[Ada] Remove obsolete uses of Unchecked_Conversion from Ada 83

Similar to a recent removal of obsolete uses of Unchecked_Deallocation.

In Ada 83 the Unchecked_Conversion was a top-level unit; since Ada 95 it
is an obsolete renaming of Ada.Unchecked_Conversion. GNAT doesn't warn
yet about uses of these obsolete renamings, but it still seems better to
avoid them.

gcc/ada/

	* atree.adb, gen_il-gen.adb, osint.adb, set_targ.adb,
	sinput.adb, table.adb, treepr.adb, types.ads: Replace uses of
	Unchecked_Conversion in the compiler itself.
	* libgnarl/a-reatim.adb, libgnarl/s-osinte__gnu.ads,
	libgnarl/s-osinte__kfreebsd-gnu.ads, libgnat/a-coboho.adb,
	libgnat/a-stuten.ads, libgnat/s-putima.adb: Likewise in the
	runtime.
	* doc/gnat_ugn/gnat_and_program_execution.rst: Likewise in
	documentation.
	* gnat_ugn.texi: Regenerate.

16 files changed, 65 insertions, 64 deletions

diff --git a/gcc/ada/atree.adb b/gcc/ada/atree.adb
index 08e3667..a949761 100644
--- a/gcc/ada/atree.adb
+++ b/gcc/ada/atree.adb
@@ -23,6 +23,7 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
+with Ada.Unchecked_Conversion;
 with Aspects;        use Aspects;
 with Debug;          use Debug;
 with Namet;          use Namet;
@@ -31,7 +32,6 @@ with Opt;            use Opt;
 with Output;         use Output;
 with Sinfo.Utils;    use Sinfo.Utils;
 with System.Storage_Elements;
-with Unchecked_Conversion;
 
 package body Atree is
 
@@ -505,7 +505,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 1);
 
          function Cast is new
-           Unchecked_Conversion (Field_Size_1_Bit, Field_Type);
+           Ada.Unchecked_Conversion (Field_Size_1_Bit, Field_Type);
          Val : constant Field_Size_1_Bit := Get_1_Bit_Val (N, Offset);
       begin
          return Cast (Val);
@@ -517,7 +517,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 2);
 
          function Cast is new
-           Unchecked_Conversion (Field_Size_2_Bit, Field_Type);
+           Ada.Unchecked_Conversion (Field_Size_2_Bit, Field_Type);
          Val : constant Field_Size_2_Bit := Get_2_Bit_Val (N, Offset);
       begin
          return Cast (Val);
@@ -529,7 +529,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 4);
 
          function Cast is new
-           Unchecked_Conversion (Field_Size_4_Bit, Field_Type);
+           Ada.Unchecked_Conversion (Field_Size_4_Bit, Field_Type);
          Val : constant Field_Size_4_Bit := Get_4_Bit_Val (N, Offset);
       begin
          return Cast (Val);
@@ -541,7 +541,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 8);
 
          function Cast is new
-           Unchecked_Conversion (Field_Size_8_Bit, Field_Type);
+           Ada.Unchecked_Conversion (Field_Size_8_Bit, Field_Type);
          Val : constant Field_Size_8_Bit := Get_8_Bit_Val (N, Offset);
       begin
          return Cast (Val);
@@ -553,7 +553,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 32);
 
          function Cast is new
-           Unchecked_Conversion (Field_Size_32_Bit, Field_Type);
+           Ada.Unchecked_Conversion (Field_Size_32_Bit, Field_Type);
 
          Val : constant Field_Size_32_Bit := Get_32_Bit_Val (N, Offset);
          Result : constant Field_Type := Cast (Val);
@@ -605,7 +605,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 1);
 
          function Cast is new
-           Unchecked_Conversion (Field_Type, Field_Size_1_Bit);
+           Ada.Unchecked_Conversion (Field_Type, Field_Size_1_Bit);
       begin
          Set_1_Bit_Val (N, Offset, Cast (Val));
       end Set_1_Bit_Field;
@@ -616,7 +616,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 2);
 
          function Cast is new
-           Unchecked_Conversion (Field_Type, Field_Size_2_Bit);
+           Ada.Unchecked_Conversion (Field_Type, Field_Size_2_Bit);
       begin
          Set_2_Bit_Val (N, Offset, Cast (Val));
       end Set_2_Bit_Field;
@@ -627,7 +627,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 4);
 
