constant in instantiations in GNAT/asis

constant in instantiations in GNAT/asis

[Chi-Hua Chen]

I am having trouble getting back the constants used in
generic instantiations from asis. For example, in a call
inside an instantiation that has three actuals: a variable
(X1), a constant (K1), and a literal, I get only the variable
and the constant when I call Function_Call_Parameters on
the call. K1 is no where to be found. (However, in the
assembly output, I do see the constant appears for the call.)

So is there a way I can get K1 for the call (other than going
back to the tree for the generic itself)?

Another perhaps related problem is when I try to get the
element_span_in_template (a gnat extension) for an aggregate
containing a constant, I get an exception

    Returned_List_Length =  3
    First part length = 2
    Second part length = 0
    Exception information: Exception name: CONSTRAINT_ERROR
    Message: asis-expressions.adb:1395 length check failed

Below is a small program extracted from
Ada.Numerics.Discrete_Random, from which I first encounter the
problem, with some modifications.

I am using GNAT 3.15p  (20020523).

Chi-Hua

========== random.ads ==========
generic
package Random is
    type Generator is limited private;
    procedure Reset(Gen : Generator);
private
    K1   : constant := 94_833_359;
    type Generator is limited record
       Gen_State : Integer;
    end record;
end Random;

========== random.adb ==========
package body Random is
    function Square_Mod_N (X, N, Z : Integer) return Integer;
    type Agg is
       record
          Field1 : Integer;
          Field2 : Integer;
          Field3 : Integer;
       end record;

    procedure Reset (Gen : Generator) is
       X1 : Integer;
       X2 : Integer;
       A1 : Agg;
    begin
       -- Only two items show up in function_call_parameters
       X1 := Square_Mod_N(X1, K1, X2);
       -- Exceptions in element_span_in_template span
       A1 := (X1, K1, 1);
       -- This one seems fine, though
       X1 := K1;
    end Reset;
    function Square_Mod_N (X, N, Z : Integer) return Integer is
    begin
       return 0;
    end Square_Mod_N;

end Random;

========== main.adb =========
with Random;
procedure Main is
    package Ada95_Random is new Random;
    G: Ada95_Random.Generator;
begin
    Ada95_Random.Reset(Gen=>G);
end Main;