[Ada] Simplify Big_Integer and Big_Real interface

2019-12-18  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/

	* libgnat/a-nbnbin.ads, libgnat/a-nbnbin.adb,
	libgnat/a-nbnbre.ads, libgnat/a-nbnbre.adb: Replace
	Optional_Big_* types by a simple check and exception raise in
	Get_Bignum.
	(Set_Bignum): Arg should be 'out' and not 'in out'.
	(Invalid_Big_Integer, No_Big_Real): Removed.
	(Is_Valid): Now convention Intrinsic.

From-SVN: r279515

gcc/ada/ChangeLog

+2019-12-18  Arnaud Charlet  <charlet@adacore.com>
+
+	* libgnat/a-nbnbin.ads, libgnat/a-nbnbin.adb,
+	libgnat/a-nbnbre.ads, libgnat/a-nbnbre.adb: Replace
+	Optional_Big_* types by a simple check and exception raise in
+	Get_Bignum.
+	(Set_Bignum): Arg should be 'out' and not 'in out'.
+	(Invalid_Big_Integer, No_Big_Real): Removed.
+	(Is_Valid): Now convention Intrinsic.
+
 2019-12-18  Piotr Trojanek  <trojanek@adacore.com>
 
 	* doc/gnat_rm/implementation_defined_pragmas.rst,

gcc/ada/libgnat/a-nbnbin.adb

@@ -44,11 +44,14 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
 
    procedure Free is new Ada.Unchecked_Deallocation (Bignum_Data, Bignum);
 
-   function Get_Bignum (Arg : Optional_Big_Integer) return Bignum is
-     (To_Bignum (Arg.Value.C));
-   --  Return the Bignum value stored in Arg
-
-   procedure Set_Bignum (Arg : in out Optional_Big_Integer; Value : Bignum)
+   function Get_Bignum (Arg : Big_Integer) return Bignum is
+     (if Arg.Value.C = System.Null_Address
+      then raise Constraint_Error with "invalid big integer"
+      else To_Bignum (Arg.Value.C));
+   --  Check for validity of Arg and return the Bignum value stored in Arg.
+   --  Raise Constraint_Error if Arg is uninitialized.
+
+   procedure Set_Bignum (Arg : out Big_Integer; Value : Bignum)
      with Inline;
    --  Set the Bignum value stored in Arg to Value
 
@@ -56,7 +59,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -- Set_Bignum --
    ----------------
 
-   procedure Set_Bignum (Arg : in out Optional_Big_Integer; Value : Bignum) is
+   procedure Set_Bignum (Arg : out Big_Integer; Value : Bignum) is
    begin
       Arg.Value.C := To_Address (Value);
    end Set_Bignum;
@@ -65,16 +68,9 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -- Is_Valid --
    --------------
 
-   function Is_Valid (Arg : Optional_Big_Integer) return Boolean is
+   function Is_Valid (Arg : Big_Integer) return Boolean is
      (Arg.Value.C /= System.Null_Address);
 
-   --------------------------
-   -- Invalid_Big_Integer --
-   --------------------------
-
-   function Invalid_Big_Integer return Optional_Big_Integer is
-     (Value => (Ada.Finalization.Controlled with C => System.Null_Address));
-
    ---------
    -- "=" --
    ---------
@@ -125,7 +121,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    --------------------
 
    function To_Big_Integer (Arg : Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, To_Bignum (Long_Long_Integer (Arg)));
       return Result;
@@ -151,7 +147,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
       --------------------
 
       function To_Big_Integer (Arg : Int) return Big_Integer is
-         Result : Optional_Big_Integer;
+         Result : Big_Integer;
       begin
          Set_Bignum (Result, To_Bignum (Long_Long_Integer (Arg)));
          return Result;
@@ -179,7 +175,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
       --------------------
 
       function To_Big_Integer (Arg : Int) return Big_Integer is
-         Result : Optional_Big_Integer;
+         Result : Big_Integer;
       begin
          Set_Bignum (Result, To_Bignum (Unsigned_64 (Arg)));
          return Result;
@@ -283,7 +279,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -----------------
 
