g-dyntab.ads, [...]: Default for Table_Low_Bound.

2017-04-27  Bob Duff  <duff@adacore.com>

	* g-dyntab.ads, g-dyntab.adb: Default for Table_Low_Bound.
	Rename Empty --> Empty_Table_Ptr, and don't duplicate code for it.
	Free renames Init, since they do the same thing.
	* g-table.ads: Default for Table_Low_Bound.
	* table.ads: Default for Table_Low_Bound, Table_Initial, and
	Table_Increment.

From-SVN: r247324

gcc/ada/ChangeLog

 2017-04-27  Bob Duff  <duff@adacore.com>
 
+	* g-dyntab.ads, g-dyntab.adb: Default for Table_Low_Bound.
+	Rename Empty --> Empty_Table_Ptr, and don't duplicate code for it.
+	Free renames Init, since they do the same thing.
+	* g-table.ads: Default for Table_Low_Bound.
+	* table.ads: Default for Table_Low_Bound, Table_Initial, and
+	Table_Increment.
+
+2017-04-27  Bob Duff  <duff@adacore.com>
+
 	* g-dyntab.ads, g-dyntab.adb: Add assertions to subprograms that
 	can reallocate.
 	* atree.adb, elists.adb, fname-uf.adb, ghost.adb, inline.adb,

gcc/ada/g-dyntab.adb

@@ -38,9 +38,6 @@ with System;
 
 package body GNAT.Dynamic_Tables is
 
-   Empty : constant Table_Ptr :=
-             Empty_Table_Array_Ptr_To_Table_Ptr (Empty_Table_Array'Access);
-
    -----------------------
    -- Local Subprograms --
    -----------------------
@@ -117,32 +114,6 @@ package body GNAT.Dynamic_Tables is
    end For_Each;
 
    ----------
-   -- Free --
-   ----------
-
-   procedure Free (T : in out Instance) is
-      pragma Assert (not T.Locked);
-      subtype Alloc_Type is Table_Type (First .. T.P.Last_Allocated);
-      type Alloc_Ptr is access all Alloc_Type;
-
-      procedure Free is new Ada.Unchecked_Deallocation (Alloc_Type, Alloc_Ptr);
-      function To_Alloc_Ptr is
-        new Ada.Unchecked_Conversion (Table_Ptr, Alloc_Ptr);
-
-      Temp : Alloc_Ptr := To_Alloc_Ptr (T.Table);
-
-   begin
-      if T.Table = Empty then
-         pragma Assert (T.P = (Last_Allocated | Last => First - 1));
-         null;
-      else
-         Free (Temp);
-         T.Table := Empty;
-         T.P := (Last_Allocated | Last => First - 1);
-      end if;
-   end Free;
-
-   ----------
    -- Grow --
    ----------
 
@@ -169,7 +140,7 @@ package body GNAT.Dynamic_Tables is
       New_Allocated_Length : Table_Length_Type;
 
    begin
-      if T.Table = Empty then
+      if T.Table = Empty_Table_Ptr then
          New_Allocated_Length := Table_Length_Type (Table_Initial);
       else
          New_Allocated_Length :=
@@ -213,7 +184,7 @@ package body GNAT.Dynamic_Tables is
          New_Table : constant Alloc_Ptr := new Alloc_Type;
 
       begin
-         if T.Table /= Empty then
+         if T.Table /= Empty_Table_Ptr then
             New_Table (First .. T.P.Last) := Old_Table (First .. T.P.Last);
             Free (Old_Table);
          end if;
@@ -223,7 +194,7 @@ package body GNAT.Dynamic_Tables is
 
       pragma Assert (New_Last <= T.P.Last_Allocated);
       pragma Assert (T.Table /= null);
-      pragma Assert (T.Table /= Empty);
+      pragma Assert (T.Table /= Empty_Table_Ptr);
    end Grow;
 
    --------------------
@@ -241,9 +212,25 @@ package body GNAT.Dynamic_Tables is
    ----------
 
    procedure Init (T : in out Instance) is
-   begin
       pragma Assert (not T.Locked);
-      Free (T);
+      subtype Alloc_Type is Table_Type (First .. T.P.Last_Allocated);
+      type Alloc_Ptr is access all Alloc_Type;
+
+      procedure Free is new Ada.Unchecked_Deallocation (Alloc_Type, Alloc_Ptr);
+      function To_Alloc_Ptr is
+        new Ada.Unchecked_Conversion (Table_Ptr, Alloc_Ptr);
+
+      Temp : Alloc_Ptr := To_Alloc_Ptr (T.Table);
+
+   begin
+      if T.Table = Empty_Table_Ptr then
+         pragma Assert (T.P = (Last_Allocated | Last => First - 1));
+         null;
+      else
+         Free (Temp);
+         T.Table := Empty_Table_Ptr;
+         T.P := (Last_Allocated | Last => First - 1);
+      end if;
    end Init;
 
    --------------
@@ -253,7 +240,7 @@ package body GNAT.Dynamic_Tables is
    function Is_Empty (T : Instance) return Boolean is
       Result : constant Boolean := T.P.Last = Table_Low_Bound - 1;
    begin
-      pragma Assert (Result = (T.Table = Empty));
+      pragma Assert (Result = (T.Table = Empty_Table_Ptr));
       return Result;
    end Is_Empty;
 
