[Ada] More complete information level for -gnatR output

This adds a 4th information level for the -gnatR output, where relevant
compiler-generated types are listed in addition to the information
already output by -gnatR3.

For the following package P:

package P is

  type Arr0 is array (Positive range <>) of Boolean;

    type Rec (D1 : Positive; D2 : Boolean) is record
       C1 : Integer;
       C2 : Arr0 (1 .. D1);

       case D2 is
          when False =>
             C3 : Character;
          when True =>
             C4 : String (1 .. 3);
             C5 : Float;
       end case;
    end record;

    type Arr1 is array (1 .. 8) of Rec (1, True);

end P;

the output generated by -gnatR4 must be:

Representation information for unit P (spec)
--------------------------------------------

for Arr0'Alignment use 1;
for Arr0'Component_Size use 8;

for Rec'Object_Size use 17179869344;
for Rec'Value_Size use (if (#2 != 0) then ((((#1 + 15) & -4) + 8) * 8)
else ((((#1 + 15) & -4) + 1) * 8) end);
for Rec'Alignment use 4;
for Rec use record
   D1 at  0 range  0 .. 31;
   D2 at  4 range  0 ..  7;
   C1 at  8 range  0 .. 31;
   C2 at 12 range  0 .. ((#1 * 8)) - 1;
   C3 at ((#1 + 15) & -4) range  0 ..  7;
   C4 at ((#1 + 15) & -4) range  0 .. 23;
   C5 at (((#1 + 15) & -4) + 4) range  0 .. 31;
end record;

for Arr1'Size use 1536;
for Arr1'Alignment use 4;
for Arr1'Component_Size use 192;

for Tarr1c'Size use 192;
for Tarr1c'Alignment use 4;
for Tarr1c use record
   D1 at  0 range  0 .. 31;
   D2 at  4 range  0 ..  7;
   C1 at  8 range  0 .. 31;
   C2 at 12 range  0 ..  7;
   C4 at 16 range  0 .. 23;
   C5 at 20 range  0 .. 31;
end record;

2018-11-14  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* doc/gnat_ugn/building_executable_programs_with_gnat.rst
	(-gnatR): Document new -gnatR4 level.
	* gnat_ugn.texi: Regenerate.
	* opt.ads (List_Representation_Info): Bump upper bound to 4.
	* repinfo.adb: Add with clause for GNAT.HTable.
	(Relevant_Entities_Size): New constant.
	(Entity_Header_Num): New type.
	(Entity_Hash): New function.
	(Relevant_Entities): New set implemented with GNAT.HTable.
	(List_Entities): Also list compiled-generated entities present
	in the Relevant_Entities set. Consider that the Component_Type
	of an array type is relevant.
	(List_Rep_Info): Reset Relevant_Entities for each unit.
	* switch-c.adb (Scan_Front_End_Switches): Add support for -gnatR4.
	* switch-m.adb (Normalize_Compiler_Switches): Likewise
	* usage.adb (Usage): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@266131 138bc75d-0d04-0410-961f-82ee72b054a4

gcc/ada/ChangeLog

@@ -1,3 +1,22 @@
+2018-11-14  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* doc/gnat_ugn/building_executable_programs_with_gnat.rst
+	(-gnatR): Document new -gnatR4 level.
+	* gnat_ugn.texi: Regenerate.
+	* opt.ads (List_Representation_Info): Bump upper bound to 4.
+	* repinfo.adb: Add with clause for GNAT.HTable.
+	(Relevant_Entities_Size): New constant.
+	(Entity_Header_Num): New type.
+	(Entity_Hash): New function.
+	(Relevant_Entities): New set implemented with GNAT.HTable.
+	(List_Entities): Also list compiled-generated entities present
+	in the Relevant_Entities set. Consider that the Component_Type
+	of an array type is relevant.
+	(List_Rep_Info): Reset Relevant_Entities for each unit.
+	* switch-c.adb (Scan_Front_End_Switches): Add support for -gnatR4.
+	* switch-m.adb (Normalize_Compiler_Switches): Likewise
+	* usage.adb (Usage): Likewise.
+
 2018-11-14  Javier Miranda  <miranda@adacore.com>
 
