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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M . C H 8 --
-- --
-- B o d y --
-- --
-- $Revision: 1.3 $
-- --
-- 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. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Util; use Exp_Util;
with Fname; use Fname;
with Freeze; use Freeze;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch4; use Sem_Ch4;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch12; use Sem_Ch12;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.CN; use Sinfo.CN;
with Snames; use Snames;
with Style; use Style;
with Table;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
package body Sem_Ch8 is
------------------------------------
-- Visibility and Name Resolution --
------------------------------------
-- This package handles name resolution and the collection of
-- interpretations for overloaded names, prior to overload resolution.
-- Name resolution is the process that establishes a mapping between source
-- identifiers and the entities they denote at each point in the program.
-- Each entity is represented by a defining occurrence. Each identifier
-- that denotes an entity points to the corresponding defining occurrence.
-- This is the entity of the applied occurrence. Each occurrence holds
-- an index into the names table, where source identifiers are stored.
-- Each entry in the names table for an identifier or designator uses the
-- Info pointer to hold a link to the currently visible entity that has
-- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
-- in package Sem_Util). The visibility is initialized at the beginning of
-- semantic processing to make entities in package Standard immediately
-- visible. The visibility table is used in a more subtle way when
-- compiling subunits (see below).
-- Entities that have the same name (i.e. homonyms) are chained. In the
-- case of overloaded entities, this chain holds all the possible meanings
-- of a given identifier. The process of overload resolution uses type
-- information to select from this chain the unique meaning of a given
-- identifier.
-- Entities are also chained in their scope, through the Next_Entity link.
-- As a consequence, the name space is organized as a sparse matrix, where
-- each row corresponds to a scope, and each column to a source identifier.
-- Open scopes, that is to say scopes currently being compiled, have their
-- corresponding rows of entities in order, innermost scope first.
-- The scopes of packages that are mentioned in context clauses appear in
-- no particular order, interspersed among open scopes. This is because
-- in the course of analyzing the context of a compilation, a package
-- declaration is first an open scope, and subsequently an element of the
-- context. If subunits or child units are present, a parent unit may
-- appear under various guises at various times in the compilation.
-- When the compilation of the innermost scope is complete, the entities
-- defined therein are no longer visible. If the scope is not a package
-- declaration, these entities are never visible subsequently, and can be
-- removed from visibility chains. If the scope is a package declaration,
-- its visible declarations may still be accessible. Therefore the entities
-- defined in such a scope are left on the visibility chains, and only
-- their visibility (immediately visibility or potential use-visibility)
-- is affected.
-- The ordering of homonyms on their chain does not necessarily follow
-- the order of their corresponding scopes on the scope stack. For
-- example, if package P and the enclosing scope both contain entities
-- named E, then when compiling the package body the chain for E will
-- hold the global entity first, and the local one (corresponding to
-- the current inner scope) next. As a result, name resolution routines
-- do not assume any relative ordering of the homonym chains, either
-- for scope nesting or to order of appearance of context clauses.
-- When compiling a child unit, entities in the parent scope are always
-- immediately visible. When compiling the body of a child unit, private
-- entities in the parent must also be made immediately visible. There
-- are separate routines to make the visible and private declarations
-- visible at various times (see package Sem_Ch7).
-- +--------+ +-----+
-- | In use |-------->| EU1 |-------------------------->
-- +--------+ +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
-- +--------+ +-----+ +-----+
-- | |
-- +---------+ | +-----+
-- | with'ed |------------------------------>| EW2 |--->
-- +---------+ | +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Scope2 |---------------->| E12 |--------------->| E22 |--->
-- +--------+ +-----+ +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Scope1 |---------------->| E11 |--------------->| E12 |--->
-- +--------+ +-----+ +-----+
-- ^ | |
-- | | |
-- | +---------+ | |
-- | | with'ed |----------------------------------------->
-- | +---------+ | |
-- | | |
-- Scope stack | |
-- (innermost first) | |
-- +----------------------------+
-- Names table => | Id1 | | | | Id2 |
-- +----------------------------+
-- Name resolution must deal with several syntactic forms: simple names,
-- qualified names, indexed names, and various forms of calls.
-- Each identifier points to an entry in the names table. The resolution
-- of a simple name consists in traversing the homonym chain, starting
-- from the names table. If an entry is immediately visible, it is the one
-- designated by the identifier. If only potemtially use-visible entities
-- are on the chain, we must verify that they do not hide each other. If
-- the entity we find is overloadable, we collect all other overloadable
-- entities on the chain as long as they are not hidden.
--
-- To resolve expanded names, we must find the entity at the intersection
-- of the entity chain for the scope (the prefix) and the homonym chain
-- for the selector. In general, homonym chains will be much shorter than
-- entity chains, so it is preferable to start from the names table as
-- well. If the entity found is overloadable, we must collect all other
-- interpretations that are defined in the scope denoted by the prefix.
-- For records, protected types, and tasks, their local entities are
-- removed from visibility chains on exit from the corresponding scope.
-- From the outside, these entities are always accessed by selected
-- notation, and the entity chain for the record type, protected type,
-- etc. is traversed sequentially in order to find the designated entity.
-- The discriminants of a type and the operations of a protected type or
-- task are unchained on exit from the first view of the type, (such as
-- a private or incomplete type declaration, or a protected type speci-
-- fication) and rechained when compiling the second view.
-- In the case of operators, we do not make operators on derived types
-- explicit. As a result, the notation P."+" may denote either a user-
-- defined function with name "+", or else an implicit declaration of the
-- operator "+" in package P. The resolution of expanded names always
-- tries to resolve an operator name as such an implicitly defined entity,
-- in addition to looking for explicit declarations.
-- All forms of names that denote entities (simple names, expanded names,
-- character literals in some cases) have a Entity attribute, which
-- identifies the entity denoted by the name.
---------------------
-- The Scope Stack --
---------------------
-- The Scope stack keeps track of the scopes currently been compiled.
-- Every entity that contains declarations (including records) is placed
-- on the scope stack while it is being processed, and removed at the end.
-- Whenever a non-package scope is exited, the entities defined therein
-- are removed from the visibility table, so that entities in outer scopes
-- become visible (see previous description). On entry to Sem, the scope
-- stack only contains the package Standard. As usual, subunits complicate
-- this picture ever so slightly.
-- The Rtsfind mechanism can force a call to Semantics while another
-- compilation is in progress. The unit retrieved by Rtsfind must be
-- compiled in its own context, and has no access to the visibility of
-- the unit currently being compiled. The procedures Save_Scope_Stack and
-- Restore_Scope_Stack make entities in current open scopes invisible
-- before compiling the retrieved unit, and restore the compilation
-- environment afterwards.
------------------------
-- Compiling subunits --
------------------------
-- Subunits must be compiled in the environment of the corresponding
-- stub, that is to say with the same visibility into the parent (and its
-- context) that is available at the point of the stub declaration, but
-- with the additional visibility provided by the context clause of the
-- subunit itself. As a result, compilation of a subunit forces compilation
-- of the parent (see description in lib-). At the point of the stub
-- declaration, Analyze is called recursively to compile the proper body
-- of the subunit, but without reinitializing the names table, nor the
-- scope stack (i.e. standard is not pushed on the stack). In this fashion
-- the context of the subunit is added to the context of the parent, and
-- the subunit is compiled in the correct environment. Note that in the
-- course of processing the context of a subunit, Standard will appear
-- twice on the scope stack: once for the parent of the subunit, and
-- once for the unit in the context clause being compiled. However, the
-- two sets of entities are not linked by homonym chains, so that the
-- compilation of any context unit happens in a fresh visibility
-- environment.
-------------------------------
-- Processing of USE Clauses --
-------------------------------
-- Every defining occurrence has a flag indicating if it is potentially use
-- visible. Resolution of simple names examines this flag. The processing
-- of use clauses consists in setting this flag on all visible entities
-- defined in the corresponding package. On exit from the scope of the use
-- clause, the corresponding flag must be reset. However, a package may
-- appear in several nested use clauses (pathological but legal, alas!)
-- which forces us to use a slightly more involved scheme:
-- a) The defining occurrence for a package holds a flag -In_Use- to
-- indicate that it is currently in the scope of a use clause. If a
-- redundant use clause is encountered, then the corresponding occurrence
-- of the package name is flagged -Redundant_Use-.
-- b) On exit from a scope, the use clauses in its declarative part are
-- scanned. The visibility flag is reset in all entities declared in
-- package named in a use clause, as long as the package is not flagged
-- as being in a redundant use clause (in which case the outer use
-- clause is still in effect, and the direct visibility of its entities
-- must be retained).
-- Note that entities are not removed from their homonym chains on exit
-- from the package specification. A subsequent use clause does not need
-- to rechain the visible entities, but only to establish their direct
-- visibility.
-----------------------------------
-- Handling private declarations --
-----------------------------------
-- The principle that each entity has a single defining occurrence clashes
-- with the presence of two separate definitions for private types: the
-- first is the private type declaration, and second is the full type
-- declaration. It is important that all references to the type point to
-- the same defining occurrence, namely the first one. To enforce the two
-- separate views of the entity, the corresponding information is swapped
-- between the two declarations. Outside of the package, the defining
-- occurrence only contains the private declaration information, while in
-- the private part and the body of the package the defining occurrence
-- contains the full declaration. To simplify the swap, the defining
-- occurrence that currently holds the private declaration points to the
-- full declaration. During semantic processing the defining occurrence
-- also points to a list of private dependents, that is to say access
-- types or composite types whose designated types or component types are
-- subtypes or derived types of the private type in question. After the
-- full declaration has been seen, the private dependents are updated to
-- indicate that they have full definitions.
------------------------------------
-- Handling of Undefined Messages --
------------------------------------
-- In normal mode, only the first use of an undefined identifier generates
-- a message. The table Urefs is used to record error messages that have
-- been issued so that second and subsequent ones do not generate further
-- messages. However, the second reference causes text to be added to the
-- original undefined message noting "(more references follow)". The
-- full error list option (-gnatf) forces messages to be generated for
-- every reference and disconnects the use of this table.
type Uref_Entry is record
Node : Node_Id;
-- Node for identifier for which original message was posted. The
-- Chars field of this identifier is used to detect later references
-- to the same identifier.
Err : Error_Msg_Id;
-- Records error message Id of original undefined message. Reset to
-- No_Error_Msg after the second occurrence, where it is used to add
-- text to the original message as described above.
Nvis : Boolean;
-- Set if the message is not visible rather than undefined
Loc : Source_Ptr;
-- Records location of error message. Used to make sure that we do
-- not consider a, b : undefined as two separate instances, which
-- would otherwise happen, since the parser converts this sequence
-- to a : undefined; b : undefined.
end record;
package Urefs is new Table.Table (
Table_Component_Type => Uref_Entry,
Table_Index_Type => Nat,
Table_Low_Bound => 1,
Table_Initial => 10,
Table_Increment => 100,
Table_Name => "Urefs");
Candidate_Renaming : Entity_Id;
-- Holds a candidate interpretation that appears in a subprogram renaming
-- declaration and does not match the given specification, but matches at
-- least on the first formal. Allows better error message when given
-- specification omits defaulted parameters, a common error.
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Generic_Renaming
(N : Node_Id;
K : Entity_Kind);
-- Common processing for all three kinds of generic renaming declarations.
-- Enter new name and indicate that it renames the generic unit.
procedure Analyze_Renamed_Character
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Renamed entity is given by a character literal, which must belong
-- to the return type of the new entity. Is_Body indicates whether the
-- declaration is a renaming_as_body. If the original declaration has
-- already been frozen (because of an intervening body, e.g.) the body of
-- the function must be built now. The same applies to the following
-- various renaming procedures.
procedure Analyze_Renamed_Dereference
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Renamed entity is given by an explicit dereference. Prefix must be a
-- conformant access_to_subprogram type.
procedure Analyze_Renamed_Entry
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- If the renamed entity in a subprogram renaming is an entry or protected
-- subprogram, build a body for the new entity whose only statement is a
-- call to the renamed entity.
procedure Analyze_Renamed_Family_Member
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Used when the renamed entity is an indexed component. The prefix must
-- denote an entry family.
procedure Attribute_Renaming (N : Node_Id);
-- Analyze renaming of attribute as function. The renaming declaration N
-- is rewritten as a function body that returns the attribute reference
-- applied to the formals of the function.
procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
-- A renaming_as_body may occur after the entity of the original decla-
-- ration has been frozen. In that case, the body of the new entity must
-- be built now, because the usual mechanism of building the renamed
-- body at the point of freezing will not work. Subp is the subprogram
-- for which N provides the Renaming_As_Body.
procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
-- Verify that the entity in a renaming declaration that is a library unit
-- is itself a library unit and not a nested unit or subunit. Also check
-- that if the renaming is a child unit of a generic parent, then the
-- renamed unit must also be a child unit of that parent. Finally, verify
-- that a renamed generic unit is not an implicit child declared within
-- an instance of the parent.
procedure Chain_Use_Clause (N : Node_Id);
-- Chain use clause onto list of uses clauses headed by First_Use_Clause
-- in the top scope table entry.
function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
-- Find a type derived from Character or Wide_Character in the prefix of N.
-- Used to resolved qualified names whose selector is a character literal.
function Find_Renamed_Entity
(N : Node_Id;
Nam : Node_Id;
New_S : Entity_Id;
Is_Actual : Boolean := False) return Entity_Id;
-- Find the renamed entity that corresponds to the given parameter profile
-- in a subprogram renaming declaration. The renamed entity may be an
-- operator, a subprogram, an entry, or a protected operation. Is_Actual
-- indicates that the renaming is the one generated for an actual subpro-
-- gram in an instance, for which special visibility checks apply.
procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
-- A subprogram defined by a renaming declaration inherits the parameter
-- profile of the renamed entity. The subtypes given in the subprogram
-- specification are discarded and replaced with those of the renamed
-- subprogram, which are then used to recheck the default values.
procedure Premature_Usage (N : Node_Id);
-- Diagnose usage of an entity before it is visible.
procedure Write_Info;
-- Write debugging information on entities declared in current scope
procedure Write_Scopes;
pragma Warnings (Off, Write_Scopes);
-- Debugging information: dump all entities on scope stack
--------------------------------
-- Analyze_Exception_Renaming --
--------------------------------
-- The language only allows a single identifier, but the tree holds
-- an identifier list. The parser has already issued an error message
-- if there is more than one element in the list.
procedure Analyze_Exception_Renaming (N : Node_Id) is
Id : constant Node_Id := Defining_Identifier (N);
Nam : constant Node_Id := Name (N);
begin
Enter_Name (Id);
Analyze (Nam);
Set_Ekind (Id, E_Exception);
Set_Exception_Code (Id, Uint_0);
Set_Etype (Id, Standard_Exception_Type);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
if not Is_Entity_Name (Nam) or else
Ekind (Entity (Nam)) /= E_Exception
then
Error_Msg_N ("invalid exception name in renaming", Nam);
else
if Present (Renamed_Object (Entity (Nam))) then
Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
else
Set_Renamed_Object (Id, Entity (Nam));
end if;
end if;
end Analyze_Exception_Renaming;
---------------------------
-- Analyze_Expanded_Name --
---------------------------
procedure Analyze_Expanded_Name (N : Node_Id) is
begin
-- If the entity pointer is already set, this is an internal node, or
-- a node that is analyzed more than once, after a tree modification.
-- In such a case there is no resolution to perform, just set the type.
-- For completeness, analyze prefix as well.
if Present (Entity (N)) then
if Is_Type (Entity (N)) then
Set_Etype (N, Entity (N));
else
Set_Etype (N, Etype (Entity (N)));
end if;
Analyze (Prefix (N));
return;
else
Find_Expanded_Name (N);
end if;
end Analyze_Expanded_Name;
----------------------------------------
-- Analyze_Generic_Function_Renaming --
----------------------------------------
procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
begin
Analyze_Generic_Renaming (N, E_Generic_Function);
end Analyze_Generic_Function_Renaming;
---------------------------------------
-- Analyze_Generic_Package_Renaming --
---------------------------------------
procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
begin
-- Apply the Text_IO Kludge here, since we may be renaming
-- one of the subpackages of Text_IO, then join common routine.
