[Ada] Clean up of GNAT.Dynamic_HTables

------------
-- Source --
------------

--  operations.adb

with Ada.Text_IO;          use Ada.Text_IO;
with GNAT;                 use GNAT;
with GNAT.Dynamic_HTables; use GNAT.Dynamic_HTables;

procedure Operations is
   procedure Destroy (Val : in out Integer) is null;
   function Hash (Key : Integer) return Bucket_Range_Type;

   package DHT is new Dynamic_Hash_Tables
     (Key_Type              => Integer,
      Value_Type            => Integer,
      No_Value              => 0,
      Expansion_Threshold   => 1.3,
      Expansion_Factor      => 2,
      Compression_Threshold => 0.3,
      Compression_Factor    => 2,
      "="                   => "=",
      Destroy_Value         => Destroy,
      Hash                  => Hash);
   use DHT;

   function Create_And_Populate
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive) return Dynamic_Hash_Table;
   --  Create a hash table with initial size Init_Size and populate it with
   --  key-value pairs where both keys and values are in the range Low_Key
   --  .. High_Key.

   procedure Check_Empty
     (Caller    : String;
      T         : Dynamic_Hash_Table;
      Low_Key   : Integer;
      High_Key  : Integer);
   --  Ensure that
   --
   --    * The key-value pairs count of hash table T is 0.
   --    * All values for the keys in range Low_Key .. High_Key are 0.

   procedure Check_Keys
     (Caller   : String;
      Iter     : in out Iterator;
      Low_Key  : Integer;
      High_Key : Integer);
   --  Ensure that iterator Iter visits every key in the range Low_Key ..
   --  High_Key exactly once.

   procedure Check_Locked_Mutations
     (Caller : String;
      T      : in out Dynamic_Hash_Table);
   --  Ensure that all mutation operations of hash table T are locked

   procedure Check_Size
     (Caller    : String;
      T         : Dynamic_Hash_Table;
      Exp_Count : Natural);
   --  Ensure that the count of key-value pairs of hash table T matches
   --  expected count Exp_Count. Emit an error if this is not the case.

   procedure Test_Create (Init_Size : Positive);
   --  Verify that all dynamic hash table operations fail on a non-created
   --  table of size Init_Size.

   procedure Test_Delete_Get_Put_Size
     (Low_Key   : Integer;
      High_Key  : Integer;
      Exp_Count : Natural;
      Init_Size : Positive);
   --  Verify that
   --
   --    * Put properly inserts values in the hash table.
   --    * Get properly retrieves all values inserted in the table.
   --    * Delete properly deletes values.
   --    * The size of the hash table properly reflects the number of key-value
   --      pairs.
   --
   --  Low_Key and High_Key denote the range of keys to be inserted, retrieved,
   --  and deleted. Exp_Count is the expected count of key-value pairs n the
   --  hash table. Init_Size denotes the initial size of the table.

   procedure Test_Iterate
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive);
   --  Verify that iterators
   --
   --    * Properly visit each key exactly once.
   --    * Mutation operations are properly locked and unlocked during
   --      iteration.
   --
   --  Low_Key and High_Key denote the range of keys to be inserted, retrieved,
   --  and deleted. Init_Size denotes the initial size of the table.

   procedure Test_Iterate_Empty (Init_Size : Positive);
   --  Verify that an iterator over an empty hash table
   --
   --    * Does not visit any key
   --    * Mutation operations are properly locked and unlocked during
   --      iteration.
   --
   --  Init_Size denotes the initial size of the table.

   procedure Test_Iterate_Forced
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive);
   --  Verify that an iterator that is forcefully advanced by just Next
   --
   --    * Properly visit each key exactly once.
   --    * Mutation operations are properly locked and unlocked during
   --      iteration.
   --
   --  Low_Key and High_Key denote the range of keys to be inserted, retrieved,
   --  and deleted. Init_Size denotes the initial size of the table.

   procedure Test_Replace
     (Low_Val   : Integer;
      High_Val  : Integer;
      Init_Size : Positive);
   --  Verify that Put properly updates the value of a particular key. Low_Val
   --  and High_Val denote the range of values to be updated. Init_Size denotes
   --  the initial size of the table.

   procedure Test_Reset
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive);
   --  Verify that Reset properly destroy and recreats a hash table. Low_Key
   --  and High_Key denote the range of keys to be inserted in the hash table.
   --  Init_Size denotes the initial size of the table.

   -------------------------
   -- Create_And_Populate --
   -------------------------

   function Create_And_Populate
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive) return Dynamic_Hash_Table
   is
      T : Dynamic_Hash_Table;

   begin
      T := Create (Init_Size);

      for Key in Low_Key .. High_Key loop
         Put (T, Key, Key);
      end loop;

      return T;
   end Create_And_Populate;

   -----------------
   -- Check_Empty --
   -----------------

   procedure Check_Empty
     (Caller    : String;
      T         : Dynamic_Hash_Table;
      Low_Key   : Integer;
      High_Key  : Integer)
   is
      Val : Integer;

   begin
      Check_Size
        (Caller    => Caller,
         T         => T,
         Exp_Count => 0);

      for Key in Low_Key .. High_Key loop
         Val := Get (T, Key);

         if Val /= 0 then
            Put_Line ("ERROR: " & Caller & ": wrong value");
            Put_Line ("expected: 0");
            Put_Line ("got     :" & Val'Img);
         end if;
      end loop;
   end Check_Empty;

