------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 8 -- -- -- -- S p e c -- -- -- -- -- -- Copyright (C) 1992-2001 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Types; use Types; package Sem_Ch8 is ----------------------------------- -- Handling extensions of System -- ----------------------------------- -- For targets that define a much larger System package than given in -- the RM, we use a child package containing additional declarations, -- which is loaded when needed, and whose entities are conceptually -- within System itself. The presence of this auxiliary package is -- controlled with the pragma Extend_System. The following variable -- holds the entity of the auxiliary package, to simplify the special -- visibility rules that apply to it. System_Aux_Id : Entity_Id := Empty; ----------------- -- Subprograms -- ----------------- procedure Analyze_Exception_Renaming (N : Node_Id); procedure Analyze_Expanded_Name (N : Node_Id); procedure Analyze_Generic_Function_Renaming (N : Node_Id); procedure Analyze_Generic_Package_Renaming (N : Node_Id); procedure Analyze_Generic_Procedure_Renaming (N : Node_Id); procedure Analyze_Object_Renaming (N : Node_Id); procedure Analyze_Package_Renaming (N : Node_Id); procedure Analyze_Subprogram_Renaming (N : Node_Id); procedure Analyze_Use_Package (N : Node_Id); procedure Analyze_Use_Type (N : Node_Id); function Applicable_Use (Pack_Name : Node_Id) return Boolean; -- Common code to Use_One_Package and Set_Use, to determine whether -- use clause must be processed. Pack_Name is an entity name that -- references the package in question. procedure End_Scope; -- Called at end of scope. On exit from blocks and bodies (subprogram, -- package, task, and protected bodies), the name of the current scope -- must be removed from the scope stack, and the local entities must be -- removed from their homonym chains. On exit from record declarations, -- from package specifications, and from tasks and protected type -- specifications, more specialized procedures are invoked. procedure End_Use_Clauses (Clause : Node_Id); -- Invoked on scope exit, to undo the effect of local use clauses. U is -- the first Use clause of a scope being exited. This can be the current -- scope, or some enclosing scopes when building a clean environment to -- compile an instance body for inlining. procedure End_Use_Package (N : Node_Id); procedure End_Use_Type (N : Node_Id); -- Subsidiaries of End_Use_Clauses. Also called directly for use clauses -- appearing in context clauses. procedure Find_Direct_Name (N : Node_Id); -- Given a direct name (Identifier or Operator_Symbol), this routine -- scans the homonym chain for the name searching for corresponding -- visible entities to find the referenced entity (or in the case of -- overloading), entities. On return, the Entity, and Etype fields -- are set. In the non-overloaded case, these are the correct final -- entries. In the overloaded case, Is_Overloaded is set, Etype and -- Entity refer to an arbitrary element of the overloads set, and -- an appropriate list of entries has been made in the overload -- interpretation table (to be disambiguated in the resolve phase). procedure Find_Expanded_Name (N : Node_Id); -- Selected component is known to be expanded name. Verify legality -- of selector given the scope denoted by prefix. procedure Find_Selected_Component (N : Node_Id); -- Resolve various cases of selected components, recognize expanded names procedure Find_Type (N : Node_Id); -- Perform name resolution, and verify that the name found is that of a -- type. On return the Entity and Etype fields of the node N are set -- appropriately. If it is an incomplete type whose full declaration has -- been seen, return the entity in the full declaration. Similarly, if -- the type is private, it has receivd a full declaration, and we are -- in the private part or body of the package, return the full -- declaration as well. Special processing for Class types as well. function Get_Full_View (T_Name : Entity_Id) return Entity_Id; -- If T_Name is an incomplete type and the full declaration has been -- seen, or is the name of a class_wide type whose root is incomplete. -- return the corresponding full declaration. function Has_Implicit_Operator (N : Node_Id) return Boolean; -- N is an expanded name whose selector is an operator name (eg P."+"). -- A declarative part contains an implicit declaration of an operator -- if it has a declaration of a type to which one of the predefined -- operators apply. The existence of this routine is an artifact of -- our implementation: a more straightforward but more space-consuming -- choice would be to make all inherited operators explicit in the -- symbol table. procedure Initialize; -- Initializes data structures used for visibility analysis. Must be -- called before analyzing each new main source program. procedure Install_Use_Clauses (Clause : Node_Id); -- applies the use clauses appearing in a given declarative part, -- when the corresponding scope has been placed back on the scope -- stack after unstacking to compile a different context (subunit or -- parent of generic body). function In_Open_Scopes (S : Entity_Id) return Boolean; -- S is the entity of a scope. This function determines if this scope -- is currently open (i.e. it appears somewhere in the scope stack). function Is_Appropriate_For_Record (T : Entity_Id) return Boolean; -- Prefix is appropriate for record if it is of a record type, or -- an access to such. function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean; -- True if it is of a task type, a protected type, or else an access -- to one of these types. procedure New_Scope (S : Entity_Id); -- Make new scope stack entry, pushing S, the entity for a scope -- onto the top of the scope table. The current setting of the scope -- suppress flags is saved for restoration on exit. procedure Pop_Scope; -- Remove top entry from scope stack, restoring the saved setting -- of the scope suppress flags. function Present_System_Aux (N : Node_Id := Empty) return Boolean; -- Return True if the auxiliary system file has been successfully loaded. -- Otherwise attempt to load it, using the name supplied by a previous -- Extend_System pragma, and report on the success of the load. -- If N is present, it is a selected component whose prefix is System, -- or else a with-clause on system. N is absent when the function is -- called to find the visibility of implicit operators. procedure Restore_Scope_Stack; procedure Save_Scope_Stack; -- These two procedures are called from Semantics, when a unit U1 is -- to be compiled in the course of the compilation of another unit U2. -- This happens whenever Rtsfind is called. U1, the unit retrieved by -- Rtsfind, must be compiled in its own context, and the current scope -- stack containing U2 and local scopes must be made unreachable. On -- return, the contents of the scope stack must be made accessible again. procedure Use_One_Package (P : Entity_Id; N : Node_Id); -- Make visible entities declarated in package P potentially use-visible -- in the current context. Also used in the analysis of subunits, when -- re-installing use clauses of parent units. N is the use_clause that -- names P (and possibly other packages). procedure Use_One_Type (Id : Node_Id); -- Id is the subtype mark from a use type clause. This procedure makes -- the primitive operators of the type potentially use-visible. procedure Set_Use (L : List_Id); -- Find use clauses that are declarative items in a package declaration -- and set the potentially use-visible flags of imported entities before -- analyzing the corresponding package body. end Sem_Ch8;