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-- Semantic analysis.
-- Copyright (C) 2002, 2003, 2004, 2005 Tristan Gingold
--
-- GHDL is free software; you can redistribute it and/or modify it under
-- the terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 2, or (at your option) any later
-- version.
--
-- GHDL is distributed in the hope that it will be useful, but WITHOUT 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
-- along with GHDL; see the file COPYING. If not, write to the Free
-- Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-- 02111-1307, USA.
with Iirs; use Iirs;
with Types; use Types;
package Sem_Scopes is
-- The purpose of SEM_NAME package is to handle association between
-- identifiers and declarations.
-- Roughly speacking, it implements ch10 of LRM: scope and visibility.
--
-- Basic elements are: declarations and declarative region.
-- Declaration should be understood in the large meaning: any textual
-- construction declaring an identifier, which can be a label.
-- A declarative region contains declarations and possibly other
-- declarative regions.
--
-- Rules are scope, visibility and overloading.
--
-- Create and close a declarative region.
-- By closing a declarative region, all declarations made in this region
-- are discarded.
procedure Open_Declarative_Region;
procedure Close_Declarative_Region;
-- Add meaning DECL for its identifier to the current declarative region.
procedure Add_Name (Decl: Iir);
pragma Inline (Add_Name);
-- Add meaning DECL to the identifier IDENT.
-- POTENTIALLY is true if the identifier comes from a use clause.
procedure Add_Name (Decl: Iir; Ident : Name_Id; Potentially: Boolean);
-- Set the visible_flag of DECL to true.
procedure Name_Visible (Decl : Iir);
-- Replace the interpretation OLD of ID by DECL.
-- ID must have a uniq interpretation OLD (ie, it must not be overloaded).
-- The interpretation must have been done in the current scope.
--
-- This procedure is used when the meaning of a name is changed due to its
-- analysis, eg: when a concurrent_procedure_call_statement becomes
-- a component_instantiation_statement.
procedure Replace_Name (Id: Name_Id; Old : Iir; Decl: Iir);
-- Interpretation is a simply linked list of what an identifier means.
-- In LRM08 12.3 Visibility, the sentence is 'the declaration defines a
-- possible meaning of this occurrence'.
-- FIXME: replace Interpretation by Meaning.
type Name_Interpretation_Type is private;
-- Return true if INTER is a valid interpretation, ie has a corresponding
-- declaration. There are only two invalids interpretations, which
-- are declared just below as constants.
function Valid_Interpretation (Inter : Name_Interpretation_Type)
return Boolean;
pragma Inline (Valid_Interpretation);
-- This pseudo interpretation marks the end of the interpretation chain,
-- and means there is no (more) interpretations for the name.
-- Unless you need to discriminate between an absence of declaration and
-- a conflict between potential declarations, you should use the
-- VALID_INTERPRETATION function.
No_Name_Interpretation : constant Name_Interpretation_Type;
-- This pseudo interpretation means the name has only conflicting potential
-- declarations, and also terminates the chain of interpretations.
-- Unless you need to discriminate between an absence of declaration and
-- a conflict between potential declarations, you should use the
-- VALID_INTERPRETATION function.
Conflict_Interpretation : constant Name_Interpretation_Type;
-- Get the first interpretation of identifier ID.
function Get_Interpretation (Id: Name_Id) return Name_Interpretation_Type;
pragma Inline (Get_Interpretation);
-- Get the next interpretation from an interpretation.
function Get_Next_Interpretation (Ni: Name_Interpretation_Type)
return Name_Interpretation_Type;
pragma Inline (Get_Next_Interpretation);
-- Get a declaration associated with an interpretation.
function Get_Declaration (Ni: Name_Interpretation_Type) return Iir;
pragma Inline (Get_Declaration);
-- Same as Get_Declaration, but get the name of non-object alias.
-- (ie, can never returns an object alias).
function Get_Non_Alias_Declaration (Ni: Name_Interpretation_Type)
return Iir;
-- Get the previous interpretation of identifier ID, ie the interpretation
-- for ID before the current interpretation of ID.
function Get_Under_Interpretation (Id : Name_Id)
return Name_Interpretation_Type;
-- Return TRUE if INTER was made directly visible via a use clause.
function Is_Potentially_Visible (Inter: Name_Interpretation_Type)
return Boolean;
pragma Inline (Is_Potentially_Visible);
-- Return TRUE if INTER was made direclty visible in the current
-- declarative region. Note this is different from being declared in the
-- current declarative region because of use clauses.
function Is_In_Current_Declarative_Region (Inter: Name_Interpretation_Type)
return Boolean;
pragma Inline (Is_In_Current_Declarative_Region);
-- Push and pop all interpretations.