   ----------------
   -- Check_Keys --
   ----------------

   procedure Check_Keys
     (Caller   : String;
      Iter     : in out Iterator;
      Low_Key  : Integer;
      High_Key : Integer)
   is
      type Bit_Vector is array (Low_Key .. High_Key) of Boolean;
      pragma Pack (Bit_Vector);

      Count : Natural;
      Key   : Integer;
      Seen  : Bit_Vector := (others => False);

   begin
      --  Compute the number of outstanding keys that have to be iterated on

      Count := High_Key - Low_Key + 1;

      while Has_Next (Iter) loop
         Next (Iter, Key);

         if Seen (Key) then
            Put_Line
              ("ERROR: " & Caller & ": Check_Keys: duplicate key" & Key'Img);
         else
            Seen (Key) := True;
            Count := Count - 1;
         end if;
      end loop;

      --  In the end, all keys must have been iterated on

      if Count /= 0 then
         for Key in Seen'Range loop
            if not Seen (Key) then
               Put_Line
                 ("ERROR: " & Caller & ": Check_Keys: missing key" & Key'Img);
            end if;
         end loop;
      end if;
   end Check_Keys;

   ----------------------------
   -- Check_Locked_Mutations --
   ----------------------------

   procedure Check_Locked_Mutations
     (Caller : String;
      T      : in out Dynamic_Hash_Table)
   is
   begin
      begin
         Delete (T, 1);
         Put_Line ("ERROR: " & Caller & ": Delete: no exception raised");
      exception
         when Iterated =>
            null;
         when others =>
           Put_Line ("ERROR: " & Caller & ": Delete: unexpected exception");
      end;

      begin
         Destroy (T);
         Put_Line ("ERROR: " & Caller & ": Destroy: no exception raised");
      exception
         when Iterated =>
            null;
         when others =>
           Put_Line ("ERROR: " & Caller & ": Destroy: unexpected exception");
      end;

      begin
         Put (T, 1, 1);
         Put_Line ("ERROR: " & Caller & ": Put: no exception raised");
      exception
         when Iterated =>
            null;
         when others =>
           Put_Line ("ERROR: " & Caller & ": Put: unexpected exception");
      end;

      begin
         Reset (T);
         Put_Line ("ERROR: " & Caller & ": Reset: no exception raised");
      exception
         when Iterated =>
            null;
         when others =>
           Put_Line ("ERROR: " & Caller & ": Reset: unexpected exception");
      end;
   end Check_Locked_Mutations;

   ----------------
   -- Check_Size --
   ----------------

   procedure Check_Size
     (Caller    : String;
      T         : Dynamic_Hash_Table;
      Exp_Count : Natural)
   is
      Count : constant Natural := Size (T);

   begin
      if Count /= Exp_Count then
         Put_Line ("ERROR: " & Caller & ": Size: wrong value");
         Put_Line ("expected:" & Exp_Count'Img);
         Put_Line ("got     :" & Count'Img);
      end if;
   end Check_Size;

   ----------
   -- Hash --
   ----------

   function Hash (Key : Integer) return Bucket_Range_Type is
   begin
      return Bucket_Range_Type (Key);
   end Hash;

   -----------------
   -- Test_Create --
   -----------------

   procedure Test_Create (Init_Size : Positive) is
      Count : Natural;
      Iter  : Iterator;
      T     : Dynamic_Hash_Table;
      Val   : Integer;

   begin
      --  Ensure that every routine defined in the API fails on a hash table
      --  which has not been created yet.

      begin
         Delete (T, 1);
         Put_Line ("ERROR: Test_Create: Delete: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Delete: unexpected exception");
      end;

      begin
         Destroy (T);
         Put_Line ("ERROR: Test_Create: Destroy: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Destroy: unexpected exception");
      end;

      begin
         Val := Get (T, 1);
         Put_Line ("ERROR: Test_Create: Get: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Get: unexpected exception");
      end;

      begin
         Iter := Iterate (T);
         Put_Line ("ERROR: Test_Create: Iterate: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Iterate: unexpected exception");
      end;

      begin
         Put (T, 1, 1);
         Put_Line ("ERROR: Test_Create: Put: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Put: unexpected exception");
      end;

      begin
         Reset (T);
         Put_Line ("ERROR: Test_Create: Reset: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Reset: unexpected exception");
      end;

      begin
         Count := Size (T);
         Put_Line ("ERROR: Test_Create: Size: no exception raised");
      exception
         when Not_Created =>
            null;
         when others =>
           Put_Line ("ERROR: Test_Create: Size: unexpected exception");
      end;

      --  Test create

      T := Create (Init_Size);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Create;

   ------------------------------
   -- Test_Delete_Get_Put_Size --
   ------------------------------

   procedure Test_Delete_Get_Put_Size
     (Low_Key   : Integer;
      High_Key  : Integer;
      Exp_Count : Natural;
      Init_Size : Positive)
   is
      Exp_Val : Integer;
      T       : Dynamic_Hash_Table;
      Val     : Integer;

   begin
      T := Create_And_Populate (Low_Key, High_Key, Init_Size);

      --  Ensure that its size matches an expected value

      Check_Size
        (Caller    => "Test_Delete_Get_Put_Size",
         T         => T,
         Exp_Count => Exp_Count);

      --  Ensure that every value for the range of keys exists

      for Key in Low_Key .. High_Key loop
         Val := Get (T, Key);

         if Val /= Key then
            Put_Line ("ERROR: Test_Delete_Get_Put_Size: Get: wrong value");
            Put_Line ("expected:" & Key'Img);
            Put_Line ("got     :" & Val'Img);
         end if;
      end loop;

      --  Delete values whose keys are divisible by 10

      for Key in Low_Key .. High_Key loop
         if Key mod 10 = 0 then
            Delete (T, Key);
         end if;
      end loop;

