[Darwin] Fix PR87030 and tidy config fragments.

This is about 32/64b host and multilib support across the range of Darwin
systems.

Prior to Darwin8 (OS X 10.4), the toolchains support only PowerPC and only 32b.

On Darwin8 it is possible to target a 64b multilib, but with support limited
to a few of the main libraries on the system (not a recommended configuration).

From Darwin9 to Darwin17 (OSX 10.5 to 10.13) it is possible to have either
32 or 64b hosted toolchains, with support for a 64 or 32b multilib respectively.

On Darwin9 the kernel is 32b, but with support for 64b executables, so it's
conventional to build a 32b host toolchain supporting a 64b multilib.  However
this is not enforced (merely a convention).

There is also some platform hardware supporting Darwin10/11 which is only 32b
and for which the same situation applies.  However, from Darwin10 to Darwin17,
the majority of platform hardware supports a 64b kernel and it's conventional
to build a 64b host toolchain with support for a 32b multilib.

On/from Darwin18 (OS X 10.14), the development headers (in the SDK) no longer
expose the interfaces for the 32b multilib support (although sufficient runtime
support remains installed that the testsuite can be run for a 32b multilib).

The PR is raised against this latter situation since the absence of exposed
interfaces causes a 'default' bootstrap fail regardless of the availability of
the runtimes.  Given the number of permutations, I felt it warranted a general
solution, especially since the current scheme of target headers and t-make
fragments has become somewhat messy.

The changes here enforce the single 32b PowerPC multilib for Darwin < 8 and the
single X86 64b multilib for Darwin >= 18.  This means that there is no longer
any need to configure Darwin18+ '--disable-multilib', but also that if you want
to use the ability to continue to test the compiler's 32b multilib there, you
need to make a configuration targeting an earlier OS version (and using the
SDK from that).

gcc/

	PR bootstrap/87030
	* config.gcc (*-*-darwin*): Don't include CPU t-darwin here.
	(i[34567]86-*-darwin*): Adjust to use biarch files. Produce
	an error message if i686-darwin configuration is attempted for
	Darwin >= 18.
	(x86_64-*-darwin*): Switch to single multilib for Darwin >= 18.
	(powerpc-*-darwin*): Use biarch files where needed.
	(powerpc64-*-darwin*): Likewise.
	* config/i386/darwin.h (REAL_LIBGCC_SPEC): Move to new biarch file.
	(DARWIN_ARCH_SPEC, DARWIN_SUBARCH_SPEC): Revise for default single
	arch case.
	* config/i386/darwin32-biarch.h: New.
	* config/i386/darwin64.h: Rename.
	* gcc/config/i386/darwin64-biarch.h: To this.
	* config/i386/t-darwin: Rename.
	* gcc/config/i386/t-darwin32-biarch: To this.
	* config/i386/t-darwin64: Rename.
	* gcc/config/i386/t-darwin64-biarch: To this.
	* config/rs6000/darwin32-biarch.h: New.
	* config/rs6000/darwin64.h: Rename.
	* config/rs6000/darwin64-biarch.h: To this.
	(DARWIN_ARCH_SPEC, DARWIN_SUBARCH_SPEC): Revise for default single
	arch case.
	* config/rs6000/t-darwin8: Rename.
	* config/rs6000/t-darwin32-biarch: To this.
	* config/rs6000/t-darwin64 Rename.
	* config/rs6000/t-darwin64-biarch: To this.

From-SVN: r273746

11 files changed, 127 insertions, 12 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c6c0f4a..16dda55 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,33 @@
+2019-07-23  Iain Sandoe  <iain@sandoe.co.uk>
+
+	PR bootstrap/87030
+	* config.gcc (*-*-darwin*): Don't include CPU t-darwin here.
+	(i[34567]86-*-darwin*): Adjust to use biarch files. Produce
+	an error message if i686-darwin configuration is attempted for
+	Darwin >= 18.
+	(x86_64-*-darwin*): Switch to single multilib for Darwin >= 18.
+	(powerpc-*-darwin*): Use biarch files where needed.
+	(powerpc64-*-darwin*): Likewise.
+	* config/i386/darwin.h (REAL_LIBGCC_SPEC): Move to new biarch file.
+	(DARWIN_ARCH_SPEC, DARWIN_SUBARCH_SPEC): Revise for default single
+	arch case.
+	* config/i386/darwin32-biarch.h: New.
+	* config/i386/darwin64.h: Rename.
+	* gcc/config/i386/darwin64-biarch.h: To this.
+	* config/i386/t-darwin: Rename.
+	* gcc/config/i386/t-darwin32-biarch: To this.
+	* config/i386/t-darwin64: Rename.
+	* gcc/config/i386/t-darwin64-biarch: To this.
+	* config/rs6000/darwin32-biarch.h: New.
+	* config/rs6000/darwin64.h: Rename.
+	* config/rs6000/darwin64-biarch.h: To this.
+	(DARWIN_ARCH_SPEC, DARWIN_SUBARCH_SPEC): Revise for default single
+	arch case.
+	* config/rs6000/t-darwin8: Rename.
+	* config/rs6000/t-darwin32-biarch: To this.
+	* config/rs6000/t-darwin64 Rename.
+	* config/rs6000/t-darwin64-biarch: To this.
+
 2019-07-23  Martin Sebor  <msebor@redhat.com>
 
