utils.c: Sign-extend addresses if required by the target

["Maciej W. Rozycki" <macro at mips dot com>]

Hello,

 There is at least one architecture, which is the MIPS one, that expands 
addresses from 32-bits to 64-bits by doing sign-extension.  It matters for 
32-bit compatibility kernel addresses, which are defined with bits 31:63 
set to one.  For these addresses, if the compatibility mode is used, it is 
common to input them as 32-bit hexadecimal constants as it would be the 
case with 32-bit processors.  However, BFD for the MIPS target is always 
64-bit and if the processor used is indeed 64-bit, these addresses have to 
be properly sign-extended to 64 bits.

 Here is probably one of the last remaining places where it is not done.  
The string_to_core_addr() is only used by the MI and Insight frontends and 
then kernel addresses are only seen on bare-iron targets (e.g. not under 
Linux, where user addresses are used only), so the problem may have 
escaped for that long.

 There is a note by Nigel included that perhaps this should be done 
through the architecture vector.  Well, I am not sure it is useful to add 
such a member there just for this single place, but perhaps it would be a 
good idea to clean up all the places it is done as a whole.  It fixes a 
regression though, so I think it is a useful fix, and the clean-up could 
be done separately, so the note should probably be kept.

 Tested for using the mipsisa32-sde-elf target, with the 
mips-sim-sde32/-EB, mips-sim-sde32/-EL, mips-sim-sde64/-mips64/-EB and 
mips-sim-sde64/-mips64/-EL boards removing 2 regressions -- this one:

-var-create a2 0x807fffa8 a
^done,name="a2",numchild="0",value="2 '\\002'",type="char"
(gdb)
FAIL: gdb.mi/mi-var-display.exp: create variable a2 in different scope

and similarly for gdb.mi/mi2-var-display.exp.

2007-11-22  Nigel Stephens  <nigel@mips.com>
            Maciej W. Rozycki  <macro@mips.com>

	* utils.c (string_to_core_addr): If executable format indicates
	that addresses should be sign-extended and there are only 8 hex
	digits in the address, then do so.
	* Makefile.in (utils.o): Depend on $(gdbcore_h).

 OK to apply?

  Maciej

14524.diff
Index: binutils-quilt/src/gdb/utils.c
===================================================================
--- binutils-quilt.orig/src/gdb/utils.c	2007-11-21 11:25:32.000000000 +0000
+++ binutils-quilt/src/gdb/utils.c	2007-11-22 14:08:27.000000000 +0000
@@ -52,6 +52,7 @@
 #include "filenames.h"
 #include "symfile.h"
 #include "gdb_obstack.h"
+#include "gdbcore.h"
 #include "top.h"
 
 #include "inferior.h"		/* for signed_pointer_to_address */
@@ -2824,7 +2825,9 @@
 CORE_ADDR
 string_to_core_addr (const char *my_string)
 {
+  int addr_bit = gdbarch_addr_bit (current_gdbarch);
   CORE_ADDR addr = 0;
+
   if (my_string[0] == '0' && tolower (my_string[1]) == 'x')
     {
       /* Assume that it is in hex.  */
@@ -2838,6 +2841,17 @@
 	  else
 	    error (_("invalid hex \"%s\""), my_string);
 	}
+
+      /* Not very modular, but if the executable format expects
+         addresses to be sign-extended, then do so if the address was
+         specified with only 32 significant bits.  Really this should
+         be determined by the target architecture, not by the object
+         file.  */
+      if (i - 2 == addr_bit / 4
+	  && exec_bfd
+	  && bfd_get_sign_extend_vma (exec_bfd))
+	addr = (addr ^ ((CORE_ADDR) 1 << (addr_bit - 1)))
+	       - ((CORE_ADDR) 1 << (addr_bit - 1));
     }
   else
     {
@@ -2851,6 +2865,7 @@
 	    error (_("invalid decimal \"%s\""), my_string);
 	}
     }
+
   return addr;
 }
 
Index: binutils-quilt/src/gdb/Makefile.in
===================================================================
--- binutils-quilt.orig/src/gdb/Makefile.in	2007-11-21 11:34:19.000000000 +0000
+++ binutils-quilt/src/gdb/Makefile.in	2007-11-22 14:01:00.000000000 +0000
@@ -2892,7 +2892,7 @@
 	$(exceptions_h) $(tui_h) $(gdbcmd_h) $(serial_h) $(bfd_h) \
 	$(target_h) $(demangle_h) $(expression_h) $(language_h) $(charset_h) \
 	$(annotate_h) $(filenames_h) $(symfile_h) $(inferior_h) $(top_h) \
-	$(gdb_curses_h) $(readline_h) $(gdb_obstack_h)
+	$(gdb_curses_h) $(readline_h) $(gdb_obstack_h) $(gdbcore_h)
 v850-tdep.o: v850-tdep.c $(defs_h) $(frame_h) $(frame_base_h) $(trad_frame_h) \
 	$(frame_unwind_h) $(dwarf2_frame_h) $(gdbtypes_h) $(inferior_h) \
 	$(gdb_string_h) $(gdb_assert_h) $(gdbcore_h) $(arch_utils_h) \