re PR ada/60411 (Ada bootstrap failure on ARM)

	PR ada/60411
	* sigtramp-armdroid.c: New file.

From-SVN: r209211

gcc/ada/ChangeLog

@@ -4,6 +4,7 @@
 	* gcc-interface/Makefile.in (arm% linux-android): Switch to EHABI.
 	* s-linux-android.ads: New file.
 	* s-intman-android.adb: Likewise.
+	* sigtramp-armdroid.c: Likewise.
 
 2014-04-07  Eric Botcazou  <ebotcazou@adacore.com>
 

gcc/ada/gcc-interface/Makefile.in

@@ -1064,7 +1064,7 @@ ifeq ($(strip $(filter-out arm% linux-androideabi,$(target_cpu) $(target_os))),)
 
   GNATRTL_SOCKETS_OBJS =
   EXTRA_GNATRTL_TASKING_OBJS=s-linux.o
-  EXTRA_LIBGNAT_OBJS+=raise-gcc.o
+  EXTRA_LIBGNAT_OBJS+=raise-gcc.o sigtramp-armdroid.o
   EXTRA_GNATRTL_NONTASKING_OBJS+=g-cppexc.o s-excmac.o
   EH_MECHANISM=-arm
   THREADSLIB =
@@ -3068,6 +3068,7 @@ mkdir.o   : mkdir.c
 socket.o  : socket.c gsocket.h
 sysdep.o  : sysdep.c
 raise.o   : raise.c raise.h
+sigtramp-armdroid.o : sigtramp-armdroid.c sigtramp.h
 sigtramp-armvxw.o : sigtramp-armvxw.c sigtramp.h
 sigtramp-ppcvxw.o : sigtramp-ppcvxw.c sigtramp.h
 terminals.o : terminals.c

