[COMMIT] Handle OpenBSD/mips64 signal trampolines

[Mark Kettenis <kettenis at gnu dot org>]

Pretty obvious I'd say, so I committed it.

Mark

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

	* mips64obsd-tdep.c: Include "trad-frame.h", "tramp-frame.h" and
	"gdb_assert.h".
	(mips64obsd_sigframe_init): New function.
	(mips64obsd_sigframe): New variable.
	(mips64obsd_init_abi): Add comments.  Prepend mips64obsd_sigrame
	unwinder.
	* Makefile.in (mips64obsd-tdep.o): Update dependencies.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.655
diff -u -p -r1.655 Makefile.in
--- Makefile.in 6 Nov 2004 17:18:10 -0000 1.655
+++ Makefile.in 7 Nov 2004 16:59:21 -0000
@@ -2238,7 +2238,8 @@ minsyms.o: minsyms.c $(defs_h) $(gdb_str
 mips64obsd-nat.o: mips64obsd-nat.c $(defs_h) $(inferior_h) $(regcache_h) \
 	$(target_h) $(inf_ptrace_h)
 mips64obsd-tdep.o: mips64obsd-tdep.c $(defs_h) $(osabi_h) $(regcache_h) \
-	$(regset_h) $(gdb_string_h) $(mips_tdep_h) $(solib_svr4_h)
+	$(regset_h) $(trad_frame_h) $(tramp_frame_h) $gdb_assert_h) \
+	$(gdb_string_h) $(mips_tdep_h) $(solib_svr4_h)
 mips-irix-tdep.o: mips-irix-tdep.c $(defs_h) $(osabi_h) $(elf_bfd_h)
 mips-linux-nat.o: mips-linux-nat.c $(defs_h) $(mips_tdep_h)
 mips-linux-tdep.o: mips-linux-tdep.c $(defs_h) $(gdbcore_h) $(target_h) \
Index: mips64obsd-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips64obsd-tdep.c,v
retrieving revision 1.1
diff -u -p -r1.1 mips64obsd-tdep.c
--- mips64obsd-tdep.c 23 Oct 2004 12:14:01 -0000 1.1
+++ mips64obsd-tdep.c 7 Nov 2004 16:59:21 -0000
@@ -23,7 +23,10 @@
 #include "osabi.h"
 #include "regcache.h"
 #include "regset.h"
+#include "trad-frame.h"
+#include "tramp-frame.h"
 
+#include "gdb_assert.h"
 #include "gdb_string.h"
 
 #include "mips-tdep.h"
@@ -74,14 +77,72 @@ mips64obsd_regset_from_core_section (str
 }
 
 
+/* Signal trampolines.  */
+
+static void
+mips64obsd_sigframe_init (const struct tramp_frame *self,
+			  struct frame_info *next_frame,
+			  struct trad_frame_cache *cache,
+			  CORE_ADDR func)
+{
+  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  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, MIPS_SP_REGNUM + NUM_REGS);
+  sigcontext_addr = sp + 32;
+
+  /* PC.  */
+  regnum = mips_regnum (gdbarch)->pc;
+  trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 16);
+
+  /* GPRs.  */
+  for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
+       regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
+    trad_frame_set_reg_addr (cache, regnum + NUM_REGS, addr);
+
+  /* HI and LO.  */
+  regnum = mips_regnum (gdbarch)->lo;
+  trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 280);
+  regnum = mips_regnum (gdbarch)->hi;
+  trad_frame_set_reg_addr (cache, regnum + NUM_REGS, sigcontext_addr + 288);
+
+  /* TODO: Handle the floating-point registers.  */
+
+  trad_frame_set_id (cache, frame_id_build (sp, func));
+}
+
+static const struct tramp_frame mips64obsd_sigframe =
+{
+  SIGTRAMP_FRAME,
+  MIPS_INSN32_SIZE,
+  {
+    { 0x67a40020, -1 },		/* daddiu  a0,sp,32 */
+    { 0x24020067, -1 },		/* li      v0,103 */
+    { 0x0000000c, -1 },		/* syscall */
+    { 0x0000000d, -1 },		/* break */
+    { TRAMP_SENTINEL_INSN, -1 }
+  },
+  mips64obsd_sigframe_init
+};
+
+
 static void
 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
+  /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
+     way GDB works, forces us to pretend we can handle them all.  */
+
   set_gdbarch_regset_from_core_section
     (gdbarch, mips64obsd_regset_from_core_section);
 
+  tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
+
   set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
 
+  /* OpenBSD/mips64 has SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 }