gcc/ada/sem_case.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S E M _ C A S E                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1996-2010, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 --  Package containing the routines to process a list of discrete choices.
  27 --  Such lists can occur in two different constructs: case statements and
  28 --  record variants. We have factorized what used to be two very similar
  29 --  sets of routines in one place. These are not currently used for the
  30 --  aggregate case, since issues with nested aggregates make that case
  31 --  substantially different.
  32
  33 with Types; use Types;
  34
  35 package Sem_Case is
  36
  37    procedure No_OP (C : Node_Id);
  38    --  The no-operation routine. Does absolutely nothing. Can be used
  39    --  in the following generic for the parameter Process_Empty_Choice.
  40
  41    generic
  42       with function Get_Alternatives (N : Node_Id) return List_Id;
  43       --  Function needed to get to the actual list of case statement
  44       --  alternatives, or array aggregate component associations or
  45       --  record variants from which we can then access the actual lists
  46       --  of discrete choices. N is the node for the original construct
  47       --  i.e. a case statement, an array aggregate or a record variant.
  48
  49       with function Get_Choices (A : Node_Id) return List_Id;
  50       --  Given a case statement alternative, array aggregate component
  51       --  association or record variant A we need different access functions
  52       --  to get to the actual list of discrete choices.
  53
  54       with procedure Process_Empty_Choice (Choice : Node_Id);
  55       --  Processing to carry out for an empty Choice
  56
  57       with procedure Process_Non_Static_Choice (Choice : Node_Id);
  58       --  Processing to carry out for a non static Choice
  59
  60       with procedure Process_Associated_Node (A : Node_Id);
  61       --  Associated with each case alternative, aggregate component
  62       --  association or record variant A there is a node or list of nodes
  63       --  that need semantic processing. This routine implements that
  64       --  processing.
  65
  66    package Generic_Choices_Processing is
  67
  68       procedure Analyze_Choices
  69         (N              : Node_Id;
  70          Subtyp         : Entity_Id;
  71          Raises_CE      : out Boolean;
  72          Others_Present : out Boolean);
  73       --  From a case expression, case statement, array aggregate or record
  74       --  variant N, this routine analyzes the corresponding list of discrete
  75       --  choices. Subtyp is the subtype of the discrete choices. The type
  76       --  against which the discrete choices must be resolved is its base type.
  77       --
  78       --  In one of the bounds of a discrete choice raises a constraint
  79       --  error the flag Raise_CE is set.
  80       --
  81       --  Finally Others_Present is set to True if an Others choice is present
  82       --  in the list of choices, and in this case the call also sets
  83       --  Others_Discrete_Choices in the N_Others_Choice node.
  84
  85    end Generic_Choices_Processing;
  86
  87 end Sem_Case;