@@ -277,7 +264,7 @@ package body GNAT.Dynamic_Tables is
       pragma Assert (Is_Empty (To));
       To := From;
 
-      From.Table            := Empty;
+      From.Table            := Empty_Table_Ptr;
       From.Locked           := False;
       From.P.Last_Allocated := Table_Low_Bound - 1;
       From.P.Last           := Table_Low_Bound - 1;
@@ -326,7 +313,7 @@ package body GNAT.Dynamic_Tables is
    begin
       if New_Last_Alloc < T.P.Last_Allocated then
          pragma Assert (T.P.Last < T.P.Last_Allocated);
-         pragma Assert (T.Table /= Empty);
+         pragma Assert (T.Table /= Empty_Table_Ptr);
 
          declare
             subtype Old_Alloc_Type is Table_Type (First .. Old_Last_Allocated);

gcc/ada/g-dyntab.ads

@@ -53,7 +53,7 @@ generic
    type Table_Component_Type is private;
    type Table_Index_Type     is range <>;
 
-   Table_Low_Bound   : Table_Index_Type;
+   Table_Low_Bound   : Table_Index_Type := Table_Index_Type'First;
    Table_Initial     : Positive := 8;
    Table_Increment   : Natural := 100;
    Release_Threshold : Natural := 0; -- size in bytes
@@ -153,12 +153,13 @@ package GNAT.Dynamic_Tables is
    Empty_Table_Array : aliased Empty_Table_Array_Type;
    function Empty_Table_Array_Ptr_To_Table_Ptr is
      new Ada.Unchecked_Conversion (Empty_Table_Array_Ptr, Table_Ptr);
+   Empty_Table_Ptr : constant Table_Ptr :=
+             Empty_Table_Array_Ptr_To_Table_Ptr (Empty_Table_Array'Access);
    --  End private use only. The above are used to initialize Table to point to
    --  an empty array.
 
    type Instance is record
-      Table : Table_Ptr :=
-                Empty_Table_Array_Ptr_To_Table_Ptr (Empty_Table_Array'Access);
+      Table : Table_Ptr := Empty_Table_Ptr;
       --  The table itself. The lower bound is the value of First. Logically
       --  the upper bound is the current value of Last (although the actual
       --  size of the allocated table may be larger than this). The program may
@@ -187,6 +188,8 @@ package GNAT.Dynamic_Tables is
    --  Reinitializes the table to empty. There is no need to call this before
    --  using a table; tables default to empty.
 
+   procedure Free (T : in out Instance) renames Init;
+
    function First return Table_Index_Type;
    pragma Inline (First);
    --  Export First as synonym for Table_Low_Bound (parallel with use of Last)
@@ -208,9 +211,6 @@ package GNAT.Dynamic_Tables is
    --  chunk of memory. In both cases current array values are not affected by
    --  this call.
 
-   procedure Free (T : in out Instance);
-   --  Same as Init
-
    procedure Set_Last (T : in out Instance; New_Val : Table_Last_Type);
    pragma Inline (Set_Last);
    --  This procedure sets Last to the indicated value. If necessary the table

gcc/ada/g-table.ads

@@ -49,7 +49,7 @@ generic
    type Table_Component_Type is private;
    type Table_Index_Type     is range <>;
 
-   Table_Low_Bound   : Table_Index_Type;
+   Table_Low_Bound   : Table_Index_Type := Table_Index_Type'First;
    Table_Initial     : Positive := 8;
    Table_Increment   : Natural := 100;
    Table_Name        : String := ""; -- for debugging printouts
@@ -70,6 +70,7 @@ package GNAT.Table is
    subtype Valid_Table_Index_Type is Tab.Valid_Table_Index_Type;
    subtype Table_Last_Type is Tab.Table_Last_Type;
    subtype Table_Type is Tab.Table_Type;
+   function "=" (X, Y : Table_Type) return Boolean renames Tab."=";
    subtype Big_Table_Type is Tab.Big_Table_Type;
 
    subtype Table_Ptr is Tab.Table_Ptr;
@@ -81,6 +82,7 @@ package GNAT.Table is
    function Is_Empty return Boolean;
 
    procedure Init;
+   procedure Free;
 
    function First return Table_Index_Type;
    pragma Inline (First);
@@ -90,8 +92,6 @@ package GNAT.Table is
 
    procedure Release;
 
-   procedure Free;
-
    procedure Set_Last (New_Val : Table_Last_Type);
    pragma Inline (Set_Last);
 

gcc/ada/table.ads

@@ -51,9 +51,9 @@ package Table is
       type Table_Component_Type is private;
       type Table_Index_Type     is range <>;
 
-      Table_Low_Bound   : Table_Index_Type;
-      Table_Initial     : Pos;
-      Table_Increment   : Nat;
+      Table_Low_Bound   : Table_Index_Type := Table_Index_Type'First;
+      Table_Initial     : Pos := 8;
+      Table_Increment   : Nat := 100;
       Table_Name        : String; -- for debugging printouts
       Release_Threshold : Nat := 0;