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

[Iain Sandoe]

We have been including the out of line save/restore functions in libgcc,
which means that we have to append -lgcc even when using shared
libgcc.  In preparation for revision of libgcc for Darwin, split this into an
endfile.

tested on powerpc-darwin9,
applied to mainline
thanks
Iain

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).


diff --git a/gcc/config/rs6000/darwin.h b/gcc/config/rs6000/darwin.h
index 705dd7f..fcc4354 100644
--- a/gcc/config/rs6000/darwin.h
+++ b/gcc/config/rs6000/darwin.h
@@ -132,6 +132,11 @@ extern int darwin_emit_picsym_stub;
 #define DARWIN_CRT2_SPEC \
   "%{!m64:%:version-compare(!> 10.4 mmacosx-version-min= crt2.o%s)}"
 
+/* The PPC regs save/restore functions are leaves and could, conceivably
+   be used by the tm destructor.  */
+#undef ENDFILE_SPEC
+#define ENDFILE_SPEC TM_DESTRUCTOR "-lef_ppc"
+
 #undef SUBTARGET_EXTRA_SPECS
 #define SUBTARGET_EXTRA_SPECS			\
   DARWIN_EXTRA_SPECS                            \
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index a589615..a6e8c20 100644

diff --git a/libgcc/config.host b/libgcc/config.host
index e6a834b..cf52b27 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1091,11 +1091,11 @@ powerpc-*-darwin*)
 	  ;;
 	esac
 	tmake_file="$tmake_file rs6000/t-ibm-ldouble"
-	extra_parts="$extra_parts crt2.o"
+	extra_parts="$extra_parts crt2.o libef_ppc.a"
 	;;
 powerpc64-*-darwin*)
 	tmake_file="$tmake_file rs6000/t-darwin64 rs6000/t-ibm-ldouble"
-	extra_parts="$extra_parts crt2.o"
+	extra_parts="$extra_parts crt2.o libef_ppc.a"
 	;;
 powerpc*-*-freebsd*)
 	tmake_file="${tmake_file} rs6000/t-ppccomm rs6000/t-savresfgpr rs6000/t-crtstuff rs6000/t-freebsd t-softfp-sfdf t-softfp-excl t-softfp"
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 $<