RFA: Correctly interpret register numbers in Dwarf2 output

[Jim Blandy]

2001-05-06  Jim Blandy  <jimb@redhat.com>

	* mn10300-tdep.c (mn10300_dwarf2_reg_to_regnum): New function.
	(mn10300_gdbarch_init): Register it as the architecture's
	dwarf2_reg_to_regnum method.

*** gdb/mn10300-tdep.c.base	Fri May  4 14:54:52 2001
--- gdb/mn10300-tdep.c	Sun May  6 20:53:08 2001
***************
*** 857,862 ****
--- 857,891 ----
    return 4;
  }
  
+ /* If DWARF2 is a register number appearing in Dwarf2 debug info, then
+    mn10300_dwarf2_reg_to_regnum (DWARF2) is the corresponding GDB
+    register number.  Why don't Dwarf2 and GDB use the same numbering?
+    Who knows?  But since people have object files lying around with
+    the existing Dwarf2 numbering, and other people have written stubs
+    to work with the existing GDB, neither of them can change.  So we
+    just have to cope.  */
+ static int
+ mn10300_dwarf2_reg_to_regnum (int dwarf2)
+ {
+   /* This table is supposed to be shaped like the REGISTER_NAMES
+      initializer in gcc/config/mn10300/mn10300.h.  Registers which
+      appear in GCC's numbering, but have no counterpart in GDB's
+      world, are marked with a -1.  */
+   static int dwarf2_to_gdb[] = {
+     0,  1,  2,  3,  4,  5,  6,  7, -1, 8,
+     15, 16, 17, 18, 19, 20, 21, 22
+   };
+   int gdb;
+ 
+   if (dwarf2 < 0
+       || dwarf2 >= (sizeof (dwarf2_to_gdb) / sizeof (dwarf2_to_gdb[0]))
+       || dwarf2_to_gdb[dwarf2] == -1)
+     internal_error (__FILE__, __LINE__,
+                     "bogus register number in debug info: %d", dwarf2);
+ 
+   return dwarf2_to_gdb[dwarf2];
+ }
+ 
  static void
  mn10300_print_register (const char *name, int regnum, int reg_width)
  {
***************
*** 1005,1010 ****
--- 1034,1040 ----
    set_gdbarch_max_register_virtual_size (gdbarch, 4);
    set_gdbarch_register_virtual_size (gdbarch, mn10300_register_virtual_size);
    set_gdbarch_register_virtual_type (gdbarch, mn10300_register_virtual_type);
+   set_gdbarch_dwarf2_reg_to_regnum (gdbarch, mn10300_dwarf2_reg_to_regnum);
    set_gdbarch_do_registers_info (gdbarch, mn10300_do_registers_info);
    set_gdbarch_fp_regnum (gdbarch, 31);