      --  Ensure that all values whose keys were not deleted still exist

      for Key in Low_Key .. High_Key loop
         if Key mod 10 = 0 then
            Exp_Val := 0;
         else
            Exp_Val := Key;
         end if;

         Val := Get (T, Key);

         if Val /= Exp_Val then
            Put_Line ("ERROR: Test_Delete_Get_Put_Size: Get: wrong value");
            Put_Line ("expected:" & Exp_Val'Img);
            Put_Line ("got     :" & Val'Img);
         end if;
      end loop;

      --  Delete all values

      for Key in Low_Key .. High_Key loop
         Delete (T, Key);
      end loop;

      --  Ensure that the hash table is empty

      Check_Empty
        (Caller   => "Test_Delete_Get_Put_Size",
         T        => T,
         Low_Key  => Low_Key,
         High_Key => High_Key);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Delete_Get_Put_Size;

   ------------------
   -- Test_Iterate --
   ------------------

   procedure Test_Iterate
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive)
   is
      Iter_1 : Iterator;
      Iter_2 : Iterator;
      T      : Dynamic_Hash_Table;

   begin
      T := Create_And_Populate (Low_Key, High_Key, Init_Size);

      --  Obtain an iterator. This action must lock all mutation operations of
      --  the hash table.

      Iter_1 := Iterate (T);

      --  Ensure that every mutation routine defined in the API fails on a hash
      --  table with at least one outstanding iterator.

      Check_Locked_Mutations
        (Caller => "Test_Iterate",
         T      => T);

      --  Obtain another iterator

      Iter_2 := Iterate (T);

      --  Ensure that every mutation is still locked

      Check_Locked_Mutations
        (Caller => "Test_Iterate",
         T      => T);

      --  Ensure that all keys are iterable. Note that this does not unlock the
      --  mutation operations of the hash table because Iter_2 is not exhausted
      --  yet.

      Check_Keys
        (Caller   => "Test_Iterate",
         Iter     => Iter_1,
         Low_Key  => Low_Key,
         High_Key => High_Key);

      Check_Locked_Mutations
        (Caller => "Test_Iterate",
         T      => T);

      --  Ensure that all keys are iterable. This action unlocks all mutation
      --  operations of the hash table because all outstanding iterators have
      --  been exhausted.

      Check_Keys
        (Caller   => "Test_Iterate",
         Iter     => Iter_2,
         Low_Key  => Low_Key,
         High_Key => High_Key);

      --  Ensure that all mutation operations are once again callable

      Delete (T, Low_Key);
      Put (T, Low_Key, Low_Key);
      Reset (T);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Iterate;

   ------------------------
   -- Test_Iterate_Empty --
   ------------------------

   procedure Test_Iterate_Empty (Init_Size : Positive) is
      Iter : Iterator;
      Key  : Integer;
      T    : Dynamic_Hash_Table;

   begin
      T := Create_And_Populate (0, -1, Init_Size);

      --  Obtain an iterator. This action must lock all mutation operations of
      --  the hash table.

      Iter := Iterate (T);

      --  Ensure that every mutation routine defined in the API fails on a hash
      --  table with at least one outstanding iterator.

      Check_Locked_Mutations
        (Caller => "Test_Iterate_Empty",
         T      => T);

      --  Attempt to iterate over the keys

      while Has_Next (Iter) loop
         Next (Iter, Key);

         Put_Line ("ERROR: Test_Iterate_Empty: key" & Key'Img & " exists");
      end loop;

      --  Ensure that all mutation operations are once again callable

      Delete (T, 1);
      Put (T, 1, 1);
      Reset (T);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Iterate_Empty;

   -------------------------
   -- Test_Iterate_Forced --
   -------------------------

   procedure Test_Iterate_Forced
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive)
   is
      Iter : Iterator;
      Key  : Integer;
      T    : Dynamic_Hash_Table;

   begin
      T := Create_And_Populate (Low_Key, High_Key, Init_Size);

      --  Obtain an iterator. This action must lock all mutation operations of
      --  the hash table.

      Iter := Iterate (T);

      --  Ensure that every mutation routine defined in the API fails on a hash
      --  table with at least one outstanding iterator.

      Check_Locked_Mutations
        (Caller => "Test_Iterate_Forced",
         T      => T);

      --  Forcibly advance the iterator until it raises an exception

      begin
         for Guard in Low_Key .. High_Key + 1 loop
            Next (Iter, Key);
         end loop;

         Put_Line
           ("ERROR: Test_Iterate_Forced: Iterator_Exhausted not raised");
      exception
         when Iterator_Exhausted =>
            null;
         when others =>
            Put_Line ("ERROR: Test_Iterate_Forced: unexpected exception");
      end;

      --  Ensure that all mutation operations are once again callable

      Delete (T, Low_Key);
      Put (T, Low_Key, Low_Key);
      Reset (T);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Iterate_Forced;

   ------------------
   -- Test_Replace --
   ------------------

   procedure Test_Replace
     (Low_Val   : Integer;
      High_Val  : Integer;
      Init_Size : Positive)
   is
      Key : constant Integer := 1;
      T   : Dynamic_Hash_Table;
      Val : Integer;

   begin
      T := Create (Init_Size);

      --  Ensure the Put properly updates values with the same key

      for Exp_Val in Low_Val .. High_Val loop
         Put (T, Key, Exp_Val);

         Val := Get (T, Key);

         if Val /= Exp_Val then
            Put_Line ("ERROR: Test_Replace: Get: wrong value");
            Put_Line ("expected:" & Exp_Val'Img);
            Put_Line ("got     :" & Val'Img);
         end if;
      end loop;