 	* exp_disp.adb (Expand_Interface_Thunk): Extend handling of

gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst

@@ -2081,7 +2081,7 @@ Alphabetical List of All Switches
 
 .. index:: -gnatR  (gcc)
 
-:switch:`-gnatR[0|1|2|3][e][j][m][s]`
+:switch:`-gnatR[0|1|2|3|4][e][j][m][s]`
   Output representation information for declared types, objects and
   subprograms. Note that this switch is not allowed if a previous
   :switch:`-gnatD` switch has been given, since these two switches
@@ -5843,13 +5843,14 @@ Debugging Control
 
 .. index:: -gnatR  (gcc)
 
-:switch:`-gnatR[0|1|2|3][e][j][m][s]`
+:switch:`-gnatR[0|1|2|3|4][e][j][m][s]`
   This switch controls output from the compiler of a listing showing
   representation information for declared types, objects and subprograms.
   For :switch:`-gnatR0`, no information is output (equivalent to omitting
   the :switch:`-gnatR` switch). For :switch:`-gnatR1` (which is the default,
   so :switch:`-gnatR` with no parameter has the same effect), size and
   alignment information is listed for declared array and record types.
+
   For :switch:`-gnatR2`, size and alignment information is listed for all
   declared types and objects. The ``Linker_Section`` is also listed for any
   entity for which the ``Linker_Section`` is set explicitly or implicitly (the
@@ -5862,9 +5863,13 @@ Debugging Control
   n'th discriminant. See source files :file:`repinfo.ads/adb` in the
   GNAT sources for full details on the format of :switch:`-gnatR3` output.
 
+  For :switch:`-gnatR4`, information for relevant compiler-generated types
+  is also listed, i.e. when they are structurally part of other declared
+  types and objects.
+
   If the switch is followed by an ``e`` (e.g. :switch:`-gnatR2e`), then
   extended representation information for record sub-components of records
-  are included.
+  is included.
 
   If the switch is followed by an ``m`` (e.g. :switch:`-gnatRm`), then
   subprogram conventions and parameter passing mechanisms for all the

gcc/ada/gnat_ugn.texi

@@ -21,7 +21,7 @@
 
 @copying
 @quotation
-GNAT User's Guide for Native Platforms , Aug 20, 2018
+GNAT User's Guide for Native Platforms , Nov 09, 2018
 
 AdaCore
 
@@ -9977,7 +9977,7 @@ Treat pragma Restrictions as Restriction_Warnings.
 
 @table @asis
 
-@item @code{-gnatR[0|1|2|3][e][j][m][s]}
+@item @code{-gnatR[0|1|2|3|4][e][j][m][s]}
 
 Output representation information for declared types, objects and
 subprograms. Note that this switch is not allowed if a previous
@@ -15092,14 +15092,15 @@ restriction warnings rather than restrictions.
 
 @table @asis
 
-@item @code{-gnatR[0|1|2|3][e][j][m][s]}
+@item @code{-gnatR[0|1|2|3|4][e][j][m][s]}
 
 This switch controls output from the compiler of a listing showing
 representation information for declared types, objects and subprograms.
 For @code{-gnatR0}, no information is output (equivalent to omitting
 the @code{-gnatR} switch). For @code{-gnatR1} (which is the default,
 so @code{-gnatR} with no parameter has the same effect), size and
 alignment information is listed for declared array and record types.
+
 For @code{-gnatR2}, size and alignment information is listed for all
 declared types and objects. The @code{Linker_Section} is also listed for any
 entity for which the @code{Linker_Section} is set explicitly or implicitly (the
@@ -15112,9 +15113,13 @@ a mostly obvious format with #n being used to represent the value of the
 n'th discriminant. See source files @code{repinfo.ads/adb} in the
 GNAT sources for full details on the format of @code{-gnatR3} output.
 
+For @code{-gnatR4}, information for relevant compiler-generated types
+is also listed, i.e. when they are structurally part of other declared
+types and objects.
+
 If the switch is followed by an @code{e} (e.g. @code{-gnatR2e}), then
 extended representation information for record sub-components of records
-are included.
+is included.
 
