody*)
 
 
+
+  # Publish an arg to allow the user to select that Darwin host (and target)
+  # libraries should be given install-names like @rpath/libfoo.dylib.  This
+  # requires that the user of the library then adds an 'rpath' to the DSO that
+  # needs access.
+  # NOTE: there are defaults below, for systems that support rpaths.  The person
+  # configuring can override the defaults for any system version that supports
+  # them - they are, however, forced off for system versions without support.
+  # Check whether --enable-darwin-at-rpath was given.
+if test "${enable_darwin_at_rpath+set}" = set; then :
+  enableval=$enable_darwin_at_rpath; if test "x$enable_darwin_at_rpath" = "xyes"; then
+    # This is not supported before macOS 10.5 / Darwin9.
+    case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host_os in
+      UNSET,darwin[4-8]*|UNSET,rhapsody*|10.[0-4][,.]*)
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Darwin @rpath library names are incompatible with OSX versions earlier than 10.5 (rpaths disabled)" >&5
+$as_echo "$as_me: WARNING: Darwin @rpath library names are incompatible with OSX versions earlier than 10.5 (rpaths disabled)" >&2;}
+	enable_darwin_at_rpath=no
+      ;;
+    esac
+   fi
+else
+  case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host_os in
+    # As above, before 10.5 / Darwin9 this does not work.
+     UNSET,darwin[4-8]*|UNSET,rhapsody*|10.[0-4][,.]*)
+       enable_darwin_at_rpath=no
+       ;;
+
+    # We cannot build and test reliably on macOS 10.11+ (Darwin15+) without use
+    # of rpaths, since runpaths set via DYLD_LIBRARY_PATH are elided by key
+    # system executables (e.g. /bin/sh).  Force rpaths on for these systems.
+      UNSET,darwin1[5-9]*|UNSET,darwin2*|10.1[1-9][,.]*|1[1-9].*[,.]* )
+      { $as_echo "$as_me:${as_lineno-$LINENO}: @rpath library names are needed on macOS versions later than 10.11 (rpaths have been enabled)" >&5
+$as_echo "$as_me: @rpath library names are needed on macOS versions later than 10.11 (rpaths have been enabled)" >&6;}
+      enable_darwin_at_rpath=yes
+      ;;
+    # NOTE: we are not (yet) doing anything for 10.5 .. 10.10, since they can
+    # work with either DYLD_LIBRARY_PATH or embedded rpaths.
+
+    esac
+
+fi
+
+
   archive_cmds_need_lc=no
   hardcode_direct=no
   hardcode_automatic=yes
@@ -18115,9 +18164,13 @@ if test -z "$aix_libpath"; then aix_libpath="/usr/lib:/lib"; fi
   esac
   if test "$_lt_dar_can_shared" = "yes"; then
     output_verbose_link_cmd=func_echo_all
-    archive_cmds="\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring $_lt_dar_single_mod${_lt_dsymutil}"
+    _lt_install_name='\$rpath/\$soname'
+    if test "x$enable_darwin_at_rpath" = "xyes"; then
+      _lt_install_name='@rpath/\$soname'
+    fi
+    archive_cmds="\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name ${_lt_install_name} \$verstring ${_lt_dsymutil}"
     module_cmds="\$CC \$allow_undefined_flag -o \$lib -bundle \$libobjs \$deplibs \$compiler_flags${_lt_dsymutil}"
-    archive_expsym_cmds="sed 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring ${_lt_dar_single_mod}${_lt_dar_export_syms}${_lt_dsymutil}"
+    archive_expsym_cmds="sed 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name ${_lt_install_name} \$verstring ${_lt_dar_export_syms}${_lt_dsymutil}"
     module_expsym_cmds="sed -e 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC \$allow_undefined_flag -o \$lib -bundle \$libobjs \$deplibs \$compiler_flags${_lt_dar_export_syms}${_lt_dsymutil}"
 
   else
@@ -19923,7 +19976,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19926 "configure"
+#line 19979 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -20029,7 +20082,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 20032 "configure"
+#line 20085 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -20905,6 +20958,49 @@ if test -z "$aix_libpath"; then aix_libpath="/usr/lib:/lib"; fi
       darwin* | rhapsody*)
 