          function Cast is new
-           Unchecked_Conversion (Field_Type, Field_Size_4_Bit);
+           Ada.Unchecked_Conversion (Field_Type, Field_Size_4_Bit);
       begin
          Set_4_Bit_Val (N, Offset, Cast (Val));
       end Set_4_Bit_Field;
@@ -638,7 +638,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 8);
 
          function Cast is new
-           Unchecked_Conversion (Field_Type, Field_Size_8_Bit);
+           Ada.Unchecked_Conversion (Field_Type, Field_Size_8_Bit);
       begin
          Set_8_Bit_Val (N, Offset, Cast (Val));
       end Set_8_Bit_Field;
@@ -649,7 +649,7 @@ package body Atree is
          pragma Assert (Field_Type'Size = 32);
 
          function Cast is new
-           Unchecked_Conversion (Field_Type, Field_Size_32_Bit);
+           Ada.Unchecked_Conversion (Field_Type, Field_Size_32_Bit);
       begin
          Set_32_Bit_Val (N, Offset, Cast (Val));
       end Set_32_Bit_Field;
@@ -854,7 +854,7 @@ package body Atree is
       ----------------------
 
       procedure Print_Atree_Info (N : Node_Or_Entity_Id) is
-         function Cast is new Unchecked_Conversion (Slot, Int);
+         function Cast is new Ada.Unchecked_Conversion (Slot, Int);
       begin
          Write_Int (Int (Size_In_Slots (N)));
          Write_Str (" slots (");
diff --git a/gcc/ada/doc/gnat_ugn/gnat_and_program_execution.rst b/gcc/ada/doc/gnat_ugn/gnat_and_program_execution.rst
index bf0fec9..c514678 100644
--- a/gcc/ada/doc/gnat_ugn/gnat_and_program_execution.rst
+++ b/gcc/ada/doc/gnat_ugn/gnat_and_program_execution.rst
@@ -2101,11 +2101,11 @@ the typing system. Consider the following complete program example:
          function to_a2 (Input : a1) return a2;
       end p2;
 
-      with Unchecked_Conversion;
+      with Ada.Unchecked_Conversion;
       package body p2 is
          function to_a2 (Input : a1) return a2 is
             function to_a2u is
-              new Unchecked_Conversion (a1, a2);
+              new Ada.Unchecked_Conversion (a1, a2);
          begin
             return to_a2u (Input);
          end to_a2;
@@ -2198,7 +2198,7 @@ the warning off:
 
      pragma Warnings (Off);
      function to_a2u is
-       new Unchecked_Conversion (a1, a2);
+       new Ada.Unchecked_Conversion (a1, a2);
      pragma Warnings (On);
 
 Of course that approach is not appropriate for this particular
diff --git a/gcc/ada/gen_il-gen.adb b/gcc/ada/gen_il-gen.adb
index adf363b..0ecc696 100644
--- a/gcc/ada/gen_il-gen.adb
+++ b/gcc/ada/gen_il-gen.adb
@@ -1425,7 +1425,7 @@ package body Gen_IL.Gen is
         (S : in out Sink; T : Type_Enum)
       is
          Pre : constant String :=
-           "function Cast is new Unchecked_Conversion (";
+           "function Cast is new Ada.Unchecked_Conversion (";
          Lo_Type : constant String := "Field_Size_" & Image (Field_Size (T)) & "_Bit";
          Hi_Type : constant String := Get_Set_Id_Image (T);
       begin
@@ -2338,7 +2338,7 @@ package body Gen_IL.Gen is
          Decrease_Indent (S, 3);
          Put (S, LF & "end Sinfo.Nodes;" & LF);
 
-         Put (B, "with Unchecked_Conversion;" & LF);
+         Put (B, "with Ada.Unchecked_Conversion;" & LF);
          Put (B, "with Atree; use Atree; use Atree.Atree_Private_Part;" & LF);
          Put (B, "with Nlists; use Nlists;" & LF);
          Put (B, "pragma Warnings (Off);" & LF);
@@ -2394,7 +2394,7 @@ package body Gen_IL.Gen is
          Decrease_Indent (S, 3);
          Put (S, LF & "end Einfo.Entities;" & LF);
 