gcc/ada/sigtramp-armdroid.c

+/****************************************************************************
+ *                                                                          *
+ *                         GNAT COMPILER COMPONENTS                         *
+ *                                                                          *
+ *                             S I G T R A M P                              *
+ *                                                                          *
+ *                         Asm Implementation File                          *
+ *                                                                          *
+ *           Copyright (C) 2014, Free Software Foundation, Inc.             *
+ *                                                                          *
+ * GNAT is free software;  you can  redistribute it  and/or modify it under *
+ * terms of the  GNU General Public License as published  by the Free Soft- *
+ * ware  Foundation;  either version 3,  or (at your option) any later ver- *
+ * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
+ * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
+ * or FITNESS FOR A PARTICULAR PURPOSE.                                     *
+ *                                                                          *
+ * As a special exception under Section 7 of GPL version 3, you are granted *
+ * additional permissions described in the GCC Runtime Library Exception,   *
+ * version 3.1, as published by the Free Software Foundation.               *
+ *                                                                          *
+ * In particular,  you can freely  distribute your programs  built with the *
+ * GNAT Pro compiler, including any required library run-time units,  using *
+ * any licensing terms  of your choosing.  See the AdaCore Software License *
+ * for full details.                                                        *
+ *                                                                          *
+ * GNAT was originally developed  by the GNAT team at  New York University. *
+ * Extensive contributions were provided by Ada Core Technologies Inc.      *
+ *                                                                          *
+ ****************************************************************************/
+
+/******************************************************
+ * ARM-Android version of the __gnat_sigtramp service *
+ ******************************************************/
+
+#include "sigtramp.h"
+/* See sigtramp.h for a general explanation of functionality.  */
+
+/* ----------------------
+   -- General comments --
+   ----------------------
+
+   Stubs are generated from toplevel asms,
+   The general idea is to establish CFA as the sigcontext
+   and state where to find the registers as offsets from there.
+
+   We support stubs for VxWorks and Android, providing unwind info for
+   common registers. We might need variants with support for floating
+   point or altivec registers as well at some point.
+
+   For Android it would be simpler to write this in Asm since there's only
+   one variant, but to keep it looking like the VxWorks stubs,
+   C is the choice for our toplevel interface.
+
+   Note that the registers we "restore" here are those to which we have
+   direct access through the system sigcontext structure, which includes
+   only a partial set of the non-volatiles ABI-wise.  */
+
+/* -----------------------------------------
+   -- Protypes for our internal asm stubs --
+   -----------------------------------------
+
+   The registers are expected to be at SIGCONTEXT + 12 (reference the
+   sicontext structure in asm/sigcontext.h which describes the first
+   3 * 4byte fields.)  Even though our symbols will remain local, the
+   prototype claims "extern" and not "static" to prevent compiler complaints
+   about a symbol used but never defined.  */
+
+/* sigtramp stub providing unwind info for common registers.  */
+
+extern void __gnat_sigtramp_common
+  (int signo, void *siginfo, void *sigcontext,
+   __sigtramphandler_t * handler);
+
+void __gnat_sigtramp (int signo, void *si, void *sc,
+                      __sigtramphandler_t * handler)
+     __attribute__((optimize(2)));
+
+void __gnat_sigtramp (int signo, void *si, void *ucontext,
+                      __sigtramphandler_t * handler)
+{
+  struct sigcontext *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
+
+  __gnat_sigtramp_common (signo, si, mcontext, handler);
+}
+
+/* asm string construction helpers.  */
+
+#define STR(TEXT) #TEXT
+/* stringify expanded TEXT, surrounding it with double quotes.  */
+
+#define S(E) STR(E)
+/* stringify E, which will resolve as text but may contain macros
+   still to be expanded.  */
+
+/* asm (TEXT) outputs <tab>TEXT. These facilitate the output of
+   multiline contents:  */
+#define TAB(S) "\t" S
+#define CR(S)  S "\n"
+
+#undef TCR
+#define TCR(S) TAB(CR(S))
+
+/* Trampoline body block
+   ---------------------  */
+
+#define SIGTRAMP_BODY \
+CR("") \
+TCR("# Allocate frame and also save r2 which is the argument register") \
+TCR("# containing the sigcontext, so that we can restore it during") \
+TCR("# unwinding and thereby load the rest of the desired context.") \
+TCR("stmfd	sp!, {r2, r3, lr}") \
+TCR("# The unwinder undo's these operations in reverse order so starting") \
+TCR("# from bottom, restore r2 from the current vsp location, move r2 into") \
+TCR("# the vsp, add 12 bytes to get the start of the register save area") \
+TCR("# then restore the 15 general purpose registers of the frame which") \
+TCR("# raised the signal.") \
+TCR(".save {r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15}") \
+TCR(".pad #12") \
+TCR(".movsp r2") \
+TCR(".save {r2}") \
+TCR("# Call the real handler. The signo, siginfo and sigcontext") \
+TCR("# arguments are the same as those we received in r0, r1 and r2.") \
+TCR("blx	r3") \
+TCR("# Restore our callee-saved items, release our frame and return") \
+TCR("# (should never get here!).") \
+TCR("ldmfd	sp, {r2, r3, pc}")
+
+/* Symbol definition block
+   -----------------------  */
+
+#define SIGTRAMP_START(SYM) \
+CR("# " S(SYM) " unwind trampoline") \
+TCR(".type " S(SYM) ", %function") \
+CR("") \
+CR(S(SYM) ":") \
+TCR(".fnstart")
+
+/* Symbol termination block
+   ------------------------  */
+
+#define SIGTRAMP_END(SYM) \
+CR(".fnend") \
+TCR(".size " S(SYM) ", .-" S(SYM))
+
+/*----------------------------
+  -- And now, the real code --
+  ---------------------------- */
+
+/* Text section start.  The compiler isn't aware of that switch.  */
+
+asm (".text\n"
+     TCR(".align 2"));
+
+/* sigtramp stub for common registers.  */
+
+#define TRAMP_COMMON __gnat_sigtramp_common
+
+asm (SIGTRAMP_START(TRAMP_COMMON));
+asm (SIGTRAMP_BODY);
+asm (SIGTRAMP_END(TRAMP_COMMON));