[gcc r12-4956] Darwin, aarch64 : Ada fixes for hosted tools.

[Iain D Sandoe <iains@gcc.gnu.org>]

https://gcc.gnu.org/g:f8a1e0699328268e98e18eb100f5af37e92dab9f

commit r12-4956-gf8a1e0699328268e98e18eb100f5af37e92dab9f
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Fri Aug 28 19:09:45 2020 +0100

    Darwin, aarch64 : Ada fixes for hosted tools.
    
    This will allow someone (with an existing Ada compiler on the
    platform - which can be provided by the experimental aarch64-darwin
    branch) - to build the host tools (gnatmake and friends) for a
    non-native cross.
    
    The existing provisions for iOS are OK for cross-compilation from
    an x86-64-darwin platform, but we need some adjustments so that these
    host tools can be built to run on aarch64-darwin.
    
    Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
    
    gcc/ada/
    
            * gcc-interface/Make-lang.in: Use iOS signal trampoline code
            for hosted Ada tools.
            * sigtramp-ios.c: Wrap the declarations in extern "C" when
            the code is built by a C++ compiler.

Diff:
---
 gcc/ada/gcc-interface/Make-lang.in | 18 +++++++++++++-----
 gcc/ada/sigtramp-ios.c             |  8 ++++++++
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/gcc/ada/gcc-interface/Make-lang.in b/gcc/ada/gcc-interface/Make-lang.in
index ba194d1369d..ab5fb72623b 100644
--- a/gcc/ada/gcc-interface/Make-lang.in
+++ b/gcc/ada/gcc-interface/Make-lang.in
@@ -725,6 +725,14 @@ endif
 # For unwind-pe.h
 CFLAGS-ada/raise-gcc.o += -I$(srcdir)/../libgcc -DEH_MECHANISM_$(EH_MECHANISM)
 
+# Under aarch64 darwin, we need to include the iOS signal trampoline.
+
+ifeq ($(strip $(filter-out aarch64 arm64 darwin%,$(host_cpu) $(host_os))),)
+  EXTRA_HOST_OBJS=ada/sigtramp-ios.o
+else
+  EXTRA_HOST_OBJS =
+endif
+
 ada/libgnat/s-excmac.o: ada/libgnat/s-excmac.ads ada/libgnat/s-excmac.adb
 
 ada/libgnat/s-excmac.ads: $(srcdir)/ada/libgnat/s-excmac__$(EH_MECHANISM).ads
@@ -738,16 +746,16 @@ ada/libgnat/s-excmac.adb: $(srcdir)/ada/libgnat/s-excmac__$(EH_MECHANISM).adb
 # Needs to be built with CC=gcc
 # Since the RTL should be built with the latest compiler, remove the
 #  stamp target in the parent directory whenever gnat1 is rebuilt
-gnat1$(exeext): $(TARGET_ADA_SRCS) $(GNAT1_OBJS) $(ADA_BACKEND) libcommon-target.a \
-		$(LIBDEPS) $(ada.prev)
+gnat1$(exeext): $(TARGET_ADA_SRCS) $(GNAT1_OBJS) $(ADA_BACKEND) $(EXTRA_HOST_OBJS) libcommon-target.a \
+		$(EXTRA_HOST_OBJS) $(LIBDEPS) $(ada.prev)
 	@$(call LINK_PROGRESS,$(INDEX.ada),start)
-	+$(GCC_LLINK) -o $@ $(GNAT1_OBJS) $(ADA_BACKEND) $(CFLAGS) \
+	+$(GCC_LLINK) -o $@ $(GNAT1_OBJS) $(ADA_BACKEND) $(EXTRA_HOST_OBJS) $(CFLAGS) \
 	  libcommon-target.a $(LIBS) $(SYSLIBS) $(BACKENDLIBS) $(GNATLIB)
 	$(RM) stamp-gnatlib2-rts stamp-tools
 	@$(call LINK_PROGRESS,$(INDEX.ada),end)
 
-gnatbind$(exeext): ada/b_gnatb.o $(CONFIG_H) $(GNATBIND_OBJS) ggc-none.o libcommon-target.a $(LIBDEPS)
-	+$(GCC_LINK) -o $@ $(CFLAGS) ada/b_gnatb.o $(GNATBIND_OBJS) ggc-none.o libcommon-target.a $(LIBS) $(SYSLIBS) $(GNATLIB)
+gnatbind$(exeext): ada/b_gnatb.o $(CONFIG_H) $(GNATBIND_OBJS) $(EXTRA_HOST_OBJS) ggc-none.o libcommon-target.a $(LIBDEPS)
+	+$(GCC_LINK) -o $@ $(CFLAGS) ada/b_gnatb.o $(GNATBIND_OBJS) $(EXTRA_HOST_OBJS) ggc-none.o libcommon-target.a $(LIBS) $(SYSLIBS) $(GNATLIB)
 
 # use target-gcc target-gnatmake target-gnatbind target-gnatlink
 gnattools: $(GCC_PARTS) $(CONFIG_H) prefix.o force
diff --git a/gcc/ada/sigtramp-ios.c b/gcc/ada/sigtramp-ios.c
index 6e2913d91f2..8403a1865ea 100644
--- a/gcc/ada/sigtramp-ios.c
+++ b/gcc/ada/sigtramp-ios.c
@@ -71,6 +71,10 @@
 
 /* sigtramp stub providing unwind info for common registers.  */
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 extern void __gnat_sigtramp_common
   (int signo, void *siginfo, void *sigcontext,
    __sigtramphandler_t * handler);
@@ -87,6 +91,10 @@ void __gnat_sigtramp (int signo, void *si, void *ucontext,
   __gnat_sigtramp_common (signo, si, mcontext, handler);
 }
 
+#if defined(__cplusplus)
+}
+#endif
+
 /* asm string construction helpers.  */
 
 #define STR(TEXT) #TEXT