-         Put (B, "with Unchecked_Conversion;" & LF);
+         Put (B, "with Ada.Unchecked_Conversion;" & LF);
          Put (B, "with Atree; use Atree; use Atree.Atree_Private_Part;" & LF);
          Put (B, "with Einfo.Utils; use Einfo.Utils;" & LF);
          --  This forms a cycle between packages (via bodies, which is OK)
diff --git a/gcc/ada/gnat_ugn.texi b/gcc/ada/gnat_ugn.texi
index 879f5fc..218c375 100644
--- a/gcc/ada/gnat_ugn.texi
+++ b/gcc/ada/gnat_ugn.texi
@@ -20478,11 +20478,11 @@ package p2 is
    function to_a2 (Input : a1) return a2;
 end p2;
 
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 package body p2 is
    function to_a2 (Input : a1) return a2 is
       function to_a2u is
-        new Unchecked_Conversion (a1, a2);
+        new Ada.Unchecked_Conversion (a1, a2);
    begin
       return to_a2u (Input);
    end to_a2;
@@ -20581,7 +20581,7 @@ the warning off:
 @example
 pragma Warnings (Off);
 function to_a2u is
-  new Unchecked_Conversion (a1, a2);
+  new Ada.Unchecked_Conversion (a1, a2);
 pragma Warnings (On);
 @end example
 @end quotation
diff --git a/gcc/ada/libgnarl/a-reatim.adb b/gcc/ada/libgnarl/a-reatim.adb
index 6bb5ae5..fda2d63 100644
--- a/gcc/ada/libgnarl/a-reatim.adb
+++ b/gcc/ada/libgnarl/a-reatim.adb
@@ -30,8 +30,8 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
+with Ada.Unchecked_Conversion;
 with System.Tasking;
-with Unchecked_Conversion;
 
 package body Ada.Real_Time with
   SPARK_Mode => Off
@@ -128,7 +128,7 @@ is
       type Duration_Rep is range -(2 ** 63) .. +((2 ** 63 - 1));
 
       function To_Integer is
-        new Unchecked_Conversion (Duration, Duration_Rep);
+        new Ada.Unchecked_Conversion (Duration, Duration_Rep);
    begin
       return Integer
                (To_Integer (Duration (Left)) / To_Integer (Duration (Right)));
diff --git a/gcc/ada/libgnarl/s-osinte__gnu.ads b/gcc/ada/libgnarl/s-osinte__gnu.ads
index e763fc9..39e20f2 100644
--- a/gcc/ada/libgnarl/s-osinte__gnu.ads
+++ b/gcc/ada/libgnarl/s-osinte__gnu.ads
@@ -40,7 +40,7 @@
 
 with Interfaces.C;
 with System.Parameters;
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 
 package System.OS_Interface is
    pragma Preelaborate;
@@ -288,14 +288,14 @@ package System.OS_Interface is
    pragma Convention (C, Thread_Body);
 
    function Thread_Body_Access is new
-     Unchecked_Conversion (System.Address, Thread_Body);
+     Ada.Unchecked_Conversion (System.Address, Thread_Body);
 
    --  From: /usr/include/bits/pthread.h:typedef int __pthread_t;
    --  /usr/include/pthread/pthreadtypes.h:typedef __pthread_t pthread_t;
    type pthread_t is new unsigned_long;
    subtype Thread_Id        is pthread_t;
 
-   function To_pthread_t is new Unchecked_Conversion
+   function To_pthread_t is new Ada.Unchecked_Conversion
      (unsigned_long, pthread_t);
 
    type pthread_mutex_t     is limited private;
diff --git a/gcc/ada/libgnarl/s-osinte__kfreebsd-gnu.ads b/gcc/ada/libgnarl/s-osinte__kfreebsd-gnu.ads
index c8d94e3..ad1a1b5 100644
--- a/gcc/ada/libgnarl/s-osinte__kfreebsd-gnu.ads
+++ b/gcc/ada/libgnarl/s-osinte__kfreebsd-gnu.ads
@@ -38,9 +38,9 @@
 --  PLEASE DO NOT add any with-clauses to this package or remove the pragma
 --  Preelaborate. This package is designed to be a bottom-level (leaf) package
 
+with Ada.Unchecked_Conversion;
 with Interfaces.C;
 with System.Parameters;
-with Unchecked_Conversion;
 
 package System.OS_Interface is
    pragma Preelaborate;
@@ -276,12 +276,12 @@ package System.OS_Interface is
    pragma Convention (C, Thread_Body);
 
    function Thread_Body_Access is new
-     Unchecked_Conversion (System.Address, Thread_Body);
+     Ada.Unchecked_Conversion (System.Address, Thread_Body);
 
    type pthread_t is new unsigned_long;
    subtype Thread_Id        is pthread_t;
 
