[Darwin, PPC] Move the out of line register save/restore to an endfile.

We have been including this in libgcc, which means that we have to append
-lgcc even when using shared libgcc. In preparation for revision of libgcc
split this into an endfile.

gcc/
2019-06-25  Iain Sandoe  <iain@sandoe.co.uk>

	* config/rs6000/darwin.h (ENDFILE_SPEC): New.

libgcc/
2019-06-25  Iain Sandoe  <iain@sandoe.co.uk>

	* config.host: Add libef_ppc.a to the extra files for powerpc-darwin.
	* config/rs6000/t-darwin: (PPC_ENDFILE_SRC, PPC_ENDFILE_OBJS): New.
	Build objects for the out of line save/restore register functions
	so that they can be used for any supported Darwin version.
	* config/t-darwin: Default the build Darwin version to Darwin8
	(MacOS 10.4).

From-SVN: r272659

3 files changed, 44 insertions, 9 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index a589615..a6e8c20 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,12 @@
+2019-06-25  Iain Sandoe  <iain@sandoe.co.uk>
+
+	* config.host: Add libef_ppc.a to the extra files for powerpc-darwin.
+	* config/rs6000/t-darwin: (PPC_ENDFILE_SRC, PPC_ENDFILE_OBJS): New.
+	Build objects for the out of line save/restore register functions
+	so that they can be used for any supported Darwin version.
+	* config/t-darwin: Default the build Darwin version to Darwin8
+	(MacOS 10.4).
+
 2019-06-25  Martin Liska  <mliska@suse.cz>
 
 	* libgcov-driver-system.c (replace_filename_variables): Do not
diff --git a/libgcc/config/rs6000/t-darwin b/libgcc/config/rs6000/t-darwin
index 61da0bd..0c238b7 100644
--- a/libgcc/config/rs6000/t-darwin
+++ b/libgcc/config/rs6000/t-darwin
@@ -3,23 +3,49 @@ DARWIN_EXTRA_CRT_BUILD_CFLAGS = -mlongcall -mmacosx-version-min=10.4
 crt2.o: $(srcdir)/config/rs6000/darwin-crt2.c
 	$(crt_compile) $(DARWIN_EXTRA_CRT_BUILD_CFLAGS) -c $<
 
+# The outlined register save/restore functions need to run anywhere, and
+# they must be leaf functions suitable for use in an endfile.
+
+PPC_ENDFILE_SRC = \
+  $(srcdir)/config/rs6000/darwin-gpsave.S \
+  $(srcdir)/config/rs6000/darwin-fpsave.S \
+  $(srcdir)/config/rs6000/darwin-vecsave.S
+
+PPC_ENDFILE_OBJS = \
+ darwin-gpsave.o \
+ darwin-fpsave.o \
+ darwin-vecsave.o
+
+darwin-gpsave.o: $(srcdir)/config/rs6000/darwin-gpsave.S
+	$(crt_compile) -mmacosx-version-min=10.1 -c $<
+
+darwin-fpsave.o: $(srcdir)/config/rs6000/darwin-fpsave.S
+	$(crt_compile) -mmacosx-version-min=10.1 -c $<
+
+darwin-vecsave.o: $(srcdir)/config/rs6000/darwin-vecsave.S
+	$(crt_compile) -mmacosx-version-min=10.1 -c $<
+
+# We build these into a library, so that they are only linked as needed and not
+# forced into every object.
+
+libef_ppc.a: $(PPC_ENDFILE_OBJS)
+	$(AR_CREATE_FOR_TARGET) $@ $(PPC_ENDFILE_OBJS)
+	$(RANLIB_FOR_TARGET) $@
+
 LIB2ADD = $(srcdir)/config/rs6000/darwin-tramp.S \
 	  $(srcdir)/config/darwin-64.c \
-	  $(srcdir)/config/rs6000/darwin-fpsave.S  \
-	  $(srcdir)/config/rs6000/darwin-gpsave.S  \
 	  $(srcdir)/config/rs6000/darwin-world.S \
 	  $(srcdir)/config/rs6000/ppc64-fp.c
 
-LIB2ADD_ST = \
-	  $(srcdir)/config/rs6000/darwin-vecsave.S
-
 # The .S files above are designed to run on all processors, even though
 # they use AltiVec instructions.
 # -Wa is used because -force_cpusubtype_ALL doesn't work with -dynamiclib.
-# -mmacosx-version-min=10.4 is used to provide compatibility for code from
-# earlier OSX versions.
-HOST_LIBGCC2_CFLAGS += -Wa,-force_cpusubtype_ALL -mmacosx-version-min=10.4
 
+HOST_LIBGCC2_CFLAGS += -Wa,-force_cpusubtype_ALL
+
+# Although the default for 10.4 is G3, we need the unwinder to be built
+# with vector support so that the "save/rest_world" outlined functions are
+# correctly invoked.
 unwind-dw2_s.o: HOST_LIBGCC2_CFLAGS += -maltivec
 unwind-dw2.o: HOST_LIBGCC2_CFLAGS += -maltivec
 
diff --git a/libgcc/config/t-darwin b/libgcc/config/t-darwin
index 8340ea2..2fcb712 100644
--- a/libgcc/config/t-darwin
+++ b/libgcc/config/t-darwin
@@ -1,6 +1,6 @@
 # Set this as a minimum (unless overriden by arch t-files) since it's a
 # reasonable lowest common denominator that works for all our archs.
-HOST_LIBGCC2_CFLAGS += -mmacosx-version-min=10.5
+HOST_LIBGCC2_CFLAGS += -mmacosx-version-min=10.4
 
 crt3.o: $(srcdir)/config/darwin-crt3.c
 	$(crt_compile) $(DARWIN_EXTRA_CRT_BUILD_CFLAGS) -c $<