Text_IO_Kludge (Name (N));
Analyze_Generic_Renaming (N, E_Generic_Package);
end Analyze_Generic_Package_Renaming;
-----------------------------------------
-- Analyze_Generic_Procedure_Renaming --
-----------------------------------------
procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
begin
Analyze_Generic_Renaming (N, E_Generic_Procedure);
end Analyze_Generic_Procedure_Renaming;
------------------------------
-- Analyze_Generic_Renaming --
------------------------------
procedure Analyze_Generic_Renaming
(N : Node_Id;
K : Entity_Kind)
is
New_P : Entity_Id := Defining_Entity (N);
Old_P : Entity_Id;
Inst : Boolean := False; -- prevent junk warning
begin
if Name (N) = Error then
return;
end if;
Generate_Definition (New_P);
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_P, Is_Pure (Current_Scope));
end if;
if Nkind (Name (N)) = N_Selected_Component then
Check_Generic_Child_Unit (Name (N), Inst);
else
Analyze (Name (N));
end if;
if not Is_Entity_Name (Name (N)) then
Error_Msg_N ("expect entity name in renaming declaration", Name (N));
Old_P := Any_Id;
else
Old_P := Entity (Name (N));
end if;
Enter_Name (New_P);
Set_Ekind (New_P, K);
if Etype (Old_P) = Any_Type then
null;
elsif Ekind (Old_P) /= K then
Error_Msg_N ("invalid generic unit name", Name (N));
else
if Present (Renamed_Object (Old_P)) then
Set_Renamed_Object (New_P, Renamed_Object (Old_P));
else
Set_Renamed_Object (New_P, Old_P);
end if;
Set_Etype (New_P, Etype (Old_P));
Set_Has_Completion (New_P);
if In_Open_Scopes (Old_P) then
Error_Msg_N ("within its scope, generic denotes its instance", N);
end if;
Check_Library_Unit_Renaming (N, Old_P);
end if;
end Analyze_Generic_Renaming;
-----------------------------
-- Analyze_Object_Renaming --
-----------------------------
procedure Analyze_Object_Renaming (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
Dec : Node_Id;
Nam : constant Node_Id := Name (N);
S : constant Entity_Id := Subtype_Mark (N);
T : Entity_Id;
T2 : Entity_Id;
begin
if Nam = Error then
return;
end if;
Set_Is_Pure (Id, Is_Pure (Current_Scope));
Enter_Name (Id);
-- The renaming of a component that depends on a discriminant
-- requires an actual subtype, because in subsequent use of the object
-- Gigi will be unable to locate the actual bounds. This explicit step
-- is required when the renaming is generated in removing side effects
-- of an already-analyzed expression.
if Nkind (Nam) = N_Selected_Component
and then Analyzed (Nam)
then
T := Etype (Nam);
Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
if Present (Dec) then
Insert_Action (N, Dec);
T := Defining_Identifier (Dec);
Set_Etype (Nam, T);
end if;
else
Find_Type (S);
T := Entity (S);
Analyze_And_Resolve (Nam, T);
end if;
-- An object renaming requires an exact match of the type;
-- class-wide matching is not allowed.
if Is_Class_Wide_Type (T)
and then Base_Type (Etype (Nam)) /= Base_Type (T)
then
Wrong_Type (Nam, T);
end if;
T2 := Etype (Nam);
Set_Ekind (Id, E_Variable);
Init_Size_Align (Id);
if T = Any_Type or else Etype (Nam) = Any_Type then
return;
-- Verify that the renamed entity is an object or a function call.
-- It may have been rewritten in several ways.
elsif Is_Object_Reference (Nam) then
if Comes_From_Source (N)
and then Is_Dependent_Component_Of_Mutable_Object (Nam)
then
Error_Msg_N
("illegal renaming of discriminant-dependent component", Nam);
else
null;
end if;
-- A static function call may have been folded into a literal
elsif Nkind (Original_Node (Nam)) = N_Function_Call
-- When expansion is disabled, attribute reference is not
-- rewritten as function call. Otherwise it may be rewritten
-- as a conversion, so check original node.
or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
and then Is_Function_Attribute_Name
(Attribute_Name (Original_Node (Nam))))
-- Weird but legal, equivalent to renaming a function call.
or else (Is_Entity_Name (Nam)
and then Ekind (Entity (Nam)) = E_Enumeration_Literal)
or else (Nkind (Nam) = N_Type_Conversion
and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
then
null;
else
if Nkind (Nam) = N_Type_Conversion then
Error_Msg_N
("renaming of conversion only allowed for tagged types", Nam);
else
Error_Msg_N ("expect object name in renaming", Nam);
end if;
end if;
Set_Etype (Id, T2);
if not Is_Variable (Nam) then
Set_Ekind (Id, E_Constant);
Set_Not_Source_Assigned (Id, True);
Set_Is_True_Constant (Id, True);
end if;
Set_Renamed_Object (Id, Nam);
end Analyze_Object_Renaming;
------------------------------
-- Analyze_Package_Renaming --
------------------------------
procedure Analyze_Package_Renaming (N : Node_Id) is
New_P : constant Entity_Id := Defining_Entity (N);
Old_P : Entity_Id;
Spec : Node_Id;
begin
if Name (N) = Error then
return;
end if;
-- Apply Text_IO kludge here, since we may be renaming one of
-- the children of Text_IO
Text_IO_Kludge (Name (N));
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_P, Is_Pure (Current_Scope));
end if;
Enter_Name (New_P);
Analyze (Name (N));
if Is_Entity_Name (Name (N)) then
Old_P := Entity (Name (N));
else
Old_P := Any_Id;
end if;
if Etype (Old_P) = Any_Type then
Error_Msg_N
("expect package name in renaming", Name (N));
elsif Ekind (Old_P) /= E_Package
and then not (Ekind (Old_P) = E_Generic_Package
and then In_Open_Scopes (Old_P))
then
if Ekind (Old_P) = E_Generic_Package then
Error_Msg_N
("generic package cannot be renamed as a package", Name (N));
else
Error_Msg_Sloc := Sloc (Old_P);
Error_Msg_NE
("expect package name in renaming, found& declared#",
Name (N), Old_P);
end if;
-- Set basic attributes to minimize cascaded errors.
Set_Ekind (New_P, E_Package);
Set_Etype (New_P, Standard_Void_Type);
elsif Ekind (Old_P) = E_Package
and then From_With_Type (Old_P)
then
Error_Msg_N ("imported package cannot be renamed", Name (N));
else
-- Entities in the old package are accessible through the
-- renaming entity. The simplest implementation is to have
-- both packages share the entity list.
Set_Ekind (New_P, E_Package);
Set_Etype (New_P, Standard_Void_Type);
if Present (Renamed_Object (Old_P)) then
Set_Renamed_Object (New_P, Renamed_Object (Old_P));
else
Set_Renamed_Object (New_P, Old_P);
end if;
Set_Has_Completion (New_P);
Set_First_Entity (New_P, First_Entity (Old_P));
Set_Last_Entity (New_P, Last_Entity (Old_P));
Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
Check_Library_Unit_Renaming (N, Old_P);
Generate_Reference (Old_P, Name (N));
-- If this is the renaming declaration of a package instantiation
-- within itself, it is the declaration that ends the list of actuals
-- for the instantiation. At this point, the subtypes that rename
-- the actuals are flagged as generic, to avoid spurious ambiguities
-- if the actuals for two distinct formals happen to coincide. If
-- the actual is a private type, the subtype has a private completion
-- that is flagged in the same fashion.
-- Resolution is identical to what is was in the original generic.
-- On exit from the generic instance, these are turned into regular
-- subtypes again, so they are compatible with types in their class.
if not Is_Generic_Instance (Old_P) then
return;
else
Spec := Specification (Unit_Declaration_Node (Old_P));
end if;
if Nkind (Spec) = N_Package_Specification
and then Present (Generic_Parent (Spec))
and then Old_P = Current_Scope
and then Chars (New_P) = Chars (Generic_Parent (Spec))
then
declare
E : Entity_Id := First_Entity (Old_P);
begin
while Present (E)
and then E /= New_P
loop
if Is_Type (E)
and then Nkind (Parent (E)) = N_Subtype_Declaration
then
Set_Is_Generic_Actual_Type (E);
if Is_Private_Type (E)
and then Present (Full_View (E))
then
Set_Is_Generic_Actual_Type (Full_View (E));
end if;
end if;
Next_Entity (E);
end loop;
end;
end if;
end if;
end Analyze_Package_Renaming;
-------------------------------
-- Analyze_Renamed_Character --
-------------------------------
procedure Analyze_Renamed_Character
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
C : constant Node_Id := Name (N);
begin
if Ekind (New_S) = E_Function then
Resolve (C, Etype (New_S));
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
else
Error_Msg_N ("character literal can only be renamed as function", N);
end if;
end Analyze_Renamed_Character;
---------------------------------
-- Analyze_Renamed_Dereference --
---------------------------------
procedure Analyze_Renamed_Dereference
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : constant Node_Id := Name (N);
P : constant Node_Id := Prefix (Nam);
Typ : Entity_Id;
I : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (P) then
if Ekind (Etype (Nam)) /= E_Subprogram_Type
or else not Type_Conformant (Etype (Nam), New_S) then
Error_Msg_N ("designated type does not match specification", P);
else
Resolve (P, Etype (P));
end if;
return;
else
Typ := Any_Type;
Get_First_Interp (Nam, I, It);
while Present (It.Nam) loop
if Ekind (It.Nam) = E_Subprogram_Type
and then Type_Conformant (It.Nam, New_S) then
if Typ /= Any_Id then
Error_Msg_N ("ambiguous renaming", P);
return;
else
Typ := It.Nam;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if Typ = Any_Type then
Error_Msg_N ("designated type does not match specification", P);
else
Resolve (N, Typ);
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end if;
end if;
end Analyze_Renamed_Dereference;
---------------------------
-- Analyze_Renamed_Entry --
---------------------------
procedure Analyze_Renamed_Entry
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : Node_Id := Name (N);
Sel : Node_Id := Selector_Name (Nam);
Old_S : Entity_Id;
begin
if Entity (Sel) = Any_Id then
-- Selector is undefined on prefix. Error emitted already.
Set_Has_Completion (New_S);
return;
end if;
-- Otherwise, find renamed entity, and build body of New_S as a call
-- to it.
Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
if Old_S = Any_Id then
Error_Msg_N (" no subprogram or entry matches specification", N);
else
if Is_Body then
Check_Subtype_Conformant (New_S, Old_S, N);
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
end if;
Inherit_Renamed_Profile (New_S, Old_S);
end if;
Set_Convention (New_S, Convention (Old_S));
Set_Has_Completion (New_S, Inside_A_Generic);
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end Analyze_Renamed_Entry;
-----------------------------------
-- Analyze_Renamed_Family_Member --
-----------------------------------
procedure Analyze_Renamed_Family_Member
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : Node_Id := Name (N);
P : Node_Id := Prefix (Nam);
Old_S : Entity_Id;
begin
if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
or else (Nkind (P) = N_Selected_Component
and then
Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
then
if Is_Entity_Name (P) then
Old_S := Entity (P);
else
Old_S := Entity (Selector_Name (P));
end if;
if not Entity_Matches_Spec (Old_S, New_S) then
Error_Msg_N ("entry family does not match specification", N);
elsif Is_Body then
Check_Subtype_Conformant (New_S, Old_S, N);
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
end if;
else
Error_Msg_N ("no entry family matches specification", N);
end if;
Set_Has_Completion (New_S, Inside_A_Generic);
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end Analyze_Renamed_Family_Member;
---------------------------------
-- Analyze_Subprogram_Renaming --
---------------------------------
procedure Analyze_Subprogram_Renaming (N : Node_Id) is
Nam : Node_Id := Name (N);
Spec : constant Node_Id := Specification (N);
New_S : Entity_Id;
Old_S : Entity_Id := Empty;
Rename_Spec : Entity_Id;
Is_Actual : Boolean := False;
Inst_Node : Node_Id := Empty;
Save_83 : Boolean := Ada_83;
begin
-- We must test for the attribute renaming case before the Analyze
-- call because otherwise Sem_Attr will complain that the attribute
-- is missing an argument when it is analyzed.
if Nkind (Nam) = N_Attribute_Reference then
Attribute_Renaming (N);
return;
end if;
-- Check whether this declaration corresponds to the instantiation
-- of a formal subprogram. This is indicated by the presence of a
-- Corresponding_Spec that is the instantiation declaration.
-- If this is an instantiation, the corresponding actual is frozen
-- and error messages can be made more precise. If this is a default
-- subprogram, the entity is already established in the generic, and
-- is not retrieved by visibility. If it is a default with a box, the
-- candidate interpretations, if any, have been collected when building
-- the renaming declaration. If overloaded, the proper interpretation
-- is determined in Find_Renamed_Entity. If the entity is an operator,
-- Find_Renamed_Entity applies additional visibility checks.
if Present (Corresponding_Spec (N)) then
Is_Actual := True;
Inst_Node := Corresponding_Spec (N);
if Is_Entity_Name (Nam)
and then Present (Entity (Nam))
and then not Comes_From_Source (Nam)
and then not Is_Overloaded (Nam)
then
Old_S := Entity (Nam);
New_S := Analyze_Spec (Spec);
if Ekind (Entity (Nam)) = E_Operator
and then Box_Present (Corresponding_Spec (N))
then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
end if;
else
Analyze (Nam);
New_S := Analyze_Spec (Spec);
end if;
Set_Corresponding_Spec (N, Empty);
else
-- Renamed entity must be analyzed first, to avoid being hidden by
-- new name (which might be the same in a generic instance).
Analyze (Nam);
-- The renaming defines a new overloaded entity, which is analyzed
-- like a subprogram declaration.
New_S := Analyze_Spec (Spec);
end if;
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_S, Is_Pure (Current_Scope));
end if;
Rename_Spec := Find_Corresponding_Spec (N);
if Present (Rename_Spec) then
-- Renaming_As_Body. Renaming declaration is the completion of
-- the declaration of Rename_Spec. We will build an actual body
-- for it at the freezing point.
Set_Corresponding_Spec (N, Rename_Spec);
Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
-- The body is created when the entity is frozen. If the context
-- is generic, freeze_all is not invoked, so we need to indicate
-- that the entity has a completion.
Set_Has_Completion (Rename_Spec, Inside_A_Generic);
if Ada_83 and then Comes_From_Source (N) then
Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
end if;
Set_Convention (New_S, Convention (Rename_Spec));
Check_Fully_Conformant (New_S, Rename_Spec);
Set_Public_Status (New_S);
-- Indicate that the entity in the declaration functions like
-- the corresponding body, and is not a new entity.
Set_Ekind (New_S, E_Subprogram_Body);
New_S := Rename_Spec;
else
Generate_Definition (New_S);
New_Overloaded_Entity (New_S);
if Is_Entity_Name (Nam)
and then Is_Intrinsic_Subprogram (Entity (Nam))
then
null;
else
Check_Delayed_Subprogram (New_S);
end if;
end if;
-- There is no need for elaboration checks on the new entity, which
-- may be called before the next freezing point where the body will
-- appear.
Set_Suppress_Elaboration_Checks (New_S, True);
if Etype (Nam) = Any_Type then
Set_Has_Completion (New_S);
return;
elsif Nkind (Nam) = N_Selected_Component then
-- Renamed entity is an entry or protected subprogram. For those
-- cases an explicit body is built (at the point of freezing of
-- this entity) that contains a call to the renamed entity.
Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
return;
elsif Nkind (Nam) = N_Explicit_Dereference then
-- Renamed entity is designated by access_to_subprogram expression.
-- Must build body to encapsulate call, as in the entry case.
Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
return;
elsif Nkind (Nam) = N_Indexed_Component then
Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
return;
elsif Nkind (Nam) = N_Character_Literal then
Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
return;
elsif (not Is_Entity_Name (Nam)
and then Nkind (Nam) /= N_Operator_Symbol)
or else not Is_Overloadable (Entity (Nam))
then
Error_Msg_N ("expect valid subprogram name in renaming", N);
return;
end if;
-- Most common case: subprogram renames subprogram. No body is
-- generated in this case, so we must indicate that the declaration
-- is complete as is.
if No (Rename_Spec) then
Set_Has_Completion (New_S);
end if;
-- Find the renamed entity that matches the given specification.
-- Disable Ada_83 because there is no requirement of full conformance
-- between renamed entity and new entity, even though the same circuit
-- is used.
Ada_83 := False;
if No (Old_S) then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
end if;
if Old_S /= Any_Id then
if Is_Actual
and then Box_Present (Inst_Node)
then
-- This is an implicit reference to the default actual
Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
else
Generate_Reference (Old_S, Nam);
end if;
-- For a renaming-as-body, require subtype conformance,
-- but if the declaration being completed has not been
-- frozen, then inherit the convention of the renamed
-- subprogram prior to checking conformance (unless the
-- renaming has an explicit convention established; the
-- rule stated in the RM doesn't seem to address this ???).
if Present (Rename_Spec) then
Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
if not Is_Frozen (Rename_Spec)
and then not Has_Convention_Pragma (Rename_Spec)
then
Set_Convention (New_S, Convention (Old_S));
end if;
Check_Frozen_Renaming (N, Rename_Spec);
Check_Subtype_Conformant (New_S, Old_S, Spec);
elsif Ekind (Old_S) /= E_Operator then
Check_Mode_Conformant (New_S, Old_S);
if Is_Actual
and then Error_Posted (New_S)
then
Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
end if;
end if;
if No (Rename_Spec) then
-- The parameter profile of the new entity is that of the renamed
-- entity: the subtypes given in the specification are irrelevant.