 
+
+  # Publish an arg to allow the user to select that Darwin host (and target)
+  # libraries should be given install-names like @rpath/libfoo.dylib.  This
+  # requires that the user of the library then adds an 'rpath' to the DSO that
+  # needs access.
+  # NOTE: there are defaults below, for systems that support rpaths.  The person
+  # configuring can override the defaults for any system version that supports
+  # them - they are, however, forced off for system versions without support.
+  # Check whether --enable-darwin-at-rpath was given.
+if test "${enable_darwin_at_rpath+set}" = set; then :
+  enableval=$enable_darwin_at_rpath; if test "x$enable_darwin_at_rpath" = "xyes"; then
+    # This is not supported before macOS 10.5 / Darwin9.
+    case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host_os in
+      UNSET,darwin[4-8]*|UNSET,rhapsody*|10.[0-4][,.]*)
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Darwin @rpath library names are incompatible with OSX versions earlier than 10.5 (rpaths disabled)" >&5
+$as_echo "$as_me: WARNING: Darwin @rpath library names are incompatible with OSX versions earlier than 10.5 (rpaths disabled)" >&2;}
+	enable_darwin_at_rpath=no
+      ;;
+    esac
+   fi
+else
+  case ${MACOSX_DEPLOYMENT_TARGET-UNSET},$host_os in
+    # As above, before 10.5 / Darwin9 this does not work.
+     UNSET,darwin[4-8]*|UNSET,rhapsody*|10.[0-4][,.]*)
+       enable_darwin_at_rpath=no
+       ;;
+
+    # We cannot build and test reliably on macOS 10.11+ (Darwin15+) without use
+    # of rpaths, since runpaths set via DYLD_LIBRARY_PATH are elided by key
+    # system executables (e.g. /bin/sh).  Force rpaths on for these systems.
+      UNSET,darwin1[5-9]*|UNSET,darwin2*|10.1[1-9][,.]*|1[1-9].*[,.]* )
+      { $as_echo "$as_me:${as_lineno-$LINENO}: @rpath library names are needed on macOS versions later than 10.11 (rpaths have been enabled)" >&5
+$as_echo "$as_me: @rpath library names are needed on macOS versions later than 10.11 (rpaths have been enabled)" >&6;}
+      enable_darwin_at_rpath=yes
+      ;;
+    # NOTE: we are not (yet) doing anything for 10.5 .. 10.10, since they can
+    # work with either DYLD_LIBRARY_PATH or embedded rpaths.
+
+    esac
+
+fi
+
+
   archive_cmds_need_lc_CXX=no
   hardcode_direct_CXX=no
   hardcode_automatic_CXX=yes
@@ -20922,12 +21018,20 @@ if test -z "$aix_libpath"; then aix_libpath="/usr/lib:/lib"; fi
   esac
   if test "$_lt_dar_can_shared" = "yes"; then
     output_verbose_link_cmd=func_echo_all
-    archive_cmds_CXX="\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring $_lt_dar_single_mod${_lt_dsymutil}"
+    _lt_install_name='\$rpath/\$soname'
+    if test "x$enable_darwin_at_rpath" = "xyes"; then
+      _lt_install_name='@rpath/\$soname'
+    fi
+    archive_cmds_CXX="\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name ${_lt_install_name} \$verstring ${_lt_dsymutil}"
     module_cmds_CXX="\$CC \$allow_undefined_flag -o \$lib -bundle \$libobjs \$deplibs \$compiler_flags${_lt_dsymutil}"
-    archive_expsym_cmds_CXX="sed 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring ${_lt_dar_single_mod}${_lt_dar_export_syms}${_lt_dsymutil}"
+    archive_expsym_cmds_CXX="sed 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \$libobjs \$deplibs \$compiler_flags -install_name ${_lt_install_name} \$verstring ${_lt_dar_export_syms}${_lt_dsymutil}"
     module_expsym_cmds_CXX="sed -e 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC \$allow_undefined_flag -o \$lib -bundle \$libobjs \$deplibs \$compiler_flags${_lt_dar_export_syms}${_lt_dsymutil}"
        if test "$lt_cv_apple_cc_single_mod" != "yes"; then
-      archive_cmds_CXX="\$CC -r -keep_private_externs -nostdlib -o \${lib}-master.o \$libobjs~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \${lib}-master.o \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring${_lt_dsymutil}"
+      _lt_install_name='\$rpath/\$soname'
+      if test "x$enable_darwin_at_rpath" = "xyes"; then
+        _lt_install_name='@rpath/\$soname'
+      fi
+      archive_cmds_CXX="\$CC -r -keep_private_externs -nostdlib -o \${lib}-master.o \$libobjs~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \${lib}-master.o \$deplibs \$compiler_flags -install_name ${_lt_install_name} \$verstring${_lt_dsymutil}"
       archive_expsym_cmds_CXX="sed 's,^,_,' < \$export_symbols > \$output_objdir/\${libname}-symbols.expsym~\$CC -r -keep_private_externs -nostdlib -o \${lib}-master.o \$libobjs~\$CC -dynamiclib \$allow_undefined_flag -o \$lib \${lib}-master.o \$deplibs \$compiler_flags -install_name \$rpath/\$soname \$verstring${_lt_dar_export_syms}${_lt_dsymutil}"
     fi
 