-   function To_pthread_t is new Unchecked_Conversion
+   function To_pthread_t is new Ada.Unchecked_Conversion
      (unsigned_long, pthread_t);
 
    type pthread_mutex_t     is limited private;
diff --git a/gcc/ada/libgnat/a-coboho.adb b/gcc/ada/libgnat/a-coboho.adb
index db885b4..25d0777 100644
--- a/gcc/ada/libgnat/a-coboho.adb
+++ b/gcc/ada/libgnat/a-coboho.adb
@@ -25,7 +25,7 @@
 -- <http://www.gnu.org/licenses/>.                                          --
 ------------------------------------------------------------------------------
 
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 with System.Put_Images;
 
 package body Ada.Containers.Bounded_Holders is
@@ -54,7 +54,7 @@ package body Ada.Containers.Bounded_Holders is
    end Size_In_Storage_Elements;
 
    function Cast is new
-     Unchecked_Conversion (System.Address, Element_Access);
+     Ada.Unchecked_Conversion (System.Address, Element_Access);
 
    ---------
    -- "=" --
diff --git a/gcc/ada/libgnat/a-stuten.ads b/gcc/ada/libgnat/a-stuten.ads
index 209c84a..618f5b0 100644
--- a/gcc/ada/libgnat/a-stuten.ads
+++ b/gcc/ada/libgnat/a-stuten.ads
@@ -36,8 +36,8 @@
 --  UTF encoded strings. Note: this package is consistent with Ada 95, and may
 --  be used in Ada 95 or Ada 2005 mode.
 
+with Ada.Unchecked_Conversion;
 with Interfaces;
-with Unchecked_Conversion;
 
 package Ada.Strings.UTF_Encoding is
    pragma Pure (UTF_Encoding);
@@ -106,13 +106,13 @@ package Ada.Strings.UTF_Encoding is
 
 private
    function To_Unsigned_8 is new
-     Unchecked_Conversion (Character, Interfaces.Unsigned_8);
+     Ada.Unchecked_Conversion (Character, Interfaces.Unsigned_8);
 
    function To_Unsigned_16 is new
-     Unchecked_Conversion (Wide_Character, Interfaces.Unsigned_16);
+     Ada.Unchecked_Conversion (Wide_Character, Interfaces.Unsigned_16);
 
    function To_Unsigned_32 is new
-     Unchecked_Conversion (Wide_Wide_Character, Interfaces.Unsigned_32);
+     Ada.Unchecked_Conversion (Wide_Wide_Character, Interfaces.Unsigned_32);
 
    subtype UTF_XE_Encoding is Encoding_Scheme range UTF_16BE .. UTF_16LE;
    --  Subtype containing only UTF_16BE and UTF_16LE entries
diff --git a/gcc/ada/libgnat/s-putima.adb b/gcc/ada/libgnat/s-putima.adb
index cc36fce..10d8b84 100644
--- a/gcc/ada/libgnat/s-putima.adb
+++ b/gcc/ada/libgnat/s-putima.adb
@@ -32,7 +32,7 @@
 with Ada.Strings.Text_Buffers.Utils;
 use Ada.Strings.Text_Buffers;
 use Ada.Strings.Text_Buffers.Utils;
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 
 package body System.Put_Images is
 
@@ -133,7 +133,7 @@ package body System.Put_Images is
    procedure Put_Image_Pointer
      (S : in out Sink'Class; X : Pointer; Type_Kind : String)
    is
-      function Cast is new Unchecked_Conversion
+      function Cast is new Ada.Unchecked_Conversion
         (System.Address, Unsigned_Address);
    begin
       if X = null then
diff --git a/gcc/ada/osint.adb b/gcc/ada/osint.adb
index af76dc7..15f0692 100644
--- a/gcc/ada/osint.adb
+++ b/gcc/ada/osint.adb
@@ -34,7 +34,7 @@ with Sdefault; use Sdefault;
 with Table;
 with Targparm; use Targparm;
 
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 
 pragma Warnings (Off);
 --  This package is used also by gnatcoll
@@ -2216,9 +2216,9 @@ package body Osint is
       --  GNAT releases are available with these functions.
 
       function To_Int is
-        new Unchecked_Conversion (OS_Time, Underlying_OS_Time);
+        new Ada.Unchecked_Conversion (OS_Time, Underlying_OS_Time);
       function From_Int is
-        new Unchecked_Conversion (Underlying_OS_Time, OS_Time);
+        new Ada.Unchecked_Conversion (Underlying_OS_Time, OS_Time);
 