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Replace;

   ----------------
   -- Test_Reset --
   ----------------

   procedure Test_Reset
     (Low_Key   : Integer;
      High_Key  : Integer;
      Init_Size : Positive)
   is
      T : Dynamic_Hash_Table;

   begin
      T := Create_And_Populate (Low_Key, High_Key, Init_Size);

      --  Reset the contents of the hash table

      Reset (T);

      --  Ensure that the hash table is empty

      Check_Empty
        (Caller   => "Test_Reset",
         T        => T,
         Low_Key  => Low_Key,
         High_Key => High_Key);

      --  Clean up the hash table to prevent memory leaks

      Destroy (T);
   end Test_Reset;

--  Start of processing for Operations

begin
   Test_Create (Init_Size => 1);
   Test_Create (Init_Size => 100);

   Test_Delete_Get_Put_Size
     (Low_Key   => 1,
      High_Key  => 1,
      Exp_Count => 1,
      Init_Size => 1);

   Test_Delete_Get_Put_Size
     (Low_Key   => 1,
      High_Key  => 1000,
      Exp_Count => 1000,
      Init_Size => 32);

   Test_Iterate
     (Low_Key   => 1,
      High_Key  => 32,
      Init_Size => 32);

   Test_Iterate_Empty (Init_Size => 32);

   Test_Iterate_Forced
     (Low_Key   => 1,
      High_Key  => 32,
      Init_Size => 32);

   Test_Replace
     (Low_Val   => 1,
      High_Val  => 10,
      Init_Size => 32);

   Test_Reset
     (Low_Key   => 1,
      High_Key  => 1000,
      Init_Size => 100);
end Operations;

----------------------------
-- Compilation and output --
----------------------------

$ gnatmake -q operations.adb -largs -lgmem
$ ./operations
$ gnatmem operations > leaks.txt
$ grep -c "non freed allocations" leaks.txt
0

2019-07-01  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* libgnat/g-dynhta.adb: Use type Dynamic_Hash_Table rather than
	Instance in various routines.
	* libgnat/g-dynhta.ads: Change type Instance to
	Dynamic_Hash_Table. Update various routines that mention the
	type.

gcc/testsuite/

	* gnat.dg/dynhash.adb, gnat.dg/dynhash1.adb: Update.

From-SVN: r272860

gcc/ada/ChangeLog

 2019-07-01  Hristian Kirtchev  <kirtchev@adacore.com>
 
+	* libgnat/g-dynhta.adb: Use type Dynamic_Hash_Table rather than
+	Instance in various routines.
+	* libgnat/g-dynhta.ads: Change type Instance to
+	Dynamic_Hash_Table. Update various routines that mention the
+	type.
+
+2019-07-01  Hristian Kirtchev  <kirtchev@adacore.com>
+
 	* exp_attr.adb, exp_ch7.adb, exp_unst.adb, sem_ch3.adb,
 	sem_util.adb, uintp.adb, uintp.ads: Minor reformatting.
 

gcc/ada/libgnat/g-dynhta.adb

@@ -364,11 +364,11 @@ package body GNAT.Dynamic_HTables is
       end Set_Next;
    end Simple_HTable;
 
-   --------------------
-   -- Dynamic_HTable --
-   --------------------
+   -------------------------
+   -- Dynamic_Hash_Tables --
+   -------------------------
 
-   package body Dynamic_HTable is
+   package body Dynamic_Hash_Tables is
       Minimum_Size : constant Bucket_Range_Type := 8;
       --  Minimum size of the buckets
 
@@ -382,7 +382,9 @@ package body GNAT.Dynamic_HTables is
       --  Maximum safe size for hash table expansion. Beyond this size, an
       --  expansion will overflow the buckets.
 
-      procedure Delete_Node (T : Instance; Nod : Node_Ptr);
+      procedure Delete_Node
+        (T   : Dynamic_Hash_Table;
+         Nod : Node_Ptr);
       pragma Inline (Delete_Node);
       --  Detach and delete node Nod from table T
 
@@ -398,12 +400,12 @@ package body GNAT.Dynamic_HTables is
       pragma Inline (Ensure_Circular);
       --  Ensure that dummy head Head is circular with respect to itself
 
-      procedure Ensure_Created (T : Instance);
+      procedure Ensure_Created (T : Dynamic_Hash_Table);
       pragma Inline (Ensure_Created);
       --  Verify that hash table T is created. Raise Not_Created if this is not
       --  the case.
 
-      procedure Ensure_Unlocked (T : Instance);
+      procedure Ensure_Unlocked (T : Dynamic_Hash_Table);
       pragma Inline (Ensure_Unlocked);
       --  Verify that hash table T is unlocked. Raise Iterated if this is not
       --  the case.
@@ -422,7 +424,7 @@ package body GNAT.Dynamic_HTables is
       --  otherwise return null.
 
       procedure First_Valid_Node
-        (T        : Instance;
+        (T        : Dynamic_Hash_Table;
          Low_Bkt  : Bucket_Range_Type;
          High_Bkt : Bucket_Range_Type;
          Idx      : out Bucket_Range_Type;
@@ -437,7 +439,8 @@ package body GNAT.Dynamic_HTables is
         new Ada.Unchecked_Deallocation (Bucket_Table, Bucket_Table_Ptr);
 
       procedure Free is
-        new Ada.Unchecked_Deallocation (Hash_Table, Instance);
+        new Ada.Unchecked_Deallocation
+              (Dynamic_Hash_Table_Attributes, Dynamic_Hash_Table);
 
       procedure Free is
         new Ada.Unchecked_Deallocation (Node, Node_Ptr);
@@ -451,15 +454,17 @@ package body GNAT.Dynamic_HTables is
       --  Determine whether node Nod is non-null and does not refer to dummy
       --  head Head, thus making it valid.
 