-- This can be used to suspend name interpretation, in case of recursive
-- semantics.
-- After a push, all names have no_name_interpretation.
-- Pop restore the previous state.
procedure Pop_Interpretations;
procedure Push_Interpretations;
-- Execute a use clause on NAME.
-- Make potentially directly visible declarations of NAMES.
--procedure Use_Selected_Name (Name : Iir);
procedure Use_All_Names (Name: Iir);
-- Achieves visibility of the selected_name of use clause CLAUSE.
procedure Add_Use_Clause (Clause : Iir_Use_Clause);
-- Add declarations for a context clause into the current declarative
-- regions.
procedure Add_Context_Clauses (Unit : Iir_Design_Unit);
-- Add declarations from an entity into the current declarative region.
-- This is needed when an architecture is analysed.
procedure Add_Entity_Declarations (Entity : Iir_Entity_Declaration);
-- Add declarations from a package into the current declarative region.
-- This is needed when a package body is analysed.
-- FIXME: this must be done as if the declarative region was extended.
procedure Add_Package_Declarations (Decl: Iir_Package_Declaration);
-- Add interfaces declaration of a component into the current declarative
-- region.
procedure Add_Component_Declarations
(Component : Iir_Component_Declaration);
-- Add declarations from a protected type declaration into the current
-- declaration region (which is expected to be the region of the protected
-- type body).
procedure Add_Protected_Type_Declarations
(Decl : Iir_Protected_Type_Declaration);
-- Add declarations of interface chain CHAIN into the current
-- declarative region.
procedure Add_Declarations_From_Interface_Chain (Chain : Iir);
-- Add all declarations for concurrent statements declared in PARENT.
procedure Add_Declarations_Of_Concurrent_Statement (Parent : Iir);
-- Add declarations of a declaration chain CHAIN.
procedure Add_Declarations (Chain : Iir; Potentially : Boolean := False);
-- Scope extension area contains declarations from another declarative
-- region. These area are abstract and only used to be able to add
-- and remove declarations.
procedure Open_Scope_Extension;
procedure Close_Scope_Extension;
-- Add any declarations that include the end of the declarative part of
-- the given block BLOCK. This follow rules of LRM93 10.2
-- FIXME: BLOCK must be an architecture at first, then blocks declared
-- inside this architecture, then a block declared inside this block...
-- This procedure must be called after an Open_Scope_Extension and
-- declarations added can be removed with Close_Scope_Extension.
procedure Extend_Scope_Of_Block_Declarations (Decl : Iir);
-- Call HANDLE_DECL for each declaration found in DECL.
-- This will generally call HANDLE_DECL with DECL.
-- For types, HANDLE_DECL is first called with the type declaration, then
-- with implicit functions, with element literals for enumeration type,
-- and units for physical type.
generic
type Arg_Type is private;
with procedure Handle_Decl (Decl : Iir; Arg : Arg_Type);
procedure Iterator_Decl (Decl : Iir; Arg : Arg_Type);
-- Call HANDLE_DECL for each declaration found in DECL_LIST.
-- Generally, HANDLE_DECL must be an ITERATOR_DECL; this is not
-- automatically done, since the user might be interested in using the
-- ITERATOR_DECL.
generic
type Arg_Type is private;
with procedure Handle_Decl (Decl : Iir; Arg : Arg_Type);
procedure Iterator_Decl_List (Decl_List : Iir_List; Arg : Arg_Type);
generic
type Arg_Type is private;
with procedure Handle_Decl (Decl : Iir; Arg : Arg_Type);
procedure Iterator_Decl_Chain (Chain_First : Iir; Arg : Arg_Type);
private
type Name_Interpretation_Type is new Int32 range 0 .. (2 ** 30) - 1;
No_Name_Interpretation : constant Name_Interpretation_Type := 0;
Conflict_Interpretation : constant Name_Interpretation_Type := 1;
First_Valid_Interpretation : constant Name_Interpretation_Type := 2;
end Sem_Scopes;
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