Enable DWARF unwinders for SPU

This patch enables use of DWARF unwinders for the SPU target.

In addition to appending the DWARF unwinders, we also need to install
a spu_dwarf_reg_to_regnum that maps the raw stack pointer register to
the cooked version (to avoid mismatches with gdbarch_sp_regnum).

This also causes confusion with the AX collect handling, so we also
install ax_pseudo_register routines to handle the cooked SP.

gdb/
2014-04-17  Ulrich Weigand  <uweigand@de.ibm.com>

	* spu-tdep.c: Include "dwarf2-frame.h" and "ax.h".
	(spu_ax_pseudo_register_collect): New function.
	(spu_ax_pseudo_register_push_stack): Likewise.
	(spu_dwarf_reg_to_regnum): Likewise.
	(spu_gdbarch_init): Install them.  Append DWARF unwinders.

1 files changed, 62 insertions, 0 deletions

diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 0f23b0f..4fc3ca5 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -44,6 +44,8 @@
 #include "observer.h"
 #include "infcall.h"
 #include "dwarf2.h"
+#include "dwarf2-frame.h"
+#include "ax.h"
 #include "exceptions.h"
 #include "spu-tdep.h"
 
@@ -311,6 +313,51 @@ spu_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
     }
 }
 
+static int
+spu_ax_pseudo_register_collect (struct gdbarch *gdbarch,
+				struct agent_expr *ax, int regnum)
+{
+  switch (regnum)
+    {
+    case SPU_SP_REGNUM:
+      ax_reg_mask (ax, SPU_RAW_SP_REGNUM);
+      return 0;
+
+    case SPU_FPSCR_REGNUM:
+    case SPU_SRR0_REGNUM:
+    case SPU_LSLR_REGNUM:
+    case SPU_DECR_REGNUM:
+    case SPU_DECR_STATUS_REGNUM:
+      return -1;
+
+    default:
+      internal_error (__FILE__, __LINE__, _("invalid regnum"));
+    }
+}
+
+static int
+spu_ax_pseudo_register_push_stack (struct gdbarch *gdbarch,
+				   struct agent_expr *ax, int regnum)
+{
+  switch (regnum)
+    {
+    case SPU_SP_REGNUM:
+      ax_reg (ax, SPU_RAW_SP_REGNUM);
+      return 0;
+
+    case SPU_FPSCR_REGNUM:
+    case SPU_SRR0_REGNUM:
+    case SPU_LSLR_REGNUM:
+    case SPU_DECR_REGNUM:
+    case SPU_DECR_STATUS_REGNUM:
+      return -1;
+
+    default:
+      internal_error (__FILE__, __LINE__, _("invalid regnum"));
+    }
+}
+
+
 /* Value conversion -- access scalar values at the preferred slot.  */
 
 static struct value *
@@ -352,6 +399,15 @@ spu_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
   return default_register_reggroup_p (gdbarch, regnum, group);
 }
 
+/* DWARF-2 register numbers.  */
+
+static int
+spu_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
+{
+  /* Use cooked instead of raw SP.  */
+  return (reg == SPU_RAW_SP_REGNUM)? SPU_SP_REGNUM : reg;
+}
+
 
 /* Address handling.  */
 
@@ -2680,6 +2736,11 @@ spu_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_pseudo_register_write (gdbarch, spu_pseudo_register_write);
   set_gdbarch_value_from_register (gdbarch, spu_value_from_register);
   set_gdbarch_register_reggroup_p (gdbarch, spu_register_reggroup_p);
+  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, spu_dwarf_reg_to_regnum);
+  set_gdbarch_ax_pseudo_register_collect
+    (gdbarch, spu_ax_pseudo_register_collect);
+  set_gdbarch_ax_pseudo_register_push_stack
+    (gdbarch, spu_ax_pseudo_register_push_stack);
 
   /* Data types.  */
   set_gdbarch_char_signed (gdbarch, 0);
@@ -2718,6 +2779,7 @@ spu_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   /* Frame handling.  */
   set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+  dwarf2_append_unwinders (gdbarch);
   frame_unwind_append_unwinder (gdbarch, &spu_frame_unwind);
   frame_base_set_default (gdbarch, &spu_frame_base);
   set_gdbarch_unwind_pc (gdbarch, spu_unwind_pc);