-      function Load_Factor (T : Instance) return Threshold_Type;
+      function Load_Factor (T : Dynamic_Hash_Table) return Threshold_Type;
       pragma Inline (Load_Factor);
       --  Calculate the load factor of hash table T
 
-      procedure Lock (T : Instance);
+      procedure Lock (T : Dynamic_Hash_Table);
       pragma Inline (Lock);
       --  Lock all mutation functionality of hash table T
 
-      procedure Mutate_And_Rehash (T : Instance; Size : Bucket_Range_Type);
+      procedure Mutate_And_Rehash
+        (T    : Dynamic_Hash_Table;
+         Size : Bucket_Range_Type);
       pragma Inline (Mutate_And_Rehash);
       --  Replace the buckets of hash table T with a new set of buckets of size
       --  Size. Rehash all key-value pairs from the old to the new buckets.
@@ -476,7 +481,7 @@ package body GNAT.Dynamic_HTables is
       pragma Inline (Present);
       --  Determine whether node Nod exists
 
-      procedure Unlock (T : Instance);
+      procedure Unlock (T : Dynamic_Hash_Table);
       pragma Inline (Unlock);
       --  Unlock all mutation functionality of hash table T
 
@@ -484,13 +489,13 @@ package body GNAT.Dynamic_HTables is
       -- Create --
       ------------
 
-      function Create (Initial_Size : Positive) return Instance is
+      function Create (Initial_Size : Positive) return Dynamic_Hash_Table is
          Size : constant Bucket_Range_Type :=
                            Bucket_Range_Type'Max
                              (Bucket_Range_Type (Initial_Size), Minimum_Size);
          --  Ensure that the buckets meet a minimum size
 
-         T : constant Instance := new Hash_Table;
+         T : constant Dynamic_Hash_Table := new Dynamic_Hash_Table_Attributes;
 
       begin
          T.Buckets      := new Bucket_Table (0 .. Size - 1);
@@ -503,7 +508,10 @@ package body GNAT.Dynamic_HTables is
       -- Delete --
       ------------
 
-      procedure Delete (T : Instance; Key : Key_Type) is
+      procedure Delete
+        (T   : Dynamic_Hash_Table;
+         Key : Key_Type)
+      is
          Head : Node_Ptr;
          Nod  : Node_Ptr;
 
@@ -531,7 +539,10 @@ package body GNAT.Dynamic_HTables is
       -- Delete_Node --
       -----------------
 
-      procedure Delete_Node (T : Instance; Nod : Node_Ptr) is
+      procedure Delete_Node
+        (T   : Dynamic_Hash_Table;
+         Nod : Node_Ptr)
+      is
          procedure Compress;
          pragma Inline (Compress);
          --  Determine whether hash table T requires compression, and if so,
@@ -586,7 +597,7 @@ package body GNAT.Dynamic_HTables is
       -- Destroy --
       -------------
 
-      procedure Destroy (T : in out Instance) is
+      procedure Destroy (T : in out Dynamic_Hash_Table) is
       begin
          Ensure_Created  (T);
          Ensure_Unlocked (T);
@@ -678,7 +689,7 @@ package body GNAT.Dynamic_HTables is
       -- Ensure_Created --
       --------------------
 
-      procedure Ensure_Created (T : Instance) is
+      procedure Ensure_Created (T : Dynamic_Hash_Table) is
       begin
          if not Present (T) then
             raise Not_Created;
@@ -689,7 +700,7 @@ package body GNAT.Dynamic_HTables is
       -- Ensure_Unlocked --
       ---------------------
 
-      procedure Ensure_Unlocked (T : Instance) is
+      procedure Ensure_Unlocked (T : Dynamic_Hash_Table) is
       begin
          pragma Assert (Present (T));
 
@@ -746,7 +757,7 @@ package body GNAT.Dynamic_HTables is
       ----------------------
 
       procedure First_Valid_Node
-        (T        : Instance;
+        (T        : Dynamic_Hash_Table;
          Low_Bkt  : Bucket_Range_Type;
          High_Bkt : Bucket_Range_Type;
          Idx      : out Bucket_Range_Type;
@@ -784,7 +795,10 @@ package body GNAT.Dynamic_HTables is
       -- Get --
       ---------
 
-      function Get (T : Instance; Key : Key_Type) return Value_Type is
+      function Get
+        (T   : Dynamic_Hash_Table;
+         Key : Key_Type) return Value_Type
+      is
          Head : Node_Ptr;
          Nod  : Node_Ptr;
 
@@ -815,7 +829,7 @@ package body GNAT.Dynamic_HTables is
 
       function Has_Next (Iter : Iterator) return Boolean is
          Is_OK : constant Boolean := Is_Valid (Iter);
-         T     : constant Instance := Iter.Table;
+         T     : constant Dynamic_Hash_Table := Iter.Table;
 
       begin
          pragma Assert (Present (T));
@@ -835,7 +849,7 @@ package body GNAT.Dynamic_HTables is
       -- Is_Empty --
       --------------
 
-      function Is_Empty (T : Instance) return Boolean is
+      function Is_Empty (T : Dynamic_Hash_Table) return Boolean is
       begin
          Ensure_Created (T);
 
@@ -870,7 +884,7 @@ package body GNAT.Dynamic_HTables is
       -- Iterate --
       -------------
 