    function From_String (Arg : String) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       --  ??? only support Long_Long_Integer, good enough for now
       Set_Bignum (Result, To_Bignum (Long_Long_Integer'Value (Arg)));
@@ -306,7 +302,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "+" (L : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, new Bignum_Data'(Get_Bignum (L).all));
       return Result;
@@ -317,7 +313,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "-" (L : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Neg (Get_Bignum (L)));
       return Result;
@@ -328,7 +324,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -----------
 
    function "abs" (L : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Abs (Get_Bignum (L)));
       return Result;
@@ -339,7 +335,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "+" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Add (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -350,7 +346,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "-" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Sub (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -361,7 +357,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "*" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Mul (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -372,7 +368,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ---------
 
    function "/" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Div (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -383,7 +379,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -----------
 
    function "mod" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Mod (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -394,7 +390,7 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    -----------
 
    function "rem" (L, R : Big_Integer) return Big_Integer is
-      Result : Optional_Big_Integer;
+      Result : Big_Integer;
    begin
       Set_Bignum (Result, Big_Rem (Get_Bignum (L), Get_Bignum (R)));
       return Result;
@@ -405,12 +401,23 @@ package body Ada.Numerics.Big_Numbers.Big_Integers is
    ----------
 
    function "**" (L : Big_Integer; R : Natural) return Big_Integer is
-      Exp    : Bignum := To_Bignum (Long_Long_Integer (R));
-      Result : Optional_Big_Integer;
    begin
-      Set_Bignum (Result, Big_Exp (Get_Bignum (L), Exp));
-      Free (Exp);
-      return Result;
+      --  Explicitly check for validity before allocating Exp so that
+      --  the call to Get_Bignum below cannot raise an exception before
+      --  we get a chance to free Exp.
+
+      if not Is_Valid (L) then
+         raise Constraint_Error with "invalid big integer";
+      end if;
+
+      declare
+         Exp    : Bignum := To_Bignum (Long_Long_Integer (R));
+         Result : Big_Integer;
+      begin
+         Set_Bignum (Result, Big_Exp (Get_Bignum (L), Exp));
+         Free (Exp);
+         return Result;
+      end;
    end "**";
 
    ---------

gcc/ada/libgnat/a-nbnbin.ads

@@ -25,19 +25,12 @@ package Ada.Numerics.Big_Numbers.Big_Integers
   with Preelaborate
 --  Nonblocking
 is
-   type Optional_Big_Integer is private
-     with Default_Initial_Condition => not Is_Valid (Optional_Big_Integer);
-   --       Integer_Literal => From_String,
+   type Big_Integer is private;
+   --  with Integer_Literal => From_String,
    --       Put_Image => Put_Image;
 
-   function Is_Valid (Arg : Optional_Big_Integer) return Boolean;
-
-   subtype Big_Integer is Optional_Big_Integer
-     with Dynamic_Predicate => Is_Valid (Big_Integer),
-          Predicate_Failure => (raise Constraint_Error);
-
-   function Invalid_Big_Integer return Optional_Big_Integer
-     with Post => not Is_Valid (Invalid_Big_Integer'Result);
+   function Is_Valid (Arg : Big_Integer) return Boolean
+     with Convention => Intrinsic;
 
    function "=" (L, R : Big_Integer) return Boolean;
 
@@ -51,18 +44,6 @@ is
 
    function To_Big_Integer (Arg : Integer) return Big_Integer;
 
-   subtype Optional_Big_Positive is Optional_Big_Integer
-     with Dynamic_Predicate =>
-            (not Is_Valid (Optional_Big_Positive))
-             or else (Optional_Big_Positive > To_Big_Integer (0)),
-          Predicate_Failure => (raise Constraint_Error);
-
-   subtype Optional_Big_Natural is Optional_Big_Integer
-     with Dynamic_Predicate =>
-            (not Is_Valid (Optional_Big_Natural))
-             or else (Optional_Big_Natural >= To_Big_Integer (0)),
-          Predicate_Failure => (raise Constraint_Error);
-
    subtype Big_Positive is Big_Integer
      with Dynamic_Predicate => Big_Positive > To_Big_Integer (0),
           Predicate_Failure => (raise Constraint_Error);
@@ -157,7 +138,7 @@ private
    procedure Adjust   (This : in out Controlled_Bignum);
    procedure Finalize (This : in out Controlled_Bignum);
 