Inherit_Renamed_Profile (New_S, Old_S);
-- A call to the subprogram is transformed into a call to the
-- renamed entity. This is transitive if the renamed entity is
-- itself a renaming.
if Present (Alias (Old_S)) then
Set_Alias (New_S, Alias (Old_S));
else
Set_Alias (New_S, Old_S);
end if;
-- Note that we do not set Is_Instrinsic_Subprogram if we have
-- a renaming as body, since the entity in this case is not an
-- intrinsic (it calls an intrinsic, but we have a real body
-- for this call, and it is in this body that the required
-- intrinsic processing will take place).
Set_Is_Intrinsic_Subprogram
(New_S, Is_Intrinsic_Subprogram (Old_S));
if Ekind (Alias (New_S)) = E_Operator then
Set_Has_Delayed_Freeze (New_S, False);
end if;
end if;
if not Is_Actual
and then (Old_S = New_S
or else (Nkind (Nam) /= N_Expanded_Name
and then Chars (Old_S) = Chars (New_S)))
then
Error_Msg_N ("subprogram cannot rename itself", N);
end if;
Set_Convention (New_S, Convention (Old_S));
Set_Is_Abstract (New_S, Is_Abstract (Old_S));
Check_Library_Unit_Renaming (N, Old_S);
-- Pathological case: procedure renames entry in the scope of
-- its task. Entry is given by simple name, but body must be built
-- for procedure. Of course if called it will deadlock.
if Ekind (Old_S) = E_Entry then
Set_Has_Completion (New_S, False);
Set_Alias (New_S, Empty);
end if;
if Is_Actual then
Freeze_Before (N, Old_S);
Set_Has_Delayed_Freeze (New_S, False);
Freeze_Before (N, New_S);
if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
and then Is_Abstract (Old_S)
then
Error_Msg_N
("abstract subprogram not allowed as generic actual", Nam);
end if;
end if;
else
-- A common error is to assume that implicit operators for types
-- are defined in Standard, or in the scope of a subtype. In those
-- cases where the renamed entity is given with an expanded name,
-- it is worth mentioning that operators for the type are not
-- declared in the scope given by the prefix.
if Nkind (Nam) = N_Expanded_Name
and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
and then Scope (Entity (Nam)) = Standard_Standard
then
declare
T : constant Entity_Id :=
Base_Type (Etype (First_Formal (New_S)));
begin
Error_Msg_Node_2 := Prefix (Nam);
Error_Msg_NE ("\operator for type& is not declared in&",
Prefix (Nam), T);
end;
else
Error_Msg_NE
("no visible subprogram matches the specification for&",
Spec, New_S);
end if;
if Present (Candidate_Renaming) then
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (Candidate_Renaming);
F2 := First_Formal (New_S);
while Present (F1) and then Present (F2) loop
Next_Formal (F1);
Next_Formal (F2);
end loop;
if Present (F1) and then Present (Default_Value (F1)) then
if Present (Next_Formal (F1)) then
Error_Msg_NE
("\missing specification for &" &
" and other formals with defaults", Spec, F1);
else
Error_Msg_NE
("\missing specification for &", Spec, F1);
end if;
end if;
end;
end if;
end if;
Ada_83 := Save_83;
end Analyze_Subprogram_Renaming;
-------------------------
-- Analyze_Use_Package --
-------------------------
-- Resolve the package names in the use clause, and make all the visible
-- entities defined in the package potentially use-visible. If the package
-- is already in use from a previous use clause, its visible entities are
-- already use-visible. In that case, mark the occurrence as a redundant
-- use. If the package is an open scope, i.e. if the use clause occurs
-- within the package itself, ignore it.
procedure Analyze_Use_Package (N : Node_Id) is
Pack_Name : Node_Id;
Pack : Entity_Id;
function In_Previous_With_Clause (P : Entity_Id) return Boolean;
-- For use clauses in a context clause, the indicated package may
-- be visible and yet illegal, if it did not appear in a previous
-- with clause.
-----------------------------
-- In_Previous_With_Clause --
-----------------------------
function In_Previous_With_Clause (P : Entity_Id) return Boolean is
Item : Node_Id;
begin
Item := First (Context_Items (Parent (N)));
while Present (Item)
and then Item /= N
loop
if Nkind (Item) = N_With_Clause
and then Entity (Name (Item)) = Pack
then
return True;
end if;
Next (Item);
end loop;
return False;
end In_Previous_With_Clause;
-- Start of processing for Analyze_Use_Package
begin
Set_Hidden_By_Use_Clause (N, No_Elist);
-- Use clause is not allowed in a spec of a predefined package
-- declaration except that packages whose file name starts a-n
-- are OK (these are children of Ada.Numerics, and such packages
-- are never loaded by Rtsfind).
if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
and then Name_Buffer (1 .. 3) /= "a-n"
and then
Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
then
Error_Msg_N ("use clause not allowed in predefined spec", N);
end if;
-- Chain clause to list of use clauses in current scope.
if Nkind (Parent (N)) /= N_Compilation_Unit then
Chain_Use_Clause (N);
end if;
-- Loop through package names to identify referenced packages
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
Analyze (Pack_Name);
if Nkind (Parent (N)) = N_Compilation_Unit
and then Nkind (Pack_Name) = N_Expanded_Name
then
declare
Pref : Node_Id := Prefix (Pack_Name);
begin
while Nkind (Pref) = N_Expanded_Name loop
Pref := Prefix (Pref);
end loop;
if Entity (Pref) = Standard_Standard then
Error_Msg_N
("predefined package Standard cannot appear"
& " in a context clause", Pref);
end if;
end;
end if;
Next (Pack_Name);
end loop;
-- Loop through package names to mark all entities as potentially
-- use visible.
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
if Is_Entity_Name (Pack_Name) then
Pack := Entity (Pack_Name);
if Ekind (Pack) /= E_Package
and then Etype (Pack) /= Any_Type
then
if Ekind (Pack) = E_Generic_Package then
Error_Msg_N
("a generic package is not allowed in a use clause",
Pack_Name);
else
Error_Msg_N ("& is not a usable package", Pack_Name);
end if;
elsif Nkind (Parent (N)) = N_Compilation_Unit
and then Nkind (Pack_Name) /= N_Expanded_Name
and then not In_Previous_With_Clause (Pack)
then
Error_Msg_N ("package is not directly visible", Pack_Name);
elsif Applicable_Use (Pack_Name) then
Use_One_Package (Pack, N);
end if;
end if;
Next (Pack_Name);
end loop;
end Analyze_Use_Package;
----------------------
-- Analyze_Use_Type --
----------------------
procedure Analyze_Use_Type (N : Node_Id) is
Id : Entity_Id;
begin
Set_Hidden_By_Use_Clause (N, No_Elist);
-- Chain clause to list of use clauses in current scope.
if Nkind (Parent (N)) /= N_Compilation_Unit then
Chain_Use_Clause (N);
end if;
Id := First (Subtype_Marks (N));
while Present (Id) loop
Find_Type (Id);
if Entity (Id) /= Any_Type then
Use_One_Type (Id, N);
end if;
Next (Id);
end loop;
end Analyze_Use_Type;
--------------------
-- Applicable_Use --
--------------------
function Applicable_Use (Pack_Name : Node_Id) return Boolean is
Pack : constant Entity_Id := Entity (Pack_Name);
begin
if In_Open_Scopes (Pack) then
return False;
elsif In_Use (Pack) then
Set_Redundant_Use (Pack_Name, True);
return False;
elsif Present (Renamed_Object (Pack))
and then In_Use (Renamed_Object (Pack))
then
Set_Redundant_Use (Pack_Name, True);
return False;
else
return True;
end if;
end Applicable_Use;
------------------------
-- Attribute_Renaming --
------------------------
procedure Attribute_Renaming (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Nam : constant Node_Id := Name (N);
Spec : constant Node_Id := Specification (N);
New_S : constant Entity_Id := Defining_Unit_Name (Spec);
Aname : constant Name_Id := Attribute_Name (Nam);
Form_Num : Nat := 0;
Expr_List : List_Id := No_List;
Attr_Node : Node_Id;
Body_Node : Node_Id;
Param_Spec : Node_Id;
begin
Generate_Definition (New_S);
-- This procedure is called in the context of subprogram renaming,
-- and thus the attribute must be one that is a subprogram. All of
-- those have at least one formal parameter, with the singular
-- exception of AST_Entry (which is a real oddity, it is odd that
-- this can be renamed at all!)
if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
if Aname /= Name_AST_Entry then
Error_Msg_N
("subprogram renaming an attribute must have formals", N);
return;
end if;
else
Param_Spec := First (Parameter_Specifications (Spec));
while Present (Param_Spec) loop
Form_Num := Form_Num + 1;
if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
Find_Type (Parameter_Type (Param_Spec));
-- The profile of the new entity denotes the base type (s) of
-- the types given in the specification. For access parameters
-- there are no subtypes involved.
Rewrite (Parameter_Type (Param_Spec),
New_Reference_To
(Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
end if;
if No (Expr_List) then
Expr_List := New_List;
end if;
Append_To (Expr_List,
Make_Identifier (Loc,
Chars => Chars (Defining_Identifier (Param_Spec))));
Next (Param_Spec);
end loop;
end if;
-- Immediate error if too many formals. Other mismatches in numbers
-- of number of types of parameters are detected when we analyze the
-- body of the subprogram that we construct.
if Form_Num > 2 then
Error_Msg_N ("too many formals for attribute", N);
elsif
Aname = Name_Compose or else
Aname = Name_Exponent or else
Aname = Name_Leading_Part or else
Aname = Name_Pos or else
Aname = Name_Round or else
Aname = Name_Scaling or else
Aname = Name_Val
then
if Nkind (N) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Spec (N))
and then Nkind (Corresponding_Spec (N)) =
N_Formal_Subprogram_Declaration
then
Error_Msg_N
("generic actual cannot be attribute involving universal type",
Nam);
else
Error_Msg_N
("attribute involving a universal type cannot be renamed",
Nam);
end if;
end if;
-- AST_Entry is an odd case. It doesn't really make much sense to
-- allow it to be renamed, but that's the DEC rule, so we have to
-- do it right. The point is that the AST_Entry call should be made
-- now, and what the function will return is the returned value.
-- Note that there is no Expr_List in this case anyway
if Aname = Name_AST_Entry then
declare
Ent : Entity_Id;
Decl : Node_Id;
begin
Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Object_Definition =>
New_Occurrence_Of (RTE (RE_AST_Handler), Loc),
Expression => Nam,
Constant_Present => True);
Set_Assignment_OK (Decl, True);
Insert_Action (N, Decl);
Attr_Node := Make_Identifier (Loc, Chars (Ent));
end;
-- For all other attributes, we rewrite the attribute node to have
-- a list of expressions corresponding to the subprogram formals.
-- A renaming declaration is not a freeze point, and the analysis of
-- the attribute reference should not freeze the type of the prefix.
else
Attr_Node :=
Make_Attribute_Reference (Loc,
Prefix => Prefix (Nam),
Attribute_Name => Aname,
Expressions => Expr_List);
Set_Must_Not_Freeze (Attr_Node);
Set_Must_Not_Freeze (Prefix (Nam));
end if;
-- Case of renaming a function
if Nkind (Spec) = N_Function_Specification then
if Is_Procedure_Attribute_Name (Aname) then
Error_Msg_N ("attribute can only be renamed as procedure", Nam);
return;
end if;
Find_Type (Subtype_Mark (Spec));
Rewrite (Subtype_Mark (Spec),
New_Reference_To (Base_Type (Entity (Subtype_Mark (Spec))), Loc));
Body_Node :=
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Return_Statement (Loc,
Expression => Attr_Node))));
-- Case of renaming a procedure
else
if not Is_Procedure_Attribute_Name (Aname) then
Error_Msg_N ("attribute can only be renamed as function", Nam);
return;
end if;
Body_Node :=
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Attr_Node)));
end if;
Rewrite (N, Body_Node);
Analyze (N);
Set_Etype (New_S, Base_Type (Etype (New_S)));
-- We suppress elaboration warnings for the resulting entity, since
-- clearly they are not needed, and more particularly, in the case
-- of a generic formal subprogram, the resulting entity can appear
-- after the instantiation itself, and thus look like a bogus case
-- of access before elaboration.
Set_Suppress_Elaboration_Warnings (New_S);
end Attribute_Renaming;
----------------------
-- Chain_Use_Clause --
----------------------
procedure Chain_Use_Clause (N : Node_Id) is
begin
Set_Next_Use_Clause (N,
Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := N;
end Chain_Use_Clause;
----------------------------
-- Check_Frozen_Renaming --
----------------------------
procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
B_Node : Node_Id;
Old_S : Entity_Id;
begin
if Is_Frozen (Subp)
and then not Has_Completion (Subp)
then
B_Node :=
Build_Renamed_Body
(Parent (Declaration_Node (Subp)), Defining_Entity (N));
if Is_Entity_Name (Name (N)) then
Old_S := Entity (Name (N));
if not Is_Frozen (Old_S) then
Ensure_Freeze_Node (Old_S);
if No (Actions (Freeze_Node (Old_S))) then
Set_Actions (Freeze_Node (Old_S), New_List (B_Node));
else
Append (B_Node, Actions (Freeze_Node (Old_S)));
end if;
else
Insert_After (N, B_Node);
Analyze (B_Node);
end if;
if Is_Intrinsic_Subprogram (Old_S)
and then not In_Instance
then
Error_Msg_N
("subprogram used in renaming_as_body cannot be intrinsic",
Name (N));
end if;
else
Insert_After (N, B_Node);
Analyze (B_Node);
end if;
end if;
end Check_Frozen_Renaming;
---------------------------------
-- Check_Library_Unit_Renaming --
---------------------------------
procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
New_E : Entity_Id;
begin
if Nkind (Parent (N)) /= N_Compilation_Unit then
return;
elsif Scope (Old_E) /= Standard_Standard
and then not Is_Child_Unit (Old_E)
then
Error_Msg_N ("renamed unit must be a library unit", Name (N));
elsif Present (Parent_Spec (N))
and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
and then not Is_Child_Unit (Old_E)
then
Error_Msg_N
("renamed unit must be a child unit of generic parent", Name (N));
elsif Nkind (N) in N_Generic_Renaming_Declaration
and then Nkind (Name (N)) = N_Expanded_Name
and then Is_Generic_Instance (Entity (Prefix (Name (N))))
and then Is_Generic_Unit (Old_E)
then
Error_Msg_N
("renamed generic unit must be a library unit", Name (N));
elsif Ekind (Old_E) = E_Package
or else Ekind (Old_E) = E_Generic_Package
then
-- Inherit categorization flags
New_E := Defining_Entity (N);
Set_Is_Pure (New_E, Is_Pure (Old_E));
Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
Set_Is_Remote_Call_Interface (New_E,
Is_Remote_Call_Interface (Old_E));
Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
end if;
end Check_Library_Unit_Renaming;
---------------
-- End_Scope --
---------------
procedure End_Scope is
Id : Entity_Id;
Prev : Entity_Id;
Outer : Entity_Id;
begin
Id := First_Entity (Current_Scope);
while Present (Id) loop
-- An entity in the current scope is not necessarily the first one
-- on its homonym chain. Find its predecessor if any,
-- If it is an internal entity, it will not be in the visibility
-- chain altogether, and there is nothing to unchain.
if Id /= Current_Entity (Id) then
Prev := Current_Entity (Id);
while Present (Prev)
and then Present (Homonym (Prev))
and then Homonym (Prev) /= Id
loop
Prev := Homonym (Prev);
end loop;
-- Skip to end of loop if Id is not in the visibility chain
if No (Prev) or else Homonym (Prev) /= Id then
goto Next_Ent;
end if;
else
Prev := Empty;
end if;
Outer := Homonym (Id);
Set_Is_Immediately_Visible (Id, False);
while Present (Outer) and then Scope (Outer) = Current_Scope loop
Outer := Homonym (Outer);
end loop;
-- Reset homonym link of other entities, but do not modify link
-- between entities in current scope, so that the back-end can have
-- a proper count of local overloadings.
if No (Prev) then
Set_Name_Entity_Id (Chars (Id), Outer);
elsif Scope (Prev) /= Scope (Id) then
Set_Homonym (Prev, Outer);
end if;
<<Next_Ent>>
Next_Entity (Id);
end loop;
-- If the scope generated freeze actions, place them before the
-- current declaration and analyze them. Type declarations and
-- the bodies of initialization procedures can generate such nodes.
