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, 7 insertions, 6 deletions

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 54eb445..ea2a22a 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -12973,18 +12973,19 @@ base_type_die (tree type, bool reverse)
 	  break;
 
 	case fixed_point_scale_factor_arbitrary:
-	  /* Arbitrary scale factors cannot be described in standard DWARF,
-	     yet.  */
+	  /* Arbitrary scale factors cannot be described in standard DWARF.  */
 	  if (!dwarf_strict)
 	    {
 	      /* Describe the scale factor as a rational constant.  */
 	      const dw_die_ref scale_factor
 		= new_die (DW_TAG_constant, comp_unit_die (), type);
 
-	      add_AT_unsigned (scale_factor, DW_AT_GNU_numerator,
-			       fpt_info.scale_factor.arbitrary.numerator);
-	      add_AT_int (scale_factor, DW_AT_GNU_denominator,
-			  fpt_info.scale_factor.arbitrary.denominator);
+	      add_scalar_info (scale_factor, DW_AT_GNU_numerator,
+			       fpt_info.scale_factor.arbitrary.numerator,
+			       dw_scalar_form_constant, NULL);
+	      add_scalar_info (scale_factor, DW_AT_GNU_denominator,
+			       fpt_info.scale_factor.arbitrary.denominator,
+			       dw_scalar_form_constant, NULL);
 
 	      add_AT_die_ref (base_type_result, DW_AT_small, scale_factor);
 	    }