1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Types; use Types;
30 -----------------------------------
31 -- Handling extensions of System --
32 -----------------------------------
34 -- For targets that define a much larger System package than given in
35 -- the RM, we use a child package containing additional declarations,
36 -- which is loaded when needed, and whose entities are conceptually
37 -- within System itself. The presence of this auxiliary package is
38 -- controlled with the pragma Extend_System. The following variable
39 -- holds the entity of the auxiliary package, to simplify the special
40 -- visibility rules that apply to it.
42 System_Aux_Id : Entity_Id := Empty;
48 procedure Analyze_Exception_Renaming (N : Node_Id);
49 procedure Analyze_Expanded_Name (N : Node_Id);
50 procedure Analyze_Generic_Function_Renaming (N : Node_Id);
51 procedure Analyze_Generic_Package_Renaming (N : Node_Id);
52 procedure Analyze_Generic_Procedure_Renaming (N : Node_Id);
53 procedure Analyze_Object_Renaming (N : Node_Id);
54 procedure Analyze_Package_Renaming (N : Node_Id);
55 procedure Analyze_Subprogram_Renaming (N : Node_Id);
56 procedure Analyze_Use_Package (N : Node_Id);
57 procedure Analyze_Use_Type (N : Node_Id);
60 -- Called at end of scope. On exit from blocks and bodies (subprogram,
61 -- package, task, and protected bodies), the name of the current scope
62 -- must be removed from the scope stack, and the local entities must be
63 -- removed from their homonym chains. On exit from record declarations,
64 -- from package specifications, and from tasks and protected type
65 -- specifications, more specialized procedures are invoked.
67 procedure End_Use_Clauses (Clause : Node_Id);
68 -- Invoked on scope exit, to undo the effect of local use clauses. Clause
69 -- is the first use-clause of a scope being exited. This can be the current
70 -- scope, or some enclosing scopes when building a clean environment to
71 -- compile an instance body for inlining.
73 procedure End_Use_Package (N : Node_Id);
74 procedure End_Use_Type (N : Node_Id);
75 -- Subsidiaries of End_Use_Clauses. Also called directly for use clauses
76 -- appearing in context clauses.
78 procedure Find_Direct_Name (N : Node_Id);
79 -- Given a direct name (Identifier or Operator_Symbol), this routine scans
80 -- the homonym chain for the name searching for corresponding visible
81 -- entities to find the referenced entity (or in the case of overloading),
82 -- entities. On return, the Entity and Etype fields are set. In the
83 -- non-overloaded case, these are the correct final entries. In the
84 -- overloaded case, Is_Overloaded is set, Etype and Entity refer to an
85 -- arbitrary element of the overloads set, and an appropriate list of
86 -- entries has been made in the overload interpretation table (to be
87 -- disambiguated in the resolve phase).
89 procedure Find_Selected_Component (N : Node_Id);
90 -- Resolve various cases of selected components, recognize expanded names
92 procedure Find_Type (N : Node_Id);
93 -- Perform name resolution, and verify that the name found is that of a
94 -- type. On return the Entity and Etype fields of the node N are set
95 -- appropriately. If it is an incomplete type whose full declaration has
96 -- been seen, they are set to the entity in the full declaration. If it
97 -- is an incomplete type associated with an interface visible through a
98 -- limited-with clause, whose full declaration has been seen, they are
99 -- set to the entity in the full declaration. Similarly, if the type is
100 -- private, it has received a full declaration, and we are in the private
101 -- part or body of the package, then the two fields are set to the entity
102 -- of the full declaration as well. This procedure also has special
103 -- processing for 'Class attribute references.
105 procedure Initialize;
106 -- Initializes data structures used for visibility analysis. Must be
107 -- called before analyzing each new main source program.
109 procedure Install_Use_Clauses
111 Force_Installation : Boolean := False);
112 -- Applies the use clauses appearing in a given declarative part,
113 -- when the corresponding scope has been placed back on the scope
114 -- stack after unstacking to compile a different context (subunit or
115 -- parent of generic body). Force_Installation is used when called from
116 -- Analyze_Subunit.Re_Install_Use_Clauses to insure that, after the
117 -- analysis of the subunit, the parent's environment is again identical.
119 function In_Open_Scopes (S : Entity_Id) return Boolean;
120 -- S is the entity of a scope. This function determines if this scope
121 -- is currently open (i.e. it appears somewhere in the scope stack).
123 procedure Push_Scope (S : Entity_Id);
124 -- Make new scope stack entry, pushing S, the entity for a scope
125 -- onto the top of the scope table. The current setting of the scope
126 -- suppress flags is saved for restoration on exit.
129 -- Remove top entry from scope stack, restoring the saved setting
130 -- of the scope suppress flags.
132 function Present_System_Aux (N : Node_Id := Empty) return Boolean;
133 -- Return True if the auxiliary system file has been successfully loaded.
134 -- Otherwise attempt to load it, using the name supplied by a previous
135 -- Extend_System pragma, and report on the success of the load.
136 -- If N is present, it is a selected component whose prefix is System,
137 -- or else a with-clause on system. N is absent when the function is
138 -- called to find the visibility of implicit operators.
140 procedure Restore_Scope_Stack (Handle_Use : Boolean := True);
141 procedure Save_Scope_Stack (Handle_Use : Boolean := True);
142 -- These two procedures are called from Semantics, when a unit U1 is
143 -- to be compiled in the course of the compilation of another unit U2.
144 -- This happens whenever Rtsfind is called. U1, the unit retrieved by
145 -- Rtsfind, must be compiled in its own context, and the current scope
146 -- stack containing U2 and local scopes must be made unreachable. On
147 -- return, the contents of the scope stack must be made accessible again.
148 -- The flag Handle_Use indicates whether local use clauses must be
149 -- removed/installed. In the case of inlining of instance bodies, the
150 -- visiblity handling is done fully in Inline_Instance_Body, and use
151 -- clauses are handled there.
153 procedure Set_Use (L : List_Id);
154 -- Find use clauses that are declarative items in a package declaration
155 -- and set the potentially use-visible flags of imported entities before
156 -- analyzing the corresponding package body.