 If the switch is followed by an @code{m} (e.g. @code{-gnatRm}), then
 subprogram conventions and parameter passing mechanisms for all the

gcc/ada/opt.ads

@@ -986,26 +986,27 @@ package Opt is
    --  the list of object dependencies (-M switch). Output depends if -a switch
    --  is used or not. This list can be used directly in a Makefile.
 
-   List_Representation_Info : Int range 0 .. 3 := 0;
+   List_Representation_Info : Int range 0 .. 4 := 0;
    --  GNAT
    --  Set non-zero by -gnatR switch to list representation information.
    --  The settings are as follows:
    --
    --    0 = no listing of representation information (default as above)
-   --    1 = list rep info for user defined record and array types
-   --    2 = list rep info for all user defined types and objects
+   --    1 = list rep info for user-defined record and array types
+   --    2 = list rep info for all user-defined types and objects
    --    3 = like 2, but variable fields are decoded symbolically
+   --    4 = like 3, but list rep info for relevant compiler-generated types
 
    List_Representation_Info_To_File : Boolean := False;
    --  GNAT
-   --  Set true by -gnatRs switch. Causes information from -gnatR/1/2/3/m to be
+   --  Set true by -gnatRs switch. Causes information from -gnatR[1-4]m to be
    --  written to file.rep (where file is the name of the source file) instead
    --  of stdout. For example, if file x.adb is compiled using -gnatR2s then
    --  representation info is written to x.adb.ref.
 
    List_Representation_Info_To_JSON : Boolean := False;
    --  GNAT
-   --  Set true by -gnatRj switch. Causes information from -gnatR/1/2/3/m to be
+   --  Set true by -gnatRj switch. Causes information from -gnatR[1-4]m to be
    --  output in the JSON data interchange format.
 
    List_Representation_Info_Mechanisms : Boolean := False;

gcc/ada/repinfo.adb

@@ -50,6 +50,8 @@ with Urealp;  use Urealp;
 
 with Ada.Unchecked_Conversion;
 
+with GNAT.HTable;
+
 package body Repinfo is
 
    SSU : constant := 8;
@@ -118,6 +120,28 @@ package body Repinfo is
    --  the current entity. Set True when a new entity is processed, and false
    --  when the blank line is output.
 
+   -------------------------------
+   --  Set of Relevant Entities --
+   -------------------------------
+
+   Relevant_Entities_Size : constant := 4093;
+   --  Number of headers in hash table
+
+   subtype Entity_Header_Num is Integer range 0 .. Relevant_Entities_Size - 1;
+   --  Range of headers in hash table
+
+   function Entity_Hash (Id : Entity_Id) return Entity_Header_Num;
+   --  Simple hash function for Entity_Ids
+
+   package Relevant_Entities is new GNAT.Htable.Simple_HTable
+     (Header_Num => Entity_Header_Num,
+      Element    => Boolean,
+      No_Element => False,
+      Key        => Entity_Id,
+      Hash       => Entity_Hash,
+      Equal      => "=");
+   --  Hash table to record which compiler-generated entities are relevant
+
    -----------------------
    -- Local Subprograms --
    -----------------------
@@ -264,6 +288,15 @@ package body Repinfo is
       return UI_From_Int (-Rep_Table.Last);
    end Create_Node;
 
+   -----------------
+   -- Entity_Hash --
+   -----------------
+
+   function Entity_Hash (Id : Entity_Id) return Entity_Header_Num is
+   begin
+      return Entity_Header_Num (Id mod Relevant_Entities_Size);
+   end Entity_Hash;
+
    ---------------------------
    -- Get_Dynamic_SO_Entity --
    ---------------------------
@@ -403,9 +436,11 @@ package body Repinfo is
             Need_Blank_Line := True;
 
             --  We list entities that come from source (excluding private or
-            --  incomplete types or deferred constants, where we will list the
-            --  info for the full view). If debug flag A is set, then all
-            --  entities are listed
+            --  incomplete types or deferred constants, for which we will list
+            --  the information for the full view). If requested, we also list
+            --  relevant entities that have been generated when processing the
+            --  original entities coming from source. But if debug flag A is
+            --  set, then all entities are listed.
 