-      function Iterate (T : Instance) return Iterator is
+      function Iterate (T : Dynamic_Hash_Table) return Iterator is
          Iter : Iterator;
 
       begin
@@ -906,7 +920,7 @@ package body GNAT.Dynamic_HTables is
       -- Load_Factor --
       -----------------
 
-      function Load_Factor (T : Instance) return Threshold_Type is
+      function Load_Factor (T : Dynamic_Hash_Table) return Threshold_Type is
          pragma Assert (Present (T));
          pragma Assert (Present (T.Buckets));
 
@@ -920,7 +934,7 @@ package body GNAT.Dynamic_HTables is
       -- Lock --
       ----------
 
-      procedure Lock (T : Instance) is
+      procedure Lock (T : Dynamic_Hash_Table) is
       begin
          --  The hash table may be locked multiple times if multiple iterators
          --  are operating over it.
@@ -932,7 +946,10 @@ package body GNAT.Dynamic_HTables is
       -- Mutate_And_Rehash --
       -----------------------
 
-      procedure Mutate_And_Rehash (T : Instance; Size : Bucket_Range_Type) is
+      procedure Mutate_And_Rehash
+        (T    : Dynamic_Hash_Table;
+         Size : Bucket_Range_Type)
+      is
          procedure Rehash (From : Bucket_Table_Ptr; To : Bucket_Table_Ptr);
          pragma Inline (Rehash);
          --  Remove all nodes from buckets From and rehash them into buckets To
@@ -1031,7 +1048,7 @@ package body GNAT.Dynamic_HTables is
       procedure Next (Iter : in out Iterator; Key : out Key_Type) is
          Is_OK : constant Boolean  := Is_Valid (Iter);
          Saved : constant Node_Ptr := Iter.Curr_Nod;
-         T     : constant Instance := Iter.Table;
+         T     : constant Dynamic_Hash_Table := Iter.Table;
          Head  : Node_Ptr;
 
       begin
@@ -1109,7 +1126,7 @@ package body GNAT.Dynamic_HTables is
       -- Present --
       -------------
 
-      function Present (T : Instance) return Boolean is
+      function Present (T : Dynamic_Hash_Table) return Boolean is
       begin
          return T /= Nil;
       end Present;
@@ -1118,7 +1135,11 @@ package body GNAT.Dynamic_HTables is
       -- Put --
       ---------
 
-      procedure Put (T : Instance; Key : Key_Type; Value : Value_Type) is
+      procedure Put
+        (T     : Dynamic_Hash_Table;
+         Key   : Key_Type;
+         Value : Value_Type)
+      is
          procedure Expand;
          pragma Inline (Expand);
          --  Determine whether hash table T requires expansion, and if so,
@@ -1223,7 +1244,7 @@ package body GNAT.Dynamic_HTables is
       -- Reset --
       -----------
 
-      procedure Reset (T : Instance) is
+      procedure Reset (T : Dynamic_Hash_Table) is
       begin
          Ensure_Created  (T);
          Ensure_Unlocked (T);
@@ -1243,7 +1264,7 @@ package body GNAT.Dynamic_HTables is
       -- Size --
       ----------
 
-      function Size (T : Instance) return Natural is
+      function Size (T : Dynamic_Hash_Table) return Natural is
       begin
          Ensure_Created (T);
 
@@ -1254,13 +1275,13 @@ package body GNAT.Dynamic_HTables is
       -- Unlock --
       ------------
 
-      procedure Unlock (T : Instance) is
+      procedure Unlock (T : Dynamic_Hash_Table) is
       begin
          --  The hash table may be locked multiple times if multiple iterators
          --  are operating over it.
 
          T.Iterators := T.Iterators - 1;
       end Unlock;
-   end Dynamic_HTable;
+   end Dynamic_Hash_Tables;
 
 end GNAT.Dynamic_HTables;

gcc/ada/libgnat/g-dynhta.ads

@@ -258,9 +258,9 @@ package GNAT.Dynamic_HTables is
       Nil : constant Instance := Instance (Tab.Nil);
    end Simple_HTable;
 
-   --------------------
-   -- Dynamic_HTable --
-   --------------------
+   -------------------------
+   -- Dynamic_Hash_Tables --
+   -------------------------
 
    --  The following package offers a hash table abstraction with the following
    --  characteristics:
@@ -275,7 +275,7 @@ package GNAT.Dynamic_HTables is
    --
    --  The following use pattern must be employed when operating this table:
    --
-   --    Table : Instance := Create (<some size>);
+   --    Table : Dynamic_Hash_Table := Create (<some size>);
    --
    --    <various operations>
    --
@@ -333,7 +333,7 @@ package GNAT.Dynamic_HTables is
       with function Hash (Key : Key_Type) return Bucket_Range_Type;
       --  Map an arbitrary key into the range of buckets
 
-   package Dynamic_HTable is
+   package Dynamic_Hash_Tables is
 
       ----------------------
       -- Table operations --
@@ -342,37 +342,44 @@ package GNAT.Dynamic_HTables is
       --  The following type denotes a hash table handle. Each instance must be
       --  created using routine Create.
 
-      type Instance is private;
-      Nil : constant Instance;
+      type Dynamic_Hash_Table is private;
+      Nil : constant Dynamic_Hash_Table;
 
-      function Create (Initial_Size : Positive) return Instance;
+      function Create (Initial_Size : Positive) return Dynamic_Hash_Table;
       --  Create a new table with bucket capacity Initial_Size. This routine
       --  must be called at the start of a hash table's lifetime.
 