@@ -23298,6 +23402,15 @@ ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
 
 
+ if test x$enable_darwin_at_rpath = xyes; then
+  ENABLE_DARWIN_AT_RPATH_TRUE=
+  ENABLE_DARWIN_AT_RPATH_FALSE='#'
+else
+  ENABLE_DARWIN_AT_RPATH_TRUE='#'
+  ENABLE_DARWIN_AT_RPATH_FALSE=
+fi
+
+
 # Identify the assembler which will work hand-in-glove with the newly
 # built GCC, so that we can examine its features.  This is the assembler
 # which will be driven by the driver program.
@@ -32995,6 +33108,10 @@ LTLIBOBJS=$ac_ltlibobjs
 
 
 
+if test -z "${ENABLE_DARWIN_AT_RPATH_TRUE}" && test -z "${ENABLE_DARWIN_AT_RPATH_FALSE}"; then
+  as_fn_error $? "conditional \"ENABLE_DARWIN_AT_RPATH\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 
 : "${CONFIG_STATUS=./config.status}"
 ac_write_fail=0
diff --git a/gcc/configure.ac b/gcc/configure.ac
index c10e007..0ac589a 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -2632,6 +2632,8 @@ AC_PROG_LIBTOOL
 AC_SUBST(objdir)
 AC_SUBST(enable_fast_install)
 
+AM_CONDITIONAL([ENABLE_DARWIN_AT_RPATH], [test x$enable_darwin_at_rpath = xyes])
+
 # Identify the assembler which will work hand-in-glove with the newly
 # built GCC, so that we can examine its features.  This is the assembler
 # which will be driven by the driver program.
diff --git a/gcc/jit/Make-lang.in b/gcc/jit/Make-lang.in
index a65f138..3fd564a 100644
--- a/gcc/jit/Make-lang.in
+++ b/gcc/jit/Make-lang.in
@@ -59,7 +59,7 @@ LIBGCCJIT_AGE = 1
 LIBGCCJIT_BASENAME = libgccjit
 
 LIBGCCJIT_SONAME = \
-  ${libdir}/$(LIBGCCJIT_BASENAME).$(LIBGCCJIT_VERSION_NUM).dylib
+  $(DARWIN_RPATH)/$(LIBGCCJIT_BASENAME).$(LIBGCCJIT_VERSION_NUM).dylib
 LIBGCCJIT_FILENAME = $(LIBGCCJIT_BASENAME).$(LIBGCCJIT_VERSION_NUM).dylib
 LIBGCCJIT_LINKER_NAME = $(LIBGCCJIT_BASENAME).dylib