| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ C H 8 -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2022, 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 3, 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 COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- 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; Chain : Boolean := True); |
| -- Analyze a use package clause and control (through the Chain parameter) |
| -- whether to add N to the use clause chain for the name denoted within |
| -- use clause N in case we are reanalyzing a use clause because of stack |
| -- manipulation. |
| |
| procedure Analyze_Use_Type (N : Node_Id; Chain : Boolean := True); |
| -- Similar to Analyze_Use_Package except the Chain parameter applies to the |
| -- type within N's subtype mark Current_Use_Clause. |
| |
| 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. Clause |
| -- 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, |
| -- one candidate interpretation). On return, the Entity and Etype fields |
| -- are set. In the non-overloaded case, these are the correct entries. |
| -- In the overloaded case, the flag Is_Overloaded is set, Etype and Entity |
| -- refer to an arbitrary element of the overloads set, and the appropriate |
| -- entries have been added to the overloads table entry for the node. The |
| -- overloading will be disambiguated during type resolution. |
| -- |
| -- Note, when this is called during semantic analysis in the overloaded |
| -- case, the entity set will be the most recently declared homonym. In |
| -- particular, the caller may follow the homonym chain checking for all |
| -- entries in the current scope, and that will give all homonyms that are |
| -- declared before the point of call in the current scope. This is useful |
| -- for example in the processing for pragma Inline. |
| -- |
| -- Flag Errors_OK should be set when error diagnostics are desired. Flag |
| -- Marker_OK should be set when a N_Variable_Reference_Marker needs to be |
| -- generated for a SPARK object in order to detect elaboration issues. Flag |
| -- Reference_OK should be set when N must generate a cross reference. |
| |
| 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, they are set to the entity in the full declaration. If it |
| -- is an incomplete type associated with an interface visible through a |
| -- limited-with clause, whose full declaration has been seen, they are |
| -- set to the entity in the full declaration. Similarly, if the type is |
| -- private, it has received a full declaration, and we are in the private |
| -- part or body of the package, then the two fields are set to the entity |
| -- of the full declaration as well. This procedure also has special |
| -- processing for 'Class attribute references. |
| |
| function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean; |
| -- S is the entity of an open scope. This function determines if there is |
| -- an inner scope of S which is a loop (i.e. it appears somewhere in the |
| -- scope stack after S). |
| |
| 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). |
| |
| 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; |
| Force_Installation : Boolean := False); |
| -- 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). Force_Installation is used when called from |
| -- Analyze_Subunit.Re_Install_Use_Clauses to insure that, after the |
| -- analysis of the subunit, the parent's environment is again identical. |
| |
| procedure Mark_Use_Clauses (Id : Node_Or_Entity_Id); |
| -- Mark a given entity or node Id's relevant use clauses as effective, |
| -- including redundant ones and ones outside of the current scope. |
| |
| procedure Push_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. |
| |
| function Save_Scope_Stack |
| (Handle_Use : Boolean := True) return Elist_Id; |
| procedure Restore_Scope_Stack |
| (List : Elist_Id; |
| Handle_Use : Boolean := True); |
| -- These two subprograms 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. This is |
| -- achieved using a call to Save_Scope_Stack. On return, the contents |
| -- of the scope stack must be made accessible again with a call to |
| -- Restore_Scope_Stack. |
| -- |
| -- The flag Handle_Use indicates whether local use clauses must be removed |
| -- or installed. In the case of inlining of instance bodies, the visibility |
| -- handling is done fully in Inline_Instance_Body, and use clauses are |
| -- handled there. Save_Scope_Stack returns the list of entities which have |
| -- been temporarily removed from visibility; that list must be passed to |
| -- Restore_Scope_Stack to restore their visibility. |
| |
| 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. |
| |
| procedure Update_Use_Clause_Chain; |
| -- Called at the end of a declarative region to detect unused use type |
| -- clauses and maintain the Current_Use_Clause for type entities. |
| |
| procedure ws; |
| -- Debugging routine for use in gdb: dump all entities on scope stack |
| |
| procedure we (S : Entity_Id); |
| -- Debugging routine for use in gdb: dump all entities in given scope |
| |
| end Sem_Ch8; |