 	* configure.ac (ACX_PROG_CXX_WARNING_OPTS): Revert r273311.
diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h
index 93bd558..fea3f73 100644
--- a/gcc/config/i386/darwin.h
+++ b/gcc/config/i386/darwin.h
@@ -139,9 +139,6 @@ along with GCC; see the file COPYING3.  If not see
   " ASM_OPTIONS " -force_cpusubtype_ALL \
   %{static}" ASM_MMACOSX_VERSION_MIN_SPEC
 
-#define DARWIN_ARCH_SPEC "%{m64:x86_64;:i386}"
-#define DARWIN_SUBARCH_SPEC DARWIN_ARCH_SPEC
-
 #undef ENDFILE_SPEC
 #define ENDFILE_SPEC \
   "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
@@ -149,12 +146,15 @@ along with GCC; see the file COPYING3.  If not see
    %{mpc64:crtprec64.o%s} \
    %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR
 
+#define DARWIN_ARCH_SPEC "x86_64"
+
+/* We default to x86_64 for single-arch builds, bi-arch overrides.  */
 #undef SUBTARGET_EXTRA_SPECS
 #define SUBTARGET_EXTRA_SPECS                                   \
   DARWIN_EXTRA_SPECS                                            \
-  { "darwin_arch", DARWIN_ARCH_SPEC },                          \
+  { "darwin_arch", DARWIN_ARCH_SPEC },				\
   { "darwin_crt2", "" },                                        \
-  { "darwin_subarch", DARWIN_SUBARCH_SPEC },
+  { "darwin_subarch", DARWIN_ARCH_SPEC },
 
 /* The Darwin assembler mostly follows AT&T syntax.  */
 #undef ASSEMBLER_DIALECT
diff --git a/gcc/config/i386/darwin32-biarch.h b/gcc/config/i386/darwin32-biarch.h
new file mode 100644
index 0000000..b7f53bf
--- /dev/null
+++ b/gcc/config/i386/darwin32-biarch.h
@@ -0,0 +1,32 @@
+/* Target definitions for i386 running Darwin.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   Contributed by Apple Computer Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#undef DARWIN_ARCH_SPEC
+#define DARWIN_ARCH_SPEC "%{m64:x86_64;:i386}"
+
+#undef  DARWIN_SUBARCH_SPEC
+#define DARWIN_SUBARCH_SPEC DARWIN_ARCH_SPEC
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS                                   \
+  DARWIN_EXTRA_SPECS                                            \
+  { "darwin_arch", DARWIN_ARCH_SPEC },                          \
+  { "darwin_crt2", "" },                                        \
+  { "darwin_subarch", DARWIN_SUBARCH_SPEC },
diff --git a/gcc/config/i386/darwin64.h b/gcc/config/i386/darwin64-biarch.h
index ebd65f9..ebd65f9 100644
--- a/gcc/config/i386/darwin64.h
+++ b/gcc/config/i386/darwin64-biarch.h
diff --git a/gcc/config/i386/t-darwin b/gcc/config/i386/t-darwin32-biarch
index bf44504..bf44504 100644
--- a/gcc/config/i386/t-darwin
+++ b/gcc/config/i386/t-darwin32-biarch
diff --git a/gcc/config/i386/t-darwin64 b/gcc/config/i386/t-darwin64-biarch
index 6a6b22f..6a6b22f 100644
--- a/gcc/config/i386/t-darwin64
+++ b/gcc/config/i386/t-darwin64-biarch
diff --git a/gcc/config/rs6000/darwin.h b/gcc/config/rs6000/darwin.h
index 1bfb577..ee44236 100644
--- a/gcc/config/rs6000/darwin.h
+++ b/gcc/config/rs6000/darwin.h
@@ -117,11 +117,10 @@ extern int darwin_emit_picsym_stub;
   %<faltivec %<fno-altivec " \
   DARWIN_CC1_SPEC
 