       TI : Underlying_OS_Time := To_Int (T);
       Y  : Year_Type;
@@ -3085,8 +3085,8 @@ package body Osint is
       type Path_String_Access is access Path_String;
 
       function Address_To_Access is new
-        Unchecked_Conversion (Source => Address,
-                              Target => Path_String_Access);
+        Ada.Unchecked_Conversion (Source => Address,
+                                  Target => Path_String_Access);
 
       Path_Access : constant Path_String_Access :=
                       Address_To_Access (Path_Addr);
diff --git a/gcc/ada/set_targ.adb b/gcc/ada/set_targ.adb
index dcb2fd0..160f510 100644
--- a/gcc/ada/set_targ.adb
+++ b/gcc/ada/set_targ.adb
@@ -31,7 +31,7 @@ with Output;   use Output;
 with System;        use System;
 with System.OS_Lib; use System.OS_Lib;
 
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 
 package body Set_Targ is
 
@@ -404,7 +404,7 @@ package body Set_Targ is
       --  Pointer to Nat or Pos value (it is harmless to treat Pos values and
       --  Nat values as Natural via Unchecked_Conversion).
 
-      function To_ANat is new Unchecked_Conversion (Address, ANat);
+      function To_ANat is new Ada.Unchecked_Conversion (Address, ANat);
 
       procedure AddC (C : Character);
       --  Add one character to buffer
@@ -566,7 +566,7 @@ package body Set_Targ is
       --  Pointer to Nat or Pos value (it is harmless to treat Pos values
       --  as Nat via Unchecked_Conversion).
 
-      function To_ANat is new Unchecked_Conversion (Address, ANat);
+      function To_ANat is new Ada.Unchecked_Conversion (Address, ANat);
 
       VP : ANat;
 
diff --git a/gcc/ada/sinput.adb b/gcc/ada/sinput.adb
index fccbacf..8e80213 100644
--- a/gcc/ada/sinput.adb
+++ b/gcc/ada/sinput.adb
@@ -41,8 +41,8 @@ with System.Storage_Elements;
 with System.Memory;
 with System.WCh_Con; use System.WCh_Con;
 
+with Ada.Unchecked_Conversion;
 with Ada.Unchecked_Deallocation;
-with Unchecked_Conversion;
 
 package body Sinput is
 
@@ -56,16 +56,16 @@ package body Sinput is
    --  used to construct improperly aliased pointer values.
 
    function To_Address is
-     new Unchecked_Conversion (Lines_Table_Ptr, Address);
+     new Ada.Unchecked_Conversion (Lines_Table_Ptr, Address);
 
    function To_Address is
-     new Unchecked_Conversion (Logical_Lines_Table_Ptr, Address);
+     new Ada.Unchecked_Conversion (Logical_Lines_Table_Ptr, Address);
 
    function To_Pointer is
-     new Unchecked_Conversion (Address, Lines_Table_Ptr);
+     new Ada.Unchecked_Conversion (Address, Lines_Table_Ptr);
 
    function To_Pointer is
-     new Unchecked_Conversion (Address, Logical_Lines_Table_Ptr);
+     new Ada.Unchecked_Conversion (Address, Logical_Lines_Table_Ptr);
 
    pragma Warnings (On);
 
@@ -378,7 +378,7 @@ package body Sinput is
       --  to first Unchecked_Convert to access-to-variable.
 
       function To_Source_Buffer_Ptr_Var is new
-        Unchecked_Conversion (Source_Buffer_Ptr, Source_Buffer_Ptr_Var);
+        Ada.Unchecked_Conversion (Source_Buffer_Ptr, Source_Buffer_Ptr_Var);
 
       Temp : Source_Buffer_Ptr_Var := To_Source_Buffer_Ptr_Var (Src);
 
diff --git a/gcc/ada/table.adb b/gcc/ada/table.adb
index ce558cd..df467f4 100644
--- a/gcc/ada/table.adb
+++ b/gcc/ada/table.adb
@@ -30,7 +30,7 @@ with System;  use System;
 
 with System.Memory; use System.Memory;
 
-with Unchecked_Conversion;
+with Ada.Unchecked_Conversion;
 
 pragma Elaborate_All (Output);
 
@@ -58,8 +58,8 @@ package body Table is
       --  internally in this package, and cannot never result in any instances
       --  of improperly aliased pointers for the client of the package.
 
-      function To_Address is new Unchecked_Conversion (Table_Ptr, Address);
-      function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr);
+      function To_Address is new Ada.Unchecked_Conversion (Table_Ptr, Address);
+      function To_Pointer is new Ada.Unchecked_Conversion (Address, Table_Ptr);
 
       pragma Warnings (On);
 
diff --git a/gcc/ada/treepr.adb b/gcc/ada/treepr.adb
index 4fd082a..32f6e81 100644
--- a/gcc/ada/treepr.adb
+++ b/gcc/ada/treepr.adb
@@ -23,6 +23,7 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
+with Ada.Unchecked_Conversion;
 with Aspects;              use Aspects;
 with Atree;                use Atree;
 with Debug;                use Debug;
@@ -49,7 +50,6 @@ with SCIL_LL;              use SCIL_LL;
 with Uintp;                use Uintp;
 with Urealp;               use Urealp;
 with Uname;                use Uname;
-with Unchecked_Conversion;
 
 package body Treepr is
 
@@ -132,8 +132,8 @@ package body Treepr is
    -- Local Procedures --
    ----------------------
 
-   function From_Union is new Unchecked_Conversion (Union_Id, Uint);
-   function From_Union is new Unchecked_Conversion (Union_Id, Ureal);
+   function From_Union is new Ada.Unchecked_Conversion (Union_Id, Uint);
+   function From_Union is new Ada.Unchecked_Conversion (Union_Id, Ureal);
 
    function To_Mixed (S : String) return String;
    --  Turns an identifier into Mixed_Case. For bootstrap reasons, we cannot
@@ -260,7 +260,7 @@ package body Treepr is
    ----------
 
    function Hash (Key : Int) return GNAT.Bucket_Range_Type is
-      function Cast is new Unchecked_Conversion
+      function Cast is new Ada.Unchecked_Conversion
         (Source => Int, Target => GNAT.Bucket_Range_Type);
    begin
       return Cast (Key);
@@ -880,7 +880,7 @@ package body Treepr is
          when Uint_Field =>
             declare
                Val : constant Uint := Get_Uint (N, FD.Offset);
-               function Cast is new Unchecked_Conversion (Uint, Int);
+               function Cast is new Ada.Unchecked_Conversion (Uint, Int);
             begin
                if Present (Val) then
                   Print_Initial;
@@ -895,7 +895,7 @@ package body Treepr is
             | Nonzero_Uint_Field =>
             declare
                Val : constant Uint := Get_Valid_Uint (N, FD.Offset);
-               function Cast is new Unchecked_Conversion (Uint, Int);
+               function Cast is new Ada.Unchecked_Conversion (Uint, Int);
             begin
                Print_Initial;
                UI_Write (Val, Format);
@@ -916,7 +916,7 @@ package body Treepr is
          when Ureal_Field =>
             declare
                Val : constant Ureal := Get_Ureal (N, FD.Offset);
-               function Cast is new Unchecked_Conversion (Ureal, Int);
+               function Cast is new Ada.Unchecked_Conversion (Ureal, Int);
             begin
                if Val /= No_Ureal then
                   Print_Initial;
@@ -980,7 +980,8 @@ package body Treepr is
    exception
       when others =>
          declare
-            function Cast is new Unchecked_Conversion (Field_Size_32_Bit, Int);
+            function Cast is new
+              Ada.Unchecked_Conversion (Field_Size_32_Bit, Int);
          begin
             Write_Eol;
             Print_Initial;
diff --git a/gcc/ada/types.ads b/gcc/ada/types.ads
index de14bf7..3b226e1 100644
--- a/gcc/ada/types.ads
+++ b/gcc/ada/types.ads
@@ -39,9 +39,9 @@
 --  2s-complement. If there are any machines for which this is not a correct
 --  assumption, a significant number of changes will be required.
 
+with Ada.Unchecked_Conversion;
 with Ada.Unchecked_Deallocation;
 with System;
-with Unchecked_Conversion;
 
 package Types is
    pragma Preelaborate;
@@ -127,7 +127,7 @@ package Types is
    --  size of zero, since there are legitimate deallocations going on.
 
    function To_Big_String_Ptr is
-     new Unchecked_Conversion (System.Address, Big_String_Ptr);
+     new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr);
    --  Used to obtain Big_String_Ptr values from external addresses
 
    subtype Word_Hex_String is String (1 .. 8);