[commit] Signal trampoline support for OpenBSD/arm

[Mark Kettenis <mark dot kettenis at xs4all dot nl>]

Fairly straightforward I'd say.  Improves the testsuite results of
course.

Committed,

Mark

Index: ChangeLog
from  Mark Kettenis  <kettenis@gnu.org>

	* armobsd-tdep.c: Include "trad-frame.h" and "tramp-frame.h".
	(armobsd_sigframe_init): New function.
	(armobsd_sigframe): New variable.
	(armobsd_init_abi): Prepend armobsd_sigframe unwinder.
	* Makefile.in (armobsd-tdep.o): Update dependencies.

Index: armobsd-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/armobsd-tdep.c,v
retrieving revision 1.2
diff -u -p -r1.2 armobsd-tdep.c
--- armobsd-tdep.c 17 Jul 2006 19:34:57 -0000 1.2
+++ armobsd-tdep.c 18 Jul 2006 21:07:50 -0000
@@ -21,11 +21,55 @@
 
 #include "defs.h"
 #include "osabi.h"
+#include "trad-frame.h"
+#include "tramp-frame.h"
 
 #include "obsd-tdep.h"
 #include "arm-tdep.h"
 #include "solib-svr4.h"
 
+/* Signal trampolines.  */
+
+static void
+armobsd_sigframe_init (const struct tramp_frame *self,
+		       struct frame_info *next_frame,
+		       struct trad_frame_cache *cache,
+		       CORE_ADDR func)
+{
+  CORE_ADDR sp, sigcontext_addr, addr;
+  int regnum;
+
+  /* We find the appropriate instance of `struct sigcontext' at a
+     fixed offset in the signal frame.  */
+  sp = frame_unwind_register_signed (next_frame, ARM_SP_REGNUM);
+  sigcontext_addr = sp + 16;
+
+  /* PC.  */
+  trad_frame_set_reg_addr (cache, ARM_PC_REGNUM, sigcontext_addr + 76);
+
+  /* GPRs.  */
+  for (regnum = ARM_A1_REGNUM, addr = sigcontext_addr + 12;
+       regnum <= ARM_LR_REGNUM; regnum++, addr += 4)
+    trad_frame_set_reg_addr (cache, regnum, addr);
+
+  trad_frame_set_id (cache, frame_id_build (sp, func));
+}
+
+static const struct tramp_frame armobsd_sigframe =
+{
+  SIGTRAMP_FRAME,
+  4,
+  {
+    { 0xe28d0010, -1 },		/* add     r0, sp, #16 */
+    { 0xef000067, -1 },		/* swi     SYS_sigreturn */
+    { 0xef000001, -1 },		/* swi     SYS_exit */
+    { 0xeafffffc, -1 },		/* b       . - 8 */
+    { TRAMP_SENTINEL_INSN, -1 }
+  },
+  armobsd_sigframe_init
+};
+
+
 static void
 armobsd_init_abi (struct gdbarch_info info,
 		  struct gdbarch *gdbarch)
@@ -35,6 +79,8 @@ armobsd_init_abi (struct gdbarch_info in
   if (tdep->fp_model == ARM_FLOAT_AUTO)
     tdep->fp_model = ARM_FLOAT_SOFT_VFP;
 
+  tramp_frame_prepend_unwinder (gdbarch, &armobsd_sigframe);
+
   /* OpenBSD/arm uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.830
diff -u -p -r1.830 Makefile.in
--- Makefile.in 17 Jul 2006 19:34:57 -0000 1.830
+++ Makefile.in 18 Jul 2006 21:07:52 -0000
@@ -1783,8 +1783,8 @@ armnbsd-nat.o: armnbsd-nat.c $(defs_h) $
 	$(regcache_h) $(target_h) $(gdb_string_h) $(arm_tdep_h) $(inf_ptrace_h)
 armnbsd-tdep.o: armnbsd-tdep.c $(defs_h) $(osabi_h) $(gdb_string_h) \
 	$(arm_tdep_h) $(solib_svr4_h)
-armobsd-tdep.o: armobsd-tdep.c $(defs_h) $(osabi_h) \
-	$(obsd_tdep_h) $(arm_tdep_h) $(solib_svr4_h)
+armobsd-tdep.o: armobsd-tdep.c $(defs_h) $(osabi_h) $(trad_frame_h) \
+	$(tramp_frame_h) $(obsd_tdep_h) $(arm_tdep_h) $(solib_svr4_h)
 arm-tdep.o: arm-tdep.c $(defs_h) $(frame_h) $(inferior_h) $(gdbcmd_h) \
 	$(gdbcore_h) $(gdb_string_h) $(dis_asm_h) $(regcache_h) \
 	$(doublest_h) $(value_h) $(arch_utils_h) $(osabi_h) \