-      procedure Delete (T : Instance; Key : Key_Type);
+      procedure Delete
+        (T   : Dynamic_Hash_Table;
+         Key : Key_Type);
       --  Delete the value which corresponds to key Key from hash table T. The
       --  routine has no effect if the value is not present in the hash table.
       --  This action will raise Iterated if the hash table has outstanding
       --  iterators. If the load factor drops below Compression_Threshold, the
       --  size of the buckets is decreased by Copression_Factor.
 
-      procedure Destroy (T : in out Instance);
+      procedure Destroy (T : in out Dynamic_Hash_Table);
       --  Destroy the contents of hash table T, rendering it unusable. This
       --  routine must be called at the end of a hash table's lifetime. This
       --  action will raise Iterated if the hash table has outstanding
       --  iterators.
 
-      function Get (T : Instance; Key : Key_Type) return Value_Type;
+      function Get
+        (T   : Dynamic_Hash_Table;
+         Key : Key_Type) return Value_Type;
       --  Obtain the value which corresponds to key Key from hash table T. If
       --  the value does not exist, return No_Value.
 
-      function Is_Empty (T : Instance) return Boolean;
+      function Is_Empty (T : Dynamic_Hash_Table) return Boolean;
       --  Determine whether hash table T is empty
 
-      function Present (T : Instance) return Boolean;
+      function Present (T : Dynamic_Hash_Table) return Boolean;
       --  Determine whether hash table T exists
 
-      procedure Put (T : Instance; Key : Key_Type; Value : Value_Type);
+      procedure Put
+        (T     : Dynamic_Hash_Table;
+         Key   : Key_Type;
+         Value : Value_Type);
       --  Associate value Value with key Key in hash table T. If the table
       --  already contains a mapping of the same key to a previous value, the
       --  previous value is overwritten. This action will raise Iterated if
@@ -380,12 +387,12 @@ package GNAT.Dynamic_HTables is
       --  over Expansion_Threshold, the size of the buckets is increased by
       --  Expansion_Factor.
 
-      procedure Reset (T : Instance);
+      procedure Reset (T : Dynamic_Hash_Table);
       --  Destroy the contents of hash table T, and reset it to its initial
       --  created state. This action will raise Iterated if the hash table
       --  has outstanding iterators.
 
-      function Size (T : Instance) return Natural;
+      function Size (T : Dynamic_Hash_Table) return Natural;
       --  Obtain the number of key-value pairs in hash table T
 
       -------------------------
@@ -412,7 +419,7 @@ package GNAT.Dynamic_HTables is
       --  iterator has been exhausted, restore all mutation functionality of
       --  the associated hash table.
 
-      function Iterate (T : Instance) return Iterator;
+      function Iterate (T : Dynamic_Hash_Table) return Iterator;
       --  Obtain an iterator over the keys of hash table T. This action locks
       --  all mutation functionality of the associated hash table.
 
@@ -461,7 +468,7 @@ package GNAT.Dynamic_HTables is
 
       --  The following type represents a hash table
 
-      type Hash_Table is record
+      type Dynamic_Hash_Table_Attributes is record
          Buckets : Bucket_Table_Ptr := null;
          --  Reference to the compressing / expanding buckets
 
@@ -475,8 +482,8 @@ package GNAT.Dynamic_HTables is
          --  Number of key-value pairs in the buckets
       end record;
 
-      type Instance is access Hash_Table;
-      Nil : constant Instance := null;
+      type Dynamic_Hash_Table is access Dynamic_Hash_Table_Attributes;
+      Nil : constant Dynamic_Hash_Table := null;
 
       --  The following type represents a key iterator
 
@@ -491,9 +498,9 @@ package GNAT.Dynamic_HTables is
          --  always point to a valid node. A value of null indicates that the
          --  iterator is exhausted.
 
-         Table : Instance := null;
+         Table : Dynamic_Hash_Table := null;
          --  Reference to the associated hash table
       end record;
-   end Dynamic_HTable;
+   end Dynamic_Hash_Tables;
 
 end GNAT.Dynamic_HTables;

gcc/testsuite/ChangeLog

 2019-07-01  Hristian Kirtchev  <kirtchev@adacore.com>
 
+	* gnat.dg/dynhash.adb, gnat.dg/dynhash1.adb: Update.
+
+2019-07-01  Hristian Kirtchev  <kirtchev@adacore.com>
+
 	* gnat.dg/freezing1.adb, gnat.dg/freezing1.ads,
 	gnat.dg/freezing1_pack.adb, gnat.dg/freezing1_pack.ads: New
 	testcase.

gcc/testsuite/gnat.dg/dynhash.adb

@@ -5,9 +5,10 @@ with GNAT;                 use GNAT;
 with GNAT.Dynamic_HTables; use GNAT.Dynamic_HTables;
 
 procedure Dynhash is
+   procedure Destroy (Val : in out Integer) is null;
    function Hash (Key : Integer) return Bucket_Range_Type;
 
-   package DHT is new Dynamic_HTable
+   package DHT is new Dynamic_Hash_Tables
      (Key_Type              => Integer,
       Value_Type            => Integer,
       No_Value              => 0,
@@ -16,20 +17,21 @@ procedure Dynhash is
       Compression_Threshold => 0.3,
       Compression_Factor    => 2,
       "="                   => "=",
+      Destroy_Value         => Destroy,
       Hash                  => Hash);
    use DHT;
 
    function Create_And_Populate
      (Low_Key   : Integer;
       High_Key  : Integer;
-      Init_Size : Positive) return Instance;
+      Init_Size : Positive) return Dynamic_Hash_Table;
    --  Create a hash table with initial size Init_Size and populate it with
    --  key-value pairs where both keys and values are in the range Low_Key
    --  .. High_Key.
 
    procedure Check_Empty
      (Caller    : String;
-      T         : Instance;
+      T         : Dynamic_Hash_Table;
       Low_Key   : Integer;
       High_Key  : Integer);
    --  Ensure that
@@ -45,12 +47,14 @@ procedure Dynhash is
    --  Ensure that iterator Iter visits every key in the range Low_Key ..
    --  High_Key exactly once.
 