             if ((Comes_From_Source (E)
                    or else (Ekind (E) = E_Block
@@ -416,6 +451,8 @@ package body Repinfo is
               and then not Is_Incomplete_Or_Private_Type (E)
               and then not (Ekind (E) = E_Constant
                               and then Present (Full_View (E))))
+              or else (List_Representation_Info = 4
+                         and then Relevant_Entities.Get (E))
               or else Debug_Flag_AA
             then
                if Is_Subprogram (E) then
@@ -448,6 +485,15 @@ package body Repinfo is
                      List_Array_Info (E, Bytes_Big_Endian);
                   end if;
 
+                  --  The component type is relevant for an array
+
+                  if List_Representation_Info = 4
+                    and then Is_Itype (Component_Type (Base_Type (E)))
+                  then
+                     Relevant_Entities.Set
+                       (Component_Type (Base_Type (E)), True);
+                  end if;
+
                elsif Is_Type (E) then
                   if List_Representation_Info >= 2 then
                      Blank_Line;
@@ -1239,7 +1285,7 @@ package body Repinfo is
             Write_Str (UI_Image_Buffer (1 .. UI_Image_Length));
 
          elsif Known_Normalized_Position (Ent)
-           and then List_Representation_Info = 3
+           and then List_Representation_Info >= 3
          then
             Spaces (Max_Spos_Length - 2);
 
@@ -1730,6 +1776,10 @@ package body Repinfo is
             if In_Extended_Main_Source_Unit (Cunit_Entity (U)) then
                Unit_Casing := Identifier_Casing (Source_Index (U));
 
+               if List_Representation_Info = 4 then
+                  Relevant_Entities.Reset;
+               end if;
+
                --  Normal case, list to standard output
 
                if not List_Representation_Info_To_File then

gcc/ada/switch-c.adb

@@ -1204,7 +1204,7 @@ package body Switch.C is
 
                   case C is
 
-                  when '0' .. '3' =>
+                  when '0' .. '4' =>
                      List_Representation_Info :=
                        Character'Pos (C) - Character'Pos ('0');
 

gcc/ada/switch-m.adb

@@ -462,37 +462,29 @@ package body Switch.M is
                      Add_Switch_Component
                        (Storing (Storing'First .. Last_Stored));
 
-                  --  -gnatR may be followed by '0', '1', '2' or '3',
-                  --  then by 's'
+                  --  -gnatR may be followed by '0', '1', '2', '3' or '4',
+                  --  then by 'e', 'j', 'm' or 's'.
 
                   when 'R' =>
                      Last_Stored := First_Stored;
                      Storing (Last_Stored) := 'R';
                      Ptr := Ptr + 1;
 
-                     if Ptr <= Max
-                       and then Switch_Chars (Ptr) in '0' .. '9'
-                     then
+                     while Ptr <= Max loop
                         C := Switch_Chars (Ptr);
 
-                        if C in '4' .. '9' then
-                           Last := 0;
-                           return;
+                        case C is
 
-                        else
+                        when '0' .. '4' | 'e' | 'j' | 'm' | 's' =>
                            Last_Stored := Last_Stored + 1;
                            Storing (Last_Stored) := C;
                            Ptr := Ptr + 1;
 
-                           if Ptr <= Max
-                             and then Switch_Chars (Ptr) = 's'
-                           then
-                              Last_Stored := Last_Stored + 1;
-                              Storing (Last_Stored) := 's';
-                              Ptr := Ptr + 1;
-                           end if;
-                        end if;
-                     end if;
+                        when others =>
+                           Last := 0;
+                           return;
+                        end case;
+                     end loop;
 
                      Add_Switch_Component
                        (Storing (Storing'First .. Last_Stored));

gcc/ada/usage.adb

@@ -402,7 +402,7 @@ begin
 
    Write_Switch_Char ("R?");
    Write_Line
-     ("List rep info (?=0/1/2/3/e/m for none/types/all/symbolic/ext/mech)");
+     ("List rep info (?=0/1/2/3/4/e/m for none/types/all/sym/cg/ext/mech)");
    Write_Switch_Char ("R?j");
    Write_Line ("List rep info in the JSON data interchange format");
    Write_Switch_Char ("R?s");