-- We follow the parent chain until we reach a list node, which is
-- the enclosing list of declarations. If the list appears within
-- a protected definition, move freeze nodes outside the protected
-- type altogether.
if Present
(Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions)
then
declare
Decl : Node_Id;
L : constant List_Id := Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions;
begin
if Is_Itype (Current_Scope) then
Decl := Associated_Node_For_Itype (Current_Scope);
else
Decl := Parent (Current_Scope);
end if;
Pop_Scope;
while not (Is_List_Member (Decl))
or else Nkind (Parent (Decl)) = N_Protected_Definition
or else Nkind (Parent (Decl)) = N_Task_Definition
loop
Decl := Parent (Decl);
end loop;
Insert_List_Before_And_Analyze (Decl, L);
end;
else
Pop_Scope;
end if;
end End_Scope;
---------------------
-- End_Use_Clauses --
---------------------
procedure End_Use_Clauses (Clause : Node_Id) is
U : Node_Id := Clause;
begin
while Present (U) loop
if Nkind (U) = N_Use_Package_Clause then
End_Use_Package (U);
elsif Nkind (U) = N_Use_Type_Clause then
End_Use_Type (U);
end if;
Next_Use_Clause (U);
end loop;
end End_Use_Clauses;
---------------------
-- End_Use_Package --
---------------------
procedure End_Use_Package (N : Node_Id) is
Pack_Name : Node_Id;
Pack : Entity_Id;
Id : Entity_Id;
Elmt : Elmt_Id;
begin
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
Pack := Entity (Pack_Name);
if Ekind (Pack) = E_Package then
if In_Open_Scopes (Pack) then
null;
elsif not Redundant_Use (Pack_Name) then
Set_In_Use (Pack, False);
Id := First_Entity (Pack);
while Present (Id) loop
-- Preserve use-visibility of operators whose formals have
-- a type that is use_visible thanks to a previous use_type
-- clause.
if Nkind (Id) = N_Defining_Operator_Symbol
and then
(In_Use (Etype (First_Formal (Id)))
or else
(Present (Next_Formal (First_Formal (Id)))
and then In_Use (Etype (Next_Formal
(First_Formal (Id))))))
then
null;
else
Set_Is_Potentially_Use_Visible (Id, False);
end if;
if Is_Private_Type (Id)
and then Present (Full_View (Id))
then
Set_Is_Potentially_Use_Visible (Full_View (Id), False);
end if;
Next_Entity (Id);
end loop;
if Present (Renamed_Object (Pack)) then
Set_In_Use (Renamed_Object (Pack), False);
end if;
if Chars (Pack) = Name_System
and then Scope (Pack) = Standard_Standard
and then Present_System_Aux
then
Id := First_Entity (System_Aux_Id);
while Present (Id) loop
Set_Is_Potentially_Use_Visible (Id, False);
if Is_Private_Type (Id)
and then Present (Full_View (Id))
then
Set_Is_Potentially_Use_Visible (Full_View (Id), False);
end if;
Next_Entity (Id);
end loop;
Set_In_Use (System_Aux_Id, False);
end if;
else
Set_Redundant_Use (Pack_Name, False);
end if;
end if;
Next (Pack_Name);
end loop;
if Present (Hidden_By_Use_Clause (N)) then
Elmt := First_Elmt (Hidden_By_Use_Clause (N));
while Present (Elmt) loop
Set_Is_Immediately_Visible (Node (Elmt));
Next_Elmt (Elmt);
end loop;
Set_Hidden_By_Use_Clause (N, No_Elist);
end if;
end End_Use_Package;
------------------
-- End_Use_Type --
------------------
procedure End_Use_Type (N : Node_Id) is
Id : Entity_Id;
Op_List : Elist_Id;
Elmt : Elmt_Id;
T : Entity_Id;
begin
Id := First (Subtype_Marks (N));
while Present (Id) loop
T := Entity (Id);
if T = Any_Type then
null;
-- Note that the use_Type clause may mention a subtype of the
-- type whose primitive operations have been made visible. Here
-- as elsewhere, it is the base type that matters for visibility.
elsif In_Open_Scopes (Scope (Base_Type (T))) then
null;
elsif not Redundant_Use (Id) then
Set_In_Use (T, False);
Set_In_Use (Base_Type (T), False);
Op_List := Collect_Primitive_Operations (T);
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then
Set_Is_Potentially_Use_Visible (Node (Elmt), False);
end if;
Next_Elmt (Elmt);
end loop;
end if;
Next (Id);
end loop;
end End_Use_Type;
----------------------
-- Find_Direct_Name --
----------------------
procedure Find_Direct_Name (N : Node_Id) is
E : Entity_Id;
E2 : Entity_Id;
Msg : Boolean;
Inst : Entity_Id := Empty;
-- Enclosing instance, if any.
Homonyms : Entity_Id;
-- Saves start of homonym chain
Nvis_Entity : Boolean;
-- Set True to indicate that at there is at least one entity on the
-- homonym chain which, while not visible, is visible enough from the
-- user point of view to warrant an error message of "not visible"
-- rather than undefined.
function From_Actual_Package (E : Entity_Id) return Boolean;
-- Returns true if the entity is declared in a package that is
-- an actual for a formal package of the current instance. Such an
-- entity requires special handling because it may be use-visible
-- but hides directly visible entities defined outside the instance.
function Known_But_Invisible (E : Entity_Id) return Boolean;
-- This function determines whether the entity E (which is not
-- visible) can reasonably be considered to be known to the writer
-- of the reference. This is a heuristic test, used only for the
-- purposes of figuring out whether we prefer to complain that an
-- entity is undefined or invisible (and identify the declaration
-- of the invisible entity in the latter case). The point here is
-- that we don't want to complain that something is invisible and
-- then point to something entirely mysterious to the writer.
procedure Nvis_Messages;
-- Called if there are no visible entries for N, but there is at least
-- one non-directly visible, or hidden declaration. This procedure
-- outputs an appropriate set of error messages.
procedure Undefined (Nvis : Boolean);
-- This function is called if the current node has no corresponding
-- visible entity or entities. The value set in Msg indicates whether
-- an error message was generated (multiple error messages for the
-- same variable are generally suppressed, see body for details).
-- Msg is True if an error message was generated, False if not. This
-- value is used by the caller to determine whether or not to output
-- additional messages where appropriate. The parameter is set False
-- to get the message "X is undefined", and True to get the message
-- "X is not visible".
-------------------------
-- From_Actual_Package --
-------------------------
function From_Actual_Package (E : Entity_Id) return Boolean is
Scop : constant Entity_Id := Scope (E);
Act : Entity_Id;
begin
if not In_Instance then
return False;
else
Inst := Current_Scope;
while Present (Inst)
and then Ekind (Inst) /= E_Package
and then not Is_Generic_Instance (Inst)
loop
Inst := Scope (Inst);
end loop;
if No (Inst) then
return False;
end if;
Act := First_Entity (Inst);
while Present (Act) loop
if Ekind (Act) = E_Package then
-- Check for end of actuals list
if Renamed_Object (Act) = Inst then
return False;
elsif Present (Associated_Formal_Package (Act))
and then Renamed_Object (Act) = Scop
then
-- Entity comes from (instance of) formal package
return True;
else
Next_Entity (Act);
end if;
else
Next_Entity (Act);
end if;
end loop;
return False;
end if;
end From_Actual_Package;
-------------------------
-- Known_But_Invisible --
-------------------------
function Known_But_Invisible (E : Entity_Id) return Boolean is
Fname : File_Name_Type;
begin
-- Entities in Standard are always considered to be known
if Sloc (E) <= Standard_Location then
return True;
-- An entity that does not come from source is always considered
-- to be unknown, since it is an artifact of code expansion.
elsif not Comes_From_Source (E) then
return False;
-- In gnat internal mode, we consider all entities known
elsif GNAT_Mode then
return True;
end if;
-- Here we have an entity that is not from package Standard, and
-- which comes from Source. See if it comes from an internal file.
Fname := Unit_File_Name (Get_Source_Unit (E));
-- Case of from internal file
if Is_Internal_File_Name (Fname) then
-- Private part entities in internal files are never considered
-- to be known to the writer of normal application code.
if Is_Hidden (E) then
return False;
end if;
-- Entities from System packages other than System and
-- System.Storage_Elements are not considered to be known.
-- System.Auxxxx files are also considered known to the user.
-- Should refine this at some point to generally distinguish
-- between known and unknown internal files ???
Get_Name_String (Fname);
return
Name_Len < 2
or else
Name_Buffer (1 .. 2) /= "s-"
or else
Name_Buffer (3 .. 8) = "stoele"
or else
Name_Buffer (3 .. 5) = "aux";
-- If not an internal file, then entity is definitely known,
-- even if it is in a private part (the message generated will
-- note that it is in a private part)
else
return True;
end if;
end Known_But_Invisible;
-------------------
-- Nvis_Messages --
-------------------
procedure Nvis_Messages is
Ent : Entity_Id;
Hidden : Boolean := False;
begin
Undefined (Nvis => True);
if Msg then
-- First loop does hidden declarations
Ent := Homonyms;
while Present (Ent) loop
if Is_Potentially_Use_Visible (Ent) then
if not Hidden then
Error_Msg_N ("multiple use clauses cause hiding!", N);
Hidden := True;
end if;
Error_Msg_Sloc := Sloc (Ent);
Error_Msg_N ("hidden declaration#!", N);
end if;
Ent := Homonym (Ent);
end loop;
-- If we found hidden declarations, then that's enough, don't
-- bother looking for non-visible declarations as well.
if Hidden then
return;
end if;
-- Second loop does non-directly visible declarations
Ent := Homonyms;
while Present (Ent) loop
if not Is_Potentially_Use_Visible (Ent) then
-- Do not bother the user with unknown entities
if not Known_But_Invisible (Ent) then
goto Continue;
end if;
Error_Msg_Sloc := Sloc (Ent);
-- Output message noting that there is a non-visible
-- declaration, distinguishing the private part case.
if Is_Hidden (Ent) then
Error_Msg_N ("non-visible (private) declaration#!", N);
else
Error_Msg_N ("non-visible declaration#!", N);
end if;
end if;
<<Continue>>
Ent := Homonym (Ent);
end loop;
end if;
end Nvis_Messages;
---------------
-- Undefined --
---------------
procedure Undefined (Nvis : Boolean) is
Emsg : Error_Msg_Id;
begin
-- A very specialized error check, if the undefined variable is
-- a case tag, and the case type is an enumeration type, check
-- for a possible misspelling, and if so, modify the identifier
-- Named aggregate should also be handled similarly ???
if Nkind (N) = N_Identifier
and then Nkind (Parent (N)) = N_Case_Statement_Alternative
then
Get_Name_String (Chars (N));
declare
Case_Str : constant String := Name_Buffer (1 .. Name_Len);
Case_Stm : constant Node_Id := Parent (Parent (N));
Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm));
Lit : Node_Id;
begin
if Is_Enumeration_Type (Case_Typ)
and then Case_Typ /= Standard_Character
and then Case_Typ /= Standard_Wide_Character
then
Lit := First_Literal (Case_Typ);
Get_Name_String (Chars (Lit));
if Chars (Lit) /= Chars (N)
and then Is_Bad_Spelling_Of
(Case_Str, Name_Buffer (1 .. Name_Len))
then
Error_Msg_Node_2 := Lit;
Error_Msg_N
("& is undefined, assume misspelling of &", N);
Rewrite (N, New_Occurrence_Of (Lit, Sloc (N)));
return;
end if;
Lit := Next_Literal (Lit);
end if;
end;
end if;
-- Normal processing
Set_Entity (N, Any_Id);
Set_Etype (N, Any_Type);
-- We use the table Urefs to keep track of entities for which we
-- have issued errors for undefined references. Multiple errors
-- for a single name are normally suppressed, however we modify
-- the error message to alert the programmer to this effect.
for J in Urefs.First .. Urefs.Last loop
if Chars (N) = Chars (Urefs.Table (J).Node) then
if Urefs.Table (J).Err /= No_Error_Msg
and then Sloc (N) /= Urefs.Table (J).Loc
then
Error_Msg_Node_1 := Urefs.Table (J).Node;
if Urefs.Table (J).Nvis then
Change_Error_Text (Urefs.Table (J).Err,
"& is not visible (more references follow)");
else
Change_Error_Text (Urefs.Table (J).Err,
"& is undefined (more references follow)");
end if;
Urefs.Table (J).Err := No_Error_Msg;
end if;
-- Although we will set Msg False, and thus suppress the
-- message, we also set Error_Posted True, to avoid any
-- cascaded messages resulting from the undefined reference.
Msg := False;
Set_Error_Posted (N, True);
return;
end if;
end loop;
-- If entry not found, this is first undefined occurrence
if Nvis then
Error_Msg_N ("& is not visible!", N);
Emsg := Get_Msg_Id;
else
Error_Msg_N ("& is undefined!", N);
Emsg := Get_Msg_Id;
-- A very bizarre special check, if the undefined identifier
-- is put or put_line, then add a special error message (since
-- this is a very common error for beginners to make).
if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then
Error_Msg_N ("\possible missing with of 'Text_'I'O!", N);
end if;
-- Now check for possible misspellings
Get_Name_String (Chars (N));
declare
E : Entity_Id;
Ematch : Entity_Id := Empty;
Last_Name_Id : constant Name_Id :=
Name_Id (Nat (First_Name_Id) +
Name_Entries_Count - 1);
S : constant String (1 .. Name_Len) :=
Name_Buffer (1 .. Name_Len);
begin
for N in First_Name_Id .. Last_Name_Id loop
E := Get_Name_Entity_Id (N);
if Present (E)
and then (Is_Immediately_Visible (E)
or else
Is_Potentially_Use_Visible (E))
then
Get_Name_String (N);
if Is_Bad_Spelling_Of
(Name_Buffer (1 .. Name_Len), S)
then
Ematch := E;
exit;
end if;
end if;
end loop;
if Present (Ematch) then
Error_Msg_NE ("\possible misspelling of&", N, Ematch);
end if;
end;
end if;
-- Make entry in undefined references table unless the full
-- errors switch is set, in which case by refraining from
-- generating the table entry, we guarantee that we get an
-- error message for every undefined reference.
if not All_Errors_Mode then
Urefs.Increment_Last;
Urefs.Table (Urefs.Last).Node := N;
Urefs.Table (Urefs.Last).Err := Emsg;
Urefs.Table (Urefs.Last).Nvis := Nvis;
Urefs.Table (Urefs.Last).Loc := Sloc (N);
end if;
Msg := True;
end Undefined;
-- Start of processing for Find_Direct_Name
begin
-- If the entity pointer is already set, this is an internal node, or
-- a node that is analyzed more than once, after a tree modification.
-- In such a case there is no resolution to perform, just set the type.
if Present (Entity (N)) then
if Is_Type (Entity (N)) then
Set_Etype (N, Entity (N));
else
declare
Entyp : constant Entity_Id := Etype (Entity (N));
begin
-- One special case here. If the Etype field is already set,
-- and references the packed array type corresponding to the
-- etype of the referenced entity, then leave it alone. This
-- happens for trees generated from Exp_Pakd, where expressions
-- can be deliberately "mis-typed" to the packed array type.
if Is_Array_Type (Entyp)
and then Is_Packed (Entyp)
and then Present (Etype (N))
and then Etype (N) = Packed_Array_Type (Entyp)
then
null;
-- If not that special case, then just reset the Etype
else
Set_Etype (N, Etype (Entity (N)));
end if;
end;
end if;
return;
end if;
-- Here if Entity pointer was not set, we need full visibility analysis
-- First we generate debugging output if the debug E flag is set.
if Debug_Flag_E then
Write_Str ("Looking for ");
Write_Name (Chars (N));
Write_Eol;
end if;
Homonyms := Current_Entity (N);
Nvis_Entity := False;
E := Homonyms;
while Present (E) loop
-- If entity is immediately visible or potentially use
-- visible, then process the entity and we are done.
if Is_Immediately_Visible (E) then
goto Immediately_Visible_Entity;
elsif Is_Potentially_Use_Visible (E) then
goto Potentially_Use_Visible_Entity;
-- Note if a known but invisible entity encountered
elsif Known_But_Invisible (E) then
Nvis_Entity := True;
end if;
-- Move to next entity in chain and continue search
E := Homonym (E);
end loop;
-- If no entries on homonym chain that were potentially visible,
-- and no entities reasonably considered as non-visible, then
-- we have a plain undefined reference, with no additional
-- explanation required!
if not Nvis_Entity then
Undefined (Nvis => False);
return;
-- Otherwise there is at least one entry on the homonym chain that
-- is reasonably considered as being known and non-visible.
else
Nvis_Messages;
return;
end if;
-- Processing for a potentially use visible entry found. We must search
-- the rest of the homonym chain for two reasons. First, if there is a
-- directly visible entry, then none of the potentially use-visible
-- entities are directly visible (RM 8.4(10)). Second, we need to check
-- for the case of multiple potentially use-visible entries hiding one
-- another and as a result being non-directly visible (RM 8.4(11)).
