DWARF: add a language hook for fixed-point types

Support for fixed-point types in GCC is not powerful enough for Ada
fixed-point types: GNAT uses regular scalar types to implement them.
This new language hook makes it possible to output the desired debugging
information anyway.

gcc/ada/ChangeLog:

	* gcc-interface/ada-tree.def (POWER_EXPR): New binary operation.
	* gcc-interface/ada-tree.h (TYPE_FIXED_POINT_P): New macro.
	(TYPE_IS_FIXED_POINT_P): New macro.
	(TYPE_SCALE_FACTOR): New macro.
	(SET_TYPE_SCALE_FACTOR): New macro.
	* gcc-interface/decl.c: Include urealp.h
	(gnat_to_gnu_entity): Attach trees to encode scale factors to
	fixed-point types.
	* gcc-interface/misc.c (gnat_print_type): Print scale factors
	for fixed-point types.
	(gnat_get_fixed_point_type_info): New.
	(gnat_init_ts): Initialize data for the POWER_EXPR binary
	operation.
	(LANG_HOOKS_GET_FIXED_POINT_INFO): Redefine macro to implement
	the get_fixed_point_type_info language hook.

gcc/ChangeLog:

	* langhooks.h (struct lang_hooks_for_types): Add a
	get_fixed_point_type_info field.
	* langhooks-def.h (LANG_HOOKS_GET_FIXED_POINT_TYPE_INFO): New
	macro.
	(LANG_HOOKS_FOR_TYPES_INITIALIZER): Initialize the
	get_fixed_point_type_info field.
	* dwarf2out.h (enum fixed_point_scale_factor): New.
	(struct fixed_point_type_info): New.
	* dwarf2out.c (base_type_die): In DWARFv3 or non-strict DWARF
	mode, get fixed-point type information using the debugging hook
	and describe it in DWARF, if any.

From-SVN: r231764

1 files changed, 29 insertions, 0 deletions

diff --git a/gcc/dwarf2out.h b/gcc/dwarf2out.h
index 7f4a24d977d..91730766beb 100644
--- a/gcc/dwarf2out.h
+++ b/gcc/dwarf2out.h
@@ -342,6 +342,35 @@ struct array_descr_info
     } dimen[10];
 };
 
+enum fixed_point_scale_factor
+{
+  fixed_point_scale_factor_binary,
+  fixed_point_scale_factor_decimal,
+  fixed_point_scale_factor_arbitrary
+};
+
+struct fixed_point_type_info
+{
+  /* A scale factor is the value one has to multiply with physical data in
+     order to get the fixed point logical data.  The DWARF standard enables one
+     to encode it in three ways.  */
+  enum fixed_point_scale_factor scale_factor_kind;
+  union
+    {
+      /* For binary scale factor, the scale factor is: 2 ** binary.  */
+      int binary;
+      /* For decimal scale factor, the scale factor is: 10 ** binary.  */
+      int decimal;
+      /* For arbitrary scale factor, the scale factor is:
+	 numerator / denominator.  */
+      struct
+	{
+	  unsigned HOST_WIDE_INT numerator;
+	  HOST_WIDE_INT denominator;
+	} arbitrary;
+    } scale_factor;
+};
+
 void dwarf2out_c_finalize (void);
 
 #endif /* GCC_DWARF2OUT_H */