-   procedure Check_Locked_Mutations (Caller : String; T : in out Instance);
+   procedure Check_Locked_Mutations
+     (Caller : String;
+      T      : in out Dynamic_Hash_Table);
    --  Ensure that all mutation operations of hash table T are locked
 
    procedure Check_Size
      (Caller    : String;
-      T         : Instance;
+      T         : Dynamic_Hash_Table;
       Exp_Count : Natural);
    --  Ensure that the count of key-value pairs of hash table T matches
    --  expected count Exp_Count. Emit an error if this is not the case.
@@ -134,9 +138,9 @@ procedure Dynhash is
    function Create_And_Populate
      (Low_Key   : Integer;
       High_Key  : Integer;
-      Init_Size : Positive) return Instance
+      Init_Size : Positive) return Dynamic_Hash_Table
    is
-      T : Instance;
+      T : Dynamic_Hash_Table;
 
    begin
       T := Create (Init_Size);
@@ -154,7 +158,7 @@ procedure Dynhash is
 
    procedure Check_Empty
      (Caller    : String;
-      T         : Instance;
+      T         : Dynamic_Hash_Table;
       Low_Key   : Integer;
       High_Key  : Integer)
    is
@@ -227,7 +231,10 @@ procedure Dynhash is
    -- Check_Locked_Mutations --
    ----------------------------
 
-   procedure Check_Locked_Mutations (Caller : String; T : in out Instance) is
+   procedure Check_Locked_Mutations
+     (Caller : String;
+      T      : in out Dynamic_Hash_Table)
+   is
    begin
       begin
          Delete (T, 1);
@@ -276,7 +283,7 @@ procedure Dynhash is
 
    procedure Check_Size 
      (Caller    : String;
-      T         : Instance;
+      T         : Dynamic_Hash_Table;
       Exp_Count : Natural)
    is
       Count : constant Natural := Size (T);
@@ -305,7 +312,7 @@ procedure Dynhash is
    procedure Test_Create (Init_Size : Positive) is
       Count : Natural;
       Iter  : Iterator;
-      T     : Instance;
+      T     : Dynamic_Hash_Table;
       Val   : Integer;
 
    begin
@@ -402,7 +409,7 @@ procedure Dynhash is
       Init_Size : Positive)
    is
       Exp_Val : Integer;
-      T       : Instance;
+      T       : Dynamic_Hash_Table;
       Val     : Integer;
 
    begin
@@ -483,7 +490,7 @@ procedure Dynhash is
    is
       Iter_1 : Iterator;
       Iter_2 : Iterator;
-      T      : Instance;
+      T      : Dynamic_Hash_Table;
 
    begin
       T := Create_And_Populate (Low_Key, High_Key, Init_Size);
@@ -552,7 +559,7 @@ procedure Dynhash is
    procedure Test_Iterate_Empty (Init_Size : Positive) is
       Iter : Iterator;
       Key  : Integer;
-      T    : Instance;
+      T    : Dynamic_Hash_Table;
 
    begin
       T := Create_And_Populate (0, -1, Init_Size);
@@ -599,7 +606,7 @@ procedure Dynhash is
    is
       Iter : Iterator;
       Key  : Integer;
-      T    : Instance;
+      T    : Dynamic_Hash_Table;
 
    begin
       T := Create_And_Populate (Low_Key, High_Key, Init_Size);
@@ -653,7 +660,7 @@ procedure Dynhash is
       Init_Size : Positive)
    is
       Key : constant Integer := 1;
-      T   : Instance;
+      T   : Dynamic_Hash_Table;
       Val : Integer;
 
    begin
@@ -687,7 +694,7 @@ procedure Dynhash is
       High_Key  : Integer;
       Init_Size : Positive)
    is
-      T : Instance;
+      T : Dynamic_Hash_Table;
 
    begin
       T := Create_And_Populate (Low_Key, High_Key, Init_Size);

gcc/testsuite/gnat.dg/dynhash1.adb

+--  { dg-do run }
+
 with Ada.Text_IO;          use Ada.Text_IO;
 with GNAT;                 use GNAT;
 with GNAT.Dynamic_HTables; use GNAT.Dynamic_HTables;
 
 procedure Dynhash1 is
+   procedure Destroy (Val : in out Integer) is null;
    function Hash (Key : Integer) return Bucket_Range_Type is
    begin
       return Bucket_Range_Type (Key);
    end Hash;
 
-   package Integer_Hash_Tables is new Dynamic_HTable
+   package Integer_Hash_Tables is new Dynamic_Hash_Tables
      (Key_Type              => Integer,
       Value_Type            => Integer,
       No_Value              => 0,
@@ -17,11 +20,12 @@ procedure Dynhash1 is
       Compression_Threshold => 0.3,
       Compression_Factor    => 2,
       "="                   => "=",
+      Destroy_Value         => Destroy,
       Hash                  => Hash);
    use Integer_Hash_Tables;
 
    Siz : Natural;
-   T   : Instance;
+   T   : Dynamic_Hash_Table;
 
 begin
    T := Create (8);