| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ C A S E -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1996-2005, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, USA. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Package containing the routines to process a list of discrete choices. |
| -- Such lists can occur in two different constructs: case statements and |
| -- record variants. We have factorized what used to be two very similar |
| -- sets of routines in one place. These are not currently used for the |
| -- aggregate case, since issues with nested aggregates make that case |
| -- substantially different. |
| |
| with Types; use Types; |
| |
| package Sem_Case is |
| |
| type Choice_Bounds is record |
| Lo : Node_Id; |
| Hi : Node_Id; |
| Node : Node_Id; |
| end record; |
| |
| type Choice_Table_Type is array (Pos range <>) of Choice_Bounds; |
| -- Table type used to sort the choices present in a case statement, |
| -- array aggregate or record variant. |
| |
| procedure No_OP (C : Node_Id); |
| -- The no-operation routine. Does absolutely nothing. Can be used |
| -- in the following generic for the parameter Proces_Empty_Choice. |
| |
| generic |
| with function Get_Alternatives (N : Node_Id) return List_Id; |
| -- Function needed to get to the actual list of case statement |
| -- alternatives, or array aggregate component associations or |
| -- record variants from which we can then access the actual lists |
| -- of discrete choices. N is the node for the original construct |
| -- ie a case statement, an array aggregate or a record variant. |
| |
| with function Get_Choices (A : Node_Id) return List_Id; |
| -- Given a case statement alternative, array aggregate component |
| -- association or record variant A we need different access functions |
| -- to get to the actual list of discrete choices. |
| |
| with procedure Process_Empty_Choice (Choice : Node_Id); |
| -- Processing to carry out for an empty Choice |
| |
| with procedure Process_Non_Static_Choice (Choice : Node_Id); |
| -- Processing to carry out for a non static Choice |
| |
| with procedure Process_Associated_Node (A : Node_Id); |
| -- Associated to each case alternative, aggregate component |
| -- association or record variant A there is a node or list of nodes |
| -- that need semantic processing. This routine implements that |
| -- processing. |
| |
| package Generic_Choices_Processing is |
| |
| function Number_Of_Choices (N : Node_Id) return Nat; |
| -- Iterates through the choices of N, (N can be a case statement, |
| -- array aggregate or record variant), counting all the Choice nodes |
| -- except for the Others choice. |
| |
| procedure Analyze_Choices |
| (N : Node_Id; |
| Subtyp : Entity_Id; |
| Choice_Table : out Choice_Table_Type; |
| Last_Choice : out Nat; |
| Raises_CE : out Boolean; |
| Others_Present : out Boolean); |
| -- From a case statement, array aggregate or record variant N, this |
| -- routine analyzes the corresponding list of discrete choices. |
| -- Subtyp is the subtype of the discrete choices. The type against |
| -- which the discrete choices must be resolved is its base type. |
| -- |
| -- On entry Choice_Table must be big enough to contain all the |
| -- discrete choices encountered. |
| -- |
| -- On exit Choice_Table contains all the static and non empty discrete |
| -- choices in sorted order. Last_Choice gives the position of the last |
| -- valid choice in Choice_Table, Choice_Table'First contains the first. |
| -- We can have Last_Choice < Choice_Table'Last for one (or several) of |
| -- the following reasons: |
| -- |
| -- (a) The list of choices contained a non static choice |
| -- |
| -- (b) The list of choices contained an empty choice |
| -- (something like "1 .. 0 => ") |
| -- |
| -- (c) One of the bounds of a discrete choice contains an |
| -- error or raises constraint error. |
| -- |
| -- In one of the bounds of a discrete choice raises a constraint |
| -- error the flag Raise_CE is set. |
| -- |
| -- Finally Others_Present is set to True if an Others choice is present |
| -- in the list of choices, and in this case the call also sets |
| -- Others_Discrete_Choices in the N_Others_Choice node. |
| |
| end Generic_Choices_Processing; |
| |
| end Sem_Case; |