-   type Optional_Big_Integer is record
+   type Big_Integer is record
       Value : Controlled_Bignum;
    end record;
 

gcc/ada/libgnat/a-nbnbre.adb

@@ -45,22 +45,15 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    -- Is_Valid --
    --------------
 
-   function Is_Valid (Arg : Optional_Big_Real) return Boolean is
+   function Is_Valid (Arg : Big_Real) return Boolean is
      (Is_Valid (Arg.Num) and then Is_Valid (Arg.Den));
 
-   -----------------
-   -- No_Big_Real --
-   -----------------
-
-   function No_Big_Real return Optional_Big_Real is
-     (Num => Invalid_Big_Integer, Den => Invalid_Big_Integer);
-
    ---------
    -- "/" --
    ---------
 
    function "/" (Num, Den : Big_Integer) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       if Den = To_Big_Integer (0) then
          raise Constraint_Error with "divide by zero";
@@ -323,7 +316,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
 
    function From_String (Arg : String) return Big_Real is
       Ten   : constant Big_Integer := To_Big_Integer (10);
-      Frac  : Optional_Big_Integer;
+      Frac  : Big_Integer;
       Exp   : Integer := 0;
       Pow   : Natural := 0;
       Index : Natural := 0;
@@ -353,7 +346,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
       end if;
 
       declare
-         Result : Optional_Big_Real;
+         Result : Big_Real;
       begin
          Result.Den := Ten ** Pow;
          Result.Num := From_String (Arg (Arg'First .. Index)) * Result.Den;
@@ -414,7 +407,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ---------
 
    function "+" (L : Big_Real) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       Result.Num := L.Num;
       Result.Den := L.Den;
@@ -440,7 +433,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ---------
 
    function "+" (L, R : Big_Real) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       Result.Num := L.Num * R.Den + R.Num * L.Den;
       Result.Den := L.Den * R.Den;
@@ -453,7 +446,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ---------
 
    function "-" (L, R : Big_Real) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       Result.Num := L.Num * R.Den - R.Num * L.Den;
       Result.Den := L.Den * R.Den;
@@ -466,7 +459,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ---------
 
    function "*" (L, R : Big_Real) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       Result.Num := L.Num * R.Num;
       Result.Den := L.Den * R.Den;
@@ -479,7 +472,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ---------
 
    function "/" (L, R : Big_Real) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       Result.Num := L.Num * R.Den;
       Result.Den := L.Den * R.Num;
@@ -492,7 +485,7 @@ package body Ada.Numerics.Big_Numbers.Big_Reals is
    ----------
 
    function "**" (L : Big_Real; R : Integer) return Big_Real is
-      Result : Optional_Big_Real;
+      Result : Big_Real;
    begin
       if R = 0 then
          Result.Num := To_Big_Integer (1);

gcc/ada/libgnat/a-nbnbre.ads

@@ -23,19 +23,11 @@ package Ada.Numerics.Big_Numbers.Big_Reals
   with Preelaborate
 --  Nonblocking, Global => in out synchronized Big_Reals
 is
-   type Optional_Big_Real is private with
-     Default_Initial_Condition => not Is_Valid (Optional_Big_Real);
---   Real_Literal => From_String,
---   Put_Image => Put_Image;
+   type Big_Real is private;
+--   with Real_Literal => From_String,
+--        Put_Image    => Put_Image;
 
-   function Is_Valid (Arg : Optional_Big_Real) return Boolean;
-
-   function No_Big_Real return Optional_Big_Real
-     with Post => not Is_Valid (No_Big_Real'Result);
-
-   subtype Big_Real is Optional_Big_Real
-     with Dynamic_Predicate => Is_Valid (Big_Real),
-          Predicate_Failure => (raise Constraint_Error);
+   function Is_Valid (Arg : Big_Real) return Boolean;
 
    function "/" (Num, Den : Big_Integers.Big_Integer) return Big_Real;
 --   with Pre => (if Big_Integers."=" (Den, Big_Integers.To_Big_Integer (0))
@@ -139,8 +131,8 @@ is
 
 private
 
-   type Optional_Big_Real is record
-      Num, Den : Big_Integers.Optional_Big_Integer;
+   type Big_Real is record
+      Num, Den : Big_Integers.Big_Integer;
    end record;
 
 end Ada.Numerics.Big_Numbers.Big_Reals;