Improve darwin X darwin cross support

[Geoffrey Keating <gkeating at apple dot com>]

This improves support for crosses between Darwin platforms.  You
should now be able to

<foo>/configure --target=<processor>-apple-darwin

on a Darwin platform, and have it Just Work.  Well, you do need to
create an <processor>-apple-darwin-ar and
<processor>-apple-darwin-ranlib, but you can make them shell scripts
that call the usual Darwin 'ar' and 'ranlib'.

Tested by building a cross to i386-darwin from powerpc-darwin, and
bootstrapping a powerpc-darwin native.

-- 
- Geoffrey Keating <geoffk@apple.com>

===File ~/patches/gcc-ezi386darwincross.patch===============
2003-08-19  Geoffrey Keating  <geoffk@apple.com>

	* config/darwin.h (LINK_COMMAND_SPEC): Add -arch and -arch_only
	options.
	* config/i386/darwin.h (ASM_SPEC): New.
	(SUBTARGET_EXTRA_SPECS): New.
	* config/rs6000/darwin.h (ASM_SPEC): New.
	(SUBTARGET_EXTRA_SPECS): New.
	* configure.in: Don't set CROSS or SYSTEM_HEADER_DIR when building
	a cross-compiler between two different processors on Darwin.
	* configure: Regenerate.

Index: configure.in
===================================================================
RCS file: /cvs/gcc/gcc/gcc/configure.in,v
retrieving revision 1.716
diff -u -p -u -p -r1.716 configure.in
--- configure.in	14 Aug 2003 20:25:14 -0000	1.716
+++ configure.in	20 Aug 2003 02:53:52 -0000
@@ -1414,6 +1414,21 @@ then
 	ALL=all.cross
 	SYSTEM_HEADER_DIR='$(CROSS_SYSTEM_HEADER_DIR)'
 	case "$host","$target" in
+	# Darwin crosses can use the host system's libraries and headers,
+	# because of the fat library support.  Of course, it must be the
+	# same version of Darwin on both sides.  Allow the user to
+	# just say --target=foo-darwin without a version number to mean
+	# "the version on this system".
+	    *-*-darwin*,*-*-darwin*)
+		hostos=`echo $host | sed 's/.*-darwin/darwin/'`
+		targetos=`echo $target | sed 's/.*-darwin/darwin/'`
+		if test $hostos = $targetos -o $targetos = darwin ; then
+		    CROSS=
+		    SYSTEM_HEADER_DIR='$(NATIVE_SYSTEM_HEADER_DIR)'
+		    with_headers=yes
+		fi
+		;;
+
 	    i?86-*-*,x86_64-*-* \
 	    | powerpc*-*-*,powerpc64*-*-*)
 		CROSS="$CROSS -DNATIVE_CROSS" ;;
Index: config/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.h,v
retrieving revision 1.59
diff -u -p -u -p -r1.59 darwin.h
--- config/darwin.h	17 Aug 2003 10:00:03 -0000	1.59
+++ config/darwin.h	20 Aug 2003 02:53:52 -0000
@@ -186,6 +186,8 @@ Boston, MA 02111-1307, USA.  */
 #define LINK_COMMAND_SPEC "\
 %{!fdump=*:%{!fsyntax-only:%{!precomp:%{!c:%{!M:%{!MM:%{!E:%{!S:\
     %{!Zdynamiclib:%(linker)}%{Zdynamiclib:/usr/bin/libtool} \
+    %{!Zdynamiclib:-arch %(darwin_arch)} \
+    %{Zdynamiclib:-arch_only %(darwin_arch)} \
     %l %X %{d} %{s} %{t} %{Z} \
     %{!Zdynamiclib:%{A} %{e*} %{m} %{N} %{n} %{r} %{u*} %{x} %{z}} \
     %{@:-o %f%u.out}%{!@:%{o*}%{!o:-o a.out}} \
Index: config/i386/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/i386/darwin.h,v
retrieving revision 1.6
diff -u -p -u -p -r1.6 darwin.h
--- config/i386/darwin.h	4 Jun 2003 17:33:50 -0000	1.6
+++ config/i386/darwin.h	20 Aug 2003 02:53:52 -0000
@@ -41,6 +41,16 @@ Boston, MA 02111-1307, USA.  */
 #undef CC1_SPEC
 #define CC1_SPEC "%{!static:-fPIC}"
 
+#define ASM_SPEC "-arch i386 \
+  %{Zforce_cpusubtype_ALL:-force_cpusubtype_ALL} \
+  %{!Zforce_cpusubtype_ALL:%{mmmx:-force_cpusubtype_ALL}\
+			   %{msse:-force_cpusubtype_ALL}\
+			   %{msse2:-force_cpusubtype_ALL}}"
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS			\
+  { "darwin_arch", "i386" },
+
 /* The Darwin assembler mostly follows AT&T syntax.  */
 #undef ASSEMBLER_DIALECT
 #define ASSEMBLER_DIALECT ASM_ATT
Index: config/rs6000/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/darwin.h,v
retrieving revision 1.39
diff -u -p -u -p -r1.39 darwin.h
--- config/rs6000/darwin.h	5 Jul 2003 00:08:10 -0000	1.39
+++ config/rs6000/darwin.h	20 Aug 2003 02:53:52 -0000
@@ -97,6 +97,14 @@ do {									\
 %{static: %{Zdynamic: %e conflicting code gen style switches are used}}\
 %{!static:%{!mdynamic-no-pic:-fPIC}}"
 
+#define ASM_SPEC "-arch ppc \
+  %{Zforce_cpusubtype_ALL:-force_cpusubtype_ALL} \
+  %{!Zforce_cpusubtype_ALL:%{faltivec:-force_cpusubtype_ALL}}"
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS			\
+  { "darwin_arch", "ppc" },
+
 /* Make both r2 and r3 available for allocation.  */
 #define FIXED_R2 0
 #define FIXED_R13 0
============================================================