gdb: Add new 'print nibbles' feature

Make an introduction of a new print setting that can be set by 'set
print nibbles [on|off]'.  The default value if OFF, which can be changed
by user manually.  Of course, 'show print nibbles' is also included in
the patch.

The new feature displays binary values by group, with four bits per
group.  The motivation for this work is to enhance the readability of
binary values.

Here's a GDB session before this patch is applied.
  (gdb) print var_a
  $1 = 1230
  (gdb) print/t var_a
  $2 = 10011001110

With this patch applied, we can use the new print setting to display the
new form of the binary values.
  (gdb) print var_a
  $1 = 1230
  (gdb) print/t var_a
  $2 = 10011001110
  (gdb) set print nibbles on
  (gdb) print/t var_a
  $3 = 0100 1100 1110

Tested on x86_64 openSUSE Tumbleweed.

1 files changed, 5 insertions, 1 deletions

diff --git a/gdb/valprint.h b/gdb/valprint.h
index ff536fb..d6ad45d 100644
--- a/gdb/valprint.h
+++ b/gdb/valprint.h
@@ -44,6 +44,9 @@ struct value_print_options
   /* Controls printing of addresses.  */
   bool addressprint;
 
+  /* Controls printing of nibbles.  */
+  bool nibblesprint;
+
   /* Controls looking up an object's derived type using what we find
      in its vtables.  */
   bool objectprint;
@@ -149,7 +152,8 @@ extern void value_print_scalar_formatted
    int size, struct ui_file *stream);
 
 extern void print_binary_chars (struct ui_file *, const gdb_byte *,
-				unsigned int, enum bfd_endian, bool);
+				unsigned int, enum bfd_endian, bool,
+				const struct value_print_options *options);
 
 extern void print_octal_chars (struct ui_file *, const gdb_byte *,
 			       unsigned int, enum bfd_endian);