-#define DARWIN_ARCH_SPEC "%{m64:ppc64;:ppc}"
+/* Default to PPC for single arch builds.  */
+#define DARWIN_ARCH_SPEC "ppc"
 
 #define DARWIN_SUBARCH_SPEC "			\
- %{m64: ppc64}					\
- %{!m64:					\
  %{mcpu=601:ppc601;				\
    mcpu=603:ppc603;				\
    mcpu=603e:ppc603;				\
@@ -136,7 +135,7 @@ extern int darwin_emit_picsym_stub;
    mcpu=970:ppc970;				\
    mcpu=power4:ppc970;				\
    mcpu=G5:ppc970;				\
-   :ppc}}"
+   :ppc}"
 
 /* We need to jam the crt to 10.5 for 10.6 (Rosetta) use.  */
 #undef DARWIN_CRT1_SPEC
diff --git a/gcc/config/rs6000/darwin32-biarch.h b/gcc/config/rs6000/darwin32-biarch.h
new file mode 100644
index 0000000..35ea075
--- /dev/null
+++ b/gcc/config/rs6000/darwin32-biarch.h
@@ -0,0 +1,49 @@
+/* Target definitions for PowerPC running Darwin (Mac OS X).
+   Copyright (C) 2006-2019 Free Software Foundation, Inc.
+   Contributed by Apple Computer Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3, or (at your
+   option) any later version.
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#undef DARWIN_ARCH_SPEC
+#define DARWIN_ARCH_SPEC "%{m64:ppc64;:ppc}"
+
+#undef DARWIN_SUBARCH_SPEC
+#define DARWIN_SUBARCH_SPEC "			\
+ %{m64: ppc64}					\
+ %{!m64:					\
+ %{mcpu=601:ppc601;				\
+   mcpu=603:ppc603;				\
+   mcpu=603e:ppc603;				\
+   mcpu=604:ppc604;				\
+   mcpu=604e:ppc604e;				\
+   mcpu=740:ppc750;				\
+   mcpu=750:ppc750;				\
+   mcpu=G3:ppc750;				\
+   mcpu=7400:ppc7400;				\
+   mcpu=G4:ppc7400;				\
+   mcpu=7450:ppc7450;				\
+   mcpu=970:ppc970;				\
+   mcpu=power4:ppc970;				\
+   mcpu=G5:ppc970;				\
+   :ppc}}"
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS			\
+  DARWIN_EXTRA_SPECS                            \
+  { "darwin_arch", DARWIN_ARCH_SPEC },		\
+  { "darwin_crt2", DARWIN_CRT2_SPEC },		\
+  { "darwin_subarch", DARWIN_SUBARCH_SPEC },
diff --git a/gcc/config/rs6000/darwin64.h b/gcc/config/rs6000/darwin64-biarch.h
index a131ff2..9f72524 100644
--- a/gcc/config/rs6000/darwin64.h
+++ b/gcc/config/rs6000/darwin64-biarch.h
@@ -1,4 +1,4 @@
-/* Target definitions for PowerPC running Darwin (Mac OS X).
+/* Target definitions for PowerPC64 running Darwin (Mac OS X).
    Copyright (C) 2006-2019 Free Software Foundation, Inc.
    Contributed by Apple Computer Inc.
 
@@ -25,8 +25,13 @@
 #undef DARWIN_ARCH_SPEC
 #define DARWIN_ARCH_SPEC "%{m32:ppc;:ppc64}"
 
+/* Actually, there's really only 970 as an active option.  */
 #undef DARWIN_SUBARCH_SPEC
 #define DARWIN_SUBARCH_SPEC DARWIN_ARCH_SPEC
 
-#undef DARWIN_CRT2_SPEC
-#define DARWIN_CRT2_SPEC ""
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS			\
+  DARWIN_EXTRA_SPECS                            \
+  { "darwin_arch", DARWIN_ARCH_SPEC },		\
+  { "darwin_crt2", "" },			\
+  { "darwin_subarch", DARWIN_SUBARCH_SPEC },
diff --git a/gcc/config/rs6000/t-darwin8 b/gcc/config/rs6000/t-darwin32-biarch
index 2f3bb32..2f3bb32 100644
--- a/gcc/config/rs6000/t-darwin8
+++ b/gcc/config/rs6000/t-darwin32-biarch
diff --git a/gcc/config/rs6000/t-darwin64 b/gcc/config/rs6000/t-darwin64-biarch
index b0a04c7..b0a04c7 100644
--- a/gcc/config/rs6000/t-darwin64
+++ b/gcc/config/rs6000/t-darwin64-biarch