Re: [RFA/DWARF] Set enum type "flag_enum" and "unsigned" flags at type creation.

[Mark Wielaard <mjw at redhat dot com>]

On Wed, 2014-02-19 at 15:34 +0100, Mark Wielaard wrote:
> Does anything break if you just remove the sign-extension part?
> If not, then you don't have to go through the whole
> update_enumeration_type_from_children. Or do you need that for anything
> else?

So, this patch doesn't show any regressions in the testsuite:

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 54c538a..0b5de99 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -14303,7 +14303,6 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
   LONGEST low, high;
   int low_default_is_valid;
   const char *name;
-  LONGEST negative_mask;
 
   orig_base_type = die_type (die, cu);
   /* If ORIG_BASE_TYPE is a typedef, it will not be TYPE_UNSIGNED,
@@ -14433,13 +14432,6 @@ read_subrange_type (struct die_info *die, struct dwarf2_cu *cu)
 	}
     }
 
-  negative_mask =
-    (LONGEST) -1 << (TYPE_LENGTH (base_type) * TARGET_CHAR_BIT - 1);
-  if (!TYPE_UNSIGNED (base_type) && (low & negative_mask))
-    low |= negative_mask;
-  if (!TYPE_UNSIGNED (base_type) && (high & negative_mask))
-    high |= negative_mask;
-
   range_type = create_range_type (NULL, orig_base_type, low, high);
 
   /* Mark arrays with dynamic length at least as an array of unspecified


So, my hope is that sign extension hack really isn't needed.
Of course it could be that there is some case where it was really needed
and there just isn't a test case for it. Does anybody know/remember?

Thanks,

Mark