Enhance debug info for fixed-point types

The Ada language supports fixed-point types as first-class citizens so
they need to be described as-is in the debug info.  We devised the
langhook get_fixed_point_type_info for this purpose a few years ago,
but it comes with a limitation for the representation of the scale
factor that we would need to lift in order to be able to represent
more fixed-point types.

gcc/ChangeLog:
	* dwarf2out.h (struct fixed_point_type_info) <scale_factor>: Turn
	numerator and denominator into a tree.
	* dwarf2out.c (base_type_die): In the case of a fixed-point type
	with arbitrary scale factor, call add_scalar_info on numerator and
	denominator to emit the appropriate attributes.

gcc/ada/ChangeLog:
	* exp_dbug.adb (Is_Handled_Scale_Factor): Delete.
	(Get_Encoded_Name): Do not call it.
	* gcc-interface/decl.c (gnat_to_gnu_entity) <Fixed_Point_Type>:
	Tidy up and always use a meaningful description for arbitrary
	scale factors.
	* gcc-interface/misc.c (gnat_get_fixed_point_type_info): Remove
	obsolete block and adjust the description of the scale factor.

1 files changed, 2 insertions, 12 deletions

diff --git a/gcc/ada/gcc-interface/misc.c b/gcc/ada/gcc-interface/misc.c
index 87724af..d0867e0 100644
--- a/gcc/ada/gcc-interface/misc.c
+++ b/gcc/ada/gcc-interface/misc.c
@@ -628,16 +628,6 @@ gnat_get_fixed_point_type_info (const_tree type,
   /* We expect here only a finite set of pattern.  See fixed-point types
      handling in gnat_to_gnu_entity.  */
 
-  /* Put invalid values when compiler internals cannot represent the scale
-     factor.  */
-  if (scale_factor == integer_zero_node)
-    {
-      info->scale_factor_kind = fixed_point_scale_factor_arbitrary;
-      info->scale_factor.arbitrary.numerator = 0;
-      info->scale_factor.arbitrary.denominator = 0;
-      return true;
-    }
-
   if (TREE_CODE (scale_factor) == RDIV_EXPR)
     {
       tree num = TREE_OPERAND (scale_factor, 0);
@@ -677,8 +667,8 @@ gnat_get_fixed_point_type_info (const_tree type,
 		  && TREE_CODE (den) == INTEGER_CST);
 
       info->scale_factor_kind = fixed_point_scale_factor_arbitrary;
-      info->scale_factor.arbitrary.numerator = tree_to_uhwi (num);
-      info->scale_factor.arbitrary.denominator = tree_to_shwi (den);
+      info->scale_factor.arbitrary.numerator = num;
+      info->scale_factor.arbitrary.denominator = den;
       return true;
     }