<<Potentially_Use_Visible_Entity>> declare
Only_One_Visible : Boolean := True;
All_Overloadable : Boolean := Is_Overloadable (E);
begin
E2 := Homonym (E);
while Present (E2) loop
if Is_Immediately_Visible (E2) then
-- If the use-visible entity comes from the actual for a
-- formal package, it hides a directly visible entity from
-- outside the instance.
if From_Actual_Package (E)
and then Scope_Depth (E2) < Scope_Depth (Inst)
then
goto Found;
else
E := E2;
goto Immediately_Visible_Entity;
end if;
elsif Is_Potentially_Use_Visible (E2) then
Only_One_Visible := False;
All_Overloadable := All_Overloadable and Is_Overloadable (E2);
end if;
E2 := Homonym (E2);
end loop;
-- On falling through this loop, we have checked that there are no
-- immediately visible entities. Only_One_Visible is set if exactly
-- one potentially use visible entity exists. All_Overloadable is
-- set if all the potentially use visible entities are overloadable.
-- The condition for legality is that either there is one potentially
-- use visible entity, or if there is more than one, then all of them
-- are overloadable.
if Only_One_Visible or All_Overloadable then
goto Found;
-- If there is more than one potentially use-visible entity and at
-- least one of them non-overloadable, we have an error (RM 8.4(11).
-- Note that E points to the first such entity on the homonym list.
-- Special case: if one of the entities is declared in an actual
-- package, it was visible in the generic, and takes precedence over
-- other entities that are potentially use-visible.
else
if In_Instance then
E2 := E;
while Present (E2) loop
if Is_Generic_Instance (Scope (E2)) then
E := E2;
goto Found;
end if;
E2 := Homonym (E2);
end loop;
Nvis_Messages;
return;
else
Nvis_Messages;
return;
end if;
end if;
end;
-- Come here with E set to the first immediately visible entity on
-- the homonym chain. This is the one we want unless there is another
-- immediately visible entity further on in the chain for a more
-- inner scope (RM 8.3(8)).
<<Immediately_Visible_Entity>> declare
Level : Int;
Scop : Entity_Id;
begin
-- Find scope level of initial entity. When compiling through
-- Rtsfind, the previous context is not completely invisible, and
-- an outer entity may appear on the chain, whose scope is below
-- the entry for Standard that delimits the current scope stack.
-- Indicate that the level for this spurious entry is outside of
-- the current scope stack.
Level := Scope_Stack.Last;
loop
Scop := Scope_Stack.Table (Level).Entity;
exit when Scop = Scope (E);
Level := Level - 1;
exit when Scop = Standard_Standard;
end loop;
-- Now search remainder of homonym chain for more inner entry
-- If the entity is Standard itself, it has no scope, and we
-- compare it with the stack entry directly.
E2 := Homonym (E);
while Present (E2) loop
if Is_Immediately_Visible (E2) then
for J in Level + 1 .. Scope_Stack.Last loop
if Scope_Stack.Table (J).Entity = Scope (E2)
or else Scope_Stack.Table (J).Entity = E2
then
Level := J;
E := E2;
exit;
end if;
end loop;
end if;
E2 := Homonym (E2);
end loop;
-- At the end of that loop, E is the innermost immediately
-- visible entity, so we are all set.
end;
-- Come here with entity found, and stored in E
<<Found>> begin
if Comes_From_Source (N)
and then Is_Remote_Access_To_Subprogram_Type (E)
and then Expander_Active
then
Rewrite (N,
New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
return;
end if;
Set_Entity (N, E);
-- Why no Style_Check here???
if Is_Type (E) then
Set_Etype (N, E);
else
Set_Etype (N, Get_Full_View (Etype (E)));
end if;
if Debug_Flag_E then
Write_Str (" found ");
Write_Entity_Info (E, " ");
end if;
-- If the Ekind of the entity is Void, it means that all homonyms
-- are hidden from all visibility (RM 8.3(5,14-20)). However, this
-- test is skipped if the current scope is a record and the name is
-- a pragma argument expression (case of Atomic and Volatile pragmas
-- and possibly other similar pragmas added later, which are allowed
-- to reference components in the current record).
if Ekind (E) = E_Void
and then
(not Is_Record_Type (Current_Scope)
or else Nkind (Parent (N)) /= N_Pragma_Argument_Association)
then
Premature_Usage (N);
-- If the entity is overloadable, collect all interpretations
-- of the name for subsequent overload resolution. We optimize
-- a bit here to do this only if we have an overloadable entity
-- that is not on its own on the homonym chain.
elsif Is_Overloadable (E)
and then (Present (Homonym (E)) or else Current_Entity (N) /= E)
then
Collect_Interps (N);
-- If no homonyms were visible, the entity is unambiguous.
if not Is_Overloaded (N) then
Generate_Reference (E, N);
end if;
-- Case of non-overloadable entity, set the entity providing that
-- we do not have the case of a discriminant reference within a
-- default expression. Such references are replaced with the
-- corresponding discriminal, which is the formal corresponding to
-- to the discriminant in the initialization procedure.
-- This replacement must not be done if we are currently processing
-- a generic spec or body.
-- The replacement is not done either for a task discriminant that
-- appears in a default expression of an entry parameter. See
-- Expand_Discriminant in exp_ch2 for details on their handling.
else
-- Entity is unambiguous, indicate that it is referenced here
-- One slightly odd case is that we do not want to set the
-- Referenced flag if the entity is a label, and the identifier
-- is the label in the source, since this is not a reference
-- from the point of view of the user
if Nkind (Parent (N)) = N_Label then
declare
R : constant Boolean := Referenced (E);
begin
Generate_Reference (E, N);
Set_Referenced (E, R);
end;
else
Generate_Reference (E, N);
end if;
if not In_Default_Expression
or else Ekind (E) /= E_Discriminant
or else Inside_A_Generic
then
Set_Entity_With_Style_Check (N, E);
elsif Is_Concurrent_Type (Scope (E)) then
declare
P : Node_Id := Parent (N);
begin
while Present (P)
and then Nkind (P) /= N_Parameter_Specification
and then Nkind (P) /= N_Component_Declaration
loop
P := Parent (P);
end loop;
if Present (P)
and then Nkind (P) = N_Parameter_Specification
then
null;
else
Set_Entity (N, Discriminal (E));
end if;
end;
else
Set_Entity (N, Discriminal (E));
end if;
end if;
end;
end Find_Direct_Name;
------------------------
-- Find_Expanded_Name --
------------------------
-- This routine searches the homonym chain of the entity until it finds
-- an entity declared in the scope denoted by the prefix. If the entity
-- is private, it may nevertheless be immediately visible, if we are in
-- the scope of its declaration.
procedure Find_Expanded_Name (N : Node_Id) is
Candidate : Entity_Id := Empty;
Selector : constant Node_Id := Selector_Name (N);
P_Name : Entity_Id;
O_Name : Entity_Id;
Id : Entity_Id;
begin
P_Name := Entity (Prefix (N));
O_Name := P_Name;
-- If the prefix is a renamed package, look for the entity
-- in the original package.
if Ekind (P_Name) = E_Package
and then Present (Renamed_Object (P_Name))
then
P_Name := Renamed_Object (P_Name);
-- Rewrite node with entity field pointing to renamed object
Rewrite (Prefix (N), New_Copy (Prefix (N)));
Set_Entity (Prefix (N), P_Name);
-- If the prefix is an object of a concurrent type, look for
-- the entity in the associated task or protected type.
elsif Is_Concurrent_Type (Etype (P_Name)) then
P_Name := Etype (P_Name);
end if;
Id := Current_Entity (Selector);
while Present (Id) loop
if Scope (Id) = P_Name then
Candidate := Id;
if Is_Child_Unit (Id) then
exit when
(Is_Visible_Child_Unit (Id)
or else Is_Immediately_Visible (Id));
else
exit when
(not Is_Hidden (Id) or else Is_Immediately_Visible (Id));
end if;
end if;
Id := Homonym (Id);
end loop;
if No (Id)
and then (Ekind (P_Name) = E_Procedure
or else
Ekind (P_Name) = E_Function)
and then Is_Generic_Instance (P_Name)
then
-- Expanded name denotes entity in (instance of) generic subprogram.
-- The entity may be in the subprogram instance, or may denote one of
-- the formals, which is declared in the enclosing wrapper package.
P_Name := Scope (P_Name);
Id := Current_Entity (Selector);
while Present (Id) loop
exit when Scope (Id) = P_Name;
Id := Homonym (Id);
end loop;
end if;
if No (Id) or else Chars (Id) /= Chars (Selector) then
Set_Etype (N, Any_Type);
-- If we are looking for an entity defined in System, try to
-- find it in the child package that may have been provided as
-- an extension to System. The Extend_System pragma will have
-- supplied the name of the extension, which may have to be loaded.
if Chars (P_Name) = Name_System
and then Scope (P_Name) = Standard_Standard
and then Present (System_Extend_Pragma_Arg)
and then Present_System_Aux (N)
then
Set_Entity (Prefix (N), System_Aux_Id);
Find_Expanded_Name (N);
return;
elsif (Nkind (Selector) = N_Operator_Symbol
and then Has_Implicit_Operator (N))
then
-- There is an implicit instance of the predefined operator in
-- the given scope. The operator entity is defined in Standard.
-- Has_Implicit_Operator makes the node into an Expanded_Name.
return;
elsif Nkind (Selector) = N_Character_Literal
and then Has_Implicit_Character_Literal (N)
then
-- If there is no literal defined in the scope denoted by the
-- prefix, the literal may belong to (a type derived from)
-- Standard_Character, for which we have no explicit literals.
return;
else
-- If the prefix is a single concurrent object, use its
-- name in the error message, rather than that of the
-- anonymous type.
if Is_Concurrent_Type (P_Name)
and then Is_Internal_Name (Chars (P_Name))
then
Error_Msg_Node_2 := Entity (Prefix (N));
else
Error_Msg_Node_2 := P_Name;
end if;
if P_Name = System_Aux_Id then
P_Name := Scope (P_Name);
Set_Entity (Prefix (N), P_Name);
end if;
if Present (Candidate) then
if Is_Child_Unit (Candidate) then
Error_Msg_N
("missing with_clause for child unit &", Selector);
else
Error_Msg_NE ("& is not a visible entity of&", N, Selector);
end if;
else
-- Within the instantiation of a child unit, the prefix may
-- denote the parent instance, but the selector has the
-- name of the original child. Find whether we are within
-- the corresponding instance, and get the proper entity, which
-- can only be an enclosing scope.
if O_Name /= P_Name
and then In_Open_Scopes (P_Name)
and then Is_Generic_Instance (P_Name)
then
declare
S : Entity_Id := Current_Scope;
P : Entity_Id;
begin
for J in reverse 0 .. Scope_Stack.Last loop
S := Scope_Stack.Table (J).Entity;
exit when S = Standard_Standard;
if Ekind (S) = E_Function
or else Ekind (S) = E_Package
or else Ekind (S) = E_Procedure
then
P := Generic_Parent (Specification
(Unit_Declaration_Node (S)));
if Present (P)
and then Chars (Scope (P)) = Chars (O_Name)
and then Chars (P) = Chars (Selector)
then
Id := S;
goto found;
end if;
end if;
end loop;
end;
end if;
if (Chars (P_Name) = Name_Ada
and then Scope (P_Name) = Standard_Standard)
then
Error_Msg_Node_2 := Selector;
Error_Msg_NE
("\missing with for `&.&`", N, P_Name);
-- If this is a selection from a dummy package, then
-- suppress the error message, of course the entity
-- is missing if the package is missing!
elsif Sloc (Error_Msg_Node_2) = No_Location then
null;
-- Here we have the case of an undefined component
else
Error_Msg_NE ("& not declared in&", N, Selector);
-- Check for misspelling of some entity in prefix.
Id := First_Entity (P_Name);
Get_Name_String (Chars (Selector));
declare
S : constant String (1 .. Name_Len) :=
Name_Buffer (1 .. Name_Len);
begin
while Present (Id) loop
Get_Name_String (Chars (Id));
if Is_Bad_Spelling_Of
(Name_Buffer (1 .. Name_Len), S)
and then not Is_Internal_Name (Chars (Id))
then
Error_Msg_NE
("possible misspelling of&", Selector, Id);
exit;
end if;
Next_Entity (Id);
end loop;
end;
-- Specialize the message if this may be an instantiation
-- of a child unit that was not mentioned in the context.
if Nkind (Parent (N)) = N_Package_Instantiation
and then Is_Generic_Instance (Entity (Prefix (N)))
and then Is_Compilation_Unit
(Generic_Parent (Parent (Entity (Prefix (N)))))
then
Error_Msg_NE
("\possible missing with clause on child unit&",
N, Selector);
end if;
end if;
end if;
Id := Any_Id;
end if;
end if;
<<found>>
if Comes_From_Source (N)
and then Is_Remote_Access_To_Subprogram_Type (Id)
then
Id := Equivalent_Type (Id);
Set_Chars (Selector, Chars (Id));
end if;
if Ekind (P_Name) = E_Package
and then From_With_Type (P_Name)
then
if From_With_Type (Id)
or else (Ekind (Id) = E_Package and then From_With_Type (Id))
then
null;
else
Error_Msg_N
("imported package can only be used to access imported type",
N);
end if;
end if;
if Is_Task_Type (P_Name)
and then ((Ekind (Id) = E_Entry
and then Nkind (Parent (N)) /= N_Attribute_Reference)
or else
(Ekind (Id) = E_Entry_Family
and then
Nkind (Parent (Parent (N))) /= N_Attribute_Reference))
then
-- It is an entry call after all, either to the current task
-- (which will deadlock) or to an enclosing task.
Analyze_Selected_Component (N);
return;
end if;
Change_Selected_Component_To_Expanded_Name (N);
Set_Entity_With_Style_Check (N, Id);
Generate_Reference (Id, N);
if Is_Type (Id) then
Set_Etype (N, Id);
else
Set_Etype (N, Get_Full_View (Etype (Id)));
end if;
-- If the Ekind of the entity is Void, it means that all homonyms
-- are hidden from all visibility (RM 8.3(5,14-20)).
if Ekind (Id) = E_Void then
Premature_Usage (N);
elsif Is_Overloadable (Id)
and then Present (Homonym (Id))
then
declare
H : Entity_Id := Homonym (Id);
begin
while Present (H) loop
if Scope (H) = Scope (Id) then
Collect_Interps (N);
exit;
end if;
H := Homonym (H);
end loop;
end;
end if;
if Nkind (Selector_Name (N)) = N_Operator_Symbol
and then Scope (Id) /= Standard_Standard
then
-- In addition to user-defined operators in the given scope,
-- there may be an implicit instance of the predefined
-- operator. The operator (defined in Standard) is found
-- in Has_Implicit_Operator, and added to the interpretations.
-- Procedure Add_One_Interp will determine which hides which.
if Has_Implicit_Operator (N) then
null;
end if;
end if;
end Find_Expanded_Name;
-------------------------
-- Find_Renamed_Entity --
-------------------------
function Find_Renamed_Entity
(N : Node_Id;
Nam : Node_Id;
New_S : Entity_Id;
Is_Actual : Boolean := False) return Entity_Id
is
I : Interp_Index;
I1 : Interp_Index := 0; -- Suppress junk warnings
It : Interp;
It1 : Interp;
Old_S : Entity_Id;
Inst : Entity_Id;
function Enclosing_Instance return Entity_Id;
-- If the renaming determines the entity for the default of a formal
-- subprogram nested within another instance, choose the innermost
-- candidate. This is because if the formal has a box, and we are within
-- an enclosing instance where some candidate interpretations are local
-- to this enclosing instance, we know that the default was properly
-- resolved when analyzing the generic, so we prefer the local
-- candidates to those that are external. This is not always the case
-- but is a reasonable heuristic on the use of nested generics.
