[Ada] Fix packed boolean array with Default_Component_Value aspect

[Eric Botcazou]

Putting the Default_Component_Value aspect on a bit-packed array type has 
never worked, so this plugs the loophole.  For the sake of consistency, the 
recent fix for PR ada/68179 is adjusted to use Has_Default_Aspect too.

Tested on x86-64/Linux, applied on the mainline and 15 branch.


2026-01-17  Eric Botcazou  <ebotca...@adacore.com>
            Lisa Felidae  <l...@felidae.bam.moe>

        PR ada/68179
        PR ada/123589
        * exp_ch3.adb (Expand_Freeze_Array_Type): Build an initialization
        procedure for a bit-packed array type if Has_Default_Aspect is set
        on the base type, but make sure not to build it twice.  Also test
        Has_Default_Aspect for a type derived from String.


2026-01-17  Eric Botcazou  <ebotca...@adacore.com>
            Lisa Felidae  <l...@felidae.bam.moe>

        * gnat.dg/component_value2.adb: New test.

-- 
Eric Botcazou
--  { dg-do run }

procedure Component_Value2 is

   type Bool_Packed_Array is array (Positive range 1 .. 20) of Boolean
     with Default_Component_Value => False, Pack;

   type Bool_Nonpacked_Array is array (Positive range 1 .. 20) of Boolean
     with Default_Component_Value => False;

   P  : Bool_Packed_Array;
   NP : Bool_Nonpacked_Array;

begin
   if not (for all I in P'Range => P(I) = False) then
      raise Program_Error;
   end if;

   if not (for all I in NP'Range => P(I) = False) then
      raise Program_Error;
   end if;
end;

diff --git a/gcc/ada/exp_ch3.adb b/gcc/ada/exp_ch3.adb
index af1b82d351d..521dbf11ca3 100644
--- a/gcc/ada/exp_ch3.adb
+++ b/gcc/ada/exp_ch3.adb
@@ -5711,6 +5711,8 @@ package body Exp_Ch3 is
           (Component_Type (Typ));
 
    begin
+      --  First, the nonpacked case
+
       if not Is_Bit_Packed_Array (Typ) then
          if No (Init_Proc (Base)) then
 
@@ -5734,7 +5736,7 @@ package body Exp_Ch3 is
             --  and do not need initialization procedures.
 
             elsif Is_Standard_String_Type (Base)
-              and then No (Default_Aspect_Component_Value (Base))
+              and then not Has_Default_Aspect (Base)
             then
                null;
 
@@ -5755,18 +5757,20 @@ package body Exp_Ch3 is
             end if;
          end if;
 
-      --  For packed case, default initialization, except if the component type
-      --  is itself a packed structure with an initialization procedure, or
-      --  initialize/normalize scalars active, and we have a base type, or the
-      --  type is public, because in that case a client might specify
-      --  Normalize_Scalars and there better be a public Init_Proc for it.
+      --  For the packed case, no initialization, except if the component type
+      --  has an initialization procedure, or Initialize/Normalize_Scalars is
+      --  active, or there is a Default_Component_Value aspect, or the type is
+      --  public, because a client might specify Initialize_Scalars and there
+      --  better be a public Init_Proc for it.
 
-      elsif (Present (Init_Proc (Component_Type (Base)))
-              and then No (Base_Init_Proc (Base)))
-        or else (Init_Or_Norm_Scalars and then Base = Typ)
+      elsif Present (Init_Proc (Component_Type (Base)))
+        or else Init_Or_Norm_Scalars
+        or else Has_Default_Aspect (Base)
         or else Is_Public (Typ)
       then
-         Build_Array_Init_Proc (Base, N);
+         if No (Init_Proc (Base)) then
+            Build_Array_Init_Proc (Base, N);
+         end if;
       end if;
    end Expand_Freeze_Array_Type;