[Ada] Fix irregular output with -gnatR3

This fixes a long-standing quirk present in the layout information for record
types displayed by the -gnatR3 switch: when a component has a variable
(starting) position, its corresponding line in the output has an irregular and
awkward format.  After this change, the format is the same as in all the other
cases.

For the following record:

    type R (m : natural) is record
        s : string (1 .. m);
        r : natural;
        b : boolean;
    end record;
    for R'alignment use 4;
    pragma Pack (R);

the output of -gnatR3 used to be:

for R'Object_Size use 17179869248;
for R'Value_Size use ((#1 + 8) * 8);
for R'Alignment use 4;
for R use record
   m at  0 range  0 .. 30;
   s at  4 range  0 .. ((#1 * 8)) - 1;
   r at bit offset (((#1 + 4) * 8)) size in bits = 31
   b at bit offset ((((#1 + 7) * 8) + 7)) size in bits = 1
end record;

and is changed into:

for R'Object_Size use 17179869248;
for R'Value_Size use ((#1 + 8) * 8);
for R'Alignment use 4;
for R use record
   m at  0 range  0 .. 30;
   s at  4 range  0 .. ((#1 * 8)) - 1;
   r at (#1 + 4) range  0 .. 30;
   b at (#1 + 7) range  7 ..  7;
end record;

2018-05-24  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* fe.h (Set_Normalized_First_Bit): Declare.
	(Set_Normalized_Position): Likewise.
	* repinfo.adb (List_Record_Layout): Do not use irregular output for a
	variable position.  Fix minor spacing issue.
	* gcc-interface/decl.c (annotate_rep): If a field has a variable
	offset, compute the normalized position and annotate it in addition to
	the bit offset.

From-SVN: r260669

1 files changed, 1 insertions, 23 deletions

diff --git a/gcc/ada/repinfo.adb b/gcc/ada/repinfo.adb
index 7f7152d..fd7a931 100644
--- a/gcc/ada/repinfo.adb
+++ b/gcc/ada/repinfo.adb
@@ -992,7 +992,6 @@ package body Repinfo is
             declare
                Ctyp : constant Entity_Id := Underlying_Type (Etype (Comp));
                Esiz : constant Uint      := Esize (Comp);
-               Bofs : constant Uint      := Component_Bit_Offset (Comp);
                Npos : constant Uint      := Normalized_Position (Comp);
                Fbit : constant Uint      := Normalized_First_Bit (Comp);
                Spos : Uint;
@@ -1047,35 +1046,14 @@ package body Repinfo is
                   Spaces (Max_Spos_Length - UI_Image_Length);
                   Write_Str (UI_Image_Buffer (1 .. UI_Image_Length));
 
-               elsif Known_Component_Bit_Offset (Comp)
-                 and then List_Representation_Info = 3
-               then
-                  Spaces (Max_Spos_Length - 2);
-                  Write_Str ("bit offset ");
-
-                  if Starting_Position /= Uint_0
-                    or else Starting_First_Bit /= Uint_0
-                  then
-                     UI_Write (Starting_Position * SSU + Starting_First_Bit);
-                     Write_Str (" + ");
-                  end if;
-
-                  Write_Val (Bofs, Paren => True);
-                  Write_Str (" size in bits = ");
-                  Write_Val (Esiz, Paren => True);
-                  Write_Eol;
-
-                  goto Continue;
-
                elsif Known_Normalized_Position (Comp)
                  and then List_Representation_Info = 3
                then
                   Spaces (Max_Spos_Length - 2);
 
                   if Starting_Position /= Uint_0 then
-                     Write_Char (' ');
                      UI_Write (Starting_Position);
-                     Write_Str (" +");
+                     Write_Str (" + ");
                   end if;
 
                   Write_Val (Npos);