-- The proper solution requires a full renaming model.
function Within (Inner, Outer : Entity_Id) return Boolean;
-- Determine whether a candidate subprogram is defined within
-- the enclosing instance. If yes, it has precedence over outer
-- candidates.
function Is_Visible_Operation (Op : Entity_Id) return Boolean;
-- If the renamed entity is an implicit operator, check whether it is
-- visible because its operand type is properly visible. This
-- check applies to explicit renamed entities that appear in the
-- source in a renaming declaration or a formal subprogram instance,
-- but not to default generic actuals with a name.
------------------------
-- Enclosing_Instance --
------------------------
function Enclosing_Instance return Entity_Id is
S : Entity_Id;
begin
if not Is_Generic_Instance (Current_Scope)
and then not Is_Actual
then
return Empty;
end if;
S := Scope (Current_Scope);
while S /= Standard_Standard loop
if Is_Generic_Instance (S) then
return S;
end if;
S := Scope (S);
end loop;
return Empty;
end Enclosing_Instance;
--------------------------
-- Is_Visible_Operation --
--------------------------
function Is_Visible_Operation (Op : Entity_Id) return Boolean is
Scop : Entity_Id;
Typ : Entity_Id;
Btyp : Entity_Id;
begin
if Ekind (Op) /= E_Operator
or else Scope (Op) /= Standard_Standard
or else (In_Instance
and then
(not Is_Actual
or else Present (Enclosing_Instance)))
then
return True;
else
-- For a fixed point type operator, check the resulting type,
-- because it may be a mixed mode integer * fixed operation.
if Present (Next_Formal (First_Formal (New_S)))
and then Is_Fixed_Point_Type (Etype (New_S))
then
Typ := Etype (New_S);
else
Typ := Etype (First_Formal (New_S));
end if;
Btyp := Base_Type (Typ);
if Nkind (Nam) /= N_Expanded_Name then
return (In_Open_Scopes (Scope (Btyp))
or else Is_Potentially_Use_Visible (Btyp)
or else In_Use (Btyp)
or else In_Use (Scope (Btyp)));
else
Scop := Entity (Prefix (Nam));
if Ekind (Scop) = E_Package
and then Present (Renamed_Object (Scop))
then
Scop := Renamed_Object (Scop);
end if;
-- Operator is visible if prefix of expanded name denotes
-- scope of type, or else type type is defined in System_Aux
-- and the prefix denotes System.
return Scope (Btyp) = Scop
or else (Scope (Btyp) = System_Aux_Id
and then Scope (Scope (Btyp)) = Scop);
end if;
end if;
end Is_Visible_Operation;
------------
-- Within --
------------
function Within (Inner, Outer : Entity_Id) return Boolean is
Sc : Entity_Id := Scope (Inner);
begin
while Sc /= Standard_Standard loop
if Sc = Outer then
return True;
else
Sc := Scope (Sc);
end if;
end loop;
return False;
end Within;
-- Start of processing for Find_Renamed_Entry
begin
Old_S := Any_Id;
Candidate_Renaming := Empty;
if not Is_Overloaded (Nam) then
if Entity_Matches_Spec (Entity (Nam), New_S)
and then Is_Visible_Operation (Entity (Nam))
then
Old_S := Entity (Nam);
elsif
Present (First_Formal (Entity (Nam)))
and then Present (First_Formal (New_S))
and then (Base_Type (Etype (First_Formal (Entity (Nam))))
= Base_Type (Etype (First_Formal (New_S))))
then
Candidate_Renaming := Entity (Nam);
end if;
else
Get_First_Interp (Nam, I, It);
while Present (It.Nam) loop
if Entity_Matches_Spec (It.Nam, New_S)
and then Is_Visible_Operation (It.Nam)
then
if Old_S /= Any_Id then
-- Note: The call to Disambiguate only happens if a
-- previous interpretation was found, in which case I1
-- has received a value.
It1 := Disambiguate (Nam, I1, I, Etype (Old_S));
if It1 = No_Interp then
Inst := Enclosing_Instance;
if Present (Inst) then
if Within (It.Nam, Inst) then
return (It.Nam);
elsif Within (Old_S, Inst) then
return (Old_S);
else
Error_Msg_N ("ambiguous renaming", N);
return Old_S;
end if;
else
Error_Msg_N ("ambiguous renaming", N);
return Old_S;
end if;
else
Old_S := It1.Nam;
exit;
end if;
else
I1 := I;
Old_S := It.Nam;
end if;
elsif
Present (First_Formal (It.Nam))
and then Present (First_Formal (New_S))
and then (Base_Type (Etype (First_Formal (It.Nam)))
= Base_Type (Etype (First_Formal (New_S))))
then
Candidate_Renaming := It.Nam;
end if;
Get_Next_Interp (I, It);
end loop;
Set_Entity (Nam, Old_S);
Set_Is_Overloaded (Nam, False);
end if;
return Old_S;
end Find_Renamed_Entity;
-----------------------------
-- Find_Selected_Component --
-----------------------------
procedure Find_Selected_Component (N : Node_Id) is
P : Node_Id := Prefix (N);
P_Name : Entity_Id;
-- Entity denoted by prefix
P_Type : Entity_Id;
-- and its type
Nam : Node_Id;
begin
Analyze (P);
if Nkind (P) = N_Error then
return;
-- If the selector already has an entity, the node has been
-- constructed in the course of expansion, and is known to be
-- valid. Do not verify that it is defined for the type (it may
-- be a private component used in the expansion of record equality).
elsif Present (Entity (Selector_Name (N))) then
if No (Etype (N))
or else Etype (N) = Any_Type
then
declare
Sel_Name : Node_Id := Selector_Name (N);
Selector : Entity_Id := Entity (Sel_Name);
C_Etype : Node_Id;
begin
Set_Etype (Sel_Name, Etype (Selector));
if not Is_Entity_Name (P) then
Resolve (P, Etype (P));
end if;
-- Build an actual subtype except for the first parameter
-- of an init_proc, where this actual subtype is by
-- definition incorrect, since the object is uninitialized
-- (and does not even have defined discriminants etc.)
if Is_Entity_Name (P)
and then Ekind (Entity (P)) = E_Function
then
Nam := New_Copy (P);
if Is_Overloaded (P) then
Save_Interps (P, Nam);
end if;
Rewrite (P,
Make_Function_Call (Sloc (P), Name => Nam));
Analyze_Call (P);
Analyze_Selected_Component (N);
return;
elsif Ekind (Selector) = E_Component
and then (not Is_Entity_Name (P)
or else Chars (Entity (P)) /= Name_uInit)
then
C_Etype :=
Build_Actual_Subtype_Of_Component (
Etype (Selector), N);
else
C_Etype := Empty;
end if;
if No (C_Etype) then
C_Etype := Etype (Selector);
else
Insert_Action (N, C_Etype);
C_Etype := Defining_Identifier (C_Etype);
end if;
Set_Etype (N, C_Etype);
end;
-- If this is the name of an entry or protected operation, and
-- the prefix is an access type, insert an explicit dereference,
-- so that entry calls are treated uniformly.
if Is_Access_Type (Etype (P))
and then Is_Concurrent_Type (Designated_Type (Etype (P)))
then
declare
New_P : Node_Id :=
Make_Explicit_Dereference (Sloc (P),
Prefix => Relocate_Node (P));
begin
Rewrite (P, New_P);
Set_Etype (P, Designated_Type (Etype (Prefix (P))));
end;
end if;
-- If the selected component appears within a default expression
-- and it has an actual subtype, the pre-analysis has not yet
-- completed its analysis, because Insert_Actions is disabled in
-- that context. Within the init_proc of the enclosing type we
-- must complete this analysis, if an actual subtype was created.
elsif Inside_Init_Proc then
declare
Typ : constant Entity_Id := Etype (N);
Decl : constant Node_Id := Declaration_Node (Typ);
begin
if Nkind (Decl) = N_Subtype_Declaration
and then not Analyzed (Decl)
and then Is_List_Member (Decl)
and then No (Parent (Decl))
then
Remove (Decl);
Insert_Action (N, Decl);
end if;
end;
end if;
return;
elsif Is_Entity_Name (P) then
P_Name := Entity (P);
-- The prefix may denote an enclosing type which is the completion
-- of an incomplete type declaration.
if Is_Type (P_Name) then
Set_Entity (P, Get_Full_View (P_Name));
Set_Etype (P, Entity (P));
P_Name := Entity (P);
end if;
P_Type := Base_Type (Etype (P));
if Debug_Flag_E then
Write_Str ("Found prefix type to be ");
Write_Entity_Info (P_Type, " "); Write_Eol;
end if;
-- First check for components of a record object (not the
-- result of a call, which is handled below).
if Is_Appropriate_For_Record (P_Type)
and then not Is_Overloadable (P_Name)
and then not Is_Type (P_Name)
then
-- Selected component of record. Type checking will validate
-- name of selector.
Analyze_Selected_Component (N);
elsif Is_Appropriate_For_Entry_Prefix (P_Type)
and then not In_Open_Scopes (P_Name)
and then (not Is_Concurrent_Type (Etype (P_Name))
or else not In_Open_Scopes (Etype (P_Name)))
then
-- Call to protected operation or entry. Type checking is
-- needed on the prefix.
Analyze_Selected_Component (N);
elsif (In_Open_Scopes (P_Name)
and then Ekind (P_Name) /= E_Void
and then not Is_Overloadable (P_Name))
or else (Is_Concurrent_Type (Etype (P_Name))
and then In_Open_Scopes (Etype (P_Name)))
then
-- Prefix denotes an enclosing loop, block, or task, i.e. an
-- enclosing construct that is not a subprogram or accept.
Find_Expanded_Name (N);
elsif Ekind (P_Name) = E_Package then
Find_Expanded_Name (N);
elsif Is_Overloadable (P_Name) then
-- The subprogram may be a renaming (of an enclosing scope) as
-- in the case of the name of the generic within an instantiation.
if (Ekind (P_Name) = E_Procedure
or else Ekind (P_Name) = E_Function)
and then Present (Alias (P_Name))
and then Is_Generic_Instance (Alias (P_Name))
then
P_Name := Alias (P_Name);
end if;
if Is_Overloaded (P) then
-- The prefix must resolve to a unique enclosing construct.
declare
Found : Boolean := False;
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
if In_Open_Scopes (It.Nam) then
if Found then
Error_Msg_N (
"prefix must be unique enclosing scope", N);
Set_Entity (N, Any_Id);
Set_Etype (N, Any_Type);
return;
else
Found := True;
P_Name := It.Nam;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
if In_Open_Scopes (P_Name) then
Set_Entity (P, P_Name);
Set_Is_Overloaded (P, False);
Find_Expanded_Name (N);
else
-- If no interpretation as an expanded name is possible, it
-- must be a selected component of a record returned by a
-- function call. Reformat prefix as a function call, the
-- rest is done by type resolution. If the prefix is a
-- procedure or entry, as is P.X; this is an error.
if Ekind (P_Name) /= E_Function
and then (not Is_Overloaded (P)
or else
Nkind (Parent (N)) = N_Procedure_Call_Statement)
then
-- Prefix may mention a package that is hidden by a local
-- declaration: let the user know. Scan the full homonym
-- chain, the candidate package may be anywhere on it.
if Present (Homonym (Current_Entity (P_Name))) then
P_Name := Current_Entity (P_Name);
while Present (P_Name) loop
exit when Ekind (P_Name) = E_Package;
P_Name := Homonym (P_Name);
end loop;
if Present (P_Name) then
Error_Msg_Sloc := Sloc (Entity (Prefix (N)));
Error_Msg_NE
("package& is hidden by declaration#",
N, P_Name);
Set_Entity (Prefix (N), P_Name);
Find_Expanded_Name (N);
return;
else
P_Name := Entity (Prefix (N));
end if;
end if;
Error_Msg_NE
("invalid prefix in selected component&", N, P_Name);
Change_Selected_Component_To_Expanded_Name (N);
Set_Entity (N, Any_Id);
Set_Etype (N, Any_Type);
else
Nam := New_Copy (P);
Save_Interps (P, Nam);
Rewrite (P,
Make_Function_Call (Sloc (P), Name => Nam));
Analyze_Call (P);
Analyze_Selected_Component (N);
end if;
end if;
-- Remaining cases generate various error messages
else
-- Format node as expanded name, to avoid cascaded errors
Change_Node (N, N_Expanded_Name);
Set_Prefix (N, P);
Set_Entity (N, Any_Id);
Set_Etype (N, Any_Type);
-- Set_Selector_Name (N, Empty); ????
-- Issue error message, but avoid this if error issued already.
-- Use identifier of prefix if one is available.
if P_Name = Any_Id then
null;
elsif Ekind (P_Name) = E_Void then
Premature_Usage (P);
elsif Nkind (P) /= N_Attribute_Reference then
Error_Msg_N (
"invalid prefix in selected component&", P);
else
Error_Msg_N (
"invalid prefix in selected component", P);
end if;
end if;
else
-- If prefix is not the name of an entity, it must be an expression,
-- whose type is appropriate for a record. This is determined by
-- type resolution.
Analyze_Selected_Component (N);
end if;
end Find_Selected_Component;
---------------
-- Find_Type --
---------------
procedure Find_Type (N : Node_Id) is
C : Entity_Id;
Typ : Entity_Id;
T : Entity_Id;
T_Name : Entity_Id;
begin
if N = Error then
return;
elsif Nkind (N) = N_Attribute_Reference then
-- Class attribute. This is only valid in Ada 95 mode, but we don't
-- do a check, since the tagged type referenced could only exist if
-- we were in 95 mode when it was declared (or, if we were in Ada
-- 83 mode, then an error message would already have been issued).
if Attribute_Name (N) = Name_Class then
Check_Restriction (No_Dispatch, N);
Find_Type (Prefix (N));
-- Propagate error from bad prefix
if Etype (Prefix (N)) = Any_Type then
Set_Entity (N, Any_Type);
Set_Etype (N, Any_Type);
return;
end if;
T := Base_Type (Entity (Prefix (N)));
-- Case of non-tagged type
if not Is_Tagged_Type (T) then
if Ekind (T) = E_Incomplete_Type then
-- It is legal to denote the class type of an incomplete
-- type. The full type will have to be tagged, of course.
Set_Is_Tagged_Type (T);
Make_Class_Wide_Type (T);
Set_Entity (N, Class_Wide_Type (T));
Set_Etype (N, Class_Wide_Type (T));
elsif Ekind (T) = E_Private_Type
and then not Is_Generic_Type (T)
and then In_Private_Part (Scope (T))
then
-- The Class attribute can be applied to an untagged
-- private type fulfilled by a tagged type prior to
-- the full type declaration (but only within the
-- parent package's private part). Create the class-wide
-- type now and check that the full type is tagged
-- later during its analysis. Note that we do not
-- mark the private type as tagged, unlike the case
-- of incomplete types, because the type must still
-- appear untagged to outside units.
if not Present (Class_Wide_Type (T)) then
Make_Class_Wide_Type (T);
end if;
Set_Entity (N, Class_Wide_Type (T));
Set_Etype (N, Class_Wide_Type (T));
else
-- Should we introduce a type Any_Tagged and use
-- Wrong_Type here, it would be a bit more consistent???
Error_Msg_NE
("tagged type required, found}",
Prefix (N), First_Subtype (T));
Set_Entity (N, Any_Type);
return;
end if;
-- Case of tagged type
else
C := Class_Wide_Type (Entity (Prefix (N)));
Set_Entity_With_Style_Check (N, C);
Generate_Reference (C, N);
Set_Etype (N, C);
if From_With_Type (C)
and then Nkind (Parent (N)) /= N_Access_Definition
and then not Analyzed (T)
then
Error_Msg_N
("imported class-wide type can only be used" &
" for access parameters", N);
end if;
end if;
-- Base attribute, allowed in Ada 95 mode only
elsif Attribute_Name (N) = Name_Base then
if Ada_83 and then Comes_From_Source (N) then
Error_Msg_N
("(Ada 83) Base attribute not allowed in subtype mark", N);
else
Find_Type (Prefix (N));
Typ := Entity (Prefix (N));
if Sloc (Typ) = Standard_Location
and then Base_Type (Typ) = Typ
and then Warn_On_Redundant_Constructs
then
Error_Msg_NE
("?redudant attribute, & is its own base type", N, Typ);
end if;
T := Base_Type (Typ);
Set_Entity (N, T);
Set_Etype (N, T);
-- Rewrite attribute reference with type itself (see similar
-- processing in Analyze_Attribute, case Base)
Rewrite (N,
New_Reference_To (Entity (N), Sloc (N)));
Set_Etype (N, T);
end if;
-- All other attributes are invalid in a subtype mark
else
Error_Msg_N ("invalid attribute in subtype mark", N);
end if;
else
Analyze (N);
if Is_Entity_Name (N) then
T_Name := Entity (N);
else
Error_Msg_N ("subtype mark required in this context", N);
Set_Etype (N, Any_Type);
return;
end if;
if T_Name = Any_Id or else Etype (N) = Any_Type then
-- Undefined id. Make it into a valid type
Set_Entity (N, Any_Type);
elsif not Is_Type (T_Name)
and then T_Name /= Standard_Void_Type
then
Error_Msg_Sloc := Sloc (T_Name);
Error_Msg_N ("subtype mark required in this context", N);
Error_Msg_NE ("\found & declared#", N, T_Name);
Set_Entity (N, Any_Type);
else
T_Name := Get_Full_View (T_Name);
if In_Open_Scopes (T_Name) then
if Ekind (Base_Type (T_Name)) = E_Task_Type then
Error_Msg_N ("task type cannot be used as type mark " &
"within its own body", N);
else
Error_Msg_N ("type declaration cannot refer to itself", N);
end if;
Set_Etype (N, Any_Type);
Set_Entity (N, Any_Type);
Set_Error_Posted (T_Name);
return;
end if;
Set_Entity (N, T_Name);
Set_Etype (N, T_Name);
end if;
end if;
if Present (Etype (N)) then
if Is_Fixed_Point_Type (Etype (N)) then
Check_Restriction (No_Fixed_Point, N);
elsif Is_Floating_Point_Type (Etype (N)) then
Check_Restriction (No_Floating_Point, N);
end if;
end if;
end Find_Type;
-------------------
-- Get_Full_View --
-------------------
function Get_Full_View (T_Name : Entity_Id) return Entity_Id is
begin
if (Ekind (T_Name) = E_Incomplete_Type
and then Present (Full_View (T_Name)))
then
return Full_View (T_Name);
elsif Is_Class_Wide_Type (T_Name)
and then Ekind (Root_Type (T_Name)) = E_Incomplete_Type
and then Present (Full_View (Root_Type (T_Name)))
then
return Class_Wide_Type (Full_View (Root_Type (T_Name)));
else
return T_Name;
end if;
end Get_Full_View;
------------------------------------
-- Has_Implicit_Character_Literal --
------------------------------------
function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is
Id : Entity_Id;
Found : Boolean := False;
P : constant Entity_Id := Entity (Prefix (N));
Priv_Id : Entity_Id := Empty;
begin
if Ekind (P) = E_Package
and then not In_Open_Scopes (P)
then
Priv_Id := First_Private_Entity (P);
end if;
if P = Standard_Standard then
Change_Selected_Component_To_Expanded_Name (N);
Rewrite (N, Selector_Name (N));
Analyze (N);
Set_Etype (Original_Node (N), Standard_Character);
return True;
end if;
Id := First_Entity (P);
while Present (Id)
and then Id /= Priv_Id
loop
if Is_Character_Type (Id)
and then (Root_Type (Id) = Standard_Character
or else Root_Type (Id) = Standard_Wide_Character)
and then Id = Base_Type (Id)
then
-- We replace the node with the literal itself, resolve as a
-- character, and set the type correctly.
if not Found then
Change_Selected_Component_To_Expanded_Name (N);
Rewrite (N, Selector_Name (N));
Analyze (N);
Set_Etype (N, Id);
Set_Etype (Original_Node (N), Id);
Found := True;
else
-- More than one type derived from Character in given scope.
-- Collect all possible interpretations.
Add_One_Interp (N, Id, Id);
end if;
end if;
Next_Entity (Id);
end loop;
return Found;
end Has_Implicit_Character_Literal;
---------------------------
-- Has_Implicit_Operator --
---------------------------
function Has_Implicit_Operator (N : Node_Id) return Boolean is
Op_Id : constant Name_Id := Chars (Selector_Name (N));
P : constant Entity_Id := Entity (Prefix (N));
Id : Entity_Id;
Priv_Id : Entity_Id := Empty;
procedure Add_Implicit_Operator (T : Entity_Id);
-- Add implicit interpretation to node N, using the type for which
-- a predefined operator exists.
---------------------------
-- Add_Implicit_Operator --
---------------------------
procedure Add_Implicit_Operator (T : Entity_Id) is
Predef_Op : Entity_Id;
begin
Predef_Op := Current_Entity (Selector_Name (N));
while Present (Predef_Op)
and then Scope (Predef_Op) /= Standard_Standard
loop
Predef_Op := Homonym (Predef_Op);
end loop;
if Nkind (N) = N_Selected_Component then
Change_Selected_Component_To_Expanded_Name (N);
end if;
Add_One_Interp (N, Predef_Op, T);
-- For operators with unary and binary interpretations, add both
if Present (Homonym (Predef_Op)) then
Add_One_Interp (N, Homonym (Predef_Op), T);
end if;
end Add_Implicit_Operator;
-- Start of processing for Has_Implicit_Operator
begin
if Ekind (P) = E_Package
and then not In_Open_Scopes (P)
then
Priv_Id := First_Private_Entity (P);
end if;
Id := First_Entity (P);
case Op_Id is
-- Boolean operators: an implicit declaration exists if the scope
-- contains a declaration for a derived Boolean type, or for an
-- array of Boolean type.
when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor =>
while Id /= Priv_Id loop
if Valid_Boolean_Arg (Id)
and then Id = Base_Type (Id)
then
Add_Implicit_Operator (Id);
return True;
end if;
Next_Entity (Id);
end loop;
-- Equality: look for any non-limited type. Result is Boolean.
when Name_Op_Eq | Name_Op_Ne =>
while Id /= Priv_Id loop
if Is_Type (Id)
and then not Is_Limited_Type (Id)
and then Id = Base_Type (Id)
then
Add_Implicit_Operator (Standard_Boolean);
return True;
end if;
Next_Entity (Id);
end loop;
-- Comparison operators: scalar type, or array of scalar.
when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge =>
while Id /= Priv_Id loop
if (Is_Scalar_Type (Id)
or else (Is_Array_Type (Id)
and then Is_Scalar_Type (Component_Type (Id))))
and then Id = Base_Type (Id)
then
Add_Implicit_Operator (Standard_Boolean);
return True;
end if;
Next_Entity (Id);
end loop;
-- Arithmetic operators: any numeric type
when Name_Op_Abs |
Name_Op_Add |
Name_Op_Mod |
Name_Op_Rem |
Name_Op_Subtract |
Name_Op_Multiply |
Name_Op_Divide |
Name_Op_Expon =>
while Id /= Priv_Id loop
if Is_Numeric_Type (Id)
and then Id = Base_Type (Id)
then
Add_Implicit_Operator (Id);
return True;
end if;
Next_Entity (Id);
end loop;
-- Concatenation: any one-dimensional array type
when Name_Op_Concat =>
while Id /= Priv_Id loop
if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1
and then Id = Base_Type (Id)
then
Add_Implicit_Operator (Id);
return True;
end if;
Next_Entity (Id);
end loop;
-- What is the others condition here? Should we be using a
-- subtype of Name_Id that would restrict to operators ???
when others => null;
end case;
-- If we fall through, then we do not have an implicit operator
return False;
end Has_Implicit_Operator;
--------------------
-- In_Open_Scopes --
--------------------
function In_Open_Scopes (S : Entity_Id) return Boolean is
begin
-- Since there are several scope stacks maintained by Scope_Stack each
-- delineated by Standard (see comments by definition of Scope_Stack)
-- it is necessary to end the search when Standard is reached.
for J in reverse 0 .. Scope_Stack.Last loop
if Scope_Stack.Table (J).Entity = S then
return True;
end if;
-- We need Is_Active_Stack_Base to tell us when to stop rather
-- than checking for Standard_Standard because there are cases
-- where Standard_Standard appears in the middle of the active
-- set of scopes. This affects the declaration and overriding
-- of private inherited operations in instantiations of generic
-- child units.
exit when Scope_Stack.Table (J).Is_Active_Stack_Base;
end loop;
return False;
end In_Open_Scopes;
-----------------------------
-- Inherit_Renamed_Profile --
-----------------------------
procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is
New_F : Entity_Id;
Old_F : Entity_Id;
Old_T : Entity_Id;
New_T : Entity_Id;
begin
if Ekind (Old_S) = E_Operator then
New_F := First_Formal (New_S);
while Present (New_F) loop
Set_Etype (New_F, Base_Type (Etype (New_F)));
Next_Formal (New_F);
end loop;
Set_Etype (New_S, Base_Type (Etype (New_S)));
else
New_F := First_Formal (New_S);
Old_F := First_Formal (Old_S);
while Present (New_F) loop
New_T := Etype (New_F);
Old_T := Etype (Old_F);
-- If the new type is a renaming of the old one, as is the
-- case for actuals in instances, retain its name, to simplify
-- later disambiguation.
if Nkind (Parent (New_T)) = N_Subtype_Declaration
and then Is_Entity_Name (Subtype_Indication (Parent (New_T)))
and then Entity (Subtype_Indication (Parent (New_T))) = Old_T
then
null;
else
Set_Etype (New_F, Old_T);
end if;
Next_Formal (New_F);
Next_Formal (Old_F);
end loop;
if Ekind (Old_S) = E_Function
or else Ekind (Old_S) = E_Enumeration_Literal
then
Set_Etype (New_S, Etype (Old_S));
end if;
end if;
end Inherit_Renamed_Profile;
----------------
-- Initialize --
----------------
procedure Initialize is
begin
Urefs.Init;
end Initialize;
-------------------------
-- Install_Use_Clauses --
-------------------------
procedure Install_Use_Clauses (Clause : Node_Id) is
U : Node_Id := Clause;
P : Node_Id;
Id : Entity_Id;
begin
while Present (U) loop
-- Case of USE package
if Nkind (U) = N_Use_Package_Clause then
P := First (Names (U));
while Present (P) loop
Id := Entity (P);
if Ekind (Id) = E_Package then
if In_Use (Id) then
Set_Redundant_Use (P, True);
elsif Present (Renamed_Object (Id))
and then In_Use (Renamed_Object (Id))
then
Set_Redundant_Use (P, True);
else
Use_One_Package (Id, U);
end if;
end if;
Next (P);
end loop;
-- case of USE TYPE
else
P := First (Subtype_Marks (U));
while Present (P) loop
if Entity (P) /= Any_Type then
Use_One_Type (P, U);
end if;
Next (P);
end loop;
end if;
Next_Use_Clause (U);
end loop;
end Install_Use_Clauses;
-------------------------------------
-- Is_Appropriate_For_Entry_Prefix --
-------------------------------------
function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is
P_Type : Entity_Id := T;
begin
if Is_Access_Type (P_Type) then
P_Type := Designated_Type (P_Type);
end if;
return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type);
end Is_Appropriate_For_Entry_Prefix;
-------------------------------
-- Is_Appropriate_For_Record --
-------------------------------
function Is_Appropriate_For_Record
(T : Entity_Id)
return Boolean
is
function Has_Components (T1 : Entity_Id) return Boolean;
-- Determine if given type has components (i.e. is either a record
-- type or a type that has discriminants).
function Has_Components (T1 : Entity_Id) return Boolean is
begin
return Is_Record_Type (T1)
or else (Is_Private_Type (T1) and then Has_Discriminants (T1))
or else (Is_Task_Type (T1) and then Has_Discriminants (T1));
end Has_Components;
-- Start of processing for Is_Appropriate_For_Record
begin
return
Present (T)
and then (Has_Components (T)
or else (Is_Access_Type (T)
and then
Has_Components (Designated_Type (T))));
end Is_Appropriate_For_Record;
---------------
-- New_Scope --
---------------
procedure New_Scope (S : Entity_Id) is
E : Entity_Id;
begin
if Ekind (S) = E_Void then
null;
-- Set scope depth if not a non-concurrent type, and we have not
-- yet set the scope depth. This means that we have the first
-- occurrence of the scope, and this is where the depth is set.
elsif (not Is_Type (S) or else Is_Concurrent_Type (S))
and then not Scope_Depth_Set (S)
then
if S = Standard_Standard then
Set_Scope_Depth_Value (S, Uint_0);
elsif Is_Child_Unit (S) then
Set_Scope_Depth_Value (S, Uint_1);
elsif not Is_Record_Type (Current_Scope) then
if Ekind (S) = E_Loop then
Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope));
else
Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1);
end if;
end if;
end if;
Scope_Stack.Increment_Last;
Scope_Stack.Table (Scope_Stack.Last).Entity := S;
Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
Scope_Suppress;
Scope_Stack.Table (Scope_Stack.Last).Save_Entity_Suppress :=
Entity_Suppress.Last;
if Scope_Stack.Last > Scope_Stack.First then
Scope_Stack.Table (Scope_Stack.Last).Component_Alignment_Default :=
Scope_Stack.Table (Scope_Stack.Last - 1).Component_Alignment_Default;
end if;
Scope_Stack.Table (Scope_Stack.Last).Last_Subprogram_Name := null;
Scope_Stack.Table (Scope_Stack.Last).Is_Transient := False;
Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := Empty;
Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions := No_List;
Scope_Stack.Table
(Scope_Stack.Last).Actions_To_Be_Wrapped_Before := No_List;
Scope_Stack.Table
(Scope_Stack.Last).Actions_To_Be_Wrapped_After := No_List;
Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := Empty;
Scope_Stack.Table (Scope_Stack.Last).Is_Active_Stack_Base := False;
if Debug_Flag_W then
Write_Str ("--> new scope: ");
Write_Name (Chars (Current_Scope));
Write_Str (", Id=");
Write_Int (Int (Current_Scope));
Write_Str (", Depth=");
Write_Int (Int (Scope_Stack.Last));
Write_Eol;
end if;
-- Copy from Scope (S) the categorization flags to S, this is not
-- done in case Scope (S) is Standard_Standard since propagation
-- is from library unit entity inwards.
if S /= Standard_Standard
and then Scope (S) /= Standard_Standard
and then not Is_Child_Unit (S)
then
E := Scope (S);
if Nkind (E) not in N_Entity then
return;
end if;
-- We only propagate inwards for library level entities,
-- inner level subprograms do not inherit the categorization.
if Is_Library_Level_Entity (S) then
Set_Is_Pure (S, Is_Pure (E));
Set_Is_Preelaborated (S, Is_Preelaborated (E));
Set_Is_Remote_Call_Interface (S, Is_Remote_Call_Interface (E));
Set_Is_Remote_Types (S, Is_Remote_Types (E));
Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
end if;
end if;
end New_Scope;
---------------
-- Pop_Scope --
---------------
procedure Pop_Scope is
E : Entity_Id;
begin
if Debug_Flag_E then
Write_Info;
end if;
Scope_Suppress :=
Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress;
while Entity_Suppress.Last >
Scope_Stack.Table (Scope_Stack.Last).Save_Entity_Suppress
loop
E := Entity_Suppress.Table (Entity_Suppress.Last).Entity;
case Entity_Suppress.Table (Entity_Suppress.Last).Check is
when Access_Check =>
Set_Suppress_Access_Checks (E, False);
when Accessibility_Check =>
Set_Suppress_Accessibility_Checks (E, False);
when Discriminant_Check =>
Set_Suppress_Discriminant_Checks (E, False);
when Division_Check =>
Set_Suppress_Division_Checks (E, False);
when Elaboration_Check =>
Set_Suppress_Elaboration_Checks (E, False);
when Index_Check =>
Set_Suppress_Index_Checks (E, False);
when Length_Check =>
Set_Suppress_Length_Checks (E, False);
when Overflow_Check =>
Set_Suppress_Overflow_Checks (E, False);
when Range_Check =>
Set_Suppress_Range_Checks (E, False);
when Storage_Check =>
Set_Suppress_Storage_Checks (E, False);
when Tag_Check =>
Set_Suppress_Tag_Checks (E, False);
-- All_Checks should not appear here (since it is entered as a
-- series of its separate checks). Bomb if it is encountered
when All_Checks =>
raise Program_Error;
end case;
Entity_Suppress.Decrement_Last;
end loop;
if Debug_Flag_W then
Write_Str ("--> exiting scope: ");
Write_Name (Chars (Current_Scope));
Write_Str (", Depth=");
Write_Int (Int (Scope_Stack.Last));
Write_Eol;
end if;
End_Use_Clauses (Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause);
-- If the actions to be wrapped are still there they will get lost
-- causing incomplete code to be generated. It is better to abort in
-- this case.
pragma Assert (Scope_Stack.Table
(Scope_Stack.Last).Actions_To_Be_Wrapped_Before = No_List);
pragma Assert (Scope_Stack.Table
(Scope_Stack.Last).Actions_To_Be_Wrapped_After = No_List);
-- Free last subprogram name if allocated, and pop scope
Free (Scope_Stack.Table (Scope_Stack.Last).Last_Subprogram_Name);
Scope_Stack.Decrement_Last;
end Pop_Scope;
---------------------
-- Premature_Usage --
---------------------
procedure Premature_Usage (N : Node_Id) is
Kind : Node_Kind := Nkind (Parent (Entity (N)));
E : Entity_Id := Entity (N);
begin
-- Within an instance, the analysis of the actual for a formal object
-- does not see the name of the object itself. This is significant
-- only if the object is an aggregate, where its analysis does not do
-- any name resolution on component associations. (see 4717-008). In
-- such a case, look for the visible homonym on the chain.
if In_Instance
and then Present (Homonym (E))
then
E := Homonym (E);
while Present (E)
and then not In_Open_Scopes (Scope (E))
loop
E := Homonym (E);
end loop;
if Present (E) then
Set_Entity (N, E);
Set_Etype (N, Etype (E));
return;
end if;
end if;
if Kind = N_Component_Declaration then
Error_Msg_N
("component&! cannot be used before end of record declaration", N);
elsif Kind = N_Parameter_Specification then
Error_Msg_N
("formal parameter&! cannot be used before end of specification",
N);
elsif Kind = N_Discriminant_Specification then
Error_Msg_N
("discriminant&! cannot be used before end of discriminant part",
N);
elsif Kind = N_Procedure_Specification
or else Kind = N_Function_Specification
then
Error_Msg_N
("subprogram&! cannot be used before end of its declaration",
N);
else
Error_Msg_N
("object& cannot be used before end of its declaration!", N);
end if;
end Premature_Usage;
------------------------
-- Present_System_Aux --
------------------------
function Present_System_Aux (N : Node_Id := Empty) return Boolean is
Loc : Source_Ptr;
Aux_Name : Name_Id;
Unum : Unit_Number_Type;
Withn : Node_Id;
With_Sys : Node_Id;
The_Unit : Node_Id;
function Find_System (C_Unit : Node_Id) return Entity_Id;
-- Scan context clause of compilation unit to find a with_clause
-- for System.
function Find_System (C_Unit : Node_Id) return Entity_Id is
With_Clause : Node_Id;
begin
With_Clause := First (Context_Items (C_Unit));
while Present (With_Clause) loop
if (Nkind (With_Clause) = N_With_Clause
and then Chars (Name (With_Clause)) = Name_System)
and then Comes_From_Source (With_Clause)
then
return With_Clause;
end if;
Next (With_Clause);
end loop;
return Empty;
end Find_System;
-- Start of processing for Present_System_Aux
begin
-- The child unit may have been loaded and analyzed already.
if Present (System_Aux_Id) then
return True;
-- If no previous pragma for System.Aux, nothing to load
elsif No (System_Extend_Pragma_Arg) then
return False;
-- Use the unit name given in the pragma to retrieve the unit.
-- Verify that System itself appears in the context clause of the
-- current compilation. If System is not present, an error will
-- have been reported already.
else
With_Sys := Find_System (Cunit (Current_Sem_Unit));
The_Unit := Unit (Cunit (Current_Sem_Unit));
if No (With_Sys)
and then (Nkind (The_Unit) = N_Package_Body
or else (Nkind (The_Unit) = N_Subprogram_Body
and then not Acts_As_Spec (Cunit (Current_Sem_Unit))))
then
With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit)));
end if;
if No (With_Sys)
and then Present (N)
then
-- If we are compiling a subunit, we need to examine its
-- context as well (Current_Sem_Unit is the parent unit);
The_Unit := Parent (N);
while Nkind (The_Unit) /= N_Compilation_Unit loop
The_Unit := Parent (The_Unit);
end loop;
if Nkind (Unit (The_Unit)) = N_Subunit then
With_Sys := Find_System (The_Unit);
end if;
end if;
if No (With_Sys) then
return False;
end if;
Loc := Sloc (With_Sys);
Get_Name_String (Chars (Expression (System_Extend_Pragma_Arg)));
Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
Name_Buffer (1 .. 7) := "system.";
Name_Buffer (Name_Len + 8) := '%';
Name_Buffer (Name_Len + 9) := 's';
Name_Len := Name_Len + 9;
Aux_Name := Name_Find;
Unum :=
Load_Unit
(Load_Name => Aux_Name,
Required => False,
Subunit => False,
Error_Node => With_Sys);
if Unum /= No_Unit then
Semantics (Cunit (Unum));
System_Aux_Id :=
Defining_Entity (Specification (Unit (Cunit (Unum))));
Withn := Make_With_Clause (Loc,
Name =>
Make_Expanded_Name (Loc,
Chars => Chars (System_Aux_Id),
Prefix =>
New_Reference_To (Scope (System_Aux_Id), Loc),
Selector_Name =>
New_Reference_To (System_Aux_Id, Loc)));
Set_Entity (Name (Withn), System_Aux_Id);
Set_Library_Unit (Withn, Cunit (Unum));
Set_Corresponding_Spec (Withn, System_Aux_Id);
Set_First_Name (Withn, True);
Set_Implicit_With (Withn, True);
Insert_After (With_Sys, Withn);
Mark_Rewrite_Insertion (Withn);
Set_Context_Installed (Withn);
return True;
-- Here if unit load failed
else
Error_Msg_Name_1 := Name_System;
Error_Msg_Name_2 := Chars (Expression (System_Extend_Pragma_Arg));
Error_Msg_N
("extension package `%.%` does not exist",
Opt.System_Extend_Pragma_Arg);
return False;
end if;
end if;
end Present_System_Aux;
-------------------------
-- Restore_Scope_Stack --
-------------------------
procedure Restore_Scope_Stack is
E : Entity_Id;
S : Entity_Id;
Comp_Unit : Node_Id;
In_Child : Boolean := False;
Full_Vis : Boolean := True;
begin
-- Restore visibility of previous scope stack, if any.
for J in reverse 0 .. Scope_Stack.Last loop
exit when Scope_Stack.Table (J).Entity = Standard_Standard
or else No (Scope_Stack.Table (J).Entity);
S := Scope_Stack.Table (J).Entity;
if not Is_Hidden_Open_Scope (S) then
-- If the parent scope is hidden, its entities are hidden as
-- well, unless the entity is the instantiation currently
-- being analyzed.
if not Is_Hidden_Open_Scope (Scope (S))
or else not Analyzed (Parent (S))
or else Scope (S) = Standard_Standard
then
Set_Is_Immediately_Visible (S, True);
end if;
E := First_Entity (S);
while Present (E) loop
if Is_Child_Unit (E) then
Set_Is_Immediately_Visible (E,
Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
else
Set_Is_Immediately_Visible (E, True);
end if;
Next_Entity (E);
if not Full_Vis then
exit when E = First_Private_Entity (S);
end if;
end loop;
-- The visibility of child units (siblings of current compilation)
-- must be restored in any case. Their declarations may appear
-- after the private part of the parent.
if not Full_Vis
and then Present (E)
then
while Present (E) loop
if Is_Child_Unit (E) then
Set_Is_Immediately_Visible (E,
Is_Visible_Child_Unit (E) or else In_Open_Scopes (E));
end if;
Next_Entity (E);
end loop;
end if;
end if;
if Is_Child_Unit (S)
and not In_Child -- check only for current unit.
then
In_Child := True;
-- restore visibility of parents according to whether the child
-- is private and whether we are in its visible part.
Comp_Unit := Parent (Unit_Declaration_Node (S));
if Nkind (Comp_Unit) = N_Compilation_Unit
and then Private_Present (Comp_Unit)
then
Full_Vis := True;
elsif (Ekind (S) = E_Package
or else Ekind (S) = E_Generic_Package)
and then (In_Private_Part (S)
or else In_Package_Body (S))
then
Full_Vis := True;
elsif (Ekind (S) = E_Procedure
or else Ekind (S) = E_Function)
and then Has_Completion (S)
then
Full_Vis := True;
else
Full_Vis := False;
end if;
else
Full_Vis := True;
end if;
end loop;
end Restore_Scope_Stack;
----------------------
-- Save_Scope_Stack --
----------------------
procedure Save_Scope_Stack is
E : Entity_Id;
S : Entity_Id;
SS_Last : constant Int := Scope_Stack.Last;
begin
if SS_Last >= Scope_Stack.First
and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
then
-- If the call is from within a compilation unit, as when
-- called from Rtsfind, make current entries in scope stack
-- invisible while we analyze the new unit.
for J in reverse 0 .. SS_Last loop
exit when Scope_Stack.Table (J).Entity = Standard_Standard
or else No (Scope_Stack.Table (J).Entity);
S := Scope_Stack.Table (J).Entity;
Set_Is_Immediately_Visible (S, False);
E := First_Entity (S);
while Present (E) loop
Set_Is_Immediately_Visible (E, False);
Next_Entity (E);
end loop;
end loop;
end if;
end Save_Scope_Stack;
-------------
-- Set_Use --
-------------
procedure Set_Use (L : List_Id) is
Decl : Node_Id;
Pack_Name : Node_Id;
Pack : Entity_Id;
Id : Entity_Id;
begin
if Present (L) then
Decl := First (L);
while Present (Decl) loop
if Nkind (Decl) = N_Use_Package_Clause then
Chain_Use_Clause (Decl);
Pack_Name := First (Names (Decl));
while Present (Pack_Name) loop
Pack := Entity (Pack_Name);
if Ekind (Pack) = E_Package
and then Applicable_Use (Pack_Name)
then
Use_One_Package (Pack, Decl);
end if;
Next (Pack_Name);
end loop;
elsif Nkind (Decl) = N_Use_Type_Clause then
Chain_Use_Clause (Decl);
Id := First (Subtype_Marks (Decl));
while Present (Id) loop
if Entity (Id) /= Any_Type then
Use_One_Type (Id, Decl);
end if;
Next (Id);
end loop;
end if;
Next (Decl);
end loop;
end if;
end Set_Use;
---------------------
-- Use_One_Package --
---------------------
procedure Use_One_Package (P : Entity_Id; N : Node_Id) is
Id : Entity_Id;
Prev : Entity_Id;
Current_Instance : Entity_Id := Empty;
Real_P : Entity_Id;
begin
if Ekind (P) /= E_Package then
return;
end if;
Set_In_Use (P);
if From_With_Type (P) then
Error_Msg_N ("imported package cannot appear in use clause", N);
end if;
-- Find enclosing instance, if any.
if In_Instance then
Current_Instance := Current_Scope;
while not Is_Generic_Instance (Current_Instance) loop
Current_Instance := Scope (Current_Instance);
end loop;
if No (Hidden_By_Use_Clause (N)) then
Set_Hidden_By_Use_Clause (N, New_Elmt_List);
end if;
end if;
-- If unit is a package renaming, indicate that the renamed
-- package is also in use (the flags on both entities must
-- remain consistent, and a subsequent use of either of them
-- should be recognized as redundant).
if Present (Renamed_Object (P)) then
Set_In_Use (Renamed_Object (P));
Real_P := Renamed_Object (P);
else
Real_P := P;
end if;
-- Loop through entities in one package making them potentially
-- use-visible.
Id := First_Entity (P);
while Present (Id)
and then Id /= First_Private_Entity (P)
loop
Prev := Current_Entity (Id);
while Present (Prev) loop
if Is_Immediately_Visible (Prev)
and then (not Is_Overloadable (Prev)
or else not Is_Overloadable (Id)
or else (Type_Conformant (Id, Prev)))
then
if No (Current_Instance) then
-- Potentially use-visible entity remains hidden
goto Next_Usable_Entity;
-- A use clause within an instance hides outer global
-- entities, which are not used to resolve local entities
-- in the instance. Note that the predefined entities in
-- Standard could not have been hidden in the generic by
-- a use clause, and therefore remain visible. Other
-- compilation units whose entities appear in Standard must
-- be hidden in an instance.
-- To determine whether an entity is external to the instance
-- we compare the scope depth of its scope with that of the
-- current instance. However, a generic actual of a subprogram
-- instance is declared in the wrapper package but will not be
-- hidden by a use-visible entity.
elsif not Is_Hidden (Id)
and then not Is_Wrapper_Package (Scope (Prev))
and then Scope_Depth (Scope (Prev)) <
Scope_Depth (Current_Instance)
and then (Scope (Prev) /= Standard_Standard
or else Sloc (Prev) > Standard_Location)
then
Set_Is_Potentially_Use_Visible (Id);
Set_Is_Immediately_Visible (Prev, False);
Append_Elmt (Prev, Hidden_By_Use_Clause (N));
end if;
-- A user-defined operator is not use-visible if the
-- predefined operator for the type is immediately visible,
-- which is the case if the type of the operand is in an open
-- scope. This does not apply to user-defined operators that
-- have operands of different types, because the predefined
-- mixed mode operations (multiplication and division) apply to
-- universal types and do not hide anything.
elsif Ekind (Prev) = E_Operator
and then Operator_Matches_Spec (Prev, Id)
and then In_Open_Scopes
(Scope (Base_Type (Etype (First_Formal (Id)))))
and then (No (Next_Formal (First_Formal (Id)))
or else Etype (First_Formal (Id))
= Etype (Next_Formal (First_Formal (Id)))
or else Chars (Prev) = Name_Op_Expon)
then
goto Next_Usable_Entity;
end if;
Prev := Homonym (Prev);
end loop;
-- On exit, we know entity is not hidden, unless it is private.
if not Is_Hidden (Id)
and then ((not Is_Child_Unit (Id))
or else Is_Visible_Child_Unit (Id))
then
Set_Is_Potentially_Use_Visible (Id);
if Is_Private_Type (Id)
and then Present (Full_View (Id))
then
Set_Is_Potentially_Use_Visible (Full_View (Id));
end if;
end if;
<<Next_Usable_Entity>>
Next_Entity (Id);
end loop;
-- Child units are also made use-visible by a use clause, but they
-- may appear after all visible declarations in the parent entity list.
while Present (Id) loop
if Is_Child_Unit (Id)
and then Is_Visible_Child_Unit (Id)
then
Set_Is_Potentially_Use_Visible (Id);
end if;
Next_Entity (Id);
end loop;
if Chars (Real_P) = Name_System
and then Scope (Real_P) = Standard_Standard
and then Present_System_Aux (N)
then
Use_One_Package (System_Aux_Id, N);
end if;
end Use_One_Package;
------------------
-- Use_One_Type --
------------------
procedure Use_One_Type (Id : Node_Id; N : Node_Id) is
T : Entity_Id;
Op_List : Elist_Id;
Elmt : Elmt_Id;
begin
-- It is the type determined by the subtype mark (8.4(8)) whose
-- operations become potentially use-visible.
T := Base_Type (Entity (Id));
-- Save current visibility status of type, before setting.
Set_Redundant_Use
(Id, In_Use (T) or else Is_Potentially_Use_Visible (T));
if In_Open_Scopes (Scope (T)) then
null;
elsif not Redundant_Use (Id) then
Set_In_Use (T);
Op_List := Collect_Primitive_Operations (T);
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol
or else Chars (Node (Elmt)) in Any_Operator_Name)
and then not Is_Hidden (Node (Elmt))
then
Set_Is_Potentially_Use_Visible (Node (Elmt));
end if;
Next_Elmt (Elmt);
end loop;
end if;
end Use_One_Type;
----------------
-- Write_Info --
----------------
procedure Write_Info is
Id : Entity_Id := First_Entity (Current_Scope);
begin
-- No point in dumping standard entities
if Current_Scope = Standard_Standard then
return;
end if;
Write_Str ("========================================================");
Write_Eol;
Write_Str (" Defined Entities in ");
Write_Name (Chars (Current_Scope));
Write_Eol;
Write_Str ("========================================================");
Write_Eol;
if No (Id) then
Write_Str ("-- none --");
Write_Eol;
else
while Present (Id) loop
Write_Entity_Info (Id, " ");
Next_Entity (Id);
end loop;
end if;
if Scope (Current_Scope) = Standard_Standard then
-- Print information on the current unit itself
Write_Entity_Info (Current_Scope, " ");
end if;
Write_Eol;
end Write_Info;
-----------------
-- Write_Scopes --
-----------------
procedure Write_Scopes is
S : Entity_Id;
begin
for J in reverse 1 .. Scope_Stack.Last loop
S := Scope_Stack.Table (J).Entity;
Write_Int (Int (S));
Write_Str (" === ");
Write_Name (Chars (S));
Write_Eol;
end loop;
end Write_Scopes;
end Sem_Ch8;