[PATCH] Fix dwarf register column to gdb register mapping

["John David Anglin" <dave@hiauly1.hia.nrc.ca>]

The following revises hppa_dwarf_reg_to_regnum and hppa64_dwarf_reg_to_regnum
to implement my understanding of the mapping needed on hppa.  The dwarf
columns essentially correspond one-to-one to the GCC internal register
numbering.  I think someone must have been looking at the dbx numbering
when these routines were first implemented.  The numbering used by gdb
for hppa is in hppa-tdep.h.

The sniffer stuff is obsolete.

Tested on hppa64-hp-hpux11.11 and hppa-unknown-linux-gnu.

Ok?

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

2008-09-13  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>

	* hppa-linux-tdep.c (hppa_dwarf_reg_to_regnum): Remove "#if 0" "#endif".
	Fix mapping of dwarf columns to gdb registers.
	(hppa_linux_init_abi): Call set_gdbarch_dwarf2_reg_to_regnum.  Delete
	disabled code.
	* hppa-tdep.c (hppa64_dwarf_reg_to_regnum): Fix mapping of dwarf columns
	to gdb registers.

Index: hppa-linux-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/hppa-linux-tdep.c,v
retrieving revision 1.31
diff -u -3 -p -r1.31 hppa-linux-tdep.c
--- hppa-linux-tdep.c	21 Aug 2008 13:19:18 -0000	1.31
+++ hppa-linux-tdep.c	13 Sep 2008 22:51:35 -0000
@@ -34,24 +34,26 @@
 
 #include "elf/common.h"
 
-#if 0
 /* Convert DWARF register number REG to the appropriate register
    number used by GDB.  */
 static int
-hppa_dwarf_reg_to_regnum (int reg)
+hppa_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
 {
-  /* registers 0 - 31 are the same in both sets */
-  if (reg < 32)
+  /* r1-r31 are the same in both sets (column for r0 is not used)  */
+  if (reg >= 1 && reg < 32)
     return reg;
 
-  /* dwarf regs 32 to 85 are fpregs 4 - 31 */
-  if (reg >= 32 && reg <= 85)
+  /* Dwarf registers 32 to 87 are the floating point registers fr4 to fr31.  */
+  if (reg >= 32 && reg < 88)
     return HPPA_FP4_REGNUM + (reg - 32);
 
+  /* Dwarf register 88 is the sar register.  */
+  if (reg == 88)
+    return HPPA_SAR_REGNUM;
+
   warning (_("Unmapped DWARF Register #%d encountered."), reg);
   return -1;
 }
-#endif
 
 static void
 hppa_linux_target_write_pc (struct regcache *regcache, CORE_ADDR v)
@@ -545,12 +548,7 @@ hppa_linux_init_abi (struct gdbarch_info
   set_gdbarch_regset_from_core_section
     (gdbarch, hppa_linux_regset_from_core_section);
 
-#if 0
-  /* Dwarf-2 unwinding support.  Not yet working.  */
   set_gdbarch_dwarf2_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum);
-  frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
-  frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer);
-#endif
 
   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
Index: hppa-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/hppa-tdep.c,v
retrieving revision 1.260
diff -u -3 -p -r1.260 hppa-tdep.c
--- hppa-tdep.c	11 Sep 2008 14:23:15 -0000	1.260
+++ hppa-tdep.c	13 Sep 2008 22:51:35 -0000
@@ -661,13 +661,17 @@ hppa64_register_name (struct gdbarch *gd
 static int
 hppa64_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
 {
-  /* r0-r31 and sar map one-to-one.  */
-  if (reg <= 32)
+  /* r1-r31 are the same in both sets (column for r0 is not used).  */
+  if (reg >= 1 && reg < 32)
     return reg;
 
-  /* fr4-fr31 are mapped from 72 in steps of 2.  */
-  if (reg >= 72 || reg < 72 + 28 * 2)
-    return HPPA64_FP4_REGNUM + (reg - 72) / 2;
+  /* fr4-fr31 are mapped to 72, 74, 76 ...  */
+  if (reg >= 32 && reg < 60)
+    return HPPA64_FP4_REGNUM + 2 * (reg - 32);
+
+  /* Dwarf register 60 is the sar register.  */
+  if (reg == 60)
+    return HPPA_SAR_REGNUM;
 
   error ("Invalid DWARF register num %